From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E3BB14AF679; Mon, 12 Oct 2026 16:38:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791823133; cv=none; b=CB9Z4lU5o2gksACyFk16/XkiqDnP0v8LngznHOmuaYaX4uXf7CT0B3C0OWbXaa2ysDVIYguya7/bAFyKXdA4uIuRnI7YCqTogBruiqLcCoWdMwXBUbqR18KxHM6RseDdvjM6moergT3GHITptKrrNrzUIRviMOm6X8ImmSfsYfA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791823133; c=relaxed/simple; bh=/mK22dta9kNjF7ZjGNr1WtxNtqsskF5mTL23V9gBXZw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kodSCRlr2X30EfEH9rbwG3EPVBhrsUGqer9QNP/vhYp5mrgYzHe7BTM4VqcYYiWZhfhlTrSHZNHKzVGO4qUDzDa/3WgO1Pd05hXLeqlpfPhCc7Mw+Yzfmw0JGtjMr6PCxuEdFHnbERbfHk9MxX6N68fxfvPIMXN0FyneZKI/RBg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PoS36Qib; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="PoS36Qib" Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id 71F8B1F0089C; Mon, 12 Oct 2026 16:38:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791823131; bh=szjcYq+EbhVJ+5lSDxxeRT3bShaf2kRoD2IGWvKJDPA=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=PoS36QibNCy6wANR4L2Qf2luYhUeNCU4kDGruG3kYtyyr9MOXSZtaicKoRM7iyNP1 kBL9ogfYAkquYe2gxoqoR5zp1rEbWm6K/MtWuY2JqFo/RXW7anLYQCRhcf6IsizknP WRyyeyPCxgZTEtFPjdNCfbgDkTuMrJGvQIuhYgwbSDl8CS1TWbZyHZMEZ1/GCHckUd fTsXc/TDd2SCdHKl3By/bzo1wLeOIXwJT9LZU1Z9EELbZWCOy9Fi4V0XTLdyq629uS 5OEer7+CPB+uVaB5xYc8t7lEQNNz+zFN68PN3hp6AY1U5Wd8ajLVGqUWeAOenRTqEE eG40W0QZWiQxQ== Date: Mon, 12 Oct 2026 09:38:51 -0700 From: "Darrick J. Wong" To: jianyungao89@gmail.com Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Jan Kara , Dan Williams , Matthew Wilcox , Alexander Viro , Christian Brauner , Brian Foster , "open list:FILESYSTEM DIRECT ACCESS (DAX)" , "open list:FILESYSTEM DIRECT ACCESS (DAX)" Subject: Re: [PATCH v2] dax: fix wrong error code returned from dax_dedupe_file_range_compare() Message-ID: <20261012163851.GU1615495@frogsfrogsfrogs> References: <20261012144925.6728-1-jianyungao89@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261012144925.6728-1-jianyungao89@gmail.com> On Mon, Oct 12, 2026 at 10:49:24PM +0800, jianyungao89@gmail.com wrote: > From: Jianyun Gao > > When dax_range_compare_iter() returns a negative error code (e.g. -EIO), > dax_dedupe_file_range_compare() incorrectly returns 'ret' which holds the > positive return value from iomap_iter() indicating more iterations remain. > This positive value leaks to the caller, where vfs_dedupe_file_range() > interprets it as success (bytes_deduped = len), causing userspace to > incorrectly believe deduplication completed. > > Return 'status' instead to propagate the actual error code. > > Fixes: 39eb05112987 ("dax: advance the iomap_iter on dedupe range") > Cc: stable@vger.kernel.org > Signed-off-by: Jianyun Gao > Reviewed-by: Jan Kara Seems fine to me, Reviewed-by: "Darrick J. Wong" --D > --- > > Changes in v2: > - Add Fixes tag and Cc stable > - Add Reviewed-by tag from Jan Kara > > v1: Link: https://lore.kernel.org/lkml/20261010021010.19575-1-jianyungao89@gmail.com/ > > fs/dax.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/dax.c b/fs/dax.c > index 6ba50142eeb2..1f6a4fbb97bd 100644 > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -2261,7 +2261,7 @@ int dax_dedupe_file_range_compare(struct inode *src, loff_t srcoff, > status = dax_range_compare_iter(&src_iter, &dst_iter, > min(src_iter.len, dst_iter.len), same); > if (status < 0) > - return ret; > + return status; > src_iter.status = dst_iter.status = status; > } > return ret; > -- > 2.34.1 >