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--- old/usr/src/uts/common/fs/fifofs/fifosubr.c
+++ new/usr/src/uts/common/fs/fifofs/fifosubr.c
1 1 /*
2 2 * CDDL HEADER START
3 3 *
4 4 * The contents of this file are subject to the terms of the
5 5 * Common Development and Distribution License (the "License").
6 6 * You may not use this file except in compliance with the License.
7 7 *
8 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 9 * or http://www.opensolaris.org/os/licensing.
10 10 * See the License for the specific language governing permissions
11 11 * and limitations under the License.
12 12 *
13 13 * When distributing Covered Code, include this CDDL HEADER in each
14 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 15 * If applicable, add the following below this CDDL HEADER, with the
16 16 * fields enclosed by brackets "[]" replaced with your own identifying
17 17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 18 *
19 19 * CDDL HEADER END
20 20 */
21 21 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
22 22
23 23 /*
24 24 * Copyright (c) 1988, 2010, Oracle and/or its affiliates. All rights reserved.
25 25 */
26 26
27 27 /*
28 28 * The routines defined in this file are supporting routines for FIFOFS
29 29 * file system type.
30 30 */
31 31 #include <sys/types.h>
32 32 #include <sys/param.h>
33 33 #include <sys/systm.h>
34 34 #include <sys/debug.h>
35 35 #include <sys/errno.h>
36 36 #include <sys/time.h>
37 37 #include <sys/kmem.h>
38 38 #include <sys/inline.h>
39 39 #include <sys/file.h>
40 40 #include <sys/proc.h>
41 41 #include <sys/stat.h>
42 42 #include <sys/sysmacros.h>
43 43 #include <sys/var.h>
44 44 #include <sys/vfs.h>
45 45 #include <sys/vfs_opreg.h>
46 46 #include <sys/vnode.h>
47 47 #include <sys/mode.h>
48 48 #include <sys/signal.h>
49 49 #include <sys/user.h>
50 50 #include <sys/uio.h>
51 51 #include <sys/flock.h>
52 52 #include <sys/stream.h>
53 53 #include <sys/fs/fifonode.h>
54 54 #include <sys/strsubr.h>
55 55 #include <sys/stropts.h>
56 56 #include <sys/cmn_err.h>
57 57 #include <fs/fs_subr.h>
58 58 #include <sys/ddi.h>
59 59
60 60
61 61 #if FIFODEBUG
62 62 int Fifo_fastmode = 1; /* pipes/fifos will be opened in fast mode */
63 63 int Fifo_verbose = 0; /* msg when switching out of fast mode */
64 64 int Fifohiwat = FIFOHIWAT; /* Modifiable FIFO high water mark */
65 65 #endif
66 66
67 67 /*
68 68 * This is the loadable module wrapper.
69 69 */
70 70 #include <sys/modctl.h>
71 71
72 72 extern struct qinit fifo_strdata;
73 73
74 74 struct vfsops *fifo_vfsops;
75 75
76 76 static vfsdef_t vfw = {
77 77 VFSDEF_VERSION,
78 78 "fifofs",
79 79 fifoinit,
80 80 VSW_ZMOUNT,
81 81 NULL
82 82 };
83 83
84 84 /*
85 85 * Module linkage information for the kernel.
86 86 */
87 87 extern struct mod_ops mod_fsops;
88 88
89 89 static struct modlfs modlfs = {
90 90 &mod_fsops, "filesystem for fifo", &vfw
91 91 };
92 92
93 93 static struct modlinkage modlinkage = {
94 94 MODREV_1, (void *)&modlfs, NULL
95 95 };
96 96
97 97 int
98 98 _init()
99 99 {
100 100 return (mod_install(&modlinkage));
101 101 }
102 102
103 103 int
104 104 _info(struct modinfo *modinfop)
105 105 {
106 106 return (mod_info(&modlinkage, modinfop));
107 107 }
108 108
109 109 /*
110 110 * Define data structures within this file.
111 111 * XXX should the hash size be configurable ?
112 112 */
113 113 #define FIFOSHFT 5
114 114 #define FIFO_HASHSZ 63
115 115
116 116 #if ((FIFO_HASHSZ & (FIFO_HASHSZ - 1)) == 0)
117 117 #define FIFOHASH(vp) (((uintptr_t)(vp) >> FIFOSHFT) & (FIFO_HASHSZ - 1))
118 118 #else
119 119 #define FIFOHASH(vp) (((uintptr_t)(vp) >> FIFOSHFT) % FIFO_HASHSZ)
120 120 #endif
121 121
122 122 fifonode_t *fifoalloc[FIFO_HASHSZ];
123 123 dev_t fifodev;
124 124 struct vfs *fifovfsp;
125 125 int fifofstype;
126 126
127 127 kmutex_t ftable_lock;
128 128 static kmutex_t fino_lock;
129 129 struct kmem_cache *fnode_cache;
130 130 struct kmem_cache *pipe_cache;
131 131
132 132 static void fifoinsert(fifonode_t *);
133 133 static fifonode_t *fifofind(vnode_t *);
134 134 static int fifo_connld(struct vnode **, int, cred_t *);
135 135 static void fifo_fastturnoff(fifonode_t *);
136 136
137 137 static void fifo_reinit_vp(vnode_t *);
138 138
139 139 static void fnode_destructor(void *, void *);
140 140
141 141 /*
142 142 * Constructor/destructor routines for fifos and pipes.
143 143 *
144 144 * In the interest of code sharing, we define a common fifodata structure
145 145 * which consists of a fifolock and one or two fnodes. A fifo contains
146 146 * one fnode; a pipe contains two. The fifolock is shared by the fnodes,
147 147 * each of which points to it:
148 148 *
149 149 * --> --> --------- --- ---
150 150 * | | | lock | | |
151 151 * | | --------- | |
152 152 * | | | | fifo |
153 153 * | --- | fnode | | |
154 154 * | | | | pipe
155 155 * | --------- --- |
156 156 * | | | |
157 157 * ------- | fnode | |
158 158 * | | |
159 159 * --------- ---
160 160 *
161 161 * Since the fifolock is at the beginning of the fifodata structure,
162 162 * the fifolock address is the same as the fifodata address. Thus,
163 163 * we can determine the fifodata address from any of its member fnodes.
164 164 * This is essential for fifo_inactive.
165 165 *
166 166 * The fnode constructor is designed to handle any fifodata structure,
167 167 * deducing the number of fnodes from the total size. Thus, the fnode
168 168 * constructor does most of the work for the pipe constructor.
