Btrfs: Take the csum mutex while reading checksums

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

1 files changed, 5 insertions, 3 deletions

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 45127e4797c8..afe42d00b5a6 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -152,7 +152,7 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
         if (!sums)
                 return -ENOMEM;
 
-        sector_sum = &sums->sums;
+        sector_sum = sums->sums;
         sums->file_offset = page_offset(bvec->bv_page) + bvec->bv_offset;
         sums->len = bio->bi_size;
         INIT_LIST_HEAD(&sums->list);
@@ -174,7 +174,7 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
                         sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
                                        GFP_NOFS);
                         BUG_ON(!sums);
-                        sector_sum = &sums->sums;
+                        sector_sum = sums->sums;
                         sums->len = bytes_left;
                         sums->file_offset = offset;
                         ordered = btrfs_lookup_ordered_extent(inode,
@@ -193,12 +193,14 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
                                  (char *)&sector_sum->sum);
                 sector_sum->offset = page_offset(bvec->bv_page) +
                         bvec->bv_offset;
+
                 sector_sum++;
                 bio_index++;
                 total_bytes += bvec->bv_len;
                 this_sum_bytes += bvec->bv_len;
                 bvec++;
         }
+        this_sum_bytes = 0;
         btrfs_add_ordered_sum(inode, ordered, sums);
         btrfs_put_ordered_extent(ordered);
         return 0;
@@ -231,7 +233,7 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
 
         path = btrfs_alloc_path();
         BUG_ON(!path);
-        sector_sum = &sums->sums;
+        sector_sum = sums->sums;
 again:
         next_offset = (u64)-1;
         found_next = 0;