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 force_bmap = 0;
  50 int logical_width = 12;
  51 int physical_width = 14;
  52 unsigned long long filesize;
  53
  54 #define FILEFRAG_FIEMAP_FLAGS_COMPAT (FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR)
  55
  56 #define FIBMAP          _IO(0x00, 1)    /* bmap access */
  57 #define FIGETBSZ        _IO(0x00, 2)    /* get the block size used for bmap */
  58 #define FS_IOC_FIEMAP   _IOWR('f', 11, struct fiemap)
  59
  60 #define EXT4_EXTENTS_FL                 0x00080000 /* Inode uses extents */
  61 #define EXT3_IOC_GETFLAGS               _IOR('f', 1, long)
  62
  63 static int int_log2(int arg)
  64 {
  65         int     l = 0;
  66
  67         arg >>= 1;
  68         while (arg) {
  69                 l++;
  70                 arg >>= 1;
  71         }
  72         return l;
  73 }
  74
  75 static int int_log10(unsigned long long arg)
  76 {
  77         int     l = 0;
  78
  79         arg = arg / 10;
  80         while (arg) {
  81                 l++;
  82                 arg = arg / 10;
  83         }
  84         return l;
  85 }
  86
  87 static unsigned int div_ceil(unsigned int a, unsigned int b)
  88 {
  89         if (!a)
  90                 return 0;
  91         return ((a - 1) / b) + 1;
  92 }
  93
  94 static int get_bmap(int fd, unsigned long block, unsigned long *phy_blk)
  95 {
  96         int     ret;
  97         unsigned int b;
  98
  99         b = block;
 100         ret = ioctl(fd, FIBMAP, &b); /* FIBMAP takes pointer to integer */
 101         if (ret < 0) {
 102                 if (errno == EPERM) {
 103                         fprintf(stderr, "No permission to use FIBMAP ioctl; "
 104                                 "must have root privileges\n");
 105                         exit(1);
 106                 }
 107                 perror("FIBMAP");
 108         }
 109         *phy_blk = b;
 110
 111         return ret;
 112 }
 113
 114 static void print_extent_info(struct fiemap_extent *fm_extent, int cur_ex,
 115                               unsigned long long expected, int blk_shift)
 116 {
 117         __u64 phy_blk;
 118         unsigned long long logical_blk;
 119         unsigned long ext_len;
 120         char flags[256] = "";
 121
 122         /* For inline data all offsets should be in terms of bytes, not blocks */
 123         if (fm_extent->fe_flags & FIEMAP_EXTENT_DATA_INLINE)
 124                 blk_shift = 0;
 125
 126         ext_len = fm_extent->fe_length >> blk_shift;
 127         logical_blk = fm_extent->fe_logical >> blk_shift;
 128         phy_blk = fm_extent->fe_physical >> blk_shift;
 129
 130         if (fm_extent->fe_flags & FIEMAP_EXTENT_UNKNOWN)
 131                 strcat(flags, "unknown,");
 132         if (fm_extent->fe_flags & FIEMAP_EXTENT_DELALLOC)
 133                 strcat(flags, "delalloc,");
 134         if (fm_extent->fe_flags & FIEMAP_EXTENT_DATA_ENCRYPTED)
 135                 strcat(flags, "encrypted,");
 136         if (fm_extent->fe_flags & FIEMAP_EXTENT_NOT_ALIGNED)
 137                 strcat(flags, "not_aligned,");
 138         if (fm_extent->fe_flags & FIEMAP_EXTENT_DATA_INLINE)
 139                 strcat(flags, "inline,");
 140         if (fm_extent->fe_flags & FIEMAP_EXTENT_DATA_TAIL)
 141                 strcat(flags, "tail_packed,");
 142         if (fm_extent->fe_flags & FIEMAP_EXTENT_UNWRITTEN)
 143                 strcat(flags, "unwritten,");
 144         if (fm_extent->fe_flags & FIEMAP_EXTENT_MERGED)
 145                 strcat(flags, "merged,");
 146
 147         if (fm_extent->fe_logical + fm_extent->fe_length >= filesize)
 148                 strcat(flags, "eof,");
 149
 150         /* Remove trailing comma, if any */
 151         if (flags[0])
 152                 flags[strlen(flags) - 1] = '\0';
 153
 154         if (expected)
 155                 printf("%4d %*llu %*llu %*llu %6lu %s\n",
 156                        cur_ex, logical_width, logical_blk,
 157                        physical_width, phy_blk, physical_width, expected,
 158                        ext_len, flags);
 159         else
 160                 printf("%4d %*llu %*llu %*s %6lu %s\n",
 161                        cur_ex, logical_width, logical_blk,
 162                        physical_width, phy_blk, physical_width, "",
 163                        ext_len, flags);
 164 }
 165
 166 static int filefrag_fiemap(int fd, int blk_shift, int *num_extents)
 167 {
 168         char buf[4096] = "";
 169         struct fiemap *fiemap = (struct fiemap *)buf;
 170         struct fiemap_extent *fm_ext = &fiemap->fm_extents[0];
