From: Michael Chan <mchan@broadcom.com>
To: <davem@davemloft.net>
Cc: <netdev@vger.kernel.org>, <nhorman@tuxdriver.com>,
Michael Chan <mchan@broadcom.com>
Subject: [PATCH 1/3] cnic: Don't take rcu_read_lock in cnic_rcv_netevent()
Date: Fri, 30 May 2014 16:18:41 -0700 [thread overview]
Message-ID: <1401491923-5480-2-git-send-email-mchan@broadcom.com> (raw)
In-Reply-To: <1401491923-5480-1-git-send-email-mchan@broadcom.com>
Because the called function, such as bnx2fc_indicate_netevent(), can sleep,
we cannot take rcu_lock(). To prevent the rcu protected ulp_ops from going
away, we use the cnic_lock mutex and set the ULP_F_CALL_PENDING flag.
The code already waits for ULP_F_CALL_PENDING flag to clear in
cnic_unregister_device().
Signed-off-by: Michael Chan <mchan@broadcom.com>
---
drivers/net/ethernet/broadcom/cnic.c | 15 +++++++++++----
1 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/cnic.c b/drivers/net/ethernet/broadcom/cnic.c
index 09f3fef..7f40a2c 100644
--- a/drivers/net/ethernet/broadcom/cnic.c
+++ b/drivers/net/ethernet/broadcom/cnic.c
@@ -5624,20 +5624,27 @@ static void cnic_rcv_netevent(struct cnic_local *cp, unsigned long event,
{
int if_type;
- rcu_read_lock();
for (if_type = 0; if_type < MAX_CNIC_ULP_TYPE; if_type++) {
struct cnic_ulp_ops *ulp_ops;
void *ctx;
- ulp_ops = rcu_dereference(cp->ulp_ops[if_type]);
- if (!ulp_ops || !ulp_ops->indicate_netevent)
+ mutex_lock(&cnic_lock);
+ ulp_ops = rcu_dereference_protected(cp->ulp_ops[if_type],
+ lockdep_is held(&cnic_lock));
+ if (!ulp_ops || !ulp_ops->indicate_netevent) {
+ mutex_unlock(&cnic_lock);
continue;
+ }
ctx = cp->ulp_handle[if_type];
+ set_bit(ULP_F_CALL_PENDING, &cp->ulp_flags[if_type]);
+ mutex_unlock(&cnic_lock);
+
ulp_ops->indicate_netevent(ctx, event, vlan_id);
+
+ clear_bit(ULP_F_CALL_PENDING, &cp->ulp_flags[if_type]);
}
- rcu_read_unlock();
}
/* netdev event handler */
--
1.7.1
next prev parent reply other threads:[~2014-05-30 21:59 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-30 23:18 [PATCH 0/3] cnic fixes Michael Chan
2014-05-30 23:18 ` Michael Chan [this message]
2014-05-30 23:18 ` [PATCH 2/3] cnic: Don't take cnic_dev_lock in cnic_alloc_uio_rings() Michael Chan
2014-05-30 22:33 ` Benjamin Poirier
2014-06-02 20:31 ` Michael Chan
2014-06-02 21:24 ` Benjamin Poirier
2014-05-30 22:50 ` Benjamin Poirier
2014-05-31 5:40 ` Michael Chan
2014-05-30 23:18 ` [PATCH 3/3] cnic: Fix missing ISCSI_KEVENT_IF_DOWN message Michael Chan
2014-05-31 13:07 ` [PATCH 2/3] cnic: Don't take cnic_dev_lock in cnic_alloc_uio_rings() Neil Horman
2014-06-01 0:07 ` Michael Chan
2014-06-02 23:53 ` [PATCH 0/3] cnic fixes David Miller
2014-06-02 23:57 ` David Miller
2014-06-03 0:08 ` Michael Chan
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