Btrfs: inline csums if we're fsyncing

The tree logging stuff needs the csums to be on the ordered extents in order
to log them properly, so mark that we're sync and inline the csum creation
so we don't have to wait on the csumming to be done when logging extents
that are still in flight.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 71c2dc1ea15a..7f4654a15207 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1472,6 +1472,7 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
         ssize_t num_written = 0;
         ssize_t err = 0;
         size_t count, ocount;
+        bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
 
         sb_start_write(inode->i_sb);
 
@@ -1529,6 +1530,9 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
                 }
         }
 
+        if (sync)
+                atomic_inc(&BTRFS_I(inode)->sync_writers);
+
         if (unlikely(file->f_flags & O_DIRECT)) {
                 num_written = __btrfs_direct_write(iocb, iov, nr_segs,
                                                    pos, ppos, count, ocount);
@@ -1563,6 +1567,8 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
                         num_written = err;
         }
 out:
+        if (sync)
+                atomic_dec(&BTRFS_I(inode)->sync_writers);
         sb_end_write(inode->i_sb);
         current->backing_dev_info = NULL;
         return num_written ? num_written : err;
@@ -1613,7 +1619,9 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
          * out of the ->i_mutex. If so, we can flush the dirty pages by
          * multi-task, and make the performance up.
          */
+        atomic_inc(&BTRFS_I(inode)->sync_writers);
         ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
+        atomic_dec(&BTRFS_I(inode)->sync_writers);
         if (ret)
                 return ret;