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, 12 insertions, 11 deletions

diff --git a/drivers/message/i2o/i2o_config.c b/drivers/message/i2o/i2o_config.c
index 068ba07..7d3cc57 100644
--- a/drivers/message/i2o/i2o_config.c
+++ b/drivers/message/i2o/i2o_config.c
@@ -31,7 +31,7 @@
  */
 
 #include <linux/miscdevice.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/compat.h>
 #include <linux/slab.h>
 
@@ -41,6 +41,7 @@
 
 #define SG_TABLESIZE		30
 
+static DEFINE_MUTEX(i2o_cfg_mutex);
 static long i2o_cfg_ioctl(struct file *, unsigned int, unsigned long);
 
 static spinlock_t i2o_config_lock;
@@ -741,7 +742,7 @@ static long i2o_cfg_compat_ioctl(struct file *file, unsigned cmd,
 				 unsigned long arg)
 {
 	int ret;
-	lock_kernel();
+	mutex_lock(&i2o_cfg_mutex);
 	switch (cmd) {
 	case I2OGETIOPS:
 		ret = i2o_cfg_ioctl(file, cmd, arg);
@@ -753,7 +754,7 @@ static long i2o_cfg_compat_ioctl(struct file *file, unsigned cmd,
 		ret = -ENOIOCTLCMD;
 		break;
 	}
-	unlock_kernel();
+	mutex_unlock(&i2o_cfg_mutex);
 	return ret;
 }
 
@@ -981,7 +982,7 @@ static long i2o_cfg_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 {
 	int ret;
 
-	lock_kernel();
+	mutex_lock(&i2o_cfg_mutex);
 	switch (cmd) {
 	case I2OGETIOPS:
 		ret = i2o_cfg_getiops(arg);
@@ -1037,7 +1038,7 @@ static long i2o_cfg_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 		osm_debug("unknown ioctl called!\n");
 		ret = -EINVAL;
 	}
-	unlock_kernel();
+	mutex_unlock(&i2o_cfg_mutex);
 	return ret;
 }
 
@@ -1051,7 +1052,7 @@ static int cfg_open(struct inode *inode, struct file *file)
 	if (!tmp)
 		return -ENOMEM;
 
-	lock_kernel();
+	mutex_lock(&i2o_cfg_mutex);
 	file->private_data = (void *)(i2o_cfg_info_id++);
 	tmp->fp = file;
 	tmp->fasync = NULL;
@@ -1065,7 +1066,7 @@ static int cfg_open(struct inode *inode, struct file *file)
 	spin_lock_irqsave(&i2o_config_lock, flags);
 	open_files = tmp;
 	spin_unlock_irqrestore(&i2o_config_lock, flags);
-	unlock_kernel();
+	mutex_unlock(&i2o_cfg_mutex);
 
 	return 0;
 }
@@ -1076,14 +1077,14 @@ static int cfg_fasync(int fd, struct file *fp, int on)
 	struct i2o_cfg_info *p;
 	int ret = -EBADF;
 
-	lock_kernel();
+	mutex_lock(&i2o_cfg_mutex);
 	for (p = open_files; p; p = p->next)
 		if (p->q_id == id)
 			break;
 
 	if (p)
 		ret = fasync_helper(fd, fp, on, &p->fasync);
-	unlock_kernel();
+	mutex_unlock(&i2o_cfg_mutex);
 	return ret;
 }
 
@@ -1093,7 +1094,7 @@ static int cfg_release(struct inode *inode, struct file *file)
 	struct i2o_cfg_info *p, **q;
 	unsigned long flags;
 
-	lock_kernel();
+	mutex_lock(&i2o_cfg_mutex);
 	spin_lock_irqsave(&i2o_config_lock, flags);
 	for (q = &open_files; (p = *q) != NULL; q = &p->next) {
 		if (p->q_id == id) {
@@ -1103,7 +1104,7 @@ static int cfg_release(struct inode *inode, struct file *file)
 		}
 	}
 	spin_unlock_irqrestore(&i2o_config_lock, flags);
-	unlock_kernel();
+	mutex_unlock(&i2o_cfg_mutex);
 
 	return 0;
 }