* [PATCH] tgt: Use scsi_init_io instead of scsi_alloc_sgtable
2007-12-13 11:37 [0/3 ver2] Last 3 patches for bidi support Boaz Harrosh
@ 2007-12-13 11:44 ` Boaz Harrosh
2008-01-04 23:02 ` James Bottomley
2007-12-13 11:47 ` [PATCH] scsi: scsi_data_buffer Boaz Harrosh
2007-12-13 11:50 ` [PATCH] scsi: bidi support Boaz Harrosh
2 siblings, 1 reply; 7+ messages in thread
From: Boaz Harrosh @ 2007-12-13 11:44 UTC (permalink / raw)
To: James Bottomley, FUJITA Tomonori, linux-scsi, Andrew Morton
- 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@panasas.com>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
---
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 --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index e273e4b..d1a4671 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -739,7 +739,8 @@ static inline unsigned int scsi_sgtable_index(unsigned short nents)
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 *cmd)
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 scsi_cmnd *cmd)
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 *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;
@@ -1120,7 +1118,7 @@ static int scsi_init_io(struct scsi_cmnd *cmd)
/*
* 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)
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_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 {
@@ -1237,7 +1236,7 @@ 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);
diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c
index 93ece8f..91630ba 100644
--- a/drivers/scsi/scsi_tgt_lib.c
+++ b/drivers/scsi/scsi_tgt_lib.c
@@ -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);
}
@@ -353,26 +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;
- 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 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;
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 3f47e52..a7be605 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -128,8 +128,8 @@ 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 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);
--
1.5.3.3
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH] scsi: scsi_data_buffer
2007-12-13 11:37 [0/3 ver2] Last 3 patches for bidi support Boaz Harrosh
2007-12-13 11:44 ` [PATCH] tgt: Use scsi_init_io instead of scsi_alloc_sgtable Boaz Harrosh
@ 2007-12-13 11:47 ` Boaz Harrosh
2007-12-13 11:50 ` [PATCH] scsi: bidi support Boaz Harrosh
2 siblings, 0 replies; 7+ messages in thread
From: Boaz Harrosh @ 2007-12-13 11:47 UTC (permalink / raw)
To: James Bottomley, FUJITA Tomonori, linux-scsi, Andrew Morton
In preparation for bidi we abstract all IO members of scsi_cmnd,
that will need to duplicate, into a substructure.
- Group all IO members of scsi_cmnd into a scsi_data_buffer
structure.
- Adjust accessors to new members.
- scsi_{alloc,free}_sgtable receive a scsi_data_buffer instead of
scsi_cmnd. And work on it.
- Adjust scsi_init_io() and scsi_release_buffers() for above
change.
- Fix other parts of scsi_lib/scsi.c to members migration. Use
accessors where appropriate.
- fix Documentation about scsi_cmnd in scsi_host.h
- scsi_error.c
* Changed needed members of struct scsi_eh_save.
* Careful considerations in scsi_eh_prep/restore_cmnd.
- sd.c and sr.c
* sd and sr would adjust IO size to align on device's block
size so code needs to change once we move to scsi_data_buff
implementation.
* Convert code to use scsi_for_each_sg
* Use data accessors where appropriate.
