sys_pipe.c revision 165347
1139804Simp/*- 213675Sdyson * Copyright (c) 1996 John S. Dyson 313675Sdyson * All rights reserved. 413675Sdyson * 513675Sdyson * Redistribution and use in source and binary forms, with or without 613675Sdyson * modification, are permitted provided that the following conditions 713675Sdyson * are met: 813675Sdyson * 1. Redistributions of source code must retain the above copyright 913675Sdyson * notice immediately at the beginning of the file, without modification, 1013675Sdyson * this list of conditions, and the following disclaimer. 1113675Sdyson * 2. Redistributions in binary form must reproduce the above copyright 1213675Sdyson * notice, this list of conditions and the following disclaimer in the 1313675Sdyson * documentation and/or other materials provided with the distribution. 1413675Sdyson * 3. Absolutely no warranty of function or purpose is made by the author 1513675Sdyson * John S. Dyson. 1614037Sdyson * 4. Modifications may be freely made to this file if the above conditions 1713675Sdyson * are met. 1813675Sdyson */ 1913675Sdyson 2013675Sdyson/* 2113675Sdyson * This file contains a high-performance replacement for the socket-based 2213675Sdyson * pipes scheme originally used in FreeBSD/4.4Lite. It does not support 2313675Sdyson * all features of sockets, but does do everything that pipes normally 2413675Sdyson * do. 2513675Sdyson */ 2613675Sdyson 2713907Sdyson/* 2813907Sdyson * This code has two modes of operation, a small write mode and a large 2913907Sdyson * write mode. The small write mode acts like conventional pipes with 3013907Sdyson * a kernel buffer. If the buffer is less than PIPE_MINDIRECT, then the 3113907Sdyson * "normal" pipe buffering is done. If the buffer is between PIPE_MINDIRECT 3213907Sdyson * and PIPE_SIZE in size, it is fully mapped and wired into the kernel, and 3313907Sdyson * the receiving process can copy it directly from the pages in the sending 3413907Sdyson * process. 3513907Sdyson * 3613907Sdyson * If the sending process receives a signal, it is possible that it will 3713913Sdyson * go away, and certainly its address space can change, because control 3813907Sdyson * is returned back to the user-mode side. In that case, the pipe code 3913907Sdyson * arranges to copy the buffer supplied by the user process, to a pageable 4013907Sdyson * kernel buffer, and the receiving process will grab the data from the 4113907Sdyson * pageable kernel buffer. Since signals don't happen all that often, 4213907Sdyson * the copy operation is normally eliminated. 4313907Sdyson * 4413907Sdyson * The constant PIPE_MINDIRECT is chosen to make sure that buffering will 4513907Sdyson * happen for small transfers so that the system will not spend all of 46118764Ssilby * its time context switching. 47117325Ssilby * 48118764Ssilby * In order to limit the resource use of pipes, two sysctls exist: 49117325Ssilby * 50118764Ssilby * kern.ipc.maxpipekva - This is a hard limit on the amount of pageable 51133790Ssilby * address space available to us in pipe_map. This value is normally 52133790Ssilby * autotuned, but may also be loader tuned. 53117325Ssilby * 54133790Ssilby * kern.ipc.pipekva - This read-only sysctl tracks the current amount of 55133790Ssilby * memory in use by pipes. 56117325Ssilby * 57133790Ssilby * Based on how large pipekva is relative to maxpipekva, the following 58133790Ssilby * will happen: 59117325Ssilby * 60133790Ssilby * 0% - 50%: 61133790Ssilby * New pipes are given 16K of memory backing, pipes may dynamically 62133790Ssilby * grow to as large as 64K where needed. 63133790Ssilby * 50% - 75%: 64133790Ssilby * New pipes are given 4K (or PAGE_SIZE) of memory backing, 65133790Ssilby * existing pipes may NOT grow. 66133790Ssilby * 75% - 100%: 67133790Ssilby * New pipes are given 4K (or PAGE_SIZE) of memory backing, 68133790Ssilby * existing pipes will be shrunk down to 4K whenever possible. 69133049Ssilby * 70133790Ssilby * Resizing may be disabled by setting kern.ipc.piperesizeallowed=0. If 71133790Ssilby * that is set, the only resize that will occur is the 0 -> SMALL_PIPE_SIZE 72133790Ssilby * resize which MUST occur for reverse-direction pipes when they are 73133790Ssilby * first used. 74133790Ssilby * 75133790Ssilby * Additional information about the current state of pipes may be obtained 76133790Ssilby * from kern.ipc.pipes, kern.ipc.pipefragretry, kern.ipc.pipeallocfail, 77133790Ssilby * and kern.ipc.piperesizefail. 78133790Ssilby * 79133049Ssilby * Locking rules: There are two locks present here: A mutex, used via 80133049Ssilby * PIPE_LOCK, and a flag, used via pipelock(). All locking is done via 81133049Ssilby * the flag, as mutexes can not persist over uiomove. The mutex 82133049Ssilby * exists only to guard access to the flag, and is not in itself a 83133790Ssilby * locking mechanism. Also note that there is only a single mutex for 84133790Ssilby * both directions of a pipe. 85133049Ssilby * 86133049Ssilby * As pipelock() may have to sleep before it can acquire the flag, it 87133049Ssilby * is important to reread all data after a call to pipelock(); everything 88133049Ssilby * in the structure may have changed. 8913907Sdyson */ 9013907Sdyson 91116182Sobrien#include <sys/cdefs.h> 92116182Sobrien__FBSDID("$FreeBSD: head/sys/kern/sys_pipe.c 165347 2006-12-19 12:52:22Z pjd $"); 93116182Sobrien 94101768Srwatson#include "opt_mac.h" 95101768Srwatson 9613675Sdyson#include <sys/param.h> 9713675Sdyson#include <sys/systm.h> 9824131Sbde#include <sys/fcntl.h> 9913675Sdyson#include <sys/file.h> 10013675Sdyson#include <sys/filedesc.h> 10124206Sbde#include <sys/filio.h> 10291372Salfred#include <sys/kernel.h> 10376166Smarkm#include <sys/lock.h> 10476827Salfred#include <sys/mutex.h> 10524206Sbde#include <sys/ttycom.h> 10613675Sdyson#include <sys/stat.h> 10791968Salfred#include <sys/malloc.h> 10829356Speter#include <sys/poll.h> 10970834Swollman#include <sys/selinfo.h> 11013675Sdyson#include <sys/signalvar.h> 111117325Ssilby#include <sys/sysctl.h> 11213675Sdyson#include <sys/sysproto.h> 11313675Sdyson#include <sys/pipe.h> 11476166Smarkm#include <sys/proc.h> 11555112Sbde#include <sys/vnode.h> 11634924Sbde#include <sys/uio.h> 11759288Sjlemon#include <sys/event.h> 11813675Sdyson 119163606Srwatson#include <security/mac/mac_framework.h> 120163606Srwatson 12113675Sdyson#include <vm/vm.h> 12213675Sdyson#include <vm/vm_param.h> 12313675Sdyson#include <vm/vm_object.h> 12413675Sdyson#include <vm/vm_kern.h> 12513675Sdyson#include <vm/vm_extern.h> 12613675Sdyson#include <vm/pmap.h> 12713675Sdyson#include <vm/vm_map.h> 12813907Sdyson#include <vm/vm_page.h> 12992751Sjeff#include <vm/uma.h> 13013675Sdyson 13114037Sdyson/* 13214037Sdyson * Use this define if you want to disable *fancy* VM things. Expect an 13314037Sdyson * approx 30% decrease in transfer rate. This could be useful for 13414037Sdyson * NetBSD or OpenBSD. 13514037Sdyson */ 13614037Sdyson/* #define PIPE_NODIRECT */ 13714037Sdyson 13814037Sdyson/* 13914037Sdyson * interfaces to the outside world 14014037Sdyson */ 141108255Sphkstatic fo_rdwr_t pipe_read; 142108255Sphkstatic fo_rdwr_t pipe_write; 143108255Sphkstatic fo_ioctl_t pipe_ioctl; 144108255Sphkstatic fo_poll_t pipe_poll; 145108255Sphkstatic fo_kqfilter_t pipe_kqfilter; 146108255Sphkstatic fo_stat_t pipe_stat; 147108255Sphkstatic fo_close_t pipe_close; 14813675Sdyson 14972521Sjlemonstatic struct fileops pipeops = { 150116546Sphk .fo_read = pipe_read, 151116546Sphk .fo_write = pipe_write, 152116546Sphk .fo_ioctl = pipe_ioctl, 153116546Sphk .fo_poll = pipe_poll, 154116546Sphk .fo_kqfilter = pipe_kqfilter, 155116546Sphk .fo_stat = pipe_stat, 156116546Sphk .fo_close = pipe_close, 157116546Sphk .fo_flags = DFLAG_PASSABLE 15872521Sjlemon}; 15913675Sdyson 16059288Sjlemonstatic void filt_pipedetach(struct knote *kn); 16159288Sjlemonstatic int filt_piperead(struct knote *kn, long hint); 16259288Sjlemonstatic int filt_pipewrite(struct knote *kn, long hint); 16359288Sjlemon 16472521Sjlemonstatic struct filterops pipe_rfiltops = 16572521Sjlemon { 1, NULL, filt_pipedetach, filt_piperead }; 16672521Sjlemonstatic struct filterops pipe_wfiltops = 16772521Sjlemon { 1, NULL, filt_pipedetach, filt_pipewrite }; 16859288Sjlemon 16913675Sdyson/* 17013675Sdyson * Default pipe buffer size(s), this can be kind-of large now because pipe 17113675Sdyson * space is pageable. The pipe code will try to maintain locality of 17213675Sdyson * reference for performance reasons, so small amounts of outstanding I/O 17313675Sdyson * will not wipe the cache. 