1 | /* |
2 | * Copyright (c) 2000-2014 Apple Inc. All rights reserved. |
3 | * |
4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
5 | * |
6 | * This file contains Original Code and/or Modifications of Original Code |
7 | * as defined in and that are subject to the Apple Public Source License |
8 | * Version 2.0 (the 'License'). You may not use this file except in |
9 | * compliance with the License. The rights granted to you under the License |
10 | * may not be used to create, or enable the creation or redistribution of, |
11 | * unlawful or unlicensed copies of an Apple operating system, or to |
12 | * circumvent, violate, or enable the circumvention or violation of, any |
13 | * terms of an Apple operating system software license agreement. |
14 | * |
15 | * Please obtain a copy of the License at |
16 | * http://www.opensource.apple.com/apsl/ and read it before using this file. |
17 | * |
18 | * The Original Code and all software distributed under the License are |
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20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
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23 | * Please see the License for the specific language governing rights and |
24 | * limitations under the License. |
25 | * |
26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
27 | */ |
28 | |
29 | /* |
30 | * Copyright 1997,1998 Julian Elischer. All rights reserved. |
31 | * julian@freebsd.org |
32 | * |
33 | * Redistribution and use in source and binary forms, with or without |
34 | * modification, are permitted provided that the following conditions are |
35 | * met: |
36 | * 1. Redistributions of source code must retain the above copyright |
37 | * notice, this list of conditions and the following disclaimer. |
38 | * 2. Redistributions in binary form must reproduce the above copyright notice, |
39 | * this list of conditions and the following disclaimer in the documentation |
40 | * and/or other materials provided with the distribution. |
41 | * |
42 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY EXPRESS |
43 | * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
44 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
45 | * DISCLAIMED. IN NO EVENT SHALL THE HOLDER OR CONTRIBUTORS BE LIABLE FOR |
46 | * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
47 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
48 | * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
49 | * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
50 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
51 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
52 | * SUCH DAMAGE. |
53 | * |
54 | * devfs_tree.c |
55 | */ |
56 | /* |
57 | * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce |
58 | * support for mandatory and extensible security protections. This notice |
59 | * is included in support of clause 2.2 (b) of the Apple Public License, |
60 | * Version 2.0. |
61 | */ |
62 | |
63 | /* |
64 | * HISTORY |
65 | * Dieter Siegmund (dieter@apple.com) Thu Apr 8 14:08:19 PDT 1999 |
66 | * - removed mounting of "hidden" mountpoint |
67 | * - fixed problem in which devnode->dn_vn pointer was not |
68 | * updated with the vnode returned from checkalias() |
69 | * - replaced devfs_vntodn() with a macro VTODN() |
70 | * - rewrote dev_finddir() to not use recursion |
71 | * - added locking to avoid data structure corruption (DEVFS_(UN)LOCK()) |
72 | * Dieter Siegmund (dieter@apple.com) Wed Jul 14 13:37:59 PDT 1999 |
73 | * - fixed problem with devfs_dntovn() checking the v_id against the |
74 | * value cached in the device node; a union mount on top of us causes |
75 | * the v_id to get incremented thus, we would end up returning a new |
76 | * vnode instead of the existing one that has the mounted_here |
77 | * field filled in; the net effect was that the filesystem mounted |
78 | * on top of us would never show up |
79 | * - added devfs_stats to store how many data structures are actually |
80 | * allocated |
81 | */ |
82 | |
83 | /* SPLIT_DEVS means each devfs uses a different devnode for the same device */ |
84 | /* Otherwise the same device always ends up at the same vnode even if */ |
85 | /* reached througgh a different devfs instance. The practical difference */ |
86 | /* is that with the same vnode, chmods and chowns show up on all instances of */ |
87 | /* a device. (etc) */ |
88 | |
89 | #define SPLIT_DEVS 1 /* maybe make this an option */ |
90 | /*#define SPLIT_DEVS 1*/ |
91 | |
92 | #include <sys/param.h> |
93 | #include <sys/systm.h> |
94 | #include <sys/kernel.h> |
95 | #include <sys/conf.h> |
96 | #include <sys/malloc.h> |
97 | #include <sys/mount_internal.h> |
98 | #include <sys/proc.h> |
99 | #include <sys/vnode_internal.h> |
100 | #include <stdarg.h> |
101 | #include <libkern/OSAtomic.h> |
102 | #include <os/refcnt.h> |
103 | #define BSD_KERNEL_PRIVATE 1 /* devfs_make_link() prototype */ |
104 | #include "devfs.h" |
105 | #include "devfsdefs.h" |
106 | |
107 | #if CONFIG_MACF |
108 | #include <security/mac_framework.h> |
109 | #endif |
110 | |
111 | #if FDESC |
112 | #include "fdesc.h" |
113 | #endif |
114 | |
115 | typedef struct devfs_vnode_event { |
116 | vnode_t dve_vp; |
117 | uint32_t dve_vid; |
118 | uint32_t dve_events; |
119 | } *devfs_vnode_event_t; |
120 | |
121 | /* |
122 | * Size of stack buffer (fast path) for notifications. If |
123 | * the number of mounts is small, no need to malloc a buffer. |
124 | */ |
125 | #define NUM_STACK_ENTRIES 5 |
126 | |
127 | typedef struct devfs_event_log { |
128 | size_t del_max; |
129 | size_t del_used; |
130 | devfs_vnode_event_t del_entries; |
131 | } *devfs_event_log_t; |
132 | |
133 | |
134 | static void dev_free_hier(devdirent_t *); |
135 | static int devfs_propogate(devdirent_t *, devdirent_t *, devfs_event_log_t); |
136 | static int dev_finddir(const char *, devnode_t *, int, devnode_t **, devfs_event_log_t); |
137 | static int dev_dup_entry(devnode_t *, devdirent_t *, devdirent_t **, struct devfsmount *); |
138 | void devfs_ref_node(devnode_t *); |
139 | void devfs_rele_node(devnode_t *); |
140 | static void devfs_record_event(devfs_event_log_t, devnode_t*, uint32_t); |
141 | static int devfs_init_event_log(devfs_event_log_t, uint32_t, devfs_vnode_event_t); |
142 | static void devfs_release_event_log(devfs_event_log_t, int); |
143 | static void devfs_bulk_notify(devfs_event_log_t); |
144 | static devdirent_t *devfs_make_node_internal(dev_t, devfstype_t type, uid_t, gid_t, int, |
145 | int (*clone)(dev_t dev, int action), const char *fmt, va_list ap); |
146 | |
147 | |
148 | static LCK_GRP_DECLARE(devfs_lck_grp, "devfs_lock" ); |
149 | LCK_MTX_DECLARE(devfs_mutex, &devfs_lck_grp); |
150 | LCK_MTX_DECLARE(devfs_attr_mutex, &devfs_lck_grp); |
151 | |
152 | os_refgrp_decl(static, devfs_refgrp, "devfs" , NULL); |
153 | |
154 | devdirent_t * dev_root = NULL; /* root of backing tree */ |
155 | struct devfs_stats devfs_stats; /* hold stats */ |
156 | |
157 | static ino_t devfs_unique_fileno = 0; |
158 | |
159 | #ifdef HIDDEN_MOUNTPOINT |
160 | static struct mount *devfs_hidden_mount; |
161 | #endif /* HIDDEN_MOINTPOINT */ |
162 | |
163 | static int devfs_ready = 0; |
164 | static uint32_t devfs_nmountplanes = 0; /* The first plane is not used for a mount */ |
165 | |
166 | #define DEVFS_NOCREATE FALSE |
167 | #define DEVFS_CREATE TRUE |
168 | |
169 | /* |
170 | * Set up the root directory node in the backing plane |
171 | * This is happenning before the vfs system has been |
172 | * set up yet, so be careful about what we reference.. |
