From: Alexander Duyck Date: Tue, 13 Mar 2018 19:45:52 -0700 Subject: [Intel-wired-lan] [next-queue PATCH] i40evf: Reorder configure_clsflower to avoid deadlock on error Message-ID: <20180314024552.7086.86874.stgit@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: From: Alexander Duyck While doing some code review I noticed that we can get into a state where we exit with the "IN_CRITICAL_TASK" bit set while notifying the PF of flower filters. This patch is meant to address that plus tweak the ordering of the while loop waiting on it slightly so that we don't wait an extra period after we have failed for the last time. Signed-off-by: Alexander Duyck --- drivers/net/ethernet/intel/i40evf/i40evf_main.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff --git a/drivers/net/ethernet/intel/i40evf/i40evf_main.c b/drivers/net/ethernet/intel/i40evf/i40evf_main.c index 52a017c42ffd..57e74f845dc4 100644 --- a/drivers/net/ethernet/intel/i40evf/i40evf_main.c +++ b/drivers/net/ethernet/intel/i40evf/i40evf_main.c @@ -2792,14 +2792,7 @@ static int i40evf_configure_clsflower(struct i40evf_adapter *adapter, { int tc = tc_classid_to_hwtc(adapter->netdev, cls_flower->classid); struct i40evf_cloud_filter *filter = NULL; - int err = 0, count = 50; - - while (test_and_set_bit(__I40EVF_IN_CRITICAL_TASK, - &adapter->crit_section)) { - udelay(1); - if (--count == 0) - return -EINVAL; - } + int err = -EINVAL, count = 50; if (tc < 0) { dev_err(&adapter->pdev->dev, "Invalid traffic class\n"); @@ -2807,10 +2800,16 @@ static int i40evf_configure_clsflower(struct i40evf_adapter *adapter, } filter = kzalloc(sizeof(*filter), GFP_KERNEL); - if (!filter) { - err = -ENOMEM; - goto clearout; + if (!filter) + return -ENOMEM; + + while (test_and_set_bit(__I40EVF_IN_CRITICAL_TASK, + &adapter->crit_section)) { + if (--count == 0) + goto err; + udelay(1); } + filter->cookie = cls_flower->cookie; /* set the mask to all zeroes to begin with */ @@ -2835,7 +2834,7 @@ static int i40evf_configure_clsflower(struct i40evf_adapter *adapter, err: if (err) kfree(filter); -clearout: + clear_bit(__I40EVF_IN_CRITICAL_TASK, &adapter->crit_section); return err; }