1 files changed, 16 insertions, 7 deletions

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 066628776e1b..25d010d449a3 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -472,6 +472,7 @@ static ssize_t sriov_numvfs_store(struct device *dev,
 				  const char *buf, size_t count)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
+	struct pci_sriov *iov = pdev->sriov;
 	int ret;
 	u16 num_vfs;
 
@@ -482,38 +483,46 @@ static ssize_t sriov_numvfs_store(struct device *dev,
 	if (num_vfs > pci_sriov_get_totalvfs(pdev))
 		return -ERANGE;
 
+	mutex_lock(&iov->dev->sriov->lock);
+
 	if (num_vfs == pdev->sriov->num_VFs)
-		return count;		/* no change */
+		goto exit;
 
 	/* is PF driver loaded w/callback */
 	if (!pdev->driver || !pdev->driver->sriov_configure) {
 		dev_info(&pdev->dev, "Driver doesn't support SRIOV configuration via sysfs\n");
-		return -ENOSYS;
+		ret = -ENOENT;
+		goto exit;
 	}
 
 	if (num_vfs == 0) {
 		/* disable VFs */
 		ret = pdev->driver->sriov_configure(pdev, 0);
-		if (ret < 0)
-			return ret;
-		return count;
+		goto exit;
 	}
 
 	/* enable VFs */
 	if (pdev->sriov->num_VFs) {
 		dev_warn(&pdev->dev, "%d VFs already enabled. Disable before enabling %d VFs\n",
 			 pdev->sriov->num_VFs, num_vfs);
-		return -EBUSY;
+		ret = -EBUSY;
+		goto exit;
 	}
 
 	ret = pdev->driver->sriov_configure(pdev, num_vfs);
 	if (ret < 0)
-		return ret;
+		goto exit;
 
 	if (ret != num_vfs)
 		dev_warn(&pdev->dev, "%d VFs requested; only %d enabled\n",
 			 num_vfs, ret);
 
+exit:
+	mutex_unlock(&iov->dev->sriov->lock);
+
+	if (ret < 0)
+		return ret;
+
 	return count;
 }