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, 8 insertions, 7 deletions

diff --git a/drivers/message/fusion/mptctl.c b/drivers/message/fusion/mptctl.c
index d8ddfdf..a3856ed 100644
--- a/drivers/message/fusion/mptctl.c
+++ b/drivers/message/fusion/mptctl.c
@@ -54,7 +54,7 @@
 #include <linux/pci.h>
 #include <linux/delay.h>	/* for mdelay */
 #include <linux/miscdevice.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/compat.h>
 
 #include <asm/io.h>
@@ -83,6 +83,7 @@ MODULE_VERSION(my_VERSION);
 
 /*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=*/
 
+static DEFINE_MUTEX(mpctl_mutex);
 static u8 mptctl_id = MPT_MAX_PROTOCOL_DRIVERS;
 static u8 mptctl_taskmgmt_id = MPT_MAX_PROTOCOL_DRIVERS;
 
@@ -601,12 +602,12 @@ mptctl_fasync(int fd, struct file *filep, int mode)
 	MPT_ADAPTER	*ioc;
 	int ret;
 
-	lock_kernel();
+	mutex_lock(&mpctl_mutex);
 	list_for_each_entry(ioc, &ioc_list, list)
 		ioc->aen_event_read_flag=0;
 
 	ret = fasync_helper(fd, filep, mode, &async_queue);
-	unlock_kernel();
+	mutex_unlock(&mpctl_mutex);
 	return ret;
 }
 
@@ -698,9 +699,9 @@ static long
 mptctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	long ret;
-	lock_kernel();
+	mutex_lock(&mpctl_mutex);
 	ret = __mptctl_ioctl(file, cmd, arg);
-	unlock_kernel();
+	mutex_unlock(&mpctl_mutex);
 	return ret;
 }
 
@@ -2926,7 +2927,7 @@ compat_mpt_command(struct file *filp, unsigned int cmd,
 static long compat_mpctl_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
 {
 	long ret;
-	lock_kernel();
+	mutex_lock(&mpctl_mutex);
 	switch (cmd) {
 	case MPTIOCINFO:
 	case MPTIOCINFO1:
@@ -2951,7 +2952,7 @@ static long compat_mpctl_ioctl(struct file *f, unsigned int cmd, unsigned long a
 		ret = -ENOIOCTLCMD;
 		break;
 	}
-	unlock_kernel();
+	mutex_unlock(&mpctl_mutex);
 	return ret;
 }