diff options
Diffstat (limited to 'sys/miscfs/union')
| -rw-r--r-- | sys/miscfs/union/union.h | 154 | ||||
| -rw-r--r-- | sys/miscfs/union/union_subr.c | 1360 | ||||
| -rw-r--r-- | sys/miscfs/union/union_vfsops.c | 485 | ||||
| -rw-r--r-- | sys/miscfs/union/union_vnops.c | 1966 |
4 files changed, 0 insertions, 3965 deletions
diff --git a/sys/miscfs/union/union.h b/sys/miscfs/union/union.h deleted file mode 100644 index 63a881c..0000000 --- a/sys/miscfs/union/union.h +++ /dev/null @@ -1,154 +0,0 @@ -/* - * Copyright (c) 1994 The Regents of the University of California. - * Copyright (c) 1994 Jan-Simon Pendry. - * All rights reserved. - * - * This code is derived from software donated to Berkeley by - * Jan-Simon Pendry. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 4. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - * - * @(#)union.h 8.9 (Berkeley) 12/10/94 - * $FreeBSD$ - */ - -struct union_args { - char *target; /* Target of loopback */ - int mntflags; /* Options on the mount */ -}; - -#define UNMNT_ABOVE 0x0001 /* Target appears below mount point */ -#define UNMNT_BELOW 0x0002 /* Target appears below mount point */ -#define UNMNT_REPLACE 0x0003 /* Target replaces mount point */ -#define UNMNT_OPMASK 0x0003 - -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 */ -}; - -#ifdef _KERNEL - -#ifndef DIAGNOSTIC -#define DIAGNOSTIC -#endif - -/* - * 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)) - -/* - * A cache of vnode references (hangs off v_data) - * - * Placing un_lock as the first elements theoretically allows us to - * use the vop_stdlock functions. However, we need to make sure of - * certain side effects so we will still punch in our own code. - */ -struct union_node { - struct lock un_lock; - 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; -#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 int union_allocvp __P((struct vnode **, struct mount *, - struct vnode *, - struct vnode *, - struct componentname *, struct vnode *, - struct vnode *, int)); -extern int union_freevp __P((struct vnode *)); -extern struct vnode *union_dircache __P((struct vnode *, struct proc *)); -extern int union_copyup __P((struct union_node *, int, struct ucred *, - struct proc *)); -extern int union_dowhiteout __P((struct union_node *, struct ucred *, - struct proc *)); -extern int union_mkshadow __P((struct union_mount *, struct vnode *, - struct componentname *, struct vnode **)); -extern int union_mkwhiteout __P((struct union_mount *, struct vnode *, - struct componentname *, char *)); -extern int union_cn_close __P((struct vnode *, int, struct ucred *, - struct proc *)); -extern void union_removed_upper __P((struct union_node *un)); -extern struct vnode *union_lowervp __P((struct vnode *)); -extern void union_newsize __P((struct vnode *, off_t, off_t)); - -extern int (*union_dircheckp) __P((struct proc *, 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 - -extern vop_t **union_vnodeop_p; -extern struct vfsops union_vfsops; -extern int uniondebug; - -#endif /* _KERNEL */ diff --git a/sys/miscfs/union/union_subr.c b/sys/miscfs/union/union_subr.c deleted file mode 100644 index ce38e2d..0000000 --- a/sys/miscfs/union/union_subr.c +++ /dev/null @@ -1,1360 +0,0 @@ -/* - * Copyright (c) 1994 Jan-Simon Pendry - * Copyright (c) 1994 - * The Regents of the University of California. All rights reserved. - * - * This code is derived from software contributed to Berkeley by - * Jan-Simon Pendry. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 4. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - * - * @(#)union_subr.c 8.20 (Berkeley) 5/20/95 - * $FreeBSD$ - */ - -#include <sys/param.h> -#include <sys/systm.h> -#include <sys/fcntl.h> -#include <sys/file.h> -#include <sys/filedesc.h> -#include <sys/kernel.h> -#include <sys/lock.h> -#include <sys/malloc.h> -#include <sys/module.h> -#include <sys/mount.h> -#include <sys/mutex.h> -#include <sys/namei.h> -#include <sys/stat.h> -#include <sys/vnode.h> - -#include <vm/vm.h> -#include <vm/vm_extern.h> /* for vnode_pager_setsize */ -#include <vm/vm_zone.h> -#include <vm/vm_object.h> /* for vm cache coherency */ - -#include <miscfs/union/union.h> - -#include <sys/proc.h> - -extern int union_init __P((void)); - -/* must be power of two, otherwise change UNION_HASH() */ -#define NHASH 32 - -/* unsigned int ... */ -#define UNION_HASH(u, l) \ - (((((uintptr_t) (u)) + ((uintptr_t) l)) >> 8) & (NHASH-1)) - -static LIST_HEAD(unhead, union_node) unhead[NHASH]; -static int unvplock[NHASH]; - -static void union_dircache_r __P((struct vnode *vp, struct vnode ***vppp, - int *cntp)); -static int union_list_lock __P((int ix)); -static void union_list_unlock __P((int ix)); -static int union_relookup __P((struct union_mount *um, struct vnode *dvp, - struct vnode **vpp, - struct componentname *cnp, - struct componentname *cn, char *path, - int pathlen)); -static void union_updatevp __P((struct union_node *un, - struct vnode *uppervp, - struct vnode *lowervp)); -static void union_newlower __P((struct union_node *, struct vnode *)); -static void union_newupper __P((struct union_node *, struct vnode *)); -static int union_copyfile __P((struct vnode *, struct vnode *, - struct ucred *, struct proc *)); -static int union_vn_create __P((struct vnode **, struct union_node *, - struct proc *)); -static int union_vn_close __P((struct vnode *, int, struct ucred *, - struct proc *)); - -int -union_init() -{ - int i; - - for (i = 0; i < NHASH; i++) - LIST_INIT(&unhead[i]); - bzero((caddr_t)unvplock, sizeof(unvplock)); - return (0); -} - -static int -union_list_lock(ix) - int ix; -{ - if (unvplock[ix] & UNVP_LOCKED) { - unvplock[ix] |= UNVP_WANT; - (void) tsleep((caddr_t) &unvplock[ix], PINOD, "unllck", 0); - return (1); - } - unvplock[ix] |= UNVP_LOCKED; - return (0); -} - -static void -union_list_unlock(ix) - int ix; -{ - unvplock[ix] &= ~UNVP_LOCKED; - - if (unvplock[ix] & UNVP_WANT) { - unvplock[ix] &= ~UNVP_WANT; - wakeup((caddr_t) &unvplock[ix]); - } -} - -/* - * union_updatevp: - * - * The uppervp, if not NULL, must be referenced and not locked by us - * The lowervp, if not NULL, must be referenced. - * - * if uppervp and lowervp match pointers already installed, nothing - * happens. The passed vp's (when matching) are not adjusted. This - * routine may only be called by union_newupper() and union_newlower(). - */ - -static void -union_updatevp(un, uppervp, lowervp) - struct union_node *un; - struct vnode *uppervp; - struct vnode *lowervp; -{ - int ohash = UNION_HASH(un->un_uppervp, un->un_lowervp); - int nhash = UNION_HASH(uppervp, lowervp); - int docache = (lowervp != NULLVP || uppervp != NULLVP); - int lhash, uhash; - - /* - * Ensure locking is ordered from lower to higher - * to avoid deadlocks. - */ - if (nhash < ohash) { - lhash = nhash; - uhash = ohash; - } else { - lhash = ohash; - uhash = nhash; - } - - if (lhash != uhash) { - while (union_list_lock(lhash)) - continue; - } - - while (union_list_lock(uhash)) - continue; - - if (ohash != nhash || !docache) { - if (un->un_flags & UN_CACHED) { - un->un_flags &= ~UN_CACHED; - LIST_REMOVE(un, un_cache); - } - } - - if (ohash != nhash) - union_list_unlock(ohash); - - if (un->un_lowervp != lowervp) { - if (un->un_lowervp) { - vrele(un->un_lowervp); - if (un->un_path) { - free(un->un_path, M_TEMP); - un->un_path = 0; - } - } - un->un_lowervp = lowervp; - un->un_lowersz = VNOVAL; - } - - if (un->un_uppervp != uppervp) { - if (un->un_uppervp) - vrele(un->un_uppervp); - un->un_uppervp = uppervp; - un->un_uppersz = VNOVAL; - } - - if (docache && (ohash != nhash)) { - LIST_INSERT_HEAD(&unhead[nhash], un, un_cache); - un->un_flags |= UN_CACHED; - } - - union_list_unlock(nhash); -} - -/* - * Set a new lowervp. The passed lowervp must be referenced and will be - * stored in the vp in a referenced state. - */ - -static void -union_newlower(un, lowervp) - struct union_node *un; - struct vnode *lowervp; -{ - union_updatevp(un, un->un_uppervp, lowervp); -} - -/* - * Set a new uppervp. The passed uppervp must be locked and will be - * stored in the vp in a locked state. The caller should not unlock - * uppervp. - */ - -static void -union_newupper(un, uppervp) - struct union_node *un; - struct vnode *uppervp; -{ - union_updatevp(un, uppervp, un->un_lowervp); -} - -/* - * Keep track of size changes in the underlying vnodes. - * If the size changes, then callback to the vm layer - * giving priority to the upper layer size. - */ -void -union_newsize(vp, uppersz, lowersz) - struct vnode *vp; - off_t uppersz, lowersz; -{ - struct union_node *un; - off_t sz; - - /* only interested in regular files */ - if (vp->v_type != VREG) - return; - - un = VTOUNION(vp); - sz = VNOVAL; - - if ((uppersz != VNOVAL) && (un->un_uppersz != uppersz)) { - un->un_uppersz = uppersz; - if (sz == VNOVAL) - sz = un->un_uppersz; - } - - if ((lowersz != VNOVAL) && (un->un_lowersz != lowersz)) { - un->un_lowersz = lowersz; - if (sz == VNOVAL) - sz = un->un_lowersz; - } - - if (sz != VNOVAL) { - UDEBUG(("union: %s size now %ld\n", - (uppersz != VNOVAL ? "upper" : "lower"), (long)sz)); - /* - * There is no need to change size of non-existent object - */ - /* vnode_pager_setsize(vp, sz); */ - } -} - -/* - * union_allocvp: allocate a union_node and associate it with a - * parent union_node and one or two vnodes. - * - * vpp Holds the returned vnode locked and referenced if no - * error occurs. - * - * mp Holds the mount point. mp may or may not be busied. - * allocvp makes no changes to mp. - * - * dvp Holds the parent union_node to the one we wish to create. - * XXX may only be used to traverse an uncopied lowervp-based - * tree? XXX - * - * dvp may or may not be locked. allocvp makes no changes - * to dvp. - * - * upperdvp Holds the parent vnode to uppervp, generally used along - * with path component information to create a shadow of - * lowervp when uppervp does not exist. - * - * upperdvp is referenced but unlocked on entry, and will be - * dereferenced on return. - * - * uppervp Holds the new uppervp vnode to be stored in the - * union_node we are allocating. uppervp is referenced but - * not locked, and will be dereferenced on return. - * - * lowervp Holds the new lowervp vnode to be stored in the - * union_node we are allocating. lowervp is referenced but - * not locked, and will be dereferenced on return. - * - * cnp Holds path component information to be coupled with - * lowervp and upperdvp to allow unionfs to create an uppervp - * later on. Only used if lowervp is valid. The conents - * of cnp is only valid for the duration of the call. - * - * docache Determine whether this node should be entered in the - * cache or whether it should be destroyed as soon as possible. - * - * all union_nodes are maintained on a singly-linked - * list. new nodes are only allocated when they cannot - * be found on this list. entries on the list are - * removed when the vfs reclaim entry is called. - * - * a single lock is kept for the entire list. this is - * needed because the getnewvnode() function can block - * waiting for a vnode to become free, in which case there - * may be more than one process trying to get the same - * vnode. this lock is only taken if we are going to - * call getnewvnode, since the kernel itself is single-threaded. - * - * if an entry is found on the list, then call vget() to - * take a reference. this is done because there may be - * zero references to it and so it needs to removed from - * the vnode free list. - */ - -int -union_allocvp(vpp, mp, dvp, upperdvp, cnp, uppervp, lowervp, docache) - struct vnode **vpp; - struct mount *mp; - struct vnode *dvp; /* parent union vnode */ - struct vnode *upperdvp; /* parent vnode of uppervp */ - struct componentname *cnp; /* may be null */ - struct vnode *uppervp; /* may be null */ - struct vnode *lowervp; /* may be null */ - int docache; -{ - int error; - struct union_node *un = 0; - struct union_mount *um = MOUNTTOUNIONMOUNT(mp); - struct proc *p = (cnp) ? cnp->cn_proc : curproc; - int hash = 0; - int vflag; - int try; - - if (uppervp == NULLVP && lowervp == NULLVP) - panic("union: unidentifiable allocation"); - - if (uppervp && lowervp && (uppervp->v_type != lowervp->v_type)) { - vrele(lowervp); - lowervp = NULLVP; - } - - /* detect the root vnode (and aliases) */ - vflag = 0; - if ((uppervp == um->um_uppervp) && - ((lowervp == NULLVP) || lowervp == um->um_lowervp)) { - if (lowervp == NULLVP) { - lowervp = um->um_lowervp; - if (lowervp != NULLVP) - VREF(lowervp); - } - vflag = VROOT; - } - -loop: - if (!docache) { - un = 0; - } else for (try = 0; try < 3; try++) { - switch (try) { - case 0: - if (lowervp == NULLVP) - continue; - hash = UNION_HASH(uppervp, lowervp); - break; - - case 1: - if (uppervp == NULLVP) - continue; - hash = UNION_HASH(uppervp, NULLVP); - break; - - case 2: - if (lowervp == NULLVP) - continue; - hash = UNION_HASH(NULLVP, lowervp); - break; - } - - while (union_list_lock(hash)) - continue; - - LIST_FOREACH(un, &unhead[hash], un_cache) { - if ((un->un_lowervp == lowervp || - un->un_lowervp == NULLVP) && - (un->un_uppervp == uppervp || - un->un_uppervp == NULLVP) && - (UNIONTOV(un)->v_mount == mp)) { - if (vget(UNIONTOV(un), 0, - cnp ? cnp->cn_proc : NULL)) { - union_list_unlock(hash); - goto loop; - } - break; - } - } - - union_list_unlock(hash); - - if (un) - break; - } - - if (un) { - /* - * Obtain a lock on the union_node. Everything is unlocked - * except for dvp, so check that case. If they match, our - * new un is already locked. Otherwise we have to lock our - * new un. - * - * A potential deadlock situation occurs when we are holding - * one lock while trying to get another. We must follow - * strict ordering rules to avoid it. We try to locate dvp - * by scanning up from un_vnode, since the most likely - * scenario is un being under dvp. - */ - - if (dvp && un->un_vnode != dvp) { - struct vnode *scan = un->un_vnode; - - do { - scan = VTOUNION(scan)->un_pvp; - } while (scan && scan->v_tag == VT_UNION && scan != dvp); - if (scan != dvp) { - /* - * our new un is above dvp (we never saw dvp - * while moving up the tree). - */ - VREF(dvp); - VOP_UNLOCK(dvp, 0, p); - error = vn_lock(un->un_vnode, LK_EXCLUSIVE, p); - vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p); - vrele(dvp); - } else { - /* - * our new un is under dvp - */ - error = vn_lock(un->un_vnode, LK_EXCLUSIVE, p); - } - } else if (dvp == NULLVP) { - /* - * dvp is NULL, we need to lock un. - */ - error = vn_lock(un->un_vnode, LK_EXCLUSIVE, p); - } else { - /* - * dvp == un->un_vnode, we are already locked. - */ - error = 0; - } - - if (error) - goto loop; - - /* - * At this point, the union_node is locked and referenced. - * - * uppervp is locked and referenced or NULL, lowervp is - * referenced or NULL. - */ - UDEBUG(("Modify existing un %p vn %p upper %p(refs %d) -> %p(refs %d)\n", - un, un->un_vnode, un->un_uppervp, - (un->un_uppervp ? un->un_uppervp->v_usecount : -99), - uppervp, - (uppervp ? uppervp->v_usecount : -99) - )); - - if (uppervp != un->un_uppervp) { - KASSERT(uppervp == NULL || uppervp->v_usecount > 0, ("union_allocvp: too few refs %d (at least 1 required) on uppervp", uppervp->v_usecount)); - union_newupper(un, uppervp); - } else if (uppervp) { - KASSERT(uppervp->v_usecount > 1, ("union_allocvp: too few refs %d (at least 2 required) on uppervp", uppervp->v_usecount)); - vrele(uppervp); - } - - /* - * Save information about the lower layer. - * This needs to keep track of pathname - * and directory information which union_vn_create - * might need. - */ - if (lowervp != un->un_lowervp) { - union_newlower(un, lowervp); - if (cnp && (lowervp != NULLVP)) { - un->un_path = malloc(cnp->cn_namelen+1, - M_TEMP, M_WAITOK); - bcopy(cnp->cn_nameptr, un->un_path, - cnp->cn_namelen); - un->un_path[cnp->cn_namelen] = '\0'; - } - } else if (lowervp) { - vrele(lowervp); - } - - /* - * and upperdvp - */ - if (upperdvp != un->un_dirvp) { - if (un->un_dirvp) - vrele(un->un_dirvp); - un->un_dirvp = upperdvp; - } else if (upperdvp) { - vrele(upperdvp); - } - - *vpp = UNIONTOV(un); - return (0); - } - - if (docache) { - /* - * otherwise lock the vp list while we call getnewvnode - * since that can block. - */ - hash = UNION_HASH(uppervp, lowervp); - - if (union_list_lock(hash)) - goto loop; - } - - /* - * Create new node rather then replace old node - */ - - error = getnewvnode(VT_UNION, mp, union_vnodeop_p, vpp); - if (error) { - /* - * If an error occurs clear out vnodes. - */ - if (lowervp) - vrele(lowervp); - if (uppervp) - vrele(uppervp); - if (upperdvp) - vrele(upperdvp); - *vpp = NULL; - goto out; - } - - MALLOC((*vpp)->v_data, void *, sizeof(struct union_node), - M_TEMP, M_WAITOK); - - (*vpp)->v_flag |= vflag; - if (uppervp) - (*vpp)->v_type = uppervp->v_type; - else - (*vpp)->v_type = lowervp->v_type; - - un = VTOUNION(*vpp); - bzero(un, sizeof(*un)); - - lockinit(&un->un_lock, PVFS, "unlock", 0, 0); - vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY, p); - - un->un_vnode = *vpp; - un->un_uppervp = uppervp; - un->un_uppersz = VNOVAL; - un->un_lowervp = lowervp; - un->un_lowersz = VNOVAL; - un->un_dirvp = upperdvp; - un->un_pvp = dvp; /* only parent dir in new allocation */ - if (dvp != NULLVP) - VREF(dvp); - un->un_dircache = 0; - un->un_openl = 0; - - if (cnp && (lowervp != NULLVP)) { - un->un_path = malloc(cnp->cn_namelen+1, M_TEMP, M_WAITOK); - bcopy(cnp->cn_nameptr, un->un_path, cnp->cn_namelen); - un->un_path[cnp->cn_namelen] = '\0'; - } else { - un->un_path = 0; - un->un_dirvp = NULL; - } - - if (docache) { - LIST_INSERT_HEAD(&unhead[hash], un, un_cache); - un->un_flags |= UN_CACHED; - } - -out: - if (docache) - union_list_unlock(hash); - - return (error); -} - -int -union_freevp(vp) - struct vnode *vp; -{ - struct union_node *un = VTOUNION(vp); - - if (un->un_flags & UN_CACHED) { - un->un_flags &= ~UN_CACHED; - LIST_REMOVE(un, un_cache); - } - - if (un->un_pvp != NULLVP) { - vrele(un->un_pvp); - un->un_pvp = NULL; - } - if (un->un_uppervp != NULLVP) { - vrele(un->un_uppervp); - un->un_uppervp = NULL; - } - if (un->un_lowervp != NULLVP) { - vrele(un->un_lowervp); - un->un_lowervp = NULL; - } - if (un->un_dirvp != NULLVP) { - vrele(un->un_dirvp); - un->un_dirvp = NULL; - } - if (un->un_path) { - free(un->un_path, M_TEMP); - un->un_path = NULL; - } - lockdestroy(&un->un_lock); - - FREE(vp->v_data, M_TEMP); - vp->v_data = 0; - - return (0); -} - -/* - * copyfile. copy the vnode (fvp) to the vnode (tvp) - * using a sequence of reads and writes. both (fvp) - * and (tvp) are locked on entry and exit. - * - * fvp and tvp are both exclusive locked on call, but their refcount's - * haven't been bumped at all. - */ -static int -union_copyfile(fvp, tvp, cred, p) - struct vnode *fvp; - struct vnode *tvp; - struct ucred *cred; - struct proc *p; -{ - char *buf; - struct uio uio; - struct iovec iov; - int error = 0; - - /* - * strategy: - * allocate a buffer of size MAXBSIZE. - * loop doing reads and writes, keeping track - * of the current uio offset. - * give up at the first sign of trouble. - */ - - bzero(&uio, sizeof(uio)); - - uio.uio_procp = p; - uio.uio_segflg = UIO_SYSSPACE; - uio.uio_offset = 0; - - VOP_LEASE(fvp, p, cred, LEASE_READ); - VOP_LEASE(tvp, p, cred, LEASE_WRITE); - - buf = malloc(MAXBSIZE, M_TEMP, M_WAITOK); - - /* ugly loop follows... */ - do { - off_t offset = uio.uio_offset; - int count; - int bufoffset; - - /* - * Setup for big read - */ - uio.uio_iov = &iov; - uio.uio_iovcnt = 1; - iov.iov_base = buf; - iov.iov_len = MAXBSIZE; - uio.uio_resid = iov.iov_len; - uio.uio_rw = UIO_READ; - - if ((error = VOP_READ(fvp, &uio, 0, cred)) != 0) - break; - - /* - * Get bytes read, handle read eof case and setup for - * write loop - */ - if ((count = MAXBSIZE - uio.uio_resid) == 0) - break; - bufoffset = 0; - - /* - * Write until an error occurs or our buffer has been - * exhausted, then update the offset for the next read. - */ - while (bufoffset < count) { - uio.uio_iov = &iov; - uio.uio_iovcnt = 1; - iov.iov_base = buf + bufoffset; - iov.iov_len = count - bufoffset; - uio.uio_offset = offset + bufoffset; - uio.uio_rw = UIO_WRITE; - uio.uio_resid = iov.iov_len; - - if ((error = VOP_WRITE(tvp, &uio, 0, cred)) != 0) - break; - bufoffset += (count - bufoffset) - uio.uio_resid; - } - uio.uio_offset = offset + bufoffset; - } while (error == 0); - - free(buf, M_TEMP); - return (error); -} - -/* - * - * un's vnode is assumed to be locked on entry and remains locked on exit. - */ - -int -union_copyup(un, docopy, cred, p) - struct union_node *un; - int docopy; - struct ucred *cred; - struct proc *p; -{ - int error; - struct mount *mp; - struct vnode *lvp, *uvp; - - /* - * If the user does not have read permission, the vnode should not - * be copied to upper layer. - */ - vn_lock(un->un_lowervp, LK_EXCLUSIVE | LK_RETRY, p); - error = VOP_ACCESS(un->un_lowervp, VREAD, cred, p); - VOP_UNLOCK(un->un_lowervp, 0, p); - if (error) - return (error); - - if ((error = vn_start_write(un->un_dirvp, &mp, V_WAIT | PCATCH)) != 0) - return (error); - if ((error = union_vn_create(&uvp, un, p)) != 0) { - vn_finished_write(mp); - return (error); - } - - lvp = un->un_lowervp; - - KASSERT(uvp->v_usecount > 0, ("copy: uvp refcount 0: %d", uvp->v_usecount)); - if (docopy) { - /* - * XX - should not ignore errors - * from VOP_CLOSE - */ - vn_lock(lvp, LK_EXCLUSIVE | LK_RETRY, p); - error = VOP_OPEN(lvp, FREAD, cred, p); - if (error == 0 && vn_canvmio(lvp) == TRUE) - error = vfs_object_create(lvp, p, cred); - if (error == 0) { - error = union_copyfile(lvp, uvp, cred, p); - VOP_UNLOCK(lvp, 0, p); - (void) VOP_CLOSE(lvp, FREAD, cred, p); - } - if (error == 0) - UDEBUG(("union: copied up %s\n", un->un_path)); - - } - VOP_UNLOCK(uvp, 0, p); - vn_finished_write(mp); - union_newupper(un, uvp); - KASSERT(uvp->v_usecount > 0, ("copy: uvp refcount 0: %d", uvp->v_usecount)); - union_vn_close(uvp, FWRITE, cred, p); - KASSERT(uvp->v_usecount > 0, ("copy: uvp refcount 0: %d", uvp->v_usecount)); - /* - * Subsequent IOs will go to the top layer, so - * call close on the lower vnode and open on the - * upper vnode to ensure that the filesystem keeps - * its references counts right. This doesn't do - * the right thing with (cred) and (FREAD) though. - * Ignoring error returns is not right, either. - */ - if (error == 0) { - int i; - - for (i = 0; i < un->un_openl; i++) { - (void) VOP_CLOSE(lvp, FREAD, cred, p); - (void) VOP_OPEN(uvp, FREAD, cred, p); - } - if (un->un_openl) { - if (vn_canvmio(uvp) == TRUE) - error = vfs_object_create(uvp, p, cred); - } - un->un_openl = 0; - } - - return (error); - -} - -/* - * union_relookup: - * - * dvp should be locked on entry and will be locked on return. No - * net change in the ref count will occur. - * - * If an error is returned, *vpp will be invalid, otherwise it - * will hold a locked, referenced vnode. If *vpp == dvp then - * remember that only one exclusive lock is held. - */ - -static int -union_relookup(um, dvp, vpp, cnp, cn, path, pathlen) - struct union_mount *um; - struct vnode *dvp; - struct vnode **vpp; - struct componentname *cnp; - struct componentname *cn; - char *path; - int pathlen; -{ - int error; - - /* - * A new componentname structure must be faked up because - * there is no way to know where the upper level cnp came - * from or what it is being used for. This must duplicate - * some of the work done by NDINIT, some of the work done - * by namei, some of the work done by lookup and some of - * the work done by VOP_LOOKUP when given a CREATE flag. - * Conclusion: Horrible. - */ - cn->cn_namelen = pathlen; - cn->cn_pnbuf = zalloc(namei_zone); - bcopy(path, cn->cn_pnbuf, cn->cn_namelen); - cn->cn_pnbuf[cn->cn_namelen] = '\0'; - - cn->cn_nameiop = CREATE; - cn->cn_flags = (LOCKPARENT|LOCKLEAF|HASBUF|SAVENAME|ISLASTCN); - cn->cn_proc = cnp->cn_proc; - if (um->um_op == UNMNT_ABOVE) - cn->cn_cred = cnp->cn_cred; - else - cn->cn_cred = um->um_cred; - cn->cn_nameptr = cn->cn_pnbuf; - cn->cn_consume = cnp->cn_consume; - - VREF(dvp); - VOP_UNLOCK(dvp, 0, cnp->cn_proc); - - /* - * Pass dvp unlocked and referenced on call to relookup(). - * - * If an error occurs, dvp will be returned unlocked and dereferenced. - */ - - if ((error = relookup(dvp, vpp, cn)) != 0) { - vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, cnp->cn_proc); - return(error); - } - - /* - * If no error occurs, dvp will be returned locked with the reference - * left as before, and vpp will be returned referenced and locked. - * - * We want to return with dvp as it was passed to us, so we get - * rid of our reference. - */ - vrele(dvp); - return (0); -} - -/* - * Create a shadow directory in the upper layer. - * The new vnode is returned locked. - * - * (um) points to the union mount structure for access to the - * the mounting process's credentials. - * (dvp) is the directory in which to create the shadow directory, - * it is locked (but not ref'd) on entry and return. - * (cnp) is the componentname to be created. - * (vpp) is the returned newly created shadow directory, which - * is returned locked and ref'd - */ -int -union_mkshadow(um, dvp, cnp, vpp) - struct union_mount *um; - struct vnode *dvp; - struct componentname *cnp; - struct vnode **vpp; -{ - int error; - struct vattr va; - struct proc *p = cnp->cn_proc; - struct componentname cn; - struct mount *mp; - - if ((error = vn_start_write(dvp, &mp, V_WAIT | PCATCH)) != 0) - return (error); - if ((error = union_relookup(um, dvp, vpp, cnp, &cn, - cnp->cn_nameptr, cnp->cn_namelen)) != 0) { - vn_finished_write(mp); - return (error); - } - - if (*vpp) { - if (cn.cn_flags & HASBUF) { - zfree(namei_zone, cn.cn_pnbuf); - cn.cn_flags &= ~HASBUF; - } - if (dvp == *vpp) - vrele(*vpp); - else - vput(*vpp); - vn_finished_write(mp); - *vpp = NULLVP; - return (EEXIST); - } - - /* - * policy: when creating the shadow directory in the - * upper layer, create it owned by the user who did - * the mount, group from parent directory, and mode - * 777 modified by umask (ie mostly identical to the - * mkdir syscall). (jsp, kb) - */ - - VATTR_NULL(&va); - va.va_type = VDIR; - va.va_mode = um->um_cmode; - - /* VOP_LEASE: dvp is locked */ - VOP_LEASE(dvp, p, cn.cn_cred, LEASE_WRITE); - - error = VOP_MKDIR(dvp, vpp, &cn, &va); - if (cn.cn_flags & HASBUF) { - zfree(namei_zone, cn.cn_pnbuf); - cn.cn_flags &= ~HASBUF; - } - /*vput(dvp);*/ - vn_finished_write(mp); - return (error); -} - -/* - * Create a whiteout entry in the upper layer. - * - * (um) points to the union mount structure for access to the - * the mounting process's credentials. - * (dvp) is the directory in which to create the whiteout. - * it is locked on entry and return. - * (cnp) is the componentname to be created. - */ -int -union_mkwhiteout(um, dvp, cnp, path) - struct union_mount *um; - struct vnode *dvp; - struct componentname *cnp; - char *path; -{ - int error; - struct proc *p = cnp->cn_proc; - struct vnode *wvp; - struct componentname cn; - struct mount *mp; - - if ((error = vn_start_write(dvp, &mp, V_WAIT | PCATCH)) != 0) - return (error); - error = union_relookup(um, dvp, &wvp, cnp, &cn, path, strlen(path)); - if (error) { - vn_finished_write(mp); - return (error); - } - - if (wvp) { - if (cn.cn_flags & HASBUF) { - zfree(namei_zone, cn.cn_pnbuf); - cn.cn_flags &= ~HASBUF; - } - if (wvp == dvp) - vrele(wvp); - else - vput(wvp); - vn_finished_write(mp); - return (EEXIST); - } - - /* VOP_LEASE: dvp is locked */ - VOP_LEASE(dvp, p, p->p_ucred, LEASE_WRITE); - - error = VOP_WHITEOUT(dvp, &cn, CREATE); - if (cn.cn_flags & HASBUF) { - zfree(namei_zone, cn.cn_pnbuf); - cn.cn_flags &= ~HASBUF; - } - vn_finished_write(mp); - return (error); -} - -/* - * union_vn_create: creates and opens a new shadow file - * on the upper union layer. this function is similar - * in spirit to calling vn_open but it avoids calling namei(). - * the problem with calling namei is that a) it locks too many - * things, and b) it doesn't start at the "right" directory, - * whereas relookup is told where to start. - * - * On entry, the vnode associated with un is locked. It remains locked - * on return. - * - * If no error occurs, *vpp contains a locked referenced vnode for your - * use. If an error occurs *vpp iis undefined. - */ -static int -union_vn_create(vpp, un, p) - struct vnode **vpp; - struct union_node *un; - struct proc *p; -{ - struct vnode *vp; - struct ucred *cred = p->p_ucred; - struct vattr vat; - struct vattr *vap = &vat; - int fmode = FFLAGS(O_WRONLY|O_CREAT|O_TRUNC|O_EXCL); - int error; - int cmode = UN_FILEMODE & ~p->p_fd->fd_cmask; - struct componentname cn; - - *vpp = NULLVP; - - /* - * Build a new componentname structure (for the same - * reasons outlines in union_mkshadow). - * The difference here is that the file is owned by - * the current user, rather than by the person who - * did the mount, since the current user needs to be - * able to write the file (that's why it is being - * copied in the first place). - */ - cn.cn_namelen = strlen(un->un_path); - cn.cn_pnbuf = zalloc(namei_zone); - bcopy(un->un_path, cn.cn_pnbuf, cn.cn_namelen+1); - cn.cn_nameiop = CREATE; - cn.cn_flags = (LOCKPARENT|LOCKLEAF|HASBUF|SAVENAME|ISLASTCN); - cn.cn_proc = p; - cn.cn_cred = p->p_ucred; - cn.cn_nameptr = cn.cn_pnbuf; - cn.cn_consume = 0; - - /* - * Pass dvp unlocked and referenced on call to relookup(). - * - * If an error occurs, dvp will be returned unlocked and dereferenced. - */ - VREF(un->un_dirvp); - error = relookup(un->un_dirvp, &vp, &cn); - if (error) - return (error); - - /* - * If no error occurs, dvp will be returned locked with the reference - * left as before, and vpp will be returned referenced and locked. - */ - if (vp) { - vput(un->un_dirvp); - if (cn.cn_flags & HASBUF) { - zfree(namei_zone, cn.cn_pnbuf); - cn.cn_flags &= ~HASBUF; - } - if (vp == un->un_dirvp) - vrele(vp); - else - vput(vp); - return (EEXIST); - } - - /* - * Good - there was no race to create the file - * so go ahead and create it. The permissions - * on the file will be 0666 modified by the - * current user's umask. Access to the file, while - * it is unioned, will require access to the top *and* - * bottom files. Access when not unioned will simply - * require access to the top-level file. - * TODO: confirm choice of access permissions. - */ - VATTR_NULL(vap); - vap->va_type = VREG; - vap->va_mode = cmode; - VOP_LEASE(un->un_dirvp, p, cred, LEASE_WRITE); - error = VOP_CREATE(un->un_dirvp, &vp, &cn, vap); - if (cn.cn_flags & HASBUF) { - zfree(namei_zone, cn.cn_pnbuf); - cn.cn_flags &= ~HASBUF; - } - vput(un->un_dirvp); - if (error) - return (error); - - error = VOP_OPEN(vp, fmode, cred, p); - if (error == 0 && vn_canvmio(vp) == TRUE) - error = vfs_object_create(vp, p, cred); - if (error) { - vput(vp); - return (error); - } - vp->v_writecount++; - *vpp = vp; - return (0); -} - -static int -union_vn_close(vp, fmode, cred, p) - struct vnode *vp; - int fmode; - struct ucred *cred; - struct proc *p; -{ - - if (fmode & FWRITE) - --vp->v_writecount; - return (VOP_CLOSE(vp, fmode, cred, p)); -} - -#if 0 - -/* - * union_removed_upper: - * - * called with union_node unlocked. XXX - */ - -void -union_removed_upper(un) - struct union_node *un; -{ - struct proc *p = curproc; /* XXX */ - struct vnode **vpp; - - /* - * Do not set the uppervp to NULLVP. If lowervp is NULLVP, - * union node will have neither uppervp nor lowervp. We remove - * the union node from cache, so that it will not be referrenced. - */ - union_newupper(un, NULLVP); - if (un->un_dircache != 0) { - for (vpp = un->un_dircache; *vpp != NULLVP; vpp++) - vrele(*vpp); - free(un->un_dircache, M_TEMP); - un->un_dircache = 0; - } - - if (un->un_flags & UN_CACHED) { - un->un_flags &= ~UN_CACHED; - LIST_REMOVE(un, un_cache); - } -} - -#endif - -/* - * determine whether a whiteout is needed - * during a remove/rmdir operation. - */ -int -union_dowhiteout(un, cred, p) - struct union_node *un; - struct ucred *cred; - struct proc *p; -{ - struct vattr va; - - if (un->un_lowervp != NULLVP) - return (1); - - if (VOP_GETATTR(un->un_uppervp, &va, cred, p) == 0 && - (va.va_flags & OPAQUE)) - return (1); - - return (0); -} - -static void -union_dircache_r(vp, vppp, cntp) - struct vnode *vp; - struct vnode ***vppp; - int *cntp; -{ - struct union_node *un; - - if (vp->v_op != union_vnodeop_p) { - if (vppp) { - VREF(vp); - *(*vppp)++ = vp; - if (--(*cntp) == 0) - panic("union: dircache table too small"); - } else { - (*cntp)++; - } - - return; - } - - un = VTOUNION(vp); - if (un->un_uppervp != NULLVP) - union_dircache_r(un->un_uppervp, vppp, cntp); - if (un->un_lowervp != NULLVP) - union_dircache_r(un->un_lowervp, vppp, cntp); -} - -struct vnode * -union_dircache(vp, p) - struct vnode *vp; - struct proc *p; -{ - int cnt; - struct vnode *nvp; - struct vnode **vpp; - struct vnode **dircache; - struct union_node *un; - int error; - - vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); - dircache = VTOUNION(vp)->un_dircache; - - nvp = NULLVP; - - if (dircache == NULL) { - cnt = 0; - union_dircache_r(vp, 0, &cnt); - cnt++; - dircache = malloc(cnt * sizeof(struct vnode *), - M_TEMP, M_WAITOK); - vpp = dircache; - union_dircache_r(vp, &vpp, &cnt); - *vpp = NULLVP; - vpp = dircache + 1; - } else { - vpp = dircache; - do { - if (*vpp++ == VTOUNION(vp)->un_uppervp) - break; - } while (*vpp != NULLVP); - } - - if (*vpp == NULLVP) - goto out; - - /*vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY, p);*/ - UDEBUG(("ALLOCVP-3 %p ref %d\n", *vpp, (*vpp ? (*vpp)->v_usecount : -99))); - VREF(*vpp); - error = union_allocvp(&nvp, vp->v_mount, NULLVP, NULLVP, NULL, *vpp, NULLVP, 0); - UDEBUG(("ALLOCVP-3B %p ref %d\n", nvp, (*vpp ? (*vpp)->v_usecount : -99))); - if (error) - goto out; - - VTOUNION(vp)->un_dircache = 0; - un = VTOUNION(nvp); - un->un_dircache = dircache; - -out: - VOP_UNLOCK(vp, 0, p); - return (nvp); -} - -/* - * Module glue to remove #ifdef UNION from vfs_syscalls.c - */ -static int -union_dircheck(struct proc *p, struct vnode **vp, struct file *fp) -{ - int error = 0; - - if ((*vp)->v_op == union_vnodeop_p) { - struct vnode *lvp; - - lvp = union_dircache(*vp, p); - if (lvp != NULLVP) { - struct vattr va; - - /* - * If the directory is opaque, - * then don't show lower entries - */ - error = VOP_GETATTR(*vp, &va, fp->f_cred, p); - if (va.va_flags & OPAQUE) { - vput(lvp); - lvp = NULL; - } - } - - if (lvp != NULLVP) { - error = VOP_OPEN(lvp, FREAD, fp->f_cred, p); - if (error == 0 && vn_canvmio(lvp) == TRUE) - error = vfs_object_create(lvp, p, fp->f_cred); - if (error) { - vput(lvp); - return (error); - } - VOP_UNLOCK(lvp, 0, p); - fp->f_data = (caddr_t) lvp; - fp->f_offset = 0; - error = vn_close(*vp, FREAD, fp->f_cred, p); - if (error) - return (error); - *vp = lvp; - return -1; /* goto unionread */ - } - } - return error; -} - -static int -union_modevent(module_t mod, int type, void *data) -{ - switch (type) { - case MOD_LOAD: - union_dircheckp = union_dircheck; - break; - case MOD_UNLOAD: - union_dircheckp = NULL; - break; - default: - break; - } - return 0; -} - -static moduledata_t union_mod = { - "union_dircheck", - union_modevent, - NULL -}; - -DECLARE_MODULE(union_dircheck, union_mod, SI_SUB_VFS, SI_ORDER_ANY); diff --git a/sys/miscfs/union/union_vfsops.c b/sys/miscfs/union/union_vfsops.c deleted file mode 100644 index d38f31e..0000000 --- a/sys/miscfs/union/union_vfsops.c +++ /dev/null @@ -1,485 +0,0 @@ -/* - * Copyright (c) 1994, 1995 The Regents of the University of California. - * Copyright (c) 1994, 1995 Jan-Simon Pendry. - * All rights reserved. - * - * This code is derived from software donated to Berkeley by - * Jan-Simon Pendry. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 4. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - * - * @(#)union_vfsops.c 8.20 (Berkeley) 5/20/95 - * $FreeBSD$ - */ - -/* - * Union Layer - */ - -#include <sys/param.h> -#include <sys/systm.h> -#include <sys/kernel.h> -#include <sys/proc.h> -#include <sys/vnode.h> -#include <sys/mount.h> -#include <sys/namei.h> -#include <sys/malloc.h> -#include <sys/filedesc.h> -#include <miscfs/union/union.h> - -static MALLOC_DEFINE(M_UNIONFSMNT, "UNION mount", "UNION mount structure"); - -extern int union_init __P((struct vfsconf *)); -static int union_mount __P((struct mount *mp, char *path, caddr_t data, - struct nameidata *ndp, struct proc *p)); -static int union_root __P((struct mount *mp, struct vnode **vpp)); -static int union_statfs __P((struct mount *mp, struct statfs *sbp, - struct proc *p)); -static int union_unmount __P((struct mount *mp, int mntflags, - struct proc *p)); - -/* - * Mount union filesystem - */ -static int -union_mount(mp, path, data, ndp, p) - struct mount *mp; - char *path; - caddr_t data; - struct nameidata *ndp; - struct proc *p; -{ - int error = 0; - struct union_args args; - struct vnode *lowerrootvp = NULLVP; - struct vnode *upperrootvp = NULLVP; - struct union_mount *um = 0; - struct ucred *cred = 0; - char *cp = 0; - int len; - u_int size; - - UDEBUG(("union_mount(mp = %p)\n", (void *)mp)); - - /* - * Disable clustered write, otherwise system becomes unstable. - */ - mp->mnt_flag |= MNT_NOCLUSTERW; - - /* - * Update is a no-op - */ - if (mp->mnt_flag & MNT_UPDATE) { - /* - * Need to provide. - * 1. a way to convert between rdonly and rdwr mounts. - * 2. support for nfs exports. - */ - error = EOPNOTSUPP; - goto bad; - } - - /* - * Get argument - */ - error = copyin(data, (caddr_t)&args, sizeof(struct union_args)); - if (error) - goto bad; - - /* - * Obtain lower vnode. Vnode is stored in mp->mnt_vnodecovered. - * We need to reference it but not lock it. - */ - - lowerrootvp = mp->mnt_vnodecovered; - VREF(lowerrootvp); - -#if 0 - /* - * Unlock lower node to avoid deadlock. - */ - if (lowerrootvp->v_op == union_vnodeop_p) - VOP_UNLOCK(lowerrootvp, 0, p); -#endif - - /* - * Obtain upper vnode by calling namei() on the path. The - * upperrootvp will be turned referenced but not locked. - */ - NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT, - UIO_USERSPACE, args.target, p); - - error = namei(ndp); - -#if 0 - if (lowerrootvp->v_op == union_vnodeop_p) - vn_lock(lowerrootvp, LK_EXCLUSIVE | LK_RETRY, p); -#endif - if (error) - goto bad; - - NDFREE(ndp, NDF_ONLY_PNBUF); - upperrootvp = ndp->ni_vp; - vrele(ndp->ni_dvp); - ndp->ni_dvp = NULL; - - UDEBUG(("mount_root UPPERVP %p locked = %d\n", upperrootvp, - VOP_ISLOCKED(upperrootvp, NULL))); - - /* - * Check multi union mount to avoid `lock myself again' panic. - * Also require that it be a directory. - */ - if (upperrootvp == VTOUNION(lowerrootvp)->un_uppervp) { -#ifdef DIAGNOSTIC - printf("union_mount: multi union mount?\n"); -#endif - error = EDEADLK; - goto bad; - } - - if (upperrootvp->v_type != VDIR) { - error = EINVAL; - goto bad; - } - - /* - * Allocate our union_mount structure and populate the fields. - * The vnode references are stored in the union_mount as held, - * unlocked references. Depending on the _BELOW flag, the - * filesystems are viewed in a different order. In effect this - * is the same as providing a mount-under option to the mount - * syscall. - */ - - um = (struct union_mount *) malloc(sizeof(struct union_mount), - M_UNIONFSMNT, M_WAITOK | M_ZERO); - - um->um_op = args.mntflags & UNMNT_OPMASK; - - switch (um->um_op) { - case UNMNT_ABOVE: - um->um_lowervp = lowerrootvp; - um->um_uppervp = upperrootvp; - upperrootvp = NULL; - lowerrootvp = NULL; - break; - - case UNMNT_BELOW: - um->um_lowervp = upperrootvp; - um->um_uppervp = lowerrootvp; - upperrootvp = NULL; - lowerrootvp = NULL; - break; - - case UNMNT_REPLACE: - vrele(lowerrootvp); - lowerrootvp = NULL; - um->um_uppervp = upperrootvp; - um->um_lowervp = lowerrootvp; - upperrootvp = NULL; - break; - - default: - error = EINVAL; - goto bad; - } - - /* - * Unless the mount is readonly, ensure that the top layer - * supports whiteout operations - */ - if ((mp->mnt_flag & MNT_RDONLY) == 0) { - error = VOP_WHITEOUT(um->um_uppervp, NULL, LOOKUP); - if (error) - goto bad; - } - - um->um_cred = p->p_ucred; - crhold(um->um_cred); - um->um_cmode = UN_DIRMODE &~ p->p_fd->fd_cmask; - - /* - * Depending on what you think the MNT_LOCAL flag might mean, - * you may want the && to be || on the conditional below. - * At the moment it has been defined that the filesystem is - * only local if it is all local, ie the MNT_LOCAL flag implies - * that the entire namespace is local. If you think the MNT_LOCAL - * flag implies that some of the files might be stored locally - * then you will want to change the conditional. - */ - if (um->um_op == UNMNT_ABOVE) { - if (((um->um_lowervp == NULLVP) || - (um->um_lowervp->v_mount->mnt_flag & MNT_LOCAL)) && - (um->um_uppervp->v_mount->mnt_flag & MNT_LOCAL)) - mp->mnt_flag |= MNT_LOCAL; - } - - /* - * Copy in the upper layer's RDONLY flag. This is for the benefit - * of lookup() which explicitly checks the flag, rather than asking - * the filesystem for its own opinion. This means, that an update - * mount of the underlying filesystem to go from rdonly to rdwr - * will leave the unioned view as read-only. - */ - mp->mnt_flag |= (um->um_uppervp->v_mount->mnt_flag & MNT_RDONLY); - - mp->mnt_data = (qaddr_t) um; - vfs_getnewfsid(mp); - - switch (um->um_op) { - case UNMNT_ABOVE: - cp = "<above>:"; - break; - case UNMNT_BELOW: - cp = "<below>:"; - break; - case UNMNT_REPLACE: - cp = ""; - break; - } - len = strlen(cp); - bcopy(cp, mp->mnt_stat.f_mntfromname, len); - - cp = mp->mnt_stat.f_mntfromname + len; - len = MNAMELEN - len; - - (void) copyinstr(args.target, cp, len - 1, &size); - bzero(cp + size, len - size); - - (void)union_statfs(mp, &mp->mnt_stat, p); - - UDEBUG(("union_mount: from %s, on %s\n", - mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname)); - return (0); - -bad: - if (um) { - if (um->um_uppervp) - vrele(um->um_uppervp); - if (um->um_lowervp) - vrele(um->um_lowervp); - /* XXX other fields */ - free(um, M_UNIONFSMNT); - } - if (cred) - crfree(cred); - if (upperrootvp) - vrele(upperrootvp); - if (lowerrootvp) - vrele(lowerrootvp); - return (error); -} - -/* - * Free reference to union layer - */ -static int -union_unmount(mp, mntflags, p) - struct mount *mp; - int mntflags; - struct proc *p; -{ - struct union_mount *um = MOUNTTOUNIONMOUNT(mp); - int error; - int freeing; - int flags = 0; - - UDEBUG(("union_unmount(mp = %p)\n", (void *)mp)); - - if (mntflags & MNT_FORCE) - flags |= FORCECLOSE; - - /* - * Keep flushing vnodes from the mount list. - * This is needed because of the un_pvp held - * reference to the parent vnode. - * If more vnodes have been freed on a given pass, - * the try again. The loop will iterate at most - * (d) times, where (d) is the maximum tree depth - * in the filesystem. - */ - for (freeing = 0; (error = vflush(mp, 0, flags)) != 0;) { - struct vnode *vp; - int n; - - /* count #vnodes held on mount list */ - n = 0; - LIST_FOREACH(vp, &mp->mnt_vnodelist, v_mntvnodes) - n++; - - /* if this is unchanged then stop */ - if (n == freeing) - break; - - /* otherwise try once more time */ - freeing = n; - } - - /* If the most recent vflush failed, the filesystem is still busy. */ - if (error) - return (error); - - /* - * Discard references to upper and lower target vnodes. - */ - if (um->um_lowervp) - vrele(um->um_lowervp); - vrele(um->um_uppervp); - crfree(um->um_cred); - /* - * Finally, throw away the union_mount structure - */ - free(mp->mnt_data, M_UNIONFSMNT); /* XXX */ - mp->mnt_data = 0; - return (0); -} - -static int -union_root(mp, vpp) - struct mount *mp; - struct vnode **vpp; -{ - struct union_mount *um = MOUNTTOUNIONMOUNT(mp); - int error; - - /* - * Supply an unlocked reference to um_uppervp and to um_lowervp. It - * is possible for um_uppervp to be locked without the associated - * root union_node being locked. We let union_allocvp() deal with - * it. - */ - UDEBUG(("union_root UPPERVP %p locked = %d\n", um->um_uppervp, - VOP_ISLOCKED(um->um_uppervp, NULL))); - - VREF(um->um_uppervp); - if (um->um_lowervp) - VREF(um->um_lowervp); - - error = union_allocvp(vpp, mp, NULLVP, NULLVP, NULL, - um->um_uppervp, um->um_lowervp, 1); - UDEBUG(("error %d\n", error)); - UDEBUG(("union_root2 UPPERVP %p locked = %d\n", um->um_uppervp, - VOP_ISLOCKED(um->um_uppervp, NULL))); - - return (error); -} - -static int -union_statfs(mp, sbp, p) - struct mount *mp; - struct statfs *sbp; - struct proc *p; -{ - int error; - struct union_mount *um = MOUNTTOUNIONMOUNT(mp); - struct statfs mstat; - int lbsize; - - UDEBUG(("union_statfs(mp = %p, lvp = %p, uvp = %p)\n", - (void *)mp, (void *)um->um_lowervp, (void *)um->um_uppervp)); - - bzero(&mstat, sizeof(mstat)); - - if (um->um_lowervp) { - error = VFS_STATFS(um->um_lowervp->v_mount, &mstat, p); - if (error) - return (error); - } - - /* now copy across the "interesting" information and fake the rest */ -#if 0 - sbp->f_type = mstat.f_type; - sbp->f_flags = mstat.f_flags; - sbp->f_bsize = mstat.f_bsize; - sbp->f_iosize = mstat.f_iosize; -#endif - lbsize = mstat.f_bsize; - sbp->f_blocks = mstat.f_blocks; - sbp->f_bfree = mstat.f_bfree; - sbp->f_bavail = mstat.f_bavail; - sbp->f_files = mstat.f_files; - sbp->f_ffree = mstat.f_ffree; - - error = VFS_STATFS(um->um_uppervp->v_mount, &mstat, p); - if (error) - return (error); - - sbp->f_flags = mstat.f_flags; - sbp->f_bsize = mstat.f_bsize; - sbp->f_iosize = mstat.f_iosize; - - /* - * if the lower and upper blocksizes differ, then frig the - * block counts so that the sizes reported by df make some - * kind of sense. none of this makes sense though. - */ - - if (mstat.f_bsize != lbsize) - sbp->f_blocks = ((off_t) sbp->f_blocks * lbsize) / mstat.f_bsize; - - /* - * The "total" fields count total resources in all layers, - * the "free" fields count only those resources which are - * free in the upper layer (since only the upper layer - * is writeable). - */ - sbp->f_blocks += mstat.f_blocks; - sbp->f_bfree = mstat.f_bfree; - sbp->f_bavail = mstat.f_bavail; - sbp->f_files += mstat.f_files; - sbp->f_ffree = mstat.f_ffree; - - if (sbp != &mp->mnt_stat) { - sbp->f_type = mp->mnt_vfc->vfc_typenum; - bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid)); - bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN); - bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN); - } - return (0); -} - -static struct vfsops union_vfsops = { - union_mount, - vfs_stdstart, /* underlying start already done */ - union_unmount, - union_root, - vfs_stdquotactl, - union_statfs, - vfs_stdsync, /* XXX assumes no cached data on union level */ - vfs_stdvget, - vfs_stdfhtovp, - vfs_stdcheckexp, - vfs_stdvptofh, - union_init, - vfs_stduninit, - vfs_stdextattrctl, -}; - -VFS_SET(union_vfsops, union, VFCF_LOOPBACK); diff --git a/sys/miscfs/union/union_vnops.c b/sys/miscfs/union/union_vnops.c deleted file mode 100644 index 3402825..0000000 --- a/sys/miscfs/union/union_vnops.c +++ /dev/null @@ -1,1966 +0,0 @@ -/* - * Copyright (c) 1992, 1993, 1994, 1995 Jan-Simon Pendry. - * Copyright (c) 1992, 1993, 1994, 1995 - * The Regents of the University of California. All rights reserved. - * - * This code is derived from software contributed to Berkeley by - * Jan-Simon Pendry. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 4. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - * - * @(#)union_vnops.c 8.32 (Berkeley) 6/23/95 - * $FreeBSD$ - */ - -#include <sys/param.h> -#include <sys/systm.h> -#include <sys/fcntl.h> -#include <sys/stat.h> -#include <sys/kernel.h> -#include <sys/vnode.h> -#include <sys/mount.h> -#include <sys/namei.h> -#include <sys/malloc.h> -#include <sys/bio.h> -#include <sys/buf.h> -#include <sys/lock.h> -#include <sys/sysctl.h> -#include <miscfs/union/union.h> - -#include <vm/vm.h> -#include <vm/vnode_pager.h> - -#include <vm/vm_page.h> -#include <vm/vm_object.h> - -int uniondebug = 0; - -#if UDEBUG_ENABLED -SYSCTL_INT(_vfs, OID_AUTO, uniondebug, CTLFLAG_RW, &uniondebug, 0, ""); -#else -SYSCTL_INT(_vfs, OID_AUTO, uniondebug, CTLFLAG_RD, &uniondebug, 0, ""); -#endif - -static int union_access __P((struct vop_access_args *ap)); -static int union_advlock __P((struct vop_advlock_args *ap)); -static int union_close __P((struct vop_close_args *ap)); -static int union_create __P((struct vop_create_args *ap)); -static int union_createvobject __P((struct vop_createvobject_args *ap)); -static int union_destroyvobject __P((struct vop_destroyvobject_args *ap)); -static int union_fsync __P((struct vop_fsync_args *ap)); -static int union_getattr __P((struct vop_getattr_args *ap)); -static int union_getvobject __P((struct vop_getvobject_args *ap)); -static int union_inactive __P((struct vop_inactive_args *ap)); -static int union_ioctl __P((struct vop_ioctl_args *ap)); -static int union_lease __P((struct vop_lease_args *ap)); -static int union_link __P((struct vop_link_args *ap)); -static int union_lock __P((struct vop_lock_args *ap)); -static int union_lookup __P((struct vop_lookup_args *ap)); -static int union_lookup1 __P((struct vnode *udvp, struct vnode **dvp, - struct vnode **vpp, - struct componentname *cnp)); -static int union_mkdir __P((struct vop_mkdir_args *ap)); -static int union_mknod __P((struct vop_mknod_args *ap)); -static int union_open __P((struct vop_open_args *ap)); -static int union_pathconf __P((struct vop_pathconf_args *ap)); -static int union_print __P((struct vop_print_args *ap)); -static int union_read __P((struct vop_read_args *ap)); -static int union_readdir __P((struct vop_readdir_args *ap)); -static int union_readlink __P((struct vop_readlink_args *ap)); -static int union_getwritemount __P((struct vop_getwritemount_args *ap)); -static int union_reclaim __P((struct vop_reclaim_args *ap)); -static int union_remove __P((struct vop_remove_args *ap)); -static int union_rename __P((struct vop_rename_args *ap)); -static int union_revoke __P((struct vop_revoke_args *ap)); -static int union_rmdir __P((struct vop_rmdir_args *ap)); -static int union_poll __P((struct vop_poll_args *ap)); -static int union_setattr __P((struct vop_setattr_args *ap)); -static int union_strategy __P((struct vop_strategy_args *ap)); -static int union_symlink __P((struct vop_symlink_args *ap)); -static int union_unlock __P((struct vop_unlock_args *ap)); -static int union_whiteout __P((struct vop_whiteout_args *ap)); -static int union_write __P((struct vop_read_args *ap)); - -static __inline -struct vnode * -union_lock_upper(struct union_node *un, struct proc *p) -{ - struct vnode *uppervp; - - if ((uppervp = un->un_uppervp) != NULL) { - VREF(uppervp); - vn_lock(uppervp, LK_EXCLUSIVE | LK_CANRECURSE | LK_RETRY, p); - } - KASSERT((uppervp == NULL || uppervp->v_usecount > 0), ("uppervp usecount is 0")); - return(uppervp); -} - -static __inline -void -union_unlock_upper(struct vnode *uppervp, struct proc *p) -{ - vput(uppervp); -} - -static __inline -struct vnode * -union_lock_other(struct union_node *un, struct proc *p) -{ - struct vnode *vp; - - if (un->un_uppervp != NULL) { - vp = union_lock_upper(un, p); - } else if ((vp = un->un_lowervp) != NULL) { - VREF(vp); - vn_lock(vp, LK_EXCLUSIVE | LK_CANRECURSE | LK_RETRY, p); - } - return(vp); -} - -static __inline -void -union_unlock_other(struct vnode *vp, struct proc *p) -{ - vput(vp); -} - -/* - * union_lookup: - * - * udvp must be exclusively locked on call and will remain - * exclusively locked on return. This is the mount point - * for out filesystem. - * - * dvp Our base directory, locked and referenced. - * The passed dvp will be dereferenced and unlocked on return - * and a new dvp will be returned which is locked and - * referenced in the same variable. - * - * vpp is filled in with the result if no error occured, - * locked and ref'd. - * - * If an error is returned, *vpp is set to NULLVP. If no - * error occurs, *vpp is returned with a reference and an - * exclusive lock. - */ - -static int -union_lookup1(udvp, pdvp, vpp, cnp) - struct vnode *udvp; - struct vnode **pdvp; - struct vnode **vpp; - struct componentname *cnp; -{ - int error; - struct proc *p = cnp->cn_proc; - struct vnode *dvp = *pdvp; - struct vnode *tdvp; - struct mount *mp; - - /* - * If stepping up the directory tree, check for going - * back across the mount point, in which case do what - * lookup would do by stepping back down the mount - * hierarchy. - */ - if (cnp->cn_flags & ISDOTDOT) { - while ((dvp != udvp) && (dvp->v_flag & VROOT)) { - /* - * Don't do the NOCROSSMOUNT check - * at this level. By definition, - * union fs deals with namespaces, not - * filesystems. - */ - tdvp = dvp; - dvp = dvp->v_mount->mnt_vnodecovered; - VREF(dvp); - vput(tdvp); - vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p); - } - } - - /* - * Set return dvp to be the upperdvp 'parent directory. - */ - *pdvp = dvp; - - /* - * If the VOP_LOOKUP call generates an error, tdvp is invalid and no - * changes will have been made to dvp, so we are set to return. - */ - - error = VOP_LOOKUP(dvp, &tdvp, cnp); - if (error) { - UDEBUG(("dvp %p error %d flags %lx\n", dvp, error, cnp->cn_flags)); - *vpp = NULL; - return (error); - } - - /* - * The parent directory will have been unlocked, unless lookup - * found the last component or if dvp == tdvp (tdvp must be locked). - * - * We want our dvp to remain locked and ref'd. We also want tdvp - * to remain locked and ref'd. - */ - UDEBUG(("parentdir %p result %p flag %lx\n", dvp, tdvp, cnp->cn_flags)); - - if (dvp != tdvp && (cnp->cn_flags & ISLASTCN) == 0) - vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p); - - /* - * Lastly check if the current node is a mount point in - * which case walk up the mount hierarchy making sure not to - * bump into the root of the mount tree (ie. dvp != udvp). - * - * We use dvp as a temporary variable here, it is no longer related - * to the dvp above. However, we have to ensure that both *pdvp and - * tdvp are locked on return. - */ - - dvp = tdvp; - while ( - dvp != udvp && - (dvp->v_type == VDIR) && - (mp = dvp->v_mountedhere) - ) { - int relock_pdvp = 0; - - if (vfs_busy(mp, 0, 0, p)) - continue; - - if (dvp == *pdvp) - relock_pdvp = 1; - vput(dvp); - dvp = NULL; - error = VFS_ROOT(mp, &dvp); - - vfs_unbusy(mp, p); - - if (relock_pdvp) - vn_lock(*pdvp, LK_EXCLUSIVE | LK_RETRY, p); - - if (error) { - *vpp = NULL; - return (error); - } - } - *vpp = dvp; - return (0); -} - -static int -union_lookup(ap) - struct vop_lookup_args /* { - struct vnodeop_desc *a_desc; - struct vnode *a_dvp; - struct vnode **a_vpp; - struct componentname *a_cnp; - } */ *ap; -{ - int error; - int uerror, lerror; - struct vnode *uppervp, *lowervp; - struct vnode *upperdvp, *lowerdvp; - struct vnode *dvp = ap->a_dvp; /* starting dir */ - struct union_node *dun = VTOUNION(dvp); /* associated union node */ - struct componentname *cnp = ap->a_cnp; - struct proc *p = cnp->cn_proc; - int lockparent = cnp->cn_flags & LOCKPARENT; - struct union_mount *um = MOUNTTOUNIONMOUNT(dvp->v_mount); - struct ucred *saved_cred = NULL; - int iswhiteout; - struct vattr va; - - *ap->a_vpp = NULLVP; - - /* - * Disallow write attemps to the filesystem mounted read-only. - */ - if ((cnp->cn_flags & ISLASTCN) && - (dvp->v_mount->mnt_flag & MNT_RDONLY) && - (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) { - return (EROFS); - } - - /* - * For any lookup's we do, always return with the parent locked - */ - cnp->cn_flags |= LOCKPARENT; - - lowerdvp = dun->un_lowervp; - uppervp = NULLVP; - lowervp = NULLVP; - iswhiteout = 0; - - uerror = ENOENT; - lerror = ENOENT; - - /* - * Get a private lock on uppervp and a reference, effectively - * taking it out of the union_node's control. - * - * We must lock upperdvp while holding our lock on dvp - * to avoid a deadlock. - */ - upperdvp = union_lock_upper(dun, p); - - /* - * do the lookup in the upper level. - * if that level comsumes additional pathnames, - * then assume that something special is going - * on and just return that vnode. - */ - if (upperdvp != NULLVP) { - /* - * We do not have to worry about the DOTDOT case, we've - * already unlocked dvp. - */ - UDEBUG(("A %p\n", upperdvp)); - - /* - * Do the lookup. We must supply a locked and referenced - * upperdvp to the function and will get a new locked and - * referenced upperdvp back with the old having been - * dereferenced. - * - * If an error is returned, uppervp will be NULLVP. If no - * error occurs, uppervp will be the locked and referenced - * return vnode or possibly NULL, depending on what is being - * requested. It is possible that the returned uppervp - * will be the same as upperdvp. - */ - uerror = union_lookup1(um->um_uppervp, &upperdvp, &uppervp, cnp); - UDEBUG(( - "uerror %d upperdvp %p %d/%d, uppervp %p ref=%d/lck=%d\n", - uerror, - upperdvp, - upperdvp->v_usecount, - VOP_ISLOCKED(upperdvp, NULL), - uppervp, - (uppervp ? uppervp->v_usecount : -99), - (uppervp ? VOP_ISLOCKED(uppervp, NULL) : -99) - )); - - /* - * Disallow write attemps to the filesystem mounted read-only. - */ - if (uerror == EJUSTRETURN && (cnp->cn_flags & ISLASTCN) && - (dvp->v_mount->mnt_flag & MNT_RDONLY) && - (cnp->cn_nameiop == CREATE || cnp->cn_nameiop == RENAME)) { - error = EROFS; - goto out; - } - - /* - * Special case. If cn_consume != 0 skip out. The result - * of the lookup is transfered to our return variable. If - * an error occured we have to throw away the results. - */ - - if (cnp->cn_consume != 0) { - if ((error = uerror) == 0) { - *ap->a_vpp = uppervp; - uppervp = NULL; - } - goto out; - } - - /* - * Calculate whiteout, fall through - */ - - if (uerror == ENOENT || uerror == EJUSTRETURN) { - if (cnp->cn_flags & ISWHITEOUT) { - iswhiteout = 1; - } else if (lowerdvp != NULLVP) { - int terror; - - terror = VOP_GETATTR(upperdvp, &va, - cnp->cn_cred, cnp->cn_proc); - if (terror == 0 && (va.va_flags & OPAQUE)) - iswhiteout = 1; - } - } - } - - /* - * in a similar way to the upper layer, do the lookup - * in the lower layer. this time, if there is some - * component magic going on, then vput whatever we got - * back from the upper layer and return the lower vnode - * instead. - */ - - if (lowerdvp != NULLVP && !iswhiteout) { - int nameiop; - - UDEBUG(("B %p\n", lowerdvp)); - - /* - * Force only LOOKUPs on the lower node, since - * we won't be making changes to it anyway. - */ - nameiop = cnp->cn_nameiop; - cnp->cn_nameiop = LOOKUP; - if (um->um_op == UNMNT_BELOW) { - saved_cred = cnp->cn_cred; - cnp->cn_cred = um->um_cred; - } - - /* - * We shouldn't have to worry about locking interactions - * between the lower layer and our union layer (w.r.t. - * `..' processing) because we don't futz with lowervp - * locks in the union-node instantiation code path. - * - * union_lookup1() requires lowervp to be locked on entry, - * and it will be unlocked on return. The ref count will - * not change. On return lowervp doesn't represent anything - * to us so we NULL it out. - */ - VREF(lowerdvp); - vn_lock(lowerdvp, LK_EXCLUSIVE | LK_RETRY, p); - lerror = union_lookup1(um->um_lowervp, &lowerdvp, &lowervp, cnp); - if (lowerdvp == lowervp) - vrele(lowerdvp); - else - vput(lowerdvp); - lowerdvp = NULL; /* lowerdvp invalid after vput */ - - if (um->um_op == UNMNT_BELOW) - cnp->cn_cred = saved_cred; - cnp->cn_nameiop = nameiop; - - if (cnp->cn_consume != 0 || lerror == EACCES) { - if ((error = lerror) == 0) { - *ap->a_vpp = lowervp; - lowervp = NULL; - } - goto out; - } - } else { - UDEBUG(("C %p\n", lowerdvp)); - if ((cnp->cn_flags & ISDOTDOT) && dun->un_pvp != NULLVP) { - if ((lowervp = LOWERVP(dun->un_pvp)) != NULL) { - VREF(lowervp); - vn_lock(lowervp, LK_EXCLUSIVE | LK_RETRY, p); - lerror = 0; - } - } - } - - /* - * Ok. Now we have uerror, uppervp, upperdvp, lerror, and lowervp. - * - * 1. If both layers returned an error, select the upper layer. - * - * 2. If the upper layer faile and the bottom layer succeeded, - * two subcases occur: - * - * a. The bottom vnode is not a directory, in which case - * just return a new union vnode referencing an - * empty top layer and the existing bottom layer. - * - * b. The button vnode is a directory, in which case - * create a new directory in the top layer and - * and fall through to case 3. - * - * 3. If the top layer succeeded then return a new union - * vnode referencing whatever the new top layer and - * whatever the bottom layer returned. - */ - - /* case 1. */ - if ((uerror != 0) && (lerror != 0)) { - error = uerror; - goto out; - } - - /* case 2. */ - if (uerror != 0 /* && (lerror == 0) */ ) { - if (lowervp->v_type == VDIR) { /* case 2b. */ - KASSERT(uppervp == NULL, ("uppervp unexpectedly non-NULL")); - /* - * oops, uppervp has a problem, we may have to shadow. - */ - uerror = union_mkshadow(um, upperdvp, cnp, &uppervp); - if (uerror) { - error = uerror; - goto out; - } - } - } - - /* - * Must call union_allocvp with both the upper and lower vnodes - * referenced and the upper vnode locked. ap->a_vpp is returned - * referenced and locked. lowervp, uppervp, and upperdvp are - * absorbed by union_allocvp() whether it succeeds or fails. - * - * upperdvp is the parent directory of uppervp which may be - * different, depending on the path, from dvp->un_uppervp. That's - * why it is a separate argument. Note that it must be unlocked. - * - * dvp must be locked on entry to the call and will be locked on - * return. - */ - - if (uppervp && uppervp != upperdvp) - VOP_UNLOCK(uppervp, 0, p); - if (lowervp) - VOP_UNLOCK(lowervp, 0, p); - if (upperdvp) - VOP_UNLOCK(upperdvp, 0, p); - - error = union_allocvp(ap->a_vpp, dvp->v_mount, dvp, upperdvp, cnp, - uppervp, lowervp, 1); - - UDEBUG(("Create %p = %p %p refs=%d\n", *ap->a_vpp, uppervp, lowervp, (*ap->a_vpp) ? ((*ap->a_vpp)->v_usecount) : -99)); - - uppervp = NULL; - upperdvp = NULL; - lowervp = NULL; - - /* - * Termination Code - * - * - put away any extra junk laying around. Note that lowervp - * (if not NULL) will never be the same as *ap->a_vp and - * neither will uppervp, because when we set that state we - * NULL-out lowervp or uppervp. On the otherhand, upperdvp - * may match uppervp or *ap->a_vpp. - * - * - relock/unlock dvp if appropriate. - */ - -out: - if (upperdvp) { - if (upperdvp == uppervp || upperdvp == *ap->a_vpp) - vrele(upperdvp); - else - vput(upperdvp); - } - - if (uppervp) - vput(uppervp); - - if (lowervp) - vput(lowervp); - - /* - * Restore LOCKPARENT state - */ - - if (!lockparent) - cnp->cn_flags &= ~LOCKPARENT; - - UDEBUG(("Out %d vpp %p/%d lower %p upper %p\n", error, *ap->a_vpp, - ((*ap->a_vpp) ? (*ap->a_vpp)->v_usecount : -99), - lowervp, uppervp)); - - /* - * dvp lock state, determine whether to relock dvp. dvp is expected - * to be locked on return if: - * - * - there was an error (except not EJUSTRETURN), or - * - we hit the last component and lockparent is true - * - * dvp_is_locked is the current state of the dvp lock, not counting - * the possibility that *ap->a_vpp == dvp (in which case it is locked - * anyway). Note that *ap->a_vpp == dvp only if no error occured. - */ - - if (*ap->a_vpp != dvp) { - if ((error == 0 || error == EJUSTRETURN) && - (!lockparent || (cnp->cn_flags & ISLASTCN) == 0)) { - VOP_UNLOCK(dvp, 0, p); - } - } - - /* - * Diagnostics - */ - -#ifdef DIAGNOSTIC - if (cnp->cn_namelen == 1 && - cnp->cn_nameptr[0] == '.' && - *ap->a_vpp != dvp) { - panic("union_lookup returning . (%p) not same as startdir (%p)", ap->a_vpp, dvp); - } -#endif - - return (error); -} - -/* - * union_create: - * - * a_dvp is locked on entry and remains locked on return. a_vpp is returned - * locked if no error occurs, otherwise it is garbage. - */ - -static int -union_create(ap) - struct vop_create_args /* { - struct vnode *a_dvp; - struct vnode **a_vpp; - struct componentname *a_cnp; - struct vattr *a_vap; - } */ *ap; -{ - struct union_node *dun = VTOUNION(ap->a_dvp); - struct componentname *cnp = ap->a_cnp; - struct proc *p = cnp->cn_proc; - struct vnode *dvp; - int error = EROFS; - - if ((dvp = union_lock_upper(dun, p)) != NULL) { - struct vnode *vp; - struct mount *mp; - - error = VOP_CREATE(dvp, &vp, cnp, ap->a_vap); - if (error == 0) { - mp = ap->a_dvp->v_mount; - VOP_UNLOCK(vp, 0, p); - UDEBUG(("ALLOCVP-1 FROM %p REFS %d\n", vp, vp->v_usecount)); - error = union_allocvp(ap->a_vpp, mp, NULLVP, NULLVP, - cnp, vp, NULLVP, 1); - UDEBUG(("ALLOCVP-2B FROM %p REFS %d\n", *ap->a_vpp, vp->v_usecount)); - } - union_unlock_upper(dvp, p); - } - return (error); -} - -static int -union_whiteout(ap) - struct vop_whiteout_args /* { - struct vnode *a_dvp; - struct componentname *a_cnp; - int a_flags; - } */ *ap; -{ - struct union_node *un = VTOUNION(ap->a_dvp); - struct componentname *cnp = ap->a_cnp; - struct vnode *uppervp; - int error = EOPNOTSUPP; - - if ((uppervp = union_lock_upper(un, cnp->cn_proc)) != NULLVP) { - error = VOP_WHITEOUT(un->un_uppervp, cnp, ap->a_flags); - union_unlock_upper(uppervp, cnp->cn_proc); - } - return(error); -} - -/* - * union_mknod: - * - * a_dvp is locked on entry and should remain locked on return. - * a_vpp is garbagre whether an error occurs or not. - */ - -static int -union_mknod(ap) - struct vop_mknod_args /* { - struct vnode *a_dvp; - struct vnode **a_vpp; - struct componentname *a_cnp; - struct vattr *a_vap; - } */ *ap; -{ - struct union_node *dun = VTOUNION(ap->a_dvp); - struct componentname *cnp = ap->a_cnp; - struct vnode *dvp; - int error = EROFS; - - if ((dvp = union_lock_upper(dun, cnp->cn_proc)) != NULL) { - error = VOP_MKNOD(dvp, ap->a_vpp, cnp, ap->a_vap); - union_unlock_upper(dvp, cnp->cn_proc); - } - return (error); -} - -/* - * union_open: - * - * run open VOP. When opening the underlying vnode we have to mimic - * vn_open. What we *really* need to do to avoid screwups if the - * open semantics change is to call vn_open(). For example, ufs blows - * up if you open a file but do not vmio it prior to writing. - */ - -static int -union_open(ap) - struct vop_open_args /* { - struct vnodeop_desc *a_desc; - struct vnode *a_vp; - int a_mode; - struct ucred *a_cred; - struct proc *a_p; - } */ *ap; -{ - struct union_node *un = VTOUNION(ap->a_vp); - struct vnode *tvp; - int mode = ap->a_mode; - struct ucred *cred = ap->a_cred; - struct proc *p = ap->a_p; - int error = 0; - int tvpisupper = 1; - - /* - * If there is an existing upper vp then simply open that. - * The upper vp takes precedence over the lower vp. When opening - * a lower vp for writing copy it to the uppervp and then open the - * uppervp. - * - * At the end of this section tvp will be left locked. - */ - if ((tvp = union_lock_upper(un, p)) == NULLVP) { - /* - * If the lower vnode is being opened for writing, then - * copy the file contents to the upper vnode and open that, - * otherwise can simply open the lower vnode. - */ - tvp = un->un_lowervp; - if ((ap->a_mode & FWRITE) && (tvp->v_type == VREG)) { - int docopy = !(mode & O_TRUNC); - error = union_copyup(un, docopy, cred, p); - tvp = union_lock_upper(un, p); - } else { - un->un_openl++; - VREF(tvp); - vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY, p); - tvpisupper = 0; - } - } - - /* - * We are holding the correct vnode, open it - */ - - if (error == 0) - error = VOP_OPEN(tvp, mode, cred, p); - - /* - * Absolutely necessary or UFS will blowup - */ - if (error == 0 && vn_canvmio(tvp) == TRUE) { - error = vfs_object_create(tvp, p, cred); - } - - /* - * Release any locks held - */ - if (tvpisupper) { - if (tvp) - union_unlock_upper(tvp, p); - } else { - vput(tvp); - } - return (error); -} - -/* - * union_close: - * - * It is unclear whether a_vp is passed locked or unlocked. Whatever - * the case we do not change it. - */ - -static int -union_close(ap) - struct vop_close_args /* { - struct vnode *a_vp; - int a_fflag; - struct ucred *a_cred; - struct proc *a_p; - } */ *ap; -{ - struct union_node *un = VTOUNION(ap->a_vp); - struct vnode *vp; - - if ((vp = un->un_uppervp) == NULLVP) { -#ifdef UNION_DIAGNOSTIC - if (un->un_openl <= 0) - panic("union: un_openl cnt"); -#endif - --un->un_openl; - vp = un->un_lowervp; - } - ap->a_vp = vp; - return (VCALL(vp, VOFFSET(vop_close), ap)); -} - -/* - * Check access permission on the union vnode. - * The access check being enforced is to check - * against both the underlying vnode, and any - * copied vnode. This ensures that no additional - * file permissions are given away simply because - * the user caused an implicit file copy. - */ -static int -union_access(ap) - struct vop_access_args /* { - struct vnodeop_desc *a_desc; - struct vnode *a_vp; - int a_mode; - struct ucred *a_cred; - struct proc *a_p; - } */ *ap; -{ - struct union_node *un = VTOUNION(ap->a_vp); - struct proc *p = ap->a_p; - int error = EACCES; - struct vnode *vp; - - /* - * Disallow write attempts on filesystems mounted read-only. - */ - if ((ap->a_mode & VWRITE) && - (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)) { - switch (ap->a_vp->v_type) { - case VREG: - case VDIR: - case VLNK: - return (EROFS); - default: - break; - } - } - - if ((vp = union_lock_upper(un, p)) != NULLVP) { - ap->a_vp = vp; - error = VCALL(vp, VOFFSET(vop_access), ap); - union_unlock_upper(vp, p); - return(error); - } - - if ((vp = un->un_lowervp) != NULLVP) { - vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); - ap->a_vp = vp; - - /* - * Remove VWRITE from a_mode if our mount point is RW, because - * we want to allow writes and lowervp may be read-only. - */ - if ((un->un_vnode->v_mount->mnt_flag & MNT_RDONLY) == 0) - ap->a_mode &= ~VWRITE; - - error = VCALL(vp, VOFFSET(vop_access), ap); - if (error == 0) { - struct union_mount *um; - - um = MOUNTTOUNIONMOUNT(un->un_vnode->v_mount); - - if (um->um_op == UNMNT_BELOW) { - ap->a_cred = um->um_cred; - error = VCALL(vp, VOFFSET(vop_access), ap); - } - } - VOP_UNLOCK(vp, 0, p); - } - return(error); -} - -/* - * We handle getattr only to change the fsid and - * track object sizes - * - * It's not clear whether VOP_GETATTR is to be - * called with the vnode locked or not. stat() calls - * it with (vp) locked, and fstat calls it with - * (vp) unlocked. - * - * Because of this we cannot use our normal locking functions - * if we do not intend to lock the main a_vp node. At the moment - * we are running without any specific locking at all, but beware - * to any programmer that care must be taken if locking is added - * to this function. - */ - -static int -union_getattr(ap) - struct vop_getattr_args /* { - struct vnode *a_vp; - struct vattr *a_vap; - struct ucred *a_cred; - struct proc *a_p; - } */ *ap; -{ - int error; - struct union_node *un = VTOUNION(ap->a_vp); - struct vnode *vp; - struct vattr *vap; - struct vattr va; - - /* - * Some programs walk the filesystem hierarchy by counting - * links to directories to avoid stat'ing all the time. - * This means the link count on directories needs to be "correct". - * The only way to do that is to call getattr on both layers - * and fix up the link count. The link count will not necessarily - * be accurate but will be large enough to defeat the tree walkers. - */ - - vap = ap->a_vap; - - if ((vp = un->un_uppervp) != NULLVP) { - error = VOP_GETATTR(vp, vap, ap->a_cred, ap->a_p); - if (error) - return (error); - /* XXX isn't this dangerouso without a lock? */ - union_newsize(ap->a_vp, vap->va_size, VNOVAL); - } - - if (vp == NULLVP) { - vp = un->un_lowervp; - } else if (vp->v_type == VDIR && un->un_lowervp != NULLVP) { - vp = un->un_lowervp; - vap = &va; - } else { - vp = NULLVP; - } - - if (vp != NULLVP) { - error = VOP_GETATTR(vp, vap, ap->a_cred, ap->a_p); - if (error) - return (error); - /* XXX isn't this dangerous without a lock? */ - union_newsize(ap->a_vp, VNOVAL, vap->va_size); - } - - if ((vap != ap->a_vap) && (vap->va_type == VDIR)) - ap->a_vap->va_nlink += vap->va_nlink; - return (0); -} - -static int -union_setattr(ap) - struct vop_setattr_args /* { - struct vnode *a_vp; - struct vattr *a_vap; - struct ucred *a_cred; - struct proc *a_p; - } */ *ap; -{ - struct union_node *un = VTOUNION(ap->a_vp); - struct proc *p = ap->a_p; - struct vattr *vap = ap->a_vap; - struct vnode *uppervp; - int error; - - /* - * Disallow write attempts on filesystems mounted read-only. - */ - if ((ap->a_vp->v_mount->mnt_flag & MNT_RDONLY) && - (vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL || - vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL || - vap->va_mtime.tv_sec != VNOVAL || - vap->va_mode != (mode_t)VNOVAL)) { - return (EROFS); - } - - /* - * Handle case of truncating lower object to zero size, - * by creating a zero length upper object. This is to - * handle the case of open with O_TRUNC and O_CREAT. - */ - if (un->un_uppervp == NULLVP && (un->un_lowervp->v_type == VREG)) { - error = union_copyup(un, (ap->a_vap->va_size != 0), - ap->a_cred, ap->a_p); - if (error) - return (error); - } - - /* - * Try to set attributes in upper layer, - * otherwise return read-only filesystem error. - */ - error = EROFS; - if ((uppervp = union_lock_upper(un, p)) != NULLVP) { - error = VOP_SETATTR(un->un_uppervp, ap->a_vap, - ap->a_cred, ap->a_p); - if ((error == 0) && (ap->a_vap->va_size != VNOVAL)) - union_newsize(ap->a_vp, ap->a_vap->va_size, VNOVAL); - union_unlock_upper(uppervp, p); - } - return (error); -} - -static int -union_read(ap) - struct vop_read_args /* { - struct vnode *a_vp; - struct uio *a_uio; - int a_ioflag; - struct ucred *a_cred; - } */ *ap; -{ - struct union_node *un = VTOUNION(ap->a_vp); - struct proc *p = ap->a_uio->uio_procp; - struct vnode *uvp; - int error; - - uvp = union_lock_other(un, p); - KASSERT(uvp != NULL, ("union_read: backing vnode missing!")); - - error = VOP_READ(uvp, ap->a_uio, ap->a_ioflag, ap->a_cred); - union_unlock_other(uvp, p); - - /* - * XXX - * perhaps the size of the underlying object has changed under - * our feet. take advantage of the offset information present - * in the uio structure. - */ - if (error == 0) { - struct union_node *un = VTOUNION(ap->a_vp); - off_t cur = ap->a_uio->uio_offset; - - if (uvp == un->un_uppervp) { - if (cur > un->un_uppersz) - union_newsize(ap->a_vp, cur, VNOVAL); - } else { - if (cur > un->un_lowersz) - union_newsize(ap->a_vp, VNOVAL, cur); - } - } - return (error); -} - -static int -union_write(ap) - struct vop_read_args /* { - struct vnode *a_vp; - struct uio *a_uio; - int a_ioflag; - struct ucred *a_cred; - } */ *ap; -{ - struct union_node *un = VTOUNION(ap->a_vp); - struct proc *p = ap->a_uio->uio_procp; - struct vnode *uppervp; - int error; - - if ((uppervp = union_lock_upper(un, p)) == NULLVP) - panic("union: missing upper layer in write"); - - error = VOP_WRITE(uppervp, ap->a_uio, ap->a_ioflag, ap->a_cred); - - /* - * the size of the underlying object may be changed by the - * write. - */ - if (error == 0) { - off_t cur = ap->a_uio->uio_offset; - - if (cur > un->un_uppersz) - union_newsize(ap->a_vp, cur, VNOVAL); - } - union_unlock_upper(uppervp, p); - return (error); -} - -static int -union_lease(ap) - struct vop_lease_args /* { - struct vnode *a_vp; - struct proc *a_p; - struct ucred *a_cred; - int a_flag; - } */ *ap; -{ - struct vnode *ovp = OTHERVP(ap->a_vp); - - ap->a_vp = ovp; - return (VCALL(ovp, VOFFSET(vop_lease), ap)); -} - -static int -union_ioctl(ap) - struct vop_ioctl_args /* { - struct vnode *a_vp; - int a_command; - caddr_t a_data; - int a_fflag; - struct ucred *a_cred; - struct proc *a_p; - } */ *ap; -{ - struct vnode *ovp = OTHERVP(ap->a_vp); - - ap->a_vp = ovp; - return (VCALL(ovp, VOFFSET(vop_ioctl), ap)); -} - -static int -union_poll(ap) - struct vop_poll_args /* { - struct vnode *a_vp; - int a_events; - struct ucred *a_cred; - struct proc *a_p; - } */ *ap; -{ - struct vnode *ovp = OTHERVP(ap->a_vp); - - ap->a_vp = ovp; - return (VCALL(ovp, VOFFSET(vop_poll), ap)); -} - -static int -union_revoke(ap) - struct vop_revoke_args /* { - struct vnode *a_vp; - int a_flags; - struct proc *a_p; - } */ *ap; -{ - struct vnode *vp = ap->a_vp; - - if (UPPERVP(vp)) - VOP_REVOKE(UPPERVP(vp), ap->a_flags); - if (LOWERVP(vp)) - VOP_REVOKE(LOWERVP(vp), ap->a_flags); - vgone(vp); - return (0); -} - -static int -union_fsync(ap) - struct vop_fsync_args /* { - struct vnode *a_vp; - struct ucred *a_cred; - int a_waitfor; - struct proc *a_p; - } */ *ap; -{ - int error = 0; - struct proc *p = ap->a_p; - struct vnode *targetvp; - struct union_node *un = VTOUNION(ap->a_vp); - - if ((targetvp = union_lock_other(un, p)) != NULLVP) { - error = VOP_FSYNC(targetvp, ap->a_cred, ap->a_waitfor, p); - union_unlock_other(targetvp, p); - } - - return (error); -} - -/* - * union_remove: - * - * Remove the specified cnp. The dvp and vp are passed to us locked - * and must remain locked on return. - */ - -static int -union_remove(ap) - struct vop_remove_args /* { - struct vnode *a_dvp; - struct vnode *a_vp; - struct componentname *a_cnp; - } */ *ap; -{ - struct union_node *dun = VTOUNION(ap->a_dvp); - struct union_node *un = VTOUNION(ap->a_vp); - struct componentname *cnp = ap->a_cnp; - struct proc *p = cnp->cn_proc; - struct vnode *uppervp; - struct vnode *upperdvp; - int error; - - if ((upperdvp = union_lock_upper(dun, p)) == NULLVP) - panic("union remove: null upper vnode"); - - if ((uppervp = union_lock_upper(un, p)) != NULLVP) { - if (union_dowhiteout(un, cnp->cn_cred, p)) - cnp->cn_flags |= DOWHITEOUT; - error = VOP_REMOVE(upperdvp, uppervp, cnp); -#if 0 - /* XXX */ - if (!error) - union_removed_upper(un); -#endif - union_unlock_upper(uppervp, p); - } else { - error = union_mkwhiteout( - MOUNTTOUNIONMOUNT(ap->a_dvp->v_mount), - upperdvp, ap->a_cnp, un->un_path); - } - union_unlock_upper(upperdvp, p); - return (error); -} - -/* - * union_link: - * - * tdvp will be locked on entry, vp will not be locked on entry. - * tdvp should remain locked on return and vp should remain unlocked - * on return. - */ - -static int -union_link(ap) - struct vop_link_args /* { - struct vnode *a_tdvp; - struct vnode *a_vp; - struct componentname *a_cnp; - } */ *ap; -{ - struct componentname *cnp = ap->a_cnp; - struct proc *p = cnp->cn_proc; - struct union_node *dun = VTOUNION(ap->a_tdvp); - struct vnode *vp; - struct vnode *tdvp; - int error = 0; - - if (ap->a_tdvp->v_op != ap->a_vp->v_op) { - vp = ap->a_vp; - } else { - struct union_node *tun = VTOUNION(ap->a_vp); - - if (tun->un_uppervp == NULLVP) { - vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, p); -#if 0 - if (dun->un_uppervp == tun->un_dirvp) { - if (dun->un_flags & UN_ULOCK) { - dun->un_flags &= ~UN_ULOCK; - VOP_UNLOCK(dun->un_uppervp, 0, p); - } - } -#endif - error = union_copyup(tun, 1, cnp->cn_cred, p); -#if 0 - if (dun->un_uppervp == tun->un_dirvp) { - vn_lock(dun->un_uppervp, - LK_EXCLUSIVE | LK_RETRY, p); - dun->un_flags |= UN_ULOCK; - } -#endif - VOP_UNLOCK(ap->a_vp, 0, p); - } - vp = tun->un_uppervp; - } - - if (error) - return (error); - - /* - * Make sure upper is locked, then unlock the union directory we were - * called with to avoid a deadlock while we are calling VOP_LINK on - * the upper (with tdvp locked and vp not locked). Our ap->a_tdvp - * is expected to be locked on return. - */ - - if ((tdvp = union_lock_upper(dun, p)) == NULLVP) - return (EROFS); - - VOP_UNLOCK(ap->a_tdvp, 0, p); /* unlock calling node */ - error = VOP_LINK(tdvp, vp, cnp); /* call link on upper */ - - /* - * We have to unlock tdvp prior to relocking our calling node in - * order to avoid a deadlock. - */ - union_unlock_upper(tdvp, p); - vn_lock(ap->a_tdvp, LK_EXCLUSIVE | LK_RETRY, p); - return (error); -} - -static int -union_rename(ap) - struct vop_rename_args /* { - struct vnode *a_fdvp; - struct vnode *a_fvp; - struct componentname *a_fcnp; - struct vnode *a_tdvp; - struct vnode *a_tvp; - struct componentname *a_tcnp; - } */ *ap; -{ - int error; - struct vnode *fdvp = ap->a_fdvp; - struct vnode *fvp = ap->a_fvp; - struct vnode *tdvp = ap->a_tdvp; - struct vnode *tvp = ap->a_tvp; - - /* - * Figure out what fdvp to pass to our upper or lower vnode. If we - * replace the fdvp, release the original one and ref the new one. - */ - - if (fdvp->v_op == union_vnodeop_p) { /* always true */ - struct union_node *un = VTOUNION(fdvp); - if (un->un_uppervp == NULLVP) { - /* - * this should never happen in normal - * operation but might if there was - * a problem creating the top-level shadow - * directory. - */ - error = EXDEV; - goto bad; - } - fdvp = un->un_uppervp; - VREF(fdvp); - vrele(ap->a_fdvp); - } - - /* - * Figure out what fvp to pass to our upper or lower vnode. If we - * replace the fvp, release the original one and ref the new one. - */ - - if (fvp->v_op == union_vnodeop_p) { /* always true */ - struct union_node *un = VTOUNION(fvp); -#if 0 - struct union_mount *um = MOUNTTOUNIONMOUNT(fvp->v_mount); -#endif - - if (un->un_uppervp == NULLVP) { - switch(fvp->v_type) { - case VREG: - vn_lock(un->un_vnode, LK_EXCLUSIVE | LK_RETRY, ap->a_fcnp->cn_proc); - error = union_copyup(un, 1, ap->a_fcnp->cn_cred, ap->a_fcnp->cn_proc); - VOP_UNLOCK(un->un_vnode, 0, ap->a_fcnp->cn_proc); - if (error) - goto bad; - break; - case VDIR: - /* - * XXX not yet. - * - * There is only one way to rename a directory - * based in the lowervp, and that is to copy - * the entire directory hierarchy. Otherwise - * it would not last across a reboot. - */ -#if 0 - vrele(fvp); - fvp = NULL; - vn_lock(fdvp, LK_EXCLUSIVE | LK_RETRY, ap->a_fcnp->cn_proc); - error = union_mkshadow(um, fdvp, - ap->a_fcnp, &un->un_uppervp); - VOP_UNLOCK(fdvp, 0, ap->a_fcnp->cn_proc); - if (un->un_uppervp) - VOP_UNLOCK(un->un_uppervp, 0, ap->a_fcnp->cn_proc); - if (error) - goto bad; - break; -#endif - default: - error = EXDEV; - goto bad; - } - } - - if (un->un_lowervp != NULLVP) - ap->a_fcnp->cn_flags |= DOWHITEOUT; - fvp = un->un_uppervp; - VREF(fvp); - vrele(ap->a_fvp); - } - - /* - * Figure out what tdvp (destination directory) to pass to the - * lower level. If we replace it with uppervp, we need to vput the - * old one. The exclusive lock is transfered to what we will pass - * down in the VOP_RENAME and we replace uppervp with a simple - * reference. - */ - - if (tdvp->v_op == union_vnodeop_p) { - struct union_node *un = VTOUNION(tdvp); - - if (un->un_uppervp == NULLVP) { - /* - * this should never happen in normal - * operation but might if there was - * a problem creating the top-level shadow - * directory. - */ - error = EXDEV; - goto bad; - } - - /* - * new tdvp is a lock and reference on uppervp, put away - * the old tdvp. - */ - tdvp = union_lock_upper(un, ap->a_tcnp->cn_proc); - vput(ap->a_tdvp); - } - - /* - * Figure out what tvp (destination file) to pass to the - * lower level. - * - * If the uppervp file does not exist put away the (wrong) - * file and change tvp to NULL. - */ - - if (tvp != NULLVP && tvp->v_op == union_vnodeop_p) { - struct union_node *un = VTOUNION(tvp); - - tvp = union_lock_upper(un, ap->a_tcnp->cn_proc); - vput(ap->a_tvp); - /* note: tvp may be NULL */ - } - - /* - * VOP_RENAME releases/vputs prior to returning, so we have no - * cleanup to do. - */ - - return (VOP_RENAME(fdvp, fvp, ap->a_fcnp, tdvp, tvp, ap->a_tcnp)); - - /* - * Error. We still have to release / vput the various elements. - */ - -bad: - vrele(fdvp); - if (fvp) - vrele(fvp); - vput(tdvp); - if (tvp != NULLVP) { - if (tvp != tdvp) - vput(tvp); - else - vrele(tvp); - } - return (error); -} - -static int -union_mkdir(ap) - struct vop_mkdir_args /* { - struct vnode *a_dvp; - struct vnode **a_vpp; - struct componentname *a_cnp; - struct vattr *a_vap; - } */ *ap; -{ - struct union_node *dun = VTOUNION(ap->a_dvp); - struct componentname *cnp = ap->a_cnp; - struct proc *p = cnp->cn_proc; - struct vnode *upperdvp; - int error = EROFS; - - if ((upperdvp = union_lock_upper(dun, p)) != NULLVP) { - struct vnode *vp; - - error = VOP_MKDIR(upperdvp, &vp, cnp, ap->a_vap); - union_unlock_upper(upperdvp, p); - - if (error == 0) { - VOP_UNLOCK(vp, 0, p); - UDEBUG(("ALLOCVP-2 FROM %p REFS %d\n", vp, vp->v_usecount)); - error = union_allocvp(ap->a_vpp, ap->a_dvp->v_mount, - ap->a_dvp, NULLVP, cnp, vp, NULLVP, 1); - UDEBUG(("ALLOCVP-2B FROM %p REFS %d\n", *ap->a_vpp, vp->v_usecount)); - } - } - return (error); -} - -static int -union_rmdir(ap) - struct vop_rmdir_args /* { - struct vnode *a_dvp; - struct vnode *a_vp; - struct componentname *a_cnp; - } */ *ap; -{ - struct union_node *dun = VTOUNION(ap->a_dvp); - struct union_node *un = VTOUNION(ap->a_vp); - struct componentname *cnp = ap->a_cnp; - struct proc *p = cnp->cn_proc; - struct vnode *upperdvp; - struct vnode *uppervp; - int error; - - if ((upperdvp = union_lock_upper(dun, p)) == NULLVP) - panic("union rmdir: null upper vnode"); - - if ((uppervp = union_lock_upper(un, p)) != NULLVP) { - if (union_dowhiteout(un, cnp->cn_cred, p)) - cnp->cn_flags |= DOWHITEOUT; - error = VOP_RMDIR(upperdvp, uppervp, ap->a_cnp); - union_unlock_upper(uppervp, p); - } else { - error = union_mkwhiteout( - MOUNTTOUNIONMOUNT(ap->a_dvp->v_mount), - dun->un_uppervp, ap->a_cnp, un->un_path); - } - union_unlock_upper(upperdvp, p); - return (error); -} - -/* - * union_symlink: - * - * dvp is locked on entry and remains locked on return. a_vpp is garbage - * (unused). - */ - -static int -union_symlink(ap) - struct vop_symlink_args /* { - struct vnode *a_dvp; - struct vnode **a_vpp; - struct componentname *a_cnp; - struct vattr *a_vap; - char *a_target; - } */ *ap; -{ - struct union_node *dun = VTOUNION(ap->a_dvp); - struct componentname *cnp = ap->a_cnp; - struct proc *p = cnp->cn_proc; - struct vnode *dvp; - int error = EROFS; - - if ((dvp = union_lock_upper(dun, p)) != NULLVP) { - error = VOP_SYMLINK(dvp, ap->a_vpp, cnp, ap->a_vap, - ap->a_target); - union_unlock_upper(dvp, p); - } - return (error); -} - -/* - * union_readdir works in concert with getdirentries and - * readdir(3) to provide a list of entries in the unioned - * directories. getdirentries is responsible for walking - * down the union stack. readdir(3) is responsible for - * eliminating duplicate names from the returned data stream. - */ -static int -union_readdir(ap) - struct vop_readdir_args /* { - struct vnode *a_vp; - struct uio *a_uio; - struct ucred *a_cred; - int *a_eofflag; - u_long *a_cookies; - int a_ncookies; - } */ *ap; -{ - struct union_node *un = VTOUNION(ap->a_vp); - struct proc *p = ap->a_uio->uio_procp; - struct vnode *uvp; - int error = 0; - - if ((uvp = union_lock_upper(un, p)) != NULLVP) { - ap->a_vp = uvp; - error = VCALL(uvp, VOFFSET(vop_readdir), ap); - union_unlock_upper(uvp, p); - } - return(error); -} - -static int -union_readlink(ap) - struct vop_readlink_args /* { - struct vnode *a_vp; - struct uio *a_uio; - struct ucred *a_cred; - } */ *ap; -{ - int error; - struct union_node *un = VTOUNION(ap->a_vp); - struct uio *uio = ap->a_uio; - struct proc *p = uio->uio_procp; - struct vnode *vp; - - vp = union_lock_other(un, p); - KASSERT(vp != NULL, ("union_readlink: backing vnode missing!")); - - ap->a_vp = vp; - error = VCALL(vp, VOFFSET(vop_readlink), ap); - union_unlock_other(vp, p); - - return (error); -} - -static int -union_getwritemount(ap) - struct vop_getwritemount_args /* { - struct vnode *a_vp; - struct mount **a_mpp; - } */ *ap; -{ - struct vnode *vp = ap->a_vp; - struct vnode *uvp = UPPERVP(vp); - - if (uvp == NULL) { - VI_LOCK(vp); - if (vp->v_flag & VFREE) { - VI_UNLOCK(vp); - return (EOPNOTSUPP); - } - VI_UNLOCK(vp); - return (EACCES); - } - return(VOP_GETWRITEMOUNT(uvp, ap->a_mpp)); -} - -/* - * union_inactive: - * - * Called with the vnode locked. We are expected to unlock the vnode. - */ - -static int -union_inactive(ap) - struct vop_inactive_args /* { - struct vnode *a_vp; - struct proc *a_p; - } */ *ap; -{ - struct vnode *vp = ap->a_vp; - struct proc *p = ap->a_p; - struct union_node *un = VTOUNION(vp); - struct vnode **vpp; - - /* - * Do nothing (and _don't_ bypass). - * Wait to vrele lowervp until reclaim, - * so that until then our union_node is in the - * cache and reusable. - * - * NEEDSWORK: Someday, consider inactive'ing - * the lowervp and then trying to reactivate it - * with capabilities (v_id) - * like they do in the name lookup cache code. - * That's too much work for now. - */ - - if (un->un_dircache != 0) { - for (vpp = un->un_dircache; *vpp != NULLVP; vpp++) - vrele(*vpp); - free (un->un_dircache, M_TEMP); - un->un_dircache = 0; - } - -#if 0 - if ((un->un_flags & UN_ULOCK) && un->un_uppervp) { - un->un_flags &= ~UN_ULOCK; - VOP_UNLOCK(un->un_uppervp, 0, p); - } -#endif - - VOP_UNLOCK(vp, 0, p); - - if ((un->un_flags & UN_CACHED) == 0) - vgone(vp); - - return (0); -} - -static int -union_reclaim(ap) - struct vop_reclaim_args /* { - struct vnode *a_vp; - } */ *ap; -{ - union_freevp(ap->a_vp); - - return (0); -} - -static int -union_lock(ap) - struct vop_lock_args *ap; -{ -#if 0 - struct vnode *vp = ap->a_vp; - struct proc *p = ap->a_p; - int flags = ap->a_flags; - struct union_node *un; -#endif - int error; - - error = vop_stdlock(ap); -#if 0 - un = VTOUNION(vp); - - if (error == 0) { - /* - * Lock the upper if it exists and this is an exclusive lock - * request. - */ - if (un->un_uppervp != NULLVP && - (flags & LK_TYPE_MASK) == LK_EXCLUSIVE) { - if ((un->un_flags & UN_ULOCK) == 0 && vp->v_usecount) { - error = vn_lock(un->un_uppervp, flags, p); - if (error) { - struct vop_unlock_args uap = { 0 }; - uap.a_vp = ap->a_vp; - uap.a_flags = ap->a_flags; - uap.a_p = ap->a_p; - vop_stdunlock(&uap); - return (error); - } - un->un_flags |= UN_ULOCK; - } - } - } -#endif - return (error); -} - -/* - * union_unlock: - * - * Unlock our union node. This also unlocks uppervp. - */ -static int -union_unlock(ap) - struct vop_unlock_args /* { - struct vnode *a_vp; - int a_flags; - struct proc *a_p; - } */ *ap; -{ -#if 0 - struct union_node *un = VTOUNION(ap->a_vp); -#endif - int error; - -#if 0 - KASSERT((un->un_uppervp == NULL || un->un_uppervp->v_usecount > 0), ("uppervp usecount is 0")); -#endif - - error = vop_stdunlock(ap); -#if 0 - - /* - * If no exclusive locks remain and we are holding an uppervp lock, - * remove the uppervp lock. - */ - - if ((un->un_flags & UN_ULOCK) && - lockstatus(&un->un_lock, NULL) != LK_EXCLUSIVE) { - un->un_flags &= ~UN_ULOCK; - VOP_UNLOCK(un->un_uppervp, LK_EXCLUSIVE, p); - } -#endif - return(error); -} - -/* - * unionvp do not hold a VM object and there is no need to create one for - * upper or lower vp because it is done in the union_open() - */ -static int -union_createvobject(ap) - struct vop_createvobject_args /* { - struct vnode *vp; - struct ucred *cred; - struct proc *p; - } */ *ap; -{ - struct vnode *vp = ap->a_vp; - - vp->v_flag |= VOBJBUF; - return (0); -} - -/* - * We have nothing to destroy and this operation shouldn't be bypassed. - */ -static int -union_destroyvobject(ap) - struct vop_destroyvobject_args /* { - struct vnode *vp; - } */ *ap; -{ - struct vnode *vp = ap->a_vp; - - vp->v_flag &= ~VOBJBUF; - return (0); -} - -/* - * Get VM object from the upper or lower vp - */ -static int -union_getvobject(ap) - struct vop_getvobject_args /* { - struct vnode *vp; - struct vm_object **objpp; - } */ *ap; -{ - struct vnode *ovp = OTHERVP(ap->a_vp); - - if (ovp == NULL) - return EINVAL; - return (VOP_GETVOBJECT(ovp, ap->a_objpp)); -} - -static int -union_print(ap) - struct vop_print_args /* { - struct vnode *a_vp; - } */ *ap; -{ - struct vnode *vp = ap->a_vp; - - printf("\ttag VT_UNION, vp=%p, uppervp=%p, lowervp=%p\n", - vp, UPPERVP(vp), LOWERVP(vp)); - if (UPPERVP(vp) != NULLVP) - vprint("union: upper", UPPERVP(vp)); - if (LOWERVP(vp) != NULLVP) - vprint("union: lower", LOWERVP(vp)); - - return (0); -} - -static int -union_pathconf(ap) - struct vop_pathconf_args /* { - struct vnode *a_vp; - int a_name; - int *a_retval; - } */ *ap; -{ - int error; - struct proc *p = curproc; /* XXX */ - struct union_node *un = VTOUNION(ap->a_vp); - struct vnode *vp; - - vp = union_lock_other(un, p); - KASSERT(vp != NULL, ("union_pathconf: backing vnode missing!")); - - ap->a_vp = vp; - error = VCALL(vp, VOFFSET(vop_pathconf), ap); - union_unlock_other(vp, p); - - return (error); -} - -static int -union_advlock(ap) - struct vop_advlock_args /* { - struct vnode *a_vp; - caddr_t a_id; - int a_op; - struct flock *a_fl; - int a_flags; - } */ *ap; -{ - register struct vnode *ovp = OTHERVP(ap->a_vp); - - ap->a_vp = ovp; - return (VCALL(ovp, VOFFSET(vop_advlock), ap)); -} - - -/* - * XXX - vop_strategy must be hand coded because it has no - * YYY - and it is not coherent with anything - * - * vnode in its arguments. - * This goes away with a merged VM/buffer cache. - */ -static int -union_strategy(ap) - struct vop_strategy_args /* { - struct vnode *a_vp; - struct buf *a_bp; - } */ *ap; -{ - struct buf *bp = ap->a_bp; - struct vnode *othervp = OTHERVP(bp->b_vp); - -#ifdef DIAGNOSTIC - if (othervp == NULLVP) - panic("union_strategy: nil vp"); - if ((bp->b_iocmd == BIO_WRITE) && - (othervp == LOWERVP(bp->b_vp))) - panic("union_strategy: writing to lowervp"); -#endif - return (VOP_STRATEGY(othervp, bp)); -} - -/* - * Global vfs data structures - */ -vop_t **union_vnodeop_p; -static struct vnodeopv_entry_desc union_vnodeop_entries[] = { - { &vop_default_desc, (vop_t *) vop_defaultop }, - { &vop_access_desc, (vop_t *) union_access }, - { &vop_advlock_desc, (vop_t *) union_advlock }, - { &vop_bmap_desc, (vop_t *) vop_eopnotsupp }, - { &vop_close_desc, (vop_t *) union_close }, - { &vop_create_desc, (vop_t *) union_create }, - { &vop_createvobject_desc, (vop_t *) union_createvobject }, - { &vop_destroyvobject_desc, (vop_t *) union_destroyvobject }, - { &vop_fsync_desc, (vop_t *) union_fsync }, - { &vop_getattr_desc, (vop_t *) union_getattr }, - { &vop_getvobject_desc, (vop_t *) union_getvobject }, - { &vop_inactive_desc, (vop_t *) union_inactive }, - { &vop_ioctl_desc, (vop_t *) union_ioctl }, - { &vop_islocked_desc, (vop_t *) vop_stdislocked }, - { &vop_lease_desc, (vop_t *) union_lease }, - { &vop_link_desc, (vop_t *) union_link }, - { &vop_lock_desc, (vop_t *) union_lock }, - { &vop_lookup_desc, (vop_t *) union_lookup }, - { &vop_mkdir_desc, (vop_t *) union_mkdir }, - { &vop_mknod_desc, (vop_t *) union_mknod }, - { &vop_open_desc, (vop_t *) union_open }, - { &vop_pathconf_desc, (vop_t *) union_pathconf }, - { &vop_poll_desc, (vop_t *) union_poll }, - { &vop_print_desc, (vop_t *) union_print }, - { &vop_read_desc, (vop_t *) union_read }, - { &vop_readdir_desc, (vop_t *) union_readdir }, - { &vop_readlink_desc, (vop_t *) union_readlink }, - { &vop_getwritemount_desc, (vop_t *) union_getwritemount }, - { &vop_reclaim_desc, (vop_t *) union_reclaim }, - { &vop_remove_desc, (vop_t *) union_remove }, - { &vop_rename_desc, (vop_t *) union_rename }, - { &vop_revoke_desc, (vop_t *) union_revoke }, - { &vop_rmdir_desc, (vop_t *) union_rmdir }, - { &vop_setattr_desc, (vop_t *) union_setattr }, - { &vop_strategy_desc, (vop_t *) union_strategy }, - { &vop_symlink_desc, (vop_t *) union_symlink }, - { &vop_unlock_desc, (vop_t *) union_unlock }, - { &vop_whiteout_desc, (vop_t *) union_whiteout }, - { &vop_write_desc, (vop_t *) union_write }, - { NULL, NULL } -}; -static struct vnodeopv_desc union_vnodeop_opv_desc = - { &union_vnodeop_p, union_vnodeop_entries }; - -VNODEOP_SET(union_vnodeop_opv_desc); |
