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      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 
     17 int 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
     34 extern char *optarg;
     35 extern 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 
     45 int verbose = 0;
     46 int no_bs = 0;		/* Don't use the files blocksize, use 1K blocksize */
     47 int sync_file = 0;	/* fsync file before getting the mapping */
     48 int xattr_map = 0;	/* get xattr mapping */
     49 int force_bmap = 0;
     50 int logical_width = 12;
     51 int physical_width = 14;
     52 unsigned long long filesize;
     53 
     54 #define FILEFRAG_FIEMAP_FLAGS_COMPAT (FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR)
     55 
     56 #define FIBMAP		_IO(0x00, 1)	/* bmap access */
     57 #define FIGETBSZ	_IO(0x00, 2)	/* get the block size used for bmap */
     58 #define FS_IOC_FIEMAP	_IOWR('f', 11, struct fiemap)
     59 
     60 #define	EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
     61 #define	EXT3_IOC_GETFLAGS		_IOR('f', 1, long)
     62 
     63 static 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 
     75 static 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 
     87 static 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 
     94 static 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 
    114 static 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 
    166 static 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 last_blk = 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 = 1, n = 0;
    179 	int last = 0;
    180 	int rc;
    181 
    182 	fiemap->fm_length = ~0ULL;
    183 
    184 	memset(fiemap, 0, sizeof(struct fiemap));
    185 
    186 	if (!verbose)
    187 		count = 0;
    188 
    189 	if (sync_file)
    190 		flags |= FIEMAP_FLAG_SYNC;
    191 
    192 	if (xattr_map)
    193 		flags |= FIEMAP_FLAG_XATTR;
    194 
    195 	do {
    196 		fiemap->fm_length = ~0ULL;
    197 		fiemap->fm_flags = flags;
    198 		fiemap->fm_extent_count = count;
    199 		rc = ioctl(fd, FS_IOC_FIEMAP, (unsigned long) fiemap);
    200 		if (rc < 0) {
    201 			if (errno == EBADR && fiemap_incompat_printed == 0) {
    202 				printf("FIEMAP failed with unsupported "
    203 				       "flags %x\n", fiemap->fm_flags);
    204 				fiemap_incompat_printed = 1;
    205 			}
    206 			return rc;
    207 		}
    208 
    209 		if (verbose && !fiemap_header_printed) {
    210 			printf(" ext %*s %*s %*s length flags\n", logical_width,
    211 			       "logical", physical_width, "physical",
    212 			       physical_width, "expected");
    213 			fiemap_header_printed = 1;
    214 		}
    215 
    216 		if (!verbose) {
    217 			*num_extents = fiemap->fm_mapped_extents;
    218 			goto out;
    219 		}
    220 
    221 		/* If 0 extents are returned, then more ioctls are not needed */
    222 		if (fiemap->fm_mapped_extents == 0)
    223 			break;
    224 
    225 		for (i = 0; i < fiemap->fm_mapped_extents; i++) {
    226 			__u64 phy_blk, logical_blk;
    227 			unsigned long ext_len;
    228 
    229 			phy_blk = fm_ext[i].fe_physical >> blk_shift;
    230 			ext_len = fm_ext[i].fe_length >> blk_shift;
    231 			logical_blk = fm_ext[i].fe_logical >> blk_shift;
    232 
    233 			if (logical_blk && phy_blk != last_blk + 1)
    234 				tot_extents++;
    235 			else
    236 				last_blk = 0;
    237 			print_extent_info(&fm_ext[i], n, last_blk, blk_shift);
    238 
    239 			last_blk = phy_blk + ext_len - 1;
    240 			if (fm_ext[i].fe_flags & FIEMAP_EXTENT_LAST)
    241 				last = 1;
    242 			n++;
    243 		}
    244 
    245 		fiemap->fm_start = (fm_ext[i-1].fe_logical +
    246 				    fm_ext[i-1].fe_length);
    247 	} while (last == 0);
    248 
    249 	*num_extents = tot_extents;
    250 out:
    251 	return 0;
    252 }
    253 
    254 #define EXT2_DIRECT	12
    255 
    256 static void frag_report(const char *filename)
    257 {
    258 	struct statfs	fsinfo;
    259 #ifdef HAVE_FSTAT64
    260 	struct stat64	fileinfo;
    261 #else
    262 	struct stat	fileinfo;
    263 #endif
    264 	int		bs;
    265 	long		fd;
    266 	unsigned long	block, last_block = 0, numblocks, i, count;
    267 	long		bpib;	/* Blocks per indirect block */
    268 	long		cylgroups;
    269 	int		num_extents = 0, expected;
    270 	int		is_ext2 = 0;
