This patch adds capability for SCSI layer to generate uevent for SCSI
sense code. The feature is gated by CONFIG_SCSI_SENSE_UEVENT.

We can configure which sense keys generate uevent for each device
through sysfs entry sense_event_filter, which is a bitmap of
"sense keys to generate uevent" For example, the following enables
uevent for MEDIUM_ERROR (0x03) and HARDWARE_ERROR (0x04) on scsi
drive sdc:

    echo 0x000c > /sys/block/sdc/device/sense_event_filter

Here is an example output captured by udevadm:

KERNEL[587.353177] change   /devices/pci0000:00/XXXXXXXXXX
ACTION=change
CDB=\x88\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x08\x00\x00
DEVPATH=/devices/pci0000:00/0000:00:01.0/0000:01:00.0/host6/XXXXXX
DEVTYPE=scsi_device
DRIVER=sd
MODALIAS=scsi:t-0x00
SDEV_SENSE=1
SENSE_BUFFER=\x72\x03\x11\x14\x00\x00\x00\x34\x00\x0a\x80 ....
SENSE_CODE=3/11/14
SEQNUM=4796
SUBSYSTEM=scsi

Signed-off-by: Song Liu <songliubrav...@fb.com>
---
 drivers/scsi/Kconfig       | 14 +++++++++++
 drivers/scsi/scsi_error.c  | 42 +++++++++++++++++++++++++++++++++
 drivers/scsi/scsi_lib.c    | 58 +++++++++++++++++++++++++++++++++++++++++++++-
 drivers/scsi/scsi_sysfs.c  | 51 ++++++++++++++++++++++++++++++++++++++++
 include/scsi/scsi_common.h |  6 +++++
 include/scsi/scsi_device.h | 27 ++++++++++++++++++++-
 6 files changed, 196 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index d384f4f..0fb672b 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -226,6 +226,20 @@ config SCSI_LOGGING
          there should be no noticeable performance impact as long as you have
          logging turned off.
 
+config SCSI_SENSE_UEVENT
+       bool "SCSI sense code logging"
+       depends on SCSI
+       default n
+       ---help---
+         This turns on uevent for SCSI sense code.
+
+         You can configure which sense keys generate uevent for each device
+         through sysfs entry sense_event_filter. For example, the following
+         enables uevent for MEDIUM_ERROR (0x03) and HARDWARE_ERROR (0x04)
+         on scsi drive sdc:
+
+         echo 0x000c > /sys/block/sdc/device/sense_event_filter
+
 config SCSI_SCAN_ASYNC
        bool "Asynchronous SCSI scanning"
        depends on SCSI
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index ea9f40e..f6107f7 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -426,6 +426,47 @@ static void scsi_report_sense(struct scsi_device *sdev,
        }
 }
 
+/*
+ * generate uevent when receiving sense code from device
+ */
+static void scsi_send_sense_uevent(struct scsi_device *sdev,
+                                  struct scsi_cmnd *scmd,
+                                  struct scsi_sense_hdr *sshdr)
+{
+#ifdef CONFIG_SCSI_SENSE_UEVENT
+       struct scsi_event *evt;
+       unsigned char sb_len;
+
+       if (!test_bit(sshdr->sense_key, &sdev->sense_event_filter))
+               return;
+       evt = sdev_evt_alloc(SDEV_EVT_SCSI_SENSE, GFP_ATOMIC);
+       if (!evt)
+               return;
+
+       evt->sense_evt_data.cmnd = kzalloc(scmd->cmd_len, GFP_ATOMIC);
+       if (!evt->sense_evt_data.cmnd)
+               goto alloc_cmd_fail;
+
+       sb_len = scsi_sense_data_length(scmd->sense_buffer);
+
+       evt->sense_evt_data.sense_buffer = kzalloc(sb_len, GFP_ATOMIC);
+       if (!evt->sense_evt_data.sense_buffer)
+               goto alloc_sense_fail;
+
+       evt->sense_evt_data.cmd_len = scmd->cmd_len;
+       evt->sense_evt_data.sb_len = sb_len;
+       memcpy(evt->sense_evt_data.cmnd, scmd->cmnd, scmd->cmd_len);
+       memcpy(evt->sense_evt_data.sense_buffer, scmd->sense_buffer, sb_len);
+
+       sdev_evt_send(sdev, evt);
+       return;
+alloc_sense_fail:
+       kfree(evt->sense_evt_data.cmnd);
+alloc_cmd_fail:
+       kfree(evt);
+#endif
+}
+
 /**
  * scsi_check_sense - Examine scsi cmd sense
  * @scmd:      Cmd to have sense checked.
@@ -446,6 +487,7 @@ int scsi_check_sense(struct scsi_cmnd *scmd)
                return FAILED;  /* no valid sense data */
 
