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[SCSI] always handle REQ_BLOCK_PC requests in common code
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LLDDs should never see REQ_BLOCK_PC requests, we can handle them just
fine in the core code.  There is a small behaviour change in that some
check in sr's rw_intr are bypassed, but I consider the old behaviour
a bug.

Mike found this cleanup opportunity and provdided early patches, so all
the credit goes to him, even if I redid the patches from scratch beause
that was easier than forward-porting the old patches.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
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Christoph Hellwig authored and James Bottomley committed Jan 14, 2006
1 parent d405423 commit 776b23a
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Showing 5 changed files with 13 additions and 92 deletions.
16 changes: 8 additions & 8 deletions drivers/scsi/scsi_lib.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1212,7 +1212,7 @@ static int scsi_issue_flush_fn(request_queue_t *q, struct gendisk *disk,
return -EOPNOTSUPP;
}

static void scsi_generic_done(struct scsi_cmnd *cmd)
static void scsi_blk_pc_done(struct scsi_cmnd *cmd)
{
BUG_ON(!blk_pc_request(cmd->request));
/*
Expand All @@ -1224,7 +1224,7 @@ static void scsi_generic_done(struct scsi_cmnd *cmd)
scsi_io_completion(cmd, cmd->bufflen, 0);
}

void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd)
static void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd)
{
struct request *req = cmd->request;

Expand All @@ -1241,8 +1241,8 @@ void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd)
cmd->transfersize = req->data_len;
cmd->allowed = req->retries;
cmd->timeout_per_command = req->timeout;
cmd->done = scsi_blk_pc_done;
}
EXPORT_SYMBOL_GPL(scsi_setup_blk_pc_cmnd);

static int scsi_prep_fn(struct request_queue *q, struct request *req)
{
Expand Down Expand Up @@ -1339,7 +1339,6 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
* happening now.
*/
if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) {
struct scsi_driver *drv;
int ret;

/*
Expand Down Expand Up @@ -1371,16 +1370,17 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
/*
* Initialize the actual SCSI command for this request.
*/
if (req->rq_disk) {
if (req->flags & REQ_BLOCK_PC) {
scsi_setup_blk_pc_cmnd(cmd);
} else if (req->rq_disk) {
struct scsi_driver *drv;

drv = *(struct scsi_driver **)req->rq_disk->private_data;
if (unlikely(!drv->init_command(cmd))) {
scsi_release_buffers(cmd);
scsi_put_command(cmd);
goto kill;
}
} else {
scsi_setup_blk_pc_cmnd(cmd);
cmd->done = scsi_generic_done;
}
}

Expand Down
42 changes: 5 additions & 37 deletions drivers/scsi/sd.c
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Original file line number Diff line number Diff line change
Expand Up @@ -232,34 +232,12 @@ static void scsi_disk_put(struct scsi_disk *sdkp)
**/
static int sd_init_command(struct scsi_cmnd * SCpnt)
{
unsigned int this_count, timeout;
struct gendisk *disk;
sector_t block;
struct scsi_device *sdp = SCpnt->device;
struct request *rq = SCpnt->request;

timeout = sdp->timeout;

/*
* SG_IO from block layer already setup, just copy cdb basically
*/
if (blk_pc_request(rq)) {
scsi_setup_blk_pc_cmnd(SCpnt);
if (rq->timeout)
timeout = rq->timeout;

goto queue;
}

/*
* we only do REQ_CMD and REQ_BLOCK_PC
*/
if (!blk_fs_request(rq))
return 0;

disk = rq->rq_disk;
block = rq->sector;
this_count = SCpnt->request_bufflen >> 9;
struct gendisk *disk = rq->rq_disk;
sector_t block = rq->sector;
unsigned int this_count = SCpnt->request_bufflen >> 9;
unsigned int timeout = sdp->timeout;

SCSI_LOG_HLQUEUE(1, printk("sd_init_command: disk=%s, block=%llu, "
"count=%d\n", disk->disk_name,
Expand Down Expand Up @@ -402,8 +380,6 @@ static int sd_init_command(struct scsi_cmnd * SCpnt)
SCpnt->transfersize = sdp->sector_size;
SCpnt->underflow = this_count << 9;
SCpnt->allowed = SD_MAX_RETRIES;

queue:
SCpnt->timeout_per_command = timeout;

