OSCL-LXR linux-6.0.1/​fs/​xfs/​libxfs/​xfs_attr.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_mount.h"
 #include "xfs_defer.h"
 #include "xfs_da_format.h"
 #include "xfs_da_btree.h"
 #include "xfs_attr_sf.h"
 #include "xfs_inode.h"
 #include "xfs_trans.h"
 #include "xfs_bmap.h"
 #include "xfs_bmap_btree.h"
 #include "xfs_attr.h"
 #include "xfs_attr_leaf.h"
 #include "xfs_attr_remote.h"
 #include "xfs_quota.h"
 #include "xfs_trans_space.h"
 #include "xfs_trace.h"
 #include "xfs_attr_item.h"
 #include "xfs_xattr.h"
 
 struct kmem_cache       *xfs_attr_intent_cache;
 
 /*
  * xfs_attr.c
  *
  * Provide the external interfaces to manage attribute lists.
  */
 
 /*========================================================================
  * Function prototypes for the kernel.
  *========================================================================*/
 
 /*
  * Internal routines when attribute list fits inside the inode.
  */
 STATIC int xfs_attr_shortform_addname(xfs_da_args_t *args);
 
 /*
  * Internal routines when attribute list is one block.
  */
 STATIC int xfs_attr_leaf_get(xfs_da_args_t *args);
 STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args);
 STATIC int xfs_attr_leaf_hasname(struct xfs_da_args *args, struct xfs_buf **bp);
 STATIC int xfs_attr_leaf_try_add(struct xfs_da_args *args);
 
 /*
  * Internal routines when attribute list is more than one block.
  */
 STATIC int xfs_attr_node_get(xfs_da_args_t *args);
 STATIC void xfs_attr_restore_rmt_blk(struct xfs_da_args *args);
 static int xfs_attr_node_try_addname(struct xfs_attr_intent *attr);
 STATIC int xfs_attr_node_addname_find_attr(struct xfs_attr_intent *attr);
 STATIC int xfs_attr_node_remove_attr(struct xfs_attr_intent *attr);
 STATIC int xfs_attr_node_lookup(struct xfs_da_args *args,
         struct xfs_da_state *state);
 
 int
 xfs_inode_hasattr(
     struct xfs_inode    *ip)
 {
     if (!xfs_inode_has_attr_fork(ip))
         return 0;
     if (ip->i_af.if_format == XFS_DINODE_FMT_EXTENTS &&
         ip->i_af.if_nextents == 0)
         return 0;
     return 1;
 }
 
 /*
  * Returns true if the there is exactly only block in the attr fork, in which
  * case the attribute fork consists of a single leaf block entry.
  */
 bool
 xfs_attr_is_leaf(
     struct xfs_inode    *ip)
 {
     struct xfs_ifork    *ifp = &ip->i_af;
     struct xfs_iext_cursor  icur;
     struct xfs_bmbt_irec    imap;
 
     if (ifp->if_nextents != 1 || ifp->if_format != XFS_DINODE_FMT_EXTENTS)
         return false;
 
     xfs_iext_first(ifp, &icur);
     xfs_iext_get_extent(ifp, &icur, &imap);
     return imap.br_startoff == 0 && imap.br_blockcount == 1;
 }
 
 /*
  * XXX (dchinner): name path state saving and refilling is an optimisation to
  * avoid needing to look up name entries after rolling transactions removing
  * remote xattr blocks between the name entry lookup and name entry removal.
  * This optimisation got sidelined when combining the set and remove state
  * machines, but the code has been left in place because it is worthwhile to
  * restore the optimisation once the combined state machine paths have settled.
  *
  * This comment is a public service announcement to remind Future Dave that he
  * still needs to restore this code to working order.
  */
 #if 0
 /*
  * Fill in the disk block numbers in the state structure for the buffers
  * that are attached to the state structure.
  * This is done so that we can quickly reattach ourselves to those buffers
  * after some set of transaction commits have released these buffers.
  */
 static int
 xfs_attr_fillstate(xfs_da_state_t *state)
 {
     xfs_da_state_path_t *path;
     xfs_da_state_blk_t *blk;
     int level;
 
     trace_xfs_attr_fillstate(state->args);
 
     /*
      * Roll down the "path" in the state structure, storing the on-disk
      * block number for those buffers in the "path".
      */
     path = &state->path;
     ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
     for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
         if (blk->bp) {
             blk->disk_blkno = xfs_buf_daddr(blk->bp);
             blk->bp = NULL;
         } else {
             blk->disk_blkno = 0;
         }
     }
 
     /*
      * Roll down the "altpath" in the state structure, storing the on-disk
      * block number for those buffers in the "altpath".
      */
     path = &state->altpath;
     ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
     for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
         if (blk->bp) {
             blk->disk_blkno = xfs_buf_daddr(blk->bp);
             blk->bp = NULL;
         } else {
             blk->disk_blkno = 0;
         }
     }
 
     return 0;
 }
 
 /*
  * Reattach the buffers to the state structure based on the disk block
  * numbers stored in the state structure.
  * This is done after some set of transaction commits have released those
  * buffers from our grip.
  */
 static int
 xfs_attr_refillstate(xfs_da_state_t *state)
 {
     xfs_da_state_path_t *path;
     xfs_da_state_blk_t *blk;
     int level, error;
 
     trace_xfs_attr_refillstate(state->args);
 
     /*
      * Roll down the "path" in the state structure, storing the on-disk
      * block number for those buffers in the "path".
      */
     path = &state->path;
     ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
     for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
         if (blk->disk_blkno) {
             error = xfs_da3_node_read_mapped(state->args->trans,
                     state->args->dp, blk->disk_blkno,
                     &blk->bp, XFS_ATTR_FORK);
             if (error)
                 return error;
         } else {
             blk->bp = NULL;
         }
     }
 
