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Commit 776b23a0 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by James Bottomley
Browse files

[SCSI] always handle REQ_BLOCK_PC requests in common code 



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: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent d4054239

drivers/scsi/scsi_lib.c

+8 −8
Original line number Diff line number Diff line
@@ -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));

	/*
@@ -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;
@@ -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)

{
@@ -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;



		/*
@@ -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;

		}

	}

drivers/scsi/sd.c

+5 −37
Original line number Diff line number Diff line
@@ -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,
@@ -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;



	/*
@@ -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:

drivers/scsi/sr.c

+0 −21
Original line number Diff line number Diff line
@@ -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) |
@@ -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)
@@ -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;

drivers/scsi/st.c

+0 −25
Original line number Diff line number Diff line
@@ -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);
@@ -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);
@@ -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();

include/scsi/scsi_cmnd.h

+0 −1
Original line number Diff line number Diff line
@@ -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 */