Btrfs: Add extra checks to avoid removing extent_state from pages we can't free
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index cf1de75..e22960e2 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -436,6 +436,12 @@
struct extent_map_tree *map;
int ret;
+ if (page_count(page) > 3) {
+ /* once for page->private, once for the caller, once
+ * once for the page cache
+ */
+ return 0;
+ }
tree = &BTRFS_I(page->mapping->host)->io_tree;
map = &BTRFS_I(page->mapping->host)->extent_tree;
ret = try_release_extent_mapping(map, tree, page, gfp_flags);