btrfs: convert the io_failure_tree to a plain rb_tree

We still have this oddity of stashing the io_failure_record in the
extent state for the io_failure_tree, which is leftover from when we
used to stuff private pointers in extent_io_trees.

However this doesn't make a lot of sense for the io failure records, we
can simply use a normal rb_tree for this.  This will allow us to further
simplify the extent_io_tree code by removing the io_failure_rec pointer
from the extent state.

Convert the io_failure_tree to an rb tree + spinlock in the inode, and
then use our rb tree simple helpers to insert and find failed records.
This greatly cleans up this code and makes it easier to separate out the
extent_io_tree code.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 69a86ae6fd50..1c4717669073 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -254,8 +254,12 @@ int btrfs_repair_eb_io_failure(const struct extent_buffer *eb, int mirror_num);
  * bio end_io callback is called to indicate things have failed.
  */
 struct io_failure_record {
+	/* Use rb_simple_node for search/insert */
+	struct {
+		struct rb_node rb_node;
+		u64 bytenr;
+	};
 	struct page *page;
-	u64 start;
 	u64 len;
 	u64 logical;
 	int this_mirror;