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0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Copyright (c) 2000-2006 Silicon Graphics, Inc.
0004  * All Rights Reserved.
0005  */
0006 #include "xfs.h"
0007 #include "xfs_fs.h"
0008 #include "xfs_shared.h"
0009 #include "xfs_format.h"
0010 #include "xfs_log_format.h"
0011 #include "xfs_trans_resv.h"
0012 #include "xfs_bit.h"
0013 #include "xfs_sb.h"
0014 #include "xfs_mount.h"
0015 #include "xfs_defer.h"
0016 #include "xfs_dir2.h"
0017 #include "xfs_inode.h"
0018 #include "xfs_btree.h"
0019 #include "xfs_trans.h"
0020 #include "xfs_alloc.h"
0021 #include "xfs_bmap.h"
0022 #include "xfs_bmap_util.h"
0023 #include "xfs_bmap_btree.h"
0024 #include "xfs_rtalloc.h"
0025 #include "xfs_errortag.h"
0026 #include "xfs_error.h"
0027 #include "xfs_quota.h"
0028 #include "xfs_trans_space.h"
0029 #include "xfs_buf_item.h"
0030 #include "xfs_trace.h"
0031 #include "xfs_attr_leaf.h"
0032 #include "xfs_filestream.h"
0033 #include "xfs_rmap.h"
0034 #include "xfs_ag.h"
0035 #include "xfs_ag_resv.h"
0036 #include "xfs_refcount.h"
0037 #include "xfs_icache.h"
0038 #include "xfs_iomap.h"
0039 
0040 struct kmem_cache       *xfs_bmap_intent_cache;
0041 
0042 /*
0043  * Miscellaneous helper functions
0044  */
0045 
0046 /*
0047  * Compute and fill in the value of the maximum depth of a bmap btree
0048  * in this filesystem.  Done once, during mount.
0049  */
0050 void
0051 xfs_bmap_compute_maxlevels(
0052     xfs_mount_t *mp,        /* file system mount structure */
0053     int     whichfork)  /* data or attr fork */
0054 {
0055     uint64_t    maxblocks;  /* max blocks at this level */
0056     xfs_extnum_t    maxleafents;    /* max leaf entries possible */
0057     int     level;      /* btree level */
0058     int     maxrootrecs;    /* max records in root block */
0059     int     minleafrecs;    /* min records in leaf block */
0060     int     minnoderecs;    /* min records in node block */
0061     int     sz;     /* root block size */
0062 
0063     /*
0064      * The maximum number of extents in a fork, hence the maximum number of
0065      * leaf entries, is controlled by the size of the on-disk extent count.
0066      *
0067      * Note that we can no longer assume that if we are in ATTR1 that the
0068      * fork offset of all the inodes will be
0069      * (xfs_default_attroffset(ip) >> 3) because we could have mounted with
0070      * ATTR2 and then mounted back with ATTR1, keeping the i_forkoff's fixed
0071      * but probably at various positions. Therefore, for both ATTR1 and
0072      * ATTR2 we have to assume the worst case scenario of a minimum size
0073      * available.
0074      */
0075     maxleafents = xfs_iext_max_nextents(xfs_has_large_extent_counts(mp),
0076                 whichfork);
0077     if (whichfork == XFS_DATA_FORK)
0078         sz = XFS_BMDR_SPACE_CALC(MINDBTPTRS);
0079     else
0080         sz = XFS_BMDR_SPACE_CALC(MINABTPTRS);
0081 
0082     maxrootrecs = xfs_bmdr_maxrecs(sz, 0);
0083     minleafrecs = mp->m_bmap_dmnr[0];
0084     minnoderecs = mp->m_bmap_dmnr[1];
0085     maxblocks = howmany_64(maxleafents, minleafrecs);
0086     for (level = 1; maxblocks > 1; level++) {
0087         if (maxblocks <= maxrootrecs)
0088             maxblocks = 1;
0089         else
0090             maxblocks = howmany_64(maxblocks, minnoderecs);
0091     }
0092     mp->m_bm_maxlevels[whichfork] = level;
0093     ASSERT(mp->m_bm_maxlevels[whichfork] <= xfs_bmbt_maxlevels_ondisk());
0094 }
0095 
0096 unsigned int
0097 xfs_bmap_compute_attr_offset(
0098     struct xfs_mount    *mp)
0099 {
0100     if (mp->m_sb.sb_inodesize == 256)
0101         return XFS_LITINO(mp) - XFS_BMDR_SPACE_CALC(MINABTPTRS);
0102     return XFS_BMDR_SPACE_CALC(6 * MINABTPTRS);
0103 }
0104 
0105 STATIC int              /* error */
0106 xfs_bmbt_lookup_eq(
0107     struct xfs_btree_cur    *cur,
0108     struct xfs_bmbt_irec    *irec,
0109     int         *stat)  /* success/failure */
0110 {
0111     cur->bc_rec.b = *irec;
0112     return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
0113 }
0114 
0115 STATIC int              /* error */
0116 xfs_bmbt_lookup_first(
0117     struct xfs_btree_cur    *cur,
0118     int         *stat)  /* success/failure */
0119 {
0120     cur->bc_rec.b.br_startoff = 0;
0121     cur->bc_rec.b.br_startblock = 0;
0122     cur->bc_rec.b.br_blockcount = 0;
0123     return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
0124 }
0125 
0126 /*
0127  * Check if the inode needs to be converted to btree format.
0128  */
0129 static inline bool xfs_bmap_needs_btree(struct xfs_inode *ip, int whichfork)
0130 {
0131     struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork);
0132 
0133     return whichfork != XFS_COW_FORK &&
0134         ifp->if_format == XFS_DINODE_FMT_EXTENTS &&
0135         ifp->if_nextents > XFS_IFORK_MAXEXT(ip, whichfork);
0136 }
0137 
0138 /*
0139  * Check if the inode should be converted to extent format.
0140  */
0141 static inline bool xfs_bmap_wants_extents(struct xfs_inode *ip, int whichfork)
0142 {
0143     struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork);
0144 
0145     return whichfork != XFS_COW_FORK &&
0146         ifp->if_format == XFS_DINODE_FMT_BTREE &&
0147         ifp->if_nextents <= XFS_IFORK_MAXEXT(ip, whichfork);
0148 }
0149 
0150 /*
0151  * Update the record referred to by cur to the value given by irec
0152  * This either works (return 0) or gets an EFSCORRUPTED error.
0153  */
0154 STATIC int
0155 xfs_bmbt_update(
0156     struct xfs_btree_cur    *cur,
0157     struct xfs_bmbt_irec    *irec)
0158 {
0159     union xfs_btree_rec rec;
0160 
0161     xfs_bmbt_disk_set_all(&rec.bmbt, irec);
0162     return xfs_btree_update(cur, &rec);
0163 }
0164 
0165 /*
0166  * Compute the worst-case number of indirect blocks that will be used
0167  * for ip's delayed extent of length "len".
0168  */
0169 STATIC xfs_filblks_t
0170 xfs_bmap_worst_indlen(
0171     xfs_inode_t *ip,        /* incore inode pointer */
0172     xfs_filblks_t   len)        /* delayed extent length */
0173 {
0174     int     level;      /* btree level number */
0175     int     maxrecs;    /* maximum record count at this level */
0176     xfs_mount_t *mp;        /* mount structure */
0177     xfs_filblks_t   rval;       /* return value */
0178 
0179     mp = ip->i_mount;
0180     maxrecs = mp->m_bmap_dmxr[0];
0181     for (level = 0, rval = 0;
0182          level < XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK);
0183          level++) {
0184         len += maxrecs - 1;
0185         do_div(len, maxrecs);
0186         rval += len;
0187         if (len == 1)
0188             return rval + XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK) -
0189                 level - 1;
0190         if (level == 0)
0191             maxrecs = mp->m_bmap_dmxr[1];
0192     }
0193     return rval;
0194 }
0195 
0196 /*
0197  * Calculate the default attribute fork offset for newly created inodes.
0198  */
0199 uint
0200 xfs_default_attroffset(
0201     struct xfs_inode    *ip)
0202 {
0203     if (ip->i_df.if_format == XFS_DINODE_FMT_DEV)
0204         return roundup(sizeof(xfs_dev_t), 8);
0205     return M_IGEO(ip->i_mount)->attr_fork_offset;
0206 }
0207 
0208 /*
0209  * Helper routine to reset inode i_forkoff field when switching attribute fork
0210  * from local to extent format - we reset it where possible to make space
0211  * available for inline data fork extents.
0212  */
0213 STATIC void
0214 xfs_bmap_forkoff_reset(
0215     xfs_inode_t *ip,
0216     int     whichfork)
0217 {
0218     if (whichfork == XFS_ATTR_FORK &&
0219         ip->i_df.if_format != XFS_DINODE_FMT_DEV &&
0220         ip->i_df.if_format != XFS_DINODE_FMT_BTREE) {
0221         uint    dfl_forkoff = xfs_default_attroffset(ip) >> 3;
0222 
0223         if (dfl_forkoff > ip->i_forkoff)
0224             ip->i_forkoff = dfl_forkoff;
0225     }
0226 }
0227 
0228 #ifdef DEBUG
0229 STATIC struct xfs_buf *
0230 xfs_bmap_get_bp(
0231     struct xfs_btree_cur    *cur,
0232     xfs_fsblock_t       bno)
0233 {
0234     struct xfs_log_item *lip;
0235     int         i;
0236 
0237     if (!cur)
0238         return NULL;
0239 
0240     for (i = 0; i < cur->bc_maxlevels; i++) {
0241         if (!cur->bc_levels[i].bp)
0242             break;
0243         if (xfs_buf_daddr(cur->bc_levels[i].bp) == bno)
0244             return cur->bc_levels[i].bp;
0245     }
0246 
0247     /* Chase down all the log items to see if the bp is there */
0248     list_for_each_entry(lip, &cur->bc_tp->t_items, li_trans) {
0249         struct xfs_buf_log_item *bip = (struct xfs_buf_log_item *)lip;
0250 
0251         if (bip->bli_item.li_type == XFS_LI_BUF &&
0252             xfs_buf_daddr(bip->bli_buf) == bno)
0253             return bip->bli_buf;
0254     }
0255 
0256     return NULL;
0257 }
0258 
0259 STATIC void
0260 xfs_check_block(
0261     struct xfs_btree_block  *block,
0262     xfs_mount_t     *mp,
0263     int         root,
0264     short           sz)
0265 {
0266     int         i, j, dmxr;
0267     __be64          *pp, *thispa;   /* pointer to block address */
0268     xfs_bmbt_key_t      *prevp, *keyp;
0269 
0270     ASSERT(be16_to_cpu(block->bb_level) > 0);
0271 
0272     prevp = NULL;
0273     for( i = 1; i <= xfs_btree_get_numrecs(block); i++) {
0274         dmxr = mp->m_bmap_dmxr[0];
0275         keyp = XFS_BMBT_KEY_ADDR(mp, block, i);
0276 
0277         if (prevp) {
0278             ASSERT(be64_to_cpu(prevp->br_startoff) <
0279                    be64_to_cpu(keyp->br_startoff));
0280         }
0281         prevp = keyp;
0282 
0283         /*
0284          * Compare the block numbers to see if there are dups.
0285          */
0286         if (root)
0287             pp = XFS_BMAP_BROOT_PTR_ADDR(mp, block, i, sz);
0288         else
0289             pp = XFS_BMBT_PTR_ADDR(mp, block, i, dmxr);
0290 
0291         for (j = i+1; j <= be16_to_cpu(block->bb_numrecs); j++) {
0292             if (root)
0293                 thispa = XFS_BMAP_BROOT_PTR_ADDR(mp, block, j, sz);
0294             else
0295                 thispa = XFS_BMBT_PTR_ADDR(mp, block, j, dmxr);
0296             if (*thispa == *pp) {
0297                 xfs_warn(mp, "%s: thispa(%d) == pp(%d) %Ld",
0298                     __func__, j, i,
0299                     (unsigned long long)be64_to_cpu(*thispa));
0300                 xfs_err(mp, "%s: ptrs are equal in node\n",
0301                     __func__);
0302                 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
0303             }
0304         }
0305     }
0306 }
0307 
0308 /*
0309  * Check that the extents for the inode ip are in the right order in all
0310  * btree leaves. THis becomes prohibitively expensive for large extent count
0311  * files, so don't bother with inodes that have more than 10,000 extents in
0312  * them. The btree record ordering checks will still be done, so for such large
0313  * bmapbt constructs that is going to catch most corruptions.
0314  */
0315 STATIC void
0316 xfs_bmap_check_leaf_extents(
0317     struct xfs_btree_cur    *cur,   /* btree cursor or null */
0318     xfs_inode_t     *ip,        /* incore inode pointer */
0319     int         whichfork)  /* data or attr fork */
0320 {
0321     struct xfs_mount    *mp = ip->i_mount;
0322     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, whichfork);
0323     struct xfs_btree_block  *block; /* current btree block */
0324     xfs_fsblock_t       bno;    /* block # of "block" */
0325     struct xfs_buf      *bp;    /* buffer for "block" */
0326     int         error;  /* error return value */
0327     xfs_extnum_t        i=0, j; /* index into the extents list */
0328     int         level;  /* btree level, for checking */
0329     __be64          *pp;    /* pointer to block address */
0330     xfs_bmbt_rec_t      *ep;    /* pointer to current extent */
0331     xfs_bmbt_rec_t      last = {0, 0}; /* last extent in prev block */
0332     xfs_bmbt_rec_t      *nextp; /* pointer to next extent */
0333     int         bp_release = 0;
0334 
0335     if (ifp->if_format != XFS_DINODE_FMT_BTREE)
0336         return;
0337 
0338     /* skip large extent count inodes */
0339     if (ip->i_df.if_nextents > 10000)
0340         return;
0341 
0342     bno = NULLFSBLOCK;
0343     block = ifp->if_broot;
0344     /*
0345      * Root level must use BMAP_BROOT_PTR_ADDR macro to get ptr out.
0346      */
0347     level = be16_to_cpu(block->bb_level);
0348     ASSERT(level > 0);
0349     xfs_check_block(block, mp, 1, ifp->if_broot_bytes);
0350     pp = XFS_BMAP_BROOT_PTR_ADDR(mp, block, 1, ifp->if_broot_bytes);
0351     bno = be64_to_cpu(*pp);
0352 
0353     ASSERT(bno != NULLFSBLOCK);
0354     ASSERT(XFS_FSB_TO_AGNO(mp, bno) < mp->m_sb.sb_agcount);
0355     ASSERT(XFS_FSB_TO_AGBNO(mp, bno) < mp->m_sb.sb_agblocks);
0356 
0357     /*
0358      * Go down the tree until leaf level is reached, following the first
0359      * pointer (leftmost) at each level.
0360      */
0361     while (level-- > 0) {
0362         /* See if buf is in cur first */
0363         bp_release = 0;
0364         bp = xfs_bmap_get_bp(cur, XFS_FSB_TO_DADDR(mp, bno));
0365         if (!bp) {
0366             bp_release = 1;
0367             error = xfs_btree_read_bufl(mp, NULL, bno, &bp,
0368                         XFS_BMAP_BTREE_REF,
0369                         &xfs_bmbt_buf_ops);
0370             if (error)
0371                 goto error_norelse;
0372         }
0373         block = XFS_BUF_TO_BLOCK(bp);
0374         if (level == 0)
0375             break;
0376 
0377         /*
0378          * Check this block for basic sanity (increasing keys and
0379          * no duplicate blocks).
0380          */
0381 
0382         xfs_check_block(block, mp, 0, 0);
0383         pp = XFS_BMBT_PTR_ADDR(mp, block, 1, mp->m_bmap_dmxr[1]);
0384         bno = be64_to_cpu(*pp);
0385         if (XFS_IS_CORRUPT(mp, !xfs_verify_fsbno(mp, bno))) {
0386             error = -EFSCORRUPTED;
0387             goto error0;
0388         }
0389         if (bp_release) {
0390             bp_release = 0;
0391             xfs_trans_brelse(NULL, bp);
0392         }
0393     }
0394 
0395     /*
0396      * Here with bp and block set to the leftmost leaf node in the tree.
0397      */
0398     i = 0;
0399 
0400     /*
0401      * Loop over all leaf nodes checking that all extents are in the right order.
0402      */
0403     for (;;) {
0404         xfs_fsblock_t   nextbno;
0405         xfs_extnum_t    num_recs;
0406 
0407 
0408         num_recs = xfs_btree_get_numrecs(block);
0409 
0410         /*
0411          * Read-ahead the next leaf block, if any.
0412          */
0413 
0414         nextbno = be64_to_cpu(block->bb_u.l.bb_rightsib);
0415 
0416         /*
0417          * Check all the extents to make sure they are OK.
0418          * If we had a previous block, the last entry should
0419          * conform with the first entry in this one.
0420          */
0421 
0422         ep = XFS_BMBT_REC_ADDR(mp, block, 1);
0423         if (i) {
0424             ASSERT(xfs_bmbt_disk_get_startoff(&last) +
0425                    xfs_bmbt_disk_get_blockcount(&last) <=
0426                    xfs_bmbt_disk_get_startoff(ep));
0427         }
0428         for (j = 1; j < num_recs; j++) {
0429             nextp = XFS_BMBT_REC_ADDR(mp, block, j + 1);
0430             ASSERT(xfs_bmbt_disk_get_startoff(ep) +
0431                    xfs_bmbt_disk_get_blockcount(ep) <=
0432                    xfs_bmbt_disk_get_startoff(nextp));
0433             ep = nextp;
0434         }
0435 
0436         last = *ep;
0437         i += num_recs;
0438         if (bp_release) {
0439             bp_release = 0;
0440             xfs_trans_brelse(NULL, bp);
0441         }
0442         bno = nextbno;
0443         /*
0444          * If we've reached the end, stop.
0445          */
0446         if (bno == NULLFSBLOCK)
0447             break;
0448 
0449         bp_release = 0;
0450         bp = xfs_bmap_get_bp(cur, XFS_FSB_TO_DADDR(mp, bno));
0451         if (!bp) {
0452             bp_release = 1;
0453             error = xfs_btree_read_bufl(mp, NULL, bno, &bp,
0454                         XFS_BMAP_BTREE_REF,
0455                         &xfs_bmbt_buf_ops);
0456             if (error)
0457                 goto error_norelse;
0458         }
0459         block = XFS_BUF_TO_BLOCK(bp);
0460     }
0461 
0462     return;
0463 
0464 error0:
0465     xfs_warn(mp, "%s: at error0", __func__);
0466     if (bp_release)
0467         xfs_trans_brelse(NULL, bp);
0468 error_norelse:
0469     xfs_warn(mp, "%s: BAD after btree leaves for %llu extents",
0470         __func__, i);
0471     xfs_err(mp, "%s: CORRUPTED BTREE OR SOMETHING", __func__);
0472     xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
0473     return;
0474 }
0475 
0476 /*
0477  * Validate that the bmbt_irecs being returned from bmapi are valid
0478  * given the caller's original parameters.  Specifically check the
0479  * ranges of the returned irecs to ensure that they only extend beyond
0480  * the given parameters if the XFS_BMAPI_ENTIRE flag was set.
0481  */
0482 STATIC void
0483 xfs_bmap_validate_ret(
0484     xfs_fileoff_t       bno,
0485     xfs_filblks_t       len,
0486     uint32_t        flags,
0487     xfs_bmbt_irec_t     *mval,
0488     int         nmap,
0489     int         ret_nmap)
0490 {
0491     int         i;      /* index to map values */
0492 
0493     ASSERT(ret_nmap <= nmap);
0494 
0495     for (i = 0; i < ret_nmap; i++) {
0496         ASSERT(mval[i].br_blockcount > 0);
0497         if (!(flags & XFS_BMAPI_ENTIRE)) {
0498             ASSERT(mval[i].br_startoff >= bno);
0499             ASSERT(mval[i].br_blockcount <= len);
0500             ASSERT(mval[i].br_startoff + mval[i].br_blockcount <=
0501                    bno + len);
0502         } else {
0503             ASSERT(mval[i].br_startoff < bno + len);
0504             ASSERT(mval[i].br_startoff + mval[i].br_blockcount >
0505                    bno);
0506         }
0507         ASSERT(i == 0 ||
0508                mval[i - 1].br_startoff + mval[i - 1].br_blockcount ==
0509                mval[i].br_startoff);
0510         ASSERT(mval[i].br_startblock != DELAYSTARTBLOCK &&
0511                mval[i].br_startblock != HOLESTARTBLOCK);
0512         ASSERT(mval[i].br_state == XFS_EXT_NORM ||
0513                mval[i].br_state == XFS_EXT_UNWRITTEN);
0514     }
0515 }
0516 
0517 #else
0518 #define xfs_bmap_check_leaf_extents(cur, ip, whichfork)     do { } while (0)
0519 #define xfs_bmap_validate_ret(bno,len,flags,mval,onmap,nmap)    do { } while (0)
0520 #endif /* DEBUG */
0521 
0522 /*
0523  * Inode fork format manipulation functions
0524  */
0525 
0526 /*
0527  * Convert the inode format to extent format if it currently is in btree format,
0528  * but the extent list is small enough that it fits into the extent format.
0529  *
0530  * Since the extents are already in-core, all we have to do is give up the space
0531  * for the btree root and pitch the leaf block.
0532  */
0533 STATIC int              /* error */
0534 xfs_bmap_btree_to_extents(
0535     struct xfs_trans    *tp,    /* transaction pointer */
0536     struct xfs_inode    *ip,    /* incore inode pointer */
0537     struct xfs_btree_cur    *cur,   /* btree cursor */
0538     int         *logflagsp, /* inode logging flags */
0539     int         whichfork)  /* data or attr fork */
0540 {
0541     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, whichfork);
0542     struct xfs_mount    *mp = ip->i_mount;
0543     struct xfs_btree_block  *rblock = ifp->if_broot;
0544     struct xfs_btree_block  *cblock;/* child btree block */
0545     xfs_fsblock_t       cbno;   /* child block number */
0546     struct xfs_buf      *cbp;   /* child block's buffer */
0547     int         error;  /* error return value */
0548     __be64          *pp;    /* ptr to block address */
0549     struct xfs_owner_info   oinfo;
0550 
0551     /* check if we actually need the extent format first: */
0552     if (!xfs_bmap_wants_extents(ip, whichfork))
0553         return 0;
0554 
0555     ASSERT(cur);
0556     ASSERT(whichfork != XFS_COW_FORK);
0557     ASSERT(ifp->if_format == XFS_DINODE_FMT_BTREE);
0558     ASSERT(be16_to_cpu(rblock->bb_level) == 1);
0559     ASSERT(be16_to_cpu(rblock->bb_numrecs) == 1);
0560     ASSERT(xfs_bmbt_maxrecs(mp, ifp->if_broot_bytes, 0) == 1);
0561 
0562     pp = XFS_BMAP_BROOT_PTR_ADDR(mp, rblock, 1, ifp->if_broot_bytes);
0563     cbno = be64_to_cpu(*pp);
0564 #ifdef DEBUG
0565     if (XFS_IS_CORRUPT(cur->bc_mp, !xfs_btree_check_lptr(cur, cbno, 1)))
0566         return -EFSCORRUPTED;
0567 #endif
0568     error = xfs_btree_read_bufl(mp, tp, cbno, &cbp, XFS_BMAP_BTREE_REF,
0569                 &xfs_bmbt_buf_ops);
0570     if (error)
0571         return error;
0572     cblock = XFS_BUF_TO_BLOCK(cbp);
0573     if ((error = xfs_btree_check_block(cur, cblock, 0, cbp)))
0574         return error;
0575     xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, whichfork);
0576     xfs_free_extent_later(cur->bc_tp, cbno, 1, &oinfo);
0577     ip->i_nblocks--;
0578     xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, -1L);
0579     xfs_trans_binval(tp, cbp);
0580     if (cur->bc_levels[0].bp == cbp)
0581         cur->bc_levels[0].bp = NULL;
0582     xfs_iroot_realloc(ip, -1, whichfork);
0583     ASSERT(ifp->if_broot == NULL);
0584     ifp->if_format = XFS_DINODE_FMT_EXTENTS;
0585     *logflagsp |= XFS_ILOG_CORE | xfs_ilog_fext(whichfork);
0586     return 0;
0587 }
0588 
0589 /*
0590  * Convert an extents-format file into a btree-format file.
0591  * The new file will have a root block (in the inode) and a single child block.
0592  */
0593 STATIC int                  /* error */
0594 xfs_bmap_extents_to_btree(
0595     struct xfs_trans    *tp,        /* transaction pointer */
0596     struct xfs_inode    *ip,        /* incore inode pointer */
0597     struct xfs_btree_cur    **curp,     /* cursor returned to caller */
0598     int         wasdel,     /* converting a delayed alloc */
0599     int         *logflagsp, /* inode logging flags */
0600     int         whichfork)  /* data or attr fork */
0601 {
0602     struct xfs_btree_block  *ablock;    /* allocated (child) bt block */
0603     struct xfs_buf      *abp;       /* buffer for ablock */
0604     struct xfs_alloc_arg    args;       /* allocation arguments */
0605     struct xfs_bmbt_rec *arp;       /* child record pointer */
0606     struct xfs_btree_block  *block;     /* btree root block */
0607     struct xfs_btree_cur    *cur;       /* bmap btree cursor */
0608     int         error;      /* error return value */
0609     struct xfs_ifork    *ifp;       /* inode fork pointer */
0610     struct xfs_bmbt_key *kp;        /* root block key pointer */
0611     struct xfs_mount    *mp;        /* mount structure */
0612     xfs_bmbt_ptr_t      *pp;        /* root block address pointer */
0613     struct xfs_iext_cursor  icur;
0614     struct xfs_bmbt_irec    rec;
0615     xfs_extnum_t        cnt = 0;
0616 
0617     mp = ip->i_mount;
0618     ASSERT(whichfork != XFS_COW_FORK);
0619     ifp = xfs_ifork_ptr(ip, whichfork);
0620     ASSERT(ifp->if_format == XFS_DINODE_FMT_EXTENTS);
0621 
0622     /*
0623      * Make space in the inode incore. This needs to be undone if we fail
0624      * to expand the root.
0625      */
0626     xfs_iroot_realloc(ip, 1, whichfork);
0627 
0628     /*
0629      * Fill in the root.
0630      */
0631     block = ifp->if_broot;
0632     xfs_btree_init_block_int(mp, block, XFS_BUF_DADDR_NULL,
0633                  XFS_BTNUM_BMAP, 1, 1, ip->i_ino,
0634                  XFS_BTREE_LONG_PTRS);
0635     /*
0636      * Need a cursor.  Can't allocate until bb_level is filled in.
0637      */
0638     cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
0639     cur->bc_ino.flags = wasdel ? XFS_BTCUR_BMBT_WASDEL : 0;
0640     /*
0641      * Convert to a btree with two levels, one record in root.
0642      */
0643     ifp->if_format = XFS_DINODE_FMT_BTREE;
0644     memset(&args, 0, sizeof(args));
0645     args.tp = tp;
0646     args.mp = mp;
0647     xfs_rmap_ino_bmbt_owner(&args.oinfo, ip->i_ino, whichfork);
0648     if (tp->t_firstblock == NULLFSBLOCK) {
0649         args.type = XFS_ALLOCTYPE_START_BNO;
0650         args.fsbno = XFS_INO_TO_FSB(mp, ip->i_ino);
0651     } else if (tp->t_flags & XFS_TRANS_LOWMODE) {
0652         args.type = XFS_ALLOCTYPE_START_BNO;
0653         args.fsbno = tp->t_firstblock;
0654     } else {
0655         args.type = XFS_ALLOCTYPE_NEAR_BNO;
0656         args.fsbno = tp->t_firstblock;
0657     }
0658     args.minlen = args.maxlen = args.prod = 1;
0659     args.wasdel = wasdel;
0660     *logflagsp = 0;
0661     error = xfs_alloc_vextent(&args);
0662     if (error)
0663         goto out_root_realloc;
0664 
0665     if (WARN_ON_ONCE(args.fsbno == NULLFSBLOCK)) {
0666         error = -ENOSPC;
0667         goto out_root_realloc;
0668     }
0669 
0670     /*
0671      * Allocation can't fail, the space was reserved.
0672      */
0673     ASSERT(tp->t_firstblock == NULLFSBLOCK ||
0674            args.agno >= XFS_FSB_TO_AGNO(mp, tp->t_firstblock));
0675     tp->t_firstblock = args.fsbno;
0676     cur->bc_ino.allocated++;
0677     ip->i_nblocks++;
0678     xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, 1L);
0679     error = xfs_trans_get_buf(tp, mp->m_ddev_targp,
0680             XFS_FSB_TO_DADDR(mp, args.fsbno),
0681             mp->m_bsize, 0, &abp);
0682     if (error)
0683         goto out_unreserve_dquot;
0684 
0685     /*
0686      * Fill in the child block.
0687      */
0688     abp->b_ops = &xfs_bmbt_buf_ops;
0689     ablock = XFS_BUF_TO_BLOCK(abp);
0690     xfs_btree_init_block_int(mp, ablock, xfs_buf_daddr(abp),
0691                 XFS_BTNUM_BMAP, 0, 0, ip->i_ino,
0692                 XFS_BTREE_LONG_PTRS);
0693 
0694     for_each_xfs_iext(ifp, &icur, &rec) {
0695         if (isnullstartblock(rec.br_startblock))
0696             continue;
0697         arp = XFS_BMBT_REC_ADDR(mp, ablock, 1 + cnt);
0698         xfs_bmbt_disk_set_all(arp, &rec);
0699         cnt++;
0700     }
0701     ASSERT(cnt == ifp->if_nextents);
0702     xfs_btree_set_numrecs(ablock, cnt);
0703 
0704     /*
0705      * Fill in the root key and pointer.
0706      */
0707     kp = XFS_BMBT_KEY_ADDR(mp, block, 1);
0708     arp = XFS_BMBT_REC_ADDR(mp, ablock, 1);
0709     kp->br_startoff = cpu_to_be64(xfs_bmbt_disk_get_startoff(arp));
0710     pp = XFS_BMBT_PTR_ADDR(mp, block, 1, xfs_bmbt_get_maxrecs(cur,
0711                         be16_to_cpu(block->bb_level)));
0712     *pp = cpu_to_be64(args.fsbno);
0713 
0714     /*
0715      * Do all this logging at the end so that
0716      * the root is at the right level.
0717      */
0718     xfs_btree_log_block(cur, abp, XFS_BB_ALL_BITS);
0719     xfs_btree_log_recs(cur, abp, 1, be16_to_cpu(ablock->bb_numrecs));
0720     ASSERT(*curp == NULL);
0721     *curp = cur;
0722     *logflagsp = XFS_ILOG_CORE | xfs_ilog_fbroot(whichfork);
0723     return 0;
0724 
0725 out_unreserve_dquot:
0726     xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, -1L);
0727 out_root_realloc:
0728     xfs_iroot_realloc(ip, -1, whichfork);
0729     ifp->if_format = XFS_DINODE_FMT_EXTENTS;
0730     ASSERT(ifp->if_broot == NULL);
0731     xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
0732 
0733     return error;
0734 }
0735 
0736 /*
0737  * Convert a local file to an extents file.
0738  * This code is out of bounds for data forks of regular files,
0739  * since the file data needs to get logged so things will stay consistent.
0740  * (The bmap-level manipulations are ok, though).
0741  */
0742 void
0743 xfs_bmap_local_to_extents_empty(
0744     struct xfs_trans    *tp,
0745     struct xfs_inode    *ip,
0746     int         whichfork)
0747 {
0748     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, whichfork);
0749 
0750     ASSERT(whichfork != XFS_COW_FORK);
0751     ASSERT(ifp->if_format == XFS_DINODE_FMT_LOCAL);
0752     ASSERT(ifp->if_bytes == 0);
0753     ASSERT(ifp->if_nextents == 0);
0754 
0755     xfs_bmap_forkoff_reset(ip, whichfork);
0756     ifp->if_u1.if_root = NULL;
0757     ifp->if_height = 0;
0758     ifp->if_format = XFS_DINODE_FMT_EXTENTS;
0759     xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
0760 }
0761 
0762 
0763 STATIC int              /* error */
0764 xfs_bmap_local_to_extents(
0765     xfs_trans_t *tp,        /* transaction pointer */
0766     xfs_inode_t *ip,        /* incore inode pointer */
0767     xfs_extlen_t    total,      /* total blocks needed by transaction */
0768     int     *logflagsp, /* inode logging flags */
0769     int     whichfork,
0770     void        (*init_fn)(struct xfs_trans *tp,
0771                    struct xfs_buf *bp,
0772                    struct xfs_inode *ip,
0773                    struct xfs_ifork *ifp))
0774 {
0775     int     error = 0;
0776     int     flags;      /* logging flags returned */
0777     struct xfs_ifork *ifp;      /* inode fork pointer */
0778     xfs_alloc_arg_t args;       /* allocation arguments */
0779     struct xfs_buf  *bp;        /* buffer for extent block */
0780     struct xfs_bmbt_irec rec;
0781     struct xfs_iext_cursor icur;
0782 
0783     /*
0784      * We don't want to deal with the case of keeping inode data inline yet.
0785      * So sending the data fork of a regular inode is invalid.
0786      */
0787     ASSERT(!(S_ISREG(VFS_I(ip)->i_mode) && whichfork == XFS_DATA_FORK));
0788     ifp = xfs_ifork_ptr(ip, whichfork);
0789     ASSERT(ifp->if_format == XFS_DINODE_FMT_LOCAL);
0790 
0791     if (!ifp->if_bytes) {
0792         xfs_bmap_local_to_extents_empty(tp, ip, whichfork);
0793         flags = XFS_ILOG_CORE;
0794         goto done;
0795     }
0796 
0797     flags = 0;
0798     error = 0;
0799     memset(&args, 0, sizeof(args));
0800     args.tp = tp;
0801     args.mp = ip->i_mount;
0802     xfs_rmap_ino_owner(&args.oinfo, ip->i_ino, whichfork, 0);
0803     /*
0804      * Allocate a block.  We know we need only one, since the
0805      * file currently fits in an inode.
0806      */
0807     if (tp->t_firstblock == NULLFSBLOCK) {
0808         args.fsbno = XFS_INO_TO_FSB(args.mp, ip->i_ino);
0809         args.type = XFS_ALLOCTYPE_START_BNO;
0810     } else {
0811         args.fsbno = tp->t_firstblock;
0812         args.type = XFS_ALLOCTYPE_NEAR_BNO;
0813     }
0814     args.total = total;
0815     args.minlen = args.maxlen = args.prod = 1;
0816     error = xfs_alloc_vextent(&args);
0817     if (error)
0818         goto done;
0819 
0820     /* Can't fail, the space was reserved. */
0821     ASSERT(args.fsbno != NULLFSBLOCK);
0822     ASSERT(args.len == 1);
0823     tp->t_firstblock = args.fsbno;
0824     error = xfs_trans_get_buf(tp, args.mp->m_ddev_targp,
0825             XFS_FSB_TO_DADDR(args.mp, args.fsbno),
0826             args.mp->m_bsize, 0, &bp);
0827     if (error)
0828         goto done;
0829 
0830     /*
0831      * Initialize the block, copy the data and log the remote buffer.
0832      *
0833      * The callout is responsible for logging because the remote format
0834      * might differ from the local format and thus we don't know how much to
0835      * log here. Note that init_fn must also set the buffer log item type
0836      * correctly.
0837      */
0838     init_fn(tp, bp, ip, ifp);
0839 
0840     /* account for the change in fork size */
0841     xfs_idata_realloc(ip, -ifp->if_bytes, whichfork);
0842     xfs_bmap_local_to_extents_empty(tp, ip, whichfork);
0843     flags |= XFS_ILOG_CORE;
0844 
0845     ifp->if_u1.if_root = NULL;
0846     ifp->if_height = 0;
0847 
0848     rec.br_startoff = 0;
0849     rec.br_startblock = args.fsbno;
0850     rec.br_blockcount = 1;
0851     rec.br_state = XFS_EXT_NORM;
0852     xfs_iext_first(ifp, &icur);
0853     xfs_iext_insert(ip, &icur, &rec, 0);
0854 
0855     ifp->if_nextents = 1;
0856     ip->i_nblocks = 1;
0857     xfs_trans_mod_dquot_byino(tp, ip,
0858         XFS_TRANS_DQ_BCOUNT, 1L);
0859     flags |= xfs_ilog_fext(whichfork);
0860 
0861 done:
0862     *logflagsp = flags;
0863     return error;
0864 }
0865 
0866 /*
0867  * Called from xfs_bmap_add_attrfork to handle btree format files.
0868  */
0869 STATIC int                  /* error */
0870 xfs_bmap_add_attrfork_btree(
0871     xfs_trans_t     *tp,        /* transaction pointer */
0872     xfs_inode_t     *ip,        /* incore inode pointer */
0873     int         *flags)     /* inode logging flags */
0874 {
0875     struct xfs_btree_block  *block = ip->i_df.if_broot;
0876     struct xfs_btree_cur    *cur;       /* btree cursor */
0877     int         error;      /* error return value */
0878     xfs_mount_t     *mp;        /* file system mount struct */
0879     int         stat;       /* newroot status */
0880 
0881     mp = ip->i_mount;
0882 
0883     if (XFS_BMAP_BMDR_SPACE(block) <= xfs_inode_data_fork_size(ip))
0884         *flags |= XFS_ILOG_DBROOT;
0885     else {
0886         cur = xfs_bmbt_init_cursor(mp, tp, ip, XFS_DATA_FORK);
0887         error = xfs_bmbt_lookup_first(cur, &stat);
0888         if (error)
0889             goto error0;
0890         /* must be at least one entry */
0891         if (XFS_IS_CORRUPT(mp, stat != 1)) {
0892             error = -EFSCORRUPTED;
0893             goto error0;
0894         }
0895         if ((error = xfs_btree_new_iroot(cur, flags, &stat)))
0896             goto error0;
0897         if (stat == 0) {
0898             xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
0899             return -ENOSPC;
0900         }
0901         cur->bc_ino.allocated = 0;
0902         xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
0903     }
0904     return 0;
0905 error0:
0906     xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
0907     return error;
0908 }
0909 
0910 /*
0911  * Called from xfs_bmap_add_attrfork to handle extents format files.
0912  */
0913 STATIC int                  /* error */
0914 xfs_bmap_add_attrfork_extents(
0915     struct xfs_trans    *tp,        /* transaction pointer */
0916     struct xfs_inode    *ip,        /* incore inode pointer */
0917     int         *flags)     /* inode logging flags */
0918 {
0919     struct xfs_btree_cur    *cur;       /* bmap btree cursor */
0920     int         error;      /* error return value */
0921 
0922     if (ip->i_df.if_nextents * sizeof(struct xfs_bmbt_rec) <=
0923         xfs_inode_data_fork_size(ip))
0924         return 0;
0925     cur = NULL;
0926     error = xfs_bmap_extents_to_btree(tp, ip, &cur, 0, flags,
0927                       XFS_DATA_FORK);
0928     if (cur) {
0929         cur->bc_ino.allocated = 0;
0930         xfs_btree_del_cursor(cur, error);
0931     }
0932     return error;
0933 }
0934 
0935 /*
0936  * Called from xfs_bmap_add_attrfork to handle local format files. Each
0937  * different data fork content type needs a different callout to do the
0938  * conversion. Some are basic and only require special block initialisation
0939  * callouts for the data formating, others (directories) are so specialised they
0940  * handle everything themselves.
0941  *
0942  * XXX (dgc): investigate whether directory conversion can use the generic
0943  * formatting callout. It should be possible - it's just a very complex
0944  * formatter.
0945  */
0946 STATIC int                  /* error */
0947 xfs_bmap_add_attrfork_local(
0948     struct xfs_trans    *tp,        /* transaction pointer */
0949     struct xfs_inode    *ip,        /* incore inode pointer */
0950     int         *flags)     /* inode logging flags */
0951 {
0952     struct xfs_da_args  dargs;      /* args for dir/attr code */
0953 
0954     if (ip->i_df.if_bytes <= xfs_inode_data_fork_size(ip))
0955         return 0;
0956 
0957     if (S_ISDIR(VFS_I(ip)->i_mode)) {
0958         memset(&dargs, 0, sizeof(dargs));
0959         dargs.geo = ip->i_mount->m_dir_geo;
0960         dargs.dp = ip;
0961         dargs.total = dargs.geo->fsbcount;
0962         dargs.whichfork = XFS_DATA_FORK;
0963         dargs.trans = tp;
0964         return xfs_dir2_sf_to_block(&dargs);
0965     }
0966 
0967     if (S_ISLNK(VFS_I(ip)->i_mode))
0968         return xfs_bmap_local_to_extents(tp, ip, 1, flags,
0969                          XFS_DATA_FORK,
0970                          xfs_symlink_local_to_remote);
0971 
0972     /* should only be called for types that support local format data */
0973     ASSERT(0);
0974     return -EFSCORRUPTED;
0975 }
0976 
0977 /*
0978  * Set an inode attr fork offset based on the format of the data fork.
0979  */
0980 static int
0981 xfs_bmap_set_attrforkoff(
0982     struct xfs_inode    *ip,
0983     int         size,
0984     int         *version)
0985 {
0986     int         default_size = xfs_default_attroffset(ip) >> 3;
0987 
0988     switch (ip->i_df.if_format) {
0989     case XFS_DINODE_FMT_DEV:
0990         ip->i_forkoff = default_size;
0991         break;
0992     case XFS_DINODE_FMT_LOCAL:
0993     case XFS_DINODE_FMT_EXTENTS:
0994     case XFS_DINODE_FMT_BTREE:
0995         ip->i_forkoff = xfs_attr_shortform_bytesfit(ip, size);
0996         if (!ip->i_forkoff)
0997             ip->i_forkoff = default_size;
0998         else if (xfs_has_attr2(ip->i_mount) && version)
0999             *version = 2;
1000         break;
1001     default:
1002         ASSERT(0);
1003         return -EINVAL;
1004     }
1005 
1006     return 0;
1007 }
1008 
1009 /*
1010  * Convert inode from non-attributed to attributed.
1011  * Must not be in a transaction, ip must not be locked.
1012  */
1013 int                     /* error code */
1014 xfs_bmap_add_attrfork(
1015     xfs_inode_t     *ip,        /* incore inode pointer */
1016     int         size,       /* space new attribute needs */
1017     int         rsvd)       /* xact may use reserved blks */
1018 {
1019     xfs_mount_t     *mp;        /* mount structure */
1020     xfs_trans_t     *tp;        /* transaction pointer */
1021     int         blks;       /* space reservation */
1022     int         version = 1;    /* superblock attr version */
1023     int         logflags;   /* logging flags */
1024     int         error;      /* error return value */
1025 
1026     ASSERT(xfs_inode_has_attr_fork(ip) == 0);
1027 
1028     mp = ip->i_mount;
1029     ASSERT(!XFS_NOT_DQATTACHED(mp, ip));
1030 
1031     blks = XFS_ADDAFORK_SPACE_RES(mp);
1032 
1033     error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_addafork, blks, 0,
1034             rsvd, &tp);
1035     if (error)
1036         return error;
1037     if (xfs_inode_has_attr_fork(ip))
1038         goto trans_cancel;
1039 
1040     xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1041     error = xfs_bmap_set_attrforkoff(ip, size, &version);
1042     if (error)
1043         goto trans_cancel;
1044 
1045     xfs_ifork_init_attr(ip, XFS_DINODE_FMT_EXTENTS, 0);
1046     logflags = 0;
1047     switch (ip->i_df.if_format) {
1048     case XFS_DINODE_FMT_LOCAL:
1049         error = xfs_bmap_add_attrfork_local(tp, ip, &logflags);
1050         break;
1051     case XFS_DINODE_FMT_EXTENTS:
1052         error = xfs_bmap_add_attrfork_extents(tp, ip, &logflags);
1053         break;
1054     case XFS_DINODE_FMT_BTREE:
1055         error = xfs_bmap_add_attrfork_btree(tp, ip, &logflags);
1056         break;
1057     default:
1058         error = 0;
1059         break;
1060     }
1061     if (logflags)
1062         xfs_trans_log_inode(tp, ip, logflags);
1063     if (error)
1064         goto trans_cancel;
1065     if (!xfs_has_attr(mp) ||
1066        (!xfs_has_attr2(mp) && version == 2)) {
1067         bool log_sb = false;
1068 
1069         spin_lock(&mp->m_sb_lock);
1070         if (!xfs_has_attr(mp)) {
1071             xfs_add_attr(mp);
1072             log_sb = true;
1073         }
1074         if (!xfs_has_attr2(mp) && version == 2) {
1075             xfs_add_attr2(mp);
1076             log_sb = true;
1077         }
1078         spin_unlock(&mp->m_sb_lock);
1079         if (log_sb)
1080             xfs_log_sb(tp);
1081     }
1082 
1083     error = xfs_trans_commit(tp);
1084     xfs_iunlock(ip, XFS_ILOCK_EXCL);
1085     return error;
1086 
1087 trans_cancel:
1088     xfs_trans_cancel(tp);
1089     xfs_iunlock(ip, XFS_ILOCK_EXCL);
1090     return error;
1091 }
1092 
1093 /*
1094  * Internal and external extent tree search functions.
1095  */
1096 
1097 struct xfs_iread_state {
1098     struct xfs_iext_cursor  icur;
1099     xfs_extnum_t        loaded;
1100 };
1101 
1102 /* Stuff every bmbt record from this block into the incore extent map. */
1103 static int
1104 xfs_iread_bmbt_block(
1105     struct xfs_btree_cur    *cur,
1106     int         level,
1107     void            *priv)
1108 {
1109     struct xfs_iread_state  *ir = priv;
1110     struct xfs_mount    *mp = cur->bc_mp;
1111     struct xfs_inode    *ip = cur->bc_ino.ip;
1112     struct xfs_btree_block  *block;
1113     struct xfs_buf      *bp;
1114     struct xfs_bmbt_rec *frp;
1115     xfs_extnum_t        num_recs;
1116     xfs_extnum_t        j;
1117     int         whichfork = cur->bc_ino.whichfork;
1118     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, whichfork);
1119 
1120     block = xfs_btree_get_block(cur, level, &bp);
1121 
1122     /* Abort if we find more records than nextents. */
1123     num_recs = xfs_btree_get_numrecs(block);
1124     if (unlikely(ir->loaded + num_recs > ifp->if_nextents)) {
1125         xfs_warn(ip->i_mount, "corrupt dinode %llu, (btree extents).",
1126                 (unsigned long long)ip->i_ino);
1127         xfs_inode_verifier_error(ip, -EFSCORRUPTED, __func__, block,
1128                 sizeof(*block), __this_address);
1129         return -EFSCORRUPTED;
1130     }
1131 
1132     /* Copy records into the incore cache. */
1133     frp = XFS_BMBT_REC_ADDR(mp, block, 1);
1134     for (j = 0; j < num_recs; j++, frp++, ir->loaded++) {
1135         struct xfs_bmbt_irec    new;
1136         xfs_failaddr_t      fa;
1137 
1138         xfs_bmbt_disk_get_all(frp, &new);
1139         fa = xfs_bmap_validate_extent(ip, whichfork, &new);
1140         if (fa) {
1141             xfs_inode_verifier_error(ip, -EFSCORRUPTED,
1142                     "xfs_iread_extents(2)", frp,
1143                     sizeof(*frp), fa);
1144             return -EFSCORRUPTED;
1145         }
1146         xfs_iext_insert(ip, &ir->icur, &new,
1147                 xfs_bmap_fork_to_state(whichfork));
1148         trace_xfs_read_extent(ip, &ir->icur,
1149                 xfs_bmap_fork_to_state(whichfork), _THIS_IP_);
1150         xfs_iext_next(ifp, &ir->icur);
1151     }
1152 
1153     return 0;
1154 }
1155 
1156 /*
1157  * Read in extents from a btree-format inode.
1158  */
1159 int
1160 xfs_iread_extents(
1161     struct xfs_trans    *tp,
1162     struct xfs_inode    *ip,
1163     int         whichfork)
1164 {
1165     struct xfs_iread_state  ir;
1166     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, whichfork);
1167     struct xfs_mount    *mp = ip->i_mount;
1168     struct xfs_btree_cur    *cur;
1169     int         error;
1170 
1171     if (!xfs_need_iread_extents(ifp))
1172         return 0;
1173 
1174     ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
1175 
1176     ir.loaded = 0;
1177     xfs_iext_first(ifp, &ir.icur);
1178     cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
1179     error = xfs_btree_visit_blocks(cur, xfs_iread_bmbt_block,
1180             XFS_BTREE_VISIT_RECORDS, &ir);
1181     xfs_btree_del_cursor(cur, error);
1182     if (error)
1183         goto out;
1184 
1185     if (XFS_IS_CORRUPT(mp, ir.loaded != ifp->if_nextents)) {
1186         error = -EFSCORRUPTED;
1187         goto out;
1188     }
1189     ASSERT(ir.loaded == xfs_iext_count(ifp));
1190     return 0;
1191 out:
1192     xfs_iext_destroy(ifp);
1193     return error;
1194 }
1195 
1196 /*
1197  * Returns the relative block number of the first unused block(s) in the given
1198  * fork with at least "len" logically contiguous blocks free.  This is the
1199  * lowest-address hole if the fork has holes, else the first block past the end
1200  * of fork.  Return 0 if the fork is currently local (in-inode).
1201  */
1202 int                     /* error */
1203 xfs_bmap_first_unused(
1204     struct xfs_trans    *tp,        /* transaction pointer */
1205     struct xfs_inode    *ip,        /* incore inode */
1206     xfs_extlen_t        len,        /* size of hole to find */
1207     xfs_fileoff_t       *first_unused,  /* unused block */
1208     int         whichfork)  /* data or attr fork */
1209 {
1210     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, whichfork);
1211     struct xfs_bmbt_irec    got;
1212     struct xfs_iext_cursor  icur;
1213     xfs_fileoff_t       lastaddr = 0;
1214     xfs_fileoff_t       lowest, max;
1215     int         error;
1216 
1217     if (ifp->if_format == XFS_DINODE_FMT_LOCAL) {
1218         *first_unused = 0;
1219         return 0;
1220     }
1221 
1222     ASSERT(xfs_ifork_has_extents(ifp));
1223 
1224     error = xfs_iread_extents(tp, ip, whichfork);
1225     if (error)
1226         return error;
1227 
1228     lowest = max = *first_unused;
1229     for_each_xfs_iext(ifp, &icur, &got) {
1230         /*
1231          * See if the hole before this extent will work.
1232          */
1233         if (got.br_startoff >= lowest + len &&
1234             got.br_startoff - max >= len)
1235             break;
1236         lastaddr = got.br_startoff + got.br_blockcount;
1237         max = XFS_FILEOFF_MAX(lastaddr, lowest);
1238     }
1239 
1240     *first_unused = max;
1241     return 0;
1242 }
1243 
1244 /*
1245  * Returns the file-relative block number of the last block - 1 before
1246  * last_block (input value) in the file.
1247  * This is not based on i_size, it is based on the extent records.
1248  * Returns 0 for local files, as they do not have extent records.
1249  */
1250 int                     /* error */
1251 xfs_bmap_last_before(
1252     struct xfs_trans    *tp,        /* transaction pointer */
1253     struct xfs_inode    *ip,        /* incore inode */
1254     xfs_fileoff_t       *last_block,    /* last block */
1255     int         whichfork)  /* data or attr fork */
1256 {
1257     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, whichfork);
1258     struct xfs_bmbt_irec    got;
1259     struct xfs_iext_cursor  icur;
1260     int         error;
1261 
1262     switch (ifp->if_format) {
1263     case XFS_DINODE_FMT_LOCAL:
1264         *last_block = 0;
1265         return 0;
1266     case XFS_DINODE_FMT_BTREE:
1267     case XFS_DINODE_FMT_EXTENTS:
1268         break;
1269     default:
1270         ASSERT(0);
1271         return -EFSCORRUPTED;
1272     }
1273 
1274     error = xfs_iread_extents(tp, ip, whichfork);
1275     if (error)
1276         return error;
1277 
1278     if (!xfs_iext_lookup_extent_before(ip, ifp, last_block, &icur, &got))
1279         *last_block = 0;
1280     return 0;
1281 }
1282 
1283 int
1284 xfs_bmap_last_extent(
1285     struct xfs_trans    *tp,
1286     struct xfs_inode    *ip,
1287     int         whichfork,
1288     struct xfs_bmbt_irec    *rec,
1289     int         *is_empty)
1290 {
1291     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, whichfork);
1292     struct xfs_iext_cursor  icur;
1293     int         error;
1294 
1295     error = xfs_iread_extents(tp, ip, whichfork);
1296     if (error)
1297         return error;
1298 
1299     xfs_iext_last(ifp, &icur);
1300     if (!xfs_iext_get_extent(ifp, &icur, rec))
1301         *is_empty = 1;
1302     else
1303         *is_empty = 0;
1304     return 0;
1305 }
1306 
1307 /*
1308  * Check the last inode extent to determine whether this allocation will result
1309  * in blocks being allocated at the end of the file. When we allocate new data
1310  * blocks at the end of the file which do not start at the previous data block,
1311  * we will try to align the new blocks at stripe unit boundaries.
1312  *
1313  * Returns 1 in bma->aeof if the file (fork) is empty as any new write will be
1314  * at, or past the EOF.
1315  */
1316 STATIC int
1317 xfs_bmap_isaeof(
1318     struct xfs_bmalloca *bma,
1319     int         whichfork)
1320 {
1321     struct xfs_bmbt_irec    rec;
1322     int         is_empty;
1323     int         error;
1324 
1325     bma->aeof = false;
1326     error = xfs_bmap_last_extent(NULL, bma->ip, whichfork, &rec,
1327                      &is_empty);
1328     if (error)
1329         return error;
1330 
1331     if (is_empty) {
1332         bma->aeof = true;
1333         return 0;
1334     }
1335 
1336     /*
1337      * Check if we are allocation or past the last extent, or at least into
1338      * the last delayed allocated extent.
1339      */
1340     bma->aeof = bma->offset >= rec.br_startoff + rec.br_blockcount ||
1341         (bma->offset >= rec.br_startoff &&
1342          isnullstartblock(rec.br_startblock));
1343     return 0;
1344 }
1345 
1346 /*
1347  * Returns the file-relative block number of the first block past eof in
1348  * the file.  This is not based on i_size, it is based on the extent records.
1349  * Returns 0 for local files, as they do not have extent records.
1350  */
1351 int
1352 xfs_bmap_last_offset(
1353     struct xfs_inode    *ip,
1354     xfs_fileoff_t       *last_block,
1355     int         whichfork)
1356 {
1357     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, whichfork);
1358     struct xfs_bmbt_irec    rec;
1359     int         is_empty;
1360     int         error;
1361 
1362     *last_block = 0;
1363 
1364     if (ifp->if_format == XFS_DINODE_FMT_LOCAL)
1365         return 0;
1366 
1367     if (XFS_IS_CORRUPT(ip->i_mount, !xfs_ifork_has_extents(ifp)))
1368         return -EFSCORRUPTED;
1369 
1370     error = xfs_bmap_last_extent(NULL, ip, whichfork, &rec, &is_empty);
1371     if (error || is_empty)
1372         return error;
1373 
1374     *last_block = rec.br_startoff + rec.br_blockcount;
1375     return 0;
1376 }
1377 
1378 /*
1379  * Extent tree manipulation functions used during allocation.
1380  */
1381 
1382 /*
1383  * Convert a delayed allocation to a real allocation.
1384  */
1385 STATIC int              /* error */
1386 xfs_bmap_add_extent_delay_real(
1387     struct xfs_bmalloca *bma,
1388     int         whichfork)
1389 {
1390     struct xfs_mount    *mp = bma->ip->i_mount;
1391     struct xfs_ifork    *ifp = xfs_ifork_ptr(bma->ip, whichfork);
1392     struct xfs_bmbt_irec    *new = &bma->got;
1393     int         error;  /* error return value */
1394     int         i;  /* temp state */
1395     xfs_fileoff_t       new_endoff; /* end offset of new entry */
1396     xfs_bmbt_irec_t     r[3];   /* neighbor extent entries */
1397                     /* left is 0, right is 1, prev is 2 */
1398     int         rval=0; /* return value (logging flags) */
1399     uint32_t        state = xfs_bmap_fork_to_state(whichfork);
1400     xfs_filblks_t       da_new; /* new count del alloc blocks used */
1401     xfs_filblks_t       da_old; /* old count del alloc blocks used */
1402     xfs_filblks_t       temp=0; /* value for da_new calculations */
1403     int         tmp_rval;   /* partial logging flags */
1404     struct xfs_bmbt_irec    old;
1405 
1406     ASSERT(whichfork != XFS_ATTR_FORK);
1407     ASSERT(!isnullstartblock(new->br_startblock));
1408     ASSERT(!bma->cur ||
1409            (bma->cur->bc_ino.flags & XFS_BTCUR_BMBT_WASDEL));
1410 
1411     XFS_STATS_INC(mp, xs_add_exlist);
1412 
1413 #define LEFT        r[0]
1414 #define RIGHT       r[1]
1415 #define PREV        r[2]
1416 
1417     /*
1418      * Set up a bunch of variables to make the tests simpler.
1419      */
1420     xfs_iext_get_extent(ifp, &bma->icur, &PREV);
1421     new_endoff = new->br_startoff + new->br_blockcount;
1422     ASSERT(isnullstartblock(PREV.br_startblock));
1423     ASSERT(PREV.br_startoff <= new->br_startoff);
1424     ASSERT(PREV.br_startoff + PREV.br_blockcount >= new_endoff);
1425 
1426     da_old = startblockval(PREV.br_startblock);
1427     da_new = 0;
1428 
1429     /*
1430      * Set flags determining what part of the previous delayed allocation
1431      * extent is being replaced by a real allocation.
1432      */
1433     if (PREV.br_startoff == new->br_startoff)
1434         state |= BMAP_LEFT_FILLING;
1435     if (PREV.br_startoff + PREV.br_blockcount == new_endoff)
1436         state |= BMAP_RIGHT_FILLING;
1437 
1438     /*
1439      * Check and set flags if this segment has a left neighbor.
1440      * Don't set contiguous if the combined extent would be too large.
1441      */
1442     if (xfs_iext_peek_prev_extent(ifp, &bma->icur, &LEFT)) {
1443         state |= BMAP_LEFT_VALID;
1444         if (isnullstartblock(LEFT.br_startblock))
1445             state |= BMAP_LEFT_DELAY;
1446     }
1447 
1448     if ((state & BMAP_LEFT_VALID) && !(state & BMAP_LEFT_DELAY) &&
1449         LEFT.br_startoff + LEFT.br_blockcount == new->br_startoff &&
1450         LEFT.br_startblock + LEFT.br_blockcount == new->br_startblock &&
1451         LEFT.br_state == new->br_state &&
1452         LEFT.br_blockcount + new->br_blockcount <= XFS_MAX_BMBT_EXTLEN)
1453         state |= BMAP_LEFT_CONTIG;
1454 
1455     /*
1456      * Check and set flags if this segment has a right neighbor.
1457      * Don't set contiguous if the combined extent would be too large.
1458      * Also check for all-three-contiguous being too large.
1459      */
1460     if (xfs_iext_peek_next_extent(ifp, &bma->icur, &RIGHT)) {
1461         state |= BMAP_RIGHT_VALID;
1462         if (isnullstartblock(RIGHT.br_startblock))
1463             state |= BMAP_RIGHT_DELAY;
1464     }
1465 
1466     if ((state & BMAP_RIGHT_VALID) && !(state & BMAP_RIGHT_DELAY) &&
1467         new_endoff == RIGHT.br_startoff &&
1468         new->br_startblock + new->br_blockcount == RIGHT.br_startblock &&
1469         new->br_state == RIGHT.br_state &&
1470         new->br_blockcount + RIGHT.br_blockcount <= XFS_MAX_BMBT_EXTLEN &&
1471         ((state & (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
1472                BMAP_RIGHT_FILLING)) !=
1473               (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
1474                BMAP_RIGHT_FILLING) ||
1475          LEFT.br_blockcount + new->br_blockcount + RIGHT.br_blockcount
1476             <= XFS_MAX_BMBT_EXTLEN))
1477         state |= BMAP_RIGHT_CONTIG;
1478 
1479     error = 0;
1480     /*
1481      * Switch out based on the FILLING and CONTIG state bits.
1482      */
1483     switch (state & (BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG |
1484              BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG)) {
1485     case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG |
1486          BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
1487         /*
1488          * Filling in all of a previously delayed allocation extent.
1489          * The left and right neighbors are both contiguous with new.
