diff options
| author | cinap_lenrek <cinap_lenrek@felloff.net> | 2022-02-16 22:31:31 +0000 |
|---|---|---|
| committer | cinap_lenrek <cinap_lenrek@felloff.net> | 2022-02-16 22:31:31 +0000 |
| commit | 7289f371a0b113c12add274c4d4aa84d0c147dee (patch) | |
| tree | caaadea3c6dff299367b9079558141efc2f1ea65 /sys/src/9/ip/nullmedium.c | |
| parent | 755880b19f365c3f98eac5c7de1d8b25f773ace3 (diff) | |
devip: dont hold ifc wlock during medium bind/unbind
Wlock()'ing the ifc causes a deadlock with Medium
bind/unbind as the routine can walk /net, while
ndb/dns or ndb/cs are currently blocked enumerating
/net/ipifc/*.
The fix is to have a fake medium, called "unbound",
that is set temporarily during the call of Medium
bind and unbind.
That way, the interface rwlock can be released while
bind/unbind is in progress.
The ipifcunbind() routine will refuse to unbind a
ifc that is currently assigned to the "unbound"
medium, preventing any accidents.
Diffstat (limited to 'sys/src/9/ip/nullmedium.c')
| -rw-r--r-- | sys/src/9/ip/nullmedium.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/sys/src/9/ip/nullmedium.c b/sys/src/9/ip/nullmedium.c index 094e103f6..3874da583 100644 --- a/sys/src/9/ip/nullmedium.c +++ b/sys/src/9/ip/nullmedium.c @@ -33,6 +33,15 @@ Medium nullmedium = .bwrite= nullbwrite, }; +/* used in ipifc to prevent unbind while bind is in progress */ +Medium unboundmedium = +{ +.name= "unbound", +.bind= nullbind, +.unbind= nullunbind, +.bwrite= nullbwrite, +}; + void nullmediumlink(void) { |