[sheepdog] [PATCH] farm: fix unalign memory alloction

[Liu Yuan]

From: Liu Yuan <tailai.ly at taobao.com>

This bug will be triggered by farm_link(), which calls retrieve_object_from_snap()
that pass the unaligned buf to misfortune farm_atomic_put().

Signed-off-by: Liu Yuan <tailai.ly at taobao.com>
---
 sheep/farm/sha1_file.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/sheep/farm/sha1_file.c b/sheep/farm/sha1_file.c
index 347c0b5..135546f 100644
--- a/sheep/farm/sha1_file.c
+++ b/sheep/farm/sha1_file.c
@@ -180,7 +180,11 @@ static void *unpack_sha1_file(void *map, unsigned long mapsize, struct sha1_file
 
 	memcpy(hdr, map, sizeof(*hdr));
 	hdr_len = sizeof(*hdr);
-	buf = xmalloc(hdr->size);
+	buf = valloc(hdr->size);
+	if (!buf) {
+		dprintf("%m\n");
+		return NULL;
+	}
 
 	memcpy(buf, (char *)map + hdr_len, mapsize - hdr_len);
 	return buf;
-- 
1.7.10.2