X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=fs%2Fxfs%2Fxfs_iomap.c;h=67f22b2b44b3c41c51ce3ac6c1f911f5db47b181;hb=ce6754235b423610e91f5300e1555c2e4ee1c03a;hp=a2c3200a099f86afe5577eddc8fb916337819f0f;hpb=579aa9caf552c639fc78168db4cfe7ffcf00c3b3;p=~andy%2Flinux

diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index a2c3200a099..67f22b2b44b 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -523,8 +523,7 @@ xfs_iomap_write_direct(
 		goto error_out;
 	}
 
-	if (unlikely(!imap.br_startblock &&
-		     !(XFS_IS_REALTIME_INODE(ip)))) {
+	if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip))) {
 		error = xfs_cmn_err_fsblock_zero(ip, &imap);
 		goto error_out;
 	}
@@ -686,8 +685,7 @@ retry:
 		goto retry;
 	}
 
-	if (unlikely(!imap[0].br_startblock &&
-		     !(XFS_IS_REALTIME_INODE(ip))))
+	if (!(imap[0].br_startblock || XFS_IS_REALTIME_INODE(ip)))
 		return xfs_cmn_err_fsblock_zero(ip, &imap[0]);
 
 	*ret_imap = imap[0];
@@ -838,9 +836,9 @@ xfs_iomap_write_allocate(
 		 * See if we were able to allocate an extent that
 		 * covers at least part of the callers request
 		 */
-		if (unlikely(!imap.br_startblock &&
-			     XFS_IS_REALTIME_INODE(ip)))
+		if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip)))
 			return xfs_cmn_err_fsblock_zero(ip, &imap);
+
 		if ((offset_fsb >= imap.br_startoff) &&
 		    (offset_fsb < (imap.br_startoff +
 				   imap.br_blockcount))) {
@@ -891,6 +889,16 @@ xfs_iomap_write_unwritten(
 	count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
 	count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb);
 
+	/*
+	 * Reserve enough blocks in this transaction for two complete extent
+	 * btree splits.  We may be converting the middle part of an unwritten
+	 * extent and in this case we will insert two new extents in the btree
+	 * each of which could cause a full split.
+	 *
+	 * This reservation amount will be used in the first call to
+	 * xfs_bmbt_split() to select an AG with enough space to satisfy the
+	 * rest of the operation.
+	 */
 	resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
 
 	do {
@@ -934,8 +942,7 @@ xfs_iomap_write_unwritten(
 		if (error)
 			return XFS_ERROR(error);
 
-		if (unlikely(!imap.br_startblock &&
-			     !(XFS_IS_REALTIME_INODE(ip))))
+		if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip)))
 			return xfs_cmn_err_fsblock_zero(ip, &imap);
 
 		if ((numblks_fsb = imap.br_blockcount) == 0) {