null_vfsops.c revision 1.33
1 /* $NetBSD: null_vfsops.c,v 1.33 2001/11/07 04:15:41 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 #define NNULLNODECACHE 16 97 98 /* 99 * Mount null layer 100 */ 101 int 102 nullfs_mount(mp, path, data, ndp, p) 103 struct mount *mp; 104 const char *path; 105 void *data; 106 struct nameidata *ndp; 107 struct proc *p; 108 { 109 struct null_args args; 110 struct vnode *lowerrootvp, *vp; 111 struct null_mount *nmp; 112 struct layer_mount *lmp; 113 size_t size; 114 int error = 0; 115 116 #ifdef NULLFS_DIAGNOSTIC 117 printf("nullfs_mount(mp = %p)\n", mp); 118 #endif 119 120 /* 121 * Get argument 122 */ 123 error = copyin(data, (caddr_t)&args, sizeof(struct null_args)); 124 if (error) 125 return (error); 126 127 /* 128 * Update only does export updating. 129 */ 130 if (mp->mnt_flag & MNT_UPDATE) { 131 lmp = MOUNTTOLAYERMOUNT(mp); 132 if (args.nulla_target == NULL) 133 return (vfs_export(mp, &lmp->layerm_export, 134 &args.la.export)); 135 else 136 return (EOPNOTSUPP); 137 } 138 139 /* 140 * Find lower node 141 */ 142 NDINIT(ndp, LOOKUP, FOLLOW|LOCKLEAF, 143 UIO_USERSPACE, args.la.target, p); 144 if ((error = namei(ndp)) != 0) 145 return (error); 146 147 /* 148 * Sanity check on lower vnode 149 */ 150 lowerrootvp = ndp->ni_vp; 151 152 /* 153 * First cut at fixing up upper mount point 154 */ 155 nmp = (struct null_mount *) malloc(sizeof(struct null_mount), 156 M_UFSMNT, M_WAITOK); /* XXX */ 157 memset((caddr_t)nmp, 0, sizeof(struct null_mount)); 158 159 mp->mnt_data = (qaddr_t) nmp; 160 nmp->nullm_vfs = lowerrootvp->v_mount; 161 if (nmp->nullm_vfs->mnt_flag & MNT_LOCAL) 162 mp->mnt_flag |= MNT_LOCAL; 163 164 /* 165 * Make sure that the mount point is sufficiently initialized 166 * that the node create call will work. 167 */ 168 vfs_getnewfsid(mp); 169 170 nmp->nullm_size = sizeof(struct null_node); 171 nmp->nullm_tag = VT_NULL; 172 nmp->nullm_bypass = layer_bypass; 173 nmp->nullm_alloc = layer_node_alloc; /* the default alloc is fine */ 174 nmp->nullm_vnodeop_p = null_vnodeop_p; 175 simple_lock_init(&nmp->nullm_hashlock); 176 nmp->nullm_node_hashtbl = hashinit(NNULLNODECACHE, HASH_LIST, M_CACHE, 177 M_WAITOK, &nmp->nullm_node_hash); 178 179 /* 180 * Fix up null node for root vnode 181 */ 182 error = layer_node_create(mp, lowerrootvp, &vp); 183 /* 184 * Make sure the fixup worked 185 */ 186 if (error) { 187 vput(lowerrootvp); 188 free(nmp, M_UFSMNT); /* XXX */ 189 return (error); 190 } 191 /* 192 * Unlock the node 193 */ 194 VOP_UNLOCK(vp, 0); 195 196 /* 197 * Keep a held reference to the root vnode. 198 * It is vrele'd in nullfs_unmount. 199 */ 200 vp->v_flag |= VROOT; 201 nmp->nullm_rootvp = vp; 202 203 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); 204 memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size); 205 (void) copyinstr(args.la.target, mp->mnt_stat.f_mntfromname, 206 MNAMELEN - 1, &size); 207 memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size); 208 #ifdef NULLFS_DIAGNOSTIC 209 printf("nullfs_mount: lower %s, alias at %s\n", 210 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 211 #endif 212 return (0); 213 } 214 215 /* 216 * Free reference to null layer 217 */ 218 int 219 nullfs_unmount(mp, mntflags, p) 220 struct mount *mp; 221 int mntflags; 222 struct proc *p; 223 { 224 struct vnode *null_rootvp = MOUNTTONULLMOUNT(mp)->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 free(mp->mnt_data, M_UFSMNT); /* XXX */ 267 mp->mnt_data = NULL; 268 return (0); 269 } 270 271 extern const struct vnodeopv_desc null_vnodeop_opv_desc; 272 273 const struct vnodeopv_desc * const nullfs_vnodeopv_descs[] = { 274 &null_vnodeop_opv_desc, 275 NULL, 276 }; 277 278 struct vfsops nullfs_vfsops = { 279 MOUNT_NULL, 280 nullfs_mount, 281 layerfs_start, 282 nullfs_unmount, 283 layerfs_root, 284 layerfs_quotactl, 285 layerfs_statfs, 286 layerfs_sync, 287 layerfs_vget, 288 layerfs_fhtovp, 289 layerfs_vptofh, 290 layerfs_init, 291 NULL, 292 layerfs_done, 293 layerfs_sysctl, 294 NULL, /* vfs_mountroot */ 295 layerfs_checkexp, 296 nullfs_vnodeopv_descs, 297 }; 298
Indexes created Thu Sep 25 16:09:42 GMT 2025