diff --git a/sys/fs/unionfs/union_vfsops.c b/sys/fs/unionfs/union_vfsops.c index 753afd601f82..90da301e8a7b 100644 --- a/sys/fs/unionfs/union_vfsops.c +++ b/sys/fs/unionfs/union_vfsops.c @@ -1,562 +1,556 @@ /* * 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 - * $Id: union_vfsops.c,v 1.21 1997/10/12 20:24:57 phk Exp $ + * $Id: union_vfsops.c,v 1.22 1997/11/18 15:07:35 phk Exp $ */ /* * Union Layer */ #include #include #include #include #include #include #include #include #include #include static MALLOC_DEFINE(M_UNIONFSMNT, "UNION mount", "UNION mount structure"); extern int union_init __P((struct vfsconf *)); extern int union_fhtovp __P((struct mount *mp, struct fid *fidp, struct mbuf *nam, struct vnode **vpp, int *exflagsp, struct ucred **credanonp)); static int union_mount __P((struct mount *mp, char *path, caddr_t data, struct nameidata *ndp, struct proc *p)); extern int union_quotactl __P((struct mount *mp, int cmd, uid_t uid, caddr_t arg, struct proc *p)); static int union_root __P((struct mount *mp, struct vnode **vpp)); static int union_start __P((struct mount *mp, int flags, struct proc *p)); static int union_statfs __P((struct mount *mp, struct statfs *sbp, struct proc *p)); extern int union_sync __P((struct mount *mp, int waitfor, struct ucred *cred, struct proc *p)); static int union_unmount __P((struct mount *mp, int mntflags, struct proc *p)); extern int union_vget __P((struct mount *mp, ino_t ino, struct vnode **vpp)); extern int union_vptofh __P((struct vnode *vp, struct fid *fhp)); /* * 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; int islowerunlocked = 0; #ifdef UNION_DIAGNOSTIC printf("union_mount(mp = %x)\n", mp); #endif /* * 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; lowerrootvp = mp->mnt_vnodecovered; VREF(lowerrootvp); /* * Unlock lower node to avoid deadlock. - * (XXX) VOP_ISLOCKED is needed? */ - if ((lowerrootvp->v_op == union_vnodeop_p) && VOP_ISLOCKED(lowerrootvp)) { + if (lowerrootvp->v_op == union_vnodeop_p) VOP_UNLOCK(lowerrootvp, 0, p); - islowerunlocked = 1; - } /* * Find upper node. */ NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT, UIO_USERSPACE, args.target, p); error = namei(ndp); - /* - * Re-lock vnode. - * (XXX) VOP_ISLOCKED is needed? - */ - if (islowerunlocked && !VOP_ISLOCKED(lowerrootvp)) + if (lowerrootvp->v_op == union_vnodeop_p) vn_lock(lowerrootvp, LK_EXCLUSIVE | LK_RETRY, p); if (error) goto bad; upperrootvp = ndp->ni_vp; vrele(ndp->ni_dvp); ndp->ni_dvp = NULL; /* * Check multi union mount to avoid `lock myself again' panic. */ 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; } um = (struct union_mount *) malloc(sizeof(struct union_mount), M_UNIONFSMNT, M_WAITOK); /* XXX */ /* * Keep a held reference to the target vnodes. * They are vrele'd in union_unmount. * * 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->um_op = args.mntflags & UNMNT_OPMASK; switch (um->um_op) { case UNMNT_ABOVE: um->um_lowervp = lowerrootvp; um->um_uppervp = upperrootvp; break; case UNMNT_BELOW: um->um_lowervp = upperrootvp; um->um_uppervp = lowerrootvp; break; case UNMNT_REPLACE: vrele(lowerrootvp); lowerrootvp = NULLVP; um->um_uppervp = upperrootvp; um->um_lowervp = lowerrootvp; 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, (struct componentname *) 0, 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 it's 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); (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size); switch (um->um_op) { case UNMNT_ABOVE: cp = ":"; break; case UNMNT_BELOW: cp = ":"; 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); #ifdef UNION_DIAGNOSTIC printf("union_mount: from %s, on %s\n", mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); #endif return (0); bad: if (um) free(um, M_UNIONFSMNT); if (cred) crfree(cred); if (upperrootvp) vrele(upperrootvp); if (lowerrootvp) vrele(lowerrootvp); return (error); } /* * VFS start. Nothing needed here - the start routine * on the underlying filesystem(s) will have been called * when that filesystem was mounted. */ static int union_start(mp, flags, p) struct mount *mp; int flags; struct proc *p; { return (0); } /* * 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); struct vnode *um_rootvp; int error; int freeing; int flags = 0; #ifdef UNION_DIAGNOSTIC printf("union_unmount(mp = %x)\n", mp); #endif if (mntflags & MNT_FORCE) flags |= FORCECLOSE; if (error = union_root(mp, &um_rootvp)) return (error); /* * 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; vflush(mp, um_rootvp, flags) != 0;) { struct vnode *vp; int n; /* count #vnodes held on mount list */ for (n = 0, vp = mp->mnt_vnodelist.lh_first; vp != NULLVP; vp = vp->v_mntvnodes.le_next) n++; /* if this is unchanged then stop */ if (n == freeing) break; /* otherwise try once more time */ freeing = n; } /* At this point the root vnode should have a single reference */ if (um_rootvp->v_usecount > 1) { vput(um_rootvp); return (EBUSY); } #ifdef UNION_DIAGNOSTIC vprint("union root", um_rootvp); #endif /* * Discard references to upper and lower target vnodes. */ if (um->um_lowervp) vrele(um->um_lowervp); vrele(um->um_uppervp); crfree(um->um_cred); /* * Release reference on underlying root vnode */ vput(um_rootvp); /* * And blow it away for future re-use */ vgone(um_rootvp); /* * 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 proc *p = curproc; /* XXX */ struct union_mount *um = MOUNTTOUNIONMOUNT(mp); int error; int loselock; + int lockadj = 0; + + if (um->um_lowervp && um->um_op != UNMNT_BELOW && + VOP_ISLOCKED(um->um_lowervp)) { + VREF(um->um_lowervp); + VOP_UNLOCK(um->um_lowervp, 0, p); + lockadj = 1; + } /* * Return locked reference to root. */ VREF(um->um_uppervp); if ((um->um_op == UNMNT_BELOW) && - VOP_ISLOCKED(um->um_uppervp)) { + VOP_ISLOCKED(um->um_uppervp)) { loselock = 1; } else { - if (VOP_ISLOCKED(um->um_uppervp)) { - /* - * XXX - * Should we check type of node? - */ -#ifdef DIAGNOSTIC - printf("union_root: multi union mount?"); -#endif - vrele(um->um_uppervp); - return EDEADLK; - } else - vn_lock(um->um_uppervp, LK_EXCLUSIVE | LK_RETRY, p); + vn_lock(um->um_uppervp, LK_EXCLUSIVE | LK_RETRY, p); loselock = 0; } if (um->um_lowervp) VREF(um->um_lowervp); error = union_allocvp(vpp, mp, (struct vnode *) 0, (struct vnode *) 0, (struct componentname *) 0, um->um_uppervp, um->um_lowervp, 1); if (error) { if (loselock) vrele(um->um_uppervp); else vput(um->um_uppervp); if (um->um_lowervp) vrele(um->um_lowervp); } else { if (loselock) VTOUNION(*vpp)->un_flags &= ~UN_ULOCK; } + if (lockadj) { + vn_lock(um->um_lowervp, LK_EXCLUSIVE | LK_RETRY, p); + vrele(um->um_lowervp); + } 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; #ifdef UNION_DIAGNOSTIC printf("union_statfs(mp = %x, lvp = %x, uvp = %x)\n", mp, um->um_lowervp, um->um_uppervp); #endif 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); } /* * XXX - Assumes no data cached at union layer. */ #define union_sync ((int (*) __P((struct mount *, int, struct ucred *, \ struct proc *)))nullop) #define union_fhtovp ((int (*) __P((struct mount *, struct fid *, \ struct sockaddr *, struct vnode **, int *, struct ucred **)))eopnotsupp) #define union_quotactl ((int (*) __P((struct mount *, int, uid_t, caddr_t, \ struct proc *)))eopnotsupp) #define union_sysctl ((int (*) __P((int *, u_int, void *, size_t *, void *, \ size_t, struct proc *)))eopnotsupp) #define union_vget ((int (*) __P((struct mount *, ino_t, struct vnode **))) \ eopnotsupp) #define union_vptofh ((int (*) __P((struct vnode *, struct fid *)))eopnotsupp) static struct vfsops union_vfsops = { union_mount, union_start, union_unmount, union_root, union_quotactl, union_statfs, union_sync, union_vget, union_fhtovp, union_vptofh, union_init, }; VFS_SET(union_vfsops, union, MOUNT_UNION, VFCF_LOOPBACK); diff --git a/sys/fs/unionfs/union_vnops.c b/sys/fs/unionfs/union_vnops.c index 83dcb3ee6514..434b6a08a4d1 100644 --- a/sys/fs/unionfs/union_vnops.c +++ b/sys/fs/unionfs/union_vnops.c @@ -1,1784 +1,1809 @@ /* * 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 - * $Id: union_vnops.c,v 1.45 1997/10/16 20:32:30 