scsi: sd: Simplify misaligned I/O check (ec029758) · Commits · 戴 / test

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;

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