null_vfsops.c revision 1.25
1 /* $NetBSD: null_vfsops.c,v 1.25 2000/03/13 23:52:41 soren 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 Similation 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/types.h> 85 #include <sys/vnode.h> 86 #include <sys/mount.h> 87 #include <sys/namei.h> 88 #include <sys/malloc.h> 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 int error = 0; 110 struct null_args args; 111 struct vnode *lowerrootvp, *vp; 112 struct null_mount *nmp; 113 struct layer_mount *lmp; 114 size_t size; 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 == 0) 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|WANTPARENT|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 vrele(ndp->ni_dvp); 153 ndp->ni_dvp = NULL; 154 155 /* 156 * First cut at fixing up upper mount point 157 */ 158 nmp = (struct null_mount *) malloc(sizeof(struct null_mount), 159 M_UFSMNT, M_WAITOK); /* XXX */ 160 memset((caddr_t)nmp, 0, sizeof(struct null_mount)); 161 162 mp->mnt_data = (qaddr_t) nmp; 163 nmp->nullm_vfs = lowerrootvp->v_mount; 164 if (nmp->nullm_vfs->mnt_flag & MNT_LOCAL) 165 mp->mnt_flag |= MNT_LOCAL; 166 167 /* 168 * Make sure that the mount point is sufficiently initialized 169 * that the node create call will work. 170 */ 171 vfs_getnewfsid(mp, MOUNT_NULL); 172 173 nmp->nullm_size = sizeof (struct null_node); 174 nmp->nullm_tag = VT_NULL; 175 nmp->nullm_bypass = layer_bypass; 176 nmp->nullm_alloc = layer_node_alloc; /* the default alloc is fine */ 177 nmp->nullm_vnodeop_p = null_vnodeop_p; 178 simple_lock_init(&nmp->nullm_hashlock); 179 nmp->nullm_node_hashtbl = hashinit(NNULLNODECACHE, M_CACHE, M_WAITOK, 180 &nmp->nullm_node_hash); 181 182 /* 183 * Fix up null node for root vnode 184 */ 185 error = layer_node_create(mp, lowerrootvp, &vp); 186 /* 187 * Make sure the fixup worked 188 */ 189 if (error) { 190 vput(lowerrootvp); 191 free(nmp, M_UFSMNT); /* XXX */ 192 return (error); 193 } 194 /* 195 * Unlock the node 196 */ 197 VOP_UNLOCK(vp, 0); 198 199 /* 200 * Keep a held reference to the root vnode. 201 * It is vrele'd in nullfs_unmount. 202 */ 203 vp->v_flag |= VROOT; 204 nmp->nullm_rootvp = vp; 205 206 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); 207 memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size); 208 (void) copyinstr(args.la.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 209 &size); 210 memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size); 211 #ifdef NULLFS_DIAGNOSTIC 212 printf("nullfs_mount: lower %s, alias at %s\n", 213 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 214 #endif 215 return (0); 216 } 217 218 /* 219 * Free reference to null layer 220 */ 221 int 222 nullfs_unmount(mp, mntflags, p) 223 struct mount *mp; 224 int mntflags; 225 struct proc *p; 226 { 227 struct vnode *null_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; 228 int error; 229 int flags = 0; 230 231 #ifdef NULLFS_DIAGNOSTIC 232 printf("nullfs_unmount(mp = %p)\n", mp); 233 #endif 234 235 if (mntflags & MNT_FORCE) 236 flags |= FORCECLOSE; 237 238 /* 239 * Clear out buffer cache. I don't think we 240 * ever get anything cached at this level at the 241 * moment, but who knows... 242 */ 243 #if 0 244 mntflushbuf(mp, 0); 245 if (mntinvalbuf(mp, 1)) 246 return (EBUSY); 247 #endif 248 if (null_rootvp->v_usecount > 1) 249 return (EBUSY); 250 if ((error = vflush(mp, null_rootvp, flags)) != 0) 251 return (error); 252 253 #ifdef NULLFS_DIAGNOSTIC 254 vprint("alias root of lower", null_rootvp); 255 #endif 256 /* 257 * Release reference on underlying root vnode 258 */ 259 vrele(null_rootvp); 260 /* 261 * And blow it away for future re-use 262 */ 263 vgone(null_rootvp); 264 /* 265 * Finally, throw away the null_mount structure 266 */ 267 free(mp->mnt_data, M_UFSMNT); /* XXX */ 268 mp->mnt_data = 0; 269 return 0; 270 } 271 272 extern struct vnodeopv_desc null_vnodeop_opv_desc; 273 274 struct vnodeopv_desc *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 layerfs_sysctl, 293 NULL, /* vfs_mountroot */ 294 layerfs_checkexp, 295 nullfs_vnodeopv_descs, 296 }; 297
Indexes created Thu Sep 25 16:09:42 GMT 2025