1 /*- 2 * Copyright (c) 2001 Dag-Erling Co�dan Sm�rgrav 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer 10 * in this position and unchanged. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. The name of the author may not be used to endorse or promote products 15 * derived from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include "opt_pseudofs.h" 33 34 #include <sys/param.h> 35 #include <sys/kernel.h> 36 #include <sys/systm.h> 37 #include <sys/lock.h> 38 #include <sys/malloc.h> 39 #include <sys/module.h> 40 #include <sys/mount.h> 41 #include <sys/mutex.h> 42 #include <sys/proc.h> 43 #include <sys/sbuf.h> 44 #include <sys/sysctl.h> 45 #include <sys/vnode.h> 46 47 #include <fs/pseudofs/pseudofs.h> 48 #include <fs/pseudofs/pseudofs_internal.h> 49 50 static MALLOC_DEFINE(M_PFSNODES, "pfs_nodes", "pseudofs nodes"); 51 52 SYSCTL_NODE(_vfs, OID_AUTO, pfs, CTLFLAG_RW, 0, 53 "pseudofs"); 54 55 #if PFS_FSNAMELEN != MFSNAMELEN 56 #error "PFS_FSNAMELEN is not equal to MFSNAMELEN" 57 #endif 58 59 /* 60 * Add a node to a directory 61 */ 62 static int 63 _pfs_add_node(struct pfs_node *parent, struct pfs_node *node) 64 { 65 KASSERT(parent != NULL, 66 ("%s(): parent is NULL", __func__)); 67 KASSERT(parent->pn_info != NULL, 68 ("%s(): parent has no pn_info", __func__)); 69 KASSERT(parent->pn_type == pfstype_dir || 70 parent->pn_type == pfstype_procdir || 71 parent->pn_type == pfstype_root, 72 ("%s(): parent is not a directory", __func__)); 73 74 /* XXX should check for duplicate names etc. */ 75 76 mtx_lock(&parent->pn_info->pi_mutex); 77 node->pn_info = parent->pn_info; 78 node->pn_parent = parent; 79 node->pn_next = parent->pn_nodes; 80 parent->pn_nodes = node; 81 /* Propagate flag to all child nodes (and thus their vnodes) */ 82 if ((parent->pn_flags & PFS_PROCDEP) != 0) 83 node->pn_flags |= PFS_PROCDEP; 84 mtx_unlock(&parent->pn_info->pi_mutex); 85 86 return (0); 87 } 88 89 /* 90 * Add . and .. to a directory 91 */ 92 static int 93 _pfs_fixup_dir(struct pfs_node *parent) 94 { 95 struct pfs_node *dir; 96 97 MALLOC(dir, struct pfs_node *, sizeof *dir, 98 M_PFSNODES, M_WAITOK|M_ZERO); 99 dir->pn_name[0] = '.'; 100 dir->pn_type = pfstype_this; 101 102 if (_pfs_add_node(parent, dir) != 0) { 103 FREE(dir, M_PFSNODES); 104 return (-1); 105 } 106 107 MALLOC(dir, struct pfs_node *, sizeof *dir, 108 M_PFSNODES, M_WAITOK|M_ZERO); 109 dir->pn_name[0] = dir->pn_name[1] = '.'; 110 dir->pn_type = pfstype_parent; 111 112 if (_pfs_add_node(parent, dir) != 0) { 113 FREE(dir, M_PFSNODES); 114 return (-1); 115 } 116 117 return (0); 118 } 119 120 /* 121 * Create a directory 122 */ 123 struct pfs_node * 124 pfs_create_dir(struct pfs_node *parent, const char *name, 125 pfs_attr_t attr, pfs_vis_t vis, pfs_destroy_t destroy, 126 int flags) 127 { 128 struct pfs_node *dir; 129 130 KASSERT(strlen(name) < PFS_NAMELEN, 131 ("%s(): node name is too long", __func__)); 132 133 MALLOC(dir, struct pfs_node *, sizeof *dir, 134 M_PFSNODES, M_WAITOK|M_ZERO); 135 strcpy(dir->pn_name, name); 136 dir->pn_type = (flags & PFS_PROCDEP) ? pfstype_procdir : pfstype_dir; 137 dir->pn_attr = attr; 138 dir->pn_vis = vis; 139 dir->pn_destroy = destroy; 140 dir->pn_flags = flags; 141 142 if (_pfs_add_node(parent, dir) != 0) { 