scsi_sysfs: protect against double execution of __scsi_remove_device()

[cascardo/linux.git] / drivers / scsi / scsi_sysfs.c

diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 9ad4116..ed91828 100644 (file)
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -773,6 +773,29 @@ static struct bin_attribute dev_attr_vpd_##_page = {               \
 sdev_vpd_pg_attr(pg83);
 sdev_vpd_pg_attr(pg80);
 
+static ssize_t show_inquiry(struct file *filep, struct kobject *kobj,
+                           struct bin_attribute *bin_attr,
+                           char *buf, loff_t off, size_t count)
+{
+       struct device *dev = container_of(kobj, struct device, kobj);
+       struct scsi_device *sdev = to_scsi_device(dev);
+
+       if (!sdev->inquiry)
+               return -EINVAL;
+
+       return memory_read_from_buffer(buf, count, &off, sdev->inquiry,
+                                      sdev->inquiry_len);
+}
+
+static struct bin_attribute dev_attr_inquiry = {
+       .attr = {
+               .name = "inquiry",
+               .mode = S_IRUGO,
+       },
+       .size = 0,
+       .read = show_inquiry,
+};
+
 static ssize_t
 show_iostat_counterbits(struct device *dev, struct device_attribute *attr,
                        char *buf)
@@ -898,7 +921,7 @@ sdev_store_queue_ramp_up_period(struct device *dev,
                return -EINVAL;
 
        sdev->queue_ramp_up_period = msecs_to_jiffies(period);
-       return period;
+       return count;
 }
 
 static DEVICE_ATTR(queue_ramp_up_period, S_IRUGO | S_IWUSR,
@@ -957,6 +980,7 @@ static struct attribute *scsi_sdev_attrs[] = {
 static struct bin_attribute *scsi_sdev_bin_attrs[] = {
        &dev_attr_vpd_pg83,
        &dev_attr_vpd_pg80,
+       &dev_attr_inquiry,
        NULL
 };
 static struct attribute_group scsi_sdev_attr_group = {
@@ -1030,11 +1054,20 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev)
                                "failed to add device: %d\n", error);
                return error;
        }
+
+       error = scsi_dh_add_device(sdev);
+       if (error) {
+               sdev_printk(KERN_INFO, sdev,
+                               "failed to add device handler: %d\n", error);
+               return error;
+       }
+
        device_enable_async_suspend(&sdev->sdev_dev);
        error = device_add(&sdev->sdev_dev);
        if (error) {
                sdev_printk(KERN_INFO, sdev,
                                "failed to add class device: %d\n", error);
+               scsi_dh_remove_device(sdev);
                device_del(&sdev->sdev_gendev);
                return error;
        }
@@ -1067,6 +1100,14 @@ void __scsi_remove_device(struct scsi_device *sdev)
 {
        struct device *dev = &sdev->sdev_gendev;
 
+       /*
+        * This cleanup path is not reentrant and while it is impossible
+        * to get a new reference with scsi_device_get() someone can still
+        * hold a previously acquired one.
+        */
+       if (sdev->sdev_state == SDEV_DEL)
+               return;
+
        if (sdev->is_visible) {
                if (scsi_device_set_state(sdev, SDEV_CANCEL) != 0)
                        return;
@@ -1074,6 +1115,7 @@ void __scsi_remove_device(struct scsi_device *sdev)
                bsg_unregister_queue(sdev->request_queue);
                device_unregister(&sdev->sdev_dev);
                transport_remove_device(dev);
+               scsi_dh_remove_device(sdev);
                device_del(dev);
        } else
                put_device(&sdev->sdev_dev);