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 |
19 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
21 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
22 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
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 | #define BSD_KERNEL_PRIVATE 1 /* devfs_make_link() prototype */ |
103 | #include "devfs.h" |
104 | #include "devfsdefs.h" |
105 | |
106 | #if CONFIG_MACF |
107 | #include <security/mac_framework.h> |
108 | #endif |
109 | |
110 | #if FDESC |
111 | #include "fdesc.h" |
112 | #endif |
113 | |
114 | typedef struct devfs_vnode_event { |
115 | vnode_t dve_vp; |
116 | uint32_t dve_vid; |
117 | uint32_t dve_events; |
118 | } *devfs_vnode_event_t; |
119 | |
120 | /* |
121 | * Size of stack buffer (fast path) for notifications. If |
122 | * the number of mounts is small, no need to malloc a buffer. |
123 | */ |
124 | #define NUM_STACK_ENTRIES 5 |
125 | |
126 | typedef struct devfs_event_log { |
127 | size_t del_max; |
128 | size_t del_used; |
129 | devfs_vnode_event_t del_entries; |
130 | } *devfs_event_log_t; |
131 | |
132 | |
133 | static void dev_free_hier(devdirent_t *); |
134 | static int devfs_propogate(devdirent_t *, devdirent_t *, devfs_event_log_t); |
135 | static int dev_finddir(const char *, devnode_t *, int, devnode_t **, devfs_event_log_t); |
136 | static int dev_dup_entry(devnode_t *, devdirent_t *, devdirent_t **, struct devfsmount *); |
137 | void devfs_ref_node(devnode_t *); |
138 | void devfs_rele_node(devnode_t *); |
139 | static void devfs_record_event(devfs_event_log_t, devnode_t*, uint32_t); |
140 | static int devfs_init_event_log(devfs_event_log_t, uint32_t, devfs_vnode_event_t); |
141 | static void devfs_release_event_log(devfs_event_log_t, int); |
142 | static void devfs_bulk_notify(devfs_event_log_t); |
143 | static devdirent_t *devfs_make_node_internal(dev_t, devfstype_t type, uid_t, gid_t, int, |
144 | int (*clone)(dev_t dev, int action), const char *fmt, va_list ap); |
145 | |
146 | |
147 | lck_grp_t * devfs_lck_grp; |
148 | lck_grp_attr_t * devfs_lck_grp_attr; |
149 | lck_attr_t * devfs_lck_attr; |
150 | lck_mtx_t devfs_mutex; |
151 | lck_mtx_t devfs_attr_mutex; |
152 | |
153 | devdirent_t * dev_root = NULL; /* root of backing tree */ |
154 | struct devfs_stats devfs_stats; /* hold stats */ |
155 | |
156 | static ino_t devfs_unique_fileno = 0; |
157 | |
158 | #ifdef HIDDEN_MOUNTPOINT |
159 | static struct mount *devfs_hidden_mount; |
160 | #endif /* HIDDEN_MOINTPOINT */ |
161 | |
162 | static int devfs_ready = 0; |
163 | static uint32_t devfs_nmountplanes = 0; /* The first plane is not used for a mount */ |
164 | |
165 | #define DEVFS_NOCREATE FALSE |
166 | #define DEVFS_CREATE TRUE |
167 | |
168 | /* |
169 | * Set up the root directory node in the backing plane |
170 | * This is happenning before the vfs system has been |
171 | * set up yet, so be careful about what we reference.. |
172 | * Notice that the ops are by indirection.. as they haven't |
173 | * been set up yet! |
174 | * DEVFS has a hidden mountpoint that is used as the anchor point |
175 | * for the internal 'blueprint' version of the dev filesystem tree. |
176 | */ |
177 | /*proto*/ |
178 | int |
179 | devfs_sinit(void) |
180 | { |
181 | int error; |
182 | |
183 | devfs_lck_grp_attr = lck_grp_attr_alloc_init(); |
184 | devfs_lck_grp = lck_grp_alloc_init("devfs_lock" , devfs_lck_grp_attr); |
185 | |
186 | devfs_lck_attr = lck_attr_alloc_init(); |
187 | |
188 | lck_mtx_init(&devfs_mutex, devfs_lck_grp, devfs_lck_attr); |
189 | lck_mtx_init(&devfs_attr_mutex, devfs_lck_grp, devfs_lck_attr); |
190 | |
191 | DEVFS_LOCK(); |
192 | error = dev_add_entry("root" , NULL, DEV_DIR, NULL, NULL, NULL, &dev_root); |
193 | DEVFS_UNLOCK(); |
194 | |
195 | if (error) { |
196 | printf("devfs_sinit: dev_add_entry failed " ); |
197 | return (ENOTSUP); |
198 | } |
199 | #ifdef HIDDEN_MOUNTPOINT |
200 | MALLOC(devfs_hidden_mount, struct mount *, sizeof(struct mount), |
201 | M_MOUNT, M_WAITOK); |
202 | bzero(devfs_hidden_mount,sizeof(struct mount)); |
203 | mount_lock_init(devfs_hidden_mount); |
204 | TAILQ_INIT(&devfs_hidden_mount->mnt_vnodelist); |
205 | TAILQ_INIT(&devfs_hidden_mount->mnt_workerqueue); |
206 | TAILQ_INIT(&devfs_hidden_mount->mnt_newvnodes); |
207 | #if CONFIG_MACF |
208 | mac_mount_label_init(devfs_hidden_mount); |
209 | mac_mount_label_associate(vfs_context_kernel(), devfs_hidden_mount); |
210 | #endif |
211 | |
212 | /* Initialize the default IO constraints */ |
213 | mp->mnt_maxreadcnt = mp->mnt_maxwritecnt = MAXPHYS; |
214 | mp->mnt_segreadcnt = mp->mnt_segwritecnt = 32; |
215 | mp->mnt_ioflags = 0; |
216 | mp->mnt_realrootvp = NULLVP; |
217 | mp->mnt_authcache_ttl = CACHED_LOOKUP_RIGHT_TTL; |
218 | |
219 | devfs_mount(devfs_hidden_mount,"dummy" ,NULL,NULL,NULL); |
220 | dev_root->de_dnp->dn_dvm |
221 | = (struct devfsmount *)devfs_hidden_mount->mnt_data; |
222 | #endif /* HIDDEN_MOUNTPOINT */ |
223 | #if CONFIG_MACF |
224 | mac_devfs_label_associate_directory("/" , strlen("/" ), |
225 | dev_root->de_dnp, "/" ); |
226 | #endif |
227 | devfs_ready = 1; |
228 | return (0); |
229 | } |
230 | |
231 | /***********************************************************************\ |
232 | ************************************************************************* |
233 | * Routines used to find our way to a point in the tree * |
234 | ************************************************************************* |
235 | \***********************************************************************/ |
236 | |
237 | |
238 | |
239 | /*************************************************************** |
240 | * Search down the linked list off a dir to find "name" |
241 | * return the devnode_t * for that node. |
242 | * |
243 | * called with DEVFS_LOCK held |
244 | ***************************************************************/ |
245 | devdirent_t * |
246 | dev_findname(devnode_t * dir, const char *name) |
247 | { |
248 | devdirent_t * newfp; |
249 | if (dir->dn_type != DEV_DIR) return 0;/*XXX*/ /* printf?*/ |
250 | |
251 | if (name[0] == '.') |
252 | { |
253 | if(name[1] == 0) |
254 | { |
255 | return dir->dn_typeinfo.Dir.myname; |
256 | } |
257 | if((name[1] == '.') && (name[2] == 0)) |
258 | { |
259 | /* for root, .. == . */ |
260 | return dir->dn_typeinfo.Dir.parent->dn_typeinfo.Dir.myname; |
261 | } |
262 | } |
263 | newfp = dir->dn_typeinfo.Dir.dirlist; |
264 | |
265 | while(newfp) |
266 | { |
267 | if(!(strncmp(name, newfp->de_name, sizeof(newfp->de_name)))) |
268 | return newfp; |
269 | newfp = newfp->de_next; |
270 | } |
271 | return NULL; |
272 | } |
273 | |
274 | /*********************************************************************** |
275 | * Given a starting node (0 for root) and a pathname, return the node |
276 | * for the end item on the path. It MUST BE A DIRECTORY. If the 'DEVFS_CREATE' |