- tgt: convert libsrp to use scsi_data_buffer
- isd200: This driver still bangs on scsi_cmnd IO members,
so need changing
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
---
drivers/scsi/libsrp.c | 4 +-
drivers/scsi/scsi.c | 2 +-
drivers/scsi/scsi_error.c | 28 +++++----------
drivers/scsi/scsi_lib.c | 77 ++++++++++++++++--------------------------
drivers/scsi/sd.c | 4 +-
drivers/scsi/sr.c | 25 +++++++------
drivers/usb/storage/isd200.c | 8 ++--
include/scsi/scsi_cmnd.h | 39 +++++++++++++--------
include/scsi/scsi_eh.h | 8 ++---
include/scsi/scsi_host.h | 4 +-
10 files changed, 91 insertions(+), 108 deletions(-)
diff --git a/drivers/scsi/libsrp.c b/drivers/scsi/libsrp.c
index 5cff020..8a8562a 100644
--- a/drivers/scsi/libsrp.c
+++ b/drivers/scsi/libsrp.c
@@ -426,8 +426,8 @@ int srp_cmd_queue(struct Scsi_Host *shost, struct srp_cmd *cmd, void *info,
sc->SCp.ptr = info;
memcpy(sc->cmnd, cmd->cdb, MAX_COMMAND_SIZE);
- sc->request_bufflen = len;
- sc->request_buffer = (void *) (unsigned long) addr;
+ sc->sdb.length = len;
+ sc->sdb.sglist = (void *) (unsigned long) addr;
sc->tag = tag;
err = scsi_tgt_queue_command(sc, itn_id, (struct scsi_lun *)&cmd->lun,
cmd->tag);
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index ebc0193..a0fd785 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -712,7 +712,7 @@ void scsi_finish_command(struct scsi_cmnd *cmd)
"Notifying upper driver of completion "
"(result %x)\n", cmd->result));
- good_bytes = cmd->request_bufflen;
+ good_bytes = scsi_bufflen(cmd);
if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) {
drv = scsi_cmd_to_driver(cmd);
if (drv->done)
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 169bc59..241ab48 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -617,29 +617,25 @@ void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses,
ses->cmd_len = scmd->cmd_len;
memcpy(ses->cmnd, scmd->cmnd, sizeof(scmd->cmnd));
ses->data_direction = scmd->sc_data_direction;
- ses->bufflen = scmd->request_bufflen;
- ses->buffer = scmd->request_buffer;
- ses->use_sg = scmd->use_sg;
- ses->resid = scmd->resid;
+ ses->sdb = scmd->sdb;
ses->result = scmd->result;
+ memset(&scmd->sdb, 0, sizeof(scmd->sdb));
+
if (sense_bytes) {
- scmd->request_bufflen = min_t(unsigned,
+ scmd->sdb.length = min_t(unsigned,
sizeof(scmd->sense_buffer), sense_bytes);
sg_init_one(&ses->sense_sgl, scmd->sense_buffer,
- scmd->request_bufflen);
- scmd->request_buffer = &ses->sense_sgl;
+ scmd->sdb.length);
+ scmd->sdb.sglist = &ses->sense_sgl;
scmd->sc_data_direction = DMA_FROM_DEVICE;
- scmd->use_sg = 1;
+ scmd->sdb.sg_count = 1;
memset(scmd->cmnd, 0, sizeof(scmd->cmnd));
scmd->cmnd[0] = REQUEST_SENSE;
- scmd->cmnd[4] = scmd->request_bufflen;
+ scmd->cmnd[4] = scmd->sdb.length;
scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
} else {
- scmd->request_buffer = NULL;
- scmd->request_bufflen = 0;
scmd->sc_data_direction = DMA_NONE;
- scmd->use_sg = 0;
if (cmnd) {
memset(scmd->cmnd, 0, sizeof(scmd->cmnd));
memcpy(scmd->cmnd, cmnd, cmnd_size);
@@ -676,10 +672,7 @@ void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, struct scsi_eh_save *ses)
scmd->cmd_len = ses->cmd_len;
memcpy(scmd->cmnd, ses->cmnd, sizeof(scmd->cmnd));
scmd->sc_data_direction = ses->data_direction;
- scmd->request_bufflen = ses->bufflen;
- scmd->request_buffer = ses->buffer;
- scmd->use_sg = ses->use_sg;
- scmd->resid = ses->resid;
+ scmd->sdb = ses->sdb;
scmd->result = ses->result;
}
EXPORT_SYMBOL(scsi_eh_restore_cmnd);
@@ -1700,8 +1693,7 @@ scsi_reset_provider(struct scsi_device *dev, int flag)
memset(&scmd->cmnd, '\0', sizeof(scmd->cmnd));
scmd->scsi_done = scsi_reset_provider_done_command;
- scmd->request_buffer = NULL;
- scmd->request_bufflen = 0;
+ memset(&scmd->sdb, 0, sizeof(scmd->sdb));
scmd->cmd_len = 0;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index d1a4671..7ac36fe 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -440,7 +440,7 @@ EXPORT_SYMBOL_GPL(scsi_execute_async);
static void scsi_init_cmd_errh(struct scsi_cmnd *cmd)
{
cmd->serial_number = 0;
- cmd->resid = 0;
+ scsi_set_resid(cmd, 0);
memset(cmd->sense_buffer, 0, sizeof cmd->sense_buffer);
if (cmd->cmd_len == 0)
cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]);
@@ -739,17 +739,15 @@ static inline unsigned int scsi_sgtable_index(unsigned short nents)
return index;
}
-static struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd,
- gfp_t gfp_mask)
+static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb,
+ unsigned short sg_count, gfp_t gfp_mask)
{
struct scsi_host_sg_pool *sgp;
struct scatterlist *sgl, *prev, *ret;
unsigned int index;
int this, left;
- BUG_ON(!cmd->use_sg);
-
- left = cmd->use_sg;
+ left = sg_count;
ret = prev = NULL;
do {
this = left;
@@ -803,8 +801,9 @@ static struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd,
* ->use_sg may get modified after dma mapping has potentially
* shrunk the number of segments, so keep a copy of it for free.
