Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  [net/9p]: Introduce basic flow-control for VirtIO transport.
  9p: use the updated offset given by generic_write_checks
  [net/9p] Don't re-pin pages on retrying virtqueue_add_buf().
  [net/9p] Set the condition just before waking up.
  [net/9p] unconditional wake_up to proc waiting for space on VirtIO ring
  fs/9p: Add v9fs_dentry2v9ses
  fs/9p: Attach writeback_fid on first open with WR flag
  fs/9p: Open writeback fid in O_SYNC mode
  fs/9p: Use truncate_setsize instead of vmtruncate
  net/9p: Fix compile warning
  net/9p: Convert the in the 9p rpc call path to GFP_NOFS
  fs/9p: Fix race in initializing writeback fid

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);