277 | * option is true, then create any missing nodes in the path and create |
278 | * and return the final node as well. |
279 | * This is used to set up a directory, before making nodes in it.. |
280 | * |
281 | * called with DEVFS_LOCK held |
282 | ***********************************************************************/ |
283 | static int |
284 | dev_finddir(const char * path, |
285 | devnode_t * dirnode, |
286 | int create, |
287 | devnode_t * * dn_pp, |
288 | devfs_event_log_t delp) |
289 | { |
290 | devnode_t * dnp = NULL; |
291 | int error = 0; |
292 | const char * scan; |
293 | #if CONFIG_MACF |
294 | char fullpath[DEVMAXPATHSIZE]; |
295 | #endif |
296 | |
297 | |
298 | if (!dirnode) /* dirnode == NULL means start at root */ |
299 | dirnode = dev_root->de_dnp; |
300 | |
301 | if (dirnode->dn_type != DEV_DIR) |
302 | return ENOTDIR; |
303 | |
304 | if (strlen(path) > (DEVMAXPATHSIZE - 1)) |
305 | return ENAMETOOLONG; |
306 | |
307 | #if CONFIG_MACF |
308 | strlcpy (fullpath, path, DEVMAXPATHSIZE); |
309 | #endif |
310 | scan = path; |
311 | |
312 | while (*scan == '/') |
313 | scan++; |
314 | |
315 | *dn_pp = NULL; |
316 | |
317 | while (1) { |
318 | char component[DEVMAXPATHSIZE]; |
319 | devdirent_t * dirent_p; |
320 | const char * start; |
321 | |
322 | if (*scan == 0) { |
323 | /* we hit the end of the string, we're done */ |
324 | *dn_pp = dirnode; |
325 | break; |
326 | } |
327 | start = scan; |
328 | while (*scan != '/' && *scan) |
329 | scan++; |
330 | |
331 | strlcpy(component, start, (scan - start) + 1); |
332 | if (*scan == '/') |
333 | scan++; |
334 | |
335 | dirent_p = dev_findname(dirnode, component); |
336 | if (dirent_p) { |
337 | dnp = dirent_p->de_dnp; |
338 | if (dnp->dn_type != DEV_DIR) { |
339 | error = ENOTDIR; |
340 | break; |
341 | } |
342 | } |
343 | else { |
344 | if (!create) { |
345 | error = ENOENT; |
346 | break; |
347 | } |
348 | error = dev_add_entry(component, dirnode, |
349 | DEV_DIR, NULL, NULL, NULL, &dirent_p); |
350 | if (error) |
351 | break; |
352 | dnp = dirent_p->de_dnp; |
353 | #if CONFIG_MACF |
354 | mac_devfs_label_associate_directory( |
355 | dirnode->dn_typeinfo.Dir.myname->de_name, |
356 | strlen(dirnode->dn_typeinfo.Dir.myname->de_name), |
357 | dnp, fullpath); |
358 | #endif |
359 | devfs_propogate(dirnode->dn_typeinfo.Dir.myname, dirent_p, delp); |
360 | } |
361 | dirnode = dnp; /* continue relative to this directory */ |
362 | } |
363 | return (error); |
364 | } |
365 | |
366 | |
367 | /*********************************************************************** |
368 | * Add a new NAME element to the devfs |
369 | * If we're creating a root node, then dirname is NULL |
370 | * Basically this creates a new namespace entry for the device node |
371 | * |
372 | * Creates a name node, and links it to the supplied node |
373 | * |
374 | * called with DEVFS_LOCK held |
375 | ***********************************************************************/ |
376 | int |
377 | dev_add_name(const char * name, devnode_t * dirnode, __unused devdirent_t * back, |
378 | devnode_t * dnp, devdirent_t * *dirent_pp) |
379 | { |
380 | devdirent_t * dirent_p = NULL; |
381 | |
382 | if(dirnode != NULL ) { |
383 | if(dirnode->dn_type != DEV_DIR) return(ENOTDIR); |
384 | |
385 | if( dev_findname(dirnode,name)) |
386 | return(EEXIST); |
387 | } |
388 | /* |
389 | * make sure the name is legal |
390 | * slightly misleading in the case of NULL |
391 | */ |
392 | if (!name || (strlen(name) > (DEVMAXNAMESIZE - 1))) |
393 | return (ENAMETOOLONG); |
394 | |
395 | /* |
396 | * Allocate and fill out a new directory entry |
397 | */ |
398 | MALLOC(dirent_p, devdirent_t *, sizeof(devdirent_t), |
399 | M_DEVFSNAME, M_WAITOK); |
400 | if (!dirent_p) { |
401 | return ENOMEM; |
402 | } |
403 | bzero(dirent_p,sizeof(devdirent_t)); |
404 | |
405 | /* inherrit our parent's mount info */ /*XXX*/ |
406 | /* a kludge but.... */ |
407 | if(dirnode && ( dnp->dn_dvm == NULL)) { |
408 | dnp->dn_dvm = dirnode->dn_dvm; |
409 | /* if(!dnp->dn_dvm) printf("parent had null dvm "); */ |
410 | } |
411 | |
412 | /* |
413 | * Link the two together |
414 | * include the implicit link in the count of links to the devnode.. |
415 | * this stops it from being accidentally freed later. |
416 | */ |
417 | dirent_p->de_dnp = dnp; |
418 | dnp->dn_links++ ; /* implicit from our own name-node */ |
419 | |
420 | /* |
421 | * Make sure that we can find all the links that reference a node |
422 | * so that we can get them all if we need to zap the node. |
423 | */ |
424 | if(dnp->dn_linklist) { |
425 | dirent_p->de_nextlink = dnp->dn_linklist; |
426 | dirent_p->de_prevlinkp = dirent_p->de_nextlink->de_prevlinkp; |
427 | dirent_p->de_nextlink->de_prevlinkp = &(dirent_p->de_nextlink); |
428 | *dirent_p->de_prevlinkp = dirent_p; |
429 | } else { |
430 | dirent_p->de_nextlink = dirent_p; |
431 | dirent_p->de_prevlinkp = &(dirent_p->de_nextlink); |
432 | } |
433 | dnp->dn_linklist = dirent_p; |
434 | |
435 | /* |
436 | * If the node is a directory, then we need to handle the |
437 | * creation of the .. link. |
438 | * A NULL dirnode indicates a root node, so point to ourself. |
439 | */ |
440 | if(dnp->dn_type == DEV_DIR) { |
441 | dnp->dn_typeinfo.Dir.myname = dirent_p; |
442 | /* |
443 | * If we are unlinking from an old dir, decrement its links |
444 | * as we point our '..' elsewhere |
445 | * Note: it's up to the calling code to remove the |
446 | * us from the original directory's list |
447 | */ |
448 | if(dnp->dn_typeinfo.Dir.parent) { |
449 | dnp->dn_typeinfo.Dir.parent->dn_links--; |
450 | } |
451 | if(dirnode) { |
452 | dnp->dn_typeinfo.Dir.parent = dirnode; |
453 | } else { |
454 | dnp->dn_typeinfo.Dir.parent = dnp; |
455 | } |
456 | dnp->dn_typeinfo.Dir.parent->dn_links++; /* account for the new '..' */ |
457 | } |
458 | |
459 | /* |
460 | * put the name into the directory entry. |
461 | */ |
462 | strlcpy(dirent_p->de_name, name, DEVMAXNAMESIZE); |
463 | |
464 | |
465 | /* |
466 | * Check if we are not making a root node.. |
467 | * (i.e. have parent) |
468 | */ |
469 | if(dirnode) { |
470 | /* |
471 | * Put it on the END of the linked list of directory entries |
472 | */ |
473 | dirent_p->de_parent = dirnode; /* null for root */ |
474 | dirent_p->de_prevp = dirnode->dn_typeinfo.Dir.dirlast; |
475 | dirent_p->de_next = *(dirent_p->de_prevp); /* should be NULL */ |
476 | /*right?*/ |
477 | *(dirent_p->de_prevp) = dirent_p; |
478 | dirnode->dn_typeinfo.Dir.dirlast = &(dirent_p->de_next); |
479 | dirnode->dn_typeinfo.Dir.entrycount++; |
480 | dirnode->dn_len += strlen(name) + 8;/*ok, ok?*/ |
481 | } |
482 | |
483 | *dirent_pp = dirent_p; |
484 | DEVFS_INCR_ENTRIES(); |
485 | return 0 ; |
486 | } |
487 | |
488 | |
489 | /*********************************************************************** |
490 | * Add a new element to the devfs plane. |
