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Commit bfe35965 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Jaegeuk Kim
Browse files

f2fs, lockdep: annotate mutex_lock_all() 



Majianpeng reported a lockdep splat for f2fs. It turns out mutex_lock_all()
acquires an array of locks (in global/local lock style).

Any such operation is always serialized using cp_mutex, therefore there is no
fs_lock[] lock-order issue; tell lockdep about this using the
mutex_lock_nest_lock() primitive.

Reported-by: default avatarmajianpeng <majianpeng@gmail.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk.kim@samsung.com>
parent f356fe0c

fs/f2fs/f2fs.h

+11 −3
Original line number Diff line number Diff line
@@ -495,9 +495,17 @@ static inline void clear_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f) 


static inline void mutex_lock_all(struct f2fs_sb_info *sbi)

{

	int i = 0;

	for (; i < NR_GLOBAL_LOCKS; i++)

		mutex_lock(&sbi->fs_lock[i]);

	int i;



	for (i = 0; i < NR_GLOBAL_LOCKS; i++) {

		/*

		 * This is the only time we take multiple fs_lock[]

		 * instances; the order is immaterial since we

		 * always hold cp_mutex, which serializes multiple

		 * such operations.

		 */

		mutex_lock_nest_lock(&sbi->fs_lock[i], &sbi->cp_mutex);

	}

}



static inline void mutex_unlock_all(struct f2fs_sb_info *sbi)