filefrag.c revision 339e457939bf1663ac2dbd52e47cd6e145726771 
1/*
2 * filefrag.c -- report if a particular file is fragmented
3 *
4 * Copyright 2003 by Theodore Ts'o.
5 *
6 * %Begin-Header%
7 * This file may be redistributed under the terms of the GNU Public
8 * License.
9 * %End-Header%
10 */
11
12#include "config.h"
13#ifndef __linux__
14#include <stdio.h>
15#include <stdlib.h>
16#include <unistd.h>
17
18int main(void) {
19    fputs("This program is only supported on Linux!\n", stderr);
20    exit(EXIT_FAILURE);
21}
22#else
23#define _LARGEFILE64_SOURCE
24
25#include <stdio.h>
26#include <stdlib.h>
27#include <unistd.h>
28#include <string.h>
29#include <time.h>
30#include <fcntl.h>
31#include <errno.h>
32#ifdef HAVE_GETOPT_H
33#include <getopt.h>
34#else
35extern char *optarg;
36extern int optind;
37#endif
38#include <sys/types.h>
39#include <sys/stat.h>
40#include <sys/vfs.h>
41#include <sys/ioctl.h>
42#include <linux/fd.h>
43#include <ext2fs/ext2_types.h>
44#include <ext2fs/fiemap.h>
45
46int verbose = 0;
47int no_bs = 0;		/* Don't use the files blocksize, use 1K blocksize */
48int sync_file = 0;	/* fsync file before getting the mapping */
49int xattr_map = 0;	/* get xattr mapping */
50int force_bmap = 0;
51int logical_width = 12;
52int physical_width = 14;
53unsigned long long filesize;
54
55#define FILEFRAG_FIEMAP_FLAGS_COMPAT (FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR)
56
57#define FIBMAP		_IO(0x00, 1)	/* bmap access */
58#define FIGETBSZ	_IO(0x00, 2)	/* get the block size used for bmap */
59
60#define	EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
61#define	EXT3_IOC_GETFLAGS		_IOR('f', 1, long)
62
63static int int_log2(int arg)
64{
65	int     l = 0;
66
67	arg >>= 1;
68	while (arg) {
69		l++;
70		arg >>= 1;
71	}
72	return l;
73}
74
75static int int_log10(unsigned long long arg)
76{
77	int     l = 0;
78
79	arg = arg / 10;
80	while (arg) {
81		l++;
82		arg = arg / 10;
83	}
84	return l;
85}
86
87static unsigned int div_ceil(unsigned int a, unsigned int b)
88{
89	if (!a)
90		return 0;
91	return ((a - 1) / b) + 1;
92}
93
94static int get_bmap(int fd, unsigned long block, unsigned long *phy_blk)
95{
96	int	ret;
97	unsigned int b;
98
99	b = block;
100	ret = ioctl(fd, FIBMAP, &b); /* FIBMAP takes pointer to integer */
101	if (ret < 0) {
102		if (errno == EPERM) {
103			fprintf(stderr, "No permission to use FIBMAP ioctl; "
104				"must have root privileges\n");
105			exit(1);
106		}
107		perror("FIBMAP");
108	}
109	*phy_blk = b;
110
111	return ret;
112}
113
114static void print_extent_info(struct fiemap_extent *fm_extent, int cur_ex,
115			      unsigned long long expected, int blk_shift)
116{
117	__u64 phy_blk;
118	unsigned long long logical_blk;
119	unsigned long ext_len;
120	char flags[256] = "";
121
122	/* For inline data all offsets should be in terms of bytes, not blocks */
123	if (fm_extent->fe_flags & FIEMAP_EXTENT_DATA_INLINE)
124		blk_shift = 0;
125
126	ext_len = fm_extent->fe_length >> blk_shift;
127	logical_blk = fm_extent->fe_logical >> blk_shift;
128	phy_blk = fm_extent->fe_physical >> blk_shift;
129
130	if (fm_extent->fe_flags & FIEMAP_EXTENT_UNKNOWN)
131		strcat(flags, "unknown,");
132	if (fm_extent->fe_flags & FIEMAP_EXTENT_DELALLOC)
133		strcat(flags, "delalloc,");
134	if (fm_extent->fe_flags & FIEMAP_EXTENT_DATA_ENCRYPTED)
135		strcat(flags, "encrypted,");
136	if (fm_extent->fe_flags & FIEMAP_EXTENT_NOT_ALIGNED)
137		strcat(flags, "not_aligned,");
138	if (fm_extent->fe_flags & FIEMAP_EXTENT_DATA_INLINE)
139		strcat(flags, "inline,");
140	if (fm_extent->fe_flags & FIEMAP_EXTENT_DATA_TAIL)
141		strcat(flags, "tail_packed,");
