io/fiemap.c

   1 /*
   2  * Copyright (c) 2010 Red Hat, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18
  19 #include "platform_defs.h"
  20 #include "command.h"
  21 #include "input.h"
  22 #include <linux/fiemap.h>
  23 #include "init.h"
  24 #include "io.h"
  25
  26 #define EXTENT_BATCH 32
  27
  28 static cmdinfo_t fiemap_cmd;
  29 static int max_extents = -1;
  30
  31 static void
  32 fiemap_help(void)
  33 {
  34         printf(_(
  35 "\n"
  36 " prints the block mapping for a file's data or attribute forks"
  37 "\n"
  38 " Example:\n"
  39 " 'fiemap -v' - tabular format verbose map\n"
  40 "\n"
  41 " fiemap prints the map of disk blocks used by the current file.\n"
  42 " The map lists each extent used by the file, as well as regions in the\n"
  43 " file that do not have any corresponding blocks (holes).\n"
  44 " By default, each line of the listing takes the following form:\n"
  45 "     extent: [startoffset..endoffset]: startblock..endblock\n"
  46 " Holes are marked by replacing the startblock..endblock with 'hole'.\n"
  47 " All the file offsets and disk blocks are in units of 512-byte blocks.\n"
  48 " -a -- prints the attribute fork map instead of the data fork.\n"
  49 " -l -- also displays the length of each extent in 512-byte blocks.\n"
  50 " -n -- query n extents.\n"
  51 " -v -- Verbose information\n"
  52 "\n"));
  53 }
  54
  55 static void
  56 print_hole(
  57            int          foff_w,
  58            int          boff_w,
  59            int          tot_w,
  60            int          cur_extent,
  61            int          lflag,
  62            bool         plain,
  63            __u64        llast,
  64            __u64        lstart)
  65 {
  66            char         lbuf[48];
  67
  68            if (plain) {
  69                 printf("\t%d: [%llu..%llu]: hole", cur_extent,
  70                        llast, lstart - 1ULL);
  71                 if (lflag)
  72                         printf(_(" %llu blocks\n"), lstart - llast);
  73                 else
  74                         printf("\n");
  75            } else {
  76                 snprintf(lbuf, sizeof(lbuf), "[%llu..%llu]:", llast,
  77                          lstart - 1ULL);
  78                 printf("%4d: %-*s %-*s %*llu\n", cur_extent, foff_w, lbuf,
  79                        boff_w, _("hole"), tot_w, lstart - llast);
  80            }
  81
  82
  83 }
  84
  85 static int
  86 print_verbose(
  87         struct fiemap_extent    *extent,
  88         int                     foff_w,
  89         int                     boff_w,
  90         int                     tot_w,
  91         int                     flg_w,
  92         int                     cur_extent,
  93         __u64                   last_logical)
  94 {
  95         __u64                   lstart;
  96         __u64                   llast;
  97         __u64                   len;
  98         __u64                   block;
  99         char                    lbuf[48];
 100         char                    bbuf[48];
 101         char                    flgbuf[16];
 102
 103         llast = BTOBBT(last_logical);
 104         lstart = BTOBBT(extent->fe_logical);
 105         len = BTOBBT(extent->fe_length);
 106         block = BTOBBT(extent->fe_physical);
 107
 108         memset(lbuf, 0, sizeof(lbuf));
 109         memset(bbuf, 0, sizeof(bbuf));
 110
 111         if (cur_extent == 0) {
 112                 printf("%4s: %-*s %-*s %*s %*s\n", _("EXT"),
 113                         foff_w, _("FILE-OFFSET"),
 114                         boff_w, _("BLOCK-RANGE"),
 115                         tot_w, _("TOTAL"),
 116                         flg_w, _("FLAGS"));
 117         }
 118
 119         if (lstart != llast) {
 120                 print_hole(foff_w, boff_w, tot_w, cur_extent, 0, false, llast,
 121                            lstart);
 122                 cur_extent++;
 123         }
 124
 125         if (cur_extent == max_extents)
 126                 return 1;
 127
 128         snprintf(lbuf, sizeof(lbuf), "[%llu..%llu]:", lstart,
 129                  lstart + len - 1ULL);
 130         snprintf(bbuf, sizeof(bbuf), "%llu..%llu", block, block + len - 1ULL);
 131         snprintf(flgbuf, sizeof(flgbuf), "0x%x", extent->fe_flags);
 132         printf("%4d: %-*s %-*s %*llu %*s\n", cur_extent, foff_w, lbuf,
