On Tue, Oct 10, 2023 at 8:38 PM Stefan Hajnoczi <stefanha@xxxxxxxxxx> wrote: > > On Thu, Oct 05, 2023 at 04:30:30PM -0400, Vivek Goyal wrote: > > virtiofs filesystem is mounted using a "tag" which is exported by the > > virtiofs device. virtiofs driver knows about all the available tags but > > these are not exported to user space. > > > > People have asked these tags to be exported to user space. Most recently > > Lennart Poettering has asked for it as he wants to scan the tags and mount > > virtiofs automatically in certain cases. > > > > https://gitlab.com/virtio-fs/virtiofsd/-/issues/128 > > > > This patch exports tags through sysfs. One tag is associated with each > > virtiofs device. A new "tag" file appears under virtiofs device dir. > > Actual filesystem tag can be obtained by reading this "tag" file. > > > > For example, if a virtiofs device exports tag "myfs", a new file "tag" > > will show up here. > > > > /sys/bus/virtio/devices/virtio<N>/tag > > > > # cat /sys/bus/virtio/devices/virtio<N>/tag > > myfs > > If you respin this series, please mention that the tag is available at > KOBJ_BIND time, but not KOBJ_ADD. Just a sentence or two is enough to > help someone trying to figure out how to use this new sysfs attr with > udev. Maybe it's also worth mention, that the tag file is created after a successful probe, so the tag should be a valid one: non-empty and unique > > > > > Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx> > > --- > > fs/fuse/virtio_fs.c | 34 ++++++++++++++++++++++++++++++++++ > > 1 file changed, 34 insertions(+) > > Reviewed-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx> -- German
