1 /*
2 * fallocate - utility to use the fallocate system call
3 *
4 * Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved.
5 * Written by Eric Sandeen <sandeen@redhat.com>
6 * Karel Zak <kzak@redhat.com>
7 *
8 * cvtnum routine taken from xfsprogs,
9 * Copyright (c) 2003-2005 Silicon Graphics, Inc.
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License as
13 * published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope that it would be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License along
21 * with this program; if not, write to the Free Software Foundation, Inc.,
22 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
23 */
24 #include <sys/stat.h>
25 #include <sys/types.h>
26 #include <sys/mman.h>
27 #include <ctype.h>
28 #include <errno.h>
29 #include <fcntl.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <unistd.h>
33 #include <getopt.h>
34 #include <limits.h>
35 #include <string.h>
36
37 #ifndef HAVE_FALLOCATE
38 # include <sys/syscall.h>
39 #endif
40
41 #if defined(HAVE_LINUX_FALLOC_H) && \
42 (!defined(FALLOC_FL_KEEP_SIZE) || !defined(FALLOC_FL_PUNCH_HOLE) || \
43 !defined(FALLOC_FL_COLLAPSE_RANGE) || !defined(FALLOC_FL_ZERO_RANGE) || \
44 !defined(FALLOC_FL_INSERT_RANGE))
45 # include <linux/falloc.h> /* non-libc fallback for FALLOC_FL_* flags */
46 #endif
47
48
49 #ifndef FALLOC_FL_KEEP_SIZE
50 # define FALLOC_FL_KEEP_SIZE 0x1
51 #endif
52
53 #ifndef FALLOC_FL_PUNCH_HOLE
54 # define FALLOC_FL_PUNCH_HOLE 0x2
55 #endif
56
57 #ifndef FALLOC_FL_COLLAPSE_RANGE
58 # define FALLOC_FL_COLLAPSE_RANGE 0x8
59 #endif
60
61 #ifndef FALLOC_FL_ZERO_RANGE
62 # define FALLOC_FL_ZERO_RANGE 0x10
63 #endif
64
65 #ifndef FALLOC_FL_INSERT_RANGE
66 # define FALLOC_FL_INSERT_RANGE 0x20
67 #endif
68
69 #include "nls.h"
70 #include "strutils.h"
71 #include "c.h"
72 #include "closestream.h"
73 #include "xalloc.h"
74 #include "optutils.h"
75
76 static int verbose;
77 static char *filename;
78
79 static void __attribute__((__noreturn__)) usage(void)
80 {
81 FILE *out = stdout;
82 fputs(USAGE_HEADER, out);
83 fprintf(out,
84 _(" %s [options] <filename>\n"), program_invocation_short_name);
85
86 fputs(USAGE_SEPARATOR, out);
87 fputs(_("Preallocate space to, or deallocate space from a file.\n"), out);
88
89 fputs(USAGE_OPTIONS, out);
90 fputs(_(" -c, --collapse-range remove a range from the file\n"), out);
91 fputs(_(" -d, --dig-holes detect zeroes and replace with holes\n"), out);
92 fputs(_(" -i, --insert-range insert a hole at range, shifting existing data\n"), out);
93 fputs(_(" -l, --length <num> length for range operations, in bytes\n"), out);
94 fputs(_(" -n, --keep-size maintain the apparent size of the file\n"), out);
95 fputs(_(" -o, --offset <num> offset for range operations, in bytes\n"), out);
