scsi: 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: linux-scsi@vger.kernel.org
Cc: "James E.J. Bottomley" <James.Bottomley@suse.de>

1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/scsi/gdth.c b/drivers/scsi/gdth.c
index b860d650a563..e927607bbf89 100644
--- a/drivers/scsi/gdth.c
+++ b/drivers/scsi/gdth.c
@@ -120,7 +120,7 @@
 #include <linux/timer.h>
 #include <linux/dma-mapping.h>
 #include <linux/list.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/slab.h>
 
 #ifdef GDTH_RTC
@@ -140,6 +140,7 @@
 #include <scsi/scsi_host.h>
 #include "gdth.h"
 
+static DEFINE_MUTEX(gdth_mutex);
 static void gdth_delay(int milliseconds);
 static void gdth_eval_mapping(u32 size, u32 *cyls, int *heads, int *secs);
 static irqreturn_t gdth_interrupt(int irq, void *dev_id);
@@ -4042,12 +4043,12 @@ static int gdth_open(struct inode *inode, struct file *filep)
 {
     gdth_ha_str *ha;
 
-    lock_kernel();
+    mutex_lock(&gdth_mutex);
     list_for_each_entry(ha, &gdth_instances, list) {
         if (!ha->sdev)
             ha->sdev = scsi_get_host_dev(ha->shost);
     }
-    unlock_kernel();
+    mutex_unlock(&gdth_mutex);
 
     TRACE(("gdth_open()\n"));
     return 0;
@@ -4615,9 +4616,9 @@ static long gdth_unlocked_ioctl(struct file *file, unsigned int cmd,
 {
 	int ret;
 
-	lock_kernel();
+	mutex_lock(&gdth_mutex);
 	ret = gdth_ioctl(file, cmd, arg);
-	unlock_kernel();
+	mutex_unlock(&gdth_mutex);
 
 	return ret;
 }