misc/e2freefrag.c

   1 /*
   2  * e2freefrag - report filesystem free-space fragmentation
   3  *
   4  * Copyright (C) 2009 Sun Microsystems, Inc.
   5  *
   6  * Author: Rupesh Thakare <rupesh@sun.com>
   7  *         Andreas Dilger <adilger@sun.com>
   8  *
   9  * %Begin-Header%
  10  * This file may be redistributed under the terms of the GNU Public
  11  * License version 2.
  12  * %End-Header%
  13  */
  14 #include "config.h"
  15 #include <stdio.h>
  16 #ifdef HAVE_UNISTD_H
  17 #include <unistd.h>
  18 #endif
  19 #ifdef HAVE_STDLIB_H
  20 #include <stdlib.h>
  21 #endif
  22 #ifdef HAVE_GETOPT_H
  23 #include <getopt.h>
  24 #else
  25 extern char *optarg;
  26 extern int optind;
  27 #endif
  28
  29 #include "ext2fs/ext2_fs.h"
  30 #include "ext2fs/ext2fs.h"
  31 #include "e2freefrag.h"
  32
  33 static void usage(const char *prog)
  34 {
  35         fprintf(stderr, "usage: %s [-c chunksize in kb] [-h] "
  36                 "device_name\n", prog);
  37 #ifndef DEBUGFS
  38         exit(1);
  39 #endif
  40 }
  41
  42 static int ul_log2(unsigned long arg)
  43 {
  44         int     l = 0;
  45
  46         arg >>= 1;
  47         while (arg) {
  48                 l++;
  49                 arg >>= 1;
  50         }
  51         return l;
  52 }
  53
  54 static void init_chunk_info(ext2_filsys fs, struct chunk_info *info)
  55 {
  56         int i;
  57
  58         info->blocksize_bits = ul_log2((unsigned long)fs->blocksize);
  59         if (info->chunkbytes) {
  60                 info->chunkbits = ul_log2(info->chunkbytes);
  61                 info->blks_in_chunk = info->chunkbytes >> info->blocksize_bits;
  62         } else {
  63                 info->chunkbits = ul_log2(DEFAULT_CHUNKSIZE);
  64                 info->blks_in_chunk = DEFAULT_CHUNKSIZE >> info->blocksize_bits;
  65         }
  66
  67         info->min = ~0UL;
  68         info->max = info->avg = 0;
  69         info->real_free_chunks = 0;
  70
  71         for (i = 0; i < MAX_HIST; i++) {
  72                 info->histogram.fc_chunks[i] = 0;
  73                 info->histogram.fc_blocks[i] = 0;
  74         }
  75 }
  76
  77 static void update_chunk_stats(struct chunk_info *info,
  78                                unsigned long chunk_size)
  79 {
  80         unsigned long idx;
  81
  82         idx = ul_log2(chunk_size) + 1;
  83         if (idx >= MAX_HIST)
  84                 idx = MAX_HIST-1;
  85         info->histogram.fc_chunks[idx]++;
  86         info->histogram.fc_blocks[idx] += chunk_size;
  87
  88         if (chunk_size > info->max)
  89                 info->max = chunk_size;
  90         if (chunk_size < info->min)
  91                 info->min = chunk_size;
  92         info->avg += chunk_size;
  93         info->real_free_chunks++;
  94 }
  95
  96 static void scan_block_bitmap(ext2_filsys fs, struct chunk_info *info)
  97 {
  98         unsigned long long blocks_count = ext2fs_blocks_count(fs->super);
  99         unsigned long long chunks = (blocks_count + info->blks_in_chunk) >>
 100                                 (info->chunkbits - info->blocksize_bits);
 101         unsigned long long chunk_num;
 102         unsigned long last_chunk_size = 0;
 103         unsigned long long chunk_start_blk = 0;
 104         int used;
 105
 106         for (chunk_num = 0; chunk_num < chunks; chunk_num++) {
 107                 unsigned long long blk, num_blks;
 108                 int chunk_free;
 109
 110                 /* Last chunk may be smaller */
 111                 if (chunk_start_blk + info->blks_in_chunk > blocks_count)
 112                         num_blks = blocks_count - chunk_start_blk;
 113                 else
 114                         num_blks = info->blks_in_chunk;
 115
 116                 chunk_free = 0;
 117
 118                 /* Initialize starting block for first chunk correctly else
 119                  * there is a segfault when blocksize = 1024 in which case
 120                  * block_map->start = 1 */
 121                 for (blk = 0; blk < num_blks; blk++, chunk_start_blk++) {
 122                         if (chunk_num == 0 && blk == 0) {