 133                boff_w, bbuf, tot_w, len, flg_w, flgbuf);
 134
 135         return 2;
 136 }
 137
 138 static int
 139 print_plain(
 140         struct fiemap_extent    *extent,
 141         int                     lflag,
 142         int                     cur_extent,
 143         __u64                   last_logical)
 144 {
 145         __u64                   lstart;
 146         __u64                   llast;
 147         __u64                   block;
 148         __u64                   len;
 149
 150         llast = BTOBBT(last_logical);
 151         lstart = BTOBBT(extent->fe_logical);
 152         len = BTOBBT(extent->fe_length);
 153         block = BTOBBT(extent->fe_physical);
 154
 155         if (lstart != llast) {
 156                 print_hole(0, 0, 0, cur_extent, lflag, true, llast, lstart);
 157                 cur_extent++;
 158         }
 159
 160         if (cur_extent == max_extents)
 161                 return 1;
 162
 163         printf("\t%d: [%llu..%llu]: %llu..%llu", cur_extent,
 164                lstart, lstart + len - 1ULL, block,
 165                block + len - 1ULL);
 166
 167         if (lflag)
 168                 printf(_(" %llu blocks\n"), len);
 169         else
 170                 printf("\n");
 171         return 2;
 172 }
 173
 174 /*
 175  * Calculate the proper extent table format based on first
 176  * set of extents
 177  */
 178 static void
 179 calc_print_format(
 180         struct fiemap           *fiemap,
 181         int                     *foff_w,
 182         int                     *boff_w,
 183         int                     *tot_w,
 184         int                     *flg_w)
 185 {
 186         int                     i;
 187         char                    lbuf[32];
 188         char                    bbuf[32];
 189         __u64                   logical;
 190         __u64                   block;
 191         __u64                   len;
 192         struct fiemap_extent    *extent;
 193
 194         for (i = 0; i < fiemap->fm_mapped_extents; i++) {
 195
 196                 extent = &fiemap->fm_extents[i];
 197                 logical = BTOBBT(extent->fe_logical);
 198                 len = BTOBBT(extent->fe_length);
 199                 block = BTOBBT(extent->fe_physical);
 200
 201                 snprintf(lbuf, sizeof(lbuf), "[%llu..%llu]", logical,
 202                          logical + len - 1);
 203                 snprintf(bbuf, sizeof(bbuf), "%llu..%llu", block,
 204                          block + len - 1);
 205                 *foff_w = max(*foff_w, strlen(lbuf));
 206                 *boff_w = max(*boff_w, strlen(bbuf));
 207                 *tot_w = max(*tot_w, numlen(len, 10));
 208                 *flg_w = max(*flg_w, numlen(extent->fe_flags, 16));
 209                 if (extent->fe_flags & FIEMAP_EXTENT_LAST)
 210                         break;
 211         }
 212 }
 213
 214 int
 215 fiemap_f(
 216         int             argc,
 217         char            **argv)
 218 {
 219         struct fiemap   *fiemap;
 220         int             last = 0;
 221         int             lflag = 0;
 222         int             vflag = 0;
 223         int             fiemap_flags = FIEMAP_FLAG_SYNC;
 224         int             c;
 225         int             i;
 226         int             map_size;
 227         int             ret;
 228         int             cur_extent = 0;
 229         int             foff_w = 16;    /* 16 just for a good minimum range */
 230         int             boff_w = 16;
 231         int             tot_w = 5;      /* 5 since its just one number */
 232         int             flg_w = 5;
 233         __u64           last_logical = 0;
 234         struct stat     st;
 235
 236         while ((c = getopt(argc, argv, "aln:v")) != EOF) {
 237                 switch (c) {
 238                 case 'a':
 239                         fiemap_flags |= FIEMAP_FLAG_XATTR;
 240                         break;
 241                 case 'l':
 242                         lflag = 1;
 243                         break;
 244                 case 'n':
 245                         max_extents = atoi(optarg);
 246                         break;
 247                 case 'v':
 248                         vflag++;
 249                         break;
 250                 default:
