Annotation of src/sys/kern/sys_pipe.c, Revision 1.86
1.86 ! ad 1: /* $NetBSD: sys_pipe.c,v 1.85 2007/07/09 21:10:56 ad Exp $ */
1.35 pk 2:
3: /*-
1.80 ad 4: * Copyright (c) 2003, 2007 The NetBSD Foundation, Inc.
1.35 pk 5: * All rights reserved.
6: *
7: * This code is derived from software contributed to The NetBSD Foundation
1.80 ad 8: * by Paul Kranenburg, and by Andrew Doran.
1.35 pk 9: *
10: * Redistribution and use in source and binary forms, with or without
11: * modification, are permitted provided that the following conditions
12: * are met:
13: * 1. Redistributions of source code must retain the above copyright
14: * notice, this list of conditions and the following disclaimer.
15: * 2. Redistributions in binary form must reproduce the above copyright
16: * notice, this list of conditions and the following disclaimer in the
17: * documentation and/or other materials provided with the distribution.
18: * 3. All advertising materials mentioning features or use of this software
19: * must display the following acknowledgement:
20: * This product includes software developed by the NetBSD
21: * Foundation, Inc. and its contributors.
22: * 4. Neither the name of The NetBSD Foundation nor the names of its
23: * contributors may be used to endorse or promote products derived
24: * from this software without specific prior written permission.
25: *
26: * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27: * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28: * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36: * POSSIBILITY OF SUCH DAMAGE.
37: */
1.2 jdolecek 38:
1.1 jdolecek 39: /*
40: * Copyright (c) 1996 John S. Dyson
41: * All rights reserved.
42: *
43: * Redistribution and use in source and binary forms, with or without
44: * modification, are permitted provided that the following conditions
45: * are met:
46: * 1. Redistributions of source code must retain the above copyright
47: * notice immediately at the beginning of the file, without modification,
48: * this list of conditions, and the following disclaimer.
49: * 2. Redistributions in binary form must reproduce the above copyright
50: * notice, this list of conditions and the following disclaimer in the
51: * documentation and/or other materials provided with the distribution.
52: * 3. Absolutely no warranty of function or purpose is made by the author
53: * John S. Dyson.
54: * 4. Modifications may be freely made to this file if the above conditions
55: * are met.
56: *
1.24 jdolecek 57: * $FreeBSD: src/sys/kern/sys_pipe.c,v 1.95 2002/03/09 22:06:31 alfred Exp $
1.1 jdolecek 58: */
59:
60: /*
61: * This file contains a high-performance replacement for the socket-based
62: * pipes scheme originally used in FreeBSD/4.4Lite. It does not support
63: * all features of sockets, but does do everything that pipes normally
64: * do.
1.2 jdolecek 65: *
66: * Adaption for NetBSD UVM, including uvm_loan() based direct write, was
67: * written by Jaromir Dolecek.
1.1 jdolecek 68: */
69:
70: /*
71: * This code has two modes of operation, a small write mode and a large
72: * write mode. The small write mode acts like conventional pipes with
73: * a kernel buffer. If the buffer is less than PIPE_MINDIRECT, then the
74: * "normal" pipe buffering is done. If the buffer is between PIPE_MINDIRECT
1.35 pk 75: * and PIPE_SIZE in size it is mapped read-only into the kernel address space
76: * using the UVM page loan facility from where the receiving process can copy
77: * the data directly from the pages in the sending process.
1.1 jdolecek 78: *
79: * The constant PIPE_MINDIRECT is chosen to make sure that buffering will
80: * happen for small transfers so that the system will not spend all of
81: * its time context switching. PIPE_SIZE is constrained by the
82: * amount of kernel virtual memory.
83: */
1.19 lukem 84:
85: #include <sys/cdefs.h>
1.86 ! ad 86: __KERNEL_RCSID(0, "$NetBSD: sys_pipe.c,v 1.85 2007/07/09 21:10:56 ad Exp $");
1.2 jdolecek 87:
1.1 jdolecek 88: #include <sys/param.h>
89: #include <sys/systm.h>
1.2 jdolecek 90: #include <sys/proc.h>
1.1 jdolecek 91: #include <sys/fcntl.h>
92: #include <sys/file.h>
93: #include <sys/filedesc.h>
94: #include <sys/filio.h>
1.24 jdolecek 95: #include <sys/kernel.h>
1.1 jdolecek 96: #include <sys/ttycom.h>
97: #include <sys/stat.h>
1.24 jdolecek 98: #include <sys/malloc.h>
1.1 jdolecek 99: #include <sys/poll.h>
1.2 jdolecek 100: #include <sys/signalvar.h>
101: #include <sys/vnode.h>
102: #include <sys/uio.h>
103: #include <sys/lock.h>
104: #include <sys/select.h>
105: #include <sys/mount.h>
106: #include <sys/syscallargs.h>
107: #include <uvm/uvm.h>
108: #include <sys/sysctl.h>
1.72 elad 109: #include <sys/kauth.h>
1.2 jdolecek 110:
1.1 jdolecek 111: #include <sys/pipe.h>
112:
1.17 jdolecek 113: /*
1.1 jdolecek 114: * Use this define if you want to disable *fancy* VM things. Expect an
1.35 pk 115: * approx 30% decrease in transfer rate.
1.1 jdolecek 116: */
117: /* #define PIPE_NODIRECT */
118:
119: /*
120: * interfaces to the outside world
121: */
1.63 perry 122: static int pipe_read(struct file *fp, off_t *offset, struct uio *uio,
1.72 elad 123: kauth_cred_t cred, int flags);
1.63 perry 124: static int pipe_write(struct file *fp, off_t *offset, struct uio *uio,
1.72 elad 125: kauth_cred_t cred, int flags);
1.69 christos 126: static int pipe_close(struct file *fp, struct lwp *l);
127: static int pipe_poll(struct file *fp, int events, struct lwp *l);
1.27 jdolecek 128: static int pipe_kqfilter(struct file *fp, struct knote *kn);
1.69 christos 129: static int pipe_stat(struct file *fp, struct stat *sb, struct lwp *l);
1.38 dsl 130: static int pipe_ioctl(struct file *fp, u_long cmd, void *data,
1.69 christos 131: struct lwp *l);
1.1 jdolecek 132:
1.62 christos 133: static const struct fileops pipeops = {
134: pipe_read, pipe_write, pipe_ioctl, fnullop_fcntl, pipe_poll,
1.35 pk 135: pipe_stat, pipe_close, pipe_kqfilter
136: };
1.1 jdolecek 137:
138: /*
139: * Default pipe buffer size(s), this can be kind-of large now because pipe
140: * space is pageable. The pipe code will try to maintain locality of
141: * reference for performance reasons, so small amounts of outstanding I/O
142: * will not wipe the cache.
143: */
144: #define MINPIPESIZE (PIPE_SIZE/3)
145: #define MAXPIPESIZE (2*PIPE_SIZE/3)
146:
147: /*
148: * Maximum amount of kva for pipes -- this is kind-of a soft limit, but
149: * is there so that on large systems, we don't exhaust it.
150: */
151: #define MAXPIPEKVA (8*1024*1024)
1.2 jdolecek 152: static int maxpipekva = MAXPIPEKVA;
1.1 jdolecek 153:
154: /*
155: * Limit for direct transfers, we cannot, of course limit
156: * the amount of kva for pipes in general though.
157: */
158: #define LIMITPIPEKVA (16*1024*1024)
1.2 jdolecek 159: static int limitpipekva = LIMITPIPEKVA;
1.1 jdolecek 160:
161: /*
162: * Limit the number of "big" pipes
163: */
1.2 jdolecek 164: #define LIMITBIGPIPES 32
165: static int maxbigpipes = LIMITBIGPIPES;
166: static int nbigpipe = 0;
1.1 jdolecek 167:
1.2 jdolecek 168: /*
169: * Amount of KVA consumed by pipe buffers.
