tmpfs_vfsops.c revision 1.21
1 /* $NetBSD: tmpfs_vfsops.c,v 1.21 2007/06/30 09:37:57 pooka Exp $ */ 2 3 /* 4 * Copyright (c) 2005, 2006 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Julio M. Merino Vidal, developed as part of Google's Summer of Code 9 * 2005 program. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * Efficient memory file system. 42 * 43 * tmpfs is a file system that uses NetBSD's virtual memory sub-system 44 * (the well-known UVM) to store file data and metadata in an efficient 45 * way. This means that it does not follow the structure of an on-disk 46 * file system because it simply does not need to. Instead, it uses 47 * memory-specific data structures and algorithms to automatically 48 * allocate and release resources. 49 */ 50 51 #include <sys/cdefs.h> 52 __KERNEL_RCSID(0, "$NetBSD: tmpfs_vfsops.c,v 1.21 2007/06/30 09:37:57 pooka Exp $"); 53 54 #include <sys/param.h> 55 #include <sys/types.h> 56 #include <sys/malloc.h> 57 #include <sys/mount.h> 58 #include <sys/stat.h> 59 #include <sys/systm.h> 60 #include <sys/vnode.h> 61 62 #include <fs/tmpfs/tmpfs.h> 63 64 MALLOC_JUSTDEFINE(M_TMPFSMNT, "tmpfs mount", "tmpfs mount structures"); 65 66 /* --------------------------------------------------------------------- */ 67 68 static int tmpfs_mount(struct mount *, const char *, void *, 69 struct nameidata *, struct lwp *); 70 static int tmpfs_start(struct mount *, int, struct lwp *); 71 static int tmpfs_unmount(struct mount *, int, struct lwp *); 72 static int tmpfs_root(struct mount *, struct vnode **); 73 static int tmpfs_quotactl(struct mount *, int, uid_t, void *, 74 struct lwp *); 75 static int tmpfs_vget(struct mount *, ino_t, struct vnode **); 76 static int tmpfs_fhtovp(struct mount *, struct fid *, struct vnode **); 77 static int tmpfs_vptofh(struct vnode *, struct fid *, size_t *); 78 static int tmpfs_statvfs(struct mount *, struct statvfs *, struct lwp *); 79 static int tmpfs_sync(struct mount *, int, kauth_cred_t, struct lwp *); 80 static void tmpfs_init(void); 81 static void tmpfs_done(void); 82 static int tmpfs_snapshot(struct mount *, struct vnode *, 83 struct timespec *); 84 85 /* --------------------------------------------------------------------- */ 86 87 static int 88 tmpfs_mount(struct mount *mp, const char *path, void *data, 89 struct nameidata *ndp, struct lwp *l) 90 { 91 int error; 92 ino_t nodes; 93 size_t pages; 94 struct tmpfs_mount *tmp; 95 struct tmpfs_node *root; 96 struct tmpfs_args args; 97 98 /* Handle retrieval of mount point arguments. */ 99 if (mp->mnt_flag & MNT_GETARGS) { 100 if (mp->mnt_data == NULL) 101 return EIO; 102 tmp = VFS_TO_TMPFS(mp); 103 104 args.ta_version = TMPFS_ARGS_VERSION; 105 args.ta_nodes_max = tmp->tm_nodes_max; 106 args.ta_size_max = tmp->tm_pages_max * PAGE_SIZE; 107 108 root = tmp->tm_root; 109 args.ta_root_uid = root->tn_uid; 110 args.ta_root_gid = root->tn_gid; 111 args.ta_root_mode = root->tn_mode; 112 113 return copyout(&args, data, sizeof(args)); 114 } 115 116 /* Verify that we have parameters, as they are required. */ 117 if (data == NULL) 118 return EINVAL; 119 120 /* Get the mount parameters. */ 121 error = copyin(data, &args, sizeof(args)); 122 if (error != 0) 123 