Messages in this thread | | | Date | Fri, 6 Jan 2023 13:52:21 -0700 | Subject | Re: [PATCH block/for-6.2-fixes] block: Drop spurious might_sleep() from blk_put_queue() | From | Jens Axboe <> |
| |
On 1/6/23 1:45 PM, Luis Chamberlain wrote: > On Fri, Jan 06, 2023 at 10:34:10AM -1000, Tejun Heo wrote: >> Dan reports the following smatch detected the following: >> >> block/blk-cgroup.c:1863 blkcg_schedule_throttle() warn: sleeping in atomic context >> >> caused by blkcg_schedule_throttle() calling blk_put_queue() in an >> non-sleepable context. >> >> blk_put_queue() acquired might_sleep() in 63f93fd6fa57 ("block: mark >> blk_put_queue as potentially blocking") which transferred the might_sleep() >> from blk_free_queue(). >> >> blk_free_queue() acquired might_sleep() in e8c7d14ac6c3 ("block: revert back >> to synchronous request_queue removal") while turning request_queue removal >> synchronous. However, this isn't necessary as nothing in the free path >> actually requires sleeping. >> >> It's pretty unusual to require a sleeping context in a put operation and >> it's not needed in the first place. Let's drop it. >> >> Signed-off-by: Tejun Heo <tj@kernel.org> >> Reported-by: Dan Carpenter <error27@gmail.com> >> Link: https://lkml.kernel.org/r/Y7g3L6fntnTtOm63@kili >> Cc: Christoph Hellwig <hch@lst.de> >> Cc: Luis Chamberlain <mcgrof@kernel.org> >> Fixes: e8c7d14ac6c3 ("block: revert back to synchronous request_queue removal") # v5.9+ > > *tons* has changed since e8c7d14ac6c3 and so the bots might think that > *if* this patch is applied upstream it is justified for older kernels > and I don't think that's yet been verified and doubt it. > > And so I think adding a "Fixes" tag is not appropriate here. > > First I'd like to hear from Christoph if he agrees with this patch > upstream. For stable, someone would have to do the homework.
Outside of the easily audited paths, the kobj release paths are the only ones of concern. And I didn't spot anything that sleeps. Looks fine to me.
-- Jens Axboe
| |