*/
- cmd->__use_sg = cmd->use_sg;
- return ret;
+ sdb->alloc_sg_count = sdb->sg_count = sg_count;
+ sdb->sglist = ret;
+ return 0;
enomem:
if (ret) {
/*
@@ -823,24 +822,24 @@ enomem:
mempool_free(prev, sgp->pool);
}
- return NULL;
+ return -ENOMEM;
}
-static void scsi_free_sgtable(struct scsi_cmnd *cmd)
+static void scsi_free_sgtable(struct scsi_data_buffer *sdb)
{
- struct scatterlist *sgl = cmd->request_buffer;
+ struct scatterlist *sgl = sdb->sglist;
struct scsi_host_sg_pool *sgp;
/*
* if this is the biggest size sglist, check if we have
* chained parts we need to free
*/
- if (cmd->__use_sg > SCSI_MAX_SG_SEGMENTS) {
+ if (sdb->alloc_sg_count > SCSI_MAX_SG_SEGMENTS) {
unsigned short this, left;
struct scatterlist *next;
unsigned int index;
- left = cmd->__use_sg - (SCSI_MAX_SG_SEGMENTS - 1);
+ left = sdb->alloc_sg_count - (SCSI_MAX_SG_SEGMENTS - 1);
next = sg_chain_ptr(&sgl[SCSI_MAX_SG_SEGMENTS - 1]);
while (left && next) {
sgl = next;
@@ -864,10 +863,10 @@ static void scsi_free_sgtable(struct scsi_cmnd *cmd)
/*
* Restore original, will be freed below
*/
- sgl = cmd->request_buffer;
+ sgl = sdb->sglist;
sgp = scsi_sg_pools + SG_MEMPOOL_NR - 1;
} else
- sgp = scsi_sg_pools + scsi_sgtable_index(cmd->__use_sg);
+ sgp = scsi_sg_pools + scsi_sgtable_index(sdb->alloc_sg_count);
mempool_free(sgl, sgp->pool);
}
@@ -891,15 +890,10 @@ static void scsi_free_sgtable(struct scsi_cmnd *cmd)
*/
void scsi_release_buffers(struct scsi_cmnd *cmd)
{
- if (cmd->use_sg)
- scsi_free_sgtable(cmd);
+ if (cmd->sdb.sglist)
+ scsi_free_sgtable(&cmd->sdb);
- /*
- * Zero these out. They now point to freed memory, and it is
- * dangerous to hang onto the pointers.
- */
- cmd->request_buffer = NULL;
- cmd->request_bufflen = 0;
+ memset(&cmd->sdb, 0, sizeof(cmd->sdb));
}
EXPORT_SYMBOL(scsi_release_buffers);
@@ -934,7 +928,7 @@ EXPORT_SYMBOL(scsi_release_buffers);
void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
{
int result = cmd->result;
- int this_count = cmd->request_bufflen;
+ int this_count = scsi_bufflen(cmd);
struct request_queue *q = cmd->device->request_queue;
struct request *req = cmd->request;
int clear_errors = 1;
@@ -942,8 +936,6 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
int sense_valid = 0;
int sense_deferred = 0;
- scsi_release_buffers(cmd);
-
if (result) {
sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
if (sense_valid)
@@ -966,9 +958,11 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
req->sense_len = len;
}
}
- req->data_len = cmd->resid;
+ req->data_len = scsi_get_resid(cmd);
}
+ scsi_release_buffers(cmd);
+
/*
* Next deal with any sectors which we were able to correctly
* handle.
