Re: missing mnt_drop_write() on open error

[Dave Hansen <haveblue@us.ibm.com>]

On Wed, 2007-09-26 at 10:38 +0200, Miklos Szeredi wrote:
> In __dentry_open() there's still a few places where fput() won't be
> called, notably when ->open fails, which is what I'm triggering I
> think.
> 
> Also even more horrible things can happen because of the
> nd->intent.open.file thing.  For example if the lookup routine calls
> lookup_instantiate_filp(), and after this, but before may_open() some
> error happens, then release_open_intent() will call fput() on the
> file, which will cause mnt_drop_write() to be called, even though a
> matching mnt_want_write() hasn't yet been called.  Ugly, eh? 

I'm not sure it is _that_ horrible. ;)

Do you see any reason we can't just shadow the
get/put_write_access(inode) calls with mnt_want/drop_write() calls?  I
think they're always matched.

-- Dave