170: */
171: static int amountpipekva = 0;
1.34 thorpej 172:
173: MALLOC_DEFINE(M_PIPE, "pipe", "Pipe structures");
1.1 jdolecek 174:
1.42 christos 175: static void pipeclose(struct file *fp, struct pipe *pipe);
1.35 pk 176: static void pipe_free_kmem(struct pipe *pipe);
177: static int pipe_create(struct pipe **pipep, int allockva);
178: static int pipelock(struct pipe *pipe, int catch);
1.70 perry 179: static inline void pipeunlock(struct pipe *pipe);
1.66 christos 180: static void pipeselwakeup(struct pipe *pipe, struct pipe *sigp, int code);
1.1 jdolecek 181: #ifndef PIPE_NODIRECT
1.42 christos 182: static int pipe_direct_write(struct file *fp, struct pipe *wpipe,
183: struct uio *uio);
1.1 jdolecek 184: #endif
1.35 pk 185: static int pipespace(struct pipe *pipe, int size);
1.2 jdolecek 186:
187: #ifndef PIPE_NODIRECT
1.24 jdolecek 188: static int pipe_loan_alloc(struct pipe *, int);
189: static void pipe_loan_free(struct pipe *);
1.2 jdolecek 190: #endif /* PIPE_NODIRECT */
191:
1.57 simonb 192: static POOL_INIT(pipe_pool, sizeof(struct pipe), 0, 0, 0, "pipepl",
1.81 ad 193: &pool_allocator_nointr, IPL_NONE);
1.24 jdolecek 194:
1.82 ad 195: static krwlock_t pipe_peer_lock;
196:
197: void
198: pipe_init(void)
199: {
200:
201: rw_init(&pipe_peer_lock);
202: }
203:
1.1 jdolecek 204: /*
205: * The pipe system call for the DTYPE_PIPE type of pipes
206: */
207:
208: /* ARGSUSED */
1.2 jdolecek 209: int
1.77 yamt 210: sys_pipe(struct lwp *l, void *v, register_t *retval)
1.1 jdolecek 211: {
212: struct file *rf, *wf;
1.53 dsl 213: struct pipe *rpipe, *wpipe;
1.1 jdolecek 214: int fd, error;
1.2 jdolecek 215:
1.6 jdolecek 216: rpipe = wpipe = NULL;
217: if (pipe_create(&rpipe, 1) || pipe_create(&wpipe, 0)) {
1.42 christos 218: pipeclose(NULL, rpipe);
219: pipeclose(NULL, wpipe);
1.6 jdolecek 220: return (ENFILE);
221: }
222:
1.2 jdolecek 223: /*
224: * Note: the file structure returned from falloc() is marked
225: * as 'larval' initially. Unless we mark it as 'mature' by
226: * FILE_SET_MATURE(), any attempt to do anything with it would
227: * return EBADF, including e.g. dup(2) or close(2). This avoids
228: * file descriptor races if we block in the second falloc().
229: */
230:
1.74 ad 231: error = falloc(l, &rf, &fd);
1.2 jdolecek 232: if (error)
233: goto free2;
234: retval[0] = fd;
235: rf->f_flag = FREAD;
236: rf->f_type = DTYPE_PIPE;
1.79 christos 237: rf->f_data = (void *)rpipe;
1.2 jdolecek 238: rf->f_ops = &pipeops;
239:
1.74 ad 240: error = falloc(l, &wf, &fd);
1.2 jdolecek 241: if (error)
242: goto free3;
243: retval[1] = fd;
244: wf->f_flag = FWRITE;
245: wf->f_type = DTYPE_PIPE;
1.79 christos 246: wf->f_data = (void *)wpipe;
1.2 jdolecek 247: wf->f_ops = &pipeops;
248:
249: rpipe->pipe_peer = wpipe;
250: wpipe->pipe_peer = rpipe;
1.1 jdolecek 251:
1.2 jdolecek 252: FILE_SET_MATURE(rf);
253: FILE_SET_MATURE(wf);
1.69 christos 254: FILE_UNUSE(rf, l);
255: FILE_UNUSE(wf, l);
1.1 jdolecek 256: return (0);
1.2 jdolecek 257: free3:
1.69 christos 258: FILE_UNUSE(rf, l);
1.2 jdolecek 259: ffree(rf);
1.74 ad 260: fdremove(l->l_proc->p_fd, retval[0]);
1.2 jdolecek 261: free2:
1.42 christos 262: pipeclose(NULL, wpipe);
263: pipeclose(NULL, rpipe);
1.2 jdolecek 264:
265: return (error);
1.1 jdolecek 266: }
267:
268: /*
269: * Allocate kva for pipe circular buffer, the space is pageable
270: * This routine will 'realloc' the size of a pipe safely, if it fails
271: * it will retain the old buffer.
272: * If it fails it will return ENOMEM.
273: */
274: static int
1.68 thorpej 275: pipespace(struct pipe *pipe, int size)
1.1 jdolecek 276: {
1.79 christos 277: void *buffer;
1.2 jdolecek 278: /*
1.35 pk 279: * Allocate pageable virtual address space. Physical memory is
280: * allocated on demand.
1.2 jdolecek 281: */
1.79 christos 282: buffer = (void *) uvm_km_alloc(kernel_map, round_page(size), 0,
1.65 yamt 283: UVM_KMF_PAGEABLE);
1.2 jdolecek 284: if (buffer == NULL)
285: return (ENOMEM);
1.1 jdolecek 286:
287: /* free old resources if we're resizing */
1.35 pk 288: pipe_free_kmem(pipe);
289: pipe->pipe_buffer.buffer = buffer;
290: pipe->pipe_buffer.size = size;
291: pipe->pipe_buffer.in = 0;
292: pipe->pipe_buffer.out = 0;
293: pipe->pipe_buffer.cnt = 0;
294: amountpipekva += pipe->pipe_buffer.size;
1.1 jdolecek 295: return (0);
296: }
297:
298: /*
1.35 pk 299: * Initialize and allocate VM and memory for pipe.
1.1 jdolecek 300: */
301: static int
1.68 thorpej 302: pipe_create(struct pipe **pipep, int allockva)
1.1 jdolecek 303: {
1.35 pk 304: struct pipe *pipe;
1.1 jdolecek 305: int error;
306:
1.55 pooka 307: pipe = *pipep = pool_get(&pipe_pool, PR_WAITOK);
1.1 jdolecek 308:
1.63 perry 309: /* Initialize */
1.35 pk 310: memset(pipe, 0, sizeof(struct pipe));
311: pipe->pipe_state = PIPE_SIGNALR;
1.1 jdolecek 312:
1.73 kardel 313: getmicrotime(&pipe->pipe_ctime);
1.35 pk 314: pipe->pipe_atime = pipe->pipe_ctime;
315: pipe->pipe_mtime = pipe->pipe_ctime;
1.80 ad 316: mutex_init(&pipe->pipe_lock, MUTEX_DEFAULT, IPL_NONE);
317: cv_init(&pipe->pipe_cv, "pipe");
318: cv_init(&pipe->pipe_lkcv, "pipelk");
1.86 ! ad 319: selinit(&pipe->pipe_sel);
1.1 jdolecek 320:
1.53 dsl 321: if (allockva && (error = pipespace(pipe, PIPE_SIZE)))
322: return (error);
323:
1.1 jdolecek 324: return (0);
325: }
326:
327:
328: /*
1.35 pk 329: * Lock a pipe for I/O, blocking other access
330: * Called with pipe spin lock held.
331: * Return with pipe spin lock released on success.
1.1 jdolecek 332: */
1.35 pk 333: static int
1.68 thorpej 334: pipelock(struct pipe *pipe, int catch)
1.1 jdolecek 335: {
1.80 ad 336: int error;
1.1 jdolecek 337:
1.80 ad 338: KASSERT(mutex_owned(&pipe->pipe_lock));
1.35 pk 339:
1.67 yamt 340: while (pipe->pipe_state & PIPE_LOCKFL) {
341: pipe->pipe_state |= PIPE_LWANT;
1.80 ad 342: if (catch) {
343: error = cv_wait_sig(&pipe->pipe_lkcv,
344: &pipe->pipe_lock);
345: if (error != 0)
346: return error;
347: } else
348: cv_wait(&pipe->pipe_lkcv, &pipe->pipe_lock);
1.1 jdolecek 349: }
1.67 yamt 350:
351: pipe->pipe_state |= PIPE_LOCKFL;
1.80 ad 352: mutex_exit(&pipe->pipe_lock);
1.67 yamt 353:
354: return 0;
1.1 jdolecek 355: }
356:
357: /*
358: * unlock a pipe I/O lock
359: */
1.70 perry 360: static inline void
1.68 thorpej 361: pipeunlock(struct pipe *pipe)
1.1 jdolecek 362: {
1.24 jdolecek 363:
1.67 yamt 364: KASSERT(pipe->pipe_state & PIPE_LOCKFL);
365:
366: pipe->pipe_state &= ~PIPE_LOCKFL;
367: if (pipe->pipe_state & PIPE_LWANT) {
368: pipe->pipe_state &= ~PIPE_LWANT;
1.80 ad 369: cv_broadcast(&pipe->pipe_lkcv);
1.67 yamt 370: }
1.1 jdolecek 371: }
372:
1.2 jdolecek 373: /*
374: * Select/poll wakup. This also sends SIGIO to peer connected to
375: * 'sigpipe' side of pipe.
