Btrfs: Make sure bio pages are adjacent during bulk csumming

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

1 files changed, 4 insertions, 2 deletions

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index ee25e50e7c04..e17cce33fe95 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -161,7 +161,6 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
         unsigned long map_len;
         unsigned long map_start;
 
-
         path = btrfs_alloc_path();
         BUG_ON(!path);
 again:
@@ -315,8 +314,11 @@ next_bvec:
         if (bio_index < bio->bi_vcnt) {
                 item = (struct btrfs_csum_item *)((char *)item +
                                                   BTRFS_CRC32_SIZE);
-                if (item < item_end)
+                if (item < item_end && offset + PAGE_CACHE_SIZE ==
+                    page_offset(bvec->bv_page)) {
+                        offset = page_offset(bvec->bv_page);
                         goto next_bvec;
+                }
         }
         if (eb_token) {
                 unmap_extent_buffer(leaf, eb_token, KM_IRQ1);