Commit 4dd2cb4a authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Ben Myers
Browse files

xfs: force buffer writeback before blocking on the ilock in inode reclaim 



If we are doing synchronous inode reclaim we block the VM from making
progress in memory reclaim.  So if we encouter a flush locked inode
promote it in the delwri list and wake up xfsbufd to write it out now.
Without this we can get hangs of up to 30 seconds during workloads hitting
synchronous inode reclaim.

The scheme is copied from what we do for dquot reclaims.

Reported-by: default avatarSimon Kirby <sim@hostway.ca>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Tested-by: default avatarSimon Kirby <sim@hostway.ca>
Signed-off-by: default avatarBen Myers <bpm@sgi.com>
parent fa8b18ed

fs/xfs/xfs_inode.c

+21 −0
Original line number Diff line number Diff line
@@ -2835,6 +2835,27 @@ corrupt_out: 
	return XFS_ERROR(EFSCORRUPTED);

}



void

xfs_promote_inode(

	struct xfs_inode	*ip)

{

	struct xfs_buf		*bp;



	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));



	bp = xfs_incore(ip->i_mount->m_ddev_targp, ip->i_imap.im_blkno,

			ip->i_imap.im_len, XBF_TRYLOCK);

	if (!bp)

		return;



	if (XFS_BUF_ISDELAYWRITE(bp)) {

		xfs_buf_delwri_promote(bp);

		wake_up_process(ip->i_mount->m_ddev_targp->bt_task);

	}



	xfs_buf_relse(bp);

}



/*

 * Return a pointer to the extent record at file index idx.

 */

fs/xfs/xfs_inode.h

+1 −0
Original line number Diff line number Diff line
@@ -498,6 +498,7 @@ int xfs_iunlink(struct xfs_trans *, xfs_inode_t *); 
void		xfs_iext_realloc(xfs_inode_t *, int, int);

void		xfs_iunpin_wait(xfs_inode_t *);

int		xfs_iflush(xfs_inode_t *, uint);

void		xfs_promote_inode(struct xfs_inode *);

void		xfs_lock_inodes(xfs_inode_t **, int, uint);

void		xfs_lock_two_inodes(xfs_inode_t *, xfs_inode_t *, uint);

fs/xfs/xfs_sync.c

+11 −0
Original line number Diff line number Diff line
@@ -770,6 +770,17 @@ restart: 
	if (!xfs_iflock_nowait(ip)) {

		if (!(sync_mode & SYNC_WAIT))

			goto out;



		/*

		 * If we only have a single dirty inode in a cluster there is

		 * a fair chance that the AIL push may have pushed it into

		 * the buffer, but xfsbufd won't touch it until 30 seconds

		 * from now, and thus we will lock up here.

		 *

		 * Promote the inode buffer to the front of the delwri list

		 * and wake up xfsbufd now.

		 */

		xfs_promote_inode(ip);

		xfs_iflock(ip);

	}

CRA Git | Maintained and supported by SUSTech CRA and CCSE