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 <stdio.h>
  15 #ifdef HAVE_UNISTD_H
  16 #include <unistd.h>
  17 #endif
  18 #ifdef HAVE_STDLIB_H
  19 #include <stdlib.h>
  20 #endif
  21 #ifdef HAVE_GETOPT_H
  22 #include <getopt.h>
  23 #else
  24 extern char *optarg;
  25 extern int optind;
  26 #endif
  27
  28 #include "ext2fs/ext2_fs.h"
  29 #include "ext2fs/ext2fs.h"
  30 #include "e2freefrag.h"
  31
  32 void usage(const char *prog)
  33 {
  34         fprintf(stderr, "usage: %s [-c chunksize in kb] [-h] "
  35                 "device_name\n", prog);
  36         exit(1);
  37 }
  38
  39 static int ul_log2(unsigned long arg)
  40 {
  41         int     l = 0;
  42
  43         arg >>= 1;
  44         while (arg) {
  45                 l++;
  46                 arg >>= 1;
  47         }
  48         return l;
  49 }
  50
  51 void init_chunk_info(ext2_filsys fs, struct chunk_info *info)
  52 {
  53         int i;
  54
  55         info->blocksize_bits = ul_log2((unsigned long)fs->blocksize);
  56         if (info->chunkbytes) {
  57                 info->chunkbits = ul_log2(info->chunkbytes);
  58                 info->blks_in_chunk = info->chunkbytes >> info->blocksize_bits;
  59         } else {
  60                 info->chunkbits = ul_log2(DEFAULT_CHUNKSIZE);
  61                 info->blks_in_chunk = DEFAULT_CHUNKSIZE >> info->blocksize_bits;
  62         }
  63
  64         info->min = ~0UL;
  65         info->max = info->avg = 0;
  66         info->real_free_chunks = 0;
  67
  68         for (i = 0; i < MAX_HIST; i++) {
  69                 info->histogram.fc_chunks[i] = 0;
  70                 info->histogram.fc_blocks[i] = 0;
  71         }
  72 }
  73
  74 void scan_block_bitmap(ext2_filsys fs, struct chunk_info *info)
  75 {
  76         unsigned long long blocks_count = fs->super->s_blocks_count;
  77         unsigned long long chunks = (blocks_count + info->blks_in_chunk) >>
  78                                 (info->chunkbits - info->blocksize_bits);
  79         unsigned long long chunk_num;
  80         unsigned long last_chunk_size = 0;
  81         unsigned long long chunk_start_blk = 0;
  82         int used;
  83
  84         for (chunk_num = 0; chunk_num < chunks; chunk_num++) {
  85                 unsigned long long blk, num_blks;
  86                 int chunk_free;
  87
  88                 /* Last chunk may be smaller */
  89                 if (chunk_start_blk + info->blks_in_chunk > blocks_count)
  90                         num_blks = blocks_count - chunk_start_blk;
  91                 else
  92                         num_blks = info->blks_in_chunk;
  93
  94                 chunk_free = 0;
  95
  96                 /* Initialize starting block for first chunk correctly else
  97                  * there is a segfault when blocksize = 1024 in which case
  98                  * block_map->start = 1 */
  99                 for (blk = 0; blk < num_blks; blk++, chunk_start_blk++) {
 100                         if (chunk_num == 0 && blk == 0) {
 101                                 blk = fs->super->s_first_data_block;
 102                                 chunk_start_blk = blk;
 103                         }
 104                         used = ext2fs_fast_test_block_bitmap(fs->block_map,
 105                                                              chunk_start_blk);
 106                         if (!used) {
 107                                 last_chunk_size++;
 108                                 chunk_free++;
 109                         }
 110
 111                         if (used && last_chunk_size != 0) {
 112                                 unsigned long index;
 113
 114                                 index = ul_log2(last_chunk_size) + 1;
 115                                 info->histogram.fc_chunks[index]++;
 116                                 info->histogram.fc_blocks[index] +=
 117                                                         last_chunk_size;
 118
 119                                 if (last_chunk_size > info->max)
 120                                         info->max = last_chunk_size;
 121                                 if (last_chunk_size < info->min)
 122                                         info->min = last_chunk_size;
 123                                 info->avg += last_chunk_size;
 124
 125                                 info->real_free_chunks++;
 126                                 last_chunk_size = 0;
 127                         }
 128                 }
 129
 130                 if (chunk_free == info->blks_in_chunk)
 131                         info->free_chunks++;
 132         }
 133 }
 134
 135 errcode_t get_chunk_info(ext2_filsys fs, struct chunk_info *info)
 136 {
 137         unsigned long total_chunks;
 138         char *unitp = "KMGTPEZY";
 139         int units = 10;
 140         unsigned long start = 0, end, cum;
 141         int i, retval = 0;
 142
 143         scan_block_bitmap(fs, info);
 144
 145         printf("Total blocks: %u\nFree blocks: %u (%0.1f%%)\n",
 146                fs->super->s_blocks_count, fs->super->s_free_blocks_count,
 147                (double)fs->super->s_free_blocks_count * 100 /
 148                                                 fs->super->s_blocks_count);
 149
 150         if (info->chunkbytes) {
 151                 printf("\nChunksize: %lu bytes (%u blocks)\n",
 152                        info->chunkbytes, info->blks_in_chunk);
 153                 total_chunks = (fs->super->s_blocks_count +
 154                                 info->blks_in_chunk) >>
 155                         (info->chunkbits - info->blocksize_bits);
