From: Suren Baghdasaryan <surenb@google.com>
To: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org
Subject: Re: [PATCH v2 6/6] mm: Handle write faults to RO pages under the VMA lock
Date: Sun, 8 Oct 2023 15:07:59 -0700 [thread overview]
Message-ID: <CAJuCfpFS7jyN9BJycH4ScjAN6zRZ4UQewmuhwC50xmgBREo6Tw@mail.gmail.com> (raw)
In-Reply-To: <20231006195318.4087158-7-willy@infradead.org>
On Fri, Oct 6, 2023 at 12:53 PM Matthew Wilcox (Oracle)
<willy@infradead.org> wrote:
>
> I think this is a pretty rare occurrence, but for consistency handle
> faults with the VMA lock held the same way that we handle other
> faults with the VMA lock held.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
> ---
> mm/memory.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/mm/memory.c b/mm/memory.c
> index e615afd28db2..3d1bc622e344 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -3301,10 +3301,9 @@ static vm_fault_t wp_pfn_shared(struct vm_fault *vmf)
> vm_fault_t ret;
>
> pte_unmap_unlock(vmf->pte, vmf->ptl);
> - 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;
>
> vmf->flags |= FAULT_FLAG_MKWRITE;
> ret = vma->vm_ops->pfn_mkwrite(vmf);
> @@ -3328,10 +3327,10 @@ static vm_fault_t wp_page_shared(struct vm_fault *vmf, struct folio *folio)
> vm_fault_t tmp;
>
> pte_unmap_unlock(vmf->pte, vmf->ptl);
> - if (vmf->flags & FAULT_FLAG_VMA_LOCK) {
> + tmp = vmf_can_call_fault(vmf);
> + if (tmp) {
> folio_put(folio);
> - vma_end_read(vmf->vma);
> - return VM_FAULT_RETRY;
> + return tmp;
> }
>
> tmp = do_page_mkwrite(vmf, folio);
> --
> 2.40.1
>
prev parent reply other threads:[~2023-10-08 22:08 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-06 19:53 [PATCH v2 0/6] Handle more faults under the VMA lock Matthew Wilcox (Oracle)
2023-10-06 19:53 ` [PATCH v2 1/6] mm: Make lock_folio_maybe_drop_mmap() VMA lock aware Matthew Wilcox (Oracle)
2023-10-08 21:47 ` Suren Baghdasaryan
2023-10-06 19:53 ` [PATCH v2 2/6] mm: Call wp_page_copy() under the VMA lock Matthew Wilcox (Oracle)
2023-10-08 22:00 ` Suren Baghdasaryan
2023-10-06 19:53 ` [PATCH v2 3/6] mm: Handle shared faults " Matthew Wilcox (Oracle)
2023-10-08 22:01 ` Suren Baghdasaryan
2023-10-20 13:23 ` kernel test robot
2023-10-06 19:53 ` [PATCH v2 4/6] mm: Handle COW " Matthew Wilcox (Oracle)
2023-10-08 22:05 ` Suren Baghdasaryan
2023-10-20 13:18 ` kernel test robot
2023-10-06 19:53 ` [PATCH v2 5/6] mm: Handle read " Matthew Wilcox (Oracle)
2023-10-08 22:06 ` Suren Baghdasaryan
2023-10-20 9:55 ` kernel test robot
2023-10-06 19:53 ` [PATCH v2 6/6] mm: Handle write faults to RO pages " Matthew Wilcox (Oracle)
2023-10-08 22:07 ` Suren Baghdasaryan [this message]
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