1490          */
1491         LEFT.br_blockcount += PREV.br_blockcount + RIGHT.br_blockcount;
1492 
1493         xfs_iext_remove(bma->ip, &bma->icur, state);
1494         xfs_iext_remove(bma->ip, &bma->icur, state);
1495         xfs_iext_prev(ifp, &bma->icur);
1496         xfs_iext_update_extent(bma->ip, state, &bma->icur, &LEFT);
1497         ifp->if_nextents--;
1498 
1499         if (bma->cur == NULL)
1500             rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
1501         else {
1502             rval = XFS_ILOG_CORE;
1503             error = xfs_bmbt_lookup_eq(bma->cur, &RIGHT, &i);
1504             if (error)
1505                 goto done;
1506             if (XFS_IS_CORRUPT(mp, i != 1)) {
1507                 error = -EFSCORRUPTED;
1508                 goto done;
1509             }
1510             error = xfs_btree_delete(bma->cur, &i);
1511             if (error)
1512                 goto done;
1513             if (XFS_IS_CORRUPT(mp, i != 1)) {
1514                 error = -EFSCORRUPTED;
1515                 goto done;
1516             }
1517             error = xfs_btree_decrement(bma->cur, 0, &i);
1518             if (error)
1519                 goto done;
1520             if (XFS_IS_CORRUPT(mp, i != 1)) {
1521                 error = -EFSCORRUPTED;
1522                 goto done;
1523             }
1524             error = xfs_bmbt_update(bma->cur, &LEFT);
1525             if (error)
1526                 goto done;
1527         }
1528         break;
1529 
1530     case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG:
1531         /*
1532          * Filling in all of a previously delayed allocation extent.
1533          * The left neighbor is contiguous, the right is not.
1534          */
1535         old = LEFT;
1536         LEFT.br_blockcount += PREV.br_blockcount;
1537 
1538         xfs_iext_remove(bma->ip, &bma->icur, state);
1539         xfs_iext_prev(ifp, &bma->icur);
1540         xfs_iext_update_extent(bma->ip, state, &bma->icur, &LEFT);
1541 
1542         if (bma->cur == NULL)
1543             rval = XFS_ILOG_DEXT;
1544         else {
1545             rval = 0;
1546             error = xfs_bmbt_lookup_eq(bma->cur, &old, &i);
1547             if (error)
1548                 goto done;
1549             if (XFS_IS_CORRUPT(mp, i != 1)) {
1550                 error = -EFSCORRUPTED;
1551                 goto done;
1552             }
1553             error = xfs_bmbt_update(bma->cur, &LEFT);
1554             if (error)
1555                 goto done;
1556         }
1557         break;
1558 
1559     case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
1560         /*
1561          * Filling in all of a previously delayed allocation extent.
1562          * The right neighbor is contiguous, the left is not. Take care
1563          * with delay -> unwritten extent allocation here because the
1564          * delalloc record we are overwriting is always written.
1565          */
1566         PREV.br_startblock = new->br_startblock;
1567         PREV.br_blockcount += RIGHT.br_blockcount;
1568         PREV.br_state = new->br_state;
1569 
1570         xfs_iext_next(ifp, &bma->icur);
1571         xfs_iext_remove(bma->ip, &bma->icur, state);
1572         xfs_iext_prev(ifp, &bma->icur);
1573         xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
1574 
1575         if (bma->cur == NULL)
1576             rval = XFS_ILOG_DEXT;
1577         else {
1578             rval = 0;
1579             error = xfs_bmbt_lookup_eq(bma->cur, &RIGHT, &i);
1580             if (error)
1581                 goto done;
1582             if (XFS_IS_CORRUPT(mp, i != 1)) {
1583                 error = -EFSCORRUPTED;
1584                 goto done;
1585             }
1586             error = xfs_bmbt_update(bma->cur, &PREV);
1587             if (error)
1588                 goto done;
1589         }
1590         break;
1591 
1592     case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
1593         /*
1594          * Filling in all of a previously delayed allocation extent.
1595          * Neither the left nor right neighbors are contiguous with
1596          * the new one.
1597          */
1598         PREV.br_startblock = new->br_startblock;
1599         PREV.br_state = new->br_state;
1600         xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
1601         ifp->if_nextents++;
1602 
1603         if (bma->cur == NULL)
1604             rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
1605         else {
1606             rval = XFS_ILOG_CORE;
1607             error = xfs_bmbt_lookup_eq(bma->cur, new, &i);
1608             if (error)
1609                 goto done;
1610             if (XFS_IS_CORRUPT(mp, i != 0)) {
1611                 error = -EFSCORRUPTED;
1612                 goto done;
1613             }
1614             error = xfs_btree_insert(bma->cur, &i);
1615             if (error)
1616                 goto done;
1617             if (XFS_IS_CORRUPT(mp, i != 1)) {
1618                 error = -EFSCORRUPTED;
1619                 goto done;
1620             }
1621         }
1622         break;
1623 
1624     case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG:
1625         /*
1626          * Filling in the first part of a previous delayed allocation.
1627          * The left neighbor is contiguous.
1628          */
1629         old = LEFT;
1630         temp = PREV.br_blockcount - new->br_blockcount;
1631         da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
1632                 startblockval(PREV.br_startblock));
1633 
1634         LEFT.br_blockcount += new->br_blockcount;
1635 
1636         PREV.br_blockcount = temp;
1637         PREV.br_startoff += new->br_blockcount;
1638         PREV.br_startblock = nullstartblock(da_new);
1639 
1640         xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
1641         xfs_iext_prev(ifp, &bma->icur);
1642         xfs_iext_update_extent(bma->ip, state, &bma->icur, &LEFT);
1643 
1644         if (bma->cur == NULL)
1645             rval = XFS_ILOG_DEXT;
1646         else {
1647             rval = 0;
1648             error = xfs_bmbt_lookup_eq(bma->cur, &old, &i);
1649             if (error)
1650                 goto done;
1651             if (XFS_IS_CORRUPT(mp, i != 1)) {
1652                 error = -EFSCORRUPTED;
1653                 goto done;
1654             }
1655             error = xfs_bmbt_update(bma->cur, &LEFT);
1656             if (error)
1657                 goto done;
1658         }
1659         break;
1660 
1661     case BMAP_LEFT_FILLING:
1662         /*
1663          * Filling in the first part of a previous delayed allocation.
1664          * The left neighbor is not contiguous.
1665          */
1666         xfs_iext_update_extent(bma->ip, state, &bma->icur, new);
1667         ifp->if_nextents++;
1668 
1669         if (bma->cur == NULL)
1670             rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
1671         else {
1672             rval = XFS_ILOG_CORE;
1673             error = xfs_bmbt_lookup_eq(bma->cur, new, &i);
1674             if (error)
1675                 goto done;
1676             if (XFS_IS_CORRUPT(mp, i != 0)) {
1677                 error = -EFSCORRUPTED;
1678                 goto done;
1679             }
1680             error = xfs_btree_insert(bma->cur, &i);
1681             if (error)
1682                 goto done;
1683             if (XFS_IS_CORRUPT(mp, i != 1)) {
1684                 error = -EFSCORRUPTED;
1685                 goto done;
1686             }
1687         }
1688 
1689         if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
1690             error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
1691                     &bma->cur, 1, &tmp_rval, whichfork);
1692             rval |= tmp_rval;
1693             if (error)
1694                 goto done;
1695         }
1696 
1697         temp = PREV.br_blockcount - new->br_blockcount;
1698         da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
1699             startblockval(PREV.br_startblock) -
1700             (bma->cur ? bma->cur->bc_ino.allocated : 0));
1701 
1702         PREV.br_startoff = new_endoff;
1703         PREV.br_blockcount = temp;
1704         PREV.br_startblock = nullstartblock(da_new);
1705         xfs_iext_next(ifp, &bma->icur);
1706         xfs_iext_insert(bma->ip, &bma->icur, &PREV, state);
1707         xfs_iext_prev(ifp, &bma->icur);
1708         break;
1709 
1710     case BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
1711         /*
1712          * Filling in the last part of a previous delayed allocation.
1713          * The right neighbor is contiguous with the new allocation.
1714          */
1715         old = RIGHT;
1716         RIGHT.br_startoff = new->br_startoff;
1717         RIGHT.br_startblock = new->br_startblock;
1718         RIGHT.br_blockcount += new->br_blockcount;
1719 
1720         if (bma->cur == NULL)
1721             rval = XFS_ILOG_DEXT;
1722         else {
1723             rval = 0;
1724             error = xfs_bmbt_lookup_eq(bma->cur, &old, &i);
1725             if (error)
1726                 goto done;
1727             if (XFS_IS_CORRUPT(mp, i != 1)) {
1728                 error = -EFSCORRUPTED;
1729                 goto done;
1730             }
1731             error = xfs_bmbt_update(bma->cur, &RIGHT);
1732             if (error)
1733                 goto done;
1734         }
1735 
1736         temp = PREV.br_blockcount - new->br_blockcount;
1737         da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
1738             startblockval(PREV.br_startblock));
1739 
1740         PREV.br_blockcount = temp;
1741         PREV.br_startblock = nullstartblock(da_new);
1742 
1743         xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
1744         xfs_iext_next(ifp, &bma->icur);
1745         xfs_iext_update_extent(bma->ip, state, &bma->icur, &RIGHT);
1746         break;
1747 
1748     case BMAP_RIGHT_FILLING:
1749         /*
1750          * Filling in the last part of a previous delayed allocation.
1751          * The right neighbor is not contiguous.
1752          */
1753         xfs_iext_update_extent(bma->ip, state, &bma->icur, new);
1754         ifp->if_nextents++;
1755 
1756         if (bma->cur == NULL)
1757             rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
1758         else {
1759             rval = XFS_ILOG_CORE;
1760             error = xfs_bmbt_lookup_eq(bma->cur, new, &i);
1761             if (error)
1762                 goto done;
1763             if (XFS_IS_CORRUPT(mp, i != 0)) {
1764                 error = -EFSCORRUPTED;
1765                 goto done;
1766             }
1767             error = xfs_btree_insert(bma->cur, &i);
1768             if (error)
1769                 goto done;
1770             if (XFS_IS_CORRUPT(mp, i != 1)) {
1771                 error = -EFSCORRUPTED;
1772                 goto done;
1773             }
1774         }
1775 
1776         if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
1777             error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
1778                 &bma->cur, 1, &tmp_rval, whichfork);
1779             rval |= tmp_rval;
1780             if (error)
1781                 goto done;
1782         }
1783 
1784         temp = PREV.br_blockcount - new->br_blockcount;
1785         da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
1786             startblockval(PREV.br_startblock) -
1787             (bma->cur ? bma->cur->bc_ino.allocated : 0));
1788 
1789         PREV.br_startblock = nullstartblock(da_new);
1790         PREV.br_blockcount = temp;
1791         xfs_iext_insert(bma->ip, &bma->icur, &PREV, state);
1792         xfs_iext_next(ifp, &bma->icur);
1793         break;
1794 
1795     case 0:
1796         /*
1797          * Filling in the middle part of a previous delayed allocation.
1798          * Contiguity is impossible here.
1799          * This case is avoided almost all the time.
1800          *
1801          * We start with a delayed allocation:
1802          *
1803          * +ddddddddddddddddddddddddddddddddddddddddddddddddddddddd+
1804          *  PREV @ idx
1805          *
1806              * and we are allocating:
1807          *                     +rrrrrrrrrrrrrrrrr+
1808          *                new
1809          *
1810          * and we set it up for insertion as:
1811          * +ddddddddddddddddddd+rrrrrrrrrrrrrrrrr+ddddddddddddddddd+
1812          *                            new
1813          *  PREV @ idx          LEFT              RIGHT
1814          *                      inserted at idx + 1
1815          */
1816         old = PREV;
1817 
1818         /* LEFT is the new middle */
1819         LEFT = *new;
1820 
1821         /* RIGHT is the new right */
1822         RIGHT.br_state = PREV.br_state;
1823         RIGHT.br_startoff = new_endoff;
1824         RIGHT.br_blockcount =
1825             PREV.br_startoff + PREV.br_blockcount - new_endoff;
1826         RIGHT.br_startblock =
1827             nullstartblock(xfs_bmap_worst_indlen(bma->ip,
1828                     RIGHT.br_blockcount));
1829 
1830         /* truncate PREV */
1831         PREV.br_blockcount = new->br_startoff - PREV.br_startoff;
1832         PREV.br_startblock =
1833             nullstartblock(xfs_bmap_worst_indlen(bma->ip,
1834                     PREV.br_blockcount));
1835         xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
1836 
1837         xfs_iext_next(ifp, &bma->icur);
1838         xfs_iext_insert(bma->ip, &bma->icur, &RIGHT, state);
1839         xfs_iext_insert(bma->ip, &bma->icur, &LEFT, state);
1840         ifp->if_nextents++;
1841 
1842         if (bma->cur == NULL)
1843             rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
1844         else {
1845             rval = XFS_ILOG_CORE;
1846             error = xfs_bmbt_lookup_eq(bma->cur, new, &i);
1847             if (error)
1848                 goto done;
1849             if (XFS_IS_CORRUPT(mp, i != 0)) {
1850                 error = -EFSCORRUPTED;
1851                 goto done;
1852             }
1853             error = xfs_btree_insert(bma->cur, &i);
1854             if (error)
1855                 goto done;
1856             if (XFS_IS_CORRUPT(mp, i != 1)) {
1857                 error = -EFSCORRUPTED;
1858                 goto done;
1859             }
1860         }
1861 
1862         if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
1863             error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
1864                     &bma->cur, 1, &tmp_rval, whichfork);
1865             rval |= tmp_rval;
1866             if (error)
1867                 goto done;
1868         }
1869 
1870         da_new = startblockval(PREV.br_startblock) +
1871              startblockval(RIGHT.br_startblock);
1872         break;
1873 
1874     case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
1875     case BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
1876     case BMAP_LEFT_FILLING | BMAP_RIGHT_CONTIG:
1877     case BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG:
1878     case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
1879     case BMAP_LEFT_CONTIG:
1880     case BMAP_RIGHT_CONTIG:
1881         /*
1882          * These cases are all impossible.
1883          */
1884         ASSERT(0);
1885     }
1886 
1887     /* add reverse mapping unless caller opted out */
1888     if (!(bma->flags & XFS_BMAPI_NORMAP))
1889         xfs_rmap_map_extent(bma->tp, bma->ip, whichfork, new);
1890 
1891     /* convert to a btree if necessary */
1892     if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
1893         int tmp_logflags;   /* partial log flag return val */
1894 
1895         ASSERT(bma->cur == NULL);
1896         error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
1897                 &bma->cur, da_old > 0, &tmp_logflags,
1898                 whichfork);
1899         bma->logflags |= tmp_logflags;
1900         if (error)
1901             goto done;
1902     }
1903 
1904     if (da_new != da_old)
1905         xfs_mod_delalloc(mp, (int64_t)da_new - da_old);
1906 
1907     if (bma->cur) {
1908         da_new += bma->cur->bc_ino.allocated;
1909         bma->cur->bc_ino.allocated = 0;
1910     }
1911 
1912     /* adjust for changes in reserved delayed indirect blocks */
1913     if (da_new != da_old) {
1914         ASSERT(state == 0 || da_new < da_old);
1915         error = xfs_mod_fdblocks(mp, (int64_t)(da_old - da_new),
1916                 false);
1917     }
1918 
1919     xfs_bmap_check_leaf_extents(bma->cur, bma->ip, whichfork);
1920 done:
1921     if (whichfork != XFS_COW_FORK)
1922         bma->logflags |= rval;
1923     return error;
1924 #undef  LEFT
1925 #undef  RIGHT
1926 #undef  PREV
1927 }
1928 
1929 /*
1930  * Convert an unwritten allocation to a real allocation or vice versa.
1931  */
1932 int                 /* error */
1933 xfs_bmap_add_extent_unwritten_real(
1934     struct xfs_trans    *tp,
1935     xfs_inode_t     *ip,    /* incore inode pointer */
1936     int         whichfork,
1937     struct xfs_iext_cursor  *icur,
1938     struct xfs_btree_cur    **curp, /* if *curp is null, not a btree */
1939     xfs_bmbt_irec_t     *new,   /* new data to add to file extents */
1940     int         *logflagsp) /* inode logging flags */
1941 {
1942     struct xfs_btree_cur    *cur;   /* btree cursor */
1943     int         error;  /* error return value */
1944     int         i;  /* temp state */
1945     struct xfs_ifork    *ifp;   /* inode fork pointer */
1946     xfs_fileoff_t       new_endoff; /* end offset of new entry */
1947     xfs_bmbt_irec_t     r[3];   /* neighbor extent entries */
1948                     /* left is 0, right is 1, prev is 2 */
1949     int         rval=0; /* return value (logging flags) */
1950     uint32_t        state = xfs_bmap_fork_to_state(whichfork);
1951     struct xfs_mount    *mp = ip->i_mount;
1952     struct xfs_bmbt_irec    old;
1953 
1954     *logflagsp = 0;
1955 
1956     cur = *curp;
1957     ifp = xfs_ifork_ptr(ip, whichfork);
1958 
1959     ASSERT(!isnullstartblock(new->br_startblock));
1960 
1961     XFS_STATS_INC(mp, xs_add_exlist);
1962 
1963 #define LEFT        r[0]
1964 #define RIGHT       r[1]
1965 #define PREV        r[2]
1966 
1967     /*
1968      * Set up a bunch of variables to make the tests simpler.
1969      */
1970     error = 0;
1971     xfs_iext_get_extent(ifp, icur, &PREV);
1972     ASSERT(new->br_state != PREV.br_state);
1973     new_endoff = new->br_startoff + new->br_blockcount;
1974     ASSERT(PREV.br_startoff <= new->br_startoff);
1975     ASSERT(PREV.br_startoff + PREV.br_blockcount >= new_endoff);
1976 
1977     /*
1978      * Set flags determining what part of the previous oldext allocation
1979      * extent is being replaced by a newext allocation.
1980      */
1981     if (PREV.br_startoff == new->br_startoff)
1982         state |= BMAP_LEFT_FILLING;
1983     if (PREV.br_startoff + PREV.br_blockcount == new_endoff)
1984         state |= BMAP_RIGHT_FILLING;
1985 
1986     /*
1987      * Check and set flags if this segment has a left neighbor.
1988      * Don't set contiguous if the combined extent would be too large.
1989      */
1990     if (xfs_iext_peek_prev_extent(ifp, icur, &LEFT)) {
1991         state |= BMAP_LEFT_VALID;
1992         if (isnullstartblock(LEFT.br_startblock))
1993             state |= BMAP_LEFT_DELAY;
1994     }
1995 
1996     if ((state & BMAP_LEFT_VALID) && !(state & BMAP_LEFT_DELAY) &&
1997         LEFT.br_startoff + LEFT.br_blockcount == new->br_startoff &&
1998         LEFT.br_startblock + LEFT.br_blockcount == new->br_startblock &&
1999         LEFT.br_state == new->br_state &&
2000         LEFT.br_blockcount + new->br_blockcount <= XFS_MAX_BMBT_EXTLEN)
2001         state |= BMAP_LEFT_CONTIG;
2002 
2003     /*
2004      * Check and set flags if this segment has a right neighbor.
2005      * Don't set contiguous if the combined extent would be too large.
2006      * Also check for all-three-contiguous being too large.
2007      */
2008     if (xfs_iext_peek_next_extent(ifp, icur, &RIGHT)) {
2009         state |= BMAP_RIGHT_VALID;
2010         if (isnullstartblock(RIGHT.br_startblock))
2011             state |= BMAP_RIGHT_DELAY;
2012     }
2013 
2014     if ((state & BMAP_RIGHT_VALID) && !(state & BMAP_RIGHT_DELAY) &&
2015         new_endoff == RIGHT.br_startoff &&
2016         new->br_startblock + new->br_blockcount == RIGHT.br_startblock &&
2017         new->br_state == RIGHT.br_state &&
2018         new->br_blockcount + RIGHT.br_blockcount <= XFS_MAX_BMBT_EXTLEN &&
2019         ((state & (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
2020                BMAP_RIGHT_FILLING)) !=
2021               (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
2022                BMAP_RIGHT_FILLING) ||
2023          LEFT.br_blockcount + new->br_blockcount + RIGHT.br_blockcount
2024             <= XFS_MAX_BMBT_EXTLEN))
2025         state |= BMAP_RIGHT_CONTIG;
2026 
2027     /*
2028      * Switch out based on the FILLING and CONTIG state bits.
2029      */
2030     switch (state & (BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG |
2031              BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG)) {
2032     case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG |
2033          BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
2034         /*
2035          * Setting all of a previous oldext extent to newext.
2036          * The left and right neighbors are both contiguous with new.
2037          */
2038         LEFT.br_blockcount += PREV.br_blockcount + RIGHT.br_blockcount;
2039 
2040         xfs_iext_remove(ip, icur, state);
2041         xfs_iext_remove(ip, icur, state);
2042         xfs_iext_prev(ifp, icur);
2043         xfs_iext_update_extent(ip, state, icur, &LEFT);
2044         ifp->if_nextents -= 2;
2045         if (cur == NULL)
2046             rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2047         else {
2048             rval = XFS_ILOG_CORE;
2049             error = xfs_bmbt_lookup_eq(cur, &RIGHT, &i);
2050             if (error)
2051                 goto done;
2052             if (XFS_IS_CORRUPT(mp, i != 1)) {
2053                 error = -EFSCORRUPTED;
2054                 goto done;
2055             }
2056             if ((error = xfs_btree_delete(cur, &i)))
2057                 goto done;
2058             if (XFS_IS_CORRUPT(mp, i != 1)) {
2059                 error = -EFSCORRUPTED;
2060                 goto done;
2061             }
2062             if ((error = xfs_btree_decrement(cur, 0, &i)))
2063                 goto done;
2064             if (XFS_IS_CORRUPT(mp, i != 1)) {
2065                 error = -EFSCORRUPTED;
2066                 goto done;
2067             }
2068             if ((error = xfs_btree_delete(cur, &i)))
2069                 goto done;
2070             if (XFS_IS_CORRUPT(mp, i != 1)) {
2071                 error = -EFSCORRUPTED;
2072                 goto done;
2073             }
2074             if ((error = xfs_btree_decrement(cur, 0, &i)))
2075                 goto done;
2076             if (XFS_IS_CORRUPT(mp, i != 1)) {
2077                 error = -EFSCORRUPTED;
2078                 goto done;
2079             }
2080             error = xfs_bmbt_update(cur, &LEFT);
2081             if (error)
2082                 goto done;
2083         }
2084         break;
2085 
2086     case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG:
2087         /*
2088          * Setting all of a previous oldext extent to newext.
2089          * The left neighbor is contiguous, the right is not.
2090          */
2091         LEFT.br_blockcount += PREV.br_blockcount;
2092 
2093         xfs_iext_remove(ip, icur, state);
2094         xfs_iext_prev(ifp, icur);
2095         xfs_iext_update_extent(ip, state, icur, &LEFT);
2096         ifp->if_nextents--;
2097         if (cur == NULL)
2098             rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2099         else {
2100             rval = XFS_ILOG_CORE;
2101             error = xfs_bmbt_lookup_eq(cur, &PREV, &i);
2102             if (error)
2103                 goto done;
2104             if (XFS_IS_CORRUPT(mp, i != 1)) {
2105                 error = -EFSCORRUPTED;
2106                 goto done;
2107             }
2108             if ((error = xfs_btree_delete(cur, &i)))
2109                 goto done;
2110             if (XFS_IS_CORRUPT(mp, i != 1)) {
2111                 error = -EFSCORRUPTED;
2112                 goto done;
2113             }
2114             if ((error = xfs_btree_decrement(cur, 0, &i)))
2115                 goto done;
2116             if (XFS_IS_CORRUPT(mp, i != 1)) {
2117                 error = -EFSCORRUPTED;
2118                 goto done;
2119             }
2120             error = xfs_bmbt_update(cur, &LEFT);
2121             if (error)
2122                 goto done;
2123         }
2124         break;
2125 
2126     case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
2127         /*
2128          * Setting all of a previous oldext extent to newext.
2129          * The right neighbor is contiguous, the left is not.
2130          */
2131         PREV.br_blockcount += RIGHT.br_blockcount;
2132         PREV.br_state = new->br_state;
2133 
2134         xfs_iext_next(ifp, icur);
2135         xfs_iext_remove(ip, icur, state);
2136         xfs_iext_prev(ifp, icur);
2137         xfs_iext_update_extent(ip, state, icur, &PREV);
2138         ifp->if_nextents--;
2139 
2140         if (cur == NULL)
2141             rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2142         else {
2143             rval = XFS_ILOG_CORE;
2144             error = xfs_bmbt_lookup_eq(cur, &RIGHT, &i);
2145             if (error)
2146                 goto done;
2147             if (XFS_IS_CORRUPT(mp, i != 1)) {
2148                 error = -EFSCORRUPTED;
2149                 goto done;
2150             }
2151             if ((error = xfs_btree_delete(cur, &i)))
2152                 goto done;
2153             if (XFS_IS_CORRUPT(mp, i != 1)) {
2154                 error = -EFSCORRUPTED;
2155                 goto done;
2156             }
2157             if ((error = xfs_btree_decrement(cur, 0, &i)))
2158                 goto done;
2159             if (XFS_IS_CORRUPT(mp, i != 1)) {
2160                 error = -EFSCORRUPTED;
2161                 goto done;
2162             }
2163             error = xfs_bmbt_update(cur, &PREV);
2164             if (error)
2165                 goto done;
2166         }
2167         break;
2168 
2169     case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
2170         /*
2171          * Setting all of a previous oldext extent to newext.
2172          * Neither the left nor right neighbors are contiguous with
2173          * the new one.
2174          */
2175         PREV.br_state = new->br_state;
2176         xfs_iext_update_extent(ip, state, icur, &PREV);
2177 
2178         if (cur == NULL)
2179             rval = XFS_ILOG_DEXT;
2180         else {
2181             rval = 0;
2182             error = xfs_bmbt_lookup_eq(cur, new, &i);
2183             if (error)
2184                 goto done;
2185             if (XFS_IS_CORRUPT(mp, i != 1)) {
2186                 error = -EFSCORRUPTED;
2187                 goto done;
2188             }
2189             error = xfs_bmbt_update(cur, &PREV);
2190             if (error)
2191                 goto done;
2192         }
2193         break;
2194 
2195     case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG:
2196         /*
2197          * Setting the first part of a previous oldext extent to newext.
2198          * The left neighbor is contiguous.
2199          */
2200         LEFT.br_blockcount += new->br_blockcount;
2201 
2202         old = PREV;
2203         PREV.br_startoff += new->br_blockcount;
2204         PREV.br_startblock += new->br_blockcount;
2205         PREV.br_blockcount -= new->br_blockcount;
2206 
2207         xfs_iext_update_extent(ip, state, icur, &PREV);
2208         xfs_iext_prev(ifp, icur);
2209         xfs_iext_update_extent(ip, state, icur, &LEFT);
2210 
2211         if (cur == NULL)
2212             rval = XFS_ILOG_DEXT;
2213         else {
2214             rval = 0;
2215             error = xfs_bmbt_lookup_eq(cur, &old, &i);
2216             if (error)
2217                 goto done;
2218             if (XFS_IS_CORRUPT(mp, i != 1)) {
2219                 error = -EFSCORRUPTED;
2220                 goto done;
2221             }
2222             error = xfs_bmbt_update(cur, &PREV);
2223             if (error)
2224                 goto done;
2225             error = xfs_btree_decrement(cur, 0, &i);
2226             if (error)
2227                 goto done;
2228             error = xfs_bmbt_update(cur, &LEFT);
2229             if (error)
2230                 goto done;
2231         }
2232         break;
2233 
2234     case BMAP_LEFT_FILLING:
2235         /*
2236          * Setting the first part of a previous oldext extent to newext.
2237          * The left neighbor is not contiguous.
2238          */
2239         old = PREV;
2240         PREV.br_startoff += new->br_blockcount;
2241         PREV.br_startblock += new->br_blockcount;
2242         PREV.br_blockcount -= new->br_blockcount;
2243 
2244         xfs_iext_update_extent(ip, state, icur, &PREV);
2245         xfs_iext_insert(ip, icur, new, state);
2246         ifp->if_nextents++;
2247 
2248         if (cur == NULL)
2249             rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2250         else {
2251             rval = XFS_ILOG_CORE;
2252             error = xfs_bmbt_lookup_eq(cur, &old, &i);
2253             if (error)
2254                 goto done;
2255             if (XFS_IS_CORRUPT(mp, i != 1)) {
2256                 error = -EFSCORRUPTED;
2257                 goto done;
2258             }
2259             error = xfs_bmbt_update(cur, &PREV);
2260             if (error)
2261                 goto done;
2262             cur->bc_rec.b = *new;
2263             if ((error = xfs_btree_insert(cur, &i)))
2264                 goto done;
2265             if (XFS_IS_CORRUPT(mp, i != 1)) {
2266                 error = -EFSCORRUPTED;
2267                 goto done;
2268             }
2269         }
2270         break;
2271 
2272     case BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
2273         /*
2274          * Setting the last part of a previous oldext extent to newext.
2275          * The right neighbor is contiguous with the new allocation.
2276          */
2277         old = PREV;
2278         PREV.br_blockcount -= new->br_blockcount;
2279 
2280         RIGHT.br_startoff = new->br_startoff;
2281         RIGHT.br_startblock = new->br_startblock;
2282         RIGHT.br_blockcount += new->br_blockcount;
2283 
2284         xfs_iext_update_extent(ip, state, icur, &PREV);
2285         xfs_iext_next(ifp, icur);
2286         xfs_iext_update_extent(ip, state, icur, &RIGHT);
2287 
2288         if (cur == NULL)
2289             rval = XFS_ILOG_DEXT;
2290         else {
2291             rval = 0;
2292             error = xfs_bmbt_lookup_eq(cur, &old, &i);
2293             if (error)
2294                 goto done;
2295             if (XFS_IS_CORRUPT(mp, i != 1)) {
2296                 error = -EFSCORRUPTED;
2297                 goto done;
2298             }
2299             error = xfs_bmbt_update(cur, &PREV);
2300             if (error)
2301                 goto done;
2302             error = xfs_btree_increment(cur, 0, &i);
2303             if (error)
2304                 goto done;
2305             error = xfs_bmbt_update(cur, &RIGHT);
2306             if (error)
2307                 goto done;
2308         }
2309         break;
2310 
2311     case BMAP_RIGHT_FILLING:
2312         /*
2313          * Setting the last part of a previous oldext extent to newext.
2314          * The right neighbor is not contiguous.
