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authorPeter Zijlstra <peterz@infradead.org>2013-05-16 20:03:12 +0200
committerJaegeuk Kim <jaegeuk.kim@samsung.com>2013-05-28 15:03:02 +0900
commitbfe35965ecdc6038314d03456b94d9ba451c289d (patch)
tree94ca44f7f48113ed0d3701851c12c334a2bba38c /fs/f2fs
parentf356fe0cba0e3523e538987916bd2acedd4e6f41 (diff)
downloadop-kernel-dev-bfe35965ecdc6038314d03456b94d9ba451c289d.zip
op-kernel-dev-bfe35965ecdc6038314d03456b94d9ba451c289d.tar.gz
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.h14
1 files changed, 11 insertions, 3 deletions
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 9360a03..9182b27 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)
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