[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, 32 insertions, 4 deletions

diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index d7c7adcc0a67..404de41a4f67 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -419,8 +419,9 @@ void mconsole_config(struct mc_request *req)
 void mconsole_remove(struct mc_request *req)
 {
         struct mc_device *dev;  
-        char *ptr = req->request.data;
-        int err;
+        char *ptr = req->request.data, *err_msg = "";
+        char error[256];
+        int err, start, end, n;
 
         ptr += strlen("remove");
         while(isspace(*ptr)) ptr++;
@@ -429,8 +430,35 @@ void mconsole_remove(struct mc_request *req)
                 mconsole_reply(req, "Bad remove option", 1, 0);
                 return;
         }
-        err = (*dev->remove)(&ptr[strlen(dev->name)]);
-        mconsole_reply(req, "", err, 0);
+
+        ptr = &ptr[strlen(dev->name)];
+
+        err = 1;
+        n = (*dev->id)(&ptr, &start, &end);
+        if(n < 0){
+                err_msg = "Couldn't parse device number";
+                goto out;
+        }
+        else if((n < start) || (n > end)){
+                sprintf(error, "Invalid device number - must be between "
+                        "%d and %d", start, end);
+                err_msg = error;
+                goto out;
+        }
+
+        err = (*dev->remove)(n);
+        switch(err){
+        case -ENODEV:
+                err_msg = "Device doesn't exist";
+                break;
+        case -EBUSY:
+                err_msg = "Device is currently open";
+                break;
+        default:
+                break;
+        }
+ out:
+        mconsole_reply(req, err_msg, err, 0);
 }
 
 #ifdef CONFIG_MAGIC_SYSRQ