return error; 124 125 if (mp->mnt_flag & MNT_UPDATE) { 126 /* XXX: There is no support yet to update file system 127 * settings. Should be added. */ 128 129 return EOPNOTSUPP; 130 } 131 132 if (args.ta_version != TMPFS_ARGS_VERSION) 133 return EINVAL; 134 135 /* Do not allow mounts if we do not have enough memory to preserve 136 * the minimum reserved pages. */ 137 if (tmpfs_mem_info(true) < TMPFS_PAGES_RESERVED) 138 return EINVAL; 139 140 /* Get the maximum number of memory pages this file system is 141 * allowed to use, based on the maximum size the user passed in 142 * the mount structure. A value of zero is treated as if the 143 * maximum available space was requested. */ 144 if (args.ta_size_max < PAGE_SIZE || args.ta_size_max >= SIZE_MAX) 145 pages = SIZE_MAX; 146 else 147 pages = args.ta_size_max / PAGE_SIZE + 148 (args.ta_size_max % PAGE_SIZE == 0 ? 0 : 1); 149 KASSERT(pages > 0); 150 151 if (args.ta_nodes_max <= 3) 152 nodes = 3 + pages * PAGE_SIZE / 1024; 153 else 154 nodes = args.ta_nodes_max; 155 KASSERT(nodes >= 3); 156 157 /* Allocate the tmpfs mount structure and fill it. */ 158 tmp = (struct tmpfs_mount *)malloc(sizeof(struct tmpfs_mount), 159 M_TMPFSMNT, M_WAITOK); 160 KASSERT(tmp != NULL); 161 162 tmp->tm_nodes_max = nodes; 163 tmp->tm_nodes_last = 2; 164 LIST_INIT(&tmp->tm_nodes_used); 165 LIST_INIT(&tmp->tm_nodes_avail); 166 167 tmp->tm_pages_max = pages; 168 tmp->tm_pages_used = 0; 169 tmpfs_pool_init(&tmp->tm_dirent_pool, sizeof(struct tmpfs_dirent), 170 "dirent", tmp); 171 tmpfs_pool_init(&tmp->tm_node_pool, sizeof(struct tmpfs_node), 172 "node", tmp); 173 tmpfs_str_pool_init(&tmp->tm_str_pool, tmp); 174 175 /* Allocate the root node. */ 176 error = tmpfs_alloc_node(tmp, VDIR, args.ta_root_uid, 177 args.ta_root_gid, args.ta_root_mode & ALLPERMS, NULL, NULL, 178 VNOVAL, l->l_proc, &root); 179 KASSERT(error == 0 && root != NULL); 180 tmp->tm_root = root; 181 182 mp->mnt_data = tmp; 183 mp->mnt_flag |= MNT_LOCAL; 184 mp->mnt_stat.f_namemax = MAXNAMLEN; 185 vfs_getnewfsid(mp); 186 187 return set_statvfs_info(path, UIO_USERSPACE, "tmpfs", UIO_SYSSPACE, 188 mp, l); 189 } 190 191 /* --------------------------------------------------------------------- */ 192 193 static int 194 tmpfs_start(struct mount *mp, int flags, 195 struct lwp *l) 196 { 197 198 return 0; 199 } 200 201 /* --------------------------------------------------------------------- */ 202 203 /* ARGSUSED2 */ 204 static int 205 tmpfs_unmount(struct mount *mp, int mntflags, struct lwp *l) 206 { 207 int error; 208 int flags = 0; 209 struct tmpfs_mount *tmp; 210 struct tmpfs_node *node; 211 212 /* Handle forced unmounts. */ 213 if (mntflags & MNT_FORCE) 214 flags |= FORCECLOSE; 215 216 /* Finalize all pending I/O. */ 217 error = vflush(mp, NULL, flags); 218 if (error != 0) 219 return error; 220 221 tmp = VFS_TO_TMPFS(mp); 222 223 /* Free all associated data. The loop iterates over the linked list 224 * we have containing all used nodes. For each of them that is 225 * a directory, we free all its directory entries. Note that after 226 * freeing a node, it will automatically go to the available list, 227 * so we will later have to iterate over it to release its items. */ 228 node = LIST_FIRST(&tmp->tm_nodes_used); 229 while (node != NULL) { 230 struct tmpfs_node *next; 231 232 if (node->tn_type == VDIR) { 233 struct tmpfs_dirent *de; 234 235 de = TAILQ_FIRST(&node->tn_spec.tn_dir.tn_dir); 236 while (de != NULL) { 237 struct tmpfs_dirent *nde; 238 239 nde = TAILQ_NEXT(de, td_entries); 240 KASSERT(de->td_node->tn_vnode == NULL); 241 tmpfs_free_dirent(tmp, de, false); 242 de = nde; 243 node->tn_size -= sizeof(struct tmpfs_dirent); 244 } 245 } 246 247 next = LIST_NEXT(node, tn_entries); 248 tmpfs_free_node(tmp, node); 249 node = next; 250 } 251 node = LIST_FIRST(&tmp->tm_nodes_avail); 252 while (node != NULL) { 253 struct tmpfs_node *next; 254 255 next = LIST_NEXT(node, tn_entries); 256 LIST_REMOVE(node, tn_entries); 257 TMPFS_POOL_PUT(&tmp->tm_node_pool, node); 258 node = next; 259 } 260 261 tmpfs_pool_destroy(&tmp->tm_dirent_pool); 262 tmpfs_pool_destroy(&tmp->tm_node_pool); 263 tmpfs_str_pool_destroy(&tmp->tm_str_pool); 264 265 KASSERT(tmp->tm_pages_used == 0); 266 267 /* Throw away the tmpfs_mount structure. */ 268 free(mp->mnt_data, M_TMPFSMNT); 269 mp->mnt_data = NULL; 270 271 return 0; 272 } 273 274 /* --------------------------------------------------------------------- */ 275 276 static int 277 tmpfs_root(struct mount *mp, struct vnode **vpp) 278 { 279 280 return tmpfs_alloc_vp(mp, VFS_TO_TMPFS(mp)->tm_root, vpp); 281 } 282 283 /* --------------------------------------------------------------------- */ 284 285 static int 286 tmpfs_quotactl(struct mount *mp, int cmd, uid_t uid, 287 void *arg, struct lwp *l) 288 { 289 290 printf("tmpfs_quotactl called; need for it unknown yet\n"); 291 return EOPNOTSUPP; 292 } 293 294 /* --------------------------------------------------------------------- */ 295 296 static int 297 tmpfs_vget(struct mount *mp, ino_t ino, 298 struct vnode **vpp) 299 { 300 301 printf("tmpfs_vget called; need for it unknown yet\n"); 302 return EOPNOTSUPP; 303 } 304 305 /* --------------------------------------------------------------------- */ 306 307 static int 308 tmpfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp) 309 { 310 bool found; 311 struct tmpfs_fid tfh; 312 struct tmpfs_mount *tmp; 313 struct tmpfs_node *node; 314 315 tmp = VFS_TO_TMPFS(mp); 316 317 if (fhp->fid_len != sizeof(struct tmpfs_fid)) 318 return EINVAL; 319 320 memcpy(&tfh, fhp, sizeof(struct tmpfs_fid)); 321 322 if (tfh.tf_id >= tmp->tm_nodes_max) 323 return EINVAL; 324 325 found = false; 326 LIST_FOREACH(node, &tmp->tm_nodes_used, tn_entries) { 327 if (node->tn_id == tfh.tf_id && 328 node->tn_gen == tfh.tf_gen) { 329 found = true; 330 break; 331 } 332 } 333 334 return found ? tmpfs_alloc_vp(mp, node, vpp) : EINVAL; 335 } 336 337 /* --------------------------------------------------------------------- */ 338 339 static int 340 tmpfs_vptofh(struct vnode *vp, struct fid *fhp, size_t *fh_size) 341 { 342 struct tmpfs_fid tfh; 343 struct tmpfs_node *node; 344 345 if (*fh_size < sizeof(struct tmpfs_fid)) { 346 *fh_size = sizeof(struct tmpfs_fid); 347 return E2BIG; 348 } 349 *fh_size = sizeof(struct tmpfs_fid); 350 node = VP_TO_TMPFS_NODE(vp); 351 352 memset(&tfh, 0, sizeof(tfh)); 353 tfh.tf_len = sizeof(struct tmpfs_fid); 354 tfh.tf_gen = node->tn_gen; 