xref: /titanic_41/usr/src/uts/common/fs/dev/sdev_comm.c (revision 26fd77009b17f8c8fb32eb362584cfd635e87ad9)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  * routines to invoke user level name lookup services
28  */
29 
30 #include <sys/types.h>
31 #include <sys/param.h>
32 #include <sys/t_lock.h>
33 #include <sys/systm.h>
34 #include <sys/sysmacros.h>
35 #include <sys/user.h>
36 #include <sys/time.h>
37 #include <sys/vfs.h>
38 #include <sys/vnode.h>
39 #include <sys/file.h>
40 #include <sys/fcntl.h>
41 #include <sys/flock.h>
42 #include <sys/kmem.h>
43 #include <sys/uio.h>
44 #include <sys/errno.h>
45 #include <sys/stat.h>
46 #include <sys/cred.h>
47 #include <sys/dirent.h>
48 #include <sys/pathname.h>
49 #include <sys/cmn_err.h>
50 #include <sys/debug.h>
51 #include <sys/mode.h>
52 #include <sys/policy.h>
53 #include <sys/disp.h>
54 #include <sys/door.h>
55 #include <fs/fs_subr.h>
56 #include <sys/mount.h>
57 #include <sys/fs/snode.h>
58 #include <sys/fs/dv_node.h>
59 #include <sys/fs/sdev_impl.h>
60 #include <sys/sunndi.h>
61 #include <sys/sunddi.h>
62 #include <sys/sunmdi.h>
63 #include <sys/conf.h>
64 #include <sys/modctl.h>
65 #include <sys/ddi.h>
66 
67 /* default timeout to wait for devfsadm response in seconds */
68 #define	DEV_DEVFSADM_STARTUP	(1 * 60)
69 #define	DEV_NODE_WAIT_TIMEOUT	(5 * 60)
70 
71 /* atomic bitset for devfsadm status */
72 volatile uint_t devfsadm_state;
73 
74 static kmutex_t devfsadm_lock;
75 static kcondvar_t devfsadm_cv;
76 
77 static int dev_node_wait_timeout = DEV_NODE_WAIT_TIMEOUT;
78 static int dev_devfsadm_startup =  DEV_DEVFSADM_STARTUP;
79 
80 /*
81  * Door used to communicate with devfsadmd
82  */
83 static door_handle_t	sdev_upcall_door = NULL;	/* Door for upcalls */
84 static char		*sdev_door_upcall_filename = NULL;
85 static int		sdev_upcall_door_revoked = 0;
86 static int		sdev_door_upcall_filename_size;
87 
88 static int sdev_devfsadm_revoked(void);
89 static int sdev_ki_call_devfsadmd(sdev_door_arg_t *, sdev_door_res_t *);
90 
91 void
92 sdev_devfsadm_lockinit(void)
93 {
94 	mutex_init(&devfsadm_lock, NULL, MUTEX_DEFAULT, NULL);
95 	cv_init(&devfsadm_cv, NULL, CV_DEFAULT, NULL);
96 }
97 
98 void
99 sdev_devfsadm_lockdestroy(void)
100 {
101 	mutex_destroy(&devfsadm_lock);
102 	cv_destroy(&devfsadm_cv);
103 }
104 
105 /*
106  * Wait for node to be created
107  */
108 int
109 sdev_wait4lookup(struct sdev_node *dv, int cmd)
110 {
111 	clock_t	expire;
112 	clock_t rv;
113 	int rval = ENOENT;
114 	int is_lookup = (cmd == SDEV_LOOKUP);
115 
116 	ASSERT(cmd == SDEV_LOOKUP || cmd == SDEV_READDIR);
117 	ASSERT(MUTEX_HELD(&dv->sdev_lookup_lock));
118 
119 	/* tick value at which wait expires */
120 	expire = ddi_get_lbolt() +
121 	    drv_usectohz(dev_node_wait_timeout * 1000000);
122 
123 	sdcmn_err6(("wait4lookup %s %s, %ld %d\n",
124 	    is_lookup ? "lookup" : "readdir",
125 	    dv->sdev_name, expire - ddi_get_lbolt(), dv->sdev_state));
126 
127 	if (SDEV_IS_LGWAITING(dv)) {
128 		/* devfsadm nodes */
129 		while (DEVNAME_DEVFSADM_IS_RUNNING(devfsadm_state) &&
130 		    !sdev_devfsadm_revoked()) {
131 			/* wait 2 sec and check devfsadm completion */
132 			rv = cv_timedwait_sig(&dv->sdev_lookup_cv,
