[PATCH 06/11] btrfs-progs: track changing_fsid flag in fs_devices

[Anand Jain <anand.jain@oracle.com>]

To prepare for reuniting separated devices due to an incomplete
fsid change task, consolidate and monitor the per device's
changing_fsid flag in the struct btrfs_fs_devices.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 kernel-shared/volumes.c | 9 +++++++++
 kernel-shared/volumes.h | 2 ++
 tune/change-uuid.c      | 4 +---
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/kernel-shared/volumes.c b/kernel-shared/volumes.c
index 4a8c559d4b20..51b3a16a39af 100644
--- a/kernel-shared/volumes.c
+++ b/kernel-shared/volumes.c
@@ -342,6 +342,9 @@ static int device_list_add(const char *path,
 	u64 devid = btrfs_stack_device_id(&disk_super->dev_item);
 	bool metadata_uuid = (btrfs_super_incompat_flags(disk_super) &
 		BTRFS_FEATURE_INCOMPAT_METADATA_UUID);
+	bool changing_fsid = (btrfs_super_flags(disk_super) &
+			      (BTRFS_SUPER_FLAG_CHANGING_FSID |
+			       BTRFS_SUPER_FLAG_CHANGING_FSID_V2));
 
 	if (metadata_uuid)
 		fs_devices = find_fsid(disk_super->fsid,
@@ -424,6 +427,12 @@ static int device_list_add(const char *path,
                 device->name = name;
         }
 
+	/*
+	 * If changing_fsid the fs_devices will still hold the status from
+	 * the other devices.
+	 */
+	if (changing_fsid)
+		fs_devices->changing_fsid = true;
 
 	if (found_transid > fs_devices->latest_trans) {
 		fs_devices->latest_devid = devid;
diff --git a/kernel-shared/volumes.h b/kernel-shared/volumes.h
index d2915681e6de..9763c677a7cc 100644
--- a/kernel-shared/volumes.h
+++ b/kernel-shared/volumes.h
@@ -99,6 +99,8 @@ struct btrfs_fs_devices {
 	struct btrfs_fs_devices *seed;
 
 	enum btrfs_chunk_allocation_policy chunk_alloc_policy;
+
+	bool changing_fsid;
 };
 
 struct btrfs_bio_stripe {
diff --git a/tune/change-uuid.c b/tune/change-uuid.c
index cbfc8634168b..30cfb145459f 100644
--- a/tune/change-uuid.c
+++ b/tune/change-uuid.c
@@ -214,10 +214,8 @@ int check_unfinished_fsid_change(struct btrfs_fs_info *fs_info,
 				 uuid_t fsid_ret, uuid_t chunk_id_ret)
 {
 	struct btrfs_root *tree_root = fs_info->tree_root;
-	u64 flags = btrfs_super_flags(fs_info->super_copy);
 
-	if (flags & (BTRFS_SUPER_FLAG_CHANGING_FSID |
-		     BTRFS_SUPER_FLAG_CHANGING_FSID_V2)) {
+	if (fs_info->fs_devices->changing_fsid) {
 		memcpy(fsid_ret, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
 		read_extent_buffer(tree_root->node, chunk_id_ret,
 				btrfs_header_chunk_tree_uuid(tree_root->node),
-- 
2.39.3