buffer: remove set_bh_page()

With all users converted to folio_set_bh(), remove this function.

Link: https://lkml.kernel.org/r/20230713035512.4139457-8-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Sterba <dsterba@suse.com>
Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Tom Rix <trix@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fs/buffer.c

@@ -1539,21 +1539,6 @@ void invalidate_bh_lrus_cpu(void)
 	bh_lru_unlock();
 }
 
-void set_bh_page(struct buffer_head *bh,
-		struct page *page, unsigned long offset)
-{
-	bh->b_page = page;
-	BUG_ON(offset >= PAGE_SIZE);
-	if (PageHighMem(page))
-		/*
-		 * This catches illegal uses and preserves the offset:
-		 */
-		bh->b_data = (char *)(0 + offset);
-	else
-		bh->b_data = page_address(page) + offset;
-}
-EXPORT_SYMBOL(set_bh_page);
-
 void folio_set_bh(struct buffer_head *bh, struct folio *folio,
 		  unsigned long offset)
 {

include/linux/buffer_head.h

@@ -194,8 +194,6 @@ void buffer_check_dirty_writeback(struct folio *folio,
 void mark_buffer_dirty(struct buffer_head *bh);
 void mark_buffer_write_io_error(struct buffer_head *bh);
 void touch_buffer(struct buffer_head *bh);
-void set_bh_page(struct buffer_head *bh,
-		struct page *page, unsigned long offset);
 void folio_set_bh(struct buffer_head *bh, struct folio *folio,
 		  unsigned long offset);
 bool try_to_free_buffers(struct folio *);