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.tomoh...@jp.fujitsu.com> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html