From 5a13f4308c5b4af28c01ca9cacdd8a6db777dfcb Mon Sep 17 00:00:00 2001
From: Anand Jain <Anand.Jain@oracle.com>
Date: Tue, 10 Mar 2015 06:38:31 +0800
Subject: Btrfs: sysfs: add pointer to access fs_info from fs_devices

adds fs_info pointer with struct btrfs_fs_devices.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.cz>

diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index f045c56..4b9a8df 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -530,6 +530,8 @@ static void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
 
 void btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info)
 {
+	btrfs_reset_fs_info_ptr(fs_info);
+
 	if (fs_info->space_info_kobj) {
 		sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
 		kobject_del(fs_info->space_info_kobj);
@@ -729,6 +731,8 @@ int btrfs_sysfs_add_one(struct btrfs_fs_info *fs_info)
 	struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
 	struct kobject *super_kobj = &fs_devs->super_kobj;
 
+	btrfs_set_fs_info_ptr(fs_info);
+
 	error = btrfs_sysfs_add_fsid(fs_devs, NULL);
 	if (error)
 		return error;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e500bfa..5719470 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6733,3 +6733,21 @@ void btrfs_update_commit_device_bytes_used(struct btrfs_root *root,
 	}
 	unlock_chunks(root);
 }
+
+void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+	while (fs_devices) {
+		fs_devices->fs_info = fs_info;
+		fs_devices = fs_devices->seed;
+	}
+}
+
+void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+	while (fs_devices) {
+		fs_devices->fs_info = NULL;
+		fs_devices = fs_devices->seed;
+	}
+}
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index ac7e938..210a643 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -254,6 +254,7 @@ struct btrfs_fs_devices {
 	 */
 	int rotating;
 
+	struct btrfs_fs_info *fs_info;
 	/* sysfs kobjects */
 	struct kobject super_kobj;
 	struct kobject *device_dir_kobj;
@@ -543,5 +544,7 @@ static inline void unlock_chunks(struct btrfs_root *root)
 }
 
 struct list_head *btrfs_get_fs_uuids(void);
+void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info);
+void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info);
 
 #endif
-- 
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