 171         int count = (sizeof(buf) - sizeof(*fiemap)) /
 172                         sizeof(struct fiemap_extent);
 173         unsigned long long last_blk = 0;
 174         unsigned long flags = 0;
 175         unsigned int i;
 176         static int fiemap_incompat_printed;
 177         int fiemap_header_printed = 0;
 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         do {
 196                 fiemap->fm_length = ~0ULL;
 197                 fiemap->fm_flags = flags;
 198                 fiemap->fm_extent_count = count;
 199                 rc = ioctl(fd, FS_IOC_FIEMAP, (unsigned long) fiemap);
 200                 if (rc < 0) {
 201                         if (errno == EBADR && fiemap_incompat_printed == 0) {
 202                                 printf("FIEMAP failed with unsupported "
 203                                        "flags %x\n", fiemap->fm_flags);
 204                                 fiemap_incompat_printed = 1;
 205                         }
 206                         return rc;
 207                 }
 208
 209                 if (verbose && !fiemap_header_printed) {
 210                         printf(" ext %*s %*s %*s length flags\n", logical_width,
 211                                "logical", physical_width, "physical",
 212                                physical_width, "expected");
 213                         fiemap_header_printed = 1;
 214                 }
 215
 216                 if (!verbose) {
 217                         *num_extents = fiemap->fm_mapped_extents;
 218                         goto out;
 219                 }
 220
 221                 /* If 0 extents are returned, then more ioctls are not needed */
 222                 if (fiemap->fm_mapped_extents == 0)
 223                         break;
 224
 225                 for (i = 0; i < fiemap->fm_mapped_extents; i++) {
 226                         __u64 phy_blk, logical_blk;
 227                         unsigned long ext_len;
 228
 229                         phy_blk = fm_ext[i].fe_physical >> blk_shift;
 230                         ext_len = fm_ext[i].fe_length >> blk_shift;
 231                         logical_blk = fm_ext[i].fe_logical >> blk_shift;
 232
 233                         if (logical_blk && phy_blk != last_blk + 1)
 234                                 tot_extents++;
 235                         else
 236                                 last_blk = 0;
 237                         print_extent_info(&fm_ext[i], n, last_blk, blk_shift);
 238
 239                         last_blk = phy_blk + ext_len - 1;
 240                         if (fm_ext[i].fe_flags & FIEMAP_EXTENT_LAST)
 241                                 last = 1;
 242                         n++;
 243                 }
 244
 245                 fiemap->fm_start = (fm_ext[i-1].fe_logical +
 246                                     fm_ext[i-1].fe_length);
 247         } while (last == 0);
 248
 249         *num_extents = tot_extents;
 250 out:
 251         return 0;
 252 }
 253
 254 #define EXT2_DIRECT     12
 255
 256 static void frag_report(const char *filename)
 257 {
 258         struct statfs   fsinfo;
 259 #ifdef HAVE_FSTAT64
 260         struct stat64   fileinfo;
 261 #else
 262         struct stat     fileinfo;
 263 #endif
 264         int             bs;
 265         long            fd;
 266         unsigned long   block, last_block = 0, numblocks, i, count;
 267         long            bpib;   /* Blocks per indirect block */
 268         long            cylgroups;
 269         int             num_extents = 0, expected;
 270         int             is_ext2 = 0;
 271         static int      once = 1;
 272         unsigned int    flags;
 273         int rc;
 274
 275 #ifdef HAVE_OPEN64
 276         fd = open64(filename, O_RDONLY);
 277 #else
 278         fd = open(filename, O_RDONLY);
 279 #endif
 280         if (fd < 0) {
 281                 perror("open");
 282                 return;
 283         }
 284
 285         if (statfs(filename, &fsinfo) < 0) {
 286                 perror("statfs");
 287                 return;
 288         }
 289 #ifdef HAVE_FSTAT64
 290         if (stat64(filename, &fileinfo) < 0) {
 291 #else
 292         if (stat(filename, &fileinfo) < 0) {
 293 #endif
 294                 perror("stat");
 295                 return;
 296         }
 297         if (ioctl(fd, EXT3_IOC_GETFLAGS, &flags) < 0)
 298                 flags = 0;
 299         if (!(flags & EXT4_EXTENTS_FL) &&
 300             ((fsinfo.f_type == 0xef51) || (fsinfo.f_type == 0xef52) ||
 301              (fsinfo.f_type == 0xef53)))
 302                 is_ext2++;
 303         if (verbose && once)
