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         printf("Num. free extent: %lu\n", info->real_free_chunks);
 181
 182         printf("\nHISTOGRAM OF FREE EXTENT SIZES:\n");
 183         printf("%s :  %12s  %12s  %7s\n", "Extent Size Range", "Free extents",
 184                "Free Blocks", "Percent");
 185         for (i = 0; i < MAX_HIST; i++) {
 186                 end = 1 << (i + info->blocksize_bits - units);
 187                 if (info->histogram.fc_chunks[i] != 0) {
 188                         char end_str[32];
 189
 190                         sprintf(end_str, "%5lu%c-", end, *unitp);
 191                         if (i == MAX_HIST-1)
 192                                 strcpy(end_str, "max ");
 193                         printf("%5lu%c...%7s  :  %12lu  %12lu  %6.2f%%\n",
 194                                start, *unitp, end_str,
 195                                info->histogram.fc_chunks[i],
 196                                info->histogram.fc_blocks[i],
 197                                (double)info->histogram.fc_blocks[i] * 100 /
 198                                fs->super->s_free_blocks_count);
 199                 }
 200                 start = end;
 201                 if (start == 1<<10) {
 202                         start = 1;
 203                         units += 10;
 204                         unitp++;
 205                 }
 206         }
 207
 208         return retval;
 209 }
 210
 211 void close_device(char *device_name, ext2_filsys fs)
 212 {
 213         int retval = ext2fs_close(fs);
 214
 215         if (retval)
 216                 com_err(device_name, retval, "while closing the filesystem.\n");
 217 }
 218
 219 void collect_info(ext2_filsys fs, struct chunk_info *chunk_info)
 220 {
 221         unsigned int retval = 0, i, free_blks;
 222
 223         printf("Device: %s\n", fs->device_name);
 224         printf("Blocksize: %u bytes\n", fs->blocksize);
 225
 226         retval = ext2fs_read_block_bitmap(fs);
 227         if (retval) {
 228                 com_err(fs->device_name, retval, "while reading block bitmap");
 229                 close_device(fs->device_name, fs);
 230                 exit(1);
 231         }
 232
 233         init_chunk_info(fs, chunk_info);
 234
 235         retval = get_chunk_info(fs, chunk_info);
 236         if (retval) {
 237                 com_err(fs->device_name, retval, "while collecting chunk info");
 238                 close_device(fs->device_name, fs);
 239                 exit(1);
 240         }
 241 }
 242
 243 void open_device(char *device_name, ext2_filsys *fs)
 244 {
 245         int retval;
 246         int flag = EXT2_FLAG_FORCE;
 247
 248         retval = ext2fs_open(device_name, flag, 0, 0, unix_io_manager, fs);
 249         if (retval) {
 250                 com_err(device_name, retval, "while opening filesystem");
 251                 exit(1);
 252         }
 253 }
 254
 255 int main(int argc, char *argv[])
 256 {
 257         struct chunk_info chunk_info = { };
 258         errcode_t retval = 0;
 259         ext2_filsys fs = NULL;
 260         char *device_name;
 261         char *progname;
 262         char *end;
 263         int c;
 264
 265         add_error_table(&et_ext2_error_table);
 266         progname = argv[0];
 267
 268         while ((c = getopt(argc, argv, "c:h")) != EOF) {
 269                 switch (c) {
 270                 case 'c':
 271                         chunk_info.chunkbytes = strtoull(optarg, &end, 0);
 272                         if (*end != '\0') {
 273                                 fprintf(stderr, "%s: bad chunk size '%s'\n",
 274                                         progname, optarg);
 275                                 usage(progname);
 276                         }
 277                         if (chunk_info.chunkbytes &
 278                             (chunk_info.chunkbytes - 1)) {
 279                                 fprintf(stderr, "%s: chunk size must be a "
 280                                         "power of 2.\n", argv[0]);
 281                                 usage(progname);
 282                         }
 283                         chunk_info.chunkbytes *= 1024;
 284                         break;
 285                 default:
 286                         fprintf(stderr, "%s: bad option '%c'\n",
 287                                 progname, c);
 288                 case 'h':
 289                         usage(progname);
 290                         break;
 291                 }
 292         }
 293
 294         if (optind == argc) {
 295                 fprintf(stderr, "%s: missing device name.\n", progname);
 296                 usage(progname);
 297         }
 298
 299         device_name = argv[optind];
 300
 301         open_device(device_name, &fs);
 302
 303         if (chunk_info.chunkbytes && (chunk_info.chunkbytes < fs->blocksize)) {
 304                 fprintf(stderr, "%s: chunksize must be greater than or equal "
 305                         "to filesystem blocksize.\n", progname);
 306                 exit(1);
 307         }
 308         collect_info(fs, &chunk_info);
 309         close_device(device_name, fs);
 310
 311         return retval;
 312 }