svn commit: r365787 - head/sys/fs/tmpfs

[Konstantin Belousov]

On Fri, Jan 01, 2021 at 06:44:00PM +0000, Alexey Dokuchaev wrote:
> On Tue, Sep 15, 2020 at 10:19:16PM +0000, Konstantin Belousov wrote:
> > New Revision: 365787
> > URL: https://svnweb.freebsd.org/changeset/base/365787
> > 
> > Log:
> >   Add tmpfs page cache read support.
> >   
> >   Or it could be explained as lockless (for vnode lock) reads.  Reads
> >   are performed from the node tn_obj object.  Tmpfs regular vnode object
> >   lifecycle is significantly different from the normal OBJT_VNODE: it is
> >   alive as far as ref_count > 0.
> 
> This causes panics for me when building ports in the tmpfs-backed tinderbox.
> Easily reproducible:
> 
> 1) ./tc tinderbuild ... -b "$@"
> 2) tail -f .../tmp/make.log4 # on the adjacent console
> 3) wait until the build job finishes
> 4) ^C in the "tail" window -> crash
What exactly 'crash' is ?  Provide literal transcription of the kernel
messages and not your interpretation of them.

>  ...
>   __mtx_lock_sleep()
>   tmpfs_free_node()
What is the source line for tmpfs_free_node() frame ?

>   tmpfs_fo_close()
>   _fdrop()
>   closef()
>   fdescfree_fds()
>   fdescfree()
>   exit1()
>   sigexit()
>   postsig()
>   ast()
>   doreit_ast()