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Commit bc7e380a authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by James Bottomley
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[SCSI] tgt: fix sesnse buffer problems 



This patch simplify the way to notify LLDs of the command completion
and addresses the following sense buffer problems:

- can't handle both data and sense.
- forces user-space to use aligned sense buffer

tgt copies sense_data from userspace to cmnd->sense_buffer (if
necessary), maps user-space pages (if necessary) and then calls
host->transfer_response (host->transfer_data is removed).

Signed-off-by: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: default avatarMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent 181011e0

drivers/scsi/ibmvscsi/ibmvstgt.c

+5 −16
Original line number Diff line number Diff line
@@ -273,23 +273,9 @@ static int ibmvstgt_rdma(struct scsi_cmnd *sc, struct scatterlist *sg, int nsg, 
		rest -= mlen;

	}

out:



	return 0;

}



static int ibmvstgt_transfer_data(struct scsi_cmnd *sc,

				  void (*done)(struct scsi_cmnd *))

{

	struct iu_entry	*iue = (struct iu_entry *) sc->SCp.ptr;

	int err;



	err = srp_transfer_data(sc, &vio_iu(iue)->srp.cmd, ibmvstgt_rdma, 1, 1);



	done(sc);



	return err;

}



static int ibmvstgt_cmd_done(struct scsi_cmnd *sc,

			     void (*done)(struct scsi_cmnd *))

{
@@ -297,7 +283,11 @@ static int ibmvstgt_cmd_done(struct scsi_cmnd *sc, 
	struct iu_entry *iue = (struct iu_entry *) sc->SCp.ptr;

	struct srp_target *target = iue->target;



	dprintk("%p %p %x\n", iue, target, vio_iu(iue)->srp.cmd.cdb[0]);

	dprintk("%p %p %x %u\n", iue, target, vio_iu(iue)->srp.cmd.cdb[0],

		cmd->usg_sg);



	if (sc->use_sg)

		srp_transfer_data(sc, &vio_iu(iue)->srp.cmd, ibmvstgt_rdma, 1, 1);



	spin_lock_irqsave(&target->lock, flags);

	list_del(&iue->ilist);
@@ -794,7 +784,6 @@ static struct scsi_host_template ibmvstgt_sht = { 
	.use_clustering		= DISABLE_CLUSTERING,

	.max_sectors		= DEFAULT_MAX_SECTORS,

	.transfer_response	= ibmvstgt_cmd_done,

	.transfer_data		= ibmvstgt_transfer_data,

	.eh_abort_handler	= ibmvstgt_eh_abort_handler,

	.tsk_mgmt_response	= ibmvstgt_tsk_mgmt_response,

	.shost_attrs		= ibmvstgt_attrs,

drivers/scsi/scsi_tgt_if.c

+4 −2
Original line number Diff line number Diff line
@@ -179,10 +179,12 @@ static int event_recv_msg(struct tgt_event *ev) 
	switch (ev->hdr.type) {

	case TGT_UEVENT_CMD_RSP:

		err = scsi_tgt_kspace_exec(ev->p.cmd_rsp.host_no,

					   ev->p.cmd_rsp.tag,

					   ev->p.cmd_rsp.result,

					   ev->p.cmd_rsp.len,

					   ev->p.cmd_rsp.tag,

					   ev->p.cmd_rsp.uaddr,

					   ev->p.cmd_rsp.len,

					   ev->p.cmd_rsp.sense_uaddr,

					   ev->p.cmd_rsp.sense_len,

					   ev->p.cmd_rsp.rw);

		break;

	case TGT_UEVENT_TSK_MGMT_RSP:

drivers/scsi/scsi_tgt_lib.c

+23 −97
Original line number Diff line number Diff line
@@ -47,9 +47,6 @@ struct scsi_tgt_cmd { 
	struct list_head hash_list;

	struct request *rq;

	u64 tag;



	void *buffer;

	unsigned bufflen;

};



#define TGT_HASH_ORDER	4
@@ -330,10 +327,14 @@ static void scsi_tgt_cmd_done(struct scsi_cmnd *cmd) 
	dprintk("cmd %p %lu\n", cmd, rq_data_dir(cmd->request));



	scsi_tgt_uspace_send_status(cmd, tcmd->tag);



	if (cmd->request_buffer)

		scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len);



	queue_work(scsi_tgtd, &tcmd->work);

