Btrfs: Fix infinite loop in btrfs_extent_post_op
btrfs_extent_post_op calls finish_current_insert and del_pending_extents. They
both may enter infinite loops.
finish_current_insert enters infinite loop if it only finds some backrefs to
update. The fix is to check for pending backref updates before restarting the
loop.
The infinite loop in del_pending_extents is due to a the skipped variable
not being properly reset before looping around.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 3bed6a7..aeaec84 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2156,7 +2156,8 @@
ret = find_first_extent_bit(&info->extent_ins, search, &start,
&end, EXTENT_WRITEBACK);
if (ret) {
- if (skipped && all && !num_inserts) {
+ if (skipped && all && !num_inserts &&
+ list_empty(&update_list)) {
skipped = 0;
search = 0;
continue;
@@ -2544,6 +2545,7 @@
if (ret) {
if (all && skipped && !nr) {
search = 0;
+ skipped = 0;
continue;
}
mutex_unlock(&info->extent_ins_mutex);