Re: Handling of duplicate inode numbers for the directories in the nfs v3 kernel client

Frank Filz
2018-12-13T16:26:28Z

On 12/12/18 10:57 AM, Ashish Sangwan wrote:
> Hi,
>
> Our NFS filer can sometimes return same inode number for different directories.
> For example /mnt/dir1/dir2 and /mnt/dir3/dir4, in same rare cases dir2
> and dir4 might end up returning the same inode number to the client.
> Though it can never happen that inode numbers will be same for two
> directories and also there parent is same. Can linux client handle
> this case? What issues it can cause?
> https://lkml.org/lkml/2006/10/2/346
> I stumbled upon this thread where it is written that nfs client can
> handle this but userspace will see inode collisions. Given that this
> will happen only for directories, userspace utils logic might not get
> affected from this as hardlinks on directories are not possible. But
> the thread is really old. Wanted to confirm if this holds true even
> now.
>
> Thanks,
> Ashish

The find tool will detect the collisions and report them, and if I
recall it stops proceeding down the directory tree from the duplicate
inode number. I know for sure I've seen it complain, and pretty sure I
saw it stop descending the tree into the directory with the duplicate
inode number.

Frank