From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 40D222D8780; Sun, 1 Mar 2026 01:33:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772328785; cv=none; b=CAxkAI7DIaucZ51JDohqC8RPXhBwsEqGYp4OaDKu6ZRCxHi1EnAU96GfNGrsfhP2IWecRjUzFPOAGLIDbQAdRVEeHWh48Nwsgpxh32v8VTlkDvUKssSLG9xgJH8UPrReIvuUTjB6nJ2ZX8YXqlm2/nlTseEs2or2IlncfsSIAdM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772328785; c=relaxed/simple; bh=P9V//pMvW5aLiUoXIAYNn/4cAlV+2ge8y7BF94/J5pU=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=YAmFU5wFRH9u1iVKitghUfjUpPcQIY8df5DTv9YM/ScXiVQ1rcfvJ+qHQVE9b2+8Hh07Qtg/DR8LzAVdzpWtbsMNfhGokcHTYRkoohjB4GGNuMp3O5LzuwKHnMvag45Ztpo61EFifYLpUaCEcmGUNYS7WjBboBSYDMb16xa+kB8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TpU5E+LM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TpU5E+LM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 626FBC19421; Sun, 1 Mar 2026 01:33:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772328785; bh=P9V//pMvW5aLiUoXIAYNn/4cAlV+2ge8y7BF94/J5pU=; h=From:To:Cc:Subject:Date:From; b=TpU5E+LMeMp3yRR+2ZExaF7wvlusvcmMKslvYN94ap2r0X0FSonGbj5xGMSaCfNOz zWjIWijb+/43oDOO/iPwMGbimaP7BOeAnZ+L64PD8ekqUFFJIQTEWCCN5UJGDbMxJE WgeUa0EMnyo8HLMpSQcys7ughwVRDeoldTiemVOvYLsGAq7CUQPCAffTkMk5gJeXSG FcFa8ooSfzRS2Q4kPEgDGM9Knq/vnCgfe7pY0IZXdWsj4ZVzWsA929FG31ITJZv6vL m+8cGZYRJ8KzOqT4CRG+8jP3xUmUFnMSq5y3ZokkzCNwcHGzSQZ+uwQFe9wBdT5SdH KMUC2+52SJT4Q== From: Sasha Levin To: stable@vger.kernel.org, yi.zhang@huawei.com Cc: Baokun Li , stable@kernel.org, Ojaswin Mujoo , Theodore Ts'o , linux-ext4@vger.kernel.org Subject: FAILED: Patch "ext4: drop extent cache after doing PARTIAL_VALID1 zeroout" failed to apply to 6.6-stable tree Date: Sat, 28 Feb 2026 20:33:03 -0500 Message-ID: <20260301013303.1692208-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Hint: ignore X-stable: review Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-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 . Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 6d882ea3b0931b43530d44149b79fcd4ffc13030 Mon Sep 17 00:00:00 2001 From: Zhang Yi Date: Sat, 29 Nov 2025 18:32:38 +0800 Subject: [PATCH] ext4: drop extent cache after doing PARTIAL_VALID1 zeroout When splitting an unwritten extent in the middle and converting it to initialized in ext4_split_extent() with the EXT4_EXT_MAY_ZEROOUT and EXT4_EXT_DATA_VALID2 flags set, it could leave a stale unwritten extent. Assume we have an unwritten file and buffered write in the middle of it without dioread_nolock enabled, it will allocate blocks as written extent. 0 A B N [UUUUUUUUUUUU] on-disk extent U: unwritten extent [UUUUUUUUUUUU] extent status tree [--DDDDDDDD--] D: valid data |<- ->| ----> this range needs to be initialized ext4_split_extent() first try to split this extent at B with EXT4_EXT_DATA_PARTIAL_VALID1 and EXT4_EXT_MAY_ZEROOUT flag set, but ext4_split_extent_at() failed to split this extent due to temporary lack of space. It zeroout B to N and leave the entire extent as unwritten. 0 A B N [UUUUUUUUUUUU] on-disk extent [UUUUUUUUUUUU] extent status tree [--DDDDDDDDZZ] Z: zeroed data ext4_split_extent() then try to split this extent at A with EXT4_EXT_DATA_VALID2 flag set. This time, it split successfully and leave an written extent from A to N. 0 A B N [UUWWWWWWWWWW] on-disk extent W: written extent [UUUUUUUUUUUU] extent status tree [--DDDDDDDDZZ] Finally ext4_map_create_blocks() only insert extent A to B to the extent status tree, and leave an stale unwritten extent in the status tree. 0 A B N [UUWWWWWWWWWW] on-disk extent W: written extent [UUWWWWWWWWUU] extent status tree [--DDDDDDDDZZ] Fix this issue by always cached extent status entry after zeroing out the second part. Signed-off-by: Zhang Yi Reviewed-by: Baokun Li Cc: stable@kernel.org Reviewed-by: Ojaswin Mujoo Message-ID: <20251129103247.686136-7-yi.zhang@huaweicloud.com> Signed-off-by: Theodore Ts'o --- fs/ext4/extents.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index be9fd2ab86679..1094e49234513 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3319,8 +3319,16 @@ static struct ext4_ext_path *ext4_split_extent_at(handle_t *handle, * extent length and ext4_split_extent() split will the * first half again. */ - if (split_flag & EXT4_EXT_DATA_PARTIAL_VALID1) + if (split_flag & EXT4_EXT_DATA_PARTIAL_VALID1) { + /* + * Drop extent cache to prevent stale unwritten + * extents remaining after zeroing out. + */ + ext4_es_remove_extent(inode, + le32_to_cpu(zero_ex.ee_block), + ext4_ext_get_actual_len(&zero_ex)); goto fix_extent_len; + } /* update the extent length and mark as initialized */ ex->ee_len = cpu_to_le16(ee_len); -- 2.51.0