/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved. */ /* * Copyright (c) 2013, Joyent, Inc. All rights reserved. */ /* * vnode ops for the /dev filesystem * * - VDIR, VCHR, CBLK, and VLNK are considered must supported files * - VREG and VDOOR are used for some internal implementations in * the global zone, e.g. devname and devfsadm communication * - other file types are unusual in this namespace and * not supported for now */ /* * sdev has a few basic goals: * o Provide /dev for the global zone as well as various non-global zones. * o Provide the basic functionality that devfsadm might need (mknod, * symlinks, etc.) * o Allow persistent permissions on files in /dev. * o Allow for dynamic directories and nodes for use by various services (pts, * zvol, net, etc.) * * The sdev file system is primarily made up of sdev_node_t's which is sdev's * counterpart to the vnode_t. There are two different classes of sdev_node_t's * that we generally care about, dynamic and otherwise. * * Persisting Information * ---------------------- * * When sdev is mounted, it keeps track of the underlying file system it is * mounted over. In certain situations, sdev will go and create entries in that * underlying file system. These underlying 'back end' nodes are used as proxies * for various changes in permissions. While specific sets of nodes, such as * dynamic ones, are exempt, this process stores permission changes against * these back end nodes. The point of all of this is to allow for these settings * to persist across host and zone reboots. As an example, consider the entry * /dev/dsk/c0t0d0 which is a character device and that / is in UFS. Upon * changing the permissions on c0t0d0 you'd have the following logical * relationships: * * +------------------+ sdev_vnode +--------------+ * | sdev_node_t |<---------------->| vnode_t | * | /dev/dsk/c0t0d0 |<---------------->| for sdev | * +------------------+ +--------------+ * | * | sdev_attrvp * | * | +---------------------+ * +--->| vnode_t for UFS|ZFS | * | /dev/dsk/c0t0d0 | * +---------------------+ * * sdev is generally in memory. Therefore when a lookup happens and there is no * entry already inside of a directory cache, it will next check the backing * store. If the backing store exists, we will reconstitute the sdev_node based * on the information that we persisted. When we create the backing store node, * we use the struct vattr information that we already have in sdev_node_t. * Because of this, we already know if the entry was previously a symlink, * directory, or some other kind of type. Note that not all types of nodes are * supported. Currently only VDIR, VCHR, VBLK, VREG, VDOOR, and VLNK are * eligible to be persisted. * * When the sdev_node is created and the lookup is done, we grab a hold on the * underlying vnode as part of the call to VOP_LOOKUP. That reference is held * until the sdev_node becomes inactive. Once its reference count reaches one * and the VOP_INACTIVE callback fires leading to the destruction of the node, * the reference on the underlying vnode will be released. * * The backing store node will be deleted only when the node itself is deleted * through the means of a VOP_REMOVE, VOP_RMDIR, or similar call. * * Not everything can be persisted, see The Rules section for more details. * * Dynamic Nodes * ------------- * * Dynamic nodes allow for specific interactions with various kernel subsystems * when looking up directory entries. This allows the lookup and readdir * functions to check against the kernel subsystem's for validity. eg. does a * zvol or nic still exist. * * More specifically, when we create various directories we check if the * directory name matches that of one of the names in the vtab[] (sdev_subr.c). * If it does, we swap out the vnode operations into a new set which combine the * normal sdev vnode operations with the dynamic set here. * * In addition, various dynamic nodes implement a verification entry point. This * verification entry is used as a part of lookup and readdir. The goal for * these dynamic nodes is to allow them to check with the underlying subsystems * to ensure that these devices are still present, or if they have gone away, to * remove them from the results. This is indicated by using the SDEV_VTOR flag * in vtab[]. * * Dynamic nodes have additional restrictions placed upon them. They may only * appear at the top level directory of the file system. In addition, users * cannot create dirents below any leve of a dynamic node aside from its special * vnops. * * Profiles * -------- * * Profiles exist for the purpose of non-global zones. They work with the zone * brands and zoneadmd to set up a filter of allowed devices that can appear in * a non-global zone's /dev. These are sent to sdev by means of libdevinfo and a * modctl system call. Specifically it allows one to add patterns of device * paths to include and exclude. It allows for a collection of symlinks to be * added and it allows for remapping names. * * When operating in a non-global zone, several of the sdev vnops are redirected * to the profile versions. These impose additional restrictions such as * enforcing that a non-global zone's /dev is read only. * * sdev_node_t States * ------------------ * * A given sdev_node_t has a field called the sdev_state which describes where * in the sdev life cycle it is. There are three primary states: SDEV_INIT, * SDEV_READY, and SDEV_ZOMBIE. * * SDEV_INIT: When a new /dev file is first looked up, a sdev_node * is allocated, initialized and added to the directory's * sdev_node cache. A node at this state will also * have the SDEV_LOOKUP flag set. * * Other threads that are trying to look up a node at * this state will be blocked until the SDEV_LOOKUP flag * is cleared. * * When the SDEV_LOOKUP flag is cleared, the node may * transition into the SDEV_READY state for a successful * lookup or the node is removed from the directory cache * and destroyed if the named node can not be found. * An ENOENT error is returned for the second case. * * SDEV_READY: A /dev file has been successfully looked up and * associated with a vnode. The /dev file is available * for the supported /dev file system operations. * * SDEV_ZOMBIE: Deletion of a /dev file has been explicitly issued * to an SDEV_READY node. The node is transitioned into * the SDEV_ZOMBIE state if the vnode reference count * is still held. A SDEV_ZOMBIE node does not support * any of the /dev file system operations. A SDEV_ZOMBIE * node is immediately removed from the directory cache * and destroyed once the reference count reaches zero. * * Historically nodes that were marked SDEV_ZOMBIE were not removed from the * underlying directory caches. This has been the source of numerous bugs and * thus to better mimic what happens on a real file system, it is no longer the * case. * * The following state machine describes the life cycle of a given node and its * associated states: * * node is . . . . . * allocated via . +-------------+ . . . . . . . vnode_t refcount * sdev_nodeinit() . | Unallocated | . reaches zero and * +--------*-----| Memory |<--------*---+ sdev_inactive is * | +-------------+ | called. * | +------------^ | called. * v | | * +-----------+ * . . sdev_nodeready() +-------------+ * | SDEV_INIT | | or related setup | SDEV_ZOMBIE | * +-----------+ | failure +-------------+ * | | ^ * | | +------------+ | * +-*----------->| SDEV_READY |--------*-----+ * . +------------+ . The node is no longer * . . node successfully . . . . . valid or we've been * inserted into the asked to remove it. * directory cache This happens via * and sdev_nodready() sdev_dirdelete(). * call successful. * * Adding and Removing Dirents, Zombie Nodes * ----------------------------------------- * * As part of doing a lookup, readdir, or an explicit creation operation like * mkdir or create, nodes may be created. Every directory has an avl tree which * contains its children, the sdev_entries tree. This is only used if the type * is VDIR. Access to this is controlled by the sdev_node_t's contents_lock and * it is managed through sdev_cache_update(). * * Every sdev_node_t has a field sdev_state, which describes the current state * of the node. A node is generally speaking in the SDEV_READY state. When it is * there, it can be looked up, accessed, and operations performed on it. When a * node is going to be removed from the directory cache it is marked as a * zombie. Once a node becomes a zombie, no other file system operations will * succeed and it will continue to exist as a node until the vnode count on the * node reaches zero. At that point, the node will be freed. However, once a * node has been marked as a zombie, it will be removed immediately from the * directory cache such that no one else may find it again. This means that * someone else can insert a new entry into that directory with the same name * and without a problem. * * To remove a node, see the section on that in The Rules. * * The Rules * --------- * These are the rules to live by when working in sdev. These are not * exhaustive. * * - Set 1: Working with Backing Nodes * o If there is a SDEV_READY sdev_node_t, it knows about its backing node. * o If we find a backing node when looking up an sdev_node_t for the first * time, we use its attributes to build our sdev_node_t. * o If there is a found backing node, or we create a backing node, that's * when we grab the hold on its vnode. * o If we mark an sdev_node_t a ZOMBIE, we must remove its backing node from * the underlying file system. It must not be searchable or findable. * o We release our hold on the backing node vnode when we destroy the * sdev_node_t. * * - Set 2: Locking rules for sdev (not exhaustive) * o The majority of nodes contain an sdev_contents rw lock. You must hold it * for read or write if manipulating its contents appropriately. * o You must lock your parent before yourself. * o If you need your vnode's v_lock and the sdev_contents rw lock, you must * grab the v_lock before the sdev_contents rw_lock. * o If you release a lock on the node as a part of upgrading it, you must * verify that the node has not become a zombie as a part of this process. * * - Set 3: Zombie Status and What it Means * o If you encounter a node that is a ZOMBIE, that means that it has been * unlinked from the backing store. * o If you release your contents lock and acquire it again (say as part of * trying to grab a write lock) you must