xfs: Add attibute set and helper functions

This patch adds xfs_attr_set_args and xfs_bmap_set_attrforkoff.
These sub-routines set the attributes specified in @args.
We will use this later for setting parent pointers as a deferred
attribute operation.

[dgc: remove attr fork init code from xfs_attr_set_args().]
[dgc: xfs_attr_try_sf_addname() NULLs args.trans after commit.]
[dgc: correct sf add error handling.]

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

4 files changed, 115 insertions, 87 deletions

diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index c15a1debec90..25431ddba1fa 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -215,9 +215,80 @@ xfs_attr_try_sf_addname(
                 xfs_trans_set_sync(args->trans);
 
         error2 = xfs_trans_commit(args->trans);
+        args->trans = NULL;
         return error ? error : error2;
 }
 
+/*
+ * Set the attribute specified in @args.
+ */
+int
+xfs_attr_set_args(
+        struct xfs_da_args      *args,
+        struct xfs_buf          **leaf_bp)
+{
+        struct xfs_inode        *dp = args->dp;
+        int                     error;
+
+        /*
+         * If the attribute list is non-existent or a shortform list,
+         * upgrade it to a single-leaf-block attribute list.
+         */
+        if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL ||
+            (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
+             dp->i_d.di_anextents == 0)) {
+
+                /*
+                 * Build initial attribute list (if required).
+                 */
+                if (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS)
+                        xfs_attr_shortform_create(args);
+
+                /*
+                 * Try to add the attr to the attribute list in the inode.
+                 */
+                error = xfs_attr_try_sf_addname(dp, args);
+                if (error != -ENOSPC)
+                        return error;
+
+                /*
+                 * 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, leaf_bp);
+                if (error)
+                        return error;
+
+                /*
+                 * Prevent the leaf buffer from being unlocked so that a
+                 * concurrent AIL push cannot grab the half-baked leaf
+                 * buffer and run into problems with the write verifier.
+                 */
+                xfs_trans_bhold(args->trans, *leaf_bp);
+
+                error = xfs_defer_finish(&args->trans);
+                if (error)
+                        return error;
+
+                /*
+                 * Commit the leaf transformation.  We'll need another
+                 * (linked) transaction to add the new attribute to the
+                 * leaf.
+                 */
+                error = xfs_trans_roll_inode(&args->trans, dp);
+                if (error)
+                        return error;
+                xfs_trans_bjoin(args->trans, *leaf_bp);
+                *leaf_bp = NULL;
+        }
+
+        if (xfs_bmap_one_block(dp, XFS_ATTR_FORK))
+                error = xfs_attr_leaf_addname(args);
+        else
+                error = xfs_attr_node_addname(args);
+        return error;
+}
+
 int
 xfs_attr_set(
         struct xfs_inode        *dp,
@@ -282,73 +353,17 @@ xfs_attr_set(
         error = xfs_trans_reserve_quota_nblks(args.trans, dp, args.total, 0,
                                 rsvd ? XFS_QMOPT_RES_REGBLKS | XFS_QMOPT_FORCE_RES :
                                        XFS_QMOPT_RES_REGBLKS);
-        if (error) {
-                xfs_iunlock(dp, XFS_ILOCK_EXCL);
-                xfs_trans_cancel(args.trans);
-                return error;
-        }
+        if (error)
+                goto out_trans_cancel;
 
         xfs_trans_ijoin(args.trans, dp, 0);
-
-        /*
-         * If the attribute list is non-existent or a shortform list,
-         * upgrade it to a single-leaf-block attribute list.
-         */
-        if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL ||
-            (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
-             dp->i_d.di_anextents == 0)) {
-
-                /*
-                 * Build initial attribute list (if required).
-                 */
-                if (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS)
-                        xfs_attr_shortform_create(&args);
-
-                /*
-                 * Try to add the attr to the attribute list in
-                 * the inode.
-                 */
-                error = xfs_attr_try_sf_addname(dp, &args);
-                if (error != -ENOSPC) {
-                        xfs_iunlock(dp, XFS_ILOCK_EXCL);
-                        return error;
-                }
-
-                /*
-                 * 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, &leaf_bp);
-                if (error)
-                        goto out;
-                /*
-                 * Prevent the leaf buffer from being unlocked so that a
-                 * concurrent AIL push cannot grab the half-baked leaf
-                 * buffer and run into problems with the write verifier.
-                 */
-                xfs_trans_bhold(args.trans, leaf_bp);
-                error = xfs_defer_finish(&args.trans);
-                if (error)
-                        goto out;
-
-                /*
-                 * Commit the leaf transformation.  We'll need another (linked)
-                 * transaction to add the new attribute to the leaf, which
-                 * means that we have to hold & join the leaf buffer here too.
-                 */
-                error = xfs_trans_roll_inode(&args.trans, dp);
-                if (error)
-                        goto out;
-                xfs_trans_bjoin(args.trans, leaf_bp);
-                leaf_bp = NULL;
-        }
-
-        if (xfs_bmap_one_block(dp, XFS_ATTR_FORK))
-                error = xfs_attr_leaf_addname(&args);
-        else
-                error = xfs_attr_node_addname(&args);
+        error = xfs_attr_set_args(&args, &leaf_bp);
         if (error)
-                goto out;
+                goto out_release_leaf;
+        if (!args.trans) {
+                /* shortform attribute has already been committed */
+                goto out_unlock;
+        }
 
