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 #include "config.h"
  13 #ifndef __linux__
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <unistd.h>
  17
  18 int main(void) {
  19     fputs("This program is only supported on Linux!\n", stderr);
  20     exit(EXIT_FAILURE);
  21 }
  22 #else
  23 #define _LARGEFILE64_SOURCE
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <unistd.h>
  28 #include <string.h>
  29 #include <time.h>
  30 #include <fcntl.h>
  31 #include <errno.h>
  32 #ifdef HAVE_GETOPT_H
  33 #include <getopt.h>
  34 #else
  35 extern char *optarg;
  36 extern int optind;
  37 #endif
  38 #include <sys/types.h>
  39 #include <sys/stat.h>
  40 #include <sys/vfs.h>
  41 #include <sys/ioctl.h>
  42 #include <linux/fd.h>
  43 #include <ext2fs/ext2_types.h>
  44 #include <ext2fs/fiemap.h>
  45
  46 int verbose = 0;
  47 int no_bs = 0;          /* Don't use the files blocksize, use 1K blocksize */
  48 int sync_file = 0;      /* fsync file before getting the mapping */
  49 int xattr_map = 0;      /* get xattr mapping */
  50 int force_bmap = 0;
  51 int logical_width = 12;
  52 int physical_width = 14;
  53 unsigned long long filesize;
  54
  55 #define FILEFRAG_FIEMAP_FLAGS_COMPAT (FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR)
  56
  57 #define FIBMAP          _IO(0x00, 1)    /* bmap access */
  58 #define FIGETBSZ        _IO(0x00, 2)    /* get the block size used for bmap */
  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 expected = 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 = 0, n = 0;
 179         int last = 0;
 180         int rc;
 181
 182         memset(fiemap, 0, sizeof(struct fiemap));
 183
 184         if (sync_file)
 185                 flags |= FIEMAP_FLAG_SYNC;
 186
 187         if (xattr_map)
 188                 flags |= FIEMAP_FLAG_XATTR;
 189
 190         do {
 191                 fiemap->fm_length = ~0ULL;
 192                 fiemap->fm_flags = flags;
 193                 fiemap->fm_extent_count = count;
 194                 rc = ioctl(fd, FS_IOC_FIEMAP, (unsigned long) fiemap);
 195                 if (rc < 0) {
 196                         if (errno == EBADR && fiemap_incompat_printed == 0) {
 197                                 printf("FIEMAP failed with unsupported "
 198                                        "flags %x\n", fiemap->fm_flags);
 199                                 fiemap_incompat_printed = 1;
 200                         }
 201                         return rc;
 202                 }
 203
 204                 /* If 0 extents are returned, then more ioctls are not needed */
 205                 if (fiemap->fm_mapped_extents == 0)
 206                         break;
 207
 208                 if (verbose && !fiemap_header_printed) {
 209                         printf(" ext %*s %*s %*s length flags\n", logical_width,
 210                                "logical", physical_width, "physical",
 211                                physical_width, "expected");
 212                         fiemap_header_printed = 1;
 213                 }
 214
 215                 for (i = 0; i < fiemap->fm_mapped_extents; i++) {
 216                         __u64 phy_blk, logical_blk;
 217                         unsigned long ext_len;
 218
 219                         phy_blk = fm_ext[i].fe_physical >> blk_shift;
 220                         ext_len = fm_ext[i].fe_length >> blk_shift;
 221                         logical_blk = fm_ext[i].fe_logical >> blk_shift;
 222
 223                         if (logical_blk && phy_blk != expected) {
 224                                 tot_extents++;
 225                         } else {
 226                                 expected = 0;
 227                                 if (!tot_extents)
 228                                         tot_extents = 1;
 229                         }
 230                         if (verbose)
 231                                 print_extent_info(&fm_ext[i], n, expected,
 232                                                   blk_shift);
 233
 234                         expected = phy_blk + ext_len;
 235                         if (fm_ext[i].fe_flags & FIEMAP_EXTENT_LAST)
 236                                 last = 1;
 237                         n++;
 238                 }
 239
 240                 fiemap->fm_start = (fm_ext[i-1].fe_logical +
 241                                     fm_ext[i-1].fe_length);
 242         } while (last == 0);
 243
 244         *num_extents = tot_extents;
 245 out:
 246         return 0;
 247 }
 248
 249 #define EXT2_DIRECT     12
 250
 251 static void frag_report(const char *filename)
 252 {
 253         struct statfs   fsinfo;
 254 #ifdef HAVE_FSTAT64
 255         struct stat64   fileinfo;
 256 #else
 257         struct stat     fileinfo;
 258 #endif
 259         int             bs;
 260         long            fd;
 261         unsigned long   block, last_block = 0, numblocks, i, count = 0;
 262         long            bpib;   /* Blocks per indirect block */
 263         long            cylgroups;
 264         int             num_extents = 0, expected;
