parisc: convert /proc/pdc/{lcd,led} to seq_file
Convert code away from ->read_proc/->write_proc interfaces.
Switch to proc_create()/proc_create_data() which make addition of
proc entries reliable wrt NULL ->proc_fops, NULL ->data and so on.
Problem with ->read_proc et al is described here
commit 786d7e1612f0b0adb6046f19b906609e4fe8b1ba
"Fix rmmod/read/write races in /proc entries"
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
diff --git a/drivers/parisc/led.c b/drivers/parisc/led.c
index 79caf1c..188bc84 100644
--- a/drivers/parisc/led.c
+++ b/drivers/parisc/led.c
@@ -38,6 +38,7 @@
#include <linux/kernel_stat.h>
#include <linux/reboot.h>
#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
#include <linux/ctype.h>
#include <linux/blkdev.h>
#include <linux/workqueue.h>
@@ -147,41 +148,34 @@
static void (*led_func_ptr) (unsigned char) __read_mostly;
#ifdef CONFIG_PROC_FS
-static int led_proc_read(char *page, char **start, off_t off, int count,
- int *eof, void *data)
+static int led_proc_show(struct seq_file *m, void *v)
{
- char *out = page;
- int len;
-
- switch ((long)data)
+ switch ((long)m->private)
{
case LED_NOLCD:
- out += sprintf(out, "Heartbeat: %d\n", led_heartbeat);
- out += sprintf(out, "Disk IO: %d\n", led_diskio);
- out += sprintf(out, "LAN Rx/Tx: %d\n", led_lanrxtx);
+ seq_printf(m, "Heartbeat: %d\n", led_heartbeat);
+ seq_printf(m, "Disk IO: %d\n", led_diskio);
+ seq_printf(m, "LAN Rx/Tx: %d\n", led_lanrxtx);
break;
case LED_HASLCD:
- out += sprintf(out, "%s\n", lcd_text);
+ seq_printf(m, "%s\n", lcd_text);
break;
default:
- *eof = 1;
return 0;
}
-
- len = out - page - off;
- if (len < count) {
- *eof = 1;
- if (len <= 0) return 0;
- } else {
- len = count;
- }
- *start = page + off;
- return len;
+ return 0;
}
-static int led_proc_write(struct file *file, const char *buf,
- unsigned long count, void *data)
+static int led_proc_open(struct inode *inode, struct file *file)
{
+ return single_open(file, led_proc_show, PDE(inode)->data);
+}
+
+
+static ssize_t led_proc_write(struct file *file, const char *buf,
+ size_t count, loff_t *pos)
+{
+ void *data = PDE(file->f_path.dentry->d_inode)->data;
char *cur, lbuf[count + 1];
int d;
@@ -234,6 +228,15 @@
return -EINVAL;
}
+static const struct file_operations led_proc_fops = {
+ .owner = THIS_MODULE,
+ .open = led_proc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+ .write = led_proc_write,
+};
+
static int __init led_create_procfs(void)
{
struct proc_dir_entry *proc_pdc_root = NULL;
@@ -243,19 +246,15 @@
proc_pdc_root = proc_mkdir("pdc", 0);
if (!proc_pdc_root) return -1;
- ent = create_proc_entry("led", S_IFREG|S_IRUGO|S_IWUSR, proc_pdc_root);
+ ent = proc_create_data("led", S_IRUGO|S_IWUSR, proc_pdc_root,
+ &led_proc_fops, (void *)LED_NOLCD); /* LED */
if (!ent) return -1;
- ent->data = (void *)LED_NOLCD; /* LED */
- ent->read_proc = led_proc_read;
- ent->write_proc = led_proc_write;
if (led_type == LED_HASLCD)
{
- ent = create_proc_entry("lcd", S_IFREG|S_IRUGO|S_IWUSR, proc_pdc_root);
+ ent = proc_create_data("lcd", S_IRUGO|S_IWUSR, proc_pdc_root,
+ &led_proc_fops, (void *)LED_HASLCD); /* LCD */
if (!ent) return -1;
- ent->data = (void *)LED_HASLCD; /* LCD */
- ent->read_proc = led_proc_read;
- ent->write_proc = led_proc_write;
}
return 0;