173 | * Notice that the ops are by indirection.. as they haven't |
174 | * been set up yet! |
175 | * DEVFS has a hidden mountpoint that is used as the anchor point |
176 | * for the internal 'blueprint' version of the dev filesystem tree. |
177 | */ |
178 | /*proto*/ |
179 | int |
180 | devfs_sinit(void) |
181 | { |
182 | int error; |
183 | |
184 | DEVFS_LOCK(); |
185 | error = dev_add_entry(name: "root" , NULL, type: DEV_DIR, NULL, NULL, NULL, nm_pp: &dev_root); |
186 | DEVFS_UNLOCK(); |
187 | |
188 | if (error) { |
189 | printf("devfs_sinit: dev_add_entry failed " ); |
190 | return ENOTSUP; |
191 | } |
192 | #ifdef HIDDEN_MOUNTPOINT |
193 | devfs_hidden_mount = zalloc_flags(mount_zone, Z_WAITOK | Z_ZERO); |
194 | mount_lock_init(devfs_hidden_mount); |
195 | TAILQ_INIT(&devfs_hidden_mount->mnt_vnodelist); |
196 | TAILQ_INIT(&devfs_hidden_mount->mnt_workerqueue); |
197 | TAILQ_INIT(&devfs_hidden_mount->mnt_newvnodes); |
198 | #if CONFIG_MACF |
199 | mac_mount_label_init(devfs_hidden_mount); |
200 | mac_mount_label_associate(vfs_context_kernel(), devfs_hidden_mount); |
201 | #endif |
202 | |
203 | /* Initialize the default IO constraints */ |
204 | mp->mnt_maxreadcnt = mp->mnt_maxwritecnt = MAXPHYS; |
205 | mp->mnt_segreadcnt = mp->mnt_segwritecnt = 32; |
206 | mp->mnt_ioflags = 0; |
207 | mp->mnt_realrootvp = NULLVP; |
208 | mp->mnt_authcache_ttl = CACHED_LOOKUP_RIGHT_TTL; |
209 | |
210 | devfs_mount(devfs_hidden_mount, "dummy" , NULL, NULL, NULL); |
211 | dev_root->de_dnp->dn_dvm |
212 | = (struct devfsmount *)devfs_hidden_mount->mnt_data; |
213 | #endif /* HIDDEN_MOUNTPOINT */ |
214 | #if CONFIG_MACF |
215 | mac_devfs_label_associate_directory(dirname: "/" , dirnamelen: (int) strlen(s: "/" ), |
216 | de: dev_root->de_dnp, fullpath: "/" ); |
217 | #endif |
218 | devfs_ready = 1; |
219 | return 0; |
220 | } |
221 | |
222 | /***********************************************************************\ |
223 | ************************************************************************* |
224 | * Routines used to find our way to a point in the tree * |
225 | ************************************************************************* |
226 | \***********************************************************************/ |
227 | |
228 | |
229 | |
230 | /*************************************************************** |
231 | * Search down the linked list off a dir to find "name" |
232 | * return the devnode_t * for that node. |
233 | * |
234 | * called with DEVFS_LOCK held |
235 | ***************************************************************/ |
236 | devdirent_t * |
237 | dev_findname(devnode_t * dir, const char *name) |
238 | { |
239 | devdirent_t * newfp; |
240 | if (dir->dn_type != DEV_DIR) { |
241 | return 0; /*XXX*/ /* printf?*/ |
242 | } |
243 | if (name[0] == '.') { |
244 | if (name[1] == 0) { |
245 | return dir->dn_typeinfo.Dir.myname; |
246 | } |
247 | if ((name[1] == '.') && (name[2] == 0)) { |
248 | /* for root, .. == . */ |
249 | return dir->dn_typeinfo.Dir.parent->dn_typeinfo.Dir.myname; |
250 | } |
251 | } |
252 | newfp = dir->dn_typeinfo.Dir.dirlist; |
253 | |
254 | while (newfp) { |
255 | if (!(strncmp(s1: name, s2: newfp->de_name, n: sizeof(newfp->de_name)))) { |
256 | return newfp; |
257 | } |
258 | newfp = newfp->de_next; |
259 | } |
260 | return NULL; |
261 | } |
262 | |
263 | /*********************************************************************** |
264 | * Given a starting node (0 for root) and a pathname, return the node |
265 | * for the end item on the path. It MUST BE A DIRECTORY. If the 'DEVFS_CREATE' |
266 | * option is true, then create any missing nodes in the path and create |
267 | * and return the final node as well. |
268 | * This is used to set up a directory, before making nodes in it.. |
269 | * |
270 | * called with DEVFS_LOCK held |
271 | ***********************************************************************/ |
272 | static int |
273 | dev_finddir(const char * path, |
274 | devnode_t * dirnode, |
275 | int create, |
276 | devnode_t * * dn_pp, |
277 | devfs_event_log_t delp) |
278 | { |
279 | devnode_t * dnp = NULL; |
280 | int error = 0; |
281 | const char * scan; |
282 | #if CONFIG_MACF |
283 | char fullpath[DEVMAXPATHSIZE]; |
284 | #endif |
285 | |
286 | |
287 | if (!dirnode) { /* dirnode == NULL means start at root */ |
288 | dirnode = dev_root->de_dnp; |
289 | } |
290 | |
291 | if (dirnode->dn_type != DEV_DIR) { |
292 | return ENOTDIR; |
293 | } |
294 | |
295 | if (strlen(s: path) > (DEVMAXPATHSIZE - 1)) { |
296 | return ENAMETOOLONG; |
297 | } |
298 | |
299 | #if CONFIG_MACF |
300 | strlcpy(dst: fullpath, src: path, DEVMAXPATHSIZE); |
301 | #endif |
302 | scan = path; |
303 | |
304 | while (*scan == '/') { |
305 | scan++; |
306 | } |
307 | |
308 | *dn_pp = NULL; |
309 | |
310 | while (1) { |
311 | char component[DEVMAXPATHSIZE]; |
312 | devdirent_t * dirent_p; |
313 | const char * start; |
314 | |
315 | if (*scan == 0) { |
316 | /* we hit the end of the string, we're done */ |
317 | *dn_pp = dirnode; |
318 | break; |
319 | } |
320 | start = scan; |
321 | while (*scan != '/' && *scan) { |
322 | scan++; |
323 | } |
324 | |
325 | strlcpy(dst: component, src: start, n: (scan - start) + 1); |
326 | if (*scan == '/') { |
327 | scan++; |
328 | } |
329 | |
330 | dirent_p = dev_findname(dir: dirnode, name: component); |
331 | if (dirent_p) { |
332 | dnp = dirent_p->de_dnp; |
333 | if (dnp->dn_type != DEV_DIR) { |
334 | error = ENOTDIR; |
335 | break; |
336 | } |
337 | } else { |
338 | if (!create) { |
339 | error = ENOENT; |
340 | break; |
341 | } |
342 | error = dev_add_entry(name: component, parent: dirnode, |
343 | type: DEV_DIR, NULL, NULL, NULL, nm_pp: &dirent_p); |
344 | if (error) { |
345 | break; |
346 | } |
347 | dnp = dirent_p->de_dnp; |
348 | #if CONFIG_MACF |
349 | mac_devfs_label_associate_directory( |
350 | dirname: dirnode->dn_typeinfo.Dir.myname->de_name, |
351 | dirnamelen: (int) strlen(s: dirnode->dn_typeinfo.Dir.myname->de_name), |
352 | de: dnp, fullpath); |
353 | #endif |
354 | devfs_propogate(dirnode->dn_typeinfo.Dir.myname, dirent_p, delp); |
355 | } |
356 | dirnode = dnp; /* continue relative to this directory */ |
357 | } |
358 | return error; |
359 | } |
360 | |
361 | |
362 | /*********************************************************************** |
363 | * Add a new NAME element to the devfs |
364 | * If we're creating a root node, then dirname is NULL |
365 | * Basically this creates a new namespace entry for the device node |
366 | * |
367 | * Creates a name node, and links it to the supplied node |
368 | * |
369 | * called with DEVFS_LOCK held |
370 | ***********************************************************************/ |
371 | int |
372 | dev_add_name(const char * name, devnode_t * dirnode, __unused devdirent_t * back, |
373 | devnode_t * dnp, devdirent_t * *dirent_pp) |
374 | { |
375 | devdirent_t * dirent_p = NULL; |
376 | |
377 | if (dirnode != NULL) { |
378 | if (dirnode->dn_type != DEV_DIR) { |
379 | return ENOTDIR; |
380 | } |
381 | |
382 | if (dev_findname(dir: dirnode, name)) { |
383 | return EEXIST; |
384 | } |
385 | } |
386 | /* |
387 | * make sure the name is legal |
388 | * slightly misleading in the case of NULL |
389 | */ |
390 | if (!name || (strlen(s: name) > (DEVMAXNAMESIZE - 1))) { |
391 | return ENAMETOOLONG; |
392 | } |
393 | |
394 | /* |
395 | * Allocate and fill out a new directory entry |
396 | */ |
397 | dirent_p = kalloc_type(devdirent_t, Z_WAITOK | Z_ZERO | Z_NOFAIL); |
398 | |
399 | /* inherrit our parent's mount info */ /*XXX*/ |
