[PATCH v6 0/2] Fix a recently introduced deadlock

[Bart Van Assche <bvanassche@acm.org>]

Hi Jens,

This patch series fixes a recently introduced deadlock triggered by modifying
request queue sysfs attributes if the dm-multipath queue_if_no_path attribute
is set. Please consider this patch series for the next merge window.

Thanks,

Bart.

Changes compared to v5:
 - Added a new patch for include/linux/backing-dev-defs.h.
 - Removed the data_race() invocations and added __data_racy annotations
   instead.

Changes compared to v4:
 - Use WRITE_ONCE() to update bdi->ra_pages.
 - Move a data_race() annotation from queue_io_timeout_store() into
   blk_queue_rq_timeout().

Changes compared to v3:
 - Added two data_race() annotations.

Changes compared to v2:
 - Dropped the controversial patch "block: Restrict the duration of sysfs
   attribute changes".

Changes compared to v1:
 - Added patch "block: Restrict the duration of sysfs attribute changes".
 - Remove queue freezing from more sysfs callbacks.

Bart Van Assche (2):
  fs: Add the __data_racy annotation to backing_dev_info.ra_pages
  block: Remove queue freezing from several sysfs store callbacks

 block/blk-sysfs.c                | 26 ++++++++------------------
 include/linux/backing-dev-defs.h |  4 +++-
 include/linux/blkdev.h           |  2 +-
 3 files changed, 12 insertions(+), 20 deletions(-)