1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed 6 * to Berkeley by John Heidemann of the UCLA Ficus project. 7 * 8 * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project 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 * 4. 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 * @(#)vfs_init.c 8.3 (Berkeley) 1/4/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/kernel.h> 43 #include <sys/linker.h> 44 #include <sys/mount.h> 45 #include <sys/proc.h> 46 #include <sys/sysctl.h> 47 #include <sys/vnode.h> 48 #include <sys/malloc.h> 49 50 51 MALLOC_DEFINE(M_VNODE, "vnodes", "Dynamically allocated vnodes"); 52 53 /* 54 * The highest defined VFS number. 55 */ 56 int maxvfsconf = VFS_GENERIC + 1; 57 58 /* 59 * Single-linked list of configured VFSes. 60 * New entries are added/deleted by vfs_register()/vfs_unregister() 61 */ 62 struct vfsconfhead vfsconf = TAILQ_HEAD_INITIALIZER(vfsconf); 63 64 /* 65 * A Zen vnode attribute structure. 66 * 67 * Initialized when the first filesystem registers by vfs_register(). 68 */ 69 struct vattr va_null; 70 71 /* 72 * vfs_init.c 73 * 74 * Allocate and fill in operations vectors. 75 * 76 * An undocumented feature of this approach to defining operations is that 77 * there can be multiple entries in vfs_opv_descs for the same operations 78 * vector. This allows third parties to extend the set of operations 79 * supported by another layer in a binary compatibile way. For example, 80 * assume that NFS needed to be modified to support Ficus. NFS has an entry 81 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 82 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 83 * listing those new operations Ficus adds to NFS, all without modifying the 84 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 85 * that is a(whole)nother story.) This is a feature. 86 */ 87 88 /* 89 * Routines having to do with the management of the vnode table. 90 */ 91 92 /* 93 * XXX: hack alert 94 */ 95 int 96 vcall(struct vnode *vp, u_int off, void *ap) 97 { 98 struct vop_vector *vop = vp->v_op; 99 vop_bypass_t **bpt; 100 int rc; 101 102 for(;;) { 103 bpt = (void *)((u_char *)vop + off); 104 if (vop != NULL && *bpt == NULL && vop->vop_bypass == NULL) { 105 vop = vop->vop_default; 106 continue; 107 } 108 break; 109 } 110 KASSERT(vop != NULL, ("No VCALL(%p...)", vp)); 111 if (*bpt != NULL) 112 rc = (*bpt)(ap); 113 else 114 rc = vop->vop_bypass(ap); 115 return (rc); 116 } 117 118 struct vfsconf * 119 vfs_byname(const char *name) 120 { 121 struct vfsconf *vfsp; 122 123 if (!strcmp(name, "ffs")) 124 name = "ufs"; 125 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) 126 if (!strcmp(name, vfsp->vfc_name)) 127 return (vfsp); 128 return (NULL); 129 } 130 131 struct vfsconf * 132 vfs_byname_kld(const char *fstype, struct thread *td, int *error) 133 { 134 struct vfsconf *vfsp; 135 linker_file_t lf; 136 137 vfsp = vfs_byname(fstype); 138 if (vfsp != NULL) 139 return (vfsp); 140 141 /* Only load modules for root (very important!). */ 142 *error = suser(td); 143 if (*error) 144 return (NULL); 145 *error = securelevel_gt(td->td_ucred, 0); 146 if (*error) 147 return (NULL); 148 *error = linker_load_module(NULL, fstype, NULL, NULL, &lf); 149 if (lf == NULL) 150 *error = ENODEV; 151 if (*error) 152 return (NULL); 153 lf->userrefs++; 154 /* Look up again to see if the VFS was loaded. */ 155 vfsp = vfs_byname(fstype); 156 if (vfsp == NULL) { 157 lf->userrefs--; 158 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 159 *error = ENODEV; 160 return (NULL); 161 } 162 return (vfsp); 163 } 164 165 166 /* Register a new filesystem type in the global table */ 167 int 168 vfs_register(struct vfsconf *vfc) 169 { 170 struct sysctl_oid *oidp; 171 struct vfsops *vfsops; 172 static int once; 173 174 if (!once) { 175 vattr_null(&va_null); 176 once = 1; 177 } 178 179 if (vfc->vfc_version != VFS_VERSION) { 180 printf("ERROR: filesystem %s, unsupported ABI version %x\n", 181 vfc->vfc_name, vfc->vfc_version); 182 return (EINVAL); 183 } 184 if (vfs_byname(vfc->vfc_name) != NULL) 185 return EEXIST; 186 187 vfc->vfc_typenum = maxvfsconf++; 188 TAILQ_INSERT_TAIL(&vfsconf, vfc, vfc_list); 189 190 /* 191 * If this filesystem has a sysctl node under vfs 192 * (i.e. vfs.xxfs), then change the oid number of that node to 193 * match the filesystem's type number. This allows user code 194 * which uses the type number to read sysctl variables defined 195 * by the filesystem to continue working. Since the oids are 196 * in a sorted list, we need to make sure the order is 197 * preserved by re-registering the oid after modifying its 198 * number. 