1 files changed, 45 insertions, 0 deletions
diff --git a/util/bitmap.c b/util/bitmap.c
index f81d8057a7..8d12e90a5a 100644
--- a/util/bitmap.c
+++ b/util/bitmap.c
@@ -240,6 +240,51 @@ void bitmap_clear(unsigned long *map, long start, long nr)
     }
 }
 
+bool bitmap_test_and_clear(unsigned long *map, long start, long nr)
+{
+    unsigned long *p = map + BIT_WORD(start);
+    const long size = start + nr;
+    int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
+    unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
+    bool dirty = false;
+
+    assert(start >= 0 && nr >= 0);
+
+    /* First word */
+    if (nr - bits_to_clear > 0) {
+        if ((*p) & mask_to_clear) {
+            dirty = true;
+        }
+        *p &= ~mask_to_clear;
+        nr -= bits_to_clear;
+        bits_to_clear = BITS_PER_LONG;
+        p++;
+    }
+
+    /* Full words */
+    if (bits_to_clear == BITS_PER_LONG) {
+        while (nr >= BITS_PER_LONG) {
+            if (*p) {
+                dirty = true;
+                *p = 0;
+            }
+            nr -= BITS_PER_LONG;
+            p++;
+        }
+    }
+
+    /* Last word */
+    if (nr) {
+        mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
+        if ((*p) & mask_to_clear) {
+            dirty = true;
+        }
+        *p &= ~mask_to_clear;
+    }
+
+    return dirty;
+}
+
 bool bitmap_test_and_clear_atomic(unsigned long *map, long start, long nr)
 {
     unsigned long *p = map + BIT_WORD(start);