From 9f2a32a8fd08bb1b48f29c88bfa398fa4eb5f2a4 Mon Sep 17 00:00:00 2001

From: Karel Zak <kzak@redhat.com>

Date: Wed, 6 Jun 2018 11:59:16 +0200

Subject: [PATCH 159/173] fallocate: backport v2.32-164-g641af90dc

* add --dig-holes

* add --collapse-range

* add --insert-range

* add --zero-range

For backward compatibility with previous RHEL7 versions we keep

O_CREAT for open(). The current upstream uses O_CREAT only when

necessary.

Addresses: http://bugzilla.redhat.com/show_bug.cgi?id=1528567

Signed-off-by: Karel Zak <kzak@redhat.com>

---

 sys-utils/fallocate.1 | 195 ++++++++++++++++++++++------

 sys-utils/fallocate.c | 349 +++++++++++++++++++++++++++++++++++++++-----------

 2 files changed, 428 insertions(+), 116 deletions(-)

diff --git a/sys-utils/fallocate.1 b/sys-utils/fallocate.1

index 376353013..d4821dcd1 100644

--- a/sys-utils/fallocate.1

+++ b/sys-utils/fallocate.1

@@ -1,72 +1,185 @@

-.\" -*- nroff -*-

-.TH FALLOCATE 1 "September 2011" "util-linux" "User Commands"

+.TH FALLOCATE 1 "April 2014" "util-linux" "User Commands"

 .SH NAME

-fallocate \- preallocate space to a file

+fallocate \- preallocate or deallocate space to a file

 .SH SYNOPSIS

 .B fallocate

-.RB [ \-n ]

-.RB [ \-p ]

+.RB [ \-c | \-p | \-z ]

 .RB [ \-o

 .IR offset ]

 .B \-l

-.IR length

+.I length

+.RB [ \-n ]

+.I filename

+.PP

+.B fallocate \-d

+.RB [ \-o

+.IR offset ]

+.RB [ \-l

+.IR length ]

 .I filename

 .PP

 .B fallocate \-x

 .RB [ \-o

 .IR offset ]

-.RB \-l

-.IR length

+.B \-l

+.I length

 .I filename

 .SH DESCRIPTION

 .B fallocate

-is used to preallocate blocks to a file.  For filesystems which support the

-fallocate system call, this is done quickly by allocating blocks and marking

-them as uninitialized, requiring no IO to the data blocks.  This is much faster

-than creating a file by filling it with zeros.

-.PP

-As of the Linux Kernel v2.6.31, the fallocate system call is supported by the

-btrfs, ext4, ocfs2, and xfs filesystems.

+is used to manipulate the allocated disk space for a file,

+either to deallocate or preallocate it.

+For filesystems which support the fallocate system call,

+preallocation is done quickly by allocating blocks and marking them as

+uninitialized, requiring no IO to the data blocks.

+This is much faster than creating a file by filling it with zeroes.

 .PP

 The exit code returned by

 .B fallocate

 is 0 on success and 1 on failure.

-.PP

 .SH OPTIONS

-The \fIlength\fR and \fIoffset\fR arguments may be followed by the multiplicative

-suffixes KiB=1024, MiB=1024*1024, and so on for GiB, TiB, PiB, EiB, ZiB and YiB

-(the "iB" is optional, e.g. "K" has the same meaning as "KiB") or the suffixes

-KB=1000, MB=1000*1000, and so on for GB, TB, PB, EB, ZB and YB.

-.IP "\fB\-n, \-\-keep-size\fP"

+The

+.I length

+and

+.I offset

+arguments may be followed by the multiplicative suffixes KiB (=1024),

+MiB (=1024*1024), and so on for GiB, TiB, PiB, EiB, ZiB, and YiB (the "iB" is

+optional, e.g., "K" has the same meaning as "KiB") or the suffixes

+KB (=1000), MB (=1000*1000), and so on for GB, TB, PB, EB, ZB, and YB.

+.PP

+The options

+.BR \-\-collapse\-range ", " \-\-dig\-holes ", " \-\-punch\-hole ,

+and

+.B \-\-zero\-range

+are mutually exclusive.

+.TP

+.BR \-c ", " \-\-collapse\-range

+Removes a byte range from a file, without leaving a hole.

+The byte range to be collapsed starts at

+.I offset

+and continues for

+.I length

+bytes.

+At the completion of the operation,

+the contents of the file starting at the location

+.IR offset + length

+will be appended at the location

+.IR offset ,

+and the file will be

+.I length

+bytes smaller.

+The option

+.B \-\-keep\-size

+may not be specified for the collapse-range operation.

+.sp

+Available since Linux 3.15 for ext4 (only for extent-based files) and XFS.

+.TP

+.BR \-d ", " \-\-dig\-holes

+Detect and dig holes.

+This makes the file sparse in-place, without using extra disk space.

+The minimum size of the hole depends on filesystem I/O block size

+(usually 4096 bytes).

