Two inodes with the same inode number

Two inodes with the same inode number

[Ross Lagerwall]

I have a setup with two hosts, A and B, both using a CIFS SMB 3.0 mount 
where the following operations take place (using 4.1 kernels):

A                  B
open X
close X
                    mv X Y
                    touch X
open X
open Y

After this, host A will have two dentries pointing to the same inode (or 
at least with the same inode number), which results in some 
'interesting' behavior.

I've seen at least two failure modes:
1) Above, both open calls will try to use the same lease key, causing 
the server to fail the second open with STATUS_INVALID_PARAMETER. (the 
server was Windows Server 2012 R2)

2) The reported file size will be different depending on which filename 
was last used to refresh the inode attributes.


Although cifs_d_revalidate updates attributes such as the file size, it 
doesn't ever update the inode number. I tried making it return 0 to drop 
the cached inode if the inode number had changed but even still, opens 
failed occasionally with STATUS_INVALID_PARAMETER. Is there an alternate 
fix for this?

Thanks,
-- 
Ross Lagerwall

Re: Two inodes with the same inode number

[Ross Lagerwall]

On 09/11/2015 12:27 PM, john.jackson-hxIV5DHgdjlWk0Htik3J/w@public.gmane.org wrote:
> Peter,  reading this person complaint regarding cifs further leads me to
> believe that the synology server may have problems managing inode numbers.
>

Just to be clear, my problem is on the client side since unmounting and 
remounting the share fixes the issue.

Thanks,
-- 
Ross Lagerwall