| /* |
| * fallocate - utility to use the fallocate system call |
| * |
| * Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved. |
| * Written by Eric Sandeen <sandeen@redhat.com> |
| * Karel Zak <kzak@redhat.com> |
| * |
| * cvtnum routine taken from xfsprogs, |
| * Copyright (c) 2003-2005 Silicon Graphics, Inc. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License as |
| * published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it would be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License along |
| * with this program; if not, write to the Free Software Foundation, Inc., |
| * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| */ |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <sys/mman.h> |
| #include <ctype.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <getopt.h> |
| #include <limits.h> |
| #include <string.h> |
| |
| #ifndef HAVE_FALLOCATE |
| # include <sys/syscall.h> |
| #endif |
| |
| #if defined(HAVE_LINUX_FALLOC_H) && \ |
| (!defined(FALLOC_FL_KEEP_SIZE) || !defined(FALLOC_FL_PUNCH_HOLE) || \ |
| !defined(FALLOC_FL_COLLAPSE_RANGE) || !defined(FALLOC_FL_ZERO_RANGE) || \ |
| !defined(FALLOC_FL_INSERT_RANGE)) |
| # include <linux/falloc.h> /* non-libc fallback for FALLOC_FL_* flags */ |
| #endif |
| |
| |
| #ifndef FALLOC_FL_KEEP_SIZE |
| # define FALLOC_FL_KEEP_SIZE 0x1 |
| #endif |
| |
| #ifndef FALLOC_FL_PUNCH_HOLE |
| # define FALLOC_FL_PUNCH_HOLE 0x2 |
| #endif |
| |
| #ifndef FALLOC_FL_COLLAPSE_RANGE |
| # define FALLOC_FL_COLLAPSE_RANGE 0x8 |
| #endif |
| |
| #ifndef FALLOC_FL_ZERO_RANGE |
| # define FALLOC_FL_ZERO_RANGE 0x10 |
| #endif |
| |
| #ifndef FALLOC_FL_INSERT_RANGE |
| # define FALLOC_FL_INSERT_RANGE 0x20 |
| #endif |
| |
| #include "nls.h" |
| #include "strutils.h" |
| #include "c.h" |
| #include "closestream.h" |
| #include "xalloc.h" |
| #include "optutils.h" |
| |
| static int verbose; |
| static char *filename; |
| |
| static void __attribute__((__noreturn__)) usage(FILE *out) |
| { |
| fputs(USAGE_HEADER, out); |
| fprintf(out, |
| _(" %s [options] <filename>\n"), program_invocation_short_name); |
| |
| fputs(USAGE_SEPARATOR, out); |
| fputs(_("Preallocate space to, or deallocate space from a file.\n"), out); |
| |
| fputs(USAGE_OPTIONS, out); |
| fputs(_(" -c, --collapse-range remove a range from the file\n"), out); |
| fputs(_(" -d, --dig-holes detect zeroes and replace with holes\n"), out); |
| fputs(_(" -i, --insert-range insert a hole at range, shifting existing data\n"), out); |
| fputs(_(" -l, --length <num> length for range operations, in bytes\n"), out); |
| fputs(_(" -n, --keep-size maintain the apparent size of the file\n"), out); |
| fputs(_(" -o, --offset <num> offset for range operations, in bytes\n"), out); |
| fputs(_(" -p, --punch-hole replace a range with a hole (implies -n)\n"), out); |
| fputs(_(" -z, --zero-range zero and ensure allocation of a range\n"), out); |
| #ifdef HAVE_POSIX_FALLOCATE |
| fputs(_(" -x, --posix use posix_fallocate(3) instead of fallocate(2)\n"), out); |
| #endif |
| fputs(_(" -v, --verbose verbose mode\n"), out); |
| |
| fputs(USAGE_SEPARATOR, out); |
| fputs(USAGE_HELP, out); |
| fputs(USAGE_VERSION, out); |
| |
| fprintf(out, USAGE_MAN_TAIL("fallocate(1)")); |
| |
| exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS); |
| } |
| |
| static loff_t cvtnum(char *s) |
| { |
| uintmax_t x; |
| |
| if (strtosize(s, &x)) |
| return -1LL; |
| |
| return x; |
| } |
| |
| static void xfallocate(int fd, int mode, off_t offset, off_t length) |
| { |
| int error; |
| #ifdef HAVE_FALLOCATE |
| error = fallocate(fd, mode, offset, length); |
| #else |
| error = syscall(SYS_fallocate, fd, mode, offset, length); |
| #endif |
| /* |
| * EOPNOTSUPP: The FALLOC_FL_KEEP_SIZE is unsupported |
| * ENOSYS: The filesystem does not support sys_fallocate |
| */ |
