Messages in this thread | | | Date | Fri, 21 Jan 2022 10:33:58 +0800 | Subject | Re: [PATCH v9 10/10] fsdax: set a CoW flag when associate reflink mappings | From | Shiyang Ruan <> |
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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.
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