From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Greetings all,
This patch allows TCM Core to process CDBs containing a received scsi_command_size()
larger than the hardcoded default of TCM_MAX_COMMAND_SIZE (32-bytes). This patch
first converts the hardcoded per struct se_cmd -> struct se_transport_task->t_task_cdb[]
to ->__t_task_cdb[TCM_MAX_COMMAND_SIZE], and turns ->t_task_cdb into a pointer used
to reference ->__t_task_cdb or an extended CDB buffer setup in transport_generic_allocate_tasks().
It next adds a new struct se_subsystem_api->get_max_cdb_len() API caller that is
used by TCM subsystem plugins to report their individual CDB size limits. Next
transport_generic_cmd_sequencer() has been changed to use ->get_max_cdb_len() for
VARIABLE_LENGTH_CMD to determine if the backstore can support the received
> TCM_MAX_COMMAND_SIZE sized CDB, or to fail the I/O with exception status.
The extended CDB buffer is setup in transport_generic_allocate_tasks() when necessary,
and a new SCF_ECDB_ALLOCATION flag is then set. The release of the extended CDB buffer
happens in transport_free_se_cmd() in the normal struct se_cmd release path.
This patch also updates TCM/pSCSI to handle extended CDBs up to PSCSI_MAX_CDB_SIZE=240
(maximum current OSD CDB size) and sets up the extra struct pscsi_plugin_task->pscsi_cdb
allocation in struct se_task context in order to complete the > TCM_MAX_COMMAND_SIZE=32
request. The IBLOCK, FILEIO, RAMDISK, and STGT subsystem plugins have been updated to
enforce the TCM_MAX_COMMAND_SIZE=32 limit via struct se_subsystem_api->get_max_cdb_len().
So far this code been tested with 'sgv4_xdwriteread -e' into a TCM_Loop -> TCM/pSCSI
-> scsi_debug backstore with a TCM_MAX_COMMAND_SIZE=16 to force the extended CDB
allocations. This was done due to the lack of an easy method to test > 32-byte CDBs
w/o an TCM/OSD fabric module.
Many thanks to Boaz Harrosh for his help in this area!
Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_file.c | 6 +++++
drivers/target/target_core_iblock.c | 6 +++++
drivers/target/target_core_pscsi.c | 39 ++++++++++++++++++++++++++++++++
drivers/target/target_core_pscsi.h | 6 ++++-
drivers/target/target_core_rd.c | 6 +++++
drivers/target/target_core_stgt.c | 6 +++++
drivers/target/target_core_transport.c | 34 +++++++++++++++++++++++----
include/target/target_core_base.h | 6 +++-
include/target/target_core_transport.h | 5 ++++
9 files changed, 106 insertions(+), 8 deletions(-)
diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index d0afb50..bf9bfc2 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -1125,6 +1125,11 @@ static unsigned char *fd_get_cdb(struct se_task *task)
return req->fd_scsi_cdb;
}
+static u32 fd_get_max_cdb_len(struct se_device *dev)
+{
+ return TCM_MAX_COMMAND_SIZE;
+}
+
/* fd_get_blocksize(): (Part of se_subsystem_api_t template)
