[PATCH v2 3/3] target: Use scsi helpers to build the sense data correctly

Sagi Grimberg
2015-07-06T08:03:00Z

Instead of open coding the sense buffer construction, use
scsi scsi_build_sense_buffer() and scsi_set_sense_information()
helpers which moved to scsi_common.

This patch also fixes wrong setting of descriptor format sense data
for t10-pi integrity errors.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
---
drivers/scsi/scsi_common.c | 98 +++++++++++++++++++++++++++++++++
drivers/scsi/scsi_error.c | 99 +---------------------------------
drivers/target/target_core_spc.c | 31 ++---------
drivers/target/target_core_transport.c | 24 +++------
include/scsi/scsi_common.h | 5 ++
include/scsi/scsi_eh.h | 7 +--
include/target/target_core_base.h | 9 +---
7 files changed, 118 insertions(+), 155 deletions(-)

diff --git a/drivers/scsi/scsi_common.c b/drivers/scsi/scsi_common.c
index 2ff0922..41432c1 100644
--- a/drivers/scsi/scsi_common.c
+++ b/drivers/scsi/scsi_common.c
@@ -5,6 +5,7 @@
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/string.h>
+#include <asm/unaligned.h>
#include <scsi/scsi_common.h>

/* NB: These are exposed through /proc/scsi/scsi and form part of the ABI.
@@ -176,3 +177,100 @@ bool scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
return true;
}
EXPORT_SYMBOL(scsi_normalize_sense);
+
+/**
+ * scsi_sense_desc_find - search for a given descriptor type in descriptor sense data format.
+ * @sense_buffer: byte array of descriptor format sense data
+ * @sb_len: number of valid bytes in sense_buffer
+ * @desc_type: value of descriptor type to find
+ * (e.g. 0 -> information)
+ *
+ * Notes:
+ * only valid when sense data is in descriptor format
+ *
+ * Return value:
+ * pointer to start of (first) descriptor if found else NULL
+ */
+const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
+ int desc_type)
+{
+ int add_sen_len, add_len, desc_len, k;
+ const u8 * descp;
+
+ if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
+ return NULL;
+ if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
+ return NULL;
+ add_sen_len = (add_sen_len < (sb_len - 8)) ?
+ add_sen_len : (sb_len - 8);
+ descp = &sense_buffer[8];
+ for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
+ descp += desc_len;
+ add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
+ desc_len = add_len + 2;
+ if (descp[0] == desc_type)
+ return descp;
+ if (add_len < 0) // short descriptor ??
+ break;
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(scsi_sense_desc_find);
+
+/**
+ * scsi_build_sense_buffer - build sense data in a buffer
+ * @desc: Sense format (non zero == descriptor format,
+ * 0 == fixed format)
+ * @buf: Where to build sense data
+ * @key: Sense key
+ * @asc: Additional sense code
+ * @ascq: Additional sense code qualifier
+ *
+ **/
+void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq)
+{
+ if (desc) {
+ buf[0] = 0x72; /* descriptor, current */
+ buf[1] = key;
+ buf[2] = asc;
+ buf[3] = ascq;
+ buf[7] = 0;
+ } else {
+ buf[0] = 0x70; /* fixed, current */
+ buf[2] = key;
+ buf[7] = 0xa;
+ buf[12] = asc;
+ buf[13] = ascq;
+ }
+}
+EXPORT_SYMBOL(scsi_build_sense_buffer);
+
+/**
+ * scsi_set_sense_information - set the information field in a
+ * formatted sense data buffer
+ * @buf: Where to build sense data
+ * @info: 64-bit information value to be set
+ *
+ **/
+void scsi_set_sense_information(u8 *buf, u64 info)
+{
+ if ((buf[0] & 0x7f) == 0x72) {
+ u8 *ucp, len;
+
+ len = buf[7];
+ ucp = (char *)scsi_sense_desc_find(buf, len + 8, 0);
+ if (!ucp) {
+ buf[7] = len + 0xa;
+ ucp = buf + 8 + len;
+ }
+ ucp[0] = 0;
+ ucp[1] = 0xa;
+ ucp[2] = 0x80; /* Valid bit */
+ ucp[3] = 0;
+ put_unaligned_be64(info, &ucp[4]);
+ } else if ((buf[0] & 0x7f) == 0x70) {
+ buf[0] |= 0x80;
+ put_unaligned_be64(info, &buf[3]);
+ }
+}
+EXPORT_SYMBOL(scsi_set_sense_information);
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 106884a..6e6b2d2 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -26,7 +26,6 @@
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
-#include <asm/unaligned.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
@@ -34,6 +33,7 @@
#include <scsi/scsi_device.h>
#include <scsi/scsi_driver.h>
#include <scsi/scsi_eh.h>
+#include <scsi/scsi_common.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_ioctl.h>
@@ -2408,45 +2408,6 @@ bool scsi_command_normalize_sense(const struct scsi_cmnd *cmd,
EXPORT_SYMBOL(scsi_command_normalize_sense);

