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 E318DC43334 for ; Mon, 20 Jun 2022 13:12:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343605AbiFTNM1 (ORCPT ); Mon, 20 Jun 2022 09:12:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53612 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343523AbiFTNJZ (ORCPT ); Mon, 20 Jun 2022 09:09:25 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F217E19286; Mon, 20 Jun 2022 06:04:24 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 189B26154E; Mon, 20 Jun 2022 13:00:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 054A9C3411B; Mon, 20 Jun 2022 13:00:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1655730056; bh=nRfTL5ZkQ+5mZ9EPEQF64YRRBhpq8ICgD3DAt2Fm7es=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GQ4JFhrDu+NEHHQSOFKRzvlZIVgqFYflLQcC0jXUJUbuLA5kbos5iWBW0hVcQW0sT J3wX00JZ2eqFoZivkyR/0iixOh3qf4emZLPEc6T8mJllv8VGIl1LWhNNHc9dJKylJe 2VVxSihQd1iAcRfCAQOz8LgXpAzv7hJXNxKhbMtY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Trond Myklebust , Chuck Lever , Leah Rumancik Subject: [PATCH 5.10 02/84] nfsd: Replace use of rwsem with errseq_t Date: Mon, 20 Jun 2022 14:50:25 +0200 Message-Id: <20220620124720.957926070@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220620124720.882450983@linuxfoundation.org> References: <20220620124720.882450983@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Trond Myklebust commit 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb upstream. The nfsd_file nf_rwsem is currently being used to separate file write and commit instances to ensure that we catch errors and apply them to the correct write/commit. We can improve scalability at the expense of a little accuracy (some extra false positives) by replacing the nf_rwsem with more careful use of the errseq_t mechanism to track errors across the different operations. Signed-off-by: Trond Myklebust Signed-off-by: Chuck Lever [ cel: rebased on zero-verifier fix ] Signed-off-by: Leah Rumancik Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/filecache.c | 1 - fs/nfsd/filecache.h | 1 - fs/nfsd/nfs4proc.c | 7 ++++--- fs/nfsd/vfs.c | 40 +++++++++++++++------------------------- 4 files changed, 19 insertions(+), 30 deletions(-) --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -194,7 +194,6 @@ nfsd_file_alloc(struct inode *inode, uns __set_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags); } nf->nf_mark = NULL; - init_rwsem(&nf->nf_rwsem); trace_nfsd_file_alloc(nf); } return nf; --- a/fs/nfsd/filecache.h +++ b/fs/nfsd/filecache.h @@ -46,7 +46,6 @@ struct nfsd_file { refcount_t nf_ref; unsigned char nf_may; struct nfsd_file_mark *nf_mark; - struct rw_semaphore nf_rwsem; }; int nfsd_file_cache_init(void); --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -1380,6 +1380,8 @@ static void nfsd4_init_copy_res(struct n static ssize_t _nfsd_copy_file_range(struct nfsd4_copy *copy) { + struct file *dst = copy->nf_dst->nf_file; + struct file *src = copy->nf_src->nf_file; ssize_t bytes_copied = 0; size_t bytes_total = copy->cp_count; u64 src_pos = copy->cp_src_pos; @@ -1388,9 +1390,8 @@ static ssize_t _nfsd_copy_file_range(str do { if (kthread_should_stop()) break; - bytes_copied = nfsd_copy_file_range(copy->nf_src->nf_file, - src_pos, copy->nf_dst->nf_file, dst_pos, - bytes_total); + bytes_copied = nfsd_copy_file_range(src, src_pos, dst, dst_pos, + bytes_total); if (bytes_copied <= 0) break; bytes_total -= bytes_copied; --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -535,10 +535,11 @@ __be32 nfsd4_clone_file_range(struct nfs { struct file *src = nf_src->nf_file; struct file *dst = nf_dst->nf_file; + errseq_t since; loff_t cloned; __be32 ret = 0; - down_write(&nf_dst->nf_rwsem); + since = READ_ONCE(dst->f_wb_err); cloned = vfs_clone_file_range(src, src_pos, dst, dst_pos, count, 0); if (cloned < 0) { ret = nfserrno(cloned); @@ -553,6 +554,8 @@ __be32 nfsd4_clone_file_range(struct nfs int status = vfs_fsync_range(dst, dst_pos, dst_end, 0); if (!status) + status = filemap_check_wb_err(dst->f_mapping, since); + if (!status) status = commit_inode_metadata(file_inode(src)); if (status < 0) { nfsd_reset_boot_verifier(net_generic(nf_dst->nf_net, @@ -561,7 +564,6 @@ __be32 nfsd4_clone_file_range(struct nfs } } out_err: - up_write(&nf_dst->nf_rwsem); return ret; } @@ -980,6 +982,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, s struct file *file = nf->nf_file; struct svc_export *exp; struct iov_iter iter; + errseq_t since; __be32 nfserr; int host_err; int use_wgather; @@ -1009,21 +1012,18 @@ nfsd_vfs_write(struct svc_rqst *rqstp, s flags |= RWF_SYNC; iov_iter_kvec(&iter, WRITE, vec, vlen, *cnt); + since = READ_ONCE(file->f_wb_err); if (flags & RWF_SYNC) { - down_write(&nf->nf_rwsem); host_err = vfs_iter_write(file, &iter, &pos, flags); if (host_err < 0) nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp), nfsd_net_id)); - up_write(&nf->nf_rwsem); } else { - down_read(&nf->nf_rwsem); if (verf) nfsd_copy_boot_verifier(verf, net_generic(SVC_NET(rqstp), nfsd_net_id)); host_err = vfs_iter_write(file, &iter, &pos, flags); - up_read(&nf->nf_rwsem); } if (host_err < 0) { nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp), @@ -1033,6 +1033,9 @@ nfsd_vfs_write(struct svc_rqst *rqstp, s *cnt = host_err; nfsdstats.io_write += *cnt; fsnotify_modify(file); + host_err = filemap_check_wb_err(file->f_mapping, since); + if (host_err < 0) + goto out_nfserr; if (stable && use_wgather) { host_err = wait_for_concurrent_writes(file); @@ -1113,19 +1116,6 @@ out: } #ifdef CONFIG_NFSD_V3 -static int -nfsd_filemap_write_and_wait_range(struct nfsd_file *nf, loff_t offset, - loff_t end) -{ - struct address_space *mapping = nf->nf_file->f_mapping; - int ret = filemap_fdatawrite_range(mapping, offset, end); - - if (ret) - return ret; - filemap_fdatawait_range_keep_errors(mapping, offset, end); - return 0; -} - /* * Commit all pending writes to stable storage. * @@ -1156,25 +1146,25 @@ nfsd_commit(struct svc_rqst *rqstp, stru if (err) goto out; if (EX_ISSYNC(fhp->fh_export)) { - int err2 = nfsd_filemap_write_and_wait_range(nf, offset, end); + errseq_t since = READ_ONCE(nf->nf_file->f_wb_err); + int err2; - down_write(&nf->nf_rwsem); - if (!err2) - err2 = vfs_fsync_range(nf->nf_file, offset, end, 0); + err2 = vfs_fsync_range(nf->nf_file, offset, end, 0); switch (err2) { case 0: nfsd_copy_boot_verifier(verf, net_generic(nf->nf_net, nfsd_net_id)); + err2 = filemap_check_wb_err(nf->nf_file->f_mapping, + since); break; case -EINVAL: err = nfserr_notsupp; break; default: - err = nfserrno(err2); nfsd_reset_boot_verifier(net_generic(nf->nf_net, nfsd_net_id)); } - up_write(&nf->nf_rwsem); + err = nfserrno(err2); } else nfsd_copy_boot_verifier(verf, net_generic(nf->nf_net, nfsd_net_id));