1 files changed, 46 insertions, 29 deletions

diff --git a/drivers/s390/char/tape_char.c b/drivers/s390/char/tape_char.c
index 31566c55adf..539045acaad 100644
--- a/drivers/s390/char/tape_char.c
+++ b/drivers/s390/char/tape_char.c
@@ -10,11 +10,15 @@
  *		 Martin Schwidefsky <schwidefsky@de.ibm.com>
  */
 
+#define KMSG_COMPONENT "tape"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/proc_fs.h>
 #include <linux/mtio.h>
 #include <linux/smp_lock.h>
+#include <linux/compat.h>
 
 #include <asm/uaccess.h>
 
@@ -33,18 +37,20 @@ 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_compat_ioctl(struct file *, unsigned int,
-			  unsigned long);
+static long tapechar_ioctl(struct file *, unsigned int, unsigned long);
+#ifdef CONFIG_COMPAT
+static long tapechar_compat_ioctl(struct file *, unsigned int, unsigned long);
+#endif
 
 static const struct file_operations tape_fops =
 {
 	.owner = THIS_MODULE,
 	.read = tapechar_read,
 	.write = tapechar_write,
-	.ioctl = tapechar_ioctl,
+	.unlocked_ioctl = tapechar_ioctl,
+#ifdef CONFIG_COMPAT
 	.compat_ioctl = tapechar_compat_ioctl,
+#endif
 	.open = tapechar_open,
 	.release = tapechar_release,
 };
@@ -170,7 +176,6 @@ tapechar_read(struct file *filp, char __user *data, size_t count, loff_t *ppos)
 	if (rc == 0) {
 		rc = block_size - request->rescnt;
 		DBF_EVENT(6, "TCHAR:rbytes:  %x\n", rc);
-		filp->f_pos += rc;
 		/* Copy data from idal buffer to user space. */
 		if (idal_buffer_to_user(device->char_data.idal_buf,
 					data, rc) != 0)
@@ -238,7 +243,6 @@ tapechar_write(struct file *filp, const char __user *data, size_t count, loff_t
 			break;
 		DBF_EVENT(6, "TCHAR:wbytes: %lx\n",
 			  block_size - request->rescnt);
-		filp->f_pos += block_size - request->rescnt;
 		written += block_size - request->rescnt;
 		if (request->rescnt != 0)
 			break;
@@ -286,26 +290,20 @@ 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_get_device(minor / TAPE_MINORS_PER_DEV);
+	device = tape_find_device(minor / TAPE_MINORS_PER_DEV);
 	if (IS_ERR(device)) {
-		DBF_EVENT(3, "TCHAR:open: tape_get_device() failed\n");
-		rc = PTR_ERR(device);
-		goto out;
+		DBF_EVENT(3, "TCHAR:open: tape_find_device() failed\n");
+		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;
 }
 
@@ -342,7 +340,8 @@ tapechar_release(struct inode *inode, struct file *filp)
 		device->char_data.idal_buf = NULL;
 	}
 	tape_release(device);
-	filp->private_data = tape_put_device(device);
+	filp->private_data = NULL;
+	tape_put_device(device);
 
 	return 0;
 }
@@ -351,16 +350,11 @@ 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;
 
@@ -453,21 +447,44 @@ 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;
+}
+
+#ifdef CONFIG_COMPAT
+static long
 tapechar_compat_ioctl(struct file *filp, unsigned int no, unsigned long data)
 {
 	struct tape_device *device = filp->private_data;
 	int rval = -ENOIOCTLCMD;
+	unsigned long argp;
 
+	/* The 'arg' argument of any ioctl function may only be used for
+	 * pointers because of the compat pointer conversion.
+	 * Consider this when adding new ioctls.
+	 */
+	argp = (unsigned long) compat_ptr(data);
 	if (device->discipline->ioctl_fn) {
-		lock_kernel();
-		rval = device->discipline->ioctl_fn(device, no, data);
-		unlock_kernel();
+		mutex_lock(&device->mutex);
+		rval = device->discipline->ioctl_fn(device, no, argp);
+		mutex_unlock(&device->mutex);
 		if (rval == -EINVAL)
 			rval = -ENOIOCTLCMD;
 	}
 
 	return rval;
 }
+#endif /* CONFIG_COMPAT */
 
 /*
  * Initialize character device frontend.