From 8c2def893afc60d88160d524acf345765cf0c447 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Mon, 3 Dec 2018 14:45:43 -0800 Subject: [PATCH] sbitmap: fix sbitmap_for_each_set() We need to ignore bits in the cleared mask when iterating over all set bits. Fixes: ea86ea2cdced ("sbitmap: ammortize cost of clearing bits") Reported-by: Jens Axboe@kernel.dk> Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe --- include/linux/sbitmap.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h index 92806a2dbab7..03f50fcedc79 100644 --- a/include/linux/sbitmap.h +++ b/include/linux/sbitmap.h @@ -265,12 +265,14 @@ static inline void __sbitmap_for_each_set(struct sbitmap *sb, nr = SB_NR_TO_BIT(sb, start); while (scanned < sb->depth) { - struct sbitmap_word *word = &sb->map[index]; - unsigned int depth = min_t(unsigned int, word->depth - nr, + unsigned long word; + unsigned int depth = min_t(unsigned int, + sb->map[index].depth - nr, sb->depth - scanned); scanned += depth; - if (!word->word) + word = sb->map[index].word & ~sb->map[index].cleared; + if (!word) goto next; /* @@ -280,7 +282,7 @@ static inline void __sbitmap_for_each_set(struct sbitmap *sb, */ depth += nr; while (1) { - nr = find_next_bit(&word->word, depth, nr); + nr = find_next_bit(&word, depth, nr); if (nr >= depth) break; if (!fn(sb, (index << sb->shift) + nr, data))