}



static int __scsi_tgt_transfer_response(struct scsi_cmnd *cmd)

static int scsi_tgt_transfer_response(struct scsi_cmnd *cmd)

{

	struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd);

	int err;
@@ -346,30 +347,12 @@ static int __scsi_tgt_transfer_response(struct scsi_cmnd *cmd) 
	case SCSI_MLQUEUE_DEVICE_BUSY:

		return -EAGAIN;

	}



	return 0;

}



static void scsi_tgt_transfer_response(struct scsi_cmnd *cmd)

{

	struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data;

	int err;



	err = __scsi_tgt_transfer_response(cmd);

	if (!err)

		return;



	cmd->result = DID_BUS_BUSY << 16;

	err = scsi_tgt_uspace_send_status(cmd, tcmd->tag);

	if (err <= 0)

		/* the eh will have to pick this up */

		printk(KERN_ERR "Could not send cmd %p status\n", cmd);

}



static int scsi_tgt_init_cmd(struct scsi_cmnd *cmd, gfp_t gfp_mask)

{

	struct request *rq = cmd->request;

	struct scsi_tgt_cmd *tcmd = rq->end_io_data;

	int count;



	cmd->use_sg = rq->nr_phys_segments;
@@ -379,31 +362,28 @@ static int scsi_tgt_init_cmd(struct scsi_cmnd *cmd, gfp_t gfp_mask) 


	cmd->request_bufflen = rq->data_len;



	dprintk("cmd %p addr %p cnt %d %lu\n", cmd, tcmd->buffer, cmd->use_sg,

		rq_data_dir(rq));

	dprintk("cmd %p cnt %d %lu\n", cmd, cmd->use_sg, rq_data_dir(rq));

	count = blk_rq_map_sg(rq->q, rq, cmd->request_buffer);

	if (likely(count <= cmd->use_sg)) {

		cmd->use_sg = count;

		return 0;

	}



	eprintk("cmd %p addr %p cnt %d\n", cmd, tcmd->buffer, cmd->use_sg);

	eprintk("cmd %p cnt %d\n", cmd, cmd->use_sg);

	scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len);

	return -EINVAL;

}



/* TODO: test this crap and replace bio_map_user with new interface maybe */

static int scsi_map_user_pages(struct scsi_tgt_cmd *tcmd, struct scsi_cmnd *cmd,

			       int rw)

			       unsigned long uaddr, unsigned int len, int rw)

{

	struct request_queue *q = cmd->request->q;

	struct request *rq = cmd->request;

	void *uaddr = tcmd->buffer;

	unsigned int len = tcmd->bufflen;

	int err;



	dprintk("%lx %u\n", (unsigned long) uaddr, len);

	err = blk_rq_map_user(q, rq, uaddr, len);

	dprintk("%lx %u\n", uaddr, len);

	err = blk_rq_map_user(q, rq, (void *)uaddr, len);

	if (err) {

		/*

		 * TODO: need to fixup sg_tablesize, max_segment_size,
@@ -430,45 +410,6 @@ unmap_rq: 
	return err;

}



static int scsi_tgt_transfer_data(struct scsi_cmnd *);



static void scsi_tgt_data_transfer_done(struct scsi_cmnd *cmd)

{

	struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data;

	int err;



	/* should we free resources here on error ? */

	if (cmd->result) {

		err = scsi_tgt_uspace_send_status(cmd, tcmd->tag);

		if (err <= 0)

			/* the tgt uspace eh will have to pick this up */

			printk(KERN_ERR "Could not send cmd %p status\n", cmd);

		return;

	}



	dprintk("cmd %p request_bufflen %u bufflen %u\n",

		cmd, cmd->request_bufflen, tcmd->bufflen);



	scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len);

	tcmd->buffer += cmd->request_bufflen;

	scsi_tgt_transfer_response(cmd);

}



static int scsi_tgt_transfer_data(struct scsi_cmnd *cmd)

{

	int err;

	struct Scsi_Host *host = scsi_tgt_cmd_to_host(cmd);



	err = host->hostt->transfer_data(cmd, scsi_tgt_data_transfer_done);

	switch (err) {

		case SCSI_MLQUEUE_HOST_BUSY:

		case SCSI_MLQUEUE_DEVICE_BUSY:

			return -EAGAIN;

	default:

		return 0;

	}

}



static int scsi_tgt_copy_sense(struct scsi_cmnd *cmd, unsigned long uaddr,

				unsigned len)

{
@@ -518,8 +459,9 @@ static struct request *tgt_cmd_hash_lookup(struct request_queue *q, u64 tag) 
	return rq;

}



int scsi_tgt_kspace_exec(int host_no, u64 tag, int result, u32 len,

			 unsigned long uaddr, u8 rw)

int scsi_tgt_kspace_exec(int host_no, int result, u64 tag,

			 unsigned long uaddr, u32 len, unsigned long sense_uaddr,

			 u32 sense_len, u8 rw)

{

	struct Scsi_Host *shost;

	struct scsi_cmnd *cmd;
@@ -564,36 +506,20 @@ int scsi_tgt_kspace_exec(int host_no, u64 tag, int result, u32 len, 
	 * in the request_* values

	 */

	tcmd = cmd->request->end_io_data;

	tcmd->buffer = (void *)uaddr;

	tcmd->bufflen = len;

	cmd->result = result;



	if (!tcmd->bufflen || cmd->request_buffer) {

		err = __scsi_tgt_transfer_response(cmd);

		goto done;

	}

	if (cmd->result == SAM_STAT_CHECK_CONDITION)

		scsi_tgt_copy_sense(cmd, sense_uaddr, sense_len);



	/*

	 * TODO: Do we need to handle case where request does not

	 * align with LLD.

	 */

	err = scsi_map_user_pages(rq->end_io_data, cmd, rw);

	if (len) {

		err = scsi_map_user_pages(rq->end_io_data, cmd, uaddr, len, rw);

		if (err) {

			eprintk("%p %d\n", cmd, err);

			err = -EAGAIN;

			goto done;

		}



	/* userspace failure */

	if (cmd->result) {

		if (status_byte(cmd->result) == CHECK_CONDITION)

			scsi_tgt_copy_sense(cmd, uaddr, len);

		err = __scsi_tgt_transfer_response(cmd);

		goto done;

	}

	/* ask the target LLD to transfer the data to the buffer */

	err = scsi_tgt_transfer_data(cmd);



	err = scsi_tgt_transfer_response(cmd);

done:

	scsi_host_put(shost);

	return err;

drivers/scsi/scsi_tgt_priv.h

+3 −2
Original line number Diff line number Diff line
@@ -18,8 +18,9 @@ extern int scsi_tgt_if_init(void); 
extern int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, struct scsi_lun *lun,

				    u64 tag);

extern int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 tag);

extern int scsi_tgt_kspace_exec(int host_no, u64 tag, int result, u32 len,

				unsigned long uaddr, u8 rw);

extern int scsi_tgt_kspace_exec(int host_no, int result, u64 tag,

				unsigned long uaddr, u32 len, unsigned long sense_uaddr,

				u32 sense_len, u8 rw);

extern int scsi_tgt_uspace_send_tsk_mgmt(int host_no, int function, u64 tag,

					 struct scsi_lun *scsilun, void *data);

extern int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 mid, int result);

include/scsi/scsi_host.h

+5 −14
Original line number Diff line number Diff line
@@ -129,6 +129,11 @@ struct scsi_host_template { 
	 * the LLD. When the driver is finished processing the command

	 * the done callback is invoked.

	 *

	 * This is called to inform the LLD to transfer

	 * cmd->request_bufflen bytes. The cmd->use_sg speciefies the

	 * number of scatterlist entried in the command and

	 * cmd->request_buffer contains the scatterlist.

	 *

	 * return values: see queuecommand

	 *

	 * If the LLD accepts the cmd, it should set the result to an
@@ -139,20 +144,6 @@ struct scsi_host_template { 
	/* TODO: rename */

	int (* transfer_response)(struct scsi_cmnd *,

				  void (*done)(struct scsi_cmnd *));

	/*

	 * This is called to inform the LLD to transfer cmd->request_bufflen

	 * bytes of the cmd at cmd->offset in the cmd. The cmd->use_sg

	 * speciefies the number of scatterlist entried in the command

	 * and cmd->request_buffer contains the scatterlist.

	 *

	 * If the command cannot be processed in one transfer_data call

	 * becuase a scatterlist within the LLD's limits cannot be

	 * created then transfer_data will be called multiple times.

	 * It is initially called from process context, and later

	 * calls are from the interrup context.

	 */

	int (* transfer_data)(struct scsi_cmnd *,

			      void (*done)(struct scsi_cmnd *));



	/* Used as callback for the completion of task management request. */

	int (* tsk_mgmt_response)(u64 mid, int result);