        scsi_report_sense(sdev, &sshdr);
+       scsi_send_sense_uevent(sdev, scmd, &sshdr);
 
        if (scsi_sense_is_deferred(&sshdr))
                return NEEDS_RETRY;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index f6097b8..7c6ab28 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2677,7 +2677,15 @@ EXPORT_SYMBOL(scsi_device_set_state);
 static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt)
 {
        int idx = 0;
-       char *envp[3];
+       char *envp[5];  /* SDEV_EVT_SCSI_SENSE needs most entries (4) */
+#ifdef CONFIG_SCSI_SENSE_UEVENT
+       char *buf = NULL;
+       int i;
+       int buf_size;
+       int offset;
+       struct scsi_sense_hdr sshdr;
+#endif
+
 
        switch (evt->evt_type) {
        case SDEV_EVT_MEDIA_CHANGE:
@@ -2702,6 +2710,49 @@ static void scsi_evt_emit(struct scsi_device *sdev, 
struct scsi_event *evt)
        case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED:
                envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED";
                break;
+#ifdef CONFIG_SCSI_SENSE_UEVENT
+       case SDEV_EVT_SCSI_SENSE:
+               /*
+                * buf is used to store 3 strings: SENSE_CODE, CDB and
+                * SENSE_BUFFER. 4 bytes are needed for each byte in cdb
+                * and sense buffer. So the total size required is:
+                *
+                *   19 (SENSE_CODE=X/XX/XX\0) + 5 (CDB=\0) +
+                *       14 (SENSE_BUFFER=\0) + 4 * (cdb_len + sb_len);
+                */
+               buf_size = (evt->sense_evt_data.cmd_len +
+                           evt->sense_evt_data.sb_len) * 4 + 38;
+               buf = kzalloc(buf_size, GFP_KERNEL);
+               if (!buf)
+                       break;
+               offset = 0;
+
+               envp[idx++] = "SDEV_SENSE=1";
+               envp[idx++] = buf;
+               scsi_normalize_sense(evt->sense_evt_data.sense_buffer,
+                                    evt->sense_evt_data.sb_len, &sshdr);
+               offset += snprintf(buf + offset, buf_size - offset,
+                                  "SENSE_CODE=%1x/%02x/%02x",
+                                  sshdr.sense_key, sshdr.asc, sshdr.ascq);
+               offset++;
+
+               envp[idx++] = buf + offset;
+               offset += snprintf(buf + offset, buf_size - offset, "CDB=");
+               for (i = 0; i < evt->sense_evt_data.cmd_len; i++)
+                       offset += snprintf(
+                               buf + offset, buf_size - offset,
+                               "\\x%02x", evt->sense_evt_data.cmnd[i]);
+
+               offset++;
+               envp[idx++] = buf + offset;
+               offset += snprintf(buf + offset, buf_size - offset,
+                                  "SENSE_BUFFER=");
+               for (i = 0; i < evt->sense_evt_data.sb_len; i++)
+                       offset += snprintf(
+                               buf + offset, buf_size - offset,
+                               "\\x%02x", evt->sense_evt_data.sense_buffer[i]);
+               break;
+#endif
        default:
                /* do nothing */
                break;
@@ -2710,6 +2761,10 @@ static void scsi_evt_emit(struct scsi_device *sdev, 
struct scsi_event *evt)
        envp[idx++] = NULL;
 
        kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp);
+
+#ifdef CONFIG_SCSI_SENSE_UEVENT
+       kfree(buf);
+#endif
 }
 
 /**
@@ -2806,6 +2861,7 @@ struct scsi_event *sdev_evt_alloc(enum scsi_device_event 
evt_type,
        case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED:
        case SDEV_EVT_LUN_CHANGE_REPORTED:
        case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED:
+       case SDEV_EVT_SCSI_SENSE:
        default:
                /* do nothing */
                break;
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index d6984df..937609c 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1074,6 +1074,54 @@ static DEVICE_ATTR(queue_ramp_up_period, S_IRUGO | 
S_IWUSR,
                   sdev_show_queue_ramp_up_period,
                   sdev_store_queue_ramp_up_period);
 
