null_vfsops.c revision 1.16
1 /* $NetBSD: null_vfsops.c,v 1.16 1997/09/10 13:44:23 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1992, 1993 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 8.2 (Berkeley) 1/21/94 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/types.h> 52 #include <sys/vnode.h> 53 #include <sys/mount.h> 54 #include <sys/namei.h> 55 #include <sys/malloc.h> 56 #include <miscfs/nullfs/null.h> 57 58 int nullfs_mount __P((struct mount *, const char *, void *, 59 struct nameidata *, struct proc *)); 60 int nullfs_start __P((struct mount *, int, struct proc *)); 61 int nullfs_unmount __P((struct mount *, int, struct proc *)); 62 int nullfs_root __P((struct mount *, struct vnode **)); 63 int nullfs_quotactl __P((struct mount *, int, uid_t, caddr_t, 64 struct proc *)); 65 int nullfs_statfs __P((struct mount *, struct statfs *, struct proc *)); 66 int nullfs_sync __P((struct mount *, int, struct ucred *, struct proc *)); 67 int nullfs_vget __P((struct mount *, ino_t, struct vnode **)); 68 int nullfs_fhtovp __P((struct mount *, struct fid *, struct mbuf *, 69 struct vnode **, int *, struct ucred **)); 70 int nullfs_vptofh __P((struct vnode *, struct fid *)); 71 /* 72 * Mount null layer 73 */ 74 int 75 nullfs_mount(mp, path, data, ndp, p) 76 struct mount *mp; 77 const char *path; 78 void *data; 79 struct nameidata *ndp; 80 struct proc *p; 81 { 82 int error = 0; 83 struct null_args args; 84 struct vnode *lowerrootvp, *vp; 85 struct vnode *nullm_rootvp; 86 struct null_mount *xmp; 87 size_t size; 88 89 #ifdef NULLFS_DIAGNOSTIC 90 printf("nullfs_mount(mp = %p)\n", mp); 91 #endif 92 93 /* 94 * Update is a no-op 95 */ 96 if (mp->mnt_flag & MNT_UPDATE) { 97 return (EOPNOTSUPP); 98 /* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, path, data, ndp, p);*/ 99 } 100 101 /* 102 * Get argument 103 */ 104 error = copyin(data, (caddr_t)&args, sizeof(struct null_args)); 105 if (error) 106 return (error); 107 108 /* 109 * Find lower node 110 */ 111 NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF, 112 UIO_USERSPACE, args.target, p); 113 if ((error = namei(ndp)) != 0) 114 return (error); 115 116 /* 117 * Sanity check on lower vnode 118 */ 119 lowerrootvp = ndp->ni_vp; 120 121 vrele(ndp->ni_dvp); 122 ndp->ni_dvp = NULL; 123 124 xmp = (struct null_mount *) malloc(sizeof(struct null_mount), 125 M_UFSMNT, M_WAITOK); /* XXX */ 126 127 /* 128 * Save reference to underlying FS 129 */ 130 xmp->nullm_vfs = lowerrootvp->v_mount; 131 132 /* 133 * Save reference. Each mount also holds 134 * a reference on the root vnode. 135 */ 136 error = null_node_create(mp, lowerrootvp, &vp, 1); 137 /* 138 * Unlock the node (either the lower or the alias) 139 */ 140 VOP_UNLOCK(vp); 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 /* 151 * Keep a held reference to the root vnode. 152 * It is vrele'd in nullfs_unmount. 153 */ 154 nullm_rootvp = vp; 155 nullm_rootvp->v_flag |= VROOT; 156 xmp->nullm_rootvp = nullm_rootvp; 157 if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL) 158 mp->mnt_flag |= MNT_LOCAL; 159 mp->mnt_data = (qaddr_t) xmp; 160 getnewfsid(mp, makefstype(MOUNT_NULL)); 161 162 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); 163 bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size); 164 (void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 165 &size); 166 bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size); 167 #ifdef NULLFS_DIAGNOSTIC 168 printf("nullfs_mount: lower %s, alias at %s\n", 169 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 170 #endif 171 return (0); 172 } 173 174 /* 175 * VFS start. Nothing needed here - the start routine 176 * on the underlying filesystem will have been called 177 * when that filesystem was mounted. 