misc/filefrag.c

   1 /*
   2  * filefrag.c -- report if a particular file is fragmented
   3  *
   4  * Copyright 2003 by Theodore Ts'o.
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Public
   8  * License.
   9  * %End-Header%
  10  */
  11
  12 #ifndef __linux__
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <unistd.h>
  16
  17 int main(void) {
  18     fputs("This program is only supported on Linux!\n", stderr);
  19     exit(EXIT_FAILURE);
  20 }
  21 #else
  22 #define _LARGEFILE64_SOURCE
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <unistd.h>
  27 #include <string.h>
  28 #include <time.h>
  29 #include <fcntl.h>
  30 #include <errno.h>
  31 #ifdef HAVE_GETOPT_H
  32 #include <getopt.h>
  33 #else
  34 extern char *optarg;
  35 extern int optind;
  36 #endif
  37 #include <sys/types.h>
  38 #include <sys/stat.h>
  39 #include <sys/vfs.h>
  40 #include <sys/ioctl.h>
  41 #include <linux/fd.h>
  42 #include <ext2fs/ext2_types.h>
  43 #include <ext2fs/fiemap.h>
  44
  45 int verbose = 0;
  46 int no_bs = 0;          /* Don't use the files blocksize, use 1K blocksize */
  47 int sync_file = 0;      /* fsync file before getting the mapping */
  48 int xattr_map = 0;      /* get xattr mapping */
  49 int logical_width = 12;
  50 int physical_width = 14;
  51 unsigned long long filesize;
  52
  53 #define FILEFRAG_FIEMAP_FLAGS_COMPAT (FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR)
  54
  55 #define FIBMAP          _IO(0x00, 1)    /* bmap access */
  56 #define FIGETBSZ        _IO(0x00, 2)    /* get the block size used for bmap */
  57 #define FS_IOC_FIEMAP   _IOWR('f', 11, struct fiemap)
  58
  59 #define EXT4_EXTENTS_FL                 0x00080000 /* Inode uses extents */
  60 #define EXT3_IOC_GETFLAGS               _IOR('f', 1, long)
  61
  62 static int int_log2(int arg)
  63 {
  64         int     l = 0;
  65
  66         arg >>= 1;
  67         while (arg) {
  68                 l++;
  69                 arg >>= 1;
  70         }
  71         return l;
  72 }
  73
  74 static int int_log10(unsigned long long arg)
  75 {
  76         int     l = 0;
  77
  78         arg = arg / 10;
  79         while (arg) {
  80                 l++;
  81                 arg = arg / 10;
  82         }
  83         return l;
  84 }
  85
  86 static unsigned int div_ceil(unsigned int a, unsigned int b)
  87 {
  88         if (!a)
  89                 return 0;
  90         return ((a - 1) / b) + 1;
  91 }
  92
  93 static int get_bmap(int fd, unsigned long block, unsigned long *phy_blk)
  94 {
  95         int     ret;
  96         unsigned int b;
  97
  98         printf("Calling get_bmap for block %lu\n", block);
  99         abort();
 100         b = block;
 101         ret = ioctl(fd, FIBMAP, &b); /* FIBMAP takes pointer to integer */
 102         if (ret < 0) {
 103                 if (errno == EPERM) {
 104                         fprintf(stderr, "No permission to use FIBMAP ioctl; "
 105                                 "must have root privileges\n");
 106                         exit(1);
 107                 }
 108                 perror("FIBMAP");
 109         }
 110         *phy_blk = b;
 111
 112         return ret;
 113 }
 114
 115 static void print_extent_info(struct fiemap_extent *fm_extent, int cur_ex,
 116                               unsigned long long expected, int blk_shift)
 117 {
 118         __u64 phy_blk;
 119         unsigned long long logical_blk;
 120         unsigned long ext_len;
 121         char flags[256] = "";
 122
 123         /* For inline data all offsets should be in terms of bytes, not blocks */
 124         if (fm_extent->fe_flags & FIEMAP_EXTENT_DATA_INLINE)
 125                 blk_shift = 0;
 126
 127         ext_len = fm_extent->fe_length >> blk_shift;
 128         logical_blk = fm_extent->fe_logical >> blk_shift;
 129         phy_blk = fm_extent->fe_physical >> blk_shift;
 130
 131         if (fm_extent->fe_flags & FIEMAP_EXTENT_UNKNOWN)
 132                 strcat(flags, "unknown,");
 133         if (fm_extent->fe_flags & FIEMAP_EXTENT_DELALLOC)
 134                 strcat(flags, "delalloc,");
 135         if (fm_extent->fe_flags & FIEMAP_EXTENT_DATA_ENCRYPTED)
 136                 strcat(flags, "encrypted,");
 137         if (fm_extent->fe_flags & FIEMAP_EXTENT_NOT_ALIGNED)
 138                 strcat(flags, "not_aligned,");
 139         if (fm_extent->fe_flags & FIEMAP_EXTENT_DATA_INLINE)
 140                 strcat(flags, "inline,");
 141         if (fm_extent->fe_flags & FIEMAP_EXTENT_DATA_TAIL)
 142                 strcat(flags, "tail_packed,");
 143         if (fm_extent->fe_flags & FIEMAP_EXTENT_UNWRITTEN)
 144                 strcat(flags, "unwritten,");
 145         if (fm_extent->fe_flags & FIEMAP_EXTENT_MERGED)
 146                 strcat(flags, "merged,");
 147
 148         if (fm_extent->fe_logical + fm_extent->fe_length >= filesize)
 149                 strcat(flags, "eof,");
 150
 151         /* Remove trailing comma, if any */
 152         if (flags[0])
