Re: Ptyfs correction.

[christos%zoulas.com@localhost (Christos Zoulas)]

On Oct 15,  5:49pm, netbsd%izyk.ru@localhost (Ilia Zykov) wrote:
-- Subject: Re: Ptyfs correction.

| 
| On 15.10.2014 16:55, Christos Zoulas wrote:
| > On Oct 15,  1:14pm, netbsd%izyk.ru@localhost (Ilia Zykov) wrote:
| > -- Subject: Re: Ptyfs correction.
| >
| > | Hello!
| > |  - corrects some wrong comments
| > |  - add XXX warning
| > |  - increase security
| > |  - make pty_vn_open() private to tty_ptm.c
| > | 
| > | Thank you.
| > | Ilia.
| >
| > Can you please explain this:
| >
| > -       if (type == PTYFSptc)
| > +       /* Activate node only after we have grabbed device. */
| > +       if (type == PTYFSpts)
| >
| >
| > Thanks.
| > christos
| >
| 
| On SMP systems(with ptyfs multiple mounts) in this point (type ==
| PTYFSptc) can be multiple threads.
| Afterwards "ptm" driver leave only one(all other will grab other
| devices), but will be time before ptyfs_inactive(),
| when its will be have active this node for other mount points.
| After, when "ptm" has grabbed device for this thread, it calls this
| function only for one winner thread
| with type == PTYFSpts.  It's situation very difficult usage because we
| do VOP_REVOKE(), but theoretically
| possible. And more reliable activate device only at one mount point when
| we have grabbed device.

Thanks, makes sense.

christos