[PATCH 1/2] fs/dax: Remove unused dax_layout_busy_page()

[Kaitao Cheng <kaitao.cheng@linux.dev>]

From: Kaitao Cheng <chengkaitao@kylinos.cn>

dax_layout_busy_page() used to let filesystems scan an entire DAX
mapping for pinned pages. All callers now use dax_break_layout(),
which also handles waiting for busy pages and deleting DAX mapping
entries once the range becomes idle.

The remaining function is only a wrapper around
dax_layout_busy_page_range() and has no in-tree users. Remove it
together with its declaration, !CONFIG_FS_DAX stub, and exported
symbol.

Signed-off-by: Kaitao Cheng <chengkaitao@kylinos.cn>
---
 fs/dax.c            | 6 ------
 include/linux/dax.h | 6 ------
 2 files changed, 12 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index dad4efea7964..1e19e4a354ce 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -841,12 +841,6 @@ struct page *dax_layout_busy_page_range(struct address_space *mapping,
 }
 EXPORT_SYMBOL_GPL(dax_layout_busy_page_range);
 
-struct page *dax_layout_busy_page(struct address_space *mapping)
-{
-	return dax_layout_busy_page_range(mapping, 0, LLONG_MAX);
-}
-EXPORT_SYMBOL_GPL(dax_layout_busy_page);
-
 static int __dax_invalidate_entry(struct address_space *mapping,
 				  pgoff_t index, bool trunc)
 {
diff --git a/include/linux/dax.h b/include/linux/dax.h
index fe6c3ded1b50..05e59e45a1c2 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -155,7 +155,6 @@ int dax_writeback_mapping_range(struct address_space *mapping,
 		struct dax_device *dax_dev, struct writeback_control *wbc);
 int dax_folio_reset_order(struct folio *folio);
 
-struct page *dax_layout_busy_page(struct address_space *mapping);
 struct page *dax_layout_busy_page_range(struct address_space *mapping, loff_t start, loff_t end);
 dax_entry_t dax_lock_folio(struct folio *folio);
 void dax_unlock_folio(struct folio *folio, dax_entry_t cookie);
@@ -173,11 +172,6 @@ static inline int fs_dax_get(struct dax_device *dax_dev, void *holder,
 {
 	return -EOPNOTSUPP;
 }
-static inline struct page *dax_layout_busy_page(struct address_space *mapping)
-{
-	return NULL;
-}
-
 static inline struct page *dax_layout_busy_page_range(struct address_space *mapping, pgoff_t start, pgoff_t nr_pages)
 {
 	return NULL;
-- 
2.50.1 (Apple Git-155)