Index: head/sys/fs/unionfs/union_subr.c =================================================================== --- head/sys/fs/unionfs/union_subr.c (revision 296715) +++ head/sys/fs/unionfs/union_subr.c (revision 296716) @@ -1,1268 +1,1265 @@ /*- * Copyright (c) 1994 Jan-Simon Pendry * Copyright (c) 1994 * The Regents of the University of California. All rights reserved. * Copyright (c) 2005, 2006, 2012 Masanori Ozawa , ONGS Inc. * Copyright (c) 2006, 2012 Daichi Goto * * 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. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)union_subr.c 8.20 (Berkeley) 5/20/95 * $FreeBSD$ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define NUNIONFSNODECACHE 16 static MALLOC_DEFINE(M_UNIONFSHASH, "UNIONFS hash", "UNIONFS hash table"); MALLOC_DEFINE(M_UNIONFSNODE, "UNIONFS node", "UNIONFS vnode private part"); MALLOC_DEFINE(M_UNIONFSPATH, "UNIONFS path", "UNIONFS path private part"); /* * Initialize */ int unionfs_init(struct vfsconf *vfsp) { UNIONFSDEBUG("unionfs_init\n"); /* printed during system boot */ return (0); } /* * Uninitialize */ int unionfs_uninit(struct vfsconf *vfsp) { return (0); } static struct unionfs_node_hashhead * unionfs_get_hashhead(struct vnode *dvp, char *path) { int count; char hash; struct unionfs_node *unp; hash = 0; unp = VTOUNIONFS(dvp); if (path != NULL) { for (count = 0; path[count]; count++) hash += path[count]; } return (&(unp->un_hashtbl[hash & (unp->un_hashmask)])); } /* * Get the cached vnode. */ static struct vnode * unionfs_get_cached_vnode(struct vnode *uvp, struct vnode *lvp, struct vnode *dvp, char *path) { struct unionfs_node_hashhead *hd; struct unionfs_node *unp; struct vnode *vp; KASSERT((uvp == NULLVP || uvp->v_type == VDIR), ("unionfs_get_cached_vnode: v_type != VDIR")); KASSERT((lvp == NULLVP || lvp->v_type == VDIR), ("unionfs_get_cached_vnode: v_type != VDIR")); VI_LOCK(dvp); hd = unionfs_get_hashhead(dvp, path); LIST_FOREACH(unp, hd, un_hash) { if (!strcmp(unp->un_path, path)) { vp = UNIONFSTOV(unp); VI_LOCK_FLAGS(vp, MTX_DUPOK); VI_UNLOCK(dvp); vp->v_iflag &= ~VI_OWEINACT; if ((vp->v_iflag & (VI_DOOMED | VI_DOINGINACT)) != 0) { VI_UNLOCK(vp); vp = NULLVP; } else VI_UNLOCK(vp); return (vp); } } VI_UNLOCK(dvp); return (NULLVP); } /* * Add the new vnode into cache. */ static struct vnode * unionfs_ins_cached_vnode(struct unionfs_node *uncp, struct vnode *dvp, char *path) { struct unionfs_node_hashhead *hd; struct unionfs_node *unp; struct vnode *vp; KASSERT((uncp->un_uppervp==NULLVP || uncp->un_uppervp->v_type==VDIR), ("unionfs_ins_cached_vnode: v_type != VDIR")); KASSERT((uncp->un_lowervp==NULLVP || uncp->un_lowervp->v_type==VDIR), ("unionfs_ins_cached_vnode: v_type != VDIR")); VI_LOCK(dvp); hd = unionfs_get_hashhead(dvp, path); LIST_FOREACH(unp, hd, un_hash) { if (!strcmp(unp->un_path, path)) { vp = UNIONFSTOV(unp); VI_LOCK_FLAGS(vp, MTX_DUPOK); vp->v_iflag &= ~VI_OWEINACT; if ((vp->v_iflag & (VI_DOOMED | VI_DOINGINACT)) != 0) { LIST_INSERT_HEAD(hd, uncp, un_hash); VI_UNLOCK(vp); vp = NULLVP; } else VI_UNLOCK(vp); VI_UNLOCK(dvp); return (vp); } } LIST_INSERT_HEAD(hd, uncp, un_hash); VI_UNLOCK(dvp); return (NULLVP); } /* * Remove the vnode. */ static void unionfs_rem_cached_vnode(struct unionfs_node *unp, struct vnode *dvp) { KASSERT((unp != NULL), ("unionfs_rem_cached_vnode: null node")); KASSERT((dvp != NULLVP), ("unionfs_rem_cached_vnode: null parent vnode")); KASSERT((unp->un_hash.le_prev != NULL), ("unionfs_rem_cached_vnode: null hash")); VI_LOCK(dvp); LIST_REMOVE(unp, un_hash); unp->un_hash.le_next = NULL; unp->un_hash.le_prev = NULL; VI_UNLOCK(dvp); } /* * Make a new or get existing unionfs node. * * uppervp and lowervp should be unlocked. Because if new unionfs vnode is * locked, uppervp or lowervp is locked too. In order to prevent dead lock, * you should not lock plurality simultaneously. */ int unionfs_nodeget(struct mount *mp, struct vnode *uppervp, struct vnode *lowervp, struct vnode *dvp, struct vnode **vpp, struct componentname *cnp, struct thread *td) { struct unionfs_mount *ump; struct unionfs_node *unp; struct vnode *vp; int error; int lkflags; enum vtype vt; char *path; ump = MOUNTTOUNIONFSMOUNT(mp); lkflags = (cnp ? cnp->cn_lkflags : 0); path = (cnp ? cnp->cn_nameptr : NULL); *vpp = NULLVP; if (uppervp == NULLVP && lowervp == NULLVP) panic("unionfs_nodeget: upper and lower is null"); vt = (uppervp != NULLVP ? uppervp->v_type : lowervp->v_type); /* If it has no ISLASTCN flag, path check is skipped. */ if (cnp && !(cnp->cn_flags & ISLASTCN)) path = NULL; /* check the cache */ if (path != NULL && dvp != NULLVP && vt == VDIR) { vp = unionfs_get_cached_vnode(uppervp, lowervp, dvp, path); if (vp != NULLVP) { vref(vp); *vpp = vp; goto unionfs_nodeget_out; } } if ((uppervp == NULLVP || ump->um_uppervp != uppervp) || (lowervp == NULLVP || ump->um_lowervp != lowervp)) { /* dvp will be NULLVP only in case of root vnode. */ if (dvp == NULLVP) return (EINVAL); } unp = malloc(sizeof(struct unionfs_node), M_UNIONFSNODE, M_WAITOK | M_ZERO); error = getnewvnode("unionfs", mp, &unionfs_vnodeops, &vp); if (error != 0) { free(unp, M_UNIONFSNODE); return (error); } error = insmntque(vp, mp); /* XXX: Too early for mpsafe fs */ if (error != 0) { free(unp, M_UNIONFSNODE); return (error); } if (dvp != NULLVP) vref(dvp); if (uppervp != NULLVP) vref(uppervp); if (lowervp != NULLVP) vref(lowervp); if (vt == VDIR) unp->un_hashtbl = hashinit(NUNIONFSNODECACHE, M_UNIONFSHASH, &(unp->un_hashmask)); unp->un_vnode = vp; unp->un_uppervp = uppervp; unp->un_lowervp = lowervp; unp->un_dvp = dvp; if (uppervp != NULLVP) vp->v_vnlock = uppervp->v_vnlock; else vp->v_vnlock = lowervp->v_vnlock; if (path != NULL) { unp->un_path = (char *) malloc(cnp->cn_namelen +1, M_UNIONFSPATH, M_WAITOK|M_ZERO); bcopy(cnp->cn_nameptr, unp->un_path, cnp->cn_namelen); unp->un_path[cnp->cn_namelen] = '\0'; } vp->v_type = vt; vp->v_data = unp; if ((uppervp != NULLVP && ump->um_uppervp == uppervp) && (lowervp != NULLVP && ump->um_lowervp == lowervp)) vp->v_vflag |= VV_ROOT; if (path != NULL && dvp != NULLVP && vt == VDIR) *vpp = unionfs_ins_cached_vnode(unp, dvp, path); if ((*vpp) != NULLVP) { if (dvp != NULLVP) vrele(dvp); if (uppervp != NULLVP) vrele(uppervp); if (lowervp != NULLVP) vrele(lowervp); unp->un_uppervp = NULLVP; unp->un_lowervp = NULLVP; unp->un_dvp = NULLVP; vrele(vp); vp = *vpp; vref(vp); } else *vpp = vp; unionfs_nodeget_out: if (lkflags & LK_TYPE_MASK) vn_lock(vp, lkflags | LK_RETRY); return (0); } /* * Clean up the unionfs node. */ void unionfs_noderem(struct vnode *vp, struct thread *td) { int count; struct unionfs_node *unp, *unp_t1, *unp_t2; struct unionfs_node_hashhead *hd; struct unionfs_node_status *unsp, *unsp_tmp; struct vnode *lvp; struct vnode *uvp; struct vnode *dvp; /* * Use the interlock to protect the clearing of v_data to * prevent faults in unionfs_lock(). */ VI_LOCK(vp); unp = VTOUNIONFS(vp); lvp = unp->un_lowervp; uvp = unp->un_uppervp; dvp = unp->un_dvp; unp->un_lowervp = unp->un_uppervp = NULLVP; vp->v_vnlock = &(vp->v_lock); vp->v_data = NULL; vp->v_object = NULL; VI_UNLOCK(vp); if (lvp != NULLVP) VOP_UNLOCK(lvp, LK_RELEASE); if (uvp != NULLVP) VOP_UNLOCK(uvp, LK_RELEASE); if (dvp != NULLVP && unp->un_hash.le_prev != NULL) unionfs_rem_cached_vnode(unp, dvp); if (lockmgr(vp->v_vnlock, LK_EXCLUSIVE, VI_MTX(vp)) != 0) panic("the lock for deletion is unacquirable."); if (lvp != NULLVP) vrele(lvp); if (uvp != NULLVP) vrele(uvp); if (dvp != NULLVP) { vrele(dvp); unp->un_dvp = NULLVP; } if (unp->un_path != NULL) { free(unp->un_path, M_UNIONFSPATH); unp->un_path = NULL; } if (unp->un_hashtbl != NULL) { for (count = 0; count <= unp->un_hashmask; count++) { hd = unp->un_hashtbl + count; LIST_FOREACH_SAFE(unp_t1, hd, un_hash, unp_t2) { LIST_REMOVE(unp_t1, un_hash); unp_t1->un_hash.le_next = NULL; unp_t1->un_hash.le_prev = NULL; } } hashdestroy(unp->un_hashtbl, M_UNIONFSHASH, unp->un_hashmask); } LIST_FOREACH_SAFE(unsp, &(unp->un_unshead), uns_list, unsp_tmp) { LIST_REMOVE(unsp, uns_list); free(unsp, M_TEMP); } free(unp, M_UNIONFSNODE); } /* * Get the unionfs node status. * You need exclusive lock this vnode. */ void unionfs_get_node_status(struct unionfs_node *unp, struct thread *td, struct unionfs_node_status **unspp) { struct unionfs_node_status *unsp; pid_t pid = td->td_proc->p_pid; KASSERT(NULL != unspp, ("null pointer")); ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), "unionfs_get_node_status"); LIST_FOREACH(unsp, &(unp->un_unshead), uns_list) { if (unsp->uns_pid == pid) { *unspp = unsp; return; } } /* create a new unionfs node status */ unsp = malloc(sizeof(struct unionfs_node_status), M_TEMP, M_WAITOK | M_ZERO); unsp->uns_pid = pid; LIST_INSERT_HEAD(&(unp->un_unshead), unsp, uns_list); *unspp = unsp; } /* * Remove the unionfs node status, if you can. * You need exclusive lock this vnode. */ void unionfs_tryrem_node_status(struct unionfs_node *unp, struct unionfs_node_status *unsp) { KASSERT(NULL != unsp, ("null pointer")); ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), "unionfs_get_node_status"); if (0 < unsp->uns_lower_opencnt || 0 < unsp->uns_upper_opencnt) return; LIST_REMOVE(unsp, uns_list); free(unsp, M_TEMP); } /* * Create upper node attr. */ void unionfs_create_uppervattr_core(struct unionfs_mount *ump, struct vattr *lva, struct vattr *uva, struct thread *td) { VATTR_NULL(uva); uva->va_type = lva->va_type; uva->va_atime = lva->va_atime; uva->va_mtime = lva->va_mtime; uva->va_ctime = lva->va_ctime; switch (ump->um_copymode) { case UNIONFS_TRANSPARENT: uva->va_mode = lva->va_mode; uva->va_uid = lva->va_uid; uva->va_gid = lva->va_gid; break; case UNIONFS_MASQUERADE: if (ump->um_uid == lva->va_uid) { uva->va_mode = lva->va_mode & 077077; uva->va_mode |= (lva->va_type == VDIR ? ump->um_udir : ump->um_ufile) & 0700; uva->va_uid = lva->va_uid; uva->va_gid = lva->va_gid; } else { uva->va_mode = (lva->va_type == VDIR ? ump->um_udir : ump->um_ufile); uva->va_uid = ump->um_uid; uva->va_gid = ump->um_gid; } break; default: /* UNIONFS_TRADITIONAL */ uva->va_mode = 0777 & ~td->td_proc->p_fd->fd_cmask; uva->va_uid = ump->um_uid; uva->va_gid = ump->um_gid; break; } } /* * Create upper node attr. */ int unionfs_create_uppervattr(struct unionfs_mount *ump, struct vnode *lvp, struct vattr *uva, struct ucred *cred, struct thread *td) { int error; struct vattr lva; if ((error = VOP_GETATTR(lvp, &lva, cred))) return (error); unionfs_create_uppervattr_core(ump, &lva, uva, td); return (error); } /* * relookup * * dvp should be locked on entry and will be locked on return. * * If an error is returned, *vpp will be invalid, otherwise it will hold a * locked, referenced vnode. If *vpp == dvp then remember that only one * LK_EXCLUSIVE lock is held. */ int unionfs_relookup(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp, struct componentname *cn, struct thread *td, char *path, int pathlen, u_long nameiop) { int error; cn->cn_namelen = pathlen; cn->cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK); bcopy(path, cn->cn_pnbuf, pathlen); cn->cn_pnbuf[pathlen] = '\0'; cn->cn_nameiop = nameiop; cn->cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN); cn->cn_lkflags = LK_EXCLUSIVE; cn->cn_thread = td; cn->cn_cred = cnp->cn_cred; cn->cn_nameptr = cn->cn_pnbuf; - cn->cn_consume = cnp->cn_consume; if (nameiop == DELETE) cn->cn_flags |= (cnp->cn_flags & (DOWHITEOUT | SAVESTART)); else if (RENAME == nameiop) cn->cn_flags |= (cnp->cn_flags & SAVESTART); else if (nameiop == CREATE) cn->cn_flags |= NOCACHE; vref(dvp); VOP_UNLOCK(dvp, LK_RELEASE); if ((error = relookup(dvp, vpp, cn))) { uma_zfree(namei_zone, cn->cn_pnbuf); cn->cn_flags &= ~HASBUF; vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); } else vrele(dvp); return (error); } /* * relookup for CREATE namei operation. * * dvp is unionfs vnode. dvp should be locked. * * If it called 'unionfs_copyfile' function by unionfs_link etc, * VOP_LOOKUP information is broken. * So it need relookup in order to create link etc. */ int unionfs_relookup_for_create(struct vnode *dvp, struct componentname *cnp, struct thread *td) { int error; struct vnode *udvp; struct vnode *vp; struct componentname cn; udvp = UNIONFSVPTOUPPERVP(dvp); vp = NULLVP; error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, strlen(cnp->cn_nameptr), CREATE); if (error) return (error); if (vp != NULLVP) { if (udvp == vp) vrele(vp); else vput(vp); error = EEXIST; } if (cn.cn_flags & HASBUF) { uma_zfree(namei_zone, cn.cn_pnbuf); cn.cn_flags &= ~HASBUF; } if (!error) { cn.cn_flags |= (cnp->cn_flags & HASBUF); cnp->cn_flags = cn.cn_flags; } return (error); } /* * relookup for DELETE namei operation. * * dvp is unionfs vnode. dvp should be locked. */ int unionfs_relookup_for_delete(struct vnode *dvp, struct componentname *cnp, struct thread *td) { int error; struct vnode *udvp; struct vnode *vp; struct componentname cn; udvp = UNIONFSVPTOUPPERVP(dvp); vp = NULLVP; error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, strlen(cnp->cn_nameptr), DELETE); if (error) return (error); if (vp == NULLVP) error = ENOENT; else { if (udvp == vp) vrele(vp); else vput(vp); } if (cn.cn_flags & HASBUF) { uma_zfree(namei_zone, cn.cn_pnbuf); cn.cn_flags &= ~HASBUF; } if (!error) { cn.cn_flags |= (cnp->cn_flags & HASBUF); cnp->cn_flags = cn.cn_flags; } return (error); } /* * relookup for RENAME namei operation. * * dvp is unionfs vnode. dvp should be locked. */ int unionfs_relookup_for_rename(struct vnode *dvp, struct componentname *cnp, struct thread *td) { int error; struct vnode *udvp; struct vnode *vp; struct componentname cn; udvp = UNIONFSVPTOUPPERVP(dvp); vp = NULLVP; error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, strlen(cnp->cn_nameptr), RENAME); if (error) return (error); if (vp != NULLVP) { if (udvp == vp) vrele(vp); else vput(vp); } if (cn.cn_flags & HASBUF) { uma_zfree(namei_zone, cn.cn_pnbuf); cn.cn_flags &= ~HASBUF; } if (!error) { cn.cn_flags |= (cnp->cn_flags & HASBUF); cnp->cn_flags = cn.cn_flags; } return (error); } /* * Update the unionfs_node. * * uvp is new locked upper vnode. unionfs vnode's lock will be exchanged to the * uvp's lock and lower's lock will be unlocked. */ static void unionfs_node_update(struct unionfs_node *unp, struct vnode *uvp, struct thread *td) { unsigned count, lockrec; struct vnode *vp; struct vnode *lvp; struct vnode *dvp; vp = UNIONFSTOV(unp); lvp = unp->un_lowervp; ASSERT_VOP_ELOCKED(lvp, "unionfs_node_update"); dvp = unp->un_dvp; /* * lock update */ VI_LOCK(vp); unp->un_uppervp = uvp; vp->v_vnlock = uvp->v_vnlock; VI_UNLOCK(vp); lockrec = lvp->v_vnlock->lk_recurse; for (count = 0; count < lockrec; count++) vn_lock(uvp, LK_EXCLUSIVE | LK_CANRECURSE | LK_RETRY); /* * cache update */ if (unp->un_path != NULL && dvp != NULLVP && vp->v_type == VDIR) { static struct unionfs_node_hashhead *hd; VI_LOCK(dvp); hd = unionfs_get_hashhead(dvp, unp->un_path); LIST_REMOVE(unp, un_hash); LIST_INSERT_HEAD(hd, unp, un_hash); VI_UNLOCK(dvp); } } /* * Create a new shadow dir. * * udvp should be locked on entry and will be locked on return. * * If no error returned, unp will be updated. */ int unionfs_mkshadowdir(struct unionfs_mount *ump, struct vnode *udvp, struct unionfs_node *unp, struct componentname *cnp, struct thread *td) { int error; struct vnode *lvp; struct vnode *uvp; struct vattr va; struct vattr lva; struct componentname cn; struct mount *mp; struct ucred *cred; struct ucred *credbk; struct uidinfo *rootinfo; if (unp->un_uppervp != NULLVP) return (EEXIST); lvp = unp->un_lowervp; uvp = NULLVP; credbk = cnp->cn_cred; /* Authority change to root */ rootinfo = uifind((uid_t)0); cred = crdup(cnp->cn_cred); /* * The calls to chgproccnt() are needed to compensate for change_ruid() * calling chgproccnt(). */ chgproccnt(cred->cr_ruidinfo, 1, 