2315          */
2316         old = PREV;
2317         PREV.br_blockcount -= new->br_blockcount;
2318 
2319         xfs_iext_update_extent(ip, state, icur, &PREV);
2320         xfs_iext_next(ifp, icur);
2321         xfs_iext_insert(ip, icur, new, state);
2322         ifp->if_nextents++;
2323 
2324         if (cur == NULL)
2325             rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2326         else {
2327             rval = XFS_ILOG_CORE;
2328             error = xfs_bmbt_lookup_eq(cur, &old, &i);
2329             if (error)
2330                 goto done;
2331             if (XFS_IS_CORRUPT(mp, i != 1)) {
2332                 error = -EFSCORRUPTED;
2333                 goto done;
2334             }
2335             error = xfs_bmbt_update(cur, &PREV);
2336             if (error)
2337                 goto done;
2338             error = xfs_bmbt_lookup_eq(cur, new, &i);
2339             if (error)
2340                 goto done;
2341             if (XFS_IS_CORRUPT(mp, i != 0)) {
2342                 error = -EFSCORRUPTED;
2343                 goto done;
2344             }
2345             if ((error = xfs_btree_insert(cur, &i)))
2346                 goto done;
2347             if (XFS_IS_CORRUPT(mp, i != 1)) {
2348                 error = -EFSCORRUPTED;
2349                 goto done;
2350             }
2351         }
2352         break;
2353 
2354     case 0:
2355         /*
2356          * Setting the middle part of a previous oldext extent to
2357          * newext.  Contiguity is impossible here.
2358          * One extent becomes three extents.
2359          */
2360         old = PREV;
2361         PREV.br_blockcount = new->br_startoff - PREV.br_startoff;
2362 
2363         r[0] = *new;
2364         r[1].br_startoff = new_endoff;
2365         r[1].br_blockcount =
2366             old.br_startoff + old.br_blockcount - new_endoff;
2367         r[1].br_startblock = new->br_startblock + new->br_blockcount;
2368         r[1].br_state = PREV.br_state;
2369 
2370         xfs_iext_update_extent(ip, state, icur, &PREV);
2371         xfs_iext_next(ifp, icur);
2372         xfs_iext_insert(ip, icur, &r[1], state);
2373         xfs_iext_insert(ip, icur, &r[0], state);
2374         ifp->if_nextents += 2;
2375 
2376         if (cur == NULL)
2377             rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
2378         else {
2379             rval = XFS_ILOG_CORE;
2380             error = xfs_bmbt_lookup_eq(cur, &old, &i);
2381             if (error)
2382                 goto done;
2383             if (XFS_IS_CORRUPT(mp, i != 1)) {
2384                 error = -EFSCORRUPTED;
2385                 goto done;
2386             }
2387             /* new right extent - oldext */
2388             error = xfs_bmbt_update(cur, &r[1]);
2389             if (error)
2390                 goto done;
2391             /* new left extent - oldext */
2392             cur->bc_rec.b = PREV;
2393             if ((error = xfs_btree_insert(cur, &i)))
2394                 goto done;
2395             if (XFS_IS_CORRUPT(mp, i != 1)) {
2396                 error = -EFSCORRUPTED;
2397                 goto done;
2398             }
2399             /*
2400              * Reset the cursor to the position of the new extent
2401              * we are about to insert as we can't trust it after
2402              * the previous insert.
2403              */
2404             error = xfs_bmbt_lookup_eq(cur, new, &i);
2405             if (error)
2406                 goto done;
2407             if (XFS_IS_CORRUPT(mp, i != 0)) {
2408                 error = -EFSCORRUPTED;
2409                 goto done;
2410             }
2411             /* new middle extent - newext */
2412             if ((error = xfs_btree_insert(cur, &i)))
2413                 goto done;
2414             if (XFS_IS_CORRUPT(mp, i != 1)) {
2415                 error = -EFSCORRUPTED;
2416                 goto done;
2417             }
2418         }
2419         break;
2420 
2421     case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
2422     case BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
2423     case BMAP_LEFT_FILLING | BMAP_RIGHT_CONTIG:
2424     case BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG:
2425     case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
2426     case BMAP_LEFT_CONTIG:
2427     case BMAP_RIGHT_CONTIG:
2428         /*
2429          * These cases are all impossible.
2430          */
2431         ASSERT(0);
2432     }
2433 
2434     /* update reverse mappings */
2435     xfs_rmap_convert_extent(mp, tp, ip, whichfork, new);
2436 
2437     /* convert to a btree if necessary */
2438     if (xfs_bmap_needs_btree(ip, whichfork)) {
2439         int tmp_logflags;   /* partial log flag return val */
2440 
2441         ASSERT(cur == NULL);
2442         error = xfs_bmap_extents_to_btree(tp, ip, &cur, 0,
2443                 &tmp_logflags, whichfork);
2444         *logflagsp |= tmp_logflags;
2445         if (error)
2446             goto done;
2447     }
2448 
2449     /* clear out the allocated field, done with it now in any case. */
2450     if (cur) {
2451         cur->bc_ino.allocated = 0;
2452         *curp = cur;
2453     }
2454 
2455     xfs_bmap_check_leaf_extents(*curp, ip, whichfork);
2456 done:
2457     *logflagsp |= rval;
2458     return error;
2459 #undef  LEFT
2460 #undef  RIGHT
2461 #undef  PREV
2462 }
2463 
2464 /*
2465  * Convert a hole to a delayed allocation.
2466  */
2467 STATIC void
2468 xfs_bmap_add_extent_hole_delay(
2469     xfs_inode_t     *ip,    /* incore inode pointer */
2470     int         whichfork,
2471     struct xfs_iext_cursor  *icur,
2472     xfs_bmbt_irec_t     *new)   /* new data to add to file extents */
2473 {
2474     struct xfs_ifork    *ifp;   /* inode fork pointer */
2475     xfs_bmbt_irec_t     left;   /* left neighbor extent entry */
2476     xfs_filblks_t       newlen=0;   /* new indirect size */
2477     xfs_filblks_t       oldlen=0;   /* old indirect size */
2478     xfs_bmbt_irec_t     right;  /* right neighbor extent entry */
2479     uint32_t        state = xfs_bmap_fork_to_state(whichfork);
2480     xfs_filblks_t       temp;    /* temp for indirect calculations */
2481 
2482     ifp = xfs_ifork_ptr(ip, whichfork);
2483     ASSERT(isnullstartblock(new->br_startblock));
2484 
2485     /*
2486      * Check and set flags if this segment has a left neighbor
2487      */
2488     if (xfs_iext_peek_prev_extent(ifp, icur, &left)) {
2489         state |= BMAP_LEFT_VALID;
2490         if (isnullstartblock(left.br_startblock))
2491             state |= BMAP_LEFT_DELAY;
2492     }
2493 
2494     /*
2495      * Check and set flags if the current (right) segment exists.
2496      * If it doesn't exist, we're converting the hole at end-of-file.
2497      */
2498     if (xfs_iext_get_extent(ifp, icur, &right)) {
2499         state |= BMAP_RIGHT_VALID;
2500         if (isnullstartblock(right.br_startblock))
2501             state |= BMAP_RIGHT_DELAY;
2502     }
2503 
2504     /*
2505      * Set contiguity flags on the left and right neighbors.
2506      * Don't let extents get too large, even if the pieces are contiguous.
2507      */
2508     if ((state & BMAP_LEFT_VALID) && (state & BMAP_LEFT_DELAY) &&
2509         left.br_startoff + left.br_blockcount == new->br_startoff &&
2510         left.br_blockcount + new->br_blockcount <= XFS_MAX_BMBT_EXTLEN)
2511         state |= BMAP_LEFT_CONTIG;
2512 
2513     if ((state & BMAP_RIGHT_VALID) && (state & BMAP_RIGHT_DELAY) &&
2514         new->br_startoff + new->br_blockcount == right.br_startoff &&
2515         new->br_blockcount + right.br_blockcount <= XFS_MAX_BMBT_EXTLEN &&
2516         (!(state & BMAP_LEFT_CONTIG) ||
2517          (left.br_blockcount + new->br_blockcount +
2518           right.br_blockcount <= XFS_MAX_BMBT_EXTLEN)))
2519         state |= BMAP_RIGHT_CONTIG;
2520 
2521     /*
2522      * Switch out based on the contiguity flags.
2523      */
2524     switch (state & (BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG)) {
2525     case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
2526         /*
2527          * New allocation is contiguous with delayed allocations
2528          * on the left and on the right.
2529          * Merge all three into a single extent record.
2530          */
2531         temp = left.br_blockcount + new->br_blockcount +
2532             right.br_blockcount;
2533 
2534         oldlen = startblockval(left.br_startblock) +
2535             startblockval(new->br_startblock) +
2536             startblockval(right.br_startblock);
2537         newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
2538                      oldlen);
2539         left.br_startblock = nullstartblock(newlen);
2540         left.br_blockcount = temp;
2541 
2542         xfs_iext_remove(ip, icur, state);
2543         xfs_iext_prev(ifp, icur);
2544         xfs_iext_update_extent(ip, state, icur, &left);
2545         break;
2546 
2547     case BMAP_LEFT_CONTIG:
2548         /*
2549          * New allocation is contiguous with a delayed allocation
2550          * on the left.
2551          * Merge the new allocation with the left neighbor.
2552          */
2553         temp = left.br_blockcount + new->br_blockcount;
2554 
2555         oldlen = startblockval(left.br_startblock) +
2556             startblockval(new->br_startblock);
2557         newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
2558                      oldlen);
2559         left.br_blockcount = temp;
2560         left.br_startblock = nullstartblock(newlen);
2561 
2562         xfs_iext_prev(ifp, icur);
2563         xfs_iext_update_extent(ip, state, icur, &left);
2564         break;
2565 
2566     case BMAP_RIGHT_CONTIG:
2567         /*
2568          * New allocation is contiguous with a delayed allocation
2569          * on the right.
2570          * Merge the new allocation with the right neighbor.
2571          */
2572         temp = new->br_blockcount + right.br_blockcount;
2573         oldlen = startblockval(new->br_startblock) +
2574             startblockval(right.br_startblock);
2575         newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
2576                      oldlen);
2577         right.br_startoff = new->br_startoff;
2578         right.br_startblock = nullstartblock(newlen);
2579         right.br_blockcount = temp;
2580         xfs_iext_update_extent(ip, state, icur, &right);
2581         break;
2582 
2583     case 0:
2584         /*
2585          * New allocation is not contiguous with another
2586          * delayed allocation.
2587          * Insert a new entry.
2588          */
2589         oldlen = newlen = 0;
2590         xfs_iext_insert(ip, icur, new, state);
2591         break;
2592     }
2593     if (oldlen != newlen) {
2594         ASSERT(oldlen > newlen);
2595         xfs_mod_fdblocks(ip->i_mount, (int64_t)(oldlen - newlen),
2596                  false);
2597         /*
2598          * Nothing to do for disk quota accounting here.
2599          */
2600         xfs_mod_delalloc(ip->i_mount, (int64_t)newlen - oldlen);
2601     }
2602 }
2603 
2604 /*
2605  * Convert a hole to a real allocation.
2606  */
2607 STATIC int              /* error */
2608 xfs_bmap_add_extent_hole_real(
2609     struct xfs_trans    *tp,
2610     struct xfs_inode    *ip,
2611     int         whichfork,
2612     struct xfs_iext_cursor  *icur,
2613     struct xfs_btree_cur    **curp,
2614     struct xfs_bmbt_irec    *new,
2615     int         *logflagsp,
2616     uint32_t        flags)
2617 {
2618     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, whichfork);
2619     struct xfs_mount    *mp = ip->i_mount;
2620     struct xfs_btree_cur    *cur = *curp;
2621     int         error;  /* error return value */
2622     int         i;  /* temp state */
2623     xfs_bmbt_irec_t     left;   /* left neighbor extent entry */
2624     xfs_bmbt_irec_t     right;  /* right neighbor extent entry */
2625     int         rval=0; /* return value (logging flags) */
2626     uint32_t        state = xfs_bmap_fork_to_state(whichfork);
2627     struct xfs_bmbt_irec    old;
2628 
2629     ASSERT(!isnullstartblock(new->br_startblock));
2630     ASSERT(!cur || !(cur->bc_ino.flags & XFS_BTCUR_BMBT_WASDEL));
2631 
2632     XFS_STATS_INC(mp, xs_add_exlist);
2633 
2634     /*
2635      * Check and set flags if this segment has a left neighbor.
2636      */
2637     if (xfs_iext_peek_prev_extent(ifp, icur, &left)) {
2638         state |= BMAP_LEFT_VALID;
2639         if (isnullstartblock(left.br_startblock))
2640             state |= BMAP_LEFT_DELAY;
2641     }
2642 
2643     /*
2644      * Check and set flags if this segment has a current value.
2645      * Not true if we're inserting into the "hole" at eof.
2646      */
2647     if (xfs_iext_get_extent(ifp, icur, &right)) {
2648         state |= BMAP_RIGHT_VALID;
2649         if (isnullstartblock(right.br_startblock))
2650             state |= BMAP_RIGHT_DELAY;
2651     }
2652 
2653     /*
2654      * We're inserting a real allocation between "left" and "right".
2655      * Set the contiguity flags.  Don't let extents get too large.
2656      */
2657     if ((state & BMAP_LEFT_VALID) && !(state & BMAP_LEFT_DELAY) &&
2658         left.br_startoff + left.br_blockcount == new->br_startoff &&
2659         left.br_startblock + left.br_blockcount == new->br_startblock &&
2660         left.br_state == new->br_state &&
2661         left.br_blockcount + new->br_blockcount <= XFS_MAX_BMBT_EXTLEN)
2662         state |= BMAP_LEFT_CONTIG;
2663 
2664     if ((state & BMAP_RIGHT_VALID) && !(state & BMAP_RIGHT_DELAY) &&
2665         new->br_startoff + new->br_blockcount == right.br_startoff &&
2666         new->br_startblock + new->br_blockcount == right.br_startblock &&
2667         new->br_state == right.br_state &&
2668         new->br_blockcount + right.br_blockcount <= XFS_MAX_BMBT_EXTLEN &&
2669         (!(state & BMAP_LEFT_CONTIG) ||
2670          left.br_blockcount + new->br_blockcount +
2671          right.br_blockcount <= XFS_MAX_BMBT_EXTLEN))
2672         state |= BMAP_RIGHT_CONTIG;
2673 
2674     error = 0;
2675     /*
2676      * Select which case we're in here, and implement it.
2677      */
2678     switch (state & (BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG)) {
2679     case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
2680         /*
2681          * New allocation is contiguous with real allocations on the
2682          * left and on the right.
2683          * Merge all three into a single extent record.
2684          */
2685         left.br_blockcount += new->br_blockcount + right.br_blockcount;
2686 
2687         xfs_iext_remove(ip, icur, state);
2688         xfs_iext_prev(ifp, icur);
2689         xfs_iext_update_extent(ip, state, icur, &left);
2690         ifp->if_nextents--;
2691 
2692         if (cur == NULL) {
2693             rval = XFS_ILOG_CORE | xfs_ilog_fext(whichfork);
2694         } else {
2695             rval = XFS_ILOG_CORE;
2696             error = xfs_bmbt_lookup_eq(cur, &right, &i);
2697             if (error)
2698                 goto done;
2699             if (XFS_IS_CORRUPT(mp, i != 1)) {
2700                 error = -EFSCORRUPTED;
2701                 goto done;
2702             }
2703             error = xfs_btree_delete(cur, &i);
2704             if (error)
2705                 goto done;
2706             if (XFS_IS_CORRUPT(mp, i != 1)) {
2707                 error = -EFSCORRUPTED;
2708                 goto done;
2709             }
2710             error = xfs_btree_decrement(cur, 0, &i);
2711             if (error)
2712                 goto done;
2713             if (XFS_IS_CORRUPT(mp, i != 1)) {
2714                 error = -EFSCORRUPTED;
2715                 goto done;
2716             }
2717             error = xfs_bmbt_update(cur, &left);
2718             if (error)
2719                 goto done;
2720         }
2721         break;
2722 
2723     case BMAP_LEFT_CONTIG:
2724         /*
2725          * New allocation is contiguous with a real allocation
2726          * on the left.
2727          * Merge the new allocation with the left neighbor.
2728          */
2729         old = left;
2730         left.br_blockcount += new->br_blockcount;
2731 
2732         xfs_iext_prev(ifp, icur);
2733         xfs_iext_update_extent(ip, state, icur, &left);
2734 
2735         if (cur == NULL) {
2736             rval = xfs_ilog_fext(whichfork);
2737         } else {
2738             rval = 0;
2739             error = xfs_bmbt_lookup_eq(cur, &old, &i);
2740             if (error)
2741                 goto done;
2742             if (XFS_IS_CORRUPT(mp, i != 1)) {
2743                 error = -EFSCORRUPTED;
2744                 goto done;
2745             }
2746             error = xfs_bmbt_update(cur, &left);
2747             if (error)
2748                 goto done;
2749         }
2750         break;
2751 
2752     case BMAP_RIGHT_CONTIG:
2753         /*
2754          * New allocation is contiguous with a real allocation
2755          * on the right.
2756          * Merge the new allocation with the right neighbor.
2757          */
2758         old = right;
2759 
2760         right.br_startoff = new->br_startoff;
2761         right.br_startblock = new->br_startblock;
2762         right.br_blockcount += new->br_blockcount;
2763         xfs_iext_update_extent(ip, state, icur, &right);
2764 
2765         if (cur == NULL) {
2766             rval = xfs_ilog_fext(whichfork);
2767         } else {
2768             rval = 0;
2769             error = xfs_bmbt_lookup_eq(cur, &old, &i);
2770             if (error)
2771                 goto done;
2772             if (XFS_IS_CORRUPT(mp, i != 1)) {
2773                 error = -EFSCORRUPTED;
2774                 goto done;
2775             }
2776             error = xfs_bmbt_update(cur, &right);
2777             if (error)
2778                 goto done;
2779         }
2780         break;
2781 
2782     case 0:
2783         /*
2784          * New allocation is not contiguous with another
2785          * real allocation.
2786          * Insert a new entry.
2787          */
2788         xfs_iext_insert(ip, icur, new, state);
2789         ifp->if_nextents++;
2790 
2791         if (cur == NULL) {
2792             rval = XFS_ILOG_CORE | xfs_ilog_fext(whichfork);
2793         } else {
2794             rval = XFS_ILOG_CORE;
2795             error = xfs_bmbt_lookup_eq(cur, new, &i);
2796             if (error)
2797                 goto done;
2798             if (XFS_IS_CORRUPT(mp, i != 0)) {
2799                 error = -EFSCORRUPTED;
2800                 goto done;
2801             }
2802             error = xfs_btree_insert(cur, &i);
2803             if (error)
2804                 goto done;
2805             if (XFS_IS_CORRUPT(mp, i != 1)) {
2806                 error = -EFSCORRUPTED;
2807                 goto done;
2808             }
2809         }
2810         break;
2811     }
2812 
2813     /* add reverse mapping unless caller opted out */
2814     if (!(flags & XFS_BMAPI_NORMAP))
2815         xfs_rmap_map_extent(tp, ip, whichfork, new);
2816 
2817     /* convert to a btree if necessary */
2818     if (xfs_bmap_needs_btree(ip, whichfork)) {
2819         int tmp_logflags;   /* partial log flag return val */
2820 
2821         ASSERT(cur == NULL);
2822         error = xfs_bmap_extents_to_btree(tp, ip, curp, 0,
2823                 &tmp_logflags, whichfork);
2824         *logflagsp |= tmp_logflags;
2825         cur = *curp;
2826         if (error)
2827             goto done;
2828     }
2829 
2830     /* clear out the allocated field, done with it now in any case. */
2831     if (cur)
2832         cur->bc_ino.allocated = 0;
2833 
2834     xfs_bmap_check_leaf_extents(cur, ip, whichfork);
2835 done:
2836     *logflagsp |= rval;
2837     return error;
2838 }
2839 
2840 /*
2841  * Functions used in the extent read, allocate and remove paths
2842  */
2843 
2844 /*
2845  * Adjust the size of the new extent based on i_extsize and rt extsize.
2846  */
2847 int
2848 xfs_bmap_extsize_align(
2849     xfs_mount_t *mp,
2850     xfs_bmbt_irec_t *gotp,      /* next extent pointer */
2851     xfs_bmbt_irec_t *prevp,     /* previous extent pointer */
2852     xfs_extlen_t    extsz,      /* align to this extent size */
2853     int     rt,     /* is this a realtime inode? */
2854     int     eof,        /* is extent at end-of-file? */
2855     int     delay,      /* creating delalloc extent? */
2856     int     convert,    /* overwriting unwritten extent? */
2857     xfs_fileoff_t   *offp,      /* in/out: aligned offset */
2858     xfs_extlen_t    *lenp)      /* in/out: aligned length */
2859 {
2860     xfs_fileoff_t   orig_off;   /* original offset */
2861     xfs_extlen_t    orig_alen;  /* original length */
2862     xfs_fileoff_t   orig_end;   /* original off+len */
2863     xfs_fileoff_t   nexto;      /* next file offset */
2864     xfs_fileoff_t   prevo;      /* previous file offset */
2865     xfs_fileoff_t   align_off;  /* temp for offset */
2866     xfs_extlen_t    align_alen; /* temp for length */
2867     xfs_extlen_t    temp;       /* temp for calculations */
2868 
2869     if (convert)
2870         return 0;
2871 
2872     orig_off = align_off = *offp;
2873     orig_alen = align_alen = *lenp;
2874     orig_end = orig_off + orig_alen;
2875 
2876     /*
2877      * If this request overlaps an existing extent, then don't
2878      * attempt to perform any additional alignment.
2879      */
2880     if (!delay && !eof &&
2881         (orig_off >= gotp->br_startoff) &&
2882         (orig_end <= gotp->br_startoff + gotp->br_blockcount)) {
2883         return 0;
2884     }
2885 
2886     /*
2887      * If the file offset is unaligned vs. the extent size
2888      * we need to align it.  This will be possible unless
2889      * the file was previously written with a kernel that didn't
2890      * perform this alignment, or if a truncate shot us in the
2891      * foot.
2892      */
2893     div_u64_rem(orig_off, extsz, &temp);
2894     if (temp) {
2895         align_alen += temp;
2896         align_off -= temp;
2897     }
2898 
2899     /* Same adjustment for the end of the requested area. */
2900     temp = (align_alen % extsz);
2901     if (temp)
2902         align_alen += extsz - temp;
2903 
2904     /*
2905      * For large extent hint sizes, the aligned extent might be larger than
2906      * XFS_BMBT_MAX_EXTLEN. In that case, reduce the size by an extsz so
2907      * that it pulls the length back under XFS_BMBT_MAX_EXTLEN. The outer
2908      * allocation loops handle short allocation just fine, so it is safe to
2909      * do this. We only want to do it when we are forced to, though, because
2910      * it means more allocation operations are required.
2911      */
2912     while (align_alen > XFS_MAX_BMBT_EXTLEN)
2913         align_alen -= extsz;
2914     ASSERT(align_alen <= XFS_MAX_BMBT_EXTLEN);
2915 
2916     /*
2917      * If the previous block overlaps with this proposed allocation
2918      * then move the start forward without adjusting the length.
2919      */
2920     if (prevp->br_startoff != NULLFILEOFF) {
2921         if (prevp->br_startblock == HOLESTARTBLOCK)
2922             prevo = prevp->br_startoff;
2923         else
2924             prevo = prevp->br_startoff + prevp->br_blockcount;
2925     } else
2926         prevo = 0;
2927     if (align_off != orig_off && align_off < prevo)
2928         align_off = prevo;
2929     /*
2930      * If the next block overlaps with this proposed allocation
2931      * then move the start back without adjusting the length,
2932      * but not before offset 0.
2933      * This may of course make the start overlap previous block,
2934      * and if we hit the offset 0 limit then the next block
2935      * can still overlap too.
2936      */
2937     if (!eof && gotp->br_startoff != NULLFILEOFF) {
2938         if ((delay && gotp->br_startblock == HOLESTARTBLOCK) ||
2939             (!delay && gotp->br_startblock == DELAYSTARTBLOCK))
2940             nexto = gotp->br_startoff + gotp->br_blockcount;
2941         else
2942             nexto = gotp->br_startoff;
2943     } else
2944         nexto = NULLFILEOFF;
2945     if (!eof &&
2946         align_off + align_alen != orig_end &&
2947         align_off + align_alen > nexto)
2948         align_off = nexto > align_alen ? nexto - align_alen : 0;
2949     /*
2950      * If we're now overlapping the next or previous extent that
2951      * means we can't fit an extsz piece in this hole.  Just move
2952      * the start forward to the first valid spot and set
2953      * the length so we hit the end.
2954      */
2955     if (align_off != orig_off && align_off < prevo)
2956         align_off = prevo;
2957     if (align_off + align_alen != orig_end &&
2958         align_off + align_alen > nexto &&
2959         nexto != NULLFILEOFF) {
2960         ASSERT(nexto > prevo);
2961         align_alen = nexto - align_off;
2962     }
2963 
2964     /*
2965      * If realtime, and the result isn't a multiple of the realtime
2966      * extent size we need to remove blocks until it is.
2967      */
2968     if (rt && (temp = (align_alen % mp->m_sb.sb_rextsize))) {
2969         /*
2970          * We're not covering the original request, or
2971          * we won't be able to once we fix the length.
2972          */
2973         if (orig_off < align_off ||
2974             orig_end > align_off + align_alen ||
2975             align_alen - temp < orig_alen)
2976             return -EINVAL;
2977         /*
2978          * Try to fix it by moving the start up.
2979          */
2980         if (align_off + temp <= orig_off) {
2981             align_alen -= temp;
2982             align_off += temp;
2983         }
2984         /*
2985          * Try to fix it by moving the end in.
2986          */
2987         else if (align_off + align_alen - temp >= orig_end)
2988             align_alen -= temp;
2989         /*
2990          * Set the start to the minimum then trim the length.
2991          */
2992         else {
2993             align_alen -= orig_off - align_off;
2994             align_off = orig_off;
2995             align_alen -= align_alen % mp->m_sb.sb_rextsize;
2996         }
2997         /*
2998          * Result doesn't cover the request, fail it.
2999          */
3000         if (orig_off < align_off || orig_end > align_off + align_alen)
3001             return -EINVAL;
3002     } else {
3003         ASSERT(orig_off >= align_off);
3004         /* see XFS_BMBT_MAX_EXTLEN handling above */
3005         ASSERT(orig_end <= align_off + align_alen ||
3006                align_alen + extsz > XFS_MAX_BMBT_EXTLEN);
3007     }
3008 
3009 #ifdef DEBUG
3010     if (!eof && gotp->br_startoff != NULLFILEOFF)
3011         ASSERT(align_off + align_alen <= gotp->br_startoff);
3012     if (prevp->br_startoff != NULLFILEOFF)
3013         ASSERT(align_off >= prevp->br_startoff + prevp->br_blockcount);
3014 #endif
3015 
3016     *lenp = align_alen;
3017     *offp = align_off;
3018     return 0;
3019 }
3020 
3021 #define XFS_ALLOC_GAP_UNITS 4
3022 
3023 void
3024 xfs_bmap_adjacent(
3025     struct xfs_bmalloca *ap)    /* bmap alloc argument struct */
3026 {
3027     xfs_fsblock_t   adjust;     /* adjustment to block numbers */
3028     xfs_agnumber_t  fb_agno;    /* ag number of ap->firstblock */
3029     xfs_mount_t *mp;        /* mount point structure */
3030     int     nullfb;     /* true if ap->firstblock isn't set */
3031     int     rt;     /* true if inode is realtime */
3032 
3033 #define ISVALID(x,y)    \
3034     (rt ? \
3035         (x) < mp->m_sb.sb_rblocks : \
3036         XFS_FSB_TO_AGNO(mp, x) == XFS_FSB_TO_AGNO(mp, y) && \
3037         XFS_FSB_TO_AGNO(mp, x) < mp->m_sb.sb_agcount && \
3038         XFS_FSB_TO_AGBNO(mp, x) < mp->m_sb.sb_agblocks)
3039 
3040     mp = ap->ip->i_mount;
3041     nullfb = ap->tp->t_firstblock == NULLFSBLOCK;
3042     rt = XFS_IS_REALTIME_INODE(ap->ip) &&
3043         (ap->datatype & XFS_ALLOC_USERDATA);
3044     fb_agno = nullfb ? NULLAGNUMBER : XFS_FSB_TO_AGNO(mp,
3045                             ap->tp->t_firstblock);
3046     /*
3047      * If allocating at eof, and there's a previous real block,
3048      * try to use its last block as our starting point.
3049      */
3050     if (ap->eof && ap->prev.br_startoff != NULLFILEOFF &&
3051         !isnullstartblock(ap->prev.br_startblock) &&
3052         ISVALID(ap->prev.br_startblock + ap->prev.br_blockcount,
3053             ap->prev.br_startblock)) {
3054         ap->blkno = ap->prev.br_startblock + ap->prev.br_blockcount;
3055         /*
3056          * Adjust for the gap between prevp and us.
3057          */
3058         adjust = ap->offset -
3059             (ap->prev.br_startoff + ap->prev.br_blockcount);
3060         if (adjust &&
3061             ISVALID(ap->blkno + adjust, ap->prev.br_startblock))
3062             ap->blkno += adjust;
3063     }
3064     /*
3065      * If not at eof, then compare the two neighbor blocks.
3066      * Figure out whether either one gives us a good starting point,
3067      * and pick the better one.
3068      */
3069     else if (!ap->eof) {
3070         xfs_fsblock_t   gotbno;     /* right side block number */
3071         xfs_fsblock_t   gotdiff=0;  /* right side difference */
3072         xfs_fsblock_t   prevbno;    /* left side block number */
3073         xfs_fsblock_t   prevdiff=0; /* left side difference */
3074 
3075         /*
3076          * If there's a previous (left) block, select a requested
3077          * start block based on it.
3078          */
3079         if (ap->prev.br_startoff != NULLFILEOFF &&
3080             !isnullstartblock(ap->prev.br_startblock) &&
3081             (prevbno = ap->prev.br_startblock +
3082                    ap->prev.br_blockcount) &&
3083             ISVALID(prevbno, ap->prev.br_startblock)) {
3084             /*
3085              * Calculate gap to end of previous block.
3086              */
3087             adjust = prevdiff = ap->offset -
3088                 (ap->prev.br_startoff +
3089                  ap->prev.br_blockcount);
3090             /*
3091              * Figure the startblock based on the previous block's
3092              * end and the gap size.
3093              * Heuristic!
3094              * If the gap is large relative to the piece we're
3095              * allocating, or using it gives us an invalid block
3096              * number, then just use the end of the previous block.
