Re: CVS commit: src/sys/fs/tmpfs

[Mindaugas Rasiukevicius <rmind%netbsd.org@localhost>]

"Juergen Hannken-Illjes" <hannken%netbsd.org@localhost> wrote:
> Module Name:  src
> Committed By: hannken
> Date:         Fri Jan  3 09:53:12 UTC 2014
> 
> Modified Files:
>       src/sys/fs/tmpfs: tmpfs_subr.c tmpfs_vnops.c
> 
> Log Message:
> Fix a race where thread1 runs VOP_REMOVE() and gets preempted in
> tmpfs_reclaim() before the call to tmpfs_free_node().  Thread2
> runs VFS_FHTOVP() and gets a new vnode attached to the node thread1
> is about to destroy.
> 
> Change tmpfs_alloc_node() to always assign non-zero generation number
> and tmpfs_inactive() to set the generation number of unlinked nodes
> to zero.

Can you explain how does this help?  It still seems racy to me.
Why not just check for tn_links == 0 in tmpfs_fhtovp()?

-- 
Mindaugas