178 */ 179 int 180 nullfs_start(mp, flags, p) 181 struct mount *mp; 182 int flags; 183 struct proc *p; 184 { 185 186 return (0); 187 /* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, p); */ 188 } 189 190 /* 191 * Free reference to null layer 192 */ 193 int 194 nullfs_unmount(mp, mntflags, p) 195 struct mount *mp; 196 int mntflags; 197 struct proc *p; 198 { 199 struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; 200 int error; 201 int flags = 0; 202 extern int doforce; 203 204 #ifdef NULLFS_DIAGNOSTIC 205 printf("nullfs_unmount(mp = %p)\n", mp); 206 #endif 207 208 if (mntflags & MNT_FORCE) { 209 /* lofs can never be rootfs so don't check for it */ 210 if (!doforce) 211 return (EINVAL); 212 flags |= FORCECLOSE; 213 } 214 215 /* 216 * Clear out buffer cache. I don't think we 217 * ever get anything cached at this level at the 218 * moment, but who knows... 219 */ 220 #if 0 221 mntflushbuf(mp, 0); 222 if (mntinvalbuf(mp, 1)) 223 return (EBUSY); 224 #endif 225 if (nullm_rootvp->v_usecount > 1) 226 return (EBUSY); 227 if ((error = vflush(mp, nullm_rootvp, flags)) != 0) 228 return (error); 229 230 #ifdef NULLFS_DIAGNOSTIC 231 vprint("alias root of lower", nullm_rootvp); 232 #endif 233 /* 234 * Release reference on underlying root vnode 235 */ 236 vrele(nullm_rootvp); 237 /* 238 * And blow it away for future re-use 239 */ 240 vgone(nullm_rootvp); 241 /* 242 * Finally, throw away the null_mount structure 243 */ 244 free(mp->mnt_data, M_UFSMNT); /* XXX */ 245 mp->mnt_data = 0; 246 return 0; 247 } 248 249 int 250 nullfs_root(mp, vpp) 251 struct mount *mp; 252 struct vnode **vpp; 253 { 254 struct vnode *vp; 255 256 #ifdef NULLFS_DIAGNOSTIC 257 printf("nullfs_root(mp = %p, vp = %p->%p)\n", mp, 258 MOUNTTONULLMOUNT(mp)->nullm_rootvp, 259 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)); 260 #endif 261 262 /* 263 * Return locked reference to root. 264 */ 265 vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; 266 VREF(vp); 267 VOP_LOCK(vp); 268 *vpp = vp; 269 return 0; 270 } 271 272 int 273 nullfs_quotactl(mp, cmd, uid, arg, p) 274 struct mount *mp; 275 int cmd; 276 uid_t uid; 277 caddr_t arg; 278 struct proc *p; 279 { 280 281 return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p); 282 } 283 284 int 285 nullfs_statfs(mp, sbp, p) 286 struct mount *mp; 287 struct statfs *sbp; 288 struct proc *p; 289 { 290 int error; 291 struct statfs mstat; 292 293 #ifdef NULLFS_DIAGNOSTIC 294 printf("nullfs_statfs(mp = %p, vp = %p->%p)\n", mp, 295 MOUNTTONULLMOUNT(mp)->nullm_rootvp, 296 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)); 297 #endif 298 299 bzero(&mstat, sizeof(mstat)); 300 301 error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p); 302 if (error) 303 return (error); 304 305 /* now copy across the "interesting" information and fake the rest */ 306 sbp->f_type = mstat.f_type; 307 sbp->f_flags = mstat.f_flags; 308 sbp->f_bsize = mstat.f_bsize; 309 sbp->f_iosize = mstat.f_iosize; 310 sbp->f_blocks = mstat.f_blocks; 311 sbp->f_bfree = mstat.f_bfree; 312 sbp->f_bavail = mstat.f_bavail; 313 sbp->f_files = mstat.f_files; 314 sbp->f_ffree = mstat.f_ffree; 315 if (sbp != &mp->mnt_stat) { 316 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid)); 317 bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN); 318 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN); 319 } 320 strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, MFSNAMELEN); 321 return (0); 322 } 323 324 int 325 nullfs_sync(mp, waitfor, cred, p) 326 struct mount *mp; 327 int waitfor; 328 struct ucred *cred; 329 struct proc *p; 330 { 331 332 /* 333 * XXX - Assumes no data cached at null layer. 334 */ 335 return (0); 336 } 337 338 int 339 nullfs_vget(mp, ino, vpp) 340 struct mount *mp; 341 ino_t ino; 342 struct vnode **vpp; 343 { 344 345 return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp); 346 } 347 348 int 349 nullfs_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp) 350 struct mount *mp; 351 struct fid *fidp; 352 struct mbuf *nam; 353 struct vnode **vpp; 354 int *exflagsp; 355 struct ucred**credanonp; 356 { 357 358 return (EOPNOTSUPP); 359 } 360 361 int 362 nullfs_vptofh(vp, fhp) 363 struct vnode *vp; 364 struct fid *fhp; 365 { 366 367 return (EOPNOTSUPP); 368 } 369 370 struct vfsops null_vfsops = { 371 MOUNT_NULL, 372 nullfs_mount, 373 nullfs_start, 374 nullfs_unmount, 375 nullfs_root, 376 nullfs_quotactl, 377 nullfs_statfs, 378 nullfs_sync, 379 nullfs_vget, 380 nullfs_fhtovp, 381 nullfs_vptofh, 382 nullfs_init, 383 }; 384
Indexes created Thu Sep 25 16:09:42 GMT 2025