* [Cluster-devel] GFS2: Fix ail list traversal
@ 2011-04-20 16:29 Steven Whitehouse
2011-04-21 10:09 ` Steven Whitehouse
0 siblings, 1 reply; 2+ messages in thread
From: Steven Whitehouse @ 2011-04-20 16:29 UTC (permalink / raw)
To: cluster-devel.redhat.com
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: Barry Marson <bmarson@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index ad1f188..0f3046a 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -89,9 +89,9 @@ void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
*
*/
-static void gfs2_ail1_start_one(struct gfs2_sbd *sdp,
- struct writeback_control *wbc,
- struct gfs2_ail *ai)
+static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,
+ struct writeback_control *wbc,
+ struct gfs2_ail *ai)
__releases(&sdp->sd_ail_lock)
__acquires(&sdp->sd_ail_lock)
{
@@ -99,6 +99,7 @@ __acquires(&sdp->sd_ail_lock)
struct address_space *mapping;
struct gfs2_bufdata *bd, *s;
struct buffer_head *bh;
+ int ldrop = 0;
restart:
list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list, bd_ail_st_list) {
@@ -121,12 +122,15 @@ restart:
list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
mapping = bh->b_page->mapping;
spin_unlock(&sdp->sd_ail_lock);
+ ldrop = 1;
generic_writepages(mapping, wbc);
spin_lock(&sdp->sd_ail_lock);
if (wbc->nr_to_write <= 0)
break;
goto restart;
}
+
+ return ldrop;
}
@@ -146,10 +150,12 @@ 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);
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [Cluster-devel] GFS2: Fix ail list traversal
2011-04-20 16:29 [Cluster-devel] GFS2: Fix ail list traversal Steven Whitehouse
@ 2011-04-21 10:09 ` Steven Whitehouse
0 siblings, 0 replies; 2+ messages in thread
From: Steven Whitehouse @ 2011-04-21 10:09 UTC (permalink / raw)
To: cluster-devel.redhat.com
Hi,
On Wed, 2011-04-20 at 17:29 +0100, Steven Whitehouse wrote:
> 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: Barry Marson <bmarson@redhat.com>
> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
>
This failed some of my tests, but this new version seems to work
correctly,
Steve.
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index ad1f188..cec26c0 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -89,9 +89,9 @@ void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
*
*/
-static void gfs2_ail1_start_one(struct gfs2_sbd *sdp,
- struct writeback_control *wbc,
- struct gfs2_ail *ai)
+static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,
+ struct writeback_control *wbc,
+ struct gfs2_ail *ai)
__releases(&sdp->sd_ail_lock)
__acquires(&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 @@ restart:
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);
^ permalink raw reply related [flat|nested] 2+ messages in thread
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