491 | * |
492 | * Creates a new dev_node to go with it if the prototype should not be |
493 | * reused. (Is a DIR, or we select SPLIT_DEVS at compile time) |
494 | * typeinfo gives us info to make our node if we don't have a prototype. |
495 | * If typeinfo is null and proto exists, then the typeinfo field of |
496 | * the proto is used intead in the DEVFS_CREATE case. |
497 | * note the 'links' count is 0 (except if a dir) |
498 | * but it is only cleared on a transition |
499 | * so this is ok till we link it to something |
500 | * Even in SPLIT_DEVS mode, |
501 | * if the node already exists on the wanted plane, just return it |
502 | * |
503 | * called with DEVFS_LOCK held |
504 | ***********************************************************************/ |
505 | int |
506 | dev_add_node(int entrytype, devnode_type_t * typeinfo, devnode_t * proto, |
507 | devnode_t * *dn_pp, struct devfsmount *dvm) |
508 | { |
509 | devnode_t * dnp = NULL; |
510 | |
511 | #if defined SPLIT_DEVS |
512 | /* |
513 | * If we have a prototype, then check if there is already a sibling |
514 | * on the mount plane we are looking at, if so, just return it. |
515 | */ |
516 | if (proto) { |
517 | dnp = proto->dn_nextsibling; |
518 | while( dnp != proto) { |
519 | if (dnp->dn_dvm == dvm) { |
520 | *dn_pp = dnp; |
521 | return (0); |
522 | } |
523 | dnp = dnp->dn_nextsibling; |
524 | } |
525 | if (typeinfo == NULL) |
526 | typeinfo = &(proto->dn_typeinfo); |
527 | } |
528 | #else /* SPLIT_DEVS */ |
529 | if ( proto ) { |
530 | switch (proto->type) { |
531 | case DEV_BDEV: |
532 | case DEV_CDEV: |
533 | *dn_pp = proto; |
534 | return 0; |
535 | } |
536 | } |
537 | #endif /* SPLIT_DEVS */ |
538 | MALLOC(dnp, devnode_t *, sizeof(devnode_t), M_DEVFSNODE, M_WAITOK); |
539 | if (!dnp) { |
540 | return ENOMEM; |
541 | } |
542 | |
543 | /* |
544 | * If we have a proto, that means that we are duplicating some |
545 | * other device, which can only happen if we are not at the back plane |
546 | */ |
547 | if (proto) { |
548 | bcopy(proto, dnp, sizeof(devnode_t)); |
549 | dnp->dn_links = 0; |
550 | dnp->dn_linklist = NULL; |
551 | dnp->dn_vn = NULL; |
552 | dnp->dn_len = 0; |
553 | /* add to END of siblings list */ |
554 | dnp->dn_prevsiblingp = proto->dn_prevsiblingp; |
555 | *(dnp->dn_prevsiblingp) = dnp; |
556 | dnp->dn_nextsibling = proto; |
557 | proto->dn_prevsiblingp = &(dnp->dn_nextsibling); |
558 | #if CONFIG_MACF |
559 | mac_devfs_label_init(dnp); |
560 | mac_devfs_label_copy(proto->dn_label, dnp->dn_label); |
561 | #endif |
562 | } else { |
563 | struct timeval tv; |
564 | |
565 | /* |
566 | * We have no prototype, so start off with a clean slate |
567 | */ |
568 | microtime(&tv); |
569 | bzero(dnp, sizeof(devnode_t)); |
570 | dnp->dn_type = entrytype; |
571 | dnp->dn_nextsibling = dnp; |
572 | dnp->dn_prevsiblingp = &(dnp->dn_nextsibling); |
573 | dnp->dn_atime.tv_sec = tv.tv_sec; |
574 | dnp->dn_mtime.tv_sec = tv.tv_sec; |
575 | dnp->dn_ctime.tv_sec = tv.tv_sec; |
576 | #if CONFIG_MACF |
577 | mac_devfs_label_init(dnp); |
578 | #endif |
579 | } |
580 | dnp->dn_dvm = dvm; |
581 | dnp->dn_refcount = 0; |
582 | dnp->dn_ino = devfs_unique_fileno; |
583 | devfs_unique_fileno++; |
584 | |
585 | /* |
586 | * fill out the dev node according to type |
587 | */ |
588 | switch(entrytype) { |
589 | case DEV_DIR: |
590 | /* |
591 | * As it's a directory, make sure |
592 | * it has a null entries list |
593 | */ |
594 | dnp->dn_typeinfo.Dir.dirlast = &(dnp->dn_typeinfo.Dir.dirlist); |
595 | dnp->dn_typeinfo.Dir.dirlist = (devdirent_t *)0; |
596 | dnp->dn_typeinfo.Dir.entrycount = 0; |
597 | /* until we know better, it has a null parent pointer*/ |
598 | dnp->dn_typeinfo.Dir.parent = NULL; |
599 | dnp->dn_links++; /* for .*/ |
600 | dnp->dn_typeinfo.Dir.myname = NULL; |
601 | /* |
602 | * make sure that the ops associated with it are the ops |
603 | * that we use (by default) for directories |
604 | */ |
605 | dnp->dn_ops = &devfs_vnodeop_p; |
606 | dnp->dn_mode |= 0555; /* default perms */ |
607 | break; |
608 | case DEV_SLNK: |
609 | /* |
610 | * As it's a symlink allocate and store the link info |
611 | * Symlinks should only ever be created by the user, |
612 | * so they are not on the back plane and should not be |
613 | * propogated forward.. a bit like directories in that way.. |
614 | * A symlink only exists on one plane and has its own |
615 | * node.. therefore we might be on any random plane. |
616 | */ |
617 | MALLOC(dnp->dn_typeinfo.Slnk.name, char *, |
618 | typeinfo->Slnk.namelen+1, |
619 | M_DEVFSNODE, M_WAITOK); |
620 | if (!dnp->dn_typeinfo.Slnk.name) { |
621 | FREE(dnp,M_DEVFSNODE); |
622 | return ENOMEM; |
623 | } |
624 | strlcpy(dnp->dn_typeinfo.Slnk.name, typeinfo->Slnk.name, |
625 | typeinfo->Slnk.namelen + 1); |
626 | dnp->dn_typeinfo.Slnk.namelen = typeinfo->Slnk.namelen; |
627 | DEVFS_INCR_STRINGSPACE(dnp->dn_typeinfo.Slnk.namelen + 1); |
628 | dnp->dn_ops = &devfs_vnodeop_p; |
629 | dnp->dn_mode |= 0555; /* default perms */ |
630 | break; |
631 | case DEV_CDEV: |
632 | case DEV_BDEV: |
633 | /* |
634 | * Make sure it has DEVICE type ops |
635 | * and device specific fields are correct |
636 | */ |
637 | dnp->dn_ops = &devfs_spec_vnodeop_p; |
638 | dnp->dn_typeinfo.dev = typeinfo->dev; |
639 | break; |
640 | |
641 | #if FDESC |
642 | /* /dev/fd is special */ |
643 | case DEV_DEVFD: |
644 | dnp->dn_ops = &devfs_devfd_vnodeop_p; |
645 | dnp->dn_mode |= 0555; /* default perms */ |
646 | break; |
647 | |
648 | #endif /* FDESC */ |
649 | default: |
650 | return EINVAL; |
651 | } |
652 | |
653 | *dn_pp = dnp; |
654 | DEVFS_INCR_NODES(); |
655 | return 0 ; |
656 | } |
657 | |
658 | |
659 | /*********************************************************************** |
660 | * called with DEVFS_LOCK held |
661 | **********************************************************************/ |
662 | void |
663 | devnode_free(devnode_t * dnp) |
664 | { |
665 | #if CONFIG_MACF |
666 | mac_devfs_label_destroy(dnp); |
667 | #endif |
668 | if (dnp->dn_type == DEV_SLNK) { |
669 | DEVFS_DECR_STRINGSPACE(dnp->dn_typeinfo.Slnk.namelen + 1); |
670 | FREE(dnp->dn_typeinfo.Slnk.name, M_DEVFSNODE); |
671 | } |
672 | DEVFS_DECR_NODES(); |
673 | FREE(dnp, M_DEVFSNODE); |
674 | } |
675 | |
676 | |
677 | /*********************************************************************** |
678 | * called with DEVFS_LOCK held |
679 | **********************************************************************/ |
680 | static void |
681 | devfs_dn_free(devnode_t * dnp) |
682 | { |
683 | if(--dnp->dn_links <= 0 ) /* can be -1 for initial free, on error */ |
684 | { |
685 | /*probably need to do other cleanups XXX */ |
686 | if (dnp->dn_nextsibling != dnp) { |
687 | devnode_t * * prevp = dnp->dn_prevsiblingp; |
688 | *prevp = dnp->dn_nextsibling; |