    271 	static int	once = 1;
    272 	unsigned int	flags;
    273 	int rc;
    274 
    275 #ifdef HAVE_OPEN64
    276 	fd = open64(filename, O_RDONLY);
    277 #else
    278 	fd = open(filename, O_RDONLY);
    279 #endif
    280 	if (fd < 0) {
    281 		perror("open");
    282 		return;
    283 	}
    284 
    285 	if (statfs(filename, &fsinfo) < 0) {
    286 		perror("statfs");
    287 		return;
    288 	}
    289 #ifdef HAVE_FSTAT64
    290 	if (stat64(filename, &fileinfo) < 0) {
    291 #else
    292 	if (stat(filename, &fileinfo) < 0) {
    293 #endif
    294 		perror("stat");
    295 		return;
    296 	}
    297 	if (ioctl(fd, EXT3_IOC_GETFLAGS, &flags) < 0)
    298 		flags = 0;
    299 	if (!(flags & EXT4_EXTENTS_FL) &&
    300 	    ((fsinfo.f_type == 0xef51) || (fsinfo.f_type == 0xef52) ||
    301 	     (fsinfo.f_type == 0xef53)))
    302 		is_ext2++;
    303 	if (verbose && once)
    304 		printf("Filesystem type is: %lx\n",
    305 		       (unsigned long) fsinfo.f_type);
    306 
    307 	cylgroups = div_ceil(fsinfo.f_blocks, fsinfo.f_bsize*8);
    308 	if (verbose && is_ext2 && once)
    309 		printf("Filesystem cylinder groups is approximately %ld\n",
    310 		       cylgroups);
    311 
    312 	physical_width = int_log10(fsinfo.f_blocks);
    313 	if (physical_width < 8)
    314 		physical_width = 8;
    315 
    316 	if (ioctl(fd, FIGETBSZ, &bs) < 0) { /* FIGETBSZ takes an int */
    317 		perror("FIGETBSZ");
    318 		close(fd);
    319 		return;
    320 	}
    321 
    322 	if (no_bs)
    323 		bs = 1024;
    324 
    325 	bpib = bs / 4;
    326 	numblocks = (fileinfo.st_size + (bs-1)) / bs;
    327 	logical_width = int_log10(numblocks);
    328 	if (logical_width < 7)
    329 		logical_width = 7;
    330 	filesize = (long long)fileinfo.st_size;
    331 	if (verbose)
    332 		printf("File size of %s is %lld (%ld block%s, blocksize %d)\n",
    333 		       filename, (long long) fileinfo.st_size, numblocks,
    334 		       numblocks == 1 ? "" : "s", bs);
    335 	if (force_bmap ||
    336 	    filefrag_fiemap(fd, int_log2(bs), &num_extents) != 0) {
    337 		for (i = 0, count = 0; i < numblocks; i++) {
    338 			if (is_ext2 && last_block) {
    339 				if (((i-EXT2_DIRECT) % bpib) == 0)
    340 					last_block++;
    341 				if (((i-EXT2_DIRECT-bpib) % (bpib*bpib)) == 0)
    342 					last_block++;
    343 				if (((i-EXT2_DIRECT-bpib-bpib*bpib) %
    344 				     (((__u64) bpib)*bpib*bpib)) == 0)
    345 					last_block++;
    346 			}
    347 			rc = get_bmap(fd, i, &block);
    348 			if (block == 0)
    349 				continue;
    350 			if (!num_extents)
    351 				num_extents++;
    352 			count++;
    353 			if (last_block && (block != last_block+1) ) {
    354 				if (verbose)
    355 					printf("Discontinuity: Block %ld is at "
    356 					       "%lu (was %lu)\n",
    357 					       i, block, last_block+1);
    358 				num_extents++;
    359 			}
    360 			last_block = block;
    361 		}
    362 	}
    363 	if (num_extents == 1)
    364 		printf("%s: 1 extent found", filename);
    365 	else
    366 		printf("%s: %d extents found", filename, num_extents);
    367 	expected = (count/((bs*8)-(fsinfo.f_files/8/cylgroups)-3))+1;
    368 	if (is_ext2 && expected < num_extents)
    369 		printf(", perfection would be %d extent%s\n", expected,
    370 			(expected>1) ? "s" : "");
    371 	else
    372 		fputc('\n', stdout);
    373 	close(fd);
    374 	once = 0;
    375 }
    376 
    377 static void usage(const char *progname)
    378 {
    379 	fprintf(stderr, "Usage: %s [-Bbvsx] file ...\n", progname);
    380 	exit(1);
    381 }
    382 
    383 int main(int argc, char**argv)
    384 {
    385 	char **cpp;
    386 	int c;
    387 
    388 	while ((c = getopt(argc, argv, "Bbsvx")) != EOF)
    389 		switch (c) {
    390 		case 'B':
    391 			force_bmap++;
    392 			break;
    393 		case 'b':
    394 			no_bs++;
    395 			break;
    396 		case 'v':
    397 			verbose++;
    398 			break;
    399 		case 's':
    400 			sync_file++;
    401 			break;
    402 		case 'x':
    403 			xattr_map++;
    404 			break;
    405 		default:
    406 			usage(argv[0]);
    407 			break;
    408 		}
    409 	if (optind == argc)
    410 		usage(argv[0]);
    411 	for (cpp=argv+optind; *cpp; cpp++)
    412 		frag_report(*cpp);
    413 	return 0;
    414 }
    415 #endif
    416