Re: [Xen-devel] [PATCH net-next v2] xen-netback: Adding debugfs "io_ring_qX" files
From: Zoltan Kiss
Date: Tue Jul 08 2014 - 10:34:14 EST
On 02/07/14 21:02, Konrad Rzeszutek Wilk wrote:
On Wed, Jul 02, 2014 at 08:53:50PM +0100, Zoltan Kiss wrote:
+static ssize_t
+xenvif_write_io_ring(struct file *filp, const char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ struct xenvif_queue *queue =
+ ((struct seq_file *)filp->private_data)->private;
+ int len;
+ char write[sizeof("kick")];
<blinks>
+
+ /* don't allow partial writes and check the length */
+ if (*ppos != 0)
+ return 0;
+ if (count < sizeof("kick") - 1)
Um, could you just use a #define please?
OK
+ return -ENOSPC;
+
+ len = simple_write_to_buffer(write,
+ sizeof(write),
+ ppos,
+ buf,
+ count);
+ if (len < 0)
+ return len;
+
+ if (!strncmp(write, "kick", sizeof("kick") - 1))
+ xenvif_interrupt(0, (void *)queue);
+ else
+ pr_warn("Unknown command to io_ring. Available: kick\n");
It is 'io_ring_q%d'?
Yes
Why don't you split that back out to the user
instead of the console?
How do you mean? Printing it into buf? I don't think the user cares
about its content after doing the write syscall. More importantly, I
don't know if that buffer is big enough to hold the message.
+ return count;
+}
+
+static int xenvif_dump_open(struct inode *inode, struct file *filp)
+{
+ int ret;
+ void *queue = NULL;
+
+ if (inode->i_private)
+ queue = inode->i_private;
+ ret = single_open(filp, xenvif_read_io_ring, queue);
+ filp->f_mode |= FMODE_PWRITE;
+ return ret;
+}
+
+static const struct file_operations xenvif_dbg_io_ring_ops_fops = {
+ .owner = THIS_MODULE,
+ .open = xenvif_dump_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+ .write = xenvif_write_io_ring,
+};
+
+static void xenvif_debugfs_addif(struct xenvif_queue *queue)
+{
+ struct dentry *pfile;
+ struct xenvif *vif = queue->vif;
+ int i;
+
+ vif->xenvif_dbg_root = debugfs_create_dir(vif->dev->name,
+ xen_netback_dbg_root);
+ if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root)) {
+ for (i = 0; i < vif->num_queues; ++i) {
+ char filename[sizeof("io_ring_q") + 4];
+
+ snprintf(filename, sizeof(filename), "io_ring_q%d", i);
+ pfile = debugfs_create_file(filename,
+ 0600,
Pls use macros for that.
OK
+ vif->xenvif_dbg_root,
+ &vif->queues[i],
+ &xenvif_dbg_io_ring_ops_fops);
+ if (IS_ERR_OR_NULL(pfile))
+ pr_warn("Creation of io_ring file returned %ld!\n",
+ PTR_ERR(pfile));
+ }
+ } else
+ netdev_warn(vif->dev,
+ "Creation of vif debugfs dir returned %ld!\n",
+ PTR_ERR(vif->xenvif_dbg_root));
+}
+
+static void xenvif_debugfs_delif(struct xenvif *vif)
+{
Could you add:
if (!IS_ERR_OR_NULL(xen_netback_dbg_root))
return;
Ok
+ if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root))
+ debugfs_remove_recursive(vif->xenvif_dbg_root);
+ vif->xenvif_dbg_root = NULL;
+}
+#endif /* CONFIG_DEBUG_FS */
+
static int netback_remove(struct xenbus_device *dev)
{
struct backend_info *be = dev_get_drvdata(&dev->dev);
@@ -246,8 +404,13 @@ static void backend_create_xenvif(struct backend_info *be)
static void backend_disconnect(struct backend_info *be)
{
- if (be->vif)
+ if (be->vif) {
+#ifdef CONFIG_DEBUG_FS
+ if (!IS_ERR_OR_NULL(xen_netback_dbg_root))
+ xenvif_debugfs_delif(be->vif);
.. and then you can remove these 'if' here
+#endif /* CONFIG_DEBUG_FS */
xenvif_disconnect(be->vif);
+ }
}
static void backend_connect(struct backend_info *be)
@@ -560,6 +723,10 @@ static void connect(struct backend_info *be)
be->vif->num_queues = queue_index;
goto err;
}
+#ifdef CONFIG_DEBUG_FS
+ if (!IS_ERR_OR_NULL(xen_netback_dbg_root))
.. and here.
+ xenvif_debugfs_addif(queue);
+#endif /* CONFIG_DEBUG_FS */
}
/* Initialisation completed, tell core driver the number of
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/