+Also, when using this option,

+.B \-\-keep\-size

+is implied.  If no range is specified by

+.B \-\-offset

+and

+.BR \-\-length ,

+then the entire file is analyzed for holes.

+.sp

+You can think of this option as doing a

+.RB """" "cp \-\-sparse" """"

+and then renaming the destination file to the original,

+without the need for extra disk space.

+.sp

+See \fB\-\-punch\-hole\fP for a list of supported filesystems.

+.TP

+.BR \-i ", " \-\-insert\-range

+Insert a hole of

+.I length

+bytes from

+.IR offset ,

+shifting existing data.

+.TP

+.BR \-l ", " "\-\-length " \fIlength

+Specifies the length of the range, in bytes.

+.TP

+.BR \-n ", " \-\-keep\-size

 Do not modify the apparent length of the file.  This may effectively allocate

 blocks past EOF, which can be removed with a truncate.

-.IP "\fB\-p, \-\-punch-hole\fP"

-Punch holes in the file, the range should not exceed the length of the file.

-.IP "\fB\-o, \-\-offset\fP \fIoffset\fP

-Specifies the beginning offset of the allocation, in bytes.

-.IP "\fB\-l, \-\-length\fP \fIlength\fP

-Specifies the length of the allocation, in bytes.

-.IP "\fB\-x , \-\-posix\fP

-Enable POSIX operation mode. In that mode allocation operation always completes,

-but it may take longer time when fast allocation is not supported by the underlying filesystem.

-.IP "\fB\-h, \-\-help\fP"

-Print help and exit.

-.IP "\fB-V, \-\-version"

-Print version and exit.

+.TP

+.BR \-o ", " "\-\-offset " \fIoffset

+Specifies the beginning offset of the range, in bytes.

+.TP

+.BR \-p ", " \-\-punch\-hole

+Deallocates space (i.e., creates a hole) in the byte range starting at

+.I offset

+and continuing for

+.I length

+bytes.

+Within the specified range, partial filesystem blocks are zeroed,

+and whole filesystem blocks are removed from the file.

+After a successful call,

+subsequent reads from this range will return zeroes.

+This option may not be specified at the same time as the

+.B \-\-zero\-range

+option.

+Also, when using this option,

+.B \-\-keep\-size

+is implied.

+.sp

+Supported for XFS (since Linux 2.6.38), ext4 (since Linux 3.0),

+Btrfs (since Linux 3.7) and tmpfs (since Linux 3.5).

+.TP

+.BR \-v ", " \-\-verbose

+Enable verbose mode.

+.TP

+.BR \-x ", " \-\-posix

+Enable POSIX operation mode.

+In that mode allocation operation always completes,

+but it may take longer time when fast allocation is not supported by

+the underlying filesystem.

+.TP

+.BR \-z ", " \-\-zero\-range

+Zeroes space in the byte range starting at

+.I offset

+and continuing for

+.I length

+bytes.

+Within the specified range, blocks are preallocated for the regions

+that span the holes in the file.

+After a successful call,

+subsequent reads from this range will return zeroes.

+.sp

+Zeroing is done within the filesystem preferably by converting the

+range into unwritten extents.  This approach means that the specified

+range will not be physically zeroed out on the device (except for

+partial blocks at the either end of the range), and I/O is

+(otherwise) required only to update metadata.

+.sp

+Option \fB\-\-keep\-size\fP can be specified to prevent file length

+modification.

+.sp

+Available since Linux 3.14 for ext4 (only for extent-based files) and XFS.

+.TP

+.BR \-V ", " \-\-version

+Display version information and exit.

+.TP

+.BR \-h ", " \-\-help

+Display help text and exit.

 .SH AUTHORS

-.UR sandeen@redhat.com

+.MT sandeen@redhat.com

 Eric Sandeen

-.UE

+.ME

 .br

-.UR kzak@redhat.com

+.MT kzak@redhat.com

 Karel Zak

-.UE

+.ME

 .SH SEE ALSO

+.BR truncate (1),

 .BR fallocate (2),

-.BR posix_fallocate (3),

-.BR truncate (1)

+.BR posix_fallocate (3)

 .SH AVAILABILITY

 The fallocate command is part of the util-linux package and is available from

-.UR ftp://\:ftp.kernel.org\:/pub\:/linux\:/utils\:/util-linux/

+.UR https://\:www.kernel.org\:/pub\:/linux\:/utils\:/util-linux/

 Linux Kernel Archive

 .UE .