0); change_euid(cred, rootinfo); change_ruid(cred, rootinfo); change_svuid(cred, (uid_t)0); uifree(rootinfo); cnp->cn_cred = cred; memset(&cn, 0, sizeof(cn)); if ((error = VOP_GETATTR(lvp, &lva, cnp->cn_cred))) goto unionfs_mkshadowdir_abort; if ((error = unionfs_relookup(udvp, &uvp, cnp, &cn, td, cnp->cn_nameptr, cnp->cn_namelen, CREATE))) goto unionfs_mkshadowdir_abort; if (uvp != NULLVP) { if (udvp == uvp) vrele(uvp); else vput(uvp); error = EEXIST; goto unionfs_mkshadowdir_free_out; } if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH))) goto unionfs_mkshadowdir_free_out; unionfs_create_uppervattr_core(ump, &lva, &va, td); error = VOP_MKDIR(udvp, &uvp, &cn, &va); if (!error) { unionfs_node_update(unp, uvp, td); /* * XXX The bug which cannot set uid/gid was corrected. * Ignore errors. */ va.va_type = VNON; VOP_SETATTR(uvp, &va, cn.cn_cred); } vn_finished_write(mp); unionfs_mkshadowdir_free_out: if (cn.cn_flags & HASBUF) { uma_zfree(namei_zone, cn.cn_pnbuf); cn.cn_flags &= ~HASBUF; } unionfs_mkshadowdir_abort: cnp->cn_cred = credbk; chgproccnt(cred->cr_ruidinfo, -1, 0); crfree(cred); return (error); } /* * Create a new whiteout. * * dvp should be locked on entry and will be locked on return. */ int unionfs_mkwhiteout(struct vnode *dvp, struct componentname *cnp, struct thread *td, char *path) { int error; struct vnode *wvp; struct componentname cn; struct mount *mp; if (path == NULL) path = cnp->cn_nameptr; wvp = NULLVP; if ((error = unionfs_relookup(dvp, &wvp, cnp, &cn, td, path, strlen(path), CREATE))) return (error); if (wvp != NULLVP) { if (cn.cn_flags & HASBUF) { uma_zfree(namei_zone, cn.cn_pnbuf); cn.cn_flags &= ~HASBUF; } if (dvp == wvp) vrele(wvp); else vput(wvp); return (EEXIST); } if ((error = vn_start_write(dvp, &mp, V_WAIT | PCATCH))) goto unionfs_mkwhiteout_free_out; error = VOP_WHITEOUT(dvp, &cn, CREATE); vn_finished_write(mp); unionfs_mkwhiteout_free_out: if (cn.cn_flags & HASBUF) { uma_zfree(namei_zone, cn.cn_pnbuf); cn.cn_flags &= ~HASBUF; } return (error); } /* * Create a new vnode for create a new shadow file. * * If an error is returned, *vpp will be invalid, otherwise it will hold a * locked, referenced and opened vnode. * * unp is never updated. */ static int unionfs_vn_create_on_upper(struct vnode **vpp, struct vnode *udvp, struct unionfs_node *unp, struct vattr *uvap, struct thread *td) { struct unionfs_mount *ump; struct vnode *vp; struct vnode *lvp; struct ucred *cred; struct vattr lva; int fmode; int error; struct componentname cn; ump = MOUNTTOUNIONFSMOUNT(UNIONFSTOV(unp)->v_mount); vp = NULLVP; lvp = unp->un_lowervp; cred = td->td_ucred; fmode = FFLAGS(O_WRONLY | O_CREAT | O_TRUNC | O_EXCL); error = 0; if ((error = VOP_GETATTR(lvp, &lva, cred)) != 0) return (error); unionfs_create_uppervattr_core(ump, &lva, uvap, td); if (unp->un_path == NULL) panic("unionfs: un_path is null"); cn.cn_namelen = strlen(unp->un_path); cn.cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK); bcopy(unp->un_path, cn.cn_pnbuf, cn.cn_namelen + 1); cn.cn_nameiop = CREATE; cn.cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN); cn.cn_lkflags = LK_EXCLUSIVE; cn.cn_thread = td; cn.cn_cred = cred; cn.cn_nameptr = cn.cn_pnbuf; - cn.cn_consume = 0; vref(udvp); if ((error = relookup(udvp, &vp, &cn)) != 0) goto unionfs_vn_create_on_upper_free_out2; vrele(udvp); if (vp != NULLVP) { if (vp == udvp) vrele(vp); else vput(vp); error = EEXIST; goto unionfs_vn_create_on_upper_free_out1; } if ((error = VOP_CREATE(udvp, &vp, &cn, uvap)) != 0) goto unionfs_vn_create_on_upper_free_out1; if ((error = VOP_OPEN(vp, fmode, cred, td, NULL)) != 0) { vput(vp); goto unionfs_vn_create_on_upper_free_out1; } VOP_ADD_WRITECOUNT(vp, 1); CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", __func__, vp, vp->v_writecount); *vpp = vp; unionfs_vn_create_on_upper_free_out1: VOP_UNLOCK(udvp, LK_RELEASE); unionfs_vn_create_on_upper_free_out2: if (cn.cn_flags & HASBUF) { uma_zfree(namei_zone, cn.cn_pnbuf); cn.cn_flags &= ~HASBUF; } return (error); } /* * Copy from lvp to uvp. * * lvp and uvp should be locked and opened on entry and will be locked and * opened on return. */ static int unionfs_copyfile_core(struct vnode *lvp, struct vnode *uvp, struct ucred *cred, struct thread *td) { int error; off_t offset; int count; int bufoffset; char *buf; struct uio uio; struct iovec iov; error = 0; memset(&uio, 0, sizeof(uio)); uio.uio_td = td; uio.uio_segflg = UIO_SYSSPACE; uio.uio_offset = 0; buf = malloc(MAXBSIZE, M_TEMP, M_WAITOK); while (error == 0) { offset = uio.uio_offset; uio.uio_iov = &iov; uio.uio_iovcnt = 1; iov.iov_base = buf; iov.iov_len = MAXBSIZE; uio.uio_resid = iov.iov_len; uio.uio_rw = UIO_READ; if ((error = VOP_READ(lvp, &uio, 0, cred)) != 0) break; if ((count = MAXBSIZE - uio.uio_resid) == 0) break; bufoffset = 0; while (bufoffset < count) { uio.uio_iov = &iov; uio.uio_iovcnt = 1; iov.iov_base = buf + bufoffset; iov.iov_len = count - bufoffset; uio.uio_offset = offset + bufoffset; uio.uio_resid = iov.iov_len; uio.uio_rw = UIO_WRITE; if ((error = VOP_WRITE(uvp, &uio, 0, cred)) != 0) break; bufoffset += (count - bufoffset) - uio.uio_resid; } uio.uio_offset = offset + bufoffset; } free(buf, M_TEMP); return (error); } /* * Copy file from lower to upper. * * If you need copy of the contents, set 1 to docopy. Otherwise, set 0 to * docopy. * * If no error returned, unp will be updated. */ int unionfs_copyfile(struct unionfs_node *unp, int docopy, struct ucred *cred, struct thread *td) { int error; struct mount *mp; struct vnode *udvp; struct vnode *lvp; struct vnode *uvp; struct vattr uva; lvp = unp->un_lowervp; uvp = NULLVP; if ((UNIONFSTOV(unp)->v_mount->mnt_flag & MNT_RDONLY)) return (EROFS); if (unp->un_dvp == NULLVP) return (EINVAL); if (unp->un_uppervp != NULLVP) return (EEXIST); udvp = VTOUNIONFS(unp->un_dvp)->un_uppervp; if (udvp == NULLVP) return (EROFS); if ((udvp->v_mount->mnt_flag & MNT_RDONLY)) return (EROFS); error = VOP_ACCESS(lvp, VREAD, cred, td); if (error != 0) return (error); if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH)) != 0) return (error); error = unionfs_vn_create_on_upper(&uvp, udvp, unp, &uva, td); if (error != 0) { vn_finished_write(mp); return (error); } if (docopy != 0) { error = VOP_OPEN(lvp, FREAD, cred, td, NULL); if (error == 0) { error = unionfs_copyfile_core(lvp, uvp, cred, td); VOP_CLOSE(lvp, FREAD, cred, td); } } VOP_CLOSE(uvp, FWRITE, cred, td); VOP_ADD_WRITECOUNT(uvp, -1); CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", __func__, uvp, uvp->v_writecount); vn_finished_write(mp); if (error == 0) { /* Reset the attributes. Ignore errors. */ uva.va_type = VNON; VOP_SETATTR(uvp, &uva, cred); } unionfs_node_update(unp, uvp, td); return (error); } /* * It checks whether vp can rmdir. (check empty) * * vp is unionfs vnode. * vp should be locked. */ int unionfs_check_rmdir(struct vnode *vp, struct ucred *cred, struct thread *td) { int error; int eofflag; int lookuperr; struct vnode *uvp; struct vnode *lvp; struct vnode *tvp; struct vattr va; struct componentname cn; /* * The size of buf needs to be larger than DIRBLKSIZ. */ char buf[256 * 6]; struct dirent *dp; struct dirent *edp; struct uio uio; struct iovec iov; ASSERT_VOP_ELOCKED(vp, "unionfs_check_rmdir"); eofflag = 0; uvp = UNIONFSVPTOUPPERVP(vp); lvp = UNIONFSVPTOLOWERVP(vp); /* check opaque */ if ((error = VOP_GETATTR(uvp, &va, cred)) != 0) return (error); if (va.va_flags & OPAQUE) return (0); /* open vnode */ #ifdef MAC if ((error = mac_vnode_check_open(cred, vp, VEXEC|VREAD)) != 0) return (error); #endif if ((error = VOP_ACCESS(vp, VEXEC|VREAD, cred, td)) != 0) return (error); if ((error = VOP_OPEN(vp, FREAD, cred, td, NULL)) != 0) return (error); uio.uio_rw = UIO_READ; uio.uio_segflg = UIO_SYSSPACE; uio.uio_td = td; uio.uio_offset = 0; #ifdef MAC error = mac_vnode_check_readdir(td->td_ucred, lvp); #endif while (!error && !eofflag) { iov.iov_base = buf; iov.iov_len = sizeof(buf); uio.uio_iov = &iov; uio.uio_iovcnt = 1; uio.uio_resid = iov.iov_len; error = VOP_READDIR(lvp, &uio, cred, &eofflag, NULL, NULL); if (error != 0) break; if (eofflag == 0 && uio.uio_resid == sizeof(buf)) { #ifdef DIAGNOSTIC panic("bad readdir response from lower FS."); #endif break; } edp = (struct dirent*)&buf[sizeof(buf) - uio.uio_resid]; for (dp = (struct dirent*)buf; !error && dp < edp; dp = (struct dirent*)((caddr_t)dp + dp->d_reclen)) { if (dp->d_type == DT_WHT || dp->d_fileno == 0 || (dp->d_namlen == 1 && dp->d_name[0] == '.') || (dp->d_namlen == 2 && !bcmp(dp->d_name, "..", 2))) continue; cn.cn_namelen = dp->d_namlen; cn.cn_pnbuf = NULL; cn.cn_nameptr = dp->d_name; cn.cn_nameiop = LOOKUP; cn.cn_flags = (LOCKPARENT | LOCKLEAF | SAVENAME | RDONLY | ISLASTCN); cn.cn_lkflags = LK_EXCLUSIVE; cn.cn_thread = td; cn.cn_cred = cred; - cn.cn_consume = 0; /* * check entry in lower. * Sometimes, readdir function returns * wrong entry. */ lookuperr = VOP_LOOKUP(lvp, &tvp, &cn); if (!lookuperr) vput(tvp); else continue; /* skip entry */ /* * check entry * If it has no exist/whiteout entry in upper, * directory is not empty. */ cn.cn_flags = (LOCKPARENT | LOCKLEAF | SAVENAME | RDONLY | ISLASTCN); lookuperr = VOP_LOOKUP(uvp, &tvp, &cn); if (!lookuperr) vput(tvp); /* ignore exist or whiteout entry */ if (!lookuperr || (lookuperr == ENOENT && (cn.cn_flags & ISWHITEOUT))) continue; error = ENOTEMPTY; } } /* close vnode */ VOP_CLOSE(vp, FREAD, cred, td); return (error); } #ifdef DIAGNOSTIC struct vnode * unionfs_checkuppervp(struct vnode *vp, char *fil, int lno) { struct unionfs_node *unp; unp = VTOUNIONFS(vp); #ifdef notyet if (vp->v_op != unionfs_vnodeop_p) { printf("unionfs_checkuppervp: on non-unionfs-node.\n"); #ifdef KDB kdb_enter(KDB_WHY_UNIONFS, "unionfs_checkuppervp: on non-unionfs-node.\n"); #endif panic("unionfs_checkuppervp"); }; #endif return (unp->un_uppervp); } struct vnode * unionfs_checklowervp(struct vnode *vp, char *fil, int lno) { struct unionfs_node *unp; unp = VTOUNIONFS(vp); #ifdef notyet if (vp->v_op != unionfs_vnodeop_p) { printf("unionfs_checklowervp: on non-unionfs-node.\n"); #ifdef KDB kdb_enter(KDB_WHY_UNIONFS, "unionfs_checklowervp: on non-unionfs-node.\n"); #endif panic("unionfs_checklowervp"); }; #endif return (unp->un_lowervp); } #endif Index: head/sys/kern/vfs_lookup.c =================================================================== --- head/sys/kern/vfs_lookup.c (revision 296715) +++ head/sys/kern/vfs_lookup.c (revision 296716) @@ -1,1278 +1,1266 @@ /*- * Copyright (c) 1982, 1986, 1989, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * 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. * 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. * * @(#)vfs_lookup.c 8.4 (Berkeley) 2/16/94 */ #include __FBSDID("$FreeBSD$"); #include "opt_capsicum.h" #include "opt_ktrace.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef KTRACE #include #endif #include #include #include #define NAMEI_DIAGNOSTIC 1 #undef NAMEI_DIAGNOSTIC SDT_PROVIDER_DECLARE(vfs); SDT_PROBE_DEFINE3(vfs, namei, lookup, entry, "struct vnode *", "char *", "unsigned long"); SDT_PROBE_DEFINE2(vfs, namei, lookup, return, "int", "struct vnode *"); /* * Allocation zone for namei */ uma_zone_t namei_zone; /* * Placeholder vnode for mp traversal */ static struct vnode *vp_crossmp; static void nameiinit(void *dummy __unused) { namei_zone = uma_zcreate("NAMEI", MAXPATHLEN, NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); getnewvnode("crossmp", NULL, &dead_vnodeops, &vp_crossmp); vn_lock(vp_crossmp, LK_EXCLUSIVE); VN_LOCK_ASHARE(vp_crossmp); VOP_UNLOCK(vp_crossmp, 0); } SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_SECOND, nameiinit, NULL); static int lookup_shared = 1; SYSCTL_INT(_vfs, OID_AUTO, lookup_shared, CTLFLAG_RWTUN, &lookup_shared, 0, "Enables/Disables shared locks for path name translation"); static void namei_cleanup_cnp(struct componentname *cnp) { uma_zfree(namei_zone, cnp->cn_pnbuf); #ifdef DIAGNOSTIC cnp->cn_pnbuf = NULL; cnp->cn_nameptr = NULL; #endif } static int namei_handle_root(struct nameidata *ndp, struct vnode **dpp) { struct componentname *cnp; cnp = &ndp->ni_cnd; if (ndp->ni_strictrelative != 0) { #ifdef KTRACE if (KTRPOINT(curthread, KTR_CAPFAIL)) ktrcapfail(CAPFAIL_LOOKUP, NULL, NULL); #endif return (ENOTCAPABLE); } while (*(cnp->cn_nameptr) == '/') { cnp->cn_nameptr++; ndp->ni_pathlen--; } *dpp = ndp->ni_rootdir; VREF(*dpp); return (0); } /* * Convert a pathname into a pointer to a locked vnode. * * The FOLLOW flag is set when symbolic links are to be followed * when they occur at the end of the name translation process. * Symbolic links are always followed for all other pathname * components other than the last. * * The segflg defines whether the name is to be copied from user * space or kernel space. * * Overall outline of namei: * * copy in name * get starting directory * while (!done && !error) { * call lookup to search path. * if symbolic link, massage name in buffer and continue * } */ int namei(struct nameidata *ndp) { struct filedesc *fdp; /* pointer to file descriptor state */ char *cp; /* pointer into pathname argument */ struct vnode *dp; /* the directory we are searching */ struct iovec aiov; /* uio for reading symbolic links */ struct uio auio; int error, linklen, startdir_used; struct componentname *cnp = &ndp->ni_cnd; struct thread *td = cnp->cn_thread; struct proc *p = td->td_proc; ndp->ni_cnd.cn_cred = ndp->ni_cnd.cn_thread->td_ucred; KASSERT(cnp->cn_cred && p, ("namei: bad cred/proc")); KASSERT((cnp->cn_nameiop & (~OPMASK)) == 0, ("namei: nameiop contaminated with flags")); KASSERT((cnp->cn_flags & OPMASK) == 0, ("namei: flags contaminated with nameiops")); MPASS(ndp->ni_startdir == NULL || ndp->ni_startdir->v_type == VDIR || ndp->ni_startdir->v_type == VBAD); if (!lookup_shared) cnp->cn_flags &= ~LOCKSHARED; fdp = p->p_fd; /* We will set this ourselves if we need it. */ cnp->cn_flags &= ~TRAILINGSLASH; /* * Get a buffer for the name to be translated, and copy the * name into the buffer. */ if ((cnp->cn_flags & HASBUF) == 0) cnp->cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK); if (ndp->ni_segflg == UIO_SYSSPACE) error = copystr(ndp->ni_dirp, cnp->cn_pnbuf, MAXPATHLEN, (size_t *)&ndp->ni_pathlen); else error = copyinstr(ndp->ni_dirp, cnp->cn_pnbuf, MAXPATHLEN, (size_t *)&ndp->ni_pathlen); /* * Don't allow empty pathnames. */ if (error == 0 && *cnp->cn_pnbuf == '\0') error = ENOENT; #ifdef CAPABILITY_MODE /* * In capability mode, lookups must be "strictly relative" (i.e. * not an absolute path, and not containing '..' components) to * a real file descriptor, not the pseudo-descriptor AT_FDCWD. */ if (error == 0 && IN_CAPABILITY_MODE(td) && (cnp->cn_flags & NOCAPCHECK) == 0) { ndp->ni_strictrelative = 1; if (ndp->ni_dirfd == AT_FDCWD) { #ifdef KTRACE if (KTRPOINT(td, KTR_CAPFAIL)) ktrcapfail(CAPFAIL_LOOKUP, NULL, NULL); #endif error = ECAPMODE; } } #endif if (error != 0) { namei_cleanup_cnp(cnp); ndp->ni_vp = NULL; return (error); } ndp->ni_loopcnt = 0; #ifdef KTRACE if (KTRPOINT(td, KTR_NAMEI)) { KASSERT(cnp->cn_thread == curthread, ("namei not using curthread")); ktrnamei(cnp->cn_pnbuf); } #endif /* * Get starting point for the translation. */ FILEDESC_SLOCK(fdp); ndp->ni_rootdir = fdp->fd_rdir; VREF(ndp->ni_rootdir); ndp->ni_topdir = fdp->fd_jdir; /* * If we are auditing the kernel pathname, save the user pathname. */ if (cnp->cn_flags & AUDITVNODE1) AUDIT_ARG_UPATH1(td, ndp->ni_dirfd, cnp->cn_pnbuf); if (cnp->cn_flags & AUDITVNODE2) AUDIT_ARG_UPATH2(td, ndp->ni_dirfd, cnp->cn_pnbuf); startdir_used = 0; dp = NULL; cnp->cn_nameptr = cnp->cn_pnbuf; if (cnp->cn_pnbuf[0] == '/') { error = namei_handle_root(ndp, &dp); } else { if (ndp->ni_startdir != NULL) { dp = ndp->ni_startdir; startdir_used = 1; } else if (ndp->ni_dirfd == AT_FDCWD) { dp = fdp->fd_cdir; VREF(dp); } else { cap_rights_t rights; rights = ndp->ni_rightsneeded; cap_rights_set(&rights, CAP_LOOKUP); if (cnp->cn_flags & AUDITVNODE1) AUDIT_ARG_ATFD1(ndp->ni_dirfd); if (cnp->cn_flags & AUDITVNODE2) AUDIT_ARG_ATFD2(ndp->ni_dirfd); error = fgetvp_rights(td, ndp->ni_dirfd, &rights, &ndp->ni_filecaps, &dp); if (error == EINVAL) error = ENOTDIR; #ifdef CAPABILITIES /* * If file descriptor doesn't have all rights, * all lookups relative to it must also be * strictly relative. */ CAP_ALL(&rights); if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || ndp->ni_filecaps.fc_nioctls != -1) { ndp->ni_strictrelative = 1; } #endif } if (error == 0 && dp->v_type != VDIR) error = ENOTDIR; } FILEDESC_SUNLOCK(fdp); if (ndp->ni_startdir != NULL && !startdir_used) vrele(ndp->ni_startdir); if (error != 0) { if (dp != NULL) vrele(dp); vrele(ndp->ni_rootdir); namei_cleanup_cnp(cnp); return (error); } SDT_PROBE3(vfs, namei, lookup, entry, dp, cnp->cn_pnbuf, cnp->cn_flags); for (;;) { ndp->ni_startdir = dp; error = lookup(ndp); if (error != 0) { vrele(ndp->ni_rootdir); namei_cleanup_cnp(cnp); SDT_PROBE2(vfs, namei, lookup, return, error, NULL); return (error); } /* * If not a symbolic link, we're done. */ if ((cnp->cn_flags & ISSYMLINK) == 0) { vrele(ndp->ni_rootdir); if ((cnp->cn_flags & (SAVENAME | SAVESTART)) == 0) { namei_cleanup_cnp(cnp); } else cnp->cn_flags |= HASBUF; SDT_PROBE2(vfs, namei, lookup, return, 0, ndp->ni_vp); return (0); } if (ndp->ni_loopcnt++ >= MAXSYMLINKS) { error = ELOOP; break; } #ifdef MAC if ((cnp->cn_flags & NOMACCHECK) == 0) { error = mac_vnode_check_readlink(td->td_ucred, ndp->ni_vp); if (error != 0) break; } #endif if (ndp->ni_pathlen > 1) cp = uma_zalloc(namei_zone, M_WAITOK); else cp = cnp->cn_pnbuf; aiov.iov_base = cp; aiov.iov_len = MAXPATHLEN; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = 0; auio.uio_rw = UIO_READ; auio.uio_segflg = UIO_SYSSPACE; auio.uio_td = td; auio.uio_resid = MAXPATHLEN; error = VOP_READLINK(ndp->ni_vp, &auio, cnp->cn_cred); if (error != 0) { if (ndp->ni_pathlen > 1) uma_zfree(namei_zone, cp); break; } linklen = MAXPATHLEN - auio.uio_resid; if (linklen == 0) { if (ndp->ni_pathlen > 1) uma_zfree(namei_zone, cp); error = ENOENT; break; } if (linklen + ndp->ni_pathlen >= MAXPATHLEN) { if (ndp->ni_pathlen > 1) uma_zfree(namei_zone, cp); error = ENAMETOOLONG; break; } if (ndp->ni_pathlen > 1) { bcopy(ndp->ni_next, cp + linklen, ndp->ni_pathlen); uma_zfree(namei_zone, cnp->cn_pnbuf); cnp->cn_pnbuf = cp; } else cnp->cn_pnbuf[linklen] = '\0'; ndp->ni_pathlen += linklen; vput(ndp->ni_vp); dp = ndp->ni_dvp; /* * Check if root directory should replace current directory. */ cnp->cn_nameptr = cnp->cn_pnbuf; if (*(cnp->cn_nameptr) == '/') { vrele(dp); error = namei_handle_root(ndp, &dp); if (error != 0) { vrele(ndp->ni_rootdir); namei_cleanup_cnp(cnp); return (error); } } } vrele(ndp->ni_rootdir); namei_cleanup_cnp(cnp); vput(ndp->ni_vp); ndp->ni_vp = NULL; vrele(ndp->ni_dvp); SDT_PROBE2(vfs, namei, lookup, return, error, NULL); return (error); } static int compute_cn_lkflags(struct mount *mp, int lkflags, int cnflags) { if (mp == NULL || ((lkflags & LK_SHARED) && (!(mp->mnt_kern_flag & MNTK_LOOKUP_SHARED) || ((cnflags & ISDOTDOT) && (mp->mnt_kern_flag & MNTK_LOOKUP_EXCL_DOTDOT))))) { lkflags &= ~LK_SHARED; lkflags |= LK_EXCLUSIVE; } lkflags |= LK_NODDLKTREAT; return (lkflags); } static __inline int needs_exclusive_leaf(struct mount *mp, int flags) { /* * Intermediate nodes can use shared locks, we only need to * force an exclusive lock for leaf nodes. */ if ((flags & (ISLASTCN | LOCKLEAF)) != (ISLASTCN | LOCKLEAF)) return (0); /* Always use exclusive locks if LOCKSHARED isn't set. */ if (!(flags & LOCKSHARED)) return (1); /* * For lookups during open(), if the mount point supports * extended shared operations, then use a shared lock for the * leaf node, otherwise use an exclusive lock. */ if ((flags & ISOPEN) != 0) return (!MNT_EXTENDED_SHARED(mp)); /* * Lookup requests outside of open() that specify LOCKSHARED * only need a shared lock on the leaf vnode. */ return (0); } /* * Search a pathname. * This is a very central and rather complicated routine. * * The pathname is pointed to by ni_ptr and is of length ni_pathlen. * The starting directory is taken from ni_startdir. The pathname is * descended until done, or a symbolic link is encountered. The variable * ni_more is clear if the path is completed; it is set to one if a * symbolic link needing interpretation is encountered. * * The flag argument is LOOKUP, CREATE, RENAME, or DELETE depending on * whether the name is to be looked up, created, renamed, or deleted. * When CREATE, RENAME, or DELETE is specified, information usable in * creating, renaming, or deleting a directory entry may be calculated. * If flag has LOCKPARENT or'ed into it, the parent directory is returned * locked. If flag has WANTPARENT or'ed into it, the parent directory is * returned unlocked. Otherwise the parent directory is not returned. If * the target of the pathname exists and LOCKLEAF is or'ed into the flag * the target is returned locked, otherwise it is returned unlocked. * When creating or renaming and LOCKPARENT is specified, the target may not * be ".". When deleting and LOCKPARENT is specified, the target may be ".". * * Overall outline of lookup: * * dirloop: * identify next component of name at ndp->ni_ptr * handle degenerate case where name is null string * if .. and crossing mount points and on mounted filesys, find parent * call VOP_LOOKUP routine for next component name * directory vnode returned in ni_dvp, unlocked unless LOCKPARENT set * component vnode returned in ni_vp (if it exists), locked. * if result vnode is mounted on and crossing mount points, * find mounted on vnode * if more components of name, do next level at dirloop * return the answer in ni_vp, locked if LOCKLEAF set * if LOCKPARENT set, return locked parent in ni_dvp * if WANTPARENT set, return unlocked parent in ni_dvp */ int lookup(struct nameidata *ndp) { char *cp; /* pointer into pathname argument */ struct vnode *dp = 0; /* the directory we are searching */ struct vnode *tdp; /* saved dp */ struct mount *mp; /* mount table entry */ struct prison *pr; int docache; /* == 0 do not cache last component */ int wantparent; /* 1 => wantparent or lockparent flag */ int rdonly; /* lookup read-only flag bit */ int error = 0; int dpunlocked = 0; /* dp has already been unlocked */ int relookup = 0; /* do not consume the path component */ struct componentname *cnp = &ndp->ni_cnd; int lkflags_save; int ni_dvp_unlocked; /* * Setup: break out flag bits into variables. */ ni_dvp_unlocked = 0; wantparent = cnp->cn_flags & (LOCKPARENT | WANTPARENT); KASSERT(cnp->cn_nameiop == LOOKUP || wantparent, ("CREATE, DELETE, RENAME require LOCKPARENT or WANTPARENT.")); docache = (cnp->cn_flags & NOCACHE) ^ NOCACHE; if (cnp->cn_nameiop == DELETE || (wantparent && cnp->cn_nameiop != CREATE && cnp->cn_nameiop != LOOKUP)) docache = 0; rdonly = cnp->cn_flags & RDONLY; cnp->cn_flags &= ~ISSYMLINK; ndp->ni_dvp = NULL; /* * We use shared locks until we hit the parent of the last cn then * we adjust based on the requesting flags. */ if (lookup_shared) cnp->cn_lkflags = LK_SHARED; else cnp->cn_lkflags = LK_EXCLUSIVE; dp = ndp->ni_startdir; ndp->ni_startdir = NULLVP; vn_lock(dp, compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags | LK_RETRY, cnp->cn_flags)); dirloop: /* * Search a new directory. * * The last component of the filename is left accessible via * cnp->cn_nameptr for callers that need the name. Callers needing * the name set the SAVENAME flag. When done, they assume * responsibility for freeing the pathname buffer. */ - cnp->cn_consume = 0; for (cp = cnp->cn_nameptr; *cp != 0 && *cp != '/'; cp++) continue; cnp->cn_namelen = cp - cnp->cn_nameptr; if (cnp->cn_namelen > NAME_MAX) { error = ENAMETOOLONG; goto bad; } #ifdef NAMEI_DIAGNOSTIC { char c = *cp; *cp = '\0'; printf("{%s}: ", cnp->cn_nameptr); *cp = c; } #endif ndp->ni_pathlen -= cnp->cn_namelen; ndp->ni_next = cp; /* * Replace multiple slashes by a single slash and trailing slashes * by a null. This must be done before VOP_LOOKUP() because some * fs's don't know about trailing slashes. Remember if there were * trailing slashes to handle symlinks, existing non-directories * and non-existing files that won't be directories specially later. */ while (*cp == '/' && (cp[1] == '/' || cp[1] == '\0')) { cp++; ndp->ni_pathlen--; if (*cp == '\0') { *ndp->ni_next = '\0'; cnp->cn_flags |= TRAILINGSLASH; } } ndp->ni_next = cp; cnp->cn_flags |= MAKEENTRY; if (*cp == '\0' && docache == 0) cnp->cn_flags &= ~MAKEENTRY; if (cnp->cn_namelen == 2 && cnp->cn_nameptr[1] == '.' && cnp->cn_nameptr[0] == '.') cnp->cn_flags |= ISDOTDOT; else cnp->cn_flags &= ~ISDOTDOT; if (*ndp->ni_next == 0) cnp->cn_flags |= ISLASTCN; else cnp->cn_flags &= ~ISLASTCN; if ((cnp->cn_flags & ISLASTCN) != 0 && cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.' && (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) { error = EINVAL; goto bad; } /* * Check for degenerate name (e.g. / or "") * which is a way of talking about a directory, * e.g. like "/." or ".". */ if (cnp->cn_nameptr[0] == '\0') { if (dp->v_type != VDIR) { error = ENOTDIR; goto bad; } if (cnp->cn_nameiop != LOOKUP) { error = EISDIR; goto bad; } if (wantparent) { ndp->ni_dvp = dp; VREF(dp); } ndp->ni_vp = dp; if (cnp->cn_flags & AUDITVNODE1) AUDIT_ARG_VNODE1(dp); else if (cnp->cn_flags & AUDITVNODE2) AUDIT_ARG_VNODE2(dp); if (!(cnp->cn_flags & (LOCKPARENT | LOCKLEAF))) VOP_UNLOCK(dp, 0); /* XXX This should probably move to the top of function. */ if (cnp->cn_flags & SAVESTART) panic("lookup: SAVESTART"); goto success; } /* * Handle "..": five special cases. * 0. If doing a capability lookup, return ENOTCAPABLE (this is a * fairly conservative design choice, but it's the only one that we * are satisfied guarantees the property we're looking for). * 1. Return an error if this is the last component of * the name and the operation is DELETE or RENAME. * 2. If at root directory (e.g. after chroot) * or at absolute root directory * then ignore it so can't get out. * 3. If this vnode is the root of a mounted * filesystem, then replace it with the * vnode which was mounted on so we take the * .. in the other filesystem. * 4. If the vnode is the top directory of * the jail or chroot, don't let them out. */ if (cnp->cn_flags & ISDOTDOT) { if (ndp->ni_strictrelative != 0) { #ifdef KTRACE if (KTRPOINT(curthread, KTR_CAPFAIL)) ktrcapfail(CAPFAIL_LOOKUP, NULL, NULL); #endif error = ENOTCAPABLE; goto bad; } if ((cnp->cn_flags & ISLASTCN) != 0 && (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) { error = EINVAL; goto bad; } for (;;) { for (pr = cnp->cn_cred->cr_prison; pr != NULL; pr = pr->pr_parent) if (dp == pr->pr_root) break; if (dp == ndp->ni_rootdir || dp == ndp->ni_topdir || dp == rootvnode || pr != NULL || ((dp->v_vflag & VV_ROOT) != 0 && (cnp->cn_flags & NOCROSSMOUNT) != 0)) { ndp->ni_dvp = dp; ndp->ni_vp = dp; VREF(dp); goto nextname; } if ((dp->v_vflag & VV_ROOT) == 0) break; if (dp->v_iflag & VI_DOOMED) { /* forced unmount */ error = ENOENT; goto bad; } tdp = dp; dp = dp->v_mount->mnt_vnodecovered; VREF(dp); vput(tdp); vn_lock(dp, compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags | LK_RETRY, ISDOTDOT)); } } /* * We now have a segment name to search for, and a directory to search. */ unionlookup: #ifdef MAC if ((cnp->cn_flags & NOMACCHECK) == 0) { error = mac_vnode_check_lookup(cnp->cn_thread->td_ucred, dp, cnp); if (error) goto bad; } #endif ndp->ni_dvp = dp; ndp->ni_vp = NULL; ASSERT_VOP_LOCKED(dp, "lookup"); /* * If we have a shared lock we may need to upgrade the lock for the * last operation. */ if (dp != vp_crossmp && VOP_ISLOCKED(dp) == LK_SHARED && (cnp->cn_flags & ISLASTCN) && (cnp->cn_flags & LOCKPARENT)) vn_lock(dp, LK_UPGRADE|LK_RETRY); if ((dp->v_iflag & VI_DOOMED) != 0) { error = ENOENT; goto bad; } /* * If we're looking up the last component and we need an exclusive * lock, adjust our lkflags. */ if (needs_exclusive_leaf(dp->v_mount, cnp->cn_flags)) cnp->cn_lkflags = LK_EXCLUSIVE; #ifdef NAMEI_DIAGNOSTIC vprint("lookup in", dp); #endif lkflags_save = cnp->cn_lkflags; cnp->cn_lkflags = compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags, cnp->cn_flags); if ((error = VOP_LOOKUP(dp, &ndp->ni_vp, cnp)) != 0) { cnp->cn_lkflags = lkflags_save; KASSERT(ndp->ni_vp == NULL, ("leaf should be empty")); #ifdef NAMEI_DIAGNOSTIC printf("not found\n"); #endif if ((error == ENOENT) && (dp->v_vflag & VV_ROOT) && (dp->v_mount != NULL) && (dp->v_mount->mnt_flag & MNT_UNION)) { tdp = dp; dp = dp->v_mount->mnt_vnodecovered; VREF(dp); vput(tdp); vn_lock(dp, compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags | LK_RETRY, cnp->cn_flags)); goto unionlookup; } if (error == ERELOOKUP) { vref(dp); ndp->ni_vp = dp; error = 0; relookup = 1; goto good; } if (error != EJUSTRETURN) goto bad; /* * At this point, we know we're at the end of the * pathname. If creating / renaming, we can consider * allowing the file or directory to be created / renamed, * provided we're not on a read-only filesystem. */ if (rdonly) { error = EROFS; goto bad; } /* trailing slash only allowed for directories */ if ((cnp->cn_flags & TRAILINGSLASH) && !(cnp->cn_flags & WILLBEDIR)) { error = ENOENT; goto bad; } if ((cnp->cn_flags & LOCKPARENT) == 0) VOP_UNLOCK(dp, 0); /* * We return with ni_vp NULL to indicate that the entry * doesn't currently exist, leaving a pointer to the * (possibly locked) directory vnode in ndp->ni_dvp. */ if (cnp->cn_flags & SAVESTART) { ndp->ni_startdir = ndp->ni_dvp; VREF(ndp->ni_startdir); } goto success; } else cnp->cn_lkflags = lkflags_save; good: #ifdef NAMEI_DIAGNOSTIC printf("found\n"); #endif - /* - * Take into account any additional components consumed by - * the underlying filesystem. - */ - if (cnp->cn_consume > 0) { - cnp->cn_nameptr += cnp->cn_consume; - ndp->ni_next += cnp->cn_consume; - ndp->ni_pathlen -= cnp->cn_consume; - cnp->cn_consume = 0; - } - dp = ndp->ni_vp; /* * Check to see if the vnode has been mounted on; * if so find the root of the mounted filesystem. */ while (dp->v_type == VDIR && (mp = dp->v_mountedhere) && (cnp->cn_flags & NOCROSSMOUNT) == 0) { if (vfs_busy(mp, 0)) continue; vput(dp); if (dp != ndp->ni_dvp) vput(ndp->ni_dvp); else vrele(ndp->ni_dvp); vref(vp_crossmp); ndp->ni_dvp = vp_crossmp; error = VFS_ROOT(mp, compute_cn_lkflags(mp, cnp->cn_lkflags, cnp->cn_flags), &tdp); vfs_unbusy(mp); if (vn_lock(vp_crossmp, LK_SHARED | LK_NOWAIT)) panic("vp_crossmp exclusively locked or reclaimed"); if (error) { dpunlocked = 1; goto bad2; } ndp->ni_vp = dp = tdp; } /* * Check for symbolic link */ if ((dp->v_type == VLNK) && ((cnp->cn_flags & FOLLOW) || (cnp->cn_flags & TRAILINGSLASH) || *ndp->ni_next == '/')) { cnp->cn_flags |= ISSYMLINK; if (dp->v_iflag & VI_DOOMED) { /* * We can't know whether the directory was mounted with * NOSYMFOLLOW, so we can't follow safely. */ error = ENOENT; goto bad2; } if (dp->v_mount->mnt_flag & MNT_NOSYMFOLLOW) { error = EACCES; goto bad2; } /* * Symlink code always expects an unlocked dvp. */ if (ndp->ni_dvp != ndp->ni_vp) { VOP_UNLOCK(ndp->ni_dvp, 0); ni_dvp_unlocked = 1; } goto success; } nextname: /* * Not a symbolic link that we will follow. Continue with the * next component if there is any; otherwise, we're done. */ KASSERT((cnp->cn_flags & ISLASTCN) || *ndp->ni_next == '/', ("lookup: invalid path state.")); if (relookup) { relookup = 0; if (ndp->ni_dvp != dp) vput(ndp->ni_dvp); else vrele(ndp->ni_dvp); goto dirloop; } if (*ndp->ni_next == '/') { cnp->cn_nameptr = ndp->ni_next; while (*cnp->cn_nameptr == '/') { cnp->cn_nameptr++; ndp->ni_pathlen--; } if (ndp->ni_dvp != dp) vput(ndp->ni_dvp); else vrele(ndp->ni_dvp); goto dirloop; } /* * If we're processing a path with a trailing slash, * check that the