userfaultfd: non-cooperative: Split the find_userfault() routine

I will need one to lookup for userfaultfd_wait_queue-s in different
wait queue

Link: http://lkml.kernel.org/r/20161216144821.5183-6-aarcange@redhat.com
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Michael Rapoport <RAPOPORT@il.ibm.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Pavel Emelyanov 2017-02-22 15:42:18 -08:00 committed by Linus Torvalds
parent a94720bf82
commit 6dcc27fd39

View file

@ -522,25 +522,30 @@ static int userfaultfd_release(struct inode *inode, struct file *file)
}
/* fault_pending_wqh.lock must be hold by the caller */
static inline struct userfaultfd_wait_queue *find_userfault(
struct userfaultfd_ctx *ctx)
static inline struct userfaultfd_wait_queue *find_userfault_in(
wait_queue_head_t *wqh)
{
wait_queue_t *wq;
struct userfaultfd_wait_queue *uwq;
VM_BUG_ON(!spin_is_locked(&ctx->fault_pending_wqh.lock));
VM_BUG_ON(!spin_is_locked(&wqh->lock));
uwq = NULL;
if (!waitqueue_active(&ctx->fault_pending_wqh))
if (!waitqueue_active(wqh))
goto out;
/* walk in reverse to provide FIFO behavior to read userfaults */
wq = list_last_entry(&ctx->fault_pending_wqh.task_list,
typeof(*wq), task_list);
wq = list_last_entry(&wqh->task_list, typeof(*wq), task_list);
uwq = container_of(wq, struct userfaultfd_wait_queue, wq);
out:
return uwq;
}
static inline struct userfaultfd_wait_queue *find_userfault(
struct userfaultfd_ctx *ctx)
{
return find_userfault_in(&ctx->fault_pending_wqh);
}
static unsigned int userfaultfd_poll(struct file *file, poll_table *wait)
{
struct userfaultfd_ctx *ctx = file->private_data;