Introduce a new class for multipathed devices, scsi_mpath_device_class. The purpose of this class is for managing the scsi_mpath_head.dev member.
The naming for the scsi_device structure is in form H:C:I:L, where H is host, C is channel, I is ID, and L is lun. However, for a multipathed scsi_device, all the naming members may be different between member scsi_device's. As such, just use a simple single-number naming index for each scsi_mpath_head. The sysfs device folder will have links to the scsi_device's so, it will be possible to lookup the member scsi_device's. An example sysfs entry is as follows: # ls -l /sys/class/scsi_mpath_device/0/ total 0 drwxr-xr-x 2 root root 0 Feb 24 11:56 power lrwxrwxrwx 1 root root 0 Feb 24 11:56 subsystem -> ../../../../class/scsi_mpath_device -rw-r--r-- 1 root root 4096 Feb 24 11:55 uevent -r--r--r-- 1 root root 4096 Feb 24 11:56 wwid # cat /sys/class/scsi_mpath_device/0/wwid naa.600140505200a986f0043c9afa1fd077 Signed-off-by: John Garry <[email protected]> --- drivers/scsi/scsi_multipath.c | 67 ++++++++++++++++++++++++++++++++++- 1 file changed, 66 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/scsi_multipath.c b/drivers/scsi/scsi_multipath.c index 49316269fad8e..05af178921cb4 100644 --- a/drivers/scsi/scsi_multipath.c +++ b/drivers/scsi/scsi_multipath.c @@ -85,6 +85,69 @@ static int scsi_mpath_unique_lun_id(struct scsi_device *sdev) return 0; } +static void scsi_mpath_delete_head(struct scsi_mpath_head *scsi_mpath_head) +{ + mutex_lock(&scsi_mpath_heads_lock); + list_del_init(&scsi_mpath_head->entry); + mutex_unlock(&scsi_mpath_heads_lock); +} + +static void scsi_mpath_head_release(struct device *dev) +{ + struct scsi_mpath_head *scsi_mpath_head = + container_of(dev, struct scsi_mpath_head, dev); + struct mpath_head *mpath_head = scsi_mpath_head->mpath_head; + + scsi_mpath_delete_head(scsi_mpath_head); + ida_free(&scsi_multipath_dev_ida, scsi_mpath_head->index); + mpath_put_head(mpath_head); + kfree(scsi_mpath_head); +} + +static ssize_t scsi_mpath_device_wwid_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct scsi_mpath_head *scsi_mpath_head = + container_of(dev, struct scsi_mpath_head, dev); + + return sysfs_emit(buf, "%s\n", scsi_mpath_head->wwid); +} + +static DEVICE_ATTR(wwid, S_IRUGO, scsi_mpath_device_wwid_show, NULL); + +static struct attribute *scsi_mpath_device_attrs[] = { + &dev_attr_wwid.attr, + NULL +}; + +static const struct attribute_group scsi_mpath_device_attrs_group = { + .attrs = scsi_mpath_device_attrs, +}; + +static bool scsi_multipath_sysfs_group_visible(struct kobject *kobj) +{ + return true; +} + +static bool scsi_multipath_sysfs_attr_visible(struct kobject *kobj, + struct attribute *attr, int n) +{ + return false; +} +DEFINE_SYSFS_GROUP_VISIBLE(scsi_multipath_sysfs) + +const struct attribute_group *scsi_mpath_device_groups[] = { + &scsi_mpath_device_attrs_group, + NULL +}; + +static const struct class scsi_mpath_device_class = { + .name = "scsi_mpath_device", + .dev_groups = scsi_mpath_device_groups, + .dev_release = scsi_mpath_head_release, +}; + static int scsi_multipath_sdev_init(struct scsi_device *sdev) { struct Scsi_Host *shost = sdev->host; @@ -129,6 +192,7 @@ static struct scsi_mpath_head *scsi_mpath_alloc_head(void) goto out_put_head; device_initialize(&scsi_mpath_head->dev); + scsi_mpath_head->dev.class = &scsi_mpath_device_class; ret = dev_set_name(&scsi_mpath_head->dev, "%d", scsi_mpath_head->index); if (ret) { put_device(&scsi_mpath_head->dev); @@ -294,11 +358,12 @@ EXPORT_SYMBOL_GPL(scsi_mpath_put_head); int __init scsi_multipath_init(void) { - return 0; + return class_register(&scsi_mpath_device_class); } void __exit scsi_multipath_exit(void) { + class_unregister(&scsi_mpath_device_class); } MODULE_LICENSE("GPL"); -- 2.43.5
