isdn: autoconvert trivial BKL users to private mutex

All these files use the big kernel lock in a trivial
way to serialize their private file operations,
typically resulting from an earlier semi-automatic
pushdown from VFS.

None of these drivers appears to want to lock against
other code, and they all use the BKL as the top-level
lock in their file operations, meaning that there
is no lock-order inversion problem.

Consequently, we can remove the BKL completely,
replacing it with a per-file mutex in every case.
Using a scripted approach means we can avoid
typos.

file=$1
name=$2
if grep -q lock_kernel ${file} ; then
    if grep -q 'include.*linux.mutex.h' ${file} ; then
            sed -i '/include.*<linux\/smp_lock.h>/d' ${file}
    else
            sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file}
    fi
    sed -i ${file} \
        -e "/^#include.*linux.mutex.h/,$ {
                1,/^\(static\|int\|long\)/ {
                     /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);

} }"  \
    -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
    -e '/[      ]*cycle_kernel_lock();/d'
else
    sed -i -e '/include.*\<smp_lock.h\>/d' ${file}  \
                -e '/cycle_kernel_lock()/d'
fi

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 10 deletions

diff --git a/drivers/isdn/hysdn/hysdn_procconf.c b/drivers/isdn/hysdn/hysdn_procconf.c
index 80966462d6dc..96b3e39c3356 100644
--- a/drivers/isdn/hysdn/hysdn_procconf.c
+++ b/drivers/isdn/hysdn/hysdn_procconf.c
@@ -17,11 +17,12 @@
 #include <linux/proc_fs.h>
 #include <linux/pci.h>
 #include <linux/slab.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <net/net_namespace.h>
 
 #include "hysdn_defs.h"
 
+static DEFINE_MUTEX(hysdn_conf_mutex);
 static char *hysdn_procconf_revision = "$Revision: 1.8.6.4 $";
 
 #define INFO_OUT_LEN 80         /* length of info line including lf */
@@ -234,7 +235,7 @@ hysdn_conf_open(struct inode *ino, struct file *filep)
         char *cp, *tmp;
 
         /* now search the addressed card */
-        lock_kernel();
+        mutex_lock(&hysdn_conf_mutex);
         card = card_root;
         while (card) {
                 pd = card->procconf;
@@ -243,7 +244,7 @@ hysdn_conf_open(struct inode *ino, struct file *filep)
                 card = card->next;      /* search next entry */
         }
         if (!card) {
-                unlock_kernel();
+                mutex_unlock(&hysdn_conf_mutex);
                 return (-ENODEV);       /* device is unknown/invalid */
         }
         if (card->debug_flags & (LOG_PROC_OPEN | LOG_PROC_ALL))
@@ -255,7 +256,7 @@ hysdn_conf_open(struct inode *ino, struct file *filep)
                 /* write only access -> write boot file or conf line */
 
                 if (!(cnf = kmalloc(sizeof(struct conf_writedata), GFP_KERNEL))) {
-                        unlock_kernel();
+                        mutex_unlock(&hysdn_conf_mutex);
                         return (-EFAULT);
                 }
                 cnf->card = card;
@@ -267,7 +268,7 @@ hysdn_conf_open(struct inode *ino, struct file *filep)
                 /* read access -> output card info data */
 
                 if (!(tmp = kmalloc(INFO_OUT_LEN * 2 + 2, GFP_KERNEL))) {
-                        unlock_kernel();
+                        mutex_unlock(&hysdn_conf_mutex);
                         return (-EFAULT);       /* out of memory */
                 }
                 filep->private_data = tmp;      /* start of string */
@@ -301,10 +302,10 @@ hysdn_conf_open(struct inode *ino, struct file *filep)
                 *cp++ = '\n';
                 *cp = 0;        /* end of string */
         } else {                /* simultaneous read/write access forbidden ! */
-                unlock_kernel();
+                mutex_unlock(&hysdn_conf_mutex);
                 return (-EPERM);        /* no permission this time */
         }
-        unlock_kernel();
+        mutex_unlock(&hysdn_conf_mutex);
         return nonseekable_open(ino, filep);
 }                               /* hysdn_conf_open */
 
@@ -319,7 +320,7 @@ hysdn_conf_close(struct inode *ino, struct file *filep)
         int retval = 0;
         struct proc_dir_entry *pd;
 
-        lock_kernel();
+        mutex_lock(&hysdn_conf_mutex);
         /* search the addressed card */
         card = card_root;
         while (card) {
@@ -329,7 +330,7 @@ hysdn_conf_close(struct inode *ino, struct file *filep)
                 card = card->next;      /* search next entry */
         }
         if (!card) {
-                unlock_kernel();
+                mutex_unlock(&hysdn_conf_mutex);
                 return (-ENODEV);       /* device is unknown/invalid */
         }
         if (card->debug_flags & (LOG_PROC_OPEN | LOG_PROC_ALL))
@@ -352,7 +353,7 @@ hysdn_conf_close(struct inode *ino, struct file *filep)
 
                 kfree(filep->private_data);     /* release memory */
         }
-        unlock_kernel();
+        mutex_unlock(&hysdn_conf_mutex);
         return (retval);
 }                               /* hysdn_conf_close */