[PATCH] Add support for the sys_vmsplice syscall

sys_splice() moves data to/from pipes with a file input/output. sys_vmsplice()
moves data to a pipe, with the input being a user address range instead.

This uses an approach suggested by Linus, where we can hold partial ranges
inside the pages[] map. Hopefully this will be useful for network
receive support as well.

Signed-off-by: Jens Axboe <axboe@suse.de>

5 files changed, 12 insertions, 4 deletions

diff --git a/include/asm-i386/unistd.h b/include/asm-i386/unistd.h
index d81d6cfc1bb4..eb4b152c82fc 100644
--- a/include/asm-i386/unistd.h
+++ b/include/asm-i386/unistd.h
@@ -321,8 +321,9 @@
 #define __NR_splice             313
 #define __NR_sync_file_range    314
 #define __NR_tee                315
+#define __NR_vmsplice           316
 
-#define NR_syscalls 316
+#define NR_syscalls 317
 
 /*
  * 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 a40ebec6aeeb..7107763168bf 100644
--- a/include/asm-ia64/unistd.h
+++ b/include/asm-ia64/unistd.h
@@ -290,12 +290,13 @@
 #define __NR_get_robust_list            1299
 #define __NR_sync_file_range            1300
 #define __NR_tee                        1301
+#define __NR_vmsplice                   1302
 
 #ifdef __KERNEL__
 
 #include <linux/config.h>
 
-#define NR_syscalls                     278 /* length of syscall table */
+#define NR_syscalls                     279 /* 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 c612f1a62772..34325e292596 100644
--- a/include/asm-powerpc/unistd.h
+++ b/include/asm-powerpc/unistd.h
@@ -303,8 +303,9 @@
 #define __NR_unshare            282
 #define __NR_splice             283
 #define __NR_tee                284
+#define __NR_vmsplice           285
 
-#define __NR_syscalls           285
+#define __NR_syscalls           286
 
 #ifdef __KERNEL__
 #define __NR__exit __NR_exit
diff --git a/include/asm-x86_64/unistd.h b/include/asm-x86_64/unistd.h
index 98c36eae567c..feb77cb8c044 100644
--- a/include/asm-x86_64/unistd.h
+++ b/include/asm-x86_64/unistd.h
@@ -615,8 +615,10 @@ __SYSCALL(__NR_splice, sys_splice)
 __SYSCALL(__NR_tee, sys_tee)
 #define __NR_sync_file_range    277
 __SYSCALL(__NR_sync_file_range, sys_sync_file_range)
+#define __NR_vmsplice           278
+__SYSCALL(__NR_vmsplice, sys_vmsplice)
 
-#define __NR_syscall_max __NR_sync_file_range
+#define __NR_syscall_max __NR_vmsplice
 
 #ifndef __NO_STUBS
 
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index d3ebc0e68b2b..3996960fc565 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -574,6 +574,9 @@ asmlinkage long sys_splice(int fd_in, loff_t __user *off_in,
                            int fd_out, loff_t __user *off_out,
                            size_t len, unsigned int flags);
 
+asmlinkage long sys_vmsplice(int fd, const struct iovec __user *iov,
+                             unsigned long nr_segs, 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,