OSCL-LXR linux-6.0.1/​fs/​xfs/​libxfs/​xfs_sb.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
  * All Rights Reserved.
  */
 #include "xfs.h"
 #include "xfs_fs.h"
 #include "xfs_shared.h"
 #include "xfs_format.h"
 #include "xfs_log_format.h"
 #include "xfs_trans_resv.h"
 #include "xfs_bit.h"
 #include "xfs_sb.h"
 #include "xfs_mount.h"
 #include "xfs_ialloc.h"
 #include "xfs_alloc.h"
 #include "xfs_error.h"
 #include "xfs_trans.h"
 #include "xfs_buf_item.h"
 #include "xfs_bmap_btree.h"
 #include "xfs_alloc_btree.h"
 #include "xfs_log.h"
 #include "xfs_rmap_btree.h"
 #include "xfs_refcount_btree.h"
 #include "xfs_da_format.h"
 #include "xfs_health.h"
 #include "xfs_ag.h"
 
 /*
  * Physical superblock buffer manipulations. Shared with libxfs in userspace.
  */
 
 /*
  * Check that all the V4 feature bits that the V5 filesystem format requires are
  * correctly set.
  */
 static bool
 xfs_sb_validate_v5_features(
     struct xfs_sb   *sbp)
 {
     /* We must not have any unknown V4 feature bits set */
     if (sbp->sb_versionnum & ~XFS_SB_VERSION_OKBITS)
         return false;
 
     /*
      * The CRC bit is considered an invalid V4 flag, so we have to add it
      * manually to the OKBITS mask.
      */
     if (sbp->sb_features2 & ~(XFS_SB_VERSION2_OKBITS |
                   XFS_SB_VERSION2_CRCBIT))
         return false;
 
     /* Now check all the required V4 feature flags are set. */
 
 #define V5_VERS_FLAGS   (XFS_SB_VERSION_NLINKBIT    | \
             XFS_SB_VERSION_ALIGNBIT     | \
             XFS_SB_VERSION_LOGV2BIT     | \
             XFS_SB_VERSION_EXTFLGBIT    | \
             XFS_SB_VERSION_DIRV2BIT     | \
             XFS_SB_VERSION_MOREBITSBIT)
 
 #define V5_FEAT_FLAGS   (XFS_SB_VERSION2_LAZYSBCOUNTBIT | \
             XFS_SB_VERSION2_ATTR2BIT    | \
             XFS_SB_VERSION2_PROJID32BIT | \
             XFS_SB_VERSION2_CRCBIT)
 
     if ((sbp->sb_versionnum & V5_VERS_FLAGS) != V5_VERS_FLAGS)
         return false;
     if ((sbp->sb_features2 & V5_FEAT_FLAGS) != V5_FEAT_FLAGS)
         return false;
     return true;
 }
 
 /*
  * We support all XFS versions newer than a v4 superblock with V2 directories.
  */
 bool
 xfs_sb_good_version(
     struct xfs_sb   *sbp)
 {
     /*
      * All v5 filesystems are supported, but we must check that all the
      * required v4 feature flags are enabled correctly as the code checks
      * those flags and not for v5 support.
      */
     if (xfs_sb_is_v5(sbp))
         return xfs_sb_validate_v5_features(sbp);
 
     /* We must not have any unknown v4 feature bits set */
     if ((sbp->sb_versionnum & ~XFS_SB_VERSION_OKBITS) ||
         ((sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT) &&
          (sbp->sb_features2 & ~XFS_SB_VERSION2_OKBITS)))
         return false;
 
     /* versions prior to v4 are not supported */
     if (XFS_SB_VERSION_NUM(sbp) < XFS_SB_VERSION_4)
         return false;
 
     /* V4 filesystems need v2 directories and unwritten extents */
     if (!(sbp->sb_versionnum & XFS_SB_VERSION_DIRV2BIT))
         return false;
     if (!(sbp->sb_versionnum & XFS_SB_VERSION_EXTFLGBIT))
         return false;
 
     /* It's a supported v4 filesystem */
     return true;
 }
 
 uint64_t
 xfs_sb_version_to_features(
     struct xfs_sb   *sbp)
 {
     uint64_t    features = 0;
 
     /* optional V4 features */
     if (sbp->sb_rblocks > 0)
         features |= XFS_FEAT_REALTIME;
     if (sbp->sb_versionnum & XFS_SB_VERSION_NLINKBIT)
         features |= XFS_FEAT_NLINK;
     if (sbp->sb_versionnum & XFS_SB_VERSION_ATTRBIT)
         features |= XFS_FEAT_ATTR;
     if (sbp->sb_versionnum & XFS_SB_VERSION_QUOTABIT)
         features |= XFS_FEAT_QUOTA;
     if (sbp->sb_versionnum & XFS_SB_VERSION_ALIGNBIT)
         features |= XFS_FEAT_ALIGN;
     if (sbp->sb_versionnum & XFS_SB_VERSION_LOGV2BIT)
         features |= XFS_FEAT_LOGV2;
     if (sbp->sb_versionnum & XFS_SB_VERSION_DALIGNBIT)
         features |= XFS_FEAT_DALIGN;
     if (sbp->sb_versionnum & XFS_SB_VERSION_EXTFLGBIT)
         features |= XFS_FEAT_EXTFLG;
     if (sbp->sb_versionnum & XFS_SB_VERSION_SECTORBIT)
         features |= XFS_FEAT_SECTOR;
     if (sbp->sb_versionnum & XFS_SB_VERSION_BORGBIT)
         features |= XFS_FEAT_ASCIICI;
     if (sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT) {
         if (sbp->sb_features2 & XFS_SB_VERSION2_LAZYSBCOUNTBIT)
             features |= XFS_FEAT_LAZYSBCOUNT;
         if (sbp->sb_features2 & XFS_SB_VERSION2_ATTR2BIT)
             features |= XFS_FEAT_ATTR2;
         if (sbp->sb_features2 & XFS_SB_VERSION2_PROJID32BIT)
             features |= XFS_FEAT_PROJID32;
         if (sbp->sb_features2 & XFS_SB_VERSION2_FTYPE)
             features |= XFS_FEAT_FTYPE;
     }
 
     if (!xfs_sb_is_v5(sbp))
         return features;
 
     /* Always on V5 features */
     features |= XFS_FEAT_ALIGN | XFS_FEAT_LOGV2 | XFS_FEAT_EXTFLG |
             XFS_FEAT_LAZYSBCOUNT | XFS_FEAT_ATTR2 | XFS_FEAT_PROJID32 |
             XFS_FEAT_V3INODES | XFS_FEAT_CRC | XFS_FEAT_PQUOTINO;
 
