1/* $NetBSD: rumpuser_bio.c,v 1.9 2014/08/25 10:21:39 justin Exp $ */ 2 3/*- 4 * Copyright (c) 2013 Antti Kantee. All Rights Reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28#include "rumpuser_port.h" 29 30#if !defined(lint) 31__RCSID("$NetBSD: rumpuser_bio.c,v 1.9 2014/08/25 10:21:39 justin Exp $"); 32#endif /* !lint */ 33 34#include <sys/types.h> 35 36#include <assert.h> 37#include <errno.h> 38#include <pthread.h> 39#include <stdint.h> 40#include <stdio.h> 41#include <string.h> 42#include <unistd.h> 43 44#include <rump/rumpuser.h> 45 46#include "rumpuser_int.h" 47 48struct rumpuser_bio { 49 int bio_fd; 50 int bio_op; 51 void *bio_data; 52 size_t bio_dlen; 53 off_t bio_off; 54 55 rump_biodone_fn bio_done; 56 void *bio_donearg; 57}; 58 59#define N_BIOS 128 60static pthread_mutex_t biomtx = PTHREAD_MUTEX_INITIALIZER; 61static pthread_cond_t biocv = PTHREAD_COND_INITIALIZER; 62static int bio_head, bio_tail; 63static struct rumpuser_bio bios[N_BIOS]; 64 65static void 66dobio(struct rumpuser_bio *biop) 67{ 68 ssize_t rv; 69 int error, dummy; 70 71 assert(biop->bio_donearg != NULL); 72 if (biop->bio_op & RUMPUSER_BIO_READ) { 73 error = 0; 74 rv = pread(biop->bio_fd, biop->bio_data, 75 biop->bio_dlen, biop->bio_off); 76 if (rv < 0) { 77 rv = 0; 78 error = rumpuser__errtrans(errno); 79 } 80 } else { 81 error = 0; 82 rv = pwrite(biop->bio_fd, biop->bio_data, 83 biop->bio_dlen, biop->bio_off); 84 if (rv < 0) { 85 rv = 0; 86 error = rumpuser__errtrans(errno); 87 } else if (biop->bio_op & RUMPUSER_BIO_SYNC) { 88#ifdef HAVE_FSYNC_RANGE 89 fsync_range(biop->bio_fd, FDATASYNC, 90 biop->bio_off, biop->bio_dlen); 91#else 92 fsync(biop->bio_fd); 93#endif 94 } 95 } 96 rumpkern_sched(0, NULL); 97 biop->bio_done(biop->bio_donearg, (size_t)rv, error); 98 rumpkern_unsched(&dummy, NULL); 99 100 /* paranoia */ 101 biop->bio_donearg = NULL; 102} 103 104static void * 105biothread(void *arg) 106{ 107 struct rumpuser_bio *biop; 108 int rv; 109 110 rumpuser__hyp.hyp_schedule(); 111 rv = rumpuser__hyp.hyp_lwproc_newlwp(0); 112 assert(rv == 0); 113 rumpuser__hyp.hyp_unschedule(); 114 NOFAIL_ERRNO(pthread_mutex_lock(&biomtx)); 115 for (;;) { 116 while (bio_head == bio_tail) 117 NOFAIL_ERRNO(pthread_cond_wait(&biocv, &biomtx)); 118 119 biop = &bios[bio_tail]; 120 pthread_mutex_unlock(&biomtx); 121 122 dobio(biop); 123 124 NOFAIL_ERRNO(pthread_mutex_lock(&biomtx)); 125 bio_tail = (bio_tail+1) % N_BIOS; 126 pthread_cond_signal(&biocv); 127 } 128 129 /* unreachable */ 130 abort(); 131} 132 133void 134rumpuser_bio(int fd, int op, void *data, size_t dlen, int64_t doff, 135 rump_biodone_fn biodone, void *bioarg) 136{ 137 struct rumpuser_bio bio; 138 static int inited = 0; 139 static int usethread = 1; 140 int nlocks; 141 142 rumpkern_unsched(&nlocks, NULL); 143 144 if (!inited) { 145 pthread_mutex_lock(&biomtx); 146 if (!inited) { 147 char buf[16]; 148 pthread_t pt; 149 150 /* 151 * duplicates policy of rump kernel. maybe a bit 152 * questionable, but since the setting is not 153 * used in normal circumstances, let's not care 154 */ 155 if (getenv_r("RUMP_THREADS", buf, sizeof(buf)) == 0) 156 usethread = *buf != '0'; 157 158 if (usethread) 159 pthread_create(&pt, NULL, biothread, NULL); 160 inited = 1; 161 } 162 pthread_mutex_unlock(&biomtx); 163 assert(inited); 164 } 165 166 bio.bio_fd = fd; 167 bio.bio_op = op; 168 bio.bio_data = data; 169 bio.bio_dlen = dlen; 170 bio.bio_off = (off_t)doff; 171 bio.bio_done = biodone; 172 bio.bio_donearg = bioarg; 173 174 if (!usethread) { 175 dobio(&bio); 176 } else { 177 pthread_mutex_lock(&biomtx); 178 while ((bio_head+1) % N_BIOS == bio_tail) 179 pthread_cond_wait(&biocv, &biomtx); 180 181 bios[bio_head] = bio; 182 bio_head = (bio_head+1) % N_BIOS; 183 184 pthread_cond_signal(&biocv); 185 pthread_mutex_unlock(&biomtx); 186 } 187 188 rumpkern_sched(nlocks, NULL); 189} 190