From 0fb1b1ed7dd92ca9775f8292cc7b85b93182dcb0 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Fri, 27 Nov 2020 17:41:23 +0100 Subject: [PATCH] /dev/mem: Only set filp->f_mapping MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When we care about pagecache maintenance, we need to make sure that both f_mapping and i_mapping point at the right mapping. But for iomem mappings we only care about the virtual/pte side of things, so f_mapping is enough. Also setting inode->i_mapping was confusing me as a driver maintainer, since in e.g. drivers/gpu we don't do that. Per Dan this seems to be copypasta from places which do care about pagecache consistency, but not needed. Hence remove it for slightly less confusion. Signed-off-by: Daniel Vetter Cc: Jason Gunthorpe Cc: Kees Cook Cc: Dan Williams Cc: Andrew Morton Cc: John Hubbard Cc: Jérôme Glisse Cc: Jan Kara Cc: Dan Williams Cc: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-samsung-soc@vger.kernel.org Cc: linux-media@vger.kernel.org Reviewed-by: Dan Williams Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20201127164131.2244124-10-daniel.vetter@ffwll.ch --- drivers/char/mem.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 94c2b55..7dcf9e4 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -891,7 +891,6 @@ static int open_port(struct inode *inode, struct file *filp) * revocations when drivers want to take over a /dev/mem mapped * range. */ - inode->i_mapping = devmem_inode->i_mapping; filp->f_mapping = inode->i_mapping; return 0; -- 2.7.4