     /* Optional V5 features */
     if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_FINOBT)
         features |= XFS_FEAT_FINOBT;
     if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_RMAPBT)
         features |= XFS_FEAT_RMAPBT;
     if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_REFLINK)
         features |= XFS_FEAT_REFLINK;
     if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_INOBTCNT)
         features |= XFS_FEAT_INOBTCNT;
     if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_FTYPE)
         features |= XFS_FEAT_FTYPE;
     if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_SPINODES)
         features |= XFS_FEAT_SPINODES;
     if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID)
         features |= XFS_FEAT_META_UUID;
     if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_BIGTIME)
         features |= XFS_FEAT_BIGTIME;
     if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR)
         features |= XFS_FEAT_NEEDSREPAIR;
     if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NREXT64)
         features |= XFS_FEAT_NREXT64;
 
     return features;
 }
 
 /* Check all the superblock fields we care about when reading one in. */
 STATIC int
 xfs_validate_sb_read(
     struct xfs_mount    *mp,
     struct xfs_sb       *sbp)
 {
     if (!xfs_sb_is_v5(sbp))
         return 0;
 
     /*
      * Version 5 superblock feature mask validation. Reject combinations
      * the kernel cannot support up front before checking anything else.
      */
     if (xfs_sb_has_compat_feature(sbp, XFS_SB_FEAT_COMPAT_UNKNOWN)) {
         xfs_warn(mp,
 "Superblock has unknown compatible features (0x%x) enabled.",
             (sbp->sb_features_compat & XFS_SB_FEAT_COMPAT_UNKNOWN));
         xfs_warn(mp,
 "Using a more recent kernel is recommended.");
     }
 
     if (xfs_sb_has_ro_compat_feature(sbp, XFS_SB_FEAT_RO_COMPAT_UNKNOWN)) {
         xfs_alert(mp,
 "Superblock has unknown read-only compatible features (0x%x) enabled.",
             (sbp->sb_features_ro_compat &
                     XFS_SB_FEAT_RO_COMPAT_UNKNOWN));
         if (!xfs_is_readonly(mp)) {
             xfs_warn(mp,
 "Attempted to mount read-only compatible filesystem read-write.");
             xfs_warn(mp,
 "Filesystem can only be safely mounted read only.");
 
             return -EINVAL;
         }
     }
     if (xfs_sb_has_incompat_feature(sbp, XFS_SB_FEAT_INCOMPAT_UNKNOWN)) {
         xfs_warn(mp,
 "Superblock has unknown incompatible features (0x%x) enabled.",
             (sbp->sb_features_incompat &
                     XFS_SB_FEAT_INCOMPAT_UNKNOWN));
         xfs_warn(mp,
 "Filesystem cannot be safely mounted by this kernel.");
         return -EINVAL;
     }
 
     return 0;
 }
 
 /* Check all the superblock fields we care about when writing one out. */
 STATIC int
 xfs_validate_sb_write(
     struct xfs_mount    *mp,
     struct xfs_buf      *bp,
     struct xfs_sb       *sbp)
 {
     /*
      * Carry out additional sb summary counter sanity checks when we write
      * the superblock.  We skip this in the read validator because there
      * could be newer superblocks in the log and if the values are garbage
      * even after replay we'll recalculate them at the end of log mount.
      *
      * mkfs has traditionally written zeroed counters to inprogress and
      * secondary superblocks, so allow this usage to continue because
      * we never read counters from such superblocks.
      */
     if (xfs_buf_daddr(bp) == XFS_SB_DADDR && !sbp->sb_inprogress &&
         (sbp->sb_fdblocks > sbp->sb_dblocks ||
          !xfs_verify_icount(mp, sbp->sb_icount) ||
          sbp->sb_ifree > sbp->sb_icount)) {
         xfs_warn(mp, "SB summary counter sanity check failed");
         return -EFSCORRUPTED;
     }
 
     if (!xfs_sb_is_v5(sbp))
         return 0;
 
     /*
      * Version 5 superblock feature mask validation. Reject combinations
      * the kernel cannot support since we checked for unsupported bits in
      * the read verifier, which means that memory is corrupt.
      */
     if (xfs_sb_has_compat_feature(sbp, XFS_SB_FEAT_COMPAT_UNKNOWN)) {
         xfs_warn(mp,
 "Corruption detected in superblock compatible features (0x%x)!",
             (sbp->sb_features_compat & XFS_SB_FEAT_COMPAT_UNKNOWN));
         return -EFSCORRUPTED;
     }
 
     if (xfs_sb_has_ro_compat_feature(sbp, XFS_SB_FEAT_RO_COMPAT_UNKNOWN)) {
         xfs_alert(mp,
 "Corruption detected in superblock read-only compatible features (0x%x)!",
             (sbp->sb_features_ro_compat &
                     XFS_SB_FEAT_RO_COMPAT_UNKNOWN));
         return -EFSCORRUPTED;
     }
     if (xfs_sb_has_incompat_feature(sbp, XFS_SB_FEAT_INCOMPAT_UNKNOWN)) {
         xfs_warn(mp,
 "Corruption detected in superblock incompatible features (0x%x)!",
             (sbp->sb_features_incompat &
                     XFS_SB_FEAT_INCOMPAT_UNKNOWN));
         return -EFSCORRUPTED;
     }
     if (xfs_sb_has_incompat_log_feature(sbp,
             XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN)) {
         xfs_warn(mp,
 "Corruption detected in superblock incompatible log features (0x%x)!",
             (sbp->sb_features_log_incompat &
                     XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN));
         return -EFSCORRUPTED;
     }
 
     /*
      * We can't read verify the sb LSN because the read verifier is called
      * before the log is allocated and processed. We know the log is set up
      * before write verifier calls, so check it here.
      */
     if (!xfs_log_check_lsn(mp, sbp->sb_lsn))
         return -EFSCORRUPTED;
 
     return 0;
 }
 
 /* Check the validity of the SB. */
 STATIC int
 xfs_validate_sb_common(
     struct xfs_mount    *mp,
     struct xfs_buf      *bp,
     struct xfs_sb       *sbp)
 {
     struct xfs_dsb      *dsb = bp->b_addr;
     uint32_t        agcount = 0;
     uint32_t        rem;
     bool            has_dalign;
 
     if (!xfs_verify_magic(bp, dsb->sb_magicnum)) {
         xfs_warn(mp,
 "Superblock has bad magic number 0x%x. Not an XFS filesystem?",
             be32_to_cpu(dsb->sb_magicnum));
         return -EWRONGFS;
     }
 
     if (!xfs_sb_good_version(sbp)) {
         xfs_warn(mp,
 "Superblock has unknown features enabled or corrupted feature masks.");
         return -EWRONGFS;
     }
 