376: */
1.35 pk 377: static void
1.68 thorpej 378: pipeselwakeup(struct pipe *selp, struct pipe *sigp, int code)
1.1 jdolecek 379: {
1.43 jdolecek 380: int band;
1.27 jdolecek 381:
1.48 jdolecek 382: selnotify(&selp->pipe_sel, NOTE_SUBMIT);
1.43 jdolecek 383:
1.35 pk 384: if (sigp == NULL || (sigp->pipe_state & PIPE_ASYNC) == 0)
385: return;
386:
1.43 jdolecek 387: switch (code) {
1.42 christos 388: case POLL_IN:
1.43 jdolecek 389: band = POLLIN|POLLRDNORM;
1.42 christos 390: break;
391: case POLL_OUT:
1.43 jdolecek 392: band = POLLOUT|POLLWRNORM;
1.42 christos 393: break;
394: case POLL_HUP:
1.43 jdolecek 395: band = POLLHUP;
1.42 christos 396: break;
397: #if POLL_HUP != POLL_ERR
398: case POLL_ERR:
1.43 jdolecek 399: band = POLLERR;
1.42 christos 400: break;
401: #endif
402: default:
1.45 christos 403: band = 0;
1.42 christos 404: #ifdef DIAGNOSTIC
405: printf("bad siginfo code %d in pipe notification.\n", code);
406: #endif
407: break;
408: }
1.43 jdolecek 409:
1.44 christos 410: fownsignal(sigp->pipe_pgid, SIGIO, code, band, selp);
1.1 jdolecek 411: }
412:
413: /* ARGSUSED */
1.2 jdolecek 414: static int
1.77 yamt 415: pipe_read(struct file *fp, off_t *offset, struct uio *uio, kauth_cred_t cred,
416: int flags)
1.1 jdolecek 417: {
418: struct pipe *rpipe = (struct pipe *) fp->f_data;
1.35 pk 419: struct pipebuf *bp = &rpipe->pipe_buffer;
1.1 jdolecek 420: int error;
1.2 jdolecek 421: size_t nread = 0;
422: size_t size;
423: size_t ocnt;
1.1 jdolecek 424:
1.80 ad 425: mutex_enter(&rpipe->pipe_lock);
1.1 jdolecek 426: ++rpipe->pipe_busy;
1.35 pk 427: ocnt = bp->cnt;
1.28 jdolecek 428:
1.35 pk 429: again:
1.1 jdolecek 430: error = pipelock(rpipe, 1);
431: if (error)
432: goto unlocked_error;
1.2 jdolecek 433:
1.1 jdolecek 434: while (uio->uio_resid) {
435: /*
436: * normal pipe buffer receive
437: */
1.35 pk 438: if (bp->cnt > 0) {
439: size = bp->size - bp->out;
440: if (size > bp->cnt)
441: size = bp->cnt;
1.2 jdolecek 442: if (size > uio->uio_resid)
443: size = uio->uio_resid;
1.1 jdolecek 444:
1.79 christos 445: error = uiomove((char *)bp->buffer + bp->out, size, uio);
1.1 jdolecek 446: if (error)
447: break;
448:
1.35 pk 449: bp->out += size;
450: if (bp->out >= bp->size)
451: bp->out = 0;
1.1 jdolecek 452:
1.35 pk 453: bp->cnt -= size;
1.1 jdolecek 454:
455: /*
456: * If there is no more to read in the pipe, reset
457: * its pointers to the beginning. This improves
458: * cache hit stats.
459: */
1.35 pk 460: if (bp->cnt == 0) {
461: bp->in = 0;
462: bp->out = 0;
1.1 jdolecek 463: }
464: nread += size;
1.85 ad 465: continue;
466: }
467:
468: /* Lock to see up-to-date value of pipe_status. */
469: mutex_enter(&rpipe->pipe_lock);
470:
1.1 jdolecek 471: #ifndef PIPE_NODIRECT
1.85 ad 472: if ((rpipe->pipe_state & PIPE_DIRECTR) != 0) {
1.35 pk 473: /*
474: * Direct copy, bypassing a kernel buffer.
475: */
1.79 christos 476: void * va;
1.35 pk 477:
478: KASSERT(rpipe->pipe_state & PIPE_DIRECTW);
1.85 ad 479: mutex_exit(&rpipe->pipe_lock);
1.35 pk 480:
481: size = rpipe->pipe_map.cnt;
1.2 jdolecek 482: if (size > uio->uio_resid)
483: size = uio->uio_resid;
1.1 jdolecek 484:
1.79 christos 485: va = (char *)rpipe->pipe_map.kva + rpipe->pipe_map.pos;
1.1 jdolecek 486: error = uiomove(va, size, uio);
487: if (error)
488: break;
489: nread += size;
490: rpipe->pipe_map.pos += size;
491: rpipe->pipe_map.cnt -= size;
492: if (rpipe->pipe_map.cnt == 0) {
1.80 ad 493: mutex_enter(&rpipe->pipe_lock);
1.35 pk 494: rpipe->pipe_state &= ~PIPE_DIRECTR;
1.80 ad 495: cv_broadcast(&rpipe->pipe_cv);
496: mutex_exit(&rpipe->pipe_lock);
1.1 jdolecek 497: }
1.85 ad 498: continue;
499: }
1.1 jdolecek 500: #endif
1.85 ad 501: /*
502: * Break if some data was read.
503: */
504: if (nread > 0) {
505: mutex_exit(&rpipe->pipe_lock);
506: break;
507: }
1.1 jdolecek 508:
1.85 ad 509: /*
510: * detect EOF condition
511: * read returns 0 on EOF, no need to set error
512: */
513: if (rpipe->pipe_state & PIPE_EOF) {
514: mutex_exit(&rpipe->pipe_lock);
515: break;
516: }
1.36 pk 517:
1.85 ad 518: /*
519: * don't block on non-blocking I/O
520: */
521: if (fp->f_flag & FNONBLOCK) {
522: mutex_exit(&rpipe->pipe_lock);
523: error = EAGAIN;
524: break;
525: }
1.1 jdolecek 526:
1.85 ad 527: /*
528: * Unlock the pipe buffer for our remaining processing.
529: * We will either break out with an error or we will
530: * sleep and relock to loop.
531: */
532: pipeunlock(rpipe);
1.2 jdolecek 533:
1.85 ad 534: /*
535: * Re-check to see if more direct writes are pending.
536: */
537: if ((rpipe->pipe_state & PIPE_DIRECTR) != 0)
538: goto again;
1.1 jdolecek 539:
1.85 ad 540: /*
541: * We want to read more, wake up select/poll.
542: */
543: pipeselwakeup(rpipe, rpipe->pipe_peer, POLL_IN);
1.35 pk 544:
1.85 ad 545: /*
546: * If the "write-side" is blocked, wake it up now.
547: */
548: if (rpipe->pipe_state & PIPE_WANTW) {
549: rpipe->pipe_state &= ~PIPE_WANTW;
550: cv_broadcast(&rpipe->pipe_cv);
551: }
1.2 jdolecek 552:
1.85 ad 553: /* Now wait until the pipe is filled */
554: rpipe->pipe_state |= PIPE_WANTR;
555: error = cv_wait_sig(&rpipe->pipe_cv, &rpipe->pipe_lock);
556: if (error != 0)
557: goto unlocked_error;
558: goto again;
1.1 jdolecek 559: }
1.35 pk 560:
561: if (error == 0)
1.73 kardel 562: getmicrotime(&rpipe->pipe_atime);
1.35 pk 563:
1.80 ad 564: mutex_enter(&rpipe->pipe_lock);
1.1 jdolecek 565: pipeunlock(rpipe);
566:
567: unlocked_error:
568: --rpipe->pipe_busy;
569:
570: /*
1.2 jdolecek 571: * PIPE_WANTCLOSE processing only makes sense if pipe_busy is 0.
1.1 jdolecek 572: */
1.2 jdolecek 573: if ((rpipe->pipe_busy == 0) && (rpipe->pipe_state & PIPE_WANTCLOSE)) {
574: rpipe->pipe_state &= ~(PIPE_WANTCLOSE|PIPE_WANTW);
1.80 ad 575: cv_broadcast(&rpipe->pipe_cv);
1.35 pk 576: } else if (bp->cnt < MINPIPESIZE) {
1.1 jdolecek 577: /*
578: * Handle write blocking hysteresis.
579: */
580: if (rpipe->pipe_state & PIPE_WANTW) {
581: rpipe->pipe_state &= ~PIPE_WANTW;
1.80 ad 582: cv_broadcast(&rpipe->pipe_cv);
1.1 jdolecek 583: }
584: }
585:
1.2 jdolecek 586: /*
587: * If anything was read off the buffer, signal to the writer it's
588: * possible to write more data. Also send signal if we are here for the
589: * first time after last write.
590: */
1.35 pk 591: if ((bp->size - bp->cnt) >= PIPE_BUF
592: && (ocnt != bp->cnt || (rpipe->pipe_state & PIPE_SIGNALR))) {
1.66 christos 593: pipeselwakeup(rpipe, rpipe->pipe_peer, POLL_OUT);
1.2 jdolecek 594: rpipe->pipe_state &= ~PIPE_SIGNALR;
595: }
1.1 jdolecek 596:
1.80 ad 597: mutex_exit(&rpipe->pipe_lock);
1.1 jdolecek 598: return (error);
599: }
600:
1.2 jdolecek 601: #ifndef PIPE_NODIRECT
602: /*
603: * Allocate structure for loan transfer.
604: */
1.18 chs 605: static int
1.68 thorpej 606: pipe_loan_alloc(struct pipe *wpipe, int npages)
1.2 jdolecek 607: {
1.18 chs 608: vsize_t len;
609:
610: len = (vsize_t)npages << PAGE_SHIFT;
1.65 yamt 611: wpipe->pipe_map.kva = uvm_km_alloc(kernel_map, len, 0,
612: UVM_KMF_VAONLY | UVM_KMF_WAITVA);
1.22 thorpej 613: if (wpipe->pipe_map.kva == 0)
1.2 jdolecek 614: return (ENOMEM);
615:
1.18 chs 616: amountpipekva += len;
1.2 jdolecek 617: wpipe->pipe_map.npages = npages;
1.18 chs 618: wpipe->pipe_map.pgs = malloc(npages * sizeof(struct vm_page *), M_PIPE,
619: M_WAITOK);
1.2 jdolecek 620: return (0);
621: }
622:
623: /*
624: * Free resources allocated for loan transfer.
