Btrfs: deal with read errors on extent buffers differently

Since we need to read and write extent buffers in their entirety we can't use
the normal bio_readpage_error stuff since it only works on a per page basis.  So
instead make it so that if we see an io error in endio we just mark the eb as
having an IO error and then in btree_read_extent_buffer_pages we will manually
try other mirrors and then overwrite the bad mirror if we find a good copy.
This works with larger than page size blocks.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 489d7945154f..38c1af7092f3 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -58,6 +58,7 @@
 #define EXTENT_PAGE_PRIVATE_FIRST_PAGE 3
 
 struct extent_state;
+struct btrfs_root;
 
 typedef int (extent_submit_bio_hook_t)(struct inode *inode, int rw,
                                        struct bio *bio, int mirror_num,
@@ -73,9 +74,7 @@ struct extent_io_ops {
                               size_t size, struct bio *bio,
                               unsigned long bio_flags);
         int (*readpage_io_hook)(struct page *page, u64 start, u64 end);
-        int (*readpage_io_failed_hook)(struct bio *bio, struct page *page,
-                                       u64 start, u64 end, int failed_mirror,
-                                       struct extent_state *state);
+        int (*readpage_io_failed_hook)(struct page *page, int failed_mirror);
         int (*writepage_io_failed_hook)(struct bio *bio, struct page *page,
                                         u64 start, u64 end,
                                        struct extent_state *state);
@@ -136,6 +135,7 @@ struct extent_buffer {
         spinlock_t refs_lock;
         atomic_t refs;
         atomic_t io_pages;
+        int failed_mirror;
         struct list_head leak_list;
         struct rcu_head rcu_head;
         pid_t lock_owner;
@@ -327,4 +327,6 @@ int repair_io_failure(struct btrfs_mapping_tree *map_tree, u64 start,
                         u64 length, u64 logical, struct page *page,
                         int mirror_num);
 int end_extent_writepage(struct page *page, int err, u64 start, u64 end);
+int repair_eb_io_failure(struct btrfs_root *root, struct extent_buffer *eb,
+                         int mirror_num);
 #endif