fs: Remove noop_invalidatepage()

We used to have to use noop_invalidatepage() to prevent
block_invalidatepage() from being called, but that behaviour is now gone.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs

drivers/dax/device.c

@@ -347,7 +347,6 @@ static unsigned long dax_get_unmapped_area(struct file *filp,
 
 static const struct address_space_operations dev_dax_aops = {
 	.set_page_dirty		= __set_page_dirty_no_writeback,
-	.invalidatepage		= noop_invalidatepage,
 };
 
 static int dax_open(struct inode *inode, struct file *filp)

fs/ext2/inode.c

@@ -1001,7 +1001,6 @@ static const struct address_space_operations ext2_dax_aops = {