sd: use READ_16 or WRITE_16 when transfer length is greater than 0xffff (e430cbc8) · Commits · 戴 / test

This change makes the scsi disk driver handle the requests whose transfer length is greater than 0xffff with READ_16 or WRITE_16. However, this is a preparation for extending the data type of max_sectors in struct Scsi_Host and scsi_host_template. So, it is impossible to happen this condition for now, because SCSI low-level drivers can not specify max_sectors greater than 0xffff due to the data type limitation. Signed-off-by:

Akinobu Mita <akinobu.mita@gmail.com> Reviewed-by:

Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by:

Christoph Hellwig <hch@lst.de>

drivers/scsi/sd.c

+1 −4

Original line number	Diff line number	Diff line
		@@ -1042,7 +1042,7 @@ static int sd_init_command(struct scsi_cmnd *SCpnt)
		SCpnt->cmnd[29] = (unsigned char) (this_count >> 16) & 0xff;
		SCpnt->cmnd[30] = (unsigned char) (this_count >> 8) & 0xff;
		SCpnt->cmnd[31] = (unsigned char) this_count & 0xff;
		} else if (sdp->use_16_for_rw) {
		} else if (sdp->use_16_for_rw \|\| (this_count > 0xffff)) {
		SCpnt->cmnd[0] += READ_16 - READ_6;
		SCpnt->cmnd[1] = protect \| ((rq->cmd_flags & REQ_FUA) ? 0x8 : 0);
		SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
		@@ -1061,9 +1061,6 @@ static int sd_init_command(struct scsi_cmnd *SCpnt)
		} else if ((this_count > 0xff) \|\| (block > 0x1fffff) \|\|
		scsi_device_protection(SCpnt->device) \|\|
		SCpnt->device->use_10_for_rw) {
		if (this_count > 0xffff)
		this_count = 0xffff;

		SCpnt->cmnd[0] += READ_10 - READ_6;
		SCpnt->cmnd[1] = protect \| ((rq->cmd_flags & REQ_FUA) ? 0x8 : 0);
		SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;

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