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>

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;
 }
 
 /*

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);

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;

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,