Merge tag 'v3.4-rc6' into spi/next

Linux 3.4-rc6

1 files changed, 13 insertions, 3 deletions

diff --git a/fs/aio.c b/fs/aio.c
index da887604dfc5..67a6db3e1b6f 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -93,9 +93,8 @@ static void aio_free_ring(struct kioctx *ctx)
 		put_page(info->ring_pages[i]);
 
 	if (info->mmap_size) {
-		down_write(&ctx->mm->mmap_sem);
-		do_munmap(ctx->mm, info->mmap_base, info->mmap_size);
-		up_write(&ctx->mm->mmap_sem);
+		BUG_ON(ctx->mm != current->mm);
+		vm_munmap(info->mmap_base, info->mmap_size);
 	}
 
 	if (info->ring_pages && info->ring_pages != info->internal_pages)
@@ -389,6 +388,17 @@ void exit_aio(struct mm_struct *mm)
 				"exit_aio:ioctx still alive: %d %d %d\n",
 				atomic_read(&ctx->users), ctx->dead,
 				ctx->reqs_active);
+		/*
+		 * We don't need to bother with munmap() here -
+		 * exit_mmap(mm) is coming and it'll unmap everything.
+		 * Since aio_free_ring() uses non-zero ->mmap_size
+		 * as indicator that it needs to unmap the area,
+		 * just set it to 0; aio_free_ring() is the only
+		 * place that uses ->mmap_size, so it's safe.
+		 * That way we get all munmap done to current->mm -
+		 * all other callers have ctx->mm == current->mm.
+		 */
+		ctx->ring_info.mmap_size = 0;
 		put_ioctx(ctx);
 	}
 }