1 /* $NetBSD: kernfs_vfsops.c,v 1.91 2011/09/27 01:23:05 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1992, 1993, 1995 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. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kernfs_vfsops.c 8.10 (Berkeley) 5/14/95 35 */ 36 37 /* 38 * Kernel params Filesystem 39 */ 40 41 #include <sys/cdefs.h> 42 __KERNEL_RCSID(0, "$NetBSD: kernfs_vfsops.c,v 1.91 2011/09/27 01:23:05 christos Exp $"); 43 44 #ifdef _KERNEL_OPT 45 #include "opt_compat_netbsd.h" 46 #endif 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/sysctl.h> 51 #include <sys/conf.h> 52 #include <sys/proc.h> 53 #include <sys/vnode.h> 54 #include <sys/mount.h> 55 #include <sys/namei.h> 56 #include <sys/dirent.h> 57 #include <sys/malloc.h> 58 #include <sys/syslog.h> 59 #include <sys/kauth.h> 60 #include <sys/module.h> 61 62 #include <miscfs/genfs/genfs.h> 63 #include <miscfs/specfs/specdev.h> 64 #include <miscfs/kernfs/kernfs.h> 65 66 MODULE(MODULE_CLASS_VFS, kernfs, NULL); 67 68 MALLOC_JUSTDEFINE(M_KERNFSMNT, "kernfs mount", "kernfs mount structures"); 69 70 dev_t rrootdev = NODEV; 71 72 VFS_PROTOS(kernfs); 73 74 void kernfs_get_rrootdev(void); 75 76 static struct sysctllog *kernfs_sysctl_log; 77 78 void 79 kernfs_init(void) 80 { 81 82 malloc_type_attach(M_KERNFSMNT); 83 kernfs_hashinit(); 84 } 85 86 void 87 kernfs_reinit(void) 88 { 89 kernfs_hashreinit(); 90 } 91 92 void 93 kernfs_done(void) 94 { 95 96 kernfs_hashdone(); 97 malloc_type_detach(M_KERNFSMNT); 98 } 99 100 void 101 kernfs_get_rrootdev(void) 102 { 103 static int tried = 0; 104 105 if (tried) { 106 /* Already did it once. */ 107 return; 108 } 109 tried = 1; 110 111 if (rootdev == NODEV) 112 return; 113 rrootdev = devsw_blk2chr(rootdev); 114 if (rrootdev != NODEV) 115 return; 116 rrootdev = NODEV; 117 printf("kernfs_get_rrootdev: no raw root device\n"); 118 } 119 120 /* 121 * Mount the Kernel params filesystem 122 */ 123 int 124 kernfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len) 125 { 126 struct lwp *l = curlwp; 127 int error = 0; 128 struct kernfs_mount *fmp; 129 130 if (UIO_MX & (UIO_MX - 1)) { 131 log(LOG_ERR, "kernfs: invalid directory entry size"); 132 return (EINVAL); 133 } 134 135 if (mp->mnt_flag & MNT_GETARGS) { 136 *data_len = 0; 137 return 0; 138 } 139 /* 140 * Update is a no-op 141 */ 142 if (mp->mnt_flag & MNT_UPDATE) 143 return (EOPNOTSUPP); 144 145 fmp = malloc(sizeof(struct kernfs_mount), M_KERNFSMNT, M_WAITOK|M_ZERO); 146 TAILQ_INIT(&fmp->nodelist); 147 148 mp->mnt_stat.f_namemax = KERNFS_MAXNAMLEN; 149 mp->mnt_flag |= MNT_LOCAL; 150 mp->mnt_data = fmp; 151 vfs_getnewfsid(mp); 152 153 if ((error = set_statvfs_info(path, UIO_USERSPACE, "kernfs", 154 UIO_SYSSPACE, mp->mnt_op->vfs_name, mp, l)) != 0) { 155 free(fmp, M_KERNFSMNT); 156 return error; 157 } 158 159 kernfs_get_rrootdev(); 160 