*
*
@@ -1224,6 +1229,7 @@ static struct se_subsystem_api fileio_template = {
.check_lba = fd_check_lba,
.check_for_SG = fd_check_for_SG,
.get_cdb = fd_get_cdb,
+ .get_max_cdb_len = fd_get_max_cdb_len,
.get_blocksize = fd_get_blocksize,
.get_device_rev = fd_get_device_rev,
.get_device_type = fd_get_device_type,
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index 2dae7fd..3337357 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -1059,6 +1059,11 @@ static unsigned char *iblock_get_cdb(struct se_task *task)
return req->ib_scsi_cdb;
}
+static u32 iblock_get_max_cdb_len(struct se_device *dev)
+{
+ return TCM_MAX_COMMAND_SIZE;
+}
+
static u32 iblock_get_blocksize(struct se_device *dev)
{
struct iblock_dev *ibd = dev->dev_ptr;
@@ -1167,6 +1172,7 @@ static struct se_subsystem_api iblock_template = {
.check_lba = iblock_check_lba,
.check_for_SG = iblock_check_for_SG,
.get_cdb = iblock_get_cdb,
+ .get_max_cdb_len = iblock_get_max_cdb_len,
.get_blocksize = iblock_get_blocksize,
.get_device_rev = iblock_get_device_rev,
.get_device_type = iblock_get_device_type,
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index 8dfedb1..b550725 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -714,13 +714,40 @@ static void *pscsi_allocate_request(
struct se_task *task,
struct se_device *dev)
{
+ struct se_cmd *cmd = task->task_se_cmd;
struct pscsi_plugin_task *pt;
+ unsigned char *cdb = T_TASK(cmd)->t_task_cdb;
pt = kzalloc(sizeof(struct pscsi_plugin_task), GFP_KERNEL);
if (!(pt)) {
printk(KERN_ERR "Unable to allocate struct pscsi_plugin_task\n");
return NULL;
}
+ /*
+ * If TCM Core is signaling a > TCM_MAX_COMMAND_SIZE allocation,
+ * allocate the extended CDB buffer for per struct se_task context
+ * pt->pscsi_cdb now.
+ */
+ if (cmd->se_cmd_flags & SCF_ECDB_ALLOCATION) {
+ /*
+ * PSCSI_MAX_CDB_SIZE is currently set to 240 bytes which
+ * allows the largest OSD CDB sizes again.
+ */
+ if (scsi_command_size(cdb) > PSCSI_MAX_CDB_SIZE) {
+ printk(KERN_ERR "pSCSI: Received CDB of size: %u larger"
+ " than PSCSI_MAX_CDB_SIZE: %u\n",
+ scsi_command_size(cdb), PSCSI_MAX_CDB_SIZE);
+ return NULL;
+ }
+
+ pt->pscsi_cdb = kzalloc(scsi_command_size(cdb), GFP_KERNEL);
+ if (!(pt->pscsi_cdb)) {
+ printk(KERN_ERR "pSCSI: Unable to allocate extended"
+ " pt->pscsi_cdb\n");
+ return NULL;
+ }
+ } else
+ pt->pscsi_cdb = &pt->__pscsi_cdb[0];
return pt;
}
@@ -818,6 +845,12 @@ static void pscsi_free_task(struct se_task *task)
{
struct pscsi_plugin_task *pt = task->transport_req;
/*
+ * Release the extended CDB allocation from pscsi_allocate_request()
+ * if one exists.
+ */
+ if (task->task_se_cmd->se_cmd_flags & SCF_ECDB_ALLOCATION)
+ kfree(pt->pscsi_cdb);
+ /*
* We do not release the bio(s) here associated with this task, as
* this is handled by bio_put() and pscsi_bi_endio().
