aoe: make error messages more specific in static minor allocation

For some special-purpose systems where udev isn't present, static
allocation of minor numbers is desirable.  This update distinguishes
different failure scenarios, to help the user understand what went
wrong.

Signed-off-by: Ed Cashin <ecashin@coraid.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/block/aoe/aoedev.c b/drivers/block/aoe/aoedev.c
index 91f7c99eb2a922b8dae749667aaf82960664b843..88ccd6d83c39b03c4e5b28e5bdb0fe81b03f047f 100644 (file)
--- a/drivers/block/aoe/aoedev.c
+++ b/drivers/block/aoe/aoedev.c
@@ -69,25 +69,34 @@ minor_get_static(ulong *sysminor, ulong aoemaj, int aoemin)
                NPERSHELF = 16,
        };
 
+       if (aoemin >= NPERSHELF) {
+               pr_err("aoe: %s %d slots per shelf\n",
+                       "static minor device numbers support only",
+                       NPERSHELF);
+               error = -1;
+               goto out;
+       }
+
        n = aoemaj * NPERSHELF + aoemin;
-       if (aoemin >= NPERSHELF || n >= N_DEVS) {
+       if (n >= N_DEVS) {
                pr_err("aoe: %s with e%ld.%d\n",
                        "cannot use static minor device numbers",
                        aoemaj, aoemin);
                error = -1;
-       } else {
-               spin_lock_irqsave(&used_minors_lock, flags);
-               if (test_bit(n, used_minors)) {
-                       pr_err("aoe: %s %lu\n",
-                               "existing device already has static minor number",
-                               n);
-                       error = -1;
-               } else
-                       set_bit(n, used_minors);
-               spin_unlock_irqrestore(&used_minors_lock, flags);
+               goto out;
        }
 
+       spin_lock_irqsave(&used_minors_lock, flags);
+       if (test_bit(n, used_minors)) {
+               pr_err("aoe: %s %lu\n",
+                       "existing device already has static minor number",
+                       n);
+               error = -1;
+       } else
+               set_bit(n, used_minors);
+       spin_unlock_irqrestore(&used_minors_lock, flags);
        *sysminor = n;
+out:
        return error;
 }