/*
Expand Down Expand Up @@ -837,15 +813,7 @@ static void sd_rw_intr(struct scsi_cmnd * SCpnt)
relatively rare error condition, no care is taken to avoid
unnecessary additional work such as memcpy's that could be avoided.
*/

/*
* If SG_IO from block layer then set good_bytes to stop retries;
* else if errors, check them, and if necessary prepare for
* (partial) retries.
*/
if (blk_pc_request(SCpnt->request))
good_bytes = this_count;
else if (driver_byte(result) != 0 &&
if (driver_byte(result) != 0 &&
sense_valid && !sense_deferred) {
switch (sshdr.sense_key) {
case MEDIUM_ERROR:
Expand Down
21 changes: 0 additions & 21 deletions drivers/scsi/sr.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -238,8 +238,6 @@ static void rw_intr(struct scsi_cmnd * SCpnt)
case ILLEGAL_REQUEST:
if (!(SCpnt->sense_buffer[0] & 0x90))
break;
if (!blk_fs_request(SCpnt->request))
break;
error_sector = (SCpnt->sense_buffer[3] << 24) |
(SCpnt->sense_buffer[4] << 16) |
(SCpnt->sense_buffer[5] << 8) |
Expand Down Expand Up @@ -317,23 +315,6 @@ static int sr_init_command(struct scsi_cmnd * SCpnt)
return 0;
}

/*
* these are already setup, just copy cdb basically
*/
if (SCpnt->request->flags & REQ_BLOCK_PC) {
scsi_setup_blk_pc_cmnd(SCpnt);

if (SCpnt->timeout_per_command)
timeout = SCpnt->timeout_per_command;

goto queue;
}

if (!(SCpnt->request->flags & REQ_CMD)) {
blk_dump_rq_flags(SCpnt->request, "sr unsup command");
return 0;
}

/*
* we do lazy blocksize switching (when reading XA sectors,
* see CDROMREADMODE2 ioctl)
Expand Down Expand Up @@ -422,8 +403,6 @@ static int sr_init_command(struct scsi_cmnd * SCpnt)
*/
SCpnt->transfersize = cd->device->sector_size;
SCpnt->underflow = this_count << 9;

queue:
SCpnt->allowed = MAX_RETRIES;
SCpnt->timeout_per_command = timeout;

Expand Down
25 changes: 0 additions & 25 deletions drivers/scsi/st.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -194,7 +194,6 @@ static int sgl_unmap_user_pages(struct scatterlist *, const unsigned int, int);

static int st_probe(struct device *);
static int st_remove(struct device *);
static int st_init_command(struct scsi_cmnd *);

static void do_create_driverfs_files(void);
static void do_remove_driverfs_files(void);
Expand All @@ -207,7 +206,6 @@ static struct scsi_driver st_template = {
.probe = st_probe,
.remove = st_remove,
},
.init_command = st_init_command,
};

static int st_compression(struct scsi_tape *, int);
Expand Down Expand Up @@ -4181,29 +4179,6 @@ static void scsi_tape_release(struct kref *kref)
return;
}

static void st_intr(struct scsi_cmnd *SCpnt)
{
/*
* The caller should be checking the request's errors
* value.
*/
scsi_io_completion(SCpnt, SCpnt->bufflen, 0);
}

/*
* st_init_command: only called via the scsi_cmd_ioctl (block SG_IO)
* interface for REQ_BLOCK_PC commands.
*/
static int st_init_command(struct scsi_cmnd *SCpnt)
{
if (!(SCpnt->request->flags & REQ_BLOCK_PC))
return 0;

scsi_setup_blk_pc_cmnd(SCpnt);
SCpnt->done = st_intr;
return 1;
}

static int __init init_st(void)
{
validate_options();
Expand Down
1 change: 0 additions & 1 deletion include/scsi/scsi_cmnd.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -151,6 +151,5 @@ extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
extern void scsi_put_command(struct scsi_cmnd *);
extern void scsi_io_completion(struct scsi_cmnd *, unsigned int, unsigned int);
extern void scsi_finish_command(struct scsi_cmnd *cmd);
extern void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd);

#endif /* _SCSI_SCSI_CMND_H */

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