diff --git a/sys/fs/unionfs/union_subr.c b/sys/fs/unionfs/union_subr.c index 557d4589df55..466c88c705f4 100644 --- a/sys/fs/unionfs/union_subr.c +++ b/sys/fs/unionfs/union_subr.c @@ -1,1327 +1,1336 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * 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. * 3. 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 #include #include #include #include #define NUNIONFSNODECACHE 16 #define UNIONFSHASHMASK (NUNIONFSNODECACHE - 1) 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"); static struct task unionfs_deferred_rele_task; static struct mtx unionfs_deferred_rele_lock; static STAILQ_HEAD(, unionfs_node) unionfs_deferred_rele_list = STAILQ_HEAD_INITIALIZER(unionfs_deferred_rele_list); static TASKQUEUE_DEFINE_THREAD(unionfs_rele); unsigned int unionfs_ndeferred = 0; SYSCTL_UINT(_vfs, OID_AUTO, unionfs_ndeferred, CTLFLAG_RD, &unionfs_ndeferred, 0, "unionfs deferred vnode release"); static void unionfs_deferred_rele(void *, int); /* * Initialize */ int unionfs_init(struct vfsconf *vfsp) { UNIONFSDEBUG("unionfs_init\n"); /* printed during system boot */ TASK_INIT(&unionfs_deferred_rele_task, 0, unionfs_deferred_rele, NULL); mtx_init(&unionfs_deferred_rele_lock, "uniondefr", NULL, MTX_DEF); return (0); } /* * Uninitialize */ int unionfs_uninit(struct vfsconf *vfsp) { taskqueue_quiesce(taskqueue_unionfs_rele); taskqueue_free(taskqueue_unionfs_rele); mtx_destroy(&unionfs_deferred_rele_lock); return (0); } static void unionfs_deferred_rele(void *arg __unused, int pending __unused) { STAILQ_HEAD(, unionfs_node) local_rele_list; struct unionfs_node *unp, *tunp; unsigned int ndeferred; ndeferred = 0; STAILQ_INIT(&local_rele_list); mtx_lock(&unionfs_deferred_rele_lock); STAILQ_CONCAT(&local_rele_list, &unionfs_deferred_rele_list); mtx_unlock(&unionfs_deferred_rele_lock); STAILQ_FOREACH_SAFE(unp, &local_rele_list, un_rele, tunp) { ++ndeferred; MPASS(unp->un_dvp != NULL); vrele(unp->un_dvp); free(unp, M_UNIONFSNODE); } /* We expect this function to be single-threaded, thus no atomic */ unionfs_ndeferred += ndeferred; } static struct unionfs_node_hashhead * unionfs_get_hashhead(struct vnode *dvp, struct vnode *lookup) { struct unionfs_node *unp; unp = VTOUNIONFS(dvp); return (&(unp->un_hashtbl[vfs_hash_index(lookup) & UNIONFSHASHMASK])); } /* * Attempt to lookup a cached unionfs vnode by upper/lower vp * from dvp, with dvp's interlock held. */ static struct vnode * unionfs_get_cached_vnode_locked(struct vnode *lookup, struct vnode *dvp) { struct unionfs_node *unp; struct unionfs_node_hashhead *hd; struct vnode *vp; hd = unionfs_get_hashhead(dvp, lookup); LIST_FOREACH(unp, hd, un_hash) { if (unp->un_uppervp == lookup || unp->un_lowervp == lookup) { vp = UNIONFSTOV(unp); VI_LOCK_FLAGS(vp, MTX_DUPOK); vp->v_iflag &= ~VI_OWEINACT; if (VN_IS_DOOMED(vp) || ((vp->v_iflag & VI_DOINGINACT) != 0)) { VI_UNLOCK(vp); vp = NULLVP; } else { vrefl(vp); VI_UNLOCK(vp); } return (vp); } } return (NULLVP); } /* * Get the cached vnode. */ static struct vnode * unionfs_get_cached_vnode(struct vnode *uvp, struct vnode *lvp, struct vnode *dvp) { struct vnode *vp; vp = NULLVP; VI_LOCK(dvp); if (uvp != NULLVP) vp = unionfs_get_cached_vnode_locked(uvp, dvp); else if (lvp != NULLVP) vp = unionfs_get_cached_vnode_locked(lvp, dvp); VI_UNLOCK(dvp); return (vp); } /* * Add the new vnode into cache. */ static struct vnode * unionfs_ins_cached_vnode(struct unionfs_node *uncp, struct vnode *dvp) { struct unionfs_node_hashhead *hd; struct vnode *vp; ASSERT_VOP_ELOCKED(uncp->un_uppervp, __func__); ASSERT_VOP_ELOCKED(uncp->un_lowervp, __func__); KASSERT(uncp->un_uppervp == NULLVP || uncp->un_uppervp->v_type == VDIR, ("%s: v_type != VDIR", __func__)); KASSERT(uncp->un_lowervp == NULLVP || uncp->un_lowervp->v_type == VDIR, ("%s: v_type != VDIR", __func__)); vp = NULLVP; VI_LOCK(dvp); if (uncp->un_uppervp != NULL) vp = unionfs_get_cached_vnode_locked(uncp->un_uppervp, dvp); else if (uncp->un_lowervp != NULL) vp = unionfs_get_cached_vnode_locked(uncp->un_lowervp, dvp); if (vp == NULLVP) { hd = unionfs_get_hashhead(dvp, (uncp->un_uppervp != NULLVP ? uncp->un_uppervp : uncp->un_lowervp)); LIST_INSERT_HEAD(hd, uncp, un_hash); } VI_UNLOCK(dvp); return (vp); } /* * Remove the vnode. */ static void unionfs_rem_cached_vnode(struct unionfs_node *unp, struct vnode *dvp) { KASSERT(unp != NULL, ("%s: null node", __func__)); KASSERT(dvp != NULLVP, ("%s: null parent vnode", __func__)); VI_LOCK(dvp); if (unp->un_hash.le_prev != NULL) { LIST_REMOVE(unp, un_hash); unp->un_hash.le_next = NULL; unp->un_hash.le_prev = NULL; } VI_UNLOCK(dvp); } /* * Common cleanup handling for unionfs_nodeget * Upper, lower, and parent directory vnodes are expected to be referenced by * the caller. Upper and lower vnodes, if non-NULL, are also expected to be * exclusively locked by the caller. * This function will return with the caller's locks and references undone. */ static void unionfs_nodeget_cleanup(struct vnode *vp, struct unionfs_node *unp) { /* * Lock and reset the default vnode lock; vgone() expects a locked * vnode, and we're going to reset the vnode ops. */ lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL); /* * Clear out private data and reset the vnode ops to avoid use of * unionfs vnode ops on a partially constructed vnode. */ VI_LOCK(vp); vp->v_data = NULL; vp->v_vnlock = &vp->v_lock; vp->v_op = &dead_vnodeops; VI_UNLOCK(vp); vgone(vp); vput(vp); if (unp->un_dvp != NULLVP) vrele(unp->un_dvp); if (unp->un_uppervp != NULLVP) vput(unp->un_uppervp); if (unp->un_lowervp != NULLVP) vput(unp->un_lowervp); if (unp->un_hashtbl != NULL) hashdestroy(unp->un_hashtbl, M_UNIONFSHASH, UNIONFSHASHMASK); free(unp->un_path, M_UNIONFSPATH); free(unp, M_UNIONFSNODE); } /* * 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) { char *path; struct unionfs_mount *ump; struct unionfs_node *unp; struct vnode *vp; u_long hashmask; int error; int lkflags; enum vtype vt; error = 0; ump = MOUNTTOUNIONFSMOUNT(mp); lkflags = (cnp ? cnp->cn_lkflags : 0); path = (cnp ? cnp->cn_nameptr : NULL); *vpp = NULLVP; if (uppervp == NULLVP && lowervp == NULLVP) panic("%s: upper and lower is null", __func__); 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 (dvp != NULLVP && vt == VDIR) { vp = unionfs_get_cached_vnode(uppervp, lowervp, dvp); if (vp != NULLVP) { *vpp = vp; goto unionfs_nodeget_out; } } 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); } 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, &hashmask); KASSERT(hashmask == UNIONFSHASHMASK, ("unexpected unionfs hash mask 0x%lx", 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 = 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'; unp->un_pathlen = cnp->cn_namelen; } vp->v_type = vt; vp->v_data = unp; /* * TODO: This is an imperfect check, as there's no guarantee that * the underlying filesystems will always return vnode pointers * for the root inodes that match our cached values. To reduce * the likelihood of failure, for example in the case where either * vnode has been forcibly doomed, we check both pointers and set * VV_ROOT if either matches. */ if (ump->um_uppervp == uppervp || ump->um_lowervp == lowervp) vp->v_vflag |= VV_ROOT; KASSERT(dvp != NULL || (vp->v_vflag & VV_ROOT) != 0, ("%s: NULL dvp for non-root vp %p", __func__, vp)); vn_lock_pair(lowervp, false, uppervp, false); error = insmntque1(vp, mp); if (error != 0) { unionfs_nodeget_cleanup(vp, unp); return (error); } if (lowervp != NULL && VN_IS_DOOMED(lowervp)) { vput(lowervp); unp->un_lowervp = NULL; } if (uppervp != NULL && VN_IS_DOOMED(uppervp)) { vput(uppervp); unp->un_uppervp = NULL; } if (unp->un_lowervp == NULL && unp->un_uppervp == NULL) { unionfs_nodeget_cleanup(vp, unp); return (ENOENT); } if (dvp != NULLVP && vt == VDIR) *vpp = unionfs_ins_cached_vnode(unp, dvp); if (*vpp != NULLVP) { unionfs_nodeget_cleanup(vp, unp); vp = *vpp; } else { if (uppervp != NULL) VOP_UNLOCK(uppervp); if (lowervp != NULL) VOP_UNLOCK(lowervp); *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 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; int count; int writerefs; - KASSERT(vp->v_vnlock->lk_recurse == 0, + /* + * The root vnode lock may be recursed during forcible, because + * it may share the same lock as the unionfs mount's covered vnode, + * which is locked across VFS_UNMOUNT(). This lock will then be + * recursively taken during the vflush() issued by unionfs_unmount(). + * But we still only need to lock the unionfs lock once, because only + * one of those lock operations was taken against a unionfs vnode and + * will be undone against a unionfs vnode. + */ + KASSERT(vp->v_vnlock->lk_recurse == 0 || (vp->v_vflag & VV_ROOT) != 0, ("%s: vnode %p locked recursively", __func__, vp)); if (lockmgr(&vp->v_lock, LK_EXCLUSIVE | LK_NOWAIT, NULL) != 0) panic("%s: failed to acquire lock for vnode lock", __func__); /* * 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; if (unp->un_hashtbl != NULL) { /* * Clear out any cached child vnodes. This should only * be necessary during forced unmount, when the vnode may * be reclaimed with a non-zero use count. Otherwise the * reference held by each child should prevent reclamation. */ for (count = 0; count <= UNIONFSHASHMASK; 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; } } } VI_UNLOCK(vp); writerefs = atomic_load_int(&vp->v_writecount); VNASSERT(writerefs >= 0, vp, ("%s: write count %d, unexpected text ref", __func__, writerefs)); /* * If we were opened for write, we leased the write reference * to the lower vnode. If this is a reclamation due to the * forced unmount, undo the reference now. */ if (writerefs > 0) { VNASSERT(uvp != NULL, vp, ("%s: write reference without upper vnode", __func__)); VOP_ADD_WRITECOUNT(uvp, -writerefs); } if (lvp != NULLVP) VOP_UNLOCK(lvp); if (uvp != NULLVP) VOP_UNLOCK(uvp); if (dvp != NULLVP) unionfs_rem_cached_vnode(unp, dvp); if (lvp != NULLVP) vrele(lvp); if (uvp != NULLVP) vrele(uvp); if (unp->un_path != NULL) { free(unp->un_path, M_UNIONFSPATH); unp->un_path = NULL; unp->un_pathlen = 0; } if (unp->un_hashtbl != NULL) { hashdestroy(unp->un_hashtbl, M_UNIONFSHASH, UNIONFSHASHMASK); } LIST_FOREACH_SAFE(unsp, &(unp->un_unshead), uns_list, unsp_tmp) { LIST_REMOVE(unsp, uns_list); free(unsp, M_TEMP); } if (dvp != NULLVP) { mtx_lock(&unionfs_deferred_rele_lock); STAILQ_INSERT_TAIL(&unionfs_deferred_rele_list, unp, un_rele); mtx_unlock(&unionfs_deferred_rele_lock); taskqueue_enqueue(taskqueue_unionfs_rele, &unionfs_deferred_rele_task); } else free(unp, M_UNIONFSNODE); } /* * Get the unionfs node status object for the vnode corresponding to unp, * for the process that owns td. Allocate a new status object if one * does not already exist. */ 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; pid = td->td_proc->p_pid; KASSERT(NULL != unspp, ("%s: NULL status", __func__)); ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), __func__); 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, ("%s: NULL status", __func__)); ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), __func__); 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_pd->pd_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) { struct vattr lva; int error; 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 = path; cn->cn_nameiop = nameiop; cn->cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN); cn->cn_lkflags = LK_EXCLUSIVE; cn->cn_cred = cnp->cn_cred; cn->cn_nameptr = cn->cn_pnbuf; 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); if ((error = relookup(dvp, vpp, cn))) { vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); } else vrele(dvp); KASSERT((cn->cn_flags & HASBUF) != 0, ("%s: HASBUF cleared", __func__)); KASSERT((cn->cn_flags & SAVENAME) != 0, ("%s: SAVENAME cleared", __func__)); KASSERT(cn->cn_pnbuf == path, ("%s: cn_pnbuf changed", __func__)); 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) { struct vnode *udvp; struct vnode *vp; struct componentname cn; int error; udvp = UNIONFSVPTOUPPERVP(dvp); vp = NULLVP; KASSERT((cnp->cn_flags & HASBUF) != 0, ("%s called without HASBUF", __func__)); error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, cnp->cn_namelen, CREATE); if (error) return (error); if (vp != NULLVP) { if (udvp == vp) vrele(vp); else vput(vp); error = EEXIST; } 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) { struct vnode *udvp; struct vnode *vp; struct componentname cn; int error; udvp = UNIONFSVPTOUPPERVP(dvp); vp = NULLVP; KASSERT((cnp->cn_flags & HASBUF) != 0, ("%s called without HASBUF", __func__)); error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, cnp->cn_namelen, DELETE); if (error) return (error); if (vp == NULLVP) error = ENOENT; else { if (udvp == vp) vrele(vp); else vput(vp); } 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) { struct vnode *udvp; struct vnode *vp; struct componentname cn; int error; udvp = UNIONFSVPTOUPPERVP(dvp); vp = NULLVP; KASSERT((cnp->cn_flags & HASBUF) != 0, ("%s called without HASBUF", __func__)); error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, cnp->cn_namelen, RENAME); if (error) return (error); if (vp != NULLVP) { if (udvp == vp) vrele(vp); else vput(vp); } 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) { struct unionfs_node_hashhead *hd; struct vnode *vp; struct vnode *lvp; struct vnode *dvp; unsigned count, lockrec; vp = UNIONFSTOV(unp); lvp = unp->un_lowervp; ASSERT_VOP_ELOCKED(lvp, __func__); ASSERT_VOP_ELOCKED(uvp, __func__); dvp = unp->un_dvp; VNASSERT(vp->v_writecount == 0, vp, ("%s: non-zero writecount", __func__)); /* - * Uppdate the upper vnode's lock state to match the lower vnode, + * Update the upper vnode's lock state to match the lower vnode, * and then switch the unionfs vnode's lock to the upper vnode. */ lockrec = lvp->v_vnlock->lk_recurse; for (count = 0; count < lockrec; count++) vn_lock(uvp, LK_EXCLUSIVE | LK_CANRECURSE | LK_RETRY); VI_LOCK(vp); unp->un_uppervp = uvp; vp->v_vnlock = uvp->v_vnlock; VI_UNLOCK(vp); /* * Re-cache the unionfs vnode against the upper vnode */ if (dvp != NULLVP && vp->v_type == VDIR) { VI_LOCK(dvp); if (unp->un_hash.le_prev != NULL) { LIST_REMOVE(unp, un_hash); hd = unionfs_get_hashhead(dvp, uvp); LIST_INSERT_HEAD(hd, unp, un_hash); } VI_UNLOCK(unp->un_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) { struct vnode *lvp; struct vnode *uvp; struct vattr va; struct vattr lva; struct nameidata nd; struct mount *mp; struct ucred *cred; struct ucred *credbk; struct uidinfo *rootinfo; int error; 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(&nd.ni_cnd, 0, sizeof(struct componentname)); NDPREINIT(&nd); if ((error = VOP_GETATTR(lvp, &lva, cnp->cn_cred))) goto unionfs_mkshadowdir_abort; if ((error = unionfs_relookup(udvp, &uvp, cnp, &nd.ni_cnd, 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_abort; } if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH))) goto unionfs_mkshadowdir_abort; unionfs_create_uppervattr_core(ump, &lva, &va, td); error = VOP_MKDIR(udvp, &uvp, &nd.ni_cnd, &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, nd.ni_cnd.cn_cred); } vn_finished_write(mp); 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 pathlen) { struct vnode *wvp; struct nameidata nd; struct mount *mp; int error; wvp = NULLVP; NDPREINIT(&nd); if ((error = unionfs_relookup(dvp, &wvp, cnp, &nd.ni_cnd, td, path, pathlen, CREATE))) { return (error); } if (wvp != NULLVP) { 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, &nd.ni_cnd, CREATE); vn_finished_write(mp); unionfs_mkwhiteout_free_out: 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; struct nameidata nd; int fmode; int error; 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("%s: NULL un_path", __func__); nd.ni_cnd.cn_namelen = unp->un_pathlen; nd.ni_cnd.cn_pnbuf = unp->un_path; nd.ni_cnd.cn_nameiop = CREATE; nd.ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN; nd.ni_cnd.cn_lkflags = LK_EXCLUSIVE; nd.ni_cnd.cn_cred = cred; nd.ni_cnd.cn_nameptr = nd.ni_cnd.cn_pnbuf; NDPREINIT(&nd); vref(udvp); if ((error = relookup(udvp, &vp, &nd.ni_cnd)) != 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, &nd.ni_cnd, 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; } error = VOP_ADD_WRITECOUNT(vp, 1); CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", __func__, vp, vp->v_writecount); if (error == 0) { *vpp = vp; } else { VOP_CLOSE(vp, fmode, cred, td); } unionfs_vn_create_on_upper_free_out1: VOP_UNLOCK(udvp); unionfs_vn_create_on_upper_free_out2: KASSERT((nd.ni_cnd.cn_flags & HASBUF) != 0, ("%s: HASBUF cleared", __func__)); KASSERT((nd.ni_cnd.cn_flags & SAVENAME) != 0, ("%s: SAVENAME cleared", __func__)); KASSERT(nd.ni_cnd.cn_pnbuf == unp->un_path, ("%s: cn_pnbuf changed", __func__)); 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) { char *buf; struct uio uio; struct iovec iov; off_t offset; int count; int error; int bufoffset; 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) { struct mount *mp; struct vnode *udvp; struct vnode *lvp; struct vnode *uvp; struct vattr uva; int error; 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_CHECKED(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) { struct vnode *uvp; struct vnode *lvp; struct vnode *tvp; struct dirent *dp; struct dirent *edp; struct componentname cn; struct iovec iov; struct uio uio; struct vattr va; int error; int eofflag; int lookuperr; /* * The size of buf needs to be larger than DIRBLKSIZ. */ char buf[256 * 6]; ASSERT_VOP_ELOCKED(vp, __func__); 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; KASSERT(eofflag != 0 || uio.uio_resid < sizeof(buf), ("%s: empty read from lower FS", __func__)); 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_cred = cred; /* * 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); } diff --git a/sys/fs/unionfs/union_vnops.c b/sys/fs/unionfs/union_vnops.c index 43378f709df7..28e306fdb3f8 100644 --- a/sys/fs/unionfs/union_vnops.c +++ b/sys/fs/unionfs/union_vnops.c @@ -1,2811 +1,2814 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1992, 1993, 1994, 1995 Jan-Simon Pendry. * Copyright (c) 1992, 1993, 1994, 1995 * The Regents of the University of California. * Copyright (c) 2005, 2006, 2012 Masanori Ozawa , ONGS Inc. * Copyright (c) 2006, 2012 Daichi Goto * 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. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)union_vnops.c 8.32 (Berkeley) 6/23/95 * $FreeBSD$ * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if 0 #define UNIONFS_INTERNAL_DEBUG(msg, args...) printf(msg, ## args) #define UNIONFS_IDBG_RENAME #else #define UNIONFS_INTERNAL_DEBUG(msg, args...) #endif #define KASSERT_UNIONFS_VNODE(vp) \ VNASSERT(((vp)->v_op == &unionfs_vnodeops), vp, \ ("%s: non-unionfs vnode", __func__)) static int unionfs_lookup(struct vop_cachedlookup_args *ap) { struct unionfs_node *dunp; struct vnode *dvp, *udvp, *ldvp, *vp, *uvp, *lvp, *dtmpvp; struct vattr va; struct componentname *cnp; struct thread *td; u_long nameiop; u_long cnflags, cnflagsbk; int iswhiteout; int lockflag; int error , uerror, lerror; iswhiteout = 0; lockflag = 0; error = uerror = lerror = ENOENT; cnp = ap->a_cnp; nameiop = cnp->cn_nameiop; cnflags = cnp->cn_flags; dvp = ap->a_dvp; dunp = VTOUNIONFS(dvp); udvp = dunp->un_uppervp; ldvp = dunp->un_lowervp; vp = uvp = lvp = NULLVP; td = curthread; *(ap->a_vpp) = NULLVP; UNIONFS_INTERNAL_DEBUG( "unionfs_lookup: enter: nameiop=%ld, flags=%lx, path=%s\n", nameiop, cnflags, cnp->cn_nameptr); if (dvp->v_type != VDIR) return (ENOTDIR); /* * If read-only and op is not LOOKUP, will return EROFS. */ if ((cnflags & ISLASTCN) && (dvp->v_mount->mnt_flag & MNT_RDONLY) && LOOKUP != nameiop) return (EROFS); /* * lookup dotdot */ if (cnflags & ISDOTDOT) { if (LOOKUP != nameiop && udvp == NULLVP) return (EROFS); if (udvp != NULLVP) { dtmpvp = udvp; if (ldvp != NULLVP) VOP_UNLOCK(ldvp); } else dtmpvp = ldvp; error = VOP_LOOKUP(dtmpvp, &vp, cnp); if (dtmpvp == udvp && ldvp != NULLVP) { VOP_UNLOCK(udvp); vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); } if (error == 0) { /* * Exchange lock and reference from vp to * dunp->un_dvp. vp is upper/lower vnode, but it * will need to return the unionfs vnode. */ if (nameiop == DELETE || nameiop == RENAME || (cnp->cn_lkflags & LK_TYPE_MASK)) VOP_UNLOCK(vp); vrele(vp); VOP_UNLOCK(dvp); *(ap->a_vpp) = dunp->un_dvp; vref(dunp->un_dvp); if (nameiop == DELETE || nameiop == RENAME) vn_lock(dunp->un_dvp, LK_EXCLUSIVE | LK_RETRY); else if (cnp->cn_lkflags & LK_TYPE_MASK) vn_lock(dunp->un_dvp, cnp->cn_lkflags | LK_RETRY); vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); } else if (error == ENOENT && (cnflags & MAKEENTRY) != 0) cache_enter(dvp, NULLVP, cnp); goto unionfs_lookup_return; } /* * lookup upper layer */ if (udvp != NULLVP) { uerror = VOP_LOOKUP(udvp, &uvp, cnp); if (uerror == 0) { if (udvp == uvp) { /* is dot */ vrele(uvp); *(ap->a_vpp) = dvp; vref(dvp); error = uerror; goto unionfs_lookup_return; } if (nameiop == DELETE || nameiop == RENAME || (cnp->cn_lkflags & LK_TYPE_MASK)) VOP_UNLOCK(uvp); } /* check whiteout */ if (uerror == ENOENT || uerror == EJUSTRETURN) if (cnp->cn_flags & ISWHITEOUT) iswhiteout = 1; /* don't lookup lower */ if (iswhiteout == 0 && ldvp != NULLVP) if (!VOP_GETATTR(udvp, &va, cnp->cn_cred) && (va.va_flags & OPAQUE)) iswhiteout = 1; /* don't lookup lower */ #if 0 UNIONFS_INTERNAL_DEBUG( "unionfs_lookup: debug: whiteout=%d, path=%s\n", iswhiteout, cnp->cn_nameptr); #endif } /* * lookup lower layer */ if (ldvp != NULLVP && !(cnflags & DOWHITEOUT) && iswhiteout == 0) { /* always op is LOOKUP */ cnp->cn_nameiop = LOOKUP; cnflagsbk = cnp->cn_flags; cnp->cn_flags = cnflags; lerror = VOP_LOOKUP(ldvp, &lvp, cnp); cnp->cn_nameiop = nameiop; if (udvp != NULLVP && (uerror == 0 || uerror == EJUSTRETURN)) cnp->cn_flags = cnflagsbk; if (lerror == 0) { if (ldvp == lvp) { /* is dot */ if (uvp != NULLVP) vrele(uvp); /* no need? */ vrele(lvp); *(ap->a_vpp) = dvp; vref(dvp); UNIONFS_INTERNAL_DEBUG( "unionfs_lookup: leave (%d)\n", lerror); return (lerror); } if (cnp->cn_lkflags & LK_TYPE_MASK) VOP_UNLOCK(lvp); } } /* * check lookup result */ if (uvp == NULLVP && lvp == NULLVP) { error = (udvp != NULLVP ? uerror : lerror); goto unionfs_lookup_return; } /* * check vnode type */ if (uvp != NULLVP && lvp != NULLVP && uvp->v_type != lvp->v_type) { vrele(lvp); lvp = NULLVP; } /* * check shadow dir */ if (uerror != 0 && uerror != EJUSTRETURN && udvp != NULLVP && lerror == 0 && lvp != NULLVP && lvp->v_type == VDIR && !(dvp->v_mount->mnt_flag & MNT_RDONLY) && (1 < cnp->cn_namelen || '.' != *(cnp->cn_nameptr))) { /* get unionfs vnode in order to create a new shadow dir. */ error = unionfs_nodeget(dvp->v_mount, NULLVP, lvp, dvp, &vp, cnp); if (error != 0) goto unionfs_lookup_cleanup; if (LK_SHARED == (cnp->cn_lkflags & LK_TYPE_MASK)) VOP_UNLOCK(vp); if (LK_EXCLUSIVE != VOP_ISLOCKED(vp)) { vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); lockflag = 1; } error = unionfs_mkshadowdir(MOUNTTOUNIONFSMOUNT(dvp->v_mount), udvp, VTOUNIONFS(vp), cnp, td); if (lockflag != 0) VOP_UNLOCK(vp); if (error != 0) { UNIONFSDEBUG( "unionfs_lookup: Unable to create shadow dir."); if ((cnp->cn_lkflags & LK_TYPE_MASK) == LK_EXCLUSIVE) vput(vp); else vrele(vp); goto unionfs_lookup_cleanup; } if ((cnp->cn_lkflags & LK_TYPE_MASK) == LK_SHARED) vn_lock(vp, LK_SHARED | LK_RETRY); } /* * get unionfs vnode. */ else { if (uvp != NULLVP) error = uerror; else error = lerror; if (error != 0) goto unionfs_lookup_cleanup; /* * get socket vnode. */ if (uvp != NULLVP && uvp->v_type == VSOCK) { vp = uvp; vref(vp); if (cnp->cn_lkflags & LK_TYPE_MASK) vn_lock(vp, cnp->cn_lkflags | LK_RETRY); } else if (lvp != NULLVP && lvp->v_type == VSOCK) { vp = lvp; vref(vp); if (cnp->cn_lkflags & LK_TYPE_MASK) vn_lock(vp, cnp->cn_lkflags | LK_RETRY); } /* * get unionfs vnode. */ else error = unionfs_nodeget(dvp->v_mount, uvp, lvp, dvp, &vp, cnp); if (error != 0) { UNIONFSDEBUG( "unionfs_lookup: Unable to create unionfs vnode."); goto unionfs_lookup_cleanup; } if ((nameiop == DELETE || nameiop == RENAME) && (cnp->cn_lkflags & LK_TYPE_MASK) == 0) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); } *(ap->a_vpp) = vp; if ((cnflags & MAKEENTRY) && vp->v_type != VSOCK) cache_enter(dvp, vp, cnp); unionfs_lookup_cleanup: if (uvp != NULLVP) vrele(uvp); if (lvp != NULLVP) vrele(lvp); if (error == ENOENT && (cnflags & MAKEENTRY) != 0) cache_enter(dvp, NULLVP, cnp); unionfs_lookup_return: /* Ensure subsequent vnops will get a valid pathname buffer. */ if (nameiop != LOOKUP && (error == 0 || error == EJUSTRETURN)) cnp->cn_flags |= SAVENAME; UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", error); return (error); } static int unionfs_create(struct vop_create_args *ap) { struct unionfs_node *dunp; struct componentname *cnp; struct vnode *udvp; struct vnode *vp; int error; UNIONFS_INTERNAL_DEBUG("unionfs_create: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_dvp); dunp = VTOUNIONFS(ap->a_dvp); cnp = ap->a_cnp; udvp = dunp->un_uppervp; error = EROFS; if (udvp != NULLVP) { error = VOP_CREATE(udvp, &vp, cnp, ap->a_vap); if (error != 0) goto unionfs_create_abort; if (vp->v_type == VSOCK) *(ap->a_vpp) = vp; else { VOP_UNLOCK(vp); error = unionfs_nodeget(ap->a_dvp->v_mount, vp, NULLVP, ap->a_dvp, ap->a_vpp, cnp); vrele(vp); } } unionfs_create_abort: UNIONFS_INTERNAL_DEBUG("unionfs_create: leave (%d)\n", error); return (error); } static int unionfs_whiteout(struct vop_whiteout_args *ap) { struct unionfs_node *dunp; struct componentname *cnp; struct vnode *udvp; int error; UNIONFS_INTERNAL_DEBUG("unionfs_whiteout: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_dvp); dunp = VTOUNIONFS(ap->a_dvp); cnp = ap->a_cnp; udvp = dunp->un_uppervp; error = EOPNOTSUPP; if (udvp != NULLVP) { switch (ap->a_flags) { case CREATE: case DELETE: case LOOKUP: error = VOP_WHITEOUT(udvp, cnp, ap->a_flags); break; default: error = EINVAL; break; } } UNIONFS_INTERNAL_DEBUG("unionfs_whiteout: leave (%d)\n", error); return (error); } static int unionfs_mknod(struct vop_mknod_args *ap) { struct unionfs_node *dunp; struct componentname *cnp; struct vnode *udvp; struct vnode *vp; int error; UNIONFS_INTERNAL_DEBUG("unionfs_mknod: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_dvp); dunp = VTOUNIONFS(ap->a_dvp); cnp = ap->a_cnp; udvp = dunp->un_uppervp; error = EROFS; if (udvp != NULLVP) { error = VOP_MKNOD(udvp, &vp, cnp, ap->a_vap); if (error != 0) goto unionfs_mknod_abort; if (vp->v_type == VSOCK) *(ap->a_vpp) = vp; else { VOP_UNLOCK(vp); error = unionfs_nodeget(ap->a_dvp->v_mount, vp, NULLVP, ap->a_dvp, ap->a_vpp, cnp); vrele(vp); } } unionfs_mknod_abort: UNIONFS_INTERNAL_DEBUG("unionfs_mknod: leave (%d)\n", error); return (error); } enum unionfs_lkupgrade { UNIONFS_LKUPGRADE_SUCCESS, /* lock successfully upgraded */ UNIONFS_LKUPGRADE_ALREADY, /* lock already held exclusive */ UNIONFS_LKUPGRADE_DOOMED /* lock was upgraded, but vnode reclaimed */ }; static inline enum unionfs_lkupgrade unionfs_upgrade_lock(struct vnode *vp) { ASSERT_VOP_LOCKED(vp, __func__); if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE) return (UNIONFS_LKUPGRADE_ALREADY); if (vn_lock(vp, LK_UPGRADE) != 0) { vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); if (VN_IS_DOOMED(vp)) return (UNIONFS_LKUPGRADE_DOOMED); } return (UNIONFS_LKUPGRADE_SUCCESS); } static inline void unionfs_downgrade_lock(struct vnode *vp, enum unionfs_lkupgrade status) { if (status != UNIONFS_LKUPGRADE_ALREADY) vn_lock(vp, LK_DOWNGRADE | LK_RETRY); } static int unionfs_open(struct vop_open_args *ap) { struct unionfs_node *unp; struct unionfs_node_status *unsp; struct vnode *vp; struct vnode *uvp; struct vnode *lvp; struct vnode *targetvp; struct ucred *cred; struct thread *td; int error; enum unionfs_lkupgrade lkstatus; UNIONFS_INTERNAL_DEBUG("unionfs_open: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_vp); error = 0; vp = ap->a_vp; targetvp = NULLVP; cred = ap->a_cred; td = ap->a_td; /* * The executable loader path may call this function with vp locked * shared. If the vnode is reclaimed while upgrading, we can't safely * use unp or do anything else unionfs- specific. */ lkstatus = unionfs_upgrade_lock(vp); if (lkstatus == UNIONFS_LKUPGRADE_DOOMED) { error = ENOENT; goto unionfs_open_cleanup; } unp = VTOUNIONFS(vp); uvp = unp->un_uppervp; lvp = unp->un_lowervp; unionfs_get_node_status(unp, td, &unsp); if (unsp->uns_lower_opencnt > 0 || unsp->uns_upper_opencnt > 0) { /* vnode is already opend. */ if (unsp->uns_upper_opencnt > 0) targetvp = uvp; else targetvp = lvp; if (targetvp == lvp && (ap->a_mode & FWRITE) && lvp->v_type == VREG) targetvp = NULLVP; } if (targetvp == NULLVP) { if (uvp == NULLVP) { if ((ap->a_mode & FWRITE) && lvp->v_type == VREG) { error = unionfs_copyfile(unp, !