[PATCH] Swap Migration V5: PF_SWAPWRITE to allow writing to swap

Add PF_SWAPWRITE to control a processes permission to write to swap.

- Use PF_SWAPWRITE in may_write_to_queue() instead of checking for kswapd
  and pdflush

- Set PF_SWAPWRITE flag for kswapd and pdflush

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 7da33619d5d0..a74662077d60 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -895,6 +895,7 @@ do { if (atomic_dec_and_test(&(tsk)->usage)) __put_task_struct(tsk); } while(0)
 #define PF_SYNCWRITE    0x00200000      /* I am doing a sync write */
 #define PF_BORROWED_MM  0x00400000      /* I am a kthread doing use_mm */
 #define PF_RANDOMIZE    0x00800000      /* randomize virtual address space */
+#define PF_SWAPWRITE    0x01000000      /* Allowed to write to swap */
 
 /*
  * Only the _current_ task can read/write to tsk->flags, but other