169 169 */
170 170 static int
171 171 fnode_constructor(void *buf, void *cdrarg, int kmflags)
172 172 {
173 173 fifodata_t *fdp = buf;
174 174 fifolock_t *flp = &fdp->fifo_lock;
175 175 fifonode_t *fnp = &fdp->fifo_fnode[0];
176 176 size_t size = (uintptr_t)cdrarg;
177 177
178 178 mutex_init(&flp->flk_lock, NULL, MUTEX_DEFAULT, NULL);
179 179 cv_init(&flp->flk_wait_cv, NULL, CV_DEFAULT, NULL);
180 180 flp->flk_ocsync = 0;
181 181
182 182 while ((char *)fnp < (char *)buf + size) {
183 183
184 184 vnode_t *vp;
185 185
186 186 vp = vn_alloc(kmflags);
187 187 if (vp == NULL) {
188 188 fnp->fn_vnode = NULL; /* mark for destructor */
189 189 fnode_destructor(buf, cdrarg);
190 190 return (-1);
191 191 }
192 192 fnp->fn_vnode = vp;
193 193
194 194 fnp->fn_lock = flp;
195 195 fnp->fn_open = 0;
196 196 fnp->fn_dest = fnp;
197 197 fnp->fn_mp = NULL;
198 198 fnp->fn_count = 0;
199 199 fnp->fn_rsynccnt = 0;
200 200 fnp->fn_wsynccnt = 0;
201 201 fnp->fn_wwaitcnt = 0;
202 202 fnp->fn_insync = 0;
203 203 fnp->fn_pcredp = NULL;
204 204 fnp->fn_cpid = -1;
205 205 /*
206 206 * 32-bit stat(2) may fail if fn_ino isn't initialized
207 207 */
208 208 fnp->fn_ino = 0;
209 209
210 210 cv_init(&fnp->fn_wait_cv, NULL, CV_DEFAULT, NULL);
211 211
212 212 vn_setops(vp, fifo_vnodeops);
213 213 vp->v_stream = NULL;
214 214 vp->v_type = VFIFO;
215 215 vp->v_data = (caddr_t)fnp;
216 216 vp->v_flag = VNOMAP | VNOSWAP;
217 217 vn_exists(vp);
218 218 fnp++;
219 219 }
220 220 return (0);
221 221 }
222 222
223 223 static void
224 224 fnode_destructor(void *buf, void *cdrarg)
225 225 {
226 226 fifodata_t *fdp = buf;
227 227 fifolock_t *flp = &fdp->fifo_lock;
228 228 fifonode_t *fnp = &fdp->fifo_fnode[0];
229 229 size_t size = (uintptr_t)cdrarg;
230 230
231 231 mutex_destroy(&flp->flk_lock);
232 232 cv_destroy(&flp->flk_wait_cv);
233 233 ASSERT(flp->flk_ocsync == 0);
234 234
235 235 while ((char *)fnp < (char *)buf + size) {
236 236
237 237 vnode_t *vp = FTOV(fnp);
238 238
239 239 if (vp == NULL) {
240 240 return; /* constructor failed here */
241 241 }
242 242
243 243 ASSERT(fnp->fn_mp == NULL);
244 244 ASSERT(fnp->fn_count == 0);
245 245 ASSERT(fnp->fn_lock == flp);
246 246 ASSERT(fnp->fn_open == 0);
247 247 ASSERT(fnp->fn_insync == 0);
248 248 ASSERT(fnp->fn_rsynccnt == 0 && fnp->fn_wsynccnt == 0);
249 249 ASSERT(fnp->fn_wwaitcnt == 0);
250 250 ASSERT(fnp->fn_pcredp == NULL);
251 251 ASSERT(vn_matchops(vp, fifo_vnodeops));
252 252 ASSERT(vp->v_stream == NULL);
253 253 ASSERT(vp->v_type == VFIFO);
254 254 ASSERT(vp->v_data == (caddr_t)fnp);
255 255 ASSERT((vp->v_flag & (VNOMAP|VNOSWAP)) == (VNOMAP|VNOSWAP));
256 256
257 257 cv_destroy(&fnp->fn_wait_cv);
258 258 vn_invalid(vp);
259 259 vn_free(vp);
260 260
261 261 fnp++;
262 262 }
263 263 }
264 264
265 265 static int
266 266 pipe_constructor(void *buf, void *cdrarg, int kmflags)
267 267 {
268 268 fifodata_t *fdp = buf;
269 269 fifonode_t *fnp1 = &fdp->fifo_fnode[0];
270 270 fifonode_t *fnp2 = &fdp->fifo_fnode[1];
271 271 vnode_t *vp1;
272 272 vnode_t *vp2;
273 273
274 274 (void) fnode_constructor(buf, cdrarg, kmflags);
275 275
276 276 vp1 = FTOV(fnp1);
277 277 vp2 = FTOV(fnp2);
278 278
279 279 vp1->v_vfsp = vp2->v_vfsp = fifovfsp;
280 280 vp1->v_rdev = vp2->v_rdev = fifodev;
281 281 fnp1->fn_realvp = fnp2->fn_realvp = NULL;
282 282 fnp1->fn_dest = fnp2;
283 283 fnp2->fn_dest = fnp1;
284 284
285 285 return (0);
286 286 }
287 287
288 288 static void
289 289 pipe_destructor(void *buf, void *cdrarg)
290 290 {
291 291 #ifdef DEBUG
292 292 fifodata_t *fdp = buf;
293 293 fifonode_t *fnp1 = &fdp->fifo_fnode[0];
294 294 fifonode_t *fnp2 = &fdp->fifo_fnode[1];
295 295 vnode_t *vp1 = FTOV(fnp1);
296 296 vnode_t *vp2 = FTOV(fnp2);
297 297
298 298 ASSERT(vp1->v_vfsp == fifovfsp);
299 299 ASSERT(vp2->v_vfsp == fifovfsp);
300 300 ASSERT(vp1->v_rdev == fifodev);
301 301 ASSERT(vp2->v_rdev == fifodev);
302 302 #endif
303 303 fnode_destructor(buf, cdrarg);
304 304 }
305 305
306 306 /*
307 307 * Reinitialize a FIFO vnode (uses normal vnode reinit, but ensures that
308 308 * vnode type and flags are reset).
309 309 */
310 310
311 311 static void fifo_reinit_vp(vnode_t *vp)
312 312 {
313 313 vn_reinit(vp);
314 314 vp->v_type = VFIFO;
315 315 vp->v_flag &= VROOT;
316 316 vp->v_flag |= VNOMAP | VNOSWAP;
317 317 }
318 318
319 319 /*
320 320 * Save file system type/index, initialize vfs operations vector, get
321 321 * unique device number for FIFOFS and initialize the FIFOFS hash.
