btrfs: set the lockdep class for log tree extent buffers

commit d3beaa253fd6fa40b8b18a216398e6e5376a9d21 upstream.

These are special extent buffers that get rewound in order to lookup
the state of the tree at a specific point in time.  As such they do not
go through the normal initialization paths that set their lockdep class,
so handle them appropriately when they are created and before they are
locked.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index a989105d39c867b6a743224593dd002cb17f38f1..c05127f506373aa4f8ff1400de398aba55f98ce6 100644 (file)
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1339,6 +1339,8 @@ tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
        btrfs_tree_read_unlock_blocking(eb);
        free_extent_buffer(eb);
 
+       btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb_rewin),
+                                      eb_rewin, btrfs_header_level(eb_rewin));
        btrfs_tree_read_lock(eb_rewin);
        __tree_mod_log_rewind(fs_info, eb_rewin, time_seq, tm);
        WARN_ON(btrfs_header_nritems(eb_rewin) >
@@ -1412,7 +1414,6 @@ get_old_root(struct btrfs_root *root, u64 time_seq)
 
        if (!eb)
                return NULL;
-       btrfs_tree_read_lock(eb);
        if (old_root) {
                btrfs_set_header_bytenr(eb, eb->start);
                btrfs_set_header_backref_rev(eb, BTRFS_MIXED_BACKREF_REV);
@@ -1420,6 +1421,9 @@ get_old_root(struct btrfs_root *root, u64 time_seq)
                btrfs_set_header_level(eb, old_root->level);
                btrfs_set_header_generation(eb, old_generation);
        }
+       btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb), eb,
+                                      btrfs_header_level(eb));
+       btrfs_tree_read_lock(eb);
        if (tm)
                __tree_mod_log_rewind(fs_info, eb, time_seq, tm);
        else