phk Exp $ + * $Id: union_vnops.c,v 1.46 1997/10/26 20:55:26 phk Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #define FIXUP(un, p) { \ if (((un)->un_flags & UN_ULOCK) == 0) { \ union_fixup(un, p); \ } \ } #define SETKLOCK(un) (un)->un_flags |= UN_KLOCK #define CLEARKLOCK(un) (un)->un_flags &= ~UN_KLOCK static int union_abortop __P((struct vop_abortop_args *ap)); static int union_access __P((struct vop_access_args *ap)); static int union_advlock __P((struct vop_advlock_args *ap)); static int union_bmap __P((struct vop_bmap_args *ap)); static int union_close __P((struct vop_close_args *ap)); static int union_create __P((struct vop_create_args *ap)); static void union_fixup __P((struct union_node *un, struct proc *p)); static int union_fsync __P((struct vop_fsync_args *ap)); static int union_getattr __P((struct vop_getattr_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_islocked __P((struct vop_islocked_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 **dvpp, 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_mmap __P((struct vop_mmap_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_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 void union_fixup(un, p) struct union_node *un; struct proc *p; { vn_lock(un->un_uppervp, LK_EXCLUSIVE | LK_RETRY, p); un->un_flags |= UN_ULOCK; } static int union_lookup1(udvp, dvpp, vpp, cnp) struct vnode *udvp; struct vnode **dvpp; struct vnode **vpp; struct componentname *cnp; { int error; struct proc *p = cnp->cn_proc; struct vnode *tdvp; struct vnode *dvp; struct mount *mp; dvp = *dvpp; /* * 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; *dvpp = dvp = dvp->v_mount->mnt_vnodecovered; vput(tdvp); VREF(dvp); vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p); } } error = VOP_LOOKUP(dvp, &tdvp, cnp); if (error) return (error); /* * The parent directory will have been unlocked, unless lookup * found the last component. In which case, re-lock the node * here to allow it to be unlocked again (phew) in union_lookup. */ if (dvp != tdvp && !(cnp->cn_flags & ISLASTCN)) vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p); dvp = tdvp; /* * 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). */ while (dvp != udvp && (dvp->v_type == VDIR) && (mp = dvp->v_mountedhere)) { if (vfs_busy(mp, 0, 0, p)) continue; error = VFS_ROOT(mp, &tdvp); vfs_unbusy(mp, p); if (error) { vput(dvp); return (error); } vput(dvp); dvp = tdvp; } *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; struct union_node *dun = VTOUNION(dvp); 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; int iswhiteout; struct vattr va; /* * 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); #ifdef notyet if (cnp->cn_namelen == 3 && cnp->cn_nameptr[2] == '.' && cnp->cn_nameptr[1] == '.' && cnp->cn_nameptr[0] == '.') { dvp = *ap->a_vpp = LOWERVP(ap->a_dvp); if (dvp == NULLVP) return (ENOENT); VREF(dvp); vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p); if (!lockparent || !(cnp->cn_flags & ISLASTCN)) VOP_UNLOCK(ap->a_dvp, 0, p); return (0); } #endif cnp->cn_flags |= LOCKPARENT; upperdvp = dun->un_uppervp; lowerdvp = dun->un_lowervp; uppervp = NULLVP; lowervp = NULLVP; iswhiteout = 0; + if (cnp->cn_flags & ISDOTDOT) { + if (upperdvp != NULL) + VREF(upperdvp); + if (lowerdvp != NULL) + VREF(lowerdvp); + } + /* * 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) { FIXUP(dun, p); /* * If we're doing `..' in the underlying filesystem, * we must drop our lock on the union node before * going up the tree in the lower file system--if we block * on the lowervp lock, and that's held by someone else * coming down the tree and who's waiting for our lock, * we would be hosed. */ if (cnp->cn_flags & ISDOTDOT) { /* retain lock on underlying VP: */ SETKLOCK(dun); VOP_UNLOCK(dvp, 0, p); CLEARKLOCK(dun); } uerror = union_lookup1(um->um_uppervp, &upperdvp, &uppervp, cnp); /* * 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)) { if (!lockparent) cnp->cn_flags &= ~LOCKPARENT; return (EROFS); } if (cnp->cn_flags & ISDOTDOT) { if (dun->un_uppervp == upperdvp) { /* * We got the underlying bugger back locked... * now take back the union node lock. Since we * hold the uppervp lock, we can diddle union * locking flags at will. :) */ dun->un_flags |= UN_ULOCK; } /* * If upperdvp got swapped out, it means we did * some mount point magic, and we do not have * dun->un_uppervp locked currently--so we get it * locked here (don't set the UN_ULOCK flag). */ vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p); } /*if (uppervp == upperdvp) dun->un_flags |= UN_KLOCK;*/ if (cnp->cn_consume != 0) { *ap->a_vpp = uppervp; if (!lockparent) cnp->cn_flags &= ~LOCKPARENT; - return (uerror); + error = uerror; + goto out; } if (uerror == ENOENT || uerror == EJUSTRETURN) { if (cnp->cn_flags & ISWHITEOUT) { iswhiteout = 1; } else if (lowerdvp != NULLVP) { lerror = VOP_GETATTR(upperdvp, &va, cnp->cn_cred, cnp->cn_proc); if (lerror == 0 && (va.va_flags & OPAQUE)) iswhiteout = 1; } } } else { uerror = ENOENT; } /* * 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; vn_lock(lowerdvp, LK_EXCLUSIVE | LK_RETRY, p); /* * Only do a LOOKUP on the bottom 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. */ lerror = union_lookup1(um->um_lowervp, &lowerdvp, &lowervp, cnp); if (um->um_op == UNMNT_BELOW) cnp->cn_cred = saved_cred; cnp->cn_nameiop = nameiop; if (lowervp != lowerdvp) VOP_UNLOCK(lowerdvp, 0, p); if (cnp->cn_consume != 0 || lerror == EACCES) { if (lerror == EACCES) lowervp = NULLVP; if (uppervp != NULLVP) { if (uppervp == upperdvp) vrele(uppervp); else vput(uppervp); uppervp = NULLVP; } *ap->a_vpp = lowervp; if (!lockparent) cnp->cn_flags &= ~LOCKPARENT; - return (lerror); + error = lerror; + goto out; } } else { lerror = ENOENT; if ((cnp->cn_flags & ISDOTDOT) && dun->un_pvp != NULLVP) { lowervp = LOWERVP(dun->un_pvp); if (lowervp != NULLVP) { VREF(lowervp); vn_lock(lowervp, LK_EXCLUSIVE | LK_RETRY, p); lerror = 0; } } } if (!lockparent) cnp->cn_flags &= ~LOCKPARENT; /* * at this point, we have uerror and lerror indicating * possible errors with the lookups in the upper and lower * layers. additionally, uppervp and lowervp are (locked) * references to existing vnodes in the upper and lower layers. * * there are now three cases to consider. * 1. if both layers returned an error, then return whatever * error the upper layer generated. * * 2. if the top layer failed and the bottom layer succeeded * then 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 bottom vnode is a directory, in which case * create a new directory in the top-level and * continue as in 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. */ *ap->a_vpp = NULLVP; /* case 1. */ if ((uerror != 0) && (lerror != 0)) { - return (uerror); + error = uerror; + goto out; } /* case 2. */ if (uerror != 0 /* && (lerror == 0) */ ) { if (lowervp->v_type == VDIR) { /* case 2b. */ dun->un_flags &= ~UN_ULOCK; VOP_UNLOCK(upperdvp, 0, p); uerror = union_mkshadow(um, upperdvp, cnp, &uppervp); vn_lock(upperdvp, LK_EXCLUSIVE | LK_RETRY, p); dun->un_flags |= UN_ULOCK; if (uerror) { if (lowervp != NULLVP) { vput(lowervp); lowervp = NULLVP; } - return (uerror); + error = uerror; + goto out; } } } if (lowervp != NULLVP) VOP_UNLOCK(lowervp, 0, p); error = union_allocvp(ap->a_vpp, dvp->v_mount, dvp, upperdvp, cnp, uppervp, lowervp, 1); if (error) { if (uppervp != NULLVP) vput(uppervp); if (lowervp != NULLVP) vrele(lowervp); } else { if (*ap->a_vpp != dvp) if (!lockparent || !