e2freefrag.c revision 5e96c5721d58acfbf9d76b62214f6ae421fe4e6b 
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
33void 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
54void 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
77void update_chunk_stats(struct chunk_info *info, unsigned long chunk_size)
78{
79	unsigned long index;
80
81	index = ul_log2(chunk_size) + 1;
82	if (index >= MAX_HIST)
83		index = MAX_HIST-1;
84	info->histogram.fc_chunks[index]++;
85	info->histogram.fc_blocks[index] += chunk_size;
86
87	if (chunk_size > info->max)
88		info->max = chunk_size;
89	if (chunk_size < info->min)
90		info->min = chunk_size;
91	info->avg += chunk_size;
92	info->real_free_chunks++;
93}
94
95void scan_block_bitmap(ext2_filsys fs, struct chunk_info *info)
96{
97	unsigned long long blocks_count = ext2fs_blocks_count(fs->super);
98	unsigned long long chunks = (blocks_count + info->blks_in_chunk) >>
99				(info->chunkbits - info->blocksize_bits);
100	unsigned long long chunk_num;
101	unsigned long last_chunk_size = 0;
102	unsigned long long chunk_start_blk = 0;
103	int used;
104
105	for (chunk_num = 0; chunk_num < chunks; chunk_num++) {
106		unsigned long long blk, num_blks;
107		int chunk_free;
108
109		/* Last chunk may be smaller */
110		if (chunk_start_blk + info->blks_in_chunk > blocks_count)
111			num_blks = blocks_count - chunk_start_blk;
112		else
113			num_blks = info->blks_in_chunk;
114
115		chunk_free = 0;
116
117		/* Initialize starting block for first chunk correctly else
118		 * there is a segfault when blocksize = 1024 in which case
119		 * block_map->start = 1 */
120		for (blk = 0; blk < num_blks; blk++, chunk_start_blk++) {
121			if (chunk_num == 0 && blk == 0) {
122				blk = fs->super->s_first_data_block;
123				chunk_start_blk = blk;
124			}
125			used = ext2fs_fast_test_block_bitmap2(fs->block_map,
126				chunk_start_blk >> fs->cluster_ratio_bits);
127			if (!used) {
128				last_chunk_size++;
129				chunk_free++;
130			}
131
132			if (used && last_chunk_size != 0) {
133				update_chunk_stats(info, last_chunk_size);
134				last_chunk_size = 0;
135			}
136		}
137
138		if (chunk_free == info->blks_in_chunk)
139			info->free_chunks++;
140	}
141	if (last_chunk_size != 0)
142		update_chunk_stats(info, last_chunk_size);
143}
144
145errcode_t get_chunk_info(ext2_filsys fs, struct chunk_info *info, FILE *f)
146{
147	unsigned long total_chunks;
148	char *unitp = "KMGTPEZY";
149	int units = 10;
150	unsigned long start = 0, end;
151	int i, retval = 0;
152
153	scan_block_bitmap(fs, info);
154
155	fprintf(f, "Total blocks: %llu\nFree blocks: %u (%0.1f%%)\n",
156		ext2fs_blocks_count(fs->super), fs->super->s_free_blocks_count,
157		(double)fs->super->s_free_blocks_count * 100 /
158		ext2fs_blocks_count(fs->super));
159
160	if (info->chunkbytes) {
161		fprintf(f, "\nChunksize: %lu bytes (%u blocks)\n",
162			info->chunkbytes, info->blks_in_chunk);
163		total_chunks = (ext2fs_blocks_count(fs->super) +
164				info->blks_in_chunk) >>
165			(info->chunkbits - info->blocksize_bits);
166		fprintf(f, "Total chunks: %lu\nFree chunks: %lu (%0.1f%%)\n",
167			total_chunks, info->free_chunks,
168			(double)info->free_chunks * 100 / total_chunks);
169	}
170
171	/* Display chunk information in KB */
172	if (info->real_free_chunks) {
173		info->min = (info->min * fs->blocksize) >> 10;
174		info->max = (info->max * fs->blocksize) >> 10;
175		info->avg = (info->avg / info->real_free_chunks *
176			     fs->blocksize) >> 10;
177	} else {
178		info->min = 0;
179	}
180
181	fprintf(f, "\nMin. free extent: %lu KB \nMax. free extent: %lu KB\n"
182		"Avg. free extent: %lu KB\n", info->min, info->max, info->avg);
183	fprintf(f, "Num. free extent: %lu\n", info->real_free_chunks);