     /*
      * Roll down the "altpath" in the state structure, storing the on-disk
      * block number for those buffers in the "altpath".
      */
     path = &state->altpath;
     ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
     for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
         if (blk->disk_blkno) {
             error = xfs_da3_node_read_mapped(state->args->trans,
                     state->args->dp, blk->disk_blkno,
                     &blk->bp, XFS_ATTR_FORK);
             if (error)
                 return error;
         } else {
             blk->bp = NULL;
         }
     }
 
     return 0;
 }
 #else
 static int xfs_attr_fillstate(xfs_da_state_t *state) { return 0; }
 #endif
 
 /*========================================================================
  * Overall external interface routines.
  *========================================================================*/
 
 /*
  * Retrieve an extended attribute and its value.  Must have ilock.
  * Returns 0 on successful retrieval, otherwise an error.
  */
 int
 xfs_attr_get_ilocked(
     struct xfs_da_args  *args)
 {
     ASSERT(xfs_isilocked(args->dp, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
 
     if (!xfs_inode_hasattr(args->dp))
         return -ENOATTR;
 
     if (args->dp->i_af.if_format == XFS_DINODE_FMT_LOCAL)
         return xfs_attr_shortform_getvalue(args);
     if (xfs_attr_is_leaf(args->dp))
         return xfs_attr_leaf_get(args);
     return xfs_attr_node_get(args);
 }
 
 /*
  * Retrieve an extended attribute by name, and its value if requested.
  *
  * If args->valuelen is zero, then the caller does not want the value, just an
  * indication whether the attribute exists and the size of the value if it
  * exists. The size is returned in args.valuelen.
  *
  * If args->value is NULL but args->valuelen is non-zero, allocate the buffer
  * for the value after existence of the attribute has been determined. The
  * caller always has to free args->value if it is set, no matter if this
  * function was successful or not.
  *
  * If the attribute is found, but exceeds the size limit set by the caller in
  * args->valuelen, return -ERANGE with the size of the attribute that was found
  * in args->valuelen.
  */
 int
 xfs_attr_get(
     struct xfs_da_args  *args)
 {
     uint            lock_mode;
     int         error;
 
     XFS_STATS_INC(args->dp->i_mount, xs_attr_get);
 
     if (xfs_is_shutdown(args->dp->i_mount))
         return -EIO;
 
     args->geo = args->dp->i_mount->m_attr_geo;
     args->whichfork = XFS_ATTR_FORK;
     args->hashval = xfs_da_hashname(args->name, args->namelen);
 
     /* Entirely possible to look up a name which doesn't exist */
     args->op_flags = XFS_DA_OP_OKNOENT;
 
     lock_mode = xfs_ilock_attr_map_shared(args->dp);
     error = xfs_attr_get_ilocked(args);
     xfs_iunlock(args->dp, lock_mode);
 
     return error;
 }
 
 /*
  * Calculate how many blocks we need for the new attribute,
  */
 int
 xfs_attr_calc_size(
     struct xfs_da_args  *args,
     int         *local)
 {
     struct xfs_mount    *mp = args->dp->i_mount;
     int         size;
     int         nblks;
 
     /*
      * Determine space new attribute will use, and if it would be
      * "local" or "remote" (note: local != inline).
      */
     size = xfs_attr_leaf_newentsize(args, local);
     nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK);
     if (*local) {
         if (size > (args->geo->blksize / 2)) {
             /* Double split possible */
             nblks *= 2;
         }
     } else {
         /*
          * Out of line attribute, cannot double split, but
          * make room for the attribute value itself.
          */
         uint    dblocks = xfs_attr3_rmt_blocks(mp, args->valuelen);
         nblks += dblocks;
         nblks += XFS_NEXTENTADD_SPACE_RES(mp, dblocks, XFS_ATTR_FORK);
     }
 
     return nblks;
 }
 
 /* Initialize transaction reservation for attr operations */
 void
 xfs_init_attr_trans(
     struct xfs_da_args  *args,
     struct xfs_trans_res    *tres,
     unsigned int        *total)
 {
     struct xfs_mount    *mp = args->dp->i_mount;
 
     if (args->value) {
         tres->tr_logres = M_RES(mp)->tr_attrsetm.tr_logres +
                  M_RES(mp)->tr_attrsetrt.tr_logres *
                  args->total;
         tres->tr_logcount = XFS_ATTRSET_LOG_COUNT;
         tres->tr_logflags = XFS_TRANS_PERM_LOG_RES;
         *total = args->total;
     } else {
         *tres = M_RES(mp)->tr_attrrm;
         *total = XFS_ATTRRM_SPACE_RES(mp);
     }
 }
 
 /*
  * Add an attr to a shortform fork. If there is no space,
  * xfs_attr_shortform_addname() will convert to leaf format and return -ENOSPC.
  * to use.
  */
 STATIC int
 xfs_attr_try_sf_addname(
     struct xfs_inode    *dp,
     struct xfs_da_args  *args)
 {
 
     int         error;
 
     /*
      * Build initial attribute list (if required).
      */
     if (dp->i_af.if_format == XFS_DINODE_FMT_EXTENTS)
         xfs_attr_shortform_create(args);
 
     error = xfs_attr_shortform_addname(args);
     if (error == -ENOSPC)
         return error;
 
     /*
      * Commit the shortform mods, and we're done.
      * NOTE: this is also the error path (EEXIST, etc).
      */
     if (!error && !(args->op_flags & XFS_DA_OP_NOTIME))
         xfs_trans_ichgtime(args->trans, dp, XFS_ICHGTIME_CHG);
 
     if (xfs_has_wsync(dp->i_mount))
         xfs_trans_set_sync(args->trans);
 
     return error;
 }
 
 static int
 xfs_attr_sf_addname(
     struct xfs_attr_intent      *attr)
 {
     struct xfs_da_args      *args = attr->xattri_da_args;
     struct xfs_inode        *dp = args->dp;
     int             error = 0;
 
     error = xfs_attr_try_sf_addname(dp, args);
     if (error != -ENOSPC) {
         ASSERT(!error || error == -EEXIST);
         attr->xattri_dela_state = XFS_DAS_DONE;
         goto out;
     }
 
