[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <9581f66e-dc3a-495b-bacb-30908a78a773@collabora.com>
Date: Fri, 1 Mar 2024 13:06:03 +0100
From: Andrzej Pietrasiewicz <andrzej.p@...labora.com>
To: Michael Grzeschik <m.grzeschik@...gutronix.de>,
Eric Van Hensbergen <ericvh@...nel.org>, Latchesar Ionkov
<lucho@...kov.net>, Dominique Martinet <asmadeus@...ewreck.org>,
Christian Schoenebeck <linux_oss@...debyte.com>,
Jonathan Corbet <corbet@....net>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: v9fs@...ts.linux.dev, linux-doc@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-usb@...r.kernel.org,
kernel@...gutronix.de
Subject: Re: [PATCH v3 0/3] usb: gadget: 9pfs transport
Hi Michael,
W dniu 26.02.2024 o 14:56, Michael Grzeschik pisze:
> This series is adding support to mount usb hostside exported 9pfs
> filesystems via the usb gadget interface. It also includes a simple tool
> (p9_fwd.py) to translate an tcp 9pfs transport and reuse it via the usb
> interface.
>
> +--------------------------+ | +--------------------------+
> | 9PFS mounting client | | | 9PFS exporting server |
> SW | | | | |
> | (this:trans_usbg) | | |(e.g. diod or nfs-ganesha)|
> +-------------^------------+ | +-------------^------------+
> | | |
> | | +------v------+
> | | | p9_fwd.py |
> | | +------^------+
> | | |
> ------------------|------------------------------------|-------------
> | | |
> +-------------v------------+ | +-------------v------------+
> | | | | |
> HW | USB Device Controller <---------> USB Host Controller |
> | | | | |
> +--------------------------+ | +--------------------------+
>
> The USB host exports a filesystem, while the gadget on the USB device
> side makes it mountable.
>
> Diod (9pfs server) and the forwarder are on the development host, where
> the root filesystem is actually stored. The gadget is initialized during
> boot (or later) on the embedded board. Then the forwarder will find it
> on the USB bus and start forwarding requests.
>
> In this case the 9p requests come from the device and are handled by the
> host. The reason is that USB device ports are normally not available on
> PCs, so a connection in the other direction would not work.
>
> One use-case is to use it as an alternative to NFS root booting during
> the development of embedded Linux devices.
>
> Signed-off-by: Michael Grzeschik <m.grzeschik@...gutronix.de>
> ---
> Changes in v3:
> - dropped patch "usb: gadget: legacy: add 9pfs multi gadget" as discussed with gregkh
I will give the dropped patch a try to see how it works, as it should work the
same way regardless of how the gadget is composed, legacy or configfs.
Speaking of the latter, IMO there _are_ valid usecases other than having 9pfs
rootfs, so configfs support should be there. If you intend to send the patches
adding configfs support then kindly Cc me and I will test and review it for you.
Regards,
Andrzej
> - Link to v2: https://lore.kernel.org/r/20240116-ml-topic-u9p-v2-0-b46cbf592962@pengutronix.de
>
> Changes in v2:
> - improved the commit messages
> - introduced an patch to move the header u_f.h to include/linux/usb to compile usb gadget functions treewide
> - moved usbg gadget function to net/9p/
> - adderessed several comments in function driver, like the cleanup path and kbuild errors
> - improved the documentation in Documentation/filesystems/9p.rst
> - Link to v1: https://lore.kernel.org/r/20240116-ml-topic-u9p-v1-0-ad8c306f9a4e@pengutronix.de
>
> ---
> Michael Grzeschik (3):
> usb: gadget: function: move u_f.h to include/linux/usb/
> net/9p/usbg: Add new usb gadget function transport
> tools: usb: p9_fwd: add usb gadget packet forwarder script
>
> Documentation/filesystems/9p.rst | 47 ++
> drivers/usb/gadget/configfs.c | 2 +-
> drivers/usb/gadget/function/f_fs.c | 2 +-
> drivers/usb/gadget/function/f_hid.c | 2 +-
> drivers/usb/gadget/function/f_loopback.c | 2 +-
> drivers/usb/gadget/function/f_midi.c | 2 +-
> drivers/usb/gadget/function/f_midi2.c | 2 +-
> drivers/usb/gadget/function/f_sourcesink.c | 2 +-
> drivers/usb/gadget/u_f.c | 2 +-
> {drivers/usb/gadget => include/linux/usb}/u_f.h | 0
> net/9p/Kconfig | 6 +
> net/9p/Makefile | 4 +
> net/9p/trans_usbg.c | 871 ++++++++++++++++++++++++
> tools/usb/p9_fwd.py | 194 ++++++
> 14 files changed, 1130 insertions(+), 8 deletions(-)
> ---
> base-commit: 41bccc98fb7931d63d03f326a746ac4d429c1dd3
> change-id: 20240116-ml-topic-u9p-895274530eb1
>
> Best regards,
Powered by blists - more mailing lists