Commit bb52d82f authored by Boaz Harrosh's avatar Boaz Harrosh Committed by James Bottomley
Browse files

[SCSI] tgt: use scsi_init_io instead of scsi_alloc_sgtable 



If we export scsi_init_io()/scsi_release_buffers() instead of
scsi_{alloc,free}_sgtable() from scsi_lib than tgt code is much more
insulated from scsi_lib changes. As a bonus it will also gain bidi
capability when it comes.

[jejb: rebase on to sg_table and fix up rejections]

Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
Acked-by: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent 03e7925d

drivers/scsi/scsi_lib.c

+9 −11
Original line number Diff line number Diff line
@@ -746,7 +746,7 @@ static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask) 
	return mempool_alloc(sgp->pool, gfp_mask);

}



int scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask)

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

{

	int ret;
@@ -762,15 +762,11 @@ int scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask) 
	return ret;

}



EXPORT_SYMBOL(scsi_alloc_sgtable);



void scsi_free_sgtable(struct scsi_cmnd *cmd)

static void scsi_free_sgtable(struct scsi_cmnd *cmd)

{

	__sg_free_table(&cmd->sg_table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free);

}



EXPORT_SYMBOL(scsi_free_sgtable);



/*

 * Function:    scsi_release_buffers()

 *
@@ -788,7 +784,7 @@ EXPORT_SYMBOL(scsi_free_sgtable); 
 *		the scatter-gather table, and potentially any bounce

 *		buffers.

 */

static void scsi_release_buffers(struct scsi_cmnd *cmd)

void scsi_release_buffers(struct scsi_cmnd *cmd)

{

	if (cmd->use_sg)

		scsi_free_sgtable(cmd);
@@ -800,6 +796,7 @@ static void scsi_release_buffers(struct scsi_cmnd *cmd) 
	cmd->request_buffer = NULL;

	cmd->request_bufflen = 0;

}

EXPORT_SYMBOL(scsi_release_buffers);



/*

 * Function:    scsi_io_completion()
@@ -1001,7 +998,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) 
 * Returns:     0 on success

 *		BLKPREP_DEFER if the failure is retryable

 */

static int scsi_init_io(struct scsi_cmnd *cmd)

int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask)

{

	struct request     *req = cmd->request;

	int		   count;
@@ -1016,7 +1013,7 @@ static int scsi_init_io(struct scsi_cmnd *cmd) 
	/*

	 * If sg table allocation fails, requeue request later.

	 */

	if (unlikely(scsi_alloc_sgtable(cmd, GFP_ATOMIC))) {

	if (unlikely(scsi_alloc_sgtable(cmd, gfp_mask))) {

		scsi_unprep_request(req);

		return BLKPREP_DEFER;

	}
@@ -1036,6 +1033,7 @@ static int scsi_init_io(struct scsi_cmnd *cmd) 
	cmd->use_sg = count;

	return BLKPREP_OK;

}

EXPORT_SYMBOL(scsi_init_io);



static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev,

		struct request *req)
@@ -1081,7 +1079,7 @@ int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req) 


		BUG_ON(!req->nr_phys_segments);



		ret = scsi_init_io(cmd);

		ret = scsi_init_io(cmd, GFP_ATOMIC);

		if (unlikely(ret))

			return ret;

	} else {
@@ -1132,7 +1130,7 @@ int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req) 
	if (unlikely(!cmd))

		return BLKPREP_DEFER;



	return scsi_init_io(cmd);

	return scsi_init_io(cmd, GFP_ATOMIC);

}

EXPORT_SYMBOL(scsi_setup_fs_cmnd);

drivers/scsi/scsi_tgt_lib.c

+5 −23
Original line number Diff line number Diff line
@@ -331,8 +331,7 @@ static void scsi_tgt_cmd_done(struct scsi_cmnd *cmd) 


	scsi_tgt_uspace_send_status(cmd, tcmd->itn_id, tcmd->tag);



	if (scsi_sglist(cmd))

		scsi_free_sgtable(cmd);

	scsi_release_buffers(cmd);



	queue_work(scsi_tgtd, &tcmd->work);

}
@@ -353,25 +352,6 @@ static int scsi_tgt_transfer_response(struct scsi_cmnd *cmd) 
	return 0;

}



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

{

	struct request *rq = cmd->request;

	int count;



	cmd->use_sg = rq->nr_phys_segments;

	if (scsi_alloc_sgtable(cmd, gfp_mask))

		return -ENOMEM;



	cmd->request_bufflen = rq->data_len;



	dprintk("cmd %p cnt %d %lu\n", cmd, scsi_sg_count(cmd),

		rq_data_dir(rq));

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

	BUG_ON(count > cmd->use_sg);

	cmd->use_sg = count;

	return 0;

}



/* 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,

			       unsigned long uaddr, unsigned int len, int rw)
@@ -397,9 +377,11 @@ static int scsi_map_user_pages(struct scsi_tgt_cmd *tcmd, struct scsi_cmnd *cmd, 
	}



	tcmd->bio = rq->bio;

	err = scsi_tgt_init_cmd(cmd, GFP_KERNEL);

	if (err)

	err = scsi_init_io(cmd, GFP_KERNEL);

	if (err) {

		scsi_release_buffers(cmd);

		goto unmap_rq;

	}



	return 0;

include/scsi/scsi_cmnd.h

+2 −2
Original line number Diff line number Diff line
@@ -127,8 +127,8 @@ extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count, 
				 size_t *offset, size_t *len);

extern void scsi_kunmap_atomic_sg(void *virt);



extern int scsi_alloc_sgtable(struct scsi_cmnd *, gfp_t);

extern void scsi_free_sgtable(struct scsi_cmnd *);

extern int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask);

extern void scsi_release_buffers(struct scsi_cmnd *cmd);



extern int scsi_dma_map(struct scsi_cmnd *cmd);

extern void scsi_dma_unmap(struct scsi_cmnd *cmd);

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