Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ec029758 authored by Martin K. Petersen's avatar Martin K. Petersen
Browse files

scsi: sd: Simplify misaligned I/O check 



Avoid open coding the checks for the supported logical block sizes and use
a mask to check for misaligned I/O. Use our helper functions to scale lba
and block count.

Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
[ bvanassche: ported this patch from kernel v4.11 to kernel v5.0 ]
Signed-off-by: default avatarBart Van Assche <bvanassche@acm.org>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent c6c93fdd

drivers/scsi/sd.c

+12 −45
Original line number Diff line number Diff line
@@ -1078,10 +1078,11 @@ static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt) 
	struct scsi_device *sdp = SCpnt->device;

	struct gendisk *disk = rq->rq_disk;

	struct scsi_disk *sdkp = scsi_disk(disk);

	sector_t lba = blk_rq_pos(rq);

	sector_t lba = sectors_to_logical(sdp, blk_rq_pos(rq));

	sector_t threshold;

	unsigned int nr_blocks = blk_rq_sectors(rq);

	unsigned int nr_blocks = sectors_to_logical(sdp, blk_rq_sectors(rq));

	unsigned int dif, dix;

	unsigned int mask = logical_to_sectors(sdp, 1) - 1;

	unsigned char protect;

	blk_status_t ret;
@@ -1115,63 +1116,29 @@ static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt) 
	}



	/*

	 * Some SD card readers can't handle multi-sector accesses which touch

	 * the last one or two hardware sectors.  Split accesses as needed.

	 * Some SD card readers can't handle accesses which touch the

	 * last one or two logical blocks. Split accesses as needed.

	 */

	threshold = get_capacity(disk) - SD_LAST_BUGGY_SECTORS *

		(sdp->sector_size / 512);

	threshold = sdkp->capacity - SD_LAST_BUGGY_SECTORS;



	if (unlikely(sdp->last_sector_bug && lba + nr_blocks > threshold)) {

		if (lba < threshold) {

			/* Access up to the threshold but not beyond */

			nr_blocks = threshold - lba;

		} else {

			/* Access only a single hardware sector */

			nr_blocks = sdp->sector_size / 512;

			/* Access only a single logical block */

			nr_blocks = 1;

		}

	}



	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt, "block=%llu\n",

					(unsigned long long)lba));



	/*

	 * If we have a 1K hardware sectorsize, prevent access to single

	 * 512 byte sectors.  In theory we could handle this - in fact

	 * the scsi cdrom driver must be able to handle this because

	 * we typically use 1K blocksizes, and cdroms typically have

	 * 2K hardware sectorsizes.  Of course, things are simpler

	 * with the cdrom, since it is read-only.  For performance

	 * reasons, the filesystems should be able to handle this

	 * and not force the scsi disk driver to use bounce buffers

	 * for this.

	 */

	if (sdp->sector_size == 1024) {

		if ((lba & 1) || (blk_rq_sectors(rq) & 1)) {

			scmd_printk(KERN_ERR, SCpnt,

				    "Bad block number requested\n");

			return BLK_STS_IOERR;

		}

		lba = lba >> 1;

		nr_blocks = nr_blocks >> 1;

	}

	if (sdp->sector_size == 2048) {

		if ((lba & 3) || (blk_rq_sectors(rq) & 3)) {

			scmd_printk(KERN_ERR, SCpnt,

				    "Bad block number requested\n");

	if ((blk_rq_pos(rq) & mask) || (blk_rq_sectors(rq) & mask)) {

		scmd_printk(KERN_ERR, SCpnt, "request not aligned to the logical block size\n");

		return BLK_STS_IOERR;

	}

		lba = lba >> 2;

		nr_blocks = nr_blocks >> 2;

	}

	if (sdp->sector_size == 4096) {

		if ((lba & 7) || (blk_rq_sectors(rq) & 7)) {

			scmd_printk(KERN_ERR, SCpnt,

				    "Bad block number requested\n");

			return BLK_STS_IOERR;

		}

		lba = lba >> 3;

		nr_blocks = nr_blocks >> 3;

	}



	if (rq_data_dir(rq) == WRITE) {

		SCpnt->cmnd[0] = WRITE_6;