tmpfs_vfsops.c revision 1.7
1 /* $NetBSD: tmpfs_vfsops.c,v 1.7 2005/09/25 16:28:43 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 1.7 2005/09/25 16:28:43 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 < PAGE_SIZE) 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 KASSERT(pages > 0); 149 150 if (args.ta_nodes_max <= 3) 151 nodes = 3 + pages * PAGE_SIZE / 1024; 152 else 153 nodes = args.ta_nodes_max; 154 KASSERT(nodes >= 3); 155 156 /* Allocate the tmpfs mount structure and fill it. */ 157 tmp = (struct tmpfs_mount *)malloc(sizeof(struct tmpfs_mount), 158 M_TMPFSMNT, M_WAITOK); 159 KASSERT(tmp != NULL); 160 161 tmp->tm_nodes_max = nodes; 162 tmp->tm_nodes_last = 2; 163 LIST_INIT(&tmp->tm_nodes_used); 164 LIST_INIT(&tmp->tm_nodes_avail); 165 166 tmp->tm_pages_max = pages; 167 tmp->tm_pages_used = 0; 168 tmpfs_pool_init(&tmp->tm_dirent_pool, sizeof(struct tmpfs_dirent), 169 "dirent", tmp); 170 tmpfs_pool_init(&tmp->tm_node_pool, sizeof(struct tmpfs_node), 171 "node", tmp); 172 tmpfs_str_pool_init(&tmp->tm_str_pool, tmp); 173 174 /* Allocate the root node. */ 175 error = tmpfs_alloc_node(tmp, VDIR, args.ta_root_uid, 176 args.ta_root_gid, args.ta_root_mode, NULL, NULL, VNOVAL, p, 177 &root); 178 KASSERT(error == 0 && root != NULL); 179 tmp->tm_root = root; 180 181 mp->mnt_data = tmp; 182 mp->mnt_flag |= MNT_LOCAL; 183 mp->mnt_stat.f_namemax = MAXNAMLEN; 184 vfs_getnewfsid(mp); 185 186 return set_statvfs_info(path, UIO_USERSPACE, "tmpfs", UIO_SYSSPACE, 187 mp, p); 188 } 189 190 /* --------------------------------------------------------------------- */ 191 192 static int 193 tmpfs_start(struct mount *mp, int flags, struct proc *p) 194 { 195 196 return 0; 197 } 198 199 /* --------------------------------------------------------------------- */ 200 201 /* ARGSUSED2 */ 202 static int 203 tmpfs_unmount(struct mount *mp, int mntflags, struct proc *p) 204 { 205 int error; 206 int flags = 0; 207 struct tmpfs_mount *tmp; 208 struct tmpfs_node *node; 209 210 /* Handle forced unmounts. */ 211 if (mntflags & MNT_FORCE) 212 flags |= FORCECLOSE; 213 214 /* Finalize all pending I/O. */ 215 error = vflush(mp, NULL, flags); 216 if (error != 0) 217 return error; 218 219 tmp = VFS_TO_TMPFS(mp); 220 221 /* Free all associated data. The loop iterates over the linked list 222 * we have containing all used nodes. For each of them that is 223 * a directory, we free all its directory entries. Note that after 224 * freeing a node, it will automatically go to the available list, 225 * so we will later have to iterate over it to release its items. */ 226 node = LIST_FIRST(&tmp->tm_nodes_used); 227 while (node != NULL) { 228 struct tmpfs_node *next; 229 230 if (node->tn_type == VDIR) { 231 struct tmpfs_dirent *de; 232 233 de = TAILQ_FIRST(&node->tn_dir); 234 while (de != NULL) { 235 struct tmpfs_dirent *nde; 236 237 nde = TAILQ_NEXT(de, td_entries); 238 tmpfs_free_dirent(tmp, de, FALSE); 239 de = nde; 240 node->tn_size -= sizeof(struct tmpfs_dirent); 241 } 242 } 243 244 next = LIST_NEXT(node, tn_entries); 245 tmpfs_free_node(tmp, node); 246 node = next; 247 } 248 node = LIST_FIRST(&tmp->tm_nodes_avail); 249 while (node != NULL) { 250 struct tmpfs_node *next; 251 252 next = LIST_NEXT(node, tn_entries); 253 LIST_REMOVE(node, tn_entries); 254 TMPFS_POOL_PUT(&tmp->tm_node_pool, node); 255 node = next; 256 } 257 258 tmpfs_pool_destroy(&tmp->tm_dirent_pool); 259 tmpfs_pool_destroy(&tmp->tm_node_pool); 260 tmpfs_str_pool_destroy(&tmp->tm_str_pool); 261 262 KASSERT(tmp->tm_pages_used == 0); 263 264 /* Throw away the tmpfs_mount structure. */ 265 free(mp->mnt_data, M_TMPFSMNT); 266 mp->mnt_data = NULL; 267 268 return 0; 269 } 270 271 /* --------------------------------------------------------------------- */ 272 273 static int 274 tmpfs_root(struct mount *mp, struct vnode **vpp) 275 { 276 277 return tmpfs_alloc_vp(mp, VFS_TO_TMPFS(mp)->tm_root, vpp); 278 } 279 280 /* --------------------------------------------------------------------- */ 281 282 static int 283 tmpfs_quotactl(struct mount *mp, int cmd, uid_t uid, void *arg, 284 struct proc *p) 285 { 286 287 printf("tmpfs_quotactl called; need for it unknown yet\n"); 288 return EOPNOTSUPP; 289 } 290 291 /* --------------------------------------------------------------------- */ 