check that the node has not become * a zombie. * o You should VERIFY that a looked up node is not a zombie. This follows * from the following logic. To mark something as a zombie means that it is * removed from the parents directory cache. To do that, you must have a * write lock on the parent's sdev_contents. To lookup through that * directory you must have a read lock. This then becomes a simple ordering * problem. If you've been granted the lock then the other operation cannot * be in progress or must have already succeeded. * * - Set 4: Removing Directory Entries (aka making nodes Zombies) * o Write lock must be held on the directory * o Write lock must be held on the node * o Remove the sdev_node_t from its parent cache * o Remove the corresponding backing store node, if it exists, eg. use * VOP_REMOVE or VOP_RMDIR. * o You must NOT make any change in the vnode reference count! Nodes should * only be cleaned up through VOP_INACTIVE callbacks. * o VOP_INACTIVE is the only one responsible for doing the final vn_rele of * the backing store vnode that was grabbed during lookup. * * - Set 5: What Nodes may be Persisted * o The root, /dev is always persisted * o Any node in vtab which is marked SDEV_DYNAMIC, may not be persisted * unless it is also marked SDEV_PERSIST * o Anything whose parent directory is marked SDEV_PERSIST will pass that * along to the child as long as it does not contradict the above rules */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /*ARGSUSED*/ static int sdev_open(struct vnode **vpp, int flag, struct cred *cred, caller_context_t *ct) { struct sdev_node *dv = VTOSDEV(*vpp); struct sdev_node *ddv = dv->sdev_dotdot; int error = 0; if ((*vpp)->v_type == VDIR) return (0); if (!SDEV_IS_GLOBAL(dv)) return (ENOTSUP); if ((*vpp)->v_type == VLNK) return (ENOENT); ASSERT((*vpp)->v_type == VREG); if ((*vpp)->v_type != VREG) return (ENOTSUP); ASSERT(ddv); rw_enter(&ddv->sdev_contents, RW_READER); if (dv->sdev_attrvp == NULL) { rw_exit(&ddv->sdev_contents); return (ENOENT); } error = VOP_OPEN(&(dv->sdev_attrvp), flag, cred, ct); rw_exit(&ddv->sdev_contents); return (error); } /*ARGSUSED1*/ static int sdev_close(struct vnode *vp, int flag, int count, offset_t offset, struct cred *cred, caller_context_t *ct) { struct sdev_node *dv = VTOSDEV(vp); if (vp->v_type == VDIR) { cleanlocks(vp, ttoproc(curthread)->p_pid, 0); cleanshares(vp, ttoproc(curthread)->p_pid); return (0); } if (!SDEV_IS_GLOBAL(dv)) return (ENOTSUP); ASSERT(vp->v_type == VREG); if (vp->v_type != VREG) return (ENOTSUP); ASSERT(dv->sdev_attrvp); return (VOP_CLOSE(dv->sdev_attrvp, flag, count, offset, cred, ct)); } /*ARGSUSED*/ static int sdev_read(struct vnode *vp, struct uio *uio, int ioflag, struct cred *cred, struct caller_context *ct) { struct sdev_node *dv = (struct sdev_node *)VTOSDEV(vp); int error; if (!SDEV_IS_GLOBAL(dv)) return (EINVAL); if (vp->v_type == VDIR) return (EISDIR); /* only supporting regular files in /dev */ ASSERT(vp->v_type == VREG); if (vp->v_type != VREG) return (EINVAL); ASSERT(RW_READ_HELD(&VTOSDEV(vp)->sdev_contents)); ASSERT(dv->sdev_attrvp); (void) VOP_RWLOCK(dv->sdev_attrvp, 0, ct); error = VOP_READ(dv->sdev_attrvp, uio, ioflag, cred, ct); VOP_RWUNLOCK(dv->sdev_attrvp, 0, ct); return (error); } /*ARGSUSED*/ static int sdev_write(struct vnode *vp, struct uio *uio, int ioflag, struct cred *cred, struct caller_context *ct) { struct sdev_node *dv = VTOSDEV(vp); int error = 0; if (!SDEV_IS_GLOBAL(dv)) return (EINVAL); if (vp->v_type == VDIR) return (EISDIR); /* only supporting regular files in /dev */ ASSERT(vp->v_type == VREG); if (vp->v_type != VREG) return (EINVAL); ASSERT(dv->sdev_attrvp); (void) VOP_RWLOCK(dv->sdev_attrvp, 1, ct); error = VOP_WRITE(dv->sdev_attrvp, uio, ioflag, cred, ct); VOP_RWUNLOCK(dv->sdev_attrvp, 1, ct); if (error == 0) { sdev_update_timestamps(dv->sdev_attrvp, kcred, AT_MTIME); } return (error); } /*ARGSUSED*/ static int sdev_ioctl(struct vnode *vp, int cmd, intptr_t arg, int flag, struct cred *cred, int *rvalp, caller_context_t *ct) { struct sdev_node *dv = VTOSDEV(vp); if (!SDEV_IS_GLOBAL(dv) || (vp->v_type == VDIR)) return (ENOTTY); ASSERT(vp->v_type == VREG); if (vp->v_type != VREG) return (EINVAL); ASSERT(dv->sdev_attrvp); return (VOP_IOCTL(dv->sdev_attrvp, cmd, arg, flag, cred, rvalp, ct)); } static int sdev_getattr(struct vnode *vp, struct vattr *vap, int flags, struct cred *cr, caller_context_t *ct) { int error = 0; struct sdev_node *dv = VTOSDEV(vp); struct sdev_node *parent = dv->sdev_dotdot; ASSERT(parent); rw_enter(&parent->sdev_contents, RW_READER); ASSERT(dv->sdev_attr || dv->sdev_attrvp); /* * search order: * - for persistent nodes (SDEV_PERSIST): backstore * - for non-persistent nodes: module ops if global, then memory */ if (dv->sdev_attrvp) { rw_exit(&parent->sdev_contents); error = VOP_GETATTR(dv->sdev_attrvp, vap, flags, cr, ct); sdev_vattr_merge(dv, vap); } else { ASSERT(dv->sdev_attr); *vap = *dv->sdev_attr; sdev_vattr_merge(dv, vap); rw_exit(&parent->sdev_contents); } return (error); } /*ARGSUSED4*/ static int sdev_setattr(struct vnode *vp, struct vattr *vap, int flags, struct cred *cred, caller_context_t *ctp) { return (devname_setattr_func(vp, vap, flags, cred, NULL, 0)); } static