akpm@xxxxxxxxxxxxxxxxxxxx wrote:
From: Kristen Carlson Accardi <kristen.c.accardi@xxxxxxxxx>
If a scsi_device supports async notification for media change, then let user
space know this capability exists by creating a new sysfs entry
"media_change_notify", which will be 1 if it is supported, and 0 if not
supported. Create a routine which allows scsi devices to send a uevent when
media change events occur.
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@xxxxxxxxx>
Acked-by: Jeff Garzik <jeff@xxxxxxxxxx>
Cc: Tejun Heo <htejun@xxxxxxxxx>
Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/scsi_lib.c | 83 +++++++++++++++++++++++++++++++++++
drivers/scsi/scsi_scan.c | 1
drivers/scsi/scsi_sysfs.c | 13 +++++
include/scsi/scsi_device.h | 15 +++++-
4 files changed, 111 insertions(+), 1 deletion(-)
committed to libata-dev.git#an as the attached patch
I changed the interface such that it takes a mask of events. We only
have one event right now, but it is now trivial to add more events
within the same interface.
commit 4e0af19e75e40d71181c4e515009e81f19a0fc04
Author: Jeff Garzik <jeff@xxxxxxxxxx>
Date: Thu Oct 25 03:13:46 2007 -0400
[SCSI] Emit asynchronous media events
Based originally on a patch by
Kristen Carlson Accardi <kristen.c.accardi@xxxxxxxxx>
Signed-off-by: Jeff Garzik <jgarzik@xxxxxxxxxx>
drivers/scsi/scsi_lib.c | 58 +++++++++++++++++++++++++++++++++++++++++++++
drivers/scsi/scsi_sysfs.c | 13 ++++++++++
include/scsi/scsi_device.h | 13 +++++++++-
3 files changed, 83 insertions(+), 1 deletion(-)
4e0af19e75e40d71181c4e515009e81f19a0fc04
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 61fdaf0..46a7f50 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2115,6 +2115,64 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
EXPORT_SYMBOL(scsi_device_set_state);
/**
+ * scsi_device_event_notify_thread - send a uevent for each scsi event
+ * @work: work struct for scsi_device
+ *
+ * Emit all queued media events as environment variables
+ * sent during a uevent.
+ */
+static void scsi_event_notify_thread(struct work_struct *work)
+{
+ struct scsi_device *sdev;
+ char *envp[3];
+ unsigned long flags, mask;
+ int i, idx;
+
+ /* must match scsi_device_event enum in scsi_device.h */
+ static char *scsi_device_event_strings[] = {
+ [SDEV_MEDIA_CHANGE] = "SDEV_MEDIA_CHANGE=1",
+ };
+
+ sdev = container_of(work, struct scsi_device, ew.work);
+
+ spin_lock_irqsave(&sdev->list_lock, flags);
+ mask = sdev->event_mask;
+ sdev->event_mask = 0;
+ spin_unlock_irqrestore(&sdev->list_lock, flags);
+
+ idx = 0;
+ for (i = 0; i < SDEV_MEDIA_LAST; i++)
+ if (mask & (1UL << i))
+ envp[idx++] = scsi_device_event_strings[i];
+ envp[idx++] = NULL;
+
+ kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp);
+}
+
+/**
+ * scsi_device_event_notify - store event info and send an event
+ * @sdev: scsi_device event occurred on
+ * @mask: the scsi device event mask
+ *
+ * Store the event information and then switch process context
+ * so that the event may be sent to user space.
+ * This may be called from interrupt context.
+ *
+ * Returns 0 if successful, -ENOMEM otherwise.
+ */
+void scsi_device_event_notify(struct scsi_device *sdev, unsigned long mask)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&sdev->list_lock, flags);
+ sdev->event_mask |= mask;
+ spin_unlock_irqrestore(&sdev->list_lock, flags);
+
+ execute_in_process_context(scsi_event_notify_thread, &sdev->ew);
+}
+EXPORT_SYMBOL_GPL(scsi_device_event_notify);
+
+/**
* scsi_device_quiesce - Block user issued commands.
* @sdev: scsi device to quiesce.
*
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index d531cee..d6e765c 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -614,6 +614,18 @@ sdev_show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
}
static DEVICE_ATTR(modalias, S_IRUGO, sdev_show_modalias, NULL);
+static ssize_t
+sdev_show_media_events(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ if (sdev->media_events)
+ return snprintf(buf, 20, "%d\n", 1);
+ else
+ return snprintf(buf, 20, "%d\n", 0);
+}
+static DEVICE_ATTR(media_events, S_IRUGO, sdev_show_media_events, NULL);
+
/* Default template for device attributes. May NOT be modified */
static struct attribute *scsi_sdev_attrs[] = {
&dev_attr_device_blocked.attr,
@@ -631,6 +643,7 @@ static struct attribute *scsi_sdev_attrs[] = {
&dev_attr_iodone_cnt.attr,
&dev_attr_ioerr_cnt.attr,
&dev_attr_modalias.attr,
+ &dev_attr_media_events.attr,
NULL
};
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index d5057bc..ca208f8 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -46,6 +46,13 @@ enum scsi_device_state {
* to the scsi lld. */
};
+/* must match scsi_device_event_strings in scsi_lib.c */
+enum scsi_device_event {
+ SDEV_MEDIA_CHANGE = 1, /* media has changed */
+
+ SDEV_MEDIA_LAST = SDEV_MEDIA_CHANGE,
+};
+
struct scsi_device {
struct Scsi_Host *host;
struct request_queue *request_queue;
@@ -126,12 +133,14 @@ struct scsi_device {
unsigned fix_capacity:1; /* READ_CAPACITY is too high by 1 */
unsigned guess_capacity:1; /* READ_CAPACITY might be too high by 1 */
unsigned retry_hwerror:1; /* Retry HARDWARE_ERROR */
-
+ unsigned media_events:1; /* dev supports async media events */
unsigned int device_blocked; /* Device returned QUEUE_FULL. */
unsigned int max_device_blocked; /* what device_blocked counts down from */
#define SCSI_DEFAULT_DEVICE_BLOCKED 3
+ unsigned long event_mask; /* SDEV_MEDIA_xxx (1<<x for mask) */
+
atomic_t iorequest_cnt;
atomic_t iodone_cnt;
atomic_t ioerr_cnt;
@@ -275,6 +284,8 @@ extern int scsi_test_unit_ready(struct scsi_device *sdev, int timeout,
int retries);
extern int scsi_device_set_state(struct scsi_device *sdev,
enum scsi_device_state state);
+extern void scsi_device_event_notify(struct scsi_device *sdev,
+ unsigned long event_mask);
extern int scsi_device_quiesce(struct scsi_device *sdev);
extern void scsi_device_resume(struct scsi_device *sdev);
extern void scsi_target_quiesce(struct scsi_target *);
