lib/sbitmap: define swap_lock as raw_spinlock_t

When called from sbitmap_queue_get(), sbitmap_deferred_clear() may be run with preempt disabled. In RT kernel, spin_lock() can sleep, then warning of "BUG: sleeping function called from invalid context" can be triggered. Fix it by replacing it with raw_spin_lock. Cc: Yang Yang <[email protected]> Fixes: 72d04bd ("sbitmap: fix io hung due to race on sbitmap_word::cleared") Signed-off-by: Ming Lei <[email protected]> Reviewed-by: Yang Yang <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]>
kdave · Sep 20, 2024 · 65f666c · 65f666c
1 parent 9ba5dcc
commit 65f666c
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diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h
@@ -40,7 +40,7 @@ struct sbitmap_word {
 	/**
 	 * @swap_lock: serializes simultaneous updates of ->word and ->cleared
 	 */
-	spinlock_t swap_lock;
+	raw_spinlock_t swap_lock;
 } ____cacheline_aligned_in_smp;
 
 /**

diff --git a/lib/sbitmap.c b/lib/sbitmap.c
@@ -65,7 +65,7 @@ static inline bool sbitmap_deferred_clear(struct sbitmap_word *map,
 {
 	unsigned long mask, word_mask;
 
-	guard(spinlock_irqsave)(&map->swap_lock);
+	guard(raw_spinlock_irqsave)(&map->swap_lock);
 
 	if (!map->cleared) {
 		if (depth == 0)
@@ -136,7 +136,7 @@ int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift,
 	}
 
 	for (i = 0; i < sb->map_nr; i++)
-		spin_lock_init(&sb->map[i].swap_lock);
+		raw_spin_lock_init(&sb->map[i].swap_lock);
 
 	return 0;
 }