diff options
| author | Christoph Hellwig <hch@infradead.org> | 2012-03-27 10:34:47 -0400 |
|---|---|---|
| committer | Ben Myers <bpm@sgi.com> | 2012-05-14 16:20:17 -0500 |
| commit | 467f78992a0743e0e71729e4faa20b67b0f25289 (patch) | |
| tree | 2757c82c33b643105a8c0b42a12f61b96d6e2a19 | |
| parent | b4d05e3019692fc5a8c573fbce60de2d48c5b7a1 (diff) | |
| download | linux-467f78992a0743e0e71729e4faa20b67b0f25289.tar.bz2 | |
xfs: reduce ilock hold times in xfs_file_aio_write_checks
We do not need the ilock for generic_write_checks and the i_size_read,
which are protected by i_mutex and/or iolock, so reduce the ilock
critical section to just the call to xfs_zero_eof.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
| -rw-r--r-- | fs/xfs/xfs_file.c | 23 |
1 files changed, 9 insertions, 14 deletions
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 54a67dd9ac0a..3537c8d0af48 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -593,35 +593,31 @@ xfs_file_aio_write_checks( struct xfs_inode *ip = XFS_I(inode); int error = 0; - xfs_rw_ilock(ip, XFS_ILOCK_EXCL); restart: error = generic_write_checks(file, pos, count, S_ISBLK(inode->i_mode)); - if (error) { - xfs_rw_iunlock(ip, XFS_ILOCK_EXCL); + if (error) return error; - } /* * If the offset is beyond the size of the file, we need to zero any * blocks that fall between the existing EOF and the start of this * write. If zeroing is needed and we are currently holding the - * iolock shared, we need to update it to exclusive which involves - * dropping all locks and relocking to maintain correct locking order. - * If we do this, restart the function to ensure all checks and values - * are still valid. + * iolock shared, we need to update it to exclusive which implies + * having to redo all checks before. */ if (*pos > i_size_read(inode)) { if (*iolock == XFS_IOLOCK_SHARED) { - xfs_rw_iunlock(ip, XFS_ILOCK_EXCL | *iolock); + xfs_rw_iunlock(ip, *iolock); *iolock = XFS_IOLOCK_EXCL; - xfs_rw_ilock(ip, XFS_ILOCK_EXCL | *iolock); + xfs_rw_ilock(ip, *iolock); goto restart; } + xfs_rw_ilock(ip, XFS_ILOCK_EXCL); error = -xfs_zero_eof(ip, *pos, i_size_read(inode)); + xfs_rw_iunlock(ip, XFS_ILOCK_EXCL); + if (error) + return error; } - xfs_rw_iunlock(ip, XFS_ILOCK_EXCL); - if (error) - return error; /* * Updating the timestamps will grab the ilock again from @@ -638,7 +634,6 @@ restart: * people from modifying setuid and setgid binaries. */ return file_remove_suid(file); - } /* |