e2freefrag.c revision d05508956734d55f7ee286085a1f6570d11848b7 
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
25extern char *optarg;
26extern int optind;
27#endif
28
29#include "ext2fs/ext2_fs.h"
30#include "ext2fs/ext2fs.h"
31#include "e2freefrag.h"
32
33static void usage(const char *prog)
34{
35	fprintf(stderr, "usage: %s [-c chunksize in kb] [-h] "
36		"device_name\n", prog);
37#ifndef DEBUGFS
38	exit(1);
39#endif
40}
41
42static int ul_log2(unsigned long arg)
43{
44        int     l = 0;
45
46        arg >>= 1;
47        while (arg) {
48                l++;
49                arg >>= 1;
50        }
51        return l;
52}
53
54static void init_chunk_info(ext2_filsys fs, struct chunk_info *info)
55{
56	int i;
57
58	info->blocksize_bits = ul_log2((unsigned long)fs->blocksize);
59	if (info->chunkbytes) {
60		info->chunkbits = ul_log2(info->chunkbytes);
61		info->blks_in_chunk = info->chunkbytes >> info->blocksize_bits;
62	} else {
63		info->chunkbits = ul_log2(DEFAULT_CHUNKSIZE);
64		info->blks_in_chunk = DEFAULT_CHUNKSIZE >> info->blocksize_bits;
65	}
66
67	info->min = ~0UL;
68	info->max = info->avg = 0;
69	info->real_free_chunks = 0;
70
71	for (i = 0; i < MAX_HIST; i++) {
72		info->histogram.fc_chunks[i] = 0;
73		info->histogram.fc_blocks[i] = 0;
74	}
75}
76
77static void update_chunk_stats(struct chunk_info *info,
78			       unsigned long chunk_size)
79{
80	unsigned long idx;
81
82	idx = ul_log2(chunk_size) + 1;
83	if (idx >= MAX_HIST)
84		idx = MAX_HIST-1;
85	info->histogram.fc_chunks[idx]++;
86	info->histogram.fc_blocks[idx] += chunk_size;
87
88	if (chunk_size > info->max)
89		info->max = chunk_size;
90	if (chunk_size < info->min)
91		info->min = chunk_size;
92	info->avg += chunk_size;
93	info->real_free_chunks++;
94}
95
96static void scan_block_bitmap(ext2_filsys fs, struct chunk_info *info)
97{
98	unsigned long long blocks_count = ext2fs_blocks_count(fs->super);
99	unsigned long long chunks = (blocks_count + info->blks_in_chunk) >>
100				(info->chunkbits - info->blocksize_bits);
101	unsigned long long chunk_num;
102	unsigned long last_chunk_size = 0;
103	unsigned long long chunk_start_blk = 0;
104	int used;
105
106	for (chunk_num = 0; chunk_num < chunks; chunk_num++) {
107		unsigned long long blk, num_blks;
108		int chunk_free;
109
110		/* Last chunk may be smaller */
111		if (chunk_start_blk + info->blks_in_chunk > blocks_count)
112			num_blks = blocks_count - chunk_start_blk;
113		else
114			num_blks = info->blks_in_chunk;
115
116		chunk_free = 0;
117
118		/* Initialize starting block for first chunk correctly else
119		 * there is a segfault when blocksize = 1024 in which case
120		 * block_map->start = 1 */
121		for (blk = 0; blk < num_blks; blk++, chunk_start_blk++) {
122			if (chunk_num == 0 && blk == 0) {
123				blk = fs->super->s_first_data_block;
124				chunk_start_blk = blk;
125			}
126			used = ext2fs_fast_test_block_bitmap2(fs->block_map,
127				chunk_start_blk >> fs->cluster_ratio_bits);
128			if (!used) {
129				last_chunk_size++;
130				chunk_free++;
131			}
132
133			if (used && last_chunk_size != 0) {
134				update_chunk_stats(info, last_chunk_size);
135				last_chunk_size = 0;
136			}
137		}
138
139		if (chunk_free == info->blks_in_chunk)
140			info->free_chunks++;
141	}
142	if (last_chunk_size != 0)
143		update_chunk_stats(info, last_chunk_size);
144}
145
146static errcode_t get_chunk_info(ext2_filsys fs, struct chunk_info *info,
147				FILE *f)
148{
149	unsigned long total_chunks;
150	const char *unitp = "KMGTPEZY";
151	int units = 10;
152	unsigned long start = 0, end;
153	int i, retval = 0;
154
155	scan_block_bitmap(fs, info);
156
157	fprintf(f, "Total blocks: %llu\nFree blocks: %u (%0.1f%%)\n",
158		ext2fs_blocks_count(fs->super), fs->super->s_free_blocks_count,
159		(double)fs->super->s_free_blocks_count * 100 /
160		ext2fs_blocks_count(fs->super));
161
162	if (info->chunkbytes) {
163		fprintf(f, "\nChunksize: %lu bytes (%u blocks)\n",
164			info->chunkbytes, info->blks_in_chunk);
165		total_chunks = (ext2fs_blocks_count(fs->super) +
166				info->blks_in_chunk) >>
167			(info->chunkbits - info->blocksize_bits);
168		fprintf(f, "Total chunks: %lu\nFree chunks: %lu (%0.1f%%)\n",
169			total_chunks, info->free_chunks,
170			(double)info->free_chunks * 100 / total_chunks);
171	}
172
