From: Anand Jain <anand.jain@xxxxxxxxxx>
As of now with out this patch the sysfs interface under dir
/sys/fs/btrfs/<fsid>/devices is just link to the block devs.
Moving forward we would need the above btrfs sysfs path to contain more
info about the btrfs devices. So this patch provides a framework for
the same.
And as of now a probe interface is added, which can be used to notify
btrfs for any change in the device status.
Signed-off-by: Anand Jain <anand.jain@xxxxxxxxxx>
---
V2: On the 2nd thought I kept the device link, but under the device name.
eg: /sys/fs/btrfs/<fsid>/devices/<sdx>/sdx-> link to blk device
/sys/fs/btrfs/<fsid>/devices/<sdx>/probe
and commit update accordingly
fs/btrfs/sysfs.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++-----
fs/btrfs/volumes.h | 2 ++
2 files changed, 69 insertions(+), 6 deletions(-)
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 9733cfc..92fb3bb 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -31,8 +31,11 @@
#include "transaction.h"
#include "sysfs.h"
#include "volumes.h"
+#include "rcu-string.h"
static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
+int btrfs_kobj_rm_device(struct btrfs_fs_info *fs_info,
+ struct btrfs_device *one_device);
static u64 get_features(struct btrfs_fs_info *fs_info,
enum btrfs_feature_set set)
@@ -490,8 +493,13 @@ void btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info)
kobject_del(fs_info->space_info_kobj);
kobject_put(fs_info->space_info_kobj);
}
- kobject_del(fs_info->device_dir_kobj);
- kobject_put(fs_info->device_dir_kobj);
+
+ if (fs_info->device_dir_kobj) {
+ btrfs_kobj_rm_device(fs_info, NULL);
+ kobject_del(fs_info->device_dir_kobj);
+ kobject_put(fs_info->device_dir_kobj);
+ }
+
addrm_unknown_feature_attrs(fs_info, false);
sysfs_remove_group(&fs_info->super_kobj, &btrfs_feature_attr_group);
__btrfs_sysfs_remove_one(fs_info);
@@ -577,21 +585,68 @@ int btrfs_kobj_rm_device(struct btrfs_fs_info *fs_info,
{
struct hd_struct *disk;
struct kobject *disk_kobj;
+ struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+ struct btrfs_device *dev;
if (!fs_info->device_dir_kobj)
return -EINVAL;
if (one_device) {
+ if (!one_device->device_kobj.parent)
+ return -EINVAL;
+
disk = one_device->bdev->bd_part;
disk_kobj = &part_to_dev(disk)->kobj;
- sysfs_remove_link(fs_info->device_dir_kobj,
+ sysfs_remove_link(&one_device->device_kobj,
disk_kobj->name);
+ kobject_del(&one_device->device_kobj);
+ kobject_put(&one_device->device_kobj);
+ return 0;
}
+ list_for_each_entry(dev, &fs_devices->devices, dev_list) {
+ if (!dev->device_kobj.parent)
+ continue;
+
+ disk = dev->bdev->bd_part;
+ disk_kobj = &part_to_dev(disk)->kobj;
+
+ sysfs_remove_link(&dev->device_kobj, disk_kobj->name);
+ kobject_del(&dev->device_kobj);
+ kobject_put(&dev->device_kobj);
+ }
return 0;
}
+#define to_btrfs_device(_kobj) container_of(_kobj, struct btrfs_device, device_kobj)
+
+static ssize_t device_kobj_probe_store(struct kobject *dev_kobj,
+ struct kobj_attribute *a, const char *buf, size_t len)
+{
+ /* Fixme: Call appropriate device check status handler */
+
+ return len;
+}
+
+BTRFS_ATTR_RW(probe, 0200, NULL, device_kobj_probe_store);
+
+static struct attribute *device_kobj_attrs[] = {
+ BTRFS_ATTR_PTR(probe),
+ NULL,
+};
+
+static void device_kobj_release(struct kobject *dev_kobj)
+{
+ /* nothing to free as of now */
+}
+
+struct kobj_type device_ktype = {
+ .sysfs_ops = &kobj_sysfs_ops,
+ .release = device_kobj_release,
+ .default_attrs = device_kobj_attrs,
+};
+
int btrfs_kobj_add_device(struct btrfs_fs_info *fs_info,
struct btrfs_device *one_device)
{
@@ -610,19 +665,25 @@ int btrfs_kobj_add_device(struct btrfs_fs_info *fs_info,
struct hd_struct *disk;
struct kobject *disk_kobj;
- if (!dev->bdev)
+ if (!dev->bdev || dev->missing || dev->device_kobj.parent)
continue;
if (one_device && one_device != dev)
continue;
+ error = kobject_init_and_add(&dev->device_kobj, &device_ktype,
+ fs_info->device_dir_kobj, "%s",
+ strrchr(rcu_str_deref(dev->name), '/') + 1);
+ if (error)
+ break;
+
disk = dev->bdev->bd_part;
disk_kobj = &part_to_dev(disk)->kobj;
-
- error = sysfs_create_link(fs_info->device_dir_kobj,
+ error = sysfs_create_link(&dev->device_kobj,
disk_kobj, disk_kobj->name);
if (error)
break;
+
}
return error;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 25f0505..d0c9c32 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -113,6 +113,8 @@ struct btrfs_device {
int dev_stats_valid;
int dev_stats_dirty; /* counters need to be written to disk */
atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
+
+ struct kobject device_kobj;
};
struct btrfs_fs_devices {
--
1.8.5.3
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