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	Thu, 12 Dec 2024 04:14:29 +0000
Date: Thu, 12 Dec 2024 04:14:29 +0000
From: Matthew Wilcox <willy@infradead.org>
To: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Theodore Ts'o <tytso@mit.edu>, Christoph Hellwig <hch@infradead.org>,
	Jens Axboe <axboe@kernel.dk>,
	caiqingfu <baicaiaichibaicai@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-ext4@vger.kernel.org, linux-block@vger.kernel.org,
	linux-fsdevel@vger.kernel.org
Subject: Re: [bugzilla:219548] the kernel crashes when storing an EXT4 file
 system in a ZRAM device
Message-ID: <Z1pjJWkheibiaWuV@casper.infradead.org>
References: <20241212035826.GH2091455@google.com>
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In-Reply-To: <20241212035826.GH2091455@google.com>

On Thu, Dec 12, 2024 at 12:58:26PM +0900, Sergey Senozhatsky wrote:
> Hi,
> 
> We've got two reports [1] [2] (could be the same person) which
> suggest that ext4 may change page content while the page is under
> write().  The particular problem here the case when ext4 is on
> the zram device.  zram compresses every page written to it, so if
> the page content can be modified concurrently with zram's compression
> then we can't really use zram with ext4.

Do you set BLK_FEAT_STABLE_WRITES on zram?