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 update_chunk_stats(struct chunk_info *info, unsigned long chunk_size)
  75 {
  76         unsigned long index;
  77
  78         index = ul_log2(chunk_size) + 1;
  79         if (index >= MAX_HIST)
  80                 index = MAX_HIST-1;
  81         info->histogram.fc_chunks[index]++;
  82         info->histogram.fc_blocks[index] += chunk_size;
  83
  84         if (chunk_size > info->max)
  85                 info->max = chunk_size;
  86         if (chunk_size < info->min)
  87                 info->min = chunk_size;
  88         info->avg += chunk_size;
  89         info->real_free_chunks++;
  90 }
  91
  92 void scan_block_bitmap(ext2_filsys fs, struct chunk_info *info)
  93 {
  94         unsigned long long blocks_count = fs->super->s_blocks_count;
  95         unsigned long long chunks = (blocks_count + info->blks_in_chunk) >>
  96                                 (info->chunkbits - info->blocksize_bits);
  97         unsigned long long chunk_num;
  98         unsigned long last_chunk_size = 0;
  99         unsigned long long chunk_start_blk = 0;
 100         int used;
 101
 102         for (chunk_num = 0; chunk_num < chunks; chunk_num++) {
 103                 unsigned long long blk, num_blks;
 104                 int chunk_free;
 105
 106                 /* Last chunk may be smaller */
 107                 if (chunk_start_blk + info->blks_in_chunk > blocks_count)
 108                         num_blks = blocks_count - chunk_start_blk;
 109                 else
 110                         num_blks = info->blks_in_chunk;
 111
 112                 chunk_free = 0;
 113
 114                 /* Initialize starting block for first chunk correctly else
 115                  * there is a segfault when blocksize = 1024 in which case
 116                  * block_map->start = 1 */
 117                 for (blk = 0; blk < num_blks; blk++, chunk_start_blk++) {
 118                         if (chunk_num == 0 && blk == 0) {
 119                                 blk = fs->super->s_first_data_block;
 120                                 chunk_start_blk = blk;
 121                         }
 122                         used = ext2fs_fast_test_block_bitmap(fs->block_map,
 123                                                              chunk_start_blk);
 124                         if (!used) {
 125                                 last_chunk_size++;
 126                                 chunk_free++;
 127                         }
 128
 129                         if (used && last_chunk_size != 0) {
 130                                 update_chunk_stats(info, last_chunk_size);
 131                                 last_chunk_size = 0;
 132                         }
 133                 }
 134
 135                 if (chunk_free == info->blks_in_chunk)
 136                         info->free_chunks++;
 137         }
 138         if (last_chunk_size != 0)
 139                 update_chunk_stats(info, last_chunk_size);
 140 }
 141
 142 errcode_t get_chunk_info(ext2_filsys fs, struct chunk_info *info)
 143 {
 144         unsigned long total_chunks;
 145         char *unitp = "KMGTPEZY";
 146         int units = 10;
 147         unsigned long start = 0, end, cum;
 148         int i, retval = 0;
 149
 150         scan_block_bitmap(fs, info);
 151
 152         printf("Total blocks: %u\nFree blocks: %u (%0.1f%%)\n",
 153                fs->super->s_blocks_count, fs->super->s_free_blocks_count,
 154                (double)fs->super->s_free_blocks_count * 100 /
 155                                                 fs->super->s_blocks_count);
 156
 157         if (info->chunkbytes) {
 158                 printf("\nChunksize: %lu bytes (%u blocks)\n",
 159                        info->chunkbytes, info->blks_in_chunk);
 160                 total_chunks = (fs->super->s_blocks_count +
 161                                 info->blks_in_chunk) >>
 162                         (info->chunkbits - info->blocksize_bits);
 163                 printf("Total chunks: %lu\nFree chunks: %lu (%0.1f%%)\n",
 164                        total_chunks, info->free_chunks,
 165                        (double)info->free_chunks * 100 / total_chunks);
 166         }
 167
 168         /* Display chunk information in KB */
 169         if (info->real_free_chunks) {
 170                 info->min = (info->min * fs->blocksize) >> 10;
 171                 info->max = (info->max * fs->blocksize) >> 10;
 172                 info->avg = (info->avg / info->real_free_chunks *
 173                              fs->blocksize) >> 10;
 174         } else {
 175                 info->min = 0;
 176         }
 177
 178         printf("\nMin. free extent: %lu KB \nMax. free extent: %lu KB\n"
 179                "Avg. free extent: %lu KB\n", info->min, info->max, info->avg);
 180
 181         printf("\nHISTOGRAM OF FREE EXTENT SIZES:\n");
 182         printf("%s :  %12s  %12s  %7s\n", "Extent Size Range", "Free extents",
