Date: Thu, 13 Jan 2005 07:43:12 +0000 (UTC) From: Gleb Smirnoff <glebius@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/netgraph ng_tty.c Message-ID: <200501130743.j0D7hC7b050947@repoman.freebsd.org>
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glebius 2005-01-13 07:43:12 UTC
FreeBSD src repository
Modified files:
sys/netgraph ng_tty.c
Log:
Locking and cleanup of tty netgraph node. Tty stack is Giant-locked,
so we need to acquire Giant in netgraph methods, so that we don't
race with line discipline methods. Remove NET_NEEDS_GIANT.
- Packets coming into node from netgraph are queued in ifqueue
attached to node private data.
- Mutex in struct ifqueue is used to lock not only the queue, but
the whole private data, and tp->t_lsc field.
- tp->t_lsc pointer is used to indicate whether line discipline is
attached to netgraph or not.
- Use FLG_DIE flag to indicate that node may be destroyed.
(This protection doesn't work, and it didn't before. Must be redesigned.)
- Increment ngt_unit atomically, removing mutex.
- Acquire Giant, when executing ngt_start() from netgraph context.
- Acquire Giant, when {,de}registering line discipline.
- Uncomment forcing queue mode on peers hook, since this is reasonable.
- Force queue mode on our hook, to avoid acquiring Giant when coming from
network stack. We may already hold some mutexes at this point.
Cleanups:
- Use callout_pending() instead of our own flag.
- Remove spl(9) calls. Now we can use return() instead of ERROUT().
style(9):
- Sort includes.
- Sparse initializer for struct linesw.
- Remove some empty lines, sort declarations.
Reviewed by: julian, phk
MFC after: 1 month
Revision Changes Path
1.34 +182 -176 src/sys/netgraph/ng_tty.c
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