libext2fs: fix filesystems larger than 2GB on Windows

SetFilePointer requires the upper 32 bit of the position to be passed
separately, which the code did not do, causing the position to be
interpreted as a 32-bit value. Use SetFilePointerEx instead and pass the
entire 64-bit value.

Signed-off-by: Steffen Kieß <kiess@ki4.de>

1 files changed, 13 insertions, 5 deletions

diff --git a/lib/ext2fs/windows_io.c b/lib/ext2fs/windows_io.c
index 83aea68b6..aefef115e 100644
--- a/lib/ext2fs/windows_io.c
+++ b/lib/ext2fs/windows_io.c
@@ -154,6 +154,14 @@ static errcode_t windows_get_stats(io_channel channel, io_stats *stats)
 	return retval;
 }
 
+static LARGE_INTEGER make_large_integer(LONGLONG value)
+{
+	LARGE_INTEGER	li;
+
+	li.QuadPart = value;
+	return li;
+}
+
 /*
  * Here are the raw I/O functions
  */
@@ -174,14 +182,14 @@ static errcode_t raw_read_blk(io_channel channel,
 	location = ((ext2_loff_t) block * channel->block_size) + data->offset;
 
 	if (data->flags & IO_FLAG_FORCE_BOUNCE) {
-		if (SetFilePointer(data->handle, location, NULL, FILE_BEGIN) == INVALID_SET_FILE_POINTER) {
+		if (!SetFilePointerEx(data->handle, make_large_integer(location), NULL, FILE_BEGIN)) {
 			retval = GetLastError();
 			goto error_out;
 		}
 		goto bounce_read;
 	}
 
-	if (SetFilePointer(data->handle, location, NULL, FILE_BEGIN) == INVALID_SET_FILE_POINTER) {
+	if (!SetFilePointerEx(data->handle, make_large_integer(location), NULL, FILE_BEGIN)) {
 		retval = GetLastError();
 		goto error_out;
 	}
@@ -261,14 +269,14 @@ static errcode_t raw_write_blk(io_channel channel,
 	location = ((ext2_loff_t) block * channel->block_size) + data->offset;
 
 	if (data->flags & IO_FLAG_FORCE_BOUNCE) {
-		if (SetFilePointer(data->handle, location, NULL, FILE_BEGIN) == INVALID_SET_FILE_POINTER) {
+		if (!SetFilePointerEx(data->handle, make_large_integer(location), NULL, FILE_BEGIN)) {
 			retval = GetLastError();
 			goto error_out;
 		}
 	goto bounce_write;
 	}
 
-		if (SetFilePointer(data->handle, location, NULL, FILE_BEGIN) == INVALID_SET_FILE_POINTER) {
+		if (!SetFilePointerEx(data->handle, make_large_integer(location), NULL, FILE_BEGIN)) {
 			retval = GetLastError();
 		goto error_out;
 	}
@@ -313,7 +321,7 @@ bounce_write:
 		if (size > channel->block_size)
 			actual = channel->block_size;
 		memcpy(data->bounce, buf, actual);
-		if (SetFilePointer(data->handle, location, NULL, FILE_BEGIN) == INVALID_SET_FILE_POINTER) {
+		if (!SetFilePointerEx(data->handle, make_large_integer(location), NULL, FILE_BEGIN)) {
 			retval = GetLastError();
 			goto error_out;
 		}