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