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 "config.h"
  15 #include <stdio.h>
  16 #ifdef HAVE_UNISTD_H
  17 #include <unistd.h>
  18 #endif
  19 #ifdef HAVE_STDLIB_H
  20 #include <stdlib.h>
  21 #endif
  22 #ifdef HAVE_GETOPT_H
  23 #include <getopt.h>
  24 #else
  25 extern char *optarg;
  26 extern int optind;
  27 #endif
  28
  29 #include "ext2fs/ext2_fs.h"
  30 #include "ext2fs/ext2fs.h"
  31 #include "e2freefrag.h"
  32
  33 void usage(const char *prog)
  34 {
  35         fprintf(stderr, "usage: %s [-c chunksize in kb] [-h] "
  36                 "device_name\n", prog);
  37         exit(1);
  38 }
  39
  40 static int ul_log2(unsigned long arg)
  41 {
  42         int     l = 0;
  43
  44         arg >>= 1;
  45         while (arg) {
  46                 l++;
  47                 arg >>= 1;
  48         }
  49         return l;
  50 }
  51
  52 void init_chunk_info(ext2_filsys fs, struct chunk_info *info)
  53 {
  54         int i;
  55
  56         info->blocksize_bits = ul_log2((unsigned long)fs->blocksize);
  57         if (info->chunkbytes) {
  58                 info->chunkbits = ul_log2(info->chunkbytes);
  59                 info->blks_in_chunk = info->chunkbytes >> info->blocksize_bits;
  60         } else {
  61                 info->chunkbits = ul_log2(DEFAULT_CHUNKSIZE);
  62                 info->blks_in_chunk = DEFAULT_CHUNKSIZE >> info->blocksize_bits;
  63         }
  64
  65         info->min = ~0UL;
  66         info->max = info->avg = 0;
  67         info->real_free_chunks = 0;
  68
  69         for (i = 0; i < MAX_HIST; i++) {
  70                 info->histogram.fc_chunks[i] = 0;
  71                 info->histogram.fc_blocks[i] = 0;
  72         }
  73 }
  74
  75 void update_chunk_stats(struct chunk_info *info, unsigned long chunk_size)
  76 {
  77         unsigned long index;
  78
  79         index = ul_log2(chunk_size) + 1;
  80         if (index >= MAX_HIST)
  81                 index = MAX_HIST-1;
  82         info->histogram.fc_chunks[index]++;
  83         info->histogram.fc_blocks[index] += chunk_size;
  84
  85         if (chunk_size > info->max)
  86                 info->max = chunk_size;
  87         if (chunk_size < info->min)
  88                 info->min = chunk_size;
  89         info->avg += chunk_size;
  90         info->real_free_chunks++;
  91 }
  92
  93 void scan_block_bitmap(ext2_filsys fs, struct chunk_info *info)
  94 {
  95         unsigned long long blocks_count = ext2fs_blocks_count(fs->super);
  96         unsigned long long chunks = (blocks_count + info->blks_in_chunk) >>
  97                                 (info->chunkbits - info->blocksize_bits);
  98         unsigned long long chunk_num;
  99         unsigned long last_chunk_size = 0;
 100         unsigned long long chunk_start_blk = 0;
 101         int used;
 102
 103         for (chunk_num = 0; chunk_num < chunks; chunk_num++) {
 104                 unsigned long long blk, num_blks;
 105                 int chunk_free;
 106
 107                 /* Last chunk may be smaller */
 108                 if (chunk_start_blk + info->blks_in_chunk > blocks_count)
 109                         num_blks = blocks_count - chunk_start_blk;
 110                 else
 111                         num_blks = info->blks_in_chunk;
 112
 113                 chunk_free = 0;
 114
 115                 /* Initialize starting block for first chunk correctly else
 116                  * there is a segfault when blocksize = 1024 in which case
 117                  * block_map->start = 1 */
 118                 for (blk = 0; blk < num_blks; blk++, chunk_start_blk++) {
 119                         if (chunk_num == 0 && blk == 0) {
 120                                 blk = fs->super->s_first_data_block;
 121                                 chunk_start_blk = blk;
 122                         }
 123                         used = ext2fs_fast_test_block_bitmap2(fs->block_map,
 124                                 chunk_start_blk >> fs->cluster_ratio_bits);
 125                         if (!used) {
 126                                 last_chunk_size++;
 127                                 chunk_free++;
 128                         }
 129
 130                         if (used && last_chunk_size != 0) {
 131                                 update_chunk_stats(info, last_chunk_size);
 132                                 last_chunk_size = 0;
 133                         }
 134                 }
 135
 136                 if (chunk_free == info->blks_in_chunk)
 137                         info->free_chunks++;
 138         }
 139         if (last_chunk_size != 0)
 140                 update_chunk_stats(info, last_chunk_size);
 141 }
 142
 143 errcode_t get_chunk_info(ext2_filsys fs, struct chunk_info *info)
 144 {
 145         unsigned long total_chunks;
 146         char *unitp = "KMGTPEZY";
 147         int units = 10;
 148         unsigned long start = 0, end;
 149         int i, retval = 0;
 150
 151         scan_block_bitmap(fs, info);
 152
 153         printf("Total blocks: %llu\nFree blocks: %u (%0.1f%%)\n",
 154                ext2fs_blocks_count(fs->super), fs->super->s_free_blocks_count,
 155                (double)fs->super->s_free_blocks_count * 100 /
 156                ext2fs_blocks_count(fs->super));
 157
 158         if (info->chunkbytes) {
 159                 printf("\nChunksize: %lu bytes (%u blocks)\n",
 160                        info->chunkbytes, info->blks_in_chunk);
 161                 total_chunks = (ext2fs_blocks_count(fs->super) +
 162                                 info->blks_in_chunk) >>
 163                         (info->chunkbits - info->blocksize_bits);
 164                 printf("Total chunks: %lu\nFree chunks: %lu (%0.1f%%)\n",