17413675Sdyson */ 17513907Sdyson#define MINPIPESIZE (PIPE_SIZE/3) 17613907Sdyson#define MAXPIPESIZE (2*PIPE_SIZE/3) 17713675Sdyson 178117325Ssilbystatic int amountpipes; 17917124Sbdestatic int amountpipekva; 180133790Ssilbystatic int pipefragretry; 181133790Ssilbystatic int pipeallocfail; 182133790Ssilbystatic int piperesizefail; 183133790Ssilbystatic int piperesizeallowed = 1; 18413907Sdyson 185121307SsilbySYSCTL_INT(_kern_ipc, OID_AUTO, maxpipekva, CTLFLAG_RDTUN, 186117325Ssilby &maxpipekva, 0, "Pipe KVA limit"); 187117325SsilbySYSCTL_INT(_kern_ipc, OID_AUTO, pipes, CTLFLAG_RD, 188117364Ssilby &amountpipes, 0, "Current # of pipes"); 189117325SsilbySYSCTL_INT(_kern_ipc, OID_AUTO, pipekva, CTLFLAG_RD, 190117325Ssilby &amountpipekva, 0, "Pipe KVA usage"); 191133790SsilbySYSCTL_INT(_kern_ipc, OID_AUTO, pipefragretry, CTLFLAG_RD, 192133790Ssilby &pipefragretry, 0, "Pipe allocation retries due to fragmentation"); 193133790SsilbySYSCTL_INT(_kern_ipc, OID_AUTO, pipeallocfail, CTLFLAG_RD, 194133790Ssilby &pipeallocfail, 0, "Pipe allocation failures"); 195133790SsilbySYSCTL_INT(_kern_ipc, OID_AUTO, piperesizefail, CTLFLAG_RD, 196133790Ssilby &piperesizefail, 0, "Pipe resize failures"); 197133790SsilbySYSCTL_INT(_kern_ipc, OID_AUTO, piperesizeallowed, CTLFLAG_RW, 198133790Ssilby &piperesizeallowed, 0, "Pipe resizing allowed"); 199117325Ssilby 20091413Salfredstatic void pipeinit(void *dummy __unused); 20191413Salfredstatic void pipeclose(struct pipe *cpipe); 20291413Salfredstatic void pipe_free_kmem(struct pipe *cpipe); 203133790Ssilbystatic int pipe_create(struct pipe *pipe, int backing); 20491413Salfredstatic __inline int pipelock(struct pipe *cpipe, int catch); 20591413Salfredstatic __inline void pipeunlock(struct pipe *cpipe); 20691413Salfredstatic __inline void pipeselwakeup(struct pipe *cpipe); 20714037Sdyson#ifndef PIPE_NODIRECT 20891413Salfredstatic int pipe_build_write_buffer(struct pipe *wpipe, struct uio *uio); 20991413Salfredstatic void pipe_destroy_write_buffer(struct pipe *wpipe); 21091413Salfredstatic int pipe_direct_write(struct pipe *wpipe, struct uio *uio); 21191413Salfredstatic void pipe_clone_write_buffer(struct pipe *wpipe); 21214037Sdyson#endif 21391413Salfredstatic int pipespace(struct pipe *cpipe, int size); 214132579Srwatsonstatic int pipespace_new(struct pipe *cpipe, int size); 21513675Sdyson 216132987Sgreenstatic int pipe_zone_ctor(void *mem, int size, void *arg, int flags); 217125293Srwatsonstatic void pipe_zone_dtor(void *mem, int size, void *arg); 218132987Sgreenstatic int pipe_zone_init(void *mem, int size, int flags); 219125293Srwatsonstatic void pipe_zone_fini(void *mem, int size); 220125293Srwatson 22192751Sjeffstatic uma_zone_t pipe_zone; 22227899Sdyson 22391372SalfredSYSINIT(vfs, SI_SUB_VFS, SI_ORDER_ANY, pipeinit, NULL); 22491372Salfred 22591372Salfredstatic void 22691372Salfredpipeinit(void *dummy __unused) 22791372Salfred{ 228118880Salc 229125293Srwatson pipe_zone = uma_zcreate("PIPE", sizeof(struct pipepair), 230125293Srwatson pipe_zone_ctor, pipe_zone_dtor, pipe_zone_init, pipe_zone_fini, 231125293Srwatson UMA_ALIGN_PTR, 0); 232118880Salc KASSERT(pipe_zone != NULL, ("pipe_zone not initialized")); 23391372Salfred} 23491372Salfred 235132987Sgreenstatic int 236132987Sgreenpipe_zone_ctor(void *mem, int size, void *arg, int flags) 237125293Srwatson{ 238125293Srwatson struct pipepair *pp; 239125293Srwatson struct pipe *rpipe, *wpipe; 240125293Srwatson 241125293Srwatson KASSERT(size == sizeof(*pp), ("pipe_zone_ctor: wrong size")); 242125293Srwatson 243125293Srwatson pp = (struct pipepair *)mem; 244125293Srwatson 245125293Srwatson /* 246125293Srwatson * We zero both pipe endpoints to make sure all the kmem pointers 247125293Srwatson * are NULL, flag fields are zero'd, etc. We timestamp both 248125293Srwatson * endpoints with the same time. 249125293Srwatson */ 250125293Srwatson rpipe = &pp->pp_rpipe; 251125293Srwatson bzero(rpipe, sizeof(*rpipe)); 252125293Srwatson vfs_timestamp(&rpipe->pipe_ctime); 253125293Srwatson rpipe->pipe_atime = rpipe->pipe_mtime = rpipe->pipe_ctime; 254125293Srwatson 255125293Srwatson wpipe = &pp->pp_wpipe; 256125293Srwatson bzero(wpipe, sizeof(*wpipe)); 257125293Srwatson wpipe->pipe_ctime = rpipe->pipe_ctime; 258125293Srwatson wpipe->pipe_atime = wpipe->pipe_mtime = rpipe->pipe_ctime; 259125293Srwatson 260125293Srwatson rpipe->pipe_peer = wpipe; 261125293Srwatson rpipe->pipe_pair = pp; 262125293Srwatson wpipe->pipe_peer = rpipe; 263125293Srwatson wpipe->pipe_pair = pp; 264125293Srwatson 265125293Srwatson /* 266125293Srwatson * Mark both endpoints as present; they will later get free'd 267125293Srwatson * one at a time. When both are free'd, then the whole pair 268125293Srwatson * is released. 269125293Srwatson */ 270125293Srwatson rpipe->pipe_present = 1; 271125293Srwatson wpipe->pipe_present = 1; 272125293Srwatson 273125293Srwatson /* 274125293Srwatson * Eventually, the MAC Framework may initialize the label 275125293Srwatson * in ctor or init, but for now we do it elswhere to avoid 276125293Srwatson * blocking in ctor or init. 277125293Srwatson */ 278125293Srwatson pp->pp_label = NULL; 279125293Srwatson 280125367Srwatson atomic_add_int(&amountpipes, 2); 281132987Sgreen return (0); 282125293Srwatson} 283125293Srwatson 284125293Srwatsonstatic void 285125293Srwatsonpipe_zone_dtor(void *mem, int size, void *arg) 286125293Srwatson{ 287125293Srwatson struct pipepair *pp; 288125293Srwatson 289125293Srwatson KASSERT(size == sizeof(*pp), ("pipe_zone_dtor: wrong size")); 290125293Srwatson 291125293Srwatson pp = (struct pipepair *)mem; 292125367Srwatson 293125367Srwatson atomic_subtract_int(&amountpipes, 2); 294125293Srwatson} 295125293Srwatson 296132987Sgreenstatic int 297132987Sgreenpipe_zone_init(void *mem, int size, int flags) 298125293Srwatson{ 299125293Srwatson struct pipepair *pp; 300125293Srwatson 301125293Srwatson KASSERT(size == sizeof(*pp), ("pipe_zone_init: wrong size")); 302125293Srwatson 303125293Srwatson pp = (struct pipepair *)mem; 304125293Srwatson 305125293Srwatson mtx_init(&pp->pp_mtx, "pipe mutex", NULL, MTX_DEF | MTX_RECURSE); 306132987Sgreen return (0); 307125293Srwatson} 308125293Srwatson 309125293Srwatsonstatic void 310125293Srwatsonpipe_zone_fini(void *mem, int size) 311125293Srwatson{ 312125293Srwatson struct pipepair *pp; 313125293Srwatson 314125293Srwatson KASSERT(size == sizeof(*pp), ("pipe_zone_fini: wrong size")); 315125293Srwatson 316125293Srwatson pp = (struct pipepair *)mem; 317125293Srwatson 318125293Srwatson mtx_destroy(&pp->pp_mtx); 319125293Srwatson} 320125293Srwatson 32113675Sdyson/* 322125293Srwatson * The pipe system call for the DTYPE_PIPE type of pipes. If we fail, 323125293Srwatson * let the zone pick up the pieces via pipeclose(). 32413675Sdyson */ 32513675Sdyson 32613675Sdyson/* ARGSUSED */ 32713675Sdysonint 32883366Sjulianpipe(td, uap) 32983366Sjulian struct thread *td; 33013675Sdyson struct pipe_args /* { 33113675Sdyson int dummy; 33213675Sdyson } */ *uap; 33313675Sdyson{ 33483366Sjulian struct filedesc *fdp = td->td_proc->p_fd; 33513675Sdyson struct file *rf, *wf; 336125293Srwatson struct pipepair *pp; 33713675Sdyson struct pipe *rpipe, *wpipe; 33813675Sdyson int fd, error; 33927899Sdyson 340125293Srwatson pp = uma_zalloc(pipe_zone, M_WAITOK); 341125293Srwatson#ifdef MAC 342125293Srwatson /* 343126249Srwatson * The MAC label is shared between the connected endpoints. As a 344126249Srwatson * result mac_init_pipe() and mac_create_pipe() are called once 345126249Srwatson * for the pair, and not on the endpoints. 