| if (error < 0) { |
| if ((mode & FALLOC_FL_KEEP_SIZE) && errno == EOPNOTSUPP) |
| errx(EXIT_FAILURE, _("fallocate failed: keep size mode is unsupported")); |
| err(EXIT_FAILURE, _("fallocate failed")); |
| } |
| } |
| |
| #ifdef HAVE_POSIX_FALLOCATE |
| static void xposix_fallocate(int fd, off_t offset, off_t length) |
| { |
| int error = posix_fallocate(fd, offset, length); |
| if (error < 0) { |
| err(EXIT_FAILURE, _("fallocate failed")); |
| } |
| } |
| #endif |
| |
| static int skip_hole(int fd, off_t *off) |
| { |
| off_t newoff; |
| |
| errno = 0; |
| newoff = lseek(fd, *off, SEEK_DATA); |
| |
| /* ENXIO means that there is no more data -- probably sparse hole at |
| * the end of the file */ |
| if (newoff < 0 && errno == ENXIO) |
| return 1; |
| |
| if (newoff > *off) { |
| *off = newoff; |
| return 0; /* success */ |
| } |
| return -1; /* no hole */ |
| } |
| |
| /* The real buffer size has to be bufsize + sizeof(uintptr_t) */ |
| static int is_nul(void *buf, size_t bufsize) |
| { |
| typedef uintptr_t word; |
| void const *vp; |
| char const *cbuf = buf, *cp; |
| word const *wp = buf; |
| |
| /* set sentinel */ |
| memset((char *) buf + bufsize, '\1', sizeof(word)); |
| |
| /* Find first nonzero *word*, or the word with the sentinel. */ |
| while (*wp++ == 0) |
| continue; |
| |
| /* Find the first nonzero *byte*, or the sentinel. */ |
| vp = wp - 1; |
| cp = vp; |
| |
| while (*cp++ == 0) |
| continue; |
| |
| return cbuf + bufsize < cp; |
| } |
| |
| static void dig_holes(int fd, off_t off, off_t len) |
| { |
| off_t end = len ? off + len : 0; |
| off_t hole_start = 0, hole_sz = 0; |
| uintmax_t ct = 0; |
| size_t bufsz; |
| char *buf; |
| struct stat st; |
| #if defined(POSIX_FADV_SEQUENTIAL) && defined(HAVE_POSIX_FADVISE) |
| off_t cache_start = off; |
| /* |
| * We don't want to call POSIX_FADV_DONTNEED to discard cached |
| * data in PAGE_SIZE steps. IMHO it's overkill (too many syscalls). |
| * |
| * Let's assume that 1MiB (on system with 4K page size) is just |
| * a good compromise. |
| * -- kzak Feb-2014 |
| */ |
| const size_t cachesz = getpagesize() * 256; |
| #endif |
| |
| if (fstat(fd, &st) != 0) |
| err(EXIT_FAILURE, _("stat of %s failed"), filename); |
| |
| bufsz = st.st_blksize; |
| |
| if (lseek(fd, off, SEEK_SET) < 0) |
| err(EXIT_FAILURE, _("seek on %s failed"), filename); |
| |
| /* buffer + extra space for is_nul() sentinel */ |
| buf = xmalloc(bufsz + sizeof(uintptr_t)); |
| #if defined(POSIX_FADV_SEQUENTIAL) && defined(HAVE_POSIX_FADVISE) |
| posix_fadvise(fd, off, 0, POSIX_FADV_SEQUENTIAL); |
| #endif |
| |
| while (end == 0 || off < end) { |
| ssize_t rsz; |
| |
| rsz = pread(fd, buf, bufsz, off); |
| if (rsz < 0 && errno) |
| err(EXIT_FAILURE, _("%s: read failed"), filename); |
| if (end && rsz > 0 && off > end - rsz) |
| rsz = end - off; |
| if (rsz <= 0) |
| break; |
| |
| if (is_nul(buf, rsz)) { |
| if (!hole_sz) { /* new hole detected */ |
| int rc = skip_hole(fd, &off); |
| if (rc == 0) |
| continue; /* hole skipped */ |
| else if (rc == 1) |
| break; /* end of file */ |
| hole_start = off; |
| } |
| hole_sz += rsz; |
| } else if (hole_sz) { |
| xfallocate(fd, FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE, |
| hole_start, hole_sz); |
| ct += hole_sz; |
| hole_sz = hole_start = 0; |
| } |
| |
| #if defined(POSIX_FADV_DONTNEED) && defined(HAVE_POSIX_FADVISE) |
| /* discard cached data */ |
| if (off - cache_start > (off_t) cachesz) { |
| size_t clen = off - cache_start; |
| |
| clen = (clen / cachesz) * cachesz; |
| posix_fadvise(fd, cache_start, clen, POSIX_FADV_DONTNEED); |
| cache_start = cache_start + clen; |
| } |
| #endif |
| off += rsz; |
| } |
| |
| if (hole_sz) { |
| xfallocate(fd, FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE, |
| hole_start, hole_sz); |
| ct += hole_sz; |
| } |
| |