return 0; 161 } 162 163 int 164 kernfs_start(struct mount *mp, int flags) 165 { 166 167 return (0); 168 } 169 170 int 171 kernfs_unmount(struct mount *mp, int mntflags) 172 { 173 int error; 174 int flags = 0; 175 176 if (mntflags & MNT_FORCE) 177 flags |= FORCECLOSE; 178 179 if ((error = vflush(mp, 0, flags)) != 0) 180 return (error); 181 182 /* 183 * Finally, throw away the kernfs_mount structure 184 */ 185 free(mp->mnt_data, M_KERNFSMNT); 186 mp->mnt_data = NULL; 187 return (0); 188 } 189 190 int 191 kernfs_root(struct mount *mp, struct vnode **vpp) 192 { 193 194 /* setup "." */ 195 return (kernfs_allocvp(mp, vpp, KFSkern, &kern_targets[0], 0)); 196 } 197 198 /*ARGSUSED*/ 199 int 200 kernfs_sync(struct mount *mp, int waitfor, 201 kauth_cred_t uc) 202 { 203 204 return (0); 205 } 206 207 /* 208 * Kernfs flat namespace lookup. 209 * Currently unsupported. 210 */ 211 int 212 kernfs_vget(struct mount *mp, ino_t ino, 213 struct vnode **vpp) 214 { 215 216 return (EOPNOTSUPP); 217 } 218 219 extern const struct vnodeopv_desc kernfs_vnodeop_opv_desc; 220 221 const struct vnodeopv_desc * const kernfs_vnodeopv_descs[] = { 222 &kernfs_vnodeop_opv_desc, 223 NULL, 224 }; 225 226 struct vfsops kernfs_vfsops = { 227 MOUNT_KERNFS, 228 0, 229 kernfs_mount, 230 kernfs_start, 231 kernfs_unmount, 232 kernfs_root, 233 (void *)eopnotsupp, /* vfs_quotactl */ 234 genfs_statvfs, 235 kernfs_sync, 236 kernfs_vget, 237 (void *)eopnotsupp, /* vfs_fhtovp */ 238 (void *)eopnotsupp, /* vfs_vptofh */ 239 kernfs_init, 240 kernfs_reinit, 241 kernfs_done, 242 NULL, /* vfs_mountroot */ 243 (int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp, 244 vfs_stdextattrctl, 245 (void *)eopnotsupp, /* vfs_suspendctl */ 246 genfs_renamelock_enter, 247 genfs_renamelock_exit, 248 (void *)eopnotsupp, 249 kernfs_vnodeopv_descs, 250 0, 251 { NULL, NULL }, 252 }; 253 254 static int 255 kernfs_modcmd(modcmd_t cmd, void *arg) 256 { 257 int error; 258 259 switch (cmd) { 260 case MODULE_CMD_INIT: 261 error = vfs_attach(&kernfs_vfsops); 262 if (error != 0) 263 break; 264 sysctl_createv(&kernfs_sysctl_log, 0, NULL, NULL, 265 CTLFLAG_PERMANENT, 266 CTLTYPE_NODE, "vfs", NULL, 267 NULL, 0, NULL, 0, 268 CTL_VFS, CTL_EOL); 269 sysctl_createv(&kernfs_sysctl_log, 0, NULL, NULL, 270 CTLFLAG_PERMANENT, 271 CTLTYPE_NODE, "kernfs", 272 SYSCTL_DESCR("/kern file system"), 273 NULL, 0, NULL, 0, 274 CTL_VFS, 11, CTL_EOL); 275 /* 276 * XXX the "11" above could be dynamic, thereby eliminating one 277 * more instance of the "number to vfs" mapping problem, but 278 * "11" is the order as taken from sys/mount.h 279 */ 280 break; 281 case MODULE_CMD_FINI: 282 error = vfs_detach(&kernfs_vfsops); 283 if (error != 0) 284 break; 285 sysctl_teardown(&kernfs_sysctl_log); 286 break; 287 default: 288 error = ENOTTY; 289 break; 290 } 291 292 return (error); 293 } 294