int sdev_getsecattr(struct vnode *vp, struct vsecattr *vsap, int flags, struct cred *cr, caller_context_t *ct) { int error; struct sdev_node *dv = VTOSDEV(vp); struct vnode *avp = dv->sdev_attrvp; if (avp == NULL) { /* return fs_fab_acl() if flavor matches, else do nothing */ if ((SDEV_ACL_FLAVOR(vp) == _ACL_ACLENT_ENABLED && (vsap->vsa_mask & (VSA_ACLCNT | VSA_DFACLCNT))) || (SDEV_ACL_FLAVOR(vp) == _ACL_ACE_ENABLED && (vsap->vsa_mask & (VSA_ACECNT | VSA_ACE)))) return (fs_fab_acl(vp, vsap, flags, cr, ct)); return (ENOSYS); } (void) VOP_RWLOCK(avp, 1, ct); error = VOP_GETSECATTR(avp, vsap, flags, cr, ct); VOP_RWUNLOCK(avp, 1, ct); return (error); } static int sdev_setsecattr(struct vnode *vp, struct vsecattr *vsap, int flags, struct cred *cr, caller_context_t *ct) { int error; struct sdev_node *dv = VTOSDEV(vp); struct vnode *avp = dv->sdev_attrvp; if (dv->sdev_state == SDEV_ZOMBIE) return (0); if (avp == NULL) { if (SDEV_IS_GLOBAL(dv) && !SDEV_IS_PERSIST(dv)) return (fs_nosys()); ASSERT(dv->sdev_attr); /* * if coming in directly, the acl system call will * have held the read-write lock via VOP_RWLOCK() * If coming in via specfs, specfs will have * held the rw lock on the realvp i.e. us. */ ASSERT(RW_WRITE_HELD(&dv->sdev_contents)); sdev_vattr_merge(dv, dv->sdev_attr); error = sdev_shadow_node(dv, cr); if (error) { return (fs_nosys()); } ASSERT(dv->sdev_attrvp); /* clean out the memory copy if any */ if (dv->sdev_attr) { kmem_free(dv->sdev_attr, sizeof (struct vattr)); dv->sdev_attr = NULL; } avp = dv->sdev_attrvp; } ASSERT(avp); (void) VOP_RWLOCK(avp, V_WRITELOCK_TRUE, ct); error = VOP_SETSECATTR(avp, vsap, flags, cr, ct); VOP_RWUNLOCK(avp, V_WRITELOCK_TRUE, ct); return (error); } int sdev_unlocked_access(void *vdv, int mode, struct cred *cr) { struct sdev_node *dv = vdv; int shift = 0; uid_t owner = dv->sdev_attr->va_uid; if (crgetuid(cr) != owner) { shift += 3; if (groupmember(dv->sdev_attr->va_gid, cr) == 0) shift += 3; } return (secpolicy_vnode_access2(cr, SDEVTOV(dv), owner, dv->sdev_attr->va_mode << shift, mode)); } static int sdev_access(struct vnode *vp, int mode, int flags, struct cred *cr, caller_context_t *ct) { struct sdev_node *dv = VTOSDEV(vp); int ret = 0; rw_enter(&dv->sdev_contents, RW_READER); ASSERT(dv->sdev_attr || dv->sdev_attrvp); if (dv->sdev_attrvp) { ret = VOP_ACCESS(dv->sdev_attrvp, mode, flags, cr, ct); } else if (dv->sdev_attr) { ret = sdev_unlocked_access(dv, mode, cr); if (ret) ret = EACCES; } rw_exit(&dv->sdev_contents); return (ret); } /* * Lookup */ /*ARGSUSED3*/ static int sdev_lookup(struct vnode *dvp, char *nm, struct vnode **vpp, struct pathname *pnp, int flags, struct vnode *rdir, struct cred *cred, caller_context_t *ct, int *direntflags, pathname_t *realpnp) { struct sdev_node *parent; int error; parent = VTOSDEV(dvp); ASSERT(parent); /* execute access is required to search the directory */ if ((error = VOP_ACCESS(dvp, VEXEC, 0, cred, ct)) != 0) return (error); if (!SDEV_IS_GLOBAL(parent)) return (prof_lookup(dvp, nm, vpp, cred)); return (devname_lookup_func(parent, nm, vpp, cred, NULL, 0)); } /*ARGSUSED2*/ static int sdev_create(struct vnode *dvp, char *nm, struct vattr *vap, vcexcl_t excl, int mode, struct vnode **vpp, struct cred *cred, int flag, caller_context_t *ct, vsecattr_t *vsecp) { struct vnode *vp = NULL; struct vnode *avp; struct sdev_node *parent; struct sdev_node *self = NULL; int error = 0; vtype_t type = vap->va_type; ASSERT(type != VNON && type != VBAD); if ((type == VFIFO) || (type == VSOCK) || (type == VPROC) || (type == VPORT)) return (ENOTSUP); parent = VTOSDEV(dvp); ASSERT(parent); rw_enter(&parent->sdev_dotdot->sdev_contents, RW_READER); if (parent->sdev_state == SDEV_ZOMBIE) { rw_exit(&parent->sdev_dotdot->sdev_contents); return (ENOENT); } /* non-global do not allow pure node creation */ if (!SDEV_IS_GLOBAL(parent)) { rw_exit(&parent->sdev_dotdot->sdev_contents); return (prof_lookup(dvp, nm, vpp, cred)); } rw_exit(&parent->sdev_dotdot->sdev_contents); /* execute access is required to search the directory */ if ((error = VOP_ACCESS(dvp, VEXEC, 0, cred, ct)) != 0) return (error); /* check existing name */ /* XXXci - We may need to translate the C-I flags on VOP_LOOKUP */ error = VOP_LOOKUP(dvp, nm, &vp, NULL, 0, NULL, cred, ct, NULL, NULL); /* name found */ if (error == 0) { ASSERT(vp); if (excl == EXCL) { error = EEXIST; } else if ((vp->v_type == VDIR) && (mode & VWRITE)) { /* allowing create/read-only an existing directory */ error = EISDIR; } else { error = VOP_ACCESS(vp, mode, 0, cred, ct); } if (error) { VN_RELE(vp); return (error); } /* truncation first */ if ((vp->v_type == VREG) && (vap->va_mask & AT_SIZE) && (vap->va_size == 0)) { ASSERT(parent->sdev_attrvp); error = VOP_CREATE(parent->sdev_attrvp, nm, vap, excl, mode, &avp, cred, flag, ct, vsecp); if (error) { VN_RELE(vp); return (error); } } sdev_update_timestamps(vp, kcred, AT_CTIME|AT_MTIME|AT_ATIME); *vpp = vp; return (0); } /* bail out early */ if (error != ENOENT) return (error); /* verify write access - compliance specifies ENXIO */ if ((error = VOP_ACCESS(dvp, VEXEC|VWRITE, 0, cred, ct)) != 0) { if (error == EACCES) error = ENXIO; return (error); } /* * For memory-based (ROFS) directory: * - either