btrfs: set the lockdep class for log tree extent buffers

[ Upstream commit d3beaa253fd6fa40b8b18a216398e6e5376a9d21 ]

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: Sasha Levin <sashal@kernel.org>

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 406ae49baa076fce12a06d2e6a8f94a1892d5eba..65689cbc362db6e35a35dcfa9c81581cc7d97be2 100644 (file)
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1360,6 +1360,8 @@ 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) >
@@ -1429,7 +1431,6 @@ 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);
@@ -1437,6 +1438,9 @@ 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(root->fs_info, eb, time_seq, tm);
        else