From: David Woodhouse Date: Tue, 19 Aug 2008 21:20:17 +0000 (+0100) Subject: Btrfs: Fix NFS exporting of subvol roots. X-Git-Tag: firefly_0821_release~15789^2~11^2~55^2~56^2~30^2~33 X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=2d4d9fbd6efa858dfa009518fca1ab85a73fd848;p=firefly-linux-kernel-4.4.55.git Btrfs: Fix NFS exporting of subvol roots. Date: Tue, 19 Aug 2008 22:20:17 +0100 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 Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c index a913b9befe68..36cbc6872fd0 100644 --- a/fs/btrfs/export.c +++ b/fs/btrfs/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);