diff options
Diffstat (limited to 'sys/miscfs/union/union_vnops.c')
| -rw-r--r-- | sys/miscfs/union/union_vnops.c | 1966 |
1 files changed, 0 insertions, 1966 deletions
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); |
