Many, many thanks to Masanori OZAWA <ozawa@ongs.co.jp>

and Daichi GOTO <daichi@FreeBSD.org> for submitting this
major rewrite of unionfs.  This rewrite was done to
try to solve many of the longstanding crashing and locking
issues in the existing unionfs implementation.  This
implementation also adds a 'MASQUERADE mode', which allows
the user to set different user, group, and file permission
modes in the upper layer.

Submitted by:	daichi, Masanori OZAWA
Reviewed by:	rodrigc (modified for minor style issues)

1 files changed, 87 insertions, 92 deletions

diff --git a/sys/fs/unionfs/union.h b/sys/fs/unionfs/union.h
index 757e242..f35e1bb 100644
--- a/sys/fs/unionfs/union.h
+++ b/sys/fs/unionfs/union.h
@@ -1,6 +1,8 @@
 /*-
  * Copyright (c) 1994 The Regents of the University of California.
  * Copyright (c) 1994 Jan-Simon Pendry.
+ * Copyright (c) 2005, 2006 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc.
+ * Copyright (c) 2006 Daichi Goto <daichi@freebsd.org>
  * All rights reserved.
  *
  * This code is derived from software donated to Berkeley by
@@ -34,107 +36,100 @@
  * $FreeBSD$
  */
 
-#define UNMNT_ABOVE	0x0001		/* Target appears above mount point */
-#define UNMNT_BELOW	0x0002		/* Target appears below mount point */
-#define UNMNT_REPLACE	0x0003		/* Target replaces mount point */
+#ifdef _KERNEL
 
-struct union_mount {
-	struct vnode	*um_uppervp;	/* UN_ULOCK holds locking state */
-	struct vnode	*um_lowervp;	/* Left unlocked */
-	struct ucred	*um_cred;	/* Credentials of user calling mount */
-	int		um_cmode;	/* cmask from mount process */
-	int		um_op;		/* Operation mode */
-	dev_t		um_upperdev;	/* Upper root node fsid[0]*/
+/* copy method of attr from lower to upper */
+typedef enum _unionfs_copymode {
+	UNIONFS_TRADITIONAL = 0,
+	UNIONFS_TRANSPARENT,
+	UNIONFS_MASQUERADE
+} unionfs_copymode;
+
+struct unionfs_mount {
+	struct vnode   *um_lowervp;	/* VREFed once */
+	struct vnode   *um_uppervp;	/* VREFed once */
+	struct vnode   *um_rootvp;	/* ROOT vnode */
+	unionfs_copymode um_copymode;
+	uid_t		um_uid;
+	gid_t		um_gid;
+	u_short		um_udir;
+	u_short		um_ufile;
 };
 
-#ifdef _KERNEL
+/* unionfs status list */
+struct unionfs_node_status {
+	LIST_ENTRY(unionfs_node_status) uns_list;	/* Status list */
+	lwpid_t		uns_tid;		/* current thread id */
+	int		uns_node_flag;		/* uns flag */
+	int		uns_lower_opencnt;	/* open count of lower */
+	int		uns_upper_opencnt;	/* open count of upper */
+	int		uns_lower_openmode;	/* open mode of lower */
+	int		uns_lower_fdidx;	/* open fdidx of lower */
+	int		uns_readdir_status;	/* read status of readdir */
+};
 
-#ifndef DIAGNOSTIC
-#define DIAGNOSTIC
-#endif
+/* union node status flags */
+#define	UNS_OPENL_4_READDIR	0x01	/* open lower layer for readdir */
+
+/* A cache of vnode references */
+struct unionfs_node {
+	LIST_ENTRY(unionfs_node) un_hash;	/* Hash list */
+	struct vnode   *un_lowervp;		/* lower side vnode */
+	struct vnode   *un_uppervp;		/* upper side vnode */
+	struct vnode   *un_dvp;			/* parent unionfs vnode */
+	struct vnode   *un_vnode;		/* Back pointer */
+	LIST_HEAD(, unionfs_node_status) un_unshead;  /* unionfs status head */
+	char           *un_path;		/* path */
+	int		un_flag;		/* unionfs node flag */
+};
 
-/*
- * DEFDIRMODE is the mode bits used to create a shadow directory.
- */
-#define VRWXMODE (VREAD|VWRITE|VEXEC)
-#define VRWMODE (VREAD|VWRITE)
-#define UN_DIRMODE ((VRWXMODE)|(VRWXMODE>>3)|(VRWXMODE>>6))
-#define UN_FILEMODE ((VRWMODE)|(VRWMODE>>3)|(VRWMODE>>6))
+/* unionfs node flags */
+#define UNIONFS_CACHED		0x01	/* is cached */
+#define UNIONFS_OPENEXTL	0x02	/* openextattr (lower) */
+#define UNIONFS_OPENEXTU	0x04	/* openextattr (upper) */
+
+#define	MOUNTTOUNIONFSMOUNT(mp) ((struct unionfs_mount *)((mp)->mnt_data))
+#define	VTOUNIONFS(vp) ((struct unionfs_node *)(vp)->v_data)
+#define	UNIONFSTOV(xp) ((xp)->un_vnode)
+
+int unionfs_init(struct vfsconf *vfsp);
+int unionfs_uninit(struct vfsconf *vfsp);
+int unionfs_nodeget(struct mount *mp, struct vnode *uppervp, struct vnode *lowervp, struct vnode *dvp, struct vnode **vpp, struct componentname *cnp, struct thread *td);
+void unionfs_hashrem(struct vnode *vp, struct thread *td);
+void unionfs_get_node_status(struct unionfs_node *unp, struct thread *td, struct unionfs_node_status **unspp);
+void unionfs_tryrem_node_status(struct unionfs_node *unp, struct thread *td, struct unionfs_node_status *unsp);
+
+int unionfs_check_rmdir(struct vnode *vp, struct ucred *cred, struct thread *td);
+int unionfs_copyfile(struct unionfs_node *unp, int docopy, struct ucred *cred, struct thread *td);
+void unionfs_create_uppervattr_core(struct unionfs_mount *ump, struct vattr *lva, struct vattr *uva, struct thread *td);
+int unionfs_create_uppervattr(struct unionfs_mount *ump, struct vnode *lvp, struct vattr *uva, struct ucred *cred, struct thread *td);
+int unionfs_mkshadowdir(struct unionfs_mount *ump, struct vnode *duvp, struct unionfs_node *unp, struct componentname *cnp, struct thread *td);
+int unionfs_mkwhiteout(struct vnode *dvp, struct componentname *cnp, struct thread *td, char *path);
+int unionfs_relookup_for_create(struct vnode *dvp, struct componentname *cnp, struct thread *td);
+int unionfs_relookup_for_delete(struct vnode *dvp, struct componentname *cnp, struct thread *td);
+int unionfs_relookup_for_rename(struct vnode *dvp, struct componentname *cnp, struct thread *td);
 
