From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9B4241ABEB1; Mon, 14 Oct 2024 15:18:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728919083; cv=none; b=tDJRlS83tqghyUSdbaLkNgsE7R8FljApSvgj/nE9LMhGDqm79JnRPt/YwpIpOlfoMTwE8frja0FGaZbei8SBXNQHWe5WT1+NV0L90FOWTT0IQlF2rAxB17/Gq7OeTYVMQlD18r1XtiatmlNsRCcIZL29lowYo36+toggsCXV06Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728919083; c=relaxed/simple; bh=ToVeGWb1ZxTCfZDwDu+MVRA47oM04N+f0qQ87sHThP4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WIAX6Aqtv+4kz2P3nsjxWic9UAkqf3BZNcPE9IQN7HQVKNKUcOm5C6sM/AvYA4C2vjrhDlVh5cY3VroLU8hBJ8EMYKnC68Nlb+S9qpXiALGN9mEfTYTStAKmjizp1lh31Gzr8vAtTQ1GVqr9MWVhx2m0bLrsDHXi4AOUa+1cFvs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CDpowf3Q; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="CDpowf3Q" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0763CC4CEC3; Mon, 14 Oct 2024 15:18:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1728919083; bh=ToVeGWb1ZxTCfZDwDu+MVRA47oM04N+f0qQ87sHThP4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CDpowf3QgUps+TGGmb1s6MgRXGkx+IM4K71Sx4qS0gYv9L6HTRHAmYmoJb0PL3zd9 kN0sAFZoM8xzSwvud5fG+YF6+GkD0vqLuhfXsrdSzd0WK3E+Bfoz0yhlILVvPeyJXS oyVMNVIhc4CiuhCF9Fpj15BBUFDnxiK9XRsMhKCc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christoph Hellwig , "Darrick J. Wong" , Christian Brauner , Sasha Levin Subject: [PATCH 6.1 509/798] iomap: handle a post-direct I/O invalidate race in iomap_write_delalloc_release Date: Mon, 14 Oct 2024 16:17:43 +0200 Message-ID: <20241014141237.976965673@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241014141217.941104064@linuxfoundation.org> References: <20241014141217.941104064@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christoph Hellwig [ Upstream commit 7a9d43eace888a0ee6095035997bb138425844d3 ] When direct I/O completions invalidates the page cache it holds neither the i_rwsem nor the invalidate_lock so it can be racing with iomap_write_delalloc_release. If the search for the end of the region that contains data returns the start offset we hit such a race and just need to look for the end of the newly created hole instead. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20240910043949.3481298-2-hch@lst.de Reviewed-by: Darrick J. Wong Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin --- fs/iomap/buffered-io.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 98617f00101d6..1833608f39318 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -990,7 +990,15 @@ static int iomap_write_delalloc_release(struct inode *inode, error = data_end; goto out_unlock; } - WARN_ON_ONCE(data_end <= start_byte); + + /* + * If we race with post-direct I/O invalidation of the page cache, + * there might be no data left at start_byte. + */ + if (data_end == start_byte) + continue; + + WARN_ON_ONCE(data_end < start_byte); WARN_ON_ONCE(data_end > scan_end_byte); error = iomap_write_delalloc_scan(inode, &punch_start_byte, -- 2.43.0