[PATCH 1/3] userfaultfd: introduce userfaultfd_init_waitqueue helper

From: Mike Rapoport
Date: Tue Feb 27 2018 - 03:20:17 EST


The helper can be used for initialization of wait queue entries for both
page-fault and non-cooperative events

Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
---
fs/userfaultfd.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index cec550c8468f..b32c7aaeca6b 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -131,6 +131,15 @@ static int userfaultfd_wake_function(wait_queue_entry_t *wq, unsigned mode,
return ret;
}

+static inline void userfaultfd_init_waitqueue(struct userfaultfd_ctx *ctx,
+ struct userfaultfd_wait_queue *uwq)
+{
+ init_waitqueue_func_entry(&uwq->wq, userfaultfd_wake_function);
+ uwq->wq.private = current;
+ uwq->ctx = ctx;
+ uwq->waken = false;
+}
+
/**
* userfaultfd_ctx_get - Acquires a reference to the internal userfaultfd
* context.
@@ -444,12 +453,9 @@ int handle_userfault(struct vm_fault *vmf, unsigned long reason)
/* take the reference before dropping the mmap_sem */
userfaultfd_ctx_get(ctx);

- init_waitqueue_func_entry(&uwq.wq, userfaultfd_wake_function);
- uwq.wq.private = current;
+ userfaultfd_init_waitqueue(ctx, &uwq);
uwq.msg = userfault_msg(vmf->address, vmf->flags, reason,
ctx->features);
- uwq.ctx = ctx;
- uwq.waken = false;

return_to_userland =
(vmf->flags & (FAULT_FLAG_USER|FAULT_FLAG_KILLABLE)) ==
--
2.7.4