null_vfsops.c revision 1.23
1 /* $NetBSD: null_vfsops.c,v 1.23 1999/02/26 23:44:45 wrstuden Exp $ */ 2 3 /* 4 * Copyright (c) 1992, 1993, 1995 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software donated to Berkeley by 8 * Jan-Simon Pendry. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * from: Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp 39 * from: @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92 40 * @(#)null_vfsops.c 8.7 (Berkeley) 5/14/95 41 */ 42 43 /* 44 * Null Layer 45 * (See null_vnops.c for a description of what this does.) 46 */ 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/time.h> 51 #include <sys/proc.h> 52 #include <sys/types.h> 53 #include <sys/vnode.h> 54 #include <sys/mount.h> 55 #include <sys/namei.h> 56 #include <sys/malloc.h> 57 #include <miscfs/nullfs/null.h> 58 59 int nullfs_mount __P((struct mount *, const char *, void *, 60 struct nameidata *, struct proc *)); 61 int nullfs_start __P((struct mount *, int, struct proc *)); 62 int nullfs_unmount __P((struct mount *, int, struct proc *)); 63 int nullfs_root __P((struct mount *, struct vnode **)); 64 int nullfs_quotactl __P((struct mount *, int, uid_t, caddr_t, 65 struct proc *)); 66 int nullfs_statfs __P((struct mount *, struct statfs *, struct proc *)); 67 int nullfs_sync __P((struct mount *, int, struct ucred *, struct proc *)); 68 int nullfs_vget __P((struct mount *, ino_t, struct vnode **)); 69 int nullfs_fhtovp __P((struct mount *, struct fid *, struct vnode **)); 70 int nullfs_checkexp __P((struct mount *, struct mbuf *, int *, 71 struct ucred **)); 72 int nullfs_vptofh __P((struct vnode *, struct fid *)); 73 int nullfs_sysctl __P((int *, u_int, void *, size_t *, void *, size_t, 74 struct proc *)); 75 /* 76 * Mount null layer 77 */ 78 int 79 nullfs_mount(mp, path, data, ndp, p) 80 struct mount *mp; 81 const char *path; 82 void *data; 83 struct nameidata *ndp; 84 struct proc *p; 85 { 86 int error = 0; 87 struct null_args args; 88 struct vnode *lowerrootvp, *vp; 89 struct vnode *nullm_rootvp; 90 struct null_mount *xmp; 91 size_t size; 92 93 #ifdef NULLFS_DIAGNOSTIC 94 printf("nullfs_mount(mp = %p)\n", mp); 95 #endif 96 97 /* 98 * Update is a no-op 99 */ 100 if (mp->mnt_flag & MNT_UPDATE) { 101 return (EOPNOTSUPP); 102 /* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, path, data, ndp, p);*/ 103 } 104 105 /* 106 * Get argument 107 */ 108 error = copyin(data, (caddr_t)&args, sizeof(struct null_args)); 109 if (error) 110 return (error); 111 112 /* 113 * Find lower node 114 */ 115 NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF, 116 UIO_USERSPACE, args.target, p); 117 if ((error = namei(ndp)) != 0) 118 return (error); 119 120 /* 121 * Sanity check on lower vnode 122 */ 123 lowerrootvp = ndp->ni_vp; 124 125 vrele(ndp->ni_dvp); 126 ndp->ni_dvp = NULL; 127 128 xmp = (struct null_mount *) malloc(sizeof(struct null_mount), 129 M_UFSMNT, M_WAITOK); /* XXX */ 130 131 /* 132 * Save reference to underlying FS 133 */ 134 xmp->nullm_vfs = lowerrootvp->v_mount; 135 136 /* 137 * Save reference. Each mount also holds 138 * a reference on the root vnode. 