filefrag.c revision f97ea10fde6d8bee670d388f02cf9524b8f2d7da 
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#ifndef __linux__
13#include <stdio.h>
14#include <stdlib.h>
15#include <unistd.h>
16
17int main(void) {
18    fputs("This program is only supported on Linux!\n", stderr);
19    exit(EXIT_FAILURE);
20}
21#else
22#define _LARGEFILE64_SOURCE
23
24#include <stdio.h>
25#include <stdlib.h>
26#include <unistd.h>
27#include <string.h>
28#include <time.h>
29#include <fcntl.h>
30#include <errno.h>
31#ifdef HAVE_GETOPT_H
32#include <getopt.h>
33#else
34extern char *optarg;
35extern int optind;
36#endif
37#include <sys/types.h>
38#include <sys/stat.h>
39#include <sys/vfs.h>
40#include <sys/ioctl.h>
41#include <linux/fd.h>
42#include <ext2fs/ext2_types.h>
43#include <ext2fs/fiemap.h>
44
45int verbose = 0;
46int no_bs = 0;		/* Don't use the files blocksize, use 1K blocksize */
47int sync_file = 0;	/* fsync file before getting the mapping */
48int xattr_map = 0;	/* get xattr mapping */
49int logical_width = 12;
50int physical_width = 14;
51unsigned long long filesize;
52
53#define FILEFRAG_FIEMAP_FLAGS_COMPAT (FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR)
54
55#define FIBMAP		_IO(0x00, 1)	/* bmap access */
56#define FIGETBSZ	_IO(0x00, 2)	/* get the block size used for bmap */
57#define FS_IOC_FIEMAP	_IOWR('f', 11, struct fiemap)
58
59#define	EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
60#define	EXT3_IOC_GETFLAGS		_IOR('f', 1, long)
61
62static int int_log2(int arg)
63{
64	int     l = 0;
65
66	arg >>= 1;
67	while (arg) {
68		l++;
69		arg >>= 1;
70	}
71	return l;
72}
73
74static int int_log10(unsigned long long arg)
75{
76	int     l = 0;
77
78	arg = arg / 10;
79	while (arg) {
80		l++;
81		arg = arg / 10;
82	}
83	return l;
84}
85
86static unsigned int div_ceil(unsigned int a, unsigned int b)
87{
88	if (!a)
89		return 0;
90	return ((a - 1) / b) + 1;
91}
92
93static int get_bmap(int fd, unsigned long block, unsigned long *phy_blk)
94{
95	int	ret;
96	unsigned int b;
97
98	printf("Calling get_bmap for block %lu\n", block);
99	abort();
100	b = block;
101	ret = ioctl(fd, FIBMAP, &b); /* FIBMAP takes pointer to integer */
102	if (ret < 0) {
103		if (errno == EPERM) {
104			fprintf(stderr, "No permission to use FIBMAP ioctl; "
105				"must have root privileges\n");
106			exit(1);
107		}
108		perror("FIBMAP");
109	}
110	*phy_blk = b;
111
112	return ret;
113}
114
115static void print_extent_info(struct fiemap_extent *fm_extent, int cur_ex,
116			      unsigned long long expected, int blk_shift)
117{
118	__u64 phy_blk;
119	unsigned long long logical_blk;
120	unsigned long ext_len;
121	char flags[256] = "";
122
123	/* For inline data all offsets should be in terms of bytes, not blocks */
124	if (fm_extent->fe_flags & FIEMAP_EXTENT_DATA_INLINE)
125		blk_shift = 0;
126
127	ext_len = fm_extent->fe_length >> blk_shift;
128	logical_blk = fm_extent->fe_logical >> blk_shift;
129	phy_blk = fm_extent->fe_physical >> blk_shift;
130
131	if (fm_extent->fe_flags & FIEMAP_EXTENT_UNKNOWN)
132		strcat(flags, "unknown,");
133	if (fm_extent->fe_flags & FIEMAP_EXTENT_DELALLOC)
134		strcat(flags, "delalloc,");
135	if (fm_extent->fe_flags & FIEMAP_EXTENT_DATA_ENCRYPTED)
136		strcat(flags, "encrypted,");
137	if (fm_extent->fe_flags & FIEMAP_EXTENT_NOT_ALIGNED)
138		strcat(flags, "not_aligned,");
139	if (fm_extent->fe_flags & FIEMAP_EXTENT_DATA_INLINE)
140		strcat(flags, "inline,");
141	if (fm_extent->fe_flags & FIEMAP_EXTENT_DATA_TAIL)
142		strcat(flags, "tail_packed,");
