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authorChristoph Hellwig <hch@lst.de>2016-05-03 18:01:10 +0200
committerDoug Ledford <dledford@redhat.com>2016-05-13 13:37:19 -0400
commite64aa657c3d0dae84c2ccc166f6fe25b7d1d28c6 (patch)
tree898c3e12c36c5d5b561aacb0b8fa2e9804714e1a /drivers/target
parenta060b5629ab066dd1d321430eeb96f70939a1790 (diff)
target: enhance and export target_alloc_sgl/target_free_sgl
The SRP target driver will need to allocate and chain it's own SGLs soon. For this export target_alloc_sgl, and add a new argument to it so that it can allocate an additional chain entry that doesn't point to a page. Also export transport_free_sgl after renaming it to target_free_sgl to free these SGLs again. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/target')
-rw-r--r--drivers/target/target_core_transport.c32
-rw-r--r--drivers/target/target_core_xcopy.c2
2 files changed, 19 insertions, 15 deletions
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index ab2bf12975e1..590384a2bf8b 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2195,7 +2195,7 @@ queue_full:
transport_handle_queue_full(cmd, cmd->se_dev);
}
-static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
+void target_free_sgl(struct scatterlist *sgl, int nents)
{
struct scatterlist *sg;
int count;
@@ -2205,6 +2205,7 @@ static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
kfree(sgl);
}
+EXPORT_SYMBOL(target_free_sgl);
static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
{
@@ -2225,7 +2226,7 @@ static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
static inline void transport_free_pages(struct se_cmd *cmd)
{
if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
- transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
+ target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
cmd->t_prot_sg = NULL;
cmd->t_prot_nents = 0;
}
@@ -2236,7 +2237,7 @@ static inline void transport_free_pages(struct se_cmd *cmd)
* SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
*/
if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
- transport_free_sgl(cmd->t_bidi_data_sg,
+ target_free_sgl(cmd->t_bidi_data_sg,
cmd->t_bidi_data_nents);
cmd->t_bidi_data_sg = NULL;
cmd->t_bidi_data_nents = 0;
@@ -2246,11 +2247,11 @@ static inline void transport_free_pages(struct se_cmd *cmd)
}
transport_reset_sgl_orig(cmd);
- transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
+ target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
cmd->t_data_sg = NULL;
cmd->t_data_nents = 0;
- transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
+ target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
cmd->t_bidi_data_sg = NULL;
cmd->t_bidi_data_nents = 0;
}
@@ -2324,20 +2325,22 @@ EXPORT_SYMBOL(transport_kunmap_data_sg);
int
target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
- bool zero_page)
+ bool zero_page, bool chainable)
{
struct scatterlist *sg;
struct page *page;
gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
- unsigned int nent;
+ unsigned int nalloc, nent;
int i = 0;
- nent = DIV_ROUND_UP(length, PAGE_SIZE);
- sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
+ nalloc = nent = DIV_ROUND_UP(length, PAGE_SIZE);
+ if (chainable)
+ nalloc++;
+ sg = kmalloc_array(nalloc, sizeof(struct scatterlist), GFP_KERNEL);
if (!sg)
return -ENOMEM;
- sg_init_table(sg, nent);
+ sg_init_table(sg, nalloc);
while (length) {
u32 page_len = min_t(u32, length, PAGE_SIZE);
@@ -2361,6 +2364,7 @@ out:
kfree(sg);
return -ENOMEM;
}
+EXPORT_SYMBOL(target_alloc_sgl);
/*
* Allocate any required resources to execute the command. For writes we
@@ -2376,7 +2380,7 @@ transport_generic_new_cmd(struct se_cmd *cmd)
if (cmd->prot_op != TARGET_PROT_NORMAL &&
!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
- cmd->prot_length, true);
+ cmd->prot_length, true, false);
if (ret < 0)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
@@ -2401,13 +2405,13 @@ transport_generic_new_cmd(struct se_cmd *cmd)
ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
&cmd->t_bidi_data_nents,
- bidi_length, zero_flag);
+ bidi_length, zero_flag, false);
if (ret < 0)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
- cmd->data_length, zero_flag);
+ cmd->data_length, zero_flag, false);
if (ret < 0)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
} else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
@@ -2421,7 +2425,7 @@ transport_generic_new_cmd(struct se_cmd *cmd)
ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
&cmd->t_bidi_data_nents,
- caw_length, zero_flag);
+ caw_length, zero_flag, false);
if (ret < 0)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
diff --git a/drivers/target/target_core_xcopy.c b/drivers/target/target_core_xcopy.c
index 47fe94ee10b8..75cd85426ae3 100644
--- a/drivers/target/target_core_xcopy.c
+++ b/drivers/target/target_core_xcopy.c
@@ -563,7 +563,7 @@ static int target_xcopy_setup_pt_cmd(
if (alloc_mem) {
rc = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
- cmd->data_length, false);
+ cmd->data_length, false, false);
if (rc < 0) {
ret = rc;
goto out;