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| author |   Peter Zijlstra <peterz@infradead.org> | 2013-05-16 20:03:12 +0200 |
|---|---|---|
| committer |   Jaegeuk Kim <jaegeuk.kim@samsung.com> | 2013-05-28 15:03:02 +0900 |
| commit | bfe35965ecdc6038314d03456b94d9ba451c289d (patch) | |
| tree | 94ca44f7f48113ed0d3701851c12c334a2bba38c /fs/f2fs | |
| parent | f2fs: add debug msgs in the recovery routine (diff) | |
| download | linux-dev-bfe35965ecdc6038314d03456b94d9ba451c289d.tar.xz linux-dev-bfe35965ecdc6038314d03456b94d9ba451c289d.zip | |
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: majianpeng <majianpeng@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Diffstat (limited to 'fs/f2fs')
| -rw-r--r-- | fs/f2fs/f2fs.h | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 9360a03fcc96..9182b2710db7 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -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) |