[PATCH] proc: convert /proc/tty/ldiscs to seq_file interface

From: Alexey Dobriyan
Date: Sat Apr 12 2008 - 17:04:22 EST


Note: THIS_MODULE and header addition aren't technically needed because
this code is not modular, but let's keep it anyway because people
can copy this code into modular code.

Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
---

fs/proc/proc_tty.c | 74 +++++++++++++++++++++++++++++++----------------------
1 file changed, 44 insertions(+), 30 deletions(-)

--- a/fs/proc/proc_tty.c
+++ b/fs/proc/proc_tty.c
@@ -5,7 +5,7 @@
*/

#include <asm/uaccess.h>
-
+#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/time.h>
@@ -136,39 +136,54 @@ static const struct file_operations proc_tty_drivers_operations = {
.release = seq_release,
};

-/*
- * This is the handler for /proc/tty/ldiscs
- */
-static int tty_ldiscs_read_proc(char *page, char **start, off_t off,
- int count, int *eof, void *data)
+static void * tty_ldiscs_seq_start(struct seq_file *m, loff_t *pos)
{
- int i;
- int len = 0;
- off_t begin = 0;
+ return (*pos < NR_LDISCS) ? pos : NULL;
+}
+
+static void * tty_ldiscs_seq_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ (*pos)++;
+ return (*pos < NR_LDISCS) ? pos : NULL;
+}
+
+static void tty_ldiscs_seq_stop(struct seq_file *m, void *v)
+{
+}
+
+static int tty_ldiscs_seq_show(struct seq_file *m, void *v)
+{
+ int i = *(loff_t *)v;
struct tty_ldisc *ld;

- for (i=0; i < NR_LDISCS; i++) {
- ld = tty_ldisc_get(i);
- if (ld == NULL)
- continue;
- len += sprintf(page+len, "%-10s %2d\n",
- ld->name ? ld->name : "???", i);
- tty_ldisc_put(i);
- if (len+begin > off+count)
- break;
- if (len+begin < off) {
- begin += len;
- len = 0;
- }
- }
- if (i >= NR_LDISCS)
- *eof = 1;
- if (off >= len+begin)
+ ld = tty_ldisc_get(i);
+ if (ld == NULL)
return 0;
- *start = page + (off-begin);
- return ((count < begin+len-off) ? count : begin+len-off);
+ seq_printf(m, "%-10s %2d\n", ld->name ? ld->name : "???", i);
+ tty_ldisc_put(i);
+ return 0;
+}
+
+static const struct seq_operations tty_ldiscs_seq_ops = {
+ .start = tty_ldiscs_seq_start,
+ .next = tty_ldiscs_seq_next,
+ .stop = tty_ldiscs_seq_stop,
+ .show = tty_ldiscs_seq_show,
+};
+
+static int proc_tty_ldiscs_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &tty_ldiscs_seq_ops);
}

+static const struct file_operations tty_ldiscs_proc_fops = {
+ .owner = THIS_MODULE,
+ .open = proc_tty_ldiscs_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
/*
* This function is called by tty_register_driver() to handle
* registering the driver's /proc handler into /proc/tty/driver/<foo>
@@ -224,7 +239,6 @@ void __init proc_tty_init(void)
* entry.
*/
proc_tty_driver = proc_mkdir_mode("tty/driver", S_IRUSR | S_IXUSR, NULL);
-
- create_proc_read_entry("tty/ldiscs", 0, NULL, tty_ldiscs_read_proc, NULL);
+ proc_create("tty/ldiscs", 0, NULL, &tty_ldiscs_proc_fops);
proc_create("tty/drivers", 0, NULL, &proc_tty_drivers_operations);
}
--
1.5.3.7


--
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/