@@ -976,7 +970,6 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, "
"%d bytes done.\n",
req->nr_sectors, good_bytes));
- SCSI_LOG_HLCOMPLETE(1, printk("use_sg is %d\n", cmd->use_sg));
if (clear_errors)
req->errors = 0;
@@ -1107,36 +1100,26 @@ int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask)
{
struct request *req = cmd->request;
int count;
+ struct scsi_data_buffer *sdb = &cmd->sdb;
- /*
- * We used to not use scatter-gather for single segment request,
- * but now we do (it makes highmem I/O easier to support without
- * kmapping pages)
- */
- cmd->use_sg = req->nr_phys_segments;
-
- /*
- * If sg table allocation fails, requeue request later.
- */
- cmd->request_buffer = scsi_alloc_sgtable(cmd, gfp_mask);
- if (unlikely(!cmd->request_buffer)) {
+ if (scsi_alloc_sgtable(sdb, req->nr_phys_segments, gfp_mask)) {
scsi_unprep_request(req);
return BLKPREP_DEFER;
}
req->buffer = NULL;
if (blk_pc_request(req))
- cmd->request_bufflen = req->data_len;
+ sdb->length = req->data_len;
else
- cmd->request_bufflen = req->nr_sectors << 9;
+ sdb->length = req->nr_sectors << 9;
/*
* Next, walk the list, and fill in the addresses and sizes of
* each segment.
*/
- count = blk_rq_map_sg(req->q, req, cmd->request_buffer);
- BUG_ON(count > cmd->use_sg);
- cmd->use_sg = count;
+ count = blk_rq_map_sg(req->q, req, sdb->sglist);
+ BUG_ON(count > sdb->sg_count);
+ sdb->sg_count = count;
return BLKPREP_OK;
}
EXPORT_SYMBOL(scsi_init_io);
@@ -1192,9 +1175,7 @@ int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
BUG_ON(req->data_len);
BUG_ON(req->data);
- cmd->request_bufflen = 0;
- cmd->request_buffer = NULL;
- cmd->use_sg = 0;
+ memset(&cmd->sdb, 0, sizeof(cmd->sdb));
req->buffer = NULL;
}
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index e6d85b0..1fcec1e 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -507,7 +507,7 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
SCpnt->cmnd[4] = (unsigned char) this_count;
SCpnt->cmnd[5] = 0;
}
- SCpnt->request_bufflen = this_count * sdp->sector_size;
+ SCpnt->sdb.length = this_count * sdp->sector_size;
/*
* We shouldn't disconnect in the middle of a sector, so with a dumb
@@ -914,7 +914,7 @@ static struct block_device_operations sd_fops = {
static int sd_done(struct scsi_cmnd *SCpnt)
{
int result = SCpnt->result;
- unsigned int xfer_size = SCpnt->request_bufflen;
+ unsigned int xfer_size = scsi_bufflen(SCpnt);
unsigned int good_bytes = result ? 0 : xfer_size;
u64 start_lba = SCpnt->request->sector;
u64 bad_lba;
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 7128d15..93d9dc8 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -233,7 +233,7 @@ out:
static int sr_done(struct scsi_cmnd *SCpnt)
{
int result = SCpnt->result;
- int this_count = SCpnt->request_bufflen;
+ int this_count = scsi_bufflen(SCpnt);
int good_bytes = (result == 0 ? this_count : 0);
int block_sectors = 0;
long error_sector;
@@ -378,17 +378,18 @@ static int sr_prep_fn(struct request_queue *q, struct request *rq)
}
{
- struct scatterlist *sg = SCpnt->request_buffer;
- int i, size = 0;
- for (i = 0; i < SCpnt->use_sg; i++)
- size += sg[i].length;
+ struct scatterlist *sg;
+ int i, size = 0, sg_count = scsi_sg_count(SCpnt);
- if (size != SCpnt->request_bufflen && SCpnt->use_sg) {
+ scsi_for_each_sg(SCpnt, sg, sg_count, i)
+ size += sg->length;
+
+ if (size != scsi_bufflen(SCpnt)) {
scmd_printk(KERN_ERR, SCpnt,
"mismatch count %d, bytes %d\n",
- size, SCpnt->request_bufflen);
- if (SCpnt->request_bufflen > size)
- SCpnt->request_bufflen = size;
+ size, scsi_bufflen(SCpnt));
+ if (scsi_bufflen(SCpnt) > size)
+ SCpnt->sdb.length = size;
}
}
@@ -396,12 +397,12 @@ static int sr_prep_fn(struct request_queue *q, struct request *rq)
* request doesn't start on hw block boundary, add scatter pads
*/
if (((unsigned int)rq->sector % (s_size >> 9)) ||
- (SCpnt->request_bufflen % s_size)) {
+ (scsi_bufflen(SCpnt) % s_size)) {
scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
goto out;
}
- this_count = (SCpnt->request_bufflen >> 9) / (s_size >> 9);
+ this_count = (scsi_bufflen(SCpnt) >> 9) / (s_size >> 9);
SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n",
