[PATCH 5.19 017/207] block: remove QUEUE_FLAG_DEAD

Greg Kroah-Hartman
2022-09-26T11:31:56Z

From: Christoph Hellwig <hch@lst.de>

[ Upstream commit 1f90307e5f0d7bc9a336ead528f616a5df8e5944 ]

Disallow setting the blk-mq state on any queue that is already dying as
setting the state even then is a bad idea, and remove the now unused
QUEUE_FLAG_DEAD flag.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20220619060552.1850436-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: 8fe4ce5836e9 ("scsi: core: Fix a use-after-free")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
block/blk-core.c | 3 ---
block/blk-mq-debugfs.c | 8 +++-----
include/linux/blkdev.h | 2 --
3 files changed, 3 insertions(+), 10 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index cc6fbcb6d252..76f070c3a3b0 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -313,9 +313,6 @@ void blk_cleanup_queue(struct request_queue *q)
* after draining finished.
*/
blk_freeze_queue(q);
-
- blk_queue_flag_set(QUEUE_FLAG_DEAD, q);
-
blk_sync_queue(q);
if (queue_is_mq(q)) {
blk_mq_cancel_work_sync(q);
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 61f179e5f151..28adb01f6441 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -116,7 +116,6 @@ static const char *const blk_queue_flag_name[] = {
QUEUE_FLAG_NAME(NOXMERGES),
QUEUE_FLAG_NAME(ADD_RANDOM),
QUEUE_FLAG_NAME(SAME_FORCE),
- QUEUE_FLAG_NAME(DEAD),
QUEUE_FLAG_NAME(INIT_DONE),
QUEUE_FLAG_NAME(STABLE_WRITES),
QUEUE_FLAG_NAME(POLL),
@@ -151,11 +150,10 @@ static ssize_t queue_state_write(void *data, const char __user *buf,
char opbuf[16] = { }, *op;

/*
- * The "state" attribute is removed after blk_cleanup_queue() has called
- * blk_mq_free_queue(). Return if QUEUE_FLAG_DEAD has been set to avoid
- * triggering a use-after-free.
+ * The "state" attribute is removed when the queue is removed. Don't
+ * allow setting the state on a dying queue to avoid a use-after-free.
*/
- if (blk_queue_dead(q))
+ if (blk_queue_dying(q))
return -ENOENT;

if (count >= sizeof(opbuf)) {
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 62e3ff52ab03..76f77eed58c3 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -559,7 +559,6 @@ struct request_queue {
#define QUEUE_FLAG_NOXMERGES 9 /* No extended merges */
#define QUEUE_FLAG_ADD_RANDOM 10 /* Contributes to random pool */
#define QUEUE_FLAG_SAME_FORCE 12 /* force complete on same CPU */
-#define QUEUE_FLAG_DEAD 13 /* queue tear-down finished */
#define QUEUE_FLAG_INIT_DONE 14 /* queue is initialized */
#define QUEUE_FLAG_STABLE_WRITES 15 /* don't modify blks until WB is done */
#define QUEUE_FLAG_POLL 16 /* IO polling enabled if set */
@@ -587,7 +586,6 @@ bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);
#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
#define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
#define blk_queue_has_srcu(q) test_bit(QUEUE_FLAG_HAS_SRCU, &(q)->queue_flags)
-#define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
#define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
#define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
#define blk_queue_noxmerges(q) \
--
2.35.1