346125293Srwatson */ 347125293Srwatson mac_init_pipe(pp); 348125293Srwatson mac_create_pipe(td->td_ucred, pp); 349125293Srwatson#endif 350125293Srwatson rpipe = &pp->pp_rpipe; 351125293Srwatson wpipe = &pp->pp_wpipe; 352125293Srwatson 353147730Sssouhlal knlist_init(&rpipe->pipe_sel.si_note, PIPE_MTX(rpipe), NULL, NULL, 354147730Sssouhlal NULL); 355147730Sssouhlal knlist_init(&wpipe->pipe_sel.si_note, PIPE_MTX(wpipe), NULL, NULL, 356147730Sssouhlal NULL); 357140369Ssilby 358133790Ssilby /* Only the forward direction pipe is backed by default */ 359155035Sglebius if ((error = pipe_create(rpipe, 1)) != 0 || 360155035Sglebius (error = pipe_create(wpipe, 0)) != 0) { 361124394Sdes pipeclose(rpipe); 362124394Sdes pipeclose(wpipe); 363155035Sglebius return (error); 36476364Salfred } 365124394Sdes 36613907Sdyson rpipe->pipe_state |= PIPE_DIRECTOK; 36713907Sdyson wpipe->pipe_state |= PIPE_DIRECTOK; 36813675Sdyson 36983366Sjulian error = falloc(td, &rf, &fd); 37070915Sdwmalone if (error) { 37170915Sdwmalone pipeclose(rpipe); 37270915Sdwmalone pipeclose(wpipe); 37370915Sdwmalone return (error); 37470915Sdwmalone } 375121256Sdwmalone /* An extra reference on `rf' has been held for us by falloc(). */ 37683366Sjulian td->td_retval[0] = fd; 37770915Sdwmalone 37870803Sdwmalone /* 37970803Sdwmalone * Warning: once we've gotten past allocation of the fd for the 38070803Sdwmalone * read-side, we can only drop the read side via fdrop() in order 38170803Sdwmalone * to avoid races against processes which manage to dup() the read 38270803Sdwmalone * side while we are blocked trying to allocate the write side. 38370803Sdwmalone */ 38489306Salfred FILE_LOCK(rf); 38513675Sdyson rf->f_flag = FREAD | FWRITE; 38613675Sdyson rf->f_type = DTYPE_PIPE; 387109153Sdillon rf->f_data = rpipe; 38813675Sdyson rf->f_ops = &pipeops; 38989306Salfred FILE_UNLOCK(rf); 39083366Sjulian error = falloc(td, &wf, &fd); 39170915Sdwmalone if (error) { 392137355Sphk fdclose(fdp, rf, td->td_retval[0], td); 39383366Sjulian fdrop(rf, td); 39470915Sdwmalone /* rpipe has been closed by fdrop(). */ 39570915Sdwmalone pipeclose(wpipe); 39670915Sdwmalone return (error); 39770915Sdwmalone } 398121256Sdwmalone /* An extra reference on `wf' has been held for us by falloc(). */ 39989306Salfred FILE_LOCK(wf); 40013675Sdyson wf->f_flag = FREAD | FWRITE; 40113675Sdyson wf->f_type = DTYPE_PIPE; 402109153Sdillon wf->f_data = wpipe; 40313675Sdyson wf->f_ops = &pipeops; 40489306Salfred FILE_UNLOCK(wf); 405121256Sdwmalone fdrop(wf, td); 40683366Sjulian td->td_retval[1] = fd; 40783366Sjulian fdrop(rf, td); 40813675Sdyson 40913675Sdyson return (0); 41013675Sdyson} 41113675Sdyson 41213909Sdyson/* 41313909Sdyson * Allocate kva for pipe circular buffer, the space is pageable 41476364Salfred * This routine will 'realloc' the size of a pipe safely, if it fails 41576364Salfred * it will retain the old buffer. 41676364Salfred * If it fails it will return ENOMEM. 41713909Sdyson */ 41876364Salfredstatic int 419132579Srwatsonpipespace_new(cpipe, size) 42013675Sdyson struct pipe *cpipe; 42176364Salfred int size; 42213675Sdyson{ 42376364Salfred caddr_t buffer; 424133790Ssilby int error, cnt, firstseg; 425117325Ssilby static int curfail = 0; 426117325Ssilby static struct timeval lastfail; 42713675Sdyson 428125293Srwatson KASSERT(!mtx_owned(PIPE_MTX(cpipe)), ("pipespace: pipe mutex locked")); 429133790Ssilby KASSERT(!(cpipe->pipe_state & PIPE_DIRECTW), 430133790Ssilby ("pipespace: resize of direct writes not allowed")); 431133790Ssilbyretry: 432133790Ssilby cnt = cpipe->pipe_buffer.cnt; 433133790Ssilby if (cnt > size) 434133790Ssilby size = cnt; 43579224Sdillon 436118764Ssilby size = round_page(size); 437118764Ssilby buffer = (caddr_t) vm_map_min(pipe_map); 43813675Sdyson 439122163Salc error = vm_map_find(pipe_map, NULL, 0, 44076364Salfred (vm_offset_t *) &buffer, size, 1, 44113688Sdyson VM_PROT_ALL, VM_PROT_ALL, 0); 44276364Salfred if (error != KERN_SUCCESS) { 443133790Ssilby if ((cpipe->pipe_buffer.buffer == NULL) && 444133790Ssilby (size > SMALL_PIPE_SIZE)) { 445133790Ssilby size = SMALL_PIPE_SIZE; 446133790Ssilby pipefragretry++; 447133790Ssilby goto retry; 448133790Ssilby } 449133790Ssilby if (cpipe->pipe_buffer.buffer == NULL) { 450133790Ssilby pipeallocfail++; 451133790Ssilby if (ppsratecheck(&lastfail, &curfail, 1)) 452133790Ssilby printf("kern.ipc.maxpipekva exceeded; see tuning(7)\n"); 453133790Ssilby } else { 454133790Ssilby piperesizefail++; 455133790Ssilby } 45676364Salfred return (ENOMEM); 45776364Salfred } 45876364Salfred 459133790Ssilby /* copy data, then free old resources if we're resizing */ 460133790Ssilby if (cnt > 0) { 461133790Ssilby if (cpipe->pipe_buffer.in <= cpipe->pipe_buffer.out) { 462133790Ssilby firstseg = cpipe->pipe_buffer.size - cpipe->pipe_buffer.out; 463133790Ssilby bcopy(&cpipe->pipe_buffer.buffer[cpipe->pipe_buffer.out], 464133790Ssilby buffer, firstseg); 465133790Ssilby if ((cnt - firstseg) > 0) 466133790Ssilby bcopy(cpipe->pipe_buffer.buffer, &buffer[firstseg], 467133790Ssilby cpipe->pipe_buffer.in); 468133790Ssilby } else { 469133790Ssilby bcopy(&cpipe->pipe_buffer.buffer[cpipe->pipe_buffer.out], 470133790Ssilby buffer, cnt); 471133790Ssilby } 472133790Ssilby } 47376364Salfred pipe_free_kmem(cpipe); 47476364Salfred cpipe->pipe_buffer.buffer = buffer; 47576364Salfred cpipe->pipe_buffer.size = size; 476133790Ssilby cpipe->pipe_buffer.in = cnt; 47776364Salfred cpipe->pipe_buffer.out = 0; 478133790Ssilby cpipe->pipe_buffer.cnt = cnt; 479110816Salc atomic_add_int(&amountpipekva, cpipe->pipe_buffer.size); 48076364Salfred return (0); 48113907Sdyson} 48213688Sdyson 48313907Sdyson/* 484132579Srwatson * Wrapper for pipespace_new() that performs locking assertions. 485132579Srwatson */ 486132579Srwatsonstatic int 487132579Srwatsonpipespace(cpipe, size) 488132579Srwatson struct pipe *cpipe; 489132579Srwatson int size; 490132579Srwatson{ 491132579Srwatson 492133049Ssilby KASSERT(cpipe->pipe_state & PIPE_LOCKFL, 493133049Ssilby ("Unlocked pipe passed to pipespace")); 494132579Srwatson return (pipespace_new(cpipe, size)); 495132579Srwatson} 496132579Srwatson 497132579Srwatson/* 49813675Sdyson * lock a pipe for I/O, blocking other access 49913675Sdyson */ 50013675Sdysonstatic __inline int 50113907Sdysonpipelock(cpipe, catch) 50213675Sdyson struct pipe *cpipe; 50313907Sdyson int catch; 50413675Sdyson{ 50513776Sdyson int error; 50676364Salfred 50791362Salfred PIPE_LOCK_ASSERT(cpipe, MA_OWNED); 50891362Salfred while (cpipe->pipe_state & PIPE_LOCKFL) { 50913675Sdyson cpipe->pipe_state |= PIPE_LWANT; 51091362Salfred error = msleep(cpipe, PIPE_MTX(cpipe), 51191362Salfred catch ? (PRIBIO | PCATCH) : PRIBIO, 51276760Salfred "pipelk", 0); 513124394Sdes if (error != 0) 51476760Salfred return (error); 51513675Sdyson } 51691362Salfred cpipe->pipe_state |= PIPE_LOCKFL; 51776760Salfred return (0); 51813675Sdyson} 51913675Sdyson 52013675Sdyson/* 52113675Sdyson * unlock a pipe I/O lock 52213675Sdyson */ 52313675Sdysonstatic __inline void 52413675Sdysonpipeunlock(cpipe) 52513675Sdyson struct pipe *cpipe; 52613675Sdyson{ 52776364Salfred 52891362Salfred PIPE_LOCK_ASSERT(cpipe, MA_OWNED); 529133049Ssilby KASSERT(cpipe->pipe_state & PIPE_LOCKFL, 530133049Ssilby ("Unlocked pipe passed to pipeunlock")); 53191362Salfred cpipe->pipe_state &= ~PIPE_LOCKFL; 53213675Sdyson if (cpipe->pipe_state & PIPE_LWANT) { 53313675Sdyson cpipe->pipe_state &= ~PIPE_LWANT; 53414177Sdyson wakeup(cpipe); 53513675Sdyson } 53613675Sdyson} 53713675Sdyson 53814037Sdysonstatic __inline void 53914037Sdysonpipeselwakeup(cpipe) 54014037Sdyson struct pipe *cpipe; 54114037Sdyson{ 54276364Salfred 543126252Srwatson PIPE_LOCK_ASSERT(cpipe, MA_OWNED); 54414037Sdyson if (cpipe->pipe_state & PIPE_SEL) { 54514037Sdyson cpipe->pipe_state &= ~PIPE_SEL; 546122352Stanimura selwakeuppri(&cpipe->pipe_sel, PSOCK); 54714037Sdyson } 54841086Struckman if ((cpipe->pipe_state & PIPE_ASYNC) && cpipe->pipe_sigio) 54995883Salfred pgsigio(&cpipe->pipe_sigio, SIGIO, 0); 550133741Sjmg KNOTE_LOCKED(&cpipe->pipe_sel.si_note, 0); 55114037Sdyson} 55214037Sdyson 553126131Sgreen/* 554126131Sgreen * Initialize and allocate VM and memory for pipe. The structure 555126131Sgreen * will start out zero'd from the ctor, so we just manage the kmem. 556126131Sgreen */ 557126131Sgreenstatic int 558133790Ssilbypipe_create(pipe, backing) 559126131Sgreen struct pipe *pipe; 560133790Ssilby int backing; 561126131Sgreen{ 562126131Sgreen int error; 563126131Sgreen 564133790Ssilby if (backing) { 565133790Ssilby if (amountpipekva > maxpipekva / 2) 566133790Ssilby error = pipespace_new(pipe, SMALL_PIPE_SIZE); 567133790Ssilby else 568133790Ssilby error = pipespace_new(pipe, PIPE_SIZE); 569133790Ssilby } else { 570133790Ssilby /* If we're not backing this pipe, no need to do anything. */ 571133790Ssilby error = 0; 572133790Ssilby } 573132579Srwatson return (error); 574126131Sgreen} 575126131Sgreen 57613675Sdyson/* ARGSUSED */ 57713675Sdysonstatic int 578101941Srwatsonpipe_read(fp, uio, active_cred, flags, td) 57913675Sdyson struct file *fp; 58013675Sdyson struct uio *uio; 581101941Srwatson struct ucred *active_cred; 58283366Sjulian struct thread *td; 58345311Sdt int flags; 58413675Sdyson{ 585109153Sdillon struct pipe *rpipe = fp->f_data; 58647748Salc int error; 58713675Sdyson int nread = 0; 58818863Sdyson u_int size; 58913675Sdyson 59091362Salfred PIPE_LOCK(rpipe); 59113675Sdyson ++rpipe->pipe_busy; 59247748Salc error = pipelock(rpipe, 1); 59347748Salc if (error) 59447748Salc goto unlocked_error; 59547748Salc 596101768Srwatson#ifdef MAC 597125293Srwatson error = mac_check_pipe_read(active_cred, rpipe->pipe_pair); 598101768Srwatson if (error) 599101768Srwatson goto locked_error; 600101768Srwatson#endif 601133790Ssilby if (amountpipekva > (3 * maxpipekva) / 4) { 602133790Ssilby if (!(rpipe->pipe_state & PIPE_DIRECTW) && 603133790Ssilby (rpipe->pipe_buffer.size > SMALL_PIPE_SIZE) && 604133790Ssilby (rpipe->pipe_buffer.cnt <= SMALL_PIPE_SIZE) && 605133790Ssilby (piperesizeallowed == 1)) { 606133790Ssilby PIPE_UNLOCK(rpipe); 607133790Ssilby pipespace(rpipe, SMALL_PIPE_SIZE); 608133790Ssilby PIPE_LOCK(rpipe); 609133790Ssilby } 610133790Ssilby } 611101768Srwatson 61213675Sdyson while (uio->uio_resid) { 61313907Sdyson /* 61413907Sdyson * normal pipe buffer receive 61513907Sdyson */ 61613675Sdyson if (rpipe->pipe_buffer.cnt > 0) { 61718863Sdyson size = rpipe->pipe_buffer.size - rpipe->pipe_buffer.out; 61813675Sdyson if (size > rpipe->pipe_buffer.cnt) 61913675Sdyson size = rpipe->pipe_buffer.cnt; 62018863Sdyson if (size > (u_int) uio->uio_resid) 62118863Sdyson size = (u_int) uio->uio_resid; 62247748Salc 62391362Salfred PIPE_UNLOCK(rpipe); 624116127Smux error = uiomove( 625116127Smux &rpipe->pipe_buffer.buffer[rpipe->pipe_buffer.out], 626116127Smux size, uio); 62791362Salfred PIPE_LOCK(rpipe); 62876760Salfred if (error) 62913675Sdyson break; 63076760Salfred 63113675Sdyson rpipe->pipe_buffer.out += size; 63213675Sdyson if (rpipe->pipe_buffer.out >= rpipe->pipe_buffer.size) 63313675Sdyson rpipe->pipe_buffer.out = 0; 63413675Sdyson 63513675Sdyson rpipe->pipe_buffer.cnt -= size; 63647748Salc 63747748Salc /* 63847748Salc * If there is no more to read in the pipe, reset 63947748Salc * its pointers to the beginning. This improves 64047748Salc * cache hit stats. 64147748Salc */ 64247748Salc if (rpipe->pipe_buffer.cnt == 0) { 64347748Salc rpipe->pipe_buffer.in = 0; 64447748Salc rpipe->pipe_buffer.out = 0; 64547748Salc } 64613675Sdyson nread += size; 64714037Sdyson#ifndef PIPE_NODIRECT 64813907Sdyson /* 64913907Sdyson * Direct copy, bypassing a kernel buffer. 65013907Sdyson */ 65113907Sdyson } else if ((size = rpipe->pipe_map.cnt) && 65247748Salc (rpipe->pipe_state & PIPE_DIRECTW)) { 65318863Sdyson if (size > (u_int) uio->uio_resid) 65418863Sdyson size = (u_int) uio->uio_resid; 65547748Salc 65691362Salfred PIPE_UNLOCK(rpipe); 657127501Salc error = uiomove_fromphys(rpipe->pipe_map.ms, 658127501Salc rpipe->pipe_map.pos, size, uio); 65991362Salfred PIPE_LOCK(rpipe); 66013907Sdyson if (error) 66113907Sdyson break; 66213907Sdyson nread += size; 66313907Sdyson rpipe->pipe_map.pos += size; 66413907Sdyson rpipe->pipe_map.cnt -= size; 66513907Sdyson if (rpipe->pipe_map.cnt == 0) { 66613907Sdyson rpipe->pipe_state &= ~PIPE_DIRECTW; 66713907Sdyson wakeup(rpipe); 66813907Sdyson } 66914037Sdyson#endif 67013675Sdyson } else { 67113675Sdyson /* 67213675Sdyson * detect EOF condition 67376760Salfred * read returns 0 on EOF, no need to set error 67413675Sdyson */ 67576760Salfred if (rpipe->pipe_state & PIPE_EOF) 67613675Sdyson break; 67743623Sdillon 67813675Sdyson /* 67913675Sdyson * If the "write-side" has been blocked, wake it up now. 68013675Sdyson */ 68113675Sdyson if (rpipe->pipe_state & PIPE_WANTW) { 68213675Sdyson rpipe->pipe_state &= ~PIPE_WANTW; 68313675Sdyson wakeup(rpipe); 68413675Sdyson } 68543623Sdillon 68643623Sdillon /* 68747748Salc * Break if some data was read. 68843623Sdillon */ 68947748Salc if (nread > 0) 69013675Sdyson break; 69116960Sdyson 69243623Sdillon /* 693124394Sdes * Unlock the pipe buffer for our remaining processing. 694116127Smux * We will either break out with an error or we will 695116127Smux * sleep and relock to loop. 69643623Sdillon */ 69747748Salc pipeunlock(rpipe); 69843623Sdillon 69913675Sdyson /* 70047748Salc * Handle non-blocking mode operation or 70147748Salc * wait for more data. 70213675Sdyson */ 70376760Salfred if (fp->f_flag & FNONBLOCK) { 70447748Salc error = EAGAIN; 70576760Salfred } else { 70647748Salc rpipe->pipe_state |= PIPE_WANTR; 70791362Salfred if ((error = msleep(rpipe, PIPE_MTX(rpipe), 70891362Salfred PRIBIO | PCATCH, 70977140Salfred "piperd", 0)) == 0) 71047748Salc error = pipelock(rpipe, 1); 71113675Sdyson } 71247748Salc if (error) 71347748Salc goto unlocked_error; 71413675Sdyson } 71513675Sdyson } 716101768Srwatson#ifdef MAC 717101768Srwatsonlocked_error: 718101768Srwatson#endif 71947748Salc pipeunlock(rpipe); 72013675Sdyson 72191362Salfred /* XXX: should probably do this before getting any locks. */ 72224101Sbde if (error == 0) 72355112Sbde vfs_timestamp(&rpipe->pipe_atime); 72447748Salcunlocked_error: 72547748Salc --rpipe->pipe_busy; 72613913Sdyson 72747748Salc /* 72847748Salc * PIPE_WANT processing only makes sense if pipe_busy is 0. 72947748Salc */ 73013675Sdyson if ((rpipe->pipe_busy == 0) && (rpipe->pipe_state & PIPE_WANT)) { 73113675Sdyson rpipe->pipe_state &= ~(PIPE_WANT|PIPE_WANTW); 73213675Sdyson wakeup(rpipe); 73313675Sdyson } else if (rpipe->pipe_buffer.cnt < MINPIPESIZE) { 73413675Sdyson /* 73547748Salc * Handle write blocking hysteresis. 73613675Sdyson */ 73713675Sdyson if (rpipe->pipe_state & PIPE_WANTW) { 73813675Sdyson rpipe->pipe_state &= ~PIPE_WANTW; 73913675Sdyson wakeup(rpipe); 74013675Sdyson } 74113675Sdyson } 74214037Sdyson 74314802Sdyson if ((rpipe->pipe_buffer.size - rpipe->pipe_buffer.cnt) >= PIPE_BUF) 74414037Sdyson pipeselwakeup(rpipe); 74514037Sdyson 74691362Salfred PIPE_UNLOCK(rpipe); 74776760Salfred return (error); 74813675Sdyson} 74913675Sdyson 75014037Sdyson#ifndef PIPE_NODIRECT 75113907Sdyson/* 75213907Sdyson * Map the sending processes' buffer into kernel space and wire it. 75313907Sdyson * This is similar to a physical write operation. 