The patch titled
md: Fix 'rdev->nr_pending' count when retrying barrier requests
has been added to the -mm tree. Its filename is
md-fix-rdev-nr_pending-count-when-retrying-barrier-requests.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
From: NeilBrown <neilb@xxxxxxx>
When retrying a failed BIO_RW_BARRIER request, we need to keep the reference
in ->nr_pending over the whole retry. Currently, we only hold the reference
if the failed request is the *last* one to finish - which is silly, because it
would normally be the first to finish.
So move the rdev_dec_pending call up into the didn't-fail branch. As the rdev
isn't used in the later code, calling rdev_dec_pending earlier doesn't hurt.
Signed-off-by: Neil Brown <neilb@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/md/raid1.c | 9 ++++-----
1 files changed, 4 insertions(+), 5 deletions(-)
diff -puN drivers/md/raid1.c~md-fix-rdev-nr_pending-count-when-retrying-barrier-requests drivers/md/raid1.c
--- 25/drivers/md/raid1.c~md-fix-rdev-nr_pending-count-when-retrying-barrier-requests Fri Apr 28 16:41:09 2006
+++ 25-akpm/drivers/md/raid1.c Fri Apr 28 16:41:09 2006
@@ -319,6 +319,7 @@ static int raid1_end_write_request(struc
set_bit(BarriersNotsupp, &conf->mirrors[mirror].rdev->flags);
set_bit(R1BIO_BarrierRetry, &r1_bio->state);
r1_bio->mddev->barriers_work = 0;
+ /* Don't rdev_dec_pending in this branch - keep it for the retry */
} else {
/*
* this branch is our 'one mirror IO has finished' event handler:
@@ -365,6 +366,7 @@ static int raid1_end_write_request(struc
}
}
}
+ rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
}
/*
*
@@ -374,11 +376,9 @@ static int raid1_end_write_request(struc
if (atomic_dec_and_test(&r1_bio->remaining)) {
if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
reschedule_retry(r1_bio);
- /* Don't dec_pending yet, we want to hold
- * the reference over the retry
- */
goto out;
}
+ /* it really is the end of this request */
if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
/* free extra copy of the data pages */
int i = bio->bi_vcnt;
@@ -393,8 +393,6 @@ static int raid1_end_write_request(struc
md_write_end(r1_bio->mddev);
raid_end_bio_io(r1_bio);
}
-
- rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
out:
if (to_put)
bio_put(to_put);
@@ -1414,6 +1412,7 @@ static void raid1d(mddev_t *mddev)
* Better resubmit without the barrier.
* We know which devices to resubmit for, because
* all others have had their bios[] entry cleared.
+ * We already have a nr_pending reference on these rdevs.
*/
int i;
clear_bit(R1BIO_BarrierRetry, &r1_bio->state);
_
Patches currently in -mm which might be from neilb@xxxxxxx are
md-avoid-oops-when-attempting-to-fix-read-errors-on-raid10.patch
md-fixed-refcounting-locking-when-attempting-read-error-correction-in-raid10.patch
md-change-enotsupp-to-eopnotsupp.patch
md-improve-detection-of-lack-of-barrier-support-in-raid1.patch
md-fix-rdev-nr_pending-count-when-retrying-barrier-requests.patch
fix-dcache-race-during-umount.patch
fix-dcache-race-during-umount-fix.patch
prune_one_dentry-tweaks.patch
remove-softlockup-from-invalidate_mapping_pages.patch
make-address_space_operations-invalidatepage-return-void-reiser4.patch
md-dm-reduce-stack-usage-with-stacked-block-devices.patch
-
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