184
185	fprintf(f, "\nHISTOGRAM OF FREE EXTENT SIZES:\n");
186	fprintf(f, "%s :  %12s  %12s  %7s\n", "Extent Size Range",
187		"Free extents", "Free Blocks", "Percent");
188	for (i = 0; i < MAX_HIST; i++) {
189		end = 1 << (i + info->blocksize_bits - units);
190		if (info->histogram.fc_chunks[i] != 0) {
191			char end_str[32];
192
193			sprintf(end_str, "%5lu%c-", end, *unitp);
194			if (i == MAX_HIST-1)
195				strcpy(end_str, "max ");
196			fprintf(f, "%5lu%c...%7s  :  %12lu  %12lu  %6.2f%%\n",
197				start, *unitp, end_str,
198				info->histogram.fc_chunks[i],
199				info->histogram.fc_blocks[i],
200				(double)info->histogram.fc_blocks[i] * 100 /
201				fs->super->s_free_blocks_count);
202		}
203		start = end;
204		if (start == 1<<10) {
205			start = 1;
206			units += 10;
207			unitp++;
208		}
209	}
210
211	return retval;
212}
213
214void close_device(char *device_name, ext2_filsys fs)
215{
216	int retval = ext2fs_close(fs);
217
218	if (retval)
219		com_err(device_name, retval, "while closing the filesystem.\n");
220}
221
222void collect_info(ext2_filsys fs, struct chunk_info *chunk_info, FILE *f)
223{
224	unsigned int retval = 0;
225
226	fprintf(f, "Device: %s\n", fs->device_name);
227	fprintf(f, "Blocksize: %u bytes\n", fs->blocksize);
228
229	retval = ext2fs_read_block_bitmap(fs);
230	if (retval) {
231		com_err(fs->device_name, retval, "while reading block bitmap");
232		close_device(fs->device_name, fs);
233		exit(1);
234	}
235
236	init_chunk_info(fs, chunk_info);
237
238	retval = get_chunk_info(fs, chunk_info, f);
239	if (retval) {
240		com_err(fs->device_name, retval, "while collecting chunk info");
241                close_device(fs->device_name, fs);
242		exit(1);
243	}
244}
245
246void open_device(char *device_name, ext2_filsys *fs)
247{
248	int retval;
249	int flag = EXT2_FLAG_FORCE;
250
251	retval = ext2fs_open(device_name, flag, 0, 0, unix_io_manager, fs);
252	if (retval) {
253		com_err(device_name, retval, "while opening filesystem");
254		exit(1);
255	}
256}
257
258#ifdef DEBUGFS
259
260#include "debugfs.h"
261
262void do_freefrag(int argc, char **argv)
263#else
264int main(int argc, char *argv[])
265#endif
266{
267	struct chunk_info chunk_info = { };
268	errcode_t retval = 0;
269	ext2_filsys fs = NULL;
270	char *device_name;
271	char *progname;
272	char *end;
273	int c;
274
275#ifdef DEBUGFS
276	if (check_fs_open(argv[0]))
277		return;
278#else
279	add_error_table(&et_ext2_error_table);
280#endif
281	progname = argv[0];
282
283	while ((c = getopt(argc, argv, "c:h")) != EOF) {
284		switch (c) {
285		case 'c':
286			chunk_info.chunkbytes = strtoull(optarg, &end, 0);
287			if (*end != '\0') {
288				fprintf(stderr, "%s: bad chunk size '%s'\n",
289					progname, optarg);
290				usage(progname);
291			}
292			if (chunk_info.chunkbytes &
293			    (chunk_info.chunkbytes - 1)) {
294				fprintf(stderr, "%s: chunk size must be a "
295					"power of 2.\n", argv[0]);
296				usage(progname);
297			}
298			chunk_info.chunkbytes *= 1024;
299			break;
300		case 'h':
301		default:
302			usage(progname);
303			break;
304		}
305	}
306
307#ifndef DEBUGFS
308	if (optind == argc) {
309		fprintf(stderr, "%s: missing device name.\n", progname);
310		usage(progname);
311	}
312
313	device_name = argv[optind];
314
315	open_device(device_name, &fs);
316#else
317	fs = current_fs;
318#endif
319
320	if (chunk_info.chunkbytes && (chunk_info.chunkbytes < fs->blocksize)) {
321		fprintf(stderr, "%s: chunksize must be greater than or equal "
322			"to filesystem blocksize.\n", progname);
323		exit(1);
324	}
325	collect_info(fs, &chunk_info, stdout);
326#ifndef DEBUGFS
327	close_device(device_name, fs);
328
329	return retval;
330#endif
331}
332