Received-SPF: pass (google.com: domain of linux-ext4+bounces-261-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
From: "Theodore Ts'o" <tytso@mit.edu>
To: linux-ext4@vger.kernel.org, Baokun Li <libaokun1@huawei.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>, adilger.kernel@dilger.ca, jack@suse.cz,
        ritesh.list@gmail.com, linux-kernel@vger.kernel.org, djwong@kernel.org,
        yi.zhang@huawei.com, yangerkun@huawei.com, yukuai3@huawei.com,
        stable@kernel.org
Subject: Re: [PATCH] ext4: prevent the normalized size from exceeding EXT_MAX_BLOCKS
Date: Fri,  1 Dec 2023 09:46:55 -0500
Message-Id: <170144199127.633830.13561950566118838688.b4-ty@mit.edu>
In-Reply-To: <20231127063313.3734294-1-libaokun1@huawei.com>
References: <20231127063313.3734294-1-libaokun1@huawei.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 8bit


On Mon, 27 Nov 2023 14:33:13 +0800, Baokun Li wrote:
> For files with logical blocks close to EXT_MAX_BLOCKS, the file size
> predicted in ext4_mb_normalize_request() may exceed EXT_MAX_BLOCKS.
> This can cause some blocks to be preallocated that will not be used.
> And after [Fixes], the following issue may be triggered:
> 
> =========================================================
>  kernel BUG at fs/ext4/mballoc.c:4653!
>  Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
>  CPU: 1 PID: 2357 Comm: xfs_io 6.7.0-rc2-00195-g0f5cc96c367f
>  Hardware name: linux,dummy-virt (DT)
>  pc : ext4_mb_use_inode_pa+0x148/0x208
>  lr : ext4_mb_use_inode_pa+0x98/0x208
>  Call trace:
>   ext4_mb_use_inode_pa+0x148/0x208
>   ext4_mb_new_inode_pa+0x240/0x4a8
>   ext4_mb_use_best_found+0x1d4/0x208
>   ext4_mb_try_best_found+0xc8/0x110
>   ext4_mb_regular_allocator+0x11c/0xf48
>   ext4_mb_new_blocks+0x790/0xaa8
>   ext4_ext_map_blocks+0x7cc/0xd20
>   ext4_map_blocks+0x170/0x600
>   ext4_iomap_begin+0x1c0/0x348
> =========================================================
> 
> [...]

Applied, thanks!

[1/1] ext4: prevent the normalized size from exceeding EXT_MAX_BLOCKS
      commit: 2dcf5fde6dffb312a4bfb8ef940cea2d1f402e32

Best regards,
-- 
Theodore Ts'o <tytso@mit.edu>