133 			    &dv->sdev_lookup_lock, ddi_get_lbolt() +
134 			    drv_usectohz(2 * 1000000));
135 
136 			if (is_lookup && (rv > 0)) {
137 				/* was this node constructed ? */
138 				if (dv->sdev_state == SDEV_READY) {
139 					rval = 0;
140 				}
141 				sdcmn_err6(("%s: wait done, %screated %d\n",
142 				    dv->sdev_name, rval ? "not " : "",
143 				    dv->sdev_state));
144 				break;
145 			} else if (rv == 0) {
146 				/* interrupted */
147 				sdcmn_err6(("%s: wait interrupted\n",
148 				    dv->sdev_name));
149 				break;
150 			} else if ((rv == -1) &&
151 			    (ddi_get_lbolt() >= expire)) {
152 				sdcmn_err6(("%s: wait time is up\n",
153 				    dv->sdev_name));
154 				break;
155 			}
156 			sdcmn_err6(("%s: wait "
157 			    "rv %ld state 0x%x expire %ld\n",
158 			    dv->sdev_name, rv, devfsadm_state,
159 			    expire - ddi_get_lbolt()));
160 		}
161 	} else {
162 		/*
163 		 * for the nodes created by
164 		 * devname_lookup_func callback
165 		 * or plug-in modules
166 		 */
167 		while (SDEV_IS_LOOKUP(dv) || SDEV_IS_READDIR(dv)) {
168 			cv_wait(&dv->sdev_lookup_cv, &dv->sdev_lookup_lock);
169 		}
170 		rval = 0;
171 	}
172 
173 	sdcmn_err6(("wait4lookup unblocking %s state 0x%x %d\n",
174 	    dv->sdev_name, devfsadm_state, dv->sdev_state));
175 
176 	if (is_lookup) {
177 		SDEV_UNBLOCK_OTHERS(dv, SDEV_LOOKUP);
178 	} else {
179 		SDEV_UNBLOCK_OTHERS(dv, SDEV_READDIR);
180 	}
181 
182 	return (rval);
183 }
184 
185 void
186 sdev_unblock_others(struct sdev_node *dv, uint_t cmd)
187 {
188 	ASSERT(MUTEX_HELD(&dv->sdev_lookup_lock));
189 
190 	SDEV_CLEAR_LOOKUP_FLAGS(dv, cmd);
191 	if (SDEV_IS_LGWAITING(dv)) {
192 		SDEV_CLEAR_LOOKUP_FLAGS(dv, SDEV_LGWAITING);
193 	}
194 	cv_broadcast(&dv->sdev_lookup_cv);
195 }
196 
197 /*
198  * In the case devfsadmd is down, it is re-started by syseventd
199  * upon receiving an event subscribed to by devfsadmd.
200  */
201 static int
202 sdev_start_devfsadmd()
203 {
204 	int		se_err = 0;
205 	sysevent_t	*ev;
206 	sysevent_id_t	eid;
207 
208 	ev = sysevent_alloc(EC_DEVFS, ESC_DEVFS_START, EP_DDI, SE_SLEEP);
209 	ASSERT(ev);
210 	if ((se_err = log_sysevent(ev, SE_SLEEP, &eid)) != 0) {
211 		switch (se_err) {
212 		case SE_NO_TRANSPORT:
213 			cmn_err(CE_WARN, "unable to start devfsadm - "
214 			    "syseventd may not be responding\n");
215 			break;
216 		default:
217 			cmn_err(CE_WARN, "unable to start devfsadm - "
218 			    "sysevent error %d\n", se_err);
219 			break;
220 		}
221 	}
222 
223 	sysevent_free(ev);
224 	return (se_err);
225 }
226 
227 static int
228 sdev_open_upcall_door()
229 {
230 	int error;
231 	clock_t rv;
232 	clock_t expire;
233 
234 	ASSERT(sdev_upcall_door == NULL);
235 
236 	/* tick value at which wait expires */
237 	expire = ddi_get_lbolt() +
238 	    drv_usectohz(dev_devfsadm_startup * 1000000);
239 
240 	if (sdev_door_upcall_filename == NULL) {
241 		if ((error = sdev_start_devfsadmd()) != 0) {
242 			return (error);
243 		}
244 
245 		/* wait for devfsadmd start */
246 		mutex_enter(&devfsadm_lock);
247 		while (sdev_door_upcall_filename == NULL) {
248 			sdcmn_err6(("waiting for dev_door creation, %ld\n",
249 			    expire - ddi_get_lbolt()));
