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    block, blk-mq: draining can't be skipped even if bypass_depth was non-zero · 776687bc
    Tejun Heo 提交于
    Currently, both blk_queue_bypass_start() and blk_mq_freeze_queue()
    skip queue draining if bypass_depth was already above zero.  The
    assumption is that the one which bumped the bypass_depth should have
    performed draining already; however, there's nothing which prevents a
    new instance of bypassing/freezing from starting before the previous
    one finishes draining.  The current code may allow the later
    bypassing/freezing instances to complete while there still are
    in-flight requests which haven't finished draining.
    
    Fix it by draining regardless of bypass_depth.  We still skip draining
    from blk_queue_bypass_start() while the queue is initializing to avoid
    introducing excessive delays during boot.  INIT_DONE setting is moved
    above the initial blk_queue_bypass_end() so that bypassing attempts
    can't slip inbetween.
    Signed-off-by: NTejun Heo <tj@kernel.org>
    Cc: Jens Axboe <axboe@kernel.dk>
    Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
    Signed-off-by: NJens Axboe <axboe@fb.com>
    776687bc
blk-sysfs.c 15.1 KB