• Tejun Heo's avatar
    block: Don't check events on close unless it was blocked · 6936217c
    Tejun Heo authored
    The block event mechanism currently always checks events when the
    device is being closed regardless of the open mode.  The intention was
    to allow detection of EJECT_REQUEST when a device is closed whether
    disk event polling is enabled or not.
    
    This is unnecessary as, for devices of interest, events are checked
    from either userland or kernel and in the former case ->check_events()
    is performed on open of each poll attempt anyway.  Furthermore, this
    unconditional event check on close makes the code susceptible to event
    loop if the block driver doesn't clear reported events correctly - an
    event triggers userland to open and close the device which in turn
    causes another event, rinse and repeat.
    
    Check events on close only if it was blocked by excl write open.
    Signed-off-by: default avatarTejun Heo <tj@kernel.org>
    Cc: Jens Axboe <axboe@kernel.dk>
    Cc: Kay Sievers <kay.sievers@vrfy.org>
    6936217c
block_dev.c 39.3 KB