     /*
      * It won't fit in the shortform, transform to a leaf block.  GROT:
      * another possible req'mt for a double-split btree op.
      */
     error = xfs_attr_shortform_to_leaf(args);
     if (error)
         return error;
 
     attr->xattri_dela_state = XFS_DAS_LEAF_ADD;
 out:
     trace_xfs_attr_sf_addname_return(attr->xattri_dela_state, args->dp);
     return error;
 }
 
 /*
  * Handle the state change on completion of a multi-state attr operation.
  *
  * If the XFS_DA_OP_REPLACE flag is set, this means the operation was the first
  * modification in a attr replace operation and we still have to do the second
  * state, indicated by @replace_state.
  *
  * We consume the XFS_DA_OP_REPLACE flag so that when we are called again on
  * completion of the second half of the attr replace operation we correctly
  * signal that it is done.
  */
 static enum xfs_delattr_state
 xfs_attr_complete_op(
     struct xfs_attr_intent  *attr,
     enum xfs_delattr_state  replace_state)
 {
     struct xfs_da_args  *args = attr->xattri_da_args;
     bool            do_replace = args->op_flags & XFS_DA_OP_REPLACE;
 
     args->op_flags &= ~XFS_DA_OP_REPLACE;
     if (do_replace) {
         args->attr_filter &= ~XFS_ATTR_INCOMPLETE;
         return replace_state;
     }
     return XFS_DAS_DONE;
 }
 
 static int
 xfs_attr_leaf_addname(
     struct xfs_attr_intent  *attr)
 {
     struct xfs_da_args  *args = attr->xattri_da_args;
     int         error;
 
     ASSERT(xfs_attr_is_leaf(args->dp));
 
     /*
      * Use the leaf buffer we may already hold locked as a result of
      * a sf-to-leaf conversion.
      */
     error = xfs_attr_leaf_try_add(args);
 
     if (error == -ENOSPC) {
         error = xfs_attr3_leaf_to_node(args);
         if (error)
             return error;
 
         /*
          * We're not in leaf format anymore, so roll the transaction and
          * retry the add to the newly allocated node block.
          */
         attr->xattri_dela_state = XFS_DAS_NODE_ADD;
         goto out;
     }
     if (error)
         return error;
 
     /*
      * We need to commit and roll if we need to allocate remote xattr blocks
      * or perform more xattr manipulations. Otherwise there is nothing more
      * to do and we can return success.
      */
     if (args->rmtblkno)
         attr->xattri_dela_state = XFS_DAS_LEAF_SET_RMT;
     else
         attr->xattri_dela_state = xfs_attr_complete_op(attr,
                             XFS_DAS_LEAF_REPLACE);
 out:
     trace_xfs_attr_leaf_addname_return(attr->xattri_dela_state, args->dp);
     return error;
 }
 
 /*
  * Add an entry to a node format attr tree.
  *
  * Note that we might still have a leaf here - xfs_attr_is_leaf() cannot tell
  * the difference between leaf + remote attr blocks and a node format tree,
  * so we may still end up having to convert from leaf to node format here.
  */
 static int
 xfs_attr_node_addname(
     struct xfs_attr_intent  *attr)
 {
     struct xfs_da_args  *args = attr->xattri_da_args;
     int         error;
 
     error = xfs_attr_node_addname_find_attr(attr);
     if (error)
         return error;
 
     error = xfs_attr_node_try_addname(attr);
     if (error == -ENOSPC) {
         error = xfs_attr3_leaf_to_node(args);
         if (error)
             return error;
         /*
          * No state change, we really are in node form now
          * but we need the transaction rolled to continue.
          */
         goto out;
     }
     if (error)
         return error;
 
     if (args->rmtblkno)
         attr->xattri_dela_state = XFS_DAS_NODE_SET_RMT;
     else
         attr->xattri_dela_state = xfs_attr_complete_op(attr,
                             XFS_DAS_NODE_REPLACE);
 out:
     trace_xfs_attr_node_addname_return(attr->xattri_dela_state, args->dp);
     return error;
 }
 
 static int
 xfs_attr_rmtval_alloc(
     struct xfs_attr_intent      *attr)
 {
     struct xfs_da_args              *args = attr->xattri_da_args;
     int             error = 0;
 
     /*
      * If there was an out-of-line value, allocate the blocks we
      * identified for its storage and copy the value.  This is done
      * after we create the attribute so that we don't overflow the
      * maximum size of a transaction and/or hit a deadlock.
      */
     if (attr->xattri_blkcnt > 0) {
         error = xfs_attr_rmtval_set_blk(attr);
         if (error)
             return error;
         /* Roll the transaction only if there is more to allocate. */
         if (attr->xattri_blkcnt > 0)
             goto out;
     }
 
     error = xfs_attr_rmtval_set_value(args);
     if (error)
         return error;
 
     attr->xattri_dela_state = xfs_attr_complete_op(attr,
                         ++attr->xattri_dela_state);
     /*
      * If we are not doing a rename, we've finished the operation but still
      * have to clear the incomplete flag protecting the new attr from
      * exposing partially initialised state if we crash during creation.
      */
     if (attr->xattri_dela_state == XFS_DAS_DONE)
         error = xfs_attr3_leaf_clearflag(args);
 out:
     trace_xfs_attr_rmtval_alloc(attr->xattri_dela_state, args->dp);
     return error;
 }
 
 /*
  * Mark an attribute entry INCOMPLETE and save pointers to the relevant buffers
  * for later deletion of the entry.
  */
 static int
 xfs_attr_leaf_mark_incomplete(
     struct xfs_da_args  *args,
     struct xfs_da_state *state)
 {
     int         error;
 
     /*
      * Fill in disk block numbers in the state structure
      * so that we can get the buffers back after we commit
      * several transactions in the following calls.
      */
     error = xfs_attr_fillstate(state);
     if (error)
         return error;
 
     /*
      * Mark the attribute as INCOMPLETE
      */
     return xfs_attr3_leaf_setflag(args);
 }
 
 /* Ensure the da state of an xattr deferred work item is ready to go. */
 static inline void
 xfs_attr_item_init_da_state(
     struct xfs_attr_intent  *attr)
 {
     struct xfs_da_args  *args = attr->xattri_da_args;
 
     if (!attr->xattri_da_state)
         attr->xattri_da_state = xfs_da_state_alloc(args);
     else
         xfs_da_state_reset(attr->xattri_da_state, args);
 }
 
