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

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
......@@ -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)
......
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