From 6851254fdf85ba3c3cd5c16d5cfb3bd452b5993f Mon Sep 17 00:00:00 2001
From: Arvid Norberg <arvid@libtorrent.org>
Date: Sun, 11 Apr 2010 00:48:48 +0000
Subject: [PATCH] fixed FIEMAP support on linux

---
 ChangeLog                       |  1 +
 examples/fragmentation_test.cpp | 19 +++++++++++++++++--
 src/file.cpp                    |  5 +++--
 3 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 98eb266ad..8714ba8dc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -26,6 +26,7 @@
 	  incoming connection
 	* added more detailed instrumentation of the disk I/O thread
 
+	* fixed FIEMAP support on linux
 	* fixed strict aliasing warning on gcc
 	* fixed inconsistency when creating torrents with symlinks
 	* properly detect windows version to initialize half-open connection limit
diff --git a/examples/fragmentation_test.cpp b/examples/fragmentation_test.cpp
index 6152da71e..cbcf33001 100644
--- a/examples/fragmentation_test.cpp
+++ b/examples/fragmentation_test.cpp
@@ -41,12 +41,27 @@ using namespace libtorrent;
 
 int main(int argc, char const* argv[])
 {
-	if (argc != 3)
+	if (argc != 3 && argc != 2)
 	{
-		fprintf(stderr, "Usage: fragmentation_test torrent-file file-storage-path\n");
+		fprintf(stderr, "Usage: fragmentation_test torrent-file file-storage-path\n"
+			"       fragmentation_test file\n\n");
 		return 1;
 	}
 
+	if (argc == 2)
+	{
+		error_code ec;
+		file f(argv[1], file::read_only, ec);
+		if (ec)
+		{
+			fprintf(stderr, "Error opening file %s: %s\n", argv[1], ec.message().c_str());
+			return 1;
+		}
+		size_type off = f.phys_offset(0);
+		printf("physical offset of file %s: %" PRId64 "\n", argv[1], off);
+		return 0;
+	}
+
 	error_code ec;
 	boost::intrusive_ptr<torrent_info> ti(new torrent_info(argv[1], ec));
 
diff --git a/src/file.cpp b/src/file.cpp
index b66b23293..13c7f4f8a 100644
--- a/src/file.cpp
+++ b/src/file.cpp
@@ -73,7 +73,8 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #include <sys/ioctl.h>
 #ifdef HAVE_LINUX_FIEMAP_H
-#include <linux/fiemap.h>
+#include <linux/fiemap.h> // FIEMAP_*
+#include <linux/fs.h>  // FS_IOC_FIEMAP
 #endif
 
 #include <asm/unistd.h> // For __NR_fallocate
@@ -1394,7 +1395,7 @@ namespace libtorrent
 
 	size_type file::phys_offset(size_type offset)
 	{
-#ifdef FS_IOC_FIEMAP
+#ifdef FIEMAP_EXTENT_UNKNOWN
 		// for documentation of this feature
 		// http://lwn.net/Articles/297696/
 		struct