From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Hubbard Subject: [PATCH v2 06/18] goldish_pipe: convert to pin_user_pages() and put_user_page() Date: Sun, 3 Nov 2019 13:18:01 -0800 Message-ID: <20191103211813.213227-7-jhubbard@nvidia.com> References: <20191103211813.213227-1-jhubbard@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20191103211813.213227-1-jhubbard@nvidia.com> Sender: linux-kernel-owner@vger.kernel.org To: Andrew Morton Cc: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman M List-Id: dri-devel@lists.freedesktop.org 1. Call the new global pin_user_pages_fast(), from pin_goldfish_pages(). 2. As required by pin_user_pages(), release these pages via put_user_page(). In this case, do so via put_user_pages_dirty_lock(). That has the side effect of calling set_page_dirty_lock(), instead of set_page_dirty(). This is probably more accurate. As Christoph Hellwig put it, "set_page_dirty() is only safe if we are dealing with a file backed page where we have reference on the inode it hangs off." [1] Another side effect is that the release code is simplified because the page[] loop is now in gup.c instead of here, so just delete the local release_user_pages() entirely, and call put_user_pages_dirty_lock() directly, instead. [1] https://lore.kernel.org/r/20190723153640.GB720@lst.de Signed-off-by: John Hubbard --- drivers/platform/goldfish/goldfish_pipe.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-) diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/g= oldfish/goldfish_pipe.c index 7ed2a21a0bac..635a8bc1b480 100644 --- a/drivers/platform/goldfish/goldfish_pipe.c +++ b/drivers/platform/goldfish/goldfish_pipe.c @@ -274,7 +274,7 @@ static int pin_goldfish_pages(unsigned long first_page, *iter_last_page_size =3D last_page_size; } =20 - ret =3D get_user_pages_fast(first_page, requested_pages, + ret =3D pin_user_pages_fast(first_page, requested_pages, !is_write ? FOLL_WRITE : 0, pages); if (ret <=3D 0) @@ -285,18 +285,6 @@ static int pin_goldfish_pages(unsigned long first_page= , return ret; } =20 -static void release_user_pages(struct page **pages, int pages_count, - int is_write, s32 consumed_size) -{ - int i; - - for (i =3D 0; i < pages_count; i++) { - if (!is_write && consumed_size > 0) - set_page_dirty(pages[i]); - put_page(pages[i]); - } -} - /* Populate the call parameters, merging adjacent pages together */ static void populate_rw_params(struct page **pages, int pages_count, @@ -372,7 +360,8 @@ static int transfer_max_buffers(struct goldfish_pipe *p= ipe, =20 *consumed_size =3D pipe->command_buffer->rw_params.consumed_size; =20 - release_user_pages(pipe->pages, pages_count, is_write, *consumed_size); + put_user_pages_dirty_lock(pipe->pages, pages_count, + !is_write && *consumed_size > 0); =20 mutex_unlock(&pipe->lock); return 0; --=20 2.23.0