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From: Christoph Hellwig <hch@lst.de>
To: Qu Wenruo <quwenruo.btrfs@gmx.com>
Cc: Naohiro Aota <naohiro.aota@wdc.com>,
	linux-btrfs@vger.kernel.org, wqu@suse.com, hch@lst.de
Subject: Re: [PATCH] btrfs: fix error propagation of split bios
Date: Thu, 10 Oct 2024 09:06:20 +0200	[thread overview]
Message-ID: <20241010070620.GC6674@lst.de> (raw)
In-Reply-To: <8f76a524-aa49-46b2-aa44-33f92fcd00a5@gmx.com>

On Thu, Oct 10, 2024 at 09:41:04AM +1030, Qu Wenruo wrote:
> My bad, this is not possible.
>
> The original bio will have 1 as __bi_remaining as the initial value.
>
> So even if the cloned one is finished first, the __bi_remaining will
> only stay at 1, not reaching 0, so the original bio will not finish,
> thus impossible to free the original bio.
>
> I need to dig further deeper to find out why the NULL pointer
> dereference happens.

Yes, that was my assumption when writing this code.  So I'd love
to understand what is going on here, as it might indicate deeper
problems with the btrfs_bio lifetime.


  reply	other threads:[~2024-10-10  7:06 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-10-09 15:57 [PATCH] btrfs: fix error propagation of split bios Naohiro Aota
2024-10-09 16:59 ` David Sterba
2024-10-10  5:51   ` Naohiro Aota
2024-10-10 11:02     ` David Sterba
2024-10-09 21:38 ` Qu Wenruo
2024-10-09 21:40   ` Qu Wenruo
2024-10-09 21:58   ` Qu Wenruo
2024-10-09 23:11     ` Qu Wenruo
2024-10-10  7:06       ` Christoph Hellwig [this message]
2024-10-10  8:53         ` Naohiro Aota
2024-10-10  9:45           ` hch
2024-10-12  6:12 ` kernel test robot

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