3097              */
3098             if (prevdiff <= XFS_ALLOC_GAP_UNITS * ap->length &&
3099                 ISVALID(prevbno + prevdiff,
3100                     ap->prev.br_startblock))
3101                 prevbno += adjust;
3102             else
3103                 prevdiff += adjust;
3104             /*
3105              * If the firstblock forbids it, can't use it,
3106              * must use default.
3107              */
3108             if (!rt && !nullfb &&
3109                 XFS_FSB_TO_AGNO(mp, prevbno) != fb_agno)
3110                 prevbno = NULLFSBLOCK;
3111         }
3112         /*
3113          * No previous block or can't follow it, just default.
3114          */
3115         else
3116             prevbno = NULLFSBLOCK;
3117         /*
3118          * If there's a following (right) block, select a requested
3119          * start block based on it.
3120          */
3121         if (!isnullstartblock(ap->got.br_startblock)) {
3122             /*
3123              * Calculate gap to start of next block.
3124              */
3125             adjust = gotdiff = ap->got.br_startoff - ap->offset;
3126             /*
3127              * Figure the startblock based on the next block's
3128              * start and the gap size.
3129              */
3130             gotbno = ap->got.br_startblock;
3131             /*
3132              * Heuristic!
3133              * If the gap is large relative to the piece we're
3134              * allocating, or using it gives us an invalid block
3135              * number, then just use the start of the next block
3136              * offset by our length.
3137              */
3138             if (gotdiff <= XFS_ALLOC_GAP_UNITS * ap->length &&
3139                 ISVALID(gotbno - gotdiff, gotbno))
3140                 gotbno -= adjust;
3141             else if (ISVALID(gotbno - ap->length, gotbno)) {
3142                 gotbno -= ap->length;
3143                 gotdiff += adjust - ap->length;
3144             } else
3145                 gotdiff += adjust;
3146             /*
3147              * If the firstblock forbids it, can't use it,
3148              * must use default.
3149              */
3150             if (!rt && !nullfb &&
3151                 XFS_FSB_TO_AGNO(mp, gotbno) != fb_agno)
3152                 gotbno = NULLFSBLOCK;
3153         }
3154         /*
3155          * No next block, just default.
3156          */
3157         else
3158             gotbno = NULLFSBLOCK;
3159         /*
3160          * If both valid, pick the better one, else the only good
3161          * one, else ap->blkno is already set (to 0 or the inode block).
3162          */
3163         if (prevbno != NULLFSBLOCK && gotbno != NULLFSBLOCK)
3164             ap->blkno = prevdiff <= gotdiff ? prevbno : gotbno;
3165         else if (prevbno != NULLFSBLOCK)
3166             ap->blkno = prevbno;
3167         else if (gotbno != NULLFSBLOCK)
3168             ap->blkno = gotbno;
3169     }
3170 #undef ISVALID
3171 }
3172 
3173 static int
3174 xfs_bmap_longest_free_extent(
3175     struct xfs_trans    *tp,
3176     xfs_agnumber_t      ag,
3177     xfs_extlen_t        *blen,
3178     int         *notinit)
3179 {
3180     struct xfs_mount    *mp = tp->t_mountp;
3181     struct xfs_perag    *pag;
3182     xfs_extlen_t        longest;
3183     int         error = 0;
3184 
3185     pag = xfs_perag_get(mp, ag);
3186     if (!pag->pagf_init) {
3187         error = xfs_alloc_read_agf(pag, tp, XFS_ALLOC_FLAG_TRYLOCK,
3188                 NULL);
3189         if (error) {
3190             /* Couldn't lock the AGF, so skip this AG. */
3191             if (error == -EAGAIN) {
3192                 *notinit = 1;
3193                 error = 0;
3194             }
3195             goto out;
3196         }
3197     }
3198 
3199     longest = xfs_alloc_longest_free_extent(pag,
3200                 xfs_alloc_min_freelist(mp, pag),
3201                 xfs_ag_resv_needed(pag, XFS_AG_RESV_NONE));
3202     if (*blen < longest)
3203         *blen = longest;
3204 
3205 out:
3206     xfs_perag_put(pag);
3207     return error;
3208 }
3209 
3210 static void
3211 xfs_bmap_select_minlen(
3212     struct xfs_bmalloca *ap,
3213     struct xfs_alloc_arg    *args,
3214     xfs_extlen_t        *blen,
3215     int         notinit)
3216 {
3217     if (notinit || *blen < ap->minlen) {
3218         /*
3219          * Since we did a BUF_TRYLOCK above, it is possible that
3220          * there is space for this request.
3221          */
3222         args->minlen = ap->minlen;
3223     } else if (*blen < args->maxlen) {
3224         /*
3225          * If the best seen length is less than the request length,
3226          * use the best as the minimum.
3227          */
3228         args->minlen = *blen;
3229     } else {
3230         /*
3231          * Otherwise we've seen an extent as big as maxlen, use that
3232          * as the minimum.
3233          */
3234         args->minlen = args->maxlen;
3235     }
3236 }
3237 
3238 STATIC int
3239 xfs_bmap_btalloc_nullfb(
3240     struct xfs_bmalloca *ap,
3241     struct xfs_alloc_arg    *args,
3242     xfs_extlen_t        *blen)
3243 {
3244     struct xfs_mount    *mp = ap->ip->i_mount;
3245     xfs_agnumber_t      ag, startag;
3246     int         notinit = 0;
3247     int         error;
3248 
3249     args->type = XFS_ALLOCTYPE_START_BNO;
3250     args->total = ap->total;
3251 
3252     startag = ag = XFS_FSB_TO_AGNO(mp, args->fsbno);
3253     if (startag == NULLAGNUMBER)
3254         startag = ag = 0;
3255 
3256     while (*blen < args->maxlen) {
3257         error = xfs_bmap_longest_free_extent(args->tp, ag, blen,
3258                              &notinit);
3259         if (error)
3260             return error;
3261 
3262         if (++ag == mp->m_sb.sb_agcount)
3263             ag = 0;
3264         if (ag == startag)
3265             break;
3266     }
3267 
3268     xfs_bmap_select_minlen(ap, args, blen, notinit);
3269     return 0;
3270 }
3271 
3272 STATIC int
3273 xfs_bmap_btalloc_filestreams(
3274     struct xfs_bmalloca *ap,
3275     struct xfs_alloc_arg    *args,
3276     xfs_extlen_t        *blen)
3277 {
3278     struct xfs_mount    *mp = ap->ip->i_mount;
3279     xfs_agnumber_t      ag;
3280     int         notinit = 0;
3281     int         error;
3282 
3283     args->type = XFS_ALLOCTYPE_NEAR_BNO;
3284     args->total = ap->total;
3285 
3286     ag = XFS_FSB_TO_AGNO(mp, args->fsbno);
3287     if (ag == NULLAGNUMBER)
3288         ag = 0;
3289 
3290     error = xfs_bmap_longest_free_extent(args->tp, ag, blen, &notinit);
3291     if (error)
3292         return error;
3293 
3294     if (*blen < args->maxlen) {
3295         error = xfs_filestream_new_ag(ap, &ag);
3296         if (error)
3297             return error;
3298 
3299         error = xfs_bmap_longest_free_extent(args->tp, ag, blen,
3300                              &notinit);
3301         if (error)
3302             return error;
3303 
3304     }
3305 
3306     xfs_bmap_select_minlen(ap, args, blen, notinit);
3307 
3308     /*
3309      * Set the failure fallback case to look in the selected AG as stream
3310      * may have moved.
3311      */
3312     ap->blkno = args->fsbno = XFS_AGB_TO_FSB(mp, ag, 0);
3313     return 0;
3314 }
3315 
3316 /* Update all inode and quota accounting for the allocation we just did. */
3317 static void
3318 xfs_bmap_btalloc_accounting(
3319     struct xfs_bmalloca *ap,
3320     struct xfs_alloc_arg    *args)
3321 {
3322     if (ap->flags & XFS_BMAPI_COWFORK) {
3323         /*
3324          * COW fork blocks are in-core only and thus are treated as
3325          * in-core quota reservation (like delalloc blocks) even when
3326          * converted to real blocks. The quota reservation is not
3327          * accounted to disk until blocks are remapped to the data
3328          * fork. So if these blocks were previously delalloc, we
3329          * already have quota reservation and there's nothing to do
3330          * yet.
3331          */
3332         if (ap->wasdel) {
3333             xfs_mod_delalloc(ap->ip->i_mount, -(int64_t)args->len);
3334             return;
3335         }
3336 
3337         /*
3338          * Otherwise, we've allocated blocks in a hole. The transaction
3339          * has acquired in-core quota reservation for this extent.
3340          * Rather than account these as real blocks, however, we reduce
3341          * the transaction quota reservation based on the allocation.
3342          * This essentially transfers the transaction quota reservation
3343          * to that of a delalloc extent.
3344          */
3345         ap->ip->i_delayed_blks += args->len;
3346         xfs_trans_mod_dquot_byino(ap->tp, ap->ip, XFS_TRANS_DQ_RES_BLKS,
3347                 -(long)args->len);
3348         return;
3349     }
3350 
3351     /* data/attr fork only */
3352     ap->ip->i_nblocks += args->len;
3353     xfs_trans_log_inode(ap->tp, ap->ip, XFS_ILOG_CORE);
3354     if (ap->wasdel) {
3355         ap->ip->i_delayed_blks -= args->len;
3356         xfs_mod_delalloc(ap->ip->i_mount, -(int64_t)args->len);
3357     }
3358     xfs_trans_mod_dquot_byino(ap->tp, ap->ip,
3359         ap->wasdel ? XFS_TRANS_DQ_DELBCOUNT : XFS_TRANS_DQ_BCOUNT,
3360         args->len);
3361 }
3362 
3363 static int
3364 xfs_bmap_compute_alignments(
3365     struct xfs_bmalloca *ap,
3366     struct xfs_alloc_arg    *args)
3367 {
3368     struct xfs_mount    *mp = args->mp;
3369     xfs_extlen_t        align = 0; /* minimum allocation alignment */
3370     int         stripe_align = 0;
3371 
3372     /* stripe alignment for allocation is determined by mount parameters */
3373     if (mp->m_swidth && xfs_has_swalloc(mp))
3374         stripe_align = mp->m_swidth;
3375     else if (mp->m_dalign)
3376         stripe_align = mp->m_dalign;
3377 
3378     if (ap->flags & XFS_BMAPI_COWFORK)
3379         align = xfs_get_cowextsz_hint(ap->ip);
3380     else if (ap->datatype & XFS_ALLOC_USERDATA)
3381         align = xfs_get_extsz_hint(ap->ip);
3382     if (align) {
3383         if (xfs_bmap_extsize_align(mp, &ap->got, &ap->prev, align, 0,
3384                     ap->eof, 0, ap->conv, &ap->offset,
3385                     &ap->length))
3386             ASSERT(0);
3387         ASSERT(ap->length);
3388     }
3389 
3390     /* apply extent size hints if obtained earlier */
3391     if (align) {
3392         args->prod = align;
3393         div_u64_rem(ap->offset, args->prod, &args->mod);
3394         if (args->mod)
3395             args->mod = args->prod - args->mod;
3396     } else if (mp->m_sb.sb_blocksize >= PAGE_SIZE) {
3397         args->prod = 1;
3398         args->mod = 0;
3399     } else {
3400         args->prod = PAGE_SIZE >> mp->m_sb.sb_blocklog;
3401         div_u64_rem(ap->offset, args->prod, &args->mod);
3402         if (args->mod)
3403             args->mod = args->prod - args->mod;
3404     }
3405 
3406     return stripe_align;
3407 }
3408 
3409 static void
3410 xfs_bmap_process_allocated_extent(
3411     struct xfs_bmalloca *ap,
3412     struct xfs_alloc_arg    *args,
3413     xfs_fileoff_t       orig_offset,
3414     xfs_extlen_t        orig_length)
3415 {
3416     int         nullfb;
3417 
3418     nullfb = ap->tp->t_firstblock == NULLFSBLOCK;
3419 
3420     /*
3421      * check the allocation happened at the same or higher AG than
3422      * the first block that was allocated.
3423      */
3424     ASSERT(nullfb ||
3425         XFS_FSB_TO_AGNO(args->mp, ap->tp->t_firstblock) <=
3426         XFS_FSB_TO_AGNO(args->mp, args->fsbno));
3427 
3428     ap->blkno = args->fsbno;
3429     if (nullfb)
3430         ap->tp->t_firstblock = args->fsbno;
3431     ap->length = args->len;
3432     /*
3433      * If the extent size hint is active, we tried to round the
3434      * caller's allocation request offset down to extsz and the
3435      * length up to another extsz boundary.  If we found a free
3436      * extent we mapped it in starting at this new offset.  If the
3437      * newly mapped space isn't long enough to cover any of the
3438      * range of offsets that was originally requested, move the
3439      * mapping up so that we can fill as much of the caller's
3440      * original request as possible.  Free space is apparently
3441      * very fragmented so we're unlikely to be able to satisfy the
3442      * hints anyway.
3443      */
3444     if (ap->length <= orig_length)
3445         ap->offset = orig_offset;
3446     else if (ap->offset + ap->length < orig_offset + orig_length)
3447         ap->offset = orig_offset + orig_length - ap->length;
3448     xfs_bmap_btalloc_accounting(ap, args);
3449 }
3450 
3451 #ifdef DEBUG
3452 static int
3453 xfs_bmap_exact_minlen_extent_alloc(
3454     struct xfs_bmalloca *ap)
3455 {
3456     struct xfs_mount    *mp = ap->ip->i_mount;
3457     struct xfs_alloc_arg    args = { .tp = ap->tp, .mp = mp };
3458     xfs_fileoff_t       orig_offset;
3459     xfs_extlen_t        orig_length;
3460     int         error;
3461 
3462     ASSERT(ap->length);
3463 
3464     if (ap->minlen != 1) {
3465         ap->blkno = NULLFSBLOCK;
3466         ap->length = 0;
3467         return 0;
3468     }
3469 
3470     orig_offset = ap->offset;
3471     orig_length = ap->length;
3472 
3473     args.alloc_minlen_only = 1;
3474 
3475     xfs_bmap_compute_alignments(ap, &args);
3476 
3477     if (ap->tp->t_firstblock == NULLFSBLOCK) {
3478         /*
3479          * Unlike the longest extent available in an AG, we don't track
3480          * the length of an AG's shortest extent.
3481          * XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT is a debug only knob and
3482          * hence we can afford to start traversing from the 0th AG since
3483          * we need not be concerned about a drop in performance in
3484          * "debug only" code paths.
3485          */
3486         ap->blkno = XFS_AGB_TO_FSB(mp, 0, 0);
3487     } else {
3488         ap->blkno = ap->tp->t_firstblock;
3489     }
3490 
3491     args.fsbno = ap->blkno;
3492     args.oinfo = XFS_RMAP_OINFO_SKIP_UPDATE;
3493     args.type = XFS_ALLOCTYPE_FIRST_AG;
3494     args.minlen = args.maxlen = ap->minlen;
3495     args.total = ap->total;
3496 
3497     args.alignment = 1;
3498     args.minalignslop = 0;
3499 
3500     args.minleft = ap->minleft;
3501     args.wasdel = ap->wasdel;
3502     args.resv = XFS_AG_RESV_NONE;
3503     args.datatype = ap->datatype;
3504 
3505     error = xfs_alloc_vextent(&args);
3506     if (error)
3507         return error;
3508 
3509     if (args.fsbno != NULLFSBLOCK) {
3510         xfs_bmap_process_allocated_extent(ap, &args, orig_offset,
3511             orig_length);
3512     } else {
3513         ap->blkno = NULLFSBLOCK;
3514         ap->length = 0;
3515     }
3516 
3517     return 0;
3518 }
3519 #else
3520 
3521 #define xfs_bmap_exact_minlen_extent_alloc(bma) (-EFSCORRUPTED)
3522 
3523 #endif
3524 
3525 STATIC int
3526 xfs_bmap_btalloc(
3527     struct xfs_bmalloca *ap)
3528 {
3529     struct xfs_mount    *mp = ap->ip->i_mount;
3530     struct xfs_alloc_arg    args = { .tp = ap->tp, .mp = mp };
3531     xfs_alloctype_t     atype = 0;
3532     xfs_agnumber_t      fb_agno;    /* ag number of ap->firstblock */
3533     xfs_agnumber_t      ag;
3534     xfs_fileoff_t       orig_offset;
3535     xfs_extlen_t        orig_length;
3536     xfs_extlen_t        blen;
3537     xfs_extlen_t        nextminlen = 0;
3538     int         nullfb; /* true if ap->firstblock isn't set */
3539     int         isaligned;
3540     int         tryagain;
3541     int         error;
3542     int         stripe_align;
3543 
3544     ASSERT(ap->length);
3545     orig_offset = ap->offset;
3546     orig_length = ap->length;
3547 
3548     stripe_align = xfs_bmap_compute_alignments(ap, &args);
3549 
3550     nullfb = ap->tp->t_firstblock == NULLFSBLOCK;
3551     fb_agno = nullfb ? NULLAGNUMBER : XFS_FSB_TO_AGNO(mp,
3552                             ap->tp->t_firstblock);
3553     if (nullfb) {
3554         if ((ap->datatype & XFS_ALLOC_USERDATA) &&
3555             xfs_inode_is_filestream(ap->ip)) {
3556             ag = xfs_filestream_lookup_ag(ap->ip);
3557             ag = (ag != NULLAGNUMBER) ? ag : 0;
3558             ap->blkno = XFS_AGB_TO_FSB(mp, ag, 0);
3559         } else {
3560             ap->blkno = XFS_INO_TO_FSB(mp, ap->ip->i_ino);
3561         }
3562     } else
3563         ap->blkno = ap->tp->t_firstblock;
3564 
3565     xfs_bmap_adjacent(ap);
3566 
3567     /*
3568      * If allowed, use ap->blkno; otherwise must use firstblock since
3569      * it's in the right allocation group.
3570      */
3571     if (nullfb || XFS_FSB_TO_AGNO(mp, ap->blkno) == fb_agno)
3572         ;
3573     else
3574         ap->blkno = ap->tp->t_firstblock;
3575     /*
3576      * Normal allocation, done through xfs_alloc_vextent.
3577      */
3578     tryagain = isaligned = 0;
3579     args.fsbno = ap->blkno;
3580     args.oinfo = XFS_RMAP_OINFO_SKIP_UPDATE;
3581 
3582     /* Trim the allocation back to the maximum an AG can fit. */
3583     args.maxlen = min(ap->length, mp->m_ag_max_usable);
3584     blen = 0;
3585     if (nullfb) {
3586         /*
3587          * Search for an allocation group with a single extent large
3588          * enough for the request.  If one isn't found, then adjust
3589          * the minimum allocation size to the largest space found.
3590          */
3591         if ((ap->datatype & XFS_ALLOC_USERDATA) &&
3592             xfs_inode_is_filestream(ap->ip))
3593             error = xfs_bmap_btalloc_filestreams(ap, &args, &blen);
3594         else
3595             error = xfs_bmap_btalloc_nullfb(ap, &args, &blen);
3596         if (error)
3597             return error;
3598     } else if (ap->tp->t_flags & XFS_TRANS_LOWMODE) {
3599         if (xfs_inode_is_filestream(ap->ip))
3600             args.type = XFS_ALLOCTYPE_FIRST_AG;
3601         else
3602             args.type = XFS_ALLOCTYPE_START_BNO;
3603         args.total = args.minlen = ap->minlen;
3604     } else {
3605         args.type = XFS_ALLOCTYPE_NEAR_BNO;
3606         args.total = ap->total;
3607         args.minlen = ap->minlen;
3608     }
3609 
3610     /*
3611      * If we are not low on available data blocks, and the underlying
3612      * logical volume manager is a stripe, and the file offset is zero then
3613      * try to allocate data blocks on stripe unit boundary. NOTE: ap->aeof
3614      * is only set if the allocation length is >= the stripe unit and the
3615      * allocation offset is at the end of file.
3616      */
3617     if (!(ap->tp->t_flags & XFS_TRANS_LOWMODE) && ap->aeof) {
3618         if (!ap->offset) {
3619             args.alignment = stripe_align;
3620             atype = args.type;
3621             isaligned = 1;
3622             /*
3623              * Adjust minlen to try and preserve alignment if we
3624              * can't guarantee an aligned maxlen extent.
3625              */
3626             if (blen > args.alignment &&
3627                 blen <= args.maxlen + args.alignment)
3628                 args.minlen = blen - args.alignment;
3629             args.minalignslop = 0;
3630         } else {
3631             /*
3632              * First try an exact bno allocation.
3633              * If it fails then do a near or start bno
3634              * allocation with alignment turned on.
3635              */
3636             atype = args.type;
3637             tryagain = 1;
3638             args.type = XFS_ALLOCTYPE_THIS_BNO;
3639             args.alignment = 1;
3640             /*
3641              * Compute the minlen+alignment for the
3642              * next case.  Set slop so that the value
3643              * of minlen+alignment+slop doesn't go up
3644              * between the calls.
3645              */
3646             if (blen > stripe_align && blen <= args.maxlen)
3647                 nextminlen = blen - stripe_align;
3648             else
3649                 nextminlen = args.minlen;
3650             if (nextminlen + stripe_align > args.minlen + 1)
3651                 args.minalignslop =
3652                     nextminlen + stripe_align -
3653                     args.minlen - 1;
3654             else
3655                 args.minalignslop = 0;
3656         }
3657     } else {
3658         args.alignment = 1;
3659         args.minalignslop = 0;
3660     }
3661     args.minleft = ap->minleft;
3662     args.wasdel = ap->wasdel;
3663     args.resv = XFS_AG_RESV_NONE;
3664     args.datatype = ap->datatype;
3665 
3666     error = xfs_alloc_vextent(&args);
3667     if (error)
3668         return error;
3669 
3670     if (tryagain && args.fsbno == NULLFSBLOCK) {
3671         /*
3672          * Exact allocation failed. Now try with alignment
3673          * turned on.
3674          */
3675         args.type = atype;
3676         args.fsbno = ap->blkno;
3677         args.alignment = stripe_align;
3678         args.minlen = nextminlen;
3679         args.minalignslop = 0;
3680         isaligned = 1;
3681         if ((error = xfs_alloc_vextent(&args)))
3682             return error;
3683     }
3684     if (isaligned && args.fsbno == NULLFSBLOCK) {
3685         /*
3686          * allocation failed, so turn off alignment and
3687          * try again.
3688          */
3689         args.type = atype;
3690         args.fsbno = ap->blkno;
3691         args.alignment = 0;
3692         if ((error = xfs_alloc_vextent(&args)))
3693             return error;
3694     }
3695     if (args.fsbno == NULLFSBLOCK && nullfb &&
3696         args.minlen > ap->minlen) {
3697         args.minlen = ap->minlen;
3698         args.type = XFS_ALLOCTYPE_START_BNO;
3699         args.fsbno = ap->blkno;
3700         if ((error = xfs_alloc_vextent(&args)))
3701             return error;
3702     }
3703     if (args.fsbno == NULLFSBLOCK && nullfb) {
3704         args.fsbno = 0;
3705         args.type = XFS_ALLOCTYPE_FIRST_AG;
3706         args.total = ap->minlen;
3707         if ((error = xfs_alloc_vextent(&args)))
3708             return error;
3709         ap->tp->t_flags |= XFS_TRANS_LOWMODE;
3710     }
3711 
3712     if (args.fsbno != NULLFSBLOCK) {
3713         xfs_bmap_process_allocated_extent(ap, &args, orig_offset,
3714             orig_length);
3715     } else {
3716         ap->blkno = NULLFSBLOCK;
3717         ap->length = 0;
3718     }
3719     return 0;
3720 }
3721 
3722 /* Trim extent to fit a logical block range. */
3723 void
3724 xfs_trim_extent(
3725     struct xfs_bmbt_irec    *irec,
3726     xfs_fileoff_t       bno,
3727     xfs_filblks_t       len)
3728 {
3729     xfs_fileoff_t       distance;
3730     xfs_fileoff_t       end = bno + len;
3731 
3732     if (irec->br_startoff + irec->br_blockcount <= bno ||
3733         irec->br_startoff >= end) {
3734         irec->br_blockcount = 0;
3735         return;
3736     }
3737 
3738     if (irec->br_startoff < bno) {
3739         distance = bno - irec->br_startoff;
3740         if (isnullstartblock(irec->br_startblock))
3741             irec->br_startblock = DELAYSTARTBLOCK;
3742         if (irec->br_startblock != DELAYSTARTBLOCK &&
3743             irec->br_startblock != HOLESTARTBLOCK)
3744             irec->br_startblock += distance;
3745         irec->br_startoff += distance;
3746         irec->br_blockcount -= distance;
3747     }
3748 
3749     if (end < irec->br_startoff + irec->br_blockcount) {
3750         distance = irec->br_startoff + irec->br_blockcount - end;
3751         irec->br_blockcount -= distance;
3752     }
3753 }
3754 
3755 /*
3756  * Trim the returned map to the required bounds
3757  */
3758 STATIC void
3759 xfs_bmapi_trim_map(
3760     struct xfs_bmbt_irec    *mval,
3761     struct xfs_bmbt_irec    *got,
3762     xfs_fileoff_t       *bno,
3763     xfs_filblks_t       len,
3764     xfs_fileoff_t       obno,
3765     xfs_fileoff_t       end,
3766     int         n,
3767     uint32_t        flags)
3768 {
3769     if ((flags & XFS_BMAPI_ENTIRE) ||
3770         got->br_startoff + got->br_blockcount <= obno) {
3771         *mval = *got;
3772         if (isnullstartblock(got->br_startblock))
3773             mval->br_startblock = DELAYSTARTBLOCK;
3774         return;
3775     }
3776 
3777     if (obno > *bno)
3778         *bno = obno;
3779     ASSERT((*bno >= obno) || (n == 0));
3780     ASSERT(*bno < end);
3781     mval->br_startoff = *bno;
3782     if (isnullstartblock(got->br_startblock))
3783         mval->br_startblock = DELAYSTARTBLOCK;
3784     else
3785         mval->br_startblock = got->br_startblock +
3786                     (*bno - got->br_startoff);
3787     /*
3788      * Return the minimum of what we got and what we asked for for
3789      * the length.  We can use the len variable here because it is
3790      * modified below and we could have been there before coming
3791      * here if the first part of the allocation didn't overlap what
3792      * was asked for.
3793      */
3794     mval->br_blockcount = XFS_FILBLKS_MIN(end - *bno,
3795             got->br_blockcount - (*bno - got->br_startoff));
3796     mval->br_state = got->br_state;
3797     ASSERT(mval->br_blockcount <= len);
3798     return;
3799 }
3800 
3801 /*
3802  * Update and validate the extent map to return
3803  */
3804 STATIC void
3805 xfs_bmapi_update_map(
3806     struct xfs_bmbt_irec    **map,
3807     xfs_fileoff_t       *bno,
3808     xfs_filblks_t       *len,
3809     xfs_fileoff_t       obno,
3810     xfs_fileoff_t       end,
3811     int         *n,
3812     uint32_t        flags)
3813 {
3814     xfs_bmbt_irec_t *mval = *map;
3815 
3816     ASSERT((flags & XFS_BMAPI_ENTIRE) ||
3817            ((mval->br_startoff + mval->br_blockcount) <= end));
3818     ASSERT((flags & XFS_BMAPI_ENTIRE) || (mval->br_blockcount <= *len) ||
3819            (mval->br_startoff < obno));
3820 
3821     *bno = mval->br_startoff + mval->br_blockcount;
3822     *len = end - *bno;
3823     if (*n > 0 && mval->br_startoff == mval[-1].br_startoff) {
3824         /* update previous map with new information */
3825         ASSERT(mval->br_startblock == mval[-1].br_startblock);
3826         ASSERT(mval->br_blockcount > mval[-1].br_blockcount);
3827         ASSERT(mval->br_state == mval[-1].br_state);
3828         mval[-1].br_blockcount = mval->br_blockcount;
3829         mval[-1].br_state = mval->br_state;
3830     } else if (*n > 0 && mval->br_startblock != DELAYSTARTBLOCK &&
3831            mval[-1].br_startblock != DELAYSTARTBLOCK &&
3832            mval[-1].br_startblock != HOLESTARTBLOCK &&
3833            mval->br_startblock == mval[-1].br_startblock +
3834                       mval[-1].br_blockcount &&
3835            mval[-1].br_state == mval->br_state) {
3836         ASSERT(mval->br_startoff ==
3837                mval[-1].br_startoff + mval[-1].br_blockcount);
3838         mval[-1].br_blockcount += mval->br_blockcount;
3839     } else if (*n > 0 &&
3840            mval->br_startblock == DELAYSTARTBLOCK &&
3841            mval[-1].br_startblock == DELAYSTARTBLOCK &&
3842            mval->br_startoff ==
3843            mval[-1].br_startoff + mval[-1].br_blockcount) {
3844         mval[-1].br_blockcount += mval->br_blockcount;
3845         mval[-1].br_state = mval->br_state;
3846     } else if (!((*n == 0) &&
3847              ((mval->br_startoff + mval->br_blockcount) <=
3848               obno))) {
3849         mval++;
3850         (*n)++;
3851     }
3852     *map = mval;
3853 }
3854 
3855 /*
3856  * Map file blocks to filesystem blocks without allocation.
