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/scsi/aacraid/linit.c b/drivers/scsi/aacraid/linit.c
index cad6f9abaeb9..6e233362dd7b 100644
--- a/drivers/scsi/aacraid/linit.c
+++ b/drivers/scsi/aacraid/linit.c
@@ -38,7 +38,7 @@
 #include <linux/moduleparam.h>
 #include <linux/pci.h>
 #include <linux/slab.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/spinlock.h>
 #include <linux/syscalls.h>
 #include <linux/delay.h>
@@ -76,6 +76,7 @@ MODULE_DESCRIPTION("Dell PERC2, 2/Si, 3/Si, 3/Di, "
 MODULE_LICENSE("GPL");
 MODULE_VERSION(AAC_DRIVER_FULL_VERSION);
 
+static DEFINE_MUTEX(aac_mutex);
 static LIST_HEAD(aac_devices);
 static int aac_cfg_major = -1;
 char aac_driver_version[] = AAC_DRIVER_FULL_VERSION;
@@ -678,7 +679,7 @@ static int aac_cfg_open(struct inode *inode, struct file *file)
         unsigned minor_number = iminor(inode);
         int err = -ENODEV;
 
-        lock_kernel();  /* BKL pushdown: nothing else protects this list */
+        mutex_lock(&aac_mutex);  /* BKL pushdown: nothing else protects this list */
         list_for_each_entry(aac, &aac_devices, entry) {
                 if (aac->id == minor_number) {
                         file->private_data = aac;
@@ -686,7 +687,7 @@ static int aac_cfg_open(struct inode *inode, struct file *file)
                         break;
                 }
         }
-        unlock_kernel();
+        mutex_unlock(&aac_mutex);
 
         return err;
 }
@@ -711,9 +712,9 @@ static long aac_cfg_ioctl(struct file *file,
         int ret;
         if (!capable(CAP_SYS_RAWIO))
                 return -EPERM;
-        lock_kernel();
+        mutex_lock(&aac_mutex);
         ret = aac_do_ioctl(file->private_data, cmd, (void __user *)arg);
-        unlock_kernel();
+        mutex_unlock(&aac_mutex);
 
         return ret;
 }
@@ -722,7 +723,7 @@ static long aac_cfg_ioctl(struct file *file,
 static long aac_compat_do_ioctl(struct aac_dev *dev, unsigned cmd, unsigned long arg)
 {
         long ret;
-        lock_kernel();
+        mutex_lock(&aac_mutex);
         switch (cmd) {
         case FSACTL_MINIPORT_REV_CHECK:
         case FSACTL_SENDFIB:
@@ -756,7 +757,7 @@ static long aac_compat_do_ioctl(struct aac_dev *dev, unsigned cmd, unsigned long
                 ret = -ENOIOCTLCMD;
                 break;
         }
-        unlock_kernel();
+        mutex_unlock(&aac_mutex);
         return ret;
 }