96 fputs(_(" -p, --punch-hole replace a range with a hole (implies -n)\n"), out);
97 fputs(_(" -z, --zero-range zero and ensure allocation of a range\n"), out);
98 #ifdef HAVE_POSIX_FALLOCATE
99 fputs(_(" -x, --posix use posix_fallocate(3) instead of fallocate(2)\n"), out);
100 #endif
101 fputs(_(" -v, --verbose verbose mode\n"), out);
102
103 fputs(USAGE_SEPARATOR, out);
104 printf(USAGE_HELP_OPTIONS(22));
105
106 fputs(USAGE_ARGUMENTS, out);
107 printf(USAGE_ARG_SIZE(_("<num>")));
108
109 printf(USAGE_MAN_TAIL("fallocate(1)"));
110
111 exit(EXIT_SUCCESS);
112 }
113
114 static loff_t cvtnum(char *s)
115 {
116 uintmax_t x;
117
118 if (strtosize(s, &x))
119 return -1LL;
120
121 return x;
122 }
123
124 static void xfallocate(int fd, int mode, off_t offset, off_t length)
125 {
126 int error;
127
128 #ifdef HAVE_FALLOCATE
129 error = fallocate(fd, mode, offset, length);
130 #else
131 error = syscall(SYS_fallocate, fd, mode, offset, length);
132 #endif
133 /*
134 * EOPNOTSUPP: The FALLOC_FL_KEEP_SIZE is unsupported
135 * ENOSYS: The filesystem does not support sys_fallocate
136 */
137 if (error < 0) {
138 if ((mode & FALLOC_FL_KEEP_SIZE) && errno == EOPNOTSUPP)
139 errx(EXIT_FAILURE, _("fallocate failed: keep size mode is unsupported"));
140 err(EXIT_FAILURE, _("fallocate failed"));
141 }
142 }
143
144 #ifdef HAVE_POSIX_FALLOCATE
145 static void xposix_fallocate(int fd, off_t offset, off_t length)
146 {
147 int error = posix_fallocate(fd, offset, length);
148 if (error < 0) {
149 err(EXIT_FAILURE, _("fallocate failed"));
150 }
151 }
152 #endif
153
154 /* The real buffer size has to be bufsize + sizeof(uintptr_t) */
155 static int is_nul(void *buf, size_t bufsize)
156 {
157 typedef uintptr_t word;
158 void const *vp;
159 char const *cbuf = buf, *cp;
160 word const *wp = buf;
161
162 /* set sentinel */
163 memset((char *) buf + bufsize, '\1', sizeof(word));
164
165 /* Find first nonzero *word*, or the word with the sentinel. */
166 while (*wp++ == 0)
167 continue;
168
169 /* Find the first nonzero *byte*, or the sentinel. */
170 vp = wp - 1;
171 cp = vp;
172
173 while (*cp++ == 0)
174 continue;
175
176 return cbuf + bufsize < cp;
177 }
178
179 static void dig_holes(int fd, off_t file_off, off_t len)
180 {
181 off_t file_end = len ? file_off + len : 0;
182 off_t hole_start = 0, hole_sz = 0;
183 uintmax_t ct = 0;
184 size_t bufsz;
185 char *buf;
186 struct stat st;
187 #if defined(POSIX_FADV_SEQUENTIAL) && defined(HAVE_POSIX_FADVISE)
188 off_t cache_start = file_off;
189 /*
190 * We don't want to call POSIX_FADV_DONTNEED to discard cached
191 * data in PAGE_SIZE steps. IMHO it's overkill (too many syscalls).
192 *
193 * Let's assume that 1MiB (on system with 4K page size) is just
194 * a good compromise.
