Before processing the extent buffer, acquire a read lock on it, so
that we're safe against concurrent updates on the extent buffer.

Signed-off-by: Filipe Manana <fdman...@suse.com>
---
 fs/btrfs/backref.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index e25564b..a1efd39 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1001,8 +1001,11 @@ again:
                                        ret = -EIO;
                                        goto out;
                                }
+                               btrfs_tree_read_lock(eb);
+                               btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
                                ret = find_extent_in_eb(eb, bytenr,
                                                        *extent_item_pos, &eie);
+                               btrfs_tree_read_unlock_blocking(eb);
                                free_extent_buffer(eb);
                                if (ret < 0)
                                        goto out;
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to