ext4: atomically set inode->i_flags in ext4_set_inode_flags()

[~andy/linux] / include / linux / bitops.h

diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index abc9ca7784568ba5737add4fce84577348428eac..be5fd38bd5a05d83eaac250055defcccacafe054 100644 (file)
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -196,6 +196,21 @@ static inline unsigned long __ffs64(u64 word)
 
 #ifdef __KERNEL__
 
+#ifndef set_mask_bits
+#define set_mask_bits(ptr, _mask, _bits)       \
+({                                                             \
+       const typeof(*ptr) mask = (_mask), bits = (_bits);      \
+       typeof(*ptr) old, new;                                  \
+                                                               \
+       do {                                                    \
+               old = ACCESS_ONCE(*ptr);                        \
+               new = (old & ~mask) | bits;                     \
+       } while (cmpxchg(ptr, old, new) != old);                \
+                                                               \
+       new;                                                    \
+})
+#endif
+
 #ifndef find_last_bit
 /**
  * find_last_bit - find the last set bit in a memory region