322 322 * Create and initialize a "generic" vfs pointer that will be placed
323 323 * in the v_vfsp field of each pipe's vnode.
324 324 */
325 325 int
326 326 fifoinit(int fstype, char *name)
327 327 {
328 328 static const fs_operation_def_t fifo_vfsops_template[] = {
329 329 NULL, NULL
330 330 };
331 331 int error;
332 332 major_t dev;
333 333
334 334 fifofstype = fstype;
335 335 error = vfs_setfsops(fstype, fifo_vfsops_template, &fifo_vfsops);
336 336 if (error != 0) {
337 337 cmn_err(CE_WARN, "fifoinit: bad vfs ops template");
338 338 return (error);
339 339 }
340 340
341 341 error = vn_make_ops(name, fifo_vnodeops_template, &fifo_vnodeops);
342 342 if (error != 0) {
343 343 (void) vfs_freevfsops_by_type(fstype);
344 344 cmn_err(CE_WARN, "fifoinit: bad vnode ops template");
345 345 return (error);
346 346 }
347 347
348 348 if ((dev = getudev()) == (major_t)-1) {
349 349 cmn_err(CE_WARN, "fifoinit: can't get unique device number");
350 350 dev = 0;
351 351 }
352 352 fifodev = makedevice(dev, 0);
353 353
354 354 fifovfsp = kmem_zalloc(sizeof (struct vfs), KM_SLEEP);
355 355 fifovfsp->vfs_next = NULL;
356 356 vfs_setops(fifovfsp, fifo_vfsops);
357 357 fifovfsp->vfs_vnodecovered = NULL;
358 358 fifovfsp->vfs_flag = 0;
359 359 fifovfsp->vfs_bsize = 1024;
360 360 fifovfsp->vfs_fstype = fifofstype;
361 361 vfs_make_fsid(&fifovfsp->vfs_fsid, fifodev, fifofstype);
362 362 fifovfsp->vfs_data = NULL;
363 363 fifovfsp->vfs_dev = fifodev;
364 364 fifovfsp->vfs_bcount = 0;
365 365
366 366 /*
367 367 * It is necessary to initialize vfs_count here to 1.
368 368 * This prevents the fifovfsp from getting freed when
369 369 * a thread does a VFS_HOLD followed by a VFS_RELE
370 370 * on the fifovfsp
371 371 *
372 372 * The fifovfsp should never be freed.
373 373 */
374 374 fifovfsp->vfs_count = 1;
375 375
376 376 mutex_init(&ftable_lock, NULL, MUTEX_DEFAULT, NULL);
377 377 mutex_init(&fino_lock, NULL, MUTEX_DEFAULT, NULL);
378 378
379 379 /*
380 380 * vnodes are cached aligned
381 381 */
382 382 fnode_cache = kmem_cache_create("fnode_cache",
383 383 sizeof (fifodata_t) - sizeof (fifonode_t), 32,
384 384 fnode_constructor, fnode_destructor, NULL,
385 385 (void *)(sizeof (fifodata_t) - sizeof (fifonode_t)), NULL, 0);
386 386
387 387 pipe_cache = kmem_cache_create("pipe_cache", sizeof (fifodata_t), 32,
388 388 pipe_constructor, pipe_destructor, NULL,
389 389 (void *)(sizeof (fifodata_t)), NULL, 0);
390 390
391 391 #if FIFODEBUG
392 392 if (Fifohiwat < FIFOHIWAT)
393 393 Fifohiwat = FIFOHIWAT;
394 394 #endif /* FIFODEBUG */
395 395 fifo_strdata.qi_minfo->mi_hiwat = Fifohiwat;
396 396
397 397 return (0);
398 398 }
399 399
400 400 /*
401 401 * Provide a shadow for a vnode. We create a new shadow before checking for an
402 402 * existing one, to minimize the amount of time we need to hold ftable_lock.
403 403 * If a vp already has a shadow in the hash list, return its shadow. If not,
404 404 * we hash the new vnode and return its pointer to the caller.
405 405 */
406 406 vnode_t *
407 407 fifovp(vnode_t *vp, cred_t *crp)
408 408 {
409 409 fifonode_t *fnp;
410 410 fifonode_t *spec_fnp; /* Speculative fnode ptr. */
411 411 fifodata_t *fdp;
412 412 vnode_t *newvp;
413 413 struct vattr va;
414 414 vnode_t *rvp;
415 415
416 416 ASSERT(vp != NULL);
417 417
418 418 fdp = kmem_cache_alloc(fnode_cache, KM_SLEEP);
419 419
420 420 fdp->fifo_lock.flk_ref = 1;
421 421 fnp = &fdp->fifo_fnode[0];
422 422
423 423 /*
424 424 * Its possible that fifo nodes on different lofs mountpoints
425 425 * shadow the same real filesystem fifo node.
426 426 * In this case its necessary to get and store the realvp.
427 427 * This way different fifo nodes sharing the same real vnode
428 428 * can use realvp for communication.
429 429 */
430 430
431 431 if (VOP_REALVP(vp, &rvp, NULL) == 0)
432 432 vp = rvp;
433 433
434 434 fnp->fn_realvp = vp;
435 435 fnp->fn_wcnt = 0;
436 436 fnp->fn_rcnt = 0;
437 437
438 438 #if FIFODEBUG
439 439 if (! Fifo_fastmode) {
440 440 fnp->fn_flag = 0;
441 441 } else {
442 442 fnp->fn_flag = FIFOFAST;
443 443 }
444 444 #else /* FIFODEBUG */
445 445 fnp->fn_flag = FIFOFAST;
446 446 #endif /* FIFODEBUG */
447 447
448 448 /*
449 449 * initialize the times from vp.
450 450 */
451 451 va.va_mask = AT_TIMES;
452 452 if (VOP_GETATTR(vp, &va, 0, crp, NULL) == 0) {
453 453 fnp->fn_atime = va.va_atime.tv_sec;
454 454 fnp->fn_mtime = va.va_mtime.tv_sec;
455 455 fnp->fn_ctime = va.va_ctime.tv_sec;
456 456 } else {
457 457 fnp->fn_atime = 0;
458 458 fnp->fn_mtime = 0;
459 459 fnp->fn_ctime = 0;
460 460 }
461 461
462 462 /*
463 463 * Grab the VP here to avoid holding locks
464 464 * whilst trying to acquire others.
465 465 */
466 466
467 467 VN_HOLD(vp);
468 468
469 469 mutex_enter(&ftable_lock);
470 470
471 471 if ((spec_fnp = fifofind(vp)) != NULL) {
472 472 mutex_exit(&ftable_lock);
473 473
474 474 /*
475 475 * Release the vnode and free up our pre-prepared fnode.
476 476 * Zero the lock reference just to explicitly signal
477 477 * this is unused.
478 478 */
479 479 VN_RELE(vp);
480 480 fdp->fifo_lock.flk_ref = 0;
481 481 kmem_cache_free(fnode_cache, fdp);
482 482
483 483 return (FTOV(spec_fnp));
484 484 }
485 485
486 486 newvp = FTOV(fnp);
487 487 fifo_reinit_vp(newvp);
488 488 /*
489 489 * Since the fifo vnode's v_vfsp needs to point to the
490 490 * underlying filesystem's vfsp we need to bump up the
491 491 * underlying filesystem's vfs reference count.
492 492 * The count is decremented when the fifo node is
493 493 * inactivated.
494 494 */
495 495
496 496 VFS_HOLD(vp->v_vfsp);
497 497 newvp->v_vfsp = vp->v_vfsp;
498 498 newvp->v_rdev = vp->v_rdev;
499 499 newvp->v_flag |= (vp->v_flag & VROOT);
500 500
501 501 fifoinsert(fnp);
502 502 mutex_exit(&ftable_lock);
503 503
504 504 return (newvp);
505 505 }
506 506
507 507 /*
508 508 * Create a pipe end by...
509 509 * allocating a vnode-fifonode pair and initializing the fifonode.
510 510 */
511 511 void
512 512 makepipe(vnode_t **vpp1, vnode_t **vpp2)
513 513 {
514 514 fifonode_t *fnp1;
515 515 fifonode_t *fnp2;
516 516 vnode_t *nvp1;
517 517 vnode_t *nvp2;
518 518 fifodata_t *fdp;
519 519 time_t now;
520 520
521 521 fdp = kmem_cache_alloc(pipe_cache, KM_SLEEP);
522 522 fdp->fifo_lock.flk_ref = 2;
523 523 fnp1 = &fdp->fifo_fnode[0];
524 524 fnp2 = &fdp->fifo_fnode[1];
525 525
526 526 fnp1->fn_wcnt = fnp2->fn_wcnt = 1;
527 527 fnp1->fn_rcnt = fnp2->fn_rcnt = 1;
528 528 #if FIFODEBUG
529 529 if (! Fifo_fastmode) {
530 530 fnp1->fn_flag = fnp2->fn_flag = ISPIPE;
531 531 } else {
532 532 fnp1->fn_flag = fnp2->fn_flag = ISPIPE | FIFOFAST;
533 533 }
534 534 #else /* FIFODEBUG */
535 535 fnp1->fn_flag = fnp2->fn_flag = ISPIPE | FIFOFAST;
536 536 #endif /* FIFODEBUG */
537 537 now = gethrestime_sec();
538 538 fnp1->fn_atime = fnp2->fn_atime = now;
539 539 fnp1->fn_mtime = fnp2->fn_mtime = now;
540 540 fnp1->fn_ctime = fnp2->fn_ctime = now;
541 541
542 542 *vpp1 = nvp1 = FTOV(fnp1);
543 543 *vpp2 = nvp2 = FTOV(fnp2);
544 544
545 545 fifo_reinit_vp(nvp1); /* Reinitialize vnodes for reuse... */
546 546 fifo_reinit_vp(nvp2);
547 547 nvp1->v_vfsp = fifovfsp; /* Need to re-establish VFS & device */
548 548 nvp2->v_vfsp = fifovfsp; /* before we can reuse this vnode. */
549 549 nvp1->v_rdev = fifodev;
550 550 nvp2->v_rdev = fifodev;
551 551 }
552 552
553 553 /*
554 554 * Attempt to establish a unique pipe id. Only un-named pipes use this
555 555 * routine.
556 556 */
557 557 ino_t
558 558 fifogetid(void)
559 559 {
560 560 static ino_t fifo_ino = 0;
561 561 ino_t fino;
562 562
563 563 mutex_enter(&fino_lock);
564 564 fino = fifo_ino++;
565 565 mutex_exit(&fino_lock);
566 566 return (fino);
567 567 }
568 568
569 569
570 570 /*
571 571 * Stream a pipe/FIFO.
572 572 * The FIFOCONNLD flag is used when CONNLD has been pushed on the stream.
573 573 * If the flag is set, a new vnode is created by calling fifo_connld().
574 574 * Connld logic was moved to fifo_connld() to speed up the open
575 575 * operation, simplify the connld/fifo interaction, and remove inherent
576 576 * race conditions between the connld module and fifos.
577 577 * This routine is single threaded for two reasons.
578 578 * 1) connld requests are synchronous; that is, they must block
579 579 * until the server does an I_RECVFD (oh, well). Single threading is
580 580 * the simplest way to accomplish this.
581 581 * 2) fifo_close() must not send M_HANGUP or M_ERROR while we are
582 582 * in stropen. Stropen() has a tendency to reset things and
583 583 * we would like streams to remember that a hangup occurred.
584 584 */
585 585 int
586 586 fifo_stropen(vnode_t **vpp, int flag, cred_t *crp, int dotwist, int lockheld)
587 587 {
588 588 int error = 0;
589 589 vnode_t *oldvp = *vpp;
590 590 fifonode_t *fnp = VTOF(*vpp);
591 591 dev_t pdev = 0;
592 592 int firstopen = 0;
593 593 fifolock_t *fn_lock;
594 594
595 595 fn_lock = fnp->fn_lock;
596 596 if (!lockheld)
597 597 mutex_enter(&fn_lock->flk_lock);
598 598 ASSERT(MUTEX_HELD(&fnp->fn_lock->flk_lock));
599 599
600 600 /*
601 601 * FIFO is in the process of opening. Wait for it
602 602 * to complete before starting another open on it
603 603 * This prevents races associated with connld open
604 604 */
605 605 while (fnp->fn_flag & FIFOOPEN) {
606 606 if (!cv_wait_sig(&fnp->fn_wait_cv, &fn_lock->flk_lock)) {
607 607 fifo_cleanup(oldvp, flag);
608 608 if (!lockheld)
609 609 mutex_exit(&fn_lock->flk_lock);
610 610 return (EINTR);
611 611 }
612 612 }
613 613
614 614 /*
615 615 * The other end of the pipe is almost closed so
616 616 * reject any other open on this end of the pipe
617 617 * This normally only happens with a pipe mounted under namefs, but
618 618 * we can also see an open via proc/fd, which should still succeed.
