[S390] tape: remove BKL from tape driver

Replace BLK with a per device mutex.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

4 files changed, 29 insertions, 22 deletions

diff --git a/drivers/s390/char/tape.h b/drivers/s390/char/tape.h
index fbe41e0377b8..7a242f073632 100644
--- a/drivers/s390/char/tape.h
+++ b/drivers/s390/char/tape.h
@@ -212,6 +212,9 @@ struct tape_device {
         struct tape_class_device *      nt;
         struct tape_class_device *      rt;
 
+        /* Device mutex to serialize tape commands. */
+        struct mutex                    mutex;
+
         /* Device discipline information. */
         struct tape_discipline *        discipline;
         void *                          discdata;
diff --git a/drivers/s390/char/tape_block.c b/drivers/s390/char/tape_block.c
index c97c6aac8ed5..4799cc2f73c3 100644
--- a/drivers/s390/char/tape_block.c
+++ b/drivers/s390/char/tape_block.c
@@ -54,7 +54,7 @@ static const struct block_device_operations tapeblock_fops = {
         .owner           = THIS_MODULE,
         .open            = tapeblock_open,
         .release         = tapeblock_release,
-        .locked_ioctl           = tapeblock_ioctl,
+        .ioctl           = tapeblock_ioctl,
         .media_changed   = tapeblock_medium_changed,
         .revalidate_disk = tapeblock_revalidate_disk,
 };
diff --git a/drivers/s390/char/tape_char.c b/drivers/s390/char/tape_char.c
index d44e6981eeac..23d773a0d113 100644
--- a/drivers/s390/char/tape_char.c
+++ b/drivers/s390/char/tape_char.c
@@ -33,8 +33,7 @@ static ssize_t tapechar_read(struct file *, char __user *, size_t, loff_t *);
 static ssize_t tapechar_write(struct file *, const char __user *, size_t, loff_t *);
 static int tapechar_open(struct inode *,struct file *);
 static int tapechar_release(struct inode *,struct file *);
-static int tapechar_ioctl(struct inode *, struct file *, unsigned int,
-                          unsigned long);
+static long tapechar_ioctl(struct file *, unsigned int, unsigned long);
 static long tapechar_compat_ioctl(struct file *, unsigned int,
                           unsigned long);
 
@@ -43,7 +42,7 @@ static const struct file_operations tape_fops =
         .owner = THIS_MODULE,
         .read = tapechar_read,
         .write = tapechar_write,
-        .ioctl = tapechar_ioctl,
+        .unlocked_ioctl = tapechar_ioctl,
         .compat_ioctl = tapechar_compat_ioctl,
         .open = tapechar_open,
         .release = tapechar_release,
@@ -284,26 +283,20 @@ tapechar_open (struct inode *inode, struct file *filp)
         if (imajor(filp->f_path.dentry->d_inode) != tapechar_major)
                 return -ENODEV;
 
-        lock_kernel();
         minor = iminor(filp->f_path.dentry->d_inode);
         device = tape_find_device(minor / TAPE_MINORS_PER_DEV);
         if (IS_ERR(device)) {
                 DBF_EVENT(3, "TCHAR:open: tape_find_device() failed\n");
-                rc = PTR_ERR(device);
-                goto out;
+                return PTR_ERR(device);
         }
 
-
         rc = tape_open(device);
         if (rc == 0) {
                 filp->private_data = device;
-                rc = nonseekable_open(inode, filp);
-        }
-        else
+                nonseekable_open(inode, filp);
+        } else
                 tape_put_device(device);
 
-out:
-        unlock_kernel();
         return rc;
 }
 
@@ -350,16 +343,11 @@ tapechar_release(struct inode *inode, struct file *filp)
  * Tape device io controls.
  */
 static int
-tapechar_ioctl(struct inode *inp, struct file *filp,
-               unsigned int no, unsigned long data)
+__tapechar_ioctl(struct tape_device *device,
+                 unsigned int no, unsigned long data)
 {
-        struct tape_device *device;
         int rc;
 
-        DBF_EVENT(6, "TCHAR:ioct\n");
-
-        device = (struct tape_device *) filp->private_data;
-
         if (no == MTIOCTOP) {
                 struct mtop op;
 
@@ -452,15 +440,30 @@ tapechar_ioctl(struct inode *inp, struct file *filp,
 }
 
 static long
+tapechar_ioctl(struct file *filp, unsigned int no, unsigned long data)
+{
+        struct tape_device *device;
+        long rc;
+
+        DBF_EVENT(6, "TCHAR:ioct\n");
+
+        device = (struct tape_device *) filp->private_data;
+        mutex_lock(&device->mutex);
+        rc = __tapechar_ioctl(device, no, data);
+        mutex_unlock(&device->mutex);
+        return rc;
+}
+
+static long
 tapechar_compat_ioctl(struct file *filp, unsigned int no, unsigned long data)
 {
         struct tape_device *device = filp->private_data;
         int rval = -ENOIOCTLCMD;
 
         if (device->discipline->ioctl_fn) {
-                lock_kernel();
+                mutex_lock(&device->mutex);
                 rval = device->discipline->ioctl_fn(device, no, data);
-                unlock_kernel();
+                mutex_unlock(&device->mutex);
                 if (rval == -EINVAL)
                         rval = -ENOIOCTLCMD;
         }
diff --git a/drivers/s390/char/tape_core.c b/drivers/s390/char/tape_core.c
index a7b7e72c691b..f5d6802dc5da 100644
--- a/drivers/s390/char/tape_core.c
+++ b/drivers/s390/char/tape_core.c
@@ -492,6 +492,7 @@ tape_alloc_device(void)
                 kfree(device);
                 return ERR_PTR(-ENOMEM);
         }
+        mutex_init(&device->mutex);
         INIT_LIST_HEAD(&device->req_queue);
         INIT_LIST_HEAD(&device->node);
         init_waitqueue_head(&device->state_change_wq);