| free(buf); |
| |
| if (verbose) { |
| char *str = size_to_human_string(SIZE_SUFFIX_3LETTER | SIZE_SUFFIX_SPACE, ct); |
| fprintf(stdout, _("%s: %s (%ju bytes) converted to sparse holes.\n"), |
| filename, str, ct); |
| free(str); |
| } |
| } |
| |
| int main(int argc, char **argv) |
| { |
| int c; |
| int fd; |
| int mode = 0; |
| int dig = 0; |
| int posix = 0; |
| loff_t length = -2LL; |
| loff_t offset = 0; |
| |
| static const struct option longopts[] = { |
| { "help", no_argument, NULL, 'h' }, |
| { "version", no_argument, NULL, 'V' }, |
| { "keep-size", no_argument, NULL, 'n' }, |
| { "punch-hole", no_argument, NULL, 'p' }, |
| { "collapse-range", no_argument, NULL, 'c' }, |
| { "dig-holes", no_argument, NULL, 'd' }, |
| { "insert-range", no_argument, NULL, 'i' }, |
| { "zero-range", no_argument, NULL, 'z' }, |
| { "offset", required_argument, NULL, 'o' }, |
| { "length", required_argument, NULL, 'l' }, |
| { "posix", no_argument, NULL, 'x' }, |
| { "verbose", no_argument, NULL, 'v' }, |
| { NULL, 0, NULL, 0 } |
| }; |
| |
| static const ul_excl_t excl[] = { /* rows and cols in ASCII order */ |
| { 'c', 'd', 'p', 'z' }, |
| { 'c', 'n' }, |
| { 'x', 'c', 'd', 'i', 'n', 'p', 'z'}, |
| { 0 } |
| }; |
| int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT; |
| |
| setlocale(LC_ALL, ""); |
| bindtextdomain(PACKAGE, LOCALEDIR); |
| textdomain(PACKAGE); |
| atexit(close_stdout); |
| |
| while ((c = getopt_long(argc, argv, "hvVncpdizxl:o:", longopts, NULL)) |
| != -1) { |
| |
| err_exclusive_options(c, longopts, excl, excl_st); |
| |
| switch(c) { |
| case 'h': |
| usage(stdout); |
| break; |
| case 'c': |
| mode |= FALLOC_FL_COLLAPSE_RANGE; |
| break; |
| case 'd': |
| dig = 1; |
| break; |
| case 'i': |
| mode |= FALLOC_FL_INSERT_RANGE; |
| break; |
| case 'l': |
| length = cvtnum(optarg); |
| break; |
| case 'n': |
| mode |= FALLOC_FL_KEEP_SIZE; |
| break; |
| case 'o': |
| offset = cvtnum(optarg); |
| break; |
| case 'p': |
| mode |= FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; |
| break; |
| case 'z': |
| mode |= FALLOC_FL_ZERO_RANGE; |
| break; |
| case 'x': |
| #ifdef HAVE_POSIX_FALLOCATE |
| posix = 1; |
| break; |
| #else |
| errx(EXIT_FAILURE, _("posix_fallocate support is not compiled")) |
| #endif |
| case 'v': |
| verbose++; |
| break; |
| case 'V': |
| printf(UTIL_LINUX_VERSION); |
| return EXIT_SUCCESS; |
| default: |
| errtryhelp(EXIT_FAILURE); |
| } |
| } |
| |
| if (optind == argc) |
| errx(EXIT_FAILURE, _("no filename specified")); |
| |
| filename = argv[optind++]; |
| |
| if (optind != argc) |
| errx(EXIT_FAILURE, _("unexpected number of arguments")); |
| |
| if (dig) { |
| /* for --dig-holes the default is analyze all file */ |
| if (length == -2LL) |
| length = 0; |
| if (length < 0) |
| errx(EXIT_FAILURE, _("invalid length value specified")); |
| } else { |
| /* it's safer to require the range specification (--length --offset) */ |
| if (length == -2LL) |
| errx(EXIT_FAILURE, _("no length argument specified")); |
| if (length <= 0) |
| errx(EXIT_FAILURE, _("invalid length value specified")); |
| } |
| if (offset < 0) |
| errx(EXIT_FAILURE, _("invalid offset value specified")); |
| |
| /* O_CREAT makes sense only for the default fallocate(2) behavior |
| * when mode is no specified and new space is allocated */ |
| fd = open(filename, O_RDWR | (!dig && !mode ? O_CREAT : 0), |
| S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH); |
| if (fd < 0) |
| err(EXIT_FAILURE, _("cannot open %s"), filename); |
| |
| if (dig) |
| dig_holes(fd, offset, length); |
| #ifdef HAVE_POSIX_FALLOCATE |
| else if (posix) |
| xposix_fallocate(fd, offset, length); |
| #endif |
| else |
| xfallocate(fd, mode, offset, length); |
| |
| if (close_fd(fd) != 0) |
| err(EXIT_FAILURE, _("write failed: %s"), filename); |
| |
| return EXIT_SUCCESS; |
| } |