btrfs_lookup_fs_root() only finds subvol roots which have already been seen and put into the cache. For btrfs_get_dentry() we actually have to go to the medium -- so use btrfs_read_fs_root_no_name() instead. In btrfs_get_parent(), notice when we've hit the root of the subvolume and return the real root instead. Signed-off-by: David Woodhouse <David.Woodhouse@xxxxxxxxx> --- Is the offset of (u64)-1 in btrfs_read_fs_root_no_name() correct? And can we have subroots (with ino == parent ino) elsewhere, or only as direct children of sb->s_root? export.c | 13 ++++++++++++- 1 files changed, 12 insertions(+), 1 deletions(-) diff --git a/export.c b/export.c index a913b9b..36cbc68 100644 --- a/export.c +++ b/export.c @@ -71,11 +71,18 @@ static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid, struct dentry *result; struct btrfs_key key; + key.objectid = root_objectid; + btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); + key.offset = (u64)-1; + + root = btrfs_read_fs_root_no_name(btrfs_sb(sb)->fs_info, &key); + if (IS_ERR(root)) + return ERR_CAST(root); + key.objectid = objectid; btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); key.offset = 0; - root = btrfs_lookup_fs_root(btrfs_sb(sb)->fs_info, root_objectid); inode = btrfs_iget(sb, &key, root, NULL); if (IS_ERR(inode)) return (void *)inode; @@ -178,6 +185,10 @@ static struct dentry *btrfs_get_parent(struct dentry *child) objectid = key.offset; + /* If we are already at the root of a subvol, return the real root */ + if (objectid == dir->i_ino) + return dget(dir->i_sb->s_root); + /* Build a new key for the inode item */ key.objectid = objectid; btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); -- 1.5.5.1 -- David Woodhouse Open Source Technology Centre David.Woodhouse@xxxxxxxxx Intel Corporation -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
