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
  35 #include <dirent.h>
  36 #include <err.h>
  37 #include <errno.h>
  38 #include <fcntl.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42 #include <sys/param.h>
  43 #include <sys/stat.h>
  44 #include <unistd.h>
  45
  46 #include "libhammer.h"
  47
  48 static u_int32_t count_snapshots(u_int32_t, char *, char *, int *);
  49
  50 libhammer_volinfo_t
  51 libhammer_get_volinfo(const char *path)
  52 {
  53         struct hammer_ioc_pseudofs_rw pseudofs;
  54         struct hammer_pseudofs_data *pfs_od;
  55         struct hammer_ioc_info info;
  56         libhammer_pfsinfo_t pfstmp;
  57         libhammer_volinfo_t hvi;
  58         int pfs_id;
  59         int fd;
  60
  61         if ((fd = open(path, O_RDONLY)) < 0)
  62                 return NULL;
  63
  64         hvi = _libhammer_malloc(sizeof(*hvi));
  65         TAILQ_INIT(&hvi->list_pseudo);
  66         if ((ioctl(fd, HAMMERIOC_GET_INFO, &info)) < 0) {
  67                 libhammer_free_volinfo(hvi);
  68                 close(fd);
  69                 return NULL;
  70         }
  71
  72         /* Fill volume information */
  73         snprintf(hvi->vol_name, TXTLEN, "%s", info.vol_name);
  74         hvi->vol_fsid = info.vol_fsid;
  75         hvi->version = info.version;
  76         hvi->nvolumes = info.nvolumes;
  77         hvi->inodes = info.inodes;
  78         hvi->bigblocks = info.bigblocks;
  79         hvi->freebigblocks = info.freebigblocks;
  80         hvi->rsvbigblocks = info.rsvbigblocks;
  81
  82         pfs_od = _libhammer_malloc(sizeof(*pfs_od));
  83
  84         /*
  85          * XXX - Iterate HAMMER_MAX_PFS (65536) PFS ids and rely on the ioctl(2)
  86          * return code to determine whether the PFS actually exists or not.
  87          * This is suboptimal. The correct way would be to extract the pseudofs
  88          * information from the control records in the B-Tree, that's in kernel
  89          * land.
  90          */
  91         for(pfs_id = 0; pfs_id < HAMMER_MAX_PFS; pfs_id++) {
  92                 bzero(&pseudofs, sizeof(pseudofs));
  93                 bzero(pfs_od, sizeof(*pfs_od));
  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                         /*
 101                          * XXX - In the case the path passed is on PFS#0 but it
 102                          * is not the mountpoint itself, it could produce a
 103                          * wrong type of PFS.
 104                          */
 105                         pfstmp = _libhammer_malloc(sizeof(*pfstmp));
 106                         pfstmp->ismaster =
 107                             (pfs_od->mirror_flags & HAMMER_PFSD_SLAVE) ? 0 : 1;
 108
 109                         if (pfs_id == 0)
 110                                 pfstmp->mountedon = strdup(path);
 111                         else
 112                                 pfstmp->mountedon =
 113                                     libhammer_find_pfs_mount(pfs_id,
 114                                         hvi->vol_fsid, pfstmp->ismaster);
 115                         /*
 116                          * Fill in structs used in the library. We don't rely on
 117                          * HAMMER own struct but we do fill our own.
 118                          */
 119                         pfstmp->version = pseudofs.version;
 120                         pfstmp->pfs_id = pseudofs.pfs_id;
 121                         pfstmp->mirror_flags = pfs_od->mirror_flags;
 122                         pfstmp->snapcount = count_snapshots(hvi->version,
 123                             pfstmp->snapshots, pfstmp->mountedon,
 124                             &pfstmp->head.error);
 125
 126                         TAILQ_INSERT_TAIL(&hvi->list_pseudo, pfstmp, entries);
 127                 }
 128         }
 129         free(pfs_od);
 130         close (fd);
 131
 132         return (hvi);
 133 }
 134
 135 void
 136 libhammer_free_volinfo(libhammer_volinfo_t volinfo)
 137 {
 138         struct libhammer_pfsinfo *pfstmp;
 139
 140         while(!TAILQ_EMPTY(&volinfo->list_pseudo)) {
 141                 pfstmp = TAILQ_FIRST(&volinfo->list_pseudo);
 142                 free(pfstmp->mountedon);
 143                 TAILQ_REMOVE(&volinfo->list_pseudo, pfstmp, entries);
 144                 free(pfstmp);
 145         }
 146         free(volinfo);
 147 }
 148
 149 static u_int32_t
 150 count_snapshots(u_int32_t version, char *pfs_snapshots, char *mountedon,
 151     int *errorp)
 152 {
 153         struct hammer_ioc_snapshot snapinfo;
 154         char *snapshots_path, *fpath;
 155         struct dirent *den;
 156         struct stat st;
 157         DIR *dir;
 158         u_int32_t snapshot_count;
 159         int fd;
 160
 161         snapshot_count = 0;
 162
 163         bzero(&snapinfo, sizeof(struct hammer_ioc_snapshot));
 164
 165         fd = open(mountedon, O_RDONLY);
 166         if (fd < 0) {
 167                 *errorp = errno;
 168                 return 0;
 169         }
 170
 171         if (version < 3) {
 172                 /*
 173                  * old style: count the number of softlinks in the snapshots dir
 174                  */
 175                 if (pfs_snapshots[0])
 176                         snapshots_path = pfs_snapshots;
 177                 else
 178                         asprintf(&snapshots_path, "%s/snapshots", mountedon);
 179                 if ((dir = opendir(snapshots_path)) != NULL) {
 180                         while ((den = readdir(dir)) != NULL) {
 181                                 if (den->d_name[0] == '.')
 182                                         continue;
 183                                 asprintf(&fpath, "%s/%s", snapshots_path,
 184                                     den->d_name);
 185                                 if (lstat(fpath, &st) == 0 &&
 186                                     S_ISLNK(st.st_mode))
 187                                         snapshot_count++;
 188                                 free(fpath);
 189                         }
 190                         closedir(dir);
 191                 }
 192         } else {
 193                 /*
 194                  * new style: file system meta-data
 195                  */
 196                 do {
 197                         if (ioctl(fd, HAMMERIOC_GET_SNAPSHOT, &snapinfo) < 0) {
 198                                 *errorp = errno;
 199                                 goto out;
 200                         }
 201
 202                         snapshot_count += snapinfo.count;
 203                 } while (snapinfo.head.error == 0 && snapinfo.count);
 204         }
 205
 206 out:
 207         if (!pfs_snapshots[0])
 208                 free(snapshots_path);
 209         if (fd != -1)
 210                 close(fd);
 211         return snapshot_count;
 212 }