619 619 * To indicate the proc/fd case the FKLYR flag is passed.
620 620 */
621 621 if ((fnp->fn_flag & (FIFOCLOSE|ISPIPE)) == (FIFOCLOSE|ISPIPE) &&
622 622 (flag & FKLYR) == 0) {
623 623 fifo_cleanup(oldvp, flag);
624 624 cv_broadcast(&fnp->fn_wait_cv);
625 625 if (!lockheld)
626 626 mutex_exit(&fn_lock->flk_lock);
627 627 return (ENXIO);
628 628 }
629 629
630 630 fnp->fn_flag |= FIFOOPEN;
631 631
632 632 /*
633 633 * can't allow close to happen while we are
634 634 * in the middle of stropen().
635 635 * M_HANGUP and M_ERROR could leave the stream in a strange state
636 636 */
637 637 while (fn_lock->flk_ocsync)
638 638 cv_wait(&fn_lock->flk_wait_cv, &fn_lock->flk_lock);
639 639
640 640 fn_lock->flk_ocsync = 1;
641 641
642 642 if (fnp->fn_flag & FIFOCONNLD) {
643 643 /*
644 644 * This is a reopen, so we should release the fifo lock
645 645 * just in case some strange module pushed on connld
646 646 * has some odd side effect.
647 647 * Note: this stropen is on the oldvp. It will
648 648 * have no impact on the connld vp returned and
649 649 * strclose() will only be called when we release
650 650 * flk_ocsync
651 651 */
652 652 mutex_exit(&fn_lock->flk_lock);
653 653 if ((error = stropen(oldvp, &pdev, flag, crp)) != 0) {
654 654 mutex_enter(&fn_lock->flk_lock);
655 655 fifo_cleanup(oldvp, flag);
656 656 fn_lock->flk_ocsync = 0;
657 657 cv_broadcast(&fn_lock->flk_wait_cv);
658 658 goto out;
659 659 }
660 660 /*
661 661 * streams open done, allow close on other end if
662 662 * required. Do this now.. it could
663 663 * be a very long time before fifo_connld returns.
664 664 */
665 665 mutex_enter(&fn_lock->flk_lock);
666 666 /*
667 667 * we need to fake an open here so that if this
668 668 * end of the pipe closes, we don't loose the
669 669 * stream head (kind of like single threading
670 670 * open and close for this end of the pipe)
671 671 * We'll need to call fifo_close() to do clean
672 672 * up in case this end of the pipe was closed
673 673 * down while we were in fifo_connld()
674 674 */
675 675 ASSERT(fnp->fn_open > 0);
676 676 fnp->fn_open++;
677 677 fn_lock->flk_ocsync = 0;
678 678 cv_broadcast(&fn_lock->flk_wait_cv);
679 679 mutex_exit(&fn_lock->flk_lock);
680 680 /*
681 681 * Connld has been pushed onto the pipe
682 682 * Create new pipe on behalf of connld
683 683 */
684 684 if (error = fifo_connld(vpp, flag, crp)) {
685 685 (void) fifo_close(oldvp, flag, 1, 0, crp, NULL);
686 686 mutex_enter(&fn_lock->flk_lock);
687 687 goto out;
688 688 }
689 689 /*
690 690 * undo fake open. We need to call fifo_close
691 691 * because some other thread could have done
692 692 * a close and detach of the named pipe while
693 693 * we were in fifo_connld(), so
694 694 * we want to make sure the close completes (yuk)
695 695 */
696 696 (void) fifo_close(oldvp, flag, 1, 0, crp, NULL);
697 697 /*
698 698 * fifo_connld has changed the vp, so we
699 699 * need to re-initialize locals
700 700 */
701 701 fnp = VTOF(*vpp);
702 702 fn_lock = fnp->fn_lock;
703 703 mutex_enter(&fn_lock->flk_lock);
704 704 } else {
705 705 /*
706 706 * release lock in case there are modules pushed that
707 707 * could have some strange side effect
708 708 */
709 709
710 710 mutex_exit(&fn_lock->flk_lock);
711 711
712 712 /*
713 713 * If this is the first open of a fifo (dotwist
714 714 * will be non-zero) we will need to twist the queues.
715 715 */
716 716 if (oldvp->v_stream == NULL)
717 717 firstopen = 1;
718 718
719 719
720 720 /*
721 721 * normal open of pipe/fifo
722 722 */
723 723
724 724 if ((error = stropen(oldvp, &pdev, flag, crp)) != 0) {
725 725 mutex_enter(&fn_lock->flk_lock);
726 726 fifo_cleanup(oldvp, flag);
727 727 ASSERT(fnp->fn_open != 0 || oldvp->v_stream == NULL);
728 728 fn_lock->flk_ocsync = 0;
729 729 cv_broadcast(&fn_lock->flk_wait_cv);
730 730 goto out;
731 731 }
732 732 mutex_enter(&fn_lock->flk_lock);
733 733
734 734 /*
735 735 * twist the ends of the fifo together
736 736 */
737 737 if (dotwist && firstopen)
738 738 strmate(*vpp, *vpp);
739 739
740 740 /*
741 741 * Show that this open has succeeded
742 742 * and allow closes or other opens to proceed
743 743 */
744 744 fnp->fn_open++;
745 745 fn_lock->flk_ocsync = 0;
746 746 cv_broadcast(&fn_lock->flk_wait_cv);
747 747 }
748 748 out:
749 749 fnp->fn_flag &= ~FIFOOPEN;
750 750 if (error == 0) {
751 751 fnp->fn_flag |= FIFOISOPEN;
752 752 /*
753 753 * If this is a FIFO and has the close flag set
754 754 * and there are now writers, clear the close flag
755 755 * Note: close flag only gets set when last writer
756 756 * on a FIFO goes away.
757 757 */
758 758 if (((fnp->fn_flag & (ISPIPE|FIFOCLOSE)) == FIFOCLOSE) &&
759 759 fnp->fn_wcnt > 0)
760 760 fnp->fn_flag &= ~FIFOCLOSE;
761 761 }
762 762 cv_broadcast(&fnp->fn_wait_cv);
763 763 if (!lockheld)
764 764 mutex_exit(&fn_lock->flk_lock);
765 765 return (error);
766 766 }
767 767
768 768 /*
769 769 * Clean up the state of a FIFO and/or mounted pipe in the
770 770 * event that a fifo_open() was interrupted while the
771 771 * process was blocked.