143	if (fm_extent->fe_flags & FIEMAP_EXTENT_UNWRITTEN)
144		strcat(flags, "unwritten,");
145	if (fm_extent->fe_flags & FIEMAP_EXTENT_MERGED)
146		strcat(flags, "merged,");
147
148	if (fm_extent->fe_logical + fm_extent->fe_length >= filesize)
149		strcat(flags, "eof,");
150
151	/* Remove trailing comma, if any */
152	if (flags[0])
153		flags[strlen(flags) - 1] = '\0';
154
155	if (expected)
156		printf("%4d %*llu %*llu %*llu %6lu %s\n",
157		       cur_ex, logical_width, logical_blk,
158		       physical_width, phy_blk, physical_width, expected,
159		       ext_len, flags);
160	else
161		printf("%4d %*llu %*llu %*s %6lu %s\n",
162		       cur_ex, logical_width, logical_blk,
163		       physical_width, phy_blk, physical_width, "",
164		       ext_len, flags);
165}
166
167int filefrag_fiemap(int fd, int blk_shift, int *num_extents)
168{
169	char buf[4096] = "";
170	struct fiemap *fiemap = (struct fiemap *)buf;
171	struct fiemap_extent *fm_ext = &fiemap->fm_extents[0];
172	int count = (sizeof(buf) - sizeof(*fiemap)) /
173			sizeof(struct fiemap_extent);
174	unsigned long long logical_blk = 0, last_blk = 0;
175	unsigned long flags = 0;
176	static int fiemap_incompat_printed;
177	int tot_extents = 1, n = 0;
178	int last = 0, eof = 0;
179	int i, rc;
180
181	fiemap->fm_length = ~0ULL;
182
183	memset(fiemap, 0, sizeof(struct fiemap));
184
185	if (!verbose)
186		count = 0;
187
188	if (sync_file)
189		flags |= FIEMAP_FLAG_SYNC;
190
191	if (xattr_map)
192		flags |= FIEMAP_FLAG_XATTR;
193
194	if (verbose)
195		printf(" ext %*s %*s %*s length flags\n", logical_width,
196		       "logical", physical_width, "physical",
197		       physical_width, "expected");
198
199	do {
200		fiemap->fm_length = ~0ULL;
201		fiemap->fm_flags = flags;
202		fiemap->fm_extent_count = count;
203		rc = ioctl(fd, FS_IOC_FIEMAP, (unsigned long) fiemap);
204		if (rc < 0) {
205			if (errno == EBADR && fiemap_incompat_printed == 0) {
206				printf("FIEMAP failed with unsupported "
207				       "flags %x\n", fiemap->fm_flags);
208				fiemap_incompat_printed = 1;
209			}
210			return rc;
211		}
212
213		if (!verbose) {
214			*num_extents = fiemap->fm_mapped_extents;
215			goto out;
216		}
217
218		/* If 0 extents are returned, then more ioctls are not needed */
219		if (fiemap->fm_mapped_extents == 0)
220			break;
221
222		for (i = 0; i < fiemap->fm_mapped_extents; i++) {
223			__u64 phy_blk, phy_start, logical_blk;
224			unsigned long ext_len;
225
226			phy_blk = fm_ext[i].fe_physical >> blk_shift;
227			ext_len = fm_ext[i].fe_length >> blk_shift;
228			logical_blk = fm_ext[i].fe_logical >> blk_shift;
229
230			if (logical_blk && phy_blk != last_blk + 1)
231				tot_extents++;
232			else
233				last_blk = 0;
234			print_extent_info(&fm_ext[i], n, last_blk, blk_shift);
235
236			last_blk = phy_blk + ext_len - 1;
237			if (fm_ext[i].fe_flags & FIEMAP_EXTENT_LAST)
238				last = 1;
239			n++;
240		}
241
242		fiemap->fm_start = (fm_ext[i-1].fe_logical +
243				    fm_ext[i-1].fe_length);
244	} while (last == 0);
245
246	*num_extents = tot_extents;
247out:
248	return 0;
249}
250
251#define EXT2_DIRECT	12
252
253static void frag_report(const char *filename)
254{
255	struct statfs	fsinfo;
256#ifdef HAVE_FSTAT64
257	struct stat64	fileinfo;
258#else
259	struct stat	fileinfo;
260#endif
261	int		bs;
262	long		fd;
263	unsigned long	block, last_block = 0, numblocks, i, count;
264	long		bpib;	/* Blocks per indirect block */
265	long		cylgroups;
266	int		num_extents = 0, expected;
267	int		is_ext2 = 0;
268	static int	once = 1;