 304                 printf("Filesystem type is: %lx\n",
 305                        (unsigned long) fsinfo.f_type);
 306
 307         cylgroups = div_ceil(fsinfo.f_blocks, fsinfo.f_bsize*8);
 308         if (verbose && is_ext2 && once)
 309                 printf("Filesystem cylinder groups is approximately %ld\n",
 310                        cylgroups);
 311
 312         physical_width = int_log10(fsinfo.f_blocks);
 313         if (physical_width < 8)
 314                 physical_width = 8;
 315
 316         if (ioctl(fd, FIGETBSZ, &bs) < 0) { /* FIGETBSZ takes an int */
 317                 perror("FIGETBSZ");
 318                 close(fd);
 319                 return;
 320         }
 321
 322         if (no_bs)
 323                 bs = 1024;
 324
 325         bpib = bs / 4;
 326         numblocks = (fileinfo.st_size + (bs-1)) / bs;
 327         logical_width = int_log10(numblocks);
 328         if (logical_width < 7)
 329                 logical_width = 7;
 330         filesize = (long long)fileinfo.st_size;
 331         if (verbose)
 332                 printf("File size of %s is %lld (%ld block%s, blocksize %d)\n",
 333                        filename, (long long) fileinfo.st_size, numblocks,
 334                        numblocks == 1 ? "" : "s", bs);
 335         if (force_bmap ||
 336             filefrag_fiemap(fd, int_log2(bs), &num_extents) != 0) {
 337                 for (i = 0, count = 0; i < numblocks; i++) {
 338                         if (is_ext2 && last_block) {
 339                                 if (((i-EXT2_DIRECT) % bpib) == 0)
 340                                         last_block++;
 341                                 if (((i-EXT2_DIRECT-bpib) % (bpib*bpib)) == 0)
 342                                         last_block++;
 343                                 if (((i-EXT2_DIRECT-bpib-bpib*bpib) %
 344                                                         (bpib*bpib*bpib)) == 0)
 345                                         last_block++;
 346                         }
 347                         rc = get_bmap(fd, i, &block);
 348                         if (block == 0)
 349                                 continue;
 350                         if (!num_extents)
 351                                 num_extents++;
 352                         count++;
 353                         if (last_block && (block != last_block+1) ) {
 354                                 if (verbose)
 355                                         printf("Discontinuity: Block %ld is at "
 356                                                "%lu (was %lu)\n",
 357                                                i, block, last_block+1);
 358                                 num_extents++;
 359                         }
 360                         last_block = block;
 361                 }
 362         }
 363         if (num_extents == 1)
 364                 printf("%s: 1 extent found", filename);
 365         else
 366                 printf("%s: %d extents found", filename, num_extents);
 367         expected = (count/((bs*8)-(fsinfo.f_files/8/cylgroups)-3))+1;
 368         if (is_ext2 && expected < num_extents)
 369                 printf(", perfection would be %d extent%s\n", expected,
 370                         (expected>1) ? "s" : "");
 371         else
 372                 fputc('\n', stdout);
 373         close(fd);
 374         once = 0;
 375 }
 376
 377 static void usage(const char *progname)
 378 {
 379         fprintf(stderr, "Usage: %s [-Bbvsx] file ...\n", progname);
 380         exit(1);
 381 }
 382
 383 int main(int argc, char**argv)
 384 {
 385         char **cpp;
 386         int c;
 387
 388         while ((c = getopt(argc, argv, "Bbsvx")) != EOF)
 389                 switch (c) {
 390                 case 'B':
 391                         force_bmap++;
 392                         break;
 393                 case 'b':
 394                         no_bs++;
 395                         break;
 396                 case 'v':
 397                         verbose++;
 398                         break;
 399                 case 's':
 400                         sync_file++;
 401                         break;
 402                 case 'x':
 403                         xattr_map++;
 404                         break;
 405                 default:
 406                         usage(argv[0]);
 407                         break;
 408                 }
 409         if (optind == argc)
 410                 usage(argv[0]);
 411         for (cpp=argv+optind; *cpp; cpp++)
 412                 frag_report(*cpp);
 413         return 0;
 414 }
 415 #endif