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 26E9B33EB13 for ; Tue, 24 Feb 2026 21:44:23 +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=1771969463; cv=none; b=KunTrTiYCaSJJUQ19IFtoYuB1UU+6vGpsVEUTRqWTTf40WpHyil4TGlUrJ9PGqcvPkGEvy46IvNg6vDqVSsNByns924M4UCgGrs3Fp8uoIRNprhXTZJEButSKe0C7gBsqnYh8NksF+Keem0+heBP/Jwk5A43O5FGgBJZo/mQED4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771969463; c=relaxed/simple; bh=HQGjEjK3/s+ITeIII/nW/HfBbGRKRyxW0VRolZAxm8Q=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=DBltR3hkC7eoNjccrRF2tQYCFPppm2YIkewRIVzlH4XYu5VaSZIaB1keHuJMHYCRnToAi1uJLNPUcYcWRGpYkYhuqrhbk7Hfxj+trVWTms1y0n/HsyJU5F1BxAedKGeZsyypcpVI6UN0rBpi6k6gcyIK4xmyRW0KKyvSeYefK7U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1jebTk5w; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="1jebTk5w" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CC061C2BC87; Tue, 24 Feb 2026 21:44:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1771969463; bh=HQGjEjK3/s+ITeIII/nW/HfBbGRKRyxW0VRolZAxm8Q=; h=Subject:To:Cc:From:Date:From; b=1jebTk5wQvuunWNAgdL9CTDo51Roo3rUX+EYM5tC+qZxx4eMWUNyiOQoqxhQ2tSDB rVd5pDQKIywvZOl0CqGsaZarKoQmgpkv/GboAmN7NryqLT96oQ1OYSq8wwHJ43gb7u YmnuDUon37J/9GJwf15OIBb5nciGb5kIFzAgQlwo= Subject: FAILED: patch "[PATCH] ext4: drop extent cache after doing PARTIAL_VALID1 zeroout" failed to apply to 5.15-stable tree To: yi.zhang@huawei.com,libaokun1@huawei.com,ojaswin@linux.ibm.com,tytso@mit.edu Cc: From: Date: Tue, 24 Feb 2026 13:44:16 -0800 Message-ID: <2026022416-dropbox-consonant-4deb@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=ANSI_X3.4-1968 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 6d882ea3b0931b43530d44149b79fcd4ffc13030 # git commit -s git send-email --to '' --in-reply-to '2026022416-dropbox-consonant-4deb@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ 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 diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index be9fd2ab8667..1094e4923451 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);