[PATCH] SCSI tape driver fixes for 2.5.51

This contains the following changes for the SCSI tape driver in 2.5.51:
- fix module bugs that prevent finding any devices
- allow opening a device with O_NONBLOCK | O_RDWR even if the tape in drive
  is write protected

Documentation/scsi/st.txt

 This file contains brief information about the SCSI tape driver.
-The driver is currently maintained by Kai M{kisara (email
+The driver is currently maintained by Kai Mäkisara (email
 Kai.Makisara@metla.fi)
 
-Last modified: Fri Jul 26 16:01:39 2002 by makisara
+Last modified: Sat Dec 14 14:35:30 2002 by makisara
 
 
 BASICS
@@ -89,7 +89,10 @@ The compile options are defined in the file linux/drivers/scsi/st_options.h.
 4. If the open option O_NONBLOCK is used, open succeeds even if the
 drive is not ready. If O_NONBLOCK is not used, the driver waits for
 the drive to become ready. If this does not happen in ST_BLOCK_SECONDS
-seconds, open fails with the errno value EIO.
+seconds, open fails with the errno value EIO. With O_NONBLOCK the
+device can be opened for writing even if there is a write protected
+tape in the drive (commands trying to write something return error if
+attempted).
 
 
 BSD AND SYS V SEMANTICS

drivers/scsi/st.c

@@ -12,13 +12,13 @@
    Copyright 1992 - 2002 Kai Makisara
    email Kai.Makisara@metla.fi
 
-   Last modified: Tue Oct 15 22:01:04 2002 by makisara
+   Last modified: Sat Dec 14 14:25:09 2002 by makisara
    Some small formal changes - aeb, 950809
 
    Last modified: 18-JAN-1998 Richard Gooch <rgooch@atnf.csiro.au> Devfs support
  */
 
-static char *verstr = "20021015";
+static char *verstr = "20021214";
 
 #include <linux/module.h>
 
@@ -923,8 +923,9 @@ static int check_tape(Scsi_Tape *STp, struct file *filp)
 
                 DEBC(printk(ST_DEB_MSG "%s: Write protected\n", name));
 
-		if ((st_flags & O_ACCMODE) == O_WRONLY ||
-		    (st_flags & O_ACCMODE) == O_RDWR) {
+		if (do_wait &&
+		    ((st_flags & O_ACCMODE) == O_WRONLY ||
+		     (st_flags & O_ACCMODE) == O_RDWR)) {
 			retval = (-EROFS);
 			goto err_out;
 		}
@@ -991,8 +992,10 @@ static int st_open(struct inode *inode, struct file *filp)
 		return (-EBUSY);
 	}
 
-	if(!scsi_device_get(STp->device))
+	if(scsi_device_get(STp->device)) {
+		write_unlock(&st_dev_arr_lock);
 		return (-ENXIO);
+	}
 	STp->in_use = 1;
 	write_unlock(&st_dev_arr_lock);
 	STp->rew_at_close = STp->autorew_dev = (minor(inode->i_rdev) & 0x80) == 0;