 156                 printf("Total chunks: %lu\nFree chunks: %lu (%0.1f%%)\n",
 157                        total_chunks, info->free_chunks,
 158                        (double)info->free_chunks * 100 / total_chunks);
 159         }
 160
 161         /* Display chunk information in KB */
 162         if (info->real_free_chunks) {
 163                 info->min = (info->min * fs->blocksize) >> 10;
 164                 info->max = (info->max * fs->blocksize) >> 10;
 165                 info->avg = (info->avg / info->real_free_chunks *
 166                              fs->blocksize) >> 10;
 167         } else {
 168                 info->min = 0;
 169         }
 170
 171         printf("\nMin. free extent: %lu KB \nMax. free extent: %lu KB\n"
 172                "Avg. free extent: %lu KB\n", info->min, info->max, info->avg);
 173
 174         printf("\nHISTOGRAM OF FREE EXTENT SIZES:\n");
 175         printf("%s :  %12s  %12s  %7s\n", "Extent Size Range", "Free extents",
 176                "Free Blocks", "Percent");
 177         for (i = 0; i < MAX_HIST; i++) {
 178                 end = 1 << (i + info->blocksize_bits - units);
 179                 if (info->histogram.fc_chunks[i] != 0)
 180                         printf("%5lu%c...%5lu%c-  :  %12lu  %12lu  %6.2f%%\n",
 181                                start, *unitp, end, *unitp,
 182                                info->histogram.fc_chunks[i],
 183                                info->histogram.fc_blocks[i],
 184                                (double)info->histogram.fc_blocks[i] * 100 /
 185                                fs->super->s_free_blocks_count);
 186                 start = end;
 187                 if (start == 1<<10) {
 188                         start = 1;
 189                         units += 10;
 190                         unitp++;
 191                 }
 192         }
 193
 194         return retval;
 195 }
 196
 197 void close_device(char *device_name, ext2_filsys fs)
 198 {
 199         int retval = ext2fs_close(fs);
 200
 201         if (retval)
 202                 com_err(device_name, retval, "while closing the filesystem.\n");
 203 }
 204
 205 void collect_info(ext2_filsys fs, struct chunk_info *chunk_info)
 206 {
 207         unsigned int retval = 0, i, free_blks;
 208
 209         printf("Device: %s\n", fs->device_name);
 210         printf("Blocksize: %u bytes\n", fs->blocksize);
 211
 212         retval = ext2fs_read_block_bitmap(fs);
 213         if (retval) {
 214                 com_err(fs->device_name, retval, "while reading block bitmap");
 215                 close_device(fs->device_name, fs);
 216                 exit(1);
 217         }
 218
 219         init_chunk_info(fs, chunk_info);
 220
 221         retval = get_chunk_info(fs, chunk_info);
 222         if (retval) {
 223                 com_err(fs->device_name, retval, "while collecting chunk info");
 224                 close_device(fs->device_name, fs);
 225                 exit(1);
 226         }
 227 }
 228
 229 void open_device(char *device_name, ext2_filsys *fs)
 230 {
 231         int retval;
 232         int flag = EXT2_FLAG_FORCE;
 233
 234         retval = ext2fs_open(device_name, flag, 0, 0, unix_io_manager, fs);
 235         if (retval) {
 236                 com_err(device_name, retval, "while opening filesystem");
 237                 exit(1);
 238         }
 239 }
 240
 241 int main(int argc, char *argv[])
 242 {
 243         struct chunk_info chunk_info = { };
 244         errcode_t retval = 0;
 245         ext2_filsys fs = NULL;
 246         char *device_name;
 247         char *progname;
 248         char c, *end;
 249
 250         add_error_table(&et_ext2_error_table);
 251         progname = argv[0];
 252
 253         while ((c = getopt(argc, argv, "c:h")) != EOF) {
 254                 switch (c) {
 255                 case 'c':
 256                         chunk_info.chunkbytes = strtoull(optarg, &end, 0);
 257                         if (*end != '\0') {
 258                                 fprintf(stderr, "%s: bad chunk size '%s'\n",
 259                                         progname, optarg);
 260                                 usage(progname);
 261                         }
 262                         if (chunk_info.chunkbytes &
 263                             (chunk_info.chunkbytes - 1)) {
 264                                 fprintf(stderr, "%s: chunk size must be a "
 265                                         "power of 2.\n", argv[0]);
 266                                 usage(progname);
 267                         }
 268                         chunk_info.chunkbytes *= 1024;
 269                         break;
 270                 default:
 271                         fprintf(stderr, "%s: bad option '%c'\n",
 272                                 progname, c);
 273                 case 'h':
 274                         usage(progname);
 275                         break;
 276                 }
 277         }
 278
 279         if (optind == argc) {
 280                 fprintf(stderr, "%s: missing device name.\n", progname);
 281                 usage(progname);
 282         }
 283
 284         device_name = argv[optind];
 285
 286         open_device(device_name, &fs);
 287
 288         if (chunk_info.chunkbytes && (chunk_info.chunkbytes < fs->blocksize)) {
 289                 fprintf(stderr, "%s: chunksize must be greater than or equal "
 290                         "to filesystem blocksize.\n", progname);
 291                 exit(1);
 292         }
 293         collect_info(fs, &chunk_info);
 294         close_device(device_name, fs);
 295
 296         return retval;
 297 }