[PATCH] splice: add direct fd <-> fd splicing support
It's more efficient for sendfile() emulation. Basically we cache an
internal private pipe and just use that as the intermediate area for
pages. Direct splicing is not available from sys_splice(), it is only
meant to be used for sendfile() emulation.
Additional patch from Ingo Molnar to avoid the PIPE_BUFFERS loop at
exit for the normal fast path.
Signed-off-by: Jens Axboe <axboe@suse.de>
diff --git a/kernel/exit.c b/kernel/exit.c
index 6c2eeb8..1a9787a 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -34,6 +34,7 @@
#include <linux/mutex.h>
#include <linux/futex.h>
#include <linux/compat.h>
+#include <linux/pipe_fs_i.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
@@ -941,6 +942,9 @@
if (tsk->io_context)
exit_io_context();
+ if (tsk->splice_pipe)
+ __free_pipe_info(tsk->splice_pipe);
+
/* PF_DEAD causes final put_task_struct after we schedule. */
preempt_disable();
BUG_ON(tsk->flags & PF_DEAD);