*/
@@ -1366,6 +1399,11 @@ static unsigned char *pscsi_get_cdb(struct se_task *task)
return pt->pscsi_cdb;
}
+static u32 pscsi_get_max_cdb_len(struct se_device *dev)
+{
+ return PSCSI_MAX_CDB_SIZE;
+}
+
/* pscsi_get_sense_buffer():
*
*
@@ -1533,6 +1571,7 @@ static struct se_subsystem_api pscsi_template = {
.check_lba = pscsi_check_lba,
.check_for_SG = pscsi_check_for_SG,
.get_cdb = pscsi_get_cdb,
+ .get_max_cdb_len = pscsi_get_max_cdb_len,
.get_sense_buffer = pscsi_get_sense_buffer,
.get_blocksize = pscsi_get_blocksize,
.get_device_rev = pscsi_get_device_rev,
diff --git a/drivers/target/target_core_pscsi.h b/drivers/target/target_core_pscsi.h
index d3c8972..e7f07e3 100644
--- a/drivers/target/target_core_pscsi.h
+++ b/drivers/target/target_core_pscsi.h
@@ -9,6 +9,9 @@
#define INQUIRY_DATA_SIZE 0x24
#endif
+/* Maximum extended CDB size for handling OSD passthrough */
+#define PSCSI_MAX_CDB_SIZE 240
+
/* used in pscsi_add_device_to_list() */
#define PSCSI_DEFAULT_QUEUEDEPTH 1
@@ -28,7 +31,8 @@ extern int linux_blockdevice_check(int, int);
#include <linux/kobject.h>
struct pscsi_plugin_task {
- unsigned char pscsi_cdb[TCM_MAX_COMMAND_SIZE];
+ unsigned char *pscsi_cdb;
+ unsigned char __pscsi_cdb[TCM_MAX_COMMAND_SIZE];
unsigned char pscsi_sense[SCSI_SENSE_BUFFERSIZE];
int pscsi_direction;
int pscsi_result;
diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
index 1debdd3..0a54c57 100644
--- a/drivers/target/target_core_rd.c
+++ b/drivers/target/target_core_rd.c
@@ -1392,6 +1392,11 @@ static unsigned char *rd_get_cdb(struct se_task *task)
return req->rd_scsi_cdb;
}
+static u32 rd_get_max_cdb_len(struct se_device *dev)
+{
+ return TCM_MAX_COMMAND_SIZE;
+}
+
/* rd_get_blocksize(): (Part of se_subsystem_api_t template)
*
*
@@ -1475,6 +1480,7 @@ static struct se_subsystem_api rd_dr_template = {
.check_lba = rd_DIRECT_check_lba,
.check_for_SG = rd_check_for_SG,
.get_cdb = rd_get_cdb,
+ .get_max_cdb_len = rd_get_max_cdb_len,
.get_blocksize = rd_get_blocksize,
.get_device_rev = rd_get_device_rev,
.get_device_type = rd_get_device_type,
diff --git a/drivers/target/target_core_stgt.c b/drivers/target/target_core_stgt.c
index fdcd7eb..ecd4601 100644
--- a/drivers/target/target_core_stgt.c
+++ b/drivers/target/target_core_stgt.c
@@ -751,6 +751,11 @@ static unsigned char *stgt_get_cdb(struct se_task *task)
return pt->stgt_cdb;
}
+static u32 stgt_get_max_cdb_len(struct se_device *dev)
+{
+ return TCM_MAX_COMMAND_SIZE;
+}
+
/* stgt_get_sense_buffer():
*
*
@@ -931,6 +936,7 @@ static struct se_subsystem_api stgt_template = {
.check_lba = stgt_check_lba,
.check_for_SG = stgt_check_for_SG,
.get_cdb = stgt_get_cdb,
+ .get_max_cdb_len = stgt_get_max_cdb_len,
.get_sense_buffer = stgt_get_sense_buffer,
.get_blocksize = stgt_get_blocksize,
.get_device_rev = stgt_get_device_rev,
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 830c5bb..866b0fa 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2860,6 +2860,11 @@ void transport_free_se_cmd(
if (se_cmd->se_tmr_req)
core_tmr_release_req(se_cmd->se_tmr_req);
/*
+ * Check and free any extended CDB buffer that was allocated
+ */
+ if (se_cmd->se_cmd_flags & SCF_ECDB_ALLOCATION)
+ kfree(T_TASK(se_cmd)->t_task_cdb);
+ /*
* Release any optional TCM fabric dependent iovecs allocated by
* transport_allocate_iovecs_for_cmd()
*/
@@ -2903,6 +2908,23 @@ int transport_generic_allocate_tasks(
if (non_data_cdb < 0)
return -1;
/*
+ * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
+ * allocate the additional extended CDB buffer now.. Otherwise
+ * setup the pointer from __t_task_cdb to t_task_cdb.