(cnp->cn_flags & ISLASTCN)) VOP_UNLOCK(dvp, 0, p); #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 } +out: + if (cnp->cn_flags & ISDOTDOT) { + if (upperdvp != NULL) + vrele(upperdvp); + if (lowerdvp != NULL) + vrele(lowerdvp); + } + return (error); } 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 *un = VTOUNION(ap->a_dvp); struct vnode *dvp = un->un_uppervp; struct componentname *cnp = ap->a_cnp; struct proc *p = cnp->cn_proc; if (dvp != NULLVP) { int error; struct vnode *vp; struct mount *mp; FIXUP(un, p); VREF(dvp); SETKLOCK(un); mp = ap->a_dvp->v_mount; vput(ap->a_dvp); CLEARKLOCK(un); error = VOP_CREATE(dvp, &vp, cnp, ap->a_vap); if (error) return (error); error = union_allocvp(ap->a_vpp, mp, NULLVP, NULLVP, cnp, vp, NULLVP, 1); if (error) vput(vp); return (error); } vput(ap->a_dvp); return (EROFS); } 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 proc *p = cnp->cn_proc; if (un->un_uppervp == NULLVP) return (EOPNOTSUPP); FIXUP(un, p); return (VOP_WHITEOUT(un->un_uppervp, cnp, ap->a_flags)); } 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 *un = VTOUNION(ap->a_dvp); struct vnode *dvp = un->un_uppervp; struct componentname *cnp = ap->a_cnp; struct proc *p = cnp->cn_proc; if (dvp != NULLVP) { int error; struct vnode *vp; struct mount *mp; FIXUP(un, p); VREF(dvp); SETKLOCK(un); mp = ap->a_dvp->v_mount; vput(ap->a_dvp); CLEARKLOCK(un); error = VOP_MKNOD(dvp, &vp, cnp, ap->a_vap); if (error) return (error); if (vp != NULLVP) { error = union_allocvp(ap->a_vpp, mp, NULLVP, NULLVP, cnp, vp, NULLVP, 1); if (error) vput(vp); } return (error); } vput(ap->a_dvp); return (EROFS); } 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; /* * If there is an existing upper vp then simply open that. */ tvp = un->un_uppervp; if (tvp == 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)) { error = union_copyup(un, (mode&O_TRUNC) == 0, cred, p); if (error == 0) error = VOP_OPEN(un->un_uppervp, mode, cred, p); return (error); } /* * Just open the lower vnode */ un->un_openl++; vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY, p); error = VOP_OPEN(tvp, mode, cred, p); VOP_UNLOCK(tvp, 0, p); return (error); } FIXUP(un, p); error = VOP_OPEN(tvp, mode, cred, p); return (error); } 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; struct vnode *savedvp; /* * 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); } } if ((vp = un->un_uppervp) != NULLVP) { FIXUP(un, p); ap->a_vp = vp; return (VCALL(vp, VOFFSET(vop_access), ap)); } if ((vp = un->un_lowervp) != NULLVP) { vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); savedvp = ap->a_vp; ap->a_vp = vp; error = VCALL(vp, VOFFSET(vop_access), ap); if (error == 0) { struct union_mount *um = MOUNTTOUNIONMOUNT(savedvp->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); if (error) return (error); } return (error); } /* * We handle getattr only to change the fsid and * track object sizes */ 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 = un->un_uppervp; struct proc *p = ap->a_p; 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; vp = un->un_uppervp; if (vp != NULLVP) { /* * 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. * In the mean time, compensate here by checking * the union_node's lock flag. */ if (un->un_flags & UN_LOCKED) FIXUP(un, p); error = VOP_GETATTR(vp, vap, ap->a_cred, ap->a_p); if (error) return (error); union_newsize(ap->a_vp, vap->va_size, VNOVAL); } if (vp == NULLVP) { vp = un->un_lowervp; } else if (vp->v_type == VDIR) { 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); 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; ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0]; 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; 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) && /* assert(un->un_lowervp != 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. */ if (un->un_uppervp != NULLVP) { FIXUP(un, p); 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); } else { error = EROFS; } 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; { int error; struct proc *p = ap->a_uio->uio_procp; struct vnode *vp = OTHERVP(ap->a_vp); int dolock = (vp == LOWERVP(ap->a_vp)); if (dolock) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); else FIXUP(VTOUNION(ap->a_vp), p); error = VOP_READ(vp, ap->a_uio, ap->a_ioflag, ap->a_cred); if (dolock) VOP_UNLOCK(vp, 0, 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 (vp == 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; { int error; struct vnode *vp; struct union_node *un = VTOUNION(ap->a_vp); struct proc *p = ap->a_uio->uio_procp; vp = UPPERVP(ap->a_vp); if (vp == NULLVP) panic("union: missing upper layer in write"); FIXUP(un, p); error = VOP_WRITE(vp, 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); } 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; { register 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; { register 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; { register 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_mmap(ap) struct vop_mmap_args /* { struct vnode *a_vp; int a_fflags; struct ucred *a_cred; struct proc *a_p; } */ *ap; { register struct vnode *ovp = OTHERVP(ap->a_vp); ap->a_vp = ovp; return (VCALL(ovp, VOFFSET(vop_mmap), ap)); } 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 = OTHERVP(ap->a_vp); struct union_node *un; int isupperlocked = 0; if (targetvp != NULLVP) { int dolock = (targetvp == LOWERVP(ap->a_vp)); un = VTOUNION(ap->a_vp); if (dolock) vn_lock(targetvp, LK_EXCLUSIVE | LK_RETRY, p); - else if ((un->un_flags & UN_ULOCK) == 0 && - VOP_ISLOCKED(targetvp) == 0) { - isupperlocked = 1; - vn_lock(targetvp, LK_EXCLUSIVE | LK_RETRY, p); - un->un_flags |= UN_ULOCK; + else { + un = VTOUNION(ap->a_vp); + if ((un->un_flags & UN_ULOCK) == 0 && + targetvp->v_data != NULL && + ((struct lock *)targetvp->v_data)->lk_lockholder + == curproc->p_pid && + VOP_ISLOCKED(targetvp) != 0) + return 0; /* XXX */ + + FIXUP(un, p); } + error = VOP_FSYNC(targetvp, ap->a_cred, ap->a_waitfor, p); if (dolock) VOP_UNLOCK(targetvp, 0, p); else if (isupperlocked) { un->un_flags &= ~UN_ULOCK; VOP_UNLOCK(targetvp, 0, p); } } return (error); } static int union_remove(ap) struct vop_remove_args /* { struct vnode *a_dvp; struct vnode *a_vp; struct componentname *a_cnp; } */ *ap; { int error; 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; if (dun->un_uppervp == NULLVP) panic("union remove: null upper vnode"); if (un->un_uppervp != NULLVP) { struct vnode *dvp = dun->un_uppervp; struct vnode *vp = un->un_uppervp; FIXUP(dun, p); VREF(dvp); SETKLOCK(dun); vput(ap->a_dvp); CLEARKLOCK(dun); FIXUP(un, p); VREF(vp); SETKLOCK(un); vput(ap->a_vp); CLEARKLOCK(un); if (union_dowhiteout(un, cnp->cn_cred, cnp->cn_proc)) cnp->cn_flags |= DOWHITEOUT; error = VOP_REMOVE(dvp, vp, cnp); if (!error) union_removed_upper(un); } else { FIXUP(dun, p); error = union_mkwhiteout( MOUNTTOUNIONMOUNT(UNIONTOV(dun)->v_mount), dun->un_uppervp, ap->a_cnp, un->un_path); vput(ap->a_dvp); vput(ap->a_vp); } return (error); } static int union_link(ap) struct vop_link_args /* { struct vnode *a_tdvp; struct vnode *a_vp; struct componentname *a_cnp; } */ *ap; { int error = 0; struct componentname *cnp = ap->a_cnp; struct proc *p = cnp->cn_proc; struct union_node *un; struct vnode *vp; struct vnode *tdvp; un = VTOUNION(ap->a_tdvp); 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 (un->un_uppervp == tun->un_dirvp) { un->un_flags &= ~UN_ULOCK; VOP_UNLOCK(un->un_uppervp, 0, p); } error = union_copyup(tun, 1, cnp->cn_cred, p); if (un->un_uppervp == tun->un_dirvp) { vn_lock(un->un_uppervp, LK_EXCLUSIVE | LK_RETRY, p); un->un_flags |= UN_ULOCK; } VOP_UNLOCK(ap->a_vp, 0, p); } vp = tun->un_uppervp; } tdvp = un->un_uppervp; if (tdvp == NULLVP) error = EROFS; if (error) { vput(ap->a_tdvp); return (error); } FIXUP(un, p); VREF(tdvp); SETKLOCK(un); vput(ap->a_tdvp); CLEARKLOCK(un); return (VOP_LINK(tdvp, vp, cnp)); } 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; int isklockset = 0; 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); } if (fvp->v_op == union_vnodeop_p) { /* always true */ struct union_node *un = VTOUNION(fvp); if (un->un_uppervp == NULLVP) { /* XXX: should do a copyup */ 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); } 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; } tdvp = un->un_uppervp; VREF(tdvp); SETKLOCK(un); vput(ap->a_tdvp); CLEARKLOCK(un); } if (tvp != NULLVP && tvp->v_op == union_vnodeop_p) { struct union_node *un = VTOUNION(tvp); tvp = un->un_uppervp; if (tvp != NULLVP) { VREF(tvp); SETKLOCK(un); isklockset = 1; } vput(ap->a_tvp); if (isklockset) CLEARKLOCK(un); } return (VOP_RENAME(fdvp, fvp, ap->a_fcnp, tdvp, tvp, ap->a_tcnp)); bad: vrele(fdvp); vrele(fvp); vput(tdvp); if (tvp != NULLVP) vput(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 *un = VTOUNION(ap->a_dvp); struct vnode *dvp = un->un_uppervp; struct componentname *cnp = ap->a_cnp; struct proc *p = cnp->cn_proc; if (dvp != NULLVP) { int error; struct vnode *vp; FIXUP(un, p); VREF(dvp); SETKLOCK(un); VOP_UNLOCK(ap->a_dvp, 0, p); CLEARKLOCK(un); error = VOP_MKDIR(dvp, &vp, cnp, ap->a_vap); if (error) { vrele(ap->a_dvp); return (error); } error = union_allocvp(ap->a_vpp, ap->a_dvp->v_mount, ap->a_dvp, NULLVP, cnp, vp, NULLVP, 1); vrele(ap->a_dvp); if (error) vput(vp); return (error); } vput(ap->a_dvp); return (EROFS); } static int union_rmdir(ap) struct vop_rmdir_args /* { struct vnode *a_dvp; struct vnode *a_vp; struct componentname *a_cnp; } */ *ap; { int error; 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; if (dun->un_uppervp == NULLVP) panic("union rmdir: null upper vnode"); if (un->un_uppervp != NULLVP) { struct vnode *dvp = dun->un_uppervp; struct vnode *vp = un->un_uppervp; FIXUP(dun, p); VREF(dvp); SETKLOCK(dun); vput(ap->a_dvp); CLEARKLOCK(dun); FIXUP(un, p); VREF(vp); SETKLOCK(un); vput(ap->a_vp); CLEARKLOCK(un); if (union_dowhiteout(un, cnp->cn_cred, cnp->cn_proc)) cnp->cn_flags |= DOWHITEOUT; error = VOP_RMDIR(dvp, vp, ap->a_cnp); if (!error) union_removed_upper(un); } else { FIXUP(dun, p); error = union_mkwhiteout( MOUNTTOUNIONMOUNT(UNIONTOV(dun)->v_mount), dun->un_uppervp, ap->a_cnp, un->un_path); vput(ap->a_dvp); vput(ap->a_vp); } return (error); } 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 *un = VTOUNION(ap->a_dvp); struct vnode *dvp = un->un_uppervp; struct componentname *cnp = ap->a_cnp; struct proc *p = cnp->cn_proc; if (dvp != NULLVP) { int error; struct vnode *vp; FIXUP(un, p); VREF(dvp); SETKLOCK(un); vput(ap->a_dvp); CLEARKLOCK(un); error = VOP_SYMLINK(dvp, &vp, cnp, ap->a_vap, ap->a_target); *ap->a_vpp = NULLVP; return (error); } vput(ap->a_dvp); return (EROFS); } /* * 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 vnode *uvp = un->un_uppervp; struct proc *p = ap->a_uio->uio_procp; if (uvp == NULLVP) return (0); FIXUP(un, p); ap->a_vp = uvp; return (VCALL(uvp, VOFFSET(vop_readdir), ap)); } 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 uio *uio = ap->a_uio; struct proc *p = uio->uio_procp; struct vnode *vp = OTHERVP(ap->a_vp); int dolock = (vp == LOWERVP(ap->a_vp)); if (dolock) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); else FIXUP(VTOUNION(ap->a_vp), p); ap->a_vp = vp; error = VCALL(vp, VOFFSET(vop_readlink), ap); if (dolock) VOP_UNLOCK(vp, 0, p); return (error); } static int union_abortop(ap) struct vop_abortop_args /* { struct vnode *a_dvp; struct componentname *a_cnp; } */ *ap; { int error; struct componentname *cnp = ap->a_cnp; struct proc *p = cnp->cn_proc; struct vnode *vp = OTHERVP(ap->a_dvp); struct union_node *un = VTOUNION(ap->a_dvp); int islocked = un->un_flags & UN_LOCKED; int dolock = (vp == LOWERVP(ap->a_dvp)); if (islocked) { if (dolock) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); else FIXUP(VTOUNION(ap->a_dvp), p); } ap->a_dvp = vp; error = VCALL(vp, VOFFSET(vop_abortop), ap); if (islocked && dolock) VOP_UNLOCK(vp, 0, p); return (error); } 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; } 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; { struct vnode *vp = ap->a_vp; struct proc *p = ap->a_p; int flags = ap->a_flags; struct union_node *un; int error; vop_nolock(ap); /* * Need to do real lockmgr-style locking here. * in the mean time, draining won't work quite right, * which could lead to a few race conditions. * the following test was here, but is not quite right, we * still need to take the lock: if ((flags & LK_TYPE_MASK) == LK_DRAIN) return (0); */ flags &= ~LK_INTERLOCK; start: un = VTOUNION(vp); if (un->un_uppervp != NULLVP) { if (((un->un_flags & (UN_ULOCK | UN_KLOCK)) == 0) && (vp->v_usecount != 0)) { error = vn_lock(un->un_uppervp, flags, p); if (error) return (error); un->un_flags |= UN_ULOCK; } } if (un->un_flags & UN_LOCKED) { #ifdef DIAGNOSTIC if (curproc && un->un_pid == curproc->p_pid && un->un_pid > -1 && curproc->p_pid > -1) panic("union: locking against myself"); #endif un->un_flags |= UN_WANT; tsleep((caddr_t)&un->un_flags, PINOD, "unionlk2", 0); goto start; } #ifdef DIAGNOSTIC if (curproc) un->un_pid = curproc->p_pid; else un->un_pid = -1; #endif un->un_flags |= UN_LOCKED; return (0); } /* * When operations want to vput() a union node yet retain a lock on * the upper vnode (say, to do some further operations like link(), * mkdir(), ...), they set UN_KLOCK on the union node, then call * vput() which calls VOP_UNLOCK() and comes here. union_unlock() * unlocks the union node (leaving the upper vnode alone), clears the * KLOCK flag, and then returns to vput(). The caller then does whatever * is left to do with the upper vnode, and ensures that it gets unlocked. * * If UN_KLOCK isn't set, then the upper vnode is unlocked here. */ static int union_unlock(ap) struct vop_unlock_args /* { struct vnode *a_vp; int a_flags; struct proc *a_p; } */ *ap; { struct union_node *un = VTOUNION(ap->a_vp); struct proc *p = ap->a_p; #ifdef DIAGNOSTIC if ((un->un_flags & UN_LOCKED) == 0) panic("union: unlock unlocked node"); if (curproc && un->un_pid != curproc->p_pid && curproc->p_pid > -1 && un->un_pid > -1) panic("union: unlocking other process's union node"); #endif un->un_flags &= ~UN_LOCKED; if ((un->un_flags & (UN_ULOCK|UN_KLOCK)) == UN_ULOCK) VOP_UNLOCK(un->un_uppervp, 0, p); un->un_flags &= ~UN_ULOCK; if (un->un_flags & UN_WANT) { un->un_flags &= ~UN_WANT; wakeup((caddr_t) &un->un_flags); } #ifdef DIAGNOSTIC un->un_pid = 0; #endif vop_nounlock(ap); return (0); } static int union_bmap(ap) struct vop_bmap_args /* { struct vnode *a_vp; daddr_t a_bn; struct vnode **a_vpp; daddr_t *a_bnp; int *a_runp; int *a_runb; } */ *ap; { int error; struct proc *p = curproc; /* XXX */ struct vnode *vp = OTHERVP(ap->a_vp); int dolock = (vp == LOWERVP(ap->a_vp)); if (dolock) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); else FIXUP(VTOUNION(ap->a_vp), p); ap->a_vp = vp; error = VCALL(vp, VOFFSET(vop_bmap), ap); if (dolock) VOP_UNLOCK(vp, 0, p); return (error); } 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_islocked(ap) struct vop_islocked_args /* { struct vnode *a_vp; } */ *ap; { return ((VTOUNION(ap->a_vp)->un_flags & UN_LOCKED) ? 1 : 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 vnode *vp = OTHERVP(ap->a_vp); int dolock = (vp == LOWERVP(ap->a_vp)); if (dolock) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); else FIXUP(VTOUNION(ap->a_vp), p); ap->a_vp = vp; error = VCALL(vp, VOFFSET(vop_pathconf), ap); if (dolock) VOP_UNLOCK(vp, 0, 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 * vnode in its arguments. * This goes away with a merged VM/buffer cache. */ static int union_strategy(ap) struct vop_strategy_args /* { struct buf *a_bp; } */ *ap; { struct buf *bp = ap->a_bp; int error; struct vnode *savedvp; savedvp = bp->b_vp; bp->b_vp = OTHERVP(bp->b_vp); #ifdef DIAGNOSTIC if (bp->b_vp == NULLVP) panic("union_strategy: nil vp"); if (((bp->b_flags & B_READ) == 0) && (bp->b_vp == LOWERVP(savedvp))) panic("union_strategy: writing to lowervp"); #endif error = VOP_STRATEGY(bp); bp->b_vp = savedvp; return (error); } /* * 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_abortop_desc, (vop_t *) union_abortop }, { &vop_access_desc, (vop_t *) union_access }, { &vop_advlock_desc, (vop_t *) union_advlock }, { &vop_bmap_desc, (vop_t *) union_bmap }, { &vop_close_desc, (vop_t *) union_close }, { &vop_create_desc, (vop_t *) union_create }, { &vop_fsync_desc, (vop_t *) union_fsync }, { &vop_getattr_desc, (vop_t *) union_getattr }, { &vop_inactive_desc, (vop_t *) union_inactive }, { &vop_ioctl_desc, (vop_t *) union_ioctl }, { &vop_islocked_desc, (vop_t *) union_islocked }, { &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_mmap_desc, (vop_t *) union_mmap }, { &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_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); diff --git a/sys/miscfs/union/union_vfsops.c b/sys/miscfs/union/union_vfsops.c index 753afd601f82..90da301e8a7b 100644 --- a/sys/miscfs/union/union_vfsops.c +++ b/sys/miscfs/union/union_vfsops.c @@ -1,562 +1,556 @@ /* * 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 - * $Id: union_vfsops.c,v 1.21 1997/10/12 20:24:57 phk Exp $ + * $Id: union_vfsops.c,v 1.22 1997/11/18 15:07:35 phk Exp $ */ /* * Union Layer */ #include #include #include #include #include #include #include #include #include #include static MALLOC_DEFINE(M_UNIONFSMNT, "UNION mount", "UNION mount structure"); extern int union_init __P((struct vfsconf *)); extern int union_fhtovp __P((struct mount *mp, struct fid *fidp, struct mbuf *nam, struct vnode **vpp, int *exflagsp, struct ucred **credanonp)); static int union_mount __P((struct mount *mp, char *path, caddr_t data, struct nameidata *ndp, struct proc *p)); extern int union_quotactl __P((struct mount *mp, int cmd, uid_t uid, caddr_t arg, struct proc *p)); static int union_root __P((struct mount *mp, struct vnode **vpp)); static int union_start __P((struct mount *mp, int flags, struct proc *p)); static int union_statfs __P((struct mount *mp, struct statfs *sbp, struct proc *p)); extern int union_sync __P((struct mount *mp, int waitfor, struct ucred *cred, struct proc *p)); static int union_unmount __P((struct mount *mp, int mntflags, struct proc *p)); extern int union_vget __P((struct mount *mp, ino_t ino, struct vnode **vpp)); extern int union_vptofh __P((struct vnode *vp, struct fid *fhp)); /* * 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; int islowerunlocked = 0; #ifdef UNION_DIAGNOSTIC printf("union_mount(mp = %x)\n", mp); #endif /* * 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; lowerrootvp = mp->mnt_vnodecovered; VREF(lowerrootvp); /* * Unlock lower node to avoid deadlock. - * (XXX) VOP_ISLOCKED is needed? */ - if ((lowerrootvp->v_op == union_vnodeop_p) && VOP_ISLOCKED(lowerrootvp)) { + if (lowerrootvp->v_op == union_vnodeop_p) VOP_UNLOCK(lowerrootvp, 0, p); - islowerunlocked = 1; - } /* * Find upper node. */ NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT, UIO_USERSPACE, args.target, p); error = namei(ndp); - /* - * Re-lock vnode. - * (XXX) VOP_ISLOCKED is needed? - */ - if (islowerunlocked && !VOP_ISLOCKED(lowerrootvp)) + if (lowerrootvp->v_op == union_vnodeop_p) vn_lock(lowerrootvp, LK_EXCLUSIVE | LK_RETRY, p); if (error) goto bad; upperrootvp = ndp->ni_vp; vrele(ndp->ni_dvp); ndp->ni_dvp = NULL; /* * Check multi union mount to avoid `lock myself again' panic. */ 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; } um = (struct union_mount *) malloc(sizeof(struct union_mount), M_UNIONFSMNT, M_WAITOK); /* XXX */ /* * Keep a held reference to the target vnodes. * They are vrele'd in union_unmount. * * 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->um_op = args.mntflags & UNMNT_OPMASK; switch (um->um_op) { case UNMNT_ABOVE: um->um_lowervp = lowerrootvp; um->um_uppervp = upperrootvp; break; case UNMNT_BELOW: um->um_lowervp = upperrootvp; um->um_uppervp = lowerrootvp; break; case UNMNT_REPLACE: vrele(lowerrootvp); lowerrootvp = NULLVP; um->um_uppervp = upperrootvp; um->um_lowervp = lowerrootvp; 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, (struct componentname *) 0, 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 it's 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); (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size); switch (um->um_op) { case UNMNT_ABOVE: cp = ":"; break; case UNMNT_BELOW: cp = ":"; 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); #ifdef UNION_DIAGNOSTIC printf("union_mount: from %s, on %s\n", mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); #endif return (0); bad: if (um) free(um, M_UNIONFSMNT); if (cred) crfree(cred); if (upperrootvp) vrele(upperrootvp); if (lowerrootvp) vrele(lowerrootvp); return (error); } /* * VFS start. Nothing needed here - the start routine * on the underlying filesystem(s) will have been called * when that filesystem was mounted. */ static int union_start(mp, flags, p) struct mount *mp; int flags; struct proc *p; { return (0); } /* * 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); struct vnode *um_rootvp; int error; int freeing; int flags = 0; #ifdef UNION_DIAGNOSTIC printf("union_unmount(mp = %x)\n", mp); #endif if (mntflags & MNT_FORCE) flags |= FORCECLOSE; if (error = union_root(mp, &um_rootvp)) return (error); /* * 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; vflush(mp, um_rootvp, flags) != 0;) { struct vnode *vp; int n; /* count #vnodes held on mount list */ for (n = 0, vp = mp->mnt_vnodelist.lh_first; vp != NULLVP; vp = vp->v_mntvnodes.le_next) n++; /* if this is unchanged then stop */ if (n == freeing) break; /* otherwise try once more time */ freeing = n; } /* At this point the root vnode should have a single reference */ if (um_rootvp->v_usecount > 1) { vput(um_rootvp); return (EBUSY); } #ifdef UNION_DIAGNOSTIC vprint("union root", um_rootvp); #endif /* * Discard references to upper and lower target vnodes. */ if (um->um_lowervp) vrele(um->um_lowervp); vrele(um->um_uppervp); crfree(um->um_cred); /* * Release reference on underlying root vnode */ vput(um_rootvp); /* * And blow it away for future re-use */ vgone(um_rootvp); /* * 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 proc *p = curproc; /* XXX */ struct union_mount *um = MOUNTTOUNIONMOUNT(mp); int error; int loselock; + int lockadj = 0; + + if (um->um_lowervp && um->um_op != UNMNT_BELOW && + VOP_ISLOCKED(um->um_lowervp)) { + VREF(um->um_lowervp); + VOP_UNLOCK(um->um_lowervp, 0, p); + lockadj = 1; + } /* * Return locked reference to root. */ VREF(um->um_uppervp); if ((um->um_op == UNMNT_BELOW) && - VOP_ISLOCKED(um->um_uppervp)) { + VOP_ISLOCKED(um->um_uppervp)) { loselock = 1; } else { - if (VOP_ISLOCKED(um->um_uppervp)) { - /* - * XXX - * Should we check type of node? - */ -#ifdef DIAGNOSTIC - printf("union_root: multi union mount?"); -#endif - vrele(um->um_uppervp); - return EDEADLK; - } else - vn_lock(um->um_uppervp, LK_EXCLUSIVE | LK_RETRY, p); + vn_lock(um->um_uppervp, LK_EXCLUSIVE | LK_RETRY, p); loselock = 0; } if (um->um_lowervp) VREF(um->um_lowervp); error = union_allocvp(vpp, mp, (struct vnode *) 0, (struct vnode *) 0, (struct componentname *) 0, um->um_uppervp, um->um_lowervp, 1); if (error) { if (loselock) vrele(um->um_uppervp); else vput(um->um_uppervp); if (um->um_lowervp) vrele(um->um_lowervp); } else { if (loselock) VTOUNION(*vpp)->un_flags &= ~UN_ULOCK; } + if (lockadj) { + vn_lock(um->um_lowervp, LK_EXCLUSIVE | LK_RETRY, p); + vrele(um->um_lowervp); + } 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; #ifdef UNION_DIAGNOSTIC printf("union_statfs(mp = %x, lvp = %x, uvp = %x)\n", mp, um->um_lowervp, um->um_uppervp); #endif 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); } /* * XXX - Assumes no data cached at union layer. */ #define union_sync ((int (*) __P((struct mount *, int, struct ucred *, \ struct proc *)))nullop) #define union_fhtovp ((int (*) __P((struct mount *, struct fid *, \ struct sockaddr *, struct vnode **, int *, struct ucred **)))eopnotsupp) #define union_quotactl ((int (*) __P((struct mount *, int, uid_t, caddr_t, \ struct proc *)))eopnotsupp) #define union_sysctl ((int (*) __P((int *, u_int, void *, size_t *, void *, \ size_t, struct proc *)))eopnotsupp) #define union_vget ((int (*) __P((struct mount *, ino_t, struct vnode **))) \ eopnotsupp) #define union_vptofh ((int (*) __P((struct vnode *, struct fid *)))eopnotsupp) static struct vfsops union_vfsops = { union_mount, union_start, union_unmount, union_root, union_quotactl, union_statfs, union_sync, union_vget, union_fhtovp, union_vptofh, union_init, }; VFS_SET(union_vfsops, union, MOUNT_UNION, VFCF_LOOPBACK); diff --git a/sys/miscfs/union/union_vnops.c b/sys/miscfs/union/union_vnops.c index 83dcb3ee6514..434b6a08a4d1 100644 --- a/sys/miscfs/union/union_vnops.c +++ b/sys/miscfs/union/union_vnops.c @@ -1,1784 +1,1809 @@ /* * 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 - * $Id: union_vnops.c,v 1.45 1997/10/16 