null_vfsops.c revision 1.3
1 /* $NetBSD: null_vfsops.c,v 1.3 1994/09/15 03:42:40 mycroft 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 /* 59 * Mount null layer 60 */ 61 int 62 nullfs_mount(mp, path, data, ndp, p) 63 struct mount *mp; 64 char *path; 65 caddr_t data; 66 struct nameidata *ndp; 67 struct proc *p; 68 { 69 int error = 0; 70 struct null_args args; 71 struct vnode *lowerrootvp, *vp; 72 struct vnode *nullm_rootvp; 73 struct null_mount *xmp; 74 u_int size; 75 76 #ifdef NULLFS_DIAGNOSTIC 77 printf("nullfs_mount(mp = %x)\n", mp); 78 #endif 79 80 /* 81 * Update is a no-op 82 */ 83 if (mp->mnt_flag & MNT_UPDATE) { 84 return (EOPNOTSUPP); 85 /* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, path, data, ndp, p);*/ 86 } 87 88 /* 89 * Get argument 90 */ 91 if (error = copyin(data, (caddr_t)&args, sizeof(struct null_args))) 92 return (error); 93 94 /* 95 * Find lower node 96 */ 97 NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF, 98 UIO_USERSPACE, args.target, p); 99 if (error = namei(ndp)) 100 return (error); 101 102 /* 103 * Sanity check on lower vnode 104 */ 105 lowerrootvp = ndp->ni_vp; 106 107 vrele(ndp->ni_dvp); 108 ndp->ni_dvp = NULL; 109 110 xmp = (struct null_mount *) malloc(sizeof(struct null_mount), 111 M_UFSMNT, M_WAITOK); /* XXX */ 112 113 /* 114 * Save reference to underlying FS 115 */ 116 xmp->nullm_vfs = lowerrootvp->v_mount; 117 118 /* 119 * Save reference. Each mount also holds 120 * a reference on the root vnode. 121 */ 122 error = null_node_create(mp, lowerrootvp, &vp); 123 /* 124 * Unlock the node (either the lower or the alias) 125 */ 126 VOP_UNLOCK(vp); 127 /* 128 * Make sure the node alias worked 129 */ 130 if (error) { 131 vrele(lowerrootvp); 132 free(xmp, M_UFSMNT); /* XXX */ 133 return (error); 134 } 135 136 /* 137 * Keep a held reference to the root vnode. 138 * It is vrele'd in nullfs_unmount. 139 */ 140 nullm_rootvp = vp; 141 nullm_rootvp->v_flag |= VROOT; 142 xmp->nullm_rootvp = nullm_rootvp; 143 if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL) 144 mp->mnt_flag |= MNT_LOCAL; 145 mp->mnt_data = (qaddr_t) xmp; 146 getnewfsid(mp, makefstype(MOUNT_LOFS)); 147 148 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); 149 bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size); 150 (void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 151 &size); 152 bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size); 153 (void)nullfs_statfs(mp, &mp->mnt_stat, p); 154 #ifdef NULLFS_DIAGNOSTIC 155 printf("nullfs_mount: lower %s, alias at %s\n", 156 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 157 #endif 158 return (0); 159 } 160 161 /* 162 * VFS start. Nothing needed here - the start routine 163 * on the underlying filesystem will have been called 164 * when that filesystem was mounted. 165 */ 166 int 167 nullfs_start(mp, flags, p) 168 struct mount *mp; 169 int flags; 170 struct proc *p; 171 { 172 173 return (0); 174 /* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, p); */ 175 } 176 177 /* 178 * Free reference to null layer 179 */ 180 int 181 nullfs_unmount(mp, mntflags, p) 182 struct mount *mp; 183 int mntflags; 184 struct proc *p; 185 { 186 struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; 187 int error; 188 int flags = 0; 189 extern int doforce; 190 191 #ifdef NULLFS_DIAGNOSTIC 192 printf("nullfs_unmount(mp = %x)\n", mp); 193 #endif 194 195 if (mntflags & MNT_FORCE) { 196 /* lofs can never be rootfs so don't check for it */ 197 if (!doforce) 198 return (EINVAL); 199 flags |= FORCECLOSE; 200 } 201 202 /* 203 * Clear out buffer cache. I don't think we 204 * ever get anything cached at this level at the 205 * moment, but who knows... 