• Tejun Heo's avatar
    [PATCH] fix queue stalling while barrier sequencing · 1bc691d3
    Tejun Heo authored
    If ordered tag isn't supported, request ordering for barrier
    sequencing is performed by queue draining, which basically hangs the
    request queue until elv_completed_request() reports completion of all
    previous fs requests.
    The condition check in elv_completed_request() was only performed for
    fs requests.  If a special request is queued between the last
    to-be-drained request and the barrier sequence, draining is never
    completed and the queue is stalled forever.
    This patch moves the end-of-draining condition check such that it's
    performed for all requests.
    Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
    Signed-off-by: default avatarJens Axboe <axboe@suse.de>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
elevator.c 18.3 KB