From c1da94fa44e60c93e3896b087680e905116d69b3 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Fri, 6 Oct 2023 20:53:17 +0100 Subject: [PATCH] UPSTREAM: mm: handle read faults under the VMA lock Most file-backed faults are already handled through ->map_pages(), but if we need to do I/O we'll come this way. Since filemap_fault() is now safe to be called under the VMA lock, we can handle these faults under the VMA lock now. Link: https://lkml.kernel.org/r/20231006195318.4087158-6-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Suren Baghdasaryan Signed-off-by: Andrew Morton (cherry picked from commit 12214eba1992642eee5813a9cc9f626e5b2d1815) Bug: 293665307 Change-Id: Iee48af98b866d88d88ec01143eb26389ab373b6b Signed-off-by: Suren Baghdasaryan --- mm/memory.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index cc0a95fc14b2..ddebfa1457f4 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4651,10 +4651,9 @@ static vm_fault_t do_read_fault(struct vm_fault *vmf) return ret; } - if (vmf->flags & FAULT_FLAG_VMA_LOCK) { - vma_end_read(vmf->vma); - return VM_FAULT_RETRY; - } + ret = vmf_can_call_fault(vmf); + if (ret) + return ret; ret = __do_fault(vmf); if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))