689 | dnp->dn_nextsibling->dn_prevsiblingp = prevp; |
690 | |
691 | } |
692 | |
693 | /* Can only free if there are no references; otherwise, wait for last vnode to be reclaimed */ |
694 | if (dnp->dn_refcount == 0) { |
695 | devnode_free(dnp); |
696 | } |
697 | else { |
698 | dnp->dn_lflags |= DN_DELETE; |
699 | } |
700 | } |
701 | } |
702 | |
703 | /***********************************************************************\ |
704 | * Front Node Operations * |
705 | * Add or delete a chain of front nodes * |
706 | \***********************************************************************/ |
707 | |
708 | |
709 | /*********************************************************************** |
710 | * Given a directory backing node, and a child backing node, add the |
711 | * appropriate front nodes to the front nodes of the directory to |
712 | * represent the child node to the user |
713 | * |
714 | * on failure, front nodes will either be correct or not exist for each |
715 | * front dir, however dirs completed will not be stripped of completed |
716 | * frontnodes on failure of a later frontnode |
717 | * |
718 | * This allows a new node to be propogated through all mounted planes |
719 | * |
720 | * called with DEVFS_LOCK held |
721 | ***********************************************************************/ |
722 | static int |
723 | devfs_propogate(devdirent_t * parent,devdirent_t * child, devfs_event_log_t delp) |
724 | { |
725 | int error; |
726 | devdirent_t * newnmp; |
727 | devnode_t * dnp = child->de_dnp; |
728 | devnode_t * pdnp = parent->de_dnp; |
729 | devnode_t * adnp = parent->de_dnp; |
730 | int type = child->de_dnp->dn_type; |
731 | uint32_t events; |
732 | |
733 | events = (dnp->dn_type == DEV_DIR ? VNODE_EVENT_DIR_CREATED : VNODE_EVENT_FILE_CREATED); |
734 | if (delp != NULL) { |
735 | devfs_record_event(delp, pdnp, events); |
736 | } |
737 | |
738 | /*********************************************** |
739 | * Find the other instances of the parent node |
740 | ***********************************************/ |
741 | for (adnp = pdnp->dn_nextsibling; |
742 | adnp != pdnp; |
743 | adnp = adnp->dn_nextsibling) |
744 | { |
745 | /* |
746 | * Make the node, using the original as a prototype) |
747 | * if the node already exists on that plane it won't be |
748 | * re-made.. |
749 | */ |
750 | if ((error = dev_add_entry(child->de_name, adnp, type, |
751 | NULL, dnp, adnp->dn_dvm, |
752 | &newnmp)) != 0) { |
753 | printf("duplicating %s failed\n" ,child->de_name); |
754 | } else { |
755 | if (delp != NULL) { |
756 | devfs_record_event(delp, adnp, events); |
757 | |
758 | /* |
759 | * Slightly subtle. We're guaranteed that there will |
760 | * only be a vnode hooked into this devnode if we're creating |
761 | * a new link to an existing node; otherwise, the devnode is new |
762 | * and no one can have looked it up yet. If we're making a link, |
763 | * then the buffer is large enough for two nodes in each |
764 | * plane; otherwise, there's no vnode and this call will |
765 | * do nothing. |
766 | */ |
767 | devfs_record_event(delp, newnmp->de_dnp, VNODE_EVENT_LINK); |
768 | } |
769 | } |
770 | } |
771 | return 0; /* for now always succeed */ |
772 | } |
773 | |
774 | static uint32_t |
775 | remove_notify_count(devnode_t *dnp) |
776 | { |
777 | uint32_t notify_count = 0; |
778 | devnode_t *dnp2; |
779 | |
780 | /* |
781 | * Could need to notify for one removed node on each mount and |
782 | * one parent for each such node. |
783 | */ |
784 | notify_count = devfs_nmountplanes; |
785 | notify_count += dnp->dn_links; |
786 | for (dnp2 = dnp->dn_nextsibling; dnp2 != dnp; dnp2 = dnp2->dn_nextsibling) { |
787 | notify_count += dnp2->dn_links; |
788 | } |
789 | |
790 | return notify_count; |
791 | |
792 | } |
793 | |
794 | /*********************************************************************** |
795 | * remove all instances of this devicename [for backing nodes..] |
796 | * note.. if there is another link to the node (non dir nodes only) |
797 | * then the devfs_node will still exist as the ref count will be non-0 |
798 | * removing a directory node will remove all sup-nodes on all planes (ZAP) |
799 | * |
800 | * Used by device drivers to remove nodes that are no longer relevant |
801 | * The argument is the 'cookie' they were given when they created the node |
802 | * this function is exported.. see devfs.h |
803 | ***********************************************************************/ |
804 | void |
805 | devfs_remove(void *dirent_p) |
806 | { |
807 | devnode_t * dnp = ((devdirent_t *)dirent_p)->de_dnp; |
808 | devnode_t * dnp2; |
809 | boolean_t lastlink; |
810 | struct devfs_event_log event_log; |
811 | uint32_t log_count = 0; |
812 | int do_notify = 0; |
813 | int need_free = 0; |
814 | struct devfs_vnode_event stackbuf[NUM_STACK_ENTRIES]; |
815 | |
816 | DEVFS_LOCK(); |
817 | |
818 | if (!devfs_ready) { |
819 | printf("devfs_remove: not ready for devices!\n" ); |
820 | goto out; |
821 | } |
822 | |
823 | log_count = remove_notify_count(dnp); |
824 | |
825 | if (log_count > NUM_STACK_ENTRIES) { |
826 | uint32_t new_count; |
827 | wrongsize: |
828 | DEVFS_UNLOCK(); |
829 | if (devfs_init_event_log(&event_log, log_count, NULL) == 0) { |
830 | do_notify = 1; |
831 | need_free = 1; |
832 | } |
833 | DEVFS_LOCK(); |
834 | |
835 | new_count = remove_notify_count(dnp); |
836 | if (need_free && (new_count > log_count)) { |
837 | devfs_release_event_log(&event_log, 1); |
838 | need_free = 0; |
839 | do_notify = 0; |
840 | log_count = log_count * 2; |
841 | goto wrongsize; |
842 | } |
843 | } else { |
844 | if (devfs_init_event_log(&event_log, NUM_STACK_ENTRIES, &stackbuf[0]) == 0) { |
845 | do_notify = 1; |
846 | } |
847 | } |
848 | |
849 | /* This file has been deleted */ |
850 | if (do_notify != 0) { |
851 | devfs_record_event(&event_log, dnp, VNODE_EVENT_DELETE); |
852 | } |
853 | |
854 | /* keep removing the next sibling till only we exist. */ |
855 | while ((dnp2 = dnp->dn_nextsibling) != dnp) { |
856 | |
857 | /* |
858 | * Keep removing the next front node till no more exist |
859 | */ |
860 | dnp->dn_nextsibling = dnp2->dn_nextsibling; |
861 | dnp->dn_nextsibling->dn_prevsiblingp = &(dnp->dn_nextsibling); |
862 | dnp2->dn_nextsibling = dnp2; |
863 | dnp2->dn_prevsiblingp = &(dnp2->dn_nextsibling); |
864 | |
865 | /* This file has been deleted in this plane */ |
866 | if (do_notify != 0) { |
867 | devfs_record_event(&event_log, dnp2, VNODE_EVENT_DELETE); |
868 | } |
869 | |
870 | if (dnp2->dn_linklist) { |
871 | do { |
872 | lastlink = (1 == dnp2->dn_links); |
873 | /* Each parent of a link to this file has lost a child in this plane */ |
874 | if (do_notify != 0) { |
875 | devfs_record_event(&event_log, dnp2->dn_linklist->de_parent, VNODE_EVENT_FILE_REMOVED); |
876 | } |
877 | dev_free_name(dnp2->dn_linklist); |
878 | } while (!lastlink); |
