tmpfs_vfsops.c revision 1.6
1 /* $NetBSD: tmpfs_vfsops.c,v 1.6 2005/09/23 15:36:15 jmmv Exp $ */ 2 3 /* 4 * Copyright (c) 2005 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 1.6 2005/09/23 15:36:15 jmmv 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/systm.h> 59 #include <sys/vnode.h> 60 61 #include <fs/tmpfs/tmpfs.h> 62 63 MALLOC_DEFINE(M_TMPFSMNT, "tmpfs mount", "tmpfs mount structures"); 64 65 /* --------------------------------------------------------------------- */ 66 67 static int tmpfs_mount(struct mount *, const char *, void *, 68 struct nameidata *, struct proc *); 69 static int tmpfs_start(struct mount *, int, struct proc *); 70 static int tmpfs_unmount(struct mount *, int, struct proc *); 71 static int tmpfs_root(struct mount *, struct vnode **); 72 static int tmpfs_quotactl(struct mount *, int, uid_t, void *, 73 struct proc *); 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 *); 77 static int tmpfs_statvfs(struct mount *, struct statvfs *, struct proc *); 78 static int tmpfs_sync(struct mount *, int, struct ucred *, struct proc *); 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, 88 struct nameidata *ndp, struct proc *p) 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; 96 97 /* Handle retrieval of mount point arguments. */ 98 if (mp->mnt_flag & MNT_GETARGS) { 99 if (mp->mnt_data == NULL) 100 return EIO; 101 tmp = VFS_TO_TMPFS(mp); 102 103 args.ta_version = TMPFS_ARGS_VERSION; 104 args.ta_nodes_max = tmp->tm_nodes_max; 105 args.ta_size_max = tmp->tm_pages_max * PAGE_SIZE; 106 107 root = tmp->tm_root; 108 args.ta_root_uid = root->tn_uid; 109 args.ta_root_gid = root->tn_gid; 110 args.ta_root_mode = root->tn_mode; 111 112 return copyout(&args, data, sizeof(args)); 113 } 114 115 /* Verify that we have parameters, as they are required. */ 116 if (data == NULL) 117 return EINVAL; 118 119 /* Get the mount parameters. */ 120 error = copyin(data, &args, sizeof(args)); 121 if (error != 0) 122 return error; 123 124 if (mp->mnt_flag & MNT_UPDATE) { 125 /* XXX: There is no support yet to update file system 126 * settings. Should be added. */ 127 128 return EOPNOTSUPP; 129 } 130 131 if (args.ta_version != TMPFS_ARGS_VERSION) 132 return EINVAL; 133 134 /* Do not allow mounts if we do not have enough memory to preserve 135 * the minimum reserved pages. */ 136 if (tmpfs_mem_info(TRUE) < TMPFS_PAGES_RESERVED) 137 return EINVAL; 138 139 /* Get the maximum number of memory pages this file system is 140 * allowed to use, based on the maximum size the user passed in 141 * the mount structure. A value of zero is treated as if the 142 * maximum available space was requested. */ 143 if (args.ta_size_max == 0) 144 pages = SIZE_MAX; 145 else 146 pages = args.ta_size_max / PAGE_SIZE + 147 (args.ta_size_max % PAGE_SIZE == 0 ? 0 : 1); 148 149 if (args.ta_nodes_max == 0) 150 nodes = pages * PAGE_SIZE / 1024; 151 else 152 nodes = args.ta_nodes_max; 153 154 /* Allocate the tmpfs mount structure and fill it. */ 155 tmp = (struct tmpfs_mount *)malloc(sizeof(struct tmpfs_mount), 156 M_TMPFSMNT, M_WAITOK); 157 KASSERT(tmp != NULL); 158 159 tmp->tm_nodes_max = nodes; 160 tmp->tm_nodes_last = 2; 161 LIST_INIT(&tmp->tm_nodes_used); 162 LIST_INIT(&tmp->tm_nodes_avail); 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, NULL, NULL, VNOVAL, p, 175 &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 vfs_getnewfsid(mp); 183 184 return set_statvfs_info(path, UIO_USERSPACE, "tmpfs", UIO_SYSSPACE, 185 mp, p); 186 } 187 188 /* --------------------------------------------------------------------- */ 