• Ming Lei's avatar
    block: cover another queue enter recursion via BIO_QUEUE_ENTERED · 698cef17
    Ming Lei authored
    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 cd4a4ae4 doesn't help this case.
    This patch covers the above case by setting BIO_QUEUE_ENTERED before calling
    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: cd4a4ae4 ("block: don't use blocking queue entered for recursive bio submits")
    Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
    Cc: NeilBrown <neilb@suse.com>
    Reviewed-by: default avatarMike Snitzer <snitzer@redhat.com>
    Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
    Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
blk-merge.c 21.4 KB