tmpfs_vfsops.c revision 1.30
1 /* $NetBSD: tmpfs_vfsops.c,v 1.30 2007/11/06 19:50:55 ad Exp $ */ 2 3 /* 4 * Copyright (c) 2005, 2006, 2007 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 1.30 2007/11/06 19:50:55 ad Exp $"); 53 54 #include <sys/param.h> 55 #include <sys/types.h> 56 #include <sys/kmem.h> 57 #include <sys/mount.h> 58 #include <sys/stat.h> 59 #include <sys/systm.h> 60 #include <sys/vnode.h> 61 #include <sys/proc.h> 62 63 #include <fs/tmpfs/tmpfs.h> 64 65 /* --------------------------------------------------------------------- */ 66 67 static int tmpfs_mount(struct mount *, const char *, void *, size_t *, 68 struct lwp *); 69 static int tmpfs_start(struct mount *, int, struct lwp *); 70 static int tmpfs_unmount(struct mount *, int, struct lwp *); 71 static int tmpfs_root(struct mount *, struct vnode **); 72 static int tmpfs_quotactl(struct mount *, int, uid_t, void *, 73 struct lwp *); 74 static int tmpfs_vget(struct mount *, ino_t, struct vnode **); 75 static int tmpfs_fhtovp(struct mount *, struct fid *, struct vnode **); 76 static int tmpfs_vptofh(struct vnode *, struct fid *, size_t *); 77 static int tmpfs_statvfs(struct mount *, struct statvfs *, struct lwp *); 78 static int tmpfs_sync(struct mount *, int, kauth_cred_t, struct lwp *); 79 static void tmpfs_init(void); 80 static void tmpfs_done(void); 81 static int tmpfs_snapshot(struct mount *, struct vnode *, 82 struct timespec *); 83 84 /* --------------------------------------------------------------------- */ 85 86 static int 87 tmpfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len, 88 struct lwp *l) 89 { 90 int error; 91 ino_t nodes; 92 size_t pages; 93 struct tmpfs_mount *tmp; 94 struct tmpfs_node *root; 95 struct tmpfs_args *args = data; 96 97 if (*data_len < sizeof *args) 98 return EINVAL; 99 100 /* Handle retrieval of mount point arguments. */ 101 if (mp->mnt_flag & MNT_GETARGS) { 102 if (mp->mnt_data == NULL) 103 return EIO; 104 tmp = VFS_TO_TMPFS(mp); 105 106 args->ta_version = TMPFS_ARGS_VERSION; 107 mutex_enter(&tmp->tm_lock); 108 args->ta_nodes_max = tmp->tm_nodes_max; 109 args->ta_size_max = tmp->tm_pages_max * PAGE_SIZE; 110 root = tmp->tm_root; 111 mutex_exit(&tmp->tm_lock); 112 113 args->ta_root_uid = root->tn_uid; 114 args->ta_root_gid = root->tn_gid; 115 args->ta_root_mode = root->tn_mode; 116 117 *data_len = sizeof *args; 118 return 0; 119 } 120 121 if (mp->mnt_flag & MNT_UPDATE) { 122 /* XXX: There is no support yet to update file system 123 * settings. Should be added. */ 124 125 return EOPNOTSUPP; 126 } 127 128 if (args->ta_version != TMPFS_ARGS_VERSION) 129 return EINVAL; 130 131 /* Do not allow mounts if we do not have enough memory to preserve 132 * the minimum reserved pages. */ 133 if (tmpfs_mem_info(true) < TMPFS_PAGES_RESERVED) 134 return EINVAL; 135 136 /* Get the maximum number of memory pages this file system is 137 * allowed to use, based on the maximum size the user passed in 138 * the mount structure. A value of zero is treated as if the 139 * maximum available space was requested. */ 140 if (args->ta_size_max < PAGE_SIZE || args->ta_size_max >= SIZE_MAX) 141 pages = SIZE_MAX; 142 else 143 pages = args->ta_size_max / PAGE_SIZE + 144 (args->ta_size_max % PAGE_SIZE == 0 ? 