75413907Sdyson */ 75513675Sdysonstatic int 75613907Sdysonpipe_build_write_buffer(wpipe, uio) 75713907Sdyson struct pipe *wpipe; 75813675Sdyson struct uio *uio; 75913675Sdyson{ 760119872Salc pmap_t pmap; 76118863Sdyson u_int size; 762119872Salc int i, j; 763112569Sjake vm_offset_t addr, endaddr; 76413907Sdyson 76591412Salfred PIPE_LOCK_ASSERT(wpipe, MA_NOTOWNED); 766133790Ssilby KASSERT(wpipe->pipe_state & PIPE_DIRECTW, 767133790Ssilby ("Clone attempt on non-direct write pipe!")); 76879224Sdillon 76918863Sdyson size = (u_int) uio->uio_iov->iov_len; 77013907Sdyson if (size > wpipe->pipe_buffer.size) 77113907Sdyson size = wpipe->pipe_buffer.size; 77213907Sdyson 773119872Salc pmap = vmspace_pmap(curproc->p_vmspace); 77440286Sdg endaddr = round_page((vm_offset_t)uio->uio_iov->iov_base + size); 77576760Salfred addr = trunc_page((vm_offset_t)uio->uio_iov->iov_base); 77676760Salfred for (i = 0; addr < endaddr; addr += PAGE_SIZE, i++) { 77799899Salc /* 77899899Salc * vm_fault_quick() can sleep. Consequently, 77999899Salc * vm_page_lock_queue() and vm_page_unlock_queue() 78099899Salc * should not be performed outside of this loop. 78199899Salc */ 782119872Salc race: 783119872Salc if (vm_fault_quick((caddr_t)addr, VM_PROT_READ) < 0) { 78499899Salc vm_page_lock_queues(); 785119872Salc for (j = 0; j < i; j++) 786118757Salc vm_page_unhold(wpipe->pipe_map.ms[j]); 78799899Salc vm_page_unlock_queues(); 78876760Salfred return (EFAULT); 78913907Sdyson } 790120000Salc wpipe->pipe_map.ms[i] = pmap_extract_and_hold(pmap, addr, 791120000Salc VM_PROT_READ); 792119872Salc if (wpipe->pipe_map.ms[i] == NULL) 793119872Salc goto race; 79413907Sdyson } 79513907Sdyson 79613907Sdyson/* 79713907Sdyson * set up the control block 79813907Sdyson */ 79913907Sdyson wpipe->pipe_map.npages = i; 80076760Salfred wpipe->pipe_map.pos = 80176760Salfred ((vm_offset_t) uio->uio_iov->iov_base) & PAGE_MASK; 80213907Sdyson wpipe->pipe_map.cnt = size; 80313907Sdyson 80413907Sdyson/* 80513907Sdyson * and update the uio data 80613907Sdyson */ 80713907Sdyson 80813907Sdyson uio->uio_iov->iov_len -= size; 809104908Smike uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + size; 81013907Sdyson if (uio->uio_iov->iov_len == 0) 81113907Sdyson uio->uio_iov++; 81213907Sdyson uio->uio_resid -= size; 81313907Sdyson uio->uio_offset += size; 81476760Salfred return (0); 81513907Sdyson} 81613907Sdyson 81713907Sdyson/* 81813907Sdyson * unmap and unwire the process buffer 81913907Sdyson */ 82013907Sdysonstatic void 82113907Sdysonpipe_destroy_write_buffer(wpipe) 82276760Salfred struct pipe *wpipe; 82313907Sdyson{ 82413907Sdyson int i; 82576364Salfred 826127501Salc PIPE_LOCK_ASSERT(wpipe, MA_OWNED); 82799899Salc vm_page_lock_queues(); 828117325Ssilby for (i = 0; i < wpipe->pipe_map.npages; i++) { 829118757Salc vm_page_unhold(wpipe->pipe_map.ms[i]); 830117325Ssilby } 83199899Salc vm_page_unlock_queues(); 83291653Stanimura wpipe->pipe_map.npages = 0; 83313907Sdyson} 83413907Sdyson 83513907Sdyson/* 83613907Sdyson * In the case of a signal, the writing process might go away. This 83713907Sdyson * code copies the data into the circular buffer so that the source 83813907Sdyson * pages can be freed without loss of data. 83913907Sdyson */ 84013907Sdysonstatic void 84113907Sdysonpipe_clone_write_buffer(wpipe) 84276364Salfred struct pipe *wpipe; 84313907Sdyson{ 844127501Salc struct uio uio; 845127501Salc struct iovec iov; 84613907Sdyson int size; 84713907Sdyson int pos; 84813907Sdyson 84991362Salfred PIPE_LOCK_ASSERT(wpipe, MA_OWNED); 85013907Sdyson size = wpipe->pipe_map.cnt; 85113907Sdyson pos = wpipe->pipe_map.pos; 85213907Sdyson 85313907Sdyson wpipe->pipe_buffer.in = size; 85413907Sdyson wpipe->pipe_buffer.out = 0; 85513907Sdyson wpipe->pipe_buffer.cnt = size; 85613907Sdyson wpipe->pipe_state &= ~PIPE_DIRECTW; 85713907Sdyson 858119811Salc PIPE_UNLOCK(wpipe); 859127501Salc iov.iov_base = wpipe->pipe_buffer.buffer; 860127501Salc iov.iov_len = size; 861127501Salc uio.uio_iov = &iov; 862127501Salc uio.uio_iovcnt = 1; 863127501Salc uio.uio_offset = 0; 864127501Salc uio.uio_resid = size; 865127501Salc uio.uio_segflg = UIO_SYSSPACE; 866127501Salc uio.uio_rw = UIO_READ; 867127501Salc uio.uio_td = curthread; 868127501Salc uiomove_fromphys(wpipe->pipe_map.ms, pos, size, &uio); 869127501Salc PIPE_LOCK(wpipe); 87013907Sdyson pipe_destroy_write_buffer(wpipe); 87113907Sdyson} 87213907Sdyson 87313907Sdyson/* 87413907Sdyson * This implements the pipe buffer write mechanism. Note that only 87513907Sdyson * a direct write OR a normal pipe write can be pending at any given time. 87613907Sdyson * If there are any characters in the pipe buffer, the direct write will 87713907Sdyson * be deferred until the receiving process grabs all of the bytes from 87813907Sdyson * the pipe buffer. Then the direct mapping write is set-up. 87913907Sdyson */ 88013907Sdysonstatic int 88113907Sdysonpipe_direct_write(wpipe, uio) 88213907Sdyson struct pipe *wpipe; 88313907Sdyson struct uio *uio; 88413907Sdyson{ 88513907Sdyson int error; 88676364Salfred 88713951Sdysonretry: 88891362Salfred PIPE_LOCK_ASSERT(wpipe, MA_OWNED); 889133049Ssilby error = pipelock(wpipe, 1); 890133049Ssilby if (wpipe->pipe_state & PIPE_EOF) 891133049Ssilby error = EPIPE; 892133049Ssilby if (error) { 893133049Ssilby pipeunlock(wpipe); 894133049Ssilby goto error1; 895133049Ssilby } 89613907Sdyson while (wpipe->pipe_state & PIPE_DIRECTW) { 89776760Salfred if (wpipe->pipe_state & PIPE_WANTR) { 89813951Sdyson wpipe->pipe_state &= ~PIPE_WANTR; 89913951Sdyson wakeup(wpipe); 90013951Sdyson } 90113992Sdyson wpipe->pipe_state |= PIPE_WANTW; 902133049Ssilby pipeunlock(wpipe); 90391362Salfred error = msleep(wpipe, PIPE_MTX(wpipe), 90491362Salfred PRIBIO | PCATCH, "pipdww", 0); 90514802Sdyson if (error) 90613907Sdyson goto error1; 907133049Ssilby else 908133049Ssilby goto retry; 90913907Sdyson } 91013907Sdyson wpipe->pipe_map.cnt = 0; /* transfer not ready yet */ 91113951Sdyson if (wpipe->pipe_buffer.cnt > 0) { 91276760Salfred if (wpipe->pipe_state & PIPE_WANTR) { 91313951Sdyson wpipe->pipe_state &= ~PIPE_WANTR; 91413951Sdyson wakeup(wpipe); 91513951Sdyson } 91613992Sdyson wpipe->pipe_state |= PIPE_WANTW; 917133049Ssilby pipeunlock(wpipe); 91891362Salfred error = msleep(wpipe, PIPE_MTX(wpipe), 91991362Salfred PRIBIO | PCATCH, "pipdwc", 0); 92014802Sdyson if (error) 92113907Sdyson goto error1; 922133049Ssilby else 923133049Ssilby goto retry; 92413907Sdyson } 92513907Sdyson 92613951Sdyson wpipe->pipe_state |= PIPE_DIRECTW; 92713951Sdyson 928119872Salc PIPE_UNLOCK(wpipe); 92913907Sdyson error = pipe_build_write_buffer(wpipe, uio); 930119872Salc PIPE_LOCK(wpipe); 93113907Sdyson if (error) { 93213907Sdyson wpipe->pipe_state &= ~PIPE_DIRECTW; 933133049Ssilby pipeunlock(wpipe); 93413907Sdyson goto error1; 93513907Sdyson } 93613907Sdyson 93713907Sdyson error = 0; 93813907Sdyson while (!error && (wpipe->pipe_state & PIPE_DIRECTW)) { 93913907Sdyson if (wpipe->pipe_state & PIPE_EOF) { 94013907Sdyson pipe_destroy_write_buffer(wpipe); 941112981Shsu pipeselwakeup(wpipe); 94213907Sdyson pipeunlock(wpipe); 94314802Sdyson error = EPIPE; 94414802Sdyson goto error1; 94513907Sdyson } 94613992Sdyson if (wpipe->pipe_state & PIPE_WANTR) { 94713992Sdyson wpipe->pipe_state &= ~PIPE_WANTR; 94813992Sdyson wakeup(wpipe); 94913992Sdyson } 95014037Sdyson pipeselwakeup(wpipe); 951133049Ssilby pipeunlock(wpipe); 95291362Salfred error = msleep(wpipe, PIPE_MTX(wpipe), PRIBIO | PCATCH, 95391362Salfred "pipdwt", 0); 954133049Ssilby pipelock(wpipe, 0); 95513907Sdyson } 95613907Sdyson 957126131Sgreen if (wpipe->pipe_state & PIPE_EOF) 958126131Sgreen error = EPIPE; 95913907Sdyson if (wpipe->pipe_state & PIPE_DIRECTW) { 96013907Sdyson /* 96113907Sdyson * this bit of trickery substitutes a kernel buffer for 96213907Sdyson * the process that might be going away. 96313907Sdyson */ 96413907Sdyson pipe_clone_write_buffer(wpipe); 96513907Sdyson } else { 96613907Sdyson pipe_destroy_write_buffer(wpipe); 96713907Sdyson } 96813907Sdyson pipeunlock(wpipe); 96976760Salfred return (error); 97013907Sdyson 97113907Sdysonerror1: 97213907Sdyson wakeup(wpipe); 97376760Salfred return (error); 97413907Sdyson} 97514037Sdyson#endif 976124394Sdes 97716960Sdysonstatic int 978101941Srwatsonpipe_write(fp, uio, active_cred, flags, td) 97916960Sdyson struct file *fp; 98013907Sdyson struct uio *uio; 981101941Srwatson struct ucred *active_cred; 98283366Sjulian struct thread *td; 98345311Sdt int flags; 98413907Sdyson{ 98513675Sdyson int error = 0; 986133790Ssilby int desiredsize, orig_resid; 98716960Sdyson struct pipe *wpipe, *rpipe; 