On 09.07.24 19:56, Josef Bacik wrote:
On Tue, Jul 09, 2024 at 01:19:16PM +0200, Hanna Czenczek wrote:
Hi,
We want to be able to mount filesystems that just consist of one regular
file via virtio-fs, i.e. no root directory, just a file as the root
node.
While that is possible via FUSE itself (through the 'rootmode' mount
option, which is automatically set by the fusermount help program to
match the mount point's inode mode), there is no virtio-fs option yet
that would allow changing the rootmode from S_IFDIR to S_IFREG.
To do that, this series introduces a new 'file' mount option that does
precisely that. Alternatively, we could provide the same 'rootmode'
option that FUSE has, but as laid out in patch 1's commit description,
that option is a bit cumbersome for virtio-fs (in a way that it is not
for FUSE), and its usefulness as a more general option is limited.
All this does is make file an alias for something a little easier for users to
read, which can easily be done in libfuse. Add the code to lib/mount.c to alias
'file' to turn it into rootmode=S_IFREG when it sends it to the kernel, it's not
necessary to do this in the kernel. Thanks,
This series is not about normal FUSE filesystems (file_system_type
fuse_fs_type, “fuse”), but about virtio-fs (file_system_type
virtio_fs_type, “virtiofs”), i.e. a case where libfuse and fusermount
are not involved at all. As far as I’m aware, mounting a virtio-fs
filesystem with a non-directory root inode is currently not possible at all.
Hanna
