1 /* 2 * Copyright (c) 2011 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 * by Antonio Huete <tuxillo@quantumachine.net> 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in 16 * the documentation and/or other materials provided with the 17 * distribution. 18 * 3. Neither the name of The DragonFly Project nor the names of its 19 * contributors may be used to endorse or promote products derived 20 * from this software without specific, prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 26 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 28 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 29 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 30 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 32 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <assert.h> 37 #include <fcntl.h> 38 #include <err.h> 39 #include <stdio.h> 40 #include <stdlib.h> 41 #include <string.h> 42 43 #include <sys/types.h> 44 #include <sys/stat.h> 45 #include <sys/mount.h> 46 #include <sys/stat.h> 47 #include <unistd.h> 48 #include <uuid.h> 49 50 #include "libhammer.h" 51 52 char * 53 libhammer_find_pfs_mount(uuid_t *unique_uuid) 54 { 55 struct hammer_ioc_pseudofs_rw pfs; 56 struct hammer_pseudofs_data pfsd; 57 struct statfs *mntbuf; 58 int mntsize; 59 int curmount; 60 int fd; 61 size_t mntbufsize; 62 uuid_t uuid; 63 char *retval; 64 65 retval = NULL; 66 67 /* Do not continue if there are no mounted filesystems */ 68 mntsize = getfsstat(NULL, 0, MNT_NOWAIT); 69 if (mntsize <= 0) 70 return retval; 71 72 mntbufsize = mntsize * sizeof(struct statfs); 73 mntbuf = _libhammer_malloc(mntbufsize); 74 75 mntsize = getfsstat(mntbuf, (long)mntbufsize, MNT_NOWAIT); 76 curmount = mntsize - 1; 77 78 /* 79 * Iterate all the mounted points looking for the PFS passed to 80 * this function. 81 */ 82 while(curmount >= 0) { 83 struct statfs *mnt = &mntbuf[curmount]; 84 /* 85 * Discard any non null(5) or hammer(5) filesystems as synthetic 86 * filesystems like procfs(5) could accept ioctl calls and thus 87 * produce bogus results. 88 */ 89 if ((strcmp("hammer", mnt->f_fstypename) != 0) && 90 (strcmp("null", mnt->f_fstypename) != 0)) { 91 curmount--; 92 continue; 93 } 94 bzero(&pfs, sizeof(pfs)); 95 bzero(&pfsd, sizeof(pfsd)); 96 pfs.pfs_id = -1; 97 pfs.ondisk = &pfsd; 98 pfs.bytes = sizeof(struct hammer_pseudofs_data); 99 fd = open(mnt->f_mntonname, O_RDONLY); 100 if (fd < 0 || (ioctl(fd, HAMMERIOC_GET_PSEUDOFS, &pfs) < 0)) { 101 close(fd); 102 curmount--; 103 continue; 104 } 105 106 memcpy(&uuid, &pfs.ondisk->unique_uuid, sizeof(uuid)); 107 if (uuid_compare(unique_uuid, &uuid, NULL) == 0) { 108 retval = strdup(mnt->f_mntonname); 109 close(fd); 110 break; 111 } 112 113 curmount--; 114 close(fd); 115 } 116 free(mntbuf); 117 118 return retval; 119 } 120 121 /* 122 * Find out the path that can be used to open(2) a PFS 123 * when it is not mounted. It allocates *path so the 124 * caller is in charge of freeing it up. 125 */ 126 void 127 libhammer_pfs_canonical_path(char * mtpt, libhammer_pfsinfo_t pip, char **path) 128 { 129 struct statfs st; 130 131 assert(pip != NULL); 132 assert(mtpt != NULL); 133 134 if ((statfs(mtpt, &st) < 0) || 135 ((strcmp("hammer", st.f_fstypename) != 0) && 136 (strcmp("null", st.f_fstypename) != 0))) { 137 *path = NULL; 138 return; 139 } 140 141 if (pip->ismaster) 142 asprintf(path, "%s/@@-1:%.5d", mtpt, 143 pip->pfs_id); 144 else 145 asprintf(path, "%s/@@0x%016jx:%.5d", mtpt, 146 pip->end_tid, pip->pfs_id); 147 } 148 149 150 /* 151 * Allocate len bytes of memory and return the pointer. 152 * It'll exit in the case no memory could be allocated. 153 * 154 * To be used only by the library itself. 155 */ 156 void * 157 _libhammer_malloc(size_t len) 158 { 159 void *m; 160 161 m = calloc(len, sizeof(char)); 162 if (m == NULL) 163 errx(1, "Failed to allocate %zd bytes", len); 164 165 return (m); 166 } 167