[PATCH] bitops: generic ext2_{set,clear}_bit_atomic()

This patch introduces the C-language equivalents of the functions below:

int ext2_set_bit_atomic(int nr, volatile unsigned long *addr);
int ext2_clear_bit_atomic(int nr, volatile unsigned long *addr);

In include/asm-generic/bitops/ext2-atomic.h

This code largely copied from: include/asm-sparc/bitops.h
Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/asm-generic/bitops/ext2-atomic.h

+#ifndef _ASM_GENERIC_BITOPS_EXT2_ATOMIC_H_
+#define _ASM_GENERIC_BITOPS_EXT2_ATOMIC_H_
+
+#define ext2_set_bit_atomic(lock, nr, addr)		\
+	({						\
+		int ret;				\
+		spin_lock(lock);			\
+		ret = ext2_set_bit((nr), (unsigned long *)(addr)); \
+		spin_unlock(lock);			\
+		ret;					\
+	})
+
+#define ext2_clear_bit_atomic(lock, nr, addr)		\
+	({						\
+		int ret;				\
+		spin_lock(lock);			\
+		ret = ext2_clear_bit((nr), (unsigned long *)(addr)); \
+		spin_unlock(lock);			\
+		ret;					\
+	})
+
+#endif /* _ASM_GENERIC_BITOPS_EXT2_ATOMIC_H_ */