+ */
+ if (scsi_command_size(cdb) > TCM_MAX_COMMAND_SIZE) {
+ T_TASK(cmd)->t_task_cdb = kzalloc(scsi_command_size(cdb),
+ GFP_KERNEL);
+ if (!(T_TASK(cmd)->t_task_cdb)) {
+ printk(KERN_ERR "Unable to allocate T_TASK(cmd)->t_task_cdb"
+ " %u > TCM_MAX_COMMAND_SIZE ops\n",
+ scsi_command_size(cdb));
+ return -1;
+ }
+ cmd->se_cmd_flags |= SCF_ECDB_ALLOCATION;
+ } else
+ T_TASK(cmd)->t_task_cdb = &T_TASK(cmd)->__t_task_cdb[0];
+ /*
* Copy the original CDB into T_TASK(cmd).
*/
memcpy(T_TASK(cmd)->t_task_cdb, cdb, scsi_command_size(cdb));
@@ -5746,13 +5768,15 @@ static int transport_generic_cmd_sequencer(
service_action = get_unaligned_be16(&cdb[8]);
/*
* Check the additional CDB length (+ 8 bytes for header) does
- * not exceed our TCM_MAX_COMMAND_SIZE.
+ * not exceed our backsores ->get_max_cdb_len()
*/
- if (scsi_varlen_cdb_length(&cdb[0]) > TCM_MAX_COMMAND_SIZE) {
+ if (scsi_varlen_cdb_length(&cdb[0]) >
+ TRANSPORT(dev)->get_max_cdb_len(dev)) {
printk(KERN_INFO "Only %u-byte extended CDBs currently"
- " supported for VARIABLE_LENGTH_CMD, received:"
- " %d for service action: 0x%04x\n",
- TCM_MAX_COMMAND_SIZE,
+ " supported for VARIABLE_LENGTH_CMD backstore %s,"
+ " received: %d for service action: 0x%04x\n",
+ TRANSPORT(dev)->get_max_cdb_len(dev),
+ TRANSPORT(dev)->name,
scsi_varlen_cdb_length(&cdb[0]), service_action);
return TGCS_INVALID_CDB_FIELD;
}
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 3905a0e..fc5300c 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -137,7 +137,8 @@ enum se_cmd_flags_table {
SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC = 0x00800000,
SCF_EMULATE_SYNC_CACHE = 0x01000000,
SCF_EMULATE_CDB_ASYNC = 0x02000000,
- SCF_EMULATE_SYNC_UNMAP = 0x04000000
+ SCF_EMULATE_SYNC_UNMAP = 0x04000000,
+ SCF_ECDB_ALLOCATION = 0x08000000
};
/* struct se_device->type for known subsystem plugins */
@@ -424,7 +425,8 @@ struct se_queue_obj {
* drivers/target/target_core_transport.c:__transport_alloc_se_cmd()
*/
struct se_transport_task {
- unsigned char t_task_cdb[MAX_COMMAND_SIZE];
+ unsigned char *t_task_cdb;
+ unsigned char __t_task_cdb[MAX_COMMAND_SIZE];
unsigned long long t_task_lba;
int t_tasks_failed;
int t_tasks_fua;
diff --git a/include/target/target_core_transport.h b/include/target/target_core_transport.h
index ab7336b..d45063e 100644
--- a/include/target/target_core_transport.h
+++ b/include/target/target_core_transport.h
@@ -519,6 +519,11 @@ struct se_subsystem_api {
*/
unsigned char *(*get_cdb)(struct se_task *);
/*
+ * get_max_cdb_len(): Used by subsystems backstoers to signal the
+ * maximum receivable SCSI CDB size.
+ */
+ u32 (*get_max_cdb_len)(struct se_device *);
+ /*
* get_blocksize():
*/
u32 (*get_blocksize)(struct se_device *);
--
1.5.6.5
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