null_vfsops.c revision 1.35
1 /* $NetBSD: null_vfsops.c,v 1.35 2001/11/07 04:55:26 enami Exp $ */ 2 3 /* 4 * Copyright (c) 1999 National Aeronautics & Space Administration 5 * All rights reserved. 6 * 7 * This software was written by William Studenmund of the 8 * Numerical Aerospace Simulation Facility, NASA Ames Research Center. 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. Neither the name of the National Aeronautics & Space Administration 19 * nor the names of its contributors may be used to endorse or promote 20 * products derived from this software without specific prior written 21 * permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE NATIONAL AERONAUTICS & SPACE ADMINISTRATION 24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE ADMINISTRATION OR CONTRIB- 27 * UTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 28 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 * POSSIBILITY OF SUCH DAMAGE. 34 */ 35 /* 36 * Copyright (c) 1992, 1993, 1995 37 * The Regents of the University of California. All rights reserved. 38 * 39 * This code is derived from software donated to Berkeley by 40 * Jan-Simon Pendry. 41 * 42 * Redistribution and use in source and binary forms, with or without 43 * modification, are permitted provided that the following conditions 44 * are met: 45 * 1. Redistributions of source code must retain the above copyright 46 * notice, this list of conditions and the following disclaimer. 47 * 2. Redistributions in binary form must reproduce the above copyright 48 * notice, this list of conditions and the following disclaimer in the 49 * documentation and/or other materials provided with the distribution. 50 * 3. All advertising materials mentioning features or use of this software 51 * must display the following acknowledgement: 52 * This product includes software developed by the University of 53 * California, Berkeley and its contributors. 54 * 4. Neither the name of the University nor the names of its contributors 55 * may be used to endorse or promote products derived from this software 56 * without specific prior written permission. 57 * 58 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 59 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 60 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 61 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 62 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 63 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 64 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 65 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 66 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 67 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 68 * SUCH DAMAGE. 69 * 70 * from: Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp 71 * from: @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92 72 * @(#)null_vfsops.c 8.7 (Berkeley) 5/14/95 73 */ 74 75 /* 76 * Null Layer 77 * (See null_vnops.c for a description of what this does.) 78 */ 79 80 #include <sys/param.h> 81 #include <sys/systm.h> 82 #include <sys/time.h> 83 #include <sys/proc.h> 84 #include <sys/vnode.h> 85 #include <sys/mount.h> 86 #include <sys/namei.h> 87 #include <sys/malloc.h> 88 89 #include <miscfs/nullfs/null.h> 90 #include <miscfs/genfs/layer_extern.h> 91 92 int nullfs_mount __P((struct mount *, const char *, void *, 93 struct nameidata *, struct proc *)); 94 int nullfs_unmount __P((struct mount *, int, struct proc *)); 95 96 /* 97 * Mount null layer 98 */ 99 int 100 nullfs_mount(mp, path, data, ndp, p) 101 struct mount *mp; 102 const char *path; 103 void *data; 104 struct nameidata *ndp; 105 struct proc *p; 106 { 107 struct null_args args; 108 struct vnode *lowerrootvp, *vp; 109 struct null_mount *nmp; 110 struct layer_mount *lmp; 111 size_t size; 112 int error = 0; 113 114 #ifdef NULLFS_DIAGNOSTIC 115 printf("nullfs_mount(mp = %p)\n", mp); 116 #endif 117 118 /* 119 * Get argument 120 */ 121 error = copyin(data, (caddr_t)&args, sizeof(struct null_args)); 122 if (error) 123 return (error); 124 125 /* 126 * Update only does export updating. 