Btrfs: Lookup readpage checksums on bio submission again

This optimization had been removed because I thought it was triggering
csum errors.  The real cause of the errors was elsewhere, and so
this optimization is back.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 9454e0a07c89..f861bd506928 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -134,7 +134,6 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
         return ret;
 }
 
-#if 0 /* broken */
 int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
                           struct bio *bio)
 {
@@ -151,6 +150,8 @@ int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 
         path = btrfs_alloc_path();
+        if (bio->bi_size > PAGE_CACHE_SIZE * 8)
+                path->reada = 2;
 
         WARN_ON(bio->bi_vcnt <= 0);
 
@@ -211,7 +212,6 @@ found:
         btrfs_free_path(path);
         return 0;
 }
-#endif
 
 int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
                        struct bio *bio)