 183                "Free Blocks", "Percent");
 184         for (i = 0; i < MAX_HIST; i++) {
 185                 end = 1 << (i + info->blocksize_bits - units);
 186                 if (info->histogram.fc_chunks[i] != 0) {
 187                         char end_str[32];
 188
 189                         sprintf(end_str, "%5lu%c-", end, *unitp);
 190                         if (i == MAX_HIST-1)
 191                                 strcpy(end_str, "max ");
 192                         printf("%5lu%c...%7s  :  %12lu  %12lu  %6.2f%%\n",
 193                                start, *unitp, end_str,
 194                                info->histogram.fc_chunks[i],
 195                                info->histogram.fc_blocks[i],
 196                                (double)info->histogram.fc_blocks[i] * 100 /
 197                                fs->super->s_free_blocks_count);
 198                 }
 199                 start = end;
 200                 if (start == 1<<10) {
 201                         start = 1;
 202                         units += 10;
 203                         unitp++;
 204                 }
 205         }
 206
 207         return retval;
 208 }
 209
 210 void close_device(char *device_name, ext2_filsys fs)
 211 {
 212         int retval = ext2fs_close(fs);
 213
 214         if (retval)
 215                 com_err(device_name, retval, "while closing the filesystem.\n");
 216 }
 217
 218 void collect_info(ext2_filsys fs, struct chunk_info *chunk_info)
 219 {
 220         unsigned int retval = 0, i, free_blks;
 221
 222         printf("Device: %s\n", fs->device_name);
 223         printf("Blocksize: %u bytes\n", fs->blocksize);
 224
 225         retval = ext2fs_read_block_bitmap(fs);
 226         if (retval) {
 227                 com_err(fs->device_name, retval, "while reading block bitmap");
 228                 close_device(fs->device_name, fs);
 229                 exit(1);
 230         }
 231
 232         init_chunk_info(fs, chunk_info);
 233
 234         retval = get_chunk_info(fs, chunk_info);
 235         if (retval) {
 236                 com_err(fs->device_name, retval, "while collecting chunk info");
 237                 close_device(fs->device_name, fs);
 238                 exit(1);
 239         }
 240 }
 241
 242 void open_device(char *device_name, ext2_filsys *fs)
 243 {
 244         int retval;
 245         int flag = EXT2_FLAG_FORCE;
 246
 247         retval = ext2fs_open(device_name, flag, 0, 0, unix_io_manager, fs);
 248         if (retval) {
 249                 com_err(device_name, retval, "while opening filesystem");
 250                 exit(1);
 251         }
 252 }
 253
 254 int main(int argc, char *argv[])
 255 {
 256         struct chunk_info chunk_info = { };
 257         errcode_t retval = 0;
 258         ext2_filsys fs = NULL;
 259         char *device_name;
 260         char *progname;
 261         char c, *end;
 262
 263         add_error_table(&et_ext2_error_table);
 264         progname = argv[0];
 265
 266         while ((c = getopt(argc, argv, "c:h")) != EOF) {
 267                 switch (c) {
 268                 case 'c':
 269                         chunk_info.chunkbytes = strtoull(optarg, &end, 0);
 270                         if (*end != '\0') {
 271                                 fprintf(stderr, "%s: bad chunk size '%s'\n",
 272                                         progname, optarg);
 273                                 usage(progname);
 274                         }
 275                         if (chunk_info.chunkbytes &
 276                             (chunk_info.chunkbytes - 1)) {
 277                                 fprintf(stderr, "%s: chunk size must be a "
 278                                         "power of 2.\n", argv[0]);
 279                                 usage(progname);
 280                         }
 281                         chunk_info.chunkbytes *= 1024;
 282                         break;
 283                 default:
 284                         fprintf(stderr, "%s: bad option '%c'\n",
 285                                 progname, c);
 286                 case 'h':
 287                         usage(progname);
 288                         break;
 289                 }
 290         }
 291
 292         if (optind == argc) {
 293                 fprintf(stderr, "%s: missing device name.\n", progname);
 294                 usage(progname);
 295         }
 296
 297         device_name = argv[optind];
 298
 299         open_device(device_name, &fs);
 300
 301         if (chunk_info.chunkbytes && (chunk_info.chunkbytes < fs->blocksize)) {
 302                 fprintf(stderr, "%s: chunksize must be greater than or equal "
 303                         "to filesystem blocksize.\n", progname);
 304                 exit(1);
 305         }
 306         collect_info(fs, &chunk_info);
 307         close_device(device_name, fs);
 308
 309         return retval;
 310 }