[SCSI] move ULD attachment into the prep function
One of the intents of the block prep function was to allow ULDs to use
it for preprocessing. The original SCSI model was to have a single prep
function and add a pointer indirect filter to build the necessary
commands. This patch reverses that, does away with the init_command
field of the scsi_driver structure and makes ULDs attach directly to the
prep function instead. The value is really that it allows us to begin
to separate the ULDs from the SCSI mid layer (as long as they don't use
any core functions---which is hard at the moment---a ULD doesn't even
need SCSI to bind).
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 2c6116f..38a4141 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -240,7 +240,6 @@
.shutdown = sd_shutdown,
},
.rescan = sd_rescan,
- .init_command = sd_init_command,
};
/*
@@ -331,14 +330,31 @@
*
* Returns 1 if successful and 0 if error (or cannot be done now).
**/
-static int sd_init_command(struct scsi_cmnd * SCpnt)
+static int sd_prep_fn(struct request_queue *q, struct request *rq)
{
- struct scsi_device *sdp = SCpnt->device;
- struct request *rq = SCpnt->request;
+ struct scsi_cmnd *SCpnt;
+ struct scsi_device *sdp = q->queuedata;
struct gendisk *disk = rq->rq_disk;
sector_t block = rq->sector;
- unsigned int this_count = SCpnt->request_bufflen >> 9;
+ unsigned int this_count = rq->nr_sectors;
unsigned int timeout = sdp->timeout;
+ int ret;
+
+ if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
+ ret = scsi_setup_blk_pc_cmnd(sdp, rq);
+ goto out;
+ } else if (rq->cmd_type != REQ_TYPE_FS) {
+ ret = BLKPREP_KILL;
+ goto out;
+ }
+ ret = scsi_setup_fs_cmnd(sdp, rq);
+ if (ret != BLKPREP_OK)
+ goto out;
+ SCpnt = rq->special;
+
+ /* from here on until we're complete, any goto out
+ * is used for a killable error condition */
+ ret = BLKPREP_KILL;
SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
"sd_init_command: block=%llu, "
@@ -353,7 +369,7 @@
rq->nr_sectors));
SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
"Retry with 0x%p\n", SCpnt));
- return 0;
+ goto out;
}
if (sdp->changed) {
@@ -362,8 +378,9 @@
* the changed bit has been reset
*/
/* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */
- return 0;
+ goto out;
}
+
SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt, "block=%llu\n",
(unsigned long long)block));
@@ -382,7 +399,7 @@
if ((block & 1) || (rq->nr_sectors & 1)) {
scmd_printk(KERN_ERR, SCpnt,
"Bad block number requested\n");
- return 0;
+ goto out;
} else {
block = block >> 1;
this_count = this_count >> 1;
@@ -392,7 +409,7 @@
if ((block & 3) || (rq->nr_sectors & 3)) {
scmd_printk(KERN_ERR, SCpnt,
"Bad block number requested\n");
- return 0;
+ goto out;
} else {
block = block >> 2;
this_count = this_count >> 2;
@@ -402,7 +419,7 @@
if ((block & 7) || (rq->nr_sectors & 7)) {
scmd_printk(KERN_ERR, SCpnt,
"Bad block number requested\n");
- return 0;
+ goto out;
} else {
block = block >> 3;
this_count = this_count >> 3;
@@ -410,7 +427,7 @@
}
if (rq_data_dir(rq) == WRITE) {
if (!sdp->writeable) {
- return 0;
+ goto out;
}
SCpnt->cmnd[0] = WRITE_6;
SCpnt->sc_data_direction = DMA_TO_DEVICE;
@@ -419,7 +436,7 @@
SCpnt->sc_data_direction = DMA_FROM_DEVICE;
} else {
scmd_printk(KERN_ERR, SCpnt, "Unknown command %x\n", rq->cmd_flags);
- return 0;
+ goto out;
}
SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
@@ -470,7 +487,7 @@
*/
scmd_printk(KERN_ERR, SCpnt,
"FUA write on READ/WRITE(6) drive\n");
- return 0;
+ goto out;
}
SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f);
@@ -501,7 +518,9 @@
* This indicates that the command is ready from our end to be
* queued.
*/
- return 1;
+ ret = BLKPREP_OK;
+ out:
+ return scsi_prep_return(q, rq, ret);
}
/**
@@ -1669,6 +1688,7 @@
sd_revalidate_disk(gd);
+ blk_queue_prep_rq(sdp->request_queue, sd_prep_fn);
blk_queue_issue_flush_fn(sdp->request_queue, sd_issue_flush);
gd->driverfs_dev = &sdp->sdev_gendev;