On 2024/9/19 10:17, Ming Lei wrote:
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@xxxxxxxx>
Fixes: 72d04bdcf3f7 ("sbitmap: fix io hung due to race on sbitmap_word::cleared")
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
include/linux/sbitmap.h | 2 +-
lib/sbitmap.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h
index c09cdcc99471..189140bf11fc 100644
--- 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 5e2e93307f0d..d3412984170c 100644
--- 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;
}
Looks good. Feel free to add:
Reviewed-by: Yang Yang <yang.yang@xxxxxxxx>
Thanks.