@@ -415,7 +416,7 @@ static int sr_prep_fn(struct request_queue *q, struct request *rq)
if (this_count > 0xffff) {
this_count = 0xffff;
- SCpnt->request_bufflen = this_count * s_size;
+ SCpnt->sdb.length = this_count * s_size;
}
SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
diff --git a/drivers/usb/storage/isd200.c b/drivers/usb/storage/isd200.c
index 178e8c2..2d9a32b 100644
--- a/drivers/usb/storage/isd200.c
+++ b/drivers/usb/storage/isd200.c
@@ -415,14 +415,14 @@ static void isd200_set_srb(struct isd200_info *info,
sg_init_one(&info->sg, buff, bufflen);
srb->sc_data_direction = dir;
- srb->request_buffer = buff ? &info->sg : NULL;
- srb->request_bufflen = bufflen;
- srb->use_sg = buff ? 1 : 0;
+ srb->sdb.sglist = buff ? &info->sg : NULL;
+ srb->sdb.length = bufflen;
+ srb->sdb.sg_count = buff ? 1 : 0;
}
static void isd200_srb_set_bufflen(struct scsi_cmnd *srb, unsigned bufflen)
{
- srb->request_bufflen = bufflen;
+ srb->sdb.length = bufflen;
}
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index a7be605..887a12a 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -12,6 +12,13 @@ struct scatterlist;
struct Scsi_Host;
struct scsi_device;
+struct scsi_data_buffer {
+ struct scatterlist *sglist;
+ unsigned length;
+ int resid;
+ unsigned short sg_count;
+ unsigned short alloc_sg_count; /* private to scsi_lib */
+};
/* embedded in scsi_cmnd */
struct scsi_pointer {
@@ -62,15 +69,10 @@ struct scsi_cmnd {
/* These elements define the operation we are about to perform */
#define MAX_COMMAND_SIZE 16
unsigned char cmnd[MAX_COMMAND_SIZE];
- unsigned request_bufflen; /* Actual request size */
struct timer_list eh_timeout; /* Used to time out the command. */
- void *request_buffer; /* Actual requested buffer */
/* These elements define the operation we ultimately want to perform */
- unsigned short use_sg; /* Number of pieces of scatter-gather */
- unsigned short __use_sg;
-
unsigned underflow; /* Return error if less than
this amount is transferred */
@@ -80,10 +82,6 @@ struct scsi_cmnd {
reconnects. Probably == sector
size */
- int resid; /* Number of bytes requested to be
- transferred less actual number
- transferred (0 if not supported) */
-
struct request *request; /* The command we are
working on */
@@ -114,6 +112,8 @@ struct scsi_cmnd {
int result; /* Status code from lower level driver */
unsigned char tag; /* SCSI-II queued command tag */
+
+ struct scsi_data_buffer sdb;
};
extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
@@ -134,18 +134,29 @@ 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);
-#define scsi_sg_count(cmd) ((cmd)->use_sg)
-#define scsi_sglist(cmd) ((struct scatterlist *)(cmd)->request_buffer)
-#define scsi_bufflen(cmd) ((cmd)->request_bufflen)
+static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
+{
+ return cmd->sdb.sg_count;
+}
+
+static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
+{
+ return cmd->sdb.sglist;
+}
+
+static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
+{
+ return cmd->sdb.length;
+}
static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
{
- cmd->resid = resid;
+ cmd->sdb.resid = resid;
}
static inline int scsi_get_resid(struct scsi_cmnd *cmd)
{
- return cmd->resid;
+ return cmd->sdb.resid;
}
#define scsi_for_each_sg(cmd, sg, nseg, __i) \
diff --git a/include/scsi/scsi_eh.h b/include/scsi/scsi_eh.h
index d21b891..1e08be1 100644
--- a/include/scsi/scsi_eh.h
+++ b/include/scsi/scsi_eh.h
@@ -68,16 +68,14 @@ extern int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
extern int scsi_reset_provider(struct scsi_device *, int);
struct scsi_eh_save {
+ /* saved state */
int result;
enum dma_data_direction data_direction;
unsigned char cmd_len;
unsigned char cmnd[MAX_COMMAND_SIZE];
+ struct scsi_data_buffer sdb;
- void *buffer;
- unsigned bufflen;
- unsigned short use_sg;
- int resid;
-
+ /* new command support */
struct scatterlist sense_sgl;
};
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 0fd4746..cb2bcab 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -136,9 +136,9 @@ struct scsi_host_template {
* the done callback is invoked.