     /*
      * Validate feature flags and state
      */
     if (xfs_sb_is_v5(sbp)) {
         if (sbp->sb_blocksize < XFS_MIN_CRC_BLOCKSIZE) {
             xfs_notice(mp,
 "Block size (%u bytes) too small for Version 5 superblock (minimum %d bytes)",
                 sbp->sb_blocksize, XFS_MIN_CRC_BLOCKSIZE);
             return -EFSCORRUPTED;
         }
 
         /* V5 has a separate project quota inode */
         if (sbp->sb_qflags & (XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD)) {
             xfs_notice(mp,
                "Version 5 of Super block has XFS_OQUOTA bits.");
             return -EFSCORRUPTED;
         }
 
         /*
          * Full inode chunks must be aligned to inode chunk size when
          * sparse inodes are enabled to support the sparse chunk
          * allocation algorithm and prevent overlapping inode records.
          */
         if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_SPINODES) {
             uint32_t    align;
 
             align = XFS_INODES_PER_CHUNK * sbp->sb_inodesize
                     >> sbp->sb_blocklog;
             if (sbp->sb_inoalignmt != align) {
                 xfs_warn(mp,
 "Inode block alignment (%u) must match chunk size (%u) for sparse inodes.",
                      sbp->sb_inoalignmt, align);
                 return -EINVAL;
             }
         }
     } else if (sbp->sb_qflags & (XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD |
                 XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD)) {
             xfs_notice(mp,
 "Superblock earlier than Version 5 has XFS_{P|G}QUOTA_{ENFD|CHKD} bits.");
             return -EFSCORRUPTED;
     }
 
     if (unlikely(
         sbp->sb_logstart == 0 && mp->m_logdev_targp == mp->m_ddev_targp)) {
         xfs_warn(mp,
         "filesystem is marked as having an external log; "
         "specify logdev on the mount command line.");
         return -EINVAL;
     }
 
     if (unlikely(
         sbp->sb_logstart != 0 && mp->m_logdev_targp != mp->m_ddev_targp)) {
         xfs_warn(mp,
         "filesystem is marked as having an internal log; "
         "do not specify logdev on the mount command line.");
         return -EINVAL;
     }
 
     /* Compute agcount for this number of dblocks and agblocks */
     if (sbp->sb_agblocks) {
         agcount = div_u64_rem(sbp->sb_dblocks, sbp->sb_agblocks, &rem);
         if (rem)
             agcount++;
     }
 
     /*
      * More sanity checking.  Most of these were stolen directly from
      * xfs_repair.
      */
     if (unlikely(
         sbp->sb_agcount <= 0                    ||
         sbp->sb_sectsize < XFS_MIN_SECTORSIZE           ||
         sbp->sb_sectsize > XFS_MAX_SECTORSIZE           ||
         sbp->sb_sectlog < XFS_MIN_SECTORSIZE_LOG            ||
         sbp->sb_sectlog > XFS_MAX_SECTORSIZE_LOG            ||
         sbp->sb_sectsize != (1 << sbp->sb_sectlog)          ||
         sbp->sb_blocksize < XFS_MIN_BLOCKSIZE           ||
         sbp->sb_blocksize > XFS_MAX_BLOCKSIZE           ||
         sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG            ||
         sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG            ||
         sbp->sb_blocksize != (1 << sbp->sb_blocklog)        ||
         sbp->sb_dirblklog + sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG ||
         sbp->sb_inodesize < XFS_DINODE_MIN_SIZE         ||
         sbp->sb_inodesize > XFS_DINODE_MAX_SIZE         ||
         sbp->sb_inodelog < XFS_DINODE_MIN_LOG           ||
         sbp->sb_inodelog > XFS_DINODE_MAX_LOG           ||
         sbp->sb_inodesize != (1 << sbp->sb_inodelog)        ||
         sbp->sb_logsunit > XLOG_MAX_RECORD_BSIZE            ||
         sbp->sb_inopblock != howmany(sbp->sb_blocksize,sbp->sb_inodesize) ||
         XFS_FSB_TO_B(mp, sbp->sb_agblocks) < XFS_MIN_AG_BYTES   ||
         XFS_FSB_TO_B(mp, sbp->sb_agblocks) > XFS_MAX_AG_BYTES   ||
         sbp->sb_agblklog != xfs_highbit32(sbp->sb_agblocks - 1) + 1 ||
         agcount == 0 || agcount != sbp->sb_agcount          ||
         (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog)   ||
         (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE)  ||
         (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE)  ||
         (sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */)    ||
         sbp->sb_dblocks == 0                    ||
         sbp->sb_dblocks > XFS_MAX_DBLOCKS(sbp)          ||
         sbp->sb_dblocks < XFS_MIN_DBLOCKS(sbp)          ||
         sbp->sb_shared_vn != 0)) {
         xfs_notice(mp, "SB sanity check failed");
         return -EFSCORRUPTED;
     }
 
     /* Validate the realtime geometry; stolen from xfs_repair */
     if (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE ||
         sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE) {
         xfs_notice(mp,
             "realtime extent sanity check failed");
         return -EFSCORRUPTED;
     }
 
     if (sbp->sb_rblocks == 0) {
         if (sbp->sb_rextents != 0 || sbp->sb_rbmblocks != 0 ||
             sbp->sb_rextslog != 0 || sbp->sb_frextents != 0) {
             xfs_notice(mp,
                 "realtime zeroed geometry check failed");
             return -EFSCORRUPTED;
         }
     } else {
         uint64_t    rexts;
         uint64_t    rbmblocks;
 
         rexts = div_u64(sbp->sb_rblocks, sbp->sb_rextsize);
         rbmblocks = howmany_64(sbp->sb_rextents,
                        NBBY * sbp->sb_blocksize);
 
         if (sbp->sb_rextents != rexts ||
             sbp->sb_rextslog != xfs_highbit32(sbp->sb_rextents) ||
             sbp->sb_rbmblocks != rbmblocks) {
             xfs_notice(mp,
                 "realtime geometry sanity check failed");
             return -EFSCORRUPTED;
         }
     }
 