206 */ 207 #if 0 208 mntflushbuf(mp, 0); 209 if (mntinvalbuf(mp, 1)) 210 return (EBUSY); 211 #endif 212 if (nullm_rootvp->v_usecount > 1) 213 return (EBUSY); 214 if (error = vflush(mp, nullm_rootvp, flags)) 215 return (error); 216 217 #ifdef NULLFS_DIAGNOSTIC 218 vprint("alias root of lower", nullm_rootvp); 219 #endif 220 /* 221 * Release reference on underlying root vnode 222 */ 223 vrele(nullm_rootvp); 224 /* 225 * And blow it away for future re-use 226 */ 227 vgone(nullm_rootvp); 228 /* 229 * Finally, throw away the null_mount structure 230 */ 231 free(mp->mnt_data, M_UFSMNT); /* XXX */ 232 mp->mnt_data = 0; 233 return 0; 234 } 235 236 int 237 nullfs_root(mp, vpp) 238 struct mount *mp; 239 struct vnode **vpp; 240 { 241 struct vnode *vp; 242 243 #ifdef NULLFS_DIAGNOSTIC 244 printf("nullfs_root(mp = %x, vp = %x->%x)\n", mp, 245 MOUNTTONULLMOUNT(mp)->nullm_rootvp, 246 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp) 247 ); 248 #endif 249 250 /* 251 * Return locked reference to root. 252 */ 253 vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; 254 VREF(vp); 255 VOP_LOCK(vp); 256 *vpp = vp; 257 return 0; 258 } 259 260 int 261 nullfs_quotactl(mp, cmd, uid, arg, p) 262 struct mount *mp; 263 int cmd; 264 uid_t uid; 265 caddr_t arg; 266 struct proc *p; 267 { 268 269 return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p); 270 } 271 272 int 273 nullfs_statfs(mp, sbp, p) 274 struct mount *mp; 275 struct statfs *sbp; 276 struct proc *p; 277 { 278 int error; 279 struct statfs mstat; 280 281 #ifdef NULLFS_DIAGNOSTIC 282 printf("nullfs_statfs(mp = %x, vp = %x->%x)\n", mp, 283 MOUNTTONULLMOUNT(mp)->nullm_rootvp, 284 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp) 285 ); 286 #endif 287 288 bzero(&mstat, sizeof(mstat)); 289 290 error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p); 291 if (error) 292 return (error); 293 294 /* now copy across the "interesting" information and fake the rest */ 295 sbp->f_type = mstat.f_type; 296 sbp->f_flags = mstat.f_flags; 297 sbp->f_bsize = mstat.f_bsize; 298 sbp->f_iosize = mstat.f_iosize; 299 sbp->f_blocks = mstat.f_blocks; 300 sbp->f_bfree = mstat.f_bfree; 301 sbp->f_bavail = mstat.f_bavail; 302 sbp->f_files = mstat.f_files; 303 sbp->f_ffree = mstat.f_ffree; 304 if (sbp != &mp->mnt_stat) { 305 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid)); 306 bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN); 307 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN); 308 } 309 strncpy(&sbp->f_fstypename[0], mp->mnt_op->vfs_name, MFSNAMELEN); 310 sbp->f_fstypename[MFSNAMELEN] = '\0'; 311 return (0); 312 } 313 314 int 315 nullfs_sync(mp, waitfor, cred, p) 316 struct mount *mp; 317 int waitfor; 318 struct ucred *cred; 319 struct proc *p; 320 { 321 322 /* 323 * XXX - Assumes no data cached at null layer. 324 */ 325 return (0); 326 } 327 328 int 329 nullfs_vget(mp, ino, vpp) 330 struct mount *mp; 331 ino_t ino; 332 struct vnode **vpp; 333 { 334 335 return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp); 336 } 337 338 int 339 nullfs_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp) 340 struct mount *mp; 341 struct fid *fidp; 342 struct mbuf *nam; 343 struct vnode **vpp; 344 int *exflagsp; 345 struct ucred**credanonp; 346 { 347 348 return VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fidp, nam, vpp, exflagsp,credanonp); 349 } 350 351 int 352 nullfs_vptofh(vp, fhp) 353 struct vnode *vp; 354 struct fid *fhp; 355 { 356 357 return VFS_VPTOFH(NULLVPTOLOWERVP(vp), fhp); 358 } 359 360 int nullfs_init __P((void)); 361 362 struct vfsops null_vfsops = { 363 MOUNT_NULL, 364 nullfs_mount, 365 nullfs_start, 366 nullfs_unmount, 367 nullfs_root, 368 nullfs_quotactl, 369 nullfs_statfs, 370 nullfs_sync, 371 nullfs_vget, 372 nullfs_fhtovp, 373 nullfs_vptofh, 374 nullfs_init, 375 }; 376
Indexes created Tue Sep 30 20:09:53 GMT 2025