/**
- * scsi_sense_desc_find - search for a given descriptor type in descriptor sense data format.
- * @sense_buffer: byte array of descriptor format sense data
- * @sb_len: number of valid bytes in sense_buffer
- * @desc_type: value of descriptor type to find
- * (e.g. 0 -> information)
- *
- * Notes:
- * only valid when sense data is in descriptor format
- *
- * Return value:
- * pointer to start of (first) descriptor if found else NULL
- */
-const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
- int desc_type)
-{
- int add_sen_len, add_len, desc_len, k;
- const u8 * descp;
-
- if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
- return NULL;
- if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
- return NULL;
- add_sen_len = (add_sen_len < (sb_len - 8)) ?
- add_sen_len : (sb_len - 8);
- descp = &sense_buffer[8];
- for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
- descp += desc_len;
- add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
- desc_len = add_len + 2;
- if (descp[0] == desc_type)
- return descp;
- if (add_len < 0) // short descriptor ??
- break;
- }
- return NULL;
-}
-EXPORT_SYMBOL(scsi_sense_desc_find);
-
-/**
* scsi_get_sense_info_fld - get information field from sense data (either fixed or descriptor format)
* @sense_buffer: byte array of sense data
* @sb_len: number of valid bytes in sense_buffer
@@ -2495,61 +2456,3 @@ int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
}
}
EXPORT_SYMBOL(scsi_get_sense_info_fld);
-
-/**
- * scsi_build_sense_buffer - build sense data in a buffer
- * @desc: Sense format (non zero == descriptor format,
- * 0 == fixed format)
- * @buf: Where to build sense data
- * @key: Sense key
- * @asc: Additional sense code
- * @ascq: Additional sense code qualifier
- *
- **/
-void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq)
-{
- if (desc) {
- buf[0] = 0x72; /* descriptor, current */
- buf[1] = key;
- buf[2] = asc;
- buf[3] = ascq;
- buf[7] = 0;
- } else {
- buf[0] = 0x70; /* fixed, current */
- buf[2] = key;
- buf[7] = 0xa;
- buf[12] = asc;
- buf[13] = ascq;
- }
-}
-EXPORT_SYMBOL(scsi_build_sense_buffer);
-
-/**
- * scsi_set_sense_information - set the information field in a
- * formatted sense data buffer
- * @buf: Where to build sense data
- * @info: 64-bit information value to be set
- *
- **/
-void scsi_set_sense_information(u8 *buf, u64 info)
-{
- if ((buf[0] & 0x7f) == 0x72) {
- u8 *ucp, len;
-
- len = buf[7];
- ucp = (char *)scsi_sense_desc_find(buf, len + 8, 0);
- if (!ucp) {
- buf[7] = len + 0xa;
- ucp = buf + 8 + len;
- }
- ucp[0] = 0;
- ucp[1] = 0xa;
- ucp[2] = 0x80; /* Valid bit */
- ucp[3] = 0;
- put_unaligned_be64(info, &ucp[4]);
- } else if ((buf[0] & 0x7f) == 0x70) {
- buf[0] |= 0x80;
- put_unaligned_be64(info, &buf[3]);
- }
-}
-EXPORT_SYMBOL(scsi_set_sense_information);
diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index b074443..c43dcbf 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -1157,32 +1157,11 @@ static sense_reason_t spc_emulate_request_sense(struct se_cmd *cmd)
if (!rbuf)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

- if (!core_scsi3_ua_clear_for_request_sense(cmd, &ua_asc, &ua_ascq)) {
- /*
- * CURRENT ERROR, UNIT ATTENTION
- */
- buf[0] = 0x70;
- buf[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
-
- /*
- * The Additional Sense Code (ASC) from the UNIT ATTENTION
- */
- buf[SPC_ASC_KEY_OFFSET] = ua_asc;
- buf[SPC_ASCQ_KEY_OFFSET] = ua_ascq;
- buf[7] = 0x0A;
- } else {
- /*
- * CURRENT ERROR, NO SENSE
- */
- buf[0] = 0x70;
- buf[SPC_SENSE_KEY_OFFSET] = NO_SENSE;
-
- /*
- * NO ADDITIONAL SENSE INFORMATION
- */
- buf[SPC_ASC_KEY_OFFSET] = 0x00;
- buf[7] = 0x0A;
- }
+ if (!core_scsi3_ua_clear_for_request_sense(cmd, &ua_asc, &ua_ascq))
+ scsi_build_sense_buffer(0, buf, UNIT_ATTENTION,
+ ua_asc, ua_ascq);
+ else
+ scsi_build_sense_buffer(0, buf, NO_SENSE, 0x0, 0x0);

memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
transport_kunmap_data_sg(cmd);
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index bbd0e57..8822da1 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2620,24 +2620,12 @@ bool transport_wait_for_tasks(struct se_cmd *cmd)
}
EXPORT_SYMBOL(transport_wait_for_tasks);