625: */
626: static void
1.68 thorpej 627: pipe_loan_free(struct pipe *wpipe)
1.2 jdolecek 628: {
1.18 chs 629: vsize_t len;
630:
631: len = (vsize_t)wpipe->pipe_map.npages << PAGE_SHIFT;
1.65 yamt 632: uvm_km_free(kernel_map, wpipe->pipe_map.kva, len, UVM_KMF_VAONLY);
1.22 thorpej 633: wpipe->pipe_map.kva = 0;
1.18 chs 634: amountpipekva -= len;
635: free(wpipe->pipe_map.pgs, M_PIPE);
636: wpipe->pipe_map.pgs = NULL;
1.2 jdolecek 637: }
638:
639: /*
640: * NetBSD direct write, using uvm_loan() mechanism.
641: * This implements the pipe buffer write mechanism. Note that only
642: * a direct write OR a normal pipe write can be pending at any given time.
643: * If there are any characters in the pipe buffer, the direct write will
644: * be deferred until the receiving process grabs all of the bytes from
645: * the pipe buffer. Then the direct mapping write is set-up.
1.35 pk 646: *
647: * Called with the long-term pipe lock held.
1.2 jdolecek 648: */
1.18 chs 649: static int
1.77 yamt 650: pipe_direct_write(struct file *fp, struct pipe *wpipe, struct uio *uio)
1.2 jdolecek 651: {
1.5 jdolecek 652: int error, npages, j;
1.18 chs 653: struct vm_page **pgs;
1.2 jdolecek 654: vaddr_t bbase, kva, base, bend;
655: vsize_t blen, bcnt;
1.5 jdolecek 656: voff_t bpos;
657:
1.35 pk 658: KASSERT(wpipe->pipe_map.cnt == 0);
1.2 jdolecek 659:
660: /*
1.14 jdolecek 661: * Handle first PIPE_CHUNK_SIZE bytes of buffer. Deal with buffers
662: * not aligned to PAGE_SIZE.
1.5 jdolecek 663: */
1.14 jdolecek 664: bbase = (vaddr_t)uio->uio_iov->iov_base;
1.5 jdolecek 665: base = trunc_page(bbase);
1.14 jdolecek 666: bend = round_page(bbase + uio->uio_iov->iov_len);
1.5 jdolecek 667: blen = bend - base;
668: bpos = bbase - base;
669:
670: if (blen > PIPE_DIRECT_CHUNK) {
671: blen = PIPE_DIRECT_CHUNK;
672: bend = base + blen;
673: bcnt = PIPE_DIRECT_CHUNK - bpos;
1.18 chs 674: } else {
1.14 jdolecek 675: bcnt = uio->uio_iov->iov_len;
1.18 chs 676: }
677: npages = blen >> PAGE_SHIFT;
1.5 jdolecek 678:
679: /*
680: * Free the old kva if we need more pages than we have
681: * allocated.
1.2 jdolecek 682: */
1.35 pk 683: if (wpipe->pipe_map.kva != 0 && npages > wpipe->pipe_map.npages)
1.5 jdolecek 684: pipe_loan_free(wpipe);
1.2 jdolecek 685:
1.5 jdolecek 686: /* Allocate new kva. */
1.22 thorpej 687: if (wpipe->pipe_map.kva == 0) {
1.18 chs 688: error = pipe_loan_alloc(wpipe, npages);
1.35 pk 689: if (error)
690: return (error);
1.18 chs 691: }
692:
1.5 jdolecek 693: /* Loan the write buffer memory from writer process */
1.18 chs 694: pgs = wpipe->pipe_map.pgs;
1.71 yamt 695: error = uvm_loan(&uio->uio_vmspace->vm_map, base, blen,
1.35 pk 696: pgs, UVM_LOAN_TOPAGE);
1.18 chs 697: if (error) {
1.35 pk 698: pipe_loan_free(wpipe);
1.61 yamt 699: return (ENOMEM); /* so that caller fallback to ordinary write */
1.18 chs 700: }
701:
1.5 jdolecek 702: /* Enter the loaned pages to kva */
703: kva = wpipe->pipe_map.kva;
1.18 chs 704: for (j = 0; j < npages; j++, kva += PAGE_SIZE) {
705: pmap_kenter_pa(kva, VM_PAGE_TO_PHYS(pgs[j]), VM_PROT_READ);
706: }
1.12 jdolecek 707: pmap_update(pmap_kernel());
1.2 jdolecek 708:
1.35 pk 709: /* Now we can put the pipe in direct write mode */
710: wpipe->pipe_map.pos = bpos;
711: wpipe->pipe_map.cnt = bcnt;
712:
713: /*
1.85 ad 714: * But before we can let someone do a direct read, we
715: * have to wait until the pipe is drained. Release the
716: * pipe lock while we wait.
1.35 pk 717: */
1.80 ad 718: mutex_enter(&wpipe->pipe_lock);
1.85 ad 719: wpipe->pipe_state |= PIPE_DIRECTW;
1.35 pk 720: pipeunlock(wpipe);
721:
722: while (error == 0 && wpipe->pipe_buffer.cnt > 0) {
723: if (wpipe->pipe_state & PIPE_WANTR) {
724: wpipe->pipe_state &= ~PIPE_WANTR;
1.80 ad 725: cv_broadcast(&wpipe->pipe_cv);
1.35 pk 726: }
727:
728: wpipe->pipe_state |= PIPE_WANTW;
1.80 ad 729: error = cv_wait_sig(&wpipe->pipe_cv, &wpipe->pipe_lock);
1.35 pk 730: if (error == 0 && wpipe->pipe_state & PIPE_EOF)
1.5 jdolecek 731: error = EPIPE;
1.35 pk 732: }
733:
734: /* Pipe is drained; next read will off the direct buffer */
735: wpipe->pipe_state |= PIPE_DIRECTR;
736:
737: /* Wait until the reader is done */
738: while (error == 0 && (wpipe->pipe_state & PIPE_DIRECTR)) {
1.5 jdolecek 739: if (wpipe->pipe_state & PIPE_WANTR) {
740: wpipe->pipe_state &= ~PIPE_WANTR;
1.80 ad 741: cv_broadcast(&wpipe->pipe_cv);
1.2 jdolecek 742: }
1.66 christos 743: pipeselwakeup(wpipe, wpipe, POLL_IN);
1.80 ad 744: error = cv_wait_sig(&wpipe->pipe_cv, &wpipe->pipe_lock);
1.35 pk 745: if (error == 0 && wpipe->pipe_state & PIPE_EOF)
746: error = EPIPE;
1.5 jdolecek 747: }
748:
1.35 pk 749: /* Take pipe out of direct write mode */
750: wpipe->pipe_state &= ~(PIPE_DIRECTW | PIPE_DIRECTR);
1.2 jdolecek 751:
1.35 pk 752: /* Acquire the pipe lock and cleanup */
753: (void)pipelock(wpipe, 0);
1.85 ad 754:
1.21 chs 755: if (pgs != NULL) {
756: pmap_kremove(wpipe->pipe_map.kva, blen);
1.18 chs 757: uvm_unloan(pgs, npages, UVM_LOAN_TOPAGE);
1.21 chs 758: }
1.5 jdolecek 759: if (error || amountpipekva > maxpipekva)
760: pipe_loan_free(wpipe);
761:
1.15 jdolecek 762: if (error) {
1.66 christos 763: pipeselwakeup(wpipe, wpipe, POLL_ERR);
1.2 jdolecek 764:
1.5 jdolecek 765: /*
1.15 jdolecek 766: * If nothing was read from what we offered, return error
1.18 chs 767: * straight on. Otherwise update uio resid first. Caller
1.15 jdolecek 768: * will deal with the error condition, returning short
769: * write, error, or restarting the write(2) as appropriate.
1.5 jdolecek 770: */
1.15 jdolecek 771: if (wpipe->pipe_map.cnt == bcnt) {
1.35 pk 772: wpipe->pipe_map.cnt = 0;
1.80 ad 773: cv_broadcast(&wpipe->pipe_cv);
1.15 jdolecek 774: return (error);
1.2 jdolecek 775: }
776:
1.15 jdolecek 777: bcnt -= wpipe->pipe_map.cnt;
1.5 jdolecek 778: }
1.2 jdolecek 779:
1.18 chs 780: uio->uio_resid -= bcnt;
1.8 jdolecek 781: /* uio_offset not updated, not set/used for write(2) */
1.18 chs 782: uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + bcnt;
1.14 jdolecek 783: uio->uio_iov->iov_len -= bcnt;
784: if (uio->uio_iov->iov_len == 0) {
785: uio->uio_iov++;
786: uio->uio_iovcnt--;
787: }
1.2 jdolecek 788:
1.35 pk 789: wpipe->pipe_map.cnt = 0;
1.15 jdolecek 790: return (error);
1.2 jdolecek 791: }
792: #endif /* !PIPE_NODIRECT */
793:
794: static int
1.77 yamt 795: pipe_write(struct file *fp, off_t *offset, struct uio *uio, kauth_cred_t cred,
796: int flags)
1.1 jdolecek 797: {
798: struct pipe *wpipe, *rpipe;
1.35 pk 799: struct pipebuf *bp;
800: int error;
1.1 jdolecek 801:
1.35 pk 802: /* We want to write to our peer */
1.1 jdolecek 803: rpipe = (struct pipe *) fp->f_data;
1.35 pk 804:
805: retry:
806: error = 0;
1.80 ad 807: mutex_enter(&rpipe->pipe_lock);
1.1 jdolecek 808: wpipe = rpipe->pipe_peer;
809:
810: /*
1.35 pk 811: * Detect loss of pipe read side, issue SIGPIPE if lost.
