From: Boaz Harrosh <bharrosh@xxxxxxxxxxx>
- 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.
Signed-off-by: Boaz Harrosh <bharrosh@xxxxxxxxxxx>
Acked-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/scsi_lib.c | 21 ++++++++++-----------
drivers/scsi/scsi_tgt_lib.c | 29 +++++------------------------
include/scsi/scsi_cmnd.h | 4 ++--
3 files changed, 17 insertions(+), 37 deletions(-)
diff -puN drivers/scsi/scsi_lib.c~tgt-use-scsi_init_io-instead-of-scsi_alloc_sgtable drivers/scsi/scsi_lib.c
--- a/drivers/scsi/scsi_lib.c~tgt-use-scsi_init_io-instead-of-scsi_alloc_sgtable
+++ a/drivers/scsi/scsi_lib.c
@@ -739,7 +739,8 @@ static inline unsigned int scsi_sgtable_
return index;
}
-struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask)
+static struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd,
+ gfp_t gfp_mask)
{
struct scsi_host_sg_pool *sgp;
struct scatterlist *sgl, *prev, *ret;
@@ -825,9 +826,7 @@ enomem:
return NULL;
}
-EXPORT_SYMBOL(scsi_alloc_sgtable);
-
-void scsi_free_sgtable(struct scsi_cmnd *cmd)
+static void scsi_free_sgtable(struct scsi_cmnd *cmd)
{
struct scatterlist *sgl = cmd->request_buffer;
struct scsi_host_sg_pool *sgp;
@@ -873,8 +872,6 @@ void scsi_free_sgtable(struct scsi_cmnd
mempool_free(sgl, sgp->pool);
}
-EXPORT_SYMBOL(scsi_free_sgtable);
-
/*
* Function: scsi_release_buffers()
*
@@ -892,7 +889,7 @@ 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);
@@ -904,6 +901,7 @@ static void scsi_release_buffers(struct
cmd->request_buffer = NULL;
cmd->request_bufflen = 0;
}
+EXPORT_SYMBOL(scsi_release_buffers);
/*
* Function: scsi_io_completion()
@@ -1105,7 +1103,7 @@ void scsi_io_completion(struct scsi_cmnd
* 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;
@@ -1120,7 +1118,7 @@ static int scsi_init_io(struct scsi_cmnd
/*
* If sg table allocation fails, requeue request later.
*/
- cmd->request_buffer = scsi_alloc_sgtable(cmd, GFP_ATOMIC);
+ cmd->request_buffer = scsi_alloc_sgtable(cmd, gfp_mask);
if (unlikely(!cmd->request_buffer)) {
scsi_unprep_request(req);
return BLKPREP_DEFER;
@@ -1141,6 +1139,7 @@ static int scsi_init_io(struct scsi_cmnd
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)
@@ -1186,7 +1185,7 @@ int scsi_setup_blk_pc_cmnd(struct scsi_d
BUG_ON(!req->nr_phys_segments);
- ret = scsi_init_io(cmd);
+ ret = scsi_init_io(cmd, GFP_ATOMIC);
if (unlikely(ret))
return ret;
} else {
@@ -1237,7 +1236,7 @@ int scsi_setup_fs_cmnd(struct scsi_devic
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 -puN drivers/scsi/scsi_tgt_lib.c~tgt-use-scsi_init_io-instead-of-scsi_alloc_sgtable drivers/scsi/scsi_tgt_lib.c
--- a/drivers/scsi/scsi_tgt_lib.c~tgt-use-scsi_init_io-instead-of-scsi_alloc_sgtable
+++ a/drivers/scsi/scsi_tgt_lib.c
@@ -331,8 +331,7 @@ static void scsi_tgt_cmd_done(struct scs
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);
}
@@ -353,26 +352,6 @@ static int scsi_tgt_transfer_response(st
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;
- cmd->request_buffer = scsi_alloc_sgtable(cmd, gfp_mask);
- if (!cmd->request_buffer)
- 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)
@@ -398,9 +377,11 @@ static int scsi_map_user_pages(struct sc
}
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 -puN include/scsi/scsi_cmnd.h~tgt-use-scsi_init_io-instead-of-scsi_alloc_sgtable include/scsi/scsi_cmnd.h
--- a/include/scsi/scsi_cmnd.h~tgt-use-scsi_init_io-instead-of-scsi_alloc_sgtable
+++ a/include/scsi/scsi_cmnd.h
@@ -128,8 +128,8 @@ extern void *scsi_kmap_atomic_sg(struct
size_t *offset, size_t *len);
extern void scsi_kunmap_atomic_sg(void *virt);
-extern struct scatterlist *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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