772 772 */
773 773 void
774 774 fifo_cleanup(vnode_t *vp, int flag)
775 775 {
776 776 fifonode_t *fnp = VTOF(vp);
777 777
778 778 ASSERT(MUTEX_HELD(&fnp->fn_lock->flk_lock));
779 779
780 780 cleanlocks(vp, curproc->p_pid, 0);
781 781 cleanshares(vp, curproc->p_pid);
782 782 if (flag & FREAD) {
783 783 fnp->fn_rcnt--;
784 784 }
785 785 if (flag & FWRITE) {
786 786 fnp->fn_wcnt--;
787 787 }
788 788 cv_broadcast(&fnp->fn_wait_cv);
789 789 }
790 790
791 791
792 792 /*
793 793 * Insert a fifonode-vnode pair onto the fifoalloc hash list.
794 794 */
795 795 static void
796 796 fifoinsert(fifonode_t *fnp)
797 797 {
798 798 int idx = FIFOHASH(fnp->fn_realvp);
799 799
800 800 /*
801 801 * We don't need to hold fn_lock since we're holding ftable_lock and
802 802 * this routine is only called right after we've allocated an fnode.
803 803 * FIFO is inserted at head of NULL terminated doubly linked list.
804 804 */
805 805
806 806 ASSERT(MUTEX_HELD(&ftable_lock));
807 807 fnp->fn_backp = NULL;
808 808 fnp->fn_nextp = fifoalloc[idx];
809 809 fifoalloc[idx] = fnp;
810 810 if (fnp->fn_nextp)
811 811 fnp->fn_nextp->fn_backp = fnp;
812 812 }
813 813
814 814 /*
815 815 * Find a fifonode-vnode pair on the fifoalloc hash list.
816 816 * vp is a vnode to be shadowed. If it's on the hash list,
817 817 * it already has a shadow, therefore return its corresponding
818 818 * fifonode.
819 819 */
820 820 static fifonode_t *
821 821 fifofind(vnode_t *vp)
822 822 {
823 823 fifonode_t *fnode;
824 824
825 825 ASSERT(MUTEX_HELD(&ftable_lock));
826 826 for (fnode = fifoalloc[FIFOHASH(vp)]; fnode; fnode = fnode->fn_nextp) {
827 827 if (fnode->fn_realvp == vp) {
828 828 VN_HOLD(FTOV(fnode));
829 829 return (fnode);
830 830 }
831 831 }
832 832 return (NULL);
833 833 }
834 834
835 835 /*
836 836 * Remove a fifonode-vnode pair from the fifoalloc hash list.
837 837 * This routine is called from the fifo_inactive() routine when a
838 838 * FIFO is being released.
839 839 * If the link to be removed is the only link, set fifoalloc to NULL.
840 840 */
841 841 void
842 842 fiforemove(fifonode_t *fnp)
843 843 {
844 844 int idx = FIFOHASH(fnp->fn_realvp);
845 845 fifonode_t *fnode;
846 846
847 847 ASSERT(MUTEX_HELD(&ftable_lock));
848 848 fnode = fifoalloc[idx];
849 849 /*
850 850 * fast path... only 1 FIFO in this list entry
851 851 */
852 852 if (fnode != NULL && fnode == fnp &&
853 853 !fnode->fn_nextp && !fnode->fn_backp) {
854 854 fifoalloc[idx] = NULL;
855 855 } else {
856 856
857 857 for (; fnode; fnode = fnode->fn_nextp) {
858 858 if (fnode == fnp) {
859 859 /*
860 860 * if we are first entry
861 861 */
862 862 if (fnp == fifoalloc[idx])
863 863 fifoalloc[idx] = fnp->fn_nextp;
864 864 if (fnode->fn_nextp)
865 865 fnode->fn_nextp->fn_backp =
866 866 fnode->fn_backp;
867 867 if (fnode->fn_backp)
868 868 fnode->fn_backp->fn_nextp =
869 869 fnode->fn_nextp;
870 870 break;
871 871 }
872 872 }
873 873 }
874 874 }
875 875
876 876 /*
877 877 * Flush all data from a fifo's message queue
878 878 */
879 879
880 880 void
881 881 fifo_fastflush(fifonode_t *fnp)
882 882 {
883 883 mblk_t *bp;
884 884 ASSERT(MUTEX_HELD(&fnp->fn_lock->flk_lock));
885 885
886 886 if ((bp = fnp->fn_mp) != NULL) {
887 887 fnp->fn_mp = NULL;
888 888 fnp->fn_count = 0;
889 889 freemsg(bp);
890 890 }
891 891 fifo_wakewriter(fnp->fn_dest, fnp->fn_lock);
892 892 }
893 893
894 894 /*
895 895 * Note: This routine is single threaded
896 896 * Protected by FIFOOPEN flag (i.e. flk_lock is not held)
897 897 * Upon successful completion, the original fifo is unlocked
898 898 * and FIFOOPEN is cleared for the original vpp.
899 899 * The new fifo returned has FIFOOPEN set.
900 900 */
901 901 static int
902 902 fifo_connld(struct vnode **vpp, int flag, cred_t *crp)
903 903 {
904 904 struct vnode *vp1;
905 905 struct vnode *vp2;
906 906 struct fifonode *oldfnp;
907 907 struct fifonode *fn_dest;
908 908 int error;
909 909 struct file *filep;
910 910 struct fifolock *fn_lock;
911 911 cred_t *c;
912 912
913 913 /*
914 914 * Get two vnodes that will represent the pipe ends for the new pipe.
915 915 */
916 916 makepipe(&vp1, &vp2);
917 917
918 918 /*
919 919 * Allocate a file descriptor and file pointer for one of the pipe
920 920 * ends. The file descriptor will be used to send that pipe end to
921 921 * the process on the other end of this stream. Note that we get
922 922 * the file structure only, there is no file list entry allocated.
923 923 */
924 924 if (error = falloc(vp1, FWRITE|FREAD, &filep, NULL)) {
925 925 VN_RELE(vp1);
926 926 VN_RELE(vp2);
927 927 return (error);
928 928 }
929 929 mutex_exit(&filep->f_tlock);
930 930 oldfnp = VTOF(*vpp);
931 931 fn_lock = oldfnp->fn_lock;
932 932 fn_dest = oldfnp->fn_dest;
933 933
934 934 /*
935 935 * Create two new stream heads and attach them to the two vnodes for
936 936 * the new pipe.
