1/* 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * John Heidemann of the UCLA Ficus project. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)null_vnops.c 8.6 (Berkeley) 5/27/95 37 * 38 * Ancestors: 39 * @(#)lofs_vnops.c 1.2 (Berkeley) 6/18/92
| 1/* 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * John Heidemann of the UCLA Ficus project. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)null_vnops.c 8.6 (Berkeley) 5/27/95 37 * 38 * Ancestors: 39 * @(#)lofs_vnops.c 1.2 (Berkeley) 6/18/92
|
40 * $Id: null_vnops.c,v 1.18 1997/05/25 04:50:02 peter Exp $
| 40 * $Id: null_vnops.c,v 1.19 1997/06/26 16:13:56 alex Exp $
|
41 * ...and... 42 * @(#)null_vnodeops.c 1.20 92/07/07 UCLA Ficus project 43 *
| 41 * ...and... 42 * @(#)null_vnodeops.c 1.20 92/07/07 UCLA Ficus project 43 *
|
44 * $Id: null_vnops.c,v 1.18 1997/05/25 04:50:02 peter Exp $
| 44 * $Id: null_vnops.c,v 1.19 1997/06/26 16:13:56 alex Exp $
|
45 */ 46 47/* 48 * Null Layer 49 * 50 * (See mount_null(8) for more information.) 51 * 52 * The null layer duplicates a portion of the file system 53 * name space under a new name. In this respect, it is 54 * similar to the loopback file system. It differs from 55 * the loopback fs in two respects: it is implemented using 56 * a stackable layers techniques, and it's "null-node"s stack above 57 * all lower-layer vnodes, not just over directory vnodes. 58 * 59 * The null layer has two purposes. First, it serves as a demonstration 60 * of layering by proving a layer which does nothing. (It actually 61 * does everything the loopback file system does, which is slightly 62 * more than nothing.) Second, the null layer can serve as a prototype 63 * layer. Since it provides all necessary layer framework, 64 * new file system layers can be created very easily be starting 65 * with a null layer. 66 * 67 * The remainder of this man page examines the null layer as a basis 68 * for constructing new layers. 69 * 70 * 71 * INSTANTIATING NEW NULL LAYERS 72 * 73 * New null layers are created with mount_null(8). 74 * Mount_null(8) takes two arguments, the pathname 75 * of the lower vfs (target-pn) and the pathname where the null 76 * layer will appear in the namespace (alias-pn). After 77 * the null layer is put into place, the contents 78 * of target-pn subtree will be aliased under alias-pn. 79 * 80 * 81 * OPERATION OF A NULL LAYER 82 * 83 * The null layer is the minimum file system layer, 84 * simply bypassing all possible operations to the lower layer 85 * for processing there. The majority of its activity centers 86 * on the bypass routine, through which nearly all vnode operations 87 * pass. 88 * 89 * The bypass routine accepts arbitrary vnode operations for 90 * handling by the lower layer. It begins by examing vnode 91 * operation arguments and replacing any null-nodes by their 92 * lower-layer equivlants. It then invokes the operation 93 * on the lower layer. Finally, it replaces the null-nodes 94 * in the arguments and, if a vnode is return by the operation, 95 * stacks a null-node on top of the returned vnode. 96 * 97 * Although bypass handles most operations, vop_getattr, vop_lock, 98 * vop_unlock, vop_inactive, vop_reclaim, and vop_print are not 99 * bypassed. Vop_getattr must change the fsid being returned. 100 * Vop_lock and vop_unlock must handle any locking for the 101 * current vnode as well as pass the lock request down. 102 * Vop_inactive and vop_reclaim are not bypassed so that 103 * they can handle freeing null-layer specific data. Vop_print 104 * is not bypassed to avoid excessive debugging information. 105 * Also, certain vnode operations change the locking state within 106 * the operation (create, mknod, remove, link, rename, mkdir, rmdir, 107 * and symlink). Ideally these operations should not change the 108 * lock state, but should be changed to let the caller of the 109 * function unlock them. Otherwise all intermediate vnode layers 110 * (such as union, umapfs, etc) must catch these functions to do 111 * the necessary locking at their layer. 112 * 113 * 114 * INSTANTIATING VNODE STACKS 115 * 116 * Mounting associates the null layer with a lower layer, 117 * effect stacking two VFSes. Vnode stacks are instead 118 * created on demand as files are accessed. 119 * 120 * The initial mount creates a single vnode stack for the 121 * root of the new null layer. All other vnode stacks 122 * are created as a result of vnode operations on 123 * this or other null vnode stacks. 124 * 125 * New vnode stacks come into existance as a result of 126 * an operation which returns a vnode. 127 * The bypass routine stacks a null-node above the new 128 * vnode before returning it to the caller. 129 * 130 * For example, imagine mounting a null layer with 131 * "mount_null /usr/include /dev/layer/null". 132 * Changing directory to /dev/layer/null will assign 133 * the root null-node (which was created when the null layer was mounted). 134 * Now consider opening "sys". A vop_lookup would be 135 * done on the root null-node. This operation would bypass through 136 * to the lower layer which would return a vnode representing 137 * the UFS "sys". Null_bypass then builds a null-node 138 * aliasing the UFS "sys" and returns this to the caller. 139 * Later operations on the null-node "sys" will repeat this 140 * process when constructing other vnode stacks. 141 * 142 * 143 * CREATING OTHER FILE SYSTEM LAYERS 144 * 145 * One of the easiest ways to construct new file system layers is to make 146 * a copy of the null layer, rename all files and variables, and 147 * then begin modifing the copy. Sed can be used to easily rename 148 * all variables. 149 * 150 * The umap layer is an example of a layer descended from the 151 * null layer. 152 * 153 * 154 * INVOKING OPERATIONS ON LOWER LAYERS 155 * 156 * There are two techniques to invoke operations on a lower layer 157 * when the operation cannot be completely bypassed. Each method 158 * is appropriate in different situations. In both cases, 159 * it is the responsibility of the aliasing layer to make 160 * the operation arguments "correct" for the lower layer 161 * by mapping an vnode arguments to the lower layer. 162 * 163 * The first approach is to call the aliasing layer's bypass routine. 164 * This method is most suitable when you wish to invoke the operation
