The patch titled
md: misc fixes for aligned-read handling
has been added to the -mm tree. Its filename is
md-misc-fixes-for-aligned-read-handling.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: md: misc fixes for aligned-read handling
From: NeilBrown <neilb@xxxxxxx>
1/ When aligned requests fail (read error) they need to be retried
via the normal method (stripe cache). As we cannot be sure that
we can process a single read in one go (we may not be able to
allocate all the stripes needed) we store a bio-being-retried
and a list of bioes-that-still-need-to-be-retried.
When find a bio that needs to be retried, we should add it to
the list, not to single-bio...
2/ The cloned bio is being used-after-free (to test BIO_UPTODATE).
3/ We forgot to add rdev->data_offset when submitting
a bio for aligned-read
4/ clone_bio calls blk_recount_segments and then we change bi_bdev,
so we need to invalidate the segment counts.
5/ We were never incrementing 'scnt' when resubmitting failed
aligned requests.
Signed-off-by: Neil Brown <neilb@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/md/raid5.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff -puN drivers/md/raid5.c~md-misc-fixes-for-aligned-read-handling drivers/md/raid5.c
--- a/drivers/md/raid5.c~md-misc-fixes-for-aligned-read-handling
+++ a/drivers/md/raid5.c
@@ -2658,8 +2658,8 @@ static void add_bio_to_retry(struct bio
spin_lock_irqsave(&conf->device_lock, flags);
- bi->bi_next = conf->retry_read_aligned;
- conf->retry_read_aligned = bi;
+ bi->bi_next = conf->retry_read_aligned_list;
+ conf->retry_read_aligned_list = bi;
spin_unlock_irqrestore(&conf->device_lock, flags);
md_wakeup_thread(conf->mddev->thread);
@@ -2698,6 +2698,7 @@ static int raid5_align_endio(struct bio
struct bio* raid_bi = bi->bi_private;
mddev_t *mddev;
raid5_conf_t *conf;
+ int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
if (bi->bi_size)
return 1;
@@ -2706,7 +2707,7 @@ static int raid5_align_endio(struct bio
mddev = raid_bi->bi_bdev->bd_disk->queue->queuedata;
conf = mddev_to_conf(mddev);
- if (!error && test_bit(BIO_UPTODATE, &bi->bi_flags)) {
+ if (!error && uptodate) {
bio_endio(raid_bi, bytes, 0);
if (atomic_dec_and_test(&conf->active_aligned_reads))
wake_up(&conf->wait_for_stripe);
@@ -2759,9 +2760,11 @@ static int chunk_aligned_read(request_qu
rcu_read_lock();
rdev = rcu_dereference(conf->disks[dd_idx].rdev);
if (rdev && test_bit(In_sync, &rdev->flags)) {
- align_bi->bi_bdev = rdev->bdev;
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
+ align_bi->bi_bdev = rdev->bdev;
+ align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
+ align_bi->bi_sector += rdev->data_offset;
spin_lock_irq(&conf->device_lock);
wait_event_lock_irq(conf->wait_for_stripe,
@@ -3151,7 +3154,8 @@ static int retry_aligned_read(raid5_con
conf);
last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9);
- for (; logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
+ for (; logical_sector < last_sector;
+ logical_sector += STRIPE_SECTORS, scnt++) {
if (scnt < raid_bio->bi_hw_segments)
/* already done this stripe */
_
Patches currently in -mm which might be from neilb@xxxxxxx are
origin.patch
auth_gss-unregister-gss_domain-when-unloading-module-fix.patch
fix-sunrpc-wakeup-execute-race-condition.patch
lockdep-annotate-nfs-nfsd-in-kernel-sockets.patch
lockdep-annotate-nfs-nfsd-in-kernel-sockets-tidy.patch
remove-lock_key-approach-to-managing-nested-bd_mutex-locks.patch
simplify-some-aspects-of-bd_mutex-nesting.patch
use-mutex_lock_nested-for-bd_mutex-to-avoid-lockdep-warning.patch
avoid-lockdep-warning-in-md.patch
bdev-fix-bd_part_count-leak.patch
lockdep-annotate-nfsd4-recover-code.patch
md-tidy-up-device-change-notification-when-an-md-array-is-stopped.patch
md-define-raid5_mergeable_bvec.patch
md-handle-bypassing-the-read-cache-assuming-nothing-fails.patch
md-allow-reads-that-have-bypassed-the-cache-to-be-retried-on-failure.patch
md-allow-reads-that-have-bypassed-the-cache-to-be-retried-on-failure-fix.patch
md-enable-bypassing-cache-for-reads.patch
md-fix-innocuous-bug-in-raid6-stripe_to_pdidx.patch
md-fix-newly-introduced-read-corruption-with-raid6.patch
md-misc-fixes-for-aligned-read-handling.patch
md-fix-a-couple-more-bugs-in-raid5-6-aligned-reads.patch
md-conditionalize-some-code.patch
md-change-lifetime-rules-for-md-devices.patch
md-dm-reduce-stack-usage-with-stacked-block-devices.patch
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