[PATCH] splice: add support for sys_tee()
Basically an in-kernel implementation of tee, which uses splice and the
pipe buffers as an intelligent way to pass data around by reference.
Where the user space tee consumes the input and produces a stdout and
file output, this syscall merely duplicates the data inside a pipe to
another pipe. No data is copied, the output just grabs a reference to the
input pipe data.
Signed-off-by: Jens Axboe <axboe@suse.de>
diff --git a/include/asm-i386/unistd.h b/include/asm-i386/unistd.h
index 6a8dd83..d81d6cf 100644
--- a/include/asm-i386/unistd.h
+++ b/include/asm-i386/unistd.h
@@ -320,8 +320,9 @@
#define __NR_get_robust_list 312
#define __NR_splice 313
#define __NR_sync_file_range 314
+#define __NR_tee 315
-#define NR_syscalls 315
+#define NR_syscalls 316
/*
* user-visible error numbers are in the range -1 - -128: see
diff --git a/include/asm-ia64/unistd.h b/include/asm-ia64/unistd.h
index 1c749ac..a40ebec 100644
--- a/include/asm-ia64/unistd.h
+++ b/include/asm-ia64/unistd.h
@@ -289,12 +289,13 @@
#define __NR_set_robust_list 1298
#define __NR_get_robust_list 1299
#define __NR_sync_file_range 1300
+#define __NR_tee 1301
#ifdef __KERNEL__
#include <linux/config.h>
-#define NR_syscalls 277 /* length of syscall table */
+#define NR_syscalls 278 /* length of syscall table */
#define __ARCH_WANT_SYS_RT_SIGACTION
diff --git a/include/asm-powerpc/unistd.h b/include/asm-powerpc/unistd.h
index 536ba08..c612f1a 100644
--- a/include/asm-powerpc/unistd.h
+++ b/include/asm-powerpc/unistd.h
@@ -302,8 +302,9 @@
#define __NR_ppoll 281
#define __NR_unshare 282
#define __NR_splice 283
+#define __NR_tee 284
-#define __NR_syscalls 284
+#define __NR_syscalls 285
#ifdef __KERNEL__
#define __NR__exit __NR_exit
diff --git a/include/asm-x86_64/unistd.h b/include/asm-x86_64/unistd.h
index f21ff2c..d86494e 100644
--- a/include/asm-x86_64/unistd.h
+++ b/include/asm-x86_64/unistd.h
@@ -611,8 +611,10 @@
__SYSCALL(__NR_get_robust_list, sys_get_robust_list)
#define __NR_splice 275
__SYSCALL(__NR_splice, sys_splice)
+#define __NR_tee 276
+__SYSCALL(__NR_tee, sys_tee)
-#define __NR_syscall_max __NR_splice
+#define __NR_syscall_max __NR_tee
#ifndef __NO_STUBS
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index 123a7c2..ef7f33c 100644
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -21,6 +21,7 @@
void (*unmap)(struct pipe_inode_info *, struct pipe_buffer *);
void (*release)(struct pipe_inode_info *, struct pipe_buffer *);
int (*steal)(struct pipe_inode_info *, struct pipe_buffer *);
+ void (*get)(struct pipe_inode_info *, struct pipe_buffer *);
};
struct pipe_inode_info {
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index f001bad..d3ebc0e 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -574,6 +574,8 @@
int fd_out, loff_t __user *off_out,
size_t len, unsigned int flags);
+asmlinkage long sys_tee(int fdin, int fdout, size_t len, unsigned int flags);
+
asmlinkage long sys_sync_file_range(int fd, loff_t offset, loff_t nbytes,
unsigned int flags);