exportfs: add fid type

Index: linux-2.6/include/linux/exportfs.h
===================================================================
@@ -7,6 +7,44 @@ struct dentry;
 struct super_block;
 struct vfsmount;
 
+/*
+ * The fileid_type identifies how the file within the filesystem is encoded.
+ * In theory this is freely set and parsed by the filesystem, but we try to
+ * stick to conventions so we can share some generic code and don't confuse
+ * sniffers like ethereal/wireshark.
+ *
+ * The filesystem must not use the value '0' or '0xff'.
+ */
+enum fid_type {
+	/*
+	 * The root, or export point, of the filesystem.
+	 * (Never actually passed down to the filesystem.
+	 */
+	FILEID_ROOT = 0,
+
+	/*
+	 * 32bit inode number, 32 bit generation number.
+	 */
+	FILEID_INO32_GEN = 1,
+
+	/*
+	 * 32bit inode number, 32 bit generation number,
+	 * 32 bit parent directory inode number.
+	 */
+	FILEID_INO32_GEN_PARENT = 2,
+};
+
+struct fid {
+	union {
+		struct {
+			u32 ino;
+			u32 gen;
+			u32 parent_ino;
+			u32 parent_gen;
+		} i32;
+		__u32 raw[6];
+	};
+};
 
 /**
  * struct export_operations - for nfsd to communicate with file systems

@@ -117,9 +155,9 @@ extern struct dentry *find_exported_dent
 	void *parent, int (*acceptable)(void *context, struct dentry *de),
 	void *context);
 
-extern int exportfs_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len,
-	int connectable);
-extern struct dentry *exportfs_decode_fh(struct vfsmount *mnt, __u32 *fh,
+extern int exportfs_encode_fh(struct dentry *dentry, struct fid *fid,
+	int *max_len, int connectable);
+extern struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
 	int fh_len, int fileid_type, int (*acceptable)(void *, struct dentry *),
 	void *context);
 

126 lines not on this page · raw message

Index: linux-2.6/fs/exportfs/expfs.c
===================================================================
@@ -434,29 +434,29 @@ out:
  * can be used to check that it is still valid.  It places them in the
  * filehandle fragment where export_decode_fh expects to find them.
  */
-static int export_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len,
-		   int connectable)
+static int export_encode_fh(struct dentry *dentry, struct fid *fid,
+		int *max_len, int connectable)
 {
 	struct inode * inode = dentry->d_inode;
 	int len = *max_len;
-	int type = 1;
+	int type = FILEID_INO32_GEN;
 	
 	if (len < 2 || (connectable && len < 4))
 		return 255;
 
 	len = 2;
-	fh[0] = inode->i_ino;
-	fh[1] = inode->i_generation;
+	fid->i32.ino = inode->i_ino;
+	fid->i32.gen = inode->i_generation;
 	if (connectable && !S_ISDIR(inode->i_mode)) {
 		struct inode *parent;
 
 		spin_lock(&dentry->d_lock);
 		parent = dentry->d_parent->d_inode;
-		fh[2] = parent->i_ino;
-		fh[3] = parent->i_generation;
+		fid->i32.parent_ino = parent->i_ino;
+		fid->i32.parent_gen = parent->i_generation;
 		spin_unlock(&dentry->d_lock);
 		len = 4;
-		type = 2;
+		type = FILEID_INO32_GEN_PARENT;
 	}
 	*max_len = len;
 	return type;

@@ -494,33 +494,33 @@ static struct dentry *export_decode_fh(s
 				   acceptable, context);
 }
 
-int exportfs_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len,
+int exportfs_encode_fh(struct dentry *dentry, struct fid *fid, int *max_len,
 		int connectable)
 {
  	struct export_operations *nop = dentry->d_sb->s_export_op;
 	int error;
 
 	if (nop->encode_fh)
-		error = nop->encode_fh(dentry, fh, max_len, connectable);
+		error = nop->encode_fh(dentry, fid->raw, max_len, connectable);
 	else
-		error = export_encode_fh(dentry, fh, max_len, connectable);
+		error = export_encode_fh(dentry, fid, max_len, connectable);
 
 	return error;
 }
 EXPORT_SYMBOL_GPL(exportfs_encode_fh);
 
-struct dentry *exportfs_decode_fh(struct vfsmount *mnt, __u32 *fh, int fh_len,
-		int fileid_type, int (*acceptable)(void *, struct dentry *),
-		void *context)
+struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
+		int fh_len, int fileid_type,
+		int (*acceptable)(void *, struct dentry *), void *context)
 {
 	struct export_operations *nop = mnt->mnt_sb->s_export_op;
 	struct dentry *result;
 
 	if (nop->decode_fh) {
-		result = nop->decode_fh(mnt->mnt_sb, fh, fh_len, fileid_type,
+		result = nop->decode_fh(mnt->mnt_sb, fid->raw, fh_len, fileid_type,
 			acceptable, context);
 	} else {
-		result = export_decode_fh(mnt->mnt_sb, fh, fh_len, fileid_type,
+		result = export_decode_fh(mnt->mnt_sb, fid->raw, fh_len, fileid_type,
 			acceptable, context);
 	}