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 B56A9346A18; Thu, 2 Jul 2026 16:44:10 +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=1783010651; cv=none; b=kvKLGBy6Sg9mSwQarVbY/Zy4ou41SmJido6XqquneYSTGlSxE7OXgQLXLl/6hatR3iVXkHU8OJdFgfmTveozzXaOozcbKpJyGyX4bgxDsjWzDW0W9uKqh4D+S1stZHRFZvMHxlUq1vi2n4UKuvqIlYSty287Xsfjw1nP9j8QQ5w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783010651; c=relaxed/simple; bh=2vSyNPBGEGjdwUzqZ5QkoroVMP8KWtk1vnVj5qV621Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Y1aHetcw2UEkd2XOYDmL9O4c4RFnVtOSCrWzYWrOTgcgExK1hdDTPeLNSqUy3CpjRcyda+SL8THN+JiO0SNmR6akjEfYS/D1f8d2AvTIqijxNn3Wbc5IvtkzjEQIcNy8qrP3XpiiiMdepPAO4lm4rZ1o4o/zGpztBBPnxkvGHiw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=lFYw/ot0; 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="lFYw/ot0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 277B91F000E9; Thu, 2 Jul 2026 16:44:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1783010650; bh=8LRK5cKpAMNkCEPTu7Xz1glu3fBEp6WtsTKcqgienHc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=lFYw/ot014YKt9HBXjPSJD/oB1ym6MmTYY+pX6bQ0FNt1sCC4jYmrJ97rQ4Unf8VP iGx6cNmSaBdmQPC9QBNdu/d5dINahwTNhLYynw+4JZFEDnzszzaVi+NKJRS9QsNECm BtsnGJv9rukVN1RnsmB3ik8/BW+/GTMgXWxvX0kM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chris Mason , Jeff Layton , Chuck Lever Subject: [PATCH 6.12 189/204] nfsd: reset write verifier on deferred writeback errors Date: Thu, 2 Jul 2026 18:20:46 +0200 Message-ID: <20260702155122.620868715@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260702155118.667618796@linuxfoundation.org> References: <20260702155118.667618796@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeff Layton commit 2090b05803faab8a9fa62fbff871007862cac1b7 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/vfs.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1203,8 +1203,10 @@ nfsd_vfs_write(struct svc_rqst *rqstp, s 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); @@ -1370,6 +1372,8 @@ nfsd_commit(struct svc_rqst *rqstp, stru 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: