From patchwork Fri Sep 17 02:56:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12500865 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 688A2C4332F for ; Fri, 17 Sep 2021 03:00:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A6BD61029 for ; Fri, 17 Sep 2021 03:00:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243478AbhIQDBU (ORCPT ); Thu, 16 Sep 2021 23:01:20 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]:56580 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243481AbhIQDBR (ORCPT ); Thu, 16 Sep 2021 23:01:17 -0400 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id D0018223BD; Fri, 17 Sep 2021 02:59:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1631847594; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=K2Rgi41wxZueRRJfJ3e7t139IMXGOwOFm/IW/86sxa8=; b=TN9g57JhoeeQCj56ZDT1Z5eH8c3azHNFurn6Qcu8WtVKUJyL+7juZYOKl1ThupKPKuR9Zk wrwCImtWXdb8m2WpjzERGLTMfrZEvG2PAT+/nYm6aGTE1kEUhzGQxoTgg4GRVdjak/X352 u75+NChOvjnDYseuYUWwfwRfaQ3y4LU= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1631847594; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=K2Rgi41wxZueRRJfJ3e7t139IMXGOwOFm/IW/86sxa8=; b=wTggxCx6C/rUpvp5f5bdxeTCzPFiiQYeoHK1ofO3v0pxvISag8G6Kmr6h1TGJJjXk9dWpv DMvK0w6KJxde2nCw== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 8AC2A13D0B; Fri, 17 Sep 2021 02:59:48 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id OQR+EqQERGGWMwAAMHmgww (envelope-from ); Fri, 17 Sep 2021 02:59:48 +0000 Subject: [PATCH 4/6] EXT4: remove congestion_wait from ext4_bio_write_page, and simplify From: NeilBrown To: Andrew Morton , Theodore Ts'o , Andreas Dilger , "Darrick J. Wong" , Matthew Wilcox , Mel Gorman , Michal Hocko , ". Dave Chinner" , Jonathan Corbet Cc: linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Date: Fri, 17 Sep 2021 12:56:57 +1000 Message-ID: <163184741781.29351.8660877195340279243.stgit@noble.brown> In-Reply-To: <163184698512.29351.4735492251524335974.stgit@noble.brown> References: <163184698512.29351.4735492251524335974.stgit@noble.brown> User-Agent: StGit/0.23 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org congestion_wait() is indistinguishable from schedule_timeout_uninterruptible(). It is best avoided and should be deprecated. It is not needed in ext4_bio_write_page(). There are two cases. If there are no ->io_bio yet, then it is appropriate to use __GFP_NOFAIL which does the waiting in a better place. The code already uses this flag on the second attempt. This patch changes to it always use that flag for this case. If there *are* ->io_bio (in which case the allocation was non-blocking) we submit the io and return the first case. No waiting is needed in this case. So remove the congestion_wait() call, and simplify the code so that the two cases are somewhat clearer. Remove the "if (io->io_bio)" before calling ext4_io_submit() as that test is performed internally by that function. Signed-off-by: NeilBrown --- fs/ext4/page-io.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index f038d578d8d8..3b6ece0d3ad6 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -506,7 +506,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io, * can't happen in the common case of blocksize == PAGE_SIZE. */ if (fscrypt_inode_uses_fs_layer_crypto(inode) && nr_to_submit) { - gfp_t gfp_flags = GFP_NOFS; + gfp_t gfp_flags; unsigned int enc_bytes = round_up(len, i_blocksize(inode)); /* @@ -514,21 +514,18 @@ int ext4_bio_write_page(struct ext4_io_submit *io, * a waiting mask (i.e. request guaranteed allocation) on the * first page of the bio. Otherwise it can deadlock. */ + retry_encrypt: if (io->io_bio) gfp_flags = GFP_NOWAIT | __GFP_NOWARN; - retry_encrypt: + else + gfp_flags = GFP_NOFS | __GFP_NOFAIL; bounce_page = fscrypt_encrypt_pagecache_blocks(page, enc_bytes, 0, gfp_flags); if (IS_ERR(bounce_page)) { ret = PTR_ERR(bounce_page); if (ret == -ENOMEM && (io->io_bio || wbc->sync_mode == WB_SYNC_ALL)) { - gfp_flags = GFP_NOFS; - if (io->io_bio) - ext4_io_submit(io); - else - gfp_flags |= __GFP_NOFAIL; - congestion_wait(BLK_RW_ASYNC, HZ/50); + ext4_io_submit(io); goto retry_encrypt; }