6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx> [ Upstream commit f1591a8bb3e02713f4ee2efe20df0d84ed80da48 ] Updates to alloc_hint in the loop in __sbitmap_get_shallow() are mostly pointless and equivalent to setting alloc_hint to zero (because SB_NR_TO_BIT() considers only low sb->shift bits from alloc_hint). So simplify the logic. Reviewed-by: Jan Kara <jack@xxxxxxx> Signed-off-by: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20230116205059.3821738-2-shikemeng@xxxxxxxxxxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Stable-dep-of: 72d04bdcf3f7 ("sbitmap: fix io hung due to race on sbitmap_word::cleared") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- lib/sbitmap.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/lib/sbitmap.c b/lib/sbitmap.c index c515072eca296..b9dd0a0a28f89 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -243,6 +243,7 @@ static int __sbitmap_get_shallow(struct sbitmap *sb, int nr = -1; index = SB_NR_TO_INDEX(sb, alloc_hint); + alloc_hint = SB_NR_TO_BIT(sb, alloc_hint); for (i = 0; i < sb->map_nr; i++) { again: @@ -250,7 +251,7 @@ static int __sbitmap_get_shallow(struct sbitmap *sb, min_t(unsigned int, __map_depth(sb, index), shallow_depth), - SB_NR_TO_BIT(sb, alloc_hint), true); + alloc_hint, true); if (nr != -1) { nr += index << sb->shift; break; @@ -260,13 +261,9 @@ static int __sbitmap_get_shallow(struct sbitmap *sb, goto again; /* Jump to next index. */ - index++; - alloc_hint = index << sb->shift; - - if (index >= sb->map_nr) { + alloc_hint = 0; + if (++index >= sb->map_nr) index = 0; - alloc_hint = 0; - } } return nr; -- 2.43.0