*
* This is called to inform the LLD to transfer
- * cmd->request_bufflen bytes. The cmd->use_sg speciefies the
+ * scsi_bufflen(cmd) bytes. scsi_sg_count(cmd) speciefies the
* number of scatterlist entried in the command and
- * cmd->request_buffer contains the scatterlist.
+ * scsi_sglist(cmd) returns the scatterlist.
*
* return values: see queuecommand
*
--
1.5.3.3
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH] scsi: bidi support
2007-12-13 11:37 [0/3 ver2] Last 3 patches for bidi support Boaz Harrosh
2007-12-13 11:44 ` [PATCH] tgt: Use scsi_init_io instead of scsi_alloc_sgtable Boaz Harrosh
2007-12-13 11:47 ` [PATCH] scsi: scsi_data_buffer Boaz Harrosh
@ 2007-12-13 11:50 ` Boaz Harrosh
2 siblings, 0 replies; 7+ messages in thread
From: Boaz Harrosh @ 2007-12-13 11:50 UTC (permalink / raw)
To: James Bottomley, FUJITA Tomonori, linux-scsi, Andrew Morton
At the block level bidi request uses req->next_rq pointer for a second
bidi_read request.
At Scsi-midlayer a second scsi_data_buffer structure is used for the
bidi_read part. This bidi scsi_data_buffer is put on
request->next_rq->special. Struct scsi_cmnd is not changed.
- Define scsi_bidi_cmnd() to return true if it is a bidi request and a
second sgtable was allocated.
- Define scsi_in()/scsi_out() to return the in or out scsi_data_buffer
from this command This API is to isolate users from the mechanics of
bidi.
- Define scsi_end_bidi_request() to do what scsi_end_request() does but
for a bidi request. This is necessary because bidi commands are a bit
tricky here. (See comments in body)
- scsi_release_buffers() will also release the bidi_read scsi_data_buffer
- scsi_io_completion() on bidi commands will now call
scsi_end_bidi_request() and return.
- The previous work done in scsi_init_io() is now done in a new
scsi_init_sgtable() (which is 99% identical to old scsi_init_io())
The new scsi_init_io() will call the above twice if needed also for
the bidi_read command. Only at this point is a command bidi.
- In scsi_error.c at scsi_eh_prep/restore_cmnd() make sure bidi-lld is not
confused by a get-sense command that looks like bidi. This is done
by puting NULL at request->next_rq, and restoring.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
---
drivers/scsi/scsi_error.c | 3 +
drivers/scsi/scsi_lib.c | 144 ++++++++++++++++++++++++++++++++++++---------
include/scsi/scsi_cmnd.h | 23 +++++++-
include/scsi/scsi_eh.h | 1 +
4 files changed, 141 insertions(+), 30 deletions(-)
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 241ab48..5c8ba6a 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -618,9 +618,11 @@ void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses,
memcpy(ses->cmnd, scmd->cmnd, sizeof(scmd->cmnd));
ses->data_direction = scmd->sc_data_direction;
ses->sdb = scmd->sdb;
+ ses->next_rq = scmd->request->next_rq;
ses->result = scmd->result;
memset(&scmd->sdb, 0, sizeof(scmd->sdb));
+ scmd->request->next_rq = NULL;
if (sense_bytes) {
scmd->sdb.length = min_t(unsigned,
@@ -673,6 +675,7 @@ void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, struct scsi_eh_save *ses)
memcpy(scmd->cmnd, ses->cmnd, sizeof(scmd->cmnd));
scmd->sc_data_direction = ses->data_direction;
scmd->sdb = ses->sdb;
+ scmd->request->next_rq = ses->next_rq;
scmd->result = ses->result;
}
EXPORT_SYMBOL(scsi_eh_restore_cmnd);
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 7ac36fe..a6aae56 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -64,6 +64,8 @@ static struct scsi_host_sg_pool scsi_sg_pools[] = {
};
#undef SP
+static struct kmem_cache *scsi_bidi_sdb_cache;
+
static void scsi_run_queue(struct request_queue *q);
/*
@@ -627,6 +629,28 @@ void scsi_run_host_queues(struct Scsi_Host *shost)
scsi_run_queue(sdev->request_queue);
}
+static void scsi_finalize_request(struct scsi_cmnd *cmd, int uptodate)
+{
+ struct request_queue *q = cmd->device->request_queue;
+ struct request *req = cmd->request;
+ unsigned long flags;
+
+ add_disk_randomness(req->rq_disk);
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ if (blk_rq_tagged(req))
+ blk_queue_end_tag(q, req);
+
+ end_that_request_last(req, uptodate);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+
+ /*
+ * This will goose the queue request function at the end, so we don't
+ * need to worry about launching another command.
