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/ethermedium.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/ethermedium.c')
| -rw-r--r-- | sys/src/9/ip/ethermedium.c | 10 |
1 files changed, 0 insertions, 10 deletions
diff --git a/sys/src/9/ip/ethermedium.c b/sys/src/9/ip/ethermedium.c index fb6d05279..8a2a50899 100644 --- a/sys/src/9/ip/ethermedium.c +++ b/sys/src/9/ip/ethermedium.c @@ -107,7 +107,6 @@ static char *nbmsg = "nonblocking"; /* * called to bind an IP ifc to an ethernet device - * called with ifc wlock'd */ static void etherbind(Ipifc *ifc, int argc, char **argv) @@ -200,9 +199,6 @@ etherbind(Ipifc *ifc, int argc, char **argv) kproc("recvarpproc", recvarpproc, ifc); } -/* - * called with ifc wlock'd - */ static void etherunbind(Ipifc *ifc) { @@ -210,7 +206,6 @@ etherunbind(Ipifc *ifc) while(waserror()) ; - /* wait for readers to start */ while(er->arpp == (void*)-1 || er->read4p == (void*)-1 || er->read6p == (void*)-1) tsleep(&up->sleep, return0, 0, 300); @@ -221,19 +216,14 @@ etherunbind(Ipifc *ifc) postnote(er->read6p, 1, "unbind", 0); if(er->arpp != nil) postnote(er->arpp, 1, "unbind", 0); - poperror(); - wunlock(ifc); while(waserror()) ; - /* wait for readers to die */ while(er->arpp != nil || er->read4p != nil || er->read6p != nil) tsleep(&up->sleep, return0, 0, 300); - poperror(); - wlock(ifc); if(er->mchan4 != nil) cclose(er->mchan4); |