From c7f91bd4102902384137dd5c50d04bfed27050dd Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Tue, 22 Feb 2022 10:43:13 -0800 Subject: [PATCH] f2fs: Restore rwsem lockdep support 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 Reported-by: syzbot+0b9cadf5fc45a98a5083@syzkaller.appspotmail.com Fixes: e4544b63a7ee ("f2fs: move f2fs to use reader-unfair rwsems") Signed-off-by: Bart Van Assche Signed-off-by: Jaegeuk Kim --- 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 c9515c3..47bf9e3 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); } -- 2.7.4