98816960Sdyson 989109153Sdillon rpipe = fp->f_data; 99016960Sdyson wpipe = rpipe->pipe_peer; 99116960Sdyson 99291395Salfred PIPE_LOCK(rpipe); 993133049Ssilby error = pipelock(wpipe, 1); 994133049Ssilby if (error) { 995133049Ssilby PIPE_UNLOCK(rpipe); 996133049Ssilby return (error); 997133049Ssilby } 99813675Sdyson /* 99913675Sdyson * detect loss of pipe read side, issue SIGPIPE if lost. 100013675Sdyson */ 1001125364Srwatson if ((!wpipe->pipe_present) || (wpipe->pipe_state & PIPE_EOF)) { 1002133049Ssilby pipeunlock(wpipe); 100391395Salfred PIPE_UNLOCK(rpipe); 100476760Salfred return (EPIPE); 100513675Sdyson } 1006101768Srwatson#ifdef MAC 1007125293Srwatson error = mac_check_pipe_write(active_cred, wpipe->pipe_pair); 1008101768Srwatson if (error) { 1009133049Ssilby pipeunlock(wpipe); 1010101768Srwatson PIPE_UNLOCK(rpipe); 1011101768Srwatson return (error); 1012101768Srwatson } 1013101768Srwatson#endif 101477676Sdillon ++wpipe->pipe_busy; 101513675Sdyson 1016133790Ssilby /* Choose a larger size if it's advantageous */ 1017133790Ssilby desiredsize = max(SMALL_PIPE_SIZE, wpipe->pipe_buffer.size); 1018133790Ssilby while (desiredsize < wpipe->pipe_buffer.cnt + uio->uio_resid) { 1019133790Ssilby if (piperesizeallowed != 1) 1020133790Ssilby break; 1021133790Ssilby if (amountpipekva > maxpipekva / 2) 1022133790Ssilby break; 1023133790Ssilby if (desiredsize == BIG_PIPE_SIZE) 1024133790Ssilby break; 1025133790Ssilby desiredsize = desiredsize * 2; 1026133790Ssilby } 102717163Sdyson 1028133790Ssilby /* Choose a smaller size if we're in a OOM situation */ 1029133790Ssilby if ((amountpipekva > (3 * maxpipekva) / 4) && 1030133790Ssilby (wpipe->pipe_buffer.size > SMALL_PIPE_SIZE) && 1031133790Ssilby (wpipe->pipe_buffer.cnt <= SMALL_PIPE_SIZE) && 1032133790Ssilby (piperesizeallowed == 1)) 1033133790Ssilby desiredsize = SMALL_PIPE_SIZE; 1034133790Ssilby 1035133790Ssilby /* Resize if the above determined that a new size was necessary */ 1036133790Ssilby if ((desiredsize != wpipe->pipe_buffer.size) && 1037133790Ssilby ((wpipe->pipe_state & PIPE_DIRECTW) == 0)) { 1038133049Ssilby PIPE_UNLOCK(wpipe); 1039133790Ssilby pipespace(wpipe, desiredsize); 1040133049Ssilby PIPE_LOCK(wpipe); 104113907Sdyson } 1042133790Ssilby if (wpipe->pipe_buffer.size == 0) { 1043133790Ssilby /* 1044133790Ssilby * This can only happen for reverse direction use of pipes 1045133790Ssilby * in a complete OOM situation. 1046133790Ssilby */ 1047133790Ssilby error = ENOMEM; 1048133790Ssilby --wpipe->pipe_busy; 1049133790Ssilby pipeunlock(wpipe); 1050133790Ssilby PIPE_UNLOCK(wpipe); 1051133790Ssilby return (error); 1052133790Ssilby } 105377676Sdillon 1054133049Ssilby pipeunlock(wpipe); 1055124394Sdes 105613913Sdyson orig_resid = uio->uio_resid; 105777676Sdillon 105813675Sdyson while (uio->uio_resid) { 105913907Sdyson int space; 106076760Salfred 1061133049Ssilby pipelock(wpipe, 0); 1062133049Ssilby if (wpipe->pipe_state & PIPE_EOF) { 1063133049Ssilby pipeunlock(wpipe); 1064133049Ssilby error = EPIPE; 1065133049Ssilby break; 1066133049Ssilby } 106714037Sdyson#ifndef PIPE_NODIRECT 106813907Sdyson /* 106913907Sdyson * If the transfer is large, we can gain performance if 107013907Sdyson * we do process-to-process copies directly. 107116416Sdyson * If the write is non-blocking, we don't use the 107216416Sdyson * direct write mechanism. 107358505Sdillon * 107458505Sdillon * The direct write mechanism will detect the reader going 107558505Sdillon * away on us. 107613907Sdyson */ 1077165347Spjd if (uio->uio_segflg == UIO_USERSPACE && 1078165347Spjd uio->uio_iov->iov_len >= PIPE_MINDIRECT && 1079165347Spjd wpipe->pipe_buffer.size >= PIPE_MINDIRECT && 1080127501Salc (fp->f_flag & FNONBLOCK) == 0) { 1081133049Ssilby pipeunlock(wpipe); 1082105009Salfred error = pipe_direct_write(wpipe, uio); 108376760Salfred if (error) 108413907Sdyson break; 108513907Sdyson continue; 108691362Salfred } 108714037Sdyson#endif 108813907Sdyson 108913907Sdyson /* 109013907Sdyson * Pipe buffered writes cannot be coincidental with 109113907Sdyson * direct writes. We wait until the currently executing 109213907Sdyson * direct write is completed before we start filling the 109358505Sdillon * pipe buffer. We break out if a signal occurs or the 109458505Sdillon * reader goes away. 109513907Sdyson */ 1096133049Ssilby if (wpipe->pipe_state & PIPE_DIRECTW) { 109713992Sdyson if (wpipe->pipe_state & PIPE_WANTR) { 109813992Sdyson wpipe->pipe_state &= ~PIPE_WANTR; 109913992Sdyson wakeup(wpipe); 110013992Sdyson } 1101133049Ssilby pipeunlock(wpipe); 110291395Salfred error = msleep(wpipe, PIPE_MTX(rpipe), PRIBIO | PCATCH, 110391362Salfred "pipbww", 0); 110413907Sdyson if (error) 110513907Sdyson break; 1106133049Ssilby else 1107133049Ssilby continue; 110813907Sdyson } 110913907Sdyson 111013907Sdyson space = wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt; 111114644Sdyson 111214644Sdyson /* Writes of size <= PIPE_BUF must be atomic. */ 111313913Sdyson if ((space < uio->uio_resid) && (orig_resid <= PIPE_BUF)) 111413913Sdyson space = 0; 111513907Sdyson 1116118230Spb if (space > 0) { 1117133049Ssilby int size; /* Transfer size */ 1118133049Ssilby int segsize; /* first segment to transfer */ 111976760Salfred 1120133049Ssilby /* 1121133049Ssilby * Transfer size is minimum of uio transfer 1122133049Ssilby * and free space in pipe buffer. 1123133049Ssilby */ 1124133049Ssilby if (space > uio->uio_resid) 1125133049Ssilby size = uio->uio_resid; 1126133049Ssilby else 1127133049Ssilby size = space; 1128133049Ssilby /* 1129133049Ssilby * First segment to transfer is minimum of 1130133049Ssilby * transfer size and contiguous space in 1131133049Ssilby * pipe buffer. If first segment to transfer 1132133049Ssilby * is less than the transfer size, we've got 1133133049Ssilby * a wraparound in the buffer. 1134133049Ssilby */ 1135133049Ssilby segsize = wpipe->pipe_buffer.size - 1136133049Ssilby wpipe->pipe_buffer.in; 1137133049Ssilby if (segsize > size) 1138133049Ssilby segsize = size; 113954534Stegge 1140133049Ssilby /* Transfer first segment */ 1141133049Ssilby 1142133049Ssilby PIPE_UNLOCK(rpipe); 1143133049Ssilby error = uiomove(&wpipe->pipe_buffer.buffer[wpipe->pipe_buffer.in], 1144133049Ssilby segsize, uio); 1145133049Ssilby PIPE_LOCK(rpipe); 1146133049Ssilby 1147133049Ssilby if (error == 0 && segsize < size) { 1148133049Ssilby KASSERT(wpipe->pipe_buffer.in + segsize == 1149133049Ssilby wpipe->pipe_buffer.size, 1150133049Ssilby ("Pipe buffer wraparound disappeared")); 115154534Stegge /* 1152133049Ssilby * Transfer remaining part now, to 1153133049Ssilby * support atomic writes. Wraparound 1154133049Ssilby * happened. 115554534Stegge */ 1156124394Sdes 115791395Salfred PIPE_UNLOCK(rpipe); 1158133049Ssilby error = uiomove( 1159133049Ssilby &wpipe->pipe_buffer.buffer[0], 1160133049Ssilby size - segsize, uio); 116191395Salfred PIPE_LOCK(rpipe); 1162133049Ssilby } 1163133049Ssilby if (error == 0) { 1164133049Ssilby wpipe->pipe_buffer.in += size; 1165133049Ssilby if (wpipe->pipe_buffer.in >= 1166133049Ssilby wpipe->pipe_buffer.size) { 1167133049Ssilby KASSERT(wpipe->pipe_buffer.in == 1168133049Ssilby size - segsize + 1169133049Ssilby wpipe->pipe_buffer.size, 1170133049Ssilby ("Expected wraparound bad")); 1171133049Ssilby wpipe->pipe_buffer.in = size - segsize; 117254534Stegge } 1173124394Sdes 1174133049Ssilby wpipe->pipe_buffer.cnt += size; 1175133049Ssilby KASSERT(wpipe->pipe_buffer.cnt <= 1176133049Ssilby wpipe->pipe_buffer.size, 1177133049Ssilby ("Pipe buffer overflow")); 117813675Sdyson } 1179133049Ssilby pipeunlock(wpipe); 1180153484Sdelphij if (error != 0) 1181153484Sdelphij break; 118213675Sdyson } else { 118313675Sdyson /* 118413675Sdyson * If the "read-side" has been blocked, wake it up now. 118513675Sdyson */ 118613675Sdyson if (wpipe->pipe_state & PIPE_WANTR) { 118713675Sdyson wpipe->pipe_state &= ~PIPE_WANTR; 118813675Sdyson wakeup(wpipe); 118913675Sdyson } 119014037Sdyson 119113675Sdyson /* 119213675Sdyson * don't block on non-blocking I/O 119313675Sdyson */ 119416960Sdyson if (fp->f_flag & FNONBLOCK) { 119513907Sdyson error = EAGAIN; 1196133049Ssilby pipeunlock(wpipe); 119713675Sdyson break; 119813675Sdyson } 119913907Sdyson 120014037Sdyson /* 120114037Sdyson * We have no more space and have something to offer, 120229356Speter * wake up select/poll. 120314037Sdyson */ 120414037Sdyson pipeselwakeup(wpipe); 120514037Sdyson 120613675Sdyson wpipe->pipe_state |= PIPE_WANTW; 1207133049Ssilby pipeunlock(wpipe); 120891395Salfred error = msleep(wpipe, PIPE_MTX(rpipe), 120991362Salfred PRIBIO | PCATCH, "pipewr", 0); 121076760Salfred if (error != 0) 121113675Sdyson break; 121213675Sdyson } 121313675Sdyson } 121413675Sdyson 1215133049Ssilby pipelock(wpipe, 0); 121614644Sdyson --wpipe->pipe_busy; 121777676Sdillon 121876760Salfred if ((wpipe->pipe_busy == 0) && (wpipe->pipe_state & PIPE_WANT)) { 121976760Salfred wpipe->pipe_state &= ~(PIPE_WANT | PIPE_WANTR); 122013675Sdyson wakeup(wpipe); 122113675Sdyson } else if (wpipe->pipe_buffer.cnt > 0) { 122213675Sdyson /* 122313675Sdyson * If we have put any characters in the buffer, we wake up 122413675Sdyson * the reader. 