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authorAndy Grover <agrover@redhat.com>2011-07-20 19:28:46 +0000
committerNicholas Bellinger <nab@linux-iscsi.org>2011-07-22 09:37:48 +0000
commitec98f7825c6eaa4a9afb0eb518826efc8a2ed4a2 (patch)
treeb4ccee24db5d7d54ccfa5e3be2441d3a4e37f295 /drivers/target/tcm_fc
parent3a86720567fd92819b449df10db85a2f73447d87 (diff)
downloadlinux-ec98f7825c6eaa4a9afb0eb518826efc8a2ed4a2.tar.bz2
target: Eliminate usage of struct se_mem
Both backstores and fabrics use arrays of struct scatterlist to describe data buffers. However TCM used struct se_mems, basically a linked list of scatterlist entries. We are able to simplify the code by eliminating this intermediate data structure and just using struct scatterlist[] throughout. Also, moved attachment of task to cmd out of transport_generic_get_task and into allocate_control_task and allocate_data_tasks. The reasoning is that it's nonintuitive that get_task should automatically add it to the cmd's task list -- it should just return an allocated, initialized task. That's all it should do, based on the function's name, so either the function shouldn't do it, or the name should change to encapsulate the entire essence of what it does. (nab: Fix compile warnings in tcm_fc, and make transport_kmap_first_data_page honor sg->offset for SGLs from contigious memory with TCM_Loop, and fix control se_cmd descriptor memory leak) Signed-off-by: Andy Grover <agrover@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target/tcm_fc')
-rw-r--r--drivers/target/tcm_fc/tfc_cmd.c25
-rw-r--r--drivers/target/tcm_fc/tfc_io.c58
2 files changed, 39 insertions, 44 deletions
diff --git a/drivers/target/tcm_fc/tfc_cmd.c b/drivers/target/tcm_fc/tfc_cmd.c
index 1017f56bbbcc..9365e53947ad 100644
--- a/drivers/target/tcm_fc/tfc_cmd.c
+++ b/drivers/target/tcm_fc/tfc_cmd.c
@@ -59,7 +59,8 @@ void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
struct fc_exch *ep;
struct fc_seq *sp;
struct se_cmd *se_cmd;
- struct se_mem *mem;
+ struct scatterlist *sg;
+ int count;
if (!(ft_debug_logging & FT_DEBUG_IO))
return;
@@ -71,15 +72,16 @@ void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
caller, cmd, cmd->cdb);
printk(KERN_INFO "%s: cmd %p lun %d\n", caller, cmd, cmd->lun);
- printk(KERN_INFO "%s: cmd %p se_num %u len %u se_cmd_flags <0x%x>\n",
- caller, cmd, se_cmd->t_tasks_se_num,
+ printk(KERN_INFO "%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
+ caller, cmd, se_cmd->t_data_nents,
se_cmd->data_length, se_cmd->se_cmd_flags);
- list_for_each_entry(mem, &se_cmd->t_mem_list, se_list)
- printk(KERN_INFO "%s: cmd %p mem %p page %p "
- "len 0x%x off 0x%x\n",
- caller, cmd, mem,
- mem->se_page, mem->se_len, mem->se_off);
+ for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
+ printk(KERN_INFO "%s: cmd %p sg %p page %p "
+ "len 0x%x off 0x%x\n",
+ caller, cmd, sg,
+ sg_page(sg), sg->length, sg->offset);
+
sp = cmd->seq;
if (sp) {
ep = fc_seq_exch(sp);
@@ -256,10 +258,9 @@ int ft_write_pending(struct se_cmd *se_cmd)
(fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
if (se_cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) {
/*
- * Map se_mem list to scatterlist, so that
- * DDP can be setup. DDP setup function require
- * scatterlist. se_mem_list is internal to
- * TCM/LIO target
+ * cmd may have been broken up into multiple
+ * tasks. Link their sgs together so we can
+ * operate on them all at once.
