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| author |   Konstantin Khlebnikov <khlebnikov@yandex-team.ru> | 2016-11-27 19:32:32 +0300 |
|---|---|---|
| committer |   Shaohua Li <shli@fb.com> | 2016-11-29 15:53:21 -0800 |
| commit | e8d7c33232e5fdfa761c3416539bc5b4acd12db5 (patch) | |
| tree | df0f691267ac01dfd9d2c52cba92a13354cab646 /drivers/md | |
| parent | md/raid5-cache: do not need to set STRIPE_PREREAD_ACTIVE repeatedly (diff) | |
| download | wireguard-linux-e8d7c33232e5fdfa761c3416539bc5b4acd12db5.tar.xz wireguard-linux-e8d7c33232e5fdfa761c3416539bc5b4acd12db5.zip | |
md/raid5: limit request size according to implementation limits
Current implementation employ 16bit counter of active stripes in lower
bits of bio->bi_phys_segments. If request is big enough to overflow
this counter bio will be completed and freed too early.
Fortunately this not happens in default configuration because several
other limits prevent that: stripe_cache_size * nr_disks effectively
limits count of active stripes. And small max_sectors_kb at lower
disks prevent that during normal read/write operations.
Overflow easily happens in discard if it's enabled by module parameter
"devices_handle_discard_safely" and stripe_cache_size is set big enough.
This patch limits requests size with 256Mb - 8Kb to prevent overflows.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Shaohua Li <shli@kernel.org>
Cc: Neil Brown <neilb@suse.com>
Cc: stable@vger.kernel.org
Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/raid5.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index db909b9e37df..6bf3c2604a2f 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -7108,6 +7108,15 @@ static int raid5_run(struct mddev *mddev) stripe = (stripe | (stripe-1)) + 1; mddev->queue->limits.discard_alignment = stripe; mddev->queue->limits.discard_granularity = stripe; + + /* + * We use 16-bit counter of active stripes in bi_phys_segments + * (minus one for over-loaded initialization) + */ + blk_queue_max_hw_sectors(mddev->queue, 0xfffe * STRIPE_SECTORS); + blk_queue_max_discard_sectors(mddev->queue, + 0xfffe * STRIPE_SECTORS); + /* * unaligned part of discard request will be ignored, so can't * guarantee discard_zeroes_data |