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Commitbf9c0538e4("ataflop: use a separate gendisk for each media format") introduced ataflop_probe_lock mutex, but forgot to unlock the mutex when atari_floppy_init() (i.e. module loading) succeeded. This will result in double lock deadlock if ataflop_probe() is called. Also, unregister_blkdev() must not be called from atari_floppy_init() with ataflop_probe_lock held when atari_floppy_init() failed, for ataflop_probe() waits for ataflop_probe_lock with major_names_lock held (i.e. AB-BA deadlock). __register_blkdev() needs to be called last in order to avoid calling ataflop_probe() when atari_floppy_init() is about to fail, for memory for completing already-started ataflop_probe() safely will be released as soon as atari_floppy_init() released ataflop_probe_lock mutex. As with commit8b52d8be86("loop: reorder loop_exit"), unregister_blkdev() needs to be called first in order to avoid calling ataflop_alloc_disk() from ataflop_probe() after del_gendisk() from atari_floppy_exit(). By relocating __register_blkdev() / unregister_blkdev() as explained above, we can remove ataflop_probe_lock mutex, for probe function and __exit function are serialized by major_names_lock mutex. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Fixes:bf9c0538e4("ataflop: use a separate gendisk for each media format") Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Link: https://lore.kernel.org/r/20211103230437.1639990-11-mcgrof@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.