On 30.04.20 10:58, Dr. David Alan Gilbert wrote: > * Max Reitz (mre...@redhat.com) wrote: >> On 29.04.20 16:57, Dr. David Alan Gilbert wrote: >>> * Dr. David Alan Gilbert (dgilb...@redhat.com) wrote: >>>> * Max Reitz (mre...@redhat.com) wrote: >>>>> Currently, setup_mounts() bind-mounts the shared directory without >>>>> MS_REC. This makes all submounts disappear. >>>>> >>>>> Pass MS_REC so that the guest can see submounts again. >>>> >>>> Thanks! >>>> >>>>> Fixes: 3ca8a2b1c83eb185c232a4e87abbb65495263756 >>>> >>>> Should this actually be 5baa3b8e95064c2434bd9e2f312edd5e9ae275dc ? >>>> >>>>> Signed-off-by: Max Reitz <mre...@redhat.com> >>>>> --- >>>>> tools/virtiofsd/passthrough_ll.c | 2 +- >>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>> >>>>> diff --git a/tools/virtiofsd/passthrough_ll.c >>>>> b/tools/virtiofsd/passthrough_ll.c >>>>> index 4c35c95b25..9d7f863e66 100644 >>>>> --- a/tools/virtiofsd/passthrough_ll.c >>>>> +++ b/tools/virtiofsd/passthrough_ll.c >>>>> @@ -2643,7 +2643,7 @@ static void setup_mounts(const char *source) >>>>> int oldroot; >>>>> int newroot; >>>>> >>>>> - if (mount(source, source, NULL, MS_BIND, NULL) < 0) { >>>>> + if (mount(source, source, NULL, MS_BIND | MS_REC, NULL) < 0) { >>>>> fuse_log(FUSE_LOG_ERR, "mount(%s, %s, MS_BIND): %m\n", source, >>>>> source); >>>>> exit(1); >>>>> } >>>> >>>> Do we want MS_SLAVE to pick up future mounts that might happenf rom the >>>> host? >>>> What's the interaction between this and the MS_REC|MS_SLAVE that we have >>>> a few lines above for / ? >>> >>> Just to confirm something from vgoyal, and what had confused me about >>> why we hadn't spotted this earlier. >>> >>> Even without this patch, the SLAVE stuff worked so if you start the >>> daemon and *then* mount under the shared directory, the guest sees it >>> with or without this patch. >> >> Hm, I don’t. Do you really? > > Yes! With your patch reverted: > > Start virtiofsd, mount in the guest: > > host: > # ./virtiofsd --socket-path=/tmp/vhostqemu -o > source=/home/dgilbert/virtio-fs/fs -o log_level=warn -o no_writeback > > guest: > # mount -t virtiofs myfs /sysroot
OK, for some reason I didn’t try to mount in the guest first, but did the host mount after starting virtiofsd. My mount test uses multiple mounts, and two of them I see mounted, but three I still don’t see mounted. Let me see whether I can come up with something reproducible that isn’t a script. [...] > Maybe this is related to what Vivek said about default behaviours on > systemd's, what does: > > # findmnt -o +PROPAGATION > TARGET SOURCE FSTYPE OPTIONS > PROPAGATION > / /dev/mapper/fedora_dgilbert--t580-root > │ xfs > rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota > shared > > say for your source= directory? I have Fedora, too, so pretty much the same. Max
signature.asc
Description: OpenPGP digital signature