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 donated to Berkeley by 6 * Jan-Simon Pendry. 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 * from: Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp 37 * from: @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92 38 * from: @(#)null_vfsops.c 8.2 (Berkeley) 1/21/94 39 * $Id: null_vfsops.c,v 1.1 1994/06/08 11:33:25 mycroft Exp $ 40 */ 41 42 /* 43 * Null Layer 44 * (See null_vnops.c for a description of what this does.) 45 */ 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/time.h> 50 #include <sys/types.h> 51 #include <sys/vnode.h> 52 #include <sys/mount.h> 53 #include <sys/namei.h> 54 #include <sys/malloc.h> 55 #include <miscfs/nullfs/null.h> 56 57 /* 58 * Mount null layer 59 */ 60 int 61 nullfs_mount(mp, path, data, ndp, p) 62 struct mount *mp; 63 char *path; 64 caddr_t data; 65 struct nameidata *ndp; 66 struct proc *p; 67 { 68 int error = 0; 69 struct null_args args; 70 struct vnode *lowerrootvp, *vp; 71 struct vnode *nullm_rootvp; 72 struct null_mount *xmp; 73 u_int size; 74 75 #ifdef NULLFS_DIAGNOSTIC 76 printf("nullfs_mount(mp = %x)\n", mp); 77 #endif 78 79 /* 80 * Update is a no-op 81 */ 82 if (mp->mnt_flag & MNT_UPDATE) { 83 return (EOPNOTSUPP); 84 /* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, path, data, ndp, p);*/ 85 } 86 87 /* 88 * Get argument 89 */ 90 if (error = copyin(data, (caddr_t)&args, sizeof(struct null_args))) 91 return (error); 92 93 /* 94 * Find lower node 95 */ 96 NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF, 97 UIO_USERSPACE, args.target, p); 98 if (error = namei(ndp)) 99 return (error); 100 101 /* 102 * Sanity check on lower vnode 103 */ 104 lowerrootvp = ndp->ni_vp; 105 106 vrele(ndp->ni_dvp); 107 ndp->ni_dvp = NULL; 108 109 xmp = (struct null_mount *) malloc(sizeof(struct null_mount), 110 M_UFSMNT, M_WAITOK); /* XXX */ 111 112 /* 113 * Save reference to underlying FS 114 */ 115 xmp->nullm_vfs = lowerrootvp->v_mount; 116 117 /* 118 * Save reference. Each mount also holds 119 * a reference on the root vnode. 120 */ 121 error = null_node_create(mp, lowerrootvp, &vp); 122 /* 123 * Unlock the node (either the lower or the alias) 124 */ 125 VOP_UNLOCK(vp); 126 /* 127 * Make sure the node alias worked 128 */ 129 if (error) { 130 vrele(lowerrootvp); 131 free(xmp, M_UFSMNT); /* XXX */ 132 return (error); 133 } 134 135 /* 136 * Keep a held reference to the root vnode. 137 * It is vrele'd in nullfs_unmount. 138 */ 139 nullm_rootvp = vp; 140 nullm_rootvp->v_flag |= VROOT; 141 xmp->nullm_rootvp = nullm_rootvp; 142 if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL) 143 mp->mnt_flag |= MNT_LOCAL; 144 mp->mnt_data = (qaddr_t) xmp; 145 getnewfsid(mp, makefstype(MOUNT_LOFS)); 146 147 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); 148 bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size); 149 (void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 150 &size); 151 bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size); 152 #ifdef NULLFS_DIAGNOSTIC 153 printf("nullfs_mount: lower %s, alias at %s\n", 154 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 155 #endif 156 return (0); 157 } 158 159 /* 160 * VFS start. Nothing needed here - the start routine 161 * on the underlying filesystem will have been called 162 * when that filesystem was mounted. 163 */ 164 int 165 nullfs_start(mp, flags, p) 166 struct mount *mp; 167 int flags; 168 struct proc *p; 169 { 170 171 return (0); 172 /* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, p); */ 173 } 174 175 /* 176 * Free reference to null layer 177 */ 178 int 179 nullfs_unmount(mp, mntflags, p) 180 struct mount *mp; 181 int mntflags; 182 struct proc *p; 183 { 184 struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; 185 int error; 186 int flags = 0; 187 extern int doforce; 188 189 #ifdef NULLFS_DIAGNOSTIC 190 printf("nullfs_unmount(mp = %x)\n", mp); 191 #endif 192 193 if (mntflags & MNT_FORCE) { 194 /* lofs can never be rootfs so don't check for it */ 195 if (!doforce) 196 return (EINVAL); 197 flags |= FORCECLOSE; 198 } 199 200 /* 201 * Clear out buffer cache. I don't think we 202 * ever get anything cached at this level at the 203 * moment, but who knows... 