diff options
| author | NeilBrown <neilb@suse.de> | 2013-03-04 12:37:14 +1100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-28 12:18:01 -0700 |
| commit | bcfe2cfc58bc50d69854365871526e243cd83f19 (patch) | |
| tree | 1e9d64968772a486ff3bb03221062848bf5141d5 | |
| parent | 0e1317e914d6bae271c13d473d3e2d69ec9b7b23 (diff) | |
md/raid5: schedule_construction should abort if nothing to do.
commit ce7d363aaf1e28be8406a2976220944ca487e8ca upstream.
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.
Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 19d77a026639..f5f2a1307f9d 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2319,17 +2319,6 @@ 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]; @@ -2342,6 +2331,21 @@ 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); @@ -2350,11 +2354,6 @@ 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) @@ -2369,6 +2368,13 @@ 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 |