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| author | NeilBrown <neilb@suse.de> | 2013-03-04 12:37:14 +1100 |
|---|---|---|
| committer | NeilBrown <neilb@suse.de> | 2013-03-20 12:16:51 +1100 |
| commit | ce7d363aaf1e28be8406a2976220944ca487e8ca (patch) | |
| tree | 2f098d1ddf1165fffc3d9ae74c91684b78bb1072 /drivers/md | |
| parent | f3378b48705154b9089affb2d2e939622aea68f1 (diff) | |
| download | linux-stable-ce7d363aaf1e28be8406a2976220944ca487e8ca.tar.gz linux-stable-ce7d363aaf1e28be8406a2976220944ca487e8ca.tar.bz2 linux-stable-ce7d363aaf1e28be8406a2976220944ca487e8ca.zip | |
md/raid5: schedule_construction should abort if nothing to do.
Since commit 1ed850f356a0a422013846b5291acff08815008b
md/raid5: make sure to_read and to_write never go negative.
It has been possible for handle_stripe_dirtying to be called
when there isn't actually any work to do.
It then calls schedule_reconstruction() which will set R5_LOCKED
on the parity block(s) even when nothing else is happening.
This then causes problems in do_release_stripe().
So add checks to schedule_reconstruction() so that if it doesn't
find anything to do, it just aborts.
This bug was introduced in v3.7, so the patch is suitable
for -stable kernels since then.
Cc: stable@vger.kernel.org (v3.7+)
Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/raid5.c | 38 |
1 files changed, 22 insertions, 16 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 35031c8b2d02..5601dda1bc40 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2283,17 +2283,6 @@ schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s, int level = conf->level; if (rcw) { - /* if we are not expanding this is a proper write request, and - * there will be bios with new data to be drained into the - * stripe cache - */ - if (!expand) { - sh->reconstruct_state = reconstruct_state_drain_run; - set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); - } else - sh->reconstruct_state = reconstruct_state_run; - - set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request); for (i = disks; i--; ) { struct r5dev *dev = &sh->dev[i]; @@ -2306,6 +2295,21 @@ schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s, s->locked++; } } + /* if we are not expanding this is a proper write request, and + * there will be bios with new data to be drained into the + * stripe cache + */ + if (!expand) { + if (!s->locked) + /* False alarm, nothing to do */ + return; + sh->reconstruct_state = reconstruct_state_drain_run; + set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); + } else + sh->reconstruct_state = reconstruct_state_run; + + set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request); + if (s->locked + conf->max_degraded == disks) if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state)) atomic_inc(&conf->pending_full_writes); @@ -2314,11 +2318,6 @@ schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s, BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) || test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags))); - sh->reconstruct_state = reconstruct_state_prexor_drain_run; - set_bit(STRIPE_OP_PREXOR, &s->ops_request); - set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); - set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request); - for (i = disks; i--; ) { struct r5dev *dev = &sh->dev[i]; if (i == pd_idx) @@ -2333,6 +2332,13 @@ schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s, s->locked++; } } + if (!s->locked) + /* False alarm - nothing to do */ + return; + sh->reconstruct_state = reconstruct_state_prexor_drain_run; + set_bit(STRIPE_OP_PREXOR, &s->ops_request); + set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); + set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request); } /* keep the parity disk(s) locked while asynchronous operations |