| 45 */ 46 47/* 48 * Null Layer 49 * 50 * (See mount_null(8) for more information.) 51 * 52 * The null layer duplicates a portion of the file system 53 * name space under a new name. In this respect, it is 54 * similar to the loopback file system. It differs from 55 * the loopback fs in two respects: it is implemented using 56 * a stackable layers techniques, and it's "null-node"s stack above 57 * all lower-layer vnodes, not just over directory vnodes. 58 * 59 * The null layer has two purposes. First, it serves as a demonstration 60 * of layering by proving a layer which does nothing. (It actually 61 * does everything the loopback file system does, which is slightly 62 * more than nothing.) Second, the null layer can serve as a prototype 63 * layer. Since it provides all necessary layer framework, 64 * new file system layers can be created very easily be starting 65 * with a null layer. 66 * 67 * The remainder of this man page examines the null layer as a basis 68 * for constructing new layers. 69 * 70 * 71 * INSTANTIATING NEW NULL LAYERS 72 * 73 * New null layers are created with mount_null(8). 74 * Mount_null(8) takes two arguments, the pathname 75 * of the lower vfs (target-pn) and the pathname where the null 76 * layer will appear in the namespace (alias-pn). After 77 * the null layer is put into place, the contents 78 * of target-pn subtree will be aliased under alias-pn. 79 * 80 * 81 * OPERATION OF A NULL LAYER 82 * 83 * The null layer is the minimum file system layer, 84 * simply bypassing all possible operations to the lower layer 85 * for processing there. The majority of its activity centers 86 * on the bypass routine, through which nearly all vnode operations 87 * pass. 88 * 89 * The bypass routine accepts arbitrary vnode operations for 90 * handling by the lower layer. It begins by examing vnode 91 * operation arguments and replacing any null-nodes by their 92 * lower-layer equivlants. It then invokes the operation 93 * on the lower layer. Finally, it replaces the null-nodes 94 * in the arguments and, if a vnode is return by the operation, 95 * stacks a null-node on top of the returned vnode. 96 * 97 * Although bypass handles most operations, vop_getattr, vop_lock, 98 * vop_unlock, vop_inactive, vop_reclaim, and vop_print are not 99 * bypassed. Vop_getattr must change the fsid being returned. 100 * Vop_lock and vop_unlock must handle any locking for the 101 * current vnode as well as pass the lock request down. 102 * Vop_inactive and vop_reclaim are not bypassed so that 103 * they can handle freeing null-layer specific data. Vop_print 104 * is not bypassed to avoid excessive debugging information. 105 * Also, certain vnode operations change the locking state within 106 * the operation (create, mknod, remove, link, rename, mkdir, rmdir, 107 * and symlink). Ideally these operations should not change the 108 * lock state, but should be changed to let the caller of the 109 * function unlock them. Otherwise all intermediate vnode layers 110 * (such as union, umapfs, etc) must catch these functions to do 111 * the necessary locking at their layer. 112 * 113 * 114 * INSTANTIATING VNODE STACKS 115 * 116 * Mounting associates the null layer with a lower layer, 117 * effect stacking two VFSes. Vnode stacks are instead 118 * created on demand as files are accessed. 119 * 120 * The initial mount creates a single vnode stack for the 121 * root of the new null layer. All other vnode stacks 122 * are created as a result of vnode operations on 123 * this or other null vnode stacks. 124 * 125 * New vnode stacks come into existance as a result of 126 * an operation which returns a vnode. 127 * The bypass routine stacks a null-node above the new 128 * vnode before returning it to the caller. 129 * 130 * For example, imagine mounting a null layer with 131 * "mount_null /usr/include /dev/layer/null". 132 * Changing directory to /dev/layer/null will assign 133 * the root null-node (which was created when the null layer was mounted). 134 * Now consider opening "sys". A vop_lookup would be 135 * done on the root null-node. This operation would bypass through 136 * to the lower layer which would return a vnode representing 137 * the UFS "sys". Null_bypass then builds a null-node 138 * aliasing the UFS "sys" and returns this to the caller. 139 * Later operations on the null-node "sys" will repeat this 140 * process when constructing other vnode stacks. 141 * 142 * 143 * CREATING OTHER FILE SYSTEM LAYERS 144 * 145 * One of the easiest ways to construct new file system layers is to make 146 * a copy of the null layer, rename all files and variables, and 147 * then begin modifing the copy. Sed can be used to easily rename 148 * all variables. 149 * 150 * The umap layer is an example of a layer descended from the 151 * null layer. 152 * 153 * 154 * INVOKING OPERATIONS ON LOWER LAYERS 155 * 156 * There are two techniques to invoke operations on a lower layer 157 * when the operation cannot be completely bypassed. Each method 158 * is appropriate in different situations. In both cases, 159 * it is the responsibility of the aliasing layer to make 160 * the operation arguments "correct" for the lower layer 161 * by mapping an vnode arguments to the lower layer. 162 * 163 * The first approach is to call the aliasing layer's bypass routine. 164 * This method is most suitable when you wish to invoke the operation
|
165 * currently being hanldled on the lower layer. It has the advantage
| 165 * currently being handled on the lower layer. It has the advantage
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166 * that the bypass routine already must do argument mapping. 167 * An example of this is null_getattrs in the null layer. 168 *
| 166 * that the bypass routine already must do argument mapping. 167 * An example of this is null_getattrs in the null layer. 168 *
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169 * A second approach is to directly invoked vnode operations on
| 169 * A second approach is to directly invoke vnode operations on
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170 * the lower layer with the VOP_OPERATIONNAME interface. 171 * The advantage of this method is that it is easy to invoke 172 * arbitrary operations on the lower layer. The disadvantage
| 170 * the lower layer with the VOP_OPERATIONNAME interface. 171 * The advantage of this method is that it is easy to invoke 172 * arbitrary operations on the lower layer. The disadvantage
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173 * is that vnodes arguments must be manualy mapped.
| 173 * is that vnode arguments must be manualy mapped.