     /*
      * Either (sb_unit and !hasdalign) or (!sb_unit and hasdalign)
      * would imply the image is corrupted.
      */
     has_dalign = sbp->sb_versionnum & XFS_SB_VERSION_DALIGNBIT;
     if (!!sbp->sb_unit ^ has_dalign) {
         xfs_notice(mp, "SB stripe alignment sanity check failed");
         return -EFSCORRUPTED;
     }
 
     if (!xfs_validate_stripe_geometry(mp, XFS_FSB_TO_B(mp, sbp->sb_unit),
             XFS_FSB_TO_B(mp, sbp->sb_width), 0, false))
         return -EFSCORRUPTED;
 
     /*
      * Currently only very few inode sizes are supported.
      */
     switch (sbp->sb_inodesize) {
     case 256:
     case 512:
     case 1024:
     case 2048:
         break;
     default:
         xfs_warn(mp, "inode size of %d bytes not supported",
                 sbp->sb_inodesize);
         return -ENOSYS;
     }
 
     return 0;
 }
 
 void
 xfs_sb_quota_from_disk(struct xfs_sb *sbp)
 {
     /*
      * older mkfs doesn't initialize quota inodes to NULLFSINO. This
      * leads to in-core values having two different values for a quota
      * inode to be invalid: 0 and NULLFSINO. Change it to a single value
      * NULLFSINO.
      *
      * Note that this change affect only the in-core values. These
      * values are not written back to disk unless any quota information
      * is written to the disk. Even in that case, sb_pquotino field is
      * not written to disk unless the superblock supports pquotino.
      */
     if (sbp->sb_uquotino == 0)
         sbp->sb_uquotino = NULLFSINO;
     if (sbp->sb_gquotino == 0)
         sbp->sb_gquotino = NULLFSINO;
     if (sbp->sb_pquotino == 0)
         sbp->sb_pquotino = NULLFSINO;
 
     /*
      * We need to do these manipilations only if we are working
      * with an older version of on-disk superblock.
      */
     if (xfs_sb_is_v5(sbp))
         return;
 
     if (sbp->sb_qflags & XFS_OQUOTA_ENFD)
         sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
                     XFS_PQUOTA_ENFD : XFS_GQUOTA_ENFD;
     if (sbp->sb_qflags & XFS_OQUOTA_CHKD)
         sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
                     XFS_PQUOTA_CHKD : XFS_GQUOTA_CHKD;
     sbp->sb_qflags &= ~(XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD);
 
     if (sbp->sb_qflags & XFS_PQUOTA_ACCT &&
         sbp->sb_gquotino != NULLFSINO)  {
         /*
          * In older version of superblock, on-disk superblock only
          * has sb_gquotino, and in-core superblock has both sb_gquotino
          * and sb_pquotino. But, only one of them is supported at any
          * point of time. So, if PQUOTA is set in disk superblock,
          * copy over sb_gquotino to sb_pquotino.  The NULLFSINO test
          * above is to make sure we don't do this twice and wipe them
          * both out!
          */
         sbp->sb_pquotino = sbp->sb_gquotino;
         sbp->sb_gquotino = NULLFSINO;
     }
 }
 
 static void
 __xfs_sb_from_disk(
     struct xfs_sb   *to,
     struct xfs_dsb  *from,
     bool        convert_xquota)
 {
     to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
     to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
     to->sb_dblocks = be64_to_cpu(from->sb_dblocks);
     to->sb_rblocks = be64_to_cpu(from->sb_rblocks);
     to->sb_rextents = be64_to_cpu(from->sb_rextents);
     memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
     to->sb_logstart = be64_to_cpu(from->sb_logstart);
     to->sb_rootino = be64_to_cpu(from->sb_rootino);
     to->sb_rbmino = be64_to_cpu(from->sb_rbmino);
     to->sb_rsumino = be64_to_cpu(from->sb_rsumino);
     to->sb_rextsize = be32_to_cpu(from->sb_rextsize);
     to->sb_agblocks = be32_to_cpu(from->sb_agblocks);
     to->sb_agcount = be32_to_cpu(from->sb_agcount);
     to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks);
     to->sb_logblocks = be32_to_cpu(from->sb_logblocks);
     to->sb_versionnum = be16_to_cpu(from->sb_versionnum);
     to->sb_sectsize = be16_to_cpu(from->sb_sectsize);
     to->sb_inodesize = be16_to_cpu(from->sb_inodesize);
     to->sb_inopblock = be16_to_cpu(from->sb_inopblock);
     memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
     to->sb_blocklog = from->sb_blocklog;
     to->sb_sectlog = from->sb_sectlog;
     to->sb_inodelog = from->sb_inodelog;
     to->sb_inopblog = from->sb_inopblog;
     to->sb_agblklog = from->sb_agblklog;
     to->sb_rextslog = from->sb_rextslog;
     to->sb_inprogress = from->sb_inprogress;
     to->sb_imax_pct = from->sb_imax_pct;
     to->sb_icount = be64_to_cpu(from->sb_icount);
     to->sb_ifree = be64_to_cpu(from->sb_ifree);
     to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks);
     to->sb_frextents = be64_to_cpu(from->sb_frextents);
     to->sb_uquotino = be64_to_cpu(from->sb_uquotino);
     to->sb_gquotino = be64_to_cpu(from->sb_gquotino);
     to->sb_qflags = be16_to_cpu(from->sb_qflags);
     to->sb_flags = from->sb_flags;
     to->sb_shared_vn = from->sb_shared_vn;
     to->sb_inoalignmt = be32_to_cpu(from->sb_inoalignmt);
     to->sb_unit = be32_to_cpu(from->sb_unit);
     to->sb_width = be32_to_cpu(from->sb_width);
     to->sb_dirblklog = from->sb_dirblklog;
     to->sb_logsectlog = from->sb_logsectlog;
     to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize);
     to->sb_logsunit = be32_to_cpu(from->sb_logsunit);
     to->sb_features2 = be32_to_cpu(from->sb_features2);
     to->sb_bad_features2 = be32_to_cpu(from->sb_bad_features2);
     to->sb_features_compat = be32_to_cpu(from->sb_features_compat);
     to->sb_features_ro_compat = be32_to_cpu(from->sb_features_ro_compat);
     to->sb_features_incompat = be32_to_cpu(from->sb_features_incompat);
     to->sb_features_log_incompat =
                 be32_to_cpu(from->sb_features_log_incompat);
     /* crc is only used on disk, not in memory; just init to 0 here. */
     to->sb_crc = 0;
     to->sb_spino_align = be32_to_cpu(from->sb_spino_align);
     to->sb_pquotino = be64_to_cpu(from->sb_pquotino);
     to->sb_lsn = be64_to_cpu(from->sb_lsn);
     /*
      * sb_meta_uuid is only on disk if it differs from sb_uuid and the
      * feature flag is set; if not set we keep it only in memory.
      */
     if (xfs_sb_is_v5(to) &&
         (to->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID))
         uuid_copy(&to->sb_meta_uuid, &from->sb_meta_uuid);
     else
         uuid_copy(&to->sb_meta_uuid, &from->sb_uuid);
     /* Convert on-disk flags to in-memory flags? */
     if (convert_xquota)
         xfs_sb_quota_from_disk(to);
 }
 