879 | } |
880 | } |
881 | |
882 | /* |
883 | * then free the main node |
884 | * If we are not running in SPLIT_DEVS mode, then |
885 | * THIS is what gets rid of the propogated nodes. |
886 | */ |
887 | if (dnp->dn_linklist) { |
888 | do { |
889 | lastlink = (1 == dnp->dn_links); |
890 | /* Each parent of a link to this file has lost a child */ |
891 | if (do_notify != 0) { |
892 | devfs_record_event(&event_log, dnp->dn_linklist->de_parent, VNODE_EVENT_FILE_REMOVED); |
893 | } |
894 | dev_free_name(dnp->dn_linklist); |
895 | } while (!lastlink); |
896 | } |
897 | out: |
898 | DEVFS_UNLOCK(); |
899 | if (do_notify != 0) { |
900 | devfs_bulk_notify(&event_log); |
901 | devfs_release_event_log(&event_log, need_free); |
902 | } |
903 | |
904 | return ; |
905 | } |
906 | |
907 | |
908 | |
909 | /*************************************************************** |
910 | * duplicate the backing tree into a tree of nodes hung off the |
911 | * mount point given as the argument. Do this by |
912 | * calling dev_dup_entry which recurses all the way |
913 | * up the tree.. |
914 | * |
915 | * called with DEVFS_LOCK held |
916 | **************************************************************/ |
917 | int |
918 | dev_dup_plane(struct devfsmount *devfs_mp_p) |
919 | { |
920 | devdirent_t * new; |
921 | int error = 0; |
922 | |
923 | if ((error = dev_dup_entry(NULL, dev_root, &new, devfs_mp_p))) |
924 | return error; |
925 | devfs_mp_p->plane_root = new; |
926 | devfs_nmountplanes++; |
927 | return error; |
928 | } |
929 | |
930 | |
931 | |
932 | /*************************************************************** |
933 | * Free a whole plane |
934 | * |
935 | * called with DEVFS_LOCK held |
936 | ***************************************************************/ |
937 | void |
938 | devfs_free_plane(struct devfsmount *devfs_mp_p) |
939 | { |
940 | devdirent_t * dirent_p; |
941 | |
942 | dirent_p = devfs_mp_p->plane_root; |
943 | if (dirent_p) { |
944 | dev_free_hier(dirent_p); |
945 | dev_free_name(dirent_p); |
946 | } |
947 | devfs_mp_p->plane_root = NULL; |
948 | devfs_nmountplanes--; |
949 | |
950 | if (devfs_nmountplanes > (devfs_nmountplanes+1)) { |
951 | panic("plane count wrapped around.\n" ); |
952 | } |
953 | } |
954 | |
955 | |
956 | /*************************************************************** |
957 | * Create and link in a new front element.. |
958 | * Parent can be 0 for a root node |
959 | * Not presently usable to make a symlink XXX |
960 | * (Ok, symlinks don't propogate) |
961 | * recursively will create subnodes corresponding to equivalent |
962 | * child nodes in the base level |
963 | * |
964 | * called with DEVFS_LOCK held |
965 | ***************************************************************/ |
966 | static int |
967 | dev_dup_entry(devnode_t * parent, devdirent_t * back, devdirent_t * *dnm_pp, |
968 | struct devfsmount *dvm) |
969 | { |
970 | devdirent_t * entry_p = NULL; |
971 | devdirent_t * newback; |
972 | devdirent_t * newfront; |
973 | int error; |
974 | devnode_t * dnp = back->de_dnp; |
975 | int type = dnp->dn_type; |
976 | |
977 | /* |
978 | * go get the node made (if we need to) |
979 | * use the back one as a prototype |
980 | */ |
981 | error = dev_add_entry(back->de_name, parent, type, NULL, dnp, |
982 | parent?parent->dn_dvm:dvm, &entry_p); |
983 | if (!error && (entry_p == NULL)) { |
984 | error = ENOMEM; /* Really can't happen, but make static analyzer happy */ |
985 | } |
986 | if (error != 0) { |
987 | printf("duplicating %s failed\n" ,back->de_name); |
988 | goto out; |
989 | } |
990 | |
991 | /* |
992 | * If we have just made the root, then insert the pointer to the |
993 | * mount information |
994 | */ |
995 | if(dvm) { |
996 | entry_p->de_dnp->dn_dvm = dvm; |
997 | } |
998 | |
999 | /* |
1000 | * If it is a directory, then recurse down all the other |
1001 | * subnodes in it.... |
1002 | * note that this time we don't pass on the mount info.. |
1003 | */ |
1004 | if (type == DEV_DIR) |
1005 | { |
1006 | for(newback = back->de_dnp->dn_typeinfo.Dir.dirlist; |
1007 | newback; newback = newback->de_next) |
1008 | { |
1009 | if((error = dev_dup_entry(entry_p->de_dnp, |
1010 | newback, &newfront, NULL)) != 0) |
1011 | { |
1012 | break; /* back out with an error */ |
1013 | } |
1014 | } |
1015 | } |
1016 | out: |
1017 | *dnm_pp = entry_p; |
1018 | return error; |
1019 | } |
1020 | |
1021 | |
1022 | /*************************************************************** |
1023 | * Free a name node |
1024 | * remember that if there are other names pointing to the |
1025 | * dev_node then it may not get freed yet |
1026 | * can handle if there is no dnp |
1027 | * |
1028 | * called with DEVFS_LOCK held |
1029 | ***************************************************************/ |
1030 | |
1031 | int |
1032 | dev_free_name(devdirent_t * dirent_p) |
1033 | { |
1034 | devnode_t * parent = dirent_p->de_parent; |
1035 | devnode_t * dnp = dirent_p->de_dnp; |
1036 | |
1037 | if(dnp) { |
1038 | if(dnp->dn_type == DEV_DIR) |
1039 | { |
1040 | devnode_t * p; |
1041 | |
1042 | if(dnp->dn_typeinfo.Dir.dirlist) |
1043 | return (ENOTEMPTY); |
1044 | p = dnp->dn_typeinfo.Dir.parent; |
1045 | devfs_dn_free(dnp); /* account for '.' */ |
1046 | devfs_dn_free(p); /* '..' */ |
1047 | } |
1048 | /* |
1049 | * unlink us from the list of links for this node |
1050 | * If we are the only link, it's easy! |
1051 | * if we are a DIR of course there should not be any |
1052 | * other links. |
1053 | */ |
1054 | if(dirent_p->de_nextlink == dirent_p) { |
1055 | dnp->dn_linklist = NULL; |
1056 | } else { |
1057 | if(dnp->dn_linklist == dirent_p) { |
1058 | dnp->dn_linklist = dirent_p->de_nextlink; |
1059 | } |
1060 | } |
1061 | devfs_dn_free(dnp); |
1062 | } |
1063 | |
1064 | dirent_p->de_nextlink->de_prevlinkp = dirent_p->de_prevlinkp; |
1065 | *(dirent_p->de_prevlinkp) = dirent_p->de_nextlink; |
1066 | |
1067 | /* |
1068 | * unlink ourselves from the directory on this plane |
1069 | */ |
1070 | if(parent) /* if not fs root */ |
1071 | { |
1072 | if( (*dirent_p->de_prevp = dirent_p->de_next) )/* yes, assign */ |
1073 | { |
1074 | dirent_p->de_next->de_prevp = dirent_p->de_prevp; |
1075 | } |
1076 | else |
1077 | { |
1078 | parent->dn_typeinfo.Dir.dirlast |
1079 | = dirent_p->de_prevp; |
1080 | } |
1081 | parent->dn_typeinfo.Dir.entrycount--; |
1082 | parent->dn_len -= strlen(dirent_p->de_name) + 8; |
1083 | } |
1084 | |
1085 | DEVFS_DECR_ENTRIES(); |
1086 | FREE(dirent_p, M_DEVFSNAME); |
1087 | return 0; |
1088 | } |
1089 | |
1090 | |
1091 | /*************************************************************** |
1092 | * Free a hierarchy starting at a directory node name |
1093 | * remember that if there are other names pointing to the |
1094 | * dev_node then it may not get freed yet |
1095 | * can handle if there is no dnp |
1096 | * leave the node itself allocated. |
