1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1990, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Mike Olson. 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. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include "namespace.h" 36 #include <sys/types.h> 37 #include <sys/mman.h> 38 #include <sys/stat.h> 39 40 #include <errno.h> 41 #include <fcntl.h> 42 #include <limits.h> 43 #include <stddef.h> 44 #include <stdio.h> 45 #include <unistd.h> 46 #include "un-namespace.h" 47 48 #include <db.h> 49 #include "recno.h" 50 51 DB * 52 __rec_open(const char *fname, int flags, int mode, const RECNOINFO *openinfo, 53 int dflags) 54 { 55 BTREE *t; 56 BTREEINFO btopeninfo; 57 DB *dbp; 58 PAGE *h; 59 struct stat sb; 60 int rfd, sverrno; 61 62 /* Open the user's file -- if this fails, we're done. */ 63 if (fname != NULL && (rfd = _open(fname, flags | O_CLOEXEC, mode)) < 0) 64 return (NULL); 65 66 /* Create a btree in memory (backed by disk). */ 67 dbp = NULL; 68 if (openinfo) { 69 if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT)) 70 goto einval; 71 btopeninfo.flags = 0; 72 btopeninfo.cachesize = openinfo->cachesize; 73 btopeninfo.maxkeypage = 0; 74 btopeninfo.minkeypage = 0; 75 btopeninfo.psize = openinfo->psize; 76 btopeninfo.compare = NULL; 77 btopeninfo.prefix = NULL; 78 btopeninfo.lorder = openinfo->lorder; 79 dbp = __bt_open(openinfo->bfname, 80 O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags); 81 } else 82 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags); 83 if (dbp == NULL) 84 goto err; 85 86 /* 87 * Some fields in the tree structure are recno specific. Fill them 88 * in and make the btree structure look like a recno structure. We 89 * don't change the bt_ovflsize value, it's close enough and slightly 90 * bigger. 91 */ 92 t = dbp->internal; 93 if (openinfo) { 94 if (openinfo->flags & R_FIXEDLEN) { 95 F_SET(t, R_FIXLEN); 96 t->bt_reclen = openinfo->reclen; 97 if (t->bt_reclen == 0) 98 goto einval; 99 } 100 t->bt_bval = openinfo->bval; 101 } else 102 t->bt_bval = '\n'; 103 104 F_SET(t, R_RECNO); 105 if (fname == NULL) 106 F_SET(t, R_EOF | R_INMEM); 107 else 108 t->bt_rfd = rfd; 109 110 if (fname != NULL) { 111 /* 112 * In 4.4BSD, stat(2) returns true for ISSOCK on pipes. 113 * Unfortunately, that's not portable, so we use lseek 114 * and check the errno values. 115 */ 116 errno = 0; 117 if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) { 118 switch (flags & O_ACCMODE) { 119 case O_RDONLY: 120 F_SET(t, R_RDONLY); 121 break; 122 default: 123 goto einval; 124 } 125 slow: if ((t->bt_rfp = fdopen(rfd, "r")) == NULL) 126 goto err; 127 F_SET(t, R_CLOSEFP); 128 t->bt_irec = 129 F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe; 130 } else { 131 switch (flags & O_ACCMODE) { 132 case O_RDONLY: 133 F_SET(t, R_RDONLY); 134 break; 135 case O_RDWR: 136 break; 137 default: 138 goto einval; 139 } 140 141 if (_fstat(rfd, &sb)) 142 goto err; 143 /* 144 * Kluge -- we'd like to test to see if the file is too 145 * big to mmap. Since, we don't know what size or type 146 * off_t's or size_t's are, what the largest unsigned 147 * integral type is, or what random insanity the local 148 * C compiler will perpetrate, doing the comparison in 149 * a portable way is flatly impossible. Hope that mmap 150 * fails if the file is too large. 151 */ 152 if (sb.st_size == 0) 153 F_SET(t, R_EOF); 154 else { 155 #ifdef MMAP_NOT_AVAILABLE 156 /* 157 * XXX 158 * Mmap doesn't work correctly on many current 159 * systems. In particular, it can fail subtly, 160 * with cache coherency problems. Don't use it 161 * for now. 162 */ 163 t->bt_msize = sb.st_size; 164 if ((t->bt_smap = mmap(NULL, t->bt_msize, 165 PROT_READ, MAP_PRIVATE, rfd, 166 (off_t)0)) == MAP_FAILED) 167 goto slow; 168 t->bt_cmap = t->bt_smap; 169 t->bt_emap = t->bt_smap + sb.st_size; 170 t->bt_irec = F_ISSET(t, R_FIXLEN) ? 171 __rec_fmap : __rec_vmap; 172 F_SET(t, R_MEMMAPPED); 173 #else 174 goto slow; 175 #endif 176 } 177 } 178 } 179 180 /* Use the recno routines. */ 181 dbp->close = __rec_close; 182 dbp->del = __rec_delete; 183 dbp->fd = __rec_fd; 184 dbp->get = __rec_get; 185 dbp->put = __rec_put; 186 dbp->seq = __rec_seq; 187 dbp->sync = __rec_sync; 188 189 /* If the root page was created, reset the flags. */ 190 if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL) 191 goto err; 192 if ((h->flags & P_TYPE) == P_BLEAF) { 193 F_CLR(h, P_TYPE); 194 F_SET(h, P_RLEAF); 195 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 196 } else 197 mpool_put(t->bt_mp, h, 0); 198 199 if (openinfo && openinfo->flags & R_SNAPSHOT && 200 !F_ISSET(t, R_EOF | R_INMEM) && 201 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 202 goto err; 203 return (dbp); 204 205 einval: errno = EINVAL; 206 err: sverrno = errno; 207 if (dbp != NULL) 208 (void)__bt_close(dbp); 209 if (fname != NULL) 210 (void)_close(rfd); 211 errno = sverrno; 212 return (NULL); 213 } 214 215 int 216 __rec_fd(const DB *dbp) 217 { 218 BTREE *t; 219 220 t = dbp->internal; 221 222 /* Toss any page pinned across calls. */ 223 if (t->bt_pinned != NULL) { 224 mpool_put(t->bt_mp, t->bt_pinned, 0); 225 t->bt_pinned = NULL; 226 } 227 228 /* In-memory database can't have a file descriptor. */ 229 if (F_ISSET(t, R_INMEM)) { 230 errno = ENOENT; 231 return (-1); 232 } 233 return (t->bt_rfd); 234 } 235