 void
 xfs_sb_from_disk(
     struct xfs_sb   *to,
     struct xfs_dsb  *from)
 {
     __xfs_sb_from_disk(to, from, true);
 }
 
 static void
 xfs_sb_quota_to_disk(
     struct xfs_dsb  *to,
     struct xfs_sb   *from)
 {
     uint16_t    qflags = from->sb_qflags;
 
     to->sb_uquotino = cpu_to_be64(from->sb_uquotino);
 
     /*
      * The in-memory superblock quota state matches the v5 on-disk format so
      * just write them out and return
      */
     if (xfs_sb_is_v5(from)) {
         to->sb_qflags = cpu_to_be16(from->sb_qflags);
         to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
         to->sb_pquotino = cpu_to_be64(from->sb_pquotino);
         return;
     }
 
     /*
      * For older superblocks (v4), the in-core version of sb_qflags do not
      * have XFS_OQUOTA_* flags, whereas the on-disk version does.  So,
      * convert incore XFS_{PG}QUOTA_* flags to on-disk XFS_OQUOTA_* flags.
      */
     qflags &= ~(XFS_PQUOTA_ENFD | XFS_PQUOTA_CHKD |
             XFS_GQUOTA_ENFD | XFS_GQUOTA_CHKD);
 
     if (from->sb_qflags &
             (XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD))
         qflags |= XFS_OQUOTA_ENFD;
     if (from->sb_qflags &
             (XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD))
         qflags |= XFS_OQUOTA_CHKD;
     to->sb_qflags = cpu_to_be16(qflags);
 
     /*
      * GQUOTINO and PQUOTINO cannot be used together in versions
      * of superblock that do not have pquotino. from->sb_flags
      * tells us which quota is active and should be copied to
      * disk. If neither are active, we should NULL the inode.
      *
      * In all cases, the separate pquotino must remain 0 because it
      * is beyond the "end" of the valid non-pquotino superblock.
      */
     if (from->sb_qflags & XFS_GQUOTA_ACCT)
         to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
     else if (from->sb_qflags & XFS_PQUOTA_ACCT)
         to->sb_gquotino = cpu_to_be64(from->sb_pquotino);
     else {
         /*
          * We can't rely on just the fields being logged to tell us
          * that it is safe to write NULLFSINO - we should only do that
          * if quotas are not actually enabled. Hence only write
          * NULLFSINO if both in-core quota inodes are NULL.
          */
         if (from->sb_gquotino == NULLFSINO &&
             from->sb_pquotino == NULLFSINO)
             to->sb_gquotino = cpu_to_be64(NULLFSINO);
     }
 
     to->sb_pquotino = 0;
 }
 
 void
 xfs_sb_to_disk(
     struct xfs_dsb  *to,
     struct xfs_sb   *from)
 {
     xfs_sb_quota_to_disk(to, from);
 
     to->sb_magicnum = cpu_to_be32(from->sb_magicnum);
     to->sb_blocksize = cpu_to_be32(from->sb_blocksize);
     to->sb_dblocks = cpu_to_be64(from->sb_dblocks);
     to->sb_rblocks = cpu_to_be64(from->sb_rblocks);
     to->sb_rextents = cpu_to_be64(from->sb_rextents);
     memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
     to->sb_logstart = cpu_to_be64(from->sb_logstart);
     to->sb_rootino = cpu_to_be64(from->sb_rootino);
     to->sb_rbmino = cpu_to_be64(from->sb_rbmino);
     to->sb_rsumino = cpu_to_be64(from->sb_rsumino);
     to->sb_rextsize = cpu_to_be32(from->sb_rextsize);
     to->sb_agblocks = cpu_to_be32(from->sb_agblocks);
     to->sb_agcount = cpu_to_be32(from->sb_agcount);
     to->sb_rbmblocks = cpu_to_be32(from->sb_rbmblocks);
     to->sb_logblocks = cpu_to_be32(from->sb_logblocks);
     to->sb_versionnum = cpu_to_be16(from->sb_versionnum);
     to->sb_sectsize = cpu_to_be16(from->sb_sectsize);
     to->sb_inodesize = cpu_to_be16(from->sb_inodesize);
     to->sb_inopblock = cpu_to_be16(from->sb_inopblock);
     memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
     to->sb_blocklog = from->sb_blocklog;
     to->sb_sectlog = from->sb_sectlog;
     to->sb_inodelog = from->sb_inodelog;
     to->sb_inopblog = from->sb_inopblog;
     to->sb_agblklog = from->sb_agblklog;
     to->sb_rextslog = from->sb_rextslog;
     to->sb_inprogress = from->sb_inprogress;
     to->sb_imax_pct = from->sb_imax_pct;
     to->sb_icount = cpu_to_be64(from->sb_icount);
     to->sb_ifree = cpu_to_be64(from->sb_ifree);
     to->sb_fdblocks = cpu_to_be64(from->sb_fdblocks);
     to->sb_frextents = cpu_to_be64(from->sb_frextents);
 
     to->sb_flags = from->sb_flags;
     to->sb_shared_vn = from->sb_shared_vn;
     to->sb_inoalignmt = cpu_to_be32(from->sb_inoalignmt);
     to->sb_unit = cpu_to_be32(from->sb_unit);
     to->sb_width = cpu_to_be32(from->sb_width);
     to->sb_dirblklog = from->sb_dirblklog;
     to->sb_logsectlog = from->sb_logsectlog;
     to->sb_logsectsize = cpu_to_be16(from->sb_logsectsize);
     to->sb_logsunit = cpu_to_be32(from->sb_logsunit);
 
