Merge branch 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block

* 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block:
  [PATCH] splice: add ->splice_write support for /dev/null
  [PATCH] splice: rearrange moving to/from pipe helpers
  [PATCH] Add support for the sys_vmsplice syscall
  [PATCH] splice: fix offset problems
  [PATCH] splice: fix min() warning

arch/ia64/kernel/entry.S

@@ -1610,5 +1610,6 @@ sys_call_table:
 	data8 sys_get_robust_list
 	data8 sys_sync_file_range		// 1300
 	data8 sys_tee
+	data8 sys_vmsplice
 
 	.org sys_call_table + 8*NR_syscalls	// guard against failures to increase NR_syscalls

arch/powerpc/kernel/systbl.S

@@ -324,6 +324,7 @@ COMPAT_SYS(ppoll)
 SYSCALL(unshare)
 SYSCALL(splice)
 SYSCALL(tee)
+SYSCALL(vmsplice)
 
 /*
  * please add new calls to arch/powerpc/platforms/cell/spu_callbacks.c

arch/powerpc/platforms/cell/spu_callbacks.c

@@ -318,6 +318,7 @@ void *spu_syscall_table[] = {
 	[__NR_unshare]			sys_unshare,
 	[__NR_splice]			sys_splice,
 	[__NR_tee]			sys_tee,
+	[__NR_vmsplice]			sys_vmsplice,
 };
 
 long spu_sys_callback(struct spu_syscall_block *s)

drivers/char/mem.c

@@ -27,6 +27,7 @@
 #include <linux/crash_dump.h>
 #include <linux/backing-dev.h>
 #include <linux/bootmem.h>
+#include <linux/pipe_fs_i.h>
 
 #include <asm/uaccess.h>
 #include <asm/io.h>
@@ -578,6 +579,18 @@ static ssize_t write_null(struct file * file, const char __user * buf,
 	return count;
 }
 
+static int pipe_to_null(struct pipe_inode_info *info, struct pipe_buffer *buf,
+			struct splice_desc *sd)
+{
+	return sd->len;
+}
+
+static ssize_t splice_write_null(struct pipe_inode_info *pipe,struct file *out,
+				 loff_t *ppos, size_t len, unsigned int flags)
+{
+	return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null);
+}
+
 #ifdef CONFIG_MMU
 /*
  * For fun, we are using the MMU for this.
@@ -785,6 +798,7 @@ static struct file_operations null_fops = {
 	.llseek		= null_lseek,
 	.read		= read_null,
 	.write		= write_null,
+	.splice_write	= splice_write_null,
 };
 
 #if defined(CONFIG_ISA) || !defined(__mc68000__)

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

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
 

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

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
 

include/linux/pipe_fs_i.h

@@ -61,4 +61,21 @@ void __free_pipe_info(struct pipe_inode_info *);
 				 /* from/to, of course */
 #define SPLICE_F_MORE	(0x04)	/* expect more data */
 
+/*
+ * Passed to the actors
+ */
+struct splice_desc {
+	unsigned int len, total_len;	/* current and remaining length */
+	unsigned int flags;		/* splice flags */
+	struct file *file;		/* file to read/write */
+	loff_t pos;			/* file position */
+};
+
+typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,
+			   struct splice_desc *);
+
+extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *,
+				loff_t *, size_t, unsigned int,
+				splice_actor *);
+
 #endif

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,