Btrfs: Add data=ordered support

This forces file data extents down the disk along with the metadata that
references them.  The current implementation is fairly simple, and just
writes out all of the dirty pages in an inode before the commit.

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

1 files changed, 5 insertions, 1 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 35c57074a376..43d23148a4fe 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -221,7 +221,9 @@ int btrfs_cow_block(struct btrfs_trans_handle *trans,
                     struct extent_buffer **cow_ret)
 {
         u64 search_start;
+        u64 header_trans;
         int ret;
+
         if (trans->transaction != root->fs_info->running_transaction) {
                 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
                        root->fs_info->running_transaction->transid);
@@ -232,7 +234,9 @@ int btrfs_cow_block(struct btrfs_trans_handle *trans,
                        root->fs_info->generation);
                 WARN_ON(1);
         }
-        if (btrfs_header_generation(buf) == trans->transid) {
+
+        header_trans = btrfs_header_generation(buf);
+        if (header_trans == trans->transid) {
                 *cow_ret = buf;
                 return 0;
         }