1097 | * |
1098 | * called with DEVFS_LOCK held |
1099 | ***************************************************************/ |
1100 | |
1101 | static void |
1102 | dev_free_hier(devdirent_t * dirent_p) |
1103 | { |
1104 | devnode_t * dnp = dirent_p->de_dnp; |
1105 | |
1106 | if(dnp) { |
1107 | if(dnp->dn_type == DEV_DIR) |
1108 | { |
1109 | while(dnp->dn_typeinfo.Dir.dirlist) |
1110 | { |
1111 | dev_free_hier(dnp->dn_typeinfo.Dir.dirlist); |
1112 | dev_free_name(dnp->dn_typeinfo.Dir.dirlist); |
1113 | } |
1114 | } |
1115 | } |
1116 | } |
1117 | |
1118 | |
1119 | /*************************************************************** |
1120 | * given a dev_node, find the appropriate vnode if one is already |
1121 | * associated, or get a new one and associate it with the dev_node |
1122 | * |
1123 | * called with DEVFS_LOCK held |
1124 | * |
1125 | * If an error is returned, then the dnp may have been freed (we |
1126 | * raced with a delete and lost). A devnode should not be accessed |
1127 | * after devfs_dntovn() fails. |
1128 | ****************************************************************/ |
1129 | int |
1130 | devfs_dntovn(devnode_t * dnp, struct vnode **vn_pp, __unused struct proc * p) |
1131 | { |
1132 | struct vnode *vn_p; |
1133 | int error = 0; |
1134 | struct vnode_fsparam vfsp; |
1135 | enum vtype vtype = 0; |
1136 | int markroot = 0; |
1137 | int nretries = 0; |
1138 | int n_minor = DEVFS_CLONE_ALLOC; /* new minor number for clone device */ |
1139 | |
1140 | /* |
1141 | * We should never come in and find that our devnode has been marked for delete. |
1142 | * The lookup should have held the lock from entry until now; it should not have |
1143 | * been able to find a removed entry. Any other pathway would have just created |
1144 | * the devnode and come here without dropping the devfs lock, so no one would |
1145 | * have a chance to delete. |
1146 | */ |
1147 | if (dnp->dn_lflags & DN_DELETE) { |
1148 | panic("devfs_dntovn: DN_DELETE set on a devnode upon entry." ); |
1149 | } |
1150 | |
1151 | devfs_ref_node(dnp); |
1152 | |
1153 | retry: |
1154 | *vn_pp = NULL; |
1155 | vn_p = dnp->dn_vn; |
1156 | |
1157 | if (vn_p) { /* already has a vnode */ |
1158 | uint32_t vid; |
1159 | |
1160 | vid = vnode_vid(vn_p); |
1161 | |
1162 | DEVFS_UNLOCK(); |
1163 | |
1164 | /* |
1165 | * We want to use the drainok variant of vnode_getwithvid |
1166 | * because we _don't_ want to get an iocount if the vnode is |
1167 | * is blocked in vnode_drain as it can cause infinite |
1168 | * loops in vn_open_auth. While in use vnodes are typically |
1169 | * only reclaimed on forced unmounts, In use devfs tty vnodes |
1170 | * can be quite frequently reclaimed by revoke(2) or by the |
1171 | * exit of a controlling process. |
1172 | */ |
1173 | error = vnode_getwithvid_drainok(vn_p, vid); |
1174 | |
1175 | DEVFS_LOCK(); |
1176 | |
1177 | if (dnp->dn_lflags & DN_DELETE) { |
1178 | /* |
1179 | * our BUSY node got marked for |
1180 | * deletion while the DEVFS lock |
1181 | * was dropped... |
1182 | */ |
1183 | if (error == 0) { |
1184 | /* |
1185 | * vnode_getwithvid returned a valid ref |
1186 | * which we need to drop |
1187 | */ |
1188 | vnode_put(vn_p); |
1189 | } |
1190 | |
1191 | /* |
1192 | * This entry is no longer in the namespace. This is only |
1193 | * possible for lookup: no other path would not find an existing |
1194 | * vnode. Therefore, ENOENT is a valid result. |
1195 | */ |
1196 | error = ENOENT; |
1197 | } else if (error == ENODEV) { |
1198 | /* |
1199 | * The Filesystem is getting unmounted. |
1200 | */ |
1201 | error = ENOENT; |
1202 | } else if (error && (nretries < DEV_MAX_VNODE_RETRY)) { |
1203 | /* |
1204 | * If we got an error from vnode_getwithvid, it means |
1205 | * we raced with a recycle and lost i.e. we asked for |
1206 | * an iocount only after vnode_drain had been entered |
1207 | * for the vnode and returned with an error only after |
1208 | * devfs_reclaim was called on the vnode. devfs_reclaim |
1209 | * sets dn_vn to NULL but while we were waiting to |
1210 | * reacquire DEVFS_LOCK, another vnode might have gotten |
1211 | * associated with the dnp. In either case, we need to |
1212 | * retry otherwise we will end up returning an ENOENT |
1213 | * for this lookup but the next lookup will succeed |
1214 | * because it creates a new vnode (or a racing lookup |
1215 | * created a new vnode already). |
1216 | */ |
1217 | error = 0; |
1218 | nretries++; |
1219 | goto retry; |
1220 | } |
1221 | if ( !error) |
1222 | *vn_pp = vn_p; |
1223 | |
1224 | goto out; |
1225 | } |
1226 | |
1227 | /* |
1228 | * If we get here, then we've beaten any deletes; |
1229 | * if someone sets DN_DELETE during a subsequent drop |
1230 | * of the devfs lock, we'll still vend a vnode. |
1231 | */ |
1232 | |
1233 | if (dnp->dn_lflags & DN_CREATE) { |
1234 | dnp->dn_lflags |= DN_CREATEWAIT; |
1235 | msleep(&dnp->dn_lflags, &devfs_mutex, PRIBIO, 0 , 0); |
1236 | goto retry; |
1237 | } |
1238 | |
1239 | dnp->dn_lflags |= DN_CREATE; |
1240 | |
1241 | switch (dnp->dn_type) { |
1242 | case DEV_SLNK: |
1243 | vtype = VLNK; |
1244 | break; |
1245 | case DEV_DIR: |
1246 | if (dnp->dn_typeinfo.Dir.parent == dnp) { |
1247 | markroot = 1; |
1248 | } |
1249 | vtype = VDIR; |
1250 | break; |
1251 | case DEV_BDEV: |
1252 | case DEV_CDEV: |
1253 | vtype = (dnp->dn_type == DEV_BDEV) ? VBLK : VCHR; |
1254 | break; |
1255 | #if FDESC |
1256 | case DEV_DEVFD: |
1257 | vtype = VDIR; |
1258 | break; |
1259 | #endif /* FDESC */ |
1260 | } |
1261 | vfsp.vnfs_mp = dnp->dn_dvm->mount; |
1262 | vfsp.vnfs_vtype = vtype; |
1263 | vfsp.vnfs_str = "devfs" ; |
1264 | vfsp.vnfs_dvp = 0; |
1265 | vfsp.vnfs_fsnode = dnp; |
1266 | vfsp.vnfs_cnp = 0; |
1267 | vfsp.vnfs_vops = *(dnp->dn_ops); |
1268 | |
1269 | if (vtype == VBLK || vtype == VCHR) { |
1270 | /* |
1271 | * Ask the clone minor number function for a new minor number |
1272 | * to use for the next device instance. If an administative |
1273 | * limit has been reached, this function will return -1. |
1274 | */ |
1275 | if (dnp->dn_clone != NULL) { |
1276 | int n_major = major(dnp->dn_typeinfo.dev); |
1277 | |
1278 | n_minor = (*dnp->dn_clone)(dnp->dn_typeinfo.dev, DEVFS_CLONE_ALLOC); |
1279 | if (n_minor == -1) { |
1280 | error = ENOMEM; |
1281 | goto out; |
1282 | } |
1283 | |
1284 | vfsp.vnfs_rdev = makedev(n_major, n_minor);; |
1285 | } else { |
1286 | vfsp.vnfs_rdev = dnp->dn_typeinfo.dev; |
1287 | } |
1288 | } else { |
1289 | vfsp.vnfs_rdev = 0; |
1290 | } |
1291 | vfsp.vnfs_filesize = 0; |
1292 | vfsp.vnfs_flags = VNFS_NOCACHE | VNFS_CANTCACHE; |
1293 | /* Tag system files */ |
1294 | vfsp.vnfs_marksystem = 0; |
1295 | vfsp.vnfs_markroot = markroot; |
1296 | |
1297 | DEVFS_UNLOCK(); |
1298 | |
1299 | error = vnode_create(VNCREATE_FLAVOR, VCREATESIZE, &vfsp, &vn_p); |
1300 | |
