ocfs2: do not fallback to buffer I/O write if appending

Now we can do direct io and do not fallback to buffered IO any more in
case of append O_DIRECT write.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Weiwei Wang <wangww631@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Xuejiufei <xuejiufei@huawei.com>
Cc: alex chen <alex.chen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 2fce3c40ad27..1055a2ece738 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2116,6 +2116,9 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
         struct dentry *dentry = file->f_path.dentry;
         struct inode *inode = dentry->d_inode;
         loff_t saved_pos = 0, end;
+        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+        int full_coherency = !(osb->s_mount_opt &
+                OCFS2_MOUNT_COHERENCY_BUFFERED);
 
         /*
          * We start with a read level meta lock and only jump to an ex
@@ -2204,7 +2207,7 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
                  * one node could wind up truncating another
                  * nodes writes.
                  */
-                if (end > i_size_read(inode)) {
+                if (end > i_size_read(inode) && !full_coherency) {
                         *direct_io = 0;
                         break;
                 }