diff mbox series

[v3,06/10] mm: Move FAULT_FLAG_VMA_LOCK check down in handle_pte_fault()

Message ID 20230724185410.1124082-7-willy@infradead.org (mailing list archive)
State New, archived
Headers show
Series Handle most file-backed faults under the VMA lock | expand

Commit Message

Matthew Wilcox July 24, 2023, 6:54 p.m. UTC 
Call do_pte_missing() under the VMA lock ... then immediately retry
in do_fault().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
---
 mm/memory.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/mm/memory.c b/mm/memory.c
index 9e4dd65e06ac..11b337876477 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4775,6 +4775,11 @@  static vm_fault_t do_fault(struct vm_fault *vmf)
 	struct mm_struct *vm_mm = vma->vm_mm;
 	vm_fault_t ret;
 
+	if (vmf->flags & FAULT_FLAG_VMA_LOCK){
+		vma_end_read(vma);
+		return VM_FAULT_RETRY;
+	}
+
 	/*
 	 * The VMA was not fully populated on mmap() or missing VM_DONTEXPAND
 	 */
@@ -5060,11 +5065,6 @@  static vm_fault_t handle_pte_fault(struct vm_fault *vmf)
 {
 	pte_t entry;
 
-	if ((vmf->flags & FAULT_FLAG_VMA_LOCK) && !vma_is_anonymous(vmf->vma)) {
-		vma_end_read(vmf->vma);
-		return VM_FAULT_RETRY;
-	}
-
 	if (unlikely(pmd_none(*vmf->pmd))) {
 		/*
 		 * Leave __pte_alloc() until later: because vm_ops->fault may
@@ -5097,6 +5097,12 @@  static vm_fault_t handle_pte_fault(struct vm_fault *vmf)
 	if (!vmf->pte)
 		return do_pte_missing(vmf);
 
+	if ((vmf->flags & FAULT_FLAG_VMA_LOCK) && !vma_is_anonymous(vmf->vma)) {
+		pte_unmap(vmf->pte);
+		vma_end_read(vmf->vma);
+		return VM_FAULT_RETRY;
+	}
+
 	if (!pte_present(vmf->orig_pte))
 		return do_swap_page(vmf);