292 293 static int 294 tmpfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp) 295 { 296 297 printf("tmpfs_vget called; need for it unknown yet\n"); 298 return EOPNOTSUPP; 299 } 300 301 /* --------------------------------------------------------------------- */ 302 303 static int 304 tmpfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp) 305 { 306 boolean_t found; 307 struct tmpfs_fid *tfhp; 308 struct tmpfs_mount *tmp; 309 struct tmpfs_node *node; 310 311 tmp = VFS_TO_TMPFS(mp); 312 313 tfhp = (struct tmpfs_fid *)fhp; 314 if (tfhp->tf_len != sizeof(struct tmpfs_fid)) 315 return EINVAL; 316 317 if (tfhp->tf_id >= tmp->tm_nodes_max) 318 return EINVAL; 319 320 found = FALSE; 321 LIST_FOREACH(node, &tmp->tm_nodes_used, tn_entries) { 322 if (node->tn_id == tfhp->tf_id && 323 node->tn_gen == tfhp->tf_gen) { 324 found = TRUE; 325 break; 326 } 327 } 328 329 return found ? tmpfs_alloc_vp(mp, node, vpp) : EINVAL; 330 } 331 332 /* --------------------------------------------------------------------- */ 333 334 static int 335 tmpfs_vptofh(struct vnode *vp, struct fid *fhp) 336 { 337 struct tmpfs_fid *tfhp; 338 struct tmpfs_node *node; 339 340 tfhp = (struct tmpfs_fid *)fhp; 341 node = VP_TO_TMPFS_NODE(vp); 342 343 tfhp->tf_len = sizeof(struct tmpfs_fid); 344 tfhp->tf_id = node->tn_id; 345 tfhp->tf_gen = node->tn_gen; 346 347 return 0; 348 } 349 350 /* --------------------------------------------------------------------- */ 351 352 /* ARGSUSED2 */ 353 static int 354 tmpfs_statvfs(struct mount *mp, struct statvfs *sbp, struct proc *p) 355 { 356 fsfilcnt_t freenodes, usednodes; 357 struct tmpfs_mount *tmp; 358 struct tmpfs_node *dummy; 359 360 tmp = VFS_TO_TMPFS(mp); 361 362 sbp->f_iosize = sbp->f_frsize = sbp->f_bsize = PAGE_SIZE; 363 364 sbp->f_blocks = TMPFS_PAGES_MAX(tmp); 365 sbp->f_bavail = sbp->f_bfree = TMPFS_PAGES_AVAIL(tmp); 366 sbp->f_bresvd = 0; 367 368 freenodes = MIN(tmp->tm_nodes_max - tmp->tm_nodes_last, 369 TMPFS_PAGES_AVAIL(tmp) * PAGE_SIZE / sizeof(struct tmpfs_node)); 370 LIST_FOREACH(dummy, &tmp->tm_nodes_avail, tn_entries) 371 freenodes++; 372 373 usednodes = 0; 374 LIST_FOREACH(dummy, &tmp->tm_nodes_used, tn_entries) 375 usednodes++; 376 377 sbp->f_files = freenodes + usednodes; 378 sbp->f_favail = sbp->f_ffree = freenodes; 379 sbp->f_fresvd = 0; 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, struct ucred *uc, struct proc *p) 391 { 392 393 return 0; 394 } 395 396 /* --------------------------------------------------------------------- */ 397 398 static void 399 tmpfs_init(void) 400 { 401 402 #ifdef _LKM 403 malloc_type_attach(M_TMPFSMNT); 404 #endif 405 } 406 407 /* --------------------------------------------------------------------- */ 408 409 static void 410 tmpfs_done(void) 411 { 412 413 #ifdef _LKM 414 malloc_type_detach(M_TMPFSMNT); 415 #endif 416 } 417 418 /* --------------------------------------------------------------------- */ 419 420 static int 421 tmpfs_snapshot(struct mount *mp, struct vnode *vp, struct timespec *ctime) 422 { 423 424 return EOPNOTSUPP; 425 } 426 427 /* --------------------------------------------------------------------- */ 428 429 /* 430 * tmpfs vfs operations. 431 */ 432 433 extern const struct vnodeopv_desc tmpfs_fifoop_opv_desc; 434 extern const struct vnodeopv_desc tmpfs_specop_opv_desc; 435 extern const struct vnodeopv_desc tmpfs_vnodeop_opv_desc; 436 437 const struct vnodeopv_desc * const tmpfs_vnodeopv_descs[] = { 438 &tmpfs_fifoop_opv_desc, 439 &tmpfs_specop_opv_desc, 440 &tmpfs_vnodeop_opv_desc, 441 NULL, 442 }; 443 444 struct vfsops tmpfs_vfsops = { 445 MOUNT_TMPFS, /* vfs_name */ 446 tmpfs_mount, /* vfs_mount */ 447 tmpfs_start, /* vfs_start */ 448 tmpfs_unmount, /* vfs_unmount */ 449 tmpfs_root, /* vfs_root */ 450 tmpfs_quotactl, /* vfs_quotactl */ 451 tmpfs_statvfs, /* vfs_statvfs */ 452 tmpfs_sync, /* vfs_sync */ 453 tmpfs_vget, /* vfs_vget */ 454 tmpfs_fhtovp, /* vfs_fhtovp */ 455 tmpfs_vptofh, /* vfs_vptofh */ 456 tmpfs_init, /* vfs_init */ 457 NULL, /* vfs_reinit */ 458 tmpfs_done, /* vfs_done */ 459 NULL, /* vfs_mountroot */ 460 tmpfs_snapshot, /* vfs_snapshot */ 461 vfs_stdextattrctl, /* vfs_extattrctl */ 462 tmpfs_vnodeopv_descs, 463 }; 464 VFS_ATTACH(tmpfs_vfsops); 465
Indexes created Wed Sep 24 15:09:51 GMT 2025