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authorChristoph Hellwig <hch@lst.de>2017-02-06 10:51:03 -0800
committerDarrick J. Wong <darrick.wong@oracle.com>2017-02-06 17:47:47 -0800
commit3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5 (patch)
tree5b9681a04b0fddce02510303a33546794f2b0568 /fs/xfs/xfs_iomap.c
parenta14234c72bf41ac96bc8c98e96e2c84b6d4bd4f2 (diff)
downloadlinux-3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5.tar.gz
xfs: allocate direct I/O COW blocks in iomap_begin
Instead of preallocating all the required COW blocks in the high-level
write code do it inside the iomap code, like we do for all other I/O.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs/xfs/xfs_iomap.c')
-rw-r--r--fs/xfs/xfs_iomap.c31
1 files changed, 12 insertions, 19 deletions
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 06bfc82dd00b..e0bc290396dc 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -995,37 +995,31 @@ xfs_file_iomap_begin(
 	offset_fsb = XFS_B_TO_FSBT(mp, offset);
 	end_fsb = XFS_B_TO_FSB(mp, offset + length);
 
-	if (xfs_is_reflink_inode(ip) &&
-	    (flags & IOMAP_WRITE) && (flags & IOMAP_DIRECT)) {
-		shared = xfs_reflink_find_cow_mapping(ip, offset, &imap);
-		if (shared) {
-			xfs_iunlock(ip, lockmode);
-			goto alloc_done;
-		}
-		ASSERT(!isnullstartblock(imap.br_startblock));
-	}
-
 	error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
 			       &nimaps, 0);
 	if (error)
 		goto out_unlock;
 
-	if ((flags & IOMAP_REPORT) ||
-	    (xfs_is_reflink_inode(ip) &&
-	     (flags & IOMAP_WRITE) && (flags & IOMAP_DIRECT))) {
+	if (flags & IOMAP_REPORT) {
 		/* Trim the mapping to the nearest shared extent boundary. */
 		error = xfs_reflink_trim_around_shared(ip, &imap, &shared,
 				&trimmed);
 		if (error)
 			goto out_unlock;
-
-		ASSERT((flags & IOMAP_REPORT) || !shared);
 	}
 
 	if ((flags & (IOMAP_WRITE | IOMAP_ZERO)) && xfs_is_reflink_inode(ip)) {
-		error = xfs_reflink_reserve_cow(ip, &imap, &shared);
-		if (error)
-			goto out_unlock;
+		if (flags & IOMAP_DIRECT) {
+			/* may drop and re-acquire the ilock */
+			error = xfs_reflink_allocate_cow(ip, &imap, &shared,
+					&lockmode);
+			if (error)
+				goto out_unlock;
+		} else {
+			error = xfs_reflink_reserve_cow(ip, &imap, &shared);
+			if (error)
+				goto out_unlock;
+		}
 
 		end_fsb = imap.br_startoff + imap.br_blockcount;
 		length = XFS_FSB_TO_B(mp, end_fsb) - offset;
@@ -1054,7 +1048,6 @@ xfs_file_iomap_begin(
 		if (error)
 			return error;
 
-alloc_done:
 		iomap->flags = IOMAP_F_NEW;
 		trace_xfs_iomap_alloc(ip, offset, length, 0, &imap);
 	} else {