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 /block/elevator.c | |
| 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 'block/elevator.c')
| -rw-r--r-- | block/elevator.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/block/elevator.c b/block/elevator.c index b81216c48b6b..cd2ce4921601 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -570,6 +570,7 @@ static struct elevator_type *elevator_get_default(struct request_queue *q) void elevator_init_mq(struct request_queue *q) { struct elevator_type *e; + unsigned int memflags; int err; WARN_ON_ONCE(blk_queue_registered(q)); @@ -590,13 +591,13 @@ void elevator_init_mq(struct request_queue *q) * * Disk isn't added yet, so verifying queue lock only manually. */ - blk_mq_freeze_queue(q); + memflags = blk_mq_freeze_queue(q); blk_mq_cancel_work_sync(q); err = blk_mq_init_sched(q, e); - blk_mq_unfreeze_queue(q); + blk_mq_unfreeze_queue(q, memflags); if (err) { pr_warn("\"%s\" elevator initialization failed, " @@ -614,11 +615,12 @@ void elevator_init_mq(struct request_queue *q) */ int elevator_switch(struct request_queue *q, struct elevator_type *new_e) { + unsigned int memflags; int ret; lockdep_assert_held(&q->sysfs_lock); - blk_mq_freeze_queue(q); + memflags = blk_mq_freeze_queue(q); blk_mq_quiesce_queue(q); if (q->elevator) { @@ -639,7 +641,7 @@ int elevator_switch(struct request_queue *q, struct elevator_type *new_e) out_unfreeze: blk_mq_unquiesce_queue(q); - blk_mq_unfreeze_queue(q); + blk_mq_unfreeze_queue(q, memflags); if (ret) { pr_warn("elv: switch to \"%s\" failed, falling back to \"none\"\n", @@ -651,9 +653,11 @@ out_unfreeze: void elevator_disable(struct request_queue *q) { + unsigned int memflags; + lockdep_assert_held(&q->sysfs_lock); - blk_mq_freeze_queue(q); + memflags = blk_mq_freeze_queue(q); blk_mq_quiesce_queue(q); elv_unregister_queue(q); @@ -664,7 +668,7 @@ void elevator_disable(struct request_queue *q) blk_add_trace_msg(q, "elv switch: none"); blk_mq_unquiesce_queue(q); - blk_mq_unfreeze_queue(q); + blk_mq_unfreeze_queue(q, memflags); } /* |