Btrfs: Keep extent mappings in ram until pending ordered extents are done
It was possible for stale mappings from disk to be used instead of the
new pending ordered extent. This adds a flag to the extent map struct
to keep it pinned until the pending ordered extent is actually on disk.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 8112327..71b1ac1 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -173,6 +173,9 @@
static int mergable_maps(struct extent_map *prev, struct extent_map *next)
{
+ if (test_bit(EXTENT_FLAG_PINNED, &prev->flags))
+ return 0;
+
if (extent_map_end(prev) == next->start &&
prev->flags == next->flags &&
prev->bdev == next->bdev &&
@@ -320,6 +323,7 @@
{
int ret = 0;
+ WARN_ON(test_bit(EXTENT_FLAG_PINNED, &em->flags));
BUG_ON(spin_trylock(&tree->lock));
rb_erase(&em->rb_node, &tree->map);
em->in_tree = 0;