3857  */
3858 int
3859 xfs_bmapi_read(
3860     struct xfs_inode    *ip,
3861     xfs_fileoff_t       bno,
3862     xfs_filblks_t       len,
3863     struct xfs_bmbt_irec    *mval,
3864     int         *nmap,
3865     uint32_t        flags)
3866 {
3867     struct xfs_mount    *mp = ip->i_mount;
3868     int         whichfork = xfs_bmapi_whichfork(flags);
3869     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, whichfork);
3870     struct xfs_bmbt_irec    got;
3871     xfs_fileoff_t       obno;
3872     xfs_fileoff_t       end;
3873     struct xfs_iext_cursor  icur;
3874     int         error;
3875     bool            eof = false;
3876     int         n = 0;
3877 
3878     ASSERT(*nmap >= 1);
3879     ASSERT(!(flags & ~(XFS_BMAPI_ATTRFORK | XFS_BMAPI_ENTIRE)));
3880     ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED|XFS_ILOCK_EXCL));
3881 
3882     if (WARN_ON_ONCE(!ifp))
3883         return -EFSCORRUPTED;
3884 
3885     if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
3886         XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT))
3887         return -EFSCORRUPTED;
3888 
3889     if (xfs_is_shutdown(mp))
3890         return -EIO;
3891 
3892     XFS_STATS_INC(mp, xs_blk_mapr);
3893 
3894     error = xfs_iread_extents(NULL, ip, whichfork);
3895     if (error)
3896         return error;
3897 
3898     if (!xfs_iext_lookup_extent(ip, ifp, bno, &icur, &got))
3899         eof = true;
3900     end = bno + len;
3901     obno = bno;
3902 
3903     while (bno < end && n < *nmap) {
3904         /* Reading past eof, act as though there's a hole up to end. */
3905         if (eof)
3906             got.br_startoff = end;
3907         if (got.br_startoff > bno) {
3908             /* Reading in a hole.  */
3909             mval->br_startoff = bno;
3910             mval->br_startblock = HOLESTARTBLOCK;
3911             mval->br_blockcount =
3912                 XFS_FILBLKS_MIN(len, got.br_startoff - bno);
3913             mval->br_state = XFS_EXT_NORM;
3914             bno += mval->br_blockcount;
3915             len -= mval->br_blockcount;
3916             mval++;
3917             n++;
3918             continue;
3919         }
3920 
3921         /* set up the extent map to return. */
3922         xfs_bmapi_trim_map(mval, &got, &bno, len, obno, end, n, flags);
3923         xfs_bmapi_update_map(&mval, &bno, &len, obno, end, &n, flags);
3924 
3925         /* If we're done, stop now. */
3926         if (bno >= end || n >= *nmap)
3927             break;
3928 
3929         /* Else go on to the next record. */
3930         if (!xfs_iext_next_extent(ifp, &icur, &got))
3931             eof = true;
3932     }
3933     *nmap = n;
3934     return 0;
3935 }
3936 
3937 /*
3938  * Add a delayed allocation extent to an inode. Blocks are reserved from the
3939  * global pool and the extent inserted into the inode in-core extent tree.
3940  *
3941  * On entry, got refers to the first extent beyond the offset of the extent to
3942  * allocate or eof is specified if no such extent exists. On return, got refers
3943  * to the extent record that was inserted to the inode fork.
3944  *
3945  * Note that the allocated extent may have been merged with contiguous extents
3946  * during insertion into the inode fork. Thus, got does not reflect the current
3947  * state of the inode fork on return. If necessary, the caller can use lastx to
3948  * look up the updated record in the inode fork.
3949  */
3950 int
3951 xfs_bmapi_reserve_delalloc(
3952     struct xfs_inode    *ip,
3953     int         whichfork,
3954     xfs_fileoff_t       off,
3955     xfs_filblks_t       len,
3956     xfs_filblks_t       prealloc,
3957     struct xfs_bmbt_irec    *got,
3958     struct xfs_iext_cursor  *icur,
3959     int         eof)
3960 {
3961     struct xfs_mount    *mp = ip->i_mount;
3962     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, whichfork);
3963     xfs_extlen_t        alen;
3964     xfs_extlen_t        indlen;
3965     int         error;
3966     xfs_fileoff_t       aoff = off;
3967 
3968     /*
3969      * Cap the alloc length. Keep track of prealloc so we know whether to
3970      * tag the inode before we return.
3971      */
3972     alen = XFS_FILBLKS_MIN(len + prealloc, XFS_MAX_BMBT_EXTLEN);
3973     if (!eof)
3974         alen = XFS_FILBLKS_MIN(alen, got->br_startoff - aoff);
3975     if (prealloc && alen >= len)
3976         prealloc = alen - len;
3977 
3978     /* Figure out the extent size, adjust alen */
3979     if (whichfork == XFS_COW_FORK) {
3980         struct xfs_bmbt_irec    prev;
3981         xfs_extlen_t        extsz = xfs_get_cowextsz_hint(ip);
3982 
3983         if (!xfs_iext_peek_prev_extent(ifp, icur, &prev))
3984             prev.br_startoff = NULLFILEOFF;
3985 
3986         error = xfs_bmap_extsize_align(mp, got, &prev, extsz, 0, eof,
3987                            1, 0, &aoff, &alen);
3988         ASSERT(!error);
3989     }
3990 
3991     /*
3992      * Make a transaction-less quota reservation for delayed allocation
3993      * blocks.  This number gets adjusted later.  We return if we haven't
3994      * allocated blocks already inside this loop.
3995      */
3996     error = xfs_quota_reserve_blkres(ip, alen);
3997     if (error)
3998         return error;
3999 
4000     /*
4001      * Split changing sb for alen and indlen since they could be coming
4002      * from different places.
4003      */
4004     indlen = (xfs_extlen_t)xfs_bmap_worst_indlen(ip, alen);
4005     ASSERT(indlen > 0);
4006 
4007     error = xfs_mod_fdblocks(mp, -((int64_t)alen), false);
4008     if (error)
4009         goto out_unreserve_quota;
4010 
4011     error = xfs_mod_fdblocks(mp, -((int64_t)indlen), false);
4012     if (error)
4013         goto out_unreserve_blocks;
4014 
4015 
4016     ip->i_delayed_blks += alen;
4017     xfs_mod_delalloc(ip->i_mount, alen + indlen);
4018 
4019     got->br_startoff = aoff;
4020     got->br_startblock = nullstartblock(indlen);
4021     got->br_blockcount = alen;
4022     got->br_state = XFS_EXT_NORM;
4023 
4024     xfs_bmap_add_extent_hole_delay(ip, whichfork, icur, got);
4025 
4026     /*
4027      * Tag the inode if blocks were preallocated. Note that COW fork
4028      * preallocation can occur at the start or end of the extent, even when
4029      * prealloc == 0, so we must also check the aligned offset and length.
4030      */
4031     if (whichfork == XFS_DATA_FORK && prealloc)
4032         xfs_inode_set_eofblocks_tag(ip);
4033     if (whichfork == XFS_COW_FORK && (prealloc || aoff < off || alen > len))
4034         xfs_inode_set_cowblocks_tag(ip);
4035 
4036     return 0;
4037 
4038 out_unreserve_blocks:
4039     xfs_mod_fdblocks(mp, alen, false);
4040 out_unreserve_quota:
4041     if (XFS_IS_QUOTA_ON(mp))
4042         xfs_quota_unreserve_blkres(ip, alen);
4043     return error;
4044 }
4045 
4046 static int
4047 xfs_bmap_alloc_userdata(
4048     struct xfs_bmalloca *bma)
4049 {
4050     struct xfs_mount    *mp = bma->ip->i_mount;
4051     int         whichfork = xfs_bmapi_whichfork(bma->flags);
4052     int         error;
4053 
4054     /*
4055      * Set the data type being allocated. For the data fork, the first data
4056      * in the file is treated differently to all other allocations. For the
4057      * attribute fork, we only need to ensure the allocated range is not on
4058      * the busy list.
4059      */
4060     bma->datatype = XFS_ALLOC_NOBUSY;
4061     if (whichfork == XFS_DATA_FORK) {
4062         bma->datatype |= XFS_ALLOC_USERDATA;
4063         if (bma->offset == 0)
4064             bma->datatype |= XFS_ALLOC_INITIAL_USER_DATA;
4065 
4066         if (mp->m_dalign && bma->length >= mp->m_dalign) {
4067             error = xfs_bmap_isaeof(bma, whichfork);
4068             if (error)
4069                 return error;
4070         }
4071 
4072         if (XFS_IS_REALTIME_INODE(bma->ip))
4073             return xfs_bmap_rtalloc(bma);
4074     }
4075 
4076     if (unlikely(XFS_TEST_ERROR(false, mp,
4077             XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT)))
4078         return xfs_bmap_exact_minlen_extent_alloc(bma);
4079 
4080     return xfs_bmap_btalloc(bma);
4081 }
4082 
4083 static int
4084 xfs_bmapi_allocate(
4085     struct xfs_bmalloca *bma)
4086 {
4087     struct xfs_mount    *mp = bma->ip->i_mount;
4088     int         whichfork = xfs_bmapi_whichfork(bma->flags);
4089     struct xfs_ifork    *ifp = xfs_ifork_ptr(bma->ip, whichfork);
4090     int         tmp_logflags = 0;
4091     int         error;
4092 
4093     ASSERT(bma->length > 0);
4094 
4095     /*
4096      * For the wasdelay case, we could also just allocate the stuff asked
4097      * for in this bmap call but that wouldn't be as good.
4098      */
4099     if (bma->wasdel) {
4100         bma->length = (xfs_extlen_t)bma->got.br_blockcount;
4101         bma->offset = bma->got.br_startoff;
4102         if (!xfs_iext_peek_prev_extent(ifp, &bma->icur, &bma->prev))
4103             bma->prev.br_startoff = NULLFILEOFF;
4104     } else {
4105         bma->length = XFS_FILBLKS_MIN(bma->length, XFS_MAX_BMBT_EXTLEN);
4106         if (!bma->eof)
4107             bma->length = XFS_FILBLKS_MIN(bma->length,
4108                     bma->got.br_startoff - bma->offset);
4109     }
4110 
4111     if (bma->flags & XFS_BMAPI_CONTIG)
4112         bma->minlen = bma->length;
4113     else
4114         bma->minlen = 1;
4115 
4116     if (bma->flags & XFS_BMAPI_METADATA) {
4117         if (unlikely(XFS_TEST_ERROR(false, mp,
4118                 XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT)))
4119             error = xfs_bmap_exact_minlen_extent_alloc(bma);
4120         else
4121             error = xfs_bmap_btalloc(bma);
4122     } else {
4123         error = xfs_bmap_alloc_userdata(bma);
4124     }
4125     if (error || bma->blkno == NULLFSBLOCK)
4126         return error;
4127 
4128     if (bma->flags & XFS_BMAPI_ZERO) {
4129         error = xfs_zero_extent(bma->ip, bma->blkno, bma->length);
4130         if (error)
4131             return error;
4132     }
4133 
4134     if (ifp->if_format == XFS_DINODE_FMT_BTREE && !bma->cur)
4135         bma->cur = xfs_bmbt_init_cursor(mp, bma->tp, bma->ip, whichfork);
4136     /*
4137      * Bump the number of extents we've allocated
4138      * in this call.
4139      */
4140     bma->nallocs++;
4141 
4142     if (bma->cur)
4143         bma->cur->bc_ino.flags =
4144             bma->wasdel ? XFS_BTCUR_BMBT_WASDEL : 0;
4145 
4146     bma->got.br_startoff = bma->offset;
4147     bma->got.br_startblock = bma->blkno;
4148     bma->got.br_blockcount = bma->length;
4149     bma->got.br_state = XFS_EXT_NORM;
4150 
4151     if (bma->flags & XFS_BMAPI_PREALLOC)
4152         bma->got.br_state = XFS_EXT_UNWRITTEN;
4153 
4154     if (bma->wasdel)
4155         error = xfs_bmap_add_extent_delay_real(bma, whichfork);
4156     else
4157         error = xfs_bmap_add_extent_hole_real(bma->tp, bma->ip,
4158                 whichfork, &bma->icur, &bma->cur, &bma->got,
4159                 &bma->logflags, bma->flags);
4160 
4161     bma->logflags |= tmp_logflags;
4162     if (error)
4163         return error;
4164 
4165     /*
4166      * Update our extent pointer, given that xfs_bmap_add_extent_delay_real
4167      * or xfs_bmap_add_extent_hole_real might have merged it into one of
4168      * the neighbouring ones.
4169      */
4170     xfs_iext_get_extent(ifp, &bma->icur, &bma->got);
4171 
4172     ASSERT(bma->got.br_startoff <= bma->offset);
4173     ASSERT(bma->got.br_startoff + bma->got.br_blockcount >=
4174            bma->offset + bma->length);
4175     ASSERT(bma->got.br_state == XFS_EXT_NORM ||
4176            bma->got.br_state == XFS_EXT_UNWRITTEN);
4177     return 0;
4178 }
4179 
4180 STATIC int
4181 xfs_bmapi_convert_unwritten(
4182     struct xfs_bmalloca *bma,
4183     struct xfs_bmbt_irec    *mval,
4184     xfs_filblks_t       len,
4185     uint32_t        flags)
4186 {
4187     int         whichfork = xfs_bmapi_whichfork(flags);
4188     struct xfs_ifork    *ifp = xfs_ifork_ptr(bma->ip, whichfork);
4189     int         tmp_logflags = 0;
4190     int         error;
4191 
4192     /* check if we need to do unwritten->real conversion */
4193     if (mval->br_state == XFS_EXT_UNWRITTEN &&
4194         (flags & XFS_BMAPI_PREALLOC))
4195         return 0;
4196 
4197     /* check if we need to do real->unwritten conversion */
4198     if (mval->br_state == XFS_EXT_NORM &&
4199         (flags & (XFS_BMAPI_PREALLOC | XFS_BMAPI_CONVERT)) !=
4200             (XFS_BMAPI_PREALLOC | XFS_BMAPI_CONVERT))
4201         return 0;
4202 
4203     /*
4204      * Modify (by adding) the state flag, if writing.
4205      */
4206     ASSERT(mval->br_blockcount <= len);
4207     if (ifp->if_format == XFS_DINODE_FMT_BTREE && !bma->cur) {
4208         bma->cur = xfs_bmbt_init_cursor(bma->ip->i_mount, bma->tp,
4209                     bma->ip, whichfork);
4210     }
4211     mval->br_state = (mval->br_state == XFS_EXT_UNWRITTEN)
4212                 ? XFS_EXT_NORM : XFS_EXT_UNWRITTEN;
4213 
4214     /*
4215      * Before insertion into the bmbt, zero the range being converted
4216      * if required.
4217      */
4218     if (flags & XFS_BMAPI_ZERO) {
4219         error = xfs_zero_extent(bma->ip, mval->br_startblock,
4220                     mval->br_blockcount);
4221         if (error)
4222             return error;
4223     }
4224 
4225     error = xfs_bmap_add_extent_unwritten_real(bma->tp, bma->ip, whichfork,
4226             &bma->icur, &bma->cur, mval, &tmp_logflags);
4227     /*
4228      * Log the inode core unconditionally in the unwritten extent conversion
4229      * path because the conversion might not have done so (e.g., if the
4230      * extent count hasn't changed). We need to make sure the inode is dirty
4231      * in the transaction for the sake of fsync(), even if nothing has
4232      * changed, because fsync() will not force the log for this transaction
4233      * unless it sees the inode pinned.
4234      *
4235      * Note: If we're only converting cow fork extents, there aren't
4236      * any on-disk updates to make, so we don't need to log anything.
4237      */
4238     if (whichfork != XFS_COW_FORK)
4239         bma->logflags |= tmp_logflags | XFS_ILOG_CORE;
4240     if (error)
4241         return error;
4242 
4243     /*
4244      * Update our extent pointer, given that
4245      * xfs_bmap_add_extent_unwritten_real might have merged it into one
4246      * of the neighbouring ones.
4247      */
4248     xfs_iext_get_extent(ifp, &bma->icur, &bma->got);
4249 
4250     /*
4251      * We may have combined previously unwritten space with written space,
4252      * so generate another request.
4253      */
4254     if (mval->br_blockcount < len)
4255         return -EAGAIN;
4256     return 0;
4257 }
4258 
4259 static inline xfs_extlen_t
4260 xfs_bmapi_minleft(
4261     struct xfs_trans    *tp,
4262     struct xfs_inode    *ip,
4263     int         fork)
4264 {
4265     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, fork);
4266 
4267     if (tp && tp->t_firstblock != NULLFSBLOCK)
4268         return 0;
4269     if (ifp->if_format != XFS_DINODE_FMT_BTREE)
4270         return 1;
4271     return be16_to_cpu(ifp->if_broot->bb_level) + 1;
4272 }
4273 
4274 /*
4275  * Log whatever the flags say, even if error.  Otherwise we might miss detecting
4276  * a case where the data is changed, there's an error, and it's not logged so we
4277  * don't shutdown when we should.  Don't bother logging extents/btree changes if
4278  * we converted to the other format.
4279  */
4280 static void
4281 xfs_bmapi_finish(
4282     struct xfs_bmalloca *bma,
4283     int         whichfork,
4284     int         error)
4285 {
4286     struct xfs_ifork    *ifp = xfs_ifork_ptr(bma->ip, whichfork);
4287 
4288     if ((bma->logflags & xfs_ilog_fext(whichfork)) &&
4289         ifp->if_format != XFS_DINODE_FMT_EXTENTS)
4290         bma->logflags &= ~xfs_ilog_fext(whichfork);
4291     else if ((bma->logflags & xfs_ilog_fbroot(whichfork)) &&
4292          ifp->if_format != XFS_DINODE_FMT_BTREE)
4293         bma->logflags &= ~xfs_ilog_fbroot(whichfork);
4294 
4295     if (bma->logflags)
4296         xfs_trans_log_inode(bma->tp, bma->ip, bma->logflags);
4297     if (bma->cur)
4298         xfs_btree_del_cursor(bma->cur, error);
4299 }
4300 
4301 /*
4302  * Map file blocks to filesystem blocks, and allocate blocks or convert the
4303  * extent state if necessary.  Details behaviour is controlled by the flags
4304  * parameter.  Only allocates blocks from a single allocation group, to avoid
4305  * locking problems.
4306  */
4307 int
4308 xfs_bmapi_write(
4309     struct xfs_trans    *tp,        /* transaction pointer */
4310     struct xfs_inode    *ip,        /* incore inode */
4311     xfs_fileoff_t       bno,        /* starting file offs. mapped */
4312     xfs_filblks_t       len,        /* length to map in file */
4313     uint32_t        flags,      /* XFS_BMAPI_... */
4314     xfs_extlen_t        total,      /* total blocks needed */
4315     struct xfs_bmbt_irec    *mval,      /* output: map values */
4316     int         *nmap)      /* i/o: mval size/count */
4317 {
4318     struct xfs_bmalloca bma = {
4319         .tp     = tp,
4320         .ip     = ip,
4321         .total      = total,
4322     };
4323     struct xfs_mount    *mp = ip->i_mount;
4324     int         whichfork = xfs_bmapi_whichfork(flags);
4325     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, whichfork);
4326     xfs_fileoff_t       end;        /* end of mapped file region */
4327     bool            eof = false;    /* after the end of extents */
4328     int         error;      /* error return */
4329     int         n;      /* current extent index */
4330     xfs_fileoff_t       obno;       /* old block number (offset) */
4331 
4332 #ifdef DEBUG
4333     xfs_fileoff_t       orig_bno;   /* original block number value */
4334     int         orig_flags; /* original flags arg value */
4335     xfs_filblks_t       orig_len;   /* original value of len arg */
4336     struct xfs_bmbt_irec    *orig_mval; /* original value of mval */
4337     int         orig_nmap;  /* original value of *nmap */
4338 
4339     orig_bno = bno;
4340     orig_len = len;
4341     orig_flags = flags;
4342     orig_mval = mval;
4343     orig_nmap = *nmap;
4344 #endif
4345 
4346     ASSERT(*nmap >= 1);
4347     ASSERT(*nmap <= XFS_BMAP_MAX_NMAP);
4348     ASSERT(tp != NULL);
4349     ASSERT(len > 0);
4350     ASSERT(ifp->if_format != XFS_DINODE_FMT_LOCAL);
4351     ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
4352     ASSERT(!(flags & XFS_BMAPI_REMAP));
4353 
4354     /* zeroing is for currently only for data extents, not metadata */
4355     ASSERT((flags & (XFS_BMAPI_METADATA | XFS_BMAPI_ZERO)) !=
4356             (XFS_BMAPI_METADATA | XFS_BMAPI_ZERO));
4357     /*
4358      * we can allocate unwritten extents or pre-zero allocated blocks,
4359      * but it makes no sense to do both at once. This would result in
4360      * zeroing the unwritten extent twice, but it still being an
4361      * unwritten extent....
4362      */
4363     ASSERT((flags & (XFS_BMAPI_PREALLOC | XFS_BMAPI_ZERO)) !=
4364             (XFS_BMAPI_PREALLOC | XFS_BMAPI_ZERO));
4365 
4366     if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
4367         XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
4368         return -EFSCORRUPTED;
4369     }
4370 
4371     if (xfs_is_shutdown(mp))
4372         return -EIO;
4373 
4374     XFS_STATS_INC(mp, xs_blk_mapw);
4375 
4376     error = xfs_iread_extents(tp, ip, whichfork);
4377     if (error)
4378         goto error0;
4379 
4380     if (!xfs_iext_lookup_extent(ip, ifp, bno, &bma.icur, &bma.got))
4381         eof = true;
4382     if (!xfs_iext_peek_prev_extent(ifp, &bma.icur, &bma.prev))
4383         bma.prev.br_startoff = NULLFILEOFF;
4384     bma.minleft = xfs_bmapi_minleft(tp, ip, whichfork);
4385 
4386     n = 0;
4387     end = bno + len;
4388     obno = bno;
4389     while (bno < end && n < *nmap) {
4390         bool            need_alloc = false, wasdelay = false;
4391 
4392         /* in hole or beyond EOF? */
4393         if (eof || bma.got.br_startoff > bno) {
4394             /*
4395              * CoW fork conversions should /never/ hit EOF or
4396              * holes.  There should always be something for us
4397              * to work on.
4398              */
4399             ASSERT(!((flags & XFS_BMAPI_CONVERT) &&
4400                      (flags & XFS_BMAPI_COWFORK)));
4401 
4402             need_alloc = true;
4403         } else if (isnullstartblock(bma.got.br_startblock)) {
4404             wasdelay = true;
4405         }
4406 
4407         /*
4408          * First, deal with the hole before the allocated space
4409          * that we found, if any.
4410          */
4411         if (need_alloc || wasdelay) {
4412             bma.eof = eof;
4413             bma.conv = !!(flags & XFS_BMAPI_CONVERT);
4414             bma.wasdel = wasdelay;
4415             bma.offset = bno;
4416             bma.flags = flags;
4417 
4418             /*
4419              * There's a 32/64 bit type mismatch between the
4420              * allocation length request (which can be 64 bits in
4421              * length) and the bma length request, which is
4422              * xfs_extlen_t and therefore 32 bits. Hence we have to
4423              * check for 32-bit overflows and handle them here.
4424              */
4425             if (len > (xfs_filblks_t)XFS_MAX_BMBT_EXTLEN)
4426                 bma.length = XFS_MAX_BMBT_EXTLEN;
4427             else
4428                 bma.length = len;
4429 
4430             ASSERT(len > 0);
4431             ASSERT(bma.length > 0);
4432             error = xfs_bmapi_allocate(&bma);
4433             if (error)
4434                 goto error0;
4435             if (bma.blkno == NULLFSBLOCK)
4436                 break;
4437 
4438             /*
4439              * If this is a CoW allocation, record the data in
4440              * the refcount btree for orphan recovery.
4441              */
4442             if (whichfork == XFS_COW_FORK)
4443                 xfs_refcount_alloc_cow_extent(tp, bma.blkno,
4444                         bma.length);
4445         }
4446 
4447         /* Deal with the allocated space we found.  */
4448         xfs_bmapi_trim_map(mval, &bma.got, &bno, len, obno,
4449                             end, n, flags);
4450 
4451         /* Execute unwritten extent conversion if necessary */
4452         error = xfs_bmapi_convert_unwritten(&bma, mval, len, flags);
4453         if (error == -EAGAIN)
4454             continue;
4455         if (error)
4456             goto error0;
4457 
4458         /* update the extent map to return */
4459         xfs_bmapi_update_map(&mval, &bno, &len, obno, end, &n, flags);
4460 
4461         /*
4462          * If we're done, stop now.  Stop when we've allocated
4463          * XFS_BMAP_MAX_NMAP extents no matter what.  Otherwise
4464          * the transaction may get too big.
4465          */
4466         if (bno >= end || n >= *nmap || bma.nallocs >= *nmap)
4467             break;
4468 
4469         /* Else go on to the next record. */
4470         bma.prev = bma.got;
4471         if (!xfs_iext_next_extent(ifp, &bma.icur, &bma.got))
4472             eof = true;
4473     }
4474     *nmap = n;
4475 
4476     error = xfs_bmap_btree_to_extents(tp, ip, bma.cur, &bma.logflags,
4477             whichfork);
4478     if (error)
4479         goto error0;
4480 
4481     ASSERT(ifp->if_format != XFS_DINODE_FMT_BTREE ||
4482            ifp->if_nextents > XFS_IFORK_MAXEXT(ip, whichfork));
4483     xfs_bmapi_finish(&bma, whichfork, 0);
4484     xfs_bmap_validate_ret(orig_bno, orig_len, orig_flags, orig_mval,
4485         orig_nmap, *nmap);
4486     return 0;
4487 error0:
4488     xfs_bmapi_finish(&bma, whichfork, error);
4489     return error;
4490 }
4491 
4492 /*
4493  * Convert an existing delalloc extent to real blocks based on file offset. This
4494  * attempts to allocate the entire delalloc extent and may require multiple
4495  * invocations to allocate the target offset if a large enough physical extent
4496  * is not available.
4497  */
4498 int
4499 xfs_bmapi_convert_delalloc(
4500     struct xfs_inode    *ip,
4501     int         whichfork,
4502     xfs_off_t       offset,
4503     struct iomap        *iomap,
4504     unsigned int        *seq)
4505 {
4506     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, whichfork);
4507     struct xfs_mount    *mp = ip->i_mount;
4508     xfs_fileoff_t       offset_fsb = XFS_B_TO_FSBT(mp, offset);
4509     struct xfs_bmalloca bma = { NULL };
4510     uint16_t        flags = 0;
4511     struct xfs_trans    *tp;
4512     int         error;
4513 
4514     if (whichfork == XFS_COW_FORK)
4515         flags |= IOMAP_F_SHARED;
4516 
4517     /*
4518      * Space for the extent and indirect blocks was reserved when the
4519      * delalloc extent was created so there's no need to do so here.
4520      */
4521     error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0,
4522                 XFS_TRANS_RESERVE, &tp);
4523     if (error)
4524         return error;
4525 
4526     xfs_ilock(ip, XFS_ILOCK_EXCL);
4527     xfs_trans_ijoin(tp, ip, 0);
4528 
4529     error = xfs_iext_count_may_overflow(ip, whichfork,
4530             XFS_IEXT_ADD_NOSPLIT_CNT);
4531     if (error == -EFBIG)
4532         error = xfs_iext_count_upgrade(tp, ip,
4533                 XFS_IEXT_ADD_NOSPLIT_CNT);
4534     if (error)
4535         goto out_trans_cancel;
4536 
4537     if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &bma.icur, &bma.got) ||
4538         bma.got.br_startoff > offset_fsb) {
4539         /*
4540          * No extent found in the range we are trying to convert.  This
4541          * should only happen for the COW fork, where another thread
4542          * might have moved the extent to the data fork in the meantime.
4543          */
4544         WARN_ON_ONCE(whichfork != XFS_COW_FORK);
4545         error = -EAGAIN;
4546         goto out_trans_cancel;
4547     }
4548 
4549     /*
4550      * If we find a real extent here we raced with another thread converting
4551      * the extent.  Just return the real extent at this offset.
4552      */
4553     if (!isnullstartblock(bma.got.br_startblock)) {
4554         xfs_bmbt_to_iomap(ip, iomap, &bma.got, 0, flags);
4555         *seq = READ_ONCE(ifp->if_seq);
4556         goto out_trans_cancel;
4557     }
4558 
4559     bma.tp = tp;
4560     bma.ip = ip;
4561     bma.wasdel = true;
4562     bma.offset = bma.got.br_startoff;
4563     bma.length = max_t(xfs_filblks_t, bma.got.br_blockcount,
4564             XFS_MAX_BMBT_EXTLEN);
4565     bma.minleft = xfs_bmapi_minleft(tp, ip, whichfork);
4566 
4567     /*
4568      * When we're converting the delalloc reservations backing dirty pages
4569      * in the page cache, we must be careful about how we create the new
4570      * extents:
4571      *
4572      * New CoW fork extents are created unwritten, turned into real extents
4573      * when we're about to write the data to disk, and mapped into the data
4574      * fork after the write finishes.  End of story.
4575      *
4576      * New data fork extents must be mapped in as unwritten and converted
4577      * to real extents after the write succeeds to avoid exposing stale
4578      * disk contents if we crash.