 /*
  * Initial setup for xfs_attr_node_removename.  Make sure the attr is there and
  * the blocks are valid.  Attr keys with remote blocks will be marked
  * incomplete.
  */
 static
 int xfs_attr_node_removename_setup(
     struct xfs_attr_intent      *attr)
 {
     struct xfs_da_args      *args = attr->xattri_da_args;
     struct xfs_da_state     *state;
     int             error;
 
     xfs_attr_item_init_da_state(attr);
     error = xfs_attr_node_lookup(args, attr->xattri_da_state);
     if (error != -EEXIST)
         goto out;
     error = 0;
 
     state = attr->xattri_da_state;
     ASSERT(state->path.blk[state->path.active - 1].bp != NULL);
     ASSERT(state->path.blk[state->path.active - 1].magic ==
         XFS_ATTR_LEAF_MAGIC);
 
     error = xfs_attr_leaf_mark_incomplete(args, state);
     if (error)
         goto out;
     if (args->rmtblkno > 0)
         error = xfs_attr_rmtval_invalidate(args);
 out:
     if (error) {
         xfs_da_state_free(attr->xattri_da_state);
         attr->xattri_da_state = NULL;
     }
 
     return error;
 }
 
 /*
  * Remove the original attr we have just replaced. This is dependent on the
  * original lookup and insert placing the old attr in args->blkno/args->index
  * and the new attr in args->blkno2/args->index2.
  */
 static int
 xfs_attr_leaf_remove_attr(
     struct xfs_attr_intent      *attr)
 {
     struct xfs_da_args              *args = attr->xattri_da_args;
     struct xfs_inode        *dp = args->dp;
     struct xfs_buf          *bp = NULL;
     int             forkoff;
     int             error;
 
     error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno,
                    &bp);
     if (error)
         return error;
 
     xfs_attr3_leaf_remove(bp, args);
 
     forkoff = xfs_attr_shortform_allfit(bp, dp);
     if (forkoff)
         error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
         /* bp is gone due to xfs_da_shrink_inode */
 
     return error;
 }
 
 /*
  * Shrink an attribute from leaf to shortform. Used by the node format remove
  * path when the node format collapses to a single block and so we have to check
  * if it can be collapsed further.
  */
 static int
 xfs_attr_leaf_shrink(
     struct xfs_da_args  *args)
 {
     struct xfs_inode    *dp = args->dp;
     struct xfs_buf      *bp;
     int         forkoff;
     int         error;
 
     if (!xfs_attr_is_leaf(dp))
         return 0;
 
     error = xfs_attr3_leaf_read(args->trans, args->dp, 0, &bp);
     if (error)
         return error;
 
     forkoff = xfs_attr_shortform_allfit(bp, dp);
     if (forkoff) {
         error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
         /* bp is gone due to xfs_da_shrink_inode */
     } else {
         xfs_trans_brelse(args->trans, bp);
     }
 
     return error;
 }
 
 /*
  * Run the attribute operation specified in @attr.
  *
  * This routine is meant to function as a delayed operation and will set the
  * state to XFS_DAS_DONE when the operation is complete.  Calling functions will
  * need to handle this, and recall the function until either an error or
  * XFS_DAS_DONE is detected.
  */
 int
 xfs_attr_set_iter(
     struct xfs_attr_intent      *attr)
 {
     struct xfs_da_args              *args = attr->xattri_da_args;
     int             error = 0;
 
     /* State machine switch */
 next_state:
     switch (attr->xattri_dela_state) {
     case XFS_DAS_UNINIT:
         ASSERT(0);
         return -EFSCORRUPTED;
     case XFS_DAS_SF_ADD:
         return xfs_attr_sf_addname(attr);
     case XFS_DAS_LEAF_ADD:
         return xfs_attr_leaf_addname(attr);
     case XFS_DAS_NODE_ADD:
         return xfs_attr_node_addname(attr);
 
     case XFS_DAS_SF_REMOVE:
         error = xfs_attr_sf_removename(args);
         attr->xattri_dela_state = xfs_attr_complete_op(attr,
                         xfs_attr_init_add_state(args));
         break;
     case XFS_DAS_LEAF_REMOVE:
         error = xfs_attr_leaf_removename(args);
         attr->xattri_dela_state = xfs_attr_complete_op(attr,
                         xfs_attr_init_add_state(args));
         break;
     case XFS_DAS_NODE_REMOVE:
         error = xfs_attr_node_removename_setup(attr);
         if (error == -ENOATTR &&
             (args->op_flags & XFS_DA_OP_RECOVERY)) {
             attr->xattri_dela_state = xfs_attr_complete_op(attr,
                         xfs_attr_init_add_state(args));
             error = 0;
             break;
         }
         if (error)
             return error;
         attr->xattri_dela_state = XFS_DAS_NODE_REMOVE_RMT;
         if (args->rmtblkno == 0)
             attr->xattri_dela_state++;
         break;
 
     case XFS_DAS_LEAF_SET_RMT:
     case XFS_DAS_NODE_SET_RMT:
         error = xfs_attr_rmtval_find_space(attr);
         if (error)
             return error;
         attr->xattri_dela_state++;
         fallthrough;
 
     case XFS_DAS_LEAF_ALLOC_RMT:
     case XFS_DAS_NODE_ALLOC_RMT:
         error = xfs_attr_rmtval_alloc(attr);
         if (error)
             return error;
         if (attr->xattri_dela_state == XFS_DAS_DONE)
             break;
         goto next_state;
 
     case XFS_DAS_LEAF_REPLACE:
     case XFS_DAS_NODE_REPLACE:
         /*
          * We must "flip" the incomplete flags on the "new" and "old"
          * attribute/value pairs so that one disappears and one appears
          * atomically.
          */
         error = xfs_attr3_leaf_flipflags(args);
         if (error)
             return error;
         /*
          * We must commit the flag value change now to make it atomic
          * and then we can start the next trans in series at REMOVE_OLD.
          */
         attr->xattri_dela_state++;
         break;
 