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174 * 175 */ 176 177#include <sys/param.h> 178#include <sys/systm.h> 179#include <sys/kernel.h> 180#include <sys/sysctl.h> 181#include <sys/proc.h> 182#include <sys/time.h> 183#include <sys/types.h> 184#include <sys/vnode.h> 185#include <sys/mount.h> 186#include <sys/namei.h> 187#include <sys/malloc.h> 188#include <sys/buf.h> 189#include <miscfs/nullfs/null.h> 190 191static int null_bug_bypass = 0; /* for debugging: enables bypass printf'ing */ 192SYSCTL_INT(_debug, OID_AUTO, nullfs_bug_bypass, CTLFLAG_RW, 193 &null_bug_bypass, 0, ""); 194 195static int null_access __P((struct vop_access_args *ap)); 196static int null_bwrite __P((struct vop_bwrite_args *ap)); 197static int null_getattr __P((struct vop_getattr_args *ap)); 198static int null_inactive __P((struct vop_inactive_args *ap)); 199static int null_lock __P((struct vop_lock_args *ap)); 200static int null_lookup __P((struct vop_lookup_args *ap)); 201static int null_print __P((struct vop_print_args *ap)); 202static int null_reclaim __P((struct vop_reclaim_args *ap)); 203static int null_setattr __P((struct vop_setattr_args *ap)); 204static int null_strategy __P((struct vop_strategy_args *ap)); 205static int null_unlock __P((struct vop_unlock_args *ap)); 206 207/* 208 * This is the 10-Apr-92 bypass routine. 209 * This version has been optimized for speed, throwing away some 210 * safety checks. It should still always work, but it's not as 211 * robust to programmer errors. 212 * Define SAFETY to include some error checking code. 213 * 214 * In general, we map all vnodes going down and unmap them on the way back. 215 * As an exception to this, vnodes can be marked "unmapped" by setting 216 * the Nth bit in operation's vdesc_flags. 217 * 218 * Also, some BSD vnode operations have the side effect of vrele'ing 219 * their arguments. With stacking, the reference counts are held 220 * by the upper node, not the lower one, so we must handle these 221 * side-effects here. This is not of concern in Sun-derived systems 222 * since there are no such side-effects. 223 * 224 * This makes the following assumptions: 225 * - only one returned vpp 226 * - no INOUT vpp's (Sun's vop_open has one of these) 227 * - the vnode operation vector of the first vnode should be used 228 * to determine what implementation of the op should be invoked 229 * - all mapped vnodes are of our vnode-type (NEEDSWORK: 230 * problems on rmdir'ing mount points and renaming?) 231 */ 232int 233null_bypass(ap) 234 struct vop_generic_args /* { 235 struct vnodeop_desc *a_desc; 236 <other random data follows, presumably> 237 } */ *ap; 238{ 239 register struct vnode **this_vp_p; 240 int error; 241 struct vnode *old_vps[VDESC_MAX_VPS]; 242 struct vnode **vps_p[VDESC_MAX_VPS]; 243 struct vnode ***vppp; 244 struct vnodeop_desc *descp = ap->a_desc; 245 int reles, i; 246 247 if (null_bug_bypass) 248 printf ("null_bypass: %s\n", descp->vdesc_name); 249 250#ifdef SAFETY 251 /* 252 * We require at least one vp. 253 */ 254 if (descp->vdesc_vp_offsets == NULL || 255 descp->vdesc_vp_offsets[0] == VDESC_NO_OFFSET) 256 panic ("null_bypass: no vp's in map."); 257#endif 258 259 /* 260 * Map the vnodes going in. 261 * Later, we'll invoke the operation based on 262 * the first mapped vnode's operation vector. 263 */ 264 reles = descp->vdesc_flags; 265 for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) { 266 if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET) 267 break; /* bail out at end of list */ 268 vps_p[i] = this_vp_p = 269 VOPARG_OFFSETTO(struct vnode**,descp->vdesc_vp_offsets[i],ap); 270 /* 271 * We're not guaranteed that any but the first vnode 272 * are of our type. Check for and don't map any 273 * that aren't. (We must always map first vp or vclean fails.) 274 */ 275 if (i && (*this_vp_p == NULLVP || 276 (*this_vp_p)->v_op != null_vnodeop_p)) { 277 old_vps[i] = NULLVP; 278 } else { 279 old_vps[i] = *this_vp_p; 280 *(vps_p[i]) = NULLVPTOLOWERVP(*this_vp_p); 281 /* 282 * XXX - Several operations have the side effect 283 * of vrele'ing their vp's. We must account for 284 * that. (This should go away in the future.) 285 */ 286 if (reles & 1) 287 VREF(*this_vp_p); 288 } 289 290 } 291 292 /* 293 * Call the operation on the lower layer 294 * with the modified argument structure. 295 */ 296 error = VCALL(*(vps_p[0]), descp->vdesc_offset, ap); 297 298 /* 299 * Maintain the illusion of call-by-value 300 * by restoring vnodes in the argument structure 301 * to their original value. 