From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 A85DE4BC023 for ; Thu, 2 Jul 2026 14:01:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783000913; cv=none; b=EHphd5ovDTH8acwsoQgLJWpGBpMJkzj8r1Kq2Vxcw35jIaFYd72Uwrqi5WVfz8jqFE0uAo430V02afpMwyXrsS1VNNFcoaqRgn2WDsLZmFnSEST4siEIunDQMvRmSU9kX/Yd83k41vIsMDU5dxVkALLyb2c9oPQometpS4mxMCg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783000913; c=relaxed/simple; bh=1LJDI0RtKZ65eDXLfXYtIaFN0fYdIPELWzalpzKNiAc=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=gz6puHlU+iIVh/AutXKbJYhw3oocKKjWvjPz1gH31p4Qb4lbQO2oHzs3UevKmf8mE6Ixt6X6sLwfO1fTC5ADQr5UDzKZG/GQdQOuOUtF4tvENtmgNiXizLaJOiNpbWmwOz5Po65Ba1w/9S/H5mYA3FBG3R7ev6nzs+qUIzxS6RI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=f0KjXZnF; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="f0KjXZnF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1EF641F000E9; Thu, 2 Jul 2026 14:01:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1783000912; bh=l+PccLDerhdmr3f8/m3F1tJBtsjt7mWpIfn0OxQOkhc=; h=Subject:To:Cc:From:Date; b=f0KjXZnFIBhXJZUobkEPu4em9D0hLqxWwffLa0NSAGPAHoskEGOWjEW6V0CV4BI5x aKJiHYud/9tHJ5m+b6chIws3yIUH8/vqdIXwWnINiSsWjpbO44pmtuu5fe/YMLhdpT bs1XvAyg7lzHklc5IBLR9LFEsojf0XJpDYpgeGaA= Subject: FAILED: patch "[PATCH] nfsd: reset write verifier on deferred writeback errors" failed to apply to 5.15-stable tree To: jlayton@kernel.org,chuck.lever@oracle.com,clm@meta.com Cc: From: Date: Thu, 02 Jul 2026 15:59:04 +0200 Message-ID: <2026070204-septum-trimness-cb0f@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 2090b05803faab8a9fa62fbff871007862cac1b7 # git commit -s git send-email --to '' --in-reply-to '2026070204-septum-trimness-cb0f@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 2090b05803faab8a9fa62fbff871007862cac1b7 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 22 May 2026 12:44:19 -0400 Subject: [PATCH] nfsd: reset write verifier on deferred writeback errors MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit nfsd_vfs_write() and nfsd_commit() both call filemap_check_wb_err() to detect deferred writeback errors, but neither rotates the server's write verifier (nn->writeverf) when this check fails. Every other durable-storage-failure path in these functions calls commit_reset_write_verifier() before returning an error. The missing rotation means clients holding UNSTABLE write data under the current verifier will COMMIT, receive the unchanged verifier back, and conclude their data is durable — silently dropping data that failed writeback. This violates the UNSTABLE+COMMIT durability contract (RFC 1813 §3.3.7, RFC 8881 §18.32). Add commit_reset_write_verifier() calls at both filemap_check_wb_err() error sites, matching the pattern used by adjacent error paths in the same functions. The helper already filters -EAGAIN and -ESTALE internally, so the calls are unconditionally safe. Reported-by: Chris Mason Fixes: 555dbf1a9aac ("nfsd: Replace use of rwsem with errseq_t") Cc: stable@vger.kernel.org Assisted-by: kres:claude-opus-4-6 Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index cba473969429..7e6468bdc723 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1513,8 +1513,10 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, nfsd_stats_io_write_add(nn, exp, *cnt); fsnotify_modify(file); host_err = filemap_check_wb_err(file->f_mapping, since); - if (host_err < 0) + if (host_err < 0) { + commit_reset_write_verifier(nn, rqstp, host_err); goto out_nfserr; + } if (stable && fhp->fh_use_wgather) { host_err = wait_for_concurrent_writes(file); @@ -1694,6 +1696,8 @@ nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, nfsd_copy_write_verifier(verf, nn); err2 = filemap_check_wb_err(nf->nf_file->f_mapping, since); + if (err2 < 0) + commit_reset_write_verifier(nn, rqstp, err2); err = nfserrno(err2); break; case -EINVAL: