Re: [PATCH] VFS: Add back check for !inode in walk_component()

[Steven Rostedt <rostedt@goodmis.org>]

On Thu, 7 May 2015 13:39:35 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> On Thu, 7 May 2015 18:28:34 +0100
> Al Viro <viro@ZenIV.linux.org.uk> wrote:
> 
> > On Thu, May 07, 2015 at 12:52:41PM -0400, Steven Rostedt wrote:
> > > 
> > > Commit 698934df8b45 "VFS: Combine inode checks with d_is_negative() and
> > > d_is_positive() in pathwalk" removed a check for inode being NULL in
> > > walk_component() where the type is tested. Stressing my tracefs create
> > > and remove instances while reading the files now triggers this:
> > 
> > So you get NULL ->d_inode with stale flags?  The thing is, ->d_inode
> > becoming NULL should happen via d_delete(), which goes throug this:
> 
> But it's not the delete, it's the creation of a new d_entry. Pehaps it
> gets linked premature? The tracing I had happened in
> tracefs_create_file().
> 

Note, this could be because of my special hack to have mkdir create
files too. We never came up with a clean solution for that.

-- Steve