From nobody Sat Oct 4 09:42:00 2025 Received: from lgeamrelo11.lge.com (lgeamrelo11.lge.com [156.147.23.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D5AF22882DC for ; Mon, 18 Aug 2025 09:28:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=156.147.23.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755509301; cv=none; b=NzfJjgX0ud/d+8MnZX+ZcT1IRhVs3mp5ygmuC8q5viXnJiS8REHqWrbMDS89O8XwEVomQU58wPKAy7ZJgq79irB9zSSiR6KJP+0Q5NFvD/FQb9PXssDbjj8YkAXGk/FZjlChwYn8TaKc4Rj39woctDZXfguKIAPi+Tz1qHObUjk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755509301; c=relaxed/simple; bh=wkxXxM55u6xiafcEX1i5/qPwViPKndBguofdjqgnuic=; h=From:To:Cc:Subject:Date:Message-Id; b=YHSgdFMBZcxk6Xh/USLbWeNovNj9SbAOLukskUq1M+begb8s+tzte3zx7a9FviTLFPaLdmCXmoK6Sj5Tx1OmSMTC9ONXIZWCMUtoKHwvG0ZaOQ2tertTzhpWQaSChofy4wJIsqzUpbun0HdtCunBk4H8mgR9JArqoCM+d+7mmJs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lge.com; spf=pass smtp.mailfrom=lge.com; arc=none smtp.client-ip=156.147.23.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lge.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lge.com Received: from unknown (HELO lgemrelse6q.lge.com) (156.147.1.121) by 156.147.23.51 with ESMTP; 18 Aug 2025 18:28:16 +0900 X-Original-SENDERIP: 156.147.1.121 X-Original-MAILFROM: chanho.min@lge.com Received: from unknown (HELO localhost.localdomain) (10.178.31.96) by 156.147.1.121 with ESMTP; 18 Aug 2025 18:28:16 +0900 X-Original-SENDERIP: 10.178.31.96 X-Original-MAILFROM: chanho.min@lge.com From: Chanho Min To: Trond Myklebust , Anna Schumaker Cc: linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Sasha Levin , Greg Kroah-Hartman , Chanho Min Subject: [PATCH] NFS: Fix up commit deadlocks Date: Mon, 18 Aug 2025 18:28:05 +0900 Message-Id: <20250818092805.38743-1-chanho.min@lge.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Trond Myklebust [ Upstream commit 133a48abf6ecc535d7eddc6da1c3e4c972445882 ] 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(). Cc: stable@vger.kernel.org # 5.4 Fixes: 723c921e7dfc ("sched/wait, fs/nfs: Convert wait_on_atomic_t() usage = to the new wait_var_event() API") Signed-off-by: Trond Myklebust [ chanho: Backports to v5.4.y ] Signed-off-by: Chanho Min Signed-off-by: Sasha Levin --- fs/nfs/direct.c | 2 +- fs/nfs/write.c | 9 ++++++--- include/linux/nfs_fs.h | 1 + 3 files changed, 8 insertions(+), 4 deletions(-) diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 0682037f972be..32dc176ea1aba 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -700,7 +700,7 @@ static void nfs_direct_commit_complete(struct nfs_commi= t_data *data) nfs_unlock_and_release_request(req); } =20 - if (atomic_dec_and_test(&cinfo.mds->rpcs_out)) + if (nfs_commit_end(cinfo.mds)) nfs_direct_write_complete(dreq); } =20 diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 10ce264a64567..c9895316fc070 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1658,10 +1658,13 @@ static void nfs_commit_begin(struct nfs_mds_commit_= info *cinfo) atomic_inc(&cinfo->rpcs_out); } =20 -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; } =20 void nfs_commitdata_release(struct nfs_commit_data *data) @@ -1756,6 +1759,7 @@ void nfs_init_commit(struct nfs_commit_data *data, data->res.fattr =3D &data->fattr; data->res.verf =3D &data->verf; nfs_fattr_init(&data->fattr); + nfs_commit_begin(cinfo->mds); } EXPORT_SYMBOL_GPL(nfs_init_commit); =20 @@ -1801,7 +1805,6 @@ nfs_commit_list(struct inode *inode, struct list_head= *head, int how, =20 /* Set up the argument struct */ nfs_init_commit(data, head, NULL, cinfo); - atomic_inc(&cinfo->mds->rpcs_out); return nfs_initiate_commit(NFS_CLIENT(inode), data, NFS_PROTO(inode), data->mds_ops, how, 0); } diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index 49cf5c855cbe5..a96b116cc9224 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -549,6 +549,7 @@ extern int nfs_wb_page_cancel(struct inode *inode, stru= ct 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); =20 static inline int nfs_have_writebacks(struct inode *inode)