139 */ 140 error = null_node_create(mp, lowerrootvp, &vp, 1); 141 /* 142 * Make sure the node alias worked 143 */ 144 if (error) { 145 vrele(lowerrootvp); 146 free(xmp, M_UFSMNT); /* XXX */ 147 return (error); 148 } 149 /* 150 * Unlock the node (either the lower or the alias) 151 */ 152 VOP_UNLOCK(vp, 0); 153 154 /* 155 * Keep a held reference to the root vnode. 156 * It is vrele'd in nullfs_unmount. 157 */ 158 nullm_rootvp = vp; 159 nullm_rootvp->v_flag |= VROOT; 160 xmp->nullm_rootvp = nullm_rootvp; 161 if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL) 162 mp->mnt_flag |= MNT_LOCAL; 163 mp->mnt_data = (qaddr_t) xmp; 164 vfs_getnewfsid(mp, MOUNT_NULL); 165 166 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); 167 memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size); 168 (void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 169 &size); 170 memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size); 171 #ifdef NULLFS_DIAGNOSTIC 172 printf("nullfs_mount: lower %s, alias at %s\n", 173 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 174 #endif 175 return (0); 176 } 177 178 /* 179 * VFS start. Nothing needed here - the start routine 180 * on the underlying filesystem will have been called 181 * when that filesystem was mounted. 182 */ 183 int 184 nullfs_start(mp, flags, p) 185 struct mount *mp; 186 int flags; 187 struct proc *p; 188 { 189 190 return (0); 191 /* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, p); */ 192 } 193 194 /* 195 * Free reference to null layer 196 */ 197 int 198 nullfs_unmount(mp, mntflags, p) 199 struct mount *mp; 200 int mntflags; 201 struct proc *p; 202 { 203 struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; 204 int error; 205 int flags = 0; 206 207 #ifdef NULLFS_DIAGNOSTIC 208 printf("nullfs_unmount(mp = %p)\n", mp); 209 #endif 210 211 if (mntflags & MNT_FORCE) 212 flags |= FORCECLOSE; 213 214 /* 215 * Clear out buffer cache. I don't think we 216 * ever get anything cached at this level at the 217 * moment, but who knows... 218 */ 219 #if 0 220 mntflushbuf(mp, 0); 221 if (mntinvalbuf(mp, 1)) 222 return (EBUSY); 223 #endif 224 if (nullm_rootvp->v_usecount > 1) 225 return (EBUSY); 226 if ((error = vflush(mp, nullm_rootvp, flags)) != 0) 227 return (error); 228 229 #ifdef NULLFS_DIAGNOSTIC 230 vprint("alias root of lower", nullm_rootvp); 231 #endif 232 /* 233 * Release reference on underlying root vnode 234 */ 235 vrele(nullm_rootvp); 236 /* 237 * And blow it away for future re-use 238 */ 239 vgone(nullm_rootvp); 240 /* 241 * Finally, throw away the null_mount structure 242 */ 243 free(mp->mnt_data, M_UFSMNT); /* XXX */ 244 mp->mnt_data = 0; 245 return 0; 246 } 247 248 int 249 nullfs_root(mp, vpp) 250 struct mount *mp; 251 struct vnode **vpp; 252 { 253 struct vnode *vp; 254 255 #ifdef NULLFS_DIAGNOSTIC 256 printf("nullfs_root(mp = %p, vp = %p->%p)\n", mp, 257 MOUNTTONULLMOUNT(mp)->nullm_rootvp, 258 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)); 259 #endif 260 261 /* 262 * Return locked reference to root. 263 */ 264 vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; 265 VREF(vp); 266 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 267 *vpp = vp; 268 return 0; 