Lockdep uses lock class keys in its analysis. init_rwsem() instantiates
one lock class key with each init_rwsem() user as follows:
#define init_rwsem(sem) \
do { \
static struct lock_class_key __key; \
\
__init_rwsem((sem), #sem, &__key); \
} while (0)
Commit e4544b63a7ee ("f2fs: move f2fs to use reader-unfair rwsems") reduced
the number of lock class keys from one per init_rwsem() user to one per
file in which init_f2fs_rwsem() is used. This causes the same lock class key
to be associated with multiple f2fs rwsems and also triggers a number of
false positive lockdep deadlock reports. Fix this by again instantiating one
lock class key with each init_f2fs_rwsem() caller.
Cc: Tim Murray <[email protected]>
Reported-by: [email protected]
Fixes: e4544b63a7ee ("f2fs: move f2fs to use reader-unfair rwsems")
Signed-off-by: Bart Van Assche <[email protected]>
---
fs/f2fs/f2fs.h | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index c9515c3c54fd..47bf9e30913f 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2115,9 +2115,17 @@ static inline void clear_ckpt_flags(struct f2fs_sb_info
*sbi, unsigned int f)
spin_unlock_irqrestore(&sbi->cp_lock, flags);
}
-static inline void init_f2fs_rwsem(struct f2fs_rwsem *sem)
+#define init_f2fs_rwsem(sem) \
+do { \
+ static struct lock_class_key __key; \
+ \
+ __init_f2fs_rwsem((sem), #sem, &__key); \
+} while (0)
+
+static inline void __init_f2fs_rwsem(struct f2fs_rwsem *sem,
+ const char *sem_name, struct lock_class_key *key)
{
- init_rwsem(&sem->internal_rwsem);
+ __init_rwsem(&sem->internal_rwsem, sem_name, key);
init_waitqueue_head(&sem->read_waiters);
}
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