937 937 */
938 938 if ((error = fifo_stropen(&vp1, FREAD|FWRITE, filep->f_cred, 0, 0)) !=
939 939 0 ||
940 940 (error = fifo_stropen(&vp2, flag, filep->f_cred, 0, 0)) != 0) {
941 941 #if DEBUG
942 942 cmn_err(CE_NOTE, "fifo stropen failed error 0x%x", error);
943 943 #endif
944 944 /*
945 945 * this will call fifo_close and VN_RELE on vp1
946 946 */
947 947 (void) closef(filep);
948 948 VN_RELE(vp2);
949 949 return (error);
950 950 }
951 951
952 952 /*
953 953 * twist the ends of the pipe together
954 954 */
955 955 strmate(vp1, vp2);
956 956
957 957 /*
958 958 * Set our end to busy in open
959 959 * Note: Don't need lock around this because we're the only
960 960 * one who knows about it
961 961 */
962 962 VTOF(vp2)->fn_flag |= FIFOOPEN;
963 963
964 964 mutex_enter(&fn_lock->flk_lock);
965 965
966 966 fn_dest->fn_flag |= FIFOSEND;
967 967 /*
968 968 * check to make sure neither end of pipe has gone away
969 969 */
970 970 if (!(fn_dest->fn_flag & FIFOISOPEN)) {
971 971 error = ENXIO;
972 972 fn_dest->fn_flag &= ~FIFOSEND;
973 973 mutex_exit(&fn_lock->flk_lock);
974 974 /*
975 975 * this will call fifo_close and VN_RELE on vp1
976 976 */
977 977 goto out;
978 978 }
979 979 mutex_exit(&fn_lock->flk_lock);
980 980
981 981 /*
982 982 * Tag the sender's credential on the pipe descriptor.
983 983 */
984 984 crhold(VTOF(vp1)->fn_pcredp = crp);
985 985 VTOF(vp1)->fn_cpid = curproc->p_pid;
986 986
987 987 /*
988 988 * send the file descriptor to other end of pipe
989 989 */
990 990 if (error = do_sendfp((*vpp)->v_stream, filep, crp)) {
991 991 mutex_enter(&fn_lock->flk_lock);
992 992 fn_dest->fn_flag &= ~FIFOSEND;
993 993 mutex_exit(&fn_lock->flk_lock);
994 994 /*
995 995 * this will call fifo_close and VN_RELE on vp1
996 996 */
997 997 goto out;
998 998 }
999 999
1000 1000 mutex_enter(&fn_lock->flk_lock);
1001 1001 /*
1002 1002 * Wait for other end to receive file descriptor
1003 1003 * FIFOCLOSE indicates that one or both sides of the pipe
1004 1004 * have gone away.
1005 1005 */
1006 1006 while ((fn_dest->fn_flag & (FIFOCLOSE | FIFOSEND)) == FIFOSEND) {
1007 1007 if (!cv_wait_sig(&oldfnp->fn_wait_cv, &fn_lock->flk_lock)) {
1008 1008 error = EINTR;
1009 1009 fn_dest->fn_flag &= ~FIFOSEND;
1010 1010 mutex_exit(&fn_lock->flk_lock);
1011 1011 goto out;
1012 1012 }
1013 1013 }
1014 1014 /*
1015 1015 * If either end of pipe has gone away and the other end did not
1016 1016 * receive pipe, reject the connld open
1017 1017 */
1018 1018 if ((fn_dest->fn_flag & FIFOSEND)) {
1019 1019 error = ENXIO;
1020 1020 fn_dest->fn_flag &= ~FIFOSEND;
1021 1021 mutex_exit(&fn_lock->flk_lock);
1022 1022 goto out;
1023 1023 }
1024 1024
1025 1025 oldfnp->fn_flag &= ~FIFOOPEN;
1026 1026 cv_broadcast(&oldfnp->fn_wait_cv);
1027 1027 mutex_exit(&fn_lock->flk_lock);
1028 1028
1029 1029 VN_RELE(*vpp);
1030 1030 *vpp = vp2;
1031 1031 (void) closef(filep);
1032 1032 return (0);
1033 1033 out:
1034 1034 c = filep->f_cred;
1035 1035 crhold(c);
1036 1036 (void) closef(filep);
1037 1037 VTOF(vp2)->fn_flag &= ~FIFOOPEN;
1038 1038 (void) fifo_close(vp2, flag, 1, (offset_t)0, c, NULL);
1039 1039 crfree(c);
1040 1040 VN_RELE(vp2);
1041 1041 return (error);
1042 1042 }
1043 1043
1044 1044 /*
1045 1045 * Disable fastpath mode.
1046 1046 */
1047 1047 void
1048 1048 fifo_fastoff(fifonode_t *fnp)
1049 1049 {
1050 1050 ASSERT(MUTEX_HELD(&fnp->fn_lock->flk_lock));
1051 1051 ASSERT(FTOV(fnp)->v_stream);
1052 1052
1053 1053 /* FIFOSTAYFAST is set => FIFOFAST is set */
1054 1054 while ((fnp->fn_flag & FIFOSTAYFAST) || ((fnp->fn_flag & ISPIPE) &&
1055 1055 (fnp->fn_dest->fn_flag & FIFOSTAYFAST))) {
1056 1056 ASSERT(fnp->fn_flag & FIFOFAST);
1057 1057 /* indicate someone is waiting to turn into stream mode */
1058 1058 fnp->fn_flag |= FIFOWAITMODE;
1059 1059 cv_wait(&fnp->fn_wait_cv, &fnp->fn_lock->flk_lock);
1060 1060 fnp->fn_flag &= ~FIFOWAITMODE;
1061 1061 }
1062 1062
1063 1063 /* as we may have relased the lock, test the FIFOFAST flag here */
1064 1064 if (!(fnp->fn_flag & FIFOFAST))
1065 1065 return;
1066 1066 #if FIFODEBUG
1067 1067 if (Fifo_verbose)
1068 1068 cmn_err(CE_NOTE, "Fifo reverting to streams mode\n");
1069 1069 #endif
1070 1070
1071 1071 fifo_fastturnoff(fnp);
1072 1072 if (fnp->fn_flag & ISPIPE) {
1073 1073 fifo_fastturnoff(fnp->fn_dest);
1074 1074 }
1075 1075 }
1076 1076
1077 1077
1078 1078 /*
1079 1079 * flk_lock must be held while calling fifo_fastturnoff() to
1080 1080 * preserve data ordering (no reads or writes allowed)
1081 1081 */
1082 1082
1083 1083 static void
1084 1084 fifo_fastturnoff(fifonode_t *fnp)
1085 1085 {
1086 1086 fifonode_t *fn_dest = fnp->fn_dest;
1087 1087 mblk_t *fn_mp;
1088 1088 int fn_flag;
1089 1089
1090 1090 ASSERT(MUTEX_HELD(&fnp->fn_lock->flk_lock));
1091 1091 /*
1092 1092 * Note: This end can't be closed if there
1093 1093 * is stuff in fn_mp
1094 1094 */
1095 1095 if ((fn_mp = fnp->fn_mp) != NULL) {
1096 1096 ASSERT(fnp->fn_flag & FIFOISOPEN);
1097 1097 ASSERT(FTOV(fnp)->v_stream != NULL);
1098 1098 ASSERT(FTOV(fnp)->v_stream->sd_wrq != NULL);
1099 1099 ASSERT(RD(FTOV(fnp)->v_stream->sd_wrq) != NULL);
1100 1100 ASSERT(strvp2wq(FTOV(fnp)) != NULL);
1101 1101 fnp->fn_mp = NULL;
1102 1102 fnp->fn_count = 0;
1103 1103 /*
1104 1104 * Don't need to drop flk_lock across the put()
1105 1105 * since we're just moving the message from the fifo
1106 1106 * node to the STREAM head...
