linux-kernel - Re: [PATCH] Fuse: Add backing file support for uring

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <7af8193e-0761-415f-9940-6c4d1c8073cf@bsbernd.com>
Date: Fri, 21 Feb 2025 19:23:21 +0100
From: Bernd Schubert <bernd@...ernd.com>
To: Moinak Bhattacharyya <moinakb001@...il.com>,
 Amir Goldstein <amir73il@...il.com>
Cc: Miklos Szeredi <miklos@...redi.hu>, linux-fsdevel@...r.kernel.org,
 linux-kernel@...r.kernel.org, io-uring@...r.kernel.org
Subject: Re: [PATCH] Fuse: Add backing file support for uring_cmd



On 2/21/25 19:13, Moinak Bhattacharyya wrote:
> I don't have the modifications to libfuse. What tree are you using for
> the uring modifications? I dont see any uring patches on the latest
> master liburing.

https://github.com/bsbernd/libfuse/tree/uring

This is a development branch, goint to create a new branch out
of that during the next days (now that I'm eventually almost through
with libfuse-3.17).

>>> It is possible, for example set FOPEN_PASSTHROUGH_FD to
>>> interpret backing_id as backing_fd, but note that in the current
>>> implementation of passthrough_hp, not every open does
>>> fuse_passthrough_open().
>>> The non-first open of an inode uses a backing_id stashed in inode,
>>> from the first open so we'd need different server logic depending on
>>> the commands channel, which is not nice.
> I wonder if we can just require URING registered FDs (using
> IORING_REGISTER_FILES). I think io_uring does checks on the file
> permissions when the FD is registered.

Could you explain how fd registration into the ring would help here?


Thanks,
Bernd