 251                         return command_usage(&fiemap_cmd);
 252                 }
 253         }
 254
 255         map_size = sizeof(struct fiemap) +
 256                 (EXTENT_BATCH * sizeof(struct fiemap_extent));
 257         fiemap = malloc(map_size);
 258         if (!fiemap) {
 259                 fprintf(stderr, _("%s: malloc of %d bytes failed.\n"),
 260                         progname, map_size);
 261                 exitcode = 1;
 262                 return 0;
 263         }
 264
 265         printf("%s:\n", file->name);
 266
 267         while (!last && (cur_extent != max_extents)) {
 268
 269                 memset(fiemap, 0, map_size);
 270                 fiemap->fm_flags = fiemap_flags;
 271                 fiemap->fm_start = last_logical;
 272                 fiemap->fm_length = -1LL;
 273                 fiemap->fm_extent_count = EXTENT_BATCH;
 274
 275                 ret = ioctl(file->fd, FS_IOC_FIEMAP, (unsigned long)fiemap);
 276                 if (ret < 0) {
 277                         fprintf(stderr, "%s: ioctl(FS_IOC_FIEMAP) [\"%s\"]: "
 278                                 "%s\n", progname, file->name, strerror(errno));
 279                         free(fiemap);
 280                         exitcode = 1;
 281                         return 0;
 282                 }
 283
 284                 /* No more extents to map, exit */
 285                 if (!fiemap->fm_mapped_extents)
 286                         break;
 287
 288                 for (i = 0; i < fiemap->fm_mapped_extents; i++) {
 289                         struct fiemap_extent    *extent;
 290                         int num_printed = 0;
 291
 292                         extent = &fiemap->fm_extents[i];
 293                         if (vflag) {
 294                                 if (cur_extent == 0) {
 295                                         calc_print_format(fiemap, &foff_w,
 296                                                           &boff_w, &tot_w,
 297                                                           &flg_w);
 298                                 }
 299
 300                                 num_printed = print_verbose(extent, foff_w,
 301                                                             boff_w, tot_w,
 302                                                             flg_w, cur_extent,
 303                                                             last_logical);
 304                         } else
 305                                 num_printed = print_plain(extent, lflag,
 306                                                           cur_extent,
 307                                                           last_logical);
 308
 309                         cur_extent += num_printed;
 310                         last_logical = extent->fe_logical + extent->fe_length;
 311
 312                         if (extent->fe_flags & FIEMAP_EXTENT_LAST) {
 313                                 last = 1;
 314                                 break;
 315                         }
 316
 317                         if (cur_extent == max_extents)
 318                                 break;
 319                 }
 320         }
 321
 322         if (cur_extent  == max_extents)
 323                 goto out;
 324
 325         memset(&st, 0, sizeof(st));
 326         if (fstat(file->fd, &st)) {
 327                 fprintf(stderr, "%s: fstat failed: %s\n", progname,
 328                         strerror(errno));
 329                 free(fiemap);
 330                 exitcode = 1;
 331                 return 0;
 332         }
 333
 334         if (cur_extent && last_logical < st.st_size)
 335                 print_hole(foff_w, boff_w, tot_w, cur_extent, lflag, !vflag,
 336                            BTOBBT(last_logical), BTOBBT(st.st_size));
 337
 338 out:
 339         free(fiemap);
 340         return 0;
 341 }
 342
 343 void
 344 fiemap_init(void)
 345 {
 346         fiemap_cmd.name = "fiemap";
 347         fiemap_cmd.cfunc = fiemap_f;
 348         fiemap_cmd.argmin = 0;
 349         fiemap_cmd.argmax = -1;
 350         fiemap_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
 351         fiemap_cmd.args = _("[-alv] [-n nx]");
 352         fiemap_cmd.oneline = _("print block mapping for a file");
 353         fiemap_cmd.help = fiemap_help;
 354
 355         add_command(&fiemap_cmd);
 356 }