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f2fs: mutex can't be used by down_write_nest_lock() 

f2fs_lock_all() calls down_write_nest_lock() to acquire a rw_sem and check
a mutex, but down_write_nest_lock() is designed for two rw_sem accoring to the
comment in include/linux/rwsem.h. And, other than f2fs, it is just called in
mm/mmap.c with two rwsem.

So, it looks it is used wrongly by f2fs. And, it causes the below compile
warning on -rt kernel too.

In file included from fs/f2fs/xattr.c:25:0:
fs/f2fs/f2fs.h: In function 'f2fs_lock_all':
fs/f2fs/f2fs.h:962:34: warning: passing argument 2 of 'down_write_nest_lock' from incompatible pointer type [-Wincompatible-pointer-types]
  f2fs_down_write(&sbi->cp_rwsem, &sbi->cp_mutex);
                                  ^
fs/f2fs/f2fs.h:27:55: note: in definition of macro 'f2fs_down_write'
 #define f2fs_down_write(x, y) down_write_nest_lock(x, y)
                                                       ^
In file included from include/linux/rwsem.h:22:0,
                 from fs/f2fs/xattr.c:21:
include/linux/rwsem_rt.h:138:20: note: expected 'struct rw_semaphore *' but argument is of type 'struct mutex *'
 static inline void down_write_nest_lock(struct rw_semaphore *sem,

Signed-off-by: Yang Shi <yang.shi@linaro.org>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
hifive-unleashed-5.1
Yang Shi 2016-02-26 16:25:25 -08:00 committed by Jaegeuk Kim
parent 8c2b1435b9
commit 59692b7c71
1 changed files with 1 additions and 3 deletions
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4
fs/f2fs/f2fs.h
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@ -25,7 +25,6 @@
#ifdef CONFIG_F2FS_CHECK_FS
#define f2fs_bug_on(sbi, condition) BUG_ON(condition)
#define f2fs_down_write(x, y) down_write_nest_lock(x, y)
#else
#define f2fs_bug_on(sbi, condition) \
do { \
@ -34,7 +33,6 @@
set_sbi_flag(sbi, SBI_NEED_FSCK); \
} \
} while (0)
#define f2fs_down_write(x, y) down_write(x)
#endif
/*
@ -1026,7 +1024,7 @@ static inline void f2fs_unlock_op(struct f2fs_sb_info *sbi)
static inline void f2fs_lock_all(struct f2fs_sb_info *sbi)
{
f2fs_down_write(&sbi->cp_rwsem, &sbi->cp_mutex);
down_write(&sbi->cp_rwsem);
}
static inline void f2fs_unlock_all(struct f2fs_sb_info *sbi)