From: Wouter Verhelst <w@uter.be>
Date: Mon, 8 Jun 2009 21:02:29 +0000 (+0200)
Subject: Fix autodetection
X-Git-Url: http://git.alex.org.uk

Fix autodetection

Everything else in nbd-server was already 64bit-clean, but this part,
where the size of a block device is autodected, wasn't.

Replace the ioctl() to BLKGETSIZE with its 64bit version, so that trying
to detect the size of a multi-terabyte block device does not fail.
---

diff --git a/nbd-server.c b/nbd-server.c
index 4ac6d1f..4426345 100644
--- a/nbd-server.c
+++ b/nbd-server.c
@@ -770,19 +770,18 @@ void sigterm_handler(int s) {
  **/
 off_t size_autodetect(int fhandle) {
 	off_t es;
-	unsigned long sectors;
+	u64 bytes;
 	struct stat stat_buf;
 	int error;
 
 #ifdef HAVE_SYS_MOUNT_H
 #ifdef HAVE_SYS_IOCTL_H
-#ifdef BLKGETSIZE
-	DEBUG("looking for export size with ioctl BLKGETSIZE\n");
-	if (!ioctl(fhandle, BLKGETSIZE, &sectors) && sectors) {
-		es = (off_t)sectors * (off_t)512;
-		return es;
+#ifdef BLKGETSIZE64
+	DEBUG("looking for export size with ioctl BLKGETSIZE64\n");
+	if (!ioctl(fhandle, BLKGETSIZE64, bytes) && bytes) {
+		return (off_t)bytes;
 	}
-#endif /* BLKGETSIZE */
+#endif /* BLKGETSIZE64 */
 #endif /* HAVE_SYS_IOCTL_H */
 #endif /* HAVE_SYS_MOUNT_H */