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 <[email protected]> --- 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