250 			rv = cv_timedwait_sig(&devfsadm_cv, &devfsadm_lock,
251 			    expire);
252 			sdcmn_err6(("dev_door wait rv %ld\n", rv));
253 			if (rv <= 0) {
254 				sdcmn_err6(("devfsadmd startup error\n"));
255 				mutex_exit(&devfsadm_lock);
256 				return (EBADF);
257 			}
258 		}
259 		sdcmn_err6(("devfsadmd is ready\n"));
260 		mutex_exit(&devfsadm_lock);
261 	}
262 
263 	if ((error = door_ki_open(sdev_door_upcall_filename,
264 	    &sdev_upcall_door)) != 0) {
265 		sdcmn_err6(("upcall_lookup: door open error %d\n",
266 		    error));
267 		return (error);
268 	}
269 
270 	return (0);
271 }
272 
273 static void
274 sdev_release_door()
275 {
276 	if (sdev_upcall_door) {
277 		door_ki_rele(sdev_upcall_door);
278 		sdev_upcall_door = NULL;
279 	}
280 	if (sdev_door_upcall_filename) {
281 		kmem_free(sdev_door_upcall_filename,
282 		    sdev_door_upcall_filename_size);
283 		sdev_door_upcall_filename = NULL;
284 	}
285 }
286 
287 static int
288 sdev_ki_call_devfsadmd(sdev_door_arg_t *argp, sdev_door_res_t *resultp)
289 {
290 	door_arg_t	darg, save_arg;
291 	int		error;
292 	int		retry;
293 
294 	if (((sdev_upcall_door == NULL) &&
295 	    ((error = sdev_open_upcall_door()) != 0)) ||
296 	    sdev_devfsadm_revoked()) {
297 		sdcmn_err6(("call_devfsadm: upcall lookup error\n"));
298 		return (error);
299 	}
300 
301 	ASSERT(argp);
302 	darg.data_ptr = (char *)argp;
303 	darg.data_size = sizeof (struct sdev_door_arg);
304 	darg.desc_ptr = NULL;
305 	darg.desc_num = 0;
306 	darg.rbuf = (char *)(resultp);
307 	darg.rsize = sizeof (struct sdev_door_res);
308 
309 	ASSERT(sdev_upcall_door);
310 	save_arg = darg;
311 	for (retry = 0; ; retry++) {
312 		sdcmn_err6(("call devfsadm: upcall lookup, retry %d\n", retry));
313 		if ((error = door_ki_upcall_limited(sdev_upcall_door, &darg,
314 		    NULL, SIZE_MAX, 0)) == 0) {
315 			sdcmn_err6(("call devfsadm: upcall lookup ok\n"));
316 			break;
317 		}
318 
319 		/*
320 		 * handle door call errors
321 		 */
322 		if (sdev_devfsadm_revoked()) {
323 			sdcmn_err6(("upcall lookup door revoked, "
324 			    "error %d\n", error));
325 			return (error);
326 		}
327 
328 		switch (error) {
329 		case EINTR:
330 			/* return error here? */
331 			sdcmn_err6(("sdev_ki_call_devfsadm: EINTR\n"));
332 			delay(hz);
333 			break;
334 		case EAGAIN:
335 			sdcmn_err6(("sdev_ki_call_devfsadm: EAGAIN\n"));
336 			delay(2 * hz);
337 			break;
338 		case EBADF:
339 			if (retry > 4) {
340 				sdcmn_err6(("sdev_ki_call_devfsadm: EBADF\n"));
341 				return (EBADF);
342 			}
343 			sdcmn_err6((
344 			    "sdev_ki_call_devfsadm: EBADF, re-binding\n"));
345 			sdev_release_door();
346 			delay(retry * hz);
347 			error = sdev_open_upcall_door();
348 			if (error != 0) {
349 				sdcmn_err6(("sdev_ki_call_devfsadm: "
350 				    "EBADF lookup error %d\n", error));
351 				if (!sdev_devfsadm_revoked())
352 					cmn_err(CE_NOTE,
353 					    "?unable to invoke devfsadm - "
354 					    "please run manually\n");
355 				return (EBADF);
356 			}
357 			break;
358 		case EINVAL:
359 		default:
360 			cmn_err(CE_CONT,
361 			    "?sdev: door_ki_upcall unexpected result %d\n",
362 			    error);
363 			return (error);
364 		}