127 */ 128 if (mp->mnt_flag & MNT_UPDATE) { 129 lmp = MOUNTTOLAYERMOUNT(mp); 130 if (args.nulla_target == NULL) 131 return (vfs_export(mp, &lmp->layerm_export, 132 &args.la.export)); 133 else 134 return (EOPNOTSUPP); 135 } 136 137 /* 138 * Find lower node 139 */ 140 NDINIT(ndp, LOOKUP, FOLLOW|LOCKLEAF, 141 UIO_USERSPACE, args.la.target, p); 142 if ((error = namei(ndp)) != 0) 143 return (error); 144 145 /* 146 * Sanity check on lower vnode 147 */ 148 lowerrootvp = ndp->ni_vp; 149 150 /* 151 * First cut at fixing up upper mount point 152 */ 153 nmp = (struct null_mount *) malloc(sizeof(struct null_mount), 154 M_UFSMNT, M_WAITOK); /* XXX */ 155 memset((caddr_t)nmp, 0, sizeof(struct null_mount)); 156 157 mp->mnt_data = (qaddr_t) nmp; 158 nmp->nullm_vfs = lowerrootvp->v_mount; 159 if (nmp->nullm_vfs->mnt_flag & MNT_LOCAL) 160 mp->mnt_flag |= MNT_LOCAL; 161 162 /* 163 * Make sure that the mount point is sufficiently initialized 164 * that the node create call will work. 165 */ 166 vfs_getnewfsid(mp); 167 168 nmp->nullm_size = sizeof(struct null_node); 169 nmp->nullm_tag = VT_NULL; 170 nmp->nullm_bypass = layer_bypass; 171 nmp->nullm_alloc = layer_node_alloc; /* the default alloc is fine */ 172 nmp->nullm_vnodeop_p = null_vnodeop_p; 173 simple_lock_init(&nmp->nullm_hashlock); 174 nmp->nullm_node_hashtbl = hashinit(desiredvnodes, HASH_LIST, M_CACHE, 175 M_WAITOK, &nmp->nullm_node_hash); 176 177 /* 178 * Fix up null node for root vnode 179 */ 180 error = layer_node_create(mp, lowerrootvp, &vp); 181 /* 182 * Make sure the fixup worked 183 */ 184 if (error) { 185 vput(lowerrootvp); 186 hashdone(nmp->nullm_node_hashtbl, M_CACHE); 187 free(nmp, M_UFSMNT); /* XXX */ 188 return (error); 189 } 190 /* 191 * Unlock the node 192 */ 193 VOP_UNLOCK(vp, 0); 194 195 /* 196 * Keep a held reference to the root vnode. 197 * It is vrele'd in nullfs_unmount. 198 */ 199 vp->v_flag |= VROOT; 200 nmp->nullm_rootvp = vp; 201 202 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); 203 memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size); 204 (void) copyinstr(args.la.target, mp->mnt_stat.f_mntfromname, 205 MNAMELEN - 1, &size); 206 memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size); 207 #ifdef NULLFS_DIAGNOSTIC 208 printf("nullfs_mount: lower %s, alias at %s\n", 209 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 210 #endif 211 return (0); 212 } 213 214 /* 215 * Free reference to null layer 216 */ 217 int 218 nullfs_unmount(mp, mntflags, p) 219 struct mount *mp; 220 int mntflags; 221 struct proc *p; 222 { 223 struct null_mount *nmp = MOUNTTONULLMOUNT(mp); 224 struct vnode *null_rootvp = nmp->nullm_rootvp; 225 int error; 226 int flags = 0; 227 228 #ifdef NULLFS_DIAGNOSTIC 229 printf("nullfs_unmount(mp = %p)\n", mp); 230 #endif 231 232 if (mntflags & MNT_FORCE) 233 flags |= FORCECLOSE; 234 235 /* 236 * Clear out buffer cache. I don't think we 237 * ever get anything cached at this level at the 238 * moment, but who knows... 239 */ 240 #if 0 241 mntflushbuf(mp, 0); 242 if (mntinvalbuf(mp, 1)) 243 return (EBUSY); 244 #endif 245 if (null_rootvp->v_usecount > 1) 246 return (EBUSY); 247 if ((error = vflush(mp, null_rootvp, flags)) != 0) 248 return (error); 249 250 #ifdef NULLFS_DIAGNOSTIC 251 vprint("alias root of lower", null_rootvp); 252 #endif 253 /* 254 * Release reference on underlying root vnode 255 */ 256 vrele(null_rootvp); 257 258 /* 259 * And blow it away for future re-use 260 */ 261 vgone(null_rootvp); 262 263 /* 264 * Finally, throw away the null_mount structure 265 */ 266 hashdone(nmp->nullm_node_hashtbl, M_CACHE); 267 free(mp->mnt_data, M_UFSMNT); /* XXX */ 268 mp->mnt_data = NULL; 269 return (0); 270 } 271 272 extern const struct vnodeopv_desc null_vnodeop_opv_desc; 273 274 const struct vnodeopv_desc * const nullfs_vnodeopv_descs[] = { 275 &null_vnodeop_opv_desc, 276 NULL, 277 }; 278 279 struct vfsops nullfs_vfsops = { 280 MOUNT_NULL, 281 nullfs_mount, 282 layerfs_start, 283 nullfs_unmount, 284 layerfs_root, 285 layerfs_quotactl, 286 layerfs_statfs, 287 layerfs_sync, 288 layerfs_vget, 289 layerfs_fhtovp, 290 layerfs_vptofh, 291 layerfs_init, 292 NULL, 293 layerfs_done, 294 layerfs_sysctl, 295 NULL, /* vfs_mountroot */ 296 layerfs_checkexp, 297 nullfs_vnodeopv_descs, 298 }; 299
Indexes created Fri Sep 26 20:09:58 GMT 2025