Re: [PATCH] autofs - use dentry flags to block walks during expire

[Takashi Iwai]

On Thu, 01 Sep 2016 03:21:14 +0200,
Ian Kent wrote:
> 
> Somewhere along the way the autofs expire operation has changed to
> hold a spin lock over expired dentry selection. The autofs indirect
> mount expired dentry selection is complicated and quite lengthy so
> it isn't appropriate to hold a spin lock over the operation.
> 
> Commit 47be6184 added a might_sleep() to dput() causing a BUG()
> about this usage to be issued.
> 
> But the spin lock doesn't need to be held over this check, the
> autofs dentry info. flags are enough to block walks into dentrys
> during the expire.
> 
> I've left the direct mount expire as it is (for now) becuase it
> is much simpler and quicker than the indirect mount expire and
> adding spin lock release and re-aquires would do nothing more
> than add overhead.
> 
> Signed-off-by: Ian Kent <raven@xxxxxxxxxx>

Looks working fine, so far.

Reported-and-tested-by: Takashi Iwai <tiwai@xxxxxxx>


thanks,

Takashi