e2freefrag.c revision 554bc091b7e8a24acc737ab68bc00d2e04354653 
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	exit(1);
38}
39
40static 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
52void 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
75void 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
93void 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
143errcode_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
212void 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
220void 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
244void 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
256int 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}
312