1.1 jdolecek 812: */
1.35 pk 813: if (wpipe == NULL)
814: error = EPIPE;
1.80 ad 815: else if (mutex_tryenter(&wpipe->pipe_lock) == 0) {
1.35 pk 816: /* Deal with race for peer */
1.80 ad 817: mutex_exit(&rpipe->pipe_lock);
1.85 ad 818: /* XXX Might be about to deadlock w/kernel_lock. */
819: yield();
1.35 pk 820: goto retry;
821: } else if ((wpipe->pipe_state & PIPE_EOF) != 0) {
1.80 ad 822: mutex_exit(&wpipe->pipe_lock);
1.35 pk 823: error = EPIPE;
1.24 jdolecek 824: }
1.2 jdolecek 825:
1.80 ad 826: mutex_exit(&rpipe->pipe_lock);
1.35 pk 827: if (error != 0)
828: return (error);
829:
1.1 jdolecek 830: ++wpipe->pipe_busy;
831:
1.35 pk 832: /* Aquire the long-term pipe lock */
833: if ((error = pipelock(wpipe,1)) != 0) {
834: --wpipe->pipe_busy;
835: if (wpipe->pipe_busy == 0
836: && (wpipe->pipe_state & PIPE_WANTCLOSE)) {
837: wpipe->pipe_state &= ~(PIPE_WANTCLOSE | PIPE_WANTR);
1.80 ad 838: cv_broadcast(&wpipe->pipe_cv);
1.35 pk 839: }
1.80 ad 840: mutex_exit(&wpipe->pipe_lock);
1.35 pk 841: return (error);
842: }
843:
844: bp = &wpipe->pipe_buffer;
845:
1.1 jdolecek 846: /*
1.35 pk 847: * If it is advantageous to resize the pipe buffer, do so.
1.1 jdolecek 848: */
849: if ((uio->uio_resid > PIPE_SIZE) &&
1.35 pk 850: (nbigpipe < maxbigpipes) &&
1.2 jdolecek 851: #ifndef PIPE_NODIRECT
1.35 pk 852: (wpipe->pipe_state & PIPE_DIRECTW) == 0 &&
1.2 jdolecek 853: #endif
1.35 pk 854: (bp->size <= PIPE_SIZE) && (bp->cnt == 0)) {
1.1 jdolecek 855:
1.35 pk 856: if (pipespace(wpipe, BIG_PIPE_SIZE) == 0)
857: nbigpipe++;
1.24 jdolecek 858: }
1.1 jdolecek 859:
860: while (uio->uio_resid) {
1.26 thorpej 861: size_t space;
1.1 jdolecek 862:
863: #ifndef PIPE_NODIRECT
864: /*
1.35 pk 865: * Pipe buffered writes cannot be coincidental with
866: * direct writes. Also, only one direct write can be
867: * in progress at any one time. We wait until the currently
868: * executing direct write is completed before continuing.
869: *
870: * We break out if a signal occurs or the reader goes away.
871: */
872: while (error == 0 && wpipe->pipe_state & PIPE_DIRECTW) {
1.80 ad 873: mutex_enter(&wpipe->pipe_lock);
1.35 pk 874: if (wpipe->pipe_state & PIPE_WANTR) {
875: wpipe->pipe_state &= ~PIPE_WANTR;
1.80 ad 876: cv_broadcast(&wpipe->pipe_cv);
1.35 pk 877: }
878: pipeunlock(wpipe);
1.80 ad 879: error = cv_wait_sig(&wpipe->pipe_cv,
880: &wpipe->pipe_lock);
1.35 pk 881:
882: (void)pipelock(wpipe, 0);
883: if (wpipe->pipe_state & PIPE_EOF)
884: error = EPIPE;
885: }
886: if (error)
887: break;
888:
889: /*
1.1 jdolecek 890: * If the transfer is large, we can gain performance if
891: * we do process-to-process copies directly.
892: * If the write is non-blocking, we don't use the
893: * direct write mechanism.
894: *
895: * The direct write mechanism will detect the reader going
896: * away on us.
897: */
1.14 jdolecek 898: if ((uio->uio_iov->iov_len >= PIPE_MINDIRECT) &&
1.1 jdolecek 899: (fp->f_flag & FNONBLOCK) == 0 &&
1.2 jdolecek 900: (wpipe->pipe_map.kva || (amountpipekva < limitpipekva))) {
1.42 christos 901: error = pipe_direct_write(fp, wpipe, uio);
1.5 jdolecek 902:
903: /*
1.49 wiz 904: * Break out if error occurred, unless it's ENOMEM.
1.14 jdolecek 905: * ENOMEM means we failed to allocate some resources
906: * for direct write, so we just fallback to ordinary
907: * write. If the direct write was successful,
908: * process rest of data via ordinary write.
1.5 jdolecek 909: */
1.35 pk 910: if (error == 0)
1.14 jdolecek 911: continue;
912:
1.5 jdolecek 913: if (error != ENOMEM)
1.1 jdolecek 914: break;
915: }
1.2 jdolecek 916: #endif /* PIPE_NODIRECT */
1.1 jdolecek 917:
1.35 pk 918: space = bp->size - bp->cnt;
1.1 jdolecek 919:
920: /* Writes of size <= PIPE_BUF must be atomic. */
1.14 jdolecek 921: if ((space < uio->uio_resid) && (uio->uio_resid <= PIPE_BUF))
1.1 jdolecek 922: space = 0;
923:
1.16 mycroft 924: if (space > 0) {
1.2 jdolecek 925: int size; /* Transfer size */
926: int segsize; /* first segment to transfer */
927:
928: /*
929: * Transfer size is minimum of uio transfer
930: * and free space in pipe buffer.
931: */
932: if (space > uio->uio_resid)
933: size = uio->uio_resid;
934: else
935: size = space;
936: /*
1.63 perry 937: * First segment to transfer is minimum of
1.2 jdolecek 938: * transfer size and contiguous space in
939: * pipe buffer. If first segment to transfer
940: * is less than the transfer size, we've got
941: * a wraparound in the buffer.
942: */
1.35 pk 943: segsize = bp->size - bp->in;
1.2 jdolecek 944: if (segsize > size)
945: segsize = size;
1.18 chs 946:
1.2 jdolecek 947: /* Transfer first segment */
1.79 christos 948: error = uiomove((char *)bp->buffer + bp->in, segsize,
949: uio);
1.18 chs 950:
1.2 jdolecek 951: if (error == 0 && segsize < size) {
1.63 perry 952: /*
1.2 jdolecek 953: * Transfer remaining part now, to
954: * support atomic writes. Wraparound
955: * happened.
956: */
957: #ifdef DEBUG
1.35 pk 958: if (bp->in + segsize != bp->size)
1.2 jdolecek 959: panic("Expected pipe buffer wraparound disappeared");
960: #endif
1.18 chs 961:
1.79 christos 962: error = uiomove(bp->buffer,
963: size - segsize, uio);
1.2 jdolecek 964: }
1.35 pk 965: if (error)
966: break;
967:
968: bp->in += size;
969: if (bp->in >= bp->size) {
1.2 jdolecek 970: #ifdef DEBUG
1.35 pk 971: if (bp->in != size - segsize + bp->size)
972: panic("Expected wraparound bad");
1.2 jdolecek 973: #endif
1.35 pk 974: bp->in = size - segsize;
975: }
1.18 chs 976:
1.35 pk 977: bp->cnt += size;
1.2 jdolecek 978: #ifdef DEBUG
1.35 pk 979: if (bp->cnt > bp->size)
980: panic("Pipe buffer overflow");
1.2 jdolecek 981: #endif
1.1 jdolecek 982: } else {
983: /*
984: * If the "read-side" has been blocked, wake it up now.
985: */
1.80 ad 986: mutex_enter(&wpipe->pipe_lock);
1.1 jdolecek 987: if (wpipe->pipe_state & PIPE_WANTR) {
988: wpipe->pipe_state &= ~PIPE_WANTR;
1.80 ad 989: cv_broadcast(&wpipe->pipe_cv);
1.1 jdolecek 990: }
1.80 ad 991: mutex_exit(&wpipe->pipe_lock);
1.1 jdolecek 992:
993: /*
994: * don't block on non-blocking I/O
995: */
996: if (fp->f_flag & FNONBLOCK) {
997: error = EAGAIN;
998: break;
999: }
1000:
1001: /*
1002: * We have no more space and have something to offer,
1003: * wake up select/poll.
1004: */
1.35 pk 1005: if (bp->cnt)
1.66 christos 1006: pipeselwakeup(wpipe, wpipe, POLL_OUT);
1.1 jdolecek 1007:
1.80 ad 1008: mutex_enter(&wpipe->pipe_lock);
1.35 pk 1009: pipeunlock(wpipe);
1.1 jdolecek 1010: wpipe->pipe_state |= PIPE_WANTW;
1.80 ad 1011: error = cv_wait_sig(&wpipe->pipe_cv,
1012: &wpipe->pipe_lock);
1.35 pk 1013: (void)pipelock(wpipe, 0);
1.1 jdolecek 1014: if (error != 0)
1015: break;
1016: /*
1017: * If read side wants to go away, we just issue a signal
1018: * to ourselves.
1019: */
1020: if (wpipe->pipe_state & PIPE_EOF) {
1021: error = EPIPE;
1022: break;
1.18 chs 1023: }
1.1 jdolecek 1024: }
1025: }
1026:
1.80 ad 1027: mutex_enter(&wpipe->pipe_lock);
1.1 jdolecek 1028: --wpipe->pipe_busy;
1.2 jdolecek 1029: if ((wpipe->pipe_busy == 0) && (wpipe->pipe_state & PIPE_WANTCLOSE)) {
1030: wpipe->pipe_state &= ~(PIPE_WANTCLOSE | PIPE_WANTR);
1.80 ad 1031: cv_broadcast(&wpipe->pipe_cv);
1.35 pk 1032: } else if (bp->cnt > 0) {
1.1 jdolecek 1033: /*
1034: * If we have put any characters in the buffer, we wake up
1035: * the reader.
1036: */
1037: if (wpipe->pipe_state & PIPE_WANTR) {
1038: wpipe->pipe_state &= ~PIPE_WANTR;
1.80 ad 1039: cv_broadcast(&wpipe->pipe_cv);
1.1 jdolecek 1040: }
1041: }
1042:
1043: /*
1044: * Don't return EPIPE if I/O was successful
1045: */
1.35 pk 1046: if (error == EPIPE && bp->cnt == 0 && uio->uio_resid == 0)
1.1 jdolecek 1047: error = 0;
1048:
1049: if (error == 0)
1.73 kardel 1050: getmicrotime(&wpipe->pipe_mtime);
1.1 jdolecek 1051:
1052: /*
1.2 jdolecek 1053: * We have something to offer, wake up select/poll.
1054: * wpipe->pipe_map.cnt is always 0 in this point (direct write
1.14 jdolecek 1055: * is only done synchronously), so check only wpipe->pipe_buffer.cnt
1.1 jdolecek 1056: */
1.35 pk 1057: if (bp->cnt)
1.66 christos 1058: pipeselwakeup(wpipe, wpipe, POLL_OUT);
1.1 jdolecek 1059:
1.2 jdolecek 1060: /*
1061: * Arrange for next read(2) to do a signal.
1062: */
1063: wpipe->pipe_state |= PIPE_SIGNALR;
1064:
1.35 pk 1065: pipeunlock(wpipe);
1.80 ad 1066: mutex_exit(&wpipe->pipe_lock);
1.1 jdolecek 1067: return (error);
1068: }
1069:
1070: /*
1071: * we implement a very minimal set of ioctls for compatibility with sockets.
1072: */
1073: int
1.69 christos 1074: pipe_ioctl(struct file *fp, u_long cmd, void *data, struct lwp *l)
1.1 jdolecek 1075: {
1.35 pk 1076: struct pipe *pipe = (struct pipe *)fp->f_data;
1.69 christos 1077: struct proc *p = l->l_proc;
1.1 jdolecek 1078:
1079: switch (cmd) {
1080:
1081: case FIONBIO:
1082: return (0);
1083:
1084: case FIOASYNC:
1.80 ad 1085: mutex_enter(&pipe->pipe_lock);
1.1 jdolecek 1086: if (*(int *)data) {
1.35 pk 1087: pipe->pipe_state |= PIPE_ASYNC;
1.1 jdolecek 1088: } else {
1.35 pk 1089: pipe->pipe_state &= ~PIPE_ASYNC;
1.1 jdolecek 1090: }
1.80 ad 1091: mutex_exit(&pipe->pipe_lock);
1.1 jdolecek 1092: return (0);
1093:
1094: case FIONREAD:
1.80 ad 1095: mutex_enter(&pipe->pipe_lock);
1.2 jdolecek 1096: #ifndef PIPE_NODIRECT
1.35 pk 1097: if (pipe->pipe_state & PIPE_DIRECTW)
1098: *(int *)data = pipe->pipe_map.cnt;
1.1 jdolecek 1099: else
1.2 jdolecek 1100: #endif
1.35 pk 1101: *(int *)data = pipe->pipe_buffer.cnt;
1.80 ad 1102: mutex_exit(&pipe->pipe_lock);
1.1 jdolecek 1103: return (0);
1104:
1.59 wrstuden 1105: case FIONWRITE:
1106: /* Look at other side */
1.83 ad 1107: rw_enter(&pipe_peer_lock, RW_READER);
1.59 wrstuden 1108: pipe = pipe->pipe_peer;
1.80 ad 1109: mutex_enter(&pipe->pipe_lock);
1.59 wrstuden 1110: #ifndef PIPE_NODIRECT
1111: if (pipe->pipe_state & PIPE_DIRECTW)
1112: *(int *)data = pipe->pipe_map.cnt;
1113: else
1114: #endif
1115: *(int *)data = pipe->pipe_buffer.cnt;
1.80 ad 1116: mutex_exit(&pipe->pipe_lock);
1.82 ad 1117: rw_exit(&pipe_peer_lock);
1.59 wrstuden 1118: return (0);
1119:
1120: case FIONSPACE:
1121: /* Look at other side */
1.83 ad 1122: rw_enter(&pipe_peer_lock, RW_READER);
1.59 wrstuden 1123: pipe = pipe->pipe_peer;
1.80 ad 1124: mutex_enter(&pipe->pipe_lock);
1.59 wrstuden 1125: #ifndef PIPE_NODIRECT
1126: /*
1127: * If we're in direct-mode, we don't really have a
1128: * send queue, and any other write will block. Thus
1129: * zero seems like the best answer.
1130: */
1131: if (pipe->pipe_state & PIPE_DIRECTW)
1132: *(int *)data = 0;
1133: else
1134: #endif
1135: *(int *)data = pipe->pipe_buffer.size -
1.82 ad 1136: pipe->pipe_buffer.cnt;
1.80 ad 1137: mutex_exit(&pipe->pipe_lock);
1.82 ad 1138: rw_exit(&pipe_peer_lock);
1.59 wrstuden 1139: return (0);
1140:
1.2 jdolecek 1141: case TIOCSPGRP:
1.43 jdolecek 1142: case FIOSETOWN:
1143: return fsetown(p, &pipe->pipe_pgid, cmd, data);
1.2 jdolecek 1144:
1145: case TIOCGPGRP:
1.43 jdolecek 1146: case FIOGETOWN:
1147: return fgetown(p, pipe->pipe_pgid, cmd, data);
1.1 jdolecek 1148:
1149: }
1.25 atatat 1150: return (EPASSTHROUGH);
1.1 jdolecek 1151: }
1152:
1153: int
1.69 christos 1154: pipe_poll(struct file *fp, int events, struct lwp *l)
1.1 jdolecek 1155: {
1156: struct pipe *rpipe = (struct pipe *)fp->f_data;
1157: struct pipe *wpipe;
1.35 pk 1158: int eof = 0;
1.1 jdolecek 1159: int revents = 0;
1160:
1.35 pk 1161: retry:
1.80 ad 1162: mutex_enter(&rpipe->pipe_lock);
1.1 jdolecek 1163: wpipe = rpipe->pipe_peer;
1.80 ad 1164: if (wpipe != NULL && mutex_tryenter(&wpipe->pipe_lock) == 0) {
1.35 pk 1165: /* Deal with race for peer */
1.80 ad 1166: mutex_exit(&rpipe->pipe_lock);
1.85 ad 1167: /* XXX Might be about to deadlock w/kernel_lock. */
1168: yield();
1.35 pk 1169: goto retry;
1170: }
1171:
1.1 jdolecek 1172: if (events & (POLLIN | POLLRDNORM))
1.2 jdolecek 1173: if ((rpipe->pipe_buffer.cnt > 0) ||
1174: #ifndef PIPE_NODIRECT
1.35 pk 1175: (rpipe->pipe_state & PIPE_DIRECTR) ||
1.2 jdolecek 1176: #endif
1.1 jdolecek 1177: (rpipe->pipe_state & PIPE_EOF))
1178: revents |= events & (POLLIN | POLLRDNORM);
1179:
1.35 pk 1180: eof |= (rpipe->pipe_state & PIPE_EOF);
1.80 ad 1181: mutex_exit(&rpipe->pipe_lock);
1.35 pk 1182:
1183: if (wpipe == NULL)
1184: revents |= events & (POLLOUT | POLLWRNORM);
1185: else {
1186: if (events & (POLLOUT | POLLWRNORM))
1187: if ((wpipe->pipe_state & PIPE_EOF) || (
1.2 jdolecek 1188: #ifndef PIPE_NODIRECT
1.35 pk 1189: (wpipe->pipe_state & PIPE_DIRECTW) == 0 &&
1.2 jdolecek 1190: #endif
1.35 pk 1191: (wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt) >= PIPE_BUF))
1192: revents |= events & (POLLOUT | POLLWRNORM);
1.1 jdolecek 1193:
1.35 pk 1194: eof |= (wpipe->pipe_state & PIPE_EOF);
1.80 ad 1195: mutex_exit(&wpipe->pipe_lock);
1.35 pk 1196: }
1197:
1198: if (wpipe == NULL || eof)
1.1 jdolecek 1199: revents |= POLLHUP;
1200:
1201: if (revents == 0) {
1.35 pk 1202: if (events & (POLLIN | POLLRDNORM))
1.69 christos 1203: selrecord(l, &rpipe->pipe_sel);
1.1 jdolecek 1204:
1.35 pk 1205: if (events & (POLLOUT | POLLWRNORM))
1.69 christos 1206: selrecord(l, &wpipe->pipe_sel);
1.1 jdolecek 1207: }
1208:
1209: return (revents);
1210: }
1211:
1212: static int
1.77 yamt 1213: pipe_stat(struct file *fp, struct stat *ub, struct lwp *l)
1.1 jdolecek 1214: {
1215: struct pipe *pipe = (struct pipe *)fp->f_data;
1216:
1.83 ad 1217: rw_enter(&pipe_peer_lock, RW_READER);
1.82 ad 1218:
1.79 christos 1219: memset((void *)ub, 0, sizeof(*ub));
1.32 jdolecek 1220: ub->st_mode = S_IFIFO | S_IRUSR | S_IWUSR;
1.1 jdolecek 1221: ub->st_blksize = pipe->pipe_buffer.size;
1.64 christos 1222: if (ub->st_blksize == 0 && pipe->pipe_peer)
1223: ub->st_blksize = pipe->pipe_peer->pipe_buffer.size;
1.1 jdolecek 1224: ub->st_size = pipe->pipe_buffer.cnt;
1.2 jdolecek 1225: ub->st_blocks = (ub->st_size) ? 1 : 0;
1.60 atatat 1226: TIMEVAL_TO_TIMESPEC(&pipe->pipe_atime, &ub->st_atimespec);
1.2 jdolecek 1227: TIMEVAL_TO_TIMESPEC(&pipe->pipe_mtime, &ub->st_mtimespec);
1228: TIMEVAL_TO_TIMESPEC(&pipe->pipe_ctime, &ub->st_ctimespec);
1.72 elad 1229: ub->st_uid = kauth_cred_geteuid(fp->f_cred);
1230: ub->st_gid = kauth_cred_getegid(fp->f_cred);
1.82 ad 1231:
1232: rw_exit(&pipe_peer_lock);
1233:
1.1 jdolecek 1234: /*
1235: * Left as 0: st_dev, st_ino, st_nlink, st_rdev, st_flags, st_gen.
