Btrfs: fix wrong reserved space in qgroup during snap/subv creation
There are two problems in the space reservation of the snapshot/
subvolume creation.
- don't reserve the space for the root item insertion
- the space which is reserved in the qgroup is different with
the free space reservation. we need reserve free space for
7 items, but in qgroup reservation, we need reserve space only
for 3 items.
So we implement new metadata reservation functions for the
snapshot/subvolume creation.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 8dcd4ff..56d9254 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -363,7 +363,7 @@
return 0;
}
-static noinline int create_subvol(struct btrfs_root *root,
+static noinline int create_subvol(struct inode *dir,
struct dentry *dentry,
char *name, int namelen,
u64 *async_transid,
@@ -374,32 +374,39 @@
struct btrfs_root_item root_item;
struct btrfs_inode_item *inode_item;
struct extent_buffer *leaf;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_root *new_root;
- struct dentry *parent = dentry->d_parent;
- struct inode *dir;
+ struct btrfs_block_rsv block_rsv;
struct timespec cur_time = CURRENT_TIME;
int ret;
int err;
u64 objectid;
u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
u64 index = 0;
+ u64 qgroup_reserved;
uuid_le new_uuid;
ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
if (ret)
return ret;
- dir = parent->d_inode;
-
+ btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
/*
- * 1 - inode item
- * 2 - refs
- * 1 - root item
- * 2 - dir items
+ * The same as the snapshot creation, please see the comment
+ * of create_snapshot().
*/
- trans = btrfs_start_transaction(root, 6);
- if (IS_ERR(trans))
- return PTR_ERR(trans);
+ ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
+ 7, &qgroup_reserved);
+ if (ret)
+ return ret;
+
+ trans = btrfs_start_transaction(root, 0);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ goto out;
+ }
+ trans->block_rsv = &block_rsv;
+ trans->bytes_reserved = block_rsv.size;
ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid, inherit);
if (ret)
@@ -515,6 +522,8 @@
BUG_ON(ret);
fail:
+ trans->block_rsv = NULL;
+ trans->bytes_reserved = 0;
if (async_transid) {
*async_transid = trans->transid;
err = btrfs_commit_transaction_async(trans, root, 1);
@@ -526,7 +535,8 @@
if (!ret)
d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
-
+out:
+ btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);
return ret;
}
@@ -549,21 +559,31 @@
btrfs_init_block_rsv(&pending_snapshot->block_rsv,
BTRFS_BLOCK_RSV_TEMP);
+ /*
+ * 1 - parent dir inode
+ * 2 - dir entries
+ * 1 - root item
+ * 2 - root ref/backref
+ * 1 - root of snapshot
+ */
+ ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
+ &pending_snapshot->block_rsv, 7,
+ &pending_snapshot->qgroup_reserved);
+ if (ret)
+ goto out;
+
pending_snapshot->dentry = dentry;
pending_snapshot->root = root;
pending_snapshot->readonly = readonly;
pending_snapshot->dir = dir;
pending_snapshot->inherit = inherit;
- trans = btrfs_start_transaction(root->fs_info->extent_root, 6);
+ trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto fail;
}
- ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
- BUG_ON(ret);
-
spin_lock(&root->fs_info->trans_lock);
list_add(&pending_snapshot->list,
&trans->transaction->pending_snapshots);
@@ -600,6 +620,10 @@
d_instantiate(dentry, inode);
ret = 0;
fail:
+ btrfs_subvolume_release_metadata(BTRFS_I(dir)->root,
+ &pending_snapshot->block_rsv,
+ pending_snapshot->qgroup_reserved);
+out:
kfree(pending_snapshot);
return ret;
}
@@ -733,8 +757,8 @@
error = create_snapshot(snap_src, dir, dentry, name, namelen,
async_transid, readonly, inherit);
} else {
- error = create_subvol(BTRFS_I(dir)->root, dentry,
- name, namelen, async_transid, inherit);
+ error = create_subvol(dir, dentry, name, namelen,
+ async_transid, inherit);
}
if (!error)
fsnotify_mkdir(dir, dentry);