xfs: fix AIM7 regression

Apparently our current rwsem code doesn't like doing the trylock, then
lock for real scheme.  So change our read/write methods to just do the
trylock for the RWF_NOWAIT case.  This fixes a ~25% regression in
AIM7.

Fixes: 91f9943e ("fs: support RWF_NOWAIT for buffered reads")
Reported-by: kernel test robot <xiaolong.ye@intel.com>
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>
This commit is contained in:
Christoph Hellwig 2017-10-23 18:31:50 -07:00 committed by Darrick J. Wong
parent 785545c898
commit 942491c9e6

View File

@ -237,11 +237,13 @@ xfs_file_dax_read(
if (!count)
return 0; /* skip atime */
if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) {
if (iocb->ki_flags & IOCB_NOWAIT)
if (iocb->ki_flags & IOCB_NOWAIT) {
if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED))
return -EAGAIN;
} else {
xfs_ilock(ip, XFS_IOLOCK_SHARED);
}
ret = dax_iomap_rw(iocb, to, &xfs_iomap_ops);
xfs_iunlock(ip, XFS_IOLOCK_SHARED);
@ -259,9 +261,10 @@ xfs_file_buffered_aio_read(
trace_xfs_file_buffered_read(ip, iov_iter_count(to), iocb->ki_pos);
if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) {
if (iocb->ki_flags & IOCB_NOWAIT)
if (iocb->ki_flags & IOCB_NOWAIT) {
if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED))
return -EAGAIN;
} else {
xfs_ilock(ip, XFS_IOLOCK_SHARED);
}
ret = generic_file_read_iter(iocb, to);
@ -552,9 +555,10 @@ xfs_file_dio_aio_write(
iolock = XFS_IOLOCK_SHARED;
}
if (!xfs_ilock_nowait(ip, iolock)) {
if (iocb->ki_flags & IOCB_NOWAIT)
if (iocb->ki_flags & IOCB_NOWAIT) {
if (!xfs_ilock_nowait(ip, iolock))
return -EAGAIN;
} else {
xfs_ilock(ip, iolock);
}
@ -606,9 +610,10 @@ xfs_file_dax_write(
size_t count;
loff_t pos;
if (!xfs_ilock_nowait(ip, iolock)) {
if (iocb->ki_flags & IOCB_NOWAIT)
if (iocb->ki_flags & IOCB_NOWAIT) {
if (!xfs_ilock_nowait(ip, iolock))
return -EAGAIN;
} else {
xfs_ilock(ip, iolock);
}