302 */ 303 reles = descp->vdesc_flags; 304 for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) { 305 if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET) 306 break; /* bail out at end of list */ 307 if (old_vps[i]) { 308 *(vps_p[i]) = old_vps[i]; 309 if (reles & 1) 310 vrele(*(vps_p[i])); 311 } 312 } 313 314 /* 315 * Map the possible out-going vpp 316 * (Assumes that the lower layer always returns 317 * a VREF'ed vpp unless it gets an error.) 318 */ 319 if (descp->vdesc_vpp_offset != VDESC_NO_OFFSET && 320 !(descp->vdesc_flags & VDESC_NOMAP_VPP) && 321 !error) { 322 /* 323 * XXX - even though some ops have vpp returned vp's, 324 * several ops actually vrele this before returning. 325 * We must avoid these ops. 326 * (This should go away when these ops are regularized.) 327 */ 328 if (descp->vdesc_flags & VDESC_VPP_WILLRELE) 329 goto out; 330 vppp = VOPARG_OFFSETTO(struct vnode***, 331 descp->vdesc_vpp_offset,ap); 332 error = null_node_create(old_vps[0]->v_mount, **vppp, *vppp); 333 } 334 335 out: 336 return (error); 337} 338 339/* 340 * We have to carry on the locking protocol on the null layer vnodes 341 * as we progress through the tree. We also have to enforce read-only 342 * if this layer is mounted read-only. 343 */ 344static int 345null_lookup(ap) 346 struct vop_lookup_args /* { 347 struct vnode * a_dvp; 348 struct vnode ** a_vpp; 349 struct componentname * a_cnp; 350 } */ *ap; 351{ 352 struct componentname *cnp = ap->a_cnp; 353 struct proc *p = cnp->cn_proc; 354 int flags = cnp->cn_flags; 355 struct vop_lock_args lockargs; 356 struct vop_unlock_args unlockargs; 357 struct vnode *dvp, *vp; 358 int error; 359 360 if ((flags & ISLASTCN) && (ap->a_dvp->v_mount->mnt_flag & MNT_RDONLY) && 361 (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) 362 return (EROFS); 363 error = null_bypass((struct vop_generic_args *)ap); 364 if (error == EJUSTRETURN && (flags & ISLASTCN) && 365 (ap->a_dvp->v_mount->mnt_flag & MNT_RDONLY) && 366 (cnp->cn_nameiop == CREATE || cnp->cn_nameiop == RENAME)) 367 error = EROFS; 368 /* 369 * We must do the same locking and unlocking at this layer as 370 * is done in the layers below us. We could figure this out 371 * based on the error return and the LASTCN, LOCKPARENT, and 372 * LOCKLEAF flags. However, it is more expidient to just find 373 * out the state of the lower level vnodes and set ours to the 374 * same state. 375 */ 376 dvp = ap->a_dvp; 377 vp = *ap->a_vpp; 378 if (dvp == vp) 379 return (error); 380 if (!VOP_ISLOCKED(dvp)) { 381 unlockargs.a_vp = dvp; 382 unlockargs.a_flags = 0; 383 unlockargs.a_p = p; 384 vop_nounlock(&unlockargs); 385 } 386 if (vp != NULLVP && VOP_ISLOCKED(vp)) { 387 lockargs.a_vp = vp; 388 lockargs.a_flags = LK_SHARED; 389 lockargs.a_p = p; 390 vop_nolock(&lockargs); 391 } 392 return (error); 393} 394 395/* 396 * Setattr call. Disallow write attempts if the layer is mounted read-only. 397 */ 398int 399null_setattr(ap) 400 struct vop_setattr_args /* { 401 struct vnodeop_desc *a_desc; 402 struct vnode *a_vp; 403 struct vattr *a_vap; 404 struct ucred *a_cred; 405 struct proc *a_p; 406 } */ *ap; 407{ 408 struct vnode *vp = ap->a_vp; 409 struct vattr *vap = ap->a_vap; 410 411 if ((vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL || 412 vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL || 413 vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL) && 414 (vp->v_mount->mnt_flag & MNT_RDONLY)) 415 return (EROFS); 416 if (vap->va_size != VNOVAL) { 417 switch (vp->v_type) { 418 case VDIR: 419 return (EISDIR); 420 case VCHR: 421 case VBLK: 422 case VSOCK: 423 case VFIFO: 424 return (0); 425 case VREG: 426 case VLNK: 427 default: 428 /* 429 * Disallow write attempts if the filesystem is 430 * mounted read-only. 431 */ 432 if (vp->v_mount->mnt_flag & MNT_RDONLY) 433 return (EROFS); 434 } 435 } 436 return (null_bypass((struct vop_generic_args *)ap)); 437} 438 439/* 440 * We handle getattr only to change the fsid. 441 */ 442static int 443null_getattr(ap) 444 struct vop_getattr_args /* { 445 struct vnode *a_vp; 446 struct vattr *a_vap; 447 struct ucred *a_cred; 448 struct proc *a_p; 449 } */ *ap; 450{ 451 int error; 452 453 if (error = null_bypass((struct vop_generic_args *)ap)) 454 return (error); 455 /* Requires that arguments be restored. */ 456 ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0]; 457 return (0); 458} 459 460static int 461null_access(ap) 462 struct vop_access_args /* { 463 struct vnode *a_vp; 464 int a_mode; 465 struct ucred *a_cred; 466 struct proc *a_p; 467 } */ *ap; 468{ 469 struct vnode *vp = ap->a_vp; 470 mode_t mode = ap->a_mode; 471 472 /* 473 * Disallow write attempts on read-only layers; 474 * unless the file is a socket, fifo, or a block or 475 * character device resident on the file system. 