From patchwork Mon Feb 7 04:46:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12736817 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D369C433EF for ; Mon, 7 Feb 2022 04:46:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AF13F6B0072; Sun, 6 Feb 2022 23:46:47 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id AA0186B0073; Sun, 6 Feb 2022 23:46:47 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 968226B0074; Sun, 6 Feb 2022 23:46:47 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 8625A6B0072 for ; Sun, 6 Feb 2022 23:46:47 -0500 (EST) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 3AFB8944CB for ; Mon, 7 Feb 2022 04:46:47 +0000 (UTC) X-FDA: 79114748454.12.4AC3B89 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by imf05.hostedemail.com (Postfix) with ESMTP id B81B3100003 for ; Mon, 7 Feb 2022 04:46:46 +0000 (UTC) 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-out2.suse.de (Postfix) with ESMTPS id 4B1AF1F37E; Mon, 7 Feb 2022 04:46:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1644209205; 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; bh=U9N4d6jiSLUN/jgU8wn+Vx5a7YFyPHoCVjyVTiQLtWo=; b=D7ClHLlXCPAnUMq8dOvwwwrzmaScoUlfNpLlP8S3SYnqtpIWp1GvKY3L1IQPtBoYiEW6PM 5jAqcWOlkakD4qjbhUmLX8EmVIZNMZy/zOHGAxZ6J6qNuD/7jguzu128xBC84FZvC0zsQH +mKe4lXZ0OsN3471M8Q8Vw/8Kn08LD0= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1644209205; 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; bh=U9N4d6jiSLUN/jgU8wn+Vx5a7YFyPHoCVjyVTiQLtWo=; b=hHkMCaHK8KlVEpuDXQEX/KtsCHk/EHsmxCbe8b1mwiiu69NFUbbVVBGfHAulbMf7Mtoe17 /WLUrlTVBvFxEqDw== 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 2F0291330E; Mon, 7 Feb 2022 04:46:41 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id L37WNTGkAGL/NAAAMHmgww (envelope-from ); Mon, 07 Feb 2022 04:46:41 +0000 Subject: [PATCH 00/21 V4] Repair SWAP-over_NFS From: NeilBrown To: Trond Myklebust , Anna Schumaker , Chuck Lever , Andrew Morton , Mark Hemment , Christoph Hellwig , David Howells Cc: linux-nfs@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Mon, 07 Feb 2022 15:46:00 +1100 Message-ID: <164420889455.29374.17958998143835612560.stgit@noble.brown> User-Agent: StGit/0.23 MIME-Version: 1.0 X-Stat-Signature: ipskt3r6w8k4imsx5gyxu7soyh5z6644 X-Rspam-User: nil Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=D7ClHLlX; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=hHkMCaHK; spf=pass (imf05.hostedemail.com: domain of neilb@suse.de designates 195.135.220.29 as permitted sender) smtp.mailfrom=neilb@suse.de; dmarc=pass (policy=none) header.from=suse.de X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: B81B3100003 X-HE-Tag: 1644209206-921909 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: This 4th version of the series address review comment, particularly tidying up "NFS: swap IO handling is slightly different for O_DIRECT IO" and collect reviewed-by etc. I've also move 3 NFS patches which depend on the MM patches to the end in case they helps maintainers land the patches in a consistent order. Those three patches might go through the NFS free after the next merge window. Original intro follows. Thanks, NeilBrown swap-over-NFS currently has a variety of problems. swap writes call generic_write_checks(), which always fails on a swap file, so it completely fails. Even without this, various deadlocks are possible - largely due to improvements in NFS memory allocation (using NOFS instead of ATOMIC) which weren't tested against swap-out. NFS is the only filesystem that has supported fs-based swap IO, and it hasn't worked for several releases, so now is a convenient time to clean up the swap-via-filesystem interfaces - we cannot break anything ! So the first few patches here clean up and improve various parts of the swap-via-filesystem code. ->activate_swap() is given a cleaner interface, a new ->swap_rw is introduced instead of burdening ->direct_IO, etc. Current swap-to-filesystem code only ever submits single-page reads and writes. These patches change that to allow multi-page IO when adjacent requests are submitted. Writes are also changed to be async rather than sync. This substantially speeds up write throughput for swap-over-NFS. Tested-by: Geert Uytterhoeven --- NeilBrown (21): MM - in merge winow MM: create new mm/swap.h header file. MM: drop swap_set_page_dirty MM: move responsibility for setting SWP_FS_OPS to ->swap_activate MM: reclaim mustn't enter FS for SWP_FS_OPS swap-space MM: introduce ->swap_rw and use it for reads from SWP_FS_OPS swap-space MM: perform async writes to SWP_FS_OPS swap-space using ->swap_rw DOC: update documentation for swap_activate and swap_rw MM: submit multipage reads for SWP_FS_OPS swap-space MM: submit multipage write for SWP_FS_OPS swap-space VFS: Add FMODE_CAN_ODIRECT file flag NFS - in merge window NFS: remove IS_SWAPFILE hack SUNRPC/call_alloc: async tasks mustn't block waiting for memory SUNRPC/auth: async tasks mustn't block waiting for memory SUNRPC/xprt: async tasks mustn't block waiting for memory SUNRPC: remove scheduling boost for "SWAPPER" tasks. NFS: discard NFS_RPC_SWAPFLAGS and RPC_TASK_ROOTCREDS SUNRPC: improve 'swap' handling: scheduling and PF_MEMALLOC NFSv4: keep state manager thread active if swap is enabled NFS - after merge window NFS: rename nfs_direct_IO and use as ->swap_rw NFS: swap IO handling is slightly different for O_DIRECT IO NFS: swap-out must always use STABLE writes. Documentation/filesystems/locking.rst | 18 +- Documentation/filesystems/vfs.rst | 17 +- drivers/block/loop.c | 4 +- fs/cifs/file.c | 7 +- fs/fcntl.c | 9 +- fs/nfs/direct.c | 67 +++++--- fs/nfs/file.c | 39 +++-- fs/nfs/nfs4_fs.h | 1 + fs/nfs/nfs4proc.c | 20 +++ fs/nfs/nfs4state.c | 39 ++++- fs/nfs/read.c | 4 - fs/nfs/write.c | 2 + fs/open.c | 9 +- fs/overlayfs/file.c | 13 +- include/linux/fs.h | 4 + include/linux/nfs_fs.h | 15 +- include/linux/nfs_xdr.h | 2 + include/linux/sunrpc/auth.h | 1 + include/linux/sunrpc/sched.h | 1 - include/linux/swap.h | 7 +- include/linux/writeback.h | 7 + include/trace/events/sunrpc.h | 1 - mm/madvise.c | 8 +- mm/memory.c | 2 +- mm/page_io.c | 237 +++++++++++++++++++------- mm/swap.h | 30 +++- mm/swap_state.c | 22 ++- mm/swapfile.c | 13 +- mm/vmscan.c | 38 +++-- net/sunrpc/auth.c | 8 +- net/sunrpc/auth_gss/auth_gss.c | 6 +- net/sunrpc/auth_unix.c | 10 +- net/sunrpc/clnt.c | 7 +- net/sunrpc/sched.c | 29 ++-- net/sunrpc/xprt.c | 19 +-- net/sunrpc/xprtrdma/transport.c | 10 +- net/sunrpc/xprtsock.c | 8 + 37 files changed, 519 insertions(+), 215 deletions(-) -- Signature