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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: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
[ bvanassche: ported this patch from kernel v4.11 to kernel v5.0 ]
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Martin K. Petersen 2019-01-15 16:49:59 -08:00
parent c6c93fdd34
commit ec029758a1
1 changed files with 12 additions and 45 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
drivers/scsi/sd.c
View File

@ -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");
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 ((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;
}
if (rq_data_dir(rq) == WRITE) {
SCpnt->cmnd[0] = WRITE_6;