1301 | /* Do this before grabbing the lock */ |
1302 | if (error == 0) { |
1303 | vnode_setneedinactive(vn_p); |
1304 | } |
1305 | |
1306 | DEVFS_LOCK(); |
1307 | |
1308 | if (error == 0) { |
1309 | vnode_settag(vn_p, VT_DEVFS); |
1310 | |
1311 | if ((dnp->dn_clone != NULL) && (dnp->dn_vn != NULLVP) ) |
1312 | panic("devfs_dntovn: cloning device with a vnode?\n" ); |
1313 | |
1314 | *vn_pp = vn_p; |
1315 | |
1316 | /* |
1317 | * Another vnode that has this devnode as its v_data. |
1318 | * This reference, unlike the one taken at the start |
1319 | * of the function, persists until a VNOP_RECLAIM |
1320 | * comes through for this vnode. |
1321 | */ |
1322 | devfs_ref_node(dnp); |
1323 | |
1324 | /* |
1325 | * A cloned vnode is not hooked into the devnode; every lookup |
1326 | * gets a new vnode. |
1327 | */ |
1328 | if (dnp->dn_clone == NULL) { |
1329 | dnp->dn_vn = vn_p; |
1330 | } |
1331 | } else if (n_minor != DEVFS_CLONE_ALLOC) { |
1332 | /* |
1333 | * If we failed the create, we need to release the cloned minor |
1334 | * back to the free list. In general, this is only useful if |
1335 | * the clone function results in a state change in the cloned |
1336 | * device for which the minor number was obtained. If we get |
1337 | * past this point withouth falling into this case, it's |
1338 | * assumed that any state to be released will be released when |
1339 | * the vnode is dropped, instead. |
1340 | */ |
1341 | (void)(*dnp->dn_clone)(dnp->dn_typeinfo.dev, DEVFS_CLONE_FREE); |
1342 | } |
1343 | |
1344 | dnp->dn_lflags &= ~DN_CREATE; |
1345 | if (dnp->dn_lflags & DN_CREATEWAIT) { |
1346 | dnp->dn_lflags &= ~DN_CREATEWAIT; |
1347 | wakeup(&dnp->dn_lflags); |
1348 | } |
1349 | |
1350 | out: |
1351 | /* |
1352 | * Release the reference we took to prevent deletion while we weren't holding the lock. |
1353 | * If not returning success, then dropping this reference could delete the devnode; |
1354 | * no one should access a devnode after a call to devfs_dntovn fails. |
1355 | */ |
1356 | devfs_rele_node(dnp); |
1357 | |
1358 | return error; |
1359 | } |
1360 | |
1361 | /* |
1362 | * Increment refcount on a devnode; prevents free of the node |
1363 | * while the devfs lock is not held. |
1364 | */ |
1365 | void |
1366 | devfs_ref_node(devnode_t *dnp) |
1367 | { |
1368 | dnp->dn_refcount++; |
1369 | } |
1370 | |
1371 | /* |
1372 | * Release a reference on a devnode. If the devnode is marked for |
1373 | * free and the refcount is dropped to zero, do the free. |
1374 | */ |
1375 | void |
1376 | devfs_rele_node(devnode_t *dnp) |
1377 | { |
1378 | dnp->dn_refcount--; |
1379 | if (dnp->dn_refcount < 0) { |
1380 | panic("devfs_rele_node: devnode with a negative refcount!\n" ); |
1381 | } else if ((dnp->dn_refcount == 0) && (dnp->dn_lflags & DN_DELETE)) { |
1382 | devnode_free(dnp); |
1383 | } |
1384 | |
1385 | } |
1386 | |
1387 | /*********************************************************************** |
1388 | * add a whole device, with no prototype.. make name element and node |
1389 | * Used for adding the original device entries |
1390 | * |
1391 | * called with DEVFS_LOCK held |
1392 | ***********************************************************************/ |
1393 | int |
1394 | dev_add_entry(const char *name, devnode_t * parent, int type, devnode_type_t * typeinfo, |
1395 | devnode_t * proto, struct devfsmount *dvm, devdirent_t * *nm_pp) |
1396 | { |
1397 | devnode_t * dnp; |
1398 | int error = 0; |
1399 | |
1400 | if ((error = dev_add_node(type, typeinfo, proto, &dnp, |
1401 | (parent?parent->dn_dvm:dvm))) != 0) |
1402 | { |
1403 | printf("devfs: %s: base node allocation failed (Errno=%d)\n" , |
1404 | name,error); |
1405 | return error; |
1406 | } |
1407 | if ((error = dev_add_name(name ,parent ,NULL, dnp, nm_pp)) != 0) |
1408 | { |
1409 | devfs_dn_free(dnp); /* 1->0 for dir, 0->(-1) for other */ |
1410 | printf("devfs: %s: name slot allocation failed (Errno=%d)\n" , |
1411 | name,error); |
1412 | |
1413 | } |
1414 | return error; |
1415 | } |
1416 | |
1417 | static void |
1418 | devfs_bulk_notify(devfs_event_log_t delp) |
1419 | { |
1420 | uint32_t i; |
1421 | for (i = 0; i < delp->del_used; i++) { |
1422 | devfs_vnode_event_t dvep = &delp->del_entries[i]; |
1423 | if (vnode_getwithvid(dvep->dve_vp, dvep->dve_vid) == 0) { |
1424 | vnode_notify(dvep->dve_vp, dvep->dve_events, NULL); |
1425 | vnode_put(dvep->dve_vp); |
1426 | } |
1427 | } |
1428 | } |
1429 | |
1430 | static void |
1431 | devfs_record_event(devfs_event_log_t delp, devnode_t *dnp, uint32_t events) |
1432 | { |
1433 | if (delp->del_used >= delp->del_max) { |
1434 | panic("devfs event log overflowed.\n" ); |
1435 | } |
1436 | |
1437 | /* Can only notify for nodes that have an associated vnode */ |
1438 | if (dnp->dn_vn != NULLVP && vnode_ismonitored(dnp->dn_vn)) { |
1439 | devfs_vnode_event_t dvep = &delp->del_entries[delp->del_used]; |
1440 | dvep->dve_vp = dnp->dn_vn; |
1441 | dvep->dve_vid = vnode_vid(dnp->dn_vn); |
1442 | dvep->dve_events = events; |
1443 | delp->del_used++; |
1444 | } |
1445 | } |
1446 | |
1447 | static int |
1448 | devfs_init_event_log(devfs_event_log_t delp, uint32_t count, devfs_vnode_event_t buf) |
1449 | { |
1450 | devfs_vnode_event_t dvearr; |
1451 | |
1452 | if (buf == NULL) { |
1453 | MALLOC(dvearr, devfs_vnode_event_t, count * sizeof(struct devfs_vnode_event), M_TEMP, M_WAITOK | M_ZERO); |
1454 | if (dvearr == NULL) { |
1455 | return ENOMEM; |
1456 | } |
1457 | } else { |
1458 | dvearr = buf; |
1459 | } |
1460 | |
1461 | delp->del_max = count; |
1462 | delp->del_used = 0; |
1463 | delp->del_entries = dvearr; |
1464 | return 0; |
1465 | } |
1466 | |
1467 | static void |
1468 | devfs_release_event_log(devfs_event_log_t delp, int need_free) |
1469 | { |
1470 | if (delp->del_entries == NULL) { |
1471 | panic("Free of devfs notify info that has not been intialized.\n" ); |
1472 | } |
1473 | |
1474 | if (need_free) { |
1475 | FREE(delp->del_entries, M_TEMP); |
1476 | } |
1477 | |
1478 | delp->del_entries = NULL; |
1479 | } |
1480 | |
1481 | /* |
1482 | * Function: devfs_make_node |
1483 | * |
1484 | * Purpose |
1485 | * Create a device node with the given pathname in the devfs namespace. |
1486 | * |
1487 | * Parameters: |
1488 | * dev - the dev_t value to associate |
1489 | * chrblk - block or character device (DEVFS_CHAR or DEVFS_BLOCK) |
1490 | * uid, gid - ownership |
1491 | * perms - permissions |
1492 | * clone - minor number cloning function |
1493 | * fmt, ... - path format string with printf args to format the path name |
1494 | * Returns: |
1495 | * A handle to a device node if successful, NULL otherwise. |
1496 | */ |
1497 | void * |
1498 | devfs_make_node_clone(dev_t dev, int chrblk, uid_t uid, |
1499 | gid_t gid, int perms, int (*clone)(dev_t dev, int action), |
1500 | const char *fmt, ...) |
1501 | { |
1502 | devdirent_t * new_dev = NULL; |
