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, 31 insertions, 23 deletions

diff --git a/drivers/isdn/hardware/avm/b1.c b/drivers/isdn/hardware/avm/b1.c
index a7c0083e78a7..c38fa0f4c729 100644
--- a/drivers/isdn/hardware/avm/b1.c
+++ b/drivers/isdn/hardware/avm/b1.c
@@ -12,6 +12,8 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/pci.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
 #include <linux/skbuff.h>
 #include <linux/delay.h>
 #include <linux/mm.h>
@@ -634,18 +636,17 @@ irqreturn_t b1_interrupt(int interrupt, void *devptr)
 }
 
 /* ------------------------------------------------------------- */
-int b1ctl_read_proc(char *page, char **start, off_t off,
-                        int count, int *eof, struct capi_ctr *ctrl)
+static int b1ctl_proc_show(struct seq_file *m, void *v)
 {
+        struct capi_ctr *ctrl = m->private;
         avmctrl_info *cinfo = (avmctrl_info *)(ctrl->driverdata);
         avmcard *card = cinfo->card;
         u8 flag;
-        int len = 0;
         char *s;
 
-        len += sprintf(page+len, "%-16s %s\n", "name", card->name);
-        len += sprintf(page+len, "%-16s 0x%x\n", "io", card->port);
-        len += sprintf(page+len, "%-16s %d\n", "irq", card->irq);
+        seq_printf(m, "%-16s %s\n", "name", card->name);
+        seq_printf(m, "%-16s 0x%x\n", "io", card->port);
+        seq_printf(m, "%-16s %d\n", "irq", card->irq);
         switch (card->cardtype) {
         case avm_b1isa: s = "B1 ISA"; break;
         case avm_b1pci: s = "B1 PCI"; break;
@@ -658,20 +659,20 @@ int b1ctl_read_proc(char *page, char **start, off_t off,
         case avm_c2: s = "C2"; break;
         default: s = "???"; break;
         }
-        len += sprintf(page+len, "%-16s %s\n", "type", s);
+        seq_printf(m, "%-16s %s\n", "type", s);
         if (card->cardtype == avm_t1isa)
-           len += sprintf(page+len, "%-16s %d\n", "cardnr", card->cardnr);
+                seq_printf(m, "%-16s %d\n", "cardnr", card->cardnr);
         if ((s = cinfo->version[VER_DRIVER]) != NULL)
-           len += sprintf(page+len, "%-16s %s\n", "ver_driver", s);
+                seq_printf(m, "%-16s %s\n", "ver_driver", s);
         if ((s = cinfo->version[VER_CARDTYPE]) != NULL)
-           len += sprintf(page+len, "%-16s %s\n", "ver_cardtype", s);
+                seq_printf(m, "%-16s %s\n", "ver_cardtype", s);
         if ((s = cinfo->version[VER_SERIAL]) != NULL)
-           len += sprintf(page+len, "%-16s %s\n", "ver_serial", s);
+                seq_printf(m, "%-16s %s\n", "ver_serial", s);
 
         if (card->cardtype != avm_m1) {
                 flag = ((u8 *)(ctrl->profile.manu))[3];
                 if (flag)
-                        len += sprintf(page+len, "%-16s%s%s%s%s%s%s%s\n",
+                        seq_printf(m, "%-16s%s%s%s%s%s%s%s\n",
                         "protocol",
                         (flag & 0x01) ? " DSS1" : "",
                         (flag & 0x02) ? " CT1" : "",
@@ -685,7 +686,7 @@ int b1ctl_read_proc(char *page, char **start, off_t off,
         if (card->cardtype != avm_m1) {
                 flag = ((u8 *)(ctrl->profile.manu))[5];
                 if (flag)
-                        len += sprintf(page+len, "%-16s%s%s%s%s\n",
+                        seq_printf(m, "%-16s%s%s%s%s\n",
                         "linetype",
                         (flag & 0x01) ? " point to point" : "",
                         (flag & 0x02) ? " point to multipoint" : "",
@@ -693,16 +694,25 @@ int b1ctl_read_proc(char *page, char **start, off_t off,
                         (flag & 0x04) ? " leased line with D-channel" : ""
                         );
         }
-        len += sprintf(page+len, "%-16s %s\n", "cardname", cinfo->cardname);
-
-        if (off+count >= len)
-           *eof = 1;
-        if (len < off)
-           return 0;
-        *start = page + off;
-        return ((count < len-off) ? count : len-off);
+        seq_printf(m, "%-16s %s\n", "cardname", cinfo->cardname);
+
+        return 0;
+}
+
+static int b1ctl_proc_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, b1ctl_proc_show, PDE(inode)->data);
 }
 
+const struct file_operations b1ctl_proc_fops = {
+        .owner          = THIS_MODULE,
+        .open           = b1ctl_proc_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+EXPORT_SYMBOL(b1ctl_proc_fops);
+
 /* ------------------------------------------------------------- */
 
 #ifdef CONFIG_PCI
@@ -781,8 +791,6 @@ EXPORT_SYMBOL(b1_send_message);
 EXPORT_SYMBOL(b1_parse_version);
 EXPORT_SYMBOL(b1_interrupt);
 
-EXPORT_SYMBOL(b1ctl_read_proc);
-
 static int __init b1_init(void)
 {
         char *p;