[SCSI] seperate max_sectors from max_hw_sectors

- export __blk_put_request and blk_execute_rq_nowait
needed for async REQ_BLOCK_PC requests
- seperate max_hw_sectors and max_sectors for block/scsi_ioctl.c and
SG_IO bio.c helpers per Jens's last comments. Since block/scsi_ioctl.c SG_IO was
already testing against max_sectors and SCSI-ml was setting max_sectors and
max_hw_sectors to the same value this does not change any scsi SG_IO behavior. It only
prepares ll_rw_blk.c, scsi_ioctl.c and bio.c for when SCSI-ml begins to set
a valid max_hw_sectors for all LLDs. Today if a LLD does not set it
SCSI-ml sets it to a safe default and some LLDs set it to a artificial low
value to overcome memory and feedback issues.

Note: Since we now cap max_sectors to BLK_DEF_MAX_SECTORS, which is 1024,
drivers that used to call blk_queue_max_sectors with a large value of
max_sectors will now see the fs requests capped to BLK_DEF_MAX_SECTORS.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 54a72f19748..14ad2a785a3 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -462,6 +462,7 @@ int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd,
 	req = blk_get_request(sdev->request_queue, write, gfp);
 	if (!req)
 		goto free_sense;
+	req->flags |= REQ_BLOCK_PC | REQ_QUIET;
 
 	if (use_sg)
 		err = scsi_req_map_sg(req, buffer, use_sg, bufflen, gfp);
@@ -477,7 +478,6 @@ int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd,
 	req->sense_len = 0;
 	req->timeout = timeout;
 	req->retries = retries;
-	req->flags |= REQ_BLOCK_PC | REQ_QUIET;
 	req->end_io_data = sioc;
 
 	sioc->data = privdata;