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