xfs: cleanup error handling in xfs_swap_extents

Use multiple lables for proper error unwinding and get rid of some now
superflous variables.

Signed-off-by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>

fs/xfs/xfs_dfrag.c

@@ -118,19 +118,17 @@ xfs_swap_extents(
 	xfs_bstat_t	*sbp = &sxp->sx_stat;
 	xfs_ifork_t	*tempifp, *ifp, *tifp;
 	int		ilf_fields, tilf_fields;
-	static uint	lock_flags = XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL;
 	int		error = 0;
 	int		aforkblks = 0;
 	int		taforkblks = 0;
 	__uint64_t	tmp;
-	char		locked = 0;
 
 	mp = ip->i_mount;
 
 	tempifp = kmem_alloc(sizeof(xfs_ifork_t), KM_MAYFAIL);
 	if (!tempifp) {
 		error = XFS_ERROR(ENOMEM);
-		goto error0;
+		goto out;
 	}
 
 	sbp = &sxp->sx_stat;
@@ -143,47 +141,46 @@ xfs_swap_extents(
 	 */
 	xfs_lock_two_inodes(ip, tip, XFS_IOLOCK_EXCL);
 	xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);
-	locked = 1;
 
 	/* Verify that both files have the same format */
 	if ((ip->i_d.di_mode & S_IFMT) != (tip->i_d.di_mode & S_IFMT)) {
 		error = XFS_ERROR(EINVAL);
-		goto error0;
+		goto out_unlock;
 	}
 
 	/* Verify both files are either real-time or non-realtime */
 	if (XFS_IS_REALTIME_INODE(ip) != XFS_IS_REALTIME_INODE(tip)) {
 		error = XFS_ERROR(EINVAL);
-		goto error0;
+		goto out_unlock;
 	}
 
 	/* Should never get a local format */
 	if (ip->i_d.di_format == XFS_DINODE_FMT_LOCAL ||
 	    tip->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
 		error = XFS_ERROR(EINVAL);
-		goto error0;
+		goto out_unlock;
 	}
 
 	if (VN_CACHED(VFS_I(tip)) != 0) {
 		xfs_inval_cached_trace(tip, 0, -1, 0, -1);
 		error = xfs_flushinval_pages(tip, 0, -1,
 				FI_REMAPF_LOCKED);
 		if (error)
-			goto error0;
+			goto out_unlock;
 	}
 
 	/* Verify O_DIRECT for ftmp */
 	if (VN_CACHED(VFS_I(tip)) != 0) {
 		error = XFS_ERROR(EINVAL);
-		goto error0;
+		goto out_unlock;
 	}
 
 	/* Verify all data are being swapped */
 	if (sxp->sx_offset != 0 ||
 	    sxp->sx_length != ip->i_d.di_size ||
 	    sxp->sx_length != tip->i_d.di_size) {
 		error = XFS_ERROR(EFAULT);
-		goto error0;
+		goto out_unlock;
 	}
 
 	/*
@@ -193,7 +190,7 @@ xfs_swap_extents(
 	 */
 	if ( XFS_IFORK_Q(ip) != XFS_IFORK_Q(tip) ) {
 		error = XFS_ERROR(EINVAL);
-		goto error0;
+		goto out_unlock;
 	}
 
 	/*
@@ -208,7 +205,7 @@ xfs_swap_extents(
 	    (sbp->bs_mtime.tv_sec != ip->i_d.di_mtime.t_sec) ||
 	    (sbp->bs_mtime.tv_nsec != ip->i_d.di_mtime.t_nsec)) {
 		error = XFS_ERROR(EBUSY);
-		goto error0;
+		goto out_unlock;
 	}
 
 	/* We need to fail if the file is memory mapped.  Once we have tossed
@@ -219,7 +216,7 @@ xfs_swap_extents(
 	 */
 	if (VN_MAPPED(VFS_I(ip))) {
 		error = XFS_ERROR(EBUSY);
-		goto error0;
+		goto out_unlock;
 	}
 
 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
@@ -242,8 +239,7 @@ xfs_swap_extents(
 		xfs_iunlock(ip,  XFS_IOLOCK_EXCL);
 		xfs_iunlock(tip, XFS_IOLOCK_EXCL);
 		xfs_trans_cancel(tp, 0);
-		locked = 0;
-		goto error0;
+		goto out;
 	}
 	xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);
 
@@ -253,19 +249,15 @@ xfs_swap_extents(
 	if ( ((XFS_IFORK_Q(ip) != 0) && (ip->i_d.di_anextents > 0)) &&
 	     (ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
 		error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &aforkblks);
-		if (error) {
-			xfs_trans_cancel(tp, 0);
-			goto error0;
-		}
+		if (error)
+			goto out_trans_cancel;
 	}
 	if ( ((XFS_IFORK_Q(tip) != 0) && (tip->i_d.di_anextents > 0)) &&
 	     (tip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
 		error = xfs_bmap_count_blocks(tp, tip, XFS_ATTR_FORK,
 			&taforkblks);
-		if (error) {
-			xfs_trans_cancel(tp, 0);
-			goto error0;
-		}
+		if (error)
+			goto out_trans_cancel;
 	}
 
 	/*
@@ -332,10 +324,10 @@ xfs_swap_extents(
 
 
 	IHOLD(ip);
-	xfs_trans_ijoin(tp, ip, lock_flags);
+	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
 
 	IHOLD(tip);
-	xfs_trans_ijoin(tp, tip, lock_flags);
+	xfs_trans_ijoin(tp, tip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
 
 	xfs_trans_log_inode(tp, ip,  ilf_fields);
 	xfs_trans_log_inode(tp, tip, tilf_fields);
@@ -344,19 +336,19 @@ xfs_swap_extents(
 	 * If this is a synchronous mount, make sure that the
 	 * transaction goes to disk before returning to the user.
 	 */
-	if (mp->m_flags & XFS_MOUNT_WSYNC) {
+	if (mp->m_flags & XFS_MOUNT_WSYNC)
 		xfs_trans_set_sync(tp);
-	}
 
 	error = xfs_trans_commit(tp, XFS_TRANS_SWAPEXT);
-	locked = 0;
 
- error0:
-	if (locked) {
-		xfs_iunlock(ip,  lock_flags);
-		xfs_iunlock(tip, lock_flags);
-	}
-	if (tempifp != NULL)
-		kmem_free(tempifp);
+out_unlock:
+	xfs_iunlock(ip,  XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
+	xfs_iunlock(tip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
+out:
+	kmem_free(tempifp);
 	return error;
+
+out_trans_cancel:
+	xfs_trans_cancel(tp, 0);
+	goto out_unlock;
 }