195 * -- kzak Feb-2014
196 */
197 const size_t cachesz = getpagesize() * 256;
198 #endif
199
200 if (fstat(fd, &st) != 0)
201 err(EXIT_FAILURE, _("stat of %s failed"), filename);
202
203 bufsz = st.st_blksize;
204
205 if (lseek(fd, file_off, SEEK_SET) < 0)
206 err(EXIT_FAILURE, _("seek on %s failed"), filename);
207
208 /* buffer + extra space for is_nul() sentinel */
209 buf = xmalloc(bufsz + sizeof(uintptr_t));
210 while (file_end == 0 || file_off < file_end) {
211 /*
212 * Detect data area (skip holes)
213 */
214 off_t end, off;
215
216 off = lseek(fd, file_off, SEEK_DATA);
217 if ((off == -1 && errno == ENXIO) ||
218 (file_end && off >= file_end))
219 break;
220
221 end = lseek(fd, off, SEEK_HOLE);
222 if (file_end && end > file_end)
223 end = file_end;
224
225 if (off < 0 || end < 0)
226 break;
227
228 #if defined(POSIX_FADV_SEQUENTIAL) && defined(HAVE_POSIX_FADVISE)
229 (void) posix_fadvise(fd, off, end, POSIX_FADV_SEQUENTIAL);
230 #endif
231 /*
232 * Dig holes in the area
233 */
234 while (off < end) {
235 ssize_t rsz = pread(fd, buf, bufsz, off);
236 if (rsz < 0 && errno)
237 err(EXIT_FAILURE, _("%s: read failed"), filename);
238 if (end && rsz > 0 && off > end - rsz)
239 rsz = end - off;
240 if (rsz <= 0)
241 break;
242
243 if (is_nul(buf, rsz)) {
244 if (!hole_sz) /* new hole detected */
245 hole_start = off;
246 hole_sz += rsz;
247 } else if (hole_sz) {
248 xfallocate(fd, FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE,
249 hole_start, hole_sz);
250 ct += hole_sz;
251 hole_sz = hole_start = 0;
252 }
253
254 #if defined(POSIX_FADV_DONTNEED) && defined(HAVE_POSIX_FADVISE)
255 /* discard cached data */
256 if (off - cache_start > (off_t) cachesz) {
257 size_t clen = off - cache_start;
258
259 clen = (clen / cachesz) * cachesz;
260 (void) posix_fadvise(fd, cache_start, clen, POSIX_FADV_DONTNEED);
261 cache_start = cache_start + clen;
262 }
263 #endif
264 off += rsz;
265 }
266 if (hole_sz) {
267 off_t alloc_sz = hole_sz;
268 if (off >= end)
269 alloc_sz += st.st_blksize; /* meet block boundary */
270 xfallocate(fd, FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE,
271 hole_start, alloc_sz);
272 ct += hole_sz;
273 }
274 file_off = off;
275 }
276
277 free(buf);
278
279 if (verbose) {
280 char *str = size_to_human_string(SIZE_SUFFIX_3LETTER | SIZE_SUFFIX_SPACE, ct);
281 fprintf(stdout, _("%s: %s (%ju bytes) converted to sparse holes.\n"),
282 filename, str, ct);
283 free(str);
284 }
285 }
286
287 int main(int argc, char **argv)
288 {
289 int c;
290 int fd;
291 int mode = 0;
292 int dig = 0;
293 int posix = 0;
294 loff_t length = -2LL;
295 loff_t offset = 0;
296
297 static const struct option longopts[] = {
298 { "help", no_argument, NULL, 'h' },
299 { "version", no_argument, NULL, 'V' },
300 { "keep-size", no_argument, NULL, 'n' },
301 { "punch-hole", no_argument, NULL, 'p' },
302 { "collapse-range", no_argument, NULL, 'c' },
303 { "dig-holes", no_argument, NULL, 'd' },
304 { "insert-range", no_argument, NULL, 'i' },
305 { "zero-range", no_argument, NULL, 'z' },
306 { "offset", required_argument, NULL, 'o' },
307 { "length", required_argument, NULL, 'l' },
308 { "posix", no_argument, NULL, 'x' },
309 { "verbose", no_argument, NULL, 'v' },
310 { NULL, 0, NULL, 0 }
311 };
312
313 static const ul_excl_t excl[] = { /* rows and cols in ASCII order */
314 { 'c', 'd', 'p', 'z' },
315 { 'c', 'n' },