     case XFS_DAS_LEAF_REMOVE_OLD:
     case XFS_DAS_NODE_REMOVE_OLD:
         /*
          * If we have a remote attr, start the process of removing it
          * by invalidating any cached buffers.
          *
          * If we don't have a remote attr, we skip the remote block
          * removal state altogether with a second state increment.
          */
         xfs_attr_restore_rmt_blk(args);
         if (args->rmtblkno) {
             error = xfs_attr_rmtval_invalidate(args);
             if (error)
                 return error;
         } else {
             attr->xattri_dela_state++;
         }
 
         attr->xattri_dela_state++;
         goto next_state;
 
     case XFS_DAS_LEAF_REMOVE_RMT:
     case XFS_DAS_NODE_REMOVE_RMT:
         error = xfs_attr_rmtval_remove(attr);
         if (error == -EAGAIN) {
             error = 0;
             break;
         }
         if (error)
             return error;
 
         /*
          * We've finished removing the remote attr blocks, so commit the
          * transaction and move on to removing the attr name from the
          * leaf/node block. Removing the attr might require a full
          * transaction reservation for btree block freeing, so we
          * can't do that in the same transaction where we removed the
          * remote attr blocks.
          */
         attr->xattri_dela_state++;
         break;
 
     case XFS_DAS_LEAF_REMOVE_ATTR:
         error = xfs_attr_leaf_remove_attr(attr);
         attr->xattri_dela_state = xfs_attr_complete_op(attr,
                         xfs_attr_init_add_state(args));
         break;
 
     case XFS_DAS_NODE_REMOVE_ATTR:
         error = xfs_attr_node_remove_attr(attr);
         if (!error)
             error = xfs_attr_leaf_shrink(args);
         attr->xattri_dela_state = xfs_attr_complete_op(attr,
                         xfs_attr_init_add_state(args));
         break;
     default:
         ASSERT(0);
         break;
     }
 
     trace_xfs_attr_set_iter_return(attr->xattri_dela_state, args->dp);
     return error;
 }
 
 
 /*
  * Return EEXIST if attr is found, or ENOATTR if not
  */
 static int
 xfs_attr_lookup(
     struct xfs_da_args  *args)
 {
     struct xfs_inode    *dp = args->dp;
     struct xfs_buf      *bp = NULL;
     struct xfs_da_state *state;
     int         error;
 
     if (!xfs_inode_hasattr(dp))
         return -ENOATTR;
 
     if (dp->i_af.if_format == XFS_DINODE_FMT_LOCAL)
         return xfs_attr_sf_findname(args, NULL, NULL);
 
     if (xfs_attr_is_leaf(dp)) {
         error = xfs_attr_leaf_hasname(args, &bp);
 
         if (bp)
             xfs_trans_brelse(args->trans, bp);
 
         return error;
     }
 
     state = xfs_da_state_alloc(args);
     error = xfs_attr_node_lookup(args, state);
     xfs_da_state_free(state);
     return error;
 }
 
 static int
 xfs_attr_intent_init(
     struct xfs_da_args  *args,
     unsigned int        op_flags,   /* op flag (set or remove) */
     struct xfs_attr_intent  **attr)     /* new xfs_attr_intent */
 {
 
     struct xfs_attr_intent  *new;
 
     new = kmem_cache_zalloc(xfs_attr_intent_cache, GFP_NOFS | __GFP_NOFAIL);
     new->xattri_op_flags = op_flags;
     new->xattri_da_args = args;
 
     *attr = new;
     return 0;
 }
 
 /* Sets an attribute for an inode as a deferred operation */
 static int
 xfs_attr_defer_add(
     struct xfs_da_args  *args)
 {
     struct xfs_attr_intent  *new;
     int         error = 0;
 
     error = xfs_attr_intent_init(args, XFS_ATTRI_OP_FLAGS_SET, &new);
     if (error)
         return error;
 
     new->xattri_dela_state = xfs_attr_init_add_state(args);
     xfs_defer_add(args->trans, XFS_DEFER_OPS_TYPE_ATTR, &new->xattri_list);
     trace_xfs_attr_defer_add(new->xattri_dela_state, args->dp);
 
     return 0;
 }
 
 /* Sets an attribute for an inode as a deferred operation */
 static int
 xfs_attr_defer_replace(
     struct xfs_da_args  *args)
 {
     struct xfs_attr_intent  *new;
     int         error = 0;
 
     error = xfs_attr_intent_init(args, XFS_ATTRI_OP_FLAGS_REPLACE, &new);
     if (error)
         return error;
 
     new->xattri_dela_state = xfs_attr_init_replace_state(args);
     xfs_defer_add(args->trans, XFS_DEFER_OPS_TYPE_ATTR, &new->xattri_list);
     trace_xfs_attr_defer_replace(new->xattri_dela_state, args->dp);
 
     return 0;
 }
 
 /* Removes an attribute for an inode as a deferred operation */
 static int
 xfs_attr_defer_remove(
     struct xfs_da_args  *args)
 {
 
     struct xfs_attr_intent  *new;
     int         error;
 
     error  = xfs_attr_intent_init(args, XFS_ATTRI_OP_FLAGS_REMOVE, &new);
     if (error)
         return error;
 
     new->xattri_dela_state = xfs_attr_init_remove_state(args);
     xfs_defer_add(args->trans, XFS_DEFER_OPS_TYPE_ATTR, &new->xattri_list);
     trace_xfs_attr_defer_remove(new->xattri_dela_state, args->dp);
 
     return 0;
 }
 
 /*
  * Note: If args->value is NULL the attribute will be removed, just like the
  * Linux ->setattr API.
  */
 int
 xfs_attr_set(
     struct xfs_da_args  *args)
 {
     struct xfs_inode    *dp = args->dp;
     struct xfs_mount    *mp = dp->i_mount;
     struct xfs_trans_res    tres;
     bool            rsvd = (args->attr_filter & XFS_ATTR_ROOT);
     int         error, local;
     int         rmt_blks = 0;
     unsigned int        total;
 
     if (xfs_is_shutdown(dp->i_mount))
         return -EIO;
 
     error = xfs_qm_dqattach(dp);
     if (error)
         return error;
 
     args->geo = mp->m_attr_geo;
     args->whichfork = XFS_ATTR_FORK;
     args->hashval = xfs_da_hashname(args->name, args->namelen);
 
