e2freefrag.c revision a6ce1349539f866334ef3d5758bc2ee44a454acd 
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
24extern char *optarg;
25extern int optind;
26#endif
27
28#include "ext2fs/ext2_fs.h"
29#include "ext2fs/ext2fs.h"
30#include "e2freefrag.h"
31
32void 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
39static 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
51void 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
74void 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
92void 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
142errcode_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
211void 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
219void 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
243void 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
255int 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}
313