Commit 4f1de018 authored by Steven Whitehouse's avatar Steven Whitehouse
Browse files

GFS2: Fix ail list traversal 



In the recent patches to update the AIL list code, I managed to
forget that the ail list lock got dropped, even though I
added a comment specifically to remind myself :(

Reported-by: default avatarBarry Marson <bmarson@redhat.com>
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent 6905d9e4

fs/gfs2/log.c

+11 −6
Original line number Diff line number Diff line
@@ -89,7 +89,7 @@ void gfs2_remove_from_ail(struct gfs2_bufdata *bd) 
 *

 */



static void gfs2_ail1_start_one(struct gfs2_sbd *sdp,

static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,

			       struct writeback_control *wbc,

			       struct gfs2_ail *ai)

__releases(&sdp->sd_ail_lock)
@@ -100,7 +100,6 @@ __acquires(&sdp->sd_ail_lock) 
	struct gfs2_bufdata *bd, *s;

	struct buffer_head *bh;



restart:

	list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list, bd_ail_st_list) {

		bh = bd->bd_bh;
@@ -120,13 +119,17 @@ __acquires(&sdp->sd_ail_lock) 
		gl = bd->bd_gl;

		list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);

		mapping = bh->b_page->mapping;

		if (!mapping)

			continue;

		spin_unlock(&sdp->sd_ail_lock);

		generic_writepages(mapping, wbc);

		spin_lock(&sdp->sd_ail_lock);

		if (wbc->nr_to_write <= 0)

			break;

		goto restart;

		return 1;

	}



	return 0;

}
@@ -146,10 +149,12 @@ void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc) 


	trace_gfs2_ail_flush(sdp, wbc, 1);

	spin_lock(&sdp->sd_ail_lock);

restart:

	list_for_each_entry_reverse(ai, head, ai_list) {

		if (wbc->nr_to_write <= 0)

			break;

		gfs2_ail1_start_one(sdp, wbc, ai); /* This may drop ail lock */

		if (gfs2_ail1_start_one(sdp, wbc, ai))

			goto restart;

	}

	spin_unlock(&sdp->sd_ail_lock);

	trace_gfs2_ail_flush(sdp, wbc, 0);