2018-07-12 21:50:26

by Tuomas Tynkkynen

Subject: [PATCH 1/3] virtio: virtconsole: Use seq_file for debugfs operations

Simplifies the code and is more conventional to what's used in the rest
of the kernel for debugfs ops.

Signed-off-by: Tuomas Tynkkynen <[email protected]>
---
drivers/char/virtio_console.c | 60 ++++++++++++++++---------------------------
1 file changed, 22 insertions(+), 38 deletions(-)

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 21085515814f..f95f980d108d 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1310,51 +1310,35 @@ static const struct attribute_group port_attribute_group = {
.attrs = port_sysfs_entries,
};

-static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
- size_t count, loff_t *offp)
+static int debugfs_show(struct seq_file *s, void *data)
{
- struct port *port;
- char *buf;
- ssize_t ret, out_offset, out_count;
+ struct port *port = s->private;
+
+ seq_printf(s, "name: %s\n", port->name ? port->name : "");
+ seq_printf(s, "guest_connected: %d\n", port->guest_connected);
+ seq_printf(s, "host_connected: %d\n", port->host_connected);
+ seq_printf(s, "outvq_full: %d\n", port->outvq_full);
+ seq_printf(s, "bytes_sent: %lu\n", port->stats.bytes_sent);
+ seq_printf(s, "bytes_received: %lu\n", port->stats.bytes_received);
+ seq_printf(s, "bytes_discarded: %lu\n", port->stats.bytes_discarded);
+ seq_printf(s, "is_console: %s\n",
+ is_console_port(port) ? "yes" : "no");
+ seq_printf(s, "console_vtermno: %u\n", port->cons.vtermno);

- out_count = 1024;
- buf = kmalloc(out_count, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
+ return 0;
+}

- port = filp->private_data;
- out_offset = 0;
- out_offset += snprintf(buf + out_offset, out_count,
- "name: %s\n", port->name ? port->name : "");
- out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "guest_connected: %d\n", port->guest_connected);
- out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "host_connected: %d\n", port->host_connected);
- out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "outvq_full: %d\n", port->outvq_full);
- out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "bytes_sent: %lu\n", port->stats.bytes_sent);
- out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "bytes_received: %lu\n",
- port->stats.bytes_received);
- out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "bytes_discarded: %lu\n",
- port->stats.bytes_discarded);
- out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "is_console: %s\n",
- is_console_port(port) ? "yes" : "no");
- out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "console_vtermno: %u\n", port->cons.vtermno);
-
- ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
- kfree(buf);
- return ret;
+static int debugfs_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, debugfs_show, inode->i_private);
}

static const struct file_operations port_debugfs_ops = {
.owner = THIS_MODULE,
- .open = simple_open,
- .read = debugfs_read,
+ .open = debugfs_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
};

static void set_console_size(struct port *port, u16 rows, u16 cols)
--
2.16.3

2018-07-13 04:49:35

by Amit Shah

Subject: Re: [PATCH 1/3] virtio: virtconsole: Use seq_file for debugfs operations

Am 12. Juli 2018 23:39:56 MESZ schrieb Tuomas Tynkkynen <[email protected]>:
>Simplifies the code and is more conventional to what's used in the rest
>of the kernel for debugfs ops.
>
>Signed-off-by: Tuomas Tynkkynen <[email protected]>

Looks good, thanks.

Reviewed-by: Amit Shah <[email protected]>


Amit

--
http://amitshah.net