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 <yang.yang@vivo.com>
Fixes: 72d04bdcf3f7 ("sbitmap: fix io hung due to race on sbitmap_word::cleared")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yang Yang <yang.yang@vivo.com>
Link: https://lore.kernel.org/r/20240919021709.511329-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h
index c09cdcc99471e170433e745f640b0a4fffbb0833..189140bf11fc4078a61d6c72c760c4cdebc41ced 100644 (file)
--- 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
index 5e2e93307f0d05f94ee9bde92144ded6f6c733d0..d3412984170c03dc6600bbe53f130404b765ac5a 100644 (file)
--- 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;
 }