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