4579      */
4580     bma.flags = XFS_BMAPI_PREALLOC;
4581     if (whichfork == XFS_COW_FORK)
4582         bma.flags |= XFS_BMAPI_COWFORK;
4583 
4584     if (!xfs_iext_peek_prev_extent(ifp, &bma.icur, &bma.prev))
4585         bma.prev.br_startoff = NULLFILEOFF;
4586 
4587     error = xfs_bmapi_allocate(&bma);
4588     if (error)
4589         goto out_finish;
4590 
4591     error = -ENOSPC;
4592     if (WARN_ON_ONCE(bma.blkno == NULLFSBLOCK))
4593         goto out_finish;
4594     error = -EFSCORRUPTED;
4595     if (WARN_ON_ONCE(!xfs_valid_startblock(ip, bma.got.br_startblock)))
4596         goto out_finish;
4597 
4598     XFS_STATS_ADD(mp, xs_xstrat_bytes, XFS_FSB_TO_B(mp, bma.length));
4599     XFS_STATS_INC(mp, xs_xstrat_quick);
4600 
4601     ASSERT(!isnullstartblock(bma.got.br_startblock));
4602     xfs_bmbt_to_iomap(ip, iomap, &bma.got, 0, flags);
4603     *seq = READ_ONCE(ifp->if_seq);
4604 
4605     if (whichfork == XFS_COW_FORK)
4606         xfs_refcount_alloc_cow_extent(tp, bma.blkno, bma.length);
4607 
4608     error = xfs_bmap_btree_to_extents(tp, ip, bma.cur, &bma.logflags,
4609             whichfork);
4610     if (error)
4611         goto out_finish;
4612 
4613     xfs_bmapi_finish(&bma, whichfork, 0);
4614     error = xfs_trans_commit(tp);
4615     xfs_iunlock(ip, XFS_ILOCK_EXCL);
4616     return error;
4617 
4618 out_finish:
4619     xfs_bmapi_finish(&bma, whichfork, error);
4620 out_trans_cancel:
4621     xfs_trans_cancel(tp);
4622     xfs_iunlock(ip, XFS_ILOCK_EXCL);
4623     return error;
4624 }
4625 
4626 int
4627 xfs_bmapi_remap(
4628     struct xfs_trans    *tp,
4629     struct xfs_inode    *ip,
4630     xfs_fileoff_t       bno,
4631     xfs_filblks_t       len,
4632     xfs_fsblock_t       startblock,
4633     uint32_t        flags)
4634 {
4635     struct xfs_mount    *mp = ip->i_mount;
4636     struct xfs_ifork    *ifp;
4637     struct xfs_btree_cur    *cur = NULL;
4638     struct xfs_bmbt_irec    got;
4639     struct xfs_iext_cursor  icur;
4640     int         whichfork = xfs_bmapi_whichfork(flags);
4641     int         logflags = 0, error;
4642 
4643     ifp = xfs_ifork_ptr(ip, whichfork);
4644     ASSERT(len > 0);
4645     ASSERT(len <= (xfs_filblks_t)XFS_MAX_BMBT_EXTLEN);
4646     ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
4647     ASSERT(!(flags & ~(XFS_BMAPI_ATTRFORK | XFS_BMAPI_PREALLOC |
4648                XFS_BMAPI_NORMAP)));
4649     ASSERT((flags & (XFS_BMAPI_ATTRFORK | XFS_BMAPI_PREALLOC)) !=
4650             (XFS_BMAPI_ATTRFORK | XFS_BMAPI_PREALLOC));
4651 
4652     if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
4653         XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
4654         return -EFSCORRUPTED;
4655     }
4656 
4657     if (xfs_is_shutdown(mp))
4658         return -EIO;
4659 
4660     error = xfs_iread_extents(tp, ip, whichfork);
4661     if (error)
4662         return error;
4663 
4664     if (xfs_iext_lookup_extent(ip, ifp, bno, &icur, &got)) {
4665         /* make sure we only reflink into a hole. */
4666         ASSERT(got.br_startoff > bno);
4667         ASSERT(got.br_startoff - bno >= len);
4668     }
4669 
4670     ip->i_nblocks += len;
4671     xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
4672 
4673     if (ifp->if_format == XFS_DINODE_FMT_BTREE) {
4674         cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
4675         cur->bc_ino.flags = 0;
4676     }
4677 
4678     got.br_startoff = bno;
4679     got.br_startblock = startblock;
4680     got.br_blockcount = len;
4681     if (flags & XFS_BMAPI_PREALLOC)
4682         got.br_state = XFS_EXT_UNWRITTEN;
4683     else
4684         got.br_state = XFS_EXT_NORM;
4685 
4686     error = xfs_bmap_add_extent_hole_real(tp, ip, whichfork, &icur,
4687             &cur, &got, &logflags, flags);
4688     if (error)
4689         goto error0;
4690 
4691     error = xfs_bmap_btree_to_extents(tp, ip, cur, &logflags, whichfork);
4692 
4693 error0:
4694     if (ip->i_df.if_format != XFS_DINODE_FMT_EXTENTS)
4695         logflags &= ~XFS_ILOG_DEXT;
4696     else if (ip->i_df.if_format != XFS_DINODE_FMT_BTREE)
4697         logflags &= ~XFS_ILOG_DBROOT;
4698 
4699     if (logflags)
4700         xfs_trans_log_inode(tp, ip, logflags);
4701     if (cur)
4702         xfs_btree_del_cursor(cur, error);
4703     return error;
4704 }
4705 
4706 /*
4707  * When a delalloc extent is split (e.g., due to a hole punch), the original
4708  * indlen reservation must be shared across the two new extents that are left
4709  * behind.
4710  *
4711  * Given the original reservation and the worst case indlen for the two new
4712  * extents (as calculated by xfs_bmap_worst_indlen()), split the original
4713  * reservation fairly across the two new extents. If necessary, steal available
4714  * blocks from a deleted extent to make up a reservation deficiency (e.g., if
4715  * ores == 1). The number of stolen blocks is returned. The availability and
4716  * subsequent accounting of stolen blocks is the responsibility of the caller.
4717  */
4718 static xfs_filblks_t
4719 xfs_bmap_split_indlen(
4720     xfs_filblks_t           ores,       /* original res. */
4721     xfs_filblks_t           *indlen1,   /* ext1 worst indlen */
4722     xfs_filblks_t           *indlen2,   /* ext2 worst indlen */
4723     xfs_filblks_t           avail)      /* stealable blocks */
4724 {
4725     xfs_filblks_t           len1 = *indlen1;
4726     xfs_filblks_t           len2 = *indlen2;
4727     xfs_filblks_t           nres = len1 + len2; /* new total res. */
4728     xfs_filblks_t           stolen = 0;
4729     xfs_filblks_t           resfactor;
4730 
4731     /*
4732      * Steal as many blocks as we can to try and satisfy the worst case
4733      * indlen for both new extents.
4734      */
4735     if (ores < nres && avail)
4736         stolen = XFS_FILBLKS_MIN(nres - ores, avail);
4737     ores += stolen;
4738 
4739      /* nothing else to do if we've satisfied the new reservation */
4740     if (ores >= nres)
4741         return stolen;
4742 
4743     /*
4744      * We can't meet the total required reservation for the two extents.
4745      * Calculate the percent of the overall shortage between both extents
4746      * and apply this percentage to each of the requested indlen values.
4747      * This distributes the shortage fairly and reduces the chances that one
4748      * of the two extents is left with nothing when extents are repeatedly
4749      * split.
4750      */
4751     resfactor = (ores * 100);
4752     do_div(resfactor, nres);
4753     len1 *= resfactor;
4754     do_div(len1, 100);
4755     len2 *= resfactor;
4756     do_div(len2, 100);
4757     ASSERT(len1 + len2 <= ores);
4758     ASSERT(len1 < *indlen1 && len2 < *indlen2);
4759 
4760     /*
4761      * Hand out the remainder to each extent. If one of the two reservations
4762      * is zero, we want to make sure that one gets a block first. The loop
4763      * below starts with len1, so hand len2 a block right off the bat if it
4764      * is zero.
4765      */
4766     ores -= (len1 + len2);
4767     ASSERT((*indlen1 - len1) + (*indlen2 - len2) >= ores);
4768     if (ores && !len2 && *indlen2) {
4769         len2++;
4770         ores--;
4771     }
4772     while (ores) {
4773         if (len1 < *indlen1) {
4774             len1++;
4775             ores--;
4776         }
4777         if (!ores)
4778             break;
4779         if (len2 < *indlen2) {
4780             len2++;
4781             ores--;
4782         }
4783     }
4784 
4785     *indlen1 = len1;
4786     *indlen2 = len2;
4787 
4788     return stolen;
4789 }
4790 
4791 int
4792 xfs_bmap_del_extent_delay(
4793     struct xfs_inode    *ip,
4794     int         whichfork,
4795     struct xfs_iext_cursor  *icur,
4796     struct xfs_bmbt_irec    *got,
4797     struct xfs_bmbt_irec    *del)
4798 {
4799     struct xfs_mount    *mp = ip->i_mount;
4800     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, whichfork);
4801     struct xfs_bmbt_irec    new;
4802     int64_t         da_old, da_new, da_diff = 0;
4803     xfs_fileoff_t       del_endoff, got_endoff;
4804     xfs_filblks_t       got_indlen, new_indlen, stolen;
4805     uint32_t        state = xfs_bmap_fork_to_state(whichfork);
4806     int         error = 0;
4807     bool            isrt;
4808 
4809     XFS_STATS_INC(mp, xs_del_exlist);
4810 
4811     isrt = (whichfork == XFS_DATA_FORK) && XFS_IS_REALTIME_INODE(ip);
4812     del_endoff = del->br_startoff + del->br_blockcount;
4813     got_endoff = got->br_startoff + got->br_blockcount;
4814     da_old = startblockval(got->br_startblock);
4815     da_new = 0;
4816 
4817     ASSERT(del->br_blockcount > 0);
4818     ASSERT(got->br_startoff <= del->br_startoff);
4819     ASSERT(got_endoff >= del_endoff);
4820 
4821     if (isrt) {
4822         uint64_t rtexts = XFS_FSB_TO_B(mp, del->br_blockcount);
4823 
4824         do_div(rtexts, mp->m_sb.sb_rextsize);
4825         xfs_mod_frextents(mp, rtexts);
4826     }
4827 
4828     /*
4829      * Update the inode delalloc counter now and wait to update the
4830      * sb counters as we might have to borrow some blocks for the
4831      * indirect block accounting.
4832      */
4833     ASSERT(!isrt);
4834     error = xfs_quota_unreserve_blkres(ip, del->br_blockcount);
4835     if (error)
4836         return error;
4837     ip->i_delayed_blks -= del->br_blockcount;
4838 
4839     if (got->br_startoff == del->br_startoff)
4840         state |= BMAP_LEFT_FILLING;
4841     if (got_endoff == del_endoff)
4842         state |= BMAP_RIGHT_FILLING;
4843 
4844     switch (state & (BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING)) {
4845     case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
4846         /*
4847          * Matches the whole extent.  Delete the entry.
4848          */
4849         xfs_iext_remove(ip, icur, state);
4850         xfs_iext_prev(ifp, icur);
4851         break;
4852     case BMAP_LEFT_FILLING:
4853         /*
4854          * Deleting the first part of the extent.
4855          */
4856         got->br_startoff = del_endoff;
4857         got->br_blockcount -= del->br_blockcount;
4858         da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip,
4859                 got->br_blockcount), da_old);
4860         got->br_startblock = nullstartblock((int)da_new);
4861         xfs_iext_update_extent(ip, state, icur, got);
4862         break;
4863     case BMAP_RIGHT_FILLING:
4864         /*
4865          * Deleting the last part of the extent.
4866          */
4867         got->br_blockcount = got->br_blockcount - del->br_blockcount;
4868         da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip,
4869                 got->br_blockcount), da_old);
4870         got->br_startblock = nullstartblock((int)da_new);
4871         xfs_iext_update_extent(ip, state, icur, got);
4872         break;
4873     case 0:
4874         /*
4875          * Deleting the middle of the extent.
4876          *
4877          * Distribute the original indlen reservation across the two new
4878          * extents.  Steal blocks from the deleted extent if necessary.
4879          * Stealing blocks simply fudges the fdblocks accounting below.
4880          * Warn if either of the new indlen reservations is zero as this
4881          * can lead to delalloc problems.
4882          */
4883         got->br_blockcount = del->br_startoff - got->br_startoff;
4884         got_indlen = xfs_bmap_worst_indlen(ip, got->br_blockcount);
4885 
4886         new.br_blockcount = got_endoff - del_endoff;
4887         new_indlen = xfs_bmap_worst_indlen(ip, new.br_blockcount);
4888 
4889         WARN_ON_ONCE(!got_indlen || !new_indlen);
4890         stolen = xfs_bmap_split_indlen(da_old, &got_indlen, &new_indlen,
4891                                del->br_blockcount);
4892 
4893         got->br_startblock = nullstartblock((int)got_indlen);
4894 
4895         new.br_startoff = del_endoff;
4896         new.br_state = got->br_state;
4897         new.br_startblock = nullstartblock((int)new_indlen);
4898 
4899         xfs_iext_update_extent(ip, state, icur, got);
4900         xfs_iext_next(ifp, icur);
4901         xfs_iext_insert(ip, icur, &new, state);
4902 
4903         da_new = got_indlen + new_indlen - stolen;
4904         del->br_blockcount -= stolen;
4905         break;
4906     }
4907 
4908     ASSERT(da_old >= da_new);
4909     da_diff = da_old - da_new;
4910     if (!isrt)
4911         da_diff += del->br_blockcount;
4912     if (da_diff) {
4913         xfs_mod_fdblocks(mp, da_diff, false);
4914         xfs_mod_delalloc(mp, -da_diff);
4915     }
4916     return error;
4917 }
4918 
4919 void
4920 xfs_bmap_del_extent_cow(
4921     struct xfs_inode    *ip,
4922     struct xfs_iext_cursor  *icur,
4923     struct xfs_bmbt_irec    *got,
4924     struct xfs_bmbt_irec    *del)
4925 {
4926     struct xfs_mount    *mp = ip->i_mount;
4927     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, XFS_COW_FORK);
4928     struct xfs_bmbt_irec    new;
4929     xfs_fileoff_t       del_endoff, got_endoff;
4930     uint32_t        state = BMAP_COWFORK;
4931 
4932     XFS_STATS_INC(mp, xs_del_exlist);
4933 
4934     del_endoff = del->br_startoff + del->br_blockcount;
4935     got_endoff = got->br_startoff + got->br_blockcount;
4936 
4937     ASSERT(del->br_blockcount > 0);
4938     ASSERT(got->br_startoff <= del->br_startoff);
4939     ASSERT(got_endoff >= del_endoff);
4940     ASSERT(!isnullstartblock(got->br_startblock));
4941 
4942     if (got->br_startoff == del->br_startoff)
4943         state |= BMAP_LEFT_FILLING;
4944     if (got_endoff == del_endoff)
4945         state |= BMAP_RIGHT_FILLING;
4946 
4947     switch (state & (BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING)) {
4948     case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
4949         /*
4950          * Matches the whole extent.  Delete the entry.
4951          */
4952         xfs_iext_remove(ip, icur, state);
4953         xfs_iext_prev(ifp, icur);
4954         break;
4955     case BMAP_LEFT_FILLING:
4956         /*
4957          * Deleting the first part of the extent.
4958          */
4959         got->br_startoff = del_endoff;
4960         got->br_blockcount -= del->br_blockcount;
4961         got->br_startblock = del->br_startblock + del->br_blockcount;
4962         xfs_iext_update_extent(ip, state, icur, got);
4963         break;
4964     case BMAP_RIGHT_FILLING:
4965         /*
4966          * Deleting the last part of the extent.
4967          */
4968         got->br_blockcount -= del->br_blockcount;
4969         xfs_iext_update_extent(ip, state, icur, got);
4970         break;
4971     case 0:
4972         /*
4973          * Deleting the middle of the extent.
4974          */
4975         got->br_blockcount = del->br_startoff - got->br_startoff;
4976 
4977         new.br_startoff = del_endoff;
4978         new.br_blockcount = got_endoff - del_endoff;
4979         new.br_state = got->br_state;
4980         new.br_startblock = del->br_startblock + del->br_blockcount;
4981 
4982         xfs_iext_update_extent(ip, state, icur, got);
4983         xfs_iext_next(ifp, icur);
4984         xfs_iext_insert(ip, icur, &new, state);
4985         break;
4986     }
4987     ip->i_delayed_blks -= del->br_blockcount;
4988 }
4989 
4990 /*
4991  * Called by xfs_bmapi to update file extent records and the btree
4992  * after removing space.
4993  */
4994 STATIC int              /* error */
4995 xfs_bmap_del_extent_real(
4996     xfs_inode_t     *ip,    /* incore inode pointer */
4997     xfs_trans_t     *tp,    /* current transaction pointer */
4998     struct xfs_iext_cursor  *icur,
4999     struct xfs_btree_cur    *cur,   /* if null, not a btree */
5000     xfs_bmbt_irec_t     *del,   /* data to remove from extents */
5001     int         *logflagsp, /* inode logging flags */
5002     int         whichfork, /* data or attr fork */
5003     uint32_t        bflags) /* bmapi flags */
5004 {
5005     xfs_fsblock_t       del_endblock=0; /* first block past del */
5006     xfs_fileoff_t       del_endoff; /* first offset past del */
5007     int         do_fx;  /* free extent at end of routine */
5008     int         error;  /* error return value */
5009     int         flags = 0;/* inode logging flags */
5010     struct xfs_bmbt_irec    got;    /* current extent entry */
5011     xfs_fileoff_t       got_endoff; /* first offset past got */
5012     int         i;  /* temp state */
5013     struct xfs_ifork    *ifp;   /* inode fork pointer */
5014     xfs_mount_t     *mp;    /* mount structure */
5015     xfs_filblks_t       nblks;  /* quota/sb block count */
5016     xfs_bmbt_irec_t     new;    /* new record to be inserted */
5017     /* REFERENCED */
5018     uint            qfield; /* quota field to update */
5019     uint32_t        state = xfs_bmap_fork_to_state(whichfork);
5020     struct xfs_bmbt_irec    old;
5021 
5022     mp = ip->i_mount;
5023     XFS_STATS_INC(mp, xs_del_exlist);
5024 
5025     ifp = xfs_ifork_ptr(ip, whichfork);
5026     ASSERT(del->br_blockcount > 0);
5027     xfs_iext_get_extent(ifp, icur, &got);
5028     ASSERT(got.br_startoff <= del->br_startoff);
5029     del_endoff = del->br_startoff + del->br_blockcount;
5030     got_endoff = got.br_startoff + got.br_blockcount;
5031     ASSERT(got_endoff >= del_endoff);
5032     ASSERT(!isnullstartblock(got.br_startblock));
5033     qfield = 0;
5034     error = 0;
5035 
5036     /*
5037      * If it's the case where the directory code is running with no block
5038      * reservation, and the deleted block is in the middle of its extent,
5039      * and the resulting insert of an extent would cause transformation to
5040      * btree format, then reject it.  The calling code will then swap blocks
5041      * around instead.  We have to do this now, rather than waiting for the
5042      * conversion to btree format, since the transaction will be dirty then.
5043      */
5044     if (tp->t_blk_res == 0 &&
5045         ifp->if_format == XFS_DINODE_FMT_EXTENTS &&
5046         ifp->if_nextents >= XFS_IFORK_MAXEXT(ip, whichfork) &&
5047         del->br_startoff > got.br_startoff && del_endoff < got_endoff)
5048         return -ENOSPC;
5049 
5050     flags = XFS_ILOG_CORE;
5051     if (whichfork == XFS_DATA_FORK && XFS_IS_REALTIME_INODE(ip)) {
5052         xfs_filblks_t   len;
5053         xfs_extlen_t    mod;
5054 
5055         len = div_u64_rem(del->br_blockcount, mp->m_sb.sb_rextsize,
5056                   &mod);
5057         ASSERT(mod == 0);
5058 
5059         if (!(bflags & XFS_BMAPI_REMAP)) {
5060             xfs_fsblock_t   bno;
5061 
5062             bno = div_u64_rem(del->br_startblock,
5063                     mp->m_sb.sb_rextsize, &mod);
5064             ASSERT(mod == 0);
5065 
5066             error = xfs_rtfree_extent(tp, bno, (xfs_extlen_t)len);
5067             if (error)
5068                 goto done;
5069         }
5070 
5071         do_fx = 0;
5072         nblks = len * mp->m_sb.sb_rextsize;
5073         qfield = XFS_TRANS_DQ_RTBCOUNT;
5074     } else {
5075         do_fx = 1;
5076         nblks = del->br_blockcount;
5077         qfield = XFS_TRANS_DQ_BCOUNT;
5078     }
5079 
5080     del_endblock = del->br_startblock + del->br_blockcount;
5081     if (cur) {
5082         error = xfs_bmbt_lookup_eq(cur, &got, &i);
5083         if (error)
5084             goto done;
5085         if (XFS_IS_CORRUPT(mp, i != 1)) {
5086             error = -EFSCORRUPTED;
5087             goto done;
5088         }
5089     }
5090 
5091     if (got.br_startoff == del->br_startoff)
5092         state |= BMAP_LEFT_FILLING;
5093     if (got_endoff == del_endoff)
5094         state |= BMAP_RIGHT_FILLING;
5095 
5096     switch (state & (BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING)) {
5097     case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
5098         /*
5099          * Matches the whole extent.  Delete the entry.
5100          */
5101         xfs_iext_remove(ip, icur, state);
5102         xfs_iext_prev(ifp, icur);
5103         ifp->if_nextents--;
5104 
5105         flags |= XFS_ILOG_CORE;
5106         if (!cur) {
5107             flags |= xfs_ilog_fext(whichfork);
5108             break;
5109         }
5110         if ((error = xfs_btree_delete(cur, &i)))
5111             goto done;
5112         if (XFS_IS_CORRUPT(mp, i != 1)) {
5113             error = -EFSCORRUPTED;
5114             goto done;
5115         }
5116         break;
5117     case BMAP_LEFT_FILLING:
5118         /*
5119          * Deleting the first part of the extent.
5120          */
5121         got.br_startoff = del_endoff;
5122         got.br_startblock = del_endblock;
5123         got.br_blockcount -= del->br_blockcount;
5124         xfs_iext_update_extent(ip, state, icur, &got);
5125         if (!cur) {
5126             flags |= xfs_ilog_fext(whichfork);
5127             break;
5128         }
5129         error = xfs_bmbt_update(cur, &got);
5130         if (error)
5131             goto done;
5132         break;
5133     case BMAP_RIGHT_FILLING:
5134         /*
5135          * Deleting the last part of the extent.
5136          */
5137         got.br_blockcount -= del->br_blockcount;
5138         xfs_iext_update_extent(ip, state, icur, &got);
5139         if (!cur) {
5140             flags |= xfs_ilog_fext(whichfork);
5141             break;
5142         }
5143         error = xfs_bmbt_update(cur, &got);
5144         if (error)
5145             goto done;
5146         break;
5147     case 0:
5148         /*
5149          * Deleting the middle of the extent.
5150          */
5151 
5152         old = got;
5153 
5154         got.br_blockcount = del->br_startoff - got.br_startoff;
5155         xfs_iext_update_extent(ip, state, icur, &got);
5156 
5157         new.br_startoff = del_endoff;
5158         new.br_blockcount = got_endoff - del_endoff;
5159         new.br_state = got.br_state;
5160         new.br_startblock = del_endblock;
5161 
5162         flags |= XFS_ILOG_CORE;
5163         if (cur) {
5164             error = xfs_bmbt_update(cur, &got);
5165             if (error)
5166                 goto done;
5167             error = xfs_btree_increment(cur, 0, &i);
5168             if (error)
5169                 goto done;
5170             cur->bc_rec.b = new;
5171             error = xfs_btree_insert(cur, &i);
5172             if (error && error != -ENOSPC)
5173                 goto done;
5174             /*
5175              * If get no-space back from btree insert, it tried a
5176              * split, and we have a zero block reservation.  Fix up
5177              * our state and return the error.
5178              */
5179             if (error == -ENOSPC) {
5180                 /*
5181                  * Reset the cursor, don't trust it after any
5182                  * insert operation.
5183                  */
5184                 error = xfs_bmbt_lookup_eq(cur, &got, &i);
5185                 if (error)
5186                     goto done;
5187                 if (XFS_IS_CORRUPT(mp, i != 1)) {
5188                     error = -EFSCORRUPTED;
5189                     goto done;
5190                 }
5191                 /*
5192                  * Update the btree record back
5193                  * to the original value.
5194                  */
5195                 error = xfs_bmbt_update(cur, &old);
5196                 if (error)
5197                     goto done;
5198                 /*
5199                  * Reset the extent record back
5200                  * to the original value.
5201                  */
5202                 xfs_iext_update_extent(ip, state, icur, &old);
5203                 flags = 0;
5204                 error = -ENOSPC;
5205                 goto done;
5206             }
5207             if (XFS_IS_CORRUPT(mp, i != 1)) {
5208                 error = -EFSCORRUPTED;
5209                 goto done;
5210             }
5211         } else
5212             flags |= xfs_ilog_fext(whichfork);
5213 
5214         ifp->if_nextents++;
5215         xfs_iext_next(ifp, icur);
5216         xfs_iext_insert(ip, icur, &new, state);
5217         break;
5218     }
5219 
5220     /* remove reverse mapping */
5221     xfs_rmap_unmap_extent(tp, ip, whichfork, del);
5222 
5223     /*
5224      * If we need to, add to list of extents to delete.
5225      */
5226     if (do_fx && !(bflags & XFS_BMAPI_REMAP)) {
5227         if (xfs_is_reflink_inode(ip) && whichfork == XFS_DATA_FORK) {
5228             xfs_refcount_decrease_extent(tp, del);
5229         } else {
5230             __xfs_free_extent_later(tp, del->br_startblock,
5231                     del->br_blockcount, NULL,
5232                     (bflags & XFS_BMAPI_NODISCARD) ||
5233                     del->br_state == XFS_EXT_UNWRITTEN);
5234         }
5235     }
5236 
5237     /*
5238      * Adjust inode # blocks in the file.
5239      */
5240     if (nblks)
5241         ip->i_nblocks -= nblks;
5242     /*
5243      * Adjust quota data.
5244      */
5245     if (qfield && !(bflags & XFS_BMAPI_REMAP))
5246         xfs_trans_mod_dquot_byino(tp, ip, qfield, (long)-nblks);
5247 
5248 done:
5249     *logflagsp = flags;
5250     return error;
5251 }
5252 
5253 /*
5254  * Unmap (remove) blocks from a file.
5255  * If nexts is nonzero then the number of extents to remove is limited to
5256  * that value.  If not all extents in the block range can be removed then
5257  * *done is set.
5258  */
5259 int                     /* error */
5260 __xfs_bunmapi(
5261     struct xfs_trans    *tp,        /* transaction pointer */
5262     struct xfs_inode    *ip,        /* incore inode */
5263     xfs_fileoff_t       start,      /* first file offset deleted */
5264     xfs_filblks_t       *rlen,      /* i/o: amount remaining */
5265     uint32_t        flags,      /* misc flags */
5266     xfs_extnum_t        nexts)      /* number of extents max */
5267 {
5268     struct xfs_btree_cur    *cur;       /* bmap btree cursor */
5269     struct xfs_bmbt_irec    del;        /* extent being deleted */
5270     int         error;      /* error return value */
5271     xfs_extnum_t        extno;      /* extent number in list */
5272     struct xfs_bmbt_irec    got;        /* current extent record */
5273     struct xfs_ifork    *ifp;       /* inode fork pointer */
5274     int         isrt;       /* freeing in rt area */
5275     int         logflags;   /* transaction logging flags */
5276     xfs_extlen_t        mod;        /* rt extent offset */
5277     struct xfs_mount    *mp = ip->i_mount;
5278     int         tmp_logflags;   /* partial logging flags */
5279     int         wasdel;     /* was a delayed alloc extent */
5280     int         whichfork;  /* data or attribute fork */
5281     xfs_fsblock_t       sum;
5282     xfs_filblks_t       len = *rlen;    /* length to unmap in file */
5283     xfs_fileoff_t       end;
5284     struct xfs_iext_cursor  icur;
5285     bool            done = false;
5286 
5287     trace_xfs_bunmap(ip, start, len, flags, _RET_IP_);
5288 
5289     whichfork = xfs_bmapi_whichfork(flags);
5290     ASSERT(whichfork != XFS_COW_FORK);
5291     ifp = xfs_ifork_ptr(ip, whichfork);
5292     if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)))
5293         return -EFSCORRUPTED;
5294     if (xfs_is_shutdown(mp))
5295         return -EIO;
5296 
5297     ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
5298     ASSERT(len > 0);
5299     ASSERT(nexts >= 0);
5300 
5301     error = xfs_iread_extents(tp, ip, whichfork);
5302     if (error)
5303         return error;
5304 
5305     if (xfs_iext_count(ifp) == 0) {
5306         *rlen = 0;
5307         return 0;
5308     }
5309     XFS_STATS_INC(mp, xs_blk_unmap);
5310     isrt = (whichfork == XFS_DATA_FORK) && XFS_IS_REALTIME_INODE(ip);
5311     end = start + len;
5312 
5313     if (!xfs_iext_lookup_extent_before(ip, ifp, &end, &icur, &got)) {
5314         *rlen = 0;
5315         return 0;
5316     }
5317     end--;
5318 
5319     logflags = 0;
5320     if (ifp->if_format == XFS_DINODE_FMT_BTREE) {
5321         ASSERT(ifp->if_format == XFS_DINODE_FMT_BTREE);
5322         cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
5323         cur->bc_ino.flags = 0;
5324     } else
5325         cur = NULL;
5326 
5327     if (isrt) {
5328         /*
5329          * Synchronize by locking the bitmap inode.
5330          */
5331         xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL|XFS_ILOCK_RTBITMAP);
5332         xfs_trans_ijoin(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
5333         xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL|XFS_ILOCK_RTSUM);
5334         xfs_trans_ijoin(tp, mp->m_rsumip, XFS_ILOCK_EXCL);
5335     }
5336 
5337     extno = 0;
5338     while (end != (xfs_fileoff_t)-1 && end >= start &&
5339            (nexts == 0 || extno < nexts)) {
5340         /*
5341          * Is the found extent after a hole in which end lives?
5342          * Just back up to the previous extent, if so.
5343          */
5344         if (got.br_startoff > end &&
5345             !xfs_iext_prev_extent(ifp, &icur, &got)) {
5346             done = true;
5347             break;
5348         }
5349         /*
5350          * Is the last block of this extent before the range
5351          * we're supposed to delete?  If so, we're done.
5352          */
5353         end = XFS_FILEOFF_MIN(end,
5354             got.br_startoff + got.br_blockcount - 1);
5355         if (end < start)
5356             break;
5357         /*
5358          * Then deal with the (possibly delayed) allocated space
5359          * we found.
5360          */
5361         del = got;
5362         wasdel = isnullstartblock(del.br_startblock);
5363 
5364         if (got.br_startoff < start) {
5365             del.br_startoff = start;
5366             del.br_blockcount -= start - got.br_startoff;
5367             if (!wasdel)
5368                 del.br_startblock += start - got.br_startoff;
5369         }
5370         if (del.br_startoff + del.br_blockcount > end + 1)
5371             del.br_blockcount = end + 1 - del.br_startoff;
5372 
5373         if (!isrt)
5374             goto delete;
5375 
5376         sum = del.br_startblock + del.br_blockcount;
5377         div_u64_rem(sum, mp->m_sb.sb_rextsize, &mod);
5378         if (mod) {
5379             /*
5380              * Realtime extent not lined up at the end.
5381              * The extent could have been split into written
5382              * and unwritten pieces, or we could just be
5383              * unmapping part of it.  But we can't really
5384              * get rid of part of a realtime extent.
5385              */
5386             if (del.br_state == XFS_EXT_UNWRITTEN) {
5387                 /*
5388                  * This piece is unwritten, or we're not
5389                  * using unwritten extents.  Skip over it.
5390                  */
5391                 ASSERT(end >= mod);
5392                 end -= mod > del.br_blockcount ?
5393                     del.br_blockcount : mod;
5394                 if (end < got.br_startoff &&
5395                     !xfs_iext_prev_extent(ifp, &icur, &got)) {
5396                     done = true;
5397                     break;
5398                 }
5399                 continue;
5400             }
5401             /*
5402              * It's written, turn it unwritten.
5403              * This is better than zeroing it.
5404              */
5405             ASSERT(del.br_state == XFS_EXT_NORM);
5406             ASSERT(tp->t_blk_res > 0);
5407             /*
5408              * If this spans a realtime extent boundary,
5409              * chop it back to the start of the one we end at.
