From 5a98025be00746c357b68c027b95888f0fbe7d6e Mon Sep 17 00:00:00 2001
From: Lawrence D'Anna <larry@elder-gods.org>
Date: Fri, 21 Apr 2017 22:42:48 -0700
Subject: [PATCH] get proper size for raw block devices.

This will let you pass through raw block devices to the guest, like this:

"-s 5,virtio-blk,/dev/disk4"
---
 src/block_if.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/block_if.c b/src/block_if.c
index 4d5df95..60534e9 100644
--- a/src/block_if.c
+++ b/src/block_if.c
@@ -512,8 +512,20 @@ blockif_open(const char *optstr, UNUSED const char *ident)
 		// 	candelete = arg.value.i;
 		// if (ioctl(fd, DIOCGPROVIDERNAME, name) == 0)
 		// 	geom = 1;
-	} else
+	} else if (S_ISBLK(sbuf.st_mode)) {
+		uint64_t num_blocks;
+		uint32_t block_size;
+		if (ioctl(fd, DKIOCGETBLOCKSIZE, (void*)&block_size) < 0) {
+			perror("DKIOCGETBLOCKSIZE");
+		}
+		if (ioctl(fd, DKIOCGETBLOCKCOUNT, (void*)&num_blocks) < 0) {
+			perror("DKIOCGETBLOCKCOUNT");
+		}
+		size = (off_t) (num_blocks * block_size);
+		sectsz = (int) block_size;
+	} else {
 		psectsz = sbuf.st_blksize;
+	}
 
 	if (ssopt != 0) {
 		if (!powerof2(ssopt) || !powerof2(pssopt) || ssopt < 512 ||