142	if (fm_extent->fe_flags & FIEMAP_EXTENT_UNWRITTEN)
143		strcat(flags, "unwritten,");
144	if (fm_extent->fe_flags & FIEMAP_EXTENT_MERGED)
145		strcat(flags, "merged,");
146
147	if (fm_extent->fe_logical + fm_extent->fe_length >= filesize)
148		strcat(flags, "eof,");
149
150	/* Remove trailing comma, if any */
151	if (flags[0])
152		flags[strlen(flags) - 1] = '\0';
153
154	if (expected)
155		printf("%4d %*llu %*llu %*llu %6lu %s\n",
156		       cur_ex, logical_width, logical_blk,
157		       physical_width, phy_blk, physical_width, expected,
158		       ext_len, flags);
159	else
160		printf("%4d %*llu %*llu %*s %6lu %s\n",
161		       cur_ex, logical_width, logical_blk,
162		       physical_width, phy_blk, physical_width, "",
163		       ext_len, flags);
164}
165
166static int filefrag_fiemap(int fd, int blk_shift, int *num_extents)
167{
168	char buf[4096] = "";
169	struct fiemap *fiemap = (struct fiemap *)buf;
170	struct fiemap_extent *fm_ext = &fiemap->fm_extents[0];
171	int count = (sizeof(buf) - sizeof(*fiemap)) /
172			sizeof(struct fiemap_extent);
173	unsigned long long expected = 0;
174	unsigned long flags = 0;
175	unsigned int i;
176	static int fiemap_incompat_printed;
177	int fiemap_header_printed = 0;
178	int tot_extents = 0, n = 0;
179	int last = 0;
180	int rc;
181
182	memset(fiemap, 0, sizeof(struct fiemap));
183
184	if (sync_file)
185		flags |= FIEMAP_FLAG_SYNC;
186
187	if (xattr_map)
188		flags |= FIEMAP_FLAG_XATTR;
189
190	do {
191		fiemap->fm_length = ~0ULL;
192		fiemap->fm_flags = flags;
193		fiemap->fm_extent_count = count;
194		rc = ioctl(fd, FS_IOC_FIEMAP, (unsigned long) fiemap);
195		if (rc < 0) {
196			if (errno == EBADR && fiemap_incompat_printed == 0) {
197				printf("FIEMAP failed with unsupported "
198				       "flags %x\n", fiemap->fm_flags);
199				fiemap_incompat_printed = 1;
200			}
201			return rc;
202		}
203
204		/* If 0 extents are returned, then more ioctls are not needed */
205		if (fiemap->fm_mapped_extents == 0)
206			break;
207
208		if (verbose && !fiemap_header_printed) {
209			printf(" ext %*s %*s %*s length flags\n", logical_width,
210			       "logical", physical_width, "physical",
211			       physical_width, "expected");
212			fiemap_header_printed = 1;
213		}
214
215		for (i = 0; i < fiemap->fm_mapped_extents; i++) {
216			__u64 phy_blk, logical_blk;
217			unsigned long ext_len;
218
219			phy_blk = fm_ext[i].fe_physical >> blk_shift;
220			ext_len = fm_ext[i].fe_length >> blk_shift;
221			logical_blk = fm_ext[i].fe_logical >> blk_shift;
222
223			if (logical_blk && phy_blk != expected) {
224				tot_extents++;
225			} else {
226				expected = 0;
227				if (!tot_extents)
228					tot_extents = 1;
229			}
230			if (verbose)
231				print_extent_info(&fm_ext[i], n, expected,
232						  blk_shift);
233
234			expected = phy_blk + ext_len;
235			if (fm_ext[i].fe_flags & FIEMAP_EXTENT_LAST)
236				last = 1;
237			n++;
238		}
239
240		fiemap->fm_start = (fm_ext[i-1].fe_logical +
241				    fm_ext[i-1].fe_length);
242	} while (last == 0);
243
244	*num_extents = tot_extents;
245out:
246	return 0;
247}
248
249#define EXT2_DIRECT	12
250
251static void frag_report(const char *filename)
252{
253	struct statfs	fsinfo;
254#ifdef HAVE_FSTAT64
255	struct stat64	fileinfo;
256#else
257	struct stat	fileinfo;
258#endif
259	int		bs;
260	long		fd;
261	unsigned long	block, last_block = 0, numblocks, i, count = 0;
262	long		bpib;	/* Blocks per indirect block */
263	long		cylgroups;
264	int		num_extents = 0, expected;
265	int		is_ext2 = 0;
266	static int	once = 1;
267	unsigned int	flags;
268	int rc;
269
270#ifdef HAVE_OPEN64
271	fd = open64(filename, O_RDONLY);
