* [RFC v3 1/2] scsi: generate uevent for SCSI sense code
2017-07-12 22:35 [RFC v3 0/2] generate uevent for SCSI sense code Song Liu
@ 2017-07-12 22:35 ` Song Liu
2017-07-13 6:39 ` Johannes Thumshirn
2017-07-12 22:35 ` [RFC v3 2/2] scsi: add rate limit to scsi sense code uevent Song Liu
1 sibling, 1 reply; 4+ messages in thread
From: Song Liu @ 2017-07-12 22:35 UTC (permalink / raw)
To: linux-scsi; +Cc: hare, James.Bottomley, axboe, axboe, bblock, emilne, Song Liu
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 <songliubraving@fb.com>
---
drivers/scsi/Kconfig | 14 +++++++++++
drivers/scsi/scsi_error.c | 43 ++++++++++++++++++++++++++++++++++
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, 197 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 ac31964..b8ef869 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -426,6 +426,48 @@ 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 & 0xf,
+ &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 +488,7 @@ 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 41c19c7..67cc0fb 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 b41ee9d..aa1ac28 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 {
@@ -196,6 +212,15 @@ 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
^ permalink raw reply related [flat|nested] 4+ messages in thread* [RFC v3 2/2] scsi: add rate limit to scsi sense code uevent
2017-07-12 22:35 [RFC v3 0/2] generate uevent for SCSI sense code Song Liu
2017-07-12 22:35 ` [RFC v3 1/2] scsi: " Song Liu
@ 2017-07-12 22:35 ` Song Liu
1 sibling, 0 replies; 4+ messages in thread
From: Song Liu @ 2017-07-12 22:35 UTC (permalink / raw)
To: linux-scsi; +Cc: hare, James.Bottomley, axboe, axboe, bblock, emilne, Song Liu
This patch adds rate limits to SCSI sense code uevets. Currently,
the rate limit is hard-coded to 64 events per second per Scsi_Host.
The code tracks nano second time of latest 64 events in a circular
buffer. When a new event arrives, the time is compared against the
latest time in the buffer. If the difference is smaller than one
second, the new event is dropped.
Signed-off-by: Song Liu <songliubraving@fb.com>
---
drivers/scsi/hosts.c | 4 ++++
drivers/scsi/scsi_error.c | 16 ++++++++++++++++
include/scsi/scsi_host.h | 13 +++++++++++++
3 files changed, 33 insertions(+)
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 831a1c8..219481b 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -408,6 +408,10 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
init_waitqueue_head(&shost->host_wait);
mutex_init(&shost->scan_mutex);
+#ifdef CONFIG_SCSI_SENSE_UEVENT
+ spin_lock_init(&shost->latest_event_lock);
+#endif
+
index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL);
if (index < 0)
goto fail_kfree;
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index b8ef869..a0f5aab 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -436,10 +436,26 @@ static void scsi_send_sense_uevent(struct scsi_device *sdev,
#ifdef CONFIG_SCSI_SENSE_UEVENT
struct scsi_event *evt;
unsigned char sb_len;
+ struct Scsi_Host *shost = sdev->host;
+ unsigned long flags;
+ u64 time_ns;
if (!test_bit(sshdr->sense_key & 0xf,
&sdev->sense_event_filter))
return;
+
+ time_ns = ktime_to_ns(ktime_get());
+ spin_lock_irqsave(&shost->latest_event_lock, flags);
+ if (time_ns - shost->latest_event_times[shost->latest_event_idx] <
+ NSEC_PER_SEC) {
+ spin_unlock_irqrestore(&shost->latest_event_lock, flags);
+ return;
+ }
+ shost->latest_event_times[shost->latest_event_idx] = time_ns;
+ shost->latest_event_idx = (shost->latest_event_idx + 1) %
+ MAX_SENSE_EVENT_PER_SECOND;
+ spin_unlock_irqrestore(&shost->latest_event_lock, flags);
+
evt = sdev_evt_alloc(SDEV_EVT_SCSI_SENSE, GFP_ATOMIC);
if (!evt)
return;
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index afb0481..8aacb15 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -731,6 +731,19 @@ struct Scsi_Host {
*/
struct device *dma_dev;
+#ifdef CONFIG_SCSI_SENSE_UEVENT
+#define MAX_SENSE_EVENT_PER_SECOND 64
+ /*
+ * To rate limit uevents to MAX_SENSE_EVENT_PER_SECOND, we track
+ * nano second time of MAX_SENSE_EVENT_PER_SECOND most recent
+ * events. If there are already MAX_SENSE_EVENT_PER_SECOND in the
+ * past seconds, new event is dropped.
+ */
+ u64 latest_event_times[MAX_SENSE_EVENT_PER_SECOND];
+ int latest_event_idx;
+ spinlock_t latest_event_lock;
+#endif
+
/*
* We should ensure that this is aligned, both for better performance
* and also because some compilers (m68k) don't automatically force
--
2.9.3
^ permalink raw reply related [flat|nested] 4+ messages in thread