355 tfh.tf_id = node->tn_id; 356 memcpy(fhp, &tfh, sizeof(tfh)); 357 358 return 0; 359 } 360 361 /* --------------------------------------------------------------------- */ 362 363 /* ARGSUSED2 */ 364 static int 365 tmpfs_statvfs(struct mount *mp, struct statvfs *sbp, struct lwp *l) 366 { 367 fsfilcnt_t freenodes, usednodes; 368 struct tmpfs_mount *tmp; 369 struct tmpfs_node *dummy; 370 371 tmp = VFS_TO_TMPFS(mp); 372 373 sbp->f_iosize = sbp->f_frsize = sbp->f_bsize = PAGE_SIZE; 374 375 sbp->f_blocks = TMPFS_PAGES_MAX(tmp); 376 sbp->f_bavail = sbp->f_bfree = TMPFS_PAGES_AVAIL(tmp); 377 sbp->f_bresvd = 0; 378 379 freenodes = MIN(tmp->tm_nodes_max - tmp->tm_nodes_last, 380 TMPFS_PAGES_AVAIL(tmp) * PAGE_SIZE / sizeof(struct tmpfs_node)); 381 LIST_FOREACH(dummy, &tmp->tm_nodes_avail, tn_entries) 382 freenodes++; 383 384 usednodes = 0; 385 LIST_FOREACH(dummy, &tmp->tm_nodes_used, tn_entries) 386 usednodes++; 387 388 sbp->f_files = freenodes + usednodes; 389 sbp->f_favail = sbp->f_ffree = freenodes; 390 sbp->f_fresvd = 0; 391 392 copy_statvfs_info(sbp, mp); 393 394 return 0; 395 } 396 397 /* --------------------------------------------------------------------- */ 398 399 /* ARGSUSED0 */ 400 static int 401 tmpfs_sync(struct mount *mp, int waitfor, 402 kauth_cred_t uc, struct lwp *l) 403 { 404 405 return 0; 406 } 407 408 /* --------------------------------------------------------------------- */ 409 410 static void 411 tmpfs_init(void) 412 { 413 414 malloc_type_attach(M_TMPFSMNT); 415 } 416 417 /* --------------------------------------------------------------------- */ 418 419 static void 420 tmpfs_done(void) 421 { 422 423 malloc_type_detach(M_TMPFSMNT); 424 } 425 426 /* --------------------------------------------------------------------- */ 427 428 static int 429 tmpfs_snapshot(struct mount *mp, struct vnode *vp, 430 struct timespec *ctime) 431 { 432 433 return EOPNOTSUPP; 434 } 435 436 /* --------------------------------------------------------------------- */ 437 438 /* 439 * tmpfs vfs operations. 440 */ 441 442 extern const struct vnodeopv_desc tmpfs_fifoop_opv_desc; 443 extern const struct vnodeopv_desc tmpfs_specop_opv_desc; 444 extern const struct vnodeopv_desc tmpfs_vnodeop_opv_desc; 445 446 const struct vnodeopv_desc * const tmpfs_vnodeopv_descs[] = { 447 &tmpfs_fifoop_opv_desc, 448 &tmpfs_specop_opv_desc, 449 &tmpfs_vnodeop_opv_desc, 450 NULL, 451 }; 452 453 struct vfsops tmpfs_vfsops = { 454 MOUNT_TMPFS, /* vfs_name */ 455 tmpfs_mount, /* vfs_mount */ 456 tmpfs_start, /* vfs_start */ 457 tmpfs_unmount, /* vfs_unmount */ 458 tmpfs_root, /* vfs_root */ 459 tmpfs_quotactl, /* vfs_quotactl */ 460 tmpfs_statvfs, /* vfs_statvfs */ 461 tmpfs_sync, /* vfs_sync */ 462 tmpfs_vget, /* vfs_vget */ 463 tmpfs_fhtovp, /* vfs_fhtovp */ 464 tmpfs_vptofh, /* vfs_vptofh */ 465 tmpfs_init, /* vfs_init */ 466 NULL, /* vfs_reinit */ 467 tmpfs_done, /* vfs_done */ 468 NULL, /* vfs_mountroot */ 469 tmpfs_snapshot, /* vfs_snapshot */ 470 vfs_stdextattrctl, /* vfs_extattrctl */ 471 vfs_stdsuspendctl, /* vfs_suspendctl */ 472 tmpfs_vnodeopv_descs, 473 0, /* vfs_refcount */ 474 { NULL, NULL }, 475 }; 476 VFS_ATTACH(tmpfs_vfsops); 477
Indexes created Thu Sep 25 02:09:54 GMT 2025