 123                                 blk = fs->super->s_first_data_block;
 124                                 chunk_start_blk = blk;
 125                         }
 126                         used = ext2fs_fast_test_block_bitmap2(fs->block_map,
 127                                 chunk_start_blk >> fs->cluster_ratio_bits);
 128                         if (!used) {
 129                                 last_chunk_size++;
 130                                 chunk_free++;
 131                         }
 132
 133                         if (used && last_chunk_size != 0) {
 134                                 update_chunk_stats(info, last_chunk_size);
 135                                 last_chunk_size = 0;
 136                         }
 137                 }
 138
 139                 if (chunk_free == info->blks_in_chunk)
 140                         info->free_chunks++;
 141         }
 142         if (last_chunk_size != 0)
 143                 update_chunk_stats(info, last_chunk_size);
 144 }
 145
 146 static errcode_t get_chunk_info(ext2_filsys fs, struct chunk_info *info,
 147                                 FILE *f)
 148 {
 149         unsigned long total_chunks;
 150         const char *unitp = "KMGTPEZY";
 151         int units = 10;
 152         unsigned long start = 0, end;
 153         int i, retval = 0;
 154
 155         scan_block_bitmap(fs, info);
 156
 157         fprintf(f, "Total blocks: %llu\nFree blocks: %u (%0.1f%%)\n",
 158                 ext2fs_blocks_count(fs->super), fs->super->s_free_blocks_count,
 159                 (double)fs->super->s_free_blocks_count * 100 /
 160                 ext2fs_blocks_count(fs->super));
 161
 162         if (info->chunkbytes) {
 163                 fprintf(f, "\nChunksize: %lu bytes (%u blocks)\n",
 164                         info->chunkbytes, info->blks_in_chunk);
 165                 total_chunks = (ext2fs_blocks_count(fs->super) +
 166                                 info->blks_in_chunk) >>
 167                         (info->chunkbits - info->blocksize_bits);
 168                 fprintf(f, "Total chunks: %lu\nFree chunks: %lu (%0.1f%%)\n",
 169                         total_chunks, info->free_chunks,
 170                         (double)info->free_chunks * 100 / total_chunks);
 171         }
 172
 173         /* Display chunk information in KB */
 174         if (info->real_free_chunks) {
 175                 info->min = (info->min * fs->blocksize) >> 10;
 176                 info->max = (info->max * fs->blocksize) >> 10;
 177                 info->avg = (info->avg / info->real_free_chunks *
 178                              fs->blocksize) >> 10;
 179         } else {
 180                 info->min = 0;
 181         }
 182
 183         fprintf(f, "\nMin. free extent: %lu KB \nMax. free extent: %lu KB\n"
 184                 "Avg. free extent: %lu KB\n", info->min, info->max, info->avg);
 185         fprintf(f, "Num. free extent: %lu\n", info->real_free_chunks);
 186
 187         fprintf(f, "\nHISTOGRAM OF FREE EXTENT SIZES:\n");
 188         fprintf(f, "%s :  %12s  %12s  %7s\n", "Extent Size Range",
 189                 "Free extents", "Free Blocks", "Percent");
 190         for (i = 0; i < MAX_HIST; i++) {
 191                 end = 1 << (i + info->blocksize_bits - units);
 192                 if (info->histogram.fc_chunks[i] != 0) {
 193                         char end_str[32];
 194
 195                         sprintf(end_str, "%5lu%c-", end, *unitp);
 196                         if (i == MAX_HIST-1)
 197                                 strcpy(end_str, "max ");
 198                         fprintf(f, "%5lu%c...%7s  :  %12lu  %12lu  %6.2f%%\n",
 199                                 start, *unitp, end_str,
 200                                 info->histogram.fc_chunks[i],
 201                                 info->histogram.fc_blocks[i],
 202                                 (double)info->histogram.fc_blocks[i] * 100 /
 203                                 fs->super->s_free_blocks_count);
 204                 }
 205                 start = end;
 206                 if (start == 1<<10) {
 207                         start = 1;
 208                         units += 10;
