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Date: Mon, 25 Mar 2024 02:06:22 +0100
From: Christoph Hellwig <hch@lst.de>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jan Kara <jack@suse.cz>, Yu Kuai <yukuai1@huaweicloud.com>,
	Christoph Hellwig <hch@lst.de>, brauner@kernel.org, axboe@kernel.dk,
	linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
	yi.zhang@huawei.com, yangerkun@huawei.com,
	"yukuai (C)" <yukuai3@huawei.com>
Subject: Re: [RFC v4 linux-next 19/19] fs & block: remove bdev->bd_inode
Message-ID: <20240325010622.GA23670@lst.de>
References: <20240317213847.GD10665@lst.de> <022204e6-c387-b4b2-5982-970fd1ed5b5b@huaweicloud.com> <20240318013208.GA23711@lst.de> <5c231b60-a2bf-383e-e641-371e7e57da67@huaweicloud.com> <ea4774db-188e-6744-6a5b-0096f6206112@huaweicloud.com> <20240318232245.GA17831@lst.de> <c62dac0e-666f-9cc9-cffe-f3d985029d6a@huaweicloud.com> <20240322063346.GB3404528@ZenIV> <20240322131030.pxbvtubien2t27zw@quack3> <20240322145728.GN538574@ZenIV>
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On Fri, Mar 22, 2024 at 02:57:28PM +0000, Al Viro wrote:
> What WRITE_ONE()?  We really shouldn't modify it without ->open_mutex; do
> we ever do that?  In current mainline:

READ_ONCE must be paired with WRITE_ONCE.  All updates are under a lock,
and if you want some other scheme than the atomic_t go ahead.  I original
did READ_ONCE/WRITE_ONCE and this was changed based on review feedback.