Currently, the top-level subvolume lacks the UUID. As a result, both
non-snapshot subvolume and snapshot of top-level subvolume do not have
Parent UUID and cannot be distinguisued. Therefore "fi show" of
top-level lists all the subvolumes which lacks the UUID in
"Snapshot(s)". Also, it lacks the otime information.
Fix this by adding the UUID and otime at the mkfs time. As a
consequence, snapshots of top-level subvolume now have a Parent UUID and
UUID tree will create an entry for top-level subvolume at mount time.
Signed-off-by: Tomohiro Misono <misono.tomohiro@xxxxxxxxxxxxxx>
---
ctree.h | 5 +++++
mkfs/common.c | 14 ++++++++++++++
mkfs/main.c | 3 +++
3 files changed, 22 insertions(+)
diff --git a/ctree.h b/ctree.h
index 2280659..5737978 100644
--- a/ctree.h
+++ b/ctree.h
@@ -2071,6 +2071,11 @@ BTRFS_SETGET_STACK_FUNCS(root_stransid, struct btrfs_root_item,
stransid, 64);
BTRFS_SETGET_STACK_FUNCS(root_rtransid, struct btrfs_root_item,
rtransid, 64);
+static inline void btrfs_set_root_uuid(struct btrfs_root_item *root_item,
+ u8 uuid[BTRFS_UUID_SIZE])
+{
+ memcpy(root_item->uuid, uuid, BTRFS_UUID_SIZE);
+}
/* struct btrfs_root_backup */
BTRFS_SETGET_STACK_FUNCS(backup_tree_root, struct btrfs_root_backup,
diff --git a/mkfs/common.c b/mkfs/common.c
index c9ce10d..808d343 100644
--- a/mkfs/common.c
+++ b/mkfs/common.c
@@ -44,6 +44,7 @@ static int btrfs_create_tree_root(int fd, struct btrfs_mkfs_config *cfg,
u32 itemoff;
int ret = 0;
int blk;
+ u8 uuid[BTRFS_UUID_SIZE];
memset(buf->data + sizeof(struct btrfs_header), 0,
cfg->nodesize - sizeof(struct btrfs_header));
@@ -77,6 +78,19 @@ static int btrfs_create_tree_root(int fd, struct btrfs_mkfs_config *cfg,
btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(nritems),
sizeof(root_item));
+ if (blk == MKFS_FS_TREE) {
+ time_t now = time(NULL);
+
+ uuid_generate(uuid);
+ btrfs_set_root_uuid(&root_item, uuid);
+ btrfs_set_stack_timespec_sec(&root_item.otime, now);
+ btrfs_set_stack_timespec_sec(&root_item.ctime, now);
+ } else {
+ memset(uuid, 0, BTRFS_UUID_SIZE);
+ btrfs_set_root_uuid(&root_item, uuid);
+ btrfs_set_stack_timespec_sec(&root_item.otime, 0);
+ btrfs_set_stack_timespec_sec(&root_item.ctime, 0);
+ }
write_extent_buffer(buf, &root_item,
btrfs_item_ptr_offset(buf, nritems),
sizeof(root_item));
diff --git a/mkfs/main.c b/mkfs/main.c
index 1b4cabc..4184a2d 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -329,6 +329,7 @@ static int create_tree(struct btrfs_trans_handle *trans,
struct btrfs_key location;
struct btrfs_root_item root_item;
struct extent_buffer *tmp;
+ u8 uuid[BTRFS_UUID_SIZE] = {0};
int ret;
ret = btrfs_copy_root(trans, root, root->node, &tmp, objectid);
@@ -339,6 +340,8 @@ static int create_tree(struct btrfs_trans_handle *trans,
btrfs_set_root_bytenr(&root_item, tmp->start);
btrfs_set_root_level(&root_item, btrfs_header_level(tmp));
btrfs_set_root_generation(&root_item, trans->transid);
+ /* clear uuid of source tree */
+ btrfs_set_root_uuid(&root_item, uuid);
free_extent_buffer(tmp);
location.objectid = objectid;
--
2.9.5
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