end result is a directory. */ if ((cnp->cn_flags & TRAILINGSLASH) && dp->v_type != VDIR) { error = ENOTDIR; goto bad2; } /* * Disallow directory write attempts on read-only filesystems. */ if (rdonly && (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) { error = EROFS; goto bad2; } if (cnp->cn_flags & SAVESTART) { ndp->ni_startdir = ndp->ni_dvp; VREF(ndp->ni_startdir); } if (!wantparent) { ni_dvp_unlocked = 2; if (ndp->ni_dvp != dp) vput(ndp->ni_dvp); else vrele(ndp->ni_dvp); } else if ((cnp->cn_flags & LOCKPARENT) == 0 && ndp->ni_dvp != dp) { VOP_UNLOCK(ndp->ni_dvp, 0); ni_dvp_unlocked = 1; } if (cnp->cn_flags & AUDITVNODE1) AUDIT_ARG_VNODE1(dp); else if (cnp->cn_flags & AUDITVNODE2) AUDIT_ARG_VNODE2(dp); if ((cnp->cn_flags & LOCKLEAF) == 0) VOP_UNLOCK(dp, 0); success: /* * Because of lookup_shared we may have the vnode shared locked, but * the caller may want it to be exclusively locked. */ if (needs_exclusive_leaf(dp->v_mount, cnp->cn_flags) && VOP_ISLOCKED(dp) != LK_EXCLUSIVE) { vn_lock(dp, LK_UPGRADE | LK_RETRY); if (dp->v_iflag & VI_DOOMED) { error = ENOENT; goto bad2; } } return (0); bad2: if (ni_dvp_unlocked != 2) { if (dp != ndp->ni_dvp && !ni_dvp_unlocked) vput(ndp->ni_dvp); else vrele(ndp->ni_dvp); } bad: if (!dpunlocked) vput(dp); ndp->ni_vp = NULL; return (error); } /* * relookup - lookup a path name component * Used by lookup to re-acquire things. */ int relookup(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp) { struct vnode *dp = 0; /* the directory we are searching */ int wantparent; /* 1 => wantparent or lockparent flag */ int rdonly; /* lookup read-only flag bit */ int error = 0; KASSERT(cnp->cn_flags & ISLASTCN, ("relookup: Not given last component.")); /* * Setup: break out flag bits into variables. */ wantparent = cnp->cn_flags & (LOCKPARENT|WANTPARENT); KASSERT(wantparent, ("relookup: parent not wanted.")); rdonly = cnp->cn_flags & RDONLY; cnp->cn_flags &= ~ISSYMLINK; dp = dvp; cnp->cn_lkflags = LK_EXCLUSIVE; vn_lock(dp, LK_EXCLUSIVE | LK_RETRY); /* * Search a new directory. * * The last component of the filename is left accessible via * cnp->cn_nameptr for callers that need the name. Callers needing * the name set the SAVENAME flag. When done, they assume * responsibility for freeing the pathname buffer. */ #ifdef NAMEI_DIAGNOSTIC printf("{%s}: ", cnp->cn_nameptr); #endif /* * Check for "" which represents the root directory after slash * removal. */ if (cnp->cn_nameptr[0] == '\0') { /* * Support only LOOKUP for "/" because lookup() * can't succeed for CREATE, DELETE and RENAME. */ KASSERT(cnp->cn_nameiop == LOOKUP, ("nameiop must be LOOKUP")); KASSERT(dp->v_type == VDIR, ("dp is not a directory")); if (!(cnp->cn_flags & LOCKLEAF)) VOP_UNLOCK(dp, 0); *vpp = dp; /* XXX This should probably move to the top of function. */ if (cnp->cn_flags & SAVESTART) panic("lookup: SAVESTART"); return (0); } if (cnp->cn_flags & ISDOTDOT) panic ("relookup: lookup on dot-dot"); /* * We now have a segment name to search for, and a directory to search. */ #ifdef NAMEI_DIAGNOSTIC vprint("search in:", dp); #endif if ((error = VOP_LOOKUP(dp, vpp, cnp)) != 0) { KASSERT(*vpp == NULL, ("leaf should be empty")); if (error != EJUSTRETURN) goto bad; /* * If creating and at end of pathname, then can consider * allowing file to be created. */ if (rdonly) { error = EROFS; goto bad; } /* ASSERT(dvp == ndp->ni_startdir) */ if (cnp->cn_flags & SAVESTART) VREF(dvp); if ((cnp->cn_flags & LOCKPARENT) == 0) VOP_UNLOCK(dp, 0); /* * We return with ni_vp NULL to indicate that the entry * doesn't currently exist, leaving a pointer to the * (possibly locked) directory vnode in ndp->ni_dvp. */ return (0); } dp = *vpp; /* * Disallow directory write attempts on read-only filesystems. */ if (rdonly && (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) { if (dvp == dp) vrele(dvp); else vput(dvp); error = EROFS; goto bad; } /* * Set the parent lock/ref state to the requested state. */ if ((cnp->cn_flags & LOCKPARENT) == 0 && dvp != dp) { if (wantparent) VOP_UNLOCK(dvp, 0); else vput(dvp); } else if (!wantparent) vrele(dvp); /* * Check for symbolic link */ KASSERT(dp->v_type != VLNK || !(cnp->cn_flags & FOLLOW), ("relookup: symlink found.\n")); /* ASSERT(dvp == ndp->ni_startdir) */ if (cnp->cn_flags & SAVESTART) VREF(dvp); if ((cnp->cn_flags & LOCKLEAF) == 0) VOP_UNLOCK(dp, 0); return (0); bad: vput(dp); *vpp = NULL; return (error); } void NDINIT_ALL(struct nameidata *ndp, u_long op, u_long flags, enum uio_seg segflg, const char *namep, int dirfd, struct vnode *startdir, cap_rights_t *rightsp, struct thread *td) { ndp->ni_cnd.cn_nameiop = op; ndp->ni_cnd.cn_flags = flags; ndp->ni_segflg = segflg; ndp->ni_dirp = namep; ndp->ni_dirfd = dirfd; ndp->ni_startdir = startdir; ndp->ni_strictrelative = 0; if (rightsp != NULL) ndp->ni_rightsneeded = *rightsp; else cap_rights_init(&ndp->ni_rightsneeded); filecaps_init(&ndp->ni_filecaps); ndp->ni_cnd.cn_thread = td; } /* * Free data allocated by namei(); see namei(9) for details. */ void NDFREE(struct nameidata *ndp, const u_int flags) { int unlock_dvp; int unlock_vp; unlock_dvp = 0; unlock_vp = 0; if (!(flags & NDF_NO_FREE_PNBUF) && (ndp->ni_cnd.cn_flags & HASBUF)) { uma_zfree(namei_zone, ndp->ni_cnd.cn_pnbuf); ndp->ni_cnd.cn_flags &= ~HASBUF; } if (!(flags & NDF_NO_VP_UNLOCK) && (ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp) unlock_vp = 1; if (!(flags & NDF_NO_VP_RELE) && ndp->ni_vp) { if (unlock_vp) { vput(ndp->ni_vp); unlock_vp = 0; } else vrele(ndp->ni_vp); ndp->ni_vp = NULL; } if (unlock_vp) VOP_UNLOCK(ndp->ni_vp, 0); if (!(flags & NDF_NO_DVP_UNLOCK) && (ndp->ni_cnd.cn_flags & LOCKPARENT) && ndp->ni_dvp != ndp->ni_vp) unlock_dvp = 1; if (!(flags & NDF_NO_DVP_RELE) && (ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) { if (unlock_dvp) { vput(ndp->ni_dvp); unlock_dvp = 0; } else vrele(ndp->ni_dvp); ndp->ni_dvp = NULL; } if (unlock_dvp) VOP_UNLOCK(ndp->ni_dvp, 0); if (!(flags & NDF_NO_STARTDIR_RELE) && (ndp->ni_cnd.cn_flags & SAVESTART)) { vrele(ndp->ni_startdir); ndp->ni_startdir = NULL; } } /* * Determine if there is a suitable alternate filename under the specified * prefix for the specified path. If the create flag is set, then the * alternate prefix will be used so long as the parent directory exists. * This is used by the various compatiblity ABIs so that Linux binaries prefer * files under /compat/linux for example. The chosen path (whether under * the prefix or under /) is returned in a kernel malloc'd buffer pointed * to by pathbuf. The caller is responsible for free'ing the buffer from * the M_TEMP bucket if one is returned. */ int kern_alternate_path(struct thread *td, const char *prefix, const char *path, enum uio_seg pathseg, char **pathbuf, int create, int dirfd) { struct nameidata nd, ndroot; char *ptr, *buf, *cp; size_t len, sz; int error; buf = (char *) malloc(MAXPATHLEN, M_TEMP, M_WAITOK); *pathbuf = buf; /* Copy the prefix into the new pathname as a starting point. */ len = strlcpy(buf, prefix, MAXPATHLEN); if (len >= MAXPATHLEN) { *pathbuf = NULL; free(buf, M_TEMP); return (EINVAL); } sz = MAXPATHLEN - len; ptr = buf + len; /* Append the filename to the prefix. */ if (pathseg == UIO_SYSSPACE) error = copystr(path, ptr, sz, &len); else error = copyinstr(path, ptr, sz, &len); if (error) { *pathbuf = NULL; free(buf, M_TEMP); return (error); } /* Only use a prefix with absolute pathnames. */ if (*ptr != '/') { error = EINVAL; goto keeporig; } if (dirfd != AT_FDCWD) { /* * We want the original because the "prefix" is * included in the already opened dirfd. */ bcopy(ptr, buf, len); return (0); } /* * We know that there is a / somewhere in this pathname. * Search backwards for it, to find the file's parent dir * to see if it exists in the alternate tree. If it does, * and we want to create a file (cflag is set). We don't * need to worry about the root comparison in this case. */ if (create) { for (cp = &ptr[len] - 1; *cp != '/'; cp--); *cp = '\0'; NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, td); error = namei(&nd); *cp = '/'; if (error != 0) goto keeporig; } else { NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, td); error = namei(&nd); if (error != 0) goto keeporig; /* * We now compare the vnode of the prefix to the one * vnode asked. If they resolve to be the same, then we * ignore the match so that the real root gets used. * This avoids the problem of traversing "../.." to find the * root directory and never finding it, because "/" resolves * to the emulation root directory. This is expensive :-( */ NDINIT(&ndroot, LOOKUP, FOLLOW, UIO_SYSSPACE, prefix, td); /* We shouldn't ever get an error from this namei(). */ error = namei(&ndroot); if (error == 0) { if (nd.ni_vp == ndroot.ni_vp) error = ENOENT; NDFREE(&ndroot, NDF_ONLY_PNBUF); vrele(ndroot.ni_vp); } } NDFREE(&nd, NDF_ONLY_PNBUF); vrele(nd.ni_vp); keeporig: /* If there was an error, use the original path name. */ if (error) bcopy(ptr, buf, len); return (error); } Index: head/sys/sys/namei.h =================================================================== --- head/sys/sys/namei.h (revision 296715) +++ head/sys/sys/namei.h (revision 296716) @@ -1,205 +1,204 @@ /*- * Copyright (c) 1985, 1989, 1991, 1993 * The Regents of the University of California. All rights reserved. * * 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. * 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. * * @(#)namei.h 8.5 (Berkeley) 1/9/95 * $FreeBSD$ */ #ifndef _SYS_NAMEI_H_ #define _SYS_NAMEI_H_ #include #include #include #include struct componentname { /* * Arguments to lookup. */ u_long cn_nameiop; /* namei operation */ u_int64_t cn_flags; /* flags to namei */ struct thread *cn_thread;/* thread requesting lookup */ struct ucred *cn_cred; /* credentials */ int cn_lkflags; /* Lock flags LK_EXCLUSIVE or LK_SHARED */ /* * Shared between lookup and commit routines. */ char *cn_pnbuf; /* pathname buffer */ char *cn_nameptr; /* pointer to looked up name */ long cn_namelen; /* length of looked up component */ - long cn_consume; /* chars to consume in lookup() */ }; /* * Encapsulation of namei parameters. */ struct nameidata { /* * Arguments to namei/lookup. */ const char *ni_dirp; /* pathname pointer */ enum uio_seg ni_segflg; /* location of pathname */ cap_rights_t ni_rightsneeded; /* rights required to look up vnode */ /* * Arguments to lookup. */ struct vnode *ni_startdir; /* starting directory */ struct vnode *ni_rootdir; /* logical root directory */ struct vnode *ni_topdir; /* logical top directory */ int ni_dirfd; /* starting directory for *at functions */ int ni_strictrelative; /* relative lookup only; no '..' */ /* * Results: returned from namei */ struct filecaps ni_filecaps; /* rights the *at base has */ /* * Results: returned from/manipulated by lookup */ struct vnode *ni_vp; /* vnode of result */ struct vnode *ni_dvp; /* vnode of intermediate directory */ /* * Shared between namei and lookup/commit routines. */ size_t ni_pathlen; /* remaining chars in path */ char *ni_next; /* next location in pathname */ u_int ni_loopcnt; /* count of symlinks encountered */ /* * Lookup parameters: this structure describes the subset of * information from the nameidata structure that is passed * through the VOP interface. */ struct componentname ni_cnd; }; #ifdef _KERNEL /* * namei operations */ #define LOOKUP 0 /* perform name lookup only */ #define CREATE 1 /* setup for file creation */ #define DELETE 2 /* setup for file deletion */ #define RENAME 3 /* setup for file renaming */ #define OPMASK 3 /* mask for operation */ /* * namei operational modifier flags, stored in ni_cnd.flags */ #define LOCKLEAF 0x0004 /* lock vnode on return */ #define LOCKPARENT 0x0008 /* want parent vnode returned locked */ #define WANTPARENT 0x0010 /* want parent vnode returned unlocked */ #define NOCACHE 0x0020 /* name must not be left in cache */ #define FOLLOW 0x0040 /* follow symbolic links */ #define LOCKSHARED 0x0100 /* Shared lock leaf */ #define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */ #define MODMASK 0x01fc /* mask of operational modifiers */ /* * Namei parameter descriptors. * * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP. * If the caller of namei sets the flag (for example execve wants to * know the name of the program that is being executed), then it must * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must * be freed by either the commit routine or the VOP_ABORT routine. * SAVESTART is set only by the callers of namei. It implies SAVENAME * plus the addition of saving the parent directory that contains the * name in ni_startdir. It allows repeated calls to lookup for the * name being sought. The caller is responsible for releasing the * buffer and for vrele'ing ni_startdir. */ #define RDONLY 0x00000200 /* lookup with read-only semantics */ #define HASBUF 0x00000400 /* has allocated pathname buffer */ #define SAVENAME 0x00000800 /* save pathname buffer */ #define SAVESTART 0x00001000 /* save starting directory */ #define ISDOTDOT 0x00002000 /* current component name is .. */ #define MAKEENTRY 0x00004000 /* entry is to be added to name cache */ #define ISLASTCN 0x00008000 /* this is last component of pathname */ #define ISSYMLINK 0x00010000 /* symlink needs interpretation */ #define ISWHITEOUT 0x00020000 /* found whiteout */ #define DOWHITEOUT 0x00040000 /* do whiteouts */ #define WILLBEDIR 0x00080000 /* new files will be dirs; allow trailing / */ #define ISUNICODE 0x00100000 /* current component name is unicode*/ #define ISOPEN 0x00200000 /* caller is opening; return a real vnode. */ #define NOCROSSMOUNT 0x00400000 /* do not cross mount points */ #define NOMACCHECK 0x00800000 /* do not perform MAC checks */ #define AUDITVNODE1 0x04000000 /* audit the looked up vnode information */ #define AUDITVNODE2 0x08000000 /* audit the looked up vnode information */ #define TRAILINGSLASH 0x10000000 /* path ended in a slash */ #define NOCAPCHECK 0x20000000 /* do not perform capability checks */ #define PARAMASK 0x3ffffe00 /* mask of parameter descriptors */ /* * Initialization of a nameidata structure. */ #define NDINIT(ndp, op, flags, segflg, namep, td) \ NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, NULL, 0, td) #define NDINIT_AT(ndp, op, flags, segflg, namep, dirfd, td) \ NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, 0, td) #define NDINIT_ATRIGHTS(ndp, op, flags, segflg, namep, dirfd, rightsp, td) \ NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, NULL, rightsp, td) #define NDINIT_ATVP(ndp, op, flags, segflg, namep, vp, td) \ NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, 0, td) void NDINIT_ALL(struct nameidata *ndp, u_long op, u_long flags, enum uio_seg segflg, const char *namep, int dirfd, struct vnode *startdir, cap_rights_t *rightsp, struct thread *td); #define NDF_NO_DVP_RELE 0x00000001 #define NDF_NO_DVP_UNLOCK 0x00000002 #define NDF_NO_DVP_PUT 0x00000003 #define NDF_NO_VP_RELE 0x00000004 #define NDF_NO_VP_UNLOCK 0x00000008 #define NDF_NO_VP_PUT 0x0000000c #define NDF_NO_STARTDIR_RELE 0x00000010 #define NDF_NO_FREE_PNBUF 0x00000020 #define NDF_ONLY_PNBUF (~NDF_NO_FREE_PNBUF) void NDFREE(struct nameidata *, const u_int); int namei(struct nameidata *ndp); int lookup(struct nameidata *ndp); int relookup(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp); #endif /* * Stats on usefulness of namei caches. */ struct nchstats { long ncs_goodhits; /* hits that we can really use */ long ncs_neghits; /* negative hits that we can use */ long ncs_badhits; /* hits we must drop */ long ncs_falsehits; /* hits with id mismatch */ long ncs_miss; /* misses */ long ncs_long; /* long names that ignore cache */ long ncs_pass2; /* names found with passes == 2 */ long ncs_2passes; /* number of times we attempt it */ }; extern struct nchstats nchstats; #endif /* !_SYS_NAMEI_H_ */