proc_fops: convert drivers/isdn/ 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"

[akpm@linux-foundation.org: CONFIG_PROC_FS=n build fix]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: Karsten Keil <keil@b1-systems.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 16 deletions

diff --git a/net/bluetooth/cmtp/capi.c b/net/bluetooth/cmtp/capi.c
index 97f8d68d574d..3487cfe74aec 100644
--- a/net/bluetooth/cmtp/capi.c
+++ b/net/bluetooth/cmtp/capi.c
@@ -21,7 +21,8 @@
 */
 
 #include <linux/module.h>
-
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
@@ -516,33 +517,37 @@ static char *cmtp_procinfo(struct capi_ctr *ctrl)
         return "CAPI Message Transport Protocol";
 }
 
-static int cmtp_ctr_read_proc(char *page, char **start, off_t off, int count, int *eof, struct capi_ctr *ctrl)
+static int cmtp_proc_show(struct seq_file *m, void *v)
 {
+        struct capi_ctr *ctrl = m->private;
         struct cmtp_session *session = ctrl->driverdata;
         struct cmtp_application *app;
         struct list_head *p, *n;
-        int len = 0;
 
-        len += sprintf(page + len, "%s\n\n", cmtp_procinfo(ctrl));
-        len += sprintf(page + len, "addr %s\n", session->name);
-        len += sprintf(page + len, "ctrl %d\n", session->num);
+        seq_printf(m, "%s\n\n", cmtp_procinfo(ctrl));
+        seq_printf(m, "addr %s\n", session->name);
+        seq_printf(m, "ctrl %d\n", session->num);
 
         list_for_each_safe(p, n, &session->applications) {
                 app = list_entry(p, struct cmtp_application, list);
-                len += sprintf(page + len, "appl %d -> %d\n", app->appl, app->mapping);
+                seq_printf(m, "appl %d -> %d\n", app->appl, app->mapping);
         }
 
-        if (off + count >= len)
-                *eof = 1;
-
-        if (len < off)
-                return 0;
-
-        *start = page + off;
+        return 0;
+}
 
-        return ((count < len - off) ? count : len - off);
+static int cmtp_proc_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, cmtp_proc_show, PDE(inode)->data);
 }
 
+static const struct file_operations cmtp_proc_fops = {
+        .owner          = THIS_MODULE,
+        .open           = cmtp_proc_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
 
 int cmtp_attach_device(struct cmtp_session *session)
 {
@@ -582,7 +587,7 @@ int cmtp_attach_device(struct cmtp_session *session)
         session->ctrl.send_message  = cmtp_send_message;
 
         session->ctrl.procinfo      = cmtp_procinfo;
-        session->ctrl.ctr_read_proc = cmtp_ctr_read_proc;
+        session->ctrl.proc_fops = &cmtp_proc_fops;
 
         if (attach_capi_ctr(&session->ctrl) < 0) {
                 BT_ERR("Can't attach new controller");