1 /* $NetBSD: null_vfsops.c,v 1.20 1998/08/09 20:51:09 perry 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 mbuf *, 70 struct vnode **, int *, struct ucred **)); 71 int nullfs_vptofh __P((struct vnode *, struct fid *)); 72 int nullfs_sysctl __P((int *, u_int, void *, size_t *, void *, size_t, 73 struct proc *)); 74 /* 75 * Mount null layer 76 */ 77 int 78 nullfs_mount(mp, path, data, ndp, p) 79 struct mount *mp; 80 const char *path; 81 void *data; 82 struct nameidata *ndp; 83 struct proc *p; 84 { 85 int error = 0; 86 struct null_args args; 87 struct vnode *lowerrootvp, *vp; 88 struct vnode *nullm_rootvp; 89 struct null_mount *xmp; 90 size_t size; 91 92 #ifdef NULLFS_DIAGNOSTIC 93 printf("nullfs_mount(mp = %p)\n", mp); 94 #endif 95 96 /* 97 * Update is a no-op 98 */ 99 if (mp->mnt_flag & MNT_UPDATE) { 100 return (EOPNOTSUPP); 101 /* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, path, data, ndp, p);*/ 102 } 103 104 /* 105 * Get argument 106 */ 107 error = copyin(data, (caddr_t)&args, sizeof(struct null_args)); 108 if (error) 109 return (error); 110 111 /* 112 * Find lower node 113 */ 114 NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF, 115 UIO_USERSPACE, args.target, p); 116 if ((error = namei(ndp)) != 0) 117 return (error); 118 119 /* 120 * Sanity check on lower vnode 121 */ 122 lowerrootvp = ndp->ni_vp; 123 124 vrele(ndp->ni_dvp); 125 ndp->ni_dvp = NULL; 126 127 xmp = (struct null_mount *) malloc(sizeof(struct null_mount), 128 M_UFSMNT, M_WAITOK); /* XXX */ 129 130 /* 131 * Save reference to underlying FS 132 */ 133 xmp->nullm_vfs = lowerrootvp->v_mount; 134 135 /* 136 * Save reference. Each mount also holds 137 * a reference on the root vnode. 138 */ 139 error = null_node_create(mp, lowerrootvp, &vp, 1); 140 /* 141 * Unlock the node (either the lower or the alias) 142 */ 143 VOP_UNLOCK(vp, 0); 144 /* 145 * Make sure the node alias worked 146 */ 147 if (error) { 148 vrele(lowerrootvp); 149 free(xmp, M_UFSMNT); /* XXX */ 150 return (error); 151 } 152 153 /* 154 * Keep a held reference to the root vnode. 155 * It is vrele'd in nullfs_unmount. 156 */ 157 nullm_rootvp = vp; 158 nullm_rootvp->v_flag |= VROOT; 159 xmp->nullm_rootvp = nullm_rootvp; 160 if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL) 161 mp->mnt_flag |= MNT_LOCAL; 162 mp->mnt_data = (qaddr_t) xmp; 163 vfs_getnewfsid(mp, MOUNT_NULL); 164 165 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); 166 memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size); 167 (void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 168 &size); 169 memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size); 170 #ifdef NULLFS_DIAGNOSTIC 171 printf("nullfs_mount: lower %s, alias at %s\n", 172 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 173 #endif 174 return (0); 175 } 176 177 /* 178 * VFS start. Nothing needed here - the start routine 179 * on the underlying filesystem will have been called 180 * when that filesystem was mounted. 181 */ 182 int 183 nullfs_start(mp, flags, p) 184 struct mount *mp; 185 int flags; 186 struct proc *p; 187 { 188 189 return (0); 190 /* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, p); */ 191 } 192 193 /* 194 * Free reference to null layer 195 */ 196 int 197 nullfs_unmount(mp, mntflags, p) 198 struct mount *mp; 199 int mntflags; 200 struct proc *p; 201 { 202 struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; 203 int error; 204 int flags = 0; 205 206 #ifdef NULLFS_DIAGNOSTIC 207 printf("nullfs_unmount(mp = %p)\n", mp); 208 #endif 209 210 if (mntflags & MNT_FORCE) 211 flags |= FORCECLOSE; 212 213 /* 214 * Clear out buffer cache. I don't think we 215 * ever get anything cached at this level at the 216 * moment, but who knows... 