Merge tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:

 - Improve the type checking of request flags (Bart)

 - Ensure queue mapping for a single queues always picks the right queue
   (Bart)

 - Sanitize the io priority handling (Jan)

 - rq-qos race fix (Jinke)

 - Reserved tags handling improvements (John)

 - Separate memory alignment from file/disk offset aligment for O_DIRECT
   (Keith)

 - Add new ublk driver, userspace block driver using io_uring for
   communication with the userspace backend (Ming)

 - Use try_cmpxchg() to cleanup the code in various spots (Uros)

 - Finally remove bdevname() (Christoph)

 - Clean up the zoned device handling (Christoph)

 - Clean up independent access range support (Christoph)

 - Clean up and improve block sysfs handling (Christoph)

 - Clean up and improve teardown of block devices.

   This turns the usual two step process into something that is simpler
   to implement and handle in block drivers (Christoph)

 - Clean up chunk size handling (Christoph)

 - Misc cleanups and fixes (Bart, Bo, Dan, GuoYong, Jason, Keith, Liu,
   Ming, Sebastian, Yang, Ying)

* tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-block: (178 commits)
  ublk_drv: fix double shift bug
  ublk_drv: make sure that correct flags(features) returned to userspace
  ublk_drv: fix error handling of ublk_add_dev
  ublk_drv: fix lockdep warning
  block: remove __blk_get_queue
  block: call blk_mq_exit_queue from disk_release for never added disks
  blk-mq: fix error handling in __blk_mq_alloc_disk
  ublk: defer disk allocation
  ublk: rewrite ublk_ctrl_get_queue_affinity to not rely on hctx->cpumask
  ublk: fold __ublk_create_dev into ublk_ctrl_add_dev
  ublk: cleanup ublk_ctrl_uring_cmd
  ublk: simplify ublk_ch_open and ublk_ch_release
  ublk: remove the empty open and release block device operations
  ublk: remove UBLK_IO_F_PREFLUSH
  ublk: add a MAINTAINERS entry
  block: don't allow the same type rq_qos add more than once
  mmc: fix disk/queue leak in case of adding disk failure
  ublk_drv: fix an IS_ERR() vs NULL check
  ublk: remove UBLK_IO_F_INTEGRITY
  ublk_drv: remove unneeded semicolon
  ...

1 files changed, 4 insertions, 8 deletions

diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index d4de0a35e066..d2724d1dd7c9 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -430,12 +430,8 @@ static inline int blkcg_unuse_delay(struct blkcg_gq *blkg)
 	 * then check to see if we were the last delay so we can drop the
 	 * congestion count on the cgroup.
 	 */
-	while (old) {
-		int cur = atomic_cmpxchg(&blkg->use_delay, old, old - 1);
-		if (cur == old)
-			break;
-		old = cur;
-	}
+	while (old && !atomic_try_cmpxchg(&blkg->use_delay, &old, old - 1))
+		;
 
 	if (old == 0)
 		return 0;
@@ -458,7 +454,7 @@ static inline void blkcg_set_delay(struct blkcg_gq *blkg, u64 delay)
 	int old = atomic_read(&blkg->use_delay);
 
 	/* We only want 1 person setting the congestion count for this blkg. */
-	if (!old && atomic_cmpxchg(&blkg->use_delay, old, -1) == old)
+	if (!old && atomic_try_cmpxchg(&blkg->use_delay, &old, -1))
 		atomic_inc(&blkg->blkcg->css.cgroup->congestion_count);
 
 	atomic64_set(&blkg->delay_nsec, delay);
@@ -475,7 +471,7 @@ static inline void blkcg_clear_delay(struct blkcg_gq *blkg)
 	int old = atomic_read(&blkg->use_delay);
 
 	/* We only want 1 person clearing the congestion count for this blkg. */
-	if (old && atomic_cmpxchg(&blkg->use_delay, old, 0) == old)
+	if (old && atomic_try_cmpxchg(&blkg->use_delay, &old, 0))
 		atomic_dec(&blkg->blkcg->css.cgroup->congestion_count);
 }