tree 61fe79788500ca99a76ad098787068ffb9e946fa
parent 348bf85ac42b92af40b67258dd8a3bccca919873
author Tejun Heo <tj@kernel.org> 1706836209 -1000
committer Tejun Heo <tj@kernel.org> 1706836209 -1000

dm-crypt: Convert from tasklet to BH workqueue

The only generic interface to execute asynchronously in the BH context is
tasklet; however, it's marked deprecated and has some design flaws. To
replace tasklets, BH workqueue support was recently added. A BH workqueue
behaves similarly to regular workqueues except that the queued work items
are executed in the BH context.

This patch converts dm-crypt from tasklet to BH workqueue.

Like a regular workqueue, a BH workqueue allows freeing the currently
executing work item. Converting from tasklet to BH workqueue removes the
need for deferring bio_endio() again to a work item, which was buggy anyway.

I tested this lightly with "--perf-no_read_workqueue
--perf-no_write_workqueue" + some code modifications, but would really
-appreciate if someone who knows the code base better could take a look.

Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/82b964f0-c2c8-a2c6-5b1f-f3145dc2c8e5@redhat.com
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@kernel.org>
Cc: dm-devel@lists.linux.dev