diff options
| author | Zach Brown <zach.brown@oracle.com> | 2010-07-23 19:32:31 +0200 |
|---|---|---|
| committer | Andy Grover <andy.grover@oracle.com> | 2010-09-09 03:16:47 +0200 |
| commit | 5adb5bc65f93e52341c3fc9d03d4030dd375e256 (patch) | |
| tree | 55b19c7757ccd64f58169a05cd63e91bee409bad /net/rds/transport.c | |
| parent | RDS: remove old rs_transport comment (diff) | |
| download | linux-5adb5bc65f93e52341c3fc9d03d4030dd375e256.tar.xz linux-5adb5bc65f93e52341c3fc9d03d4030dd375e256.zip | |
RDS: have sockets get transport module references
Right now there's nothing to stop the various paths that use
rs->rs_transport from racing with rmmod and executing freed transport
code. The simple fix is to have binding to a transport also hold a
reference to the transport's module, removing this class of races.
We already had an unused t_owner field which was set for the modular
transports and which wasn't set for the built-in loop transport.
Signed-off-by: Zach Brown <zach.brown@oracle.com>
Diffstat (limited to 'net/rds/transport.c')
| -rw-r--r-- | net/rds/transport.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/net/rds/transport.c b/net/rds/transport.c index 7e1067901353..7f2ac4fec367 100644 --- a/net/rds/transport.c +++ b/net/rds/transport.c @@ -71,19 +71,28 @@ void rds_trans_unregister(struct rds_transport *trans) } EXPORT_SYMBOL_GPL(rds_trans_unregister); +void rds_trans_put(struct rds_transport *trans) +{ + if (trans && trans->t_owner) + module_put(trans->t_owner); +} + struct rds_transport *rds_trans_get_preferred(__be32 addr) { struct rds_transport *ret = NULL; - int i; + struct rds_transport *trans; + unsigned int i; if (IN_LOOPBACK(ntohl(addr))) return &rds_loop_transport; down_read(&rds_trans_sem); - for (i = 0; i < RDS_TRANS_COUNT; i++) - { - if (transports[i] && (transports[i]->laddr_check(addr) == 0)) { - ret = transports[i]; + for (i = 0; i < RDS_TRANS_COUNT; i++) { + trans = transports[i]; + + if (trans && (trans->laddr_check(addr) == 0) && + (!trans->t_owner || try_module_get(trans->t_owner))) { + ret = trans; break; } } |