Btrfs: fix extent buffer reference for tree mod log roots
authorJan Schmidt <list.btrfs@jan-o-sch.net>
Tue, 23 Oct 2012 12:21:05 +0000 (14:21 +0200)
committerJan Schmidt <list.btrfs@jan-o-sch.net>
Wed, 24 Oct 2012 10:36:39 +0000 (12:36 +0200)
In get_old_root we grab a lock on the extent buffer before we obtain a
reference on that buffer. That order is changed now.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
fs/btrfs/ctree.c

index ef68c33eefd9caaac2f9d2cff353d915081c1b6e..f6739903d072273246c499b6935b91867272374d 100644 (file)
@@ -1279,6 +1279,7 @@ get_old_root(struct btrfs_root *root, u64 time_seq)
 
        if (!eb)
                return NULL;
+       extent_buffer_get(eb);
        btrfs_tree_read_lock(eb);
        if (old_root) {
                btrfs_set_header_bytenr(eb, eb->start);
@@ -1291,7 +1292,6 @@ get_old_root(struct btrfs_root *root, u64 time_seq)
                __tree_mod_log_rewind(eb, time_seq, tm);
        else
                WARN_ON(btrfs_header_level(eb) != 0);
-       extent_buffer_get(eb);
        WARN_ON(btrfs_header_nritems(eb) > BTRFS_NODEPTRS_PER_BLOCK(root));
 
        return eb;