disallow node creation; * - or implement VOP_CREATE of its own */ rw_enter(&parent->sdev_contents, RW_WRITER); if (!SDEV_IS_PERSIST(parent)) { rw_exit(&parent->sdev_contents); return (ENOTSUP); } ASSERT(parent->sdev_attrvp); error = sdev_mknode(parent, nm, &self, vap, NULL, NULL, cred, SDEV_READY); if (error) { rw_exit(&parent->sdev_contents); if (self) SDEV_RELE(self); return (error); } rw_exit(&parent->sdev_contents); ASSERT(self); /* take care the timestamps for the node and its parent */ sdev_update_timestamps(SDEVTOV(self), kcred, AT_CTIME|AT_MTIME|AT_ATIME); sdev_update_timestamps(dvp, kcred, AT_MTIME|AT_ATIME); if (SDEV_IS_GLOBAL(parent)) atomic_inc_ulong(&parent->sdev_gdir_gen); /* wake up other threads blocked on looking up this node */ mutex_enter(&self->sdev_lookup_lock); SDEV_UNBLOCK_OTHERS(self, SDEV_LOOKUP); mutex_exit(&self->sdev_lookup_lock); error = sdev_to_vp(self, vpp); return (error); } static int sdev_remove(struct vnode *dvp, char *nm, struct cred *cred, caller_context_t *ct, int flags) { int error; struct sdev_node *parent = (struct sdev_node *)VTOSDEV(dvp); struct vnode *vp = NULL; struct sdev_node *dv = NULL; int len; int bkstore; /* bail out early */ len = strlen(nm); if (nm[0] == '.') { if (len == 1) { return (EINVAL); } else if (len == 2 && nm[1] == '.') { return (EEXIST); } } ASSERT(parent); rw_enter(&parent->sdev_contents, RW_READER); if (!SDEV_IS_GLOBAL(parent)) { rw_exit(&parent->sdev_contents); return (ENOTSUP); } /* execute access is required to search the directory */ if ((error = VOP_ACCESS(dvp, VEXEC, 0, cred, ct)) != 0) { rw_exit(&parent->sdev_contents); return (error); } /* check existence first */ dv = sdev_cache_lookup(parent, nm); if (dv == NULL) { rw_exit(&parent->sdev_contents); return (ENOENT); } vp = SDEVTOV(dv); if ((dv->sdev_state == SDEV_INIT) || (dv->sdev_state == SDEV_ZOMBIE)) { rw_exit(&parent->sdev_contents); VN_RELE(vp); return (ENOENT); } /* write access is required to remove an entry */ if ((error = VOP_ACCESS(dvp, VWRITE, 0, cred, ct)) != 0) { rw_exit(&parent->sdev_contents); VN_RELE(vp); return (error); } bkstore = SDEV_IS_PERSIST(dv) ? 1 : 0; if (!rw_tryupgrade(&parent->sdev_contents)) { rw_exit(&parent->sdev_contents); rw_enter(&parent->sdev_contents, RW_WRITER); /* Make sure we didn't become a zombie */ if (parent->sdev_state == SDEV_ZOMBIE) { rw_exit(&parent->sdev_contents); VN_RELE(vp); return (ENOENT); } } /* we do not support unlinking a non-empty directory */ if (vp->v_type == VDIR && dv->sdev_nlink > 2) { rw_exit(&parent->sdev_contents); VN_RELE(vp); return (EBUSY); } /* * sdev_dirdelete does the real job of: * - make sure no open ref count * - destroying the sdev_node * - releasing the hold on attrvp */ sdev_cache_update(parent, &dv, nm, SDEV_CACHE_DELETE); VN_RELE(vp); rw_exit(&parent->sdev_contents); /* * best efforts clean up the backing store */ if (bkstore) { ASSERT(parent->sdev_attrvp); error = VOP_REMOVE(parent->sdev_attrvp, nm, cred, ct, flags); /* * do not report BUSY error * because the backing store ref count is released * when the last ref count on the sdev_node is * released. */ if (error == EBUSY) { sdcmn_err2(("sdev_remove: device %s is still on" "disk %s\n", nm, parent->sdev_path)); error = 0; } } return (error); } /* * Some restrictions for this file system: * - both oldnm and newnm are in the scope of /dev file system, * to simply the namespace management model. */ /*ARGSUSED6*/ static int sdev_rename(struct vnode *odvp, char *onm, struct vnode *ndvp, char *nnm, struct cred *cred, caller_context_t *ct, int flags) { struct sdev_node *fromparent = NULL; struct vattr vattr; struct sdev_node *toparent; struct sdev_node *fromdv = NULL; /* source node */ struct vnode *ovp = NULL; /* source vnode */ struct sdev_node *todv = NULL; /* destination node */ struct vnode *nvp = NULL; /* destination vnode */ int samedir = 0; /* set if odvp == ndvp */ struct vnode *realvp; int error = 0; dev_t fsid; int bkstore = 0; vtype_t type; /* prevent modifying "." and ".." */ if ((onm[0] == '.' && (onm[1] == '\0' || (onm[1] == '.' && onm[2] == '\0'))) || (nnm[0] == '.' && (nnm[1] == '\0' || (nnm[1] == '.' && nnm[2] == '\0')))) { return (EINVAL); } fromparent = VTOSDEV(odvp); toparent = VTOSDEV(ndvp); /* ZOMBIE parent doesn't allow new node creation */ rw_enter(&fromparent->sdev_dotdot->sdev_contents, RW_READER); if (fromparent->sdev_state == SDEV_ZOMBIE) { rw_exit(&fromparent->sdev_dotdot->sdev_contents); return (ENOENT); } /* renaming only supported for global device nodes */ if (!SDEV_IS_GLOBAL(fromparent)) { rw_exit(&fromparent->sdev_dotdot->sdev_contents); return (ENOTSUP); } rw_exit(&fromparent->sdev_dotdot->sdev_contents); rw_enter(&toparent->sdev_dotdot->sdev_contents, RW_READER); if (toparent->sdev_state == SDEV_ZOMBIE) { rw_exit(&toparent->sdev_dotdot->sdev_contents); return (ENOENT); } rw_exit(&toparent->sdev_dotdot->sdev_contents); /* * acquire the global lock to prevent * mount/unmount/other rename activities. */ mutex_enter(&sdev_lock); /* check existence of the source node */ /* XXXci - We may need to translate the C-I flags on VOP_LOOKUP */ error = VOP_LOOKUP(odvp, onm, &ovp, NULL, 0, NULL, cred, ct, NULL, NULL); if (error) { sdcmn_err2(("sdev_rename: the source