122513675Sdyson */ 122613675Sdyson if (wpipe->pipe_state & PIPE_WANTR) { 122713675Sdyson wpipe->pipe_state &= ~PIPE_WANTR; 122813675Sdyson wakeup(wpipe); 122913675Sdyson } 123013675Sdyson } 123113909Sdyson 123213909Sdyson /* 123313909Sdyson * Don't return EPIPE if I/O was successful 123413909Sdyson */ 123513907Sdyson if ((wpipe->pipe_buffer.cnt == 0) && 123677676Sdillon (uio->uio_resid == 0) && 123777676Sdillon (error == EPIPE)) { 123813907Sdyson error = 0; 123977676Sdillon } 124013913Sdyson 124124101Sbde if (error == 0) 124255112Sbde vfs_timestamp(&wpipe->pipe_mtime); 124324101Sbde 124414037Sdyson /* 124514037Sdyson * We have something to offer, 124629356Speter * wake up select/poll. 124714037Sdyson */ 124814177Sdyson if (wpipe->pipe_buffer.cnt) 124914037Sdyson pipeselwakeup(wpipe); 125013907Sdyson 1251133049Ssilby pipeunlock(wpipe); 125291395Salfred PIPE_UNLOCK(rpipe); 125376760Salfred return (error); 125413675Sdyson} 125513675Sdyson 125613675Sdyson/* 125713675Sdyson * we implement a very minimal set of ioctls for compatibility with sockets. 125813675Sdyson */ 1259104094Sphkstatic int 1260102003Srwatsonpipe_ioctl(fp, cmd, data, active_cred, td) 126113675Sdyson struct file *fp; 126236735Sdfr u_long cmd; 126399009Salfred void *data; 1264102003Srwatson struct ucred *active_cred; 126583366Sjulian struct thread *td; 126613675Sdyson{ 1267109153Sdillon struct pipe *mpipe = fp->f_data; 1268101768Srwatson int error; 126913675Sdyson 1270104269Srwatson PIPE_LOCK(mpipe); 1271104269Srwatson 1272104269Srwatson#ifdef MAC 1273125293Srwatson error = mac_check_pipe_ioctl(active_cred, mpipe->pipe_pair, cmd, data); 1274121970Srwatson if (error) { 1275121970Srwatson PIPE_UNLOCK(mpipe); 1276101768Srwatson return (error); 1277121970Srwatson } 1278101768Srwatson#endif 1279101768Srwatson 1280137752Sphk error = 0; 128113675Sdyson switch (cmd) { 128213675Sdyson 128313675Sdyson case FIONBIO: 1284137752Sphk break; 128513675Sdyson 128613675Sdyson case FIOASYNC: 128713675Sdyson if (*(int *)data) { 128813675Sdyson mpipe->pipe_state |= PIPE_ASYNC; 128913675Sdyson } else { 129013675Sdyson mpipe->pipe_state &= ~PIPE_ASYNC; 129113675Sdyson } 1292137752Sphk break; 129313675Sdyson 129413675Sdyson case FIONREAD: 129514037Sdyson if (mpipe->pipe_state & PIPE_DIRECTW) 129614037Sdyson *(int *)data = mpipe->pipe_map.cnt; 129714037Sdyson else 129814037Sdyson *(int *)data = mpipe->pipe_buffer.cnt; 1299137752Sphk break; 130013675Sdyson 130141086Struckman case FIOSETOWN: 1302138032Srwatson PIPE_UNLOCK(mpipe); 1303137752Sphk error = fsetown(*(int *)data, &mpipe->pipe_sigio); 1304138032Srwatson goto out_unlocked; 130541086Struckman 130641086Struckman case FIOGETOWN: 1307104393Struckman *(int *)data = fgetown(&mpipe->pipe_sigio); 1308137752Sphk break; 130913675Sdyson 131041086Struckman /* This is deprecated, FIOSETOWN should be used instead. */ 131141086Struckman case TIOCSPGRP: 1312138032Srwatson PIPE_UNLOCK(mpipe); 1313137752Sphk error = fsetown(-(*(int *)data), &mpipe->pipe_sigio); 1314138032Srwatson goto out_unlocked; 131541086Struckman 131641086Struckman /* This is deprecated, FIOGETOWN should be used instead. */ 131718863Sdyson case TIOCGPGRP: 1318104393Struckman *(int *)data = -fgetown(&mpipe->pipe_sigio); 1319137752Sphk break; 132013675Sdyson 1321137752Sphk default: 1322137752Sphk error = ENOTTY; 1323137764Sphk break; 132413675Sdyson } 1325104269Srwatson PIPE_UNLOCK(mpipe); 1326138032Srwatsonout_unlocked: 1327137752Sphk return (error); 132813675Sdyson} 132913675Sdyson 1330104094Sphkstatic int 1331101983Srwatsonpipe_poll(fp, events, active_cred, td) 133213675Sdyson struct file *fp; 133329356Speter int events; 1334101983Srwatson struct ucred *active_cred; 133583366Sjulian struct thread *td; 133613675Sdyson{ 1337109153Sdillon struct pipe *rpipe = fp->f_data; 133813675Sdyson struct pipe *wpipe; 133929356Speter int revents = 0; 1340101768Srwatson#ifdef MAC 1341101768Srwatson int error; 1342101768Srwatson#endif 134313675Sdyson 134413675Sdyson wpipe = rpipe->pipe_peer; 134591362Salfred PIPE_LOCK(rpipe); 1346101768Srwatson#ifdef MAC 1347125293Srwatson error = mac_check_pipe_poll(active_cred, rpipe->pipe_pair); 1348101768Srwatson if (error) 1349101768Srwatson goto locked_error; 1350101768Srwatson#endif 135129356Speter if (events & (POLLIN | POLLRDNORM)) 135229356Speter if ((rpipe->pipe_state & PIPE_DIRECTW) || 135329356Speter (rpipe->pipe_buffer.cnt > 0) || 135429356Speter (rpipe->pipe_state & PIPE_EOF)) 135529356Speter revents |= events & (POLLIN | POLLRDNORM); 135613675Sdyson 135729356Speter if (events & (POLLOUT | POLLWRNORM)) 1358125364Srwatson if (!wpipe->pipe_present || (wpipe->pipe_state & PIPE_EOF) || 135943311Sdillon (((wpipe->pipe_state & PIPE_DIRECTW) == 0) && 136043311Sdillon (wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt) >= PIPE_BUF)) 136129356Speter revents |= events & (POLLOUT | POLLWRNORM); 136213675Sdyson 136329356Speter if ((rpipe->pipe_state & PIPE_EOF) || 1364125364Srwatson (!wpipe->pipe_present) || 136529356Speter (wpipe->pipe_state & PIPE_EOF)) 136629356Speter revents |= POLLHUP; 136729356Speter 136829356Speter if (revents == 0) { 136929356Speter if (events & (POLLIN | POLLRDNORM)) { 137083805Sjhb selrecord(td, &rpipe->pipe_sel); 137129356Speter rpipe->pipe_state |= PIPE_SEL; 137213675Sdyson } 137313675Sdyson 137429356Speter if (events & (POLLOUT | POLLWRNORM)) { 137583805Sjhb selrecord(td, &wpipe->pipe_sel); 137630164Speter wpipe->pipe_state |= PIPE_SEL; 137713907Sdyson } 137813675Sdyson } 1379101768Srwatson#ifdef MAC 1380101768Srwatsonlocked_error: 1381101768Srwatson#endif 138291362Salfred PIPE_UNLOCK(rpipe); 138329356Speter 138429356Speter return (revents); 138513675Sdyson} 138613675Sdyson 138798989Salfred/* 138898989Salfred * We shouldn't need locks here as we're doing a read and this should 138998989Salfred * be a natural race. 139098989Salfred */ 139152983Speterstatic int 1392101983Srwatsonpipe_stat(fp, ub, active_cred, td) 139352983Speter struct file *fp; 139452983Speter struct stat *ub; 1395101983Srwatson struct ucred *active_cred; 139683366Sjulian struct thread *td; 139713675Sdyson{ 1398109153Sdillon struct pipe *pipe = fp->f_data; 1399101768Srwatson#ifdef MAC 1400101768Srwatson int error; 140152983Speter 1402104269Srwatson PIPE_LOCK(pipe); 1403125293Srwatson error = mac_check_pipe_stat(active_cred, pipe->pipe_pair); 1404104269Srwatson PIPE_UNLOCK(pipe); 1405101768Srwatson if (error) 1406101768Srwatson return (error); 1407101768Srwatson#endif 1408100527Salfred bzero(ub, sizeof(*ub)); 140917124Sbde ub->st_mode = S_IFIFO; 1410133790Ssilby ub->st_blksize = PAGE_SIZE; 1411132436Ssilby if (pipe->pipe_state & PIPE_DIRECTW) 1412132436Ssilby ub->st_size = pipe->pipe_map.cnt; 1413132436Ssilby else 1414132436Ssilby ub->st_size = pipe->pipe_buffer.cnt; 141513675Sdyson ub->st_blocks = (ub->st_size + ub->st_blksize - 1) / ub->st_blksize; 141634901Sphk ub->st_atimespec = pipe->pipe_atime; 141734901Sphk ub->st_mtimespec = pipe->pipe_mtime; 141834901Sphk ub->st_ctimespec = pipe->pipe_ctime; 141960404Schris ub->st_uid = fp->f_cred->cr_uid; 142060404Schris ub->st_gid = fp->f_cred->cr_gid; 142117124Sbde /* 142260404Schris * Left as 0: st_dev, st_ino, st_nlink, st_rdev, st_flags, st_gen. 142317124Sbde * XXX (st_dev, st_ino) should be unique. 