316 { 'x', 'c', 'd', 'i', 'n', 'p', 'z'},
317 { 0 }
318 };
319 int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
320
321 setlocale(LC_ALL, "");
322 bindtextdomain(PACKAGE, LOCALEDIR);
323 textdomain(PACKAGE);
324 close_stdout_atexit();
325
326 while ((c = getopt_long(argc, argv, "hvVncpdizxl:o:", longopts, NULL))
327 != -1) {
328
329 err_exclusive_options(c, longopts, excl, excl_st);
330
331 switch(c) {
332 case 'c':
333 mode |= FALLOC_FL_COLLAPSE_RANGE;
334 break;
335 case 'd':
336 dig = 1;
337 break;
338 case 'i':
339 mode |= FALLOC_FL_INSERT_RANGE;
340 break;
341 case 'l':
342 length = cvtnum(optarg);
343 break;
344 case 'n':
345 mode |= FALLOC_FL_KEEP_SIZE;
346 break;
347 case 'o':
348 offset = cvtnum(optarg);
349 break;
350 case 'p':
351 mode |= FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
352 break;
353 case 'z':
354 mode |= FALLOC_FL_ZERO_RANGE;
355 break;
356 case 'x':
357 #ifdef HAVE_POSIX_FALLOCATE
358 posix = 1;
359 break;
360 #else
361 errx(EXIT_FAILURE, _("posix_fallocate support is not compiled"));
362 #endif
363 case 'v':
364 verbose++;
365 break;
366
367 case 'h':
368 usage();
369 case 'V':
370 print_version(EXIT_SUCCESS);
371 default:
372 errtryhelp(EXIT_FAILURE);
373 }
374 }
375
376 if (optind == argc)
377 errx(EXIT_FAILURE, _("no filename specified"));
378
379 filename = argv[optind++];
380
381 if (optind != argc)
382 errx(EXIT_FAILURE, _("unexpected number of arguments"));
383
384 if (dig) {
385 /* for --dig-holes the default is analyze all file */
386 if (length == -2LL)
387 length = 0;
388 if (length < 0)
389 errx(EXIT_FAILURE, _("invalid length value specified"));
390 } else {
391 /* it's safer to require the range specification (--length --offset) */
392 if (length == -2LL)
393 errx(EXIT_FAILURE, _("no length argument specified"));
394 if (length <= 0)
395 errx(EXIT_FAILURE, _("invalid length value specified"));
396 }
397 if (offset < 0)
398 errx(EXIT_FAILURE, _("invalid offset value specified"));
399
400 /* O_CREAT makes sense only for the default fallocate(2) behavior
401 * when mode is no specified and new space is allocated */
402 fd = open(filename, O_RDWR | (!dig && !mode ? O_CREAT : 0),
403 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
404 if (fd < 0)
405 err(EXIT_FAILURE, _("cannot open %s"), filename);
406
407 if (dig)
408 dig_holes(fd, offset, length);
409 else {
410 #ifdef HAVE_POSIX_FALLOCATE
411 if (posix)
412 xposix_fallocate(fd, offset, length);
413 else
414 #endif
415 xfallocate(fd, mode, offset, length);
416
417 if (verbose) {
418 char *str = size_to_human_string(SIZE_SUFFIX_3LETTER | SIZE_SUFFIX_SPACE, length);
419
420 if (mode & FALLOC_FL_PUNCH_HOLE)
421 fprintf(stdout, _("%s: %s (%ju bytes) hole created.\n"),
422 filename, str, length);
423 else if (mode & FALLOC_FL_COLLAPSE_RANGE)
424 fprintf(stdout, _("%s: %s (%ju bytes) removed.\n"),
425 filename, str, length);
426 else if (mode & FALLOC_FL_INSERT_RANGE)
427 fprintf(stdout, _("%s: %s (%ju bytes) inserted.\n"),
428 filename, str, length);
429 else if (mode & FALLOC_FL_ZERO_RANGE)
430 fprintf(stdout, _("%s: %s (%ju bytes) zeroed.\n"),
431 filename, str, length);
432 else
433 fprintf(stdout, _("%s: %s (%ju bytes) allocated.\n"),
434 filename, str, length);
435 free(str);
436 }
437 }
438
439 if (close_fd(fd) != 0)
440 err(EXIT_FAILURE, _("write failed: %s"), filename);
441
442 return EXIT_SUCCESS;
443 }