[0/2,v3] block: Fix deadlock when merging requests with BFQ

Message

Jan Kara May 28, 2021, 12:30 p.m. UTC

Hello,

This patch series fixes a lockdep complaint and a possible deadlock that
can happen when blk_mq_sched_try_insert_merge() merges and frees a request.
Jens, can you please merge the series? Thanks!

Changed since v2:
* Added reviewed-by tags

Changes since v1:
* Remove patch disabling recursing request merging during request insertion
* Modified BFQ to cleanup merged request already in its .merge_requests handler
* Added code to handle multiple requests that need freeing after being merged

								Honza