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-rw-r--r--sys-utils/fallocate.c412
1 files changed, 412 insertions, 0 deletions
diff --git a/sys-utils/fallocate.c b/sys-utils/fallocate.c
new file mode 100644
index 0000000..ba3867c
--- /dev/null
+++ b/sys-utils/fallocate.c
@@ -0,0 +1,412 @@
+/*
+ * 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(void)
+{
+ FILE *out = stdout;
+ 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);
+ printf(USAGE_HELP_OPTIONS(22));
+
+ printf(USAGE_MAN_TAIL("fallocate(1)"));
+
+ exit(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
+
+/* 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 file_off, off_t len)
+{
+ off_t file_end = len ? file_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 = file_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, file_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));
+ while (file_end == 0 || file_off < file_end) {
+ /*
+ * Detect data area (skip holes)
+ */
+ off_t end, off;
+
+ off = lseek(fd, file_off, SEEK_DATA);
+ if ((off == -1 && errno == ENXIO) ||
+ (file_end && off >= file_end))
+ break;
+
+ end = lseek(fd, off, SEEK_HOLE);
+ if (file_end && end > file_end)
+ end = file_end;
+
+#if defined(POSIX_FADV_SEQUENTIAL) && defined(HAVE_POSIX_FADVISE)
+ posix_fadvise(fd, off, end, POSIX_FADV_SEQUENTIAL);
+#endif
+ /*
+ * Dig holes in the area
+ */
+ while (off < end) {
+ ssize_t 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 */
+ 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;
+ }
+ file_off = off;
+ }
+
+ 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();
+ 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;
+}
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