From: Christoph Hellwig <hch@infradead.org>
To: Bart Van Assche <bvanassche@acm.org>
Cc: "Martin K . Petersen" <martin.petersen@oracle.com>,
Jaegeuk Kim <jaegeuk@kernel.org>,
linux-scsi@vger.kernel.org,
"James E.J. Bottomley" <jejb@linux.ibm.com>,
Can Guo <cang@codeaurora.org>, Bean Huo <beanhuo@micron.com>,
Stanley Chu <stanley.chu@mediatek.com>,
Adrian Hunter <adrian.hunter@intel.com>,
Asutosh Das <asutoshd@codeaurora.org>,
Hannes Reinecke <hare@suse.com>,
John Garry <john.garry@huawei.com>
Subject: Re: [PATCH 2/2] scsi: ufs: Fix a deadlock in the error handler
Date: Wed, 3 Nov 2021 00:40:52 -0700 [thread overview]
Message-ID: <YYI9BLBhrFbgridf@infradead.org> (raw)
In-Reply-To: <20211103000529.1549411-3-bvanassche@acm.org>
On Tue, Nov 02, 2021 at 05:05:29PM -0700, Bart Van Assche wrote:
> - req = blk_get_request(q, REQ_OP_DRV_OUT, 0);
> + req = blk_mq_alloc_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED);
blk_get_request will be gone in 5.16-rc, so this won't apply.
But more importantly: SCSI LLDDs have absolutel no business calling
blk_get_request or blk_mq_alloc_request directly, but as usual UFS is
completely fucked up here.
Please add a SCSI midlayer helper to allocate the reserved tags, and
switch _all_ of this UFS we're sending our own commands crap to it
so it doesn't mix with the actual SCSI requests. We might or might not
want a separate request_queue for them as well as non-SCSI requests
really should not show up in ->queuecommand. Hannes and John have been
looking into this for a while and we need to sort this out properly.
next prev parent reply other threads:[~2021-11-03 7:41 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-03 0:05 [PATCH 0/2] Fix a deadlock in the UFS error handler Bart Van Assche
2021-11-03 0:05 ` [PATCH 1/2] scsi: core: Add support for reserved tags Bart Van Assche
2021-11-09 21:09 ` Bart Van Assche
2021-11-10 6:59 ` Hannes Reinecke
2021-11-10 19:19 ` Bart Van Assche
2021-11-11 6:54 ` Hannes Reinecke
2021-11-15 18:46 ` Bart Van Assche
2021-11-17 0:46 ` Bart Van Assche
2021-11-03 0:05 ` [PATCH 2/2] scsi: ufs: Fix a deadlock in the error handler Bart Van Assche
2021-11-03 6:56 ` Adrian Hunter
2021-11-03 13:40 ` Bart Van Assche
2021-11-03 14:03 ` Adrian Hunter
2021-11-07 11:07 ` Avri Altman
2021-11-08 18:26 ` Bart Van Assche
2021-11-03 7:40 ` Christoph Hellwig [this message]
2021-11-03 8:37 ` Adrian Hunter
2021-11-03 16:33 ` Christoph Hellwig
2021-11-03 16:48 ` Bart Van Assche
2021-11-03 13:45 ` Bart Van Assche
2021-11-03 16:27 ` Christoph Hellwig
2021-11-03 16:39 ` Bart Van Assche
2021-11-03 16:41 ` Christoph Hellwig
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