+#ifdef CONFIG_SCSI_SENSE_UEVENT
+
+/*
+ * SCSI sense key could be 0x00 - 0x0f,
+ */
+#define SCSI_SENSE_EVENT_FILTER_MASK   0xffff
+
+static ssize_t
+sdev_show_sense_event_filter(struct device *dev,
+                            struct device_attribute *attr,
+                            char *buf)
+{
+       struct scsi_device *sdev;
+
+       sdev = to_scsi_device(dev);
+       return snprintf(buf, 20, "0x%04lx\n",
+                       (sdev->sense_event_filter &
+                        SCSI_SENSE_EVENT_FILTER_MASK));
+}
+
+static ssize_t
+sdev_store_sense_event_filter(struct device *dev,
+                             struct device_attribute *attr,
+                             const char *buf, size_t count)
+{
+       struct scsi_device *sdev = to_scsi_device(dev);
+       unsigned long filter;
+       int i;
+
+       if (kstrtoul(buf, 0, &filter))
+               return -EINVAL;
+
+       if ((filter & 0xffff) != filter)
+               return -EINVAL;
+
+       for (i = 0; i < 16; i++)
+               if (filter & SCSI_SENSE_EVENT_FILTER_MASK  & (1 << i))
+                       set_bit(i, &sdev->sense_event_filter);
+               else
+                       clear_bit(i, &sdev->sense_event_filter);
+       return count;
+}
+
+static DEVICE_ATTR(sense_event_filter, 0644,
+                  sdev_show_sense_event_filter,
+                  sdev_store_sense_event_filter);
+#endif
+
 static umode_t scsi_sdev_attr_is_visible(struct kobject *kobj,
                                         struct attribute *attr, int i)
 {
@@ -1144,6 +1192,9 @@ static struct attribute *scsi_sdev_attrs[] = {
        &dev_attr_preferred_path.attr,
 #endif
        &dev_attr_queue_ramp_up_period.attr,
+#ifdef CONFIG_SCSI_SENSE_UEVENT
+       &dev_attr_sense_event_filter.attr,
+#endif
        REF_EVT(media_change),
        REF_EVT(inquiry_change_reported),
        REF_EVT(capacity_change_reported),
diff --git a/include/scsi/scsi_common.h b/include/scsi/scsi_common.h
index 20bf7ea..832ff62 100644
--- a/include/scsi/scsi_common.h
+++ b/include/scsi/scsi_common.h
@@ -24,6 +24,12 @@ scsi_command_size(const unsigned char *cmnd)
                scsi_varlen_cdb_length(cmnd) : COMMAND_SIZE(cmnd[0]);
 }
 
+static inline unsigned char
+scsi_sense_data_length(const unsigned char *sense_buffer)
+{
+       return sense_buffer[7] + 8;
+}
+
 /* Returns a human-readable name for the device */
 extern const char *scsi_device_type(unsigned type);
 
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 0979a5f..ba4a575 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -64,13 +64,24 @@ enum scsi_device_event {
        SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED,        /* 2A 01  UA reported */
        SDEV_EVT_LUN_CHANGE_REPORTED,                   /* 3F 0E  UA reported */
        SDEV_EVT_ALUA_STATE_CHANGE_REPORTED,            /* 2A 06  UA reported */
+       SDEV_EVT_SCSI_SENSE,
 
        SDEV_EVT_FIRST          = SDEV_EVT_MEDIA_CHANGE,
-       SDEV_EVT_LAST           = SDEV_EVT_ALUA_STATE_CHANGE_REPORTED,
+       SDEV_EVT_LAST           = SDEV_EVT_SCSI_SENSE,
 
        SDEV_EVT_MAXBITS        = SDEV_EVT_LAST + 1
 };
 
+#ifdef CONFIG_SCSI_SENSE_UEVENT
+/* data for for SDEV_EVT_SCSI_SENSE */
+struct scsi_sense_uevent_data {
+       unsigned char           cmd_len;
+       unsigned char           *cmnd;
+       unsigned char           sb_len;
+       unsigned char           *sense_buffer;
+};
+#endif
+
 struct scsi_event {
        enum scsi_device_event  evt_type;
        struct list_head        node;
@@ -78,6 +89,11 @@ struct scsi_event {
        /* put union of data structures, for non-simple event types,
         * here
         */
+       union {
+#ifdef CONFIG_SCSI_SENSE_UEVENT
+               struct scsi_sense_uevent_data sense_evt_data;
+#endif
+       };
 };
 
 struct scsi_device {
@@ -197,6 +213,15 @@ struct scsi_device {
        atomic_t iodone_cnt;
        atomic_t ioerr_cnt;
 
+#ifdef CONFIG_SCSI_SENSE_UEVENT
+       /*
+        * filter of sense code uevent
+        * setting bit X (0x00 - 0x0e) of sense_event_filter enables
+        * uevent for sense key X
+        */
+       unsigned long           sense_event_filter;
+#endif
+
        struct device           sdev_gendev,
                                sdev_dev;
 
-- 
2.9.3

Reply via email to