0 : 1); 145 KASSERT(pages > 0); 146 147 if (args->ta_nodes_max <= 3) 148 nodes = 3 + pages * PAGE_SIZE / 1024; 149 else 150 nodes = args->ta_nodes_max; 151 KASSERT(nodes >= 3); 152 153 /* Allocate the tmpfs mount structure and fill it. */ 154 tmp = kmem_alloc(sizeof(struct tmpfs_mount), KM_SLEEP); 155 if (tmp == NULL) 156 return ENOMEM; 157 158 tmp->tm_nodes_max = nodes; 159 tmp->tm_nodes_cnt = 0; 160 LIST_INIT(&tmp->tm_nodes); 161 162 mutex_init(&tmp->tm_lock, MUTEX_DEFAULT, IPL_NONE); 163 164 tmp->tm_pages_max = pages; 165 tmp->tm_pages_used = 0; 166 tmpfs_pool_init(&tmp->tm_dirent_pool, sizeof(struct tmpfs_dirent), 167 "dirent", tmp); 168 tmpfs_pool_init(&tmp->tm_node_pool, sizeof(struct tmpfs_node), 169 "node", tmp); 170 tmpfs_str_pool_init(&tmp->tm_str_pool, tmp); 171 172 /* Allocate the root node. */ 173 error = tmpfs_alloc_node(tmp, VDIR, args->ta_root_uid, 174 args->ta_root_gid, args->ta_root_mode & ALLPERMS, NULL, NULL, 175 VNOVAL, l->l_proc, &root); 176 KASSERT(error == 0 && root != NULL); 177 tmp->tm_root = root; 178 179 mp->mnt_data = tmp; 180 mp->mnt_flag |= MNT_LOCAL; 181 mp->mnt_stat.f_namemax = MAXNAMLEN; 182 mp->mnt_fs_bshift = PAGE_SHIFT; 183 mp->mnt_dev_bshift = DEV_BSHIFT; 184 mp->mnt_iflag |= IMNT_MPSAFE; 185 vfs_getnewfsid(mp); 186 187 return set_statvfs_info(path, UIO_USERSPACE, "tmpfs", UIO_SYSSPACE, 188 mp->mnt_op->vfs_name, 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 while ((node = LIST_FIRST(&tmp->tm_nodes)) != NULL) { 229 if (node->tn_type == VDIR) { 230 struct tmpfs_dirent *de; 231 232 de = TAILQ_FIRST(&node->tn_spec.tn_dir.tn_dir); 233 while (de != NULL) { 234 struct tmpfs_dirent *nde; 235 236 nde = TAILQ_NEXT(de, td_entries); 237 KASSERT(de->td_node->tn_vnode == NULL); 238 tmpfs_free_dirent(tmp, de, false); 239 de = nde; 240 node->tn_size -= sizeof(struct tmpfs_dirent); 241 } 242 } 243 244 tmpfs_free_node(tmp, node); 245 } 246 247 tmpfs_pool_destroy(&tmp->tm_dirent_pool); 248 tmpfs_pool_destroy(&tmp->tm_node_pool); 249 tmpfs_str_pool_destroy(&tmp->tm_str_pool); 250 251 KASSERT(tmp->tm_pages_used == 0); 252 253 /* Throw away the tmpfs_mount structure. */ 254 mutex_destroy(&tmp->tm_lock); 255 kmem_free(tmp, sizeof(*tmp)); 256 mp->mnt_data = NULL; 257 258 return 0; 259 } 260 261 /* --------------------------------------------------------------------- */ 262 263 static int 264 tmpfs_root(struct mount *mp, struct vnode **vpp) 265 { 266 267 return tmpfs_alloc_vp(mp, VFS_TO_TMPFS(mp)->tm_root, vpp); 268 } 269 270 /* --------------------------------------------------------------------- */ 271 272 static int 273 tmpfs_quotactl(struct mount *mp, int cmd, uid_t uid, 274 void *arg, struct lwp *l) 275 { 276 277 printf("tmpfs_quotactl called; need for it unknown yet\n"); 278 return EOPNOTSUPP; 279 } 280 281 /* --------------------------------------------------------------------- */ 282 283 static int 284 tmpfs_vget(struct mount *mp, ino_t ino, 285 struct vnode **vpp) 286 { 287 288 printf("tmpfs_vget called; need for it unknown yet\n"); 289 return EOPNOTSUPP; 290 } 291 292 /* --------------------------------------------------------------------- */ 293 294 static int 295 tmpfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp) 296 { 297 bool found; 298 struct tmpfs_fid tfh; 299 struct tmpfs_mount *tmp; 300 struct tmpfs_node *node; 301 302 tmp = VFS_TO_TMPFS(mp); 303 304 if (fhp->fid_len != sizeof(struct tmpfs_fid)) 305 return EINVAL; 306 307 memcpy(&tfh, fhp, sizeof(struct tmpfs_fid)); 308 309 mutex_enter(&tmp->tm_lock); 310 if (tfh.tf_id >= tmp->tm_nodes_max) { 311 mutex_exit(&tmp->tm_lock); 312 return EINVAL; 313 } 314 315 found = false; 316 LIST_FOREACH(node, &tmp->tm_nodes, tn_entries) { 317 if (node->tn_id == tfh.tf_id && 318 node->tn_gen == tfh.tf_gen) { 319 found = true; 320 break; 321 } 322 } 323 mutex_exit(&tmp->tm_lock); 324 325 /* XXXAD nothing to prevent 'node' from being removed. */ 326 return found ? tmpfs_alloc_vp(mp, node, vpp) : EINVAL; 