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author | NeilBrown <neilb@suse.de> | 2010-03-31 11:21:44 +1100 |
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committer | NeilBrown <neilb@suse.de> | 2010-05-18 15:27:57 +1000 |
commit | e555190d82c0f58e825e3cbd9e6ebe2e7ac713bd (patch) | |
tree | ea9c8e548c4d5eb5fc903bab05af3bda4192ed00 /drivers/md/bitmap.h | |
parent | d754c5ae1ff76b20d3ecde8ad666d7865eada8ae (diff) | |
download | op-kernel-dev-e555190d82c0f58e825e3cbd9e6ebe2e7ac713bd.zip op-kernel-dev-e555190d82c0f58e825e3cbd9e6ebe2e7ac713bd.tar.gz |
md/raid1: delay reads that could overtake behind-writes.
When a raid1 array is configured to support write-behind
on some devices, it normally only reads from other devices.
If all devices are write-behind (because the rest have failed)
it is possible for a read request to be serviced before a
behind-write request, which would appear as data corruption.
So when forced to read from a WriteMostly device, wait for any
write-behind to complete, and don't start any more behind-writes.
Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md/bitmap.h')
-rw-r--r-- | drivers/md/bitmap.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/md/bitmap.h b/drivers/md/bitmap.h index aa82b7c..3797dea 100644 --- a/drivers/md/bitmap.h +++ b/drivers/md/bitmap.h @@ -240,6 +240,7 @@ struct bitmap { atomic_t pending_writes; /* pending writes to the bitmap file */ wait_queue_head_t write_wait; wait_queue_head_t overflow_wait; + wait_queue_head_t behind_wait; struct sysfs_dirent *sysfs_can_clear; }; |