     /*
      * We have no control over the attribute names that userspace passes us
      * to remove, so we have to allow the name lookup prior to attribute
      * removal to fail as well.  Preserve the logged flag, since we need
      * to pass that through to the logging code.
      */
     args->op_flags = XFS_DA_OP_OKNOENT |
                     (args->op_flags & XFS_DA_OP_LOGGED);
 
     if (args->value) {
         XFS_STATS_INC(mp, xs_attr_set);
         args->total = xfs_attr_calc_size(args, &local);
 
         /*
          * If the inode doesn't have an attribute fork, add one.
          * (inode must not be locked when we call this routine)
          */
         if (xfs_inode_has_attr_fork(dp) == 0) {
             int sf_size = sizeof(struct xfs_attr_sf_hdr) +
                 xfs_attr_sf_entsize_byname(args->namelen,
                         args->valuelen);
 
             error = xfs_bmap_add_attrfork(dp, sf_size, rsvd);
             if (error)
                 return error;
         }
 
         if (!local)
             rmt_blks = xfs_attr3_rmt_blocks(mp, args->valuelen);
     } else {
         XFS_STATS_INC(mp, xs_attr_remove);
         rmt_blks = xfs_attr3_rmt_blocks(mp, XFS_XATTR_SIZE_MAX);
     }
 
     /*
      * Root fork attributes can use reserved data blocks for this
      * operation if necessary
      */
     xfs_init_attr_trans(args, &tres, &total);
     error = xfs_trans_alloc_inode(dp, &tres, total, 0, rsvd, &args->trans);
     if (error)
         return error;
 
     if (args->value || xfs_inode_hasattr(dp)) {
         error = xfs_iext_count_may_overflow(dp, XFS_ATTR_FORK,
                 XFS_IEXT_ATTR_MANIP_CNT(rmt_blks));
         if (error == -EFBIG)
             error = xfs_iext_count_upgrade(args->trans, dp,
                     XFS_IEXT_ATTR_MANIP_CNT(rmt_blks));
         if (error)
             goto out_trans_cancel;
     }
 
     error = xfs_attr_lookup(args);
     switch (error) {
     case -EEXIST:
         /* if no value, we are performing a remove operation */
         if (!args->value) {
             error = xfs_attr_defer_remove(args);
             break;
         }
         /* Pure create fails if the attr already exists */
         if (args->attr_flags & XATTR_CREATE)
             goto out_trans_cancel;
 
         error = xfs_attr_defer_replace(args);
         break;
     case -ENOATTR:
         /* Can't remove what isn't there. */
         if (!args->value)
             goto out_trans_cancel;
 
         /* Pure replace fails if no existing attr to replace. */
         if (args->attr_flags & XATTR_REPLACE)
             goto out_trans_cancel;
 
         error = xfs_attr_defer_add(args);
         break;
     default:
         goto out_trans_cancel;
     }
     if (error)
         goto out_trans_cancel;
 
     /*
      * If this is a synchronous mount, make sure that the
      * transaction goes to disk before returning to the user.
      */
     if (xfs_has_wsync(mp))
         xfs_trans_set_sync(args->trans);
 
     if (!(args->op_flags & XFS_DA_OP_NOTIME))
         xfs_trans_ichgtime(args->trans, dp, XFS_ICHGTIME_CHG);
 
     /*
      * Commit the last in the sequence of transactions.
      */
     xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
     error = xfs_trans_commit(args->trans);
 out_unlock:
     xfs_iunlock(dp, XFS_ILOCK_EXCL);
     return error;
 
 out_trans_cancel:
     if (args->trans)
         xfs_trans_cancel(args->trans);
     goto out_unlock;
 }
 
 /*========================================================================
  * External routines when attribute list is inside the inode
  *========================================================================*/
 
 static inline int xfs_attr_sf_totsize(struct xfs_inode *dp)
 {
     struct xfs_attr_shortform *sf;
 
     sf = (struct xfs_attr_shortform *)dp->i_af.if_u1.if_data;
     return be16_to_cpu(sf->hdr.totsize);
 }
 
 /*
  * Add a name to the shortform attribute list structure
  * This is the external routine.
  */
 static int
 xfs_attr_shortform_addname(
     struct xfs_da_args  *args)
 {
     int         newsize, forkoff;
     int         error;
 
     trace_xfs_attr_sf_addname(args);
 
     error = xfs_attr_shortform_lookup(args);
     switch (error) {
     case -ENOATTR:
         if (args->op_flags & XFS_DA_OP_REPLACE)
             return error;
         break;
     case -EEXIST:
         if (!(args->op_flags & XFS_DA_OP_REPLACE))
             return error;
 
         error = xfs_attr_sf_removename(args);
         if (error)
             return error;
 
         /*
          * Since we have removed the old attr, clear XFS_DA_OP_REPLACE
          * so that the new attr doesn't fit in shortform format, the
          * leaf format add routine won't trip over the attr not being
          * around.
          */
         args->op_flags &= ~XFS_DA_OP_REPLACE;
         break;
     case 0:
         break;
     default:
         return error;
     }
 
     if (args->namelen >= XFS_ATTR_SF_ENTSIZE_MAX ||
         args->valuelen >= XFS_ATTR_SF_ENTSIZE_MAX)
         return -ENOSPC;
 
     newsize = xfs_attr_sf_totsize(args->dp);
     newsize += xfs_attr_sf_entsize_byname(args->namelen, args->valuelen);
 
     forkoff = xfs_attr_shortform_bytesfit(args->dp, newsize);
     if (!forkoff)
         return -ENOSPC;
 
     xfs_attr_shortform_add(args, forkoff);
     return 0;
 }
 
 
 /*========================================================================
  * External routines when attribute list is one block
  *========================================================================*/
 