 265         int             is_ext2 = 0;
 266         static int      once = 1;
 267         unsigned int    flags;
 268         int rc;
 269
 270 #ifdef HAVE_OPEN64
 271         fd = open64(filename, O_RDONLY);
 272 #else
 273         fd = open(filename, O_RDONLY);
 274 #endif
 275         if (fd < 0) {
 276                 perror("open");
 277                 return;
 278         }
 279
 280         if (statfs(filename, &fsinfo) < 0) {
 281                 perror("statfs");
 282                 return;
 283         }
 284 #ifdef HAVE_FSTAT64
 285         if (stat64(filename, &fileinfo) < 0) {
 286 #else
 287         if (stat(filename, &fileinfo) < 0) {
 288 #endif
 289                 perror("stat");
 290                 return;
 291         }
 292         if (ioctl(fd, EXT3_IOC_GETFLAGS, &flags) < 0)
 293                 flags = 0;
 294         if (!(flags & EXT4_EXTENTS_FL) &&
 295             ((fsinfo.f_type == 0xef51) || (fsinfo.f_type == 0xef52) ||
 296              (fsinfo.f_type == 0xef53)))
 297                 is_ext2++;
 298         if (verbose && once)
 299                 printf("Filesystem type is: %lx\n",
 300                        (unsigned long) fsinfo.f_type);
 301
 302         cylgroups = div_ceil(fsinfo.f_blocks, fsinfo.f_bsize*8);
 303         if (verbose && is_ext2 && once)
 304                 printf("Filesystem cylinder groups is approximately %ld\n",
 305                        cylgroups);
 306
 307         physical_width = int_log10(fsinfo.f_blocks);
 308         if (physical_width < 8)
 309                 physical_width = 8;
 310
 311         if (ioctl(fd, FIGETBSZ, &bs) < 0) { /* FIGETBSZ takes an int */
 312                 perror("FIGETBSZ");
 313                 close(fd);
 314                 return;
 315         }
 316
 317         if (no_bs)
 318                 bs = 1024;
 319
 320         bpib = bs / 4;
 321         numblocks = (fileinfo.st_size + (bs-1)) / bs;
 322         logical_width = int_log10(numblocks);
 323         if (logical_width < 7)
 324                 logical_width = 7;
 325         filesize = (long long)fileinfo.st_size;
 326         if (verbose)
 327                 printf("File size of %s is %lld (%ld block%s, blocksize %d)\n",
 328                        filename, (long long) fileinfo.st_size, numblocks,
 329                        numblocks == 1 ? "" : "s", bs);
 330         if (force_bmap ||
 331             filefrag_fiemap(fd, int_log2(bs), &num_extents) != 0) {
 332                 for (i = 0, count = 0; i < numblocks; i++) {
 333                         if (is_ext2 && last_block) {
 334                                 if (((i-EXT2_DIRECT) % bpib) == 0)
 335                                         last_block++;
 336                                 if (((i-EXT2_DIRECT-bpib) % (bpib*bpib)) == 0)
 337                                         last_block++;
 338                                 if (((i-EXT2_DIRECT-bpib-bpib*bpib) %
 339                                      (((__u64) bpib)*bpib*bpib)) == 0)
 340                                         last_block++;
 341                         }
 342                         rc = get_bmap(fd, i, &block);
 343                         if (block == 0)
 344                                 continue;
 345                         if (!num_extents)
 346                                 num_extents++;
 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         /* count, and thus expected, only set for indirect FIBMAP'd files */
 363         expected = (count/((bs*8)-(fsinfo.f_files/8/cylgroups)-3))+1;
 364         if (is_ext2 && expected && expected < num_extents)
 365                 printf(", perfection would be %d extent%s\n", expected,
 366                         (expected>1) ? "s" : "");
 367         else
 368                 fputc('\n', stdout);
 369         close(fd);
 370         once = 0;
 371 }
 372
 373 static void usage(const char *progname)
 374 {
 375         fprintf(stderr, "Usage: %s [-Bbvsx] file ...\n", progname);
 376         exit(1);
 377 }
 378
 379 int main(int argc, char**argv)
 380 {
 381         char **cpp;
 382         int c;
 383
 384         while ((c = getopt(argc, argv, "Bbsvx")) != EOF)
 385                 switch (c) {
 386                 case 'B':
 387                         force_bmap++;
 388                         break;
 389                 case 'b':
 390                         no_bs++;
 391                         break;
 392                 case 'v':
 393                         verbose++;
 394                         break;
 395                 case 's':
 396                         sync_file++;
 397                         break;
 398                 case 'x':
 399                         xattr_map++;
 400                         break;
 401                 default:
 402                         usage(argv[0]);
 403                         break;
 404                 }
 405         if (optind == argc)
 406                 usage(argv[0]);
 407         for (cpp=argv+optind; *cpp; cpp++)
 408                 frag_report(*cpp);
 409         return 0;
 410 }
 411 #endif