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 <unistd.h> 47 #include <uuid.h> 48 49 #include "libhammer.h" 50 51 char * 52 libhammer_find_pfs_mount(uuid_t *unique_uuid) 53 { 54 struct hammer_ioc_pseudofs_rw pfs; 55 struct hammer_pseudofs_data pfsd; 56 struct statfs *mntbuf; 57 int mntsize; 58 int curmount; 59 int fd; 60 size_t mntbufsize; 61 uuid_t uuid; 62 char *retval; 63 64 retval = NULL; 65 66 /* Do not continue if there are no mounted filesystems */ 67 mntsize = getfsstat(NULL, 0, MNT_NOWAIT); 68 if (mntsize <= 0) 69 return retval; 70 71 mntbufsize = mntsize * sizeof(struct statfs); 72 mntbuf = _libhammer_malloc(mntbufsize); 73 74 mntsize = getfsstat(mntbuf, (long)mntbufsize, MNT_NOWAIT); 75 curmount = mntsize - 1; 76 77 /* 78 * Iterate all the mounted points looking for the PFS passed to 79 * this function. 80 */ 81 while(curmount >= 0) { 82 struct statfs *mnt = &mntbuf[curmount]; 83 /* 84 * Discard any non null(5) or hammer(5) filesystems as synthetic 85 * filesystems like procfs(5) could accept ioctl calls and thus 86 * produce bogus results. 87 */ 88 if ((strcmp("hammer", mnt->f_fstypename) != 0) && 89 (strcmp("null", mnt->f_fstypename) != 0)) { 90 curmount--; 91 continue; 92 } 93 bzero(&pfs, sizeof(pfs)); 94 bzero(&pfsd, sizeof(pfsd)); 95 pfs.pfs_id = -1; 96 pfs.ondisk = &pfsd; 97 pfs.bytes = sizeof(struct hammer_pseudofs_data); 98 fd = open(mnt->f_mntonname, O_RDONLY); 99 if (fd < 0 || (ioctl(fd, HAMMERIOC_GET_PSEUDOFS, &pfs) < 0)) { 100 close(fd); 101 curmount--; 102 continue; 103 } 104 105 memcpy(&uuid, &pfs.ondisk->unique_uuid, sizeof(uuid)); 106 if (uuid_compare(unique_uuid, &uuid, NULL) == 0) { 107 retval = strdup(mnt->f_mntonname); 108 close(fd); 109 break; 110 } 111 112 curmount--; 113 close(fd); 114 } 115 free(mntbuf); 116 117 return retval; 118 } 119 120 /* 121 * Find out the path that can be used to open(2) a PFS 122 * when it is not mounted. It allocates *path so the 123 * caller is in charge of freeing it up. 124 */ 125 void 126 libhammer_pfs_canonical_path(char * mtpt, libhammer_pfsinfo_t pip, char **path) 127 { 128 struct statfs st; 129 130 assert(pip != NULL); 131 assert(mtpt != NULL); 132 133 if ((statfs(mtpt, &st) < 0) || 134 ((strcmp("hammer", st.f_fstypename) != 0) && 135 (strcmp("null", st.f_fstypename) != 0))) { 136 *path = NULL; 137 return; 138 } 139 140 if (pip->ismaster) 141 asprintf(path, "%s/@@-1:%.5d", mtpt, 142 pip->pfs_id); 143 else 144 asprintf(path, "%s/@@0x%016jx:%.5d", mtpt, 145 pip->end_tid, pip->pfs_id); 146 } 147 148 149 /* 150 * Allocate len bytes of memory and return the pointer. 151 * It'll exit in the case no memory could be allocated. 152 * 153 * To be used only by the library itself. 154 */ 155 void * 156 _libhammer_malloc(size_t len) 157 { 158 void *m; 159 160 m = calloc(len, sizeof(char)); 161 if (m == NULL) 162 errx(1, "Failed to allocate %zd bytes", len); 163 164 return (m); 165 } 166