1236: * XXX (st_dev, st_ino) should be unique.
1237: */
1238: return (0);
1239: }
1240:
1241: /* ARGSUSED */
1242: static int
1.77 yamt 1243: pipe_close(struct file *fp, struct lwp *l)
1.1 jdolecek 1244: {
1.35 pk 1245: struct pipe *pipe = (struct pipe *)fp->f_data;
1.1 jdolecek 1246:
1247: fp->f_data = NULL;
1.42 christos 1248: pipeclose(fp, pipe);
1.1 jdolecek 1249: return (0);
1250: }
1251:
1252: static void
1.68 thorpej 1253: pipe_free_kmem(struct pipe *pipe)
1.1 jdolecek 1254: {
1255:
1.35 pk 1256: if (pipe->pipe_buffer.buffer != NULL) {
1257: if (pipe->pipe_buffer.size > PIPE_SIZE)
1.1 jdolecek 1258: --nbigpipe;
1.35 pk 1259: amountpipekva -= pipe->pipe_buffer.size;
1.2 jdolecek 1260: uvm_km_free(kernel_map,
1.35 pk 1261: (vaddr_t)pipe->pipe_buffer.buffer,
1.65 yamt 1262: pipe->pipe_buffer.size, UVM_KMF_PAGEABLE);
1.35 pk 1263: pipe->pipe_buffer.buffer = NULL;
1.1 jdolecek 1264: }
1265: #ifndef PIPE_NODIRECT
1.35 pk 1266: if (pipe->pipe_map.kva != 0) {
1267: pipe_loan_free(pipe);
1268: pipe->pipe_map.cnt = 0;
1269: pipe->pipe_map.kva = 0;
1270: pipe->pipe_map.pos = 0;
1271: pipe->pipe_map.npages = 0;
1.1 jdolecek 1272: }
1.2 jdolecek 1273: #endif /* !PIPE_NODIRECT */
1.1 jdolecek 1274: }
1275:
1276: /*
1277: * shutdown the pipe
1278: */
1279: static void
1.77 yamt 1280: pipeclose(struct file *fp, struct pipe *pipe)
1.1 jdolecek 1281: {
1282: struct pipe *ppipe;
1283:
1.35 pk 1284: if (pipe == NULL)
1.2 jdolecek 1285: return;
1286:
1.82 ad 1287: retry:
1.83 ad 1288: rw_enter(&pipe_peer_lock, RW_WRITER);
1.80 ad 1289: mutex_enter(&pipe->pipe_lock);
1.35 pk 1290:
1.66 christos 1291: pipeselwakeup(pipe, pipe, POLL_HUP);
1.1 jdolecek 1292:
1.2 jdolecek 1293: /*
1294: * If the other side is blocked, wake it up saying that
1295: * we want to close it down.
1296: */
1.66 christos 1297: pipe->pipe_state |= PIPE_EOF;
1.82 ad 1298: if (pipe->pipe_busy) {
1299: rw_exit(&pipe_peer_lock);
1300: while (pipe->pipe_busy) {
1301: cv_broadcast(&pipe->pipe_cv);
1302: pipe->pipe_state |= PIPE_WANTCLOSE;
1303: cv_wait_sig(&pipe->pipe_cv, &pipe->pipe_lock);
1304: }
1305: if (!rw_tryenter(&pipe_peer_lock, RW_READER)) {
1306: mutex_exit(&pipe->pipe_lock);
1.85 ad 1307: /* XXX Might be about to deadlock w/kernel_lock. */
1308: yield();
1.82 ad 1309: goto retry;
1310: }
1.2 jdolecek 1311: }
1.1 jdolecek 1312:
1.2 jdolecek 1313: /*
1314: * Disconnect from peer
1315: */
1.35 pk 1316: if ((ppipe = pipe->pipe_peer) != NULL) {
1317: /* Deal with race for peer */
1.80 ad 1318: if (mutex_tryenter(&ppipe->pipe_lock) == 0) {
1319: mutex_exit(&pipe->pipe_lock);
1.82 ad 1320: rw_exit(&pipe_peer_lock);
1.85 ad 1321: /* XXX Might be about to deadlock w/kernel_lock. */
1322: yield();
1.35 pk 1323: goto retry;
1324: }
1.66 christos 1325: pipeselwakeup(ppipe, ppipe, POLL_HUP);
1.1 jdolecek 1326:
1.2 jdolecek 1327: ppipe->pipe_state |= PIPE_EOF;
1.80 ad 1328: cv_broadcast(&ppipe->pipe_cv);
1.2 jdolecek 1329: ppipe->pipe_peer = NULL;
1.80 ad 1330: mutex_exit(&ppipe->pipe_lock);
1.1 jdolecek 1331: }
1.35 pk 1332:
1.67 yamt 1333: KASSERT((pipe->pipe_state & PIPE_LOCKFL) == 0);
1334:
1.80 ad 1335: mutex_exit(&pipe->pipe_lock);
1.82 ad 1336: rw_exit(&pipe_peer_lock);
1.35 pk 1337:
1.2 jdolecek 1338: /*
1339: * free resources
1340: */
1.35 pk 1341: pipe_free_kmem(pipe);
1.80 ad 1342: mutex_destroy(&pipe->pipe_lock);
1343: cv_destroy(&pipe->pipe_cv);
1344: cv_destroy(&pipe->pipe_lkcv);
1.86 ! ad 1345: seldestroy(&pipe->pipe_sel);
1.35 pk 1346: pool_put(&pipe_pool, pipe);
1.1 jdolecek 1347: }
1348:
1.27 jdolecek 1349: static void
1350: filt_pipedetach(struct knote *kn)
1.1 jdolecek 1351: {
1.35 pk 1352: struct pipe *pipe = (struct pipe *)kn->kn_fp->f_data;
1.1 jdolecek 1353:
1.83 ad 1354: rw_enter(&pipe_peer_lock, RW_READER);
1.82 ad 1355:
1.27 jdolecek 1356: switch(kn->kn_filter) {
1.1 jdolecek 1357: case EVFILT_WRITE:
1.27 jdolecek 1358: /* need the peer structure, not our own */
1.35 pk 1359: pipe = pipe->pipe_peer;
1.27 jdolecek 1360:
1361: /* if reader end already closed, just return */
1.82 ad 1362: if (pipe == NULL) {
1363: rw_exit(&pipe_peer_lock);
1.27 jdolecek 1364: return;
1.82 ad 1365: }
1.27 jdolecek 1366:
1.1 jdolecek 1367: break;
1368: default:
1.27 jdolecek 1369: /* nothing to do */
1.29 kristerw 1370: break;
1.1 jdolecek 1371: }
1.24 jdolecek 1372:
1.27 jdolecek 1373: #ifdef DIAGNOSTIC
1.35 pk 1374: if (kn->kn_hook != pipe)
1.27 jdolecek 1375: panic("filt_pipedetach: inconsistent knote");
1376: #endif
1.1 jdolecek 1377:
1.80 ad 1378: mutex_enter(&pipe->pipe_lock);
1.35 pk 1379: SLIST_REMOVE(&pipe->pipe_sel.sel_klist, kn, knote, kn_selnext);
1.80 ad 1380: mutex_exit(&pipe->pipe_lock);
1.82 ad 1381: rw_exit(&pipe_peer_lock);
1.1 jdolecek 1382: }
1383:
1384: /*ARGSUSED*/
1385: static int
1386: filt_piperead(struct knote *kn, long hint)
1387: {
1388: struct pipe *rpipe = (struct pipe *)kn->kn_fp->f_data;
1.82 ad 1389: struct pipe *wpipe;
1390:
1.83 ad 1391: if ((hint & NOTE_SUBMIT) == 0) {
1392: rw_enter(&pipe_peer_lock, RW_READER);
1393: mutex_enter(&rpipe->pipe_lock);
1394: }
1.82 ad 1395: wpipe = rpipe->pipe_peer;
1.83 ad 1396: kn->kn_data = rpipe->pipe_buffer.cnt;
1.1 jdolecek 1397:
1398: if ((kn->kn_data == 0) && (rpipe->pipe_state & PIPE_DIRECTW))
