[PATCH] Introduce sys_splice() system call

This adds support for the sys_splice system call. Using a pipe as a
transport, it can connect to files or sockets (latter as output only).

From the splice.c comments:

   "splice": joining two ropes together by interweaving their strands.

   This is the "extended pipe" functionality, where a pipe is used as
   an arbitrary in-memory buffer. Think of a pipe as a small kernel
   buffer that you can use to transfer data from one end to the other.

   The traditional unix read/write is extended with a "splice()" operation
   that transfers data buffers to or from a pipe buffer.

   Named by Larry McVoy, original implementation from Linus, extended by
   Jens to support splicing to files and fixing the initial implementation
   bugs.

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/include/asm-x86_64/unistd.h b/include/asm-x86_64/unistd.h
index fcc516353087..f21ff2c1e960 100644
--- a/include/asm-x86_64/unistd.h
+++ b/include/asm-x86_64/unistd.h
@@ -609,8 +609,10 @@ __SYSCALL(__NR_unshare,	sys_unshare)
 __SYSCALL(__NR_set_robust_list, sys_set_robust_list)
 #define __NR_get_robust_list    274
 __SYSCALL(__NR_get_robust_list, sys_get_robust_list)
+#define __NR_splice             275
+__SYSCALL(__NR_splice, sys_splice)
 
-#define __NR_syscall_max __NR_get_robust_list
+#define __NR_syscall_max __NR_splice
 
 #ifndef __NO_STUBS