Author: np
Date: Fri Jun 22 20:19:33 2018
New Revision: 335561
URL: https://svnweb.freebsd.org/changeset/base/335561
Log:
cxgbe(4): Determine early in the ioctl whether it is allowed to sleep or
not, instead of always starting a non-sleepable operation and
re-adjusting later. This ensures that an operation that is allowed to
sleep (ifconfig up/down) never fails with EBUSY on the initial attempt
to start a synchronized operation.
This is a direct commit to stable/11. The driver ioctl is always
allowed to sleep in head.
Sponsored by: Chelsio Communications
Modified:
stable/11/sys/dev/cxgbe/t4_main.c
Modified: stable/11/sys/dev/cxgbe/t4_main.c
==============================================================================
--- stable/11/sys/dev/cxgbe/t4_main.c Fri Jun 22 17:58:56 2018
(r335560)
+++ stable/11/sys/dev/cxgbe/t4_main.c Fri Jun 22 20:19:33 2018
(r335561)
@@ -1607,7 +1607,7 @@ cxgbe_init(void *arg)
static int
cxgbe_ioctl(struct ifnet *ifp, unsigned long cmd, caddr_t data)
{
- int rc = 0, mtu, flags, can_sleep;
+ int rc = 0, mtu, can_sleep, if_flags, if_drv_flags, vi_if_flags;
struct vi_info *vi = ifp->if_softc;
struct port_info *pi = vi->pi;
struct adapter *sc = pi->adapter;
@@ -1633,48 +1633,57 @@ cxgbe_ioctl(struct ifnet *ifp, unsigned long cmd, cadd
break;
case SIOCSIFFLAGS:
- can_sleep = 0;
-redo_sifflags:
+ /*
+ * Decide what to do, with the port lock held.
+ */
+ PORT_LOCK(pi);
+ if_flags = ifp->if_flags;
+ if_drv_flags = ifp->if_drv_flags;
+ vi_if_flags = vi->if_flags;
+ if (if_flags & IFF_UP && if_drv_flags & IFF_DRV_RUNNING &&
+ (vi_if_flags ^ if_flags) & (IFF_PROMISC | IFF_ALLMULTI)) {
+ can_sleep = 0;
+ } else {
+ can_sleep = 1;
+ }
+ PORT_UNLOCK(pi);
+
+ /*
+ * ifp/vi flags may change here but we'll just do what our local
+ * copy of the flags indicates and then update the driver owned
+ * ifp/vi flags (in a synch-op and with the port lock held) to
+ * reflect what we did.
+ */
+
rc = begin_synchronized_op(sc, vi,
can_sleep ? (SLEEP_OK | INTR_OK) : HOLD_LOCK, "t4flg");
if (rc) {
if_printf(ifp, "%ssleepable synch operation failed: %d."
" if_flags 0x%08x, if_drv_flags 0x%08x\n",
- can_sleep ? "" : "non-", rc, ifp->if_flags,
- ifp->if_drv_flags);
+ can_sleep ? "" : "non-", rc, if_flags,
+ if_drv_flags);
return (rc);
}
- if (ifp->if_flags & IFF_UP) {
- if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
- flags = vi->if_flags;
- if ((ifp->if_flags ^ flags) &
+ if (if_flags & IFF_UP) {
+ if (if_drv_flags & IFF_DRV_RUNNING) {
+ if ((if_flags ^ vi_if_flags) &
(IFF_PROMISC | IFF_ALLMULTI)) {
- if (can_sleep == 1) {
- end_synchronized_op(sc, 0);
- can_sleep = 0;
- goto redo_sifflags;
- }
+ MPASS(can_sleep == 0);
rc = update_mac_settings(ifp,
XGMAC_PROMISC | XGMAC_ALLMULTI);
}
} else {
- if (can_sleep == 0) {
- end_synchronized_op(sc, LOCK_HELD);
- can_sleep = 1;
- goto redo_sifflags;
- }
+ MPASS(can_sleep == 1);
rc = cxgbe_init_synchronized(vi);
}
- vi->if_flags = ifp->if_flags;
- } else if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
- if (can_sleep == 0) {
- end_synchronized_op(sc, LOCK_HELD);
- can_sleep = 1;
- goto redo_sifflags;
- }
+ } else if (if_drv_flags & IFF_DRV_RUNNING) {
+ MPASS(can_sleep == 1);
rc = cxgbe_uninit_synchronized(vi);
}
+ PORT_LOCK(pi);
+ vi->if_flags = if_flags;
+ PORT_UNLOCK(pi);
end_synchronized_op(sc, can_sleep ? 0 : LOCK_HELD);
break;
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