1107 1107 */
1108 1108 put(RD(strvp2wq(FTOV(fnp))), fn_mp);
1109 1109 }
1110 1110
1111 1111 /*
1112 1112 * Need to re-issue any pending poll requests
1113 1113 * so that the STREAMS framework sees them
1114 1114 * Writers would be waiting on fnp and readers on fn_dest
1115 1115 */
1116 1116 if ((fnp->fn_flag & (FIFOISOPEN | FIFOPOLLW)) ==
1117 1117 (FIFOISOPEN | FIFOPOLLW)) {
1118 1118 strpollwakeup(FTOV(fnp), POLLWRNORM);
1119 1119 }
1120 1120 fn_flag = fn_dest->fn_flag;
1121 1121 if ((fn_flag & FIFOISOPEN) == FIFOISOPEN) {
1122 1122 if ((fn_flag & (FIFOPOLLR | FIFOPOLLRBAND))) {
1123 1123 strpollwakeup(FTOV(fn_dest), POLLIN|POLLRDNORM);
1124 1124 }
1125 1125 }
1126 1126 /*
1127 1127 * wake up any sleeping processes so they can notice we went
1128 1128 * to streams mode
1129 1129 */
1130 1130 fnp->fn_flag &= ~(FIFOFAST|FIFOWANTW|FIFOWANTR);
1131 1131 cv_broadcast(&fnp->fn_wait_cv);
1132 1132 }
1133 1133
1134 1134 /*
1135 1135 * Alternative version of fifo_fastoff()
1136 1136 * optimized for putmsg/getmsg.
1137 1137 */
1138 1138 void
1139 1139 fifo_vfastoff(vnode_t *vp)
1140 1140 {
1141 1141 fifonode_t *fnp = VTOF(vp);
1142 1142
1143 1143 mutex_enter(&fnp->fn_lock->flk_lock);
1144 1144 if (!(fnp->fn_flag & FIFOFAST)) {
1145 1145 mutex_exit(&fnp->fn_lock->flk_lock);
1146 1146 return;
1147 1147 }
1148 1148 fifo_fastoff(fnp);
1149 1149 mutex_exit(&fnp->fn_lock->flk_lock);
1150 1150 }
1151 1151
1152 1152 /*
1153 1153 * Wake any sleeping writers, poll and send signals if necessary
1154 1154 * This module is only called when we drop below the hi water mark
1155 1155 * FIFOWANTW indicates that a process is sleeping in fifo_write()
1156 1156 * FIFOHIWATW indicates that we have either attempted a poll or
1157 1157 * non-blocking write and were over the high water mark
1158 1158 * This routine assumes a low water mark of 0.
1159 1159 */
1160 1160
1161 1161 void
1162 1162 fifo_wakewriter(fifonode_t *fn_dest, fifolock_t *fn_lock)
1163 1163 {
1164 1164 int fn_dflag = fn_dest->fn_flag;
1165 1165
1166 1166 ASSERT(MUTEX_HELD(&fn_lock->flk_lock));
1167 1167 ASSERT(fn_dest->fn_dest->fn_count < Fifohiwat);
1168 1168 if ((fn_dflag & FIFOWANTW)) {
1169 1169 cv_broadcast(&fn_dest->fn_wait_cv);
1170 1170 }
1171 1171 if ((fn_dflag & (FIFOHIWATW | FIFOISOPEN)) ==
1172 1172 (FIFOHIWATW | FIFOISOPEN)) {
1173 1173 if (fn_dflag & FIFOPOLLW)
1174 1174 strpollwakeup(FTOV(fn_dest), POLLWRNORM);
1175 1175 if (fn_dflag & FIFOSETSIG)
1176 1176 str_sendsig(FTOV(fn_dest), S_WRNORM, 0, 0);
1177 1177 }
1178 1178 /*
1179 1179 * FIFOPOLLW can't be set without setting FIFOHIWAT
1180 1180 * This allows us to clear both here.
1181 1181 */
1182 1182 fn_dest->fn_flag = fn_dflag & ~(FIFOWANTW | FIFOHIWATW | FIFOPOLLW);
1183 1183 }
1184 1184
1185 1185 /*
1186 1186 * wake up any sleeping readers, poll or send signal if needed
1187 1187 * FIFOWANTR indicates that a process is waiting in fifo_read() for data
1188 1188 * FIFOSETSIG indicates that SIGPOLL should be sent to process
1189 1189 * FIFOPOLLR indicates that a poll request for reading on the fifo was made
1190 1190 */
1191 1191
1192 1192 void
1193 1193 fifo_wakereader(fifonode_t *fn_dest, fifolock_t *fn_lock)
1194 1194 {
1195 1195 int fn_dflag = fn_dest->fn_flag;
1196 1196
1197 1197 ASSERT(MUTEX_HELD(&fn_lock->flk_lock));
1198 1198 if (fn_dflag & FIFOWANTR) {
1199 1199 cv_broadcast(&fn_dest->fn_wait_cv);
1200 1200 }
1201 1201 if (fn_dflag & FIFOISOPEN) {
1202 1202 if (fn_dflag & FIFOPOLLR)
1203 1203 strpollwakeup(FTOV(fn_dest), POLLIN | POLLRDNORM);
1204 1204 if (fn_dflag & FIFOSETSIG)
1205 1205 str_sendsig(FTOV(fn_dest), S_INPUT | S_RDNORM, 0, 0);
1206 1206 }
1207 1207 fn_dest->fn_flag = fn_dflag & ~(FIFOWANTR | FIFOPOLLR);
1208 1208 }
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