20:32:30 phk Exp $ + * $Id: union_vnops.c,v 1.46 1997/10/26 20:55:26 phk Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #define FIXUP(un, p) { \ if (((un)->un_flags & UN_ULOCK) == 0) { \ union_fixup(un, p); \ } \ } #define SETKLOCK(un) (un)->un_flags |= UN_KLOCK #define CLEARKLOCK(un) (un)->un_flags &= ~UN_KLOCK static int union_abortop __P((struct vop_abortop_args *ap)); static int union_access __P((struct vop_access_args *ap)); static int union_advlock __P((struct vop_advlock_args *ap)); static int union_bmap __P((struct vop_bmap_args *ap)); static int union_close __P((struct vop_close_args *ap)); static int union_create __P((struct vop_create_args *ap)); static void union_fixup __P((struct union_node *un, struct proc *p)); static int union_fsync __P((struct vop_fsync_args *ap)); static int union_getattr __P((struct vop_getattr_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_islocked __P((struct vop_islocked_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 **dvpp, 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_mmap __P((struct vop_mmap_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_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 void union_fixup(un, p) struct union_node *un; struct proc *p; { vn_lock(un->un_uppervp, LK_EXCLUSIVE | LK_RETRY, p); un->un_flags |= UN_ULOCK; } static int union_lookup1(udvp, dvpp, vpp, cnp) struct vnode *udvp; struct vnode **dvpp; struct vnode **vpp; struct componentname *cnp; { int error; struct proc *p = cnp->cn_proc; struct vnode *tdvp; struct vnode *dvp; struct mount *mp; dvp = *dvpp; /* * 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; *dvpp = dvp = dvp->v_mount->mnt_vnodecovered; vput(tdvp); VREF(dvp); vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p); } } error = VOP_LOOKUP(dvp, &tdvp, cnp); if (error) return (error); /* * The parent directory will have been unlocked, unless lookup * found the last component. In which case, re-lock the node * here to allow it to be unlocked again (phew) in union_lookup. */ if (dvp != tdvp && !(cnp->cn_flags & ISLASTCN)) vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p); dvp = tdvp; /* * 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). */ while (dvp != udvp && (dvp->v_type == VDIR) && (mp = dvp->v_mountedhere)) { if (vfs_busy(mp, 0, 0, p)) continue; error = VFS_ROOT(mp, &tdvp); vfs_unbusy(mp, p); if (error) { vput(dvp); return (error); } vput(dvp); dvp = tdvp; } *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; struct union_node *dun = VTOUNION(dvp); 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; int iswhiteout; struct vattr va; /* * 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); #ifdef notyet if (cnp->cn_namelen == 3 && cnp->cn_nameptr[2] == '.' && cnp->cn_nameptr[1] == '.' && cnp->cn_nameptr[0] == '.') { dvp = *ap->a_vpp = LOWERVP(ap->a_dvp); if (dvp == NULLVP) return (ENOENT); VREF(dvp); vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p); if (!lockparent || !(cnp->cn_flags & ISLASTCN)) VOP_UNLOCK(ap->a_dvp, 0, p); return (0); } #endif cnp->cn_flags |= LOCKPARENT; upperdvp = dun->un_uppervp; lowerdvp = dun->un_lowervp; uppervp = NULLVP; lowervp = NULLVP; iswhiteout = 0; + if (cnp->cn_flags & ISDOTDOT) { + if (upperdvp != NULL) + VREF(upperdvp); + if (lowerdvp != NULL) + VREF(lowerdvp); + } + /* * 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) { FIXUP(dun, p); /* * If we're doing `..' in the underlying filesystem, * we must drop our lock on the union node before * going up the tree in the lower file system--if we block * on the lowervp lock, and that's held by someone else * coming down the tree and who's waiting for our lock, * we would be hosed. */ if (cnp->cn_flags & ISDOTDOT) { /* retain lock on underlying VP: */ SETKLOCK(dun); VOP_UNLOCK(dvp, 0, p); CLEARKLOCK(dun); } uerror = union_lookup1(um->um_uppervp, &upperdvp, &uppervp, cnp); /* * 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)) { if (!lockparent) cnp->cn_flags &= ~LOCKPARENT; return (EROFS); } if (cnp->cn_flags & ISDOTDOT) { if (dun->un_uppervp == upperdvp) { /* * We got the underlying bugger back locked... * now take back the union node lock. Since we * hold the uppervp lock, we can diddle union * locking flags at will. :) */ dun->un_flags |= UN_ULOCK; } /* * If upperdvp got swapped out, it means we did * some mount point magic, and we do not have * dun->un_uppervp locked currently--so we get it * locked here (don't set the UN_ULOCK flag). */ vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p); } /*if (uppervp == upperdvp) dun->un_flags |= UN_KLOCK;*/ if (cnp->cn_consume != 0) { *ap->a_vpp = uppervp; if (!lockparent) cnp->cn_flags &= ~LOCKPARENT; - return (uerror); + error = uerror; + goto out; } if (uerror == ENOENT || uerror == EJUSTRETURN) { if (cnp->cn_flags & ISWHITEOUT) { iswhiteout = 1; } else if (lowerdvp != NULLVP) { lerror = VOP_GETATTR(upperdvp, &va, cnp->cn_cred, cnp->cn_proc); if (lerror == 0 && (va.va_flags & OPAQUE)) iswhiteout = 1; } } } else { uerror = ENOENT; } /* * 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; vn_lock(lowerdvp, LK_EXCLUSIVE | LK_RETRY, p); /* * Only do a LOOKUP on the bottom 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. */ lerror = union_lookup1(um->um_lowervp, &lowerdvp, &lowervp, cnp); if (um->um_op == UNMNT_BELOW) cnp->cn_cred = saved_cred; cnp->cn_nameiop = nameiop; if (lowervp != lowerdvp) VOP_UNLOCK(lowerdvp, 0, p); if (cnp->cn_consume != 0 || lerror == EACCES) { if (lerror == EACCES) lowervp = NULLVP; if (uppervp != NULLVP) { if (uppervp == upperdvp) vrele(uppervp); else vput(uppervp); uppervp = NULLVP; } *ap->a_vpp = lowervp; if (!lockparent) cnp->cn_flags &= ~LOCKPARENT; - return (lerror); + error = lerror; + goto out; } } else { lerror = ENOENT; if ((cnp->cn_flags & ISDOTDOT) && dun->un_pvp != NULLVP) { lowervp = LOWERVP(dun->un_pvp); if (lowervp != NULLVP) { VREF(lowervp); vn_lock(lowervp, LK_EXCLUSIVE | LK_RETRY, p); lerror = 0; } } } if (!lockparent) cnp->cn_flags &= ~LOCKPARENT; /* * at this point, we have uerror and lerror indicating * possible errors with the lookups in the upper and lower * layers. additionally, uppervp and lowervp are (locked) * references to existing vnodes in the upper and lower layers. * * there are now three cases to consider. * 1. if both layers returned an error, then return whatever * error the upper layer generated. * * 2. if the top layer failed and the bottom layer succeeded * then 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 bottom vnode is a directory, in which case * create a new directory in the top-level and * continue as in 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. */ *ap->a_vpp = NULLVP; /* case 1. */ if ((uerror != 0) && (lerror != 0)) { - return (uerror); + error = uerror; + goto out; } /* case 2. */ if (uerror != 0 /* && (lerror == 0) */ ) { if (lowervp->v_type == VDIR) { /* case 2b. */ dun->un_flags &= ~UN_ULOCK; VOP_UNLOCK(upperdvp, 0, p); uerror = union_mkshadow(um, upperdvp, cnp, &uppervp); vn_lock(upperdvp, LK_EXCLUSIVE | LK_RETRY, p); dun->un_flags |= UN_ULOCK; if (uerror) { if (lowervp != NULLVP) { vput(lowervp); lowervp = NULLVP; } - return (uerror); + error = uerror; + goto out; } } } if (lowervp != NULLVP) VOP_UNLOCK(lowervp, 0, p); error = union_allocvp(ap->a_vpp, dvp->v_mount, dvp, upperdvp, cnp, uppervp, lowervp, 1); if (error) { if (uppervp != NULLVP) vput(uppervp); if (lowervp != NULLVP) vrele(lowervp); } else { if (*ap->a_vpp != dvp) if (!lockparent || !