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a7cfa0af0c
Recursive spin_lock/unlock_irq() is not safe, because spin_unlock_irq()
will enable irq unconditionally:
spin_lock_irq queue_lock -> disable irq
spin_lock_irq ioc->lock
spin_unlock_irq ioc->lock -> enable irq
/*
* AA dead lock will be triggered if current context is preempted by irq,
* and irq try to hold queue_lock again.
*/
spin_unlock_irq queue_lock
Fix this problem by using spin_lock/unlock() directly for 'ioc->lock'.
Fixes: 5a0ac57c48 ("blk-ioc: protect ioc_destroy_icq() by 'queue_lock'")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230606011438.3743440-1-yukuai1@huaweicloud.com
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.