Re: tty's use of file_list_lock and file_move

From: Jon Smirl
Date: Mon Jul 10 2006 - 18:34:05 EST


On 7/10/06, Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote:
We hold file_list_lock because we have to find everyone using that tty
and hang up their instance of it, then flip the file operations not
because we need to protect against tty structs going away. It's needed
in order to walk the file list and protects against the file list itself
changing rather than the tty structs. It may well be possible to move
that to a tty layer private lock with care, but it would need care to
deal with VFS operations.

Assuming do_SAK has blocked anyone's ability to newly open the tty,
why does it need to search every file handle in the system instead of
just using tty->tty_files? tty->tty_files should contain a list of
everyone who has the tty open. Is this global search needed because of
duplicated handles?

--
Jon Smirl
jonsmirl@xxxxxxxxx
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