476 */ 477 if (mode & VWRITE) { 478 switch (vp->v_type) { 479 case VDIR: 480 case VLNK: 481 case VREG: 482 if (vp->v_mount->mnt_flag & MNT_RDONLY) 483 return (EROFS); 484 break; 485 } 486 } 487 return (null_bypass((struct vop_generic_args *)ap)); 488} 489 490/* 491 * We need to process our own vnode lock and then clear the 492 * interlock flag as it applies only to our vnode, not the 493 * vnodes below us on the stack. 494 */ 495static int 496null_lock(ap) 497 struct vop_lock_args /* { 498 struct vnode *a_vp; 499 int a_flags; 500 struct proc *a_p; 501 } */ *ap; 502{ 503 504 vop_nolock(ap); 505 if ((ap->a_flags & LK_TYPE_MASK) == LK_DRAIN) 506 return (0); 507 ap->a_flags &= ~LK_INTERLOCK; 508 return (null_bypass((struct vop_generic_args *)ap)); 509} 510 511/* 512 * We need to process our own vnode unlock and then clear the 513 * interlock flag as it applies only to our vnode, not the 514 * vnodes below us on the stack. 515 */ 516static int 517null_unlock(ap) 518 struct vop_unlock_args /* { 519 struct vnode *a_vp; 520 int a_flags; 521 struct proc *a_p; 522 } */ *ap; 523{ 524 struct vnode *vp = ap->a_vp; 525 526 vop_nounlock(ap); 527 ap->a_flags &= ~LK_INTERLOCK; 528 return (null_bypass((struct vop_generic_args *)ap)); 529} 530 531static int 532null_inactive(ap) 533 struct vop_inactive_args /* { 534 struct vnode *a_vp; 535 struct proc *a_p; 536 } */ *ap; 537{ 538 /* 539 * Do nothing (and _don't_ bypass). 540 * Wait to vrele lowervp until reclaim, 541 * so that until then our null_node is in the 542 * cache and reusable. 543 * 544 * NEEDSWORK: Someday, consider inactive'ing 545 * the lowervp and then trying to reactivate it 546 * with capabilities (v_id) 547 * like they do in the name lookup cache code. 548 * That's too much work for now. 549 */ 550 VOP_UNLOCK(ap->a_vp, 0, ap->a_p); 551 return (0); 552} 553 554static int 555null_reclaim(ap) 556 struct vop_reclaim_args /* { 557 struct vnode *a_vp; 558 struct proc *a_p; 559 } */ *ap; 560{ 561 struct vnode *vp = ap->a_vp; 562 struct null_node *xp = VTONULL(vp); 563 struct vnode *lowervp = xp->null_lowervp; 564 565 /* 566 * Note: in vop_reclaim, vp->v_op == dead_vnodeop_p, 567 * so we can't call VOPs on ourself. 568 */ 569 /* After this assignment, this node will not be re-used. */ 570 xp->null_lowervp = NULLVP; 571 LIST_REMOVE(xp, null_hash); 572 FREE(vp->v_data, M_TEMP); 573 vp->v_data = NULL; 574 vrele (lowervp); 575 return (0); 576} 577 578static int 579null_print(ap) 580 struct vop_print_args /* { 581 struct vnode *a_vp; 582 } */ *ap; 583{ 584 register struct vnode *vp = ap->a_vp; 585 printf ("\ttag VT_NULLFS, vp=%p, lowervp=%p\n", vp, NULLVPTOLOWERVP(vp)); 586 return (0); 587} 588 589/* 590 * XXX - vop_strategy must be hand coded because it has no 591 * vnode in its arguments. 592 * This goes away with a merged VM/buffer cache. 593 */ 594static int 595null_strategy(ap) 596 struct vop_strategy_args /* { 597 struct buf *a_bp; 598 } */ *ap; 599{ 600 struct buf *bp = ap->a_bp; 601 int error; 602 struct vnode *savedvp; 603 604 savedvp = bp->b_vp; 605 bp->b_vp = NULLVPTOLOWERVP(bp->b_vp); 606 607 error = VOP_STRATEGY(bp); 608 609 bp->b_vp = savedvp; 610 611 return (error); 612} 613 614/* 615 * XXX - like vop_strategy, vop_bwrite must be hand coded because it has no 616 * vnode in its arguments. 617 * This goes away with a merged VM/buffer cache. 618 */ 619static int 620null_bwrite(ap) 621 struct vop_bwrite_args /* { 622 struct buf *a_bp; 623 } */ *ap; 624{ 625 struct buf *bp = ap->a_bp; 626 int error; 627 struct vnode *savedvp; 628 629 savedvp = bp->b_vp; 630 bp->b_vp = NULLVPTOLOWERVP(bp->b_vp); 631 632 error = VOP_BWRITE(bp); 633 634 bp->b_vp = savedvp; 635 636 return (error); 637} 638 639/* 640 * Global vfs data structures 641 */ 642vop_t **null_vnodeop_p; 643static struct vnodeopv_entry_desc null_vnodeop_entries[] = { 644 { &vop_default_desc, (vop_t *)null_bypass }, 645 646 { &vop_lookup_desc, (vop_t *)null_lookup }, 647 { &vop_setattr_desc, (vop_t *)null_setattr }, 648 { &vop_getattr_desc, (vop_t *)null_getattr }, 649 { &vop_access_desc, (vop_t *)null_access }, 650 { &vop_lock_desc, (vop_t *)null_lock }, 651 { &vop_unlock_desc, (vop_t *)null_unlock }, 652 { &vop_inactive_desc, (vop_t *)null_inactive }, 653 { &vop_reclaim_desc, (vop_t *)null_reclaim }, 654 { &vop_print_desc, (vop_t *)null_print }, 655 656 { &vop_strategy_desc, (vop_t *)null_strategy }, 657 { &vop_bwrite_desc, (vop_t *)null_bwrite }, 658 659 { NULL, NULL } 660}; 661static struct vnodeopv_desc null_vnodeop_opv_desc = 662 { &null_vnodeop_p, null_vnodeop_entries }; 663 664VNODEOP_SET(null_vnodeop_opv_desc);
