Re: [PATCH 1/2] mm: move filemap_range_needs_writeback() into header

On Fri, Dec 03, 2021 at 08:38:28AM -0700, Jens Axboe wrote:

fs.h is the wrong place for these functions; they're pagecache
functionality, so they should be in pagemap.h.

+/* Returns true if writeback might be needed or already in progress. */
+static inline bool mapping_needs_writeback(struct address_space *mapping)
+{
+	return mapping->nrpages;
+}

I don't like this function -- mapping_needs_writeback says to me that it
tests a flag in mapping->flags.  Plus, it does exactly the same thing as
!mapping_empty(), so perhaps ...

+static inline bool filemap_range_needs_writeback(struct address_space *mapping,
+						 loff_t start_byte,
+						 loff_t end_byte)
+{
+	if (!mapping_needs_writeback(mapping))
+		return false;

just make this
	if (mapping_empty(mapping))
		return false;

Other than that, no objections to making this static inline.