[Qemu-devel] [Bug 646427] Re: VirtFS mapped symlinks resolved wrong

[Venkateswararao Jujjuri \(JV\)]

Responding to multiple issues raised above.

- Let us track this bug for the security/symlink issue and open a different 
defect for the mount issue.
- I tried to reproduce this defect with the QEMU mainline. I don't see the 
problem. More description on
  the environment (Host OS/Guest OS/ QEMU command line etc) and how to 
reproduce the problem will
  be helpful.
  address@hidden mmnt]# cat file1
  omg it is important
  address@hidden mmnt]# ln -sf file1 sym1
  address@hidden mmnt]# ls -l
  total 16
  -rw-r--r-- 1 root root 20 2010-09-24 01:24 file1
  lrwxrwxrwx 1 root root  6 2010-09-24 01:24 sym1 -> file1
  address@hidden mmnt]# logout
- Moshroom: 
  - There are multiple security models here, if you use 'passthrough' same type 
of files are created on the 
     host/guest. But if you use 'mapped' security model this is how we do it. 
     This security model is for cloud use case scenarios. Please read more in 
this post
     http://www.mail-archive.com/address@hidden/msg31452.html
  - No need to use lsetattr/lgetattr here because we always create regular 
files in this model.

-- 
VirtFS mapped symlinks resolved wrong
https://bugs.launchpad.net/bugs/646427
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Status in QEMU: New

Bug description:
I tried to map a folder with qemu-kvm qemu-kvm-0.13.0-rc1-3-gc9c2179 (this is 
v0.13.0-rc1-16667-gc9c2179). I mounted it first in passthrough mode and saw all 
symlinks as expected. Then I used mapped and noticed that the target of a 
symlink changed to the actual data inside the linked folder as target instead 
of the target filename.

So for example if you have a file abc with the content "omg, this is important 
stuff" and a symlink lnkme -> abc then it wiill look inside the kvm with 
mounted 9p virtio (mapped) like that:

lnkme -> omg, this is important stuff



Another problem I noticed was that I cannot mount it (mapped or passthrough) 
using /etc/rc.local or /etc/fstab, but after login as root using

mount /mnt

or

mount -t 9p -o trans=virtio host_share /mnt

(the same stuff i tried inside /etc/rc.local)

The only output on a failed mount in rc.local/fstab I get is 

[   15.035920] device: '9p-1': device_add
[   15.038180] 9p: no channels available
[   15.038937] device: '9p-1': device_unregister
[   15.049123] device: '9p-1': device_create_release