 153                 flags[strlen(flags) - 1] = '\0';
 154
 155         if (expected)
 156                 printf("%4d %*llu %*llu %*llu %6lu %s\n",
 157                        cur_ex, logical_width, logical_blk,
 158                        physical_width, phy_blk, physical_width, expected,
 159                        ext_len, flags);
 160         else
 161                 printf("%4d %*llu %*llu %*s %6lu %s\n",
 162                        cur_ex, logical_width, logical_blk,
 163                        physical_width, phy_blk, physical_width, "",
 164                        ext_len, flags);
 165 }
 166
 167 static int filefrag_fiemap(int fd, int blk_shift, int *num_extents)
 168 {
 169         char buf[4096] = "";
 170         struct fiemap *fiemap = (struct fiemap *)buf;
 171         struct fiemap_extent *fm_ext = &fiemap->fm_extents[0];
 172         int count = (sizeof(buf) - sizeof(*fiemap)) /
 173                         sizeof(struct fiemap_extent);
 174         unsigned long long last_blk = 0;
 175         unsigned long flags = 0;
 176         unsigned int i;
 177         static int fiemap_incompat_printed;
 178         int tot_extents = 1, n = 0;
 179         int last = 0;
 180         int rc;
 181
 182         fiemap->fm_length = ~0ULL;
 183
 184         memset(fiemap, 0, sizeof(struct fiemap));
 185
 186         if (!verbose)
 187                 count = 0;
 188
 189         if (sync_file)
 190                 flags |= FIEMAP_FLAG_SYNC;
 191
 192         if (xattr_map)
 193                 flags |= FIEMAP_FLAG_XATTR;
 194
 195         if (verbose)
 196                 printf(" ext %*s %*s %*s length flags\n", logical_width,
 197                        "logical", physical_width, "physical",
 198                        physical_width, "expected");
 199
 200         do {
 201                 fiemap->fm_length = ~0ULL;
 202                 fiemap->fm_flags = flags;
 203                 fiemap->fm_extent_count = count;
 204                 rc = ioctl(fd, FS_IOC_FIEMAP, (unsigned long) fiemap);
 205                 if (rc < 0) {
 206                         if (errno == EBADR && fiemap_incompat_printed == 0) {
 207                                 printf("FIEMAP failed with unsupported "
 208                                        "flags %x\n", fiemap->fm_flags);
 209                                 fiemap_incompat_printed = 1;
 210                         }
 211                         return rc;
 212                 }
 213
 214                 if (!verbose) {
 215                         *num_extents = fiemap->fm_mapped_extents;
 216                         goto out;
 217                 }
 218
 219                 /* If 0 extents are returned, then more ioctls are not needed */
 220                 if (fiemap->fm_mapped_extents == 0)
 221                         break;
 222
 223                 for (i = 0; i < fiemap->fm_mapped_extents; i++) {
 224                         __u64 phy_blk, logical_blk;
 225                         unsigned long ext_len;
 226
 227                         phy_blk = fm_ext[i].fe_physical >> blk_shift;
 228                         ext_len = fm_ext[i].fe_length >> blk_shift;
 229                         logical_blk = fm_ext[i].fe_logical >> blk_shift;
 230
 231                         if (logical_blk && phy_blk != last_blk + 1)
 232                                 tot_extents++;
 233                         else
 234                                 last_blk = 0;
 235                         print_extent_info(&fm_ext[i], n, last_blk, blk_shift);
 236
 237                         last_blk = phy_blk + ext_len - 1;
 238                         if (fm_ext[i].fe_flags & FIEMAP_EXTENT_LAST)
 239                                 last = 1;
 240                         n++;
 241                 }
 242
 243                 fiemap->fm_start = (fm_ext[i-1].fe_logical +
 244                                     fm_ext[i-1].fe_length);
 245         } while (last == 0);
 246
 247         *num_extents = tot_extents;
 248 out:
 249         return 0;
 250 }
 251
 252 #define EXT2_DIRECT     12
 253
 254 static void frag_report(const char *filename)
 255 {
 256         struct statfs   fsinfo;
 257 #ifdef HAVE_FSTAT64
 258         struct stat64   fileinfo;
 259 #else
 260         struct stat     fileinfo;
 261 #endif
 262         int             bs;
 263         long            fd;
 264         unsigned long   block, last_block = 0, numblocks, i, count;
 265         long            bpib;   /* Blocks per indirect block */
 266         long            cylgroups;
 267         int             num_extents = 0, expected;
 268         int             is_ext2 = 0;
 269         static int      once = 1;
 270         unsigned int    flags;
 271         int rc;
 272
 273 #ifdef HAVE_OPEN64
 274         fd = open64(filename, O_RDONLY);
 275 #else
 276         fd = open(filename, O_RDONLY);
 277 #endif
 278         if (fd < 0) {
 279                 perror("open");
 280                 return;
 281         }
 282
 283         if (statfs(filename, &fsinfo) < 0) {
