1 files changed, 64 insertions, 0 deletions
diff --git a/fs/9p/fid.h b/fs/9p/fid.h
new file mode 100644
index 0000000000..29281b7c38
--- /dev/null
+++ b/fs/9p/fid.h
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * V9FS FID Management
+ *
+ *  Copyright (C) 2005 by Eric Van Hensbergen <ericvh@gmail.com>
+ */
+#ifndef FS_9P_FID_H
+#define FS_9P_FID_H
+#include <linux/list.h>
+#include "v9fs.h"
+
+struct p9_fid *v9fs_fid_find_inode(struct inode *inode, bool want_writeable,
+	kuid_t uid, bool any);
+struct p9_fid *v9fs_fid_lookup(struct dentry *dentry);
+static inline struct p9_fid *v9fs_parent_fid(struct dentry *dentry)
+{
+	return v9fs_fid_lookup(dentry->d_parent);
+}
+void v9fs_fid_add(struct dentry *dentry, struct p9_fid **fid);
+void v9fs_open_fid_add(struct inode *inode, struct p9_fid **fid);
+static inline struct p9_fid *clone_fid(struct p9_fid *fid)
+{
+	return IS_ERR(fid) ? fid :  p9_client_walk(fid, 0, NULL, 1);
+}
+static inline struct p9_fid *v9fs_fid_clone(struct dentry *dentry)
+{
+	struct p9_fid *fid, *nfid;
+
+	fid = v9fs_fid_lookup(dentry);
+	if (!fid || IS_ERR(fid))
+		return fid;
+
+	nfid = clone_fid(fid);
+	p9_fid_put(fid);
+	return nfid;
+}
+/**
+ * v9fs_fid_addmodes - add cache flags to fid mode (for client use only)
+ * @fid: fid to augment
+ * @s_flags: session info mount flags
+ * @s_cache: session info cache flags
+ * @f_flags: unix open flags
+ *
+ * make sure mode reflects flags of underlying mounts
+ * also qid.version == 0 reflects a synthetic or legacy file system
+ * NOTE: these are set after open so only reflect 9p client not
+ * underlying file system on server.
+ */
+static inline void v9fs_fid_add_modes(struct p9_fid *fid, unsigned int s_flags,
+	unsigned int s_cache, unsigned int f_flags)
+{
+	if (fid->qid.type != P9_QTFILE)
+		return;
+
+	if ((!s_cache) ||
+	   ((fid->qid.version == 0) && !(s_flags & V9FS_IGNORE_QV)) ||
+	   (s_flags & V9FS_DIRECT_IO) || (f_flags & O_DIRECT)) {
+		fid->mode |= P9L_DIRECT; /* no read or write cache */
+	} else if ((!(s_cache & CACHE_WRITEBACK)) ||
+				(f_flags & O_DSYNC) || (s_flags & V9FS_SYNC)) {
+		fid->mode |= P9L_NOWRITECACHE;
+	}
+}
+#endif