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