1 /* 2 * Copyright (c) 2008 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Matthew Dillon <dillon@backplane.com> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * $DragonFly: src/sbin/hammer/cycle.c,v 1.5 2008/07/07 00:27:22 dillon Exp $ 35 */ 36 37 #include "hammer.h" 38 39 void 40 hammer_get_cycle(hammer_base_elm_t base, hammer_tid_t *extra) 41 { 42 struct stat st; 43 int fd; 44 45 if (CyclePath && (fd = open(CyclePath, O_RDONLY)) >= 0) { 46 if (fstat(fd, &st) < 0) { 47 fprintf(stderr, "cycle-file %s: cannot stat\n", 48 CyclePath); 49 close(fd); 50 return; 51 } 52 if (st.st_size < (off_t)sizeof(*base)) { 53 fprintf(stderr, "cycle-file %s: clearing old version\n", 54 CyclePath); 55 close(fd); 56 remove(CyclePath); 57 return; 58 } 59 if (read(fd, base, sizeof(*base)) != sizeof(*base)) { 60 fprintf(stderr, "cycle-file %s: read failed %s\n", 61 CyclePath, strerror(errno)); 62 return; 63 } 64 if (extra) { 65 if (read(fd, extra, sizeof(*extra)) != sizeof(*extra)) { 66 fprintf(stderr, "cycle-file %s: Warning, malformed\n", 67 CyclePath); 68 } 69 } 70 close(fd); 71 } 72 /* ok if the file does not exist */ 73 } 74 75 void 76 hammer_set_cycle(hammer_base_elm_t base, hammer_tid_t extra) 77 { 78 int fd; 79 80 if ((fd = open(CyclePath, O_RDWR|O_CREAT|O_TRUNC, 0666)) >= 0) { 81 write(fd, base, sizeof(*base)); 82 write(fd, &extra, sizeof(extra)); 83 close(fd); 84 } else { 85 fprintf(stderr, "Warning: Unable to write to %s: %s\n", 86 CyclePath, strerror(errno)); 87 } 88 } 89 90 void 91 hammer_reset_cycle(void) 92 { 93 remove(CyclePath); 94 } 95 96