 /* Save the current remote block info and clear the current pointers. */
 static void
 xfs_attr_save_rmt_blk(
     struct xfs_da_args  *args)
 {
     args->blkno2 = args->blkno;
     args->index2 = args->index;
     args->rmtblkno2 = args->rmtblkno;
     args->rmtblkcnt2 = args->rmtblkcnt;
     args->rmtvaluelen2 = args->rmtvaluelen;
     args->rmtblkno = 0;
     args->rmtblkcnt = 0;
     args->rmtvaluelen = 0;
 }
 
 /* Set stored info about a remote block */
 static void
 xfs_attr_restore_rmt_blk(
     struct xfs_da_args  *args)
 {
     args->blkno = args->blkno2;
     args->index = args->index2;
     args->rmtblkno = args->rmtblkno2;
     args->rmtblkcnt = args->rmtblkcnt2;
     args->rmtvaluelen = args->rmtvaluelen2;
 }
 
 /*
  * Tries to add an attribute to an inode in leaf form
  *
  * This function is meant to execute as part of a delayed operation and leaves
  * the transaction handling to the caller.  On success the attribute is added
  * and the inode and transaction are left dirty.  If there is not enough space,
  * the attr data is converted to node format and -ENOSPC is returned. Caller is
  * responsible for handling the dirty inode and transaction or adding the attr
  * in node format.
  */
 STATIC int
 xfs_attr_leaf_try_add(
     struct xfs_da_args  *args)
 {
     struct xfs_buf      *bp;
     int         error;
 
     error = xfs_attr3_leaf_read(args->trans, args->dp, 0, &bp);
     if (error)
         return error;
 
     /*
      * Look up the xattr name to set the insertion point for the new xattr.
      */
     error = xfs_attr3_leaf_lookup_int(bp, args);
     switch (error) {
     case -ENOATTR:
         if (args->op_flags & XFS_DA_OP_REPLACE)
             goto out_brelse;
         break;
     case -EEXIST:
         if (!(args->op_flags & XFS_DA_OP_REPLACE))
             goto out_brelse;
 
         trace_xfs_attr_leaf_replace(args);
         /*
          * Save the existing remote attr state so that the current
          * values reflect the state of the new attribute we are about to
          * add, not the attribute we just found and will remove later.
          */
         xfs_attr_save_rmt_blk(args);
         break;
     case 0:
         break;
     default:
         goto out_brelse;
     }
 
     return xfs_attr3_leaf_add(bp, args);
 
 out_brelse:
     xfs_trans_brelse(args->trans, bp);
     return error;
 }
 
 /*
  * Return EEXIST if attr is found, or ENOATTR if not
  */
 STATIC int
 xfs_attr_leaf_hasname(
     struct xfs_da_args  *args,
     struct xfs_buf      **bp)
 {
     int                     error = 0;
 
     error = xfs_attr3_leaf_read(args->trans, args->dp, 0, bp);
     if (error)
         return error;
 
     error = xfs_attr3_leaf_lookup_int(*bp, args);
     if (error != -ENOATTR && error != -EEXIST)
         xfs_trans_brelse(args->trans, *bp);
 
     return error;
 }
 
 /*
  * Remove a name from the leaf attribute list structure
  *
  * This leaf block cannot have a "remote" value, we only call this routine
  * if bmap_one_block() says there is only one block (ie: no remote blks).
  */
 STATIC int
 xfs_attr_leaf_removename(
     struct xfs_da_args  *args)
 {
     struct xfs_inode    *dp;
     struct xfs_buf      *bp;
     int         error, forkoff;
 
     trace_xfs_attr_leaf_removename(args);
 
     /*
      * Remove the attribute.
      */
     dp = args->dp;
 
     error = xfs_attr_leaf_hasname(args, &bp);
     if (error == -ENOATTR) {
         xfs_trans_brelse(args->trans, bp);
         if (args->op_flags & XFS_DA_OP_RECOVERY)
             return 0;
         return error;
     } else if (error != -EEXIST)
         return error;
 
     xfs_attr3_leaf_remove(bp, args);
 
     /*
      * If the result is small enough, shrink it all into the inode.
      */
     forkoff = xfs_attr_shortform_allfit(bp, dp);
     if (forkoff)
         return xfs_attr3_leaf_to_shortform(bp, args, forkoff);
         /* bp is gone due to xfs_da_shrink_inode */
 
     return 0;
 }
 
 /*
  * Look up a name in a leaf attribute list structure.
  *
  * This leaf block cannot have a "remote" value, we only call this routine
  * if bmap_one_block() says there is only one block (ie: no remote blks).
  *
  * Returns 0 on successful retrieval, otherwise an error.
  */
 STATIC int
 xfs_attr_leaf_get(xfs_da_args_t *args)
 {
     struct xfs_buf *bp;
     int error;
 
     trace_xfs_attr_leaf_get(args);
 
     error = xfs_attr_leaf_hasname(args, &bp);
 
     if (error == -ENOATTR)  {
         xfs_trans_brelse(args->trans, bp);
         return error;
     } else if (error != -EEXIST)
         return error;
 
 
     error = xfs_attr3_leaf_getvalue(bp, args);
     xfs_trans_brelse(args->trans, bp);
     return error;
 }
 
 /* Return EEXIST if attr is found, or ENOATTR if not. */
 STATIC int
 xfs_attr_node_lookup(
     struct xfs_da_args  *args,
     struct xfs_da_state *state)
 {
     int         retval, error;
 
     /*
      * Search to see if name exists, and get back a pointer to it.
      */
     error = xfs_da3_node_lookup_int(state, &retval);
     if (error)
         return error;
 
     return retval;
 }
 
 /*========================================================================
  * External routines when attribute list size > geo->blksize
  *========================================================================*/
 
 STATIC int
 xfs_attr_node_addname_find_attr(
      struct xfs_attr_intent *attr)
 {
     struct xfs_da_args  *args = attr->xattri_da_args;
     int         error;
 
