From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch breaks up the ->map_task_SG() backend call into two seperate
->map_control_SG() and ->map_data_SG() in order to better address
IBLOCK and pSCSI. IBLOCK only allocates bios for ->map_data_SG(), and
pSCSI will allocate a struct request for both cases.
This patch fixes incorrect usage of ->map_task_SG() for all se_cmd descriptors
in transport_generic_new_cmd() by moving the call into it's proper location
directly inside of transport_allocate_data_tasks()
Reported-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_iblock.c | 4 +-
drivers/target/target_core_pscsi.c | 14 ++++++---
drivers/target/target_core_transport.c | 45 +++++++++++++++++--------------
include/target/target_core_transport.h | 8 ++++-
4 files changed, 42 insertions(+), 29 deletions(-)
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index 251fc66..7e12341 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -591,7 +591,7 @@ static struct bio *iblock_get_bio(
return bio;
}
-static int iblock_map_task_SG(struct se_task *task)
+static int iblock_map_data_SG(struct se_task *task)
{
struct se_cmd *cmd = task->task_se_cmd;
struct se_device *dev = cmd->se_dev;
@@ -755,7 +755,7 @@ static struct se_subsystem_api iblock_template = {
.name = "iblock",
.owner = THIS_MODULE,
.transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
- .map_task_SG = iblock_map_task_SG,
+ .map_data_SG = iblock_map_data_SG,
.attach_hba = iblock_attach_hba,
.detach_hba = iblock_detach_hba,
.allocate_virtdevice = iblock_allocate_virtdevice,
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index a2ce599..2b7b0da 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -1049,7 +1049,7 @@ static inline struct bio *pscsi_get_bio(int sg_num)
return bio;
}
-static int __pscsi_map_task_SG(
+static int __pscsi_map_SG(
struct se_task *task,
struct scatterlist *task_sg,
u32 task_sg_num,
@@ -1198,7 +1198,10 @@ fail:
return ret;
}
-static int pscsi_map_task_SG(struct se_task *task)
+/*
+ * pSCSI maps both ->map_control_SG() and ->map_data_SG() to a single call.
+ */
+static int pscsi_map_SG(struct se_task *task)
{
int ret;
@@ -1206,13 +1209,13 @@ static int pscsi_map_task_SG(struct se_task *task)
* Setup the main struct request for the task->task_sg[] payload
*/
- ret = __pscsi_map_task_SG(task, task->task_sg, task->task_sg_nents, 0);
+ ret = __pscsi_map_SG(task, task->task_sg, task->task_sg_nents, 0);
if (ret >= 0 && task->task_sg_bidi) {
/*
* If present, set up the extra BIDI-COMMAND SCSI READ
* struct request and payload.
*/
- ret = __pscsi_map_task_SG(task, task->task_sg_bidi,
+ ret = __pscsi_map_SG(task, task->task_sg_bidi,
task->task_sg_nents, 1);
}
@@ -1340,7 +1343,8 @@ static struct se_subsystem_api pscsi_template = {
.owner = THIS_MODULE,
.transport_type = TRANSPORT_PLUGIN_PHBA_PDEV,
.cdb_none = pscsi_CDB_none,
- .map_task_SG = pscsi_map_task_SG,
+ .map_control_SG = pscsi_map_SG,
+ .map_data_SG = pscsi_map_SG,
.attach_hba = pscsi_attach_hba,
.detach_hba = pscsi_detach_hba,
.pmode_enable_hba = pscsi_pmode_enable_hba,
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 55b6588..007cfc1 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -4081,8 +4081,7 @@ static int transport_allocate_data_tasks(
struct se_device *dev = cmd->se_dev;
unsigned long flags;
sector_t sectors;
- int task_count;
- int i;
+ int task_count, i, ret;
sector_t dev_max_sectors = dev->se_sub_dev->se_dev_attrib.max_sectors;
u32 sector_size = dev->se_sub_dev->se_dev_attrib.block_size;
struct scatterlist *sg;
@@ -4129,7 +4128,7 @@ static int transport_allocate_data_tasks(
task->task_padded_sg = 1;
}
- task->task_sg = kmalloc(sizeof(struct scatterlist) * \
+ task->task_sg = kmalloc(sizeof(struct scatterlist) *
task->task_sg_nents, GFP_KERNEL);
if (!task->task_sg) {
cmd->se_dev->transport->free_task(task);
@@ -4157,6 +4156,20 @@ static int transport_allocate_data_tasks(
list_add_tail(&task->t_list, &cmd->t_task_list);
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
}
+ /*
+ * Now perform the memory map of task->task_sg[] into backend
+ * subsystem memory..
+ */
+ list_for_each_entry(task, &cmd->t_task_list, t_list) {
+ if (atomic_read(&task->task_sent))
+ continue;
+ if (!dev->transport->map_data_SG)
+ continue;
+
+ ret = dev->transport->map_data_SG(task);
+ if (ret < 0)
+ return 0;
+ }
return task_count;
}
@@ -4196,8 +4209,8 @@ transport_allocate_control_task(struct se_cmd *cmd)
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
if (cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB) {
- if (dev->transport->map_task_SG)
- ret = dev->transport->map_task_SG(task);
+ if (dev->transport->map_control_SG)
+ ret = dev->transport->map_control_SG(task);
} else if (cmd->se_cmd_flags & SCF_SCSI_NON_DATA_CDB) {
if (dev->transport->cdb_none)
ret = dev->transport->cdb_none(task);
@@ -4239,8 +4252,6 @@ static u32 transport_allocate_tasks(
*/
int transport_generic_new_cmd(struct se_cmd *cmd)
{
- struct se_task *task;
- struct se_device *dev = cmd->se_dev;
int ret = 0;
/*
@@ -4254,22 +4265,16 @@ int transport_generic_new_cmd(struct se_cmd *cmd)
if (ret < 0)
return ret;
}
-
+ /*
+ * Call transport_new_cmd_obj() to invoke transport_allocate_tasks() for
+ * control or data CDB types, and perform the map to backend subsystem
+ * code from SGL memory allocated here by transport_generic_get_mem(), or
+ * via pre-existing SGL memory setup explictly by fabric module code with
+ * transport_generic_map_mem_to_cmd().
+ */
ret = transport_new_cmd_obj(cmd);
if (ret < 0)
return ret;
-
- list_for_each_entry(task, &cmd->t_task_list, t_list) {
- if (atomic_read(&task->task_sent))
- continue;
- if (!dev->transport->map_task_SG)
- continue;
-
- ret = dev->transport->map_task_SG(task);
- if (ret < 0)
- return ret;
- }
-
/*
* For WRITEs, let the fabric know its buffer is ready..
* This WRITE struct se_cmd (and all of its associated struct se_task's)
diff --git a/include/target/target_core_transport.h b/include/target/target_core_transport.h
index 7409576..54af39d 100644
--- a/include/target/target_core_transport.h
+++ b/include/target/target_core_transport.h
@@ -239,9 +239,13 @@ struct se_subsystem_api {
*/
int (*cdb_none)(struct se_task *);
/*
- * For SCF_SCSI_DATA_SG_IO_CDB and SCF_SCSI_CONTROL_SG_IO_CDB
+ * For SCF_SCSI_DATA_SG_IO_CDB
*/
- int (*map_task_SG)(struct se_task *);
+ int (*map_data_SG)(struct se_task *);
+ /*
+ * For SCF_SCSI_CONTROL_SG_IO_CDB
+ */
+ int (*map_control_SG)(struct se_task *);
/*
* attach_hba():
*/
--
1.7.6
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