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 B47E833065C; Thu, 28 May 2026 20:05:12 +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=1779998713; cv=none; b=XaQslgM8WaKwgM/j+JPaZQUCbwmEjCCtl0ukjO43BVJmpUbOkB4C4yKXeM8Ox0RYoz54OSUMvBvaxTqXbD0whKaZB1LcwLa/JRkcqmbCtT8hoCmkmJAGUQ+msV4B7ZR7kouDr7i0cpXpkkE2CpbNkjkfs+JKNDCsp/+j0hK01pU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779998713; c=relaxed/simple; bh=rZi7BIY6KSq9sP+x3ZPQ6prc9h8upvnCe/ykifN9vEA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=J3w7t8KIE3B26Sb5WKIXqoCDlbR2oNrlPX/ZQ8nsJdJ0Of/5Tw4sSAR0LHCixXu7hNFdXRBH+eCUJuv+YD95w7z+3rx0e7Re7/+HVkEKyI4got76ide4XEOvMBU1CrWDjrn3TZhNfHAjMtLuHY3CxLB3FPa5xV7VlU+/5dGKQhQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=IzdDOjU5; 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="IzdDOjU5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D0F61F000E9; Thu, 28 May 2026 20:05:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779998712; bh=TrWz2AvGzVpJ0jRyFEiX52TuMClE7PYID+L/NfdGNHE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=IzdDOjU5rGj3/JyH1y6eX9qmz6HPtz0YXxKwcm348w0B8Pjd5vlD/gxpQhpBvBGwx J7MjtDNzTyUd2oigP9nUV70qCm8nV6cRraG8AZKp2llHH1K2ctTrHo3wcqIhJjXxZz bkRSeYrLvpE/8bl45JCRF5ltxMoUZ2VmQax5Wtr4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, David Howells , Marc Dionne , linux-afs@lists.infradead.org, linux-fsdevel@vger.kernel.org, Christian Brauner , Sasha Levin Subject: [PATCH 7.0 270/461] netfs, afs: Fix write skipping in dir/link writepages Date: Thu, 28 May 2026 21:46:39 +0200 Message-ID: <20260528194654.984963048@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260528194646.819809818@linuxfoundation.org> References: <20260528194646.819809818@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-Transfer-Encoding: 8bit 7.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Howells [ Upstream commit 9871938f99cc6cb266a77265491660e2375271f5 ] Fix netfs_write_single() and afs_single_writepages() to better handle a write that would be skipped due to lock contention and WB_SYNC_NONE by returning 1 from netfs_write_single() if it skipped and making afs_single_writepages() skip also. If a skip occurs, the inode must be re-marked as the VFS may have cleared the mark. This is really only theoretical for directories in netfs_write_single() as the only path to that is through afs_single_writepages() that takes the ->validate_lock around it, thereby serialising it. Fixes: 6dd80936618c ("afs: Use netfslib for directories") Signed-off-by: David Howells Link: https://patch.msgid.link/20260512123404.719402-24-dhowells@redhat.com cc: Marc Dionne cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin --- fs/afs/dir.c | 11 ++++++++++- fs/netfs/write_issue.c | 7 ++++++- 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/fs/afs/dir.c b/fs/afs/dir.c index 78caef3f13388..068a892d39c4e 100644 --- a/fs/afs/dir.c +++ b/fs/afs/dir.c @@ -2206,7 +2206,14 @@ int afs_single_writepages(struct address_space *mapping, /* Need to lock to prevent the folio queue and folios from being thrown * away. */ - down_read(&dvnode->validate_lock); + if (!down_read_trylock(&dvnode->validate_lock)) { + if (wbc->sync_mode == WB_SYNC_NONE) { + /* The VFS will have undirtied the inode. */ + netfs_single_mark_inode_dirty(&dvnode->netfs.inode); + return 0; + } + down_read(&dvnode->validate_lock); + } if (is_dir ? test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags) : @@ -2214,6 +2221,8 @@ int afs_single_writepages(struct address_space *mapping, iov_iter_folio_queue(&iter, ITER_SOURCE, dvnode->directory, 0, 0, i_size_read(&dvnode->netfs.inode)); ret = netfs_writeback_single(mapping, wbc, &iter); + if (ret == 1) + ret = 0; /* Skipped write due to lock conflict. */ } up_read(&dvnode->validate_lock); diff --git a/fs/netfs/write_issue.c b/fs/netfs/write_issue.c index 03961622996be..c03c7cc45e471 100644 --- a/fs/netfs/write_issue.c +++ b/fs/netfs/write_issue.c @@ -830,6 +830,9 @@ static int netfs_write_folio_single(struct netfs_io_request *wreq, * * Write a monolithic, non-pagecache object back to the server and/or * the cache. + * + * Return: 0 if successful; 1 if skipped due to lock conflict and WB_SYNC_NONE; + * or a negative error code. */ int netfs_writeback_single(struct address_space *mapping, struct writeback_control *wbc, @@ -846,8 +849,10 @@ int netfs_writeback_single(struct address_space *mapping, if (!mutex_trylock(&ictx->wb_lock)) { if (wbc->sync_mode == WB_SYNC_NONE) { + /* The VFS will have undirtied the inode. */ + netfs_single_mark_inode_dirty(&ictx->inode); netfs_stat(&netfs_n_wb_lock_skip); - return 0; + return 1; } netfs_stat(&netfs_n_wb_lock_wait); mutex_lock(&ictx->wb_lock); -- 2.53.0