splice: fix unexpected size truncation

@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 means 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 <xiaoguangrong@linux.vnet.ibm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Xiao Guangrong 2014-01-27 17:07:12 -08:00 committed by Linus Torvalds
parent e7ca255236
commit 53e0ee9fc5
1 changed files with 2 additions and 1 deletions

View File

@ -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