bcache: Fix moving_pred()

Avoid a potential null pointer deref (e.g. from check keys for cache misses) Signed-off-by: Kent Overstreet <kmo@daterainc.com>

bcache: Fix moving_pred()
Avoid a potential null pointer deref (e.g. from check keys for cache misses) Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Kent Overstreet
1 parent da415a096f
Showing 1 changed file with 3 additions and 5 deletions Side-by-side Diff
drivers/md/bcache/movinggc.c
@@ -24,12 +24,10 @@
 					   moving_gc_keys);
 	unsigned i;
  
-	for (i = 0; i < KEY_PTRS(k); i++) {
-		struct bucket *g = PTR_BUCKET(c, k, i);
-
-		if (GC_MOVE(g))
+	for (i = 0; i < KEY_PTRS(k); i++)
+		if (ptr_available(c, k, i) &&
+		    GC_MOVE(PTR_BUCKET(c, k, i)))
 			return true;
-	}
  
 	return false;
 }
...	...	@@ -24,12 +24,10 @@
24	24	moving_gc_keys);
25	25	unsigned i;
26	26
27		- for (i = 0; i < KEY_PTRS(k); i++) {
28		- struct bucket *g = PTR_BUCKET(c, k, i);
29		-
30		- if (GC_MOVE(g))
	27	+ for (i = 0; i < KEY_PTRS(k); i++)
	28	+ if (ptr_available(c, k, i) &&
	29	+ GC_MOVE(PTR_BUCKET(c, k, i)))
31	30	return true;
32		- }
33	31
34	32	return false;
35	33	}