diff options
| author | NeilBrown <neilb@suse.de> | 2015-05-27 08:43:45 +1000 |
|---|---|---|
| committer | NeilBrown <neilb@suse.de> | 2015-05-28 11:34:40 +1000 |
| commit | d0852df543e5aa7db34c1ad26d053782bcbf48f1 (patch) | |
| tree | 0276829b09beb6d16a4349afe2c75b3eaed80d47 /drivers/md/raid5.h | |
| parent | 2b6b24574256c05be145936f1493aec74c6904e5 (diff) | |
md/raid5: close race between STRIPE_BIT_DELAY and batching.
When we add a write to a stripe we need to make sure the bitmap
bit is set. While doing that the stripe is not locked so it could
be added to a batch after which further changes to STRIPE_BIT_DELAY
and ->bm_seq are ineffective.
So we need to hold off adding to a stripe until bitmap_startwrite has
completed at least once, and we need to avoid further changes to
STRIPE_BIT_DELAY once the stripe has been added to a batch.
If a bitmap_startwrite() completes after the stripe was added to a
batch, it will not have set the bit, only incremented a counter, so no
extra delay of the stripe is needed.
Reported-by: Shaohua Li <shli@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md/raid5.h')
| -rw-r--r-- | drivers/md/raid5.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index 7dc0dd86074b..01cdb9f3a0c4 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -337,6 +337,9 @@ enum { STRIPE_ON_RELEASE_LIST, STRIPE_BATCH_READY, STRIPE_BATCH_ERR, + STRIPE_BITMAP_PENDING, /* Being added to bitmap, don't add + * to batch yet. + */ }; #define STRIPE_EXPAND_SYNC_FLAG \ |