From patchwork Sun Dec 19 01:38:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Trond Myklebust X-Patchwork-Id: 12686587 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 628E9C43217 for ; Sun, 19 Dec 2021 01:44:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234000AbhLSBo4 (ORCPT ); Sat, 18 Dec 2021 20:44:56 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:60862 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234021AbhLSBo4 (ORCPT ); Sat, 18 Dec 2021 20:44:56 -0500 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 8EA6760C8A for ; Sun, 19 Dec 2021 01:44:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A4A4FC36AE5; Sun, 19 Dec 2021 01:44:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1639878295; bh=0s/YrDE9wWIpyqHRdcF+SoTQu3BUO7YN1DUITLJ5H+I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=atTd80dyC0P2W98e7u1/8UqpKZFU8pzdpm0mwul3RHwncO0rAygFo2bzbjrTInE+Z XPSxiWztMuauuvUiBWTj5MEF361VoAsqnPalyb2wtvIaiRIn4U0JpNbFMKwWoxOrdO gsMwTXMNLztA8kuPo7KnS91G9FN8CY50NVVVaH9qbI2R7Sqzx6Wcji6z42+Ri2qMTM Y69mhn7AruzEoFYO8DtKdGqfWqoCajYaAdUbC1HM3vnc3KSwOGbGxWUyPyxSmTQDqW EosG7l3Z5bL8JTd55tb5K2KuhclkaPHXHIeiVo/K31FSJkpeXy65YHN/3svEwMCtSq XeYeXVZ221pEQ== From: trondmy@kernel.org To: Chuck Lever , "J. Bruce Fields" Cc: linux-nfs@vger.kernel.org Subject: [PATCH v2 08/10] nfsd: Replace use of rwsem with errseq_t Date: Sat, 18 Dec 2021 20:38:01 -0500 Message-Id: <20211219013803.324724-9-trondmy@kernel.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211219013803.324724-8-trondmy@kernel.org> References: <20211219013803.324724-1-trondmy@kernel.org> <20211219013803.324724-2-trondmy@kernel.org> <20211219013803.324724-3-trondmy@kernel.org> <20211219013803.324724-4-trondmy@kernel.org> <20211219013803.324724-5-trondmy@kernel.org> <20211219013803.324724-6-trondmy@kernel.org> <20211219013803.324724-7-trondmy@kernel.org> <20211219013803.324724-8-trondmy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Trond Myklebust 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 --- fs/nfsd/filecache.c | 1 - fs/nfsd/filecache.h | 1 - fs/nfsd/nfs4proc.c | 16 +++++++++------- fs/nfsd/vfs.c | 40 +++++++++++++++------------------------- 4 files changed, 24 insertions(+), 34 deletions(-) diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index fdf89fcf1a0c..36f5a06d1067 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -194,7 +194,6 @@ nfsd_file_alloc(struct inode *inode, unsigned int may, unsigned int hashval, __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; diff --git a/fs/nfsd/filecache.h b/fs/nfsd/filecache.h index 7872df5a0fe3..435ceab27897 100644 --- 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); diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 35f33959a083..8d2b9ad3b84a 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -1510,6 +1510,9 @@ static void nfsd4_init_copy_res(struct nfsd4_copy *copy, bool sync) 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; + errseq_t since; ssize_t bytes_copied = 0; u64 bytes_total = copy->cp_count; u64 src_pos = copy->cp_src_pos; @@ -1522,9 +1525,8 @@ static ssize_t _nfsd_copy_file_range(struct nfsd4_copy *copy) 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; @@ -1534,11 +1536,11 @@ static ssize_t _nfsd_copy_file_range(struct nfsd4_copy *copy) } while (bytes_total > 0 && !copy->cp_synchronous); /* for a non-zero asynchronous copy do a commit of data */ if (!copy->cp_synchronous && copy->cp_res.wr_bytes_written > 0) { - down_write(©->nf_dst->nf_rwsem); - status = vfs_fsync_range(copy->nf_dst->nf_file, - copy->cp_dst_pos, + since = READ_ONCE(dst->f_wb_err); + status = vfs_fsync_range(dst, copy->cp_dst_pos, copy->cp_res.wr_bytes_written, 0); - up_write(©->nf_dst->nf_rwsem); + if (!status) + status = filemap_check_wb_err(dst->f_mapping, since); if (!status) copy->committed = true; } diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 4d2964d08097..8a48bf18028c 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -530,10 +530,11 @@ __be32 nfsd4_clone_file_range(struct svc_rqst *rqstp, { 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); @@ -547,6 +548,8 @@ __be32 nfsd4_clone_file_range(struct svc_rqst *rqstp, loff_t dst_end = count ? dst_pos + count - 1 : LLONG_MAX; 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) { @@ -562,7 +565,6 @@ __be32 nfsd4_clone_file_range(struct svc_rqst *rqstp, } } out_err: - up_write(&nf_dst->nf_rwsem); return ret; } @@ -970,6 +972,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, struct super_block *sb = file_inode(file)->i_sb; struct svc_export *exp; struct iov_iter iter; + errseq_t since; __be32 nfserr; int host_err; int use_wgather; @@ -1010,21 +1013,18 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, 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), @@ -1034,6 +1034,9 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, *cnt = host_err; nfsd_stats_io_write_add(exp, *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); @@ -1114,19 +1117,6 @@ nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, } #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. * @@ -1157,25 +1147,25 @@ nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, 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));