Commit 8e1fab9c authored by Thomas Fourier's avatar Thomas Fourier Committed by Jens Axboe
Browse files

block: mtip32xx: Fix usage of dma_map_sg() 



The dma_map_sg() can fail and, in case of failure, returns 0.  If it
fails, mtip_hw_submit_io() returns an error.

The dma_unmap_sg() requires the nents parameter to be the same as the
one passed to dma_map_sg(). This patch saves the nents in
command->scatter_ents.

Fixes: 88523a61 ("block: Add driver for Micron RealSSD pcie flash cards")
Signed-off-by: default avatarThomas Fourier <fourier.thomas@gmail.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250627121123.203731-2-fourier.thomas@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 5a593def

drivers/block/mtip32xx/mtip32xx.c

+17 −10
Original line number Diff line number Diff line
@@ -2040,9 +2040,10 @@ static int mtip_hw_ioctl(struct driver_data *dd, unsigned int cmd, 
 * @dir      Direction (read or write)

 *

 * return value

 *	None

 *	0	The IO completed successfully.

 *	-ENOMEM	The DMA mapping failed.

 */

static void mtip_hw_submit_io(struct driver_data *dd, struct request *rq,

static int mtip_hw_submit_io(struct driver_data *dd, struct request *rq,

			     struct mtip_cmd *command,

			     struct blk_mq_hw_ctx *hctx)

{
@@ -2056,12 +2057,14 @@ static void mtip_hw_submit_io(struct driver_data *dd, struct request *rq, 
	unsigned int nents;



	/* Map the scatter list for DMA access */

	nents = blk_rq_map_sg(rq, command->sg);

	nents = dma_map_sg(&dd->pdev->dev, command->sg, nents, dma_dir);

	command->scatter_ents = blk_rq_map_sg(rq, command->sg);

	nents = dma_map_sg(&dd->pdev->dev, command->sg,

			   command->scatter_ents, dma_dir);

	if (!nents)

		return -ENOMEM;



	prefetch(&port->flags);



	command->scatter_ents = nents;

	prefetch(&port->flags);



	/*

	 * The number of retries for this command before it is
@@ -2112,11 +2115,13 @@ static void mtip_hw_submit_io(struct driver_data *dd, struct request *rq, 
	if (unlikely(port->flags & MTIP_PF_PAUSE_IO)) {

		set_bit(rq->tag, port->cmds_to_issue);

		set_bit(MTIP_PF_ISSUE_CMDS_BIT, &port->flags);

		return;

		return 0;

	}



	/* Issue the command to the hardware */

	mtip_issue_ncq_command(port, rq->tag);



	return 0;

}



/*
@@ -3315,7 +3320,9 @@ static blk_status_t mtip_queue_rq(struct blk_mq_hw_ctx *hctx, 


	blk_mq_start_request(rq);



	mtip_hw_submit_io(dd, rq, cmd, hctx);

	if (mtip_hw_submit_io(dd, rq, cmd, hctx))

		return BLK_STS_IOERR;



	return BLK_STS_OK;

}