diff options
| author | Christoph Hellwig <hch@lst.de> | 2025-01-31 13:03:47 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2025-01-31 07:20:08 -0700 |
| commit | 1e1a9cecfab3f22ebef0a976f849c87be8d03c1c (patch) | |
| tree | 34fa7958ed94c56127aa0fc55347bb409574af3a /include/linux | |
| parent | 14ef49657ff3b7156952b2eadcf2e5bafd735795 (diff) | |
block: force noio scope in blk_mq_freeze_queue
When block drivers or the core block code perform allocations with a
frozen queue, this could try to recurse into the block device to
reclaim memory and deadlock. Thus all allocations done by a process
that froze a queue need to be done without __GFP_IO and __GFP_FS.
Instead of tying to track all of them down, force a noio scope as
part of freezing the queue.
Note that nvme is a bit of a mess here due to the non-owner freezes,
and they will be addressed separately.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250131120352.1315351-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/blk-mq.h | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index a0a9007cc1e3..9ebb53f031cd 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -900,8 +900,22 @@ void blk_mq_delay_run_hw_queues(struct request_queue *q, unsigned long msecs); void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset, busy_tag_iter_fn *fn, void *priv); void blk_mq_tagset_wait_completed_request(struct blk_mq_tag_set *tagset); -void blk_mq_freeze_queue(struct request_queue *q); -void blk_mq_unfreeze_queue(struct request_queue *q); +void blk_mq_freeze_queue_nomemsave(struct request_queue *q); +void blk_mq_unfreeze_queue_nomemrestore(struct request_queue *q); +static inline unsigned int __must_check +blk_mq_freeze_queue(struct request_queue *q) +{ + unsigned int memflags = memalloc_noio_save(); + + blk_mq_freeze_queue_nomemsave(q); + return memflags; +} +static inline void +blk_mq_unfreeze_queue(struct request_queue *q, unsigned int memflags) +{ + blk_mq_unfreeze_queue_nomemrestore(q); + memalloc_noio_restore(memflags); +} void blk_freeze_queue_start(struct request_queue *q); void blk_mq_freeze_queue_wait(struct request_queue *q); int blk_mq_freeze_queue_wait_timeout(struct request_queue *q, |