| 174 * 175 */ 176 177#include <sys/param.h> 178#include <sys/systm.h> 179#include <sys/kernel.h> 180#include <sys/sysctl.h> 181#include <sys/proc.h> 182#include <sys/time.h> 183#include <sys/types.h> 184#include <sys/vnode.h> 185#include <sys/mount.h> 186#include <sys/namei.h> 187#include <sys/malloc.h> 188#include <sys/buf.h> 189#include <miscfs/nullfs/null.h> 190 191static int null_bug_bypass = 0; /* for debugging: enables bypass printf'ing */ 192SYSCTL_INT(_debug, OID_AUTO, nullfs_bug_bypass, CTLFLAG_RW, 193 &null_bug_bypass, 0, ""); 194 195static int null_access __P((struct vop_access_args *ap)); 196static int null_bwrite __P((struct vop_bwrite_args *ap)); 197static int null_getattr __P((struct vop_getattr_args *ap)); 198static int null_inactive __P((struct vop_inactive_args *ap)); 199static int null_lock __P((struct vop_lock_args *ap)); 200static int null_lookup __P((struct vop_lookup_args *ap)); 201static int null_print __P((struct vop_print_args *ap)); 202static int null_reclaim __P((struct vop_reclaim_args *ap)); 203static int null_setattr __P((struct vop_setattr_args *ap)); 204static int null_strategy __P((struct vop_strategy_args *ap)); 205static int null_unlock __P((struct vop_unlock_args *ap)); 206 207/* 208 * This is the 10-Apr-92 bypass routine. 209 * This version has been optimized for speed, throwing away some 210 * safety checks. It should still always work, but it's not as 211 * robust to programmer errors. 212 * Define SAFETY to include some error checking code. 213 * 214 * In general, we map all vnodes going down and unmap them on the way back. 215 * As an exception to this, vnodes can be marked "unmapped" by setting 216 * the Nth bit in operation's vdesc_flags. 217 * 218 * Also, some BSD vnode operations have the side effect of vrele'ing 219 * their arguments. With stacking, the reference counts are held 220 * by the upper node, not the lower one, so we must handle these 221 * side-effects here. This is not of concern in Sun-derived systems 222 * since there are no such side-effects. 223 * 224 * This makes the following assumptions: 225 * - only one returned vpp 226 * - no INOUT vpp's (Sun's vop_open has one of these) 227 * - the vnode operation vector of the first vnode should be used 228 * to determine what implementation of the op should be invoked 229 * - all mapped vnodes are of our vnode-type (NEEDSWORK: 230 * problems on rmdir'ing mount points and renaming?) 231 */ 232int 233null_bypass(ap) 234 struct vop_generic_args /* { 235 struct vnodeop_desc *a_desc; 236 <other random data follows, presumably> 237 } */ *ap; 238{ 239 register struct vnode **this_vp_p; 240 int error; 241 struct vnode *old_vps[VDESC_MAX_VPS]; 242 struct vnode **vps_p[VDESC_MAX_VPS]; 243 struct vnode ***vppp; 244 struct vnodeop_desc *descp = ap->a_desc; 245 int reles, i; 246 247 if (null_bug_bypass) 248 printf ("null_bypass: %s\n", descp->vdesc_name); 249 250#ifdef SAFETY 251 /* 252 * We require at least one vp. 253 */ 254 if (descp->vdesc_vp_offsets == NULL || 255 descp->vdesc_vp_offsets[0] == VDESC_NO_OFFSET) 256 panic ("null_bypass: no vp's in map."); 257#endif 258 259 /* 260 * Map the vnodes going in. 261 * Later, we'll invoke the operation based on 262 * the first mapped vnode's operation vector. 263 */ 264 reles = descp->vdesc_flags; 265 for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) { 266 if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET) 267 break; /* bail out at end of list */ 268 vps_p[i] = this_vp_p = 269 VOPARG_OFFSETTO(struct vnode**,descp->vdesc_vp_offsets[i],ap); 270 /* 271 * We're not guaranteed that any but the first vnode 272 * are of our type. Check for and don't map any 273 * that aren't. (We must always map first vp or vclean fails.) 274 */ 275 if (i && (*this_vp_p == NULLVP || 276 (*this_vp_p)->v_op != null_vnodeop_p)) { 277 old_vps[i] = NULLVP; 278 } else { 279 old_vps[i] = *this_vp_p; 280 *(vps_p[i]) = NULLVPTOLOWERVP(*this_vp_p); 281 /* 282 * XXX - Several operations have the side effect 283 * of vrele'ing their vp's. We must account for 284 * that. (This should go away in the future.) 285 */ 286 if (reles & 1) 287 VREF(*this_vp_p); 288 } 289 290 } 291 292 /* 293 * Call the operation on the lower layer 294 * with the modified argument structure. 295 */ 296 error = VCALL(*(vps_p[0]), descp->vdesc_offset, ap); 297 298 /* 299 * Maintain the illusion of call-by-value 300 * by restoring vnodes in the argument structure 301 * to their original value. 