 165                        total_chunks, info->free_chunks,
 166                        (double)info->free_chunks * 100 / total_chunks);
 167         }
 168
 169         /* Display chunk information in KB */
 170         if (info->real_free_chunks) {
 171                 info->min = (info->min * fs->blocksize) >> 10;
 172                 info->max = (info->max * fs->blocksize) >> 10;
 173                 info->avg = (info->avg / info->real_free_chunks *
 174                              fs->blocksize) >> 10;
 175         } else {
 176                 info->min = 0;
 177         }
 178
 179         printf("\nMin. free extent: %lu KB \nMax. free extent: %lu KB\n"
 180                "Avg. free extent: %lu KB\n", info->min, info->max, info->avg);
 181         printf("Num. free extent: %lu\n", info->real_free_chunks);
 182
 183         printf("\nHISTOGRAM OF FREE EXTENT SIZES:\n");
 184         printf("%s :  %12s  %12s  %7s\n", "Extent Size Range", "Free extents",
 185                "Free Blocks", "Percent");
 186         for (i = 0; i < MAX_HIST; i++) {
 187                 end = 1 << (i + info->blocksize_bits - units);
 188                 if (info->histogram.fc_chunks[i] != 0) {
 189                         char end_str[32];
 190
 191                         sprintf(end_str, "%5lu%c-", end, *unitp);
 192                         if (i == MAX_HIST-1)
 193                                 strcpy(end_str, "max ");
 194                         printf("%5lu%c...%7s  :  %12lu  %12lu  %6.2f%%\n",
 195                                start, *unitp, end_str,
 196                                info->histogram.fc_chunks[i],
 197                                info->histogram.fc_blocks[i],
 198                                (double)info->histogram.fc_blocks[i] * 100 /
 199                                fs->super->s_free_blocks_count);
 200                 }
 201                 start = end;
 202                 if (start == 1<<10) {
 203                         start = 1;
 204                         units += 10;
 205                         unitp++;
 206                 }
 207         }
 208
 209         return retval;
 210 }
 211
 212 void close_device(char *device_name, ext2_filsys fs)
 213 {
 214         int retval = ext2fs_close(fs);
 215
 216         if (retval)
 217                 com_err(device_name, retval, "while closing the filesystem.\n");
 218 }
 219
 220 void collect_info(ext2_filsys fs, struct chunk_info *chunk_info)
 221 {
 222         unsigned int retval = 0;
 223
 224         printf("Device: %s\n", fs->device_name);
 225         printf("Blocksize: %u bytes\n", fs->blocksize);
 226
 227         retval = ext2fs_read_block_bitmap(fs);
 228         if (retval) {
 229                 com_err(fs->device_name, retval, "while reading block bitmap");
 230                 close_device(fs->device_name, fs);
 231                 exit(1);
 232         }
 233
 234         init_chunk_info(fs, chunk_info);
 235
 236         retval = get_chunk_info(fs, chunk_info);
 237         if (retval) {
 238                 com_err(fs->device_name, retval, "while collecting chunk info");
 239                 close_device(fs->device_name, fs);
 240                 exit(1);
 241         }
 242 }
 243
 244 void open_device(char *device_name, ext2_filsys *fs)
 245 {
 246         int retval;
 247         int flag = EXT2_FLAG_FORCE;
 248
 249         retval = ext2fs_open(device_name, flag, 0, 0, unix_io_manager, fs);
 250         if (retval) {
 251                 com_err(device_name, retval, "while opening filesystem");
 252                 exit(1);
 253         }
 254 }
 255
 256 int main(int argc, char *argv[])
 257 {
 258         struct chunk_info chunk_info = { };
 259         errcode_t retval = 0;
 260         ext2_filsys fs = NULL;
 261         char *device_name;
 262         char *progname;
 263         char *end;
 264         int c;
 265
 266         add_error_table(&et_ext2_error_table);
 267         progname = argv[0];
 268
 269         while ((c = getopt(argc, argv, "c:h")) != EOF) {
 270                 switch (c) {
 271                 case 'c':
 272                         chunk_info.chunkbytes = strtoull(optarg, &end, 0);
 273                         if (*end != '\0') {
 274                                 fprintf(stderr, "%s: bad chunk size '%s'\n",
 275                                         progname, optarg);
 276                                 usage(progname);
 277                         }
 278                         if (chunk_info.chunkbytes &
 279                             (chunk_info.chunkbytes - 1)) {
 280                                 fprintf(stderr, "%s: chunk size must be a "
 281                                         "power of 2.\n", argv[0]);
 282                                 usage(progname);
 283                         }
 284                         chunk_info.chunkbytes *= 1024;
 285                         break;
 286                 case 'h':
 287                 default:
 288                         usage(progname);
 289                         break;
 290                 }
 291         }
 292
 293         if (optind == argc) {
 294                 fprintf(stderr, "%s: missing device name.\n", progname);
 295                 usage(progname);
 296         }
 297
 298         device_name = argv[optind];
 299
 300         open_device(device_name, &fs);
 301
 302         if (chunk_info.chunkbytes && (chunk_info.chunkbytes < fs->blocksize)) {
 303                 fprintf(stderr, "%s: chunksize must be greater than or equal "
 304                         "to filesystem blocksize.\n", progname);
 305                 exit(1);
 306         }
 307         collect_info(fs, &chunk_info);
 308         close_device(device_name, fs);
 309
 310         return retval;
 311 }