From patchwork Wed Apr 7 01:44:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michel Lespinasse X-Patchwork-Id: 12186487 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNWANTED_LANGUAGE_BODY, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 77F7CC433B4 for ; Wed, 7 Apr 2021 01:46:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 25A20610CE for ; Wed, 7 Apr 2021 01:46:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 25A20610CE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=lespinasse.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7B9E28E0017; Tue, 6 Apr 2021 21:45:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C48238E0007; Tue, 6 Apr 2021 21:45:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 822696B0087; Tue, 6 Apr 2021 21:45:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0042.hostedemail.com [216.40.44.42]) by kanga.kvack.org (Postfix) with ESMTP id 2A9746B008A for ; Tue, 6 Apr 2021 21:45:09 -0400 (EDT) Received: from smtpin34.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id E8C8B62E8 for ; Wed, 7 Apr 2021 01:45:08 +0000 (UTC) X-FDA: 78003877896.34.3BB6C31 Received: from server.lespinasse.org (server.lespinasse.org [63.205.204.226]) by imf15.hostedemail.com (Postfix) with ESMTP id AAFACA00038D for ; Wed, 7 Apr 2021 01:45:07 +0000 (UTC) DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=lespinasse.org; i=@lespinasse.org; q=dns/txt; s=srv-11-ed; t=1617759903; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : from; bh=ju1TjADkBaEpCEmd9Uqz5VcWNno1/6nZtl53IX9hdVk=; b=/HgvOzN+4gZlXg2dAh/dfK0OJzmp3nnbAfpOyKVZoxCdy/rO8VsbHIDa7Q1uVsUm7LtGD bvH0KxRDERX19z8BQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lespinasse.org; i=@lespinasse.org; q=dns/txt; s=srv-11-rsa; t=1617759903; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : from; bh=ju1TjADkBaEpCEmd9Uqz5VcWNno1/6nZtl53IX9hdVk=; b=Rcx14jUFCUpobMRsi8OfvXrqjWZOos2yAkHdBv79ZVxOdRacMFpS8AsU3XbW3uHcixZB0 /TCi7hSxf0Z6Nynm7jE5MjAn5NeNb1Gn/QZTRkp0ETZkiK1cXV4QS0m13vSMNRHM11eblxb fSh42ACDbmP4crGwYQmmZGl0TyO87HVPSbgMucCnANko0TsXp7XbIRZ3sNlx2q7DSpjk7It 9dUw6OVWwxnTC5OfRNzODM+M75isQYJRrL/a1oFedkln0KPu80bmhZro68EOOo0NyCF3V+t PBGZA0rAdIUXBGvMRZAqO246iJzXzfXJhxoSZCEnQRoaI+mhig14LMymHUZQ== Received: from zeus.lespinasse.org (zeus.lespinasse.org [IPv6:fd00::150:0]) by server.lespinasse.org (Postfix) with ESMTPS id 5048116064D; Tue, 6 Apr 2021 18:45:03 -0700 (PDT) Received: by zeus.lespinasse.org (Postfix, from userid 1000) id 42E6D19F31E; Tue, 6 Apr 2021 18:45:03 -0700 (PDT) From: Michel Lespinasse To: Linux-MM Cc: Laurent Dufour , Peter Zijlstra , Michal Hocko , Matthew Wilcox , Rik van Riel , Paul McKenney , Andrew Morton , Suren Baghdasaryan , Joel Fernandes , Rom Lemarchand , Linux-Kernel , Michel Lespinasse Subject: [RFC PATCH 32/37] f2fs: implement speculative fault handling Date: Tue, 6 Apr 2021 18:44:57 -0700 Message-Id: <20210407014502.24091-33-michel@lespinasse.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210407014502.24091-1-michel@lespinasse.org> References: <20210407014502.24091-1-michel@lespinasse.org> MIME-Version: 1.0 X-Rspamd-Queue-Id: AAFACA00038D X-Stat-Signature: itofyocypxi9fe3i6ofpoo7q4niduw3t X-Rspamd-Server: rspam02 Received-SPF: none (lespinasse.org>: No applicable sender policy available) receiver=imf15; identity=mailfrom; envelope-from=""; helo=server.lespinasse.org; client-ip=63.205.204.226 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1617759907-434049 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: We just need to make sure f2fs_filemap_fault() doesn't block in the speculative case as it is called with an rcu read lock held. Signed-off-by: Michel Lespinasse --- fs/f2fs/file.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index d26ff2ae3f5e..c1cfdc3ec98e 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -37,7 +37,12 @@ static vm_fault_t f2fs_filemap_fault(struct vm_fault *vmf) struct inode *inode = file_inode(vmf->vma->vm_file); vm_fault_t ret; - down_read(&F2FS_I(inode)->i_mmap_sem); + if (vmf->flags & FAULT_FLAG_SPECULATIVE) { + if (!down_read_trylock(&F2FS_I(inode)->i_mmap_sem)) + return VM_FAULT_RETRY; + } else { + down_read(&F2FS_I(inode)->i_mmap_sem); + } ret = filemap_fault(vmf); up_read(&F2FS_I(inode)->i_mmap_sem); @@ -171,6 +176,7 @@ static const struct vm_operations_struct f2fs_file_vm_ops = { .fault = f2fs_filemap_fault, .map_pages = filemap_map_pages, .page_mkwrite = f2fs_vm_page_mkwrite, + .speculative = true, }; static int get_parent_ino(struct inode *inode, nid_t *pino)