     /*
      * Search to see if name already exists, and get back a pointer
      * to where it should go.
      */
     xfs_attr_item_init_da_state(attr);
     error = xfs_attr_node_lookup(args, attr->xattri_da_state);
     switch (error) {
     case -ENOATTR:
         if (args->op_flags & XFS_DA_OP_REPLACE)
             goto error;
         break;
     case -EEXIST:
         if (!(args->op_flags & XFS_DA_OP_REPLACE))
             goto error;
 
 
         trace_xfs_attr_node_replace(args);
         /*
          * Save the existing remote attr state so that the current
          * values reflect the state of the new attribute we are about to
          * add, not the attribute we just found and will remove later.
          */
         xfs_attr_save_rmt_blk(args);
         break;
     case 0:
         break;
     default:
         goto error;
     }
 
     return 0;
 error:
     if (attr->xattri_da_state) {
         xfs_da_state_free(attr->xattri_da_state);
         attr->xattri_da_state = NULL;
     }
     return error;
 }
 
 /*
  * Add a name to a Btree-format attribute list.
  *
  * This will involve walking down the Btree, and may involve splitting
  * leaf nodes and even splitting intermediate nodes up to and including
  * the root node (a special case of an intermediate node).
  */
 static int
 xfs_attr_node_try_addname(
     struct xfs_attr_intent      *attr)
 {
     struct xfs_da_state     *state = attr->xattri_da_state;
     struct xfs_da_state_blk     *blk;
     int             error;
 
     trace_xfs_attr_node_addname(state->args);
 
     blk = &state->path.blk[state->path.active-1];
     ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
 
     error = xfs_attr3_leaf_add(blk->bp, state->args);
     if (error == -ENOSPC) {
         if (state->path.active == 1) {
             /*
              * Its really a single leaf node, but it had
              * out-of-line values so it looked like it *might*
              * have been a b-tree. Let the caller deal with this.
              */
             goto out;
         }
 
         /*
          * Split as many Btree elements as required.
          * This code tracks the new and old attr's location
          * in the index/blkno/rmtblkno/rmtblkcnt fields and
          * in the index2/blkno2/rmtblkno2/rmtblkcnt2 fields.
          */
         error = xfs_da3_split(state);
         if (error)
             goto out;
     } else {
         /*
          * Addition succeeded, update Btree hashvals.
          */
         xfs_da3_fixhashpath(state, &state->path);
     }
 
 out:
     xfs_da_state_free(state);
     attr->xattri_da_state = NULL;
     return error;
 }
 
 static int
 xfs_attr_node_removename(
     struct xfs_da_args  *args,
     struct xfs_da_state *state)
 {
     struct xfs_da_state_blk *blk;
     int         retval;
 
     /*
      * Remove the name and update the hashvals in the tree.
      */
     blk = &state->path.blk[state->path.active-1];
     ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
     retval = xfs_attr3_leaf_remove(blk->bp, args);
     xfs_da3_fixhashpath(state, &state->path);
 
     return retval;
 }
 
 static int
 xfs_attr_node_remove_attr(
     struct xfs_attr_intent      *attr)
 {
     struct xfs_da_args      *args = attr->xattri_da_args;
     struct xfs_da_state     *state = xfs_da_state_alloc(args);
     int             retval = 0;
     int             error = 0;
 
     /*
      * The attr we are removing has already been marked incomplete, so
      * we need to set the filter appropriately to re-find the "old"
      * attribute entry after any split ops.
      */
     args->attr_filter |= XFS_ATTR_INCOMPLETE;
     error = xfs_da3_node_lookup_int(state, &retval);
     if (error)
         goto out;
 
     error = xfs_attr_node_removename(args, state);
 
     /*
      * Check to see if the tree needs to be collapsed.
      */
     if (retval && (state->path.active > 1)) {
         error = xfs_da3_join(state);
         if (error)
             goto out;
     }
     retval = error = 0;
 
 out:
     xfs_da_state_free(state);
     if (error)
         return error;
     return retval;
 }
 
 /*
  * Retrieve the attribute data from a node attribute list.
  *
  * This routine gets called for any attribute fork that has more than one
  * block, ie: both true Btree attr lists and for single-leaf-blocks with
  * "remote" values taking up more blocks.
  *
  * Returns 0 on successful retrieval, otherwise an error.
  */
 STATIC int
 xfs_attr_node_get(
     struct xfs_da_args  *args)
 {
     struct xfs_da_state *state;
     struct xfs_da_state_blk *blk;
     int         i;
     int         error;
 
     trace_xfs_attr_node_get(args);
 
     /*
      * Search to see if name exists, and get back a pointer to it.
      */
     state = xfs_da_state_alloc(args);
     error = xfs_attr_node_lookup(args, state);
     if (error != -EEXIST)
         goto out_release;
 
     /*
      * Get the value, local or "remote"
      */
     blk = &state->path.blk[state->path.active - 1];
     error = xfs_attr3_leaf_getvalue(blk->bp, args);
 
     /*
      * If not in a transaction, we have to release all the buffers.
      */
 out_release:
     for (i = 0; i < state->path.active; i++) {
         xfs_trans_brelse(args->trans, state->path.blk[i].bp);
         state->path.blk[i].bp = NULL;
     }
 
     xfs_da_state_free(state);
     return error;
 }
 
 /* Returns true if the attribute entry name is valid. */
 bool
 xfs_attr_namecheck(
     const void  *name,
     size_t      length)
 {
     /*
      * MAXNAMELEN includes the trailing null, but (name/length) leave it
      * out, so use >= for the length check.
      */
     if (length >= MAXNAMELEN)
         return false;
 
     /* There shouldn't be any nulls here */
     return !memchr(name, 0, length);
 }
 
 int __init
 xfs_attr_intent_init_cache(void)
 {
     xfs_attr_intent_cache = kmem_cache_create("xfs_attr_intent",
             sizeof(struct xfs_attr_intent),
             0, 0, NULL);
 
     return xfs_attr_intent_cache != NULL ? 0 : -ENOMEM;
 }
 
 void
 xfs_attr_intent_destroy_cache(void)
 {
     kmem_cache_destroy(xfs_attr_intent_cache);
     xfs_attr_intent_cache = NULL;
 }

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