142417124Sbde */ 142576760Salfred return (0); 142613675Sdyson} 142713675Sdyson 142813675Sdyson/* ARGSUSED */ 142913675Sdysonstatic int 143083366Sjulianpipe_close(fp, td) 143113675Sdyson struct file *fp; 143283366Sjulian struct thread *td; 143313675Sdyson{ 1434109153Sdillon struct pipe *cpipe = fp->f_data; 143516322Sgpalmer 143649413Sgreen fp->f_ops = &badfileops; 1437109153Sdillon fp->f_data = NULL; 143896122Salfred funsetown(&cpipe->pipe_sigio); 143913675Sdyson pipeclose(cpipe); 144076760Salfred return (0); 144113675Sdyson} 144213675Sdyson 144376364Salfredstatic void 144476364Salfredpipe_free_kmem(cpipe) 144576364Salfred struct pipe *cpipe; 144676364Salfred{ 144791412Salfred 1448125293Srwatson KASSERT(!mtx_owned(PIPE_MTX(cpipe)), 1449125293Srwatson ("pipe_free_kmem: pipe mutex locked")); 145076364Salfred 145176364Salfred if (cpipe->pipe_buffer.buffer != NULL) { 1452110816Salc atomic_subtract_int(&amountpipekva, cpipe->pipe_buffer.size); 1453118764Ssilby vm_map_remove(pipe_map, 1454118764Ssilby (vm_offset_t)cpipe->pipe_buffer.buffer, 1455118764Ssilby (vm_offset_t)cpipe->pipe_buffer.buffer + cpipe->pipe_buffer.size); 145676364Salfred cpipe->pipe_buffer.buffer = NULL; 145776364Salfred } 145876364Salfred#ifndef PIPE_NODIRECT 1459127501Salc { 146076364Salfred cpipe->pipe_map.cnt = 0; 146176364Salfred cpipe->pipe_map.pos = 0; 146276364Salfred cpipe->pipe_map.npages = 0; 146376364Salfred } 146476364Salfred#endif 146576364Salfred} 146676364Salfred 146713675Sdyson/* 146813675Sdyson * shutdown the pipe 146913675Sdyson */ 147013675Sdysonstatic void 147113675Sdysonpipeclose(cpipe) 147213675Sdyson struct pipe *cpipe; 147313675Sdyson{ 1474125293Srwatson struct pipepair *pp; 147513907Sdyson struct pipe *ppipe; 147676364Salfred 1477125293Srwatson KASSERT(cpipe != NULL, ("pipeclose: cpipe == NULL")); 147891968Salfred 1479125293Srwatson PIPE_LOCK(cpipe); 1480133049Ssilby pipelock(cpipe, 0); 1481125293Srwatson pp = cpipe->pipe_pair; 148291968Salfred 148391968Salfred pipeselwakeup(cpipe); 148413907Sdyson 148591968Salfred /* 148691968Salfred * If the other side is blocked, wake it up saying that 148791968Salfred * we want to close it down. 148891968Salfred */ 1489126131Sgreen cpipe->pipe_state |= PIPE_EOF; 149091968Salfred while (cpipe->pipe_busy) { 149191968Salfred wakeup(cpipe); 1492126131Sgreen cpipe->pipe_state |= PIPE_WANT; 1493133049Ssilby pipeunlock(cpipe); 149491968Salfred msleep(cpipe, PIPE_MTX(cpipe), PRIBIO, "pipecl", 0); 1495133049Ssilby pipelock(cpipe, 0); 149691968Salfred } 149713675Sdyson 1498101768Srwatson 149991968Salfred /* 1500125293Srwatson * Disconnect from peer, if any. 150191968Salfred */ 1502125293Srwatson ppipe = cpipe->pipe_peer; 1503125293Srwatson if (ppipe->pipe_present != 0) { 150491968Salfred pipeselwakeup(ppipe); 150513907Sdyson 150691968Salfred ppipe->pipe_state |= PIPE_EOF; 150791968Salfred wakeup(ppipe); 1508133741Sjmg KNOTE_LOCKED(&ppipe->pipe_sel.si_note, 0); 150991968Salfred } 1510125293Srwatson 151191968Salfred /* 1512125293Srwatson * Mark this endpoint as free. Release kmem resources. We 1513125293Srwatson * don't mark this endpoint as unused until we've finished 1514125293Srwatson * doing that, or the pipe might disappear out from under 1515125293Srwatson * us. 151691968Salfred */ 1517125293Srwatson PIPE_UNLOCK(cpipe); 1518125293Srwatson pipe_free_kmem(cpipe); 1519125293Srwatson PIPE_LOCK(cpipe); 1520125293Srwatson cpipe->pipe_present = 0; 1521126131Sgreen pipeunlock(cpipe); 1522133741Sjmg knlist_clear(&cpipe->pipe_sel.si_note, 1); 1523133741Sjmg knlist_destroy(&cpipe->pipe_sel.si_note); 1524125293Srwatson 1525125293Srwatson /* 1526125293Srwatson * If both endpoints are now closed, release the memory for the 1527125293Srwatson * pipe pair. If not, unlock. 1528125293Srwatson */ 1529125293Srwatson if (ppipe->pipe_present == 0) { 153091968Salfred PIPE_UNLOCK(cpipe); 1531125293Srwatson#ifdef MAC 1532125293Srwatson mac_destroy_pipe(pp); 1533125293Srwatson#endif 1534125293Srwatson uma_zfree(pipe_zone, cpipe->pipe_pair); 1535125293Srwatson } else 1536125293Srwatson PIPE_UNLOCK(cpipe); 153713675Sdyson} 153859288Sjlemon 153972521Sjlemon/*ARGSUSED*/ 154059288Sjlemonstatic int 154172521Sjlemonpipe_kqfilter(struct file *fp, struct knote *kn) 154259288Sjlemon{ 154389306Salfred struct pipe *cpipe; 154459288Sjlemon 1545109153Sdillon cpipe = kn->kn_fp->f_data; 1546126131Sgreen PIPE_LOCK(cpipe); 154772521Sjlemon switch (kn->kn_filter) { 154872521Sjlemon case EVFILT_READ: 154972521Sjlemon kn->kn_fop = &pipe_rfiltops; 155072521Sjlemon break; 155172521Sjlemon case EVFILT_WRITE: 155272521Sjlemon kn->kn_fop = &pipe_wfiltops; 1553126131Sgreen if (!cpipe->pipe_peer->pipe_present) { 1554101382Sdes /* other end of pipe has been closed */ 1555126131Sgreen PIPE_UNLOCK(cpipe); 1556118929Sjmg return (EPIPE); 1557126131Sgreen } 1558126131Sgreen cpipe = cpipe->pipe_peer; 155972521Sjlemon break; 156072521Sjlemon default: 1561126131Sgreen PIPE_UNLOCK(cpipe); 1562133741Sjmg return (EINVAL); 156372521Sjlemon } 156478292Sjlemon 1565133741Sjmg knlist_add(&cpipe->pipe_sel.si_note, kn, 1); 156691372Salfred PIPE_UNLOCK(cpipe); 156759288Sjlemon return (0); 156859288Sjlemon} 156959288Sjlemon 157059288Sjlemonstatic void 157159288Sjlemonfilt_pipedetach(struct knote *kn) 157259288Sjlemon{ 1573121018Sjmg struct pipe *cpipe = (struct pipe *)kn->kn_fp->f_data; 157459288Sjlemon 1575126131Sgreen PIPE_LOCK(cpipe); 1576121018Sjmg if (kn->kn_filter == EVFILT_WRITE) { 1577126131Sgreen if (!cpipe->pipe_peer->pipe_present) { 1578126131Sgreen PIPE_UNLOCK(cpipe); 1579121018Sjmg return; 1580126131Sgreen } 1581121018Sjmg cpipe = cpipe->pipe_peer; 1582121018Sjmg } 1583133741Sjmg knlist_remove(&cpipe->pipe_sel.si_note, kn, 1); 158491372Salfred PIPE_UNLOCK(cpipe); 158559288Sjlemon} 158659288Sjlemon 158759288Sjlemon/*ARGSUSED*/ 158859288Sjlemonstatic int 158959288Sjlemonfilt_piperead(struct knote *kn, long hint) 159059288Sjlemon{ 1591109153Sdillon struct pipe *rpipe = kn->kn_fp->f_data; 159259288Sjlemon struct pipe *wpipe = rpipe->pipe_peer; 1593133741Sjmg int ret; 159459288Sjlemon 159591372Salfred PIPE_LOCK(rpipe); 159659288Sjlemon kn->kn_data = rpipe->pipe_buffer.cnt; 159759288Sjlemon if ((kn->kn_data == 0) && (rpipe->pipe_state & PIPE_DIRECTW)) 159859288Sjlemon kn->kn_data = rpipe->pipe_map.cnt; 159959288Sjlemon 160059288Sjlemon if ((rpipe->pipe_state & PIPE_EOF) || 1601125364Srwatson (!wpipe->pipe_present) || (wpipe->pipe_state & PIPE_EOF)) { 160291372Salfred kn->kn_flags |= EV_EOF; 160391372Salfred PIPE_UNLOCK(rpipe); 160459288Sjlemon return (1); 160559288Sjlemon } 1606133741Sjmg ret = kn->kn_data > 0; 160791372Salfred PIPE_UNLOCK(rpipe); 1608133741Sjmg return ret; 160959288Sjlemon} 161059288Sjlemon 161159288Sjlemon/*ARGSUSED*/ 161259288Sjlemonstatic int 161359288Sjlemonfilt_pipewrite(struct knote *kn, long hint) 161459288Sjlemon{ 1615109153Sdillon struct pipe *rpipe = kn->kn_fp->f_data; 161659288Sjlemon struct pipe *wpipe = rpipe->pipe_peer; 161759288Sjlemon 161891372Salfred PIPE_LOCK(rpipe); 1619125364Srwatson if ((!wpipe->pipe_present) || (wpipe->pipe_state & PIPE_EOF)) { 162059288Sjlemon kn->kn_data = 0; 1621124394Sdes kn->kn_flags |= EV_EOF; 162291372Salfred PIPE_UNLOCK(rpipe); 162359288Sjlemon return (1); 162459288Sjlemon } 162559288Sjlemon kn->kn_data = wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt; 162665855Sjlemon if (wpipe->pipe_state & PIPE_DIRECTW) 162759288Sjlemon kn->kn_data = 0; 162859288Sjlemon 162991372Salfred PIPE_UNLOCK(rpipe); 163059288Sjlemon return (kn->kn_data >= PIPE_BUF); 163159288Sjlemon} 1632