Provide a link in sysfs from a scsi_mpath_device to member scsi_device's.
An example is as follows:
# ls -l /sys/class/scsi_mpath_device/0/multipath/
total 0
lrwxrwxrwx 1 root root 0 Feb 24 12:01 8:0:0:0 -> ../../../../platform/host8/session1/target8:0:0/8:0:0:0
lrwxrwxrwx 1 root root 0 Feb 24 12:01 9:0:0:0 -> ../../../../platform/host9/session2/target9:0:0/9:0:0:0
Signed-off-by: John Garry <john.g.garry@oracle.com>
---
drivers/scsi/scsi_multipath.c | 45 +++++++++++++++++++++++++++++++++++
drivers/scsi/scsi_sysfs.c | 5 ++++
include/scsi/scsi_multipath.h | 9 +++++++
3 files changed, 59 insertions(+)
diff --git a/drivers/scsi/scsi_multipath.c b/drivers/scsi/scsi_multipath.c
index 05af178921cb4..ac55f9f39a5b2 100644
--- a/drivers/scsi/scsi_multipath.c
+++ b/drivers/scsi/scsi_multipath.c
@@ -125,6 +125,15 @@ static const struct attribute_group scsi_mpath_device_attrs_group = {
.attrs = scsi_mpath_device_attrs,
};
+static struct attribute dummy_attr = {
+ .name = "dummy",
+};
+
+static struct attribute *scsi_mpath_attrs[] = {
+ &dummy_attr,
+ NULL
+};
+
static bool scsi_multipath_sysfs_group_visible(struct kobject *kobj)
{
return true;
@@ -137,11 +146,47 @@ static bool scsi_multipath_sysfs_attr_visible(struct kobject *kobj,
}
DEFINE_SYSFS_GROUP_VISIBLE(scsi_multipath_sysfs)
+static const struct attribute_group scsi_mpath_attr_group = {
+ .name = "multipath",
+ .attrs = scsi_mpath_attrs,
+ .is_visible = SYSFS_GROUP_VISIBLE(scsi_multipath_sysfs),
+};
+
const struct attribute_group *scsi_mpath_device_groups[] = {
&scsi_mpath_device_attrs_group,
+ &scsi_mpath_attr_group,
NULL
};
+void scsi_mpath_add_sysfs_link(struct scsi_device *sdev)
+{
+ struct device *target = &sdev->sdev_gendev;
+ struct scsi_mpath_head *scsi_mpath_head =
+ sdev->scsi_mpath_dev->scsi_mpath_head;
+ struct device *source = &scsi_mpath_head->dev;
+ int error;
+
+ error = sysfs_add_link_to_group(&source->kobj, "multipath",
+ &target->kobj, dev_name(target));
+ if (error) {
+ sdev_printk(KERN_INFO, sdev, "Failed to create mpath sysfs link, errno=%d\n",
+ error);
+ }
+}
+EXPORT_SYMBOL_GPL(scsi_mpath_add_sysfs_link);
+
+void scsi_mpath_remove_sysfs_link(struct scsi_device *sdev)
+{
+ struct device *target = &sdev->sdev_gendev;
+ struct scsi_mpath_head *scsi_mpath_head =
+ sdev->scsi_mpath_dev->scsi_mpath_head;
+ struct device *source = &scsi_mpath_head->dev;
+
+ sysfs_remove_link_from_group(&source->kobj, "multipath",
+ dev_name(target));
+}
+EXPORT_SYMBOL_GPL(scsi_mpath_remove_sysfs_link);
+
static const struct class scsi_mpath_device_class = {
.name = "scsi_mpath_device",
.dev_groups = scsi_mpath_device_groups,
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 287a683e89ae5..3b03ee00c8df3 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1389,6 +1389,9 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev)
transport_add_device(&sdev->sdev_gendev);
sdev->is_visible = 1;
+ if (sdev->scsi_mpath_dev)
+ scsi_mpath_add_sysfs_link(sdev);
+
if (IS_ENABLED(CONFIG_BLK_DEV_BSG)) {
sdev->bsg_dev = scsi_bsg_register_queue(sdev);
if (IS_ERR(sdev->bsg_dev)) {
@@ -1441,6 +1444,8 @@ void __scsi_remove_device(struct scsi_device *sdev)
if (IS_ENABLED(CONFIG_BLK_DEV_BSG) && sdev->bsg_dev)
bsg_unregister_queue(sdev->bsg_dev);
+ if (sdev->scsi_mpath_dev)
+ scsi_mpath_remove_sysfs_link(sdev);
device_unregister(&sdev->sdev_dev);
transport_remove_device(dev);
device_del(dev);
diff --git a/include/scsi/scsi_multipath.h b/include/scsi/scsi_multipath.h
index 38953b05a44dc..d8102df329d6b 100644
--- a/include/scsi/scsi_multipath.h
+++ b/include/scsi/scsi_multipath.h
@@ -46,6 +46,8 @@ void scsi_mpath_dev_release(struct scsi_device *sdev);
int scsi_multipath_init(void);
void scsi_multipath_exit(void);
void scsi_mpath_remove_device(struct scsi_mpath_device *scsi_mpath_dev);
+void scsi_mpath_add_sysfs_link(struct scsi_device *sdev);
+void scsi_mpath_remove_sysfs_link(struct scsi_device *sdev);
int scsi_mpath_get_head(struct scsi_mpath_head *);
void scsi_mpath_put_head(struct scsi_mpath_head *);
#else /* CONFIG_SCSI_MULTIPATH */
@@ -80,5 +82,12 @@ static inline int scsi_mpath_get_head(struct scsi_mpath_head *)
static inline void scsi_mpath_put_head(struct scsi_mpath_head *)
{
}
+
+static inline void scsi_mpath_add_sysfs_link(struct scsi_device *sdev)
+{
+}
+static inline void scsi_mpath_remove_sysfs_link(struct scsi_device *sdev)
+{
+}
#endif /* CONFIG_SCSI_MULTIPATH */
#endif /* _SCSI_SCSI_MULTIPATH_H */
--
2.43.5