365 
366 		darg = save_arg;
367 	}
368 
369 	if (!error) {
370 		ASSERT((struct sdev_door_res *)(intptr_t)darg.rbuf == resultp);
371 		if (resultp->devfsadm_error != 0) {
372 			sdcmn_err6(("sdev_ki_call_devfsadmd: result %d\n",
373 			    resultp->devfsadm_error));
374 			error = resultp->devfsadm_error;
375 		}
376 	} else {
377 		sdcmn_err6(("sdev_ki_call_devfsadmd with error %d\n", error));
378 	}
379 
380 	return (error);
381 }
382 
383 static int
384 sdev_devfsadm_revoked(void)
385 {
386 	struct door_info info;
387 	int rv;
388 	extern int sys_shutdown;
389 
390 	if (sys_shutdown) {
391 		sdcmn_err6(("dev: shutdown observed\n"));
392 		return (1);
393 	}
394 
395 	if (sdev_upcall_door && !sdev_upcall_door_revoked) {
396 		rv = door_ki_info(sdev_upcall_door, &info);
397 		if ((rv == 0) && info.di_attributes & DOOR_REVOKED) {
398 			sdcmn_err6(("lookup door: revoked\n"));
399 			sdev_upcall_door_revoked = 1;
400 		}
401 	}
402 
403 	return (sdev_upcall_door_revoked);
404 }
405 
406 /*ARGSUSED*/
407 static void
408 sdev_config_all_thread(struct sdev_node *dv)
409 {
410 	int32_t error = 0;
411 	sdev_door_arg_t	*argp;
412 	sdev_door_res_t result;
413 
414 	argp = kmem_zalloc(sizeof (sdev_door_arg_t), KM_SLEEP);
415 	argp->devfsadm_cmd = DEVFSADMD_RUN_ALL;
416 
417 	error = sdev_ki_call_devfsadmd(argp, &result);
418 	if (!error) {
419 		sdcmn_err6(("devfsadm result error: %d\n",
420 		    result.devfsadm_error));
421 		if (!result.devfsadm_error) {
422 			DEVNAME_DEVFSADM_SET_RUN(devfsadm_state);
423 		} else {
424 			DEVNAME_DEVFSADM_SET_STOP(devfsadm_state);
425 		}
426 	} else {
427 		DEVNAME_DEVFSADM_SET_STOP(devfsadm_state);
428 	}
429 
430 	kmem_free(argp, sizeof (sdev_door_arg_t));
431 done:
432 	sdcmn_err6(("sdev_config_all_thread: stopping, devfsadm state 0x%x\n",
433 	    devfsadm_state));
434 	thread_exit();
435 }
436 
437 /*
438  * launch an asynchronous thread to do the devfsadm dev_config_all
439  */
440 /*ARGSUSED*/
441 void
442 sdev_devfsadmd_thread(struct sdev_node *ddv, struct sdev_node *dv,
443     struct cred *cred)
444 {
445 	ASSERT(i_ddi_io_initialized());
446 	DEVNAME_DEVFSADM_SET_RUNNING(devfsadm_state);
447 	(void) thread_create(NULL, 0, sdev_config_all_thread, dv, 0,
448 	    &p0, TS_RUN, MINCLSYSPRI);
449 }
450 
451 int
452 devname_filename_register(char *name)
453 {
454 	int error = 0;
455 	char *strbuf;
456 	char *namep;
457 	int n;
458 
459 	strbuf = kmem_zalloc(MOD_MAXPATH, KM_SLEEP);
460 
461 	if (copyinstr(name, strbuf, MOD_MAXPATH, 0)) {
462 		sdcmn_err6(("error copyin \n"));
463 		error = EFAULT;
464 	} else {
465 		sdcmn_err6(("file %s is registering\n", strbuf));
466 		/* handling the daemon re-start situations */
467 		n = strlen(strbuf) + 1;
468 		namep = i_ddi_strdup(strbuf, KM_SLEEP);
469 		mutex_enter(&devfsadm_lock);
470 		sdev_release_door();
471 		sdev_door_upcall_filename_size = n;
472 		sdev_door_upcall_filename = namep;
473 		sdcmn_err6(("size %d file name %s\n",
474 		    sdev_door_upcall_filename_size,
475 		    sdev_door_upcall_filename));
476 		cv_broadcast(&devfsadm_cv);
477 		mutex_exit(&devfsadm_lock);
478 	}
479 
480 	kmem_free(strbuf, MOD_MAXPATH);
481 	return (error);
482 }
483