s390/qdio: simplify debugfs code

There's no need for error handling, the debugfs core is smart enough to
deal with IS_ERR() internally.

This will also keep us from creating the debugfs files if the device
directory doesn't exist. Currently (because irq_ptr->debugfs_dev gets set
to NULL on error) the files would be placed into the debugfs root - without
any association to their parent device.

On teardown, use the debugfs_remove_recursive() helper to avoid keeping
track of each created file/directory.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

diff --git a/drivers/s390/cio/qdio.h b/drivers/s390/cio/qdio.h
index 85d5309..e24a2cd 100644 (file)
--- a/drivers/s390/cio/qdio.h
+++ b/drivers/s390/cio/qdio.h
@@ -254,7 +254,6 @@ struct qdio_q {
        /* upper-layer program handler */
        qdio_handler_t (*handler);
 
-       struct dentry *debugfs_q;
        struct qdio_irq *irq_ptr;
        struct sl *sl;
        /*
@@ -270,7 +269,6 @@ struct qdio_irq {
        struct ccw_device *cdev;
        struct list_head entry;         /* list of thinint devices */
        struct dentry *debugfs_dev;
-       struct dentry *debugfs_perf;
 
        unsigned long int_parm;
        struct subchannel_id schid;

diff --git a/drivers/s390/cio/qdio_debug.c b/drivers/s390/cio/qdio_debug.c
index 9c0370b..bf8d825 100644 (file)
--- a/drivers/s390/cio/qdio_debug.c
+++ b/drivers/s390/cio/qdio_debug.c
@@ -284,17 +284,14 @@ static const struct file_operations debugfs_perf_fops = {
        .release = single_release,
 };
 
-static void setup_debugfs_entry(struct qdio_q *q)
+static void setup_debugfs_entry(struct dentry *parent, struct qdio_q *q)
 {
        char name[QDIO_DEBUGFS_NAME_LEN];
 
        snprintf(name, QDIO_DEBUGFS_NAME_LEN, "%s_%d",
                 q->is_input_q ? "input" : "output",
                 q->nr);
-       q->debugfs_q = debugfs_create_file(name, 0444,
-                               q->irq_ptr->debugfs_dev, q, &qstat_fops);
-       if (IS_ERR(q->debugfs_q))
-               q->debugfs_q = NULL;
+       debugfs_create_file(name, 0444, parent, q, &qstat_fops);
 }
 
 void qdio_setup_debug_entries(struct qdio_irq *irq_ptr, struct ccw_device *cdev)
@@ -304,33 +301,18 @@ void qdio_setup_debug_entries(struct qdio_irq *irq_ptr, struct ccw_device *cdev)
 
        irq_ptr->debugfs_dev = debugfs_create_dir(dev_name(&cdev->dev),
                                                  debugfs_root);
-       if (IS_ERR(irq_ptr->debugfs_dev))
-               irq_ptr->debugfs_dev = NULL;
-
-       irq_ptr->debugfs_perf = debugfs_create_file("statistics",
-                               S_IFREG | S_IRUGO | S_IWUSR,
-                               irq_ptr->debugfs_dev, irq_ptr,
-                               &debugfs_perf_fops);
-       if (IS_ERR(irq_ptr->debugfs_perf))
-               irq_ptr->debugfs_perf = NULL;
+       debugfs_create_file("statistics", S_IFREG | S_IRUGO | S_IWUSR,
+                           irq_ptr->debugfs_dev, irq_ptr, &debugfs_perf_fops);
 
        for_each_input_queue(irq_ptr, q, i)
-               setup_debugfs_entry(q);
+               setup_debugfs_entry(irq_ptr->debugfs_dev, q);
        for_each_output_queue(irq_ptr, q, i)
-               setup_debugfs_entry(q);
+               setup_debugfs_entry(irq_ptr->debugfs_dev, q);
 }
 
 void qdio_shutdown_debug_entries(struct qdio_irq *irq_ptr)
 {
-       struct qdio_q *q;
-       int i;
-
-       for_each_input_queue(irq_ptr, q, i)
-               debugfs_remove(q->debugfs_q);
-       for_each_output_queue(irq_ptr, q, i)
-               debugfs_remove(q->debugfs_q);
-       debugfs_remove(irq_ptr->debugfs_perf);
-       debugfs_remove(irq_ptr->debugfs_dev);
+       debugfs_remove_recursive(irq_ptr->debugfs_dev);
 }
 
 int __init qdio_debug_init(void)
@@ -352,7 +334,7 @@ int __init qdio_debug_init(void)
 void qdio_debug_exit(void)
 {
        qdio_clear_dbf_list();
-       debugfs_remove(debugfs_root);
+       debugfs_remove_recursive(debugfs_root);
        debug_unregister(qdio_dbf_setup);
        debug_unregister(qdio_dbf_error);
 }

diff --git a/drivers/s390/cio/qdio_setup.c b/drivers/s390/cio/qdio_setup.c
index d57b115..ad04947 100644 (file)
--- a/drivers/s390/cio/qdio_setup.c
+++ b/drivers/s390/cio/qdio_setup.c
@@ -461,7 +461,7 @@ int qdio_setup_irq(struct qdio_irq *irq_ptr, struct qdio_initialize *init_data)
        memset(&irq_ptr->ssqd_desc, 0, sizeof(irq_ptr->ssqd_desc));
        memset(&irq_ptr->perf_stat, 0, sizeof(irq_ptr->perf_stat));
 
-       irq_ptr->debugfs_dev = irq_ptr->debugfs_perf = NULL;
+       irq_ptr->debugfs_dev = NULL;
        irq_ptr->sch_token = irq_ptr->perf_stat_enabled = 0;
        irq_ptr->state = QDIO_IRQ_STATE_INACTIVE;