node %s exists\n", onm)); mutex_exit(&sdev_lock); return (error); } if (VOP_REALVP(ovp, &realvp, ct) == 0) { VN_HOLD(realvp); VN_RELE(ovp); ovp = realvp; } /* check existence of destination */ /* XXXci - We may need to translate the C-I flags on VOP_LOOKUP */ error = VOP_LOOKUP(ndvp, nnm, &nvp, NULL, 0, NULL, cred, ct, NULL, NULL); if (error && (error != ENOENT)) { mutex_exit(&sdev_lock); VN_RELE(ovp); return (error); } if (nvp && (VOP_REALVP(nvp, &realvp, ct) == 0)) { VN_HOLD(realvp); VN_RELE(nvp); nvp = realvp; } /* * make sure the source and the destination are * in the same dev filesystem */ if (odvp != ndvp) { vattr.va_mask = AT_FSID; if (error = VOP_GETATTR(odvp, &vattr, 0, cred, ct)) { mutex_exit(&sdev_lock); VN_RELE(ovp); if (nvp != NULL) VN_RELE(nvp); return (error); } fsid = vattr.va_fsid; vattr.va_mask = AT_FSID; if (error = VOP_GETATTR(ndvp, &vattr, 0, cred, ct)) { mutex_exit(&sdev_lock); VN_RELE(ovp); if (nvp != NULL) VN_RELE(nvp); return (error); } if (fsid != vattr.va_fsid) { mutex_exit(&sdev_lock); VN_RELE(ovp); if (nvp != NULL) VN_RELE(nvp); return (EXDEV); } } /* make sure the old entry can be deleted */ error = VOP_ACCESS(odvp, VWRITE, 0, cred, ct); if (error) { mutex_exit(&sdev_lock); VN_RELE(ovp); if (nvp != NULL) VN_RELE(nvp); return (error); } /* make sure the destination allows creation */ samedir = (fromparent == toparent); if (!samedir) { error = VOP_ACCESS(ndvp, VEXEC|VWRITE, 0, cred, ct); if (error) { mutex_exit(&sdev_lock); VN_RELE(ovp); if (nvp != NULL) VN_RELE(nvp); return (error); } } fromdv = VTOSDEV(ovp); ASSERT(fromdv); /* destination file exists */ if (nvp != NULL) { todv = VTOSDEV(nvp); ASSERT(todv); } if ((fromdv->sdev_flags & SDEV_DYNAMIC) != 0 || (todv != NULL && (todv->sdev_flags & SDEV_DYNAMIC) != 0)) { mutex_exit(&sdev_lock); if (nvp != NULL) VN_RELE(nvp); VN_RELE(ovp); return (EACCES); } /* * link source to new target in the memory. Regardless of failure, we * must rele our hold on nvp. */ error = sdev_rnmnode(fromparent, fromdv, toparent, &todv, nnm, cred); if (nvp != NULL) VN_RELE(nvp); if (error) { sdcmn_err2(("sdev_rename: renaming %s to %s failed " " with error %d\n", onm, nnm, error)); mutex_exit(&sdev_lock); VN_RELE(ovp); return (error); } /* * unlink from source */ rw_enter(&fromparent->sdev_contents, RW_READER); fromdv = sdev_cache_lookup(fromparent, onm); if (fromdv == NULL) { rw_exit(&fromparent->sdev_contents); mutex_exit(&sdev_lock); VN_RELE(ovp); sdcmn_err2(("sdev_rename: the source is deleted already\n")); return (0); } if (fromdv->sdev_state == SDEV_ZOMBIE) { rw_exit(&fromparent->sdev_contents); mutex_exit(&sdev_lock); VN_RELE(SDEVTOV(fromdv)); VN_RELE(ovp); sdcmn_err2(("sdev_rename: the source is being deleted\n")); return (0); } rw_exit(&fromparent->sdev_contents); ASSERT(SDEVTOV(fromdv) == ovp); VN_RELE(ovp); /* clean out the directory contents before it can be removed */ type = SDEVTOV(fromdv)->v_type; if (type == VDIR) { error = sdev_cleandir(fromdv, NULL, 0); sdcmn_err2(("sdev_rename: cleandir finished with %d\n", error)); if (error == EBUSY) error = 0; } rw_enter(&fromparent->sdev_contents, RW_WRITER); bkstore = SDEV_IS_PERSIST(fromdv) ? 1 : 0; sdev_cache_update(fromparent, &fromdv, onm, SDEV_CACHE_DELETE); VN_RELE(SDEVTOV(fromdv)); /* best effforts clean up the backing store */ if (bkstore) { ASSERT(fromparent->sdev_attrvp); if (type != VDIR) { /* XXXci - We may need to translate the C-I flags on VOP_REMOVE */ error = VOP_REMOVE(fromparent->sdev_attrvp, onm, kcred, ct, 0); } else { /* XXXci - We may need to translate the C-I flags on VOP_RMDIR */ error = VOP_RMDIR(fromparent->sdev_attrvp, onm, fromparent->sdev_attrvp, kcred, ct, 0); } if (error) { sdcmn_err2(("sdev_rename: device %s is " "still on disk %s\n", onm, fromparent->sdev_path)); error = 0; } } rw_exit(&fromparent->sdev_contents); mutex_exit(&sdev_lock); /* once reached to this point, the rename is regarded successful */ return (0); } /* * dev-fs version of "ln -s path dev-name" * tnm - path, e.g. /devices/... or /dev/... * lnm - dev_name */ /*ARGSUSED6*/ static int sdev_symlink(struct vnode *dvp, char *lnm, struct vattr *tva, char *tnm, struct cred *cred, caller_context_t *ct, int flags) { int error; struct vnode *vp = NULL; struct sdev_node *parent = (struct sdev_node *)VTOSDEV(dvp); struct sdev_node *self = (struct sdev_node *)NULL; ASSERT(parent); rw_enter(&parent->sdev_dotdot->sdev_contents, RW_READER); if (parent->sdev_state == SDEV_ZOMBIE) { rw_exit(&parent->sdev_dotdot->sdev_contents); sdcmn_err2(("sdev_symlink: parent %s is ZOMBIED \n", parent->sdev_name)); return (ENOENT); } if (!SDEV_IS_GLOBAL(parent)) { rw_exit(&parent->sdev_dotdot->sdev_contents); return (ENOTSUP); } rw_exit(&parent->sdev_dotdot->sdev_contents); /* execute access is required to search a directory */ if ((error = VOP_ACCESS(dvp, VEXEC, 0, cred, ct)) != 0) return (error); /* find existing name */ /* XXXci - We may need to translate the C-I flags here */ error = VOP_LOOKUP(dvp, lnm, &vp, NULL, 0, NULL, cred, ct, NULL, NULL); if (error == 0) { ASSERT(vp); VN_RELE(vp); sdcmn_err2(("sdev_symlink: node %s already exists\n", lnm)); return (EEXIST); } if (error != ENOENT) return (error); /* write access is required to create a symlink */ if ((error = VOP_ACCESS(dvp, VWRITE, 0, cred, ct)) != 0) return (error); /* put it into memory cache */ rw_enter(&parent->sdev_contents, RW_WRITER); error = sdev_mknode(parent, lnm, &self, tva, NULL, (void *)tnm, cred, SDEV_READY); if (error) { rw_exit(&parent->sdev_contents); sdcmn_err2(("sdev_symlink: node %s creation failed\n", lnm)); if (self) SDEV_RELE(self); return (error); } ASSERT(self && (self->sdev_state == SDEV_READY)); rw_exit(&parent->sdev_contents); /* take care the timestamps for the node and its parent */ sdev_update_timestamps(SDEVTOV(self), kcred, AT_CTIME|AT_MTIME|AT_ATIME); sdev_update_timestamps(dvp, kcred, AT_MTIME|AT_ATIME); if (SDEV_IS_GLOBAL(parent)) atomic_inc_ulong(&parent->sdev_gdir_gen); /* wake up other threads blocked on looking up this node */ mutex_enter(&self->sdev_lookup_lock); SDEV_UNBLOCK_OTHERS(self, SDEV_LOOKUP); mutex_exit(&self->sdev_lookup_lock); SDEV_RELE(self); /* don't return with vnode held */ return (0); } /*ARGSUSED6*/ static int sdev_mkdir(struct vnode *dvp, char *nm, struct vattr *va, struct vnode **vpp, struct cred *cred, caller_context_t *ct, int flags, vsecattr_t *vsecp) { int error; struct sdev_node *parent = (struct sdev_node *)VTOSDEV(dvp); struct sdev_node *self = NULL; struct vnode *vp = NULL; ASSERT(parent && parent->sdev_dotdot); rw_enter(&parent->sdev_dotdot->sdev_contents, RW_READER); if (parent->sdev_state == SDEV_ZOMBIE) { rw_exit(&parent->sdev_dotdot->sdev_contents); return (ENOENT); } /* non-global do not allow pure directory creation */ if (!SDEV_IS_GLOBAL(parent)) { rw_exit(&parent->sdev_dotdot->sdev_contents); return (prof_lookup(dvp, nm, vpp, cred)); } rw_exit(&parent->sdev_dotdot->sdev_contents); /* execute access is required to search the directory */ if ((error = VOP_ACCESS(dvp, VEXEC, 0, cred, ct)) != 0) { return (error); } /* find existing name */ /* XXXci - We may need to translate the C-I flags on VOP_LOOKUP */ error = VOP_LOOKUP(dvp, nm, &vp, NULL, 0, NULL, cred, ct, NULL, NULL); if (error == 0) { VN_RELE(vp); return (EEXIST); } if (error != ENOENT) return (error); /* require write access to create a directory */ if ((error = VOP_ACCESS(dvp, VWRITE, 0, cred, ct)) != 0) { return (error); } /* put it into memory */ rw_enter(&parent->sdev_contents, RW_WRITER); error = sdev_mknode(parent, nm, &self, va, NULL, NULL, cred, SDEV_READY); if (error) { rw_exit(&parent->sdev_contents); if (self) SDEV_RELE(self); return (error); } ASSERT(self && (self->sdev_state == SDEV_READY)); rw_exit(&parent->sdev_contents); /* take care the timestamps for the node and its parent */ sdev_update_timestamps(SDEVTOV(self), kcred, AT_CTIME|AT_MTIME|AT_ATIME); sdev_update_timestamps(dvp, kcred, AT_MTIME|AT_ATIME); if (SDEV_IS_GLOBAL(parent)) atomic_inc_ulong(&parent->sdev_gdir_gen); /* wake up other threads blocked on looking up this node */ mutex_enter(&self->sdev_lookup_lock); SDEV_UNBLOCK_OTHERS(self, SDEV_LOOKUP); mutex_exit(&self->sdev_lookup_lock); *vpp = SDEVTOV(self); return (0); } /* * allowing removing an empty directory under /dev */ /*ARGSUSED*/ static int sdev_rmdir(struct vnode *dvp, char *nm, struct vnode *cdir, struct cred *cred, caller_context_t *ct, int flags) { int error = 0; struct sdev_node *parent = (struct sdev_node *)VTOSDEV(dvp); struct sdev_node *self = NULL; struct vnode *vp = NULL; /* bail out early */ if (strcmp(nm, ".") == 0) return (EINVAL); if (strcmp(nm, "..") == 0) return (EEXIST); /* should be ENOTEMPTY */ /* no destruction of non-global node */ ASSERT(parent && parent->sdev_dotdot); rw_enter(&parent->sdev_dotdot->sdev_contents, RW_READER); if (!SDEV_IS_GLOBAL(parent)) { rw_exit(&parent->sdev_dotdot->sdev_contents); return (ENOTSUP); } rw_exit(&parent->sdev_dotdot->sdev_contents); /* execute access is required to search the directory */ if ((error = VOP_ACCESS(dvp, VEXEC|VWRITE, 0, cred, ct)) != 0) return (error); /* check existing name */ rw_enter(&parent->sdev_contents, RW_WRITER); self = sdev_cache_lookup(parent, nm); if (self == NULL) { rw_exit(&parent->sdev_contents); return (ENOENT); } vp = SDEVTOV(self); if ((self->sdev_state == SDEV_INIT) || (self->sdev_state == SDEV_ZOMBIE)) { rw_exit(&parent->sdev_contents); VN_RELE(vp); return (ENOENT); } /* some sanity checks */ if (vp == dvp || vp == cdir) { rw_exit(&parent->sdev_contents); VN_RELE(vp); return (EINVAL); } if (vp->v_type != VDIR) { rw_exit(&parent->sdev_contents); VN_RELE(vp); return (ENOTDIR); } if (vn_vfswlock(vp)) { rw_exit(&parent->sdev_contents); VN_RELE(vp); return (EBUSY); } if (vn_mountedvfs(vp) != NULL) { rw_exit(&parent->sdev_contents); vn_vfsunlock(vp); VN_RELE(vp); return (EBUSY); } self = VTOSDEV(vp); /* bail out on a non-empty directory */ rw_enter(&self->sdev_contents, RW_READER); if (self->sdev_nlink > 2) { rw_exit(&self->sdev_contents); rw_exit(&parent->sdev_contents); vn_vfsunlock(vp); VN_RELE(vp); return (ENOTEMPTY); } rw_exit(&self->sdev_contents); /* unlink it from the directory cache */ sdev_cache_update(parent, &self, nm, SDEV_CACHE_DELETE); rw_exit(&parent->sdev_contents); vn_vfsunlock(vp); VN_RELE(vp); /* best effort to clean up the backing store */ if (SDEV_IS_PERSIST(parent)) { ASSERT(parent->sdev_attrvp); error = VOP_RMDIR(parent->sdev_attrvp, nm, parent->sdev_attrvp, kcred, ct, flags); if (error) sdcmn_err2(("sdev_rmdir: cleaning device %s is on" " disk error %d\n", parent->sdev_path, error)); if (error == EBUSY) error = 0; } return (error); } /* * read the contents of a symbolic link */ static int sdev_readlink(struct vnode *vp, struct uio *uiop, struct cred *cred, caller_context_t *ct) { struct sdev_node *dv; int error = 0; ASSERT(vp->v_type == VLNK); dv = VTOSDEV(vp); if (dv->sdev_attrvp) { /* non-NULL attrvp implys a persisted node at READY state */ return (VOP_READLINK(dv->sdev_attrvp, uiop, cred, ct)); } else if (dv->sdev_symlink != NULL) { /* memory nodes, e.g. local nodes */ rw_enter(&dv->sdev_contents, RW_READER); sdcmn_err2(("sdev_readlink link is %s\n", dv->sdev_symlink)); error = uiomove(dv->sdev_symlink, strlen(dv->sdev_symlink), UIO_READ, uiop); rw_exit(&dv->sdev_contents); return (error); } return (ENOENT); } /*ARGSUSED4*/ static int sdev_readdir(struct vnode *dvp, struct uio *uiop, struct cred *cred, int *eofp, caller_context_t *ct, int flags) { struct sdev_node *parent = VTOSDEV(dvp); int error; /* * We must check that we have execute access to search the directory -- * but because our sdev_contents lock is already held as a reader (the * caller must have done a VOP_RWLOCK()), we call directly into the * underlying access routine if sdev_attr is non-NULL. */ if (parent->sdev_attr != NULL) { VERIFY(RW_READ_HELD(&parent->sdev_contents)); if (sdev_unlocked_access(parent, VEXEC, cred) != 0) return (EACCES); } else { if ((error = VOP_ACCESS(dvp, VEXEC, 0, cred, ct)) != 0) return (error); } ASSERT(parent); if (!SDEV_IS_GLOBAL(parent)) prof_filldir(parent); return (devname_readdir_func(dvp, uiop, cred, eofp, SDEV_BROWSE)); } /*ARGSUSED1*/ static void sdev_inactive(struct vnode *vp, struct cred *cred, caller_context_t *ct) { devname_inactive_func(vp, cred, NULL); } /*ARGSUSED2*/ static int sdev_fid(struct vnode *vp, struct fid *fidp, caller_context_t *ct) { struct sdev_node *dv = VTOSDEV(vp); struct sdev_fid *sdev_fid; if (fidp->fid_len < (sizeof (struct sdev_fid) - sizeof (ushort_t))) { fidp->fid_len = sizeof (struct sdev_fid) - sizeof (ushort_t); return (ENOSPC); } sdev_fid = (struct sdev_fid *)fidp; bzero(sdev_fid, sizeof (struct sdev_fid)); sdev_fid->sdevfid_len = (int)sizeof (struct sdev_fid) - sizeof (ushort_t); sdev_fid->sdevfid_ino = dv->sdev_ino; return (0); } /* * This pair of routines bracket all VOP_READ, VOP_WRITE * and VOP_READDIR requests. The contents lock stops things * moving around while we're looking at them. */ /*ARGSUSED2*/ static int sdev_rwlock(struct vnode *vp, int write_flag, caller_context_t *ctp) { rw_enter(&VTOSDEV(vp)->sdev_contents, write_flag ? RW_WRITER : RW_READER); return (write_flag ? V_WRITELOCK_TRUE : V_WRITELOCK_FALSE); } /*ARGSUSED1*/ static void sdev_rwunlock(struct vnode *vp, int write_flag, caller_context_t *ctp) { rw_exit(&VTOSDEV(vp)->sdev_contents); } /*ARGSUSED1*/ static int sdev_seek(struct vnode *vp, offset_t ooff, offset_t *noffp, caller_context_t *ct) { struct vnode *attrvp = VTOSDEV(vp)->sdev_attrvp; ASSERT(vp->v_type != VCHR && vp->v_type != VBLK && vp->v_type != VLNK); if (vp->v_type == VDIR) return (fs_seek(vp, ooff, noffp, ct)); ASSERT(attrvp); return (VOP_SEEK(attrvp, ooff, noffp, ct)); } /*ARGSUSED1*/ static int sdev_frlock(struct vnode *vp, int cmd, struct flock64 *bfp, int flag, offset_t offset, struct flk_callback *flk_cbp, struct cred *cr, caller_context_t *ct) { int error; struct sdev_node *dv = VTOSDEV(vp); ASSERT(dv); ASSERT(dv->sdev_attrvp); error = VOP_FRLOCK(dv->sdev_attrvp, cmd, bfp, flag, offset, flk_cbp, cr, ct); return (error); } static int sdev_pathconf(vnode_t *vp, int cmd, ulong_t *valp, cred_t *cr, caller_context_t *ct) { switch (cmd) { case _PC_ACL_ENABLED: *valp = SDEV_ACL_FLAVOR(vp); return (0); } return (fs_pathconf(vp, cmd, valp, cr, ct)); } vnodeops_t *sdev_vnodeops; const fs_operation_def_t sdev_vnodeops_tbl[] = { VOPNAME_OPEN, { .vop_open = sdev_open }, VOPNAME_CLOSE, { .vop_close = sdev_close }, VOPNAME_READ, { .vop_read = sdev_read }, VOPNAME_WRITE, { .vop_write = sdev_write }, VOPNAME_IOCTL, { .vop_ioctl = sdev_ioctl }, VOPNAME_GETATTR, { .vop_getattr = sdev_getattr }, VOPNAME_SETATTR, { .vop_setattr = sdev_setattr }, VOPNAME_ACCESS, { .vop_access = sdev_access }, VOPNAME_LOOKUP, { .vop_lookup = sdev_lookup }, VOPNAME_CREATE, { .vop_create = sdev_create }, VOPNAME_RENAME, { .vop_rename = sdev_rename }, VOPNAME_REMOVE, { .vop_remove = sdev_remove }, VOPNAME_MKDIR, { .vop_mkdir = sdev_mkdir }, VOPNAME_RMDIR, { .vop_rmdir = sdev_rmdir }, VOPNAME_READDIR, { .vop_readdir = sdev_readdir }, VOPNAME_SYMLINK, { .vop_symlink = sdev_symlink }, VOPNAME_READLINK, { .vop_readlink = sdev_readlink }, VOPNAME_INACTIVE, { .vop_inactive = sdev_inactive }, VOPNAME_FID, { .vop_fid = sdev_fid }, VOPNAME_RWLOCK, { .vop_rwlock = sdev_rwlock }, VOPNAME_RWUNLOCK, { .vop_rwunlock = sdev_rwunlock }, VOPNAME_SEEK, { .vop_seek = sdev_seek }, VOPNAME_FRLOCK, { .vop_frlock = sdev_frlock }, VOPNAME_PATHCONF, { .vop_pathconf = sdev_pathconf }, VOPNAME_SETSECATTR, { .vop_setsecattr = sdev_setsecattr }, VOPNAME_GETSECATTR, { .vop_getsecattr = sdev_getsecattr }, NULL, NULL }; int sdev_vnodeops_tbl_size = sizeof (sdev_vnodeops_tbl);