(ap->a_mode & O_TRUNC), cred, td); if (error != 0) goto unionfs_open_abort; targetvp = uvp = unp->un_uppervp; } else targetvp = lvp; } else targetvp = uvp; } error = VOP_OPEN(targetvp, ap->a_mode, cred, td, ap->a_fp); if (error == 0) { if (targetvp == uvp) { if (uvp->v_type == VDIR && lvp != NULLVP && unsp->uns_lower_opencnt <= 0) { /* open lower for readdir */ error = VOP_OPEN(lvp, FREAD, cred, td, NULL); if (error != 0) { VOP_CLOSE(uvp, ap->a_mode, cred, td); goto unionfs_open_abort; } unsp->uns_node_flag |= UNS_OPENL_4_READDIR; unsp->uns_lower_opencnt++; } unsp->uns_upper_opencnt++; } else { unsp->uns_lower_opencnt++; unsp->uns_lower_openmode = ap->a_mode; } vp->v_object = targetvp->v_object; } unionfs_open_abort: if (error != 0) unionfs_tryrem_node_status(unp, unsp); unionfs_open_cleanup: unionfs_downgrade_lock(vp, lkstatus); UNIONFS_INTERNAL_DEBUG("unionfs_open: leave (%d)\n", error); return (error); } static int unionfs_close(struct vop_close_args *ap) { struct unionfs_node *unp; struct unionfs_node_status *unsp; struct ucred *cred; struct thread *td; struct vnode *vp; struct vnode *ovp; int error; enum unionfs_lkupgrade lkstatus;; UNIONFS_INTERNAL_DEBUG("unionfs_close: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_vp); vp = ap->a_vp; cred = ap->a_cred; td = ap->a_td; error = 0; /* * If the vnode is reclaimed while upgrading, we can't safely use unp * or do anything else unionfs- specific. */ lkstatus = unionfs_upgrade_lock(vp); if (lkstatus == UNIONFS_LKUPGRADE_DOOMED) goto unionfs_close_cleanup; unp = VTOUNIONFS(vp); unionfs_get_node_status(unp, td, &unsp); if (unsp->uns_lower_opencnt <= 0 && unsp->uns_upper_opencnt <= 0) { #ifdef DIAGNOSTIC printf("unionfs_close: warning: open count is 0\n"); #endif if (unp->un_uppervp != NULLVP) ovp = unp->un_uppervp; else ovp = unp->un_lowervp; } else if (unsp->uns_upper_opencnt > 0) ovp = unp->un_uppervp; else ovp = unp->un_lowervp; error = VOP_CLOSE(ovp, ap->a_fflag, cred, td); if (error != 0) goto unionfs_close_abort; vp->v_object = ovp->v_object; if (ovp == unp->un_uppervp) { unsp->uns_upper_opencnt--; if (unsp->uns_upper_opencnt == 0) { if (unsp->uns_node_flag & UNS_OPENL_4_READDIR) { VOP_CLOSE(unp->un_lowervp, FREAD, cred, td); unsp->uns_node_flag &= ~UNS_OPENL_4_READDIR; unsp->uns_lower_opencnt--; } if (unsp->uns_lower_opencnt > 0) vp->v_object = unp->un_lowervp->v_object; } } else unsp->uns_lower_opencnt--; unionfs_close_abort: unionfs_tryrem_node_status(unp, unsp); unionfs_close_cleanup: unionfs_downgrade_lock(vp, lkstatus); UNIONFS_INTERNAL_DEBUG("unionfs_close: leave (%d)\n", error); return (error); } /* * Check the access mode toward shadow file/dir. */ static int unionfs_check_corrected_access(accmode_t accmode, struct vattr *va, struct ucred *cred) { uid_t uid; /* upper side vnode's uid */ gid_t gid; /* upper side vnode's gid */ u_short vmode; /* upper side vnode's mode */ u_short mask; mask = 0; uid = va->va_uid; gid = va->va_gid; vmode = va->va_mode; /* check owner */ if (cred->cr_uid == uid) { if (accmode & VEXEC) mask |= S_IXUSR; if (accmode & VREAD) mask |= S_IRUSR; if (accmode & VWRITE) mask |= S_IWUSR; return ((vmode & mask) == mask ? 0 : EACCES); } /* check group */ if (groupmember(gid, cred)) { if (accmode & VEXEC) mask |= S_IXGRP; if (accmode & VREAD) mask |= S_IRGRP; if (accmode & VWRITE) mask |= S_IWGRP; return ((vmode & mask) == mask ? 0 : EACCES); } /* check other */ if (accmode & VEXEC) mask |= S_IXOTH; if (accmode & VREAD) mask |= S_IROTH; if (accmode & VWRITE) mask |= S_IWOTH; return ((vmode & mask) == mask ? 0 : EACCES); } static int unionfs_access(struct vop_access_args *ap) { struct unionfs_mount *ump; struct unionfs_node *unp; struct vnode *uvp; struct vnode *lvp; struct thread *td; struct vattr va; accmode_t accmode; int error; UNIONFS_INTERNAL_DEBUG("unionfs_access: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_vp); ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount); unp = VTOUNIONFS(ap->a_vp); uvp = unp->un_uppervp; lvp = unp->un_lowervp; td = ap->a_td; accmode = ap->a_accmode; error = EACCES; if ((accmode & VWRITE) && (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)) { switch (ap->a_vp->v_type) { case VREG: case VDIR: case VLNK: return (EROFS); default: break; } } if (uvp != NULLVP) { error = VOP_ACCESS(uvp, accmode, ap->a_cred, td); UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error); return (error); } if (lvp != NULLVP) { if (accmode & VWRITE) { if (ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY) { switch (ap->a_vp->v_type) { case VREG: case VDIR: case VLNK: return (EROFS); default: break; } } else if (ap->a_vp->v_type == VREG || ap->a_vp->v_type == VDIR) { /* check shadow file/dir */ if (ump->um_copymode != UNIONFS_TRANSPARENT) { error = unionfs_create_uppervattr(ump, lvp, &va, ap->a_cred, td); if (error != 0) return (error); error = unionfs_check_corrected_access( accmode, &va, ap->a_cred); if (error != 0) return (error); } } accmode &= ~(VWRITE | VAPPEND); accmode |= VREAD; /* will copy to upper */ } error = VOP_ACCESS(lvp, accmode, ap->a_cred, td); } UNIONFS_INTERNAL_DEBUG("unionfs_access: leave (%d)\n", error); return (error); } static int unionfs_getattr(struct vop_getattr_args *ap) { struct unionfs_node *unp; struct unionfs_mount *ump; struct vnode *uvp; struct vnode *lvp; struct thread *td; struct vattr va; int error; UNIONFS_INTERNAL_DEBUG("unionfs_getattr: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_vp); unp = VTOUNIONFS(ap->a_vp); ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount); uvp = unp->un_uppervp; lvp = unp->un_lowervp; td = curthread; if (uvp != NULLVP) { if ((error = VOP_GETATTR(uvp, ap->a_vap, ap->a_cred)) == 0) ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0]; UNIONFS_INTERNAL_DEBUG( "unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n", ap->a_vap->va_mode, ap->a_vap->va_uid, ap->a_vap->va_gid, error); return (error); } error = VOP_GETATTR(lvp, ap->a_vap, ap->a_cred); if (error == 0 && !(ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY)) { /* correct the attr toward shadow file/dir. */ if (ap->a_vp->v_type == VREG || ap->a_vp->v_type == VDIR) { unionfs_create_uppervattr_core(ump, ap->a_vap, &va, td); ap->a_vap->va_mode = va.va_mode; ap->a_vap->va_uid = va.va_uid; ap->a_vap->va_gid = va.va_gid; } } if (error == 0) ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0]; UNIONFS_INTERNAL_DEBUG( "unionfs_getattr: leave mode=%o, uid=%d, gid=%d (%d)\n", ap->a_vap->va_mode, ap->a_vap->va_uid, ap->a_vap->va_gid, error); return (error); } static int unionfs_setattr(struct vop_setattr_args *ap) { struct unionfs_node *unp; struct vnode *uvp; struct vnode *lvp; struct thread *td; struct vattr *vap; int error; UNIONFS_INTERNAL_DEBUG("unionfs_setattr: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_vp); error = EROFS; unp = VTOUNIONFS(ap->a_vp); uvp = unp->un_uppervp; lvp = unp->un_lowervp; td = curthread; vap = ap->a_vap; 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); if (uvp == NULLVP && lvp->v_type == VREG) { error = unionfs_copyfile(unp, (vap->va_size != 0), ap->a_cred, td); if (error != 0) return (error); uvp = unp->un_uppervp; } if (uvp != NULLVP) error = VOP_SETATTR(uvp, vap, ap->a_cred); UNIONFS_INTERNAL_DEBUG("unionfs_setattr: leave (%d)\n", error); return (error); } static int unionfs_read(struct vop_read_args *ap) { struct unionfs_node *unp; struct vnode *tvp; int error; /* UNIONFS_INTERNAL_DEBUG("unionfs_read: enter\n"); */ KASSERT_UNIONFS_VNODE(ap->a_vp); unp = VTOUNIONFS(ap->a_vp); tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp); error = VOP_READ(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred); /* UNIONFS_INTERNAL_DEBUG("unionfs_read: leave (%d)\n", error); */ return (error); } static int unionfs_write(struct vop_write_args *ap) { struct unionfs_node *unp; struct vnode *tvp; int error; /* UNIONFS_INTERNAL_DEBUG("unionfs_write: enter\n"); */ KASSERT_UNIONFS_VNODE(ap->a_vp); unp = VTOUNIONFS(ap->a_vp); tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp); error = VOP_WRITE(tvp, ap->a_uio, ap->a_ioflag, ap->a_cred); /* UNIONFS_INTERNAL_DEBUG("unionfs_write: leave (%d)\n", error); */ return (error); } static int unionfs_ioctl(struct vop_ioctl_args *ap) { struct unionfs_node *unp; struct unionfs_node_status *unsp; struct vnode *ovp; int error; UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_vp); vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY); unp = VTOUNIONFS(ap->a_vp); unionfs_get_node_status(unp, ap->a_td, &unsp); ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp); unionfs_tryrem_node_status(unp, unsp); VOP_UNLOCK(ap->a_vp); if (ovp == NULLVP) return (EBADF); error = VOP_IOCTL(ovp, ap->a_command, ap->a_data, ap->a_fflag, ap->a_cred, ap->a_td); UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: leave (%d)\n", error); return (error); } static int unionfs_poll(struct vop_poll_args *ap) { struct unionfs_node *unp; struct unionfs_node_status *unsp; struct vnode *ovp; KASSERT_UNIONFS_VNODE(ap->a_vp); vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY); unp = VTOUNIONFS(ap->a_vp); unionfs_get_node_status(unp, ap->a_td, &unsp); ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp); unionfs_tryrem_node_status(unp, unsp); VOP_UNLOCK(ap->a_vp); if (ovp == NULLVP) return (EBADF); return (VOP_POLL(ovp, ap->a_events, ap->a_cred, ap->a_td)); } static int unionfs_fsync(struct vop_fsync_args *ap) { struct unionfs_node *unp; struct unionfs_node_status *unsp; struct vnode *ovp; KASSERT_UNIONFS_VNODE(ap->a_vp); unp = VTOUNIONFS(ap->a_vp); unionfs_get_node_status(unp, ap->a_td, &unsp); ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp); unionfs_tryrem_node_status(unp, unsp); if (ovp == NULLVP) return (EBADF); return (VOP_FSYNC(ovp, ap->a_waitfor, ap->a_td)); } static int unionfs_remove(struct vop_remove_args *ap) { char *path; struct unionfs_node *dunp; struct unionfs_node *unp; struct unionfs_mount *ump; struct vnode *udvp; struct vnode *uvp; struct vnode *lvp; struct vnode *vp; struct componentname *cnp; struct componentname cn; struct thread *td; int error; int pathlen; UNIONFS_INTERNAL_DEBUG("unionfs_remove: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_dvp); error = 0; dunp = VTOUNIONFS(ap->a_dvp); udvp = dunp->un_uppervp; cnp = ap->a_cnp; td = curthread; if (ap->a_vp->v_op != &unionfs_vnodeops) { if (ap->a_vp->v_type != VSOCK) return (EINVAL); ump = NULL; vp = uvp = lvp = NULLVP; /* search vnode */ VOP_UNLOCK(ap->a_vp); error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, cnp->cn_namelen, DELETE); if (error != 0 && error != ENOENT) { vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY); return (error); } if (error == 0 && vp == ap->a_vp) { /* target vnode in upper */ uvp = vp; vrele(vp); } else { /* target vnode in lower */ if (vp != NULLVP) { if (udvp == vp) vrele(vp); else vput(vp); } vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY); lvp = ap->a_vp; } path = cnp->cn_nameptr; pathlen = cnp->cn_namelen; } else { ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount); unp = VTOUNIONFS(ap->a_vp); uvp = unp->un_uppervp; lvp = unp->un_lowervp; path = unp->un_path; pathlen = unp->un_pathlen; } if (udvp == NULLVP) return (EROFS); if (uvp != NULLVP) { /* * XXX: if the vnode type is VSOCK, it will create whiteout * after remove. */ if (ump == NULL || ump->um_whitemode == UNIONFS_WHITE_ALWAYS || lvp != NULLVP) cnp->cn_flags |= DOWHITEOUT; error = VOP_REMOVE(udvp, uvp, cnp); } else if (lvp != NULLVP) error = unionfs_mkwhiteout(udvp, cnp, td, path, pathlen); UNIONFS_INTERNAL_DEBUG("unionfs_remove: leave (%d)\n", error); return (error); } static int unionfs_link(struct vop_link_args *ap) { struct unionfs_node *dunp; struct unionfs_node *unp; struct vnode *udvp; struct vnode *uvp; struct componentname *cnp; struct thread *td; int error; int needrelookup; UNIONFS_INTERNAL_DEBUG("unionfs_link: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_tdvp); KASSERT_UNIONFS_VNODE(ap->a_vp); error = 0; needrelookup = 0; dunp = VTOUNIONFS(ap->a_tdvp); unp = NULL; udvp = dunp->un_uppervp; uvp = NULLVP; cnp = ap->a_cnp; td = curthread; if (udvp == NULLVP) return (EROFS); if (ap->a_vp->v_op != &unionfs_vnodeops) uvp = ap->a_vp; else { unp = VTOUNIONFS(ap->a_vp); if (unp->un_uppervp == NULLVP) { if (ap->a_vp->v_type != VREG) return (EOPNOTSUPP); error = unionfs_copyfile(unp, 1, cnp->cn_cred, td); if (error != 0) return (error); needrelookup = 1; } uvp = unp->un_uppervp; } if (needrelookup != 0) error = unionfs_relookup_for_create(ap->a_tdvp, cnp, td); if (error == 0) error = VOP_LINK(udvp, uvp, cnp); UNIONFS_INTERNAL_DEBUG("unionfs_link: leave (%d)\n", error); return (error); } static int unionfs_rename(struct vop_rename_args *ap) { struct vnode *fdvp; struct vnode *fvp; struct componentname *fcnp; struct vnode *tdvp; struct vnode *tvp; struct componentname *tcnp; struct vnode *ltdvp; struct vnode *ltvp; struct thread *td; /* rename target vnodes */ struct vnode *rfdvp; struct vnode *rfvp; struct vnode *rtdvp; struct vnode *rtvp; struct unionfs_mount *ump; struct unionfs_node *unp; int error; int needrelookup; UNIONFS_INTERNAL_DEBUG("unionfs_rename: enter\n"); error = 0; fdvp = ap->a_fdvp; fvp = ap->a_fvp; fcnp = ap->a_fcnp; tdvp = ap->a_tdvp; tvp = ap->a_tvp; tcnp = ap->a_tcnp; ltdvp = NULLVP; ltvp = NULLVP; td = curthread; rfdvp = fdvp; rfvp = fvp; rtdvp = tdvp; rtvp = tvp; needrelookup = 0; #ifdef DIAGNOSTIC if (!(fcnp->cn_flags & HASBUF) || !(tcnp->cn_flags & HASBUF)) panic("unionfs_rename: no name"); #endif /* check for cross device rename */ if (fvp->v_mount != tdvp->v_mount || (tvp != NULLVP && fvp->v_mount != tvp->v_mount)) { if (fvp->v_op != &unionfs_vnodeops) error = ENODEV; else error = EXDEV; goto unionfs_rename_abort; } /* Renaming a file to itself has no effect. */ if (fvp == tvp) goto unionfs_rename_abort; /* * from/to vnode is unionfs node. */ KASSERT_UNIONFS_VNODE(fdvp); KASSERT_UNIONFS_VNODE(fvp); KASSERT_UNIONFS_VNODE(tdvp); if (tvp != NULLVP) KASSERT_UNIONFS_VNODE(tvp); unp = VTOUNIONFS(fdvp); #ifdef UNIONFS_IDBG_RENAME UNIONFS_INTERNAL_DEBUG("fdvp=%p, ufdvp=%p, lfdvp=%p\n", fdvp, unp->un_uppervp, unp->un_lowervp); #endif if (unp->un_uppervp == NULLVP) { error = ENODEV; goto unionfs_rename_abort; } rfdvp = unp->un_uppervp; vref(rfdvp); unp = VTOUNIONFS(fvp); #ifdef UNIONFS_IDBG_RENAME UNIONFS_INTERNAL_DEBUG("fvp=%p, ufvp=%p, lfvp=%p\n", fvp, unp->un_uppervp, unp->un_lowervp); #endif ump = MOUNTTOUNIONFSMOUNT(fvp->v_mount); if (unp->un_uppervp == NULLVP) { switch (fvp->v_type) { case VREG: if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0) goto unionfs_rename_abort; error = unionfs_copyfile(unp, 1, fcnp->cn_cred, td); VOP_UNLOCK(fvp); if (error != 0) goto unionfs_rename_abort; break; case VDIR: if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0) goto unionfs_rename_abort; error = unionfs_mkshadowdir(ump, rfdvp, unp, fcnp, td); VOP_UNLOCK(fvp); if (error != 0) goto unionfs_rename_abort; break; default: error = ENODEV; goto unionfs_rename_abort; } needrelookup = 1; } if (unp->un_lowervp != NULLVP) fcnp->cn_flags |= DOWHITEOUT; rfvp = unp->un_uppervp; vref(rfvp); unp = VTOUNIONFS(tdvp); #ifdef UNIONFS_IDBG_RENAME UNIONFS_INTERNAL_DEBUG("tdvp=%p, utdvp=%p, ltdvp=%p\n", tdvp, unp->un_uppervp, unp->un_lowervp); #endif if (unp->un_uppervp == NULLVP) { error = ENODEV; goto unionfs_rename_abort; } rtdvp = unp->un_uppervp; ltdvp = unp->un_lowervp; vref(rtdvp); if (tdvp == tvp) { rtvp = rtdvp; vref(rtvp); } else if (tvp != NULLVP) { unp = VTOUNIONFS(tvp); #ifdef UNIONFS_IDBG_RENAME UNIONFS_INTERNAL_DEBUG("tvp=%p, utvp=%p, ltvp=%p\n", tvp, unp->un_uppervp, unp->un_lowervp); #endif if (unp->un_uppervp == NULLVP) rtvp = NULLVP; else { if (tvp->v_type == VDIR) { error = EINVAL; goto unionfs_rename_abort; } rtvp = unp->un_uppervp; ltvp = unp->un_lowervp; vref(rtvp); } } if (rfvp == rtvp) goto unionfs_rename_abort; if (needrelookup != 0) { if ((error = vn_lock(fdvp, LK_EXCLUSIVE)) != 0) goto unionfs_rename_abort; error = unionfs_relookup_for_delete(fdvp, fcnp, td); VOP_UNLOCK(fdvp); if (error != 0) goto unionfs_rename_abort; /* Lock of tvp is canceled in order to avoid recursive lock. */ if (tvp != NULLVP && tvp != tdvp) VOP_UNLOCK(tvp); error = unionfs_relookup_for_rename(tdvp, tcnp, td); if (tvp != NULLVP && tvp != tdvp) vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY); if (error != 0) goto unionfs_rename_abort; } error = VOP_RENAME(rfdvp, rfvp, fcnp, rtdvp, rtvp, tcnp); if (error == 0) { if (rtvp != NULLVP && rtvp->v_type == VDIR) cache_purge(tdvp); if (fvp->v_type == VDIR && fdvp != tdvp) cache_purge(fdvp); } if (ltdvp != NULLVP) VOP_UNLOCK(ltdvp); if (tdvp != rtdvp) vrele(tdvp); if (ltvp != NULLVP) VOP_UNLOCK(ltvp); if (tvp != rtvp && tvp != NULLVP) { if (rtvp == NULLVP) vput(tvp); else vrele(tvp); } if (fdvp != rfdvp) vrele(fdvp); if (fvp != rfvp) vrele(fvp); UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error); return (error); unionfs_rename_abort: vput(tdvp); if (tdvp != rtdvp) vrele(rtdvp); if (tvp != NULLVP) { if (tdvp != tvp) vput(tvp); else vrele(tvp); } if (tvp != rtvp && rtvp != NULLVP) vrele(rtvp); if (fdvp != rfdvp) vrele(rfdvp); if (fvp != rfvp) vrele(rfvp); vrele(fdvp); vrele(fvp); UNIONFS_INTERNAL_DEBUG("unionfs_rename: leave (%d)\n", error); return (error); } static int unionfs_mkdir(struct vop_mkdir_args *ap) { struct unionfs_node *dunp; struct componentname *cnp; struct vnode *udvp; struct vnode *uvp; struct vattr va; int error; int lkflags; UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_dvp); error = EROFS; dunp = VTOUNIONFS(ap->a_dvp); cnp = ap->a_cnp; lkflags = cnp->cn_lkflags; udvp = dunp->un_uppervp; if (udvp != NULLVP) { /* check opaque */ if (!(cnp->cn_flags & ISWHITEOUT)) { error = VOP_GETATTR(udvp, &va, cnp->cn_cred); if (error != 0) return (error); if ((va.va_flags & OPAQUE) != 0) cnp->cn_flags |= ISWHITEOUT; } if ((error = VOP_MKDIR(udvp, &uvp, cnp, ap->a_vap)) == 0) { VOP_UNLOCK(uvp); cnp->cn_lkflags = LK_EXCLUSIVE; error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP, ap->a_dvp, ap->a_vpp, cnp); cnp->cn_lkflags = lkflags; vrele(uvp); } } UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: leave (%d)\n", error); return (error); } static int unionfs_rmdir(struct vop_rmdir_args *ap) { struct unionfs_node *dunp; struct unionfs_node *unp; struct unionfs_mount *ump; struct componentname *cnp; struct thread *td; struct vnode *udvp; struct vnode *uvp; struct vnode *lvp; int error; UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_dvp); KASSERT_UNIONFS_VNODE(ap->a_vp); error = 0; dunp = VTOUNIONFS(ap->a_dvp); unp = VTOUNIONFS(ap->a_vp); cnp = ap->a_cnp; td = curthread; udvp = dunp->un_uppervp; uvp = unp->un_uppervp; lvp = unp->un_lowervp; if (udvp == NULLVP) return (EROFS); if (udvp == uvp) return (EOPNOTSUPP); if (uvp != NULLVP) { if (lvp != NULLVP) { error = unionfs_check_rmdir(ap->a_vp, cnp->cn_cred, td); if (error != 0) return (error); } ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount); if (ump->um_whitemode == UNIONFS_WHITE_ALWAYS || lvp != NULLVP) cnp->cn_flags |= DOWHITEOUT; /* * The relookup path will need to relock the parent dvp and * possibly the vp as well. Locking is expected to be done * in parent->child order; drop the lock on vp to avoid LOR * and potential recursion on vp's lock. * vp is expected to remain referenced during VOP_RMDIR(), * so vref/vrele should not be necessary here. */ VOP_UNLOCK(ap->a_vp); VNPASS(vrefcnt(ap->a_vp) > 0, ap->a_vp); error = unionfs_relookup_for_delete(ap->a_dvp, cnp, td); vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY); /* * VOP_RMDIR is dispatched against udvp, so if uvp became * doomed while the lock was dropped above the target * filesystem may not be able to cope. */ if (error == 0 && VN_IS_DOOMED(uvp)) error = ENOENT; if (error == 0) error = VOP_RMDIR(udvp, uvp, cnp); } else if (lvp != NULLVP) error = unionfs_mkwhiteout(udvp, cnp, td, unp->un_path, unp->un_pathlen); if (error == 0) { cache_purge(ap->a_dvp); cache_purge(ap->a_vp); } UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: leave (%d)\n", error); return (error); } static int unionfs_symlink(struct vop_symlink_args *ap) { struct unionfs_node *dunp; struct componentname *cnp; struct vnode *udvp; struct vnode *uvp; int error; int lkflags; UNIONFS_INTERNAL_DEBUG("unionfs_symlink: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_dvp); error = EROFS; dunp = VTOUNIONFS(ap->a_dvp); cnp = ap->a_cnp; lkflags = cnp->cn_lkflags; udvp = dunp->un_uppervp; if (udvp != NULLVP) { error = VOP_SYMLINK(udvp, &uvp, cnp, ap->a_vap, ap->a_target); if (error == 0) { VOP_UNLOCK(uvp); cnp->cn_lkflags = LK_EXCLUSIVE; error = unionfs_nodeget(ap->a_dvp->v_mount, uvp, NULLVP, ap->a_dvp, ap->a_vpp, cnp); cnp->cn_lkflags = lkflags; vrele(uvp); } } UNIONFS_INTERNAL_DEBUG("unionfs_symlink: leave (%d)\n", error); return (error); } static int unionfs_readdir(struct vop_readdir_args *ap) { struct unionfs_node *unp; struct unionfs_node_status *unsp; struct uio *uio; struct vnode *vp; struct vnode *uvp; struct vnode *lvp; struct thread *td; struct vattr va; uint64_t *cookies_bk; int error; int eofflag; int ncookies_bk; int uio_offset_bk; enum unionfs_lkupgrade lkstatus; UNIONFS_INTERNAL_DEBUG("unionfs_readdir: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_vp); error = 0; eofflag = 0; uio_offset_bk = 0; uio = ap->a_uio; uvp = NULLVP; lvp = NULLVP; td = uio->uio_td; ncookies_bk = 0; cookies_bk = NULL; vp = ap->a_vp; if (vp->v_type != VDIR) return (ENOTDIR); /* * If the vnode is reclaimed while upgrading, we can't safely use unp * or do anything else unionfs- specific. */ lkstatus = unionfs_upgrade_lock(vp); if (lkstatus == UNIONFS_LKUPGRADE_DOOMED) error = EBADF; if (error == 0) { unp = VTOUNIONFS(vp); uvp = unp->un_uppervp; lvp = unp->un_lowervp; /* check the open count. unionfs needs open before readdir. */ unionfs_get_node_status(unp, td, &unsp); if ((uvp != NULLVP && unsp->uns_upper_opencnt <= 0) || (lvp != NULLVP && unsp->uns_lower_opencnt <= 0)) { unionfs_tryrem_node_status(unp, unsp); error = EBADF; } } unionfs_downgrade_lock(vp, lkstatus); if (error != 0) goto unionfs_readdir_exit; /* check opaque */ if (uvp != NULLVP && lvp != NULLVP) { if ((error = VOP_GETATTR(uvp, &va, ap->a_cred)) != 0) goto unionfs_readdir_exit; if (va.va_flags & OPAQUE) lvp = NULLVP; } /* upper only */ if (uvp != NULLVP && lvp == NULLVP) { error = VOP_READDIR(uvp, uio, ap->a_cred, ap->a_eofflag, ap->a_ncookies, ap->a_cookies); unsp->uns_readdir_status = 0; goto unionfs_readdir_exit; } /* lower only */ if (uvp == NULLVP && lvp != NULLVP) { error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag, ap->a_ncookies, ap->a_cookies); unsp->uns_readdir_status = 2; goto unionfs_readdir_exit; } /* * readdir upper and lower */ KASSERT(uvp != NULLVP, ("unionfs_readdir: null upper vp")); KASSERT(lvp != NULLVP, ("unionfs_readdir: null lower vp")); if (uio->uio_offset == 0) unsp->uns_readdir_status = 0; if (unsp->uns_readdir_status == 0) { /* read upper */ error = VOP_READDIR(uvp, uio, ap->a_cred, &eofflag, ap->a_ncookies, ap->a_cookies); if (error != 0 || eofflag == 0) goto unionfs_readdir_exit; unsp->uns_readdir_status = 1; /* * UFS(and other FS) needs size of uio_resid larger than * DIRBLKSIZ. * size of DIRBLKSIZ equals DEV_BSIZE. * (see: ufs/ufs/ufs_vnops.c ufs_readdir func , ufs/ufs/dir.h) */ if (uio->uio_resid <= (uio->uio_resid & (DEV_BSIZE -1))) goto unionfs_readdir_exit; /* * Backup cookies. * It prepares to readdir in lower. */ if (ap->a_ncookies != NULL) { ncookies_bk = *(ap->a_ncookies); *(ap->a_ncookies) = 0; } if (ap->a_cookies != NULL) { cookies_bk = *(ap->a_cookies); *(ap->a_cookies) = NULL; } } /* initialize for readdir in lower */ if (unsp->uns_readdir_status == 1) { unsp->uns_readdir_status = 2; /* * Backup uio_offset. See the comment after the * VOP_READDIR call on the lower layer. */ uio_offset_bk = uio->uio_offset; uio->uio_offset = 0; } if (lvp == NULLVP) { error = EBADF; goto unionfs_readdir_exit; } /* read lower */ error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag, ap->a_ncookies, ap->a_cookies); /* * We can't return an uio_offset of 0: this would trigger an * infinite loop, because the next call to unionfs_readdir would * always restart with the upper layer (uio_offset == 0) and * always return some data. * * This happens when the lower layer root directory is removed. * (A root directory deleting of unionfs should not be permitted. * But current VFS can not do it.) */ if (uio->uio_offset == 0) uio->uio_offset = uio_offset_bk; if (cookies_bk != NULL) { /* merge cookies */ int size; uint64_t *newcookies, *pos; size = *(ap->a_ncookies) + ncookies_bk; newcookies = (uint64_t *) malloc(size * sizeof(*newcookies), M_TEMP, M_WAITOK); pos = newcookies; memcpy(pos, cookies_bk, ncookies_bk * sizeof(*newcookies)); pos += ncookies_bk; memcpy(pos, *(ap->a_cookies), *(ap->a_ncookies) * sizeof(*newcookies)); free(cookies_bk, M_TEMP); free(*(ap->a_cookies), M_TEMP); *(ap->a_ncookies) = size; *(ap->a_cookies) = newcookies; } unionfs_readdir_exit: if (error != 0 && ap->a_eofflag != NULL) *(ap->a_eofflag) = 1; UNIONFS_INTERNAL_DEBUG("unionfs_readdir: leave (%d)\n", error); return (error); } static int unionfs_readlink(struct vop_readlink_args *ap) { struct unionfs_node *unp; struct vnode *vp; int error; UNIONFS_INTERNAL_DEBUG("unionfs_readlink: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_vp); unp = VTOUNIONFS(ap->a_vp); vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp); error = VOP_READLINK(vp, ap->a_uio, ap->a_cred); UNIONFS_INTERNAL_DEBUG("unionfs_readlink: leave (%d)\n", error); return (error); } static int unionfs_getwritemount(struct vop_getwritemount_args *ap) { struct vnode *uvp; struct vnode *vp; int error; UNIONFS_INTERNAL_DEBUG("unionfs_getwritemount: enter\n"); error = 0; vp = ap->a_vp; if (vp == NULLVP || (vp->v_mount->mnt_flag & MNT_RDONLY)) return (EACCES); KASSERT_UNIONFS_VNODE(vp); uvp = UNIONFSVPTOUPPERVP(vp); if (uvp == NULLVP && VREG == vp->v_type) uvp = UNIONFSVPTOUPPERVP(VTOUNIONFS(vp)->un_dvp); if (uvp != NULLVP) error = VOP_GETWRITEMOUNT(uvp, ap->a_mpp); else { VI_LOCK(vp); if (vp->v_holdcnt == 0) error = EOPNOTSUPP; else error = EACCES; VI_UNLOCK(vp); } UNIONFS_INTERNAL_DEBUG("unionfs_getwritemount: leave (%d)\n", error); return (error); } static int unionfs_inactive(struct vop_inactive_args *ap) { ap->a_vp->v_object = NULL; vrecycle(ap->a_vp); return (0); } static int unionfs_reclaim(struct vop_reclaim_args *ap) { /* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: enter\n"); */ unionfs_noderem(ap->a_vp); /* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: leave\n"); */ return (0); } static int unionfs_print(struct vop_print_args *ap) { struct unionfs_node *unp; /* struct unionfs_node_status *unsp; */ unp = VTOUNIONFS(ap->a_vp); /* unionfs_get_node_status(unp, curthread, &unsp); */ printf("unionfs_vp=%p, uppervp=%p, lowervp=%p\n", ap->a_vp, unp->un_uppervp, unp->un_lowervp); /* printf("unionfs opencnt: uppervp=%d, lowervp=%d\n", unsp->uns_upper_opencnt, unsp->uns_lower_opencnt); */ if (unp->un_uppervp != NULLVP) vn_printf(unp->un_uppervp, "unionfs: upper "); if (unp->un_lowervp != NULLVP) vn_printf(unp->un_lowervp, "unionfs: lower "); return (0); } static int unionfs_islocked(struct vop_islocked_args *ap) { struct unionfs_node *unp; KASSERT_UNIONFS_VNODE(ap->a_vp); unp = VTOUNIONFS(ap->a_vp); if (unp == NULL) return (vop_stdislocked(ap)); if (unp->un_uppervp != NULLVP) return (VOP_ISLOCKED(unp->un_uppervp)); if (unp->un_lowervp != NULLVP) return (VOP_ISLOCKED(unp->un_lowervp)); return (vop_stdislocked(ap)); } static int unionfs_get_llt_revlock(struct vnode *vp, int flags) { int revlock; revlock = 0; switch (flags & LK_TYPE_MASK) { case LK_SHARED: if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE) revlock = LK_UPGRADE; else revlock = LK_RELEASE; break; case LK_EXCLUSIVE: case LK_UPGRADE: revlock = LK_RELEASE; break; case LK_DOWNGRADE: revlock = LK_UPGRADE; break; default: break; } return (revlock); } /* * The state of an acquired lock is adjusted similarly to * the time of error generating. * flags: LK_RELEASE or LK_UPGRADE */ static void unionfs_revlock(struct vnode *vp, int flags) { if (flags & LK_RELEASE) VOP_UNLOCK_FLAGS(vp, flags); else { /* UPGRADE */ if (vn_lock(vp, flags) != 0) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); } } static int unionfs_lock(struct vop_lock1_args *ap) { struct unionfs_node *unp; struct vnode *vp; struct vnode *uvp; struct vnode *lvp; int error; int flags; int revlock; int interlock; int uhold; /* * TODO: rework the unionfs locking scheme. * It's not guaranteed to be safe to blindly lock two vnodes on * different mounts as is done here. Further, the entanglement * of locking both vnodes with the various options that can be * passed to VOP_LOCK() makes this code hard to reason about. * Instead, consider locking only the upper vnode, or the lower * vnode is the upper is not present, and taking separate measures * to lock both vnodes in the few cases when that is needed. */ error = 0; interlock = 1; uhold = 0; flags = ap->a_flags; vp = ap->a_vp; if (LK_RELEASE == (flags & LK_TYPE_MASK) || !