5410              */
5411             if (del.br_blockcount > mod) {
5412                 del.br_startoff += del.br_blockcount - mod;
5413                 del.br_startblock += del.br_blockcount - mod;
5414                 del.br_blockcount = mod;
5415             }
5416             del.br_state = XFS_EXT_UNWRITTEN;
5417             error = xfs_bmap_add_extent_unwritten_real(tp, ip,
5418                     whichfork, &icur, &cur, &del,
5419                     &logflags);
5420             if (error)
5421                 goto error0;
5422             goto nodelete;
5423         }
5424         div_u64_rem(del.br_startblock, mp->m_sb.sb_rextsize, &mod);
5425         if (mod) {
5426             xfs_extlen_t off = mp->m_sb.sb_rextsize - mod;
5427 
5428             /*
5429              * Realtime extent is lined up at the end but not
5430              * at the front.  We'll get rid of full extents if
5431              * we can.
5432              */
5433             if (del.br_blockcount > off) {
5434                 del.br_blockcount -= off;
5435                 del.br_startoff += off;
5436                 del.br_startblock += off;
5437             } else if (del.br_startoff == start &&
5438                    (del.br_state == XFS_EXT_UNWRITTEN ||
5439                     tp->t_blk_res == 0)) {
5440                 /*
5441                  * Can't make it unwritten.  There isn't
5442                  * a full extent here so just skip it.
5443                  */
5444                 ASSERT(end >= del.br_blockcount);
5445                 end -= del.br_blockcount;
5446                 if (got.br_startoff > end &&
5447                     !xfs_iext_prev_extent(ifp, &icur, &got)) {
5448                     done = true;
5449                     break;
5450                 }
5451                 continue;
5452             } else if (del.br_state == XFS_EXT_UNWRITTEN) {
5453                 struct xfs_bmbt_irec    prev;
5454                 xfs_fileoff_t       unwrite_start;
5455 
5456                 /*
5457                  * This one is already unwritten.
5458                  * It must have a written left neighbor.
5459                  * Unwrite the killed part of that one and
5460                  * try again.
5461                  */
5462                 if (!xfs_iext_prev_extent(ifp, &icur, &prev))
5463                     ASSERT(0);
5464                 ASSERT(prev.br_state == XFS_EXT_NORM);
5465                 ASSERT(!isnullstartblock(prev.br_startblock));
5466                 ASSERT(del.br_startblock ==
5467                        prev.br_startblock + prev.br_blockcount);
5468                 unwrite_start = max3(start,
5469                              del.br_startoff - mod,
5470                              prev.br_startoff);
5471                 mod = unwrite_start - prev.br_startoff;
5472                 prev.br_startoff = unwrite_start;
5473                 prev.br_startblock += mod;
5474                 prev.br_blockcount -= mod;
5475                 prev.br_state = XFS_EXT_UNWRITTEN;
5476                 error = xfs_bmap_add_extent_unwritten_real(tp,
5477                         ip, whichfork, &icur, &cur,
5478                         &prev, &logflags);
5479                 if (error)
5480                     goto error0;
5481                 goto nodelete;
5482             } else {
5483                 ASSERT(del.br_state == XFS_EXT_NORM);
5484                 del.br_state = XFS_EXT_UNWRITTEN;
5485                 error = xfs_bmap_add_extent_unwritten_real(tp,
5486                         ip, whichfork, &icur, &cur,
5487                         &del, &logflags);
5488                 if (error)
5489                     goto error0;
5490                 goto nodelete;
5491             }
5492         }
5493 
5494 delete:
5495         if (wasdel) {
5496             error = xfs_bmap_del_extent_delay(ip, whichfork, &icur,
5497                     &got, &del);
5498         } else {
5499             error = xfs_bmap_del_extent_real(ip, tp, &icur, cur,
5500                     &del, &tmp_logflags, whichfork,
5501                     flags);
5502             logflags |= tmp_logflags;
5503         }
5504 
5505         if (error)
5506             goto error0;
5507 
5508         end = del.br_startoff - 1;
5509 nodelete:
5510         /*
5511          * If not done go on to the next (previous) record.
5512          */
5513         if (end != (xfs_fileoff_t)-1 && end >= start) {
5514             if (!xfs_iext_get_extent(ifp, &icur, &got) ||
5515                 (got.br_startoff > end &&
5516                  !xfs_iext_prev_extent(ifp, &icur, &got))) {
5517                 done = true;
5518                 break;
5519             }
5520             extno++;
5521         }
5522     }
5523     if (done || end == (xfs_fileoff_t)-1 || end < start)
5524         *rlen = 0;
5525     else
5526         *rlen = end - start + 1;
5527 
5528     /*
5529      * Convert to a btree if necessary.
5530      */
5531     if (xfs_bmap_needs_btree(ip, whichfork)) {
5532         ASSERT(cur == NULL);
5533         error = xfs_bmap_extents_to_btree(tp, ip, &cur, 0,
5534                 &tmp_logflags, whichfork);
5535         logflags |= tmp_logflags;
5536     } else {
5537         error = xfs_bmap_btree_to_extents(tp, ip, cur, &logflags,
5538             whichfork);
5539     }
5540 
5541 error0:
5542     /*
5543      * Log everything.  Do this after conversion, there's no point in
5544      * logging the extent records if we've converted to btree format.
5545      */
5546     if ((logflags & xfs_ilog_fext(whichfork)) &&
5547         ifp->if_format != XFS_DINODE_FMT_EXTENTS)
5548         logflags &= ~xfs_ilog_fext(whichfork);
5549     else if ((logflags & xfs_ilog_fbroot(whichfork)) &&
5550          ifp->if_format != XFS_DINODE_FMT_BTREE)
5551         logflags &= ~xfs_ilog_fbroot(whichfork);
5552     /*
5553      * Log inode even in the error case, if the transaction
5554      * is dirty we'll need to shut down the filesystem.
5555      */
5556     if (logflags)
5557         xfs_trans_log_inode(tp, ip, logflags);
5558     if (cur) {
5559         if (!error)
5560             cur->bc_ino.allocated = 0;
5561         xfs_btree_del_cursor(cur, error);
5562     }
5563     return error;
5564 }
5565 
5566 /* Unmap a range of a file. */
5567 int
5568 xfs_bunmapi(
5569     xfs_trans_t     *tp,
5570     struct xfs_inode    *ip,
5571     xfs_fileoff_t       bno,
5572     xfs_filblks_t       len,
5573     uint32_t        flags,
5574     xfs_extnum_t        nexts,
5575     int         *done)
5576 {
5577     int         error;
5578 
5579     error = __xfs_bunmapi(tp, ip, bno, &len, flags, nexts);
5580     *done = (len == 0);
5581     return error;
5582 }
5583 
5584 /*
5585  * Determine whether an extent shift can be accomplished by a merge with the
5586  * extent that precedes the target hole of the shift.
5587  */
5588 STATIC bool
5589 xfs_bmse_can_merge(
5590     struct xfs_bmbt_irec    *left,  /* preceding extent */
5591     struct xfs_bmbt_irec    *got,   /* current extent to shift */
5592     xfs_fileoff_t       shift)  /* shift fsb */
5593 {
5594     xfs_fileoff_t       startoff;
5595 
5596     startoff = got->br_startoff - shift;
5597 
5598     /*
5599      * The extent, once shifted, must be adjacent in-file and on-disk with
5600      * the preceding extent.
5601      */
5602     if ((left->br_startoff + left->br_blockcount != startoff) ||
5603         (left->br_startblock + left->br_blockcount != got->br_startblock) ||
5604         (left->br_state != got->br_state) ||
5605         (left->br_blockcount + got->br_blockcount > XFS_MAX_BMBT_EXTLEN))
5606         return false;
5607 
5608     return true;
5609 }
5610 
5611 /*
5612  * A bmap extent shift adjusts the file offset of an extent to fill a preceding
5613  * hole in the file. If an extent shift would result in the extent being fully
5614  * adjacent to the extent that currently precedes the hole, we can merge with
5615  * the preceding extent rather than do the shift.
5616  *
5617  * This function assumes the caller has verified a shift-by-merge is possible
5618  * with the provided extents via xfs_bmse_can_merge().
5619  */
5620 STATIC int
5621 xfs_bmse_merge(
5622     struct xfs_trans        *tp,
5623     struct xfs_inode        *ip,
5624     int             whichfork,
5625     xfs_fileoff_t           shift,      /* shift fsb */
5626     struct xfs_iext_cursor      *icur,
5627     struct xfs_bmbt_irec        *got,       /* extent to shift */
5628     struct xfs_bmbt_irec        *left,      /* preceding extent */
5629     struct xfs_btree_cur        *cur,
5630     int             *logflags)  /* output */
5631 {
5632     struct xfs_ifork        *ifp = xfs_ifork_ptr(ip, whichfork);
5633     struct xfs_bmbt_irec        new;
5634     xfs_filblks_t           blockcount;
5635     int             error, i;
5636     struct xfs_mount        *mp = ip->i_mount;
5637 
5638     blockcount = left->br_blockcount + got->br_blockcount;
5639 
5640     ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
5641     ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
5642     ASSERT(xfs_bmse_can_merge(left, got, shift));
5643 
5644     new = *left;
5645     new.br_blockcount = blockcount;
5646 
5647     /*
5648      * Update the on-disk extent count, the btree if necessary and log the
5649      * inode.
5650      */
5651     ifp->if_nextents--;
5652     *logflags |= XFS_ILOG_CORE;
5653     if (!cur) {
5654         *logflags |= XFS_ILOG_DEXT;
5655         goto done;
5656     }
5657 
5658     /* lookup and remove the extent to merge */
5659     error = xfs_bmbt_lookup_eq(cur, got, &i);
5660     if (error)
5661         return error;
5662     if (XFS_IS_CORRUPT(mp, i != 1))
5663         return -EFSCORRUPTED;
5664 
5665     error = xfs_btree_delete(cur, &i);
5666     if (error)
5667         return error;
5668     if (XFS_IS_CORRUPT(mp, i != 1))
5669         return -EFSCORRUPTED;
5670 
5671     /* lookup and update size of the previous extent */
5672     error = xfs_bmbt_lookup_eq(cur, left, &i);
5673     if (error)
5674         return error;
5675     if (XFS_IS_CORRUPT(mp, i != 1))
5676         return -EFSCORRUPTED;
5677 
5678     error = xfs_bmbt_update(cur, &new);
5679     if (error)
5680         return error;
5681 
5682     /* change to extent format if required after extent removal */
5683     error = xfs_bmap_btree_to_extents(tp, ip, cur, logflags, whichfork);
5684     if (error)
5685         return error;
5686 
5687 done:
5688     xfs_iext_remove(ip, icur, 0);
5689     xfs_iext_prev(ifp, icur);
5690     xfs_iext_update_extent(ip, xfs_bmap_fork_to_state(whichfork), icur,
5691             &new);
5692 
5693     /* update reverse mapping. rmap functions merge the rmaps for us */
5694     xfs_rmap_unmap_extent(tp, ip, whichfork, got);
5695     memcpy(&new, got, sizeof(new));
5696     new.br_startoff = left->br_startoff + left->br_blockcount;
5697     xfs_rmap_map_extent(tp, ip, whichfork, &new);
5698     return 0;
5699 }
5700 
5701 static int
5702 xfs_bmap_shift_update_extent(
5703     struct xfs_trans    *tp,
5704     struct xfs_inode    *ip,
5705     int         whichfork,
5706     struct xfs_iext_cursor  *icur,
5707     struct xfs_bmbt_irec    *got,
5708     struct xfs_btree_cur    *cur,
5709     int         *logflags,
5710     xfs_fileoff_t       startoff)
5711 {
5712     struct xfs_mount    *mp = ip->i_mount;
5713     struct xfs_bmbt_irec    prev = *got;
5714     int         error, i;
5715 
5716     *logflags |= XFS_ILOG_CORE;
5717 
5718     got->br_startoff = startoff;
5719 
5720     if (cur) {
5721         error = xfs_bmbt_lookup_eq(cur, &prev, &i);
5722         if (error)
5723             return error;
5724         if (XFS_IS_CORRUPT(mp, i != 1))
5725             return -EFSCORRUPTED;
5726 
5727         error = xfs_bmbt_update(cur, got);
5728         if (error)
5729             return error;
5730     } else {
5731         *logflags |= XFS_ILOG_DEXT;
5732     }
5733 
5734     xfs_iext_update_extent(ip, xfs_bmap_fork_to_state(whichfork), icur,
5735             got);
5736 
5737     /* update reverse mapping */
5738     xfs_rmap_unmap_extent(tp, ip, whichfork, &prev);
5739     xfs_rmap_map_extent(tp, ip, whichfork, got);
5740     return 0;
5741 }
5742 
5743 int
5744 xfs_bmap_collapse_extents(
5745     struct xfs_trans    *tp,
5746     struct xfs_inode    *ip,
5747     xfs_fileoff_t       *next_fsb,
5748     xfs_fileoff_t       offset_shift_fsb,
5749     bool            *done)
5750 {
5751     int         whichfork = XFS_DATA_FORK;
5752     struct xfs_mount    *mp = ip->i_mount;
5753     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, whichfork);
5754     struct xfs_btree_cur    *cur = NULL;
5755     struct xfs_bmbt_irec    got, prev;
5756     struct xfs_iext_cursor  icur;
5757     xfs_fileoff_t       new_startoff;
5758     int         error = 0;
5759     int         logflags = 0;
5760 
5761     if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
5762         XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
5763         return -EFSCORRUPTED;
5764     }
5765 
5766     if (xfs_is_shutdown(mp))
5767         return -EIO;
5768 
5769     ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL));
5770 
5771     error = xfs_iread_extents(tp, ip, whichfork);
5772     if (error)
5773         return error;
5774 
5775     if (ifp->if_format == XFS_DINODE_FMT_BTREE) {
5776         cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
5777         cur->bc_ino.flags = 0;
5778     }
5779 
5780     if (!xfs_iext_lookup_extent(ip, ifp, *next_fsb, &icur, &got)) {
5781         *done = true;
5782         goto del_cursor;
5783     }
5784     if (XFS_IS_CORRUPT(mp, isnullstartblock(got.br_startblock))) {
5785         error = -EFSCORRUPTED;
5786         goto del_cursor;
5787     }
5788 
5789     new_startoff = got.br_startoff - offset_shift_fsb;
5790     if (xfs_iext_peek_prev_extent(ifp, &icur, &prev)) {
5791         if (new_startoff < prev.br_startoff + prev.br_blockcount) {
5792             error = -EINVAL;
5793             goto del_cursor;
5794         }
5795 
5796         if (xfs_bmse_can_merge(&prev, &got, offset_shift_fsb)) {
5797             error = xfs_bmse_merge(tp, ip, whichfork,
5798                     offset_shift_fsb, &icur, &got, &prev,
5799                     cur, &logflags);
5800             if (error)
5801                 goto del_cursor;
5802             goto done;
5803         }
5804     } else {
5805         if (got.br_startoff < offset_shift_fsb) {
5806             error = -EINVAL;
5807             goto del_cursor;
5808         }
5809     }
5810 
5811     error = xfs_bmap_shift_update_extent(tp, ip, whichfork, &icur, &got,
5812             cur, &logflags, new_startoff);
5813     if (error)
5814         goto del_cursor;
5815 
5816 done:
5817     if (!xfs_iext_next_extent(ifp, &icur, &got)) {
5818         *done = true;
5819         goto del_cursor;
5820     }
5821 
5822     *next_fsb = got.br_startoff;
5823 del_cursor:
5824     if (cur)
5825         xfs_btree_del_cursor(cur, error);
5826     if (logflags)
5827         xfs_trans_log_inode(tp, ip, logflags);
5828     return error;
5829 }
5830 
5831 /* Make sure we won't be right-shifting an extent past the maximum bound. */
5832 int
5833 xfs_bmap_can_insert_extents(
5834     struct xfs_inode    *ip,
5835     xfs_fileoff_t       off,
5836     xfs_fileoff_t       shift)
5837 {
5838     struct xfs_bmbt_irec    got;
5839     int         is_empty;
5840     int         error = 0;
5841 
5842     ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
5843 
5844     if (xfs_is_shutdown(ip->i_mount))
5845         return -EIO;
5846 
5847     xfs_ilock(ip, XFS_ILOCK_EXCL);
5848     error = xfs_bmap_last_extent(NULL, ip, XFS_DATA_FORK, &got, &is_empty);
5849     if (!error && !is_empty && got.br_startoff >= off &&
5850         ((got.br_startoff + shift) & BMBT_STARTOFF_MASK) < got.br_startoff)
5851         error = -EINVAL;
5852     xfs_iunlock(ip, XFS_ILOCK_EXCL);
5853 
5854     return error;
5855 }
5856 
5857 int
5858 xfs_bmap_insert_extents(
5859     struct xfs_trans    *tp,
5860     struct xfs_inode    *ip,
5861     xfs_fileoff_t       *next_fsb,
5862     xfs_fileoff_t       offset_shift_fsb,
5863     bool            *done,
5864     xfs_fileoff_t       stop_fsb)
5865 {
5866     int         whichfork = XFS_DATA_FORK;
5867     struct xfs_mount    *mp = ip->i_mount;
5868     struct xfs_ifork    *ifp = xfs_ifork_ptr(ip, whichfork);
5869     struct xfs_btree_cur    *cur = NULL;
5870     struct xfs_bmbt_irec    got, next;
5871     struct xfs_iext_cursor  icur;
5872     xfs_fileoff_t       new_startoff;
5873     int         error = 0;
5874     int         logflags = 0;
5875 
5876     if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
5877         XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
5878         return -EFSCORRUPTED;
5879     }
5880 
5881     if (xfs_is_shutdown(mp))
5882         return -EIO;
5883 
5884     ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL));
5885 
5886     error = xfs_iread_extents(tp, ip, whichfork);
5887     if (error)
5888         return error;
5889 
5890     if (ifp->if_format == XFS_DINODE_FMT_BTREE) {
5891         cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
5892         cur->bc_ino.flags = 0;
5893     }
5894 
5895     if (*next_fsb == NULLFSBLOCK) {
5896         xfs_iext_last(ifp, &icur);
5897         if (!xfs_iext_get_extent(ifp, &icur, &got) ||
5898             stop_fsb > got.br_startoff) {
5899             *done = true;
5900             goto del_cursor;
5901         }
5902     } else {
5903         if (!xfs_iext_lookup_extent(ip, ifp, *next_fsb, &icur, &got)) {
5904             *done = true;
5905             goto del_cursor;
5906         }
5907     }
5908     if (XFS_IS_CORRUPT(mp, isnullstartblock(got.br_startblock))) {
5909         error = -EFSCORRUPTED;
5910         goto del_cursor;
5911     }
5912 
5913     if (XFS_IS_CORRUPT(mp, stop_fsb > got.br_startoff)) {
5914         error = -EFSCORRUPTED;
5915         goto del_cursor;
5916     }
5917 
5918     new_startoff = got.br_startoff + offset_shift_fsb;
5919     if (xfs_iext_peek_next_extent(ifp, &icur, &next)) {
5920         if (new_startoff + got.br_blockcount > next.br_startoff) {
5921             error = -EINVAL;
5922             goto del_cursor;
5923         }
5924 
5925         /*
5926          * Unlike a left shift (which involves a hole punch), a right
5927          * shift does not modify extent neighbors in any way.  We should
5928          * never find mergeable extents in this scenario.  Check anyways
5929          * and warn if we encounter two extents that could be one.
5930          */
5931         if (xfs_bmse_can_merge(&got, &next, offset_shift_fsb))
5932             WARN_ON_ONCE(1);
5933     }
5934 
5935     error = xfs_bmap_shift_update_extent(tp, ip, whichfork, &icur, &got,
5936             cur, &logflags, new_startoff);
5937     if (error)
5938         goto del_cursor;
5939 
5940     if (!xfs_iext_prev_extent(ifp, &icur, &got) ||
5941         stop_fsb >= got.br_startoff + got.br_blockcount) {
5942         *done = true;
5943         goto del_cursor;
5944     }
5945 
5946     *next_fsb = got.br_startoff;
5947 del_cursor:
5948     if (cur)
5949         xfs_btree_del_cursor(cur, error);
5950     if (logflags)
5951         xfs_trans_log_inode(tp, ip, logflags);
5952     return error;
5953 }
5954 
5955 /*
5956  * Splits an extent into two extents at split_fsb block such that it is the
5957  * first block of the current_ext. @ext is a target extent to be split.
5958  * @split_fsb is a block where the extents is split.  If split_fsb lies in a
5959  * hole or the first block of extents, just return 0.
5960  */
5961 int
5962 xfs_bmap_split_extent(
5963     struct xfs_trans    *tp,
5964     struct xfs_inode    *ip,
5965     xfs_fileoff_t       split_fsb)
5966 {
5967     int             whichfork = XFS_DATA_FORK;
5968     struct xfs_ifork        *ifp = xfs_ifork_ptr(ip, whichfork);
5969     struct xfs_btree_cur        *cur = NULL;
5970     struct xfs_bmbt_irec        got;
5971     struct xfs_bmbt_irec        new; /* split extent */
5972     struct xfs_mount        *mp = ip->i_mount;
5973     xfs_fsblock_t           gotblkcnt; /* new block count for got */
5974     struct xfs_iext_cursor      icur;
5975     int             error = 0;
5976     int             logflags = 0;
5977     int             i = 0;
5978 
5979     if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ifp)) ||
5980         XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
5981         return -EFSCORRUPTED;
5982     }
5983 
5984     if (xfs_is_shutdown(mp))
5985         return -EIO;
5986 
5987     /* Read in all the extents */
5988     error = xfs_iread_extents(tp, ip, whichfork);
5989     if (error)
5990         return error;
5991 
5992     /*
5993      * If there are not extents, or split_fsb lies in a hole we are done.
5994      */
5995     if (!xfs_iext_lookup_extent(ip, ifp, split_fsb, &icur, &got) ||
5996         got.br_startoff >= split_fsb)
5997         return 0;
5998 
5999     gotblkcnt = split_fsb - got.br_startoff;
6000     new.br_startoff = split_fsb;
6001     new.br_startblock = got.br_startblock + gotblkcnt;
6002     new.br_blockcount = got.br_blockcount - gotblkcnt;
6003     new.br_state = got.br_state;
6004 
6005     if (ifp->if_format == XFS_DINODE_FMT_BTREE) {
6006         cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
6007         cur->bc_ino.flags = 0;
6008         error = xfs_bmbt_lookup_eq(cur, &got, &i);
6009         if (error)
6010             goto del_cursor;
6011         if (XFS_IS_CORRUPT(mp, i != 1)) {
6012             error = -EFSCORRUPTED;
6013             goto del_cursor;
6014         }
6015     }
6016 
6017     got.br_blockcount = gotblkcnt;
6018     xfs_iext_update_extent(ip, xfs_bmap_fork_to_state(whichfork), &icur,
6019             &got);
6020 
6021     logflags = XFS_ILOG_CORE;
6022     if (cur) {
6023         error = xfs_bmbt_update(cur, &got);
6024         if (error)
6025             goto del_cursor;
6026     } else
6027         logflags |= XFS_ILOG_DEXT;
6028 
6029     /* Add new extent */
6030     xfs_iext_next(ifp, &icur);
6031     xfs_iext_insert(ip, &icur, &new, 0);
6032     ifp->if_nextents++;
6033 
6034     if (cur) {
6035         error = xfs_bmbt_lookup_eq(cur, &new, &i);
6036         if (error)
6037             goto del_cursor;
6038         if (XFS_IS_CORRUPT(mp, i != 0)) {
6039             error = -EFSCORRUPTED;
6040             goto del_cursor;
6041         }
6042         error = xfs_btree_insert(cur, &i);
6043         if (error)
6044             goto del_cursor;
6045         if (XFS_IS_CORRUPT(mp, i != 1)) {
6046             error = -EFSCORRUPTED;
6047             goto del_cursor;
6048         }
6049     }
6050 
6051     /*
6052      * Convert to a btree if necessary.
6053      */
6054     if (xfs_bmap_needs_btree(ip, whichfork)) {
6055         int tmp_logflags; /* partial log flag return val */
6056 
6057         ASSERT(cur == NULL);
6058         error = xfs_bmap_extents_to_btree(tp, ip, &cur, 0,
6059                 &tmp_logflags, whichfork);
6060         logflags |= tmp_logflags;
6061     }
6062 
6063 del_cursor:
6064     if (cur) {
6065         cur->bc_ino.allocated = 0;
6066         xfs_btree_del_cursor(cur, error);
6067     }
6068 
6069     if (logflags)
6070         xfs_trans_log_inode(tp, ip, logflags);
6071     return error;
6072 }
6073 
6074 /* Deferred mapping is only for real extents in the data fork. */
6075 static bool
6076 xfs_bmap_is_update_needed(
6077     struct xfs_bmbt_irec    *bmap)
6078 {
6079     return  bmap->br_startblock != HOLESTARTBLOCK &&
6080         bmap->br_startblock != DELAYSTARTBLOCK;
6081 }
6082 
6083 /* Record a bmap intent. */
6084 static int
6085 __xfs_bmap_add(
6086     struct xfs_trans        *tp,
6087     enum xfs_bmap_intent_type   type,
6088     struct xfs_inode        *ip,
6089     int             whichfork,
6090     struct xfs_bmbt_irec        *bmap)
6091 {
6092     struct xfs_bmap_intent      *bi;
6093 
6094     trace_xfs_bmap_defer(tp->t_mountp,
6095             XFS_FSB_TO_AGNO(tp->t_mountp, bmap->br_startblock),
6096             type,
6097             XFS_FSB_TO_AGBNO(tp->t_mountp, bmap->br_startblock),
6098             ip->i_ino, whichfork,
6099             bmap->br_startoff,
6100             bmap->br_blockcount,
6101             bmap->br_state);
6102 
6103     bi = kmem_cache_alloc(xfs_bmap_intent_cache, GFP_NOFS | __GFP_NOFAIL);
6104     INIT_LIST_HEAD(&bi->bi_list);
6105     bi->bi_type = type;
6106     bi->bi_owner = ip;
6107     bi->bi_whichfork = whichfork;
6108     bi->bi_bmap = *bmap;
6109 
6110     xfs_defer_add(tp, XFS_DEFER_OPS_TYPE_BMAP, &bi->bi_list);
6111     return 0;
6112 }
6113 
6114 /* Map an extent into a file. */
6115 void
6116 xfs_bmap_map_extent(
6117     struct xfs_trans    *tp,
6118     struct xfs_inode    *ip,
6119     struct xfs_bmbt_irec    *PREV)
6120 {
6121     if (!xfs_bmap_is_update_needed(PREV))
6122         return;
6123 
6124     __xfs_bmap_add(tp, XFS_BMAP_MAP, ip, XFS_DATA_FORK, PREV);
6125 }
6126 
6127 /* Unmap an extent out of a file. */
6128 void
6129 xfs_bmap_unmap_extent(
6130     struct xfs_trans    *tp,
6131     struct xfs_inode    *ip,
6132     struct xfs_bmbt_irec    *PREV)
6133 {
6134     if (!xfs_bmap_is_update_needed(PREV))
6135         return;
6136 
6137     __xfs_bmap_add(tp, XFS_BMAP_UNMAP, ip, XFS_DATA_FORK, PREV);
6138 }
6139 
6140 /*
6141  * Process one of the deferred bmap operations.  We pass back the
6142  * btree cursor to maintain our lock on the bmapbt between calls.
6143  */
6144 int
6145 xfs_bmap_finish_one(
6146     struct xfs_trans        *tp,
6147     struct xfs_inode        *ip,
6148     enum xfs_bmap_intent_type   type,
6149     int             whichfork,
6150     xfs_fileoff_t           startoff,
6151     xfs_fsblock_t           startblock,
6152     xfs_filblks_t           *blockcount,
6153     xfs_exntst_t            state)
6154 {
6155     int             error = 0;
6156 
6157     ASSERT(tp->t_firstblock == NULLFSBLOCK);
6158 
6159     trace_xfs_bmap_deferred(tp->t_mountp,
6160             XFS_FSB_TO_AGNO(tp->t_mountp, startblock), type,
6161             XFS_FSB_TO_AGBNO(tp->t_mountp, startblock),
6162             ip->i_ino, whichfork, startoff, *blockcount, state);
6163 
6164     if (WARN_ON_ONCE(whichfork != XFS_DATA_FORK))
6165         return -EFSCORRUPTED;
6166 
6167     if (XFS_TEST_ERROR(false, tp->t_mountp,
6168             XFS_ERRTAG_BMAP_FINISH_ONE))
6169         return -EIO;
6170 
6171     switch (type) {
6172     case XFS_BMAP_MAP:
6173         error = xfs_bmapi_remap(tp, ip, startoff, *blockcount,
6174                 startblock, 0);
6175         *blockcount = 0;
6176         break;
6177     case XFS_BMAP_UNMAP:
6178         error = __xfs_bunmapi(tp, ip, startoff, blockcount,
6179                 XFS_BMAPI_REMAP, 1);
6180         break;
6181     default:
6182         ASSERT(0);
6183         error = -EFSCORRUPTED;
6184     }
6185 
6186     return error;
6187 }
6188 
6189 /* Check that an inode's extent does not have invalid flags or bad ranges. */
6190 xfs_failaddr_t
6191 xfs_bmap_validate_extent(
6192     struct xfs_inode    *ip,
6193     int         whichfork,
6194     struct xfs_bmbt_irec    *irec)
6195 {
6196     struct xfs_mount    *mp = ip->i_mount;
6197 
6198     if (!xfs_verify_fileext(mp, irec->br_startoff, irec->br_blockcount))
6199         return __this_address;
6200 
6201     if (XFS_IS_REALTIME_INODE(ip) && whichfork == XFS_DATA_FORK) {
6202         if (!xfs_verify_rtext(mp, irec->br_startblock,
6203                       irec->br_blockcount))
6204             return __this_address;
6205     } else {
6206         if (!xfs_verify_fsbext(mp, irec->br_startblock,
6207                        irec->br_blockcount))
6208             return __this_address;
6209     }
6210     if (irec->br_state != XFS_EXT_NORM && whichfork != XFS_DATA_FORK)
6211         return __this_address;
6212     return NULL;
6213 }
6214 
6215 int __init
6216 xfs_bmap_intent_init_cache(void)
6217 {
6218     xfs_bmap_intent_cache = kmem_cache_create("xfs_bmap_intent",
6219             sizeof(struct xfs_bmap_intent),
6220             0, 0, NULL);
6221 
6222     return xfs_bmap_intent_cache != NULL ? 0 : -ENOMEM;
6223 }
6224 
6225 void
6226 xfs_bmap_intent_destroy_cache(void)
6227 {
6228     kmem_cache_destroy(xfs_bmap_intent_cache);
6229     xfs_bmap_intent_cache = NULL;
6230 }
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