204 */ 205 #if 0 206 mntflushbuf(mp, 0); 207 if (mntinvalbuf(mp, 1)) 208 return (EBUSY); 209 #endif 210 if (nullm_rootvp->v_usecount > 1) 211 return (EBUSY); 212 if (error = vflush(mp, nullm_rootvp, flags)) 213 return (error); 214 215 #ifdef NULLFS_DIAGNOSTIC 216 vprint("alias root of lower", nullm_rootvp); 217 #endif 218 /* 219 * Release reference on underlying root vnode 220 */ 221 vrele(nullm_rootvp); 222 /* 223 * And blow it away for future re-use 224 */ 225 vgone(nullm_rootvp); 226 /* 227 * Finally, throw away the null_mount structure 228 */ 229 free(mp->mnt_data, M_UFSMNT); /* XXX */ 230 mp->mnt_data = 0; 231 return 0; 232 } 233 234 int 235 nullfs_root(mp, vpp) 236 struct mount *mp; 237 struct vnode **vpp; 238 { 239 struct vnode *vp; 240 241 #ifdef NULLFS_DIAGNOSTIC 242 printf("nullfs_root(mp = %x, vp = %x->%x)\n", mp, 243 MOUNTTONULLMOUNT(mp)->nullm_rootvp, 244 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp) 245 ); 246 #endif 247 248 /* 249 * Return locked reference to root. 250 */ 251 vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; 252 VREF(vp); 253 VOP_LOCK(vp); 254 *vpp = vp; 255 return 0; 256 } 257 258 int 259 nullfs_quotactl(mp, cmd, uid, arg, p) 260 struct mount *mp; 261 int cmd; 262 uid_t uid; 263 caddr_t arg; 264 struct proc *p; 265 { 266 267 return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p); 268 } 269 270 int 271 nullfs_statfs(mp, sbp, p) 272 struct mount *mp; 273 struct statfs *sbp; 274 struct proc *p; 275 { 276 int error; 277 struct statfs mstat; 278 279 #ifdef NULLFS_DIAGNOSTIC 280 printf("nullfs_statfs(mp = %x, vp = %x->%x)\n", mp, 281 MOUNTTONULLMOUNT(mp)->nullm_rootvp, 282 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp) 283 ); 284 #endif 285 286 bzero(&mstat, sizeof(mstat)); 287 288 error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p); 289 if (error) 290 return (error); 291 292 /* now copy across the "interesting" information and fake the rest */ 293 sbp->f_type = mstat.f_type; 294 sbp->f_flags = mstat.f_flags; 295 sbp->f_bsize = mstat.f_bsize; 296 sbp->f_iosize = mstat.f_iosize; 297 sbp->f_blocks = mstat.f_blocks; 298 sbp->f_bfree = mstat.f_bfree; 299 sbp->f_bavail = mstat.f_bavail; 300 sbp->f_files = mstat.f_files; 301 sbp->f_ffree = mstat.f_ffree; 302 if (sbp != &mp->mnt_stat) { 303 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid)); 304 bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN); 305 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN); 306 } 307 strncpy(&sbp->f_fstypename[0], &mstat.f_fstypename[0], MFSNAMELEN); 308 sbp->f_fstypename[MFSNAMELEN] = '\0'; 309 return (0); 310 } 311 312 int 313 nullfs_sync(mp, waitfor, cred, p) 314 struct mount *mp; 315 int waitfor; 316 struct ucred *cred; 317 struct proc *p; 318 { 319 320 /* 321 * XXX - Assumes no data cached at null layer. 322 */ 323 return (0); 324 } 325 326 int 327 nullfs_vget(mp, ino, vpp) 328 struct mount *mp; 329 ino_t ino; 330 struct vnode **vpp; 331 { 332 333 return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp); 334 } 335 336 int 337 nullfs_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp) 338 struct mount *mp; 339 struct fid *fidp; 340 struct mbuf *nam; 341 struct vnode **vpp; 342 int *exflagsp; 343 struct ucred**credanonp; 344 { 345 346 return VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fidp, nam, vpp, exflagsp,credanonp); 347 } 348 349 int 350 nullfs_vptofh(vp, fhp) 351 struct vnode *vp; 352 struct fid *fhp; 353 { 354 355 return VFS_VPTOFH(NULLVPTOLOWERVP(vp), fhp); 356 } 357 358 int nullfs_init __P((void)); 359 360 struct vfsops null_vfsops = { 361 MOUNT_NULL, 362 nullfs_mount, 363 nullfs_start, 364 nullfs_unmount, 365 nullfs_root, 366 nullfs_quotactl, 367 nullfs_statfs, 368 nullfs_sync, 369 nullfs_vget, 370 nullfs_fhtovp, 371 nullfs_vptofh, 372 nullfs_init, 373 }; 374