Update Linux to v5.4.148
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz
Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 9d30acc..043eec6 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -233,6 +233,17 @@
struct extent_map *merge = NULL;
struct rb_node *rb;
+ /*
+ * We can't modify an extent map that is in the tree and that is being
+ * used by another task, as it can cause that other task to see it in
+ * inconsistent state during the merging. We always have 1 reference for
+ * the tree and 1 for this task (which is unpinning the extent map or
+ * clearing the logging flag), so anything > 2 means it's being used by
+ * other tasks too.
+ */
+ if (refcount_read(&em->refs) > 2)
+ return;
+
if (em->start != 0) {
rb = rb_prev(&em->rb_node);
if (rb)