diff --git a/sys-utils/fallocate.c b/sys-utils/fallocate.c

index 17ae5fe69..75d89a7a9 100644

--- a/sys-utils/fallocate.c

+++ b/sys-utils/fallocate.c

@@ -23,6 +23,7 @@

  */

 #include <sys/stat.h>

 #include <sys/types.h>

+#include <sys/mman.h>

 #include <ctype.h>

 #include <errno.h>

 #include <fcntl.h>

@@ -31,50 +32,110 @@

 #include <unistd.h>

 #include <getopt.h>

 #include <limits.h>

+#include <string.h>

 #ifndef HAVE_FALLOCATE

 # include <sys/syscall.h>

 #endif

-#ifdef HAVE_LINUX_FALLOC_H

-# include <linux/falloc.h>	/* for FALLOC_FL_* flags */

+#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 1

+# define FALLOC_FL_KEEP_SIZE		0x1

 #endif

 #ifndef FALLOC_FL_PUNCH_HOLE

-# define FALLOC_FL_PUNCH_HOLE 2

+# 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 void __attribute__((__noreturn__)) usage(FILE *out)

+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(_(" -n, --keep-size     don't modify the length of the file\n"

-		" -p, --punch-hole    punch holes in the file\n"

-		" -o, --offset <num>  offset of the allocation, in bytes\n"

-		" -l, --length <num>  length of the allocation, in bytes\n"), 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);

+	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)"));

+	printf(USAGE_HELP_OPTIONS(22));

+

+	printf(USAGE_MAN_TAIL("fallocate(1)"));

-	exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);

+	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)

@@ -86,41 +147,163 @@ static void xposix_fallocate(int fd, off_t offset, off_t length)

 }

 #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;

-static loff_t cvtnum(char *s)

+	/* 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)

 {

-	uintmax_t x;

+	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 (strtosize(s, &x))

-		return -1LL;

+	if (fstat(fd, &st) != 0)

+		err(EXIT_FAILURE, _("stat of %s failed"), filename);

-	return x;

+	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)

 {

-	char	*fname;

 	int	c;

-	int	error = 0;

 	int	fd;

 	int	mode = 0;

-	int	posix = 0;

+	int	dig = 0;

+	int posix = 0;

 	loff_t	length = -2LL;

 	loff_t	offset = 0;

 	static const struct option longopts[] = {

-	    { "help",      0, 0, 'h' },

-	    { "version",   0, 0, 'V' },

-	    { "keep-size", 0, 0, 'n' },

-	    { "punch-hole", 0, 0, 'p' },

-	    { "offset",    1, 0, 'o' },

-	    { "length",    1, 0, 'l' },

-	    { "posix",     0, 0, 'x' },

-	    { NULL,        0, 0, 0 }

+	    { "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 */

-		{ 'x', 'n', 'p' },

+	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;

@@ -130,29 +313,39 @@ int main(int argc, char **argv)

 	textdomain(PACKAGE);

 	atexit(close_stdout);

-	while ((c = getopt_long(argc, argv, "hVnpl:o:x", longopts, NULL)) != -1) {

+	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);

+			usage();

 			break;

-		case 'V':

-			printf(UTIL_LINUX_VERSION);

-			return EXIT_SUCCESS;

-		case 'p':

-			mode |= FALLOC_FL_PUNCH_HOLE;

-			/* fall through */

-		case 'n':

-			mode |= FALLOC_FL_KEEP_SIZE;

+		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;

@@ -160,53 +353,59 @@ int main(int argc, char **argv)

 #else

 			errx(EXIT_FAILURE, _("posix_fallocate support is not compiled"))

 #endif

-		default:

-			usage(stderr);

+		case 'v':

+			verbose++;

 			break;

+		case 'V':

+			printf(UTIL_LINUX_VERSION);

+			return EXIT_SUCCESS;

+		default:

+			errtryhelp(EXIT_FAILURE);

 		}

 	}

-	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"));

 	if (optind == argc)

-		errx(EXIT_FAILURE, _("no filename specified."));

+		errx(EXIT_FAILURE, _("no filename specified"));

+

+	filename = argv[optind++];

-	fname = argv[optind++];

+	if (optind != argc)

+		errx(EXIT_FAILURE, _("unexpected number of arguments"));

-	if (optind != argc) {

-		warnx(_("unexpected number of arguments"));

-		usage(stderr);

+	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"));

-	fd = open(fname, O_WRONLY|O_CREAT, 0644);

+	/* O_CREAT makes sense only for the default fallocate(2) behavior

+	 * when mode is no specified and new space is allocated

+	 *

+	 * RHEL7.6: for backward compatibility in RHEL7 we keep O_CREAT there.

+	 */

+	fd = open(filename, O_RDWR | O_CREAT,

+		  S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);

 	if (fd < 0)

-		err(EXIT_FAILURE, _("cannot open %s"), fname);

+		err(EXIT_FAILURE, _("cannot open %s"), filename);

+	if (dig)

+		dig_holes(fd, offset, length);

 #ifdef HAVE_POSIX_FALLOCATE

-	if (posix)

+	else if (posix)

 		xposix_fallocate(fd, offset, length);

-	else

 #endif

-

-#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,

-				_("keep size mode (-n option) unsupported"));

-		err(EXIT_FAILURE, _("%s: fallocate failed"), fname);

-	}

+	else

+		xfallocate(fd, mode, offset, length);

 	close(fd);

 	return EXIT_SUCCESS;

-- 

2.14.4