[0/3] Fix queue freeze and limit locking order

Message

Damien Le Moal Jan. 4, 2025, 1:25 p.m. UTC

Three patches to fix the ordering of freezing a queue with
blk_mq_freeze_queue() and obtaining a device queue limits lock with
queue_limits_start_update(). These changes ensure that a devie queue is
always frozen after the device limits lock is obtained to avoid
potential ABBA deadlocks in drivers that need to issue commands to probe
a device limits with the limits lock held (e.g. the SCSI sd driver).

Damien Le Moal (3):
  block: Fix sysfs queue freeze and limits lock order
  block: Fix __blk_mq_update_nr_hw_queues() queue freeze and limits lock
    order
  nvme: Fix queue freeze and limits lock order

 block/blk-mq.c           |  25 +++++---
 block/blk-sysfs.c        | 123 ++++++++++++++++++++-------------------
 drivers/nvme/host/core.c |   8 ++-
 3 files changed, 85 insertions(+), 71 deletions(-)