189 190 static int 191 tmpfs_start(struct mount *mp, int flags, struct proc *p) 192 { 193 194 return 0; 195 } 196 197 /* --------------------------------------------------------------------- */ 198 199 /* ARGSUSED2 */ 200 static int 201 tmpfs_unmount(struct mount *mp, int mntflags, struct proc *p) 202 { 203 int error; 204 int flags = 0; 205 struct tmpfs_mount *tmp; 206 struct tmpfs_node *node; 207 208 /* Handle forced unmounts. */ 209 if (mntflags & MNT_FORCE) 210 flags |= FORCECLOSE; 211 212 /* Finalize all pending I/O. */ 213 error = vflush(mp, NULL, flags); 214 if (error != 0) 215 return error; 216 217 tmp = VFS_TO_TMPFS(mp); 218 219 /* Free all associated data. The loop iterates over the linked list 220 * we have containing all used nodes. For each of them that is 221 * a directory, we free all its directory entries. Note that after 222 * freeing a node, it will automatically go to the available list, 223 * so we will later have to iterate over it to release its items. */ 224 node = LIST_FIRST(&tmp->tm_nodes_used); 225 while (node != NULL) { 226 struct tmpfs_node *next; 227 228 if (node->tn_type == VDIR) { 229 struct tmpfs_dirent *de; 230 231 de = TAILQ_FIRST(&node->tn_dir); 232 while (de != NULL) { 233 struct tmpfs_dirent *nde; 234 235 nde = TAILQ_NEXT(de, td_entries); 236 tmpfs_free_dirent(tmp, de, FALSE); 237 de = nde; 238 node->tn_size -= sizeof(struct tmpfs_dirent); 239 } 240 } 241 242 next = LIST_NEXT(node, tn_entries); 243 tmpfs_free_node(tmp, node); 244 node = next; 245 } 246 node = LIST_FIRST(&tmp->tm_nodes_avail); 247 while (node != NULL) { 248 struct tmpfs_node *next; 249 250 next = LIST_NEXT(node, tn_entries); 251 LIST_REMOVE(node, tn_entries); 252 TMPFS_POOL_PUT(&tmp->tm_node_pool, node); 253 node = next; 254 } 255 256 tmpfs_pool_destroy(&tmp->tm_dirent_pool); 257 tmpfs_pool_destroy(&tmp->tm_node_pool); 258 tmpfs_str_pool_destroy(&tmp->tm_str_pool); 259 260 KASSERT(tmp->tm_pages_used == 0); 261 262 /* Throw away the tmpfs_mount structure. */ 263 free(mp->mnt_data, M_TMPFSMNT); 264 mp->mnt_data = NULL; 265 266 return 0; 267 } 268 269 /* --------------------------------------------------------------------- */ 270 271 static int 272 tmpfs_root(struct mount *mp, struct vnode **vpp) 273 { 274 275 return tmpfs_alloc_vp(mp, VFS_TO_TMPFS(mp)->tm_root, vpp); 276 } 277 278 /* --------------------------------------------------------------------- */ 279 280 static int 281 tmpfs_quotactl(struct mount *mp, int cmd, uid_t uid, void *arg, 282 struct proc *p) 283 { 284 285 printf("tmpfs_quotactl called; need for it unknown yet\n"); 286 return EOPNOTSUPP; 287 } 288 289 /* --------------------------------------------------------------------- */ 290 291 static int 292 tmpfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp) 293 { 294 295 printf("tmpfs_vget called; need for it unknown yet\n"); 296 return EOPNOTSUPP; 297 } 298 299 /* --------------------------------------------------------------------- */ 300 301 static int 302 tmpfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp) 303 { 304 boolean_t found; 305 struct tmpfs_fid *tfhp; 306 struct tmpfs_mount *tmp; 307 struct tmpfs_node *node; 308 309 tmp = VFS_TO_TMPFS(mp); 310 311 tfhp = (struct tmpfs_fid *)fhp; 312 if (tfhp->tf_len != sizeof(struct tmpfs_fid)) 313 return EINVAL; 314 315 if (tfhp->tf_id >= tmp->tm_nodes_max) 316 return EINVAL; 317 318 found = FALSE; 319 LIST_FOREACH(node, &tmp->tm_nodes_used, tn_entries) { 320 if (node->tn_id == tfhp->tf_id && 321 node->tn_gen == tfhp->tf_gen) { 322 found = TRUE; 323 break; 324 } 325 } 326 327 return