[PATCH 1/3] tcm: Remove task_offset parameter from transport_map_sg_to_mem()

From: Nicholas A. Bellinger
Date: Wed Aug 18 2010 - 18:30:32 EST


From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>

This patch removes the unused task_offset parameter from transport_map_sg_to_mem(),
which was originally used to determine an offset into the first
struct scatterlist -> struct se_mem mapping. With the removal of task_offset,
the code is simplified, and assumes a 1:1 mapping between the source struct
scatterlist and the destination struct se_mem.

It also updates transport_generic_map_mem_to_cmd() and removes it's local
usage of se_mem_task_off.

Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_transport.c | 74 ++++++++-----------------------
include/target/target_core_transport.h | 2 +-
2 files changed, 20 insertions(+), 56 deletions(-)

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 9e92e93..dbedb7a 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -6244,7 +6244,7 @@ int transport_generic_map_mem_to_cmd(
void *mem,
u32 se_mem_num)
{
- u32 se_mem_cnt_out = 0, se_mem_task_off = 0;
+ u32 se_mem_cnt_out = 0;
int ret;

if (!(mem) || !(se_mem_num))
@@ -6275,8 +6275,7 @@ int transport_generic_map_mem_to_cmd(
return -1;

ret = transport_map_sg_to_mem(cmd,
- T_TASK(cmd)->t_mem_list, mem, &se_mem_cnt_out,
- &se_mem_task_off);
+ T_TASK(cmd)->t_mem_list, mem, &se_mem_cnt_out);
if (ret < 0)
return -1;

@@ -6682,12 +6681,11 @@ int transport_map_sg_to_mem(
struct se_cmd *cmd,
struct list_head *se_mem_list,
void *in_mem,
- u32 *se_mem_cnt,
- u32 *task_offset)
+ u32 *se_mem_cnt)
{
struct se_mem *se_mem;
struct scatterlist *sg;
- u32 sg_count = 0, saved_task_offset = 0, task_size = cmd->data_length;
+ u32 sg_count = 1, cmd_size = cmd->data_length;

if (!in_mem) {
printk(KERN_ERR "No source scatterlist\n");
@@ -6695,65 +6693,31 @@ int transport_map_sg_to_mem(
}
sg = (struct scatterlist *)in_mem;

- while (task_size) {
+ while (cmd_size) {
se_mem = kmem_cache_zalloc(se_mem_cache, GFP_KERNEL);
if (!(se_mem)) {
printk(KERN_ERR "Unable to allocate struct se_mem\n");
return -1;
}
INIT_LIST_HEAD(&se_mem->se_list);
- DEBUG_MEM("sg_to_mem: Starting loop with task_size: %u"
- " sg_page: %p offset: %d length: %d\n", task_size,
+ DEBUG_MEM("sg_to_mem: Starting loop with cmd_size: %u"
+ " sg_page: %p offset: %d length: %d\n", cmd_size,
sg_page(sg), sg->offset, sg->length);

- if (*task_offset == 0) {
- se_mem->se_page = sg_page(sg);
- se_mem->se_off = sg->offset;
-
- if (task_size >= sg->length) {
- se_mem->se_len = sg->length;
- sg = sg_next(sg);
- sg_count++;
- } else {
- se_mem->se_len = task_size;
-
- task_size -= se_mem->se_len;
- if (!(task_size)) {
- *task_offset = (se_mem->se_len +
- saved_task_offset);
- goto next;
- }
- }
-
- if (saved_task_offset)
- *task_offset = saved_task_offset;
- } else {
- se_mem->se_page = sg_page(sg);
- se_mem->se_off = (*task_offset + sg->offset);
+ se_mem->se_page = sg_page(sg);
+ se_mem->se_off = sg->offset;

- if ((sg->length - *task_offset) > task_size) {
- se_mem->se_len = task_size;
+ if (cmd_size > sg->length) {
+ se_mem->se_len = sg->length;
+ sg = sg_next(sg);
+ sg_count++;
+ } else
+ se_mem->se_len = cmd_size;

- task_size -= se_mem->se_len;
- if (!(task_size)) {
- *task_offset += se_mem->se_len;
- goto next;
- }
- } else {
- se_mem->se_len = (sg->length - *task_offset);
- sg = sg_next(sg);
- sg_count++;
- }
+ cmd_size -= se_mem->se_len;

- saved_task_offset = *task_offset;
- *task_offset = 0;
- }
- task_size -= se_mem->se_len;
-next:
- DEBUG_MEM("sg_to_mem: *se_mem_cnt: %u task_size: %u, *task_offset: %u "
- "saved_task_offset: %d\n", *se_mem_cnt, task_size, *task_offset,
- saved_task_offset);
-
+ DEBUG_MEM("sg_to_mem: *se_mem_cnt: %u cmd_size: %u\n",
+ *se_mem_cnt, cmd_size);
DEBUG_MEM("sg_to_mem: Final se_page: %p se_off: %d se_len: %d\n",
se_mem->se_page, se_mem->se_off, se_mem->se_len);

diff --git a/include/target/target_core_transport.h b/include/target/target_core_transport.h
index 4e5591b..9a04033 100644
--- a/include/target/target_core_transport.h
+++ b/include/target/target_core_transport.h
@@ -279,7 +279,7 @@ extern void transport_free_se_mem_list(struct list_head *);
extern int transport_generic_get_mem(struct se_cmd *, u32, u32);
extern u32 transport_calc_sg_num(struct se_task *, struct se_mem *, u32);
extern int transport_map_sg_to_mem(struct se_cmd *, struct list_head *,
- void *, u32 *, u32 *);
+ void *, u32 *);
extern int transport_map_mem_to_mem(struct se_task *, struct list_head *,
void *, struct se_mem *,
struct se_mem **, u32 *, u32 *);
--
1.5.6.5

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