cygutils 1.4.17-2: lssparse -H does not print hole at offset 0 if more data exists

Sat Apr 5 14:56:09 GMT 2025

On Wed, Apr 2, 2025 at 4:01 PM Christian Franke via Cygwin
<cygwin@cygwin.com> wrote:
>> Testcase for a minor issue:
>> $ > sparse_file
>> $ chattr +S sparse_file
>> $ dd if=/dev/zero bs=1M count=1 conv=sparse,notrunc of=sparse_file
> ...
> $ lssparse sparse_file # OK
>> $ lssparse -H sparse_file # OK
> Hole range[0]: offset=0x0, length=0x100000
>> $ printf X >> sparse_file
>> $ lssparse sparse_file # OK
> Data range[1]: offset=0x100000, length=0x1
>> $ lssparse -H sparse_file # Missing 'Hole range[0]'
> Data range[1]: offset=0x100000, length=0x1
>> The condition at lssparse.c:161 is never true:
>> 141 for (i=1 ;;) {
> ...
> 161 if (print_holes && (i == 0) && (data_start > 0)) {
>> Possible patch attached. Important: Not tested with other corner cases.

1. *Thanks* ... :-)
2. New version is available from
http://svn.nrubsig.org/svn/people/gisburn/code/sparsefiles/lssparse.c
3. I did these two changes (GoogleMail might ruin the whitespaces,
please use http://svn.nrubsig.org/svn/people/gisburn/code/sparsefiles/lssparse.c
for the original version):
-------- snip --------
>From ed7f138e1682b7da95d606125b81abf754653a0f Mon Sep 17 00:00:00 2001
From: Roland Mainz <roland.mainz@nrubsig.org>
Date: Sat, 5 Apr 2025 16:43:13 +0200
Subject: [PATCH 1/2] lssparse -H does not print hole at offset 0 if
more data exists
lssparse -H does not print hole at offset 0 if more data exists.
Fixes: https://cygwin.com/pipermail/cygwin/2025-April/257843.html
Reported-by: Christian Franke <Christian.Franke@t-online.de>
---
lssparse.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
index 4adb200..6fc269e 100644

--- a/lssparse.c
+++ b/lssparse.c
@@ -2,7 +2,7 @@
/*
 * MIT License
 *
- * Copyright (c) 2011-2012 Roland Mainz <roland.mainz@nrubsig.org>
+ * Copyright (c) 2011-2025 Roland Mainz <roland.mainz@nrubsig.org>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@@ -139,7 +139,8 @@ int main(int argc, char *argv[])
 * $ /cygdrive/c/Windows/system32/fsutil sparse queryrange ... #
 * output
 */
- for (i=1 ;;) {
+#define LSSPARSE_START_INDEX 1
+ for (i=LSSPARSE_START_INDEX ;;) {
 data_start = lseek(fd, offset, SEEK_DATA);
 if (data_start == -1)
 break;
@@ -159,7 +160,8 @@ int main(int argc, char *argv[])
 }
 }
- if (print_holes && (i == 0) && (data_start > 0)) {
+ if (print_holes &&
+ (i == LSSPARSE_START_INDEX) && (data_start > 0)) {
 (void)printf((pb == pb_hex)?
 "Hole range[%ld]: offset=0x%llx,\tlength=0x%llx\n":
 "Hole range[%ld]: offset=%lld,\tlength=%lld\n",
@@ -215,7 +217,7 @@ int main(int argc, char *argv[])
 (void)printf((pb == pb_hex)?
 "Hole range[%ld]: offset=0x%llx,\tlength=0x%llx\n":
 "Hole range[%ld]: offset=%lld,\tlength=%lld\n",
- (long)0,
+ (long)LSSPARSE_START_INDEX,
 (long long)0LL,
 (long long)file_size);
 }
--
2.45.1
>From 1b23534234fa58633bc96137220a9b9b32d4aa5f Mon Sep 17 00:00:00 2001
From: Roland Mainz <roland.mainz@nrubsig.org>
Date: Sat, 5 Apr 2025 16:48:36 +0200
Subject: [PATCH 2/2] lssparse usage message should print all options in
short form line
lssparse usage message should print all options in short form line.
---
lssparse.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
index 6fc269e..399ac75 100644
--- a/lssparse.c
+++ b/lssparse.c
@@ -42,7 +42,7 @@
static
void usage(const char *progname)
{
- (void)fprintf(stderr, "Usage: %s [-h] <sparse_file>\n"
+ (void)fprintf(stderr, "Usage: %s [-h] [-xdH] <sparse_file>\n"
 " -h: Display this help message\n"
 " -x: Print offsets in hexadecimal (base 16)\n"
 " -d: Print offsets in decimal (base 10)\n"
-------- snip --------
----
Bye,
Roland
-- 
 __ . . __
 (o.\ \/ /.o) roland.mainz@nrubsig.org
 \__\/\/__/ MPEG specialist, C&&JAVA&&Sun&&Unix programmer
 /O /==\ O\ TEL +49 641 3992797
 (;O/ \/ \O;)
