1 files changed, 15 insertions, 4 deletions

diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index cd63e002d826..0ee594569dcc 100644
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -134,7 +134,7 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry,
         struct v9fs_session_info *v9ses;
         struct p9_fid *fid, *old_fid = NULL;
 
-        v9ses = v9fs_inode2v9ses(dentry->d_inode);
+        v9ses = v9fs_dentry2v9ses(dentry);
         access = v9ses->flags & V9FS_ACCESS_MASK;
         fid = v9fs_fid_find(dentry, uid, any);
         if (fid)
@@ -237,7 +237,7 @@ struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
         int  any, access;
         struct v9fs_session_info *v9ses;
 
-        v9ses = v9fs_inode2v9ses(dentry->d_inode);
+        v9ses = v9fs_dentry2v9ses(dentry);
         access = v9ses->flags & V9FS_ACCESS_MASK;
         switch (access) {
         case V9FS_ACCESS_SINGLE:
@@ -286,9 +286,11 @@ static struct p9_fid *v9fs_fid_clone_with_uid(struct dentry *dentry, uid_t uid)
 
 struct p9_fid *v9fs_writeback_fid(struct dentry *dentry)
 {
-        int err;
+        int err, flags;
         struct p9_fid *fid;
+        struct v9fs_session_info *v9ses;
 
+        v9ses = v9fs_dentry2v9ses(dentry);
         fid = v9fs_fid_clone_with_uid(dentry, 0);
         if (IS_ERR(fid))
                 goto error_out;
@@ -297,8 +299,17 @@ struct p9_fid *v9fs_writeback_fid(struct dentry *dentry)
          * dirty pages. We always request for the open fid in read-write
          * mode so that a partial page write which result in page
          * read can work.
+         *
+         * we don't have a tsyncfs operation for older version
+         * of protocol. So make sure the write back fid is
+         * opened in O_SYNC mode.
          */
-        err = p9_client_open(fid, O_RDWR);
+        if (!v9fs_proto_dotl(v9ses))
+                flags = O_RDWR | O_SYNC;
+        else
+                flags = O_RDWR;
+
+        err = p9_client_open(fid, flags);
         if (err < 0) {
                 p9_client_clunk(fid);
                 fid = ERR_PTR(err);