[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: Boaz Harrosh <bharrosh@panasas.com>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 7c4c889..69fd6218 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -746,7 +746,7 @@
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 @@
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 @@
* 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 @@
cmd->request_buffer = NULL;
cmd->request_bufflen = 0;
}
+EXPORT_SYMBOL(scsi_release_buffers);
/*
* Function: scsi_io_completion()
@@ -1001,7 +998,7 @@
* 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 @@
/*
* 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 @@
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 @@
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 @@
if (unlikely(!cmd))
return BLKPREP_DEFER;
- return scsi_init_io(cmd);
+ return scsi_init_io(cmd, GFP_ATOMIC);
}
EXPORT_SYMBOL(scsi_setup_fs_cmnd);
diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c
index 01e03f3..91630ba 100644
--- a/drivers/scsi/scsi_tgt_lib.c
+++ b/drivers/scsi/scsi_tgt_lib.c
@@ -331,8 +331,7 @@
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 @@
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 @@
}
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;
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index a457fca..09d44f9 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -127,8 +127,8 @@
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);