From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B3148E94114 for ; Fri, 6 Oct 2023 20:15:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233390AbjJFUPL (ORCPT ); Fri, 6 Oct 2023 16:15:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50448 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233167AbjJFUPJ (ORCPT ); Fri, 6 Oct 2023 16:15:09 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E823CBF for ; Fri, 6 Oct 2023 13:15:07 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 226DFC433C9; Fri, 6 Oct 2023 20:15:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1696623307; bh=Sz8jb7z7RHRBRPEGw7ORbresLyrUiohwi3cDhNeH/hk=; h=Date:To:From:Subject:From; b=YrHvI1+ZCxUwKL9r3zyTWog2uxES2hMxGWeTlIZH3p5k/1YIczUCi6wCg6M2lqgGO M3E0HIk7Nz4uIkjacQGidurfqTASbpg0uGhAASfn/WFwhVRbSlJ8FHjoV7qWg419gC P2yNoeh4/kkk3+/q4fS39jTFwHI7ONX0EMy2IsYQ= Date: Fri, 06 Oct 2023 13:15:04 -0700 To: mm-commits@vger.kernel.org, surenb@google.com, willy@infradead.org, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-handle-write-faults-to-ro-pages-under-the-vma-lock.patch added to mm-unstable branch Message-Id: <20231006201507.226DFC433C9@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm: handle write faults to RO pages under the VMA lock has been added to the -mm mm-unstable branch. Its filename is mm-handle-write-faults-to-ro-pages-under-the-vma-lock.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-handle-write-faults-to-ro-pages-under-the-vma-lock.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: "Matthew Wilcox (Oracle)" Subject: mm: handle write faults to RO pages under the VMA lock Date: Fri, 6 Oct 2023 20:53:18 +0100 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. Link: https://lkml.kernel.org/r/20231006195318.4087158-7-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton --- mm/memory.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) --- a/mm/memory.c~mm-handle-write-faults-to-ro-pages-under-the-vma-lock +++ a/mm/memory.c @@ -3304,10 +3304,9 @@ static vm_fault_t wp_pfn_shared(struct v 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); @@ -3331,10 +3330,10 @@ static vm_fault_t wp_page_shared(struct 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); _ Patches currently in -mm which might be from willy@infradead.org are mm-make-lock_folio_maybe_drop_mmap-vma-lock-aware.patch mm-call-wp_page_copy-under-the-vma-lock.patch mm-handle-shared-faults-under-the-vma-lock.patch mm-handle-cow-faults-under-the-vma-lock.patch mm-handle-read-faults-under-the-vma-lock.patch mm-handle-write-faults-to-ro-pages-under-the-vma-lock.patch iomap-hold-state_lock-over-call-to-ifs_set_range_uptodate.patch iomap-protect-read_bytes_pending-with-the-state_lock.patch mm-add-folio_end_read.patch ext4-use-folio_end_read.patch buffer-use-folio_end_read.patch iomap-use-folio_end_read.patch bitops-add-xor_unlock_is_negative_byte.patch alpha-implement-xor_unlock_is_negative_byte.patch m68k-implement-xor_unlock_is_negative_byte.patch mips-implement-xor_unlock_is_negative_byte.patch powerpc-implement-arch_xor_unlock_is_negative_byte-on-32-bit.patch riscv-implement-xor_unlock_is_negative_byte.patch s390-implement-arch_xor_unlock_is_negative_byte.patch mm-delete-checks-for-xor_unlock_is_negative_byte.patch mm-add-folio_xor_flags_has_waiters.patch mm-make-__end_folio_writeback-return-void.patch mm-use-folio_xor_flags_has_waiters-in-folio_end_writeback.patch