Btrfs: Fix logic to avoid reading checksums for -o nodatasum,compress

When compression was on, we were improperly ignoring -o nodatasum.  This
reworks the logic a bit to properly honor all the flags.

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

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 6739424..dd9cd01 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -833,28 +833,29 @@ int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 {
        struct btrfs_root *root = BTRFS_I(inode)->root;
        int ret = 0;
+       int skip_sum;
 
        ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
        BUG_ON(ret);
 
-       if (btrfs_test_opt(root, NODATASUM) ||
-           btrfs_test_flag(inode, NODATASUM)) {
-               goto mapit;
-       }
+       skip_sum = btrfs_test_opt(root, NODATASUM) ||
+               btrfs_test_flag(inode, NODATASUM);
 
        if (!(rw & (1 << BIO_RW))) {
-               btrfs_lookup_bio_sums(root, inode, bio);
+               if (!skip_sum)
+                       btrfs_lookup_bio_sums(root, inode, bio);
 
-               if (bio_flags & EXTENT_BIO_COMPRESSED) {
+               if (bio_flags & EXTENT_BIO_COMPRESSED)
                        return btrfs_submit_compressed_read(inode, bio,
                                                    mirror_num, bio_flags);
-               }
-
                goto mapit;
-       }
-       return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
+       } else if (!skip_sum) {
+               /* we're doing a write, do the async checksumming */
+               return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
                                   inode, rw, bio, mirror_num,
                                   bio_flags, __btrfs_submit_bio_hook);
+       }
+
 mapit:
        return btrfs_map_bio(root, rw, bio, mirror_num, 0);
 }