 284                 perror("statfs");
 285                 return;
 286         }
 287 #ifdef HAVE_FSTAT64
 288         if (stat64(filename, &fileinfo) < 0) {
 289 #else
 290         if (stat(filename, &fileinfo) < 0) {
 291 #endif
 292                 perror("stat");
 293                 return;
 294         }
 295         if (ioctl(fd, EXT3_IOC_GETFLAGS, &flags) < 0)
 296                 flags = 0;
 297         if (!(flags & EXT4_EXTENTS_FL) &&
 298             ((fsinfo.f_type == 0xef51) || (fsinfo.f_type == 0xef52) ||
 299              (fsinfo.f_type == 0xef53)))
 300                 is_ext2++;
 301         if (verbose && once)
 302                 printf("Filesystem type is: %lx\n",
 303                        (unsigned long) fsinfo.f_type);
 304
 305         cylgroups = div_ceil(fsinfo.f_blocks, fsinfo.f_bsize*8);
 306         if (verbose && is_ext2 && once)
 307                 printf("Filesystem cylinder groups is approximately %ld\n",
 308                        cylgroups);
 309
 310         physical_width = int_log10(fsinfo.f_blocks);
 311         if (physical_width < 8)
 312                 physical_width = 8;
 313
 314         if (ioctl(fd, FIGETBSZ, &bs) < 0) { /* FIGETBSZ takes an int */
 315                 perror("FIGETBSZ");
 316                 close(fd);
 317                 return;
 318         }
 319
 320         if (no_bs)
 321                 bs = 1024;
 322
 323         bpib = bs / 4;
 324         numblocks = (fileinfo.st_size + (bs-1)) / bs;
 325         logical_width = int_log10(numblocks);
 326         if (logical_width < 7)
 327                 logical_width = 7;
 328         filesize = (long long)fileinfo.st_size;
 329         if (verbose)
 330                 printf("File size of %s is %lld (%ld block%s, blocksize %d)\n",
 331                        filename, (long long) fileinfo.st_size, numblocks,
 332                        numblocks == 1 ? "" : "s", bs);
 333         if (filefrag_fiemap(fd, int_log2(bs), &num_extents) != 0) {
 334                 for (i = 0, count = 0; i < numblocks; i++) {
 335                         if (is_ext2 && last_block) {
 336                                 if (((i-EXT2_DIRECT) % bpib) == 0)
 337                                         last_block++;
 338                                 if (((i-EXT2_DIRECT-bpib) % (bpib*bpib)) == 0)
 339                                         last_block++;
 340                                 if (((i-EXT2_DIRECT-bpib-bpib*bpib) %
 341                                                         (bpib*bpib*bpib)) == 0)
 342                                         last_block++;
 343                         }
 344                         rc = get_bmap(fd, i, &block);
 345                         if (block == 0)
 346                                 continue;
 347                         count++;
 348                         if (last_block && (block != last_block+1) ) {
 349                                 if (verbose)
 350                                         printf("Discontinuity: Block %ld is at "
 351                                                "%lu (was %lu)\n",
 352                                                i, block, last_block+1);
 353                                 num_extents++;
 354                         }
 355                         last_block = block;
 356                 }
 357         }
 358         if (num_extents == 1)
 359                 printf("%s: 1 extent found", filename);
 360         else
 361                 printf("%s: %d extents found", filename, num_extents);
 362         expected = (count/((bs*8)-(fsinfo.f_files/8/cylgroups)-3))+1;
 363         if (is_ext2 && expected < num_extents)
 364                 printf(", perfection would be %d extent%s\n", expected,
 365                         (expected>1) ? "s" : "");
 366         else
 367                 fputc('\n', stdout);
 368         close(fd);
 369         once = 0;
 370 }
 371
 372 static void usage(const char *progname)
 373 {
 374         fprintf(stderr, "Usage: %s [-bvsx] file ...\n", progname);
 375         exit(1);
 376 }
 377
 378 int main(int argc, char**argv)
 379 {
 380         char **cpp;
 381         int c;
 382
 383         while ((c = getopt(argc, argv, "bsvx")) != EOF)
 384                 switch (c) {
 385                 case 'b':
 386                         no_bs++;
 387                         break;
 388                 case 'v':
 389                         verbose++;
 390                         break;
 391                 case 's':
 392                         sync_file++;
 393                         break;
 394                 case 'x':
 395                         xattr_map++;
 396                         break;
 397                 default:
 398                         usage(argv[0]);
 399                         break;
 400                 }
 401         if (optind == argc)
 402                 usage(argv[0]);
 403         for (cpp=argv+optind; *cpp; cpp++)
 404                 frag_report(*cpp);
 405         return 0;
 406 }
 407 #endif