269 } 270 271 int 272 nullfs_quotactl(mp, cmd, uid, arg, p) 273 struct mount *mp; 274 int cmd; 275 uid_t uid; 276 caddr_t arg; 277 struct proc *p; 278 { 279 280 return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p); 281 } 282 283 int 284 nullfs_statfs(mp, sbp, p) 285 struct mount *mp; 286 struct statfs *sbp; 287 struct proc *p; 288 { 289 int error; 290 struct statfs mstat; 291 292 #ifdef NULLFS_DIAGNOSTIC 293 printf("nullfs_statfs(mp = %p, vp = %p->%p)\n", mp, 294 MOUNTTONULLMOUNT(mp)->nullm_rootvp, 295 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)); 296 #endif 297 298 memset(&mstat, 0, sizeof(mstat)); 299 300 error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p); 301 if (error) 302 return (error); 303 304 /* now copy across the "interesting" information and fake the rest */ 305 sbp->f_type = mstat.f_type; 306 sbp->f_flags = mstat.f_flags; 307 sbp->f_bsize = mstat.f_bsize; 308 sbp->f_iosize = mstat.f_iosize; 309 sbp->f_blocks = mstat.f_blocks; 310 sbp->f_bfree = mstat.f_bfree; 311 sbp->f_bavail = mstat.f_bavail; 312 sbp->f_files = mstat.f_files; 313 sbp->f_ffree = mstat.f_ffree; 314 if (sbp != &mp->mnt_stat) { 315 memcpy(&sbp->f_fsid, &mp->mnt_stat.f_fsid, sizeof(sbp->f_fsid)); 316 memcpy(sbp->f_mntonname, mp->mnt_stat.f_mntonname, MNAMELEN); 317 memcpy(sbp->f_mntfromname, mp->mnt_stat.f_mntfromname, MNAMELEN); 318 } 319 strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, MFSNAMELEN); 320 return (0); 321 } 322 323 int 324 nullfs_sync(mp, waitfor, cred, p) 325 struct mount *mp; 326 int waitfor; 327 struct ucred *cred; 328 struct proc *p; 329 { 330 331 /* 332 * XXX - Assumes no data cached at null layer. 333 */ 334 return (0); 335 } 336 337 int 338 nullfs_vget(mp, ino, vpp) 339 struct mount *mp; 340 ino_t ino; 341 struct vnode **vpp; 342 { 343 344 return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp); 345 } 346 347 int 348 nullfs_fhtovp(mp, fidp, vpp) 349 struct mount *mp; 350 struct fid *fidp; 351 struct vnode **vpp; 352 { 353 354 return (EOPNOTSUPP); 355 } 356 357 int 358 nullfs_checkexp(mp, nam, exflagsp, credanonp) 359 struct mount *mp; 360 struct mbuf *nam; 361 int *exflagsp; 362 struct ucred**credanonp; 363 { 364 365 return (EOPNOTSUPP); 366 } 367 368 int 369 nullfs_vptofh(vp, fhp) 370 struct vnode *vp; 371 struct fid *fhp; 372 { 373 374 return (EOPNOTSUPP); 375 } 376 377 int 378 nullfs_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p) 379 int *name; 380 u_int namelen; 381 void *oldp; 382 size_t *oldlenp; 383 void *newp; 384 size_t newlen; 385 struct proc *p; 386 { 387 return (EOPNOTSUPP); 388 } 389 390 extern struct vnodeopv_desc null_vnodeop_opv_desc; 391 392 struct vnodeopv_desc *nullfs_vnodeopv_descs[] = { 393 &null_vnodeop_opv_desc, 394 NULL, 395 }; 396 397 struct vfsops nullfs_vfsops = { 398 MOUNT_NULL, 399 nullfs_mount, 400 nullfs_start, 401 nullfs_unmount, 402 nullfs_root, 403 nullfs_quotactl, 404 nullfs_statfs, 405 nullfs_sync, 406 nullfs_vget, 407 nullfs_fhtovp, 408 nullfs_vptofh, 409 nullfs_init, 410 nullfs_sysctl, 411 NULL, /* vfs_mountroot */ 412 nullfs_checkexp, 413 nullfs_vnodeopv_descs, 414 }; 415
Indexes created Tue Sep 30 20:09:53 GMT 2025