400 | /* a kludge but.... */ |
401 | if (dirnode && (dnp->dn_dvm == NULL)) { |
402 | dnp->dn_dvm = dirnode->dn_dvm; |
403 | /* if(!dnp->dn_dvm) printf("parent had null dvm "); */ |
404 | } |
405 | |
406 | /* |
407 | * Link the two together |
408 | * include the implicit link in the count of links to the devnode.. |
409 | * this stops it from being accidentally freed later. |
410 | */ |
411 | dirent_p->de_dnp = dnp; |
412 | dnp->dn_links++; /* implicit from our own name-node */ |
413 | |
414 | /* |
415 | * Make sure that we can find all the links that reference a node |
416 | * so that we can get them all if we need to zap the node. |
417 | */ |
418 | if (dnp->dn_linklist) { |
419 | dirent_p->de_nextlink = dnp->dn_linklist; |
420 | dirent_p->de_prevlinkp = dirent_p->de_nextlink->de_prevlinkp; |
421 | dirent_p->de_nextlink->de_prevlinkp = &(dirent_p->de_nextlink); |
422 | *dirent_p->de_prevlinkp = dirent_p; |
423 | } else { |
424 | dirent_p->de_nextlink = dirent_p; |
425 | dirent_p->de_prevlinkp = &(dirent_p->de_nextlink); |
426 | } |
427 | dnp->dn_linklist = dirent_p; |
428 | |
429 | /* |
430 | * If the node is a directory, then we need to handle the |
431 | * creation of the .. link. |
432 | * A NULL dirnode indicates a root node, so point to ourself. |
433 | */ |
434 | if (dnp->dn_type == DEV_DIR) { |
435 | dnp->dn_typeinfo.Dir.myname = dirent_p; |
436 | /* |
437 | * If we are unlinking from an old dir, decrement its links |
438 | * as we point our '..' elsewhere |
439 | * Note: it's up to the calling code to remove the |
440 | * us from the original directory's list |
441 | */ |
442 | if (dnp->dn_typeinfo.Dir.parent) { |
443 | dnp->dn_typeinfo.Dir.parent->dn_links--; |
444 | } |
445 | if (dirnode) { |
446 | dnp->dn_typeinfo.Dir.parent = dirnode; |
447 | } else { |
448 | dnp->dn_typeinfo.Dir.parent = dnp; |
449 | } |
450 | dnp->dn_typeinfo.Dir.parent->dn_links++; /* account for the new '..' */ |
451 | } |
452 | |
453 | /* |
454 | * put the name into the directory entry. |
455 | */ |
456 | strlcpy(dst: dirent_p->de_name, src: name, DEVMAXNAMESIZE); |
457 | |
458 | |
459 | /* |
460 | * Check if we are not making a root node.. |
461 | * (i.e. have parent) |
462 | */ |
463 | if (dirnode) { |
464 | /* |
465 | * Put it on the END of the linked list of directory entries |
466 | */ |
467 | dirent_p->de_parent = dirnode; /* null for root */ |
468 | dirent_p->de_prevp = dirnode->dn_typeinfo.Dir.dirlast; |
469 | dirent_p->de_next = *(dirent_p->de_prevp); /* should be NULL */ |
470 | /*right?*/ |
471 | *(dirent_p->de_prevp) = dirent_p; |
472 | dirnode->dn_typeinfo.Dir.dirlast = &(dirent_p->de_next); |
473 | dirnode->dn_typeinfo.Dir.entrycount++; |
474 | dirnode->dn_len += strlen(s: name) + 8;/*ok, ok?*/ |
475 | } |
476 | |
477 | *dirent_pp = dirent_p; |
478 | DEVFS_INCR_ENTRIES(); |
479 | return 0; |
480 | } |
481 | |
482 | |
483 | /*********************************************************************** |
484 | * Add a new element to the devfs plane. |
485 | * |
486 | * Creates a new dev_node to go with it if the prototype should not be |
487 | * reused. (Is a DIR, or we select SPLIT_DEVS at compile time) |
488 | * typeinfo gives us info to make our node if we don't have a prototype. |
489 | * If typeinfo is null and proto exists, then the typeinfo field of |
490 | * the proto is used intead in the DEVFS_CREATE case. |
491 | * note the 'links' count is 0 (except if a dir) |
492 | * but it is only cleared on a transition |
493 | * so this is ok till we link it to something |
494 | * Even in SPLIT_DEVS mode, |
495 | * if the node already exists on the wanted plane, just return it |
496 | * |
497 | * called with DEVFS_LOCK held |
498 | ***********************************************************************/ |
499 | int |
500 | dev_add_node(int entrytype, devnode_type_t * typeinfo, devnode_t * proto, |
501 | devnode_t * *dn_pp, struct devfsmount *dvm) |
502 | { |
503 | devnode_t * dnp = NULL; |
504 | int error = 0; |
505 | |
506 | #if defined SPLIT_DEVS |
507 | /* |
508 | * If we have a prototype, then check if there is already a sibling |
509 | * on the mount plane we are looking at, if so, just return it. |
510 | */ |
511 | if (proto) { |
512 | dnp = proto->dn_nextsibling; |
513 | while (dnp != proto) { |
514 | if (dnp->dn_dvm == dvm) { |
515 | *dn_pp = dnp; |
516 | return 0; |
517 | } |
518 | dnp = dnp->dn_nextsibling; |
519 | } |
520 | if (typeinfo == NULL) { |
521 | typeinfo = &(proto->dn_typeinfo); |
522 | } |
523 | } |
524 | #else /* SPLIT_DEVS */ |
525 | if (proto) { |
526 | switch (proto->type) { |
527 | case DEV_BDEV: |
528 | case DEV_CDEV: |
529 | *dn_pp = proto; |
530 | return 0; |
531 | } |
532 | } |
533 | #endif /* SPLIT_DEVS */ |
534 | dnp = kalloc_type(devnode_t, Z_WAITOK | Z_ZERO | Z_NOFAIL); |
535 | |
536 | /* |
537 | * If we have a proto, that means that we are duplicating some |
538 | * other device, which can only happen if we are not at the back plane |
539 | */ |
540 | if (proto) { |
541 | bcopy(src: proto, dst: dnp, n: sizeof(devnode_t)); |
542 | dnp->dn_links = 0; |
543 | dnp->dn_linklist = NULL; |
544 | dnp->dn_vn = NULL; |
545 | dnp->dn_len = 0; |
546 | /* add to END of siblings list */ |
547 | dnp->dn_prevsiblingp = proto->dn_prevsiblingp; |
548 | *(dnp->dn_prevsiblingp) = dnp; |
549 | dnp->dn_nextsibling = proto; |
550 | proto->dn_prevsiblingp = &(dnp->dn_nextsibling); |
551 | #if CONFIG_MACF |
552 | mac_devfs_label_init(de: dnp); |
553 | mac_devfs_label_copy(mac_devfs_label(de: proto), label: mac_devfs_label(de: dnp)); |
554 | #endif |
555 | } else { |
556 | struct timeval tv; |
557 | |
558 | /* |
559 | * We have no prototype, so start off with a clean slate |
560 | */ |
561 | microtime(tv: &tv); |
562 | dnp->dn_type = entrytype; |
563 | dnp->dn_nextsibling = dnp; |
564 | dnp->dn_prevsiblingp = &(dnp->dn_nextsibling); |
565 | dnp->dn_atime.tv_sec = tv.tv_sec; |
566 | dnp->dn_mtime.tv_sec = tv.tv_sec; |
567 | dnp->dn_ctime.tv_sec = tv.tv_sec; |
568 | #if CONFIG_MACF |
569 | mac_devfs_label_init(de: dnp); |
570 | #endif |
571 | } |
572 | dnp->dn_dvm = dvm; |
573 | |
574 | /* Note: this inits the reference count to 1, this is considered unreferenced */ |
575 | os_ref_init_raw(&dnp->dn_refcount, &devfs_refgrp); |
576 | dnp->dn_ino = devfs_unique_fileno; |
577 | devfs_unique_fileno++; |
578 | |
579 | /* |
580 | * fill out the dev node according to type |
581 | */ |
582 | switch (entrytype) { |
583 | case DEV_DIR: |
584 | /* |
585 | * As it's a directory, make sure |
586 | * it has a null entries list |
587 | */ |
588 | dnp->dn_typeinfo.Dir.dirlast = &(dnp->dn_typeinfo.Dir.dirlist); |
589 | dnp->dn_typeinfo.Dir.dirlist = (devdirent_t *)0; |
590 | dnp->dn_typeinfo.Dir.entrycount = 0; |
591 | /* until we know better, it has a null parent pointer*/ |
592 | dnp->dn_typeinfo.Dir.parent = NULL; |
593 | dnp->dn_links++; /* for .*/ |
594 | dnp->dn_typeinfo.Dir.myname = NULL; |
595 | /* |
596 | * make sure that the ops associated with it are the ops |
597 | * that we use (by default) for directories |
598 | */ |
599 | dnp->dn_ops = &devfs_vnodeop_p; |
600 | dnp->dn_mode |= 0555; /* default perms */ |
601 | break; |
602 | case DEV_SLNK: |
603 | /* |
604 | * As it's a symlink allocate and store the link info |
605 | * Symlinks should only ever be created by the user, |
606 | * so they are not on the back plane and should not be |
607 | * propogated forward.. a bit like directories in that way.. |
608 | * A symlink only exists on one plane and has its own |
609 | * node.. therefore we might be on any random plane. |
610 | */ |