1503 | devfstype_t type; |
1504 | va_list ap; |
1505 | |
1506 | switch (chrblk) { |
1507 | case DEVFS_CHAR: |
1508 | type = DEV_CDEV; |
1509 | break; |
1510 | case DEVFS_BLOCK: |
1511 | type = DEV_BDEV; |
1512 | break; |
1513 | default: |
1514 | goto out; |
1515 | } |
1516 | |
1517 | va_start(ap, fmt); |
1518 | new_dev = devfs_make_node_internal(dev, type, uid, gid, perms, clone, fmt, ap); |
1519 | va_end(ap); |
1520 | out: |
1521 | return new_dev; |
1522 | } |
1523 | |
1524 | |
1525 | /* |
1526 | * Function: devfs_make_node |
1527 | * |
1528 | * Purpose |
1529 | * Create a device node with the given pathname in the devfs namespace. |
1530 | * |
1531 | * Parameters: |
1532 | * dev - the dev_t value to associate |
1533 | * chrblk - block or character device (DEVFS_CHAR or DEVFS_BLOCK) |
1534 | * uid, gid - ownership |
1535 | * perms - permissions |
1536 | * fmt, ... - path format string with printf args to format the path name |
1537 | * Returns: |
1538 | * A handle to a device node if successful, NULL otherwise. |
1539 | */ |
1540 | void * |
1541 | devfs_make_node(dev_t dev, int chrblk, uid_t uid, |
1542 | gid_t gid, int perms, const char *fmt, ...) |
1543 | { |
1544 | devdirent_t * new_dev = NULL; |
1545 | devfstype_t type; |
1546 | va_list ap; |
1547 | |
1548 | if (chrblk != DEVFS_CHAR && chrblk != DEVFS_BLOCK) |
1549 | goto out; |
1550 | |
1551 | type = (chrblk == DEVFS_BLOCK ? DEV_BDEV : DEV_CDEV); |
1552 | |
1553 | va_start(ap, fmt); |
1554 | new_dev = devfs_make_node_internal(dev, type, uid, gid, perms, NULL, fmt, ap); |
1555 | va_end(ap); |
1556 | |
1557 | out: |
1558 | return new_dev; |
1559 | } |
1560 | |
1561 | static devdirent_t * |
1562 | devfs_make_node_internal(dev_t dev, devfstype_t type, uid_t uid, |
1563 | gid_t gid, int perms, int (*clone)(dev_t dev, int action), const char *fmt, va_list ap) |
1564 | { |
1565 | devdirent_t * new_dev = NULL; |
1566 | devnode_t * dnp; |
1567 | devnode_type_t typeinfo; |
1568 | |
1569 | char *name, buf[256]; /* XXX */ |
1570 | const char *path; |
1571 | #if CONFIG_MACF |
1572 | char buff[sizeof(buf)]; |
1573 | #endif |
1574 | int i; |
1575 | uint32_t log_count; |
1576 | struct devfs_event_log event_log; |
1577 | struct devfs_vnode_event stackbuf[NUM_STACK_ENTRIES]; |
1578 | int need_free = 0; |
1579 | |
1580 | vsnprintf(buf, sizeof(buf), fmt, ap); |
1581 | |
1582 | #if CONFIG_MACF |
1583 | bcopy(buf, buff, sizeof(buff)); |
1584 | buff[sizeof(buff)-1] = 0; |
1585 | #endif |
1586 | name = NULL; |
1587 | |
1588 | for(i=strlen(buf); i>0; i--) |
1589 | if(buf[i] == '/') { |
1590 | name=&buf[i]; |
1591 | buf[i]=0; |
1592 | break; |
1593 | } |
1594 | |
1595 | if (name) { |
1596 | *name++ = '\0'; |
1597 | path = buf; |
1598 | } else { |
1599 | name = buf; |
1600 | path = "/" ; |
1601 | } |
1602 | |
1603 | log_count = devfs_nmountplanes; |
1604 | if (log_count > NUM_STACK_ENTRIES) { |
1605 | wrongsize: |
1606 | need_free = 1; |
1607 | if (devfs_init_event_log(&event_log, log_count, NULL) != 0) { |
1608 | return NULL; |
1609 | } |
1610 | } else { |
1611 | need_free = 0; |
1612 | log_count = NUM_STACK_ENTRIES; |
1613 | if (devfs_init_event_log(&event_log, log_count, &stackbuf[0]) != 0) { |
1614 | return NULL; |
1615 | } |
1616 | } |
1617 | |
1618 | DEVFS_LOCK(); |
1619 | if (log_count < devfs_nmountplanes) { |
1620 | DEVFS_UNLOCK(); |
1621 | devfs_release_event_log(&event_log, need_free); |
1622 | log_count = log_count * 2; |
1623 | goto wrongsize; |
1624 | } |
1625 | |
1626 | if (!devfs_ready) { |
1627 | printf("devfs_make_node: not ready for devices!\n" ); |
1628 | goto out; |
1629 | } |
1630 | |
1631 | /* find/create directory path ie. mkdir -p */ |
1632 | if (dev_finddir(path, NULL, DEVFS_CREATE, &dnp, &event_log) == 0) { |
1633 | typeinfo.dev = dev; |
1634 | if (dev_add_entry(name, dnp, type, &typeinfo, NULL, NULL, &new_dev) == 0) { |
1635 | new_dev->de_dnp->dn_gid = gid; |
1636 | new_dev->de_dnp->dn_uid = uid; |
1637 | new_dev->de_dnp->dn_mode |= perms; |
1638 | new_dev->de_dnp->dn_clone = clone; |
1639 | #if CONFIG_MACF |
1640 | mac_devfs_label_associate_device(dev, new_dev->de_dnp, buff); |
1641 | #endif |
1642 | devfs_propogate(dnp->dn_typeinfo.Dir.myname, new_dev, &event_log); |
1643 | } |
1644 | } |
1645 | |
1646 | out: |
1647 | DEVFS_UNLOCK(); |
1648 | |
1649 | devfs_bulk_notify(&event_log); |
1650 | devfs_release_event_log(&event_log, need_free); |
1651 | return new_dev; |
1652 | } |
1653 | |
1654 | /* |
1655 | * Function: devfs_make_link |
1656 | * |
1657 | * Purpose: |
1658 | * Create a link to a previously created device node. |
1659 | * |
1660 | * Returns: |
1661 | * 0 if successful, -1 if failed |
1662 | */ |
1663 | int |
1664 | devfs_make_link(void *original, char *fmt, ...) |
1665 | { |
1666 | devdirent_t * new_dev = NULL; |
1667 | devdirent_t * orig = (devdirent_t *) original; |
1668 | devnode_t * dirnode; /* devnode for parent directory */ |
1669 | struct devfs_event_log event_log; |
1670 | uint32_t log_count; |
1671 | |
1672 | va_list ap; |
1673 | char *p, buf[256]; /* XXX */ |
1674 | int i; |
1675 | |
1676 | DEVFS_LOCK(); |
1677 | |
1678 | if (!devfs_ready) { |
1679 | DEVFS_UNLOCK(); |
1680 | printf("devfs_make_link: not ready for devices!\n" ); |
1681 | return -1; |
1682 | } |
1683 | DEVFS_UNLOCK(); |
1684 | |
1685 | va_start(ap, fmt); |
1686 | vsnprintf(buf, sizeof(buf), fmt, ap); |
1687 | va_end(ap); |
1688 | |
1689 | p = NULL; |
1690 | |
1691 | for(i=strlen(buf); i>0; i--) { |
1692 | if(buf[i] == '/') { |
1693 | p=&buf[i]; |
1694 | buf[i]=0; |
1695 | break; |
1696 | } |
1697 | } |
1698 | |
1699 | /* |
1700 | * One slot for each directory, one for each devnode |
1701 | * whose link count changes |
1702 | */ |
1703 | log_count = devfs_nmountplanes * 2; |
1704 | wrongsize: |
1705 | if (devfs_init_event_log(&event_log, log_count, NULL) != 0) { |
1706 | /* No lock held, no allocations done, can just return */ |
1707 | return -1; |
1708 | } |
1709 | |
1710 | DEVFS_LOCK(); |
1711 | |
1712 | if (log_count < devfs_nmountplanes) { |
1713 | DEVFS_UNLOCK(); |
1714 | devfs_release_event_log(&event_log, 1); |
1715 | log_count = log_count * 2; |
1716 | goto wrongsize; |
1717 | } |
1718 | |
1719 | if (p) { |
1720 | *p++ = '\0'; |
1721 | |
1722 | if (dev_finddir(buf, NULL, DEVFS_CREATE, &dirnode, &event_log) |
1723 | || dev_add_name(p, dirnode, NULL, orig->de_dnp, &new_dev)) |
1724 | goto fail; |
1725 | } else { |
1726 | if (dev_finddir("" , NULL, DEVFS_CREATE, &dirnode, &event_log) |
1727 | || dev_add_name(buf, dirnode, NULL, orig->de_dnp, &new_dev)) |
1728 | goto fail; |
1729 | } |
1730 | devfs_propogate(dirnode->dn_typeinfo.Dir.myname, new_dev, &event_log); |
1731 | fail: |
1732 | DEVFS_UNLOCK(); |
1733 | devfs_bulk_notify(&event_log); |
1734 | devfs_release_event_log(&event_log, 1); |
1735 | |
1736 | return ((new_dev != NULL) ? 0 : -1); |
1737 | } |
1738 | |