From patchwork Tue Oct 5 16:10:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Trond Myklebust X-Patchwork-Id: 12537143 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D603C433EF for ; Tue, 5 Oct 2021 16:10:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 08CE96126A for ; Tue, 5 Oct 2021 16:10:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233975AbhJEQMg (ORCPT ); Tue, 5 Oct 2021 12:12:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:53132 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236259AbhJEQMg (ORCPT ); Tue, 5 Oct 2021 12:12:36 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 879716126A for ; Tue, 5 Oct 2021 16:10:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1633450245; bh=8FJCMBdaJcwHhmtTOPTDpez9ZiFg+Yirbda9tnIqJpQ=; h=From:To:Subject:Date:In-Reply-To:References:From; b=b2qqdGN3iLQwaAG+4n1n48Mj26FBnhP6wAgIjgZ5VVpvCavASl4vE767IMT3uzKpQ lrK0BtNm4h/OwpmDcKy9WijOANC+k0Snes2J82NndP7tEiSrn+2BwUNrwxB7LlBXZS O2/eH6nPn8ZqE0hT6Y5jx3w/9+ETCKz54boqMWKl3wzIuzW+JSVvF+VCzJaySYFPFS +2IEmH69ZVeyt14yQeACarpXrCGFhpfF7QmDCdxO0zWZZp0033dPWdN+LrQ55gcR97 Mgang+xN9jxDQMDon5Txc6RO4W7/tbyKB4ruc5XesxluYpMk9+rgRCKYEtCLyawOgc vutGwjfNCh+aQ== From: trondmy@kernel.org To: linux-nfs@vger.kernel.org Subject: [PATCH 2/2] NFS: Fix up commit deadlocks Date: Tue, 5 Oct 2021 12:10:36 -0400 Message-Id: <20211005161036.1054428-2-trondmy@kernel.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211005161036.1054428-1-trondmy@kernel.org> References: <20211005161036.1054428-1-trondmy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Trond Myklebust If O_DIRECT bumps the commit_info rpcs_out field, then that could lead to fsync() hangs. The fix is to ensure that O_DIRECT calls nfs_commit_end(). Signed-off-by: Trond Myklebust --- fs/nfs/direct.c | 2 +- fs/nfs/pnfs_nfs.c | 2 -- fs/nfs/write.c | 9 ++++++--- include/linux/nfs_fs.h | 1 + 4 files changed, 8 insertions(+), 6 deletions(-) diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 2e894fec036b..3c0335c15a73 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -620,7 +620,7 @@ static void nfs_direct_commit_complete(struct nfs_commit_data *data) nfs_unlock_and_release_request(req); } - if (atomic_dec_and_test(&cinfo.mds->rpcs_out)) + if (nfs_commit_end(cinfo.mds)) nfs_direct_write_complete(dreq); } diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c index 02bd6e83961d..316f68f96e57 100644 --- a/fs/nfs/pnfs_nfs.c +++ b/fs/nfs/pnfs_nfs.c @@ -468,7 +468,6 @@ pnfs_bucket_alloc_ds_commits(struct list_head *list, goto out_error; data->ds_commit_index = i; list_add_tail(&data->list, list); - atomic_inc(&cinfo->mds->rpcs_out); nreq++; } mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex); @@ -520,7 +519,6 @@ pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages, data->ds_commit_index = -1; list_splice_init(mds_pages, &data->pages); list_add_tail(&data->list, &list); - atomic_inc(&cinfo->mds->rpcs_out); nreq++; } diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 38f181e1343a..465220f47142 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1673,10 +1673,13 @@ static void nfs_commit_begin(struct nfs_mds_commit_info *cinfo) atomic_inc(&cinfo->rpcs_out); } -static void nfs_commit_end(struct nfs_mds_commit_info *cinfo) +bool nfs_commit_end(struct nfs_mds_commit_info *cinfo) { - if (atomic_dec_and_test(&cinfo->rpcs_out)) + if (atomic_dec_and_test(&cinfo->rpcs_out)) { wake_up_var(&cinfo->rpcs_out); + return true; + } + return false; } void nfs_commitdata_release(struct nfs_commit_data *data) @@ -1776,6 +1779,7 @@ void nfs_init_commit(struct nfs_commit_data *data, data->res.fattr = &data->fattr; data->res.verf = &data->verf; nfs_fattr_init(&data->fattr); + nfs_commit_begin(cinfo->mds); } EXPORT_SYMBOL_GPL(nfs_init_commit); @@ -1822,7 +1826,6 @@ nfs_commit_list(struct inode *inode, struct list_head *head, int how, /* Set up the argument struct */ nfs_init_commit(data, head, NULL, cinfo); - atomic_inc(&cinfo->mds->rpcs_out); if (NFS_SERVER(inode)->nfs_client->cl_minorversion) task_flags = RPC_TASK_MOVEABLE; return nfs_initiate_commit(NFS_CLIENT(inode), data, NFS_PROTO(inode), diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index 5893b986fa3b..140187b57db8 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -574,6 +574,7 @@ extern int nfs_wb_page_cancel(struct inode *inode, struct page* page); extern int nfs_commit_inode(struct inode *, int); extern struct nfs_commit_data *nfs_commitdata_alloc(bool never_fail); extern void nfs_commit_free(struct nfs_commit_data *data); +bool nfs_commit_end(struct nfs_mds_commit_info *cinfo); static inline int nfs_have_writebacks(struct inode *inode)