611 | dnp->dn_typeinfo.Slnk.name = kalloc_data(typeinfo->Slnk.namelen + 1, Z_WAITOK); |
612 | if (!dnp->dn_typeinfo.Slnk.name) { |
613 | error = ENOMEM; |
614 | break; |
615 | } |
616 | strlcpy(dst: dnp->dn_typeinfo.Slnk.name, src: typeinfo->Slnk.name, |
617 | n: typeinfo->Slnk.namelen + 1); |
618 | dnp->dn_typeinfo.Slnk.namelen = typeinfo->Slnk.namelen; |
619 | DEVFS_INCR_STRINGSPACE(space: dnp->dn_typeinfo.Slnk.namelen + 1); |
620 | dnp->dn_ops = &devfs_vnodeop_p; |
621 | dnp->dn_mode |= 0555; /* default perms */ |
622 | break; |
623 | case DEV_CDEV: |
624 | case DEV_BDEV: |
625 | /* |
626 | * Make sure it has DEVICE type ops |
627 | * and device specific fields are correct |
628 | */ |
629 | dnp->dn_ops = &devfs_spec_vnodeop_p; |
630 | dnp->dn_typeinfo.dev = typeinfo->dev; |
631 | break; |
632 | |
633 | #if FDESC |
634 | /* /dev/fd is special */ |
635 | case DEV_DEVFD: |
636 | dnp->dn_ops = &devfs_devfd_vnodeop_p; |
637 | dnp->dn_mode |= 0555; /* default perms */ |
638 | break; |
639 | |
640 | #endif /* FDESC */ |
641 | default: |
642 | error = EINVAL; |
643 | } |
644 | |
645 | if (error) { |
646 | kfree_type(devnode_t, dnp); |
647 | } else { |
648 | *dn_pp = dnp; |
649 | DEVFS_INCR_NODES(); |
650 | } |
651 | |
652 | return error; |
653 | } |
654 | |
655 | |
656 | /*********************************************************************** |
657 | * called with DEVFS_LOCK held |
658 | **********************************************************************/ |
659 | void |
660 | devnode_free(devnode_t * dnp) |
661 | { |
662 | #if CONFIG_MACF |
663 | mac_devfs_label_destroy(de: dnp); |
664 | #endif |
665 | if (dnp->dn_type == DEV_SLNK) { |
666 | DEVFS_DECR_STRINGSPACE(space: dnp->dn_typeinfo.Slnk.namelen + 1); |
667 | kfree_data(dnp->dn_typeinfo.Slnk.name, dnp->dn_typeinfo.Slnk.namelen + 1); |
668 | } |
669 | DEVFS_DECR_NODES(); |
670 | kfree_type(devnode_t, dnp); |
671 | } |
672 | |
673 | |
674 | /*********************************************************************** |
675 | * called with DEVFS_LOCK held |
676 | **********************************************************************/ |
677 | static void |
678 | devfs_dn_free(devnode_t * dnp) |
679 | { |
680 | if (--dnp->dn_links <= 0) { /* can be -1 for initial free, on error */ |
681 | /*probably need to do other cleanups XXX */ |
682 | if (dnp->dn_nextsibling != dnp) { |
683 | devnode_t * * prevp = dnp->dn_prevsiblingp; |
684 | *prevp = dnp->dn_nextsibling; |
685 | dnp->dn_nextsibling->dn_prevsiblingp = prevp; |
686 | } |
687 | |
688 | /* Can only free if there are no references; otherwise, wait for last vnode to be reclaimed */ |
689 | os_ref_count_t rc = os_ref_get_count_raw(rc: &dnp->dn_refcount); |
690 | if (rc == 1) { |
691 | /* release final reference from dev_add_node */ |
692 | (void) os_ref_release_locked_raw(&dnp->dn_refcount, &devfs_refgrp); |
693 | devnode_free(dnp); |
694 | } else { |
695 | dnp->dn_lflags |= DN_DELETE; |
696 | } |
697 | } |
698 | } |
699 | |
700 | /***********************************************************************\ |
701 | * Front Node Operations * |
702 | * Add or delete a chain of front nodes * |
703 | \***********************************************************************/ |
704 | |
705 | |
706 | /*********************************************************************** |
707 | * Given a directory backing node, and a child backing node, add the |
708 | * appropriate front nodes to the front nodes of the directory to |
709 | * represent the child node to the user |
710 | * |
711 | * on failure, front nodes will either be correct or not exist for each |
712 | * front dir, however dirs completed will not be stripped of completed |
713 | * frontnodes on failure of a later frontnode |
714 | * |
715 | * This allows a new node to be propogated through all mounted planes |
716 | * |
717 | * called with DEVFS_LOCK held |
718 | ***********************************************************************/ |
719 | static int |
720 | devfs_propogate(devdirent_t * parent, devdirent_t * child, devfs_event_log_t delp) |
721 | { |
722 | int error; |
723 | devdirent_t * newnmp; |
724 | devnode_t * dnp = child->de_dnp; |
725 | devnode_t * pdnp = parent->de_dnp; |
726 | devnode_t * adnp = parent->de_dnp; |
727 | int type = child->de_dnp->dn_type; |
728 | uint32_t events; |
729 | |
730 | events = (dnp->dn_type == DEV_DIR ? VNODE_EVENT_DIR_CREATED : VNODE_EVENT_FILE_CREATED); |
731 | if (delp != NULL) { |
732 | devfs_record_event(delp, pdnp, events); |
733 | } |
734 | |
735 | /*********************************************** |
736 | * Find the other instances of the parent node |
737 | ***********************************************/ |
738 | for (adnp = pdnp->dn_nextsibling; |
739 | adnp != pdnp; |
740 | adnp = adnp->dn_nextsibling) { |
741 | /* |
742 | * Make the node, using the original as a prototype) |
743 | * if the node already exists on that plane it won't be |
744 | * re-made.. |
745 | */ |
746 | if ((error = dev_add_entry(name: child->de_name, parent: adnp, type, |
747 | NULL, proto: dnp, dvm: adnp->dn_dvm, |
748 | nm_pp: &newnmp)) != 0) { |
749 | printf("duplicating %s failed\n" , child->de_name); |
750 | } else { |
751 | if (delp != NULL) { |
752 | devfs_record_event(delp, adnp, events); |
753 | |
754 | /* |
755 | * Slightly subtle. We're guaranteed that there will |
756 | * only be a vnode hooked into this devnode if we're creating |
757 | * a new link to an existing node; otherwise, the devnode is new |
758 | * and no one can have looked it up yet. If we're making a link, |
759 | * then the buffer is large enough for two nodes in each |
760 | * plane; otherwise, there's no vnode and this call will |
761 | * do nothing. |
762 | */ |
763 | devfs_record_event(delp, newnmp->de_dnp, VNODE_EVENT_LINK); |
764 | } |
765 | } |
766 | } |
767 | return 0; /* for now always succeed */ |
768 | } |
769 | |
770 | static uint32_t |
771 | remove_notify_count(devnode_t *dnp) |
772 | { |
773 | uint32_t notify_count = 0; |
774 | devnode_t *dnp2; |
775 | |
776 | /* |
777 | * Could need to notify for one removed node on each mount and |
778 | * one parent for each such node. |
779 | */ |
780 | notify_count = devfs_nmountplanes; |
781 | notify_count += dnp->dn_links; |
782 | for (dnp2 = dnp->dn_nextsibling; dnp2 != dnp; dnp2 = dnp2->dn_nextsibling) { |
783 | notify_count += dnp2->dn_links; |
784 | } |
785 | |
786 | return notify_count; |
787 | } |
788 | |
789 | /*********************************************************************** |
790 | * remove all instances of this devicename [for backing nodes..] |
791 | * note.. if there is another link to the node (non dir nodes only) |
792 | * then the devfs_node will still exist as the ref count will be non-0 |
793 | * removing a directory node will remove all sup-nodes on all planes (ZAP) |
794 | * |
795 | * Used by device drivers to remove nodes that are no longer relevant |
796 | * The argument is the 'cookie' they were given when they created the node |
797 | * this function is exported.. see devfs.h |
798 | ***********************************************************************/ |
799 | void |
800 | devfs_remove(void *dirent_p) |
801 | { |
802 | devnode_t * dnp = ((devdirent_t *)dirent_p)->de_dnp; |
803 | devnode_t * dnp2; |
804 | boolean_t lastlink; |
805 | struct devfs_event_log event_log; |
806 | uint32_t log_count = 0; |
807 | int do_notify = 0; |
808 | int need_free = 0; |
809 | struct devfs_vnode_event stackbuf[NUM_STACK_ENTRIES]; |
810 | |
811 | DEVFS_LOCK(); |
812 | |
813 | if (!devfs_ready) { |
814 | printf("devfs_remove: not ready for devices!\n" ); |
815 | goto out; |
816 | } |
817 | |
818 | log_count = remove_notify_count(dnp); |
819 | |
820 | if (log_count > NUM_STACK_ENTRIES) { |
821 | uint32_t new_count; |
822 | wrongsize: |
823 | DEVFS_UNLOCK(); |
824 | if (devfs_init_event_log(&event_log, log_count, NULL) == 0) { |
825 | do_notify = 1; |
826 | need_free = 1; |
827 | } |
828 | DEVFS_LOCK(); |
829 | |
830 | new_count = remove_notify_count(dnp); |
831 | if (need_free && (new_count > log_count)) { |
832 | devfs_release_event_log(&event_log, 1); |
833 | need_free = 0; |
834 | do_notify = 0; |
835 | log_count = log_count * 2; |
836 | goto wrongsize; |
837 | } |
838 | } else { |
839 | if (devfs_init_event_log(&event_log, NUM_STACK_ENTRIES, &stackbuf[0]) == 0) { |
840 | do_notify = 1; |
841 | } |
842 | } |
843 | |
844 | /* This file has been deleted */ |
845 | if (do_notify != 0) { |
846 | devfs_record_event(&event_log, dnp, VNODE_EVENT_DELETE); |
847 | } |
848 | |
849 | /* keep removing the next sibling till only we exist. */ |
850 | while ((dnp2 = dnp->dn_nextsibling) != dnp) { |
851 | /* |
852 | * Keep removing the next front node till no more exist |
853 | */ |
854 | dnp->dn_nextsibling = dnp2->dn_nextsibling; |
855 | dnp->dn_nextsibling->dn_prevsiblingp = &(dnp->dn_nextsibling); |
856 | dnp2->dn_nextsibling = dnp2; |
857 | dnp2->dn_prevsiblingp = &(dnp2->dn_nextsibling); |
858 | |
859 | /* This file has been deleted in this plane */ |
860 | if (do_notify != 0) { |
861 | devfs_record_event(&event_log, dnp2, VNODE_EVENT_DELETE); |
862 | } |
863 | |
864 | if (dnp2->dn_linklist) { |
865 | do { |
866 | lastlink = (1 == dnp2->dn_links); |
867 | /* Each parent of a link to this file has lost a child in this plane */ |
868 | if (do_notify != 0) { |
869 | devfs_record_event(&event_log, dnp2->dn_linklist->de_parent, VNODE_EVENT_FILE_REMOVED); |
870 | } |
871 | dev_free_name(dirent_p: dnp2->dn_linklist); |
872 | } while (!lastlink); |
873 | } |
874 | } |
875 | |
876 | /* |
877 | * then free the main node |
878 | * If we are not running in SPLIT_DEVS mode, then |
879 | * THIS is what gets rid of the propogated nodes. |
880 | */ |
881 | if (dnp->dn_linklist) { |
882 | do { |
883 | lastlink = (1 == dnp->dn_links); |
884 | /* Each parent of a link to this file has lost a child */ |
885 | if (do_notify != 0) { |
886 | devfs_record_event(&event_log, dnp->dn_linklist->de_parent, VNODE_EVENT_FILE_REMOVED); |
887 | } |
888 | dev_free_name(dirent_p: dnp->dn_linklist); |
889 | } while (!lastlink); |
890 | } |
891 | out: |
892 | DEVFS_UNLOCK(); |
893 | if (do_notify != 0) { |
894 | devfs_bulk_notify(&event_log); |
895 | devfs_release_event_log(&event_log, need_free); |
896 | } |
897 | |
898 | return; |
899 | } |
900 | |
901 | |
902 | |
903 | /*************************************************************** |
904 | * duplicate the backing tree into a tree of nodes hung off the |
905 | * mount point given as the argument. Do this by |
906 | * calling dev_dup_entry which recurses all the way |
907 | * up the tree.. |
908 | * |
909 | * called with DEVFS_LOCK held |
910 | **************************************************************/ |
911 | int |
912 | dev_dup_plane(struct devfsmount *devfs_mp_p) |
913 | { |
914 | devdirent_t * new; |
915 | int error = 0; |
916 | |
917 | if ((error = dev_dup_entry(NULL, dev_root, &new, devfs_mp_p))) { |
918 | return error; |
919 | } |
920 | devfs_mp_p->plane_root = new; |
921 | devfs_nmountplanes++; |
922 | return error; |
923 | } |
924 | |
925 | |
926 | |
927 | /*************************************************************** |
928 | * Free a whole plane |
929 | * |
930 | * called with DEVFS_LOCK held |
931 | ***************************************************************/ |
932 | void |
933 | devfs_free_plane(struct devfsmount *devfs_mp_p) |
934 | { |
935 | devdirent_t * dirent_p; |
936 | |
937 | dirent_p = devfs_mp_p->plane_root; |
938 | if (dirent_p) { |
939 | dev_free_hier(dirent_p); |
940 | dev_free_name(dirent_p); |
941 | } |
942 | devfs_mp_p->plane_root = NULL; |
943 | devfs_nmountplanes--; |
944 | |
945 | if (devfs_nmountplanes > (devfs_nmountplanes + 1)) { |
946 | panic("plane count wrapped around." ); |
947 | } |
948 | } |
949 | |
950 | |
951 | /*************************************************************** |
952 | * Create and link in a new front element.. |
953 | * Parent can be 0 for a root node |
954 | * Not presently usable to make a symlink XXX |
955 | * (Ok, symlinks don't propogate) |
956 | * recursively will create subnodes corresponding to equivalent |
957 | * child nodes in the base level |
958 | * |
959 | * called with DEVFS_LOCK held |
960 | ***************************************************************/ |
961 | static int |
962 | dev_dup_entry(devnode_t * parent, devdirent_t * back, devdirent_t * *dnm_pp, |
963 | struct devfsmount *dvm) |
964 | { |
965 | devdirent_t * entry_p = NULL; |
966 | devdirent_t * newback; |
967 | devdirent_t * newfront; |
968 | int error; |
969 | devnode_t * dnp = back->de_dnp; |
970 | int type = dnp->dn_type; |
971 | |
972 | /* |
973 | * go get the node made (if we need to) |
974 | * use the back one as a prototype |
975 | */ |
976 | error = dev_add_entry(name: back->de_name, parent, type, NULL, proto: dnp, |
977 | dvm: parent?parent->dn_dvm:dvm, nm_pp: &entry_p); |
978 | if (!error && (entry_p == NULL)) { |
979 | error = ENOMEM; /* Really can't happen, but make static analyzer happy */ |
980 | } |
981 | if (error != 0) { |
982 | printf("duplicating %s failed\n" , back->de_name); |
983 | goto out; |
984 | } |
985 | |
986 | /* |
987 | * If we have just made the root, then insert the pointer to the |
988 | * mount information |
989 | */ |
990 | if (dvm) { |
991 | entry_p->de_dnp->dn_dvm = dvm; |
992 | } |
993 | |
994 | /* |
995 | * If it is a directory, then recurse down all the other |
996 | * subnodes in it.... |
997 | * note that this time we don't pass on the mount info.. |
998 | */ |
999 | if (type == DEV_DIR) { |
1000 | for (newback = back->de_dnp->dn_typeinfo.Dir.dirlist; |
1001 | newback; newback = newback->de_next) { |
1002 | if ((error = dev_dup_entry(parent: entry_p->de_dnp, |
1003 | back: newback, dnm_pp: &newfront, NULL)) != 0) { |
1004 | break; /* back out with an error */ |
1005 | } |
1006 | } |
1007 | } |
1008 | out: |
1009 | *dnm_pp = entry_p; |
1010 | return error; |
1011 | } |
1012 | |
1013 | |
1014 | /*************************************************************** |
1015 | * Free a name node |
1016 | * remember that if there are other names pointing to the |
1017 | * dev_node then it may not get freed yet |
1018 | * can handle if there is no dnp |
1019 | * |
1020 | * called with DEVFS_LOCK held |
1021 | ***************************************************************/ |
1022 | |
1023 | int |
1024 | dev_free_name(devdirent_t * dirent_p) |
1025 | { |
1026 | devnode_t * parent = dirent_p->de_parent; |
1027 | devnode_t * dnp = dirent_p->de_dnp; |
1028 | |
1029 | if (dnp) { |
1030 | if (dnp->dn_type == DEV_DIR) { |
1031 | devnode_t * p; |
1032 | |
1033 | if (dnp->dn_typeinfo.Dir.dirlist) { |
1034 | return ENOTEMPTY; |
1035 | } |
1036 | p = dnp->dn_typeinfo.Dir.parent; |
1037 | devfs_dn_free(dnp); /* account for '.' */ |
1038 | devfs_dn_free(dnp: p); /* '..' */ |
1039 | } |
1040 | /* |
1041 | * unlink us from the list of links for this node |
1042 | * If we are the only link, it's easy! |
1043 | * if we are a DIR of course there should not be any |
1044 | * other links. |
1045 | */ |
1046 | if (dirent_p->de_nextlink == dirent_p) { |
1047 | dnp->dn_linklist = NULL; |
1048 | } else { |