*/
transport_do_task_sg_chain(se_cmd);
cmd->sg = se_cmd->t_tasks_sg_chained;
diff --git a/drivers/target/tcm_fc/tfc_io.c b/drivers/target/tcm_fc/tfc_io.c
index 837660728563..3563a9029c4a 100644
--- a/drivers/target/tcm_fc/tfc_io.c
+++ b/drivers/target/tcm_fc/tfc_io.c
@@ -68,17 +68,17 @@ int ft_queue_data_in(struct se_cmd *se_cmd)
struct fc_frame *fp = NULL;
struct fc_exch *ep;
struct fc_lport *lport;
- struct se_mem *mem;
+ struct scatterlist *sg = NULL;
size_t remaining;
u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
- u32 mem_off;
+ u32 mem_off = 0;
u32 fh_off = 0;
u32 frame_off = 0;
size_t frame_len = 0;
- size_t mem_len;
+ size_t mem_len = 0;
size_t tlen;
size_t off_in_page;
- struct page *page;
+ struct page *page = NULL;
int use_sg;
int error;
void *page_addr;
@@ -94,13 +94,12 @@ int ft_queue_data_in(struct se_cmd *se_cmd)
/*
* Setup to use first mem list entry, unless no data.
*/
- BUG_ON(remaining && list_empty(&se_cmd->t_mem_list));
+ BUG_ON(remaining && !se_cmd->t_data_sg);
if (remaining) {
- mem = list_first_entry(&se_cmd->t_mem_list,
- struct se_mem, se_list);
- mem_len = mem->se_len;
- mem_off = mem->se_off;
- page = mem->se_page;
+ sg = se_cmd->t_data_sg;
+ mem_len = sg->length;
+ mem_off = sg->offset;
+ page = sg_page(sg);
}
/* no scatter/gather in skb for odd word length due to fc_seq_send() */
@@ -108,12 +107,10 @@ int ft_queue_data_in(struct se_cmd *se_cmd)
while (remaining) {
if (!mem_len) {
- BUG_ON(!mem);
- mem = list_entry(mem->se_list.next,
- struct se_mem, se_list);
- mem_len = min((size_t)mem->se_len, remaining);
- mem_off = mem->se_off;
- page = mem->se_page;
+ sg = sg_next(sg);
+ mem_len = min((size_t)sg->length, remaining);
+ mem_off = sg->offset;
+ page = sg_page(sg);
}
if (!frame_len) {
/*
@@ -200,13 +197,13 @@ void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
struct fc_exch *ep;
struct fc_lport *lport;
struct fc_frame_header *fh;
- struct se_mem *mem;
- u32 mem_off;
+ struct scatterlist *sg = NULL;
+ u32 mem_off = 0;
u32 rel_off;
size_t frame_len;
- size_t mem_len;
+ size_t mem_len = 0;
size_t tlen;
- struct page *page;
+ struct page *page = NULL;
void *page_addr;
void *from;
void *to;
@@ -288,23 +285,20 @@ void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
/*
* Setup to use first mem list entry, unless no data.
*/
- BUG_ON(frame_len && list_empty(&se_cmd->t_mem_list));
+ BUG_ON(frame_len && !se_cmd->t_data_sg);
if (frame_len) {
- mem = list_first_entry(&se_cmd->t_mem_list,
- struct se_mem, se_list);
- mem_len = mem->se_len;
- mem_off = mem->se_off;
- page = mem->se_page;
+ sg = se_cmd->t_data_sg;
+ mem_len = sg->length;
+ mem_off = sg->offset;
+ page = sg_page(sg);
}
while (frame_len) {
if (!mem_len) {
- BUG_ON(!mem);
- mem = list_entry(mem->se_list.next,
- struct se_mem, se_list);
- mem_len = mem->se_len;
- mem_off = mem->se_off;
- page = mem->se_page;
+ sg = sg_next(sg);
+ mem_len = sg->length;
+ mem_off = sg->offset;
+ page = sg_page(sg);
}
if (rel_off >= mem_len) {
rel_off -= mem_len;