From 6e708bcf6583f663da9fe7bc5292cc62f0a8410d Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Fri, 22 Nov 2013 10:41:16 +1100 Subject: [PATCH] xfs: align initial file allocations correctly The function xfs_bmap_isaeof() is used to indicate that an allocation is occurring at or past the end of file, and as such should be aligned to the underlying storage geometry if possible. Commit 27a3f8f ("xfs: introduce xfs_bmap_last_extent") changed the behaviour of this function for empty files - it turned off allocation alignment for this case accidentally. Hence large initial allocations from direct IO are not getting correctly aligned to the underlying geometry, and that is cause write performance to drop in alignment sensitive configurations. Fix it by considering allocation into empty files as requiring aligned allocation again. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Ben Myers (cherry picked from commit f9b395a8ef8f34d19cae2cde361e19c96e097fad) --- fs/xfs/xfs_bmap.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c index 3ef11b22e750..8401f11f378f 100644 --- a/fs/xfs/xfs_bmap.c +++ b/fs/xfs/xfs_bmap.c @@ -1635,7 +1635,7 @@ xfs_bmap_last_extent( * blocks at the end of the file which do not start at the previous data block, * we will try to align the new blocks at stripe unit boundaries. * - * Returns 0 in bma->aeof if the file (fork) is empty as any new write will be + * Returns 1 in bma->aeof if the file (fork) is empty as any new write will be * at, or past the EOF. */ STATIC int @@ -1650,9 +1650,14 @@ xfs_bmap_isaeof( bma->aeof = 0; error = xfs_bmap_last_extent(NULL, bma->ip, whichfork, &rec, &is_empty); - if (error || is_empty) + if (error) return error; + if (is_empty) { + bma->aeof = 1; + return 0; + } + /* * Check if we are allocation or past the last extent, or at least into * the last delayed allocated extent. -- 2.30.2