+ */
+ scsi_next_command(cmd);
+}
+
/*
* Function: scsi_end_request()
*
@@ -654,7 +678,6 @@ static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int uptodate,
{
struct request_queue *q = cmd->device->request_queue;
struct request *req = cmd->request;
- unsigned long flags;
/*
* If there are blocks left over at the end, set up the command
@@ -683,19 +706,7 @@ static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int uptodate,
}
}
- add_disk_randomness(req->rq_disk);
-
- spin_lock_irqsave(q->queue_lock, flags);
- if (blk_rq_tagged(req))
- blk_queue_end_tag(q, req);
- end_that_request_last(req, uptodate);
- spin_unlock_irqrestore(q->queue_lock, flags);
-
- /*
- * This will goose the queue request function at the end, so we don't
- * need to worry about launching another command.
- */
- scsi_next_command(cmd);
+ scsi_finalize_request(cmd, uptodate);
return NULL;
}
@@ -894,10 +905,39 @@ void scsi_release_buffers(struct scsi_cmnd *cmd)
scsi_free_sgtable(&cmd->sdb);
memset(&cmd->sdb, 0, sizeof(cmd->sdb));
+
+ if (scsi_bidi_cmnd(cmd)) {
+ struct scsi_data_buffer *bidi_sdb =
+ cmd->request->next_rq->special;
+ scsi_free_sgtable(bidi_sdb);
+ kmem_cache_free(scsi_bidi_sdb_cache, bidi_sdb);
+ cmd->request->next_rq->special = NULL;
+ }
}
EXPORT_SYMBOL(scsi_release_buffers);
/*
+ * Bidi commands Must be complete as a whole, both sides at once.
+ * If part of the bytes were written and lld returned
+ * scsi_in()->resid and/or scsi_out()->resid this information will be left
+ * in req->data_len and req->next_rq->data_len. The upper-layer driver can
+ * decide what to do with this information.
+ */
+void scsi_end_bidi_request(struct scsi_cmnd *cmd)
+{
+ struct request *req = cmd->request;
+
+ end_that_request_chunk(req, 1, req->data_len);
+ req->data_len = scsi_out(cmd)->resid;
+
+ end_that_request_chunk(req->next_rq, 1, req->next_rq->data_len);
+ req->next_rq->data_len = scsi_in(cmd)->resid;
+
+ scsi_release_buffers(cmd);
+ scsi_finalize_request(cmd, 1);
+}
+
+/*
* Function: scsi_io_completion()
*
* Purpose: Completion processing for block device I/O requests.
@@ -958,9 +998,15 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
req->sense_len = len;
}
}
+ if (scsi_bidi_cmnd(cmd)) {
+ /* will also release_buffers */
+ scsi_end_bidi_request(cmd);
+ return;
+ }
req->data_len = scsi_get_resid(cmd);
}
+ BUG_ON(blk_bidi_rq(req)); /* bidi not support for !blk_pc_request yet */
scsi_release_buffers(cmd);
/*
@@ -1086,24 +1132,12 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
scsi_end_request(cmd, 0, this_count, !result);
}
-/*
- * Function: scsi_init_io()
- *
- * Purpose: SCSI I/O initialize function.
- *
- * Arguments: cmd - Command descriptor we wish to initialize
- *
- * Returns: 0 on success
- * BLKPREP_DEFER if the failure is retryable
- */
-int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask)
+static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb,
+ gfp_t gfp_mask)
{
- struct request *req = cmd->request;
- int count;
- struct scsi_data_buffer *sdb = &cmd->sdb;
+ int count;
if (scsi_alloc_sgtable(sdb, req->nr_phys_segments, gfp_mask)) {
- scsi_unprep_request(req);
return BLKPREP_DEFER;
}
@@ -1122,6 +1156,50 @@ int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask)
sdb->sg_count = count;
return BLKPREP_OK;
}
+
+/*
+ * Function: scsi_init_io()
+ *
+ * Purpose: SCSI I/O initialize function.
+ *
+ * Arguments: cmd - Command descriptor we wish to initialize
+ *
+ * Returns: 0 on success
+ * BLKPREP_DEFER if the failure is retryable
+ * BLKPREP_KILL if the failure is fatal
+ */
+int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask)
+{
+ int error = scsi_init_sgtable(cmd->request, &cmd->sdb, gfp_mask);
+ if (error)
+ goto err_exit;
+
+ if (blk_bidi_rq(cmd->request)) {
+ struct scsi_data_buffer *bidi_sdb = kmem_cache_zalloc(
+ scsi_bidi_sdb_cache, GFP_ATOMIC);
+ if (!bidi_sdb) {
+ error = BLKPREP_DEFER;
+ goto err_exit;
+ }
+
+ cmd->request->next_rq->special = bidi_sdb;
+ error = scsi_init_sgtable(cmd->request->next_rq, bidi_sdb,
+ GFP_ATOMIC);
+ if (error)
+ goto err_exit;
+ }
+
+ return BLKPREP_OK ;
+
+err_exit:
+ scsi_release_buffers(cmd);
+ if (error == BLKPREP_KILL)
+ scsi_put_command(cmd);
+ else /* BLKPREP_DEFER */
+ scsi_unprep_request(cmd->request);
+
+ return error;
+}
EXPORT_SYMBOL(scsi_init_io);
static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev,
@@ -1731,6 +1809,14 @@ int __init scsi_init_queue(void)
return -ENOMEM;
}
+ scsi_bidi_sdb_cache = kmem_cache_create("scsi_bidi_sdb",
+ sizeof(struct scsi_data_buffer),
+ 0, 0, NULL);
+ if (!scsi_bidi_sdb_cache) {
+ printk(KERN_ERR "SCSI: can't init scsi bidi sdb cache\n");
+ return -ENOMEM;
+ }
+
for (i = 0; i < SG_MEMPOOL_NR; i++) {
struct scsi_host_sg_pool *sgp = scsi_sg_pools + i;
int size = sgp->size * sizeof(struct scatterlist);
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 887a12a..cd2851a 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -2,12 +2,12 @@
#define _SCSI_SCSI_CMND_H
#include <linux/dma-mapping.h>
+#include <linux/blkdev.h>
#include <linux/list.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/scatterlist.h>
-struct request;
struct scatterlist;
struct Scsi_Host;
struct scsi_device;
@@ -162,4 +162,25 @@ static inline int scsi_get_resid(struct scsi_cmnd *cmd)
#define scsi_for_each_sg(cmd, sg, nseg, __i) \
for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
+static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
+{
+ return blk_bidi_rq(cmd->request) &&
+ (cmd->request->next_rq->special != NULL);
+}
+
+static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
+{
+ WARN_ON((cmd->sc_data_direction != DMA_FROM_DEVICE) &&
+ !scsi_bidi_cmnd(cmd));
+ return scsi_bidi_cmnd(cmd) ?
+ cmd->request->next_rq->special : &cmd->sdb;
+}
+
+static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
+{
+ WARN_ON((cmd->sc_data_direction != DMA_TO_DEVICE) &&
+ !scsi_bidi_cmnd(cmd));
+ return &cmd->sdb;
+}
+
#endif /* _SCSI_SCSI_CMND_H */
diff --git a/include/scsi/scsi_eh.h b/include/scsi/scsi_eh.h
index 1e08be1..25071d5 100644
--- a/include/scsi/scsi_eh.h
+++ b/include/scsi/scsi_eh.h
@@ -74,6 +74,7 @@ struct scsi_eh_save {
unsigned char cmd_len;
unsigned char cmnd[MAX_COMMAND_SIZE];
struct scsi_data_buffer sdb;
+ struct request *next_rq;
/* new command support */
struct scatterlist sense_sgl;
--
1.5.3.3
^ permalink raw reply related [flat|nested] 7+ messages in thread