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From: Miklos Szeredi <miklos@szeredi.hu>
Date: Fri, 17 May 2024 17:23:56 +0200
Message-ID: <CAJfpegvr9Ufqg4oe7BnL2Kjsa6M_A-LTyZ9LdvbjnG0GVN_jdw@mail.gmail.com>
Subject: Re: [PATCH] fuse: annotate potential data-race in num_background
To: Breno Leitao <leitao@debian.org>
Cc: paulmck@kernel.org, 
	"open list:FUSE: FILESYSTEM IN USERSPACE" <linux-fsdevel@vger.kernel.org>, open list <linux-kernel@vger.kernel.org>, 
	Matthew Wilcox <willy@infradead.org>
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On Mon, 13 May 2024 at 14:41, Breno Leitao <leitao@debian.org> wrote:

> That said, if the reader (fuse_readahead()) can handle possible
> corrupted data, we can mark is with data_race() annotation. Then I
> understand we don't need to mark the write with WRITE_ONCE().

Adding Willy, since the readahead code in fuse is fairly special.

I don't think it actually matters if  "fc->num_background >=
fc->congestion_threshold" returns false positive or false negative,
but I don't have a full understanding of how readahead works.

Willy, can you please look at fuse_readahead() to confirm that
breaking out of the loop is okay if (rac->ra->async_size >=
readahead_count(rac)) no mater what?

Thanks,
Miklos