mirror of https://gitee.com/openkylin/linux.git
dm: fix missing imposition of queue_limits from dm_wq_work() thread
If a DM device was suspended when bios were issued to it, those bios
would be deferred using queue_io(). Once the DM device was resumed
dm_process_bio() could be called by dm_wq_work() for original bio that
still needs splitting. dm_process_bio()'s check for current->bio_list
(meaning call chain is within ->submit_bio) as a prerequisite for
calling blk_queue_split() for "abnormal IO" would result in
dm_process_bio() never imposing corresponding queue_limits
(e.g. discard_granularity, discard_max_bytes, etc).
Fix this by always having dm_wq_work() resubmit deferred bios using
submit_bio_noacct().
Side-effect is blk_queue_split() is always called for "abnormal IO" from
->submit_bio, be it from application thread or dm_wq_work() workqueue,
so proper bio splitting and depth-first bio submission is performed.
For sake of clarity, remove current->bio_list check before call to
blk_queue_split().
Also, remove dm_wq_work()'s use of dm_{get,put}_live_table() -- no
longer needed since IO will be reissued in terms of ->submit_bio.
And rename bio variable from 'c' to 'bio'.
Fixes: cf9c378655
("dm: fix comment in dm_process_bio()")
Reported-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
parent
7d837c0dd9
commit
0c2915b8c6
drivers/md
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@ -1676,17 +1676,11 @@ static blk_qc_t dm_process_bio(struct mapped_device *md,
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}
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}
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/*
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/*
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* If in ->submit_bio we need to use blk_queue_split(), otherwise
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* Use blk_queue_split() for abnormal IO (e.g. discard, writesame, etc)
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* queue_limits for abnormal requests (e.g. discard, writesame, etc)
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* otherwise associated queue_limits won't be imposed.
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* won't be imposed.
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* If called from dm_wq_work() for deferred bio processing, bio
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* was already handled by following code with previous ->submit_bio.
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*/
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*/
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if (current->bio_list) {
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if (is_abnormal_io(bio))
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if (is_abnormal_io(bio))
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blk_queue_split(&bio);
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blk_queue_split(&bio);
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/* regular IO is split by __split_and_process_bio */
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}
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if (dm_get_md_type(md) == DM_TYPE_NVME_BIO_BASED)
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if (dm_get_md_type(md) == DM_TYPE_NVME_BIO_BASED)
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return __process_bio(md, map, bio);
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return __process_bio(md, map, bio);
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@ -2383,29 +2377,19 @@ static int dm_wait_for_completion(struct mapped_device *md, long task_state)
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*/
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*/
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static void dm_wq_work(struct work_struct *work)
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static void dm_wq_work(struct work_struct *work)
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{
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{
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struct mapped_device *md = container_of(work, struct mapped_device,
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struct mapped_device *md = container_of(work, struct mapped_device, work);
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work);
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struct bio *bio;
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struct bio *c;
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int srcu_idx;
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struct dm_table *map;
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map = dm_get_live_table(md, &srcu_idx);
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while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
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while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
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spin_lock_irq(&md->deferred_lock);
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spin_lock_irq(&md->deferred_lock);
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c = bio_list_pop(&md->deferred);
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bio = bio_list_pop(&md->deferred);
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spin_unlock_irq(&md->deferred_lock);
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spin_unlock_irq(&md->deferred_lock);
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if (!c)
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if (!bio)
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break;
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break;
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if (dm_request_based(md))
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submit_bio_noacct(bio);
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(void) submit_bio_noacct(c);
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else
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(void) dm_process_bio(md, map, c);
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}
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}
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dm_put_live_table(md, srcu_idx);
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}
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}
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static void dm_queue_flush(struct mapped_device *md)
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static void dm_queue_flush(struct mapped_device *md)
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