173	/* Display chunk information in KB */
174	if (info->real_free_chunks) {
175		unsigned int scale = fs->blocksize >> 10;
176		info->min = info->min * scale;
177		info->max = info->max * scale;
178		info->avg = info->avg / info->real_free_chunks * scale;
179	} else {
180		info->min = 0;
181	}
182
183	fprintf(f, "\nMin. free extent: %lu KB \nMax. free extent: %lu KB\n"
184		"Avg. free extent: %lu KB\n", info->min, info->max, info->avg);
185	fprintf(f, "Num. free extent: %lu\n", info->real_free_chunks);
186
187	fprintf(f, "\nHISTOGRAM OF FREE EXTENT SIZES:\n");
188	fprintf(f, "%s :  %12s  %12s  %7s\n", "Extent Size Range",
189		"Free extents", "Free Blocks", "Percent");
190	for (i = 0; i < MAX_HIST; i++) {
191		end = 1 << (i + info->blocksize_bits - units);
192		if (info->histogram.fc_chunks[i] != 0) {
193			char end_str[32];
194
195			sprintf(end_str, "%5lu%c-", end, *unitp);
196			if (i == MAX_HIST-1)
197				strcpy(end_str, "max ");
198			fprintf(f, "%5lu%c...%7s  :  %12lu  %12lu  %6.2f%%\n",
199				start, *unitp, end_str,
200				info->histogram.fc_chunks[i],
201				info->histogram.fc_blocks[i],
202				(double)info->histogram.fc_blocks[i] * 100 /
203				fs->super->s_free_blocks_count);
204		}
205		start = end;
206		if (start == 1<<10) {
207			start = 1;
208			units += 10;
209			unitp++;
210		}
211	}
212
213	return retval;
214}
215
216static void close_device(char *device_name, ext2_filsys fs)
217{
218	int retval = ext2fs_close(fs);
219
220	if (retval)
221		com_err(device_name, retval, "while closing the filesystem.\n");
222}
223
224static void collect_info(ext2_filsys fs, struct chunk_info *chunk_info, FILE *f)
225{
226	unsigned int retval = 0;
227
228	fprintf(f, "Device: %s\n", fs->device_name);
229	fprintf(f, "Blocksize: %u bytes\n", fs->blocksize);
230
231	retval = ext2fs_read_block_bitmap(fs);
232	if (retval) {
233		com_err(fs->device_name, retval, "while reading block bitmap");
234		close_device(fs->device_name, fs);
235		exit(1);
236	}
237
238	init_chunk_info(fs, chunk_info);
239
240	retval = get_chunk_info(fs, chunk_info, f);
241	if (retval) {
242		com_err(fs->device_name, retval, "while collecting chunk info");
243                close_device(fs->device_name, fs);
244		exit(1);
245	}
246}
247
248#ifndef DEBUGFS
249static void open_device(char *device_name, ext2_filsys *fs)
250{
251	int retval;
252	int flag = EXT2_FLAG_FORCE | EXT2_FLAG_64BITS;
253
254	retval = ext2fs_open(device_name, flag, 0, 0, unix_io_manager, fs);
255	if (retval) {
256		com_err(device_name, retval, "while opening filesystem");
257		exit(1);
258	}
259	(*fs)->default_bitmap_type = EXT2FS_BMAP64_RBTREE;
260}
261#endif
262
263#ifdef DEBUGFS
264#include "debugfs.h"
265
266void do_freefrag(int argc, char **argv)
267#else
268int main(int argc, char *argv[])
269#endif
270{
271	struct chunk_info chunk_info;
272	ext2_filsys fs = NULL;
273	char *progname;
274	char *end;
275	int c;
276
277#ifdef DEBUGFS
278	if (check_fs_open(argv[0]))
279		return;
280#else
281	char *device_name;
282
283	add_error_table(&et_ext2_error_table);
284#endif
285	progname = argv[0];
286	memset(&chunk_info, 0, sizeof(chunk_info));
287
288	while ((c = getopt(argc, argv, "c:h")) != EOF) {
289		switch (c) {
290		case 'c':
291			chunk_info.chunkbytes = strtoull(optarg, &end, 0);
292			if (*end != '\0') {
293				fprintf(stderr, "%s: bad chunk size '%s'\n",
294					progname, optarg);
295				usage(progname);
296			}
297			if (chunk_info.chunkbytes &
298			    (chunk_info.chunkbytes - 1)) {
299				fprintf(stderr, "%s: chunk size must be a "
300					"power of 2.\n", argv[0]);
301				usage(progname);
302			}
303			chunk_info.chunkbytes *= 1024;
304			break;
305		case 'h':
306		default:
307			usage(progname);
308			break;
309		}
310	}
311
312#ifndef DEBUGFS
313	if (optind == argc) {
314		fprintf(stderr, "%s: missing device name.\n", progname);
315		usage(progname);
316	}
317
318	device_name = argv[optind];
319
320	open_device(device_name, &fs);
321#else
322	fs = current_fs;
323#endif
324
325	if (chunk_info.chunkbytes && (chunk_info.chunkbytes < fs->blocksize)) {
326		fprintf(stderr, "%s: chunksize must be greater than or equal "
327			"to filesystem blocksize.\n", progname);
328		exit(1);
329	}
330	collect_info(fs, &chunk_info, stdout);
331#ifndef DEBUGFS
332	close_device(device_name, fs);
333
334	return 0;
335#endif
336}
337