xfs: don't stall cowblocks scan if we can't take locks

Don't stall the cowblocks scan on a locked inode if we possibly can.
We'd much rather the background scanner keep moving.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
This commit is contained in:
Darrick J. Wong 2021-01-22 16:48:35 -08:00
parent a636b1d1cf
commit f41a0716f4

View File

@ -1605,17 +1605,31 @@ xfs_inode_free_cowblocks(
void *args)
{
struct xfs_eofblocks *eofb = args;
bool wait;
int ret = 0;
wait = eofb && (eofb->eof_flags & XFS_EOF_FLAGS_SYNC);
if (!xfs_prep_free_cowblocks(ip))
return 0;
if (!xfs_inode_matches_eofb(ip, eofb))
return 0;
/* Free the CoW blocks */
xfs_ilock(ip, XFS_IOLOCK_EXCL);
xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
/*
* If the caller is waiting, return -EAGAIN to keep the background
* scanner moving and revisit the inode in a subsequent pass.
*/
if (!xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
if (wait)
return -EAGAIN;
return 0;
}
if (!xfs_ilock_nowait(ip, XFS_MMAPLOCK_EXCL)) {
if (wait)
ret = -EAGAIN;
goto out_iolock;
}
/*
* Check again, nobody else should be able to dirty blocks or change
@ -1625,6 +1639,7 @@ xfs_inode_free_cowblocks(
ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, false);
xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
out_iolock:
xfs_iunlock(ip, XFS_IOLOCK_EXCL);
return ret;