scsi-mq: fix requests that use a separate CDB buffer (6f4a1626) · Commits · 戴 / test

This patch fixes code such as the following with scsi-mq enabled: rq = blk_get_request(...); blk_rq_set_block_pc(rq); rq->cmd = my_cmd_buffer; /* separate CDB buffer */ blk_execute_rq_nowait(...); Code like this appears in e.g. sg_start_req() in drivers/scsi/sg.c (for large CDBs only). Without this patch, scsi_mq_prep_fn() will set rq->cmd back to rq->__cmd, causing the wrong CDB to be sent to the device. Signed-off-by:

Tony Battersby <tonyb@cybernetics.com> Signed-off-by:

Jens Axboe <axboe@fb.com>

block/blk-core.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -1252,7 +1252,6 @@ void blk_rq_set_block_pc(struct request *rq)
		rq->__sector = (sector_t) -1;
		rq->bio = rq->biotail = NULL;
		memset(rq->__cmd, 0, sizeof(rq->__cmd));
		rq->cmd = rq->__cmd;
		}
		EXPORT_SYMBOL(blk_rq_set_block_pc);

block/blk-mq.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -176,6 +176,8 @@ static void blk_mq_rq_ctx_init(struct request_queue q, struct blk_mq_ctx ctx,
		/* tag was already set */
		rq->errors = 0;

		rq->cmd = rq->__cmd;

		rq->extra_len = 0;
		rq->sense_len = 0;
		rq->resid_len = 0;

drivers/scsi/scsi_lib.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -1808,7 +1808,6 @@ static int scsi_mq_prep_fn(struct request *req)

		cmd->tag = req->tag;

		req->cmd = req->__cmd;
		cmd->cmnd = req->cmd;
		cmd->prot_op = SCSI_PROT_NORMAL;

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