272#else
273	fd = open(filename, O_RDONLY);
274#endif
275	if (fd < 0) {
276		perror("open");
277		return;
278	}
279
280	if (statfs(filename, &fsinfo) < 0) {
281		perror("statfs");
282		return;
283	}
284#ifdef HAVE_FSTAT64
285	if (stat64(filename, &fileinfo) < 0) {
286#else
287	if (stat(filename, &fileinfo) < 0) {
288#endif
289		perror("stat");
290		return;
291	}
292	if (ioctl(fd, EXT3_IOC_GETFLAGS, &flags) < 0)
293		flags = 0;
294	if (!(flags & EXT4_EXTENTS_FL) &&
295	    ((fsinfo.f_type == 0xef51) || (fsinfo.f_type == 0xef52) ||
296	     (fsinfo.f_type == 0xef53)))
297		is_ext2++;
298	if (verbose && once)
299		printf("Filesystem type is: %lx\n",
300		       (unsigned long) fsinfo.f_type);
301
302	cylgroups = div_ceil(fsinfo.f_blocks, fsinfo.f_bsize*8);
303	if (verbose && is_ext2 && once)
304		printf("Filesystem cylinder groups is approximately %ld\n",
305		       cylgroups);
306
307	physical_width = int_log10(fsinfo.f_blocks);
308	if (physical_width < 8)
309		physical_width = 8;
310
311	if (ioctl(fd, FIGETBSZ, &bs) < 0) { /* FIGETBSZ takes an int */
312		perror("FIGETBSZ");
313		close(fd);
314		return;
315	}
316
317	if (no_bs)
318		bs = 1024;
319
320	bpib = bs / 4;
321	numblocks = (fileinfo.st_size + (bs-1)) / bs;
322	logical_width = int_log10(numblocks);
323	if (logical_width < 7)
324		logical_width = 7;
325	filesize = (long long)fileinfo.st_size;
326	if (verbose)
327		printf("File size of %s is %lld (%ld block%s, blocksize %d)\n",
328		       filename, (long long) fileinfo.st_size, numblocks,
329		       numblocks == 1 ? "" : "s", bs);
330	if (force_bmap ||
331	    filefrag_fiemap(fd, int_log2(bs), &num_extents) != 0) {
332		for (i = 0, count = 0; i < numblocks; i++) {
333			if (is_ext2 && last_block) {
334				if (((i-EXT2_DIRECT) % bpib) == 0)
335					last_block++;
336				if (((i-EXT2_DIRECT-bpib) % (bpib*bpib)) == 0)
337					last_block++;
338				if (((i-EXT2_DIRECT-bpib-bpib*bpib) %
339				     (((__u64) bpib)*bpib*bpib)) == 0)
340					last_block++;
341			}
342			rc = get_bmap(fd, i, &block);
343			if (block == 0)
344				continue;
345			if (!num_extents)
346				num_extents++;
347			count++;
348			if (last_block && (block != last_block+1) ) {
349				if (verbose)
350					printf("Discontinuity: Block %ld is at "
351					       "%lu (was %lu)\n",
352					       i, block, last_block+1);
353				num_extents++;
354			}
355			last_block = block;
356		}
357	}
358	if (num_extents == 1)
359		printf("%s: 1 extent found", filename);
360	else
361		printf("%s: %d extents found", filename, num_extents);
362	/* count, and thus expected, only set for indirect FIBMAP'd files */
363	if (is_ext2) {
364		expected = (count/((bs*8)-(fsinfo.f_files/8/cylgroups)-3))+1;
365		if (expected && expected < num_extents)
366			printf(", perfection would be %d extent%s\n", expected,
367				(expected>1) ? "s" : "");
368	} else
369		fputc('\n', stdout);
370	close(fd);
371	once = 0;
372}
373
374static void usage(const char *progname)
375{
376	fprintf(stderr, "Usage: %s [-Bbvsx] file ...\n", progname);
377	exit(1);
378}
379
380int main(int argc, char**argv)
381{
382	char **cpp;
383	int c;
384
385	while ((c = getopt(argc, argv, "Bbsvx")) != EOF)
386		switch (c) {
387		case 'B':
388			force_bmap++;
389			break;
390		case 'b':
391			no_bs++;
392			break;
393		case 'v':
394			verbose++;
395			break;
396		case 's':
397			sync_file++;
398			break;
399		case 'x':
400			xattr_map++;
401			break;
402		default:
403			usage(argv[0]);
404			break;
405		}
406	if (optind == argc)
407		usage(argv[0]);
408	for (cpp=argv+optind; *cpp; cpp++)
409		frag_report(*cpp);
410	return 0;
411}
412#endif
413