1399: kn->kn_data = rpipe->pipe_map.cnt;
1400:
1401: if ((rpipe->pipe_state & PIPE_EOF) ||
1402: (wpipe == NULL) || (wpipe->pipe_state & PIPE_EOF)) {
1.24 jdolecek 1403: kn->kn_flags |= EV_EOF;
1.83 ad 1404: if ((hint & NOTE_SUBMIT) == 0) {
1.80 ad 1405: mutex_exit(&rpipe->pipe_lock);
1.83 ad 1406: rw_exit(&pipe_peer_lock);
1407: }
1.1 jdolecek 1408: return (1);
1409: }
1.83 ad 1410:
1411: if ((hint & NOTE_SUBMIT) == 0) {
1.80 ad 1412: mutex_exit(&rpipe->pipe_lock);
1.83 ad 1413: rw_exit(&pipe_peer_lock);
1414: }
1.1 jdolecek 1415: return (kn->kn_data > 0);
1416: }
1417:
1418: /*ARGSUSED*/
1419: static int
1420: filt_pipewrite(struct knote *kn, long hint)
1421: {
1422: struct pipe *rpipe = (struct pipe *)kn->kn_fp->f_data;
1.82 ad 1423: struct pipe *wpipe;
1424:
1.83 ad 1425: if ((hint & NOTE_SUBMIT) == 0) {
1426: rw_enter(&pipe_peer_lock, RW_READER);
1427: mutex_enter(&rpipe->pipe_lock);
1428: }
1.82 ad 1429: wpipe = rpipe->pipe_peer;
1.1 jdolecek 1430:
1431: if ((wpipe == NULL) || (wpipe->pipe_state & PIPE_EOF)) {
1432: kn->kn_data = 0;
1.63 perry 1433: kn->kn_flags |= EV_EOF;
1.83 ad 1434: if ((hint & NOTE_SUBMIT) == 0) {
1.80 ad 1435: mutex_exit(&rpipe->pipe_lock);
1.83 ad 1436: rw_exit(&pipe_peer_lock);
1437: }
1.1 jdolecek 1438: return (1);
1439: }
1440: kn->kn_data = wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt;
1441: if (wpipe->pipe_state & PIPE_DIRECTW)
1442: kn->kn_data = 0;
1443:
1.83 ad 1444: if ((hint & NOTE_SUBMIT) == 0) {
1.80 ad 1445: mutex_exit(&rpipe->pipe_lock);
1.83 ad 1446: rw_exit(&pipe_peer_lock);
1447: }
1.1 jdolecek 1448: return (kn->kn_data >= PIPE_BUF);
1449: }
1.27 jdolecek 1450:
1451: static const struct filterops pipe_rfiltops =
1452: { 1, NULL, filt_pipedetach, filt_piperead };
1453: static const struct filterops pipe_wfiltops =
1454: { 1, NULL, filt_pipedetach, filt_pipewrite };
1455:
1456: /*ARGSUSED*/
1457: static int
1.77 yamt 1458: pipe_kqfilter(struct file *fp, struct knote *kn)
1.27 jdolecek 1459: {
1.35 pk 1460: struct pipe *pipe;
1.27 jdolecek 1461:
1.83 ad 1462: rw_enter(&pipe_peer_lock, RW_READER);
1.35 pk 1463: pipe = (struct pipe *)kn->kn_fp->f_data;
1.82 ad 1464:
1.27 jdolecek 1465: switch (kn->kn_filter) {
1466: case EVFILT_READ:
1467: kn->kn_fop = &pipe_rfiltops;
1468: break;
1469: case EVFILT_WRITE:
1470: kn->kn_fop = &pipe_wfiltops;
1.35 pk 1471: pipe = pipe->pipe_peer;
1472: if (pipe == NULL) {
1.27 jdolecek 1473: /* other end of pipe has been closed */
1.82 ad 1474: rw_exit(&pipe_peer_lock);
1.27 jdolecek 1475: return (EBADF);
1476: }
1477: break;
1478: default:
1.82 ad 1479: rw_exit(&pipe_peer_lock);
1.27 jdolecek 1480: return (1);
1481: }
1.82 ad 1482:
1.35 pk 1483: kn->kn_hook = pipe;
1.80 ad 1484: mutex_enter(&pipe->pipe_lock);
1.35 pk 1485: SLIST_INSERT_HEAD(&pipe->pipe_sel.sel_klist, kn, kn_selnext);
1.80 ad 1486: mutex_exit(&pipe->pipe_lock);
1.82 ad 1487: rw_exit(&pipe_peer_lock);
1488:
1.27 jdolecek 1489: return (0);
1490: }
1.2 jdolecek 1491:
1492: /*
1493: * Handle pipe sysctls.
1494: */
1.47 atatat 1495: SYSCTL_SETUP(sysctl_kern_pipe_setup, "sysctl kern.pipe subtree setup")
1496: {
1497:
1.54 atatat 1498: sysctl_createv(clog, 0, NULL, NULL,
1499: CTLFLAG_PERMANENT,
1.47 atatat 1500: CTLTYPE_NODE, "kern", NULL,
1501: NULL, 0, NULL, 0,
1502: CTL_KERN, CTL_EOL);
1.54 atatat 1503: sysctl_createv(clog, 0, NULL, NULL,
1504: CTLFLAG_PERMANENT,
1.56 atatat 1505: CTLTYPE_NODE, "pipe",
1506: SYSCTL_DESCR("Pipe settings"),
1.47 atatat 1507: NULL, 0, NULL, 0,
1508: CTL_KERN, KERN_PIPE, CTL_EOL);
1509:
1.54 atatat 1510: sysctl_createv(clog, 0, NULL, NULL,
1511: CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.56 atatat 1512: CTLTYPE_INT, "maxkvasz",
1513: SYSCTL_DESCR("Maximum amount of kernel memory to be "
1514: "used for pipes"),
1.47 atatat 1515: NULL, 0, &maxpipekva, 0,
1516: CTL_KERN, KERN_PIPE, KERN_PIPE_MAXKVASZ, CTL_EOL);
1.54 atatat 1517: sysctl_createv(clog, 0, NULL, NULL,
1518: CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.56 atatat 1519: CTLTYPE_INT, "maxloankvasz",
1520: SYSCTL_DESCR("Limit for direct transfers via page loan"),
1.47 atatat 1521: NULL, 0, &limitpipekva, 0,
1522: CTL_KERN, KERN_PIPE, KERN_PIPE_LIMITKVA, CTL_EOL);
1.54 atatat 1523: sysctl_createv(clog, 0, NULL, NULL,
1524: CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.56 atatat 1525: CTLTYPE_INT, "maxbigpipes",
1526: SYSCTL_DESCR("Maximum number of \"big\" pipes"),
1.47 atatat 1527: NULL, 0, &maxbigpipes, 0,
1528: CTL_KERN, KERN_PIPE, KERN_PIPE_MAXBIGPIPES, CTL_EOL);
1.54 atatat 1529: sysctl_createv(clog, 0, NULL, NULL,
1530: CTLFLAG_PERMANENT,
1.56 atatat 1531: CTLTYPE_INT, "nbigpipes",
1532: SYSCTL_DESCR("Number of \"big\" pipes"),
1.47 atatat 1533: NULL, 0, &nbigpipe, 0,
1534: CTL_KERN, KERN_PIPE, KERN_PIPE_NBIGPIPES, CTL_EOL);
1.54 atatat 1535: sysctl_createv(clog, 0, NULL, NULL,
1536: CTLFLAG_PERMANENT,
1.56 atatat 1537: CTLTYPE_INT, "kvasize",
1538: SYSCTL_DESCR("Amount of kernel memory consumed by pipe "
1539: "buffers"),
1.47 atatat 1540: NULL, 0, &amountpipekva, 0,
1541: CTL_KERN, KERN_PIPE, KERN_PIPE_KVASIZE, CTL_EOL);
1.2 jdolecek 1542: }
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