在 2022/1/20 16:59, Christoph Hellwig 写道:
On Sun, Dec 26, 2021 at 10:34:39PM +0800, Shiyang Ruan wrote:
+#define FS_DAX_MAPPING_COW 1UL
+
+#define MAPPING_SET_COW(m) (m = (struct address_space *)FS_DAX_MAPPING_COW)
+#define MAPPING_TEST_COW(m) (((unsigned long)m & FS_DAX_MAPPING_COW) == \
+ FS_DAX_MAPPING_COW)
These really should be inline functions and probably use lower case
names.
OK.
But different question, how does this not conflict with:
#define PAGE_MAPPING_ANON 0x1
in page-flags.h?
Now we are treating dax pages, so I think its flags should be different
from normal page. In another word, PAGE_MAPPING_ANON is a flag of rmap
mechanism for normal page, it doesn't work for dax page. And now, we
have dax rmap for dax page. So, I think this two kinds of flags are
supposed to be used in different mechanisms and won't conflect.
Either way I think this flag should move to page-flags.h and be
integrated with the PAGE_MAPPING_FLAGS infrastucture.
And that's why I keep them in this dax.c file.
--
Thanks,
Ruan.
