From: Mike Christie <michaelc@xxxxxxxxxxx>
If a device goes offline while the device is opened then closed
while it is still offline, udev will remove the /dev/disk/by-id
link. If the device comes back and is set to running, userspace
is not notified, and the by-id link will not get remade.
This patch has scsi-ml send a KOBJ_CHANGE event so tools like udev
will know that it can being to use the device again. With this patch
udev see the KOBJ_CHANGE event and will reprobe the device and recreate
a /dev/disk/by-id link.
v2
- Added SDEV_EVT_STATE_RUNNING evt type.
Signed-off-by: Mike Christie <michaelc@xxxxxxxxxxx>
---
drivers/scsi/scsi_lib.c | 9 +++++++++
include/scsi/scsi_device.h | 2 ++
2 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index c61ab0c..ed5bcb2 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2061,6 +2061,7 @@ int
scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
{
enum scsi_device_state oldstate = sdev->sdev_state;
+ int change_evt = 0;
if (state == oldstate)
return 0;
@@ -2079,6 +2080,11 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
switch (oldstate) {
case SDEV_OFFLINE:
case SDEV_TRANSPORT_OFFLINE:
+ /*
+ * Notify userspace we can accept IO by sending
+ * change event.
+ */
+ change_evt = 1;
case SDEV_QUIESCE:
case SDEV_BLOCK:
case SDEV_CREATED:
@@ -2160,6 +2166,8 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
}
sdev->sdev_state = state;
+ if (change_evt)
+ sdev_evt_send_simple(sdev, SDEV_EVT_STATE_RUNNING, GFP_ATOMIC);
return 0;
illegal:
@@ -2283,6 +2291,7 @@ struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
/* evt_type-specific initialization, if any */
switch (evt_type) {
case SDEV_EVT_MEDIA_CHANGE:
+ case SDEV_EVT_STATE_RUNNING:
default:
/* do nothing */
break;
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 5ff8180..0759433 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -52,6 +52,8 @@ enum scsi_device_state {
enum scsi_device_event {
SDEV_EVT_MEDIA_CHANGE = 1, /* media has changed */
+ SDEV_EVT_STATE_RUNNING = 2, /* state has gone from offline to
+ * running */
SDEV_EVT_LAST = SDEV_EVT_MEDIA_CHANGE,
SDEV_EVT_MAXBITS = SDEV_EVT_LAST + 1
--
1.7.7.6
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