-/*
- * A cache of vnode references	(hangs off v_data)
- */
-struct union_node {
-	LIST_ENTRY(union_node)	un_cache;	/* Hash chain */
-	struct vnode		*un_vnode;	/* Back pointer */
-	struct vnode	        *un_uppervp;	/* overlaying object */
-	struct vnode	        *un_lowervp;	/* underlying object */
-	struct vnode		*un_dirvp;	/* Parent dir of uppervp */
-	struct vnode		*un_pvp;	/* Parent vnode */
-	char			*un_path;	/* saved component name */
-	int			un_openl;	/* # of opens on lowervp */
-	int			un_exclcnt;	/* exclusive count */
-	unsigned int		un_flags;
-	struct vnode		**un_dircache;	/* cached union stack */
-	off_t			un_uppersz;	/* size of upper object */
-	off_t			un_lowersz;	/* size of lower object */
 #ifdef DIAGNOSTIC
-	pid_t			un_pid;
+struct vnode   *unionfs_checklowervp(struct vnode *vp, char *fil, int lno);
+struct vnode   *unionfs_checkuppervp(struct vnode *vp, char *fil, int lno);
+#define	UNIONFSVPTOLOWERVP(vp) unionfs_checklowervp((vp), __FILE__, __LINE__)
+#define	UNIONFSVPTOUPPERVP(vp) unionfs_checkuppervp((vp), __FILE__, __LINE__)
+#else
+#define	UNIONFSVPTOLOWERVP(vp) (VTOUNIONFS(vp)->un_lowervp)
+#define	UNIONFSVPTOUPPERVP(vp) (VTOUNIONFS(vp)->un_uppervp)
 #endif
-};
-
-/*
- * XXX UN_ULOCK -	indicates that the uppervp is locked
- *
- * UN_CACHED -	node is in the union cache
- */
-
-/*#define UN_ULOCK	0x04*/	/* Upper node is locked */
-#define UN_CACHED	0x10	/* In union cache */
-
-/*
- * Hash table locking flags
- */
 
-#define UNVP_WANT	0x01
-#define UNVP_LOCKED	0x02
+extern struct vop_vector unionfs_vnodeops;
 
-extern int union_allocvp(struct vnode **, struct mount *,
-				struct vnode *, 
-				struct vnode *, 
-				struct componentname *, struct vnode *,
-				struct vnode *, int);
-extern int union_freevp(struct vnode *);
-extern struct vnode *union_dircache_get(struct vnode *, struct thread *);
-extern void union_dircache_free(struct union_node *);
-extern int union_copyup(struct union_node *, int, struct ucred *,
-				struct thread *);
-extern int union_dowhiteout(struct union_node *, struct ucred *,
-					struct thread *);
-extern int union_mkshadow(struct union_mount *, struct vnode *,
-				struct componentname *, struct vnode **);
-extern int union_mkwhiteout(struct union_mount *, struct vnode *,
-				struct componentname *, char *);
-extern int union_cn_close(struct vnode *, int, struct ucred *,
-				struct thread *);
-extern void union_removed_upper(struct union_node *un);
-extern struct vnode *union_lowervp(struct vnode *);
-extern void union_newsize(struct vnode *, off_t, off_t);
-
-extern int (*union_dircheckp)(struct thread *, struct vnode **,
-				 struct file *);
-
-#define	MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data))
-#define	VTOUNION(vp) ((struct union_node *)(vp)->v_data)
-#define	UNIONTOV(un) ((un)->un_vnode)
-#define	LOWERVP(vp) (VTOUNION(vp)->un_lowervp)
-#define	UPPERVP(vp) (VTOUNION(vp)->un_uppervp)
-#define OTHERVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : LOWERVP(vp))
-
-#define UDEBUG(x)	if (uniondebug) printf x
-#define UDEBUG_ENABLED	1
+#ifdef MALLOC_DECLARE
+MALLOC_DECLARE(M_UNIONFSNODE);
+MALLOC_DECLARE(M_UNIONFSPATH);
+#endif
 
-extern struct vop_vector union_vnodeops;
-extern int uniondebug;
+#ifdef UNIONFS_DEBUG
+#define UNIONFSDEBUG(format, args...) printf(format ,## args)
+#else
+#define UNIONFSDEBUG(format, args...)
+#endif				/* UNIONFS_DEBUG */
 
-#endif /* _KERNEL */
+#endif				/* _KERNEL */