         /*
          * If this is a synchronous mount, make sure that the
@@ -365,17 +380,17 @@ xfs_attr_set(
          */
         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:
+out_release_leaf:
         if (leaf_bp)
                 xfs_trans_brelse(args.trans, leaf_bp);
+out_trans_cancel:
         if (args.trans)
                 xfs_trans_cancel(args.trans);
-        xfs_iunlock(dp, XFS_ILOCK_EXCL);
-        return error;
+        goto out_unlock;
 }
 
 /*
diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
index 033ff8c478e2..f608ac8f306f 100644
--- a/fs/xfs/libxfs/xfs_attr.h
+++ b/fs/xfs/libxfs/xfs_attr.h
@@ -140,6 +140,7 @@ int xfs_attr_get(struct xfs_inode *ip, const unsigned char *name,
                  unsigned char *value, int *valuelenp, int flags);
 int xfs_attr_set(struct xfs_inode *dp, const unsigned char *name,
                  unsigned char *value, int valuelen, int flags);
+int xfs_attr_set_args(struct xfs_da_args *args, struct xfs_buf **leaf_bp);
 int xfs_attr_remove(struct xfs_inode *dp, const unsigned char *name, int flags);
 int xfs_attr_list(struct xfs_inode *dp, char *buffer, int bufsize,
                   int flags, struct attrlist_cursor_kern *cursor);
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index da6b768664e3..74d7228e755b 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -1019,6 +1019,34 @@ xfs_bmap_add_attrfork_local(
         return -EFSCORRUPTED;
 }
 
+/* Set an inode attr fork off based on the format */
+int
+xfs_bmap_set_attrforkoff(
+        struct xfs_inode        *ip,
+        int                     size,
+        int                     *version)
+{
+        switch (ip->i_d.di_format) {
+        case XFS_DINODE_FMT_DEV:
+                ip->i_d.di_forkoff = roundup(sizeof(xfs_dev_t), 8) >> 3;
+                break;
+        case XFS_DINODE_FMT_LOCAL:
+        case XFS_DINODE_FMT_EXTENTS:
+        case XFS_DINODE_FMT_BTREE:
+                ip->i_d.di_forkoff = xfs_attr_shortform_bytesfit(ip, size);
+                if (!ip->i_d.di_forkoff)
+                        ip->i_d.di_forkoff = xfs_default_attroffset(ip) >> 3;
+                else if ((ip->i_mount->m_flags & XFS_MOUNT_ATTR2) && version)
+                        *version = 2;
+                break;
+        default:
+                ASSERT(0);
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
 /*
  * Convert inode from non-attributed to attributed.
  * Must not be in a transaction, ip must not be locked.
@@ -1070,26 +1098,9 @@ xfs_bmap_add_attrfork(
 
         xfs_trans_ijoin(tp, ip, 0);
         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
-
-        switch (ip->i_d.di_format) {
-        case XFS_DINODE_FMT_DEV:
-                ip->i_d.di_forkoff = roundup(sizeof(xfs_dev_t), 8) >> 3;
-                break;
-        case XFS_DINODE_FMT_LOCAL:
-        case XFS_DINODE_FMT_EXTENTS:
-        case XFS_DINODE_FMT_BTREE:
-                ip->i_d.di_forkoff = xfs_attr_shortform_bytesfit(ip, size);
-                if (!ip->i_d.di_forkoff)
-                        ip->i_d.di_forkoff = xfs_default_attroffset(ip) >> 3;
-                else if (mp->m_flags & XFS_MOUNT_ATTR2)
-                        version = 2;
-                break;
-        default:
-                ASSERT(0);
-                error = -EINVAL;
+        error = xfs_bmap_set_attrforkoff(ip, size, &version);
+        if (error)
                 goto trans_cancel;
-        }
-
         ASSERT(ip->i_afp == NULL);
         ip->i_afp = kmem_zone_zalloc(xfs_ifork_zone, KM_SLEEP);
         ip->i_afp->if_flags = XFS_IFEXTENTS;
diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h
index b6e9b639e731..488dc8860fd7 100644
--- a/fs/xfs/libxfs/xfs_bmap.h
+++ b/fs/xfs/libxfs/xfs_bmap.h
@@ -183,6 +183,7 @@ void	xfs_trim_extent(struct xfs_bmbt_irec *irec, xfs_fileoff_t bno,
                 xfs_filblks_t len);
 void    xfs_trim_extent_eof(struct xfs_bmbt_irec *, struct xfs_inode *);
 int     xfs_bmap_add_attrfork(struct xfs_inode *ip, int size, int rsvd);
+int     xfs_bmap_set_attrforkoff(struct xfs_inode *ip, int size, int *version);
 void    xfs_bmap_local_to_extents_empty(struct xfs_inode *ip, int whichfork);
 void    __xfs_bmap_add_free(struct xfs_trans *tp, xfs_fsblock_t bno,
                 xfs_filblks_t len, struct xfs_owner_info *oinfo,