The fsync prototype change commit 
02c24a82187d accidentally overwrote
the ssize_t return value of xfs_file_aio_write with 0 for SYNC type
writes. Fix this by checking if an error occured when calling
xfs_file_fsync and only change the return value in this case.
In addition xfs_file_fsync actually returns a normal negative error, so
fix this, too.
Signed-off-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
        /* Handle various SYNC-type writes */
        if ((file->f_flags & O_DSYNC) || IS_SYNC(inode)) {
                loff_t end = pos + ret - 1;
+               int error;
 
                xfs_rw_iunlock(ip, iolock);
-               ret = -xfs_file_fsync(file, pos, end,
+               error = xfs_file_fsync(file, pos, end,
                                      (file->f_flags & __O_SYNC) ? 0 : 1);
                xfs_rw_ilock(ip, iolock);
+               if (error)
+                       ret = error;
        }
 
 out_unlock: