[PATCH] uml: hot-unplug code cleanup

Clean up the hot-unplugging code.  There is now an id procedure which is
called to figure out what device we're talking to.  The error messages from
that are now done from mconsole_remove instead of the driver.  remove is now
called with the device number, after it has been checked, so doesn't need to
do sanity checking on it.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 24 insertions, 13 deletions

diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 2a7f6892c55c..344b24d09a7c 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -754,24 +754,34 @@ static int ubd_get_config(char *name, char *str, int size, char **error_out)
         return(len);
 }
 
-static int ubd_remove(char *str)
+static int ubd_id(char **str, int *start_out, int *end_out)
+{
+        int n;
+
+        n = parse_unit(str);
+        *start_out = 0;
+        *end_out = MAX_DEV - 1;
+        return n;
+}
+
+static int ubd_remove(int n)
 {
         struct ubd *dev;
-        int n, err = -ENODEV;
+        int err = -ENODEV;
 
-        n = parse_unit(&str);
+        spin_lock(&ubd_lock);
 
-        if((n < 0) || (n >= MAX_DEV))
-                return(err);
+        if(ubd_gendisk[n] == NULL)
+                goto out;
 
         dev = &ubd_dev[n];
-        if(dev->count > 0)
-                return(-EBUSY); /* you cannot remove a open disk */
 
-        err = 0;
-        spin_lock(&ubd_lock);
+        if(dev->file == NULL)
+                goto out;
 
-        if(ubd_gendisk[n] == NULL)
+        /* you cannot remove a open disk */
+        err = -EBUSY;
+        if(dev->count > 0)
                 goto out;
 
         del_gendisk(ubd_gendisk[n]);
@@ -787,15 +797,16 @@ static int ubd_remove(char *str)
         platform_device_unregister(&dev->pdev);
         *dev = ((struct ubd) DEFAULT_UBD);
         err = 0;
- out:
-        spin_unlock(&ubd_lock);
-        return(err);
+out:
+        spin_unlock(&ubd_lock);
+        return err;
 }
 
 static struct mc_device ubd_mc = {
         .name           = "ubd",
         .config         = ubd_config,
         .get_config     = ubd_get_config,
+        .id             = ubd_id,
         .remove         = ubd_remove,
 };