 209                         unitp++;
 210                 }
 211         }
 212
 213         return retval;
 214 }
 215
 216 static void close_device(char *device_name, ext2_filsys fs)
 217 {
 218         int retval = ext2fs_close(fs);
 219
 220         if (retval)
 221                 com_err(device_name, retval, "while closing the filesystem.\n");
 222 }
 223
 224 static void collect_info(ext2_filsys fs, struct chunk_info *chunk_info, FILE *f)
 225 {
 226         unsigned int retval = 0;
 227
 228         fprintf(f, "Device: %s\n", fs->device_name);
 229         fprintf(f, "Blocksize: %u bytes\n", fs->blocksize);
 230
 231         retval = ext2fs_read_block_bitmap(fs);
 232         if (retval) {
 233                 com_err(fs->device_name, retval, "while reading block bitmap");
 234                 close_device(fs->device_name, fs);
 235                 exit(1);
 236         }
 237
 238         init_chunk_info(fs, chunk_info);
 239
 240         retval = get_chunk_info(fs, chunk_info, f);
 241         if (retval) {
 242                 com_err(fs->device_name, retval, "while collecting chunk info");
 243                 close_device(fs->device_name, fs);
 244                 exit(1);
 245         }
 246 }
 247
 248 #ifndef DEBUGFS
 249 static void open_device(char *device_name, ext2_filsys *fs)
 250 {
 251         int retval;
 252         int flag = EXT2_FLAG_FORCE;
 253
 254         retval = ext2fs_open(device_name, flag, 0, 0, unix_io_manager, fs);
 255         if (retval) {
 256                 com_err(device_name, retval, "while opening filesystem");
 257                 exit(1);
 258         }
 259 }
 260 #endif
 261
 262 #ifdef DEBUGFS
 263 #include "debugfs.h"
 264
 265 void do_freefrag(int argc, char **argv)
 266 #else
 267 int main(int argc, char *argv[])
 268 #endif
 269 {
 270         struct chunk_info chunk_info;
 271         ext2_filsys fs = NULL;
 272         char *progname;
 273         char *end;
 274         int c;
 275
 276 #ifdef DEBUGFS
 277         if (check_fs_open(argv[0]))
 278                 return;
 279 #else
 280         char *device_name;
 281
 282         add_error_table(&et_ext2_error_table);
 283 #endif
 284         progname = argv[0];
 285         memset(&chunk_info, 0, sizeof(chunk_info));
 286
 287         while ((c = getopt(argc, argv, "c:h")) != EOF) {
 288                 switch (c) {
 289                 case 'c':
 290                         chunk_info.chunkbytes = strtoull(optarg, &end, 0);
 291                         if (*end != '\0') {
 292                                 fprintf(stderr, "%s: bad chunk size '%s'\n",
 293                                         progname, optarg);
 294                                 usage(progname);
 295                         }
 296                         if (chunk_info.chunkbytes &
 297                             (chunk_info.chunkbytes - 1)) {
 298                                 fprintf(stderr, "%s: chunk size must be a "
 299                                         "power of 2.\n", argv[0]);
 300                                 usage(progname);
 301                         }
 302                         chunk_info.chunkbytes *= 1024;
 303                         break;
 304                 case 'h':
 305                 default:
 306                         usage(progname);
 307                         break;
 308                 }
 309         }
 310
 311 #ifndef DEBUGFS
 312         if (optind == argc) {
 313                 fprintf(stderr, "%s: missing device name.\n", progname);
 314                 usage(progname);
 315         }
 316
 317         device_name = argv[optind];
 318
 319         open_device(device_name, &fs);
 320 #else
 321         fs = current_fs;
 322 #endif
 323
 324         if (chunk_info.chunkbytes && (chunk_info.chunkbytes < fs->blocksize)) {
 325                 fprintf(stderr, "%s: chunksize must be greater than or equal "
 326                         "to filesystem blocksize.\n", progname);
 327                 exit(1);
 328         }
 329         collect_info(fs, &chunk_info, stdout);
 330 #ifndef DEBUGFS
 331         close_device(device_name, fs);
 332
 333         return 0;
 334 #endif
 335 }