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| author | Konstantin Khlebnikov <khlebnikov@yandex-team.ru> | 2016-11-27 19:32:32 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-01-09 10:21:56 +0300 |
| commit | b202064f0b3f92d4ce3feec09ad55a20e771947b (patch) | |
| tree | be4631f06649e2246bfe7569944f6ea85cf40992 | |
| parent | 47090341ec97222f47c9ac7dc35b587b85bf1d0d (diff) | |
| download | linux-b202064f0b3f92d4ce3feec09ad55a20e771947b.tar.xz | |
md/raid5: limit request size according to implementation limits
commit e8d7c33232e5fdfa761c3416539bc5b4acd12db5 upstream.
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>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 ee7fc3701700..a87549be8e53 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -7017,6 +7017,15 @@ 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 |