199 */ 200 SLIST_FOREACH(oidp, &sysctl__vfs_children, oid_link) 201 if (strcmp(oidp->oid_name, vfc->vfc_name) == 0) { 202 sysctl_unregister_oid(oidp); 203 oidp->oid_number = vfc->vfc_typenum; 204 sysctl_register_oid(oidp); 205 } 206 207 /* 208 * Initialise unused ``struct vfsops'' fields, to use 209 * the vfs_std*() functions. Note, we need the mount 210 * and unmount operations, at the least. The check 211 * for vfsops available is just a debugging aid. 212 */ 213 KASSERT(vfc->vfc_vfsops != NULL, 214 ("Filesystem %s has no vfsops", vfc->vfc_name)); 215 /* 216 * Check the mount and unmount operations. 217 */ 218 vfsops = vfc->vfc_vfsops; 219 KASSERT(vfsops->vfs_mount != NULL, 220 ("Filesystem %s has no mount op", vfc->vfc_name)); 221 KASSERT(vfsops->vfs_unmount != NULL, 222 ("Filesystem %s has no unmount op", vfc->vfc_name)); 223 224 if (vfsops->vfs_start == NULL) 225 /* make a file system operational */ 226 vfsops->vfs_start = vfs_stdstart; 227 if (vfsops->vfs_root == NULL) 228 /* return file system's root vnode */ 229 vfsops->vfs_root = vfs_stdroot; 230 if (vfsops->vfs_quotactl == NULL) 231 /* quota control */ 232 vfsops->vfs_quotactl = vfs_stdquotactl; 233 if (vfsops->vfs_statfs == NULL) 234 /* return file system's status */ 235 vfsops->vfs_statfs = vfs_stdstatfs; 236 if (vfsops->vfs_sync == NULL) 237 /* 238 * flush unwritten data (nosync) 239 * file systems can use vfs_stdsync 240 * explicitly by setting it in the 241 * vfsop vector. 242 */ 243 vfsops->vfs_sync = vfs_stdnosync; 244 if (vfsops->vfs_vget == NULL) 245 /* convert an inode number to a vnode */ 246 vfsops->vfs_vget = vfs_stdvget; 247 if (vfsops->vfs_fhtovp == NULL) 248 /* turn an NFS file handle into a vnode */ 249 vfsops->vfs_fhtovp = vfs_stdfhtovp; 250 if (vfsops->vfs_checkexp == NULL) 251 /* check if file system is exported */ 252 vfsops->vfs_checkexp = vfs_stdcheckexp; 253 if (vfsops->vfs_vptofh == NULL) 254 /* turn a vnode into an NFS file handle */ 255 vfsops->vfs_vptofh = vfs_stdvptofh; 256 if (vfsops->vfs_init == NULL) 257 /* file system specific initialisation */ 258 vfsops->vfs_init = vfs_stdinit; 259 if (vfsops->vfs_uninit == NULL) 260 /* file system specific uninitialisation */ 261 vfsops->vfs_uninit = vfs_stduninit; 262 if (vfsops->vfs_extattrctl == NULL) 263 /* extended attribute control */ 264 vfsops->vfs_extattrctl = vfs_stdextattrctl; 265 if (vfsops->vfs_sysctl == NULL) 266 vfsops->vfs_sysctl = vfs_stdsysctl; 267 268 /* 269 * Call init function for this VFS... 270 */ 271 (*(vfc->vfc_vfsops->vfs_init))(vfc); 272 273 return 0; 274 } 275 276 277 /* Remove registration of a filesystem type */ 278 int 279 vfs_unregister(struct vfsconf *vfc) 280 { 281 struct vfsconf *vfsp; 282 int error, i, maxtypenum; 283 284 i = vfc->vfc_typenum; 285 286 vfsp = vfs_byname(vfc->vfc_name); 287 if (vfsp == NULL) 288 return EINVAL; 289 if (vfsp->vfc_refcount) 290 return EBUSY; 291 if (vfc->vfc_vfsops->vfs_uninit != NULL) { 292 error = (*vfc->vfc_vfsops->vfs_uninit)(vfsp); 293 if (error) 294 return (error); 295 } 296 TAILQ_REMOVE(&vfsconf, vfsp, vfc_list); 297 maxtypenum = VFS_GENERIC; 298 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) 299 if (maxtypenum < vfsp->vfc_typenum) 300 maxtypenum = vfsp->vfc_typenum; 301 maxvfsconf = maxtypenum + 1; 302 return 0; 303 } 304 305 /* 306 * Standard kernel module handling code for filesystem modules. 307 * Referenced from VFS_SET(). 308 */ 309 int 310 vfs_modevent(module_t mod, int type, void *data) 311 { 312 struct vfsconf *vfc; 313 int error = 0; 314 315 vfc = (struct vfsconf *)data; 316 317 switch (type) { 318 case MOD_LOAD: 319 if (vfc) 320 error = vfs_register(vfc); 321 break; 322 323 case MOD_UNLOAD: 324 if (vfc) 325 error = vfs_unregister(vfc); 326 break; 327 default: 328 error = EOPNOTSUPP; 329 break; 330 } 331 return (error); 332 } 333