269	unsigned int	flags;
270	unsigned long	first_blk, last_blk;
271	int rc;
272
273#ifdef HAVE_OPEN64
274	fd = open64(filename, O_RDONLY);
275#else
276	fd = open(filename, O_RDONLY);
277#endif
278	if (fd < 0) {
279		perror("open");
280		return;
281	}
282
283	if (statfs(filename, &fsinfo) < 0) {
284		perror("statfs");
285		return;
286	}
287#ifdef HAVE_FSTAT64
288	if (stat64(filename, &fileinfo) < 0) {
289#else
290	if (stat(filename, &fileinfo) < 0) {
291#endif
292		perror("stat");
293		return;
294	}
295	if (ioctl(fd, EXT3_IOC_GETFLAGS, &flags) < 0)
296		flags = 0;
297	if (!(flags & EXT4_EXTENTS_FL) &&
298	    ((fsinfo.f_type == 0xef51) || (fsinfo.f_type == 0xef52) ||
299	     (fsinfo.f_type == 0xef53)))
300		is_ext2++;
301	if (verbose && once)
302		printf("Filesystem type is: %lx\n",
303		       (unsigned long) fsinfo.f_type);
304
305	cylgroups = div_ceil(fsinfo.f_blocks, fsinfo.f_bsize*8);
306	if (verbose && is_ext2 && once)
307		printf("Filesystem cylinder groups is approximately %ld\n",
308		       cylgroups);
309
310	physical_width = int_log10(fsinfo.f_blocks);
311	if (physical_width < 8)
312		physical_width = 8;
313
314	if (ioctl(fd, FIGETBSZ, &bs) < 0) { /* FIGETBSZ takes an int */
315		perror("FIGETBSZ");
316		close(fd);
317		return;
318	}
319
320	if (no_bs)
321		bs = 1024;
322
323	bpib = bs / 4;
324	numblocks = (fileinfo.st_size + (bs-1)) / bs;
325	logical_width = int_log10(numblocks);
326	if (logical_width < 7)
327		logical_width = 7;
328	filesize = (long long)fileinfo.st_size;
329	if (verbose)
330		printf("File size of %s is %lld (%ld block%s, blocksize %d)\n",
331		       filename, (long long) fileinfo.st_size, numblocks,
332		       numblocks == 1 ? "" : "s", bs);
333	if (filefrag_fiemap(fd, int_log2(bs), &num_extents) != 0) {
334		for (i = 0; i < numblocks; i++) {
335			if (is_ext2 && last_block) {
336				if (((i-EXT2_DIRECT) % bpib) == 0)
337					last_block++;
338				if (((i-EXT2_DIRECT-bpib) % (bpib*bpib)) == 0)
339					last_block++;
340				if (((i-EXT2_DIRECT-bpib-bpib*bpib) %
341							(bpib*bpib*bpib)) == 0)
342					last_block++;
343			}
344			rc = get_bmap(fd, i, &block);
345			if (block == 0)
346				continue;
347			if (last_block && (block != last_block+1) ) {
348				if (verbose)
349					printf("Discontinuity: Block %ld is at "
350					       "%lu (was %lu)\n",
351					       i, block, last_block+1);
352				num_extents++;
353			}
354			last_block = block;
355		}
356	}
357	if (num_extents == 1)
358		printf("%s: 1 extent found", filename);
359	else
360		printf("%s: %d extents found", filename, num_extents);
361	expected = (count/((bs*8)-(fsinfo.f_files/8/cylgroups)-3))+1;
362	if (is_ext2 && expected < num_extents)
363		printf(", perfection would be %d extent%s\n", expected,
364			(expected>1) ? "s" : "");
365	else
366		fputc('\n', stdout);
367	close(fd);
368	once = 0;
369}
370
371static void usage(const char *progname)
372{
373	fprintf(stderr, "Usage: %s [-bvsx] file ...\n", progname);
374	exit(1);
375}
376
377int main(int argc, char**argv)
378{
379	char **cpp;
380	int c;
381	int ret;
382
383	while ((c = getopt(argc, argv, "bsvx")) != EOF)
384		switch (c) {
385		case 'b':
386			no_bs++;
387			break;
388		case 'v':
389			verbose++;
390			break;
391		case 's':
392			sync_file++;
393			break;
394		case 'x':
395			xattr_map++;
396			break;
397		default:
398			usage(argv[0]);
399			break;
400		}
401	if (optind == argc)
402		usage(argv[0]);
403	for (cpp=argv+optind; *cpp; cpp++)
404		frag_report(*cpp);
405	return 0;
406}
407#endif
408