     /*
      * We need to ensure that bad_features2 always matches features2.
      * Hence we enforce that here rather than having to remember to do it
      * everywhere else that updates features2.
      */
     from->sb_bad_features2 = from->sb_features2;
     to->sb_features2 = cpu_to_be32(from->sb_features2);
     to->sb_bad_features2 = cpu_to_be32(from->sb_bad_features2);
 
     if (!xfs_sb_is_v5(from))
         return;
 
     to->sb_features_compat = cpu_to_be32(from->sb_features_compat);
     to->sb_features_ro_compat =
             cpu_to_be32(from->sb_features_ro_compat);
     to->sb_features_incompat =
             cpu_to_be32(from->sb_features_incompat);
     to->sb_features_log_incompat =
             cpu_to_be32(from->sb_features_log_incompat);
     to->sb_spino_align = cpu_to_be32(from->sb_spino_align);
     to->sb_lsn = cpu_to_be64(from->sb_lsn);
     if (from->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID)
         uuid_copy(&to->sb_meta_uuid, &from->sb_meta_uuid);
 }
 
 /*
  * If the superblock has the CRC feature bit set or the CRC field is non-null,
  * check that the CRC is valid.  We check the CRC field is non-null because a
  * single bit error could clear the feature bit and unused parts of the
  * superblock are supposed to be zero. Hence a non-null crc field indicates that
  * we've potentially lost a feature bit and we should check it anyway.
  *
  * However, past bugs (i.e. in growfs) left non-zeroed regions beyond the
  * last field in V4 secondary superblocks.  So for secondary superblocks,
  * we are more forgiving, and ignore CRC failures if the primary doesn't
  * indicate that the fs version is V5.
  */
 static void
 xfs_sb_read_verify(
     struct xfs_buf      *bp)
 {
     struct xfs_sb       sb;
     struct xfs_mount    *mp = bp->b_mount;
     struct xfs_dsb      *dsb = bp->b_addr;
     int         error;
 
     /*
      * open code the version check to avoid needing to convert the entire
      * superblock from disk order just to check the version number
      */
     if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC) &&
         (((be16_to_cpu(dsb->sb_versionnum) & XFS_SB_VERSION_NUMBITS) ==
                         XFS_SB_VERSION_5) ||
          dsb->sb_crc != 0)) {
 
         if (!xfs_buf_verify_cksum(bp, XFS_SB_CRC_OFF)) {
             /* Only fail bad secondaries on a known V5 filesystem */
             if (xfs_buf_daddr(bp) == XFS_SB_DADDR ||
                 xfs_has_crc(mp)) {
                 error = -EFSBADCRC;
                 goto out_error;
             }
         }
     }
 
     /*
      * Check all the superblock fields.  Don't byteswap the xquota flags
      * because _verify_common checks the on-disk values.
      */
     __xfs_sb_from_disk(&sb, dsb, false);
     error = xfs_validate_sb_common(mp, bp, &sb);
     if (error)
         goto out_error;
     error = xfs_validate_sb_read(mp, &sb);
 
 out_error:
     if (error == -EFSCORRUPTED || error == -EFSBADCRC)
         xfs_verifier_error(bp, error, __this_address);
     else if (error)
         xfs_buf_ioerror(bp, error);
 }
 
 /*
  * We may be probed for a filesystem match, so we may not want to emit
  * messages when the superblock buffer is not actually an XFS superblock.
  * If we find an XFS superblock, then run a normal, noisy mount because we are
  * really going to mount it and want to know about errors.
  */
 static void
 xfs_sb_quiet_read_verify(
     struct xfs_buf  *bp)
 {
     struct xfs_dsb  *dsb = bp->b_addr;
 
     if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC)) {
         /* XFS filesystem, verify noisily! */
         xfs_sb_read_verify(bp);
         return;
     }
     /* quietly fail */
     xfs_buf_ioerror(bp, -EWRONGFS);
 }
 
 static void
 xfs_sb_write_verify(
     struct xfs_buf      *bp)
 {
     struct xfs_sb       sb;
     struct xfs_mount    *mp = bp->b_mount;
     struct xfs_buf_log_item *bip = bp->b_log_item;
     struct xfs_dsb      *dsb = bp->b_addr;
     int         error;
 
     /*
      * Check all the superblock fields.  Don't byteswap the xquota flags
      * because _verify_common checks the on-disk values.
      */
     __xfs_sb_from_disk(&sb, dsb, false);
     error = xfs_validate_sb_common(mp, bp, &sb);
     if (error)
         goto out_error;
     error = xfs_validate_sb_write(mp, bp, &sb);
     if (error)
         goto out_error;
 
     if (!xfs_sb_is_v5(&sb))
         return;
 
     if (bip)
         dsb->sb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
 
     xfs_buf_update_cksum(bp, XFS_SB_CRC_OFF);
     return;
 
 out_error:
     xfs_verifier_error(bp, error, __this_address);
 }
 
 const struct xfs_buf_ops xfs_sb_buf_ops = {
     .name = "xfs_sb",
     .magic = { cpu_to_be32(XFS_SB_MAGIC), cpu_to_be32(XFS_SB_MAGIC) },
     .verify_read = xfs_sb_read_verify,
     .verify_write = xfs_sb_write_verify,
 };
 
 const struct xfs_buf_ops xfs_sb_quiet_buf_ops = {
     .name = "xfs_sb_quiet",
     .magic = { cpu_to_be32(XFS_SB_MAGIC), cpu_to_be32(XFS_SB_MAGIC) },
     .verify_read = xfs_sb_quiet_read_verify,
     .verify_write = xfs_sb_write_verify,
 };
 
 /*
  * xfs_mount_common
  *
  * Mount initialization code establishing various mount
  * fields from the superblock associated with the given
  * mount structure.
  *
  * Inode geometry are calculated in xfs_ialloc_setup_geometry.
  */
 void
 xfs_sb_mount_common(
     struct xfs_mount    *mp,
     struct xfs_sb       *sbp)
 {
     mp->m_agfrotor = mp->m_agirotor = 0;
     mp->m_maxagi = mp->m_sb.sb_agcount;
     mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG;
     mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT;
     mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT;
     mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1;
     mp->m_blockmask = sbp->sb_blocksize - 1;
     mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG;
     mp->m_blockwmask = mp->m_blockwsize - 1;
 
     mp->m_alloc_mxr[0] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 1);
     mp->m_alloc_mxr[1] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 0);
     mp->m_alloc_mnr[0] = mp->m_alloc_mxr[0] / 2;
     mp->m_alloc_mnr[1] = mp->m_alloc_mxr[1] / 2;
 
     mp->m_bmap_dmxr[0] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 1);
     mp->m_bmap_dmxr[1] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 0);
     mp->m_bmap_dmnr[0] = mp->m_bmap_dmxr[0] / 2;
     mp->m_bmap_dmnr[1] = mp->m_bmap_dmxr[1] / 2;
 
