Date: Thu, 26 Jun 2008 23:05:28 +0000 (UTC) From: Robert Watson <rwatson@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/net if.c if_var.h Message-ID: <200806262305.m5QN5VYF081649@repoman.freebsd.org>
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rwatson 2008-06-26 23:05:28 UTC
FreeBSD src repository
Modified files:
sys/net if.c if_var.h
Log:
SVN rev 180042 on 2008-06-26 23:05:28Z by rwatson
Introduce locking around use of ifindex_table, whose use was previously
unsynchronized. While races were extremely rare, we've now had a
couple of reports of panics in environments involving large numbers of
IPSEC tunnels being added very quickly on an active system.
- Add accessor functions ifnet_byindex(), ifaddr_byindex(),
ifdev_byindex() to replace existing accessor macros. These functions
now acquire the ifnet lock before derefencing the table.
- Add IFNET_WLOCK_ASSERT().
- Add static accessor functions ifnet_setbyindex(), ifdev_setbyindex(),
which set values in the table either asserting of acquiring the ifnet
lock.
- Use accessor functions throughout if.c to modify and read
ifindex_table.
- Rework ifnet attach/detach to lock around ifindex_table modification.
Note that these changes simply close races around use of ifindex_table,
and make no attempt to solve the probem of disappearing ifnets. Further
refinement of this work, including with respect to ifindex_table
resizing, is still required.
In a future change, the ifnet lock should be converted from a mutex to an
rwlock in order to reduce contention.
Reviewed and tested by: brooks
Revision Changes Path
1.281 +69 -12 src/sys/net/if.c
1.119 +4 -4 src/sys/net/if_var.h
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