143 FREE(dir, M_PFSNODES); 144 return (NULL); 145 } 146 147 if (_pfs_fixup_dir(dir) != 0) { 148 pfs_destroy(dir); 149 return (NULL); 150 } 151 152 return (dir); 153 } 154 155 /* 156 * Create a file 157 */ 158 struct pfs_node * 159 pfs_create_file(struct pfs_node *parent, const char *name, pfs_fill_t fill, 160 pfs_attr_t attr, pfs_vis_t vis, pfs_destroy_t destroy, 161 int flags) 162 { 163 struct pfs_node *node; 164 165 KASSERT(strlen(name) < PFS_NAMELEN, 166 ("%s(): node name is too long", __func__)); 167 168 MALLOC(node, struct pfs_node *, sizeof *node, 169 M_PFSNODES, M_WAITOK|M_ZERO); 170 strcpy(node->pn_name, name); 171 node->pn_type = pfstype_file; 172 node->pn_func = fill; 173 node->pn_attr = attr; 174 node->pn_vis = vis; 175 node->pn_destroy = destroy; 176 node->pn_flags = flags; 177 178 if (_pfs_add_node(parent, node) != 0) { 179 FREE(node, M_PFSNODES); 180 return (NULL); 181 } 182 183 return (node); 184 } 185 186 /* 187 * Create a symlink 188 */ 189 struct pfs_node * 190 pfs_create_link(struct pfs_node *parent, const char *name, pfs_fill_t fill, 191 pfs_attr_t attr, pfs_vis_t vis, pfs_destroy_t destroy, 192 int flags) 193 { 194 struct pfs_node *node; 195 196 node = pfs_create_file(parent, name, fill, attr, vis, destroy, flags); 197 if (node == NULL) 198 return (NULL); 199 node->pn_type = pfstype_symlink; 200 return (node); 201 } 202 203 /* 204 * Locate a node by name 205 */ 206 struct pfs_node * 207 pfs_find_node(struct pfs_node *parent, const char *name) 208 { 209 struct pfs_node *node; 210 211 for (node = parent->pn_nodes; node != NULL; node = node->pn_next) 212 if (strcmp(node->pn_name, name) == 0) 213 return (node); 214 return (NULL); 215 } 216 217 /* 218 * Destroy a node or a tree of nodes 219 */ 220 int 221 pfs_destroy(struct pfs_node *node) 222 { 223 struct pfs_node *parent, *rover; 224 225 KASSERT(node != NULL, 226 ("%s(): node is NULL", __func__)); 227 KASSERT(node->pn_info != NULL, 228 ("%s(): node has no pn_info", __func__)); 229 230 /* destroy children */ 231 if (node->pn_type == pfstype_dir || 232 node->pn_type == pfstype_procdir || 233 node->pn_type == pfstype_root) 234 while (node->pn_nodes != NULL) 235 pfs_destroy(node->pn_nodes); 236 237 /* unlink from parent */ 238 if ((parent = node->pn_parent) != NULL) { 239 KASSERT(parent->pn_info == node->pn_info, 240 ("%s(): parent has different pn_info", __func__)); 241 mtx_lock(&node->pn_info->pi_mutex); 242 if (parent->pn_nodes == node) { 243 parent->pn_nodes = node->pn_next; 244 } else { 245 rover = parent->pn_nodes; 246 while (rover->pn_next != NULL) { 247 if (rover->pn_next == node) { 248 rover->pn_next = node->pn_next; 249 break; 250 } 251 rover = rover->pn_next; 252 } 253 } 254 mtx_unlock(&node->pn_info->pi_mutex); 255 } 256 257 /* callback to free any private resources */ 258 if(node->pn_destroy != NULL) 259 (node->pn_destroy)(node); 260 261 /* revoke vnodes and release memory */ 262 pfs_disable(node); 263 FREE(node, M_PFSNODES); 264 265 return (0); 266 } 267 268 /* 269 * Mount a pseudofs instance 270 */ 271 int 272 pfs_mount(struct pfs_info *pi, struct mount *mp, struct thread *td) 273 { 274 struct statfs *sbp; 275 276 if (mp->mnt_flag & MNT_UPDATE) 277 return (EOPNOTSUPP); 278 279 mp->mnt_flag |= MNT_LOCAL; 