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Date:   Thu, 21 Jul 2022 16:45:08 +0200
From:   David Sterba <dsterba@suse.cz>
To:     Matthew Wilcox <willy@infradead.org>
Cc:     David Sterba <dsterba@suse.com>, torvalds@linux-foundation.org,
        linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [GIT PULL] Btrfs fixes for 5.19-rc7
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 <YtLadOkHl0lDNwbM@casper.infradead.org>
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On Sat, Jul 16, 2022 at 04:34:12PM +0100, Matthew Wilcox wrote:
> On Sat, Jul 16, 2022 at 04:06:20PM +0200, David Sterba wrote:
> > Note about the xarray API:
> > 
> > The possible sleeping is documented next to xa_insert, however there's
> > no runtime check for that, like is eg. in radix_tree_preload.  The
> > context does not need to be atomic so it's not as simple as
> > 
> >   might_sleep_if(gfpflags_allow_blocking(gfp));
> > 
> > or
> > 
> >   WARN_ON_ONCE(gfpflags_allow_blocking(gfp));
> > 
> > Some kind of development time debugging/assertion aid would be nice.
> 
> Are you saying that
> https://git.infradead.org/users/willy/xarray.git/commitdiff/c195d497ca1ff673c2e6935152a0a5b6be2efdc9
> 
> is wrong?  It's been in linux-next for the last week since you drew it
> to my attention that this would be useful.

I have misinterpreted what might_sleep_if does in case it's under mutex,
it won't warn so the linked commit (adding might_alloc) should be
enough, thanks.