(cnp->cn_flags & ISLASTCN)) VOP_UNLOCK(dvp, 0, p); #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 } +out: + if (cnp->cn_flags & ISDOTDOT) { + if (upperdvp != NULL) + vrele(upperdvp); + if (lowerdvp != NULL) + vrele(lowerdvp); + } + return (error); } 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 *un = VTOUNION(ap->a_dvp); struct vnode *dvp = un->un_uppervp; struct componentname *cnp = ap->a_cnp; struct proc *p = cnp->cn_proc; if (dvp != NULLVP) { int error; struct vnode *vp; struct mount *mp; FIXUP(un, p); VREF(dvp); SETKLOCK(un); mp = ap->a_dvp->v_mount; vput(ap->a_dvp); CLEARKLOCK(un); error = VOP_CREATE(dvp, &vp, cnp, ap->a_vap); if (error) return (error); error = union_allocvp(ap->a_vpp, mp, NULLVP, NULLVP, cnp, vp, NULLVP, 1); if (error) vput(vp); return (error); } vput(ap->a_dvp); return (EROFS); } 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 proc *p = cnp->cn_proc; if (un->un_uppervp == NULLVP) return (EOPNOTSUPP); FIXUP(un, p); return (VOP_WHITEOUT(un->un_uppervp, cnp, ap->a_flags)); } 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 *un = VTOUNION(ap->a_dvp); struct vnode *dvp = un->un_uppervp; struct componentname *cnp = ap->a_cnp; struct proc *p = cnp->cn_proc; if (dvp != NULLVP) { int error; struct vnode *vp; struct mount *mp; FIXUP(un, p); VREF(dvp); SETKLOCK(un); mp = ap->a_dvp->v_mount; vput(ap->a_dvp); CLEARKLOCK(un); error = VOP_MKNOD(dvp, &vp, cnp, ap->a_vap); if (error) return (error); if (vp != NULLVP) { error = union_allocvp(ap->a_vpp, mp, NULLVP, NULLVP, cnp, vp, NULLVP, 1); if (error) vput(vp); } return (error); } vput(ap->a_dvp); return (EROFS); } 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; /* * If there is an existing upper vp then simply open that. */ tvp = un->un_uppervp; if (tvp == 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)) { error = union_copyup(un, (mode&O_TRUNC) == 0, cred, p); if (error == 0) error = VOP_OPEN(un->un_uppervp, mode, cred, p); return (error); } /* * Just open the lower vnode */ un->un_openl++; vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY, p); error = VOP_OPEN(tvp, mode, cred, p); VOP_UNLOCK(tvp, 0, p); return (error); } FIXUP(un, p); error = VOP_OPEN(tvp, mode, cred, p); return (error); } 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; struct vnode *savedvp; /* * 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); } } if ((vp = un->un_uppervp) != NULLVP) { FIXUP(un, p); ap->a_vp = vp; return (VCALL(vp, VOFFSET(vop_access), ap)); } if ((vp = un->un_lowervp) != NULLVP) { vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); savedvp = ap->a_vp; ap->a_vp = vp; error = VCALL(vp, VOFFSET(vop_access), ap); if (error == 0) { struct union_mount *um = MOUNTTOUNIONMOUNT(savedvp->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); if (error) return (error); } return (error); } /* * We handle getattr only to change the fsid and * track object sizes */ 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 = un->un_uppervp; struct proc *p = ap->a_p; 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; vp = un->un_uppervp; if (vp != NULLVP) { /* * 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. * In the mean time, compensate here by checking * the union_node's lock flag. */ if (un->un_flags & UN_LOCKED) FIXUP(un, p); error = VOP_GETATTR(vp, vap, ap->a_cred, ap->a_p); if (error) return (error); union_newsize(ap->a_vp, vap->va_size, VNOVAL); } if (vp == NULLVP) { vp = un->un_lowervp; } else if (vp->v_type == VDIR) { 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); 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; ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0]; 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; 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) && /* assert(un->un_lowervp != 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. */ if (un->un_uppervp != NULLVP) { FIXUP(un, p); 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); } else { error = EROFS; } 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; { int error; struct proc *p = ap->a_uio->uio_procp; struct vnode *vp = OTHERVP(ap->a_vp); int dolock = (vp == LOWERVP(ap->a_vp)); if (dolock) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); else FIXUP(VTOUNION(ap->a_vp), p); error = VOP_READ(vp, ap->a_uio, ap->a_ioflag, ap->a_cred); if (dolock) VOP_UNLOCK(vp, 0, 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 (vp == 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; { int error; struct vnode *vp; struct union_node *un = VTOUNION(ap->a_vp); struct proc *p = ap->a_uio->uio_procp; vp = UPPERVP(ap->a_vp); if (vp == NULLVP) panic("union: missing upper layer in write"); FIXUP(un, p); error = VOP_WRITE(vp, 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); } 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; { register 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; { register 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; { register 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_mmap(ap) struct vop_mmap_args /* { struct vnode *a_vp; int a_fflags; struct ucred *a_cred; struct proc *a_p; } */ *ap; { register struct vnode *ovp = OTHERVP(ap->a_vp); ap->a_vp = ovp; return (VCALL(ovp, VOFFSET(vop_mmap), ap)); } 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 = OTHERVP(ap->a_vp); struct union_node *un; int isupperlocked = 0; if (targetvp != NULLVP) { int dolock = (targetvp == LOWERVP(ap->a_vp)); un = VTOUNION(ap->a_vp); if (dolock) vn_lock(targetvp, LK_EXCLUSIVE | LK_RETRY, p); - else if ((un->un_flags & UN_ULOCK) == 0 && - VOP_ISLOCKED(targetvp) == 0) { - isupperlocked = 1; - vn_lock(targetvp, LK_EXCLUSIVE | LK_RETRY, p); - un->un_flags |= UN_ULOCK; + else { + un = VTOUNION(ap->a_vp); + if ((un->un_flags & UN_ULOCK) == 0 && + targetvp->v_data != NULL && + ((struct lock *)targetvp->v_data)->lk_lockholder + == curproc->p_pid && + VOP_ISLOCKED(targetvp) != 0) + return 0; /* XXX */ + + FIXUP(un, p); } + error = VOP_FSYNC(targetvp, ap->a_cred, ap->a_waitfor, p); if (dolock) VOP_UNLOCK(targetvp, 0, p); else if (isupperlocked) { un->un_flags &= ~UN_ULOCK; VOP_UNLOCK(targetvp, 0, p); } } return (error); } static int union_remove(ap) struct vop_remove_args /* { struct vnode *a_dvp; struct vnode *a_vp; struct componentname *a_cnp; } */ *ap; { int error; 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; if (dun->un_uppervp == NULLVP) panic("union remove: null upper vnode"); if (un->un_uppervp != NULLVP) { struct vnode *dvp = dun->un_uppervp; struct vnode *vp = un->un_uppervp; FIXUP(dun, p); VREF(dvp); SETKLOCK(dun); vput(ap->a_dvp); CLEARKLOCK(dun); FIXUP(un, p); VREF(vp); SETKLOCK(un); vput(ap->a_vp); CLEARKLOCK(un); if (union_dowhiteout(un, cnp->cn_cred, cnp->cn_proc)) cnp->cn_flags |= DOWHITEOUT; error = VOP_REMOVE(dvp, vp, cnp); if (!error) union_removed_upper(un); } else { FIXUP(dun, p); error = union_mkwhiteout( MOUNTTOUNIONMOUNT(UNIONTOV(dun)->v_mount), dun->un_uppervp, ap->a_cnp, un->un_path); vput(ap->a_dvp); vput(ap->a_vp); } return (error); } static int union_link(ap) struct vop_link_args /* { struct vnode *a_tdvp; struct vnode *a_vp; struct componentname *a_cnp; } */ *ap; { int error = 0; struct componentname *cnp = ap->a_cnp; struct proc *p = cnp->cn_proc; struct union_node *un; struct vnode *vp; struct vnode *tdvp; un = VTOUNION(ap->a_tdvp); 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 (un->un_uppervp == tun->un_dirvp) { un->un_flags &= ~UN_ULOCK; VOP_UNLOCK(un->un_uppervp, 0, p); } error = union_copyup(tun, 1, cnp->cn_cred, p); if (un->un_uppervp == tun->un_dirvp) { vn_lock(un->un_uppervp, LK_EXCLUSIVE | LK_RETRY, p); un->un_flags |= UN_ULOCK; } VOP_UNLOCK(ap->a_vp, 0, p); } vp = tun->un_uppervp; } tdvp = un->un_uppervp; if (tdvp == NULLVP) error = EROFS; if (error) { vput(ap->a_tdvp); return (error); } FIXUP(un, p); VREF(tdvp); SETKLOCK(un); vput(ap->a_tdvp); CLEARKLOCK(un); return (VOP_LINK(tdvp, vp, cnp)); } 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; int isklockset = 0; 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); } if (fvp->v_op == union_vnodeop_p) { /* always true */ struct union_node *un = VTOUNION(fvp); if (un->un_uppervp == NULLVP) { /* XXX: should do a copyup */ 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); } 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; } tdvp = un->un_uppervp; VREF(tdvp); SETKLOCK(un); vput(ap->a_tdvp); CLEARKLOCK(un); } if (tvp != NULLVP && tvp->v_op == union_vnodeop_p) { struct union_node *un = VTOUNION(tvp); tvp = un->un_uppervp; if (tvp != NULLVP) { VREF(tvp); SETKLOCK(un); isklockset = 1; } vput(ap->a_tvp); if (isklockset) CLEARKLOCK(un); } return (VOP_RENAME(fdvp, fvp, ap->a_fcnp, tdvp, tvp, ap->a_tcnp)); bad: vrele(fdvp); vrele(fvp); vput(tdvp); if (tvp != NULLVP) vput(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 *un = VTOUNION(ap->a_dvp); struct vnode *dvp = un->un_uppervp; struct componentname *cnp = ap->a_cnp; struct proc *p = cnp->cn_proc; if (dvp != NULLVP) { int error; struct vnode *vp; FIXUP(un, p); VREF(dvp); SETKLOCK(un); VOP_UNLOCK(ap->a_dvp, 0, p); CLEARKLOCK(un); error = VOP_MKDIR(dvp, &vp, cnp, ap->a_vap); if (error) { vrele(ap->a_dvp); return (error); } error = union_allocvp(ap->a_vpp, ap->a_dvp->v_mount, ap->a_dvp, NULLVP, cnp, vp, NULLVP, 1); vrele(ap->a_dvp); if (error) vput(vp); return (error); } vput(ap->a_dvp); return (EROFS); } static int union_rmdir(ap) struct vop_rmdir_args /* { struct vnode *a_dvp; struct vnode *a_vp; struct componentname *a_cnp; } */ *ap; { int error; 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; if (dun->un_uppervp == NULLVP) panic("union rmdir: null upper vnode"); if (un->un_uppervp != NULLVP) { struct vnode *dvp = dun->un_uppervp; struct vnode *vp = un->un_uppervp; FIXUP(dun, p); VREF(dvp); SETKLOCK(dun); vput(ap->a_dvp); CLEARKLOCK(dun); FIXUP(un, p); VREF(vp); SETKLOCK(un); vput(ap->a_vp); CLEARKLOCK(un); if (union_dowhiteout(un, cnp->cn_cred, cnp->cn_proc)) cnp->cn_flags |= DOWHITEOUT; error = VOP_RMDIR(dvp, vp, ap->a_cnp); if (!error) union_removed_upper(un); } else { FIXUP(dun, p); error = union_mkwhiteout( MOUNTTOUNIONMOUNT(UNIONTOV(dun)->v_mount), dun->un_uppervp, ap->a_cnp, un->un_path); vput(ap->a_dvp); vput(ap->a_vp); } return (error); } 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 *un = VTOUNION(ap->a_dvp); struct vnode *dvp = un->un_uppervp; struct componentname *cnp = ap->a_cnp; struct proc *p = cnp->cn_proc; if (dvp != NULLVP) { int error; struct vnode *vp; FIXUP(un, p); VREF(dvp); SETKLOCK(un); vput(ap->a_dvp); CLEARKLOCK(un); error = VOP_SYMLINK(dvp, &vp, cnp, ap->a_vap, ap->a_target); *ap->a_vpp = NULLVP; return (error); } vput(ap->a_dvp); return (EROFS); } /* * 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 vnode *uvp = un->un_uppervp; struct proc *p = ap->a_uio->uio_procp; if (uvp == NULLVP) return (0); FIXUP(un, p); ap->a_vp = uvp; return (VCALL(uvp, VOFFSET(vop_readdir), ap)); } 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 uio *uio = ap->a_uio; struct proc *p = uio->uio_procp; struct vnode *vp = OTHERVP(ap->a_vp); int dolock = (vp == LOWERVP(ap->a_vp)); if (dolock) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); else FIXUP(VTOUNION(ap->a_vp), p); ap->a_vp = vp; error = VCALL(vp, VOFFSET(vop_readlink), ap); if (dolock) VOP_UNLOCK(vp, 0, p); return (error); } static int union_abortop(ap) struct vop_abortop_args /* { struct vnode *a_dvp; struct componentname *a_cnp; } */ *ap; { int error; struct componentname *cnp = ap->a_cnp; struct proc *p = cnp->cn_proc; struct vnode *vp = OTHERVP(ap->a_dvp); struct union_node *un = VTOUNION(ap->a_dvp); int islocked = un->un_flags & UN_LOCKED; int dolock = (vp == LOWERVP(ap->a_dvp)); if (islocked) { if (dolock) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); else FIXUP(VTOUNION(ap->a_dvp), p); } ap->a_dvp = vp; error = VCALL(vp, VOFFSET(vop_abortop), ap); if (islocked && dolock) VOP_UNLOCK(vp, 0, p); return (error); } 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; } 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; { struct vnode *vp = ap->a_vp; struct proc *p = ap->a_p; int flags = ap->a_flags; struct union_node *un; int error; vop_nolock(ap); /* * Need to do real lockmgr-style locking here. * in the mean time, draining won't work quite right, * which could lead to a few race conditions. * the following test was here, but is not quite right, we * still need to take the lock: if ((flags & LK_TYPE_MASK) == LK_DRAIN) return (0); */ flags &= ~LK_INTERLOCK; start: un = VTOUNION(vp); if (un->un_uppervp != NULLVP) { if (((un->un_flags & (UN_ULOCK | UN_KLOCK)) == 0) && (vp->v_usecount != 0)) { error = vn_lock(un->un_uppervp, flags, p); if (error) return (error); un->un_flags |= UN_ULOCK; } } if (un->un_flags & UN_LOCKED) { #ifdef DIAGNOSTIC if (curproc && un->un_pid == curproc->p_pid && un->un_pid > -1 && curproc->p_pid > -1) panic("union: locking against myself"); #endif un->un_flags |= UN_WANT; tsleep((caddr_t)&un->un_flags, PINOD, "unionlk2", 0); goto start; } #ifdef DIAGNOSTIC if (curproc) un->un_pid = curproc->p_pid; else un->un_pid = -1; #endif un->un_flags |= UN_LOCKED; return (0); } /* * When operations want to vput() a union node yet retain a lock on * the upper vnode (say, to do some further operations like link(), * mkdir(), ...), they set UN_KLOCK on the union node, then call * vput() which calls VOP_UNLOCK() and comes here. union_unlock() * unlocks the union node (leaving the upper vnode alone), clears the * KLOCK flag, and then returns to vput(). The caller then does whatever * is left to do with the upper vnode, and ensures that it gets unlocked. * * If UN_KLOCK isn't set, then the upper vnode is unlocked here. */ static int union_unlock(ap) struct vop_unlock_args /* { struct vnode *a_vp; int a_flags; struct proc *a_p; } */ *ap; { struct union_node *un = VTOUNION(ap->a_vp); struct proc *p = ap->a_p; #ifdef DIAGNOSTIC if ((un->un_flags & UN_LOCKED) == 0) panic("union: unlock unlocked node"); if (curproc && un->un_pid != curproc->p_pid && curproc->p_pid > -1 && un->un_pid > -1) panic("union: unlocking other process's union node"); #endif un->un_flags &= ~UN_LOCKED; if ((un->un_flags & (UN_ULOCK|UN_KLOCK)) == UN_ULOCK) VOP_UNLOCK(un->un_uppervp, 0, p); un->un_flags &= ~UN_ULOCK; if (un->un_flags & UN_WANT) { un->un_flags &= ~UN_WANT; wakeup((caddr_t) &un->un_flags); } #ifdef DIAGNOSTIC un->un_pid = 0; #endif vop_nounlock(ap); return (0); } static int union_bmap(ap) struct vop_bmap_args /* { struct vnode *a_vp; daddr_t a_bn; struct vnode **a_vpp; daddr_t *a_bnp; int *a_runp; int *a_runb; } */ *ap; { int error; struct proc *p = curproc; /* XXX */ struct vnode *vp = OTHERVP(ap->a_vp); int dolock = (vp == LOWERVP(ap->a_vp)); if (dolock) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); else FIXUP(VTOUNION(ap->a_vp), p); ap->a_vp = vp; error = VCALL(vp, VOFFSET(vop_bmap), ap); if (dolock) VOP_UNLOCK(vp, 0, p); return (error); } 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_islocked(ap) struct vop_islocked_args /* { struct vnode *a_vp; } */ *ap; { return ((VTOUNION(ap->a_vp)->un_flags & UN_LOCKED) ? 1 : 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 vnode *vp = OTHERVP(ap->a_vp); int dolock = (vp == LOWERVP(ap->a_vp)); if (dolock) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); else FIXUP(VTOUNION(ap->a_vp), p); ap->a_vp = vp; error = VCALL(vp, VOFFSET(vop_pathconf), ap); if (dolock) VOP_UNLOCK(vp, 0, 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 * vnode in its arguments. * This goes away with a merged VM/buffer cache. */ static int union_strategy(ap) struct vop_strategy_args /* { struct buf *a_bp; } */ *ap; { struct buf *bp = ap->a_bp; int error; struct vnode *savedvp; savedvp = bp->b_vp; bp->b_vp = OTHERVP(bp->b_vp); #ifdef DIAGNOSTIC if (bp->b_vp == NULLVP) panic("union_strategy: nil vp"); if (((bp->b_flags & B_READ) == 0) && (bp->b_vp == LOWERVP(savedvp))) panic("union_strategy: writing to lowervp"); #endif error = VOP_STRATEGY(bp); bp->b_vp = savedvp; return (error); } /* * 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_abortop_desc, (vop_t *) union_abortop }, { &vop_access_desc, (vop_t *) union_access }, { &vop_advlock_desc, (vop_t *) union_advlock }, { &vop_bmap_desc, (vop_t *) union_bmap }, { &vop_close_desc, (vop_t *) union_close }, { &vop_create_desc, (vop_t *) union_create }, { &vop_fsync_desc, (vop_t *) union_fsync }, { &vop_getattr_desc, (vop_t *) union_getattr }, { &vop_inactive_desc, (vop_t *) union_inactive }, { &vop_ioctl_desc, (vop_t *) union_ioctl }, { &vop_islocked_desc, (vop_t *) union_islocked }, { &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_mmap_desc, (vop_t *) union_mmap }, { &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_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);