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| author | David Chinner <dgc@sgi.com> | 2008-03-06 03:43:42 +0100 |
|---|---|---|
| committer | Lachlan McIlroy <lachlan@redback.melbourne.sgi.com> | 2008-04-18 03:37:32 +0200 |
| commit | a3f74ffb6d1448d9a8f482e593b80ec15f1695d4 (patch) | |
| tree | e7a9ea7ba4032340e771605000002da4349719cb /fs/xfs/xfs_trans_buf.c | |
| parent | [XFS] Factor xfs_itobp() and xfs_inotobp(). (diff) | |
| download | linux-a3f74ffb6d1448d9a8f482e593b80ec15f1695d4.tar.xz linux-a3f74ffb6d1448d9a8f482e593b80ec15f1695d4.zip | |
[XFS] Don't block pdflush when writing back inodes
When pdflush is writing back inodes, it can get stuck on inode cluster
buffers that are currently under I/O. This occurs when we write data to
multiple inodes in the same inode cluster at the same time.
Effectively, delayed allocation marks the inode dirty during the data
writeback. Hence if the inode cluster was flushed during the writeback of
the first inode, the writeback of the second inode will block waiting for
the inode cluster write to complete before writing it again for the newly
dirtied inode.
Basically, we want to avoid this from happening so we don't block pdflush
and slow down all of writeback. Hence we introduce a non-blocking async
inode flush flag that pdflush uses. If this flag is set, we use
non-blocking operations (e.g. try locks) whereever we can to avoid
blocking or extra I/O being issued.
SGI-PV: 970925
SGI-Modid: xfs-linux-melb:xfs-kern:30501a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Diffstat (limited to 'fs/xfs/xfs_trans_buf.c')
| -rw-r--r-- | fs/xfs/xfs_trans_buf.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c index 60b6b898022b..4e5c010f5040 100644 --- a/fs/xfs/xfs_trans_buf.c +++ b/fs/xfs/xfs_trans_buf.c @@ -304,7 +304,8 @@ xfs_trans_read_buf( if (tp == NULL) { bp = xfs_buf_read_flags(target, blkno, len, flags | BUF_BUSY); if (!bp) - return XFS_ERROR(ENOMEM); + return (flags & XFS_BUF_TRYLOCK) ? + EAGAIN : XFS_ERROR(ENOMEM); if ((bp != NULL) && (XFS_BUF_GETERROR(bp) != 0)) { xfs_ioerror_alert("xfs_trans_read_buf", mp, |