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    Subject[ 02/70] floppy: Cleanup disk->queue before caling put_disk() if add_disk() was never called
    3.2-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Vivek Goyal <vgoyal@redhat.com>

    commit 3f9a5aabd0a9fe0e0cd308506f48963d79169aa7 upstream.

    add_disk() takes gendisk reference on request queue. If driver failed during
    initialization and never called add_disk() then that extra reference is not
    taken. That reference is put in put_disk(). floppy driver allocates the
    disk, allocates queue, sets disk->queue and then relizes that floppy
    controller is not present. It tries to tear down everything and tries to
    put a reference down in put_disk() which was never taken.

    In such error cases cleanup disk->queue before calling put_disk() so that
    we never try to put down a reference which was never taken in first place.

    Reported-and-tested-by: Suresh Jayaraman <sjayaraman@suse.com>
    Tested-by: Dirk Gouders <gouders@et.bocholt.fh-gelsenkirchen.de>
    Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
    Acked-by: Tejun Heo <tj@kernel.org>
    Signed-off-by: Jens Axboe <axboe@kernel.dk>
    Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
    ---
    drivers/block/floppy.c | 8 +++++++-
    1 file changed, 7 insertions(+), 1 deletion(-)

    diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
    index 510fb10..401ba78 100644
    --- a/drivers/block/floppy.c
    +++ b/drivers/block/floppy.c
    @@ -4368,8 +4368,14 @@ out_unreg_blkdev:
    out_put_disk:
    while (dr--) {
    del_timer_sync(&motor_off_timer[dr]);
    - if (disks[dr]->queue)
    + if (disks[dr]->queue) {
    blk_cleanup_queue(disks[dr]->queue);
    + /*
    + * put_disk() is not paired with add_disk() and
    + * will put queue reference one extra time. fix it.
    + */
    + disks[dr]->queue = NULL;
    + }
    put_disk(disks[dr]);
    }
    return err;



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