From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Josef Bacik To: kernel-team@fb.com, linux-kernel@vger.kernel.org, hannes@cmpxchg.org, tj@kernel.org, linux-fsdevel@vger.kernel.org, akpm@linux-foundation.org, riel@redhat.com, linux-mm@kvack.org, linux-btrfs@vger.kernel.org Subject: [PATCH 8/9] mm: allow ->page_mkwrite to do retries Date: Wed, 26 Sep 2018 17:08:55 -0400 Message-Id: <20180926210856.7895-9-josef@toxicpanda.com> In-Reply-To: <20180926210856.7895-1-josef@toxicpanda.com> References: <20180926210856.7895-1-josef@toxicpanda.com> Sender: owner-linux-mm@kvack.org List-ID: Before we didn't set the retry flag on our vm_fault. We want to allow file systems to drop the mmap_sem if they so choose, so set this flag and deal with VM_FAULT_RETRY appropriately. Signed-off-by: Josef Bacik --- mm/memory.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 6f8abde84986..821435855177 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2384,11 +2384,13 @@ static vm_fault_t do_page_mkwrite(struct vm_fault *vmf) unsigned int old_flags = vmf->flags; vmf->flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE; + vmf->flags |= old_flags & FAULT_FLAG_ALLOW_RETRY; ret = vmf->vma->vm_ops->page_mkwrite(vmf); /* Restore original flags so that caller is not surprised */ vmf->flags = old_flags; - if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE))) + if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | + VM_FAULT_RETRY))) return ret; if (unlikely(!(ret & VM_FAULT_LOCKED))) { lock_page(page); @@ -2683,7 +2685,8 @@ static vm_fault_t wp_page_shared(struct vm_fault *vmf) pte_unmap_unlock(vmf->pte, vmf->ptl); tmp = do_page_mkwrite(vmf); if (unlikely(!tmp || (tmp & - (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) { + (VM_FAULT_ERROR | VM_FAULT_NOPAGE | + VM_FAULT_RETRY)))) { put_page(vmf->page); return tmp; } @@ -3716,7 +3719,8 @@ static vm_fault_t do_shared_fault(struct vm_fault *vmf) unlock_page(vmf->page); tmp = do_page_mkwrite(vmf); if (unlikely(!tmp || - (tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) { + (tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | + VM_FAULT_RETRY)))) { put_page(vmf->page); return tmp; } -- 2.14.3