Commit 3c04af00 authored by Ming Lei's avatar Ming Lei Committed by Zheng Zengkai
Browse files

dm rq: don't queue request to blk-mq during DM suspend 

mainline inclusion
from mainline-v5.15-rc6
commit b4459b11
category: panic
bugzilla: 185513 https://gitee.com/openeuler/kernel/issues/I4V82O?from=project-issue


CVE: NA

-------------------------------------------------

DM uses blk-mq's quiesce/unquiesce to stop/start device mapper queue.

But blk-mq's unquiesce may come from outside events, such as elevator
switch, updating nr_requests or others, and request may come during
suspend, so simply ask for blk-mq to requeue it.

Fixes one kernel panic issue when running updating nr_requests and
dm-mpath suspend/resume stress test.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarLuo Meng <luomeng12@huawei.com>
Reviewed-by: default avatarZhang Yi <yi.zhang@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent a17b20ea

drivers/md/dm-core.h

+13 −0
Original line number Diff line number Diff line
@@ -122,6 +122,19 @@ struct mapped_device { 
	struct srcu_struct io_barrier;

};



/*

 * Bits for the flags field of struct mapped_device.

 */

#define DMF_BLOCK_IO_FOR_SUSPEND 0

#define DMF_SUSPENDED 1

#define DMF_FROZEN 2

#define DMF_FREEING 3

#define DMF_DELETING 4

#define DMF_NOFLUSH_SUSPENDING 5

#define DMF_DEFERRED_REMOVE 6

#define DMF_SUSPENDED_INTERNALLY 7

#define DMF_POST_SUSPENDING 8



void disable_discard(struct mapped_device *md);

void disable_write_same(struct mapped_device *md);

void disable_write_zeroes(struct mapped_device *md);

drivers/md/dm-rq.c

+8 −0
Original line number Diff line number Diff line
@@ -490,6 +490,14 @@ static blk_status_t dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx, 
	struct mapped_device *md = tio->md;

	struct dm_target *ti = md->immutable_target;



	/*

	 * blk-mq's unquiesce may come from outside events, such as

	 * elevator switch, updating nr_requests or others, and request may

	 * come during suspend, so simply ask for blk-mq to requeue it.

	 */

	if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)))

		return BLK_STS_RESOURCE;



	if (unlikely(!ti)) {

		int srcu_idx;

		struct dm_table *map;

drivers/md/dm.c

+0 −13
Original line number Diff line number Diff line
@@ -132,19 +132,6 @@ EXPORT_SYMBOL_GPL(dm_bio_get_target_bio_nr); 


#define MINOR_ALLOCED ((void *)-1)



/*

 * Bits for the md->flags field.

 */

#define DMF_BLOCK_IO_FOR_SUSPEND 0

#define DMF_SUSPENDED 1

#define DMF_FROZEN 2

#define DMF_FREEING 3

#define DMF_DELETING 4

#define DMF_NOFLUSH_SUSPENDING 5

#define DMF_DEFERRED_REMOVE 6

#define DMF_SUSPENDED_INTERNALLY 7

#define DMF_POST_SUSPENDING 8



#define DM_NUMA_NODE NUMA_NO_NODE

static int dm_numa_node = DM_NUMA_NODE;