diff options
Diffstat (limited to 'sys/net/if.c')
| -rw-r--r-- | sys/net/if.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/sys/net/if.c b/sys/net/if.c index 1d76fc9..0944d44 100644 --- a/sys/net/if.c +++ b/sys/net/if.c @@ -50,6 +50,7 @@ #include <sys/sockio.h> #include <sys/syslog.h> #include <sys/sysctl.h> +#include <sys/taskqueue.h> #include <sys/domain.h> #include <sys/jail.h> #include <machine/stdarg.h> @@ -92,6 +93,7 @@ static void if_unroute(struct ifnet *, int flag, int fam); static void link_rtrequest(int, struct rtentry *, struct rt_addrinfo *); static int if_rtdel(struct radix_node *, void *); static int ifhwioctl(u_long, struct ifnet *, caddr_t, struct thread *); +static void if_start_deferred(void *context, int pending); #ifdef INET6 /* * XXX: declare here to avoid to include many inet6 related files.. @@ -365,6 +367,7 @@ if_attach(struct ifnet *ifp) struct sockaddr_dl *sdl; struct ifaddr *ifa; + TASK_INIT(&ifp->if_starttask, 0, if_start_deferred, ifp); IF_AFDATA_LOCK_INIT(ifp); ifp->if_afdata_initialized = 0; IFNET_WLOCK(); @@ -983,6 +986,10 @@ if_qflush(struct ifaltq *ifq) * Handle interface watchdog timer routines. Called * from softclock, we decrement timers (if set) and * call the appropriate interface routine on expiration. + * + * XXXRW: Note that because timeouts run with Giant, if_watchdog() is called + * holding Giant. If we switch to an MPSAFE callout, we likely need to grab + * Giant before entering if_watchdog() on an IFF_NEEDSGIANT interface. */ static void if_slowtimo(void *arg) @@ -1839,5 +1846,47 @@ if_printf(struct ifnet *ifp, const char * fmt, ...) return (retval); } +/* + * When an interface is marked IFF_NEEDSGIANT, its if_start() routine cannot + * be called without Giant. However, we often can't acquire the Giant lock + * at those points; instead, we run it via a task queue that holds Giant via + * if_start_deferred. + * + * XXXRW: We need to make sure that the ifnet isn't fully detached until any + * outstanding if_start_deferred() tasks that will run after the free. This + * probably means waiting in if_detach(). + */ +void +if_start(struct ifnet *ifp) +{ + + NET_ASSERT_GIANT(); + + if ((ifp->if_flags & IFF_NEEDSGIANT) != 0 && debug_mpsafenet != 0) { + if (mtx_owned(&Giant)) + (*(ifp)->if_start)(ifp); + else + taskqueue_enqueue(taskqueue_swi_giant, + &ifp->if_starttask); + } else + (*(ifp)->if_start)(ifp); +} + +static void +if_start_deferred(void *context, int pending) +{ + struct ifnet *ifp; + + /* + * This code must be entered with Giant, and should never run if + * we're not running with debug.mpsafenet. + */ + KASSERT(debug_mpsafenet != 0, ("if_start_deferred: debug.mpsafenet")); + GIANT_REQUIRED; + + ifp = (struct ifnet *)context; + (ifp->if_start)(ifp); +} + SYSCTL_NODE(_net, PF_LINK, link, CTLFLAG_RW, 0, "Link layers"); SYSCTL_NODE(_net_link, 0, generic, CTLFLAG_RW, 0, "Generic link-management"); |