1049 | if (dnp->dn_linklist == dirent_p) { |
1050 | dnp->dn_linklist = dirent_p->de_nextlink; |
1051 | } |
1052 | } |
1053 | devfs_dn_free(dnp); |
1054 | } |
1055 | |
1056 | dirent_p->de_nextlink->de_prevlinkp = dirent_p->de_prevlinkp; |
1057 | *(dirent_p->de_prevlinkp) = dirent_p->de_nextlink; |
1058 | |
1059 | /* |
1060 | * unlink ourselves from the directory on this plane |
1061 | */ |
1062 | if (parent) { /* if not fs root */ |
1063 | if ((*dirent_p->de_prevp = dirent_p->de_next)) {/* yes, assign */ |
1064 | dirent_p->de_next->de_prevp = dirent_p->de_prevp; |
1065 | } else { |
1066 | parent->dn_typeinfo.Dir.dirlast |
1067 | = dirent_p->de_prevp; |
1068 | } |
1069 | parent->dn_typeinfo.Dir.entrycount--; |
1070 | parent->dn_len -= strlen(s: dirent_p->de_name) + 8; |
1071 | } |
1072 | |
1073 | DEVFS_DECR_ENTRIES(); |
1074 | kfree_type(devdirent_t, dirent_p); |
1075 | return 0; |
1076 | } |
1077 | |
1078 | |
1079 | /*************************************************************** |
1080 | * Free a hierarchy starting at a directory node name |
1081 | * remember that if there are other names pointing to the |
1082 | * dev_node then it may not get freed yet |
1083 | * can handle if there is no dnp |
1084 | * leave the node itself allocated. |
1085 | * |
1086 | * called with DEVFS_LOCK held |
1087 | ***************************************************************/ |
1088 | |
1089 | static void |
1090 | dev_free_hier(devdirent_t * dirent_p) |
1091 | { |
1092 | devnode_t * dnp = dirent_p->de_dnp; |
1093 | |
1094 | if (dnp) { |
1095 | if (dnp->dn_type == DEV_DIR) { |
1096 | while (dnp->dn_typeinfo.Dir.dirlist) { |
1097 | dev_free_hier(dirent_p: dnp->dn_typeinfo.Dir.dirlist); |
1098 | dev_free_name(dirent_p: dnp->dn_typeinfo.Dir.dirlist); |
1099 | } |
1100 | } |
1101 | } |
1102 | } |
1103 | |
1104 | |
1105 | /*************************************************************** |
1106 | * given a dev_node, find the appropriate vnode if one is already |
1107 | * associated, or get a new one and associate it with the dev_node |
1108 | * |
1109 | * called with DEVFS_LOCK held |
1110 | * |
1111 | * If an error is returned, then the dnp may have been freed (we |
1112 | * raced with a delete and lost). A devnode should not be accessed |
1113 | * after devfs_dntovn() fails. |
1114 | ****************************************************************/ |
1115 | int |
1116 | devfs_dntovn(devnode_t * dnp, struct vnode **vn_pp, __unused struct proc * p) |
1117 | { |
1118 | struct vnode *vn_p; |
1119 | int error = 0; |
1120 | struct vnode_fsparam vfsp; |
1121 | enum vtype vtype = 0; |
1122 | int markroot = 0; |
1123 | int nretries = 0; |
1124 | int n_minor = DEVFS_CLONE_ALLOC; /* new minor number for clone device */ |
1125 | |
1126 | /* |
1127 | * We should never come in and find that our devnode has been marked for delete. |
1128 | * The lookup should have held the lock from entry until now; it should not have |
1129 | * been able to find a removed entry. Any other pathway would have just created |
1130 | * the devnode and come here without dropping the devfs lock, so no one would |
1131 | * have a chance to delete. |
1132 | */ |
1133 | if (dnp->dn_lflags & DN_DELETE) { |
1134 | panic("devfs_dntovn: DN_DELETE set on a devnode upon entry." ); |
1135 | } |
1136 | |
1137 | devfs_ref_node(dnp); |
1138 | |
1139 | retry: |
1140 | *vn_pp = NULL; |
1141 | vn_p = dnp->dn_vn; |
1142 | |
1143 | if (vn_p) { /* already has a vnode */ |
1144 | uint32_t vid; |
1145 | |
1146 | vid = vnode_vid(vp: vn_p); |
1147 | |
1148 | vnode_hold(vp: vn_p); |
1149 | DEVFS_UNLOCK(); |
1150 | |
1151 | /* |
1152 | * We want to use the drainok variant of vnode_getwithvid |
1153 | * because we _don't_ want to get an iocount if the vnode is |
1154 | * is blocked in vnode_drain as it can cause infinite |
1155 | * loops in vn_open_auth. While in use vnodes are typically |
1156 | * only reclaimed on forced unmounts, In use devfs tty vnodes |
1157 | * can be quite frequently reclaimed by revoke(2) or by the |
1158 | * exit of a controlling process. |
1159 | */ |
1160 | error = vnode_getwithvid_drainok(vn_p, vid); |
1161 | |
1162 | vnode_drop(vp: vn_p); |
1163 | DEVFS_LOCK(); |
1164 | |
1165 | if (dnp->dn_lflags & DN_DELETE) { |
1166 | /* |
1167 | * our BUSY node got marked for |
1168 | * deletion while the DEVFS lock |
1169 | * was dropped... |
1170 | */ |
1171 | if (error == 0) { |
1172 | /* |
1173 | * vnode_getwithvid returned a valid ref |
1174 | * which we need to drop |
1175 | */ |
1176 | vnode_put(vp: vn_p); |
1177 | } |
1178 | |
1179 | /* |
1180 | * This entry is no longer in the namespace. This is only |
1181 | * possible for lookup: no other path would not find an existing |
1182 | * vnode. Therefore, ENOENT is a valid result. |
1183 | */ |
1184 | error = ENOENT; |
1185 | } else if (error == ENODEV) { |
1186 | /* |
1187 | * The Filesystem is getting unmounted. |
1188 | */ |
1189 | error = ENOENT; |
1190 | } else if (error && (nretries < DEV_MAX_VNODE_RETRY)) { |
1191 | /* |
1192 | * If we got an error from vnode_getwithvid, it means |
1193 | * we raced with a recycle and lost i.e. we asked for |
1194 | * an iocount only after vnode_drain had been entered |
1195 | * for the vnode and returned with an error only after |
1196 | * devfs_reclaim was called on the vnode. devfs_reclaim |
1197 | * sets dn_vn to NULL but while we were waiting to |
1198 | * reacquire DEVFS_LOCK, another vnode might have gotten |
1199 | * associated with the dnp. In either case, we need to |
1200 | * retry otherwise we will end up returning an ENOENT |
1201 | * for this lookup but the next lookup will succeed |
1202 | * because it creates a new vnode (or a racing lookup |
1203 | * created a new vnode already). |
1204 | */ |
1205 | error = 0; |
1206 | nretries++; |
1207 | goto retry; |
1208 | } |
1209 | if (!error) { |
1210 | *vn_pp = vn_p; |
1211 | } |
1212 | |
1213 | goto out; |
1214 | } |
1215 | |
1216 | /* |
1217 | * If we get here, then we've beaten any deletes; |
1218 | * if someone sets DN_DELETE during a subsequent drop |
1219 | * of the devfs lock, we'll still vend a vnode. |
1220 | */ |
1221 | |
1222 | if (dnp->dn_lflags & DN_CREATE) { |
1223 | dnp->dn_lflags |= DN_CREATEWAIT; |
1224 | msleep(chan: &dnp->dn_lflags, mtx: &devfs_mutex, PRIBIO, wmesg: 0, ts: 0); |
1225 | goto retry; |
1226 | } |
1227 | |
1228 | dnp->dn_lflags |= DN_CREATE; |
1229 | |
1230 | switch (dnp->dn_type) { |
1231 | case DEV_SLNK: |
1232 | vtype = VLNK; |
1233 | break; |
1234 | case DEV_DIR: |
1235 | if (dnp->dn_typeinfo.Dir.parent == dnp) { |
1236 | markroot = 1; |
1237 | } |
1238 | vtype = VDIR; |
1239 | break; |
1240 | case DEV_BDEV: |
1241 | case DEV_CDEV: |
1242 | vtype = (dnp->dn_type == DEV_BDEV) ? VBLK : VCHR; |
1243 | break; |
1244 | #if FDESC |
1245 | case DEV_DEVFD: |
1246 | vtype = VDIR; |
1247 | break; |
1248 | #endif /* FDESC */ |
1249 | } |
1250 | vfsp.vnfs_mp = dnp->dn_dvm->mount; |
1251 | vfsp.vnfs_vtype = vtype; |
1252 | vfsp.vnfs_str = "devfs" ; |
1253 | vfsp.vnfs_dvp = 0; |
1254 | vfsp.vnfs_fsnode = dnp; |
1255 | vfsp.vnfs_cnp = 0; |
1256 | vfsp.vnfs_vops = *(dnp->dn_ops); |
1257 | |
1258 | if (vtype == VBLK || vtype == VCHR) { |
1259 | /* |
1260 | * Ask the clone minor number function for a new minor number |
1261 | * to use for the next device instance. If an administative |
1262 | * limit has been reached, this function will return -1. |
1263 | */ |
1264 | if (dnp->dn_clone != NULL) { |
1265 | int n_major = major(dnp->dn_typeinfo.dev); |
1266 | |
1267 | n_minor = (*dnp->dn_clone)(dnp->dn_typeinfo.dev, DEVFS_CLONE_ALLOC); |
