lib/libhammer/info.c

   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 Antonio Huete <tuxillo@quantumachine.net>
   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 #include <dirent.h>
  35 #include <err.h>
  36 #include <errno.h>
  37 #include <fcntl.h>
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <string.h>
  41 #include <sys/param.h>
  42 #include <sys/stat.h>
  43 #include <unistd.h>
  44
  45 #include <libhammer.h>
  46
  47 static u_int32_t count_snapshots(u_int32_t, char *, char *, int *);
  48
  49 libhammer_volinfo_t
  50 libhammer_get_volinfo(const char *path)
  51 {
  52         struct hammer_ioc_pseudofs_rw pseudofs;
  53         struct hammer_pseudofs_data *pfs_od;
  54         struct hammer_ioc_info info;
  55         libhammer_pfsinfo_t pfstmp;
  56         libhammer_volinfo_t hvi;
  57         int pfs_id;
  58         int fd;
  59
  60         hvi = _libhammer_malloc(sizeof(*hvi));
  61
  62         TAILQ_INIT(&hvi->list_pseudo);
  63
  64         if ((fd = open(path, O_RDONLY)) < 0)
  65                 goto error1;
  66
  67         if ((ioctl(fd, HAMMERIOC_GET_INFO, &info)) < 0)
  68                 goto error1;
  69
  70         /* Fill volume information */
  71         snprintf(hvi->vol_name, TXTLEN, "%s", info.vol_name);
  72         hvi->vol_fsid = info.vol_fsid;
  73         hvi->version = info.version;
  74         hvi->nvolumes = info.nvolumes;
  75         hvi->inodes = info.inodes;
  76         hvi->bigblocks = info.bigblocks;
  77         hvi->freebigblocks = info.freebigblocks;
  78         hvi->rsvbigblocks = info.rsvbigblocks;
  79
  80         /*
  81          * XXX - By now we iterate the whole range of +65000 possible
  82          * pseudofs to discover the ones that are in use. Of course
  83          * this is suboptimal. Best way would be to extract the
  84          * pseudofs information from the control records in the
  85          * B-Tree, that's in kernel land.
  86          */
  87         pfs_od = _libhammer_malloc(sizeof(*pfs_od));
  88
  89         for(pfs_id = 0; pfs_id < HAMMER_MAX_PFS; pfs_id++) {
  90                 /* Clear the struct to be passed to the ioctl. */
  91                 bzero(&pseudofs, sizeof(pseudofs));
  92
  93                 pfstmp = _libhammer_malloc(sizeof(*pfstmp));
  94
  95                 pseudofs.pfs_id = pfs_id;
  96                 pseudofs.ondisk = pfs_od;
  97                 pseudofs.bytes = sizeof(struct hammer_pseudofs_data);
  98                 pseudofs.version = HAMMER_IOC_PSEUDOFS_VERSION;
  99                 if (ioctl(fd, HAMMERIOC_GET_PSEUDOFS, &pseudofs) != -1) {
 100                         /* XXX
 101                          * It may be completely wrong in the case that we pass a path
 102                          * that is in PFS 0 but isn't the mount path of it. There's no
 103                          * easy way to do this.
 104                          */
 105                         pfstmp->ismaster = (pfs_od->mirror_flags & HAMMER_PFSD_SLAVE)
 106                             ? 0 : 1;
 107
 108                         if (pfs_id == 0)
 109                                 pfstmp->mountedon = strdup(path);
 110                         else
 111                                 pfstmp->mountedon = libhammer_find_pfs_mount(pfs_id,
 112                                     hvi->vol_fsid, pfstmp->ismaster);
 113                         /*
 114                          * Fill in structs used in the library. We don't rely on
 115                          * HAMMER own struct but we do fill our own.
 116                          */
 117                         pfstmp->version = pseudofs.version;
 118                         pfstmp->pfs_id = pseudofs.pfs_id;
 119                         pfstmp->mirror_flags = pfs_od->mirror_flags;
 120                         pfstmp->snapcount = count_snapshots(hvi->version,
 121                             pfstmp->snapshots, pfstmp->mountedon, &pfstmp->head.error);
 122
 123                         TAILQ_INSERT_TAIL(&hvi->list_pseudo, pfstmp, entries);
 124                 }
 125         }
 126
 127         goto end;
 128
 129 error1:
 130         libhammer_free_volinfo(hvi);
 131         if (fd != -1)
 132                 close(fd);
 133
 134 end:
 135         return (hvi);
 136 }
 137
 138 void
 139 libhammer_free_volinfo(libhammer_volinfo_t volinfo)
 140 {
 141         struct libhammer_pfsinfo *pfstmp;
 142
 143         while(!TAILQ_EMPTY(&volinfo->list_pseudo)) {
 144                 pfstmp = TAILQ_FIRST(&volinfo->list_pseudo);
 145                 free(pfstmp->mountedon);
 146                 TAILQ_REMOVE(&volinfo->list_pseudo, pfstmp, entries);
 147                 free(pfstmp);
 148         }
 149         free(volinfo);
 150 }
 151
 152 static u_int32_t
 153 count_snapshots(u_int32_t version, char *pfs_snapshots, char *mountedon, int *errorp)
 154 {
 155         struct hammer_ioc_snapshot snapinfo;
 156         char *snapshots_path, *fpath;
 157         struct dirent *den;
 158         struct stat st;
 159         DIR *dir;
 160         u_int32_t snapshot_count;
 161         int fd;
 162
 163         snapshot_count = 0;
 164
 165         bzero(&snapinfo, sizeof(struct hammer_ioc_snapshot));
 166
 167         fd = open(mountedon, O_RDONLY);
 168         if (fd < 0) {
 169                 *errorp = errno;
 170                 return 0;
 171         }
 172
 173         if (version < 3) {
 174                 /*
 175                  * old style: count the number of softlinks in the snapshots dir
 176                  */
 177                 if (pfs_snapshots[0])
 178                         snapshots_path = pfs_snapshots;
 179                 else
 180                         asprintf(&snapshots_path, "%s/snapshots", mountedon);
 181                 if ((dir = opendir(snapshots_path)) != NULL) {
 182                         while ((den = readdir(dir)) != NULL) {
 183                                 if (den->d_name[0] == '.')
 184                                         continue;
 185                                 asprintf(&fpath, "%s/%s", snapshots_path,
 186                                     den->d_name);
 187                                 if (lstat(fpath, &st) == 0 &&
 188                                     S_ISLNK(st.st_mode))
 189                                         snapshot_count++;
 190                                 free(fpath);
 191                         }
 192                         closedir(dir);
 193                 }
 194         } else {
 195                 /*
 196                  * new style: file system meta-data
 197                  */
 198                 do {
 199                         if (ioctl(fd, HAMMERIOC_GET_SNAPSHOT, &snapinfo) < 0) {
 200                                 *errorp = errno;
 201                                 goto out;
 202                         }
 203
 204                         snapshot_count += snapinfo.count;
 205                 } while (snapinfo.head.error == 0 && snapinfo.count);
 206         }
 207
 208 out:
 209         if (fd != -1)
 210                 close(fd);
 211         return snapshot_count;
 212 }