     mp->m_rmap_mxr[0] = xfs_rmapbt_maxrecs(sbp->sb_blocksize, 1);
     mp->m_rmap_mxr[1] = xfs_rmapbt_maxrecs(sbp->sb_blocksize, 0);
     mp->m_rmap_mnr[0] = mp->m_rmap_mxr[0] / 2;
     mp->m_rmap_mnr[1] = mp->m_rmap_mxr[1] / 2;
 
     mp->m_refc_mxr[0] = xfs_refcountbt_maxrecs(sbp->sb_blocksize, true);
     mp->m_refc_mxr[1] = xfs_refcountbt_maxrecs(sbp->sb_blocksize, false);
     mp->m_refc_mnr[0] = mp->m_refc_mxr[0] / 2;
     mp->m_refc_mnr[1] = mp->m_refc_mxr[1] / 2;
 
     mp->m_bsize = XFS_FSB_TO_BB(mp, 1);
     mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
     mp->m_ag_max_usable = xfs_alloc_ag_max_usable(mp);
 }
 
 /*
  * xfs_log_sb() can be used to copy arbitrary changes to the in-core superblock
  * into the superblock buffer to be logged.  It does not provide the higher
  * level of locking that is needed to protect the in-core superblock from
  * concurrent access.
  */
 void
 xfs_log_sb(
     struct xfs_trans    *tp)
 {
     struct xfs_mount    *mp = tp->t_mountp;
     struct xfs_buf      *bp = xfs_trans_getsb(tp);
 
     /*
      * Lazy sb counters don't update the in-core superblock so do that now.
      * If this is at unmount, the counters will be exactly correct, but at
      * any other time they will only be ballpark correct because of
      * reservations that have been taken out percpu counters. If we have an
      * unclean shutdown, this will be corrected by log recovery rebuilding
      * the counters from the AGF block counts.
      *
      * Do not update sb_frextents here because it is not part of the lazy
      * sb counters, despite having a percpu counter. It is always kept
      * consistent with the ondisk rtbitmap by xfs_trans_apply_sb_deltas()
      * and hence we don't need have to update it here.
      */
     if (xfs_has_lazysbcount(mp)) {
         mp->m_sb.sb_icount = percpu_counter_sum(&mp->m_icount);
         mp->m_sb.sb_ifree = percpu_counter_sum(&mp->m_ifree);
         mp->m_sb.sb_fdblocks = percpu_counter_sum(&mp->m_fdblocks);
     }
 
     xfs_sb_to_disk(bp->b_addr, &mp->m_sb);
     xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF);
     xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsb) - 1);
 }
 
 /*
  * xfs_sync_sb
  *
  * Sync the superblock to disk.
  *
  * Note that the caller is responsible for checking the frozen state of the
  * filesystem. This procedure uses the non-blocking transaction allocator and
  * thus will allow modifications to a frozen fs. This is required because this
  * code can be called during the process of freezing where use of the high-level
  * allocator would deadlock.
  */
 int
 xfs_sync_sb(
     struct xfs_mount    *mp,
     bool            wait)
 {
     struct xfs_trans    *tp;
     int         error;
 
     error = xfs_trans_alloc(mp, &M_RES(mp)->tr_sb, 0, 0,
             XFS_TRANS_NO_WRITECOUNT, &tp);
     if (error)
         return error;
 
     xfs_log_sb(tp);
     if (wait)
         xfs_trans_set_sync(tp);
     return xfs_trans_commit(tp);
 }
 
 /*
  * Update all the secondary superblocks to match the new state of the primary.
  * Because we are completely overwriting all the existing fields in the
  * secondary superblock buffers, there is no need to read them in from disk.
  * Just get a new buffer, stamp it and write it.
  *
  * The sb buffers need to be cached here so that we serialise against other
  * operations that access the secondary superblocks, but we don't want to keep
  * them in memory once it is written so we mark it as a one-shot buffer.
  */
 int
 xfs_update_secondary_sbs(
     struct xfs_mount    *mp)
 {
     struct xfs_perag    *pag;
     xfs_agnumber_t      agno = 1;
     int         saved_error = 0;
     int         error = 0;
     LIST_HEAD       (buffer_list);
 
     /* update secondary superblocks. */
     for_each_perag_from(mp, agno, pag) {
         struct xfs_buf      *bp;
 
         error = xfs_buf_get(mp->m_ddev_targp,
                  XFS_AG_DADDR(mp, pag->pag_agno, XFS_SB_DADDR),
                  XFS_FSS_TO_BB(mp, 1), &bp);
         /*
          * If we get an error reading or writing alternate superblocks,
          * continue.  xfs_repair chooses the "best" superblock based
          * on most matches; if we break early, we'll leave more
          * superblocks un-updated than updated, and xfs_repair may
          * pick them over the properly-updated primary.
          */
         if (error) {
             xfs_warn(mp,
         "error allocating secondary superblock for ag %d",
                 pag->pag_agno);
             if (!saved_error)
                 saved_error = error;
             continue;
         }
 
         bp->b_ops = &xfs_sb_buf_ops;
         xfs_buf_oneshot(bp);
         xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
         xfs_sb_to_disk(bp->b_addr, &mp->m_sb);
         xfs_buf_delwri_queue(bp, &buffer_list);
         xfs_buf_relse(bp);
 
         /* don't hold too many buffers at once */
         if (agno % 16)
             continue;
 
         error = xfs_buf_delwri_submit(&buffer_list);
         if (error) {
             xfs_warn(mp,
         "write error %d updating a secondary superblock near ag %d",
                 error, pag->pag_agno);
             if (!saved_error)
                 saved_error = error;
             continue;
         }
     }
     error = xfs_buf_delwri_submit(&buffer_list);
     if (error) {
         xfs_warn(mp,
         "write error %d updating a secondary superblock near ag %d",
             error, agno);
     }
 
     return saved_error ? saved_error : error;
 }
 
 /*
  * Same behavior as xfs_sync_sb, except that it is always synchronous and it
  * also writes the superblock buffer to disk sector 0 immediately.
  */
 int
 xfs_sync_sb_buf(
     struct xfs_mount    *mp)
 {
     struct xfs_trans    *tp;
     struct xfs_buf      *bp;
     int         error;
 
     error = xfs_trans_alloc(mp, &M_RES(mp)->tr_sb, 0, 0, 0, &tp);
     if (error)
         return error;
 
     bp = xfs_trans_getsb(tp);
     xfs_log_sb(tp);
     xfs_trans_bhold(tp, bp);
     xfs_trans_set_sync(tp);
     error = xfs_trans_commit(tp);
     if (error)
         goto out;
     /*
      * write out the sb buffer to get the changes to disk
      */
     error = xfs_bwrite(bp);
 out:
     xfs_buf_relse(bp);
     return error;
 }
 
