On 1/22/19 10:15 AM, Mike Snitzer wrote: > On Tue, Jan 22 2019 at 3:20am -0500, > Ming Lei <[email protected]> wrote: > >> Except for blk_queue_split(), bio_split() is used for splitting bio too, >> then the remained bio is often resubmit to queue via generic_make_request(). >> So the same queue enter recursion exits in this case too. Unfortunatley >> commit cd4a4ae4683dc2 doesn't help this case. >> >> This patch covers the above case by setting BIO_QUEUE_ENTERED before calling >> q->make_request_fn. >> >> In theory the per-bio flag is used to simulate one stack variable, it is >> just fine to clear it after q->make_request_fn is returned. Especially >> the same bio can't be submitted from another context. >> >> Fixes: cd4a4ae4683dc2 ("block: don't use blocking queue entered for >> recursive bio submits") >> Cc: Tetsuo Handa <[email protected]> >> Cc: Mike Snitzer <[email protected]> >> Cc: NeilBrown <[email protected]> >> Signed-off-by: Ming Lei <[email protected]> > > Looks good, I'll drop my DM patch that set/cleared BIO_QUEUE_ENTERED. > > Jens, you OK with picking this up for 5.0-rc? > > Reviewed-by: Mike Snitzer <[email protected]>
I am, thanks both of you for looking into this. I'm a bit behind on email and patches from over the long weekend. -- Jens Axboe