217 */ 218 #if 0 219 mntflushbuf(mp, 0); 220 if (mntinvalbuf(mp, 1)) 221 return (EBUSY); 222 #endif 223 if (nullm_rootvp->v_usecount > 1) 224 return (EBUSY); 225 if ((error = vflush(mp, nullm_rootvp, flags)) != 0) 226 return (error); 227 228 #ifdef NULLFS_DIAGNOSTIC 229 vprint("alias root of lower", nullm_rootvp); 230 #endif 231 /* 232 * Release reference on underlying root vnode 233 */ 234 vrele(nullm_rootvp); 235 /* 236 * And blow it away for future re-use 237 */ 238 vgone(nullm_rootvp); 239 /* 240 * Finally, throw away the null_mount structure 241 */ 242 free(mp->mnt_data, M_UFSMNT); /* XXX */ 243 mp->mnt_data = 0; 244 return 0; 245 } 246 247 int 248 nullfs_root(mp, vpp) 249 struct mount *mp; 250 struct vnode **vpp; 251 { 252 struct vnode *vp; 253 254 #ifdef NULLFS_DIAGNOSTIC 255 printf("nullfs_root(mp = %p, vp = %p->%p)\n", mp, 256 MOUNTTONULLMOUNT(mp)->nullm_rootvp, 257 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)); 258 #endif 259 260 /* 261 * Return locked reference to root. 262 */ 263 vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; 264 VREF(vp); 265 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 266 *vpp = vp; 267 return 0; 268 } 269 270 int 271 nullfs_quotactl(mp, cmd, uid, arg, p) 272 struct mount *mp; 273 int cmd; 274 uid_t uid; 275 caddr_t arg; 276 struct proc *p; 277 { 278 279 return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p); 280 } 281 282 int 283 nullfs_statfs(mp, sbp, p) 284 struct mount *mp; 285 struct statfs *sbp; 286 struct proc *p; 287 { 288 int error; 289 struct statfs mstat; 290 291 #ifdef NULLFS_DIAGNOSTIC 292 printf("nullfs_statfs(mp = %p, vp = %p->%p)\n", mp, 293 MOUNTTONULLMOUNT(mp)->nullm_rootvp, 294 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)); 295 #endif 296 297 memset(&mstat, 0, sizeof(mstat)); 298 299 error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p); 300 if (error) 301 return (error); 302 303 /* now copy across the "interesting" information and fake the rest */ 304 sbp->f_type = mstat.f_type; 305 sbp->f_flags = mstat.f_flags; 306 sbp->f_bsize = mstat.f_bsize; 307 sbp->f_iosize = mstat.f_iosize; 308 sbp->f_blocks = mstat.f_blocks; 309 sbp->f_bfree = mstat.f_bfree; 310 sbp->f_bavail = mstat.f_bavail; 311 sbp->f_files = mstat.f_files; 312 sbp->f_ffree = mstat.f_ffree; 313 if (sbp != &mp->mnt_stat) { 314 memcpy(&sbp->f_fsid, &mp->mnt_stat.f_fsid, sizeof(sbp->f_fsid)); 315 memcpy(sbp->f_mntonname, mp->mnt_stat.f_mntonname, MNAMELEN); 316 memcpy(sbp->f_mntfromname, mp->mnt_stat.f_mntfromname, MNAMELEN); 317 } 318 strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, MFSNAMELEN); 319 return (0); 320 } 321 322 int 323 nullfs_sync(mp, waitfor, cred, p) 324 struct mount *mp; 325 int waitfor; 326 struct ucred *cred; 327 struct proc *p; 328 { 329 330 /* 331 * XXX - Assumes no data cached at null layer. 332 */ 333 return (0); 334 } 335 336 int 337 nullfs_vget(mp, ino, vpp) 338 struct mount *mp; 339 ino_t ino; 340 struct vnode **vpp; 341 { 342 343 return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp); 344 } 345 346 int 347 nullfs_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp) 348 struct mount *mp; 349 struct fid *fidp; 350 struct mbuf *nam; 351 struct vnode **vpp; 352 int *exflagsp; 353 struct ucred**credanonp; 354 { 355 356 return (EOPNOTSUPP); 357 } 358 359 int 360 nullfs_vptofh(vp, fhp) 361 struct vnode *vp; 362 struct fid *fhp; 363 { 364 365 return (EOPNOTSUPP); 366 } 367 368 int 369 nullfs_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p) 370 int *name; 371 u_int namelen; 372 void *oldp; 373 size_t *oldlenp; 374 void *newp; 375 size_t newlen; 376 struct proc *p; 377 { 378 return (EOPNOTSUPP); 379 } 380 381 extern struct vnodeopv_desc null_vnodeop_opv_desc; 382 383 struct vnodeopv_desc *nullfs_vnodeopv_descs[] = { 384 &null_vnodeop_opv_desc, 385 NULL, 386 }; 387 388 struct vfsops nullfs_vfsops = { 389 MOUNT_NULL, 390 nullfs_mount, 391 nullfs_start, 392 nullfs_unmount, 393 nullfs_root, 394 nullfs_quotactl, 395 nullfs_statfs, 396 nullfs_sync, 397 nullfs_vget, 398 nullfs_fhtovp, 399 nullfs_vptofh, 400 nullfs_init, 401 nullfs_sysctl, 402 NULL, /* vfs_mountroot */ 403 nullfs_vnodeopv_descs, 404 }; 405