 void
 xfs_fs_geometry(
     struct xfs_mount    *mp,
     struct xfs_fsop_geom    *geo,
     int         struct_version)
 {
     struct xfs_sb       *sbp = &mp->m_sb;
 
     memset(geo, 0, sizeof(struct xfs_fsop_geom));
 
     geo->blocksize = sbp->sb_blocksize;
     geo->rtextsize = sbp->sb_rextsize;
     geo->agblocks = sbp->sb_agblocks;
     geo->agcount = sbp->sb_agcount;
     geo->logblocks = sbp->sb_logblocks;
     geo->sectsize = sbp->sb_sectsize;
     geo->inodesize = sbp->sb_inodesize;
     geo->imaxpct = sbp->sb_imax_pct;
     geo->datablocks = sbp->sb_dblocks;
     geo->rtblocks = sbp->sb_rblocks;
     geo->rtextents = sbp->sb_rextents;
     geo->logstart = sbp->sb_logstart;
     BUILD_BUG_ON(sizeof(geo->uuid) != sizeof(sbp->sb_uuid));
     memcpy(geo->uuid, &sbp->sb_uuid, sizeof(sbp->sb_uuid));
 
     if (struct_version < 2)
         return;
 
     geo->sunit = sbp->sb_unit;
     geo->swidth = sbp->sb_width;
 
     if (struct_version < 3)
         return;
 
     geo->version = XFS_FSOP_GEOM_VERSION;
     geo->flags = XFS_FSOP_GEOM_FLAGS_NLINK |
              XFS_FSOP_GEOM_FLAGS_DIRV2 |
              XFS_FSOP_GEOM_FLAGS_EXTFLG;
     if (xfs_has_attr(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_ATTR;
     if (xfs_has_quota(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_QUOTA;
     if (xfs_has_align(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_IALIGN;
     if (xfs_has_dalign(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_DALIGN;
     if (xfs_has_asciici(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_DIRV2CI;
     if (xfs_has_lazysbcount(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_LAZYSB;
     if (xfs_has_attr2(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_ATTR2;
     if (xfs_has_projid32(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_PROJID32;
     if (xfs_has_crc(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_V5SB;
     if (xfs_has_ftype(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_FTYPE;
     if (xfs_has_finobt(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_FINOBT;
     if (xfs_has_sparseinodes(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_SPINODES;
     if (xfs_has_rmapbt(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_RMAPBT;
     if (xfs_has_reflink(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_REFLINK;
     if (xfs_has_bigtime(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_BIGTIME;
     if (xfs_has_inobtcounts(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_INOBTCNT;
     if (xfs_has_sector(mp)) {
         geo->flags |= XFS_FSOP_GEOM_FLAGS_SECTOR;
         geo->logsectsize = sbp->sb_logsectsize;
     } else {
         geo->logsectsize = BBSIZE;
     }
     if (xfs_has_large_extent_counts(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_NREXT64;
     geo->rtsectsize = sbp->sb_blocksize;
     geo->dirblocksize = xfs_dir2_dirblock_bytes(sbp);
 
     if (struct_version < 4)
         return;
 
     if (xfs_has_logv2(mp))
         geo->flags |= XFS_FSOP_GEOM_FLAGS_LOGV2;
 
     geo->logsunit = sbp->sb_logsunit;
 
     if (struct_version < 5)
         return;
 
     geo->version = XFS_FSOP_GEOM_VERSION_V5;
 }
 
 /* Read a secondary superblock. */
 int
 xfs_sb_read_secondary(
     struct xfs_mount    *mp,
     struct xfs_trans    *tp,
     xfs_agnumber_t      agno,
     struct xfs_buf      **bpp)
 {
     struct xfs_buf      *bp;
     int         error;
 
     ASSERT(agno != 0 && agno != NULLAGNUMBER);
     error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
             XFS_AG_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
             XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_sb_buf_ops);
     if (error)
         return error;
     xfs_buf_set_ref(bp, XFS_SSB_REF);
     *bpp = bp;
     return 0;
 }
 
 /* Get an uninitialised secondary superblock buffer. */
 int
 xfs_sb_get_secondary(
     struct xfs_mount    *mp,
     struct xfs_trans    *tp,
     xfs_agnumber_t      agno,
     struct xfs_buf      **bpp)
 {
     struct xfs_buf      *bp;
     int         error;
 
     ASSERT(agno != 0 && agno != NULLAGNUMBER);
     error = xfs_trans_get_buf(tp, mp->m_ddev_targp,
             XFS_AG_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
             XFS_FSS_TO_BB(mp, 1), 0, &bp);
     if (error)
         return error;
     bp->b_ops = &xfs_sb_buf_ops;
     xfs_buf_oneshot(bp);
     *bpp = bp;
     return 0;
 }
 
 /*
  * sunit, swidth, sectorsize(optional with 0) should be all in bytes,
  * so users won't be confused by values in error messages.
  */
 bool
 xfs_validate_stripe_geometry(
     struct xfs_mount    *mp,
     __s64           sunit,
     __s64           swidth,
     int         sectorsize,
     bool            silent)
 {
     if (swidth > INT_MAX) {
         if (!silent)
             xfs_notice(mp,
 "stripe width (%lld) is too large", swidth);
         return false;
     }
 
     if (sunit > swidth) {
         if (!silent)
             xfs_notice(mp,
 "stripe unit (%lld) is larger than the stripe width (%lld)", sunit, swidth);
         return false;
     }
 
     if (sectorsize && (int)sunit % sectorsize) {
         if (!silent)
             xfs_notice(mp,
 "stripe unit (%lld) must be a multiple of the sector size (%d)",
                    sunit, sectorsize);
         return false;
     }
 
     if (sunit && !swidth) {
         if (!silent)
             xfs_notice(mp,
 "invalid stripe unit (%lld) and stripe width of 0", sunit);
         return false;
     }
 
     if (!sunit && swidth) {
         if (!silent)
             xfs_notice(mp,
 "invalid stripe width (%lld) and stripe unit of 0", swidth);
         return false;
     }
 
     if (sunit && (int)swidth % (int)sunit) {
         if (!silent)
             xfs_notice(mp,
 "stripe width (%lld) must be a multiple of the stripe unit (%lld)",
                    swidth, sunit);
         return false;
     }
     return true;
 }

This page was automatically generated by the 2.1.0 LXR engine. The LXR team