Commit f41a0716 authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

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: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
parent a636b1d1

fs/xfs/xfs_icache.c

+18 −3
Original line number Diff line number Diff line
@@ -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;