diff options
| author | NeilBrown <neilb@suse.de> | 2014-12-03 08:07:58 +0300 |
|---|---|---|
| committer | NeilBrown <neilb@suse.de> | 2014-12-03 08:07:58 +0300 |
| commit | 108cef3aa41669610e1836fe638812dd067d72de (patch) | |
| tree | 65d0fe1bbfbfbaf5bee3eff388e89c6cd420b360 /drivers/md | |
| parent | 3a18ca061311f2f1ee9c44012f89c7436d392117 (diff) | |
| download | linux-108cef3aa41669610e1836fe638812dd067d72de.tar.xz | |
md/raid5: fetch_block must fetch all the blocks handle_stripe_dirtying wants.
It is critical that fetch_block() and handle_stripe_dirtying()
are consistent in their analysis of what needs to be loaded.
Otherwise raid5 can wait forever for a block that won't be loaded.
Currently when writing to a RAID5 that is resyncing, to a location
beyond the resync offset, handle_stripe_dirtying chooses a
reconstruct-write cycle, but fetch_block() assumes a
read-modify-write, and a lockup can happen.
So treat that case just like RAID6, just as we do in
handle_stripe_dirtying. RAID6 always does reconstruct-write.
This bug was introduced when the behaviour of handle_stripe_dirtying
was changed in 3.7, so the patch is suitable for any kernel since,
though it will need careful merging for some versions.
Cc: stable@vger.kernel.org (v3.7+)
Fixes: a7854487cd7128a30a7f4f5259de9f67d5efb95f
Reported-by: Henry Cai <henryplusplus@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/raid5.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 9c66e5997fc8..c1b0d52bfcb0 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2917,8 +2917,11 @@ static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s, (sh->raid_conf->level <= 5 && s->failed && fdev[0]->towrite && (!test_bit(R5_Insync, &dev->flags) || test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) && !test_bit(R5_OVERWRITE, &fdev[0]->flags)) || - (sh->raid_conf->level == 6 && s->failed && s->to_write && - s->to_write - s->non_overwrite < sh->raid_conf->raid_disks - 2 && + ((sh->raid_conf->level == 6 || + sh->sector >= sh->raid_conf->mddev->recovery_cp) + && s->failed && s->to_write && + (s->to_write - s->non_overwrite < + sh->raid_conf->raid_disks - sh->raid_conf->max_degraded) && (!test_bit(R5_Insync, &dev->flags) || test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))))) { /* we would like to get this block, possibly by computing it, * otherwise read it if the backing disk is insync |