Adrian Hunter
f5ef336fd2
The UFS driver uses blk_mq_tagset_busy_iter() when identifying task management requests to complete, however blk_mq_tagset_busy_iter() doesn't work. blk_mq_tagset_busy_iter() only iterates requests dispatched by the block layer. That appears as if it might have started since commit37f4a24c24("blk-mq: centralise related handling into blk_mq_get_driver_tag") which removed 'data->hctx->tags->rqs[rq->tag] = rq' from blk_mq_rq_ctx_init() which gets called: blk_get_request blk_mq_alloc_request __blk_mq_alloc_request blk_mq_rq_ctx_init Since UFS task management requests are not dispatched by the block layer, hctx->tags->rqs[rq->tag] remains NULL, and since blk_mq_tagset_busy_iter() relies on finding requests using hctx->tags->rqs[rq->tag], UFS task management requests are never found by blk_mq_tagset_busy_iter(). By using blk_mq_tagset_busy_iter(), the UFS driver was relying on internal details of the block layer, which was fragile and subsequently got broken. Fix by removing the use of blk_mq_tagset_busy_iter() and having the driver keep track of task management requests. Link: https://lore.kernel.org/r/20210922091059.4040-1-adrian.hunter@intel.com Fixes:1235fc569e("scsi: ufs: core: Fix task management request completion timeout") Fixes:69a6c269c0("scsi: ufs: Use blk_{get,put}_request() to allocate and free TMFs") Cc: stable@vger.kernel.org Tested-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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.