found ? tmpfs_alloc_vp(mp, node, vpp) : EINVAL; 328 } 329 330 /* --------------------------------------------------------------------- */ 331 332 static int 333 tmpfs_vptofh(struct vnode *vp, struct fid *fhp) 334 { 335 struct tmpfs_fid *tfhp; 336 struct tmpfs_node *node; 337 338 tfhp = (struct tmpfs_fid *)fhp; 339 node = VP_TO_TMPFS_NODE(vp); 340 341 tfhp->tf_len = sizeof(struct tmpfs_fid); 342 tfhp->tf_id = node->tn_id; 343 tfhp->tf_gen = node->tn_gen; 344 345 return 0; 346 } 347 348 /* --------------------------------------------------------------------- */ 349 350 /* ARGSUSED2 */ 351 static int 352 tmpfs_statvfs(struct mount *mp, struct statvfs *sbp, struct proc *p) 353 { 354 fsfilcnt_t freenodes, usednodes; 355 struct tmpfs_mount *tmp; 356 struct tmpfs_node *dummy; 357 358 tmp = VFS_TO_TMPFS(mp); 359 360 sbp->f_iosize = sbp->f_frsize = sbp->f_bsize = PAGE_SIZE; 361 362 sbp->f_blocks = TMPFS_PAGES_MAX(tmp); 363 sbp->f_bavail = sbp->f_bfree = TMPFS_PAGES_AVAIL(tmp); 364 sbp->f_bresvd = 0; 365 366 freenodes = MIN(tmp->tm_nodes_max - tmp->tm_nodes_last, 367 TMPFS_PAGES_AVAIL(tmp) * PAGE_SIZE / sizeof(struct tmpfs_node)); 368 LIST_FOREACH(dummy, &tmp->tm_nodes_avail, tn_entries) 369 freenodes++; 370 371 usednodes = 0; 372 LIST_FOREACH(dummy, &tmp->tm_nodes_used, tn_entries) 373 usednodes++; 374 375 sbp->f_files = freenodes + usednodes; 376 sbp->f_favail = sbp->f_ffree = freenodes; 377 sbp->f_fresvd = 0; 378 379 copy_statvfs_info(sbp, mp); 380 381 return 0; 382 } 383 384 /* --------------------------------------------------------------------- */ 385 386 /* ARGSUSED0 */ 387 static int 388 tmpfs_sync(struct mount *mp, int waitfor, struct ucred *uc, struct proc *p) 389 { 390 391 return 0; 392 } 393 394 /* --------------------------------------------------------------------- */ 395 396 static void 397 tmpfs_init(void) 398 { 399 400 #ifdef _LKM 401 malloc_type_attach(M_TMPFSMNT); 402 #endif 403 } 404 405 /* --------------------------------------------------------------------- */ 406 407 static void 408 tmpfs_done(void) 409 { 410 411 #ifdef _LKM 412 malloc_type_detach(M_TMPFSMNT); 413 #endif 414 } 415 416 /* --------------------------------------------------------------------- */ 417 418 static int 419 tmpfs_snapshot(struct mount *mp, struct vnode *vp, struct timespec *ctime) 420 { 421 422 return EOPNOTSUPP; 423 } 424 425 /* --------------------------------------------------------------------- */ 426 427 /* 428 * tmpfs vfs operations. 429 */ 430 431 extern const struct vnodeopv_desc tmpfs_fifoop_opv_desc; 432 extern const struct vnodeopv_desc tmpfs_specop_opv_desc; 433 extern const struct vnodeopv_desc tmpfs_vnodeop_opv_desc; 434 435 const struct vnodeopv_desc * const tmpfs_vnodeopv_descs[] = { 436 &tmpfs_fifoop_opv_desc, 437 &tmpfs_specop_opv_desc, 438 &tmpfs_vnodeop_opv_desc, 439 NULL, 440 }; 441 442 struct vfsops tmpfs_vfsops = { 443 MOUNT_TMPFS, /* vfs_name */ 444 tmpfs_mount, /* vfs_mount */ 445 tmpfs_start, /* vfs_start */ 446 tmpfs_unmount, /* vfs_unmount */ 447 tmpfs_root, /* vfs_root */ 448 tmpfs_quotactl, /* vfs_quotactl */ 449 tmpfs_statvfs, /* vfs_statvfs */ 450 tmpfs_sync, /* vfs_sync */ 451 tmpfs_vget, /* vfs_vget */ 452 tmpfs_fhtovp, /* vfs_fhtovp */ 453 tmpfs_vptofh, /* vfs_vptofh */ 454 tmpfs_init, /* vfs_init */ 455 NULL, /* vfs_reinit */ 456 tmpfs_done, /* vfs_done */ 457 NULL, /* vfs_mountroot */ 458 tmpfs_snapshot, /* vfs_snapshot */ 459 vfs_stdextattrctl, /* vfs_extattrctl */ 460 tmpfs_vnodeopv_descs, 461 }; 462 VFS_ATTACH(tmpfs_vfsops); 463
Indexes created Wed Sep 24 15:09:51 GMT 2025