50e34d7881
The elevator is only used for file system requests, which are stopped in
del_gendisk. Move disabling the elevator and freeing the scheduler tags
to the end of del_gendisk instead of doing that work in disk_release and
blk_cleanup_queue to avoid a use after free on q->tag_set from
disk_release as the tag_set might not be alive at that point.
Move the blk_qos_exit call as well, as it just depends on the elevator
exit and would be the only reason to keep the not exactly cheap queue
freeze in disk_release.
Fixes: e155b0c238b2 ("blk-mq: Use shared tags for shared sbitmap support")
Reported-by: syzbot+3e3f419f4a7816471838@syzkaller.appspotmail.com
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: syzbot+3e3f419f4a7816471838@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20220614074827.458955-2-hch@lst.de
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.