302 */ 303 reles = descp->vdesc_flags; 304 for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) { 305 if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET) 306 break; /* bail out at end of list */ 307 if (old_vps[i]) { 308 *(vps_p[i]) = old_vps[i]; 309 if (reles & 1) 310 vrele(*(vps_p[i])); 311 } 312 } 313 314 /* 315 * Map the possible out-going vpp 316 * (Assumes that the lower layer always returns 317 * a VREF'ed vpp unless it gets an error.) 318 */ 319 if (descp->vdesc_vpp_offset != VDESC_NO_OFFSET && 320 !(descp->vdesc_flags & VDESC_NOMAP_VPP) && 321 !error) { 322 /* 323 * XXX - even though some ops have vpp returned vp's, 324 * several ops actually vrele this before returning. 325 * We must avoid these ops. 326 * (This should go away when these ops are regularized.) 327 */ 328 if (descp->vdesc_flags & VDESC_VPP_WILLRELE) 329 goto out; 330 vppp = VOPARG_OFFSETTO(struct vnode***, 331 descp->vdesc_vpp_offset,ap); 332 error = null_node_create(old_vps[0]->v_mount, **vppp, *vppp); 333 } 334 335 out: 336 return (error); 337} 338 339/* 340 * We have to carry on the locking protocol on the null layer vnodes 341 * as we progress through the tree. We also have to enforce read-only 342 * if this layer is mounted read-only. 343 */ 344static int 345null_lookup(ap) 346 struct vop_lookup_args /* { 347 struct vnode * a_dvp; 348 struct vnode ** a_vpp; 349 struct componentname * a_cnp; 350 } */ *ap; 351{ 352 struct componentname *cnp = ap->a_cnp; 353 struct proc *p = cnp->cn_proc; 354 int flags = cnp->cn_flags; 355 struct vop_lock_args lockargs; 356 struct vop_unlock_args unlockargs; 357 struct vnode *dvp, *vp; 358 int error; 359 360 if ((flags & ISLASTCN) && (ap->a_dvp->v_mount->mnt_flag & MNT_RDONLY) && 361 (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) 362 return (EROFS); 363 error = null_bypass((struct vop_generic_args *)ap); 364 if (error == EJUSTRETURN && (flags & ISLASTCN) && 365 (ap->a_dvp->v_mount->mnt_flag & MNT_RDONLY) && 366 (cnp->cn_nameiop == CREATE || cnp->cn_nameiop == RENAME)) 367 error = EROFS; 368 /* 369 * We must do the same locking and unlocking at this layer as 370 * is done in the layers below us. We could figure this out 371 * based on the error return and the LASTCN, LOCKPARENT, and 372 * LOCKLEAF flags. However, it is more expidient to just find 373 * out the state of the lower level vnodes and set ours to the 374 * same state. 375 */ 376 dvp = ap->a_dvp; 377 vp = *ap->a_vpp; 378 if (dvp == vp) 379 return (error); 380 if (!VOP_ISLOCKED(dvp)) { 381 unlockargs.a_vp = dvp; 382 unlockargs.a_flags = 0; 383 unlockargs.a_p = p; 384 vop_nounlock(&unlockargs); 385 } 386 if (vp != NULLVP && VOP_ISLOCKED(vp)) { 387 lockargs.a_vp = vp; 388 lockargs.a_flags = LK_SHARED; 389 lockargs.a_p = p; 390 vop_nolock(&lockargs); 391 } 392 return (error); 393} 394 395/* 396 * Setattr call. Disallow write attempts if the layer is mounted read-only. 397 */ 398int 399null_setattr(ap) 400 struct vop_setattr_args /* { 401 struct vnodeop_desc *a_desc; 402 struct vnode *a_vp; 403 struct vattr *a_vap; 404 struct ucred *a_cred; 405 struct proc *a_p; 406 } */ *ap; 407{ 408 struct vnode *vp = ap->a_vp; 409 struct vattr *vap = ap->a_vap; 410 411 if ((vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL || 412 vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL || 413 vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL) && 414 (vp->v_mount->mnt_flag & MNT_RDONLY)) 415 return (EROFS); 416 if (vap->va_size != VNOVAL) { 417 switch (vp->v_type) { 418 case VDIR: 419 return (EISDIR); 420 case VCHR: 421 case VBLK: 422 case VSOCK: 423 case VFIFO: 424 return (0); 425 case VREG: 426 case VLNK: 427 default: 428 /* 429 * Disallow write attempts if the filesystem is 430 * mounted read-only. 431 */ 432 if (vp->v_mount->mnt_flag & MNT_RDONLY) 433 return (EROFS); 434 } 435 } 436 return (null_bypass((struct vop_generic_args *)ap)); 437} 438 439/* 440 * We handle getattr only to change the fsid. 441 */ 442static int 443null_getattr(ap) 444 struct vop_getattr_args /* { 445 struct vnode *a_vp; 446 struct vattr *a_vap; 447 struct ucred *a_cred; 448 struct proc *a_p; 449 } */ *ap; 450{ 451 int error; 452 453 if (error = null_bypass((struct vop_generic_args *)ap)) 454 return (error); 455 /* Requires that arguments be restored. */ 456 ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0]; 457 return (0); 458} 459 460static int 461null_access(ap) 462 struct vop_access_args /* { 463 struct vnode *a_vp; 464 int a_mode; 465 struct ucred *a_cred; 466 struct proc *a_p; 467 } */ *ap; 468{ 469 struct vnode *vp = ap->a_vp; 470 mode_t mode = ap->a_mode; 471 472 /* 473 * Disallow write attempts on read-only layers; 474 * unless the file is a socket, fifo, or a block or 475 * character device resident on the file system. 