-static
-void transport_err_sector_info(unsigned char *buffer, sector_t bad_sector)
-{
- /* Place failed LBA in sense data information descriptor 0. */
- buffer[SPC_ADD_SENSE_LEN_OFFSET] = 0xc;
- buffer[SPC_DESC_TYPE_OFFSET] = 0; /* Information */
- buffer[SPC_ADDITIONAL_DESC_LEN_OFFSET] = 0xa;
- buffer[SPC_VALIDITY_OFFSET] = 0x80;
-
- /* Descriptor Information: failing sector */
- put_unaligned_be64(bad_sector, &buffer[12]);
-}
-
struct sense_info {
u8 key;
u8 asc;
u8 ascq;
bool add_sector_info;
+ int desc_format;
};

static const struct sense_info sense_info_table[] = {
@@ -2721,18 +2709,21 @@ static const struct sense_info sense_info_table[] = {
.asc = 0x10,
.ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
.add_sector_info = true,
+ .desc_format = 1,
},
[TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
.key = ILLEGAL_REQUEST,
.asc = 0x10,
.ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
.add_sector_info = true,
+ .desc_format = 1,
},
[TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
.key = ILLEGAL_REQUEST,
.asc = 0x10,
.ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
.add_sector_info = true,
+ .desc_format = 1,
},
[TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
/*
@@ -2758,7 +2749,6 @@ static void translate_sense_reason(struct se_cmd *cmd, int r)
si = &sense_info_table[(__force int)
TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];

- buffer[SPC_SENSE_KEY_OFFSET] = si->key;
if (r == (__force int)TCM_CHECK_CONDITION_UNIT_ATTENTION) {
core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
WARN_ON_ONCE(asc == 0);
@@ -2770,10 +2760,10 @@ static void translate_sense_reason(struct se_cmd *cmd, int r)
asc = si->asc;
ascq = si->ascq;
}
- buffer[SPC_ASC_KEY_OFFSET] = asc;
- buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
+
+ scsi_build_sense_buffer(si->desc_format, buffer, si->key, asc, ascq);
if (si->add_sector_info)
- transport_err_sector_info(cmd->sense_buffer, cmd->bad_sector);
+ scsi_set_sense_information(buffer, cmd->bad_sector);
}

int
diff --git a/include/scsi/scsi_common.h b/include/scsi/scsi_common.h
index 676b03b..156d673 100644
--- a/include/scsi/scsi_common.h
+++ b/include/scsi/scsi_common.h
@@ -61,4 +61,9 @@ static inline bool scsi_sense_valid(const struct scsi_sense_hdr *sshdr)
extern bool scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
struct scsi_sense_hdr *sshdr);

+extern void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq);
+extern void scsi_set_sense_information(u8 *buf, u64 info);
+extern const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
+ int desc_type);
+
#endif /* _SCSI_COMMON_H_ */
diff --git a/include/scsi/scsi_eh.h b/include/scsi/scsi_eh.h
index 4942710..dbb8c64 100644
--- a/include/scsi/scsi_eh.h
+++ b/include/scsi/scsi_eh.h
@@ -4,6 +4,7 @@
#include <linux/scatterlist.h>

#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_common.h>
struct scsi_device;
struct Scsi_Host;

@@ -21,15 +22,9 @@ static inline bool scsi_sense_is_deferred(const struct scsi_sense_hdr *sshdr)
return ((sshdr->response_code >= 0x70) && (sshdr->response_code & 1));
}

-extern const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
- int desc_type);
-
extern int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
u64 * info_out);

-extern void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq);
-extern void scsi_set_sense_information(u8 *buf, u64 info);
-
extern int scsi_ioctl_reset(struct scsi_device *, int __user *);

struct scsi_eh_save {
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index a681644..a26271e 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -7,6 +7,7 @@
#include <linux/blkdev.h>
#include <linux/percpu_ida.h>
#include <linux/t10-pi.h>
+#include <scsi/scsi_common.h>
#include <net/sock.h>
#include <net/tcp.h>

@@ -22,14 +23,6 @@
* defined 96, but the real limit is 252 (or 260 including the header)
*/
#define TRANSPORT_SENSE_BUFFER 96
-/* Used by transport_send_check_condition_and_sense() */
-#define SPC_SENSE_KEY_OFFSET 2
-#define SPC_ADD_SENSE_LEN_OFFSET 7
-#define SPC_DESC_TYPE_OFFSET 8
-#define SPC_ADDITIONAL_DESC_LEN_OFFSET 9
-#define SPC_VALIDITY_OFFSET 10
-#define SPC_ASC_KEY_OFFSET 12
-#define SPC_ASCQ_KEY_OFFSET 13
#define TRANSPORT_IQN_LEN 224
/* Used by target_core_store_alua_lu_gp() and target_core_alua_lu_gp_show_attr_members() */
#define LU_GROUP_NAME_BUF 256
--
1.8.4.3