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authorNeilBrown <neilb@suse.de>2012-11-27 12:14:40 +1100
committerNeilBrown <neilb@suse.de>2012-11-27 12:14:40 +1100
commit874807a83139abc094f939e93623c5623573d543 (patch)
treec36b108b47272d31cbe906cb4267829c02e9c121
parent884162df2aadd7414bef4935e1a54976fd4e3988 (diff)
downloadop-kernel-dev-874807a83139abc094f939e93623c5623573d543.zip
op-kernel-dev-874807a83139abc094f939e93623c5623573d543.tar.gz
md/raid1{,0}: fix deadlock in bitmap_unplug.
If the raid1 or raid10 unplug function gets called from a make_request function (which is very possible) when there are bios on the current->bio_list list, then it will not be able to successfully call bitmap_unplug() and it could need to submit more bios and wait for them to complete. But they won't complete while current->bio_list is non-empty. So detect that case and handle the unplugging off to another thread just like we already do when called from within the scheduler. RAID1 version of bug was introduced in 3.6, so that part of fix is suitable for 3.6.y. RAID10 part won't apply. Cc: stable@vger.kernel.org Reported-by: Torsten Kaiser <just.for.lkml@googlemail.com> Reported-by: Peter Maloney <peter.maloney@brockmann-consult.de> Signed-off-by: NeilBrown <neilb@suse.de>
-rw-r--r--drivers/md/raid1.c2
-rw-r--r--drivers/md/raid10.c2
2 files changed, 2 insertions, 2 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 636bae0..a0f7309 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -963,7 +963,7 @@ static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
struct r1conf *conf = mddev->private;
struct bio *bio;
- if (from_schedule) {
+ if (from_schedule || current->bio_list) {
spin_lock_irq(&conf->device_lock);
bio_list_merge(&conf->pending_bio_list, &plug->pending);
conf->pending_count += plug->pending_cnt;
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 0d5d0ff..c9acbd7 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1069,7 +1069,7 @@ static void raid10_unplug(struct blk_plug_cb *cb, bool from_schedule)
struct r10conf *conf = mddev->private;
struct bio *bio;
- if (from_schedule) {
+ if (from_schedule || current->bio_list) {
spin_lock_irq(&conf->device_lock);
bio_list_merge(&conf->pending_bio_list, &plug->pending);
conf->pending_count += plug->pending_cnt;
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