476 */ 477 if (mode & VWRITE) { 478 switch (vp->v_type) { 479 case VDIR: 480 case VLNK: 481 case VREG: 482 if (vp->v_mount->mnt_flag & MNT_RDONLY) 483 return (EROFS); 484 break; 485 } 486 } 487 return (null_bypass((struct vop_generic_args *)ap)); 488} 489 490/* 491 * We need to process our own vnode lock and then clear the 492 * interlock flag as it applies only to our vnode, not the 493 * vnodes below us on the stack. 494 */ 495static int 496null_lock(ap) 497 struct vop_lock_args /* { 498 struct vnode *a_vp; 499 int a_flags; 500 struct proc *a_p; 501 } */ *ap; 502{ 503 504 vop_nolock(ap); 505 if ((ap->a_flags & LK_TYPE_MASK) == LK_DRAIN) 506 return (0); 507 ap->a_flags &= ~LK_INTERLOCK; 508 return (null_bypass((struct vop_generic_args *)ap)); 509} 510 511/* 512 * We need to process our own vnode unlock and then clear the 513 * interlock flag as it applies only to our vnode, not the 514 * vnodes below us on the stack. 515 */ 516static int 517null_unlock(ap) 518 struct vop_unlock_args /* { 519 struct vnode *a_vp; 520 int a_flags; 521 struct proc *a_p; 522 } */ *ap; 523{ 524 struct vnode *vp = ap->a_vp; 525 526 vop_nounlock(ap); 527 ap->a_flags &= ~LK_INTERLOCK; 528 return (null_bypass((struct vop_generic_args *)ap)); 529} 530 531static int 532null_inactive(ap) 533 struct vop_inactive_args /* { 534 struct vnode *a_vp; 535 struct proc *a_p; 536 } */ *ap; 537{ 538 /* 539 * Do nothing (and _don't_ bypass). 540 * Wait to vrele lowervp until reclaim, 541 * so that until then our null_node is in the 542 * cache and reusable. 543 * 544 * NEEDSWORK: Someday, consider inactive'ing 545 * the lowervp and then trying to reactivate it 546 * with capabilities (v_id) 547 * like they do in the name lookup cache code. 548 * That's too much work for now. 549 */ 550 VOP_UNLOCK(ap->a_vp, 0, ap->a_p); 551 return (0); 552} 553 554static int 555null_reclaim(ap) 556 struct vop_reclaim_args /* { 557 struct vnode *a_vp; 558 struct proc *a_p; 559 } */ *ap; 560{ 561 struct vnode *vp = ap->a_vp; 562 struct null_node *xp = VTONULL(vp); 563 struct vnode *lowervp = xp->null_lowervp; 564 565 /* 566 * Note: in vop_reclaim, vp->v_op == dead_vnodeop_p, 567 * so we can't call VOPs on ourself. 568 */ 569 /* After this assignment, this node will not be re-used. */ 570 xp->null_lowervp = NULLVP; 571 LIST_REMOVE(xp, null_hash); 572 FREE(vp->v_data, M_TEMP); 573 vp->v_data = NULL; 574 vrele (lowervp); 575 return (0); 576} 577 578static int 579null_print(ap) 580 struct vop_print_args /* { 581 struct vnode *a_vp; 582 } */ *ap; 583{ 584 register struct vnode *vp = ap->a_vp; 585 printf ("\ttag VT_NULLFS, vp=%p, lowervp=%p\n", vp, NULLVPTOLOWERVP(vp)); 586 return (0); 587} 588 589/* 590 * XXX - vop_strategy must be hand coded because it has no 591 * vnode in its arguments. 592 * This goes away with a merged VM/buffer cache. 593 */ 594static int 595null_strategy(ap) 596 struct vop_strategy_args /* { 597 struct buf *a_bp; 598 } */ *ap; 599{ 600 struct buf *bp = ap->a_bp; 601 int error; 602 struct vnode *savedvp; 603 604 savedvp = bp->b_vp; 605 bp->b_vp = NULLVPTOLOWERVP(bp->b_vp); 606 607 error = VOP_STRATEGY(bp); 608 609 bp->b_vp = savedvp; 610 611 return (error); 612} 613 614/* 615 * XXX - like vop_strategy, vop_bwrite must be hand coded because it has no 616 * vnode in its arguments. 617 * This goes away with a merged VM/buffer cache. 618 */ 619static int 620null_bwrite(ap) 621 struct vop_bwrite_args /* { 622 struct buf *a_bp; 623 } */ *ap; 624{ 625 struct buf *bp = ap->a_bp; 626 int error; 627 struct vnode *savedvp; 628 629 savedvp = bp->b_vp; 630 bp->b_vp = NULLVPTOLOWERVP(bp->b_vp); 631 632 error = VOP_BWRITE(bp); 633 634 bp->b_vp = savedvp; 635 636 return (error); 637} 638 639/* 640 * Global vfs data structures 641 */ 642vop_t **null_vnodeop_p; 643static struct vnodeopv_entry_desc null_vnodeop_entries[] = { 644 { &vop_default_desc, (vop_t *)null_bypass }, 645 646 { &vop_lookup_desc, (vop_t *)null_lookup }, 647 { &vop_setattr_desc, (vop_t *)null_setattr }, 648 { &vop_getattr_desc, (vop_t *)null_getattr }, 649 { &vop_access_desc, (vop_t *)null_access }, 650 { &vop_lock_desc, (vop_t *)null_lock }, 651 { &vop_unlock_desc, (vop_t *)null_unlock }, 652 { &vop_inactive_desc, (vop_t *)null_inactive }, 653 { &vop_reclaim_desc, (vop_t *)null_reclaim }, 654 { &vop_print_desc, (vop_t *)null_print }, 655 656 { &vop_strategy_desc, (vop_t *)null_strategy }, 657 { &vop_bwrite_desc, (vop_t *)null_bwrite }, 658 659 { NULL, NULL } 660}; 661static struct vnodeopv_desc null_vnodeop_opv_desc = 662 { &null_vnodeop_p, null_vnodeop_entries }; 663 664VNODEOP_SET(null_vnodeop_opv_desc);
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