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authorNeilBrown <neilb@suse.de>2013-06-12 11:01:22 +1000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-08-20 08:26:28 -0700
commit1b9203bb4c658c0242afa6fdb025c71d2fc3ad76 (patch)
tree1dfbea2025be2872abb7b435b630bce988b6e032
parentefb5fbe89cdcc97ce170bf53c0764d7d00b7a4a6 (diff)
downloadlinux-linaro-stable-1b9203bb4c658c0242afa6fdb025c71d2fc3ad76.tar.gz
md/raid1,raid10: use freeze_array in place of raise_barrier in various places.
commit e2d59925221cd562e07fee38ec8839f7209ae603 upstream. Various places in raid1 and raid10 are calling raise_barrier when they really should call freeze_array. The former is only intended to be called from "make_request". The later has extra checks for 'nr_queued' and makes a call to flush_pending_writes(), so it is safe to call it from within the management thread. Using raise_barrier will sometimes deadlock. Using freeze_array should not. As 'freeze_array' currently expects one request to be pending (in handle_read_error - the only previous caller), we need to pass it the number of pending requests (extra) to ignore. The deadlock was made particularly noticeable by commits 050b66152f87c7 (raid10) and 6b740b8d79252f13 (raid1) which appeared in 3.4, so the fix is appropriate for any -stable kernel since then. This patch probably won't apply directly to some early kernels and will need to be applied by hand. Cc: stable@vger.kernel.org Reported-by: Alexander Lyakas <alex.bolshoy@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de> [adjust context to make it can be apply on top of 3.4 ] Signed-off-by: Jack Wang <jinpu.wang@profitbricks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/md/raid1.c22
-rw-r--r--drivers/md/raid10.c14
2 files changed, 18 insertions, 18 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index b424a2015917..ce5f0449e1b6 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -812,17 +812,17 @@ static void allow_barrier(struct r1conf *conf)
wake_up(&conf->wait_barrier);
}
-static void freeze_array(struct r1conf *conf)
+static void freeze_array(struct r1conf *conf, int extra)
{
/* stop syncio and normal IO and wait for everything to
* go quite.
* We increment barrier and nr_waiting, and then
- * wait until nr_pending match nr_queued+1
+ * wait until nr_pending match nr_queued+extra
* This is called in the context of one normal IO request
* that has failed. Thus any sync request that might be pending
* will be blocked by nr_pending, and we need to wait for
* pending IO requests to complete or be queued for re-try.
- * Thus the number queued (nr_queued) plus this request (1)
+ * Thus the number queued (nr_queued) plus this request (extra)
* must match the number of pending IOs (nr_pending) before
* we continue.
*/
@@ -830,7 +830,7 @@ static void freeze_array(struct r1conf *conf)
conf->barrier++;
conf->nr_waiting++;
wait_event_lock_irq(conf->wait_barrier,
- conf->nr_pending == conf->nr_queued+1,
+ conf->nr_pending == conf->nr_queued+extra,
conf->resync_lock,
flush_pending_writes(conf));
spin_unlock_irq(&conf->resync_lock);
@@ -1432,8 +1432,8 @@ static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
* we wait for all outstanding requests to complete.
*/
synchronize_sched();
- raise_barrier(conf);
- lower_barrier(conf);
+ freeze_array(conf, 0);
+ unfreeze_array(conf);
clear_bit(Unmerged, &rdev->flags);
}
md_integrity_add_rdev(rdev, mddev);
@@ -1481,11 +1481,11 @@ static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
*/
struct md_rdev *repl =
conf->mirrors[conf->raid_disks + number].rdev;
- raise_barrier(conf);
+ freeze_array(conf, 0);
clear_bit(Replacement, &repl->flags);
p->rdev = repl;
conf->mirrors[conf->raid_disks + number].rdev = NULL;
- lower_barrier(conf);
+ unfreeze_array(conf);
clear_bit(WantReplacement, &rdev->flags);
} else
clear_bit(WantReplacement, &rdev->flags);
@@ -2100,7 +2100,7 @@ static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
* frozen
*/
if (mddev->ro == 0) {
- freeze_array(conf);
+ freeze_array(conf, 1);
fix_read_error(conf, r1_bio->read_disk,
r1_bio->sector, r1_bio->sectors);
unfreeze_array(conf);
@@ -2855,7 +2855,7 @@ static int raid1_reshape(struct mddev *mddev)
return -ENOMEM;
}
- raise_barrier(conf);
+ freeze_array(conf, 0);
/* ok, everything is stopped */
oldpool = conf->r1bio_pool;
@@ -2887,7 +2887,7 @@ static int raid1_reshape(struct mddev *mddev)
mddev->delta_disks = 0;
conf->last_used = 0; /* just make sure it is in-range */
- lower_barrier(conf);
+ unfreeze_array(conf);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 54ba53153420..f7febd8e3720 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -952,17 +952,17 @@ static void allow_barrier(struct r10conf *conf)
wake_up(&conf->wait_barrier);
}
-static void freeze_array(struct r10conf *conf)
+static void freeze_array(struct r10conf *conf, int extra)
{
/* stop syncio and normal IO and wait for everything to
* go quiet.
* We increment barrier and nr_waiting, and then
- * wait until nr_pending match nr_queued+1
+ * wait until nr_pending match nr_queued+extra
* This is called in the context of one normal IO request
* that has failed. Thus any sync request that might be pending
* will be blocked by nr_pending, and we need to wait for
* pending IO requests to complete or be queued for re-try.
- * Thus the number queued (nr_queued) plus this request (1)
+ * Thus the number queued (nr_queued) plus this request (extra)
* must match the number of pending IOs (nr_pending) before
* we continue.
*/
@@ -970,7 +970,7 @@ static void freeze_array(struct r10conf *conf)
conf->barrier++;
conf->nr_waiting++;
wait_event_lock_irq(conf->wait_barrier,
- conf->nr_pending == conf->nr_queued+1,
+ conf->nr_pending == conf->nr_queued+extra,
conf->resync_lock,
flush_pending_writes(conf));
@@ -1619,8 +1619,8 @@ static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev)
* we wait for all outstanding requests to complete.
*/
synchronize_sched();
- raise_barrier(conf, 0);
- lower_barrier(conf);
+ freeze_array(conf, 0);
+ unfreeze_array(conf);
clear_bit(Unmerged, &rdev->flags);
}
md_integrity_add_rdev(rdev, mddev);
@@ -2410,7 +2410,7 @@ static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
r10_bio->devs[slot].bio = NULL;
if (mddev->ro == 0) {
- freeze_array(conf);
+ freeze_array(conf, 1);
fix_read_error(conf, mddev, r10_bio);
unfreeze_array(conf);
} else