280 mp->mnt_data = (qaddr_t)pi; 281 vfs_getnewfsid(mp); 282 283 sbp = &mp->mnt_stat; 284 vfs_mountedfrom(mp, pi->pi_name); 285 sbp->f_bsize = PAGE_SIZE; 286 sbp->f_iosize = PAGE_SIZE; 287 sbp->f_blocks = 1; 288 sbp->f_bfree = 0; 289 sbp->f_bavail = 0; 290 sbp->f_files = 1; 291 sbp->f_ffree = 0; 292 293 return (0); 294 } 295 296 /* 297 * Compatibility shim for old mount(2) system call. 298 */ 299 int 300 pfs_cmount(struct mntarg *ma, void *data, int flags, struct thread *td) 301 { 302 return kernel_mount(ma, flags); 303 } 304 305 /* 306 * Unmount a pseudofs instance 307 */ 308 int 309 pfs_unmount(struct mount *mp, int mntflags, struct thread *td) 310 { 311 struct pfs_info *pi; 312 int error; 313 314 pi = (struct pfs_info *)mp->mnt_data; 315 316 /* XXX do stuff with pi... */ 317 318 error = vflush(mp, 0, (mntflags & MNT_FORCE) ? FORCECLOSE : 0, td); 319 return (error); 320 } 321 322 /* 323 * Return a root vnode 324 */ 325 int 326 pfs_root(struct mount *mp, int flags, struct vnode **vpp, struct thread *td) 327 { 328 struct pfs_info *pi; 329 330 pi = (struct pfs_info *)mp->mnt_data; 331 return pfs_vncache_alloc(mp, vpp, pi->pi_root, NO_PID); 332 } 333 334 /* 335 * Return filesystem stats 336 */ 337 int 338 pfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td) 339 { 340 /* no-op: always called with mp->mnt_stat */ 341 return (0); 342 } 343 344 /* 345 * Initialize a pseudofs instance 346 */ 347 int 348 pfs_init(struct pfs_info *pi, struct vfsconf *vfc) 349 { 350 struct pfs_node *root; 351 int error; 352 353 mtx_init(&pi->pi_mutex, "pseudofs", NULL, MTX_DEF); 354 355 /* set up the root diretory */ 356 MALLOC(root, struct pfs_node *, sizeof *root, 357 M_PFSNODES, M_WAITOK|M_ZERO); 358 root->pn_type = pfstype_root; 359 root->pn_name[0] = '/'; 360 root->pn_info = pi; 361 if (_pfs_fixup_dir(root) != 0) { 362 FREE(root, M_PFSNODES); 363 return (ENODEV); /* XXX not really the right errno */ 364 } 365 pi->pi_root = root; 366 367 /* construct file hierarchy */ 368 error = (pi->pi_init)(pi, vfc); 369 if (error) { 370 pfs_destroy(root); 371 pi->pi_root = NULL; 372 mtx_destroy(&pi->pi_mutex); 373 return (error); 374 } 375 376 pfs_fileno_init(pi); 377 if (bootverbose) 378 printf("%s registered\n", pi->pi_name); 379 return (0); 380 } 381 382 /* 383 * Destroy a pseudofs instance 384 */ 385 int 386 pfs_uninit(struct pfs_info *pi, struct vfsconf *vfc) 387 { 388 int error; 389 390 pfs_fileno_uninit(pi); 391 pfs_destroy(pi->pi_root); 392 pi->pi_root = NULL; 393 mtx_destroy(&pi->pi_mutex); 394 if (bootverbose) 395 printf("%s unregistered\n", pi->pi_name); 396 error = (pi->pi_uninit)(pi, vfc); 397 return (error); 398 } 399 400 /* 401 * Handle load / unload events 402 */ 403 static int 404 pfs_modevent(module_t mod, int evt, void *arg) 405 { 406 switch (evt) { 407 case MOD_LOAD: 408 pfs_vncache_load(); 409 break; 410 case MOD_UNLOAD: 411 case MOD_SHUTDOWN: 412 pfs_vncache_unload(); 413 break; 414 default: 415 return EOPNOTSUPP; 416 break; 417 } 418 return 0; 419 } 420 421 /* 422 * Module declaration 423 */ 424 static moduledata_t pseudofs_data = { 425 "pseudofs", 426 pfs_modevent, 427 NULL 428 }; 429 DECLARE_MODULE(pseudofs, pseudofs_data, SI_SUB_EXEC, SI_ORDER_FIRST); 430 MODULE_VERSION(pseudofs, 1); 431