sbitmap: simplify wrap check
authorPavel Begunkov <asml.silence@gmail.com>
Sun, 22 Nov 2020 15:35:48 +0000 (15:35 +0000)
committerJens Axboe <axboe@kernel.dk>
Tue, 8 Dec 2020 00:12:49 +0000 (17:12 -0700)
__sbitmap_get_word() doesn't warp if it's starting from the beginning
(i.e. initial hint is 0). Instead of stashing the original hint just set
@wrap accordingly.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
lib/sbitmap.c

index c18b518..d693d92 100644 (file)
@@ -97,9 +97,11 @@ EXPORT_SYMBOL_GPL(sbitmap_resize);
 static int __sbitmap_get_word(unsigned long *word, unsigned long depth,
                              unsigned int hint, bool wrap)
 {
-       unsigned int orig_hint = hint;
        int nr;
 
+       /* don't wrap if starting from 0 */
+       wrap = wrap && hint;
+
        while (1) {
                nr = find_next_zero_bit(word, depth, hint);
                if (unlikely(nr >= depth)) {
@@ -108,8 +110,8 @@ static int __sbitmap_get_word(unsigned long *word, unsigned long depth,
                         * offset to 0 in a failure case, so start from 0 to
                         * exhaust the map.
                         */
-                       if (orig_hint && hint && wrap) {
-                               hint = orig_hint = 0;
+                       if (hint && wrap) {
+                               hint = 0;
                                continue;
                        }
                        return -1;