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Commit 8c2def89 authored by Omar Sandoval's avatar Omar Sandoval Committed by Jens Axboe
Browse files

sbitmap: fix sbitmap_for_each_set() 



We need to ignore bits in the cleared mask when iterating over all set
bits.

Fixes: ea86ea2c ("sbitmap: ammortize cost of clearing bits")
Reported-by: default avatarJens <Axboe@kernel.dk>
Signed-off-by: default avatarOmar Sandoval <osandov@fb.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent fe1f4526

include/linux/sbitmap.h

+6 −4
Original line number Diff line number Diff line
@@ -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))