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From: Hongling Zeng <zhongling0719@126.com>
To: Christoph Hellwig <hch@infradead.org>,
	 Hongling Zeng <zenghongling@kylinos.cn>
Cc: cem@kernel.org, djwong@kernel.org, hans.holmberg@wdc.com,
	 linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org,
	 stable@vger.kernel.org
Subject: Re: [PATCH] xfs: check split_sectors validity before bio_split call
Date: Wed, 29 Jul 2026 15:35:18 +0800	[thread overview]
Message-ID: <6A69AD36.1070702@126.com> (raw)
In-Reply-To: <ammjJTqoOHsW9AXJ@infradead.org>


在 2026年07月29日 14:52, Christoph Hellwig 写道:
> On Wed, Jul 29, 2026 at 02:31:17PM +0800, Hongling Zeng wrote:
>> Fix by changing the check from !split_sectors to split_sectors <= 0
>> immediately after bio_split_rw_at() and before any arithmetic operations.
>> This prevents both the negative error code propagation and the undefined
>> behavior from left-shifting negative values.
>>
>> When NULL is returned, the caller's while loop naturally terminates,
>> which is the correct behavior for "cannot split" cases.
>>
>> Fixes: 080d01c41d44f ("xfs: implement zoned garbage collection")
>> Cc: <stable@vger.kernel.org>
> Nothing can actually hit that.  It only happens for invalid flags,
> or unaligned I/O, none of which can happen for GC I/O.
>
> I think checking all cases of the return value is fine, but the fixes
> is a bit bogus, and it really is not stable material.
  Thanks for the review. Updated v2 below - removed Fixes/stable
   tags and reworded as code improvement.


      reply	other threads:[~2026-07-29  7:36 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-29  6:31 [PATCH] xfs: check split_sectors validity before bio_split call Hongling Zeng
2026-07-29  6:52 ` Christoph Hellwig
2026-07-29  7:35   ` Hongling Zeng [this message]

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