1268 | if (n_minor == -1) { |
1269 | error = ENOMEM; |
1270 | goto out; |
1271 | } |
1272 | |
1273 | vfsp.vnfs_rdev = makedev(n_major, n_minor); |
1274 | } else { |
1275 | vfsp.vnfs_rdev = dnp->dn_typeinfo.dev; |
1276 | } |
1277 | } else { |
1278 | vfsp.vnfs_rdev = 0; |
1279 | } |
1280 | vfsp.vnfs_filesize = 0; |
1281 | vfsp.vnfs_flags = VNFS_NOCACHE | VNFS_CANTCACHE; |
1282 | /* Tag system files */ |
1283 | vfsp.vnfs_marksystem = 0; |
1284 | vfsp.vnfs_markroot = markroot; |
1285 | |
1286 | DEVFS_UNLOCK(); |
1287 | |
1288 | error = vnode_create_ext(VNCREATE_FLAVOR, VCREATESIZE, data: &vfsp, vpp: &vn_p, |
1289 | VNODE_CREATE_DEFAULT); |
1290 | |
1291 | /* Do this before grabbing the lock */ |
1292 | if (error == 0) { |
1293 | vnode_setneedinactive(vn_p); |
1294 | } |
1295 | |
1296 | DEVFS_LOCK(); |
1297 | |
1298 | if (error == 0) { |
1299 | vnode_settag(vp: vn_p, tag: VT_DEVFS); |
1300 | |
1301 | if ((dnp->dn_clone != NULL) && (dnp->dn_vn != NULLVP)) { |
1302 | panic("devfs_dntovn: cloning device with a vnode?" ); |
1303 | } |
1304 | |
1305 | *vn_pp = vn_p; |
1306 | |
1307 | /* |
1308 | * Another vnode that has this devnode as its v_data. |
1309 | * This reference, unlike the one taken at the start |
1310 | * of the function, persists until a VNOP_RECLAIM |
1311 | * comes through for this vnode. |
1312 | */ |
1313 | devfs_ref_node(dnp); |
1314 | |
1315 | /* |
1316 | * A cloned vnode is not hooked into the devnode; every lookup |
1317 | * gets a new vnode. |
1318 | */ |
1319 | if (dnp->dn_clone == NULL) { |
1320 | dnp->dn_vn = vn_p; |
1321 | } |
1322 | } else if (n_minor != DEVFS_CLONE_ALLOC) { |
1323 | /* |
1324 | * If we failed the create, we need to release the cloned minor |
1325 | * back to the free list. In general, this is only useful if |
1326 | * the clone function results in a state change in the cloned |
1327 | * device for which the minor number was obtained. If we get |
1328 | * past this point withouth falling into this case, it's |
1329 | * assumed that any state to be released will be released when |
1330 | * the vnode is dropped, instead. |
1331 | */ |
1332 | (void)(*dnp->dn_clone)(dnp->dn_typeinfo.dev, DEVFS_CLONE_FREE); |
1333 | } |
1334 | |
1335 | dnp->dn_lflags &= ~DN_CREATE; |
1336 | if (dnp->dn_lflags & DN_CREATEWAIT) { |
1337 | dnp->dn_lflags &= ~DN_CREATEWAIT; |
1338 | wakeup(chan: &dnp->dn_lflags); |
1339 | } |
1340 | |
1341 | out: |
1342 | /* |
1343 | * Release the reference we took to prevent deletion while we weren't holding the lock. |
1344 | * If not returning success, then dropping this reference could delete the devnode; |
1345 | * no one should access a devnode after a call to devfs_dntovn fails. |
1346 | */ |
1347 | devfs_rele_node(dnp); |
1348 | |
1349 | return error; |
1350 | } |
1351 | |
1352 | /* |
1353 | * Increment refcount on a devnode; prevents free of the node |
1354 | * while the devfs lock is not held. |
1355 | */ |
1356 | void |
1357 | devfs_ref_node(devnode_t *dnp) |
1358 | { |
1359 | os_ref_retain_locked_raw(&dnp->dn_refcount, &devfs_refgrp); |
1360 | } |
1361 | |
1362 | /* |
1363 | * Release a reference on a devnode. If the devnode is marked for |
1364 | * free and the refcount is dropped to one, do the free. |
1365 | */ |
1366 | void |
1367 | devfs_rele_node(devnode_t *dnp) |
1368 | { |
1369 | os_ref_count_t rc = os_ref_release_locked_raw(&dnp->dn_refcount, &devfs_refgrp); |
1370 | if (rc < 1) { |
1371 | panic("devfs_rele_node: devnode without a refcount!" ); |
1372 | } else if ((rc == 1) && (dnp->dn_lflags & DN_DELETE)) { |
1373 | /* release final reference from dev_add_node */ |
1374 | (void) os_ref_release_locked_raw(&dnp->dn_refcount, &devfs_refgrp); |
1375 | devnode_free(dnp); |
1376 | } |
1377 | } |
1378 | |
1379 | /*********************************************************************** |
1380 | * add a whole device, with no prototype.. make name element and node |
1381 | * Used for adding the original device entries |
1382 | * |
1383 | * called with DEVFS_LOCK held |
1384 | ***********************************************************************/ |
1385 | int |
1386 | dev_add_entry(const char *name, devnode_t * parent, int type, devnode_type_t * typeinfo, |
1387 | devnode_t * proto, struct devfsmount *dvm, devdirent_t * *nm_pp) |
1388 | { |
1389 | devnode_t * dnp; |
1390 | int error = 0; |
1391 | |
1392 | if ((error = dev_add_node(entrytype: type, typeinfo, proto, dn_pp: &dnp, |
1393 | dvm: (parent?parent->dn_dvm:dvm))) != 0) { |
1394 | printf("devfs: %s: base node allocation failed (Errno=%d)\n" , |
1395 | name, error); |
1396 | return error; |
1397 | } |
1398 | if ((error = dev_add_name(name, dirnode: parent, NULL, dnp, dirent_pp: nm_pp)) != 0) { |
1399 | devfs_dn_free(dnp); /* 1->0 for dir, 0->(-1) for other */ |
1400 | printf("devfs: %s: name slot allocation failed (Errno=%d)\n" , |
1401 | name, error); |
1402 | } |
1403 | return error; |
1404 | } |
1405 | |
1406 | static void |
1407 | devfs_bulk_notify(devfs_event_log_t delp) |
1408 | { |
1409 | uint32_t i; |
1410 | for (i = 0; i < delp->del_used; i++) { |
1411 | devfs_vnode_event_t dvep = &delp->del_entries[i]; |
1412 | if (vnode_getwithvid(dvep->dve_vp, dvep->dve_vid) == 0) { |
1413 | vnode_notify(vp: dvep->dve_vp, events: dvep->dve_events, NULL); |
1414 | vnode_put(vp: dvep->dve_vp); |
1415 | } |
1416 | vnode_drop(vp: dvep->dve_vp); |
1417 | } |
1418 | } |
1419 | |
1420 | static void |
1421 | devfs_record_event(devfs_event_log_t delp, devnode_t *dnp, uint32_t events) |
1422 | { |
1423 | if (delp->del_used >= delp->del_max) { |
1424 | panic("devfs event log overflowed." ); |
1425 | } |
1426 | |
1427 | /* Can only notify for nodes that have an associated vnode */ |
1428 | if (dnp->dn_vn != NULLVP && vnode_ismonitored(vp: dnp->dn_vn)) { |
1429 | devfs_vnode_event_t dvep = &delp->del_entries[delp->del_used]; |
1430 | dvep->dve_vp = dnp->dn_vn; |
1431 | dvep->dve_vid = vnode_vid(vp: dnp->dn_vn); |
1432 | vnode_hold(vp: dvep->dve_vp); |
1433 | dvep->dve_events = events; |
1434 | delp->del_used++; |
1435 | } |
1436 | } |
1437 | |
1438 | static int |
1439 | devfs_init_event_log(devfs_event_log_t delp, uint32_t count, devfs_vnode_event_t buf) |
1440 | { |
1441 | devfs_vnode_event_t dvearr; |
1442 | |
1443 | if (buf == NULL) { |
1444 | dvearr = kalloc_type(struct devfs_vnode_event, count, |
1445 | Z_WAITOK | Z_ZERO); |
1446 | if (dvearr == NULL) { |
1447 | return ENOMEM; |
1448 | } |
1449 | } else { |
1450 | dvearr = buf; |
1451 | } |
1452 | |
1453 | delp->del_max = count; |
1454 | delp->del_used = 0; |
1455 | delp->del_entries = dvearr; |
1456 | return 0; |
1457 | } |
1458 | |
1459 | static void |
1460 | devfs_release_event_log(devfs_event_log_t delp, int need_free) |
1461 | { |
1462 | if (delp->del_entries == NULL) { |
1463 | panic("Free of devfs notify info that has not been intialized." ); |
1464 | } |
1465 | |
1466 | if (need_free) { |
1467 | kfree_type(struct devfs_vnode_event, delp->del_max, |
1468 | delp->del_entries); |
1469 | } |
1470 | |
1471 | delp->del_entries = NULL; |
1472 | } |
1473 | |
1474 | /* |
1475 | * Function: devfs_make_node |
1476 | * |
1477 | * Purpose |
1478 | * Create a device node with the given pathname in the devfs namespace. |
1479 | * |
1480 | * Parameters: |
1481 | * dev - the dev_t value to associate |
1482 | * chrblk - block or character device (DEVFS_CHAR or DEVFS_BLOCK) |
1483 | * uid, gid - ownership |
1484 | * perms - permissions |
1485 | * clone - minor number cloning function |
1486 | * fmt, ... - path format string with printf args to format the path name |
1487 | * Returns: |
1488 | * A handle to a device node if successful, NULL otherwise. |
1489 | */ |
1490 | void * |
1491 | devfs_make_node_clone(dev_t dev, int chrblk, uid_t uid, |
1492 | gid_t gid, int perms, int (*clone)(dev_t dev, int action), |
1493 | const char *fmt, ...) |
1494 | { |
1495 | devdirent_t * new_dev = NULL; |
1496 | devfstype_t type; |
1497 | va_list ap; |
1498 | |
1499 | switch (chrblk) { |
1500 | case DEVFS_CHAR: |
1501 | type = DEV_CDEV; |
1502 | break; |
1503 | case DEVFS_BLOCK: |
1504 | type = DEV_BDEV; |
1505 | break; |
1506 | default: |
1507 | goto out; |
1508 | } |
1509 | |
1510 | va_start(ap, fmt); |
1511 | new_dev = devfs_make_node_internal(dev, type, uid, gid, perms, clone, fmt, ap); |
1512 | va_end(ap); |
1513 | out: |
1514 | return new_dev; |
1515 | } |
1516 | |
1517 | |
1518 | /* |
1519 | * Function: devfs_make_node |
1520 | * |
1521 | * Purpose |
1522 | * Create a device node with the given pathname in the devfs namespace. |
1523 | * |
1524 | * Parameters: |
1525 | * dev - the dev_t value to associate |
1526 | * chrblk - block or character device (DEVFS_CHAR or DEVFS_BLOCK) |
1527 | * uid, gid - ownership |
1528 | * perms - permissions |
1529 | * fmt, ... - path format string with printf args to format the path name |
1530 | * Returns: |
1531 | * A handle to a device node if successful, NULL otherwise. |
1532 | */ |
1533 | void * |
1534 | devfs_make_node(dev_t dev, int chrblk, uid_t uid, |
1535 | gid_t gid, int perms, const char *fmt, ...) |
1536 | { |
1537 | devdirent_t * new_dev = NULL; |
1538 | devfstype_t type; |
1539 | va_list ap; |
1540 | |
1541 | if (chrblk != DEVFS_CHAR && chrblk != DEVFS_BLOCK) { |
1542 | goto out; |
1543 | } |
1544 | |
1545 | type = (chrblk == DEVFS_BLOCK ? DEV_BDEV : DEV_CDEV); |
1546 | |
1547 | va_start(ap, fmt); |
1548 | new_dev = devfs_make_node_internal(dev, type, uid, gid, perms, NULL, fmt, ap); |
1549 | va_end(ap); |
1550 | |
1551 | out: |
1552 | return new_dev; |
1553 | } |
1554 | |
1555 | __printflike(7, 0) |
1556 | static devdirent_t * |
1557 | devfs_make_node_internal(dev_t dev, devfstype_t type, uid_t uid, |
1558 | gid_t gid, int perms, int (*clone)(dev_t dev, int action), const char *fmt, va_list ap) |
1559 | { |
1560 | devdirent_t * new_dev = NULL; |
1561 | devnode_t * dnp; |
1562 | devnode_type_t typeinfo; |
1563 | |
1564 | char *name, buf[256]; /* XXX */ |
1565 | const char *path; |
1566 | #if CONFIG_MACF |
1567 | char buff[sizeof(buf)]; |
1568 | #endif |
1569 | size_t i; |
1570 | uint32_t log_count; |
1571 | struct devfs_event_log event_log; |
1572 | struct devfs_vnode_event stackbuf[NUM_STACK_ENTRIES]; |
1573 | int need_free = 0; |
1574 | |
1575 | vsnprintf(buf, sizeof(buf), fmt, ap); |
1576 | |
1577 | #if CONFIG_MACF |
1578 | bcopy(src: buf, dst: buff, n: sizeof(buff)); |
1579 | buff[sizeof(buff) - 1] = 0; |
1580 | #endif |
1581 | name = NULL; |
1582 | |
1583 | for (i = strlen(s: buf); i > 0; i--) { |
1584 | if (buf[i] == '/') { |
1585 | name = &buf[i]; |
1586 | buf[i] = 0; |
1587 | break; |
1588 | } |
1589 | } |
1590 | |
1591 | if (name) { |
1592 | *name++ = '\0'; |
1593 | path = buf; |
1594 | } else { |
1595 | name = buf; |
1596 | path = "/" ; |
1597 | } |
1598 | |
1599 | log_count = devfs_nmountplanes; |
1600 | if (log_count > NUM_STACK_ENTRIES) { |
1601 | wrongsize: |
1602 | need_free = 1; |
1603 | if (devfs_init_event_log(delp: &event_log, count: log_count, NULL) != 0) { |
1604 | return NULL; |
1605 | } |
1606 | } else { |
1607 | need_free = 0; |
1608 | log_count = NUM_STACK_ENTRIES; |
1609 | if (devfs_init_event_log(delp: &event_log, count: log_count, buf: &stackbuf[0]) != 0) { |
1610 | return NULL; |
1611 | } |
1612 | } |
1613 | |
1614 | DEVFS_LOCK(); |
1615 | if (log_count < devfs_nmountplanes) { |
1616 | DEVFS_UNLOCK(); |
1617 | devfs_release_event_log(delp: &event_log, need_free); |
1618 | log_count = log_count * 2; |
1619 | goto wrongsize; |
1620 | } |
1621 | |
1622 | if (!devfs_ready) { |
1623 | printf("devfs_make_node: not ready for devices!\n" ); |
1624 | goto out; |
1625 | } |
1626 | |
1627 | /* find/create directory path ie. mkdir -p */ |
1628 | if (dev_finddir(path, NULL, DEVFS_CREATE, dn_pp: &dnp, delp: &event_log) == 0) { |
1629 | typeinfo.dev = dev; |
1630 | if (dev_add_entry(name, parent: dnp, type, typeinfo: &typeinfo, NULL, NULL, nm_pp: &new_dev) == 0) { |
1631 | new_dev->de_dnp->dn_gid = gid; |
1632 | new_dev->de_dnp->dn_uid = uid; |
1633 | new_dev->de_dnp->dn_mode |= perms; |
1634 | new_dev->de_dnp->dn_clone = clone; |
1635 | #if CONFIG_MACF |
1636 | mac_devfs_label_associate_device(dev, de: new_dev->de_dnp, fullpath: buff); |
1637 | #endif |
1638 | devfs_propogate(parent: dnp->dn_typeinfo.Dir.myname, child: new_dev, delp: &event_log); |
1639 | } |
1640 | } |
1641 | |
1642 | out: |
1643 | DEVFS_UNLOCK(); |
1644 | |
1645 | devfs_bulk_notify(delp: &event_log); |
1646 | devfs_release_event_log(delp: &event_log, need_free); |
1647 | return new_dev; |
1648 | } |
1649 | |
1650 | /* |
1651 | * Function: devfs_make_link |
1652 | * |
1653 | * Purpose: |
1654 | * Create a link to a previously created device node. |
1655 | * |
1656 | * Returns: |
1657 | * 0 if successful, -1 if failed |
1658 | */ |
1659 | int |
1660 | devfs_make_link(void *original, char *fmt, ...) |
1661 | { |
1662 | devdirent_t * new_dev = NULL; |
1663 | devdirent_t * orig = (devdirent_t *) original; |
1664 | devnode_t * dirnode; /* devnode for parent directory */ |
1665 | struct devfs_event_log event_log; |
1666 | uint32_t log_count; |
1667 | |
1668 | va_list ap; |
1669 | char *p, buf[256]; /* XXX */ |
1670 | size_t i; |
1671 | |
1672 | DEVFS_LOCK(); |
1673 | |
1674 | if (!devfs_ready) { |
1675 | DEVFS_UNLOCK(); |
1676 | printf("devfs_make_link: not ready for devices!\n" ); |
1677 | return -1; |
1678 | } |
1679 | DEVFS_UNLOCK(); |
1680 | |
1681 | va_start(ap, fmt); |
1682 | vsnprintf(buf, sizeof(buf), fmt, ap); |
1683 | va_end(ap); |
1684 | |
1685 | p = NULL; |
1686 | |
1687 | for (i = strlen(s: buf); i > 0; i--) { |
1688 | if (buf[i] == '/') { |
1689 | p = &buf[i]; |
1690 | buf[i] = 0; |
1691 | break; |
1692 | } |
1693 | } |
1694 | |
1695 | /* |
1696 | * One slot for each directory, one for each devnode |
1697 | * whose link count changes |
1698 | */ |
1699 | log_count = devfs_nmountplanes * 2; |
1700 | wrongsize: |
1701 | if (devfs_init_event_log(delp: &event_log, count: log_count, NULL) != 0) { |
1702 | /* No lock held, no allocations done, can just return */ |
1703 | return -1; |
1704 | } |
1705 | |
1706 | DEVFS_LOCK(); |
1707 | |
1708 | if (log_count < devfs_nmountplanes) { |
1709 | DEVFS_UNLOCK(); |
1710 | devfs_release_event_log(delp: &event_log, need_free: 1); |
1711 | log_count = log_count * 2; |
1712 | goto wrongsize; |
1713 | } |
1714 | |
1715 | if (p) { |
1716 | *p++ = '\0'; |
1717 | |
1718 | if (dev_finddir(path: buf, NULL, DEVFS_CREATE, dn_pp: &dirnode, delp: &event_log) |
1719 | || dev_add_name(name: p, dirnode, NULL, dnp: orig->de_dnp, dirent_pp: &new_dev)) { |
1720 | goto fail; |
1721 | } |
1722 | } else { |
1723 | if (dev_finddir(path: "" , NULL, DEVFS_CREATE, dn_pp: &dirnode, delp: &event_log) |
1724 | || dev_add_name(name: buf, dirnode, NULL, dnp: orig->de_dnp, dirent_pp: &new_dev)) { |
1725 | goto fail; |
1726 | } |
1727 | } |
1728 | devfs_propogate(parent: dirnode->dn_typeinfo.Dir.myname, child: new_dev, delp: &event_log); |
1729 | fail: |
1730 | DEVFS_UNLOCK(); |
1731 | devfs_bulk_notify(delp: &event_log); |
1732 | devfs_release_event_log(delp: &event_log, need_free: 1); |
1733 | |
1734 | return (new_dev != NULL) ? 0 : -1; |
1735 | } |
1736 | |