@splice_desc.total_len is 32 bit(unsigned int) which is used to store the
size passed from userspace which is 64 bit(size_t) so that the size is
unexpectedly truncated
That causes vmsplice can not work if the size passed from userspace is >= 4G,
for example, we noticed in vmsplice, splice-reader does not do anything and
splice-writer is waiting for available buffer forever if the size is 4G
Fix it by extending @splice_desc.total_len to 64 bits as well
Signed-off-by: Xiao Guangrong <[email protected]>
---
include/linux/splice.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/linux/splice.h b/include/linux/splice.h
index 74575cb..1e85396 100644
--- a/include/linux/splice.h
+++ b/include/linux/splice.h
@@ -24,7 +24,8 @@
* Passed to the actors
*/
struct splice_desc {
- unsigned int len, total_len; /* current and remaining length */
+ size_t total_len; /* remaining length */
+ unsigned int len; /* current length */
unsigned int flags; /* splice flags */
/*
* actor() private data
--
1.8.1.4