(flags & LK_TYPE_MASK)) return (VOP_UNLOCK_FLAGS(vp, flags | LK_RELEASE)); if ((flags & LK_INTERLOCK) == 0) VI_LOCK(vp); unp = VTOUNIONFS(vp); if (unp == NULL) goto unionfs_lock_null_vnode; KASSERT_UNIONFS_VNODE(ap->a_vp); lvp = unp->un_lowervp; uvp = unp->un_uppervp; if ((revlock = unionfs_get_llt_revlock(vp, flags)) == 0) panic("unknown lock type: 0x%x", flags & LK_TYPE_MASK); if ((flags & LK_TYPE_MASK) != LK_DOWNGRADE && (vp->v_iflag & VI_OWEINACT) != 0) flags |= LK_NOWAIT; /* - * Sometimes, lower or upper is already exclusive locked. - * (ex. vfs_domount: mounted vnode is already locked.) + * During unmount, the root vnode lock may be taken recursively, + * because it may share the same v_vnlock field as the vnode covered by + * the unionfs mount. The covered vnode is locked across VFS_UNMOUNT(), + * and the same lock may be taken recursively here during vflush() + * issued by unionfs_unmount(). */ if ((flags & LK_TYPE_MASK) == LK_EXCLUSIVE && (vp->v_vflag & VV_ROOT) != 0) flags |= LK_CANRECURSE; if (lvp != NULLVP) { if (uvp != NULLVP && flags & LK_UPGRADE) { /* * Share Lock is once released and a deadlock is * avoided. */ vholdnz(uvp); uhold = 1; VOP_UNLOCK(uvp); unp = VTOUNIONFS(vp); if (unp == NULL) { /* vnode is released. */ VI_UNLOCK(vp); VOP_UNLOCK(lvp); vdrop(uvp); return (EBUSY); } } VI_LOCK_FLAGS(lvp, MTX_DUPOK); flags |= LK_INTERLOCK; vholdl(lvp); VI_UNLOCK(vp); ap->a_flags &= ~LK_INTERLOCK; error = VOP_LOCK(lvp, flags); VI_LOCK(vp); unp = VTOUNIONFS(vp); if (unp == NULL) { /* vnode is released. */ VI_UNLOCK(vp); if (error == 0) VOP_UNLOCK(lvp); vdrop(lvp); if (uhold != 0) vdrop(uvp); return (vop_stdlock(ap)); } } if (error == 0 && uvp != NULLVP) { if (uhold && flags & LK_UPGRADE) { flags &= ~LK_TYPE_MASK; flags |= LK_EXCLUSIVE; } VI_LOCK_FLAGS(uvp, MTX_DUPOK); flags |= LK_INTERLOCK; if (uhold == 0) { vholdl(uvp); uhold = 1; } VI_UNLOCK(vp); ap->a_flags &= ~LK_INTERLOCK; error = VOP_LOCK(uvp, flags); VI_LOCK(vp); unp = VTOUNIONFS(vp); if (unp == NULL) { /* vnode is released. */ VI_UNLOCK(vp); if (error == 0) VOP_UNLOCK(uvp); vdrop(uvp); if (lvp != NULLVP) { VOP_UNLOCK(lvp); vdrop(lvp); } return (vop_stdlock(ap)); } if (error != 0 && lvp != NULLVP) { /* rollback */ VI_UNLOCK(vp); unionfs_revlock(lvp, revlock); interlock = 0; } } if (interlock) VI_UNLOCK(vp); if (lvp != NULLVP) vdrop(lvp); if (uhold != 0) vdrop(uvp); return (error); unionfs_lock_null_vnode: ap->a_flags |= LK_INTERLOCK; return (vop_stdlock(ap)); } static int unionfs_unlock(struct vop_unlock_args *ap) { struct vnode *vp; struct vnode *lvp; struct vnode *uvp; struct unionfs_node *unp; int error; int uhold; KASSERT_UNIONFS_VNODE(ap->a_vp); error = 0; uhold = 0; vp = ap->a_vp; unp = VTOUNIONFS(vp); if (unp == NULL) goto unionfs_unlock_null_vnode; lvp = unp->un_lowervp; uvp = unp->un_uppervp; if (lvp != NULLVP) { vholdnz(lvp); error = VOP_UNLOCK(lvp); } if (error == 0 && uvp != NULLVP) { vholdnz(uvp); uhold = 1; error = VOP_UNLOCK(uvp); } if (lvp != NULLVP) vdrop(lvp); if (uhold != 0) vdrop(uvp); return error; unionfs_unlock_null_vnode: return (vop_stdunlock(ap)); } static int unionfs_pathconf(struct vop_pathconf_args *ap) { struct unionfs_node *unp; struct vnode *vp; KASSERT_UNIONFS_VNODE(ap->a_vp); unp = VTOUNIONFS(ap->a_vp); vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp); return (VOP_PATHCONF(vp, ap->a_name, ap->a_retval)); } static int unionfs_advlock(struct vop_advlock_args *ap) { struct unionfs_node *unp; struct unionfs_node_status *unsp; struct vnode *vp; struct vnode *uvp; struct thread *td; int error; UNIONFS_INTERNAL_DEBUG("unionfs_advlock: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_vp); vp = ap->a_vp; td = curthread; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); unp = VTOUNIONFS(ap->a_vp); uvp = unp->un_uppervp; if (uvp == NULLVP) { error = unionfs_copyfile(unp, 1, td->td_ucred, td); if (error != 0) goto unionfs_advlock_abort; uvp = unp->un_uppervp; unionfs_get_node_status(unp, td, &unsp); if (unsp->uns_lower_opencnt > 0) { /* try reopen the vnode */ error = VOP_OPEN(uvp, unsp->uns_lower_openmode, td->td_ucred, td, NULL); if (error) goto unionfs_advlock_abort; unsp->uns_upper_opencnt++; VOP_CLOSE(unp->un_lowervp, unsp->uns_lower_openmode, td->td_ucred, td); unsp->uns_lower_opencnt--; } else unionfs_tryrem_node_status(unp, unsp); } VOP_UNLOCK(vp); error = VOP_ADVLOCK(uvp, ap->a_id, ap->a_op, ap->a_fl, ap->a_flags); UNIONFS_INTERNAL_DEBUG("unionfs_advlock: leave (%d)\n", error); return error; unionfs_advlock_abort: VOP_UNLOCK(vp); UNIONFS_INTERNAL_DEBUG("unionfs_advlock: leave (%d)\n", error); return error; } static int unionfs_strategy(struct vop_strategy_args *ap) { struct unionfs_node *unp; struct vnode *vp; KASSERT_UNIONFS_VNODE(ap->a_vp); unp = VTOUNIONFS(ap->a_vp); vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp); #ifdef DIAGNOSTIC if (vp == NULLVP) panic("unionfs_strategy: nullvp"); if (ap->a_bp->b_iocmd == BIO_WRITE && vp == unp->un_lowervp) panic("unionfs_strategy: writing to lowervp"); #endif return (VOP_STRATEGY(vp, ap->a_bp)); } static int unionfs_getacl(struct vop_getacl_args *ap) { struct unionfs_node *unp; struct vnode *vp; int error; KASSERT_UNIONFS_VNODE(ap->a_vp); unp = VTOUNIONFS(ap->a_vp); vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp); UNIONFS_INTERNAL_DEBUG("unionfs_getacl: enter\n"); error = VOP_GETACL(vp, ap->a_type, ap->a_aclp, ap->a_cred, ap->a_td); UNIONFS_INTERNAL_DEBUG("unionfs_getacl: leave (%d)\n", error); return (error); } static int unionfs_setacl(struct vop_setacl_args *ap) { struct unionfs_node *unp; struct vnode *uvp; struct vnode *lvp; struct thread *td; int error; UNIONFS_INTERNAL_DEBUG("unionfs_setacl: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_vp); error = EROFS; unp = VTOUNIONFS(ap->a_vp); uvp = unp->un_uppervp; lvp = unp->un_lowervp; td = ap->a_td; if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY) return (EROFS); if (uvp == NULLVP && lvp->v_type == VREG) { if ((error = unionfs_copyfile(unp, 1, ap->a_cred, td)) != 0) return (error); uvp = unp->un_uppervp; } if (uvp != NULLVP) error = VOP_SETACL(uvp, ap->a_type, ap->a_aclp, ap->a_cred, td); UNIONFS_INTERNAL_DEBUG("unionfs_setacl: leave (%d)\n", error); return (error); } static int unionfs_aclcheck(struct vop_aclcheck_args *ap) { struct unionfs_node *unp; struct vnode *vp; int error; UNIONFS_INTERNAL_DEBUG("unionfs_aclcheck: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_vp); unp = VTOUNIONFS(ap->a_vp); vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp); error = VOP_ACLCHECK(vp, ap->a_type, ap->a_aclp, ap->a_cred, ap->a_td); UNIONFS_INTERNAL_DEBUG("unionfs_aclcheck: leave (%d)\n", error); return (error); } static int unionfs_openextattr(struct vop_openextattr_args *ap) { struct unionfs_node *unp; struct vnode *vp; struct vnode *tvp; int error; KASSERT_UNIONFS_VNODE(ap->a_vp); vp = ap->a_vp; unp = VTOUNIONFS(vp); tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp); if ((tvp == unp->un_uppervp && (unp->un_flag & UNIONFS_OPENEXTU)) || (tvp == unp->un_lowervp && (unp->un_flag & UNIONFS_OPENEXTL))) return (EBUSY); error = VOP_OPENEXTATTR(tvp, ap->a_cred, ap->a_td); if (error == 0) { if (vn_lock(vp, LK_UPGRADE) != 0) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); if (!VN_IS_DOOMED(vp)) { if (tvp == unp->un_uppervp) unp->un_flag |= UNIONFS_OPENEXTU; else unp->un_flag |= UNIONFS_OPENEXTL; } vn_lock(vp, LK_DOWNGRADE | LK_RETRY); } return (error); } static int unionfs_closeextattr(struct vop_closeextattr_args *ap) { struct unionfs_node *unp; struct vnode *vp; struct vnode *tvp; int error; KASSERT_UNIONFS_VNODE(ap->a_vp); vp = ap->a_vp; unp = VTOUNIONFS(vp); tvp = NULLVP; if (unp->un_flag & UNIONFS_OPENEXTU) tvp = unp->un_uppervp; else if (unp->un_flag & UNIONFS_OPENEXTL) tvp = unp->un_lowervp; if (tvp == NULLVP) return (EOPNOTSUPP); error = VOP_CLOSEEXTATTR(tvp, ap->a_commit, ap->a_cred, ap->a_td); if (error == 0) { if (vn_lock(vp, LK_UPGRADE) != 0) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); if (!VN_IS_DOOMED(vp)) { if (tvp == unp->un_uppervp) unp->un_flag &= ~UNIONFS_OPENEXTU; else unp->un_flag &= ~UNIONFS_OPENEXTL; } vn_lock(vp, LK_DOWNGRADE | LK_RETRY); } return (error); } static int unionfs_getextattr(struct vop_getextattr_args *ap) { struct unionfs_node *unp; struct vnode *vp; KASSERT_UNIONFS_VNODE(ap->a_vp); unp = VTOUNIONFS(ap->a_vp); vp = NULLVP; if (unp->un_flag & UNIONFS_OPENEXTU) vp = unp->un_uppervp; else if (unp->un_flag & UNIONFS_OPENEXTL) vp = unp->un_lowervp; if (vp == NULLVP) return (EOPNOTSUPP); return (VOP_GETEXTATTR(vp, ap->a_attrnamespace, ap->a_name, ap->a_uio, ap->a_size, ap->a_cred, ap->a_td)); } static int unionfs_setextattr(struct vop_setextattr_args *ap) { struct unionfs_node *unp; struct vnode *uvp; struct vnode *lvp; struct vnode *ovp; struct ucred *cred; struct thread *td; int error; KASSERT_UNIONFS_VNODE(ap->a_vp); error = EROFS; unp = VTOUNIONFS(ap->a_vp); uvp = unp->un_uppervp; lvp = unp->un_lowervp; ovp = NULLVP; cred = ap->a_cred; td = ap->a_td; UNIONFS_INTERNAL_DEBUG("unionfs_setextattr: enter (un_flag=%x)\n", unp->un_flag); if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY) return (EROFS); if (unp->un_flag & UNIONFS_OPENEXTU) ovp = unp->un_uppervp; else if (unp->un_flag & UNIONFS_OPENEXTL) ovp = unp->un_lowervp; if (ovp == NULLVP) return (EOPNOTSUPP); if (ovp == lvp && lvp->v_type == VREG) { VOP_CLOSEEXTATTR(lvp, 0, cred, td); if (uvp == NULLVP && (error = unionfs_copyfile(unp, 1, cred, td)) != 0) { unionfs_setextattr_reopen: if ((unp->un_flag & UNIONFS_OPENEXTL) && VOP_OPENEXTATTR(lvp, cred, td)) { #ifdef DIAGNOSTIC panic("unionfs: VOP_OPENEXTATTR failed"); #endif unp->un_flag &= ~UNIONFS_OPENEXTL; } goto unionfs_setextattr_abort; } uvp = unp->un_uppervp; if ((error = VOP_OPENEXTATTR(uvp, cred, td)) != 0) goto unionfs_setextattr_reopen; unp->un_flag &= ~UNIONFS_OPENEXTL; unp->un_flag |= UNIONFS_OPENEXTU; ovp = uvp; } if (ovp == uvp) error = VOP_SETEXTATTR(ovp, ap->a_attrnamespace, ap->a_name, ap->a_uio, cred, td); unionfs_setextattr_abort: UNIONFS_INTERNAL_DEBUG("unionfs_setextattr: leave (%d)\n", error); return (error); } static int unionfs_listextattr(struct vop_listextattr_args *ap) { struct unionfs_node *unp; struct vnode *vp; KASSERT_UNIONFS_VNODE(ap->a_vp); unp = VTOUNIONFS(ap->a_vp); vp = NULLVP; if (unp->un_flag & UNIONFS_OPENEXTU) vp = unp->un_uppervp; else if (unp->un_flag & UNIONFS_OPENEXTL) vp = unp->un_lowervp; if (vp == NULLVP) return (EOPNOTSUPP); return (VOP_LISTEXTATTR(vp, ap->a_attrnamespace, ap->a_uio, ap->a_size, ap->a_cred, ap->a_td)); } static int unionfs_deleteextattr(struct vop_deleteextattr_args *ap) { struct unionfs_node *unp; struct vnode *uvp; struct vnode *lvp; struct vnode *ovp; struct ucred *cred; struct thread *td; int error; KASSERT_UNIONFS_VNODE(ap->a_vp); error = EROFS; unp = VTOUNIONFS(ap->a_vp); uvp = unp->un_uppervp; lvp = unp->un_lowervp; ovp = NULLVP; cred = ap->a_cred; td = ap->a_td; UNIONFS_INTERNAL_DEBUG("unionfs_deleteextattr: enter (un_flag=%x)\n", unp->un_flag); if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY) return (EROFS); if (unp->un_flag & UNIONFS_OPENEXTU) ovp = unp->un_uppervp; else if (unp->un_flag & UNIONFS_OPENEXTL) ovp = unp->un_lowervp; if (ovp == NULLVP) return (EOPNOTSUPP); if (ovp == lvp && lvp->v_type == VREG) { VOP_CLOSEEXTATTR(lvp, 0, cred, td); if (uvp == NULLVP && (error = unionfs_copyfile(unp, 1, cred, td)) != 0) { unionfs_deleteextattr_reopen: if ((unp->un_flag & UNIONFS_OPENEXTL) && VOP_OPENEXTATTR(lvp, cred, td)) { #ifdef DIAGNOSTIC panic("unionfs: VOP_OPENEXTATTR failed"); #endif unp->un_flag &= ~UNIONFS_OPENEXTL; } goto unionfs_deleteextattr_abort; } uvp = unp->un_uppervp; if ((error = VOP_OPENEXTATTR(uvp, cred, td)) != 0) goto unionfs_deleteextattr_reopen; unp->un_flag &= ~UNIONFS_OPENEXTL; unp->un_flag |= UNIONFS_OPENEXTU; ovp = uvp; } if (ovp == uvp) error = VOP_DELETEEXTATTR(ovp, ap->a_attrnamespace, ap->a_name, ap->a_cred, ap->a_td); unionfs_deleteextattr_abort: UNIONFS_INTERNAL_DEBUG("unionfs_deleteextattr: leave (%d)\n", error); return (error); } static int unionfs_setlabel(struct vop_setlabel_args *ap) { struct unionfs_node *unp; struct vnode *uvp; struct vnode *lvp; struct thread *td; int error; UNIONFS_INTERNAL_DEBUG("unionfs_setlabel: enter\n"); KASSERT_UNIONFS_VNODE(ap->a_vp); error = EROFS; unp = VTOUNIONFS(ap->a_vp); uvp = unp->un_uppervp; lvp = unp->un_lowervp; td = ap->a_td; if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY) return (EROFS); if (uvp == NULLVP && lvp->v_type == VREG) { if ((error = unionfs_copyfile(unp, 1, ap->a_cred, td)) != 0) return (error); uvp = unp->un_uppervp; } if (uvp != NULLVP) error = VOP_SETLABEL(uvp, ap->a_label, ap->a_cred, td); UNIONFS_INTERNAL_DEBUG("unionfs_setlabel: leave (%d)\n", error); return (error); } static int unionfs_vptofh(struct vop_vptofh_args *ap) { return (EOPNOTSUPP); } static int unionfs_add_writecount(struct vop_add_writecount_args *ap) { struct vnode *tvp, *vp; struct unionfs_node *unp; int error, writerefs; vp = ap->a_vp; unp = VTOUNIONFS(vp); tvp = unp->un_uppervp; KASSERT(tvp != NULL, ("%s: adding write ref without upper vnode", __func__)); error = VOP_ADD_WRITECOUNT(tvp, ap->a_inc); if (error != 0) return (error); /* * We need to track the write refs we've passed to the underlying * vnodes so that we can undo them in case we are forcibly unmounted. */ writerefs = atomic_fetchadd_int(&vp->v_writecount, ap->a_inc); /* text refs are bypassed to lowervp */ VNASSERT(writerefs >= 0, vp, ("%s: invalid write count %d", __func__, writerefs)); VNASSERT(writerefs + ap->a_inc >= 0, vp, ("%s: invalid write count inc %d + %d", __func__, writerefs, ap->a_inc)); return (0); } static int unionfs_vput_pair(struct vop_vput_pair_args *ap) { struct mount *mp; struct vnode *dvp, *vp, **vpp, *lvp, *ldvp, *uvp, *udvp, *tempvp; struct unionfs_node *dunp, *unp; int error, res; dvp = ap->a_dvp; vpp = ap->a_vpp; vp = NULLVP; lvp = NULLVP; uvp = NULLVP; unp = NULL; dunp = VTOUNIONFS(dvp); udvp = dunp->un_uppervp; ldvp = dunp->un_lowervp; /* * Underlying vnodes should be locked because the encompassing unionfs * node is locked, but will not be referenced, as the reference will * only be on the unionfs node. Reference them now so that the vput()s * performed by VOP_VPUT_PAIR() will have a reference to drop. */ if (udvp != NULLVP) vref(udvp); if (ldvp != NULLVP) vref(ldvp); if (vpp != NULL) vp = *vpp; if (vp != NULLVP) { unp = VTOUNIONFS(vp); uvp = unp->un_uppervp; lvp = unp->un_lowervp; if (uvp != NULLVP) vref(uvp); if (lvp != NULLVP) vref(lvp); /* * If we're being asked to return a locked child vnode, then * we may need to create a replacement vnode in case the * original is reclaimed while the lock is dropped. In that * case we'll need to ensure the mount and the underlying * vnodes aren't also recycled during that window. */ if (!ap->a_unlock_vp) { vhold(vp); if (uvp != NULLVP) vhold(uvp); if (lvp != NULLVP) vhold(lvp); mp = vp->v_mount; vfs_ref(mp); } } /* * TODO: Because unionfs_lock() locks both the lower and upper vnodes * (if available), we must also call VOP_VPUT_PAIR() on both the lower * and upper parent/child pairs. If unionfs_lock() is reworked to lock * only a single vnode, this code will need to change to also only * operate on one vnode pair. */ ASSERT_VOP_LOCKED(ldvp, __func__); ASSERT_VOP_LOCKED(udvp, __func__); ASSERT_VOP_LOCKED(lvp, __func__); ASSERT_VOP_LOCKED(uvp, __func__); KASSERT(lvp == NULLVP || ldvp != NULLVP, ("%s: NULL ldvp with non-NULL lvp", __func__)); if (ldvp != NULLVP) res = VOP_VPUT_PAIR(ldvp, lvp != NULLVP ? &lvp : NULL, true); KASSERT(uvp == NULLVP || udvp != NULLVP, ("%s: NULL udvp with non-NULL uvp", __func__)); if (udvp != NULLVP) res = VOP_VPUT_PAIR(udvp, uvp != NULLVP ? &uvp : NULL, true); ASSERT_VOP_UNLOCKED(ldvp, __func__); ASSERT_VOP_UNLOCKED(udvp, __func__); ASSERT_VOP_UNLOCKED(lvp, __func__); ASSERT_VOP_UNLOCKED(uvp, __func__); /* * VOP_VPUT_PAIR() dropped the references we added to the underlying * vnodes, now drop the caller's reference to the unionfs vnodes. */ if (vp != NULLVP && ap->a_unlock_vp) vrele(vp); vrele(dvp); if (vp == NULLVP || ap->a_unlock_vp) return (res); /* * We're being asked to return a locked vnode. At this point, the * underlying vnodes have been unlocked, so vp may have been reclaimed. */ vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); if (vp->v_data == NULL && vfs_busy(mp, MBF_NOWAIT) == 0) { vput(vp); error = unionfs_nodeget(mp, uvp, lvp, dvp, &tempvp, NULL); if (error == 0) { vn_lock(tempvp, LK_EXCLUSIVE | LK_RETRY); *vpp = tempvp; } else vget(vp, LK_EXCLUSIVE | LK_RETRY); vfs_unbusy(mp); } if (lvp != NULLVP) vdrop(lvp); if (uvp != NULLVP) vdrop(uvp); vdrop(vp); vfs_rel(mp); return (res); } static int unionfs_set_text(struct vop_set_text_args *ap) { struct vnode *tvp; struct unionfs_node *unp; int error; /* * We assume text refs are managed against lvp/uvp through the * executable mapping backed by its VM object. We therefore don't * need to track leased text refs in the case of a forcible unmount. */ unp = VTOUNIONFS(ap->a_vp); ASSERT_VOP_LOCKED(ap->a_vp, __func__); tvp = unp->un_uppervp != NULL ? unp->un_uppervp : unp->un_lowervp; error = VOP_SET_TEXT(tvp); return (error); } static int unionfs_unset_text(struct vop_unset_text_args *ap) { struct vnode *tvp; struct unionfs_node *unp; ASSERT_VOP_LOCKED(ap->a_vp, __func__); unp = VTOUNIONFS(ap->a_vp); tvp = unp->un_uppervp != NULL ? unp->un_uppervp : unp->un_lowervp; VOP_UNSET_TEXT_CHECKED(tvp); return (0); } struct vop_vector unionfs_vnodeops = { .vop_default = &default_vnodeops, .vop_access = unionfs_access, .vop_aclcheck = unionfs_aclcheck, .vop_advlock = unionfs_advlock, .vop_bmap = VOP_EOPNOTSUPP, .vop_cachedlookup = unionfs_lookup, .vop_close = unionfs_close, .vop_closeextattr = unionfs_closeextattr, .vop_create = unionfs_create, .vop_deleteextattr = unionfs_deleteextattr, .vop_fsync = unionfs_fsync, .vop_getacl = unionfs_getacl, .vop_getattr = unionfs_getattr, .vop_getextattr = unionfs_getextattr, .vop_getwritemount = unionfs_getwritemount, .vop_inactive = unionfs_inactive, .vop_need_inactive = vop_stdneed_inactive, .vop_islocked = unionfs_islocked, .vop_ioctl = unionfs_ioctl, .vop_link = unionfs_link, .vop_listextattr = unionfs_listextattr, .vop_lock1 = unionfs_lock, .vop_lookup = vfs_cache_lookup, .vop_mkdir = unionfs_mkdir, .vop_mknod = unionfs_mknod, .vop_open = unionfs_open, .vop_openextattr = unionfs_openextattr, .vop_pathconf = unionfs_pathconf, .vop_poll = unionfs_poll, .vop_print = unionfs_print, .vop_read = unionfs_read, .vop_readdir = unionfs_readdir, .vop_readlink = unionfs_readlink, .vop_reclaim = unionfs_reclaim, .vop_remove = unionfs_remove, .vop_rename = unionfs_rename, .vop_rmdir = unionfs_rmdir, .vop_setacl = unionfs_setacl, .vop_setattr = unionfs_setattr, .vop_setextattr = unionfs_setextattr, .vop_setlabel = unionfs_setlabel, .vop_strategy = unionfs_strategy, .vop_symlink = unionfs_symlink, .vop_unlock = unionfs_unlock, .vop_whiteout = unionfs_whiteout, .vop_write = unionfs_write, .vop_vptofh = unionfs_vptofh, .vop_add_writecount = unionfs_add_writecount, .vop_vput_pair = unionfs_vput_pair, .vop_set_text = unionfs_set_text, .vop_unset_text = unionfs_unset_text, }; VFS_VOP_VECTOR_REGISTER(unionfs_vnodeops);