btrfs-progs: update generation_v2 in btrfs_update_root

This addresses the same issue as did:

2bd1169 btrfs-progs: root_item generation_v2 is out of sync after btrfsck

but rather than optionally updating generation_v2 based
on the size of the existing item, increase the size of the
item as needed, and unconditionally set generation_v2.
This matches the kernel code, and keeping things in sync is a
Good Thing.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
master
Eric Sandeen 2013-04-22 00:16:41 -05:00 committed by David Sterba
parent 3456bf0866
commit 2417dd4cc9
1 changed files with 37 additions and 0 deletions

View File

@ -69,6 +69,7 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
int ret;
int slot;
unsigned long ptr;
u32 old_len;
path = btrfs_alloc_path();
BUG_ON(!path);
@ -79,6 +80,42 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
l = path->nodes[0];
slot = path->slots[0];
ptr = btrfs_item_ptr_offset(l, slot);
old_len = btrfs_item_size_nr(l, slot);
/*
* If this is the first time we update the root item which originated
* from an older kernel, we need to enlarge the item size to make room
* for the added fields.
*/
if (old_len < sizeof(*item)) {
btrfs_release_path(root, path);
ret = btrfs_search_slot(trans, root, key, path,
-1, 1);
if (ret < 0) {
goto out;
}
ret = btrfs_del_item(trans, root, path);
if (ret < 0) {
goto out;
}
btrfs_release_path(root, path);
ret = btrfs_insert_empty_item(trans, root, path,
key, sizeof(*item));
if (ret < 0) {
goto out;
}
l = path->nodes[0];
slot = path->slots[0];
ptr = btrfs_item_ptr_offset(l, slot);
}
/*
* Update generation_v2 so at the next mount we know the new root
* fields are valid.
*/
btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
write_extent_buffer(l, item, ptr, sizeof(*item));
btrfs_mark_buffer_dirty(path->nodes[0]);
out: