Commit 17d77684 authored by Bob Peterson's avatar Bob Peterson Committed by Andreas Gruenbacher
Browse files

gfs2: Don't get stuck with I/O plugged in gfs2_ail1_flush 



In gfs2_ail1_flush, we're using I/O plugging to give the block layer a
better chance of merging I/O requests.  If we're too aggressive here, we
can end up waiting on I/O to complete while still plugged.  Fix that in
a way similar to writeback_sb_inodes, except that we can't use
blk_flush_plug because blk_flush_plug_list is not exported.

Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
parent 803074ad

fs/gfs2/log.c

+7 −2
Original line number Diff line number Diff line
@@ -91,7 +91,7 @@ void gfs2_remove_from_ail(struct gfs2_bufdata *bd) 


static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,

			       struct writeback_control *wbc,

			       struct gfs2_trans *tr)

			       struct gfs2_trans *tr, struct blk_plug *plug)

__releases(&sdp->sd_ail_lock)

__acquires(&sdp->sd_ail_lock)

{
@@ -133,6 +133,11 @@ __acquires(&sdp->sd_ail_lock) 
			continue;

		spin_unlock(&sdp->sd_ail_lock);

		ret = generic_writepages(mapping, wbc);

		if (need_resched()) {

			blk_finish_plug(plug);

			cond_resched();

			blk_start_plug(plug);

		}

		spin_lock(&sdp->sd_ail_lock);

		if (ret == -ENODATA) /* if a jdata write into a new hole */

			ret = 0; /* ignore it */
@@ -207,7 +212,7 @@ void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc) 
	list_for_each_entry_reverse(tr, head, tr_list) {

		if (wbc->nr_to_write <= 0)

			break;

		ret = gfs2_ail1_start_one(sdp, wbc, tr);

		ret = gfs2_ail1_start_one(sdp, wbc, tr, &plug);

		if (ret) {

			if (ret == -EBUSY)

				goto restart;