327 } 328 329 /* --------------------------------------------------------------------- */ 330 331 static int 332 tmpfs_vptofh(struct vnode *vp, struct fid *fhp, size_t *fh_size) 333 { 334 struct tmpfs_fid tfh; 335 struct tmpfs_node *node; 336 337 if (*fh_size < sizeof(struct tmpfs_fid)) { 338 *fh_size = sizeof(struct tmpfs_fid); 339 return E2BIG; 340 } 341 *fh_size = sizeof(struct tmpfs_fid); 342 node = VP_TO_TMPFS_NODE(vp); 343 344 memset(&tfh, 0, sizeof(tfh)); 345 tfh.tf_len = sizeof(struct tmpfs_fid); 346 tfh.tf_gen = node->tn_gen; 347 tfh.tf_id = node->tn_id; 348 memcpy(fhp, &tfh, sizeof(tfh)); 349 350 return 0; 351 } 352 353 /* --------------------------------------------------------------------- */ 354 355 /* ARGSUSED2 */ 356 static int 357 tmpfs_statvfs(struct mount *mp, struct statvfs *sbp, struct lwp *l) 358 { 359 fsfilcnt_t freenodes; 360 struct tmpfs_mount *tmp; 361 362 tmp = VFS_TO_TMPFS(mp); 363 364 mutex_enter(&tmp->tm_lock); 365 366 sbp->f_iosize = sbp->f_frsize = sbp->f_bsize = PAGE_SIZE; 367 368 sbp->f_blocks = TMPFS_PAGES_MAX(tmp); 369 sbp->f_bavail = sbp->f_bfree = TMPFS_PAGES_AVAIL(tmp); 370 sbp->f_bresvd = 0; 371 372 freenodes = MIN(tmp->tm_nodes_max - tmp->tm_nodes_cnt, 373 TMPFS_PAGES_AVAIL(tmp) * PAGE_SIZE / sizeof(struct tmpfs_node)); 374 375 sbp->f_files = tmp->tm_nodes_cnt + freenodes; 376 sbp->f_favail = sbp->f_ffree = freenodes; 377 sbp->f_fresvd = 0; 378 379 mutex_exit(&tmp->tm_lock); 380 381 copy_statvfs_info(sbp, mp); 382 383 return 0; 384 } 385 386 /* --------------------------------------------------------------------- */ 387 388 /* ARGSUSED0 */ 389 static int 390 tmpfs_sync(struct mount *mp, int waitfor, 391 kauth_cred_t uc, struct lwp *l) 392 { 393 394 return 0; 395 } 396 397 /* --------------------------------------------------------------------- */ 398 399 static void 400 tmpfs_init(void) 401 { 402 403 } 404 405 /* --------------------------------------------------------------------- */ 406 407 static void 408 tmpfs_done(void) 409 { 410 411 } 412 413 /* --------------------------------------------------------------------- */ 414 415 static int 416 tmpfs_snapshot(struct mount *mp, struct vnode *vp, 417 struct timespec *ctime) 418 { 419 420 return EOPNOTSUPP; 421 } 422 423 /* --------------------------------------------------------------------- */ 424 425 /* 426 * tmpfs vfs operations. 427 */ 428 429 extern const struct vnodeopv_desc tmpfs_fifoop_opv_desc; 430 extern const struct vnodeopv_desc tmpfs_specop_opv_desc; 431 extern const struct vnodeopv_desc tmpfs_vnodeop_opv_desc; 432 433 const struct vnodeopv_desc * const tmpfs_vnodeopv_descs[] = { 434 &tmpfs_fifoop_opv_desc, 435 &tmpfs_specop_opv_desc, 436 &tmpfs_vnodeop_opv_desc, 437 NULL, 438 }; 439 440 struct vfsops tmpfs_vfsops = { 441 MOUNT_TMPFS, /* vfs_name */ 442 sizeof (struct tmpfs_args), 443 tmpfs_mount, /* vfs_mount */ 444 tmpfs_start, /* vfs_start */ 445 tmpfs_unmount, /* vfs_unmount */ 446 tmpfs_root, /* vfs_root */ 447 tmpfs_quotactl, /* vfs_quotactl */ 448 tmpfs_statvfs, /* vfs_statvfs */ 449 tmpfs_sync, /* vfs_sync */ 450 tmpfs_vget, /* vfs_vget */ 451 tmpfs_fhtovp, /* vfs_fhtovp */ 452 tmpfs_vptofh, /* vfs_vptofh */ 453 tmpfs_init, /* vfs_init */ 454 NULL, /* vfs_reinit */ 455 tmpfs_done, /* vfs_done */ 456 NULL, /* vfs_mountroot */ 457 tmpfs_snapshot, /* vfs_snapshot */ 458 vfs_stdextattrctl, /* vfs_extattrctl */ 459 (void *)eopnotsupp, /* vfs_suspendctl */ 460 tmpfs_vnodeopv_descs, 461 0, /* vfs_refcount */ 462 { NULL, NULL }, 463 }; 464 VFS_ATTACH(tmpfs_vfsops); 465
Indexes created Thu Sep 25 02:09:54 GMT 2025