a61528d997
There is a deadlock between sm_release and sm_cache_flush_work
which is a work item. The cancel_work_sync in sm_release will
not return until sm_cache_flush_work is finished. If we hold
mutex_lock and use cancel_work_sync to wait the work item to
finish, the work item also requires mutex_lock. As a result,
the sm_release will be blocked forever. The race condition is
shown below:
(Thread 1) | (Thread 2)
sm_release |
mutex_lock(&ftl->mutex) | sm_cache_flush_work
| mutex_lock(&ftl->mutex)
cancel_work_sync | ...
This patch moves del_timer_sync and cancel_work_sync out of
mutex_lock in order to mitigate deadlock.
Fixes: 7d17c02a01a1 ("mtd: Add new SmartMedia/xD FTL")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220524044841.10517-1-duoming@zju.edu.cn
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.