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sd: don't use scsi_setup_blk_pc_cmnd for write same requests 

Simplify handling of write same requests by setting up the command directly
instead of initializing request fields and then calling
scsi_setup_blk_pc_cmnd to propagate the information into the command.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Webb Scales <webbnh@hp.com>
This commit is contained in:
Christoph Hellwig 2014-06-28 12:22:22 +02:00
parent a118c6c1d9
commit 59b1134c5a
1 changed files with 28 additions and 16 deletions
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44
drivers/scsi/sd.c
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@ -799,14 +799,15 @@ out:
/**
* sd_setup_write_same_cmnd - write the same data to multiple blocks
* @sdp: scsi device to operate one
* @rq: Request to prepare
* @cmd: command to prepare
*
* Will issue either WRITE SAME(10) or WRITE SAME(16) depending on
* preference indicated by target device.
**/
static int sd_setup_write_same_cmnd(struct scsi_device *sdp, struct request *rq)
static int sd_setup_write_same_cmnd(struct scsi_cmnd *cmd)
{
struct request *rq = cmd->request;
struct scsi_device *sdp = cmd->device;
struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
struct bio *bio = rq->bio;
sector_t sector = blk_rq_pos(rq);
@ -822,25 +823,36 @@ static int sd_setup_write_same_cmnd(struct scsi_device *sdp, struct request *rq)
sector >>= ilog2(sdp->sector_size) - 9;
nr_sectors >>= ilog2(sdp->sector_size) - 9;
rq->__data_len = sdp->sector_size;
rq->timeout = SD_WRITE_SAME_TIMEOUT;
memset(rq->cmd, 0, rq->cmd_len);
if (sdkp->ws16 || sector > 0xffffffff || nr_sectors > 0xffff) {
rq->cmd_len = 16;
rq->cmd[0] = WRITE_SAME_16;
put_unaligned_be64(sector, &rq->cmd[2]);
put_unaligned_be32(nr_sectors, &rq->cmd[10]);
cmd->cmd_len = 16;
cmd->cmnd[0] = WRITE_SAME_16;
put_unaligned_be64(sector, &cmd->cmnd[2]);
put_unaligned_be32(nr_sectors, &cmd->cmnd[10]);
} else {
rq->cmd_len = 10;
rq->cmd[0] = WRITE_SAME;
put_unaligned_be32(sector, &rq->cmd[2]);
put_unaligned_be16(nr_sectors, &rq->cmd[7]);
cmd->cmd_len = 10;
cmd->cmnd[0] = WRITE_SAME;
put_unaligned_be32(sector, &cmd->cmnd[2]);
put_unaligned_be16(nr_sectors, &cmd->cmnd[7]);
}
ret = scsi_setup_blk_pc_cmnd(sdp, rq);
rq->__data_len = nr_bytes;
cmd->transfersize = sdp->sector_size;
cmd->allowed = rq->retries;
/*
* For WRITE_SAME the data transferred in the DATA IN buffer is
* different from the amount of data actually written to the target.
*
* We set up __data_len to the amount of data transferred from the
* DATA IN buffer so that blk_rq_map_sg set up the proper S/G list
* to transfer a single sector of data first, but then reset it to
* the amount of data to be written right after so that the I/O path
* knows how much to actually write.
*/
rq->__data_len = sdp->sector_size;
ret = scsi_init_io(cmd, GFP_ATOMIC);
rq->__data_len = nr_bytes;
return ret;
}
@ -894,7 +906,7 @@ static int sd_init_command(struct scsi_cmnd *SCpnt)
ret = sd_setup_discard_cmnd(sdp, rq);
goto out;
} else if (rq->cmd_flags & REQ_WRITE_SAME) {
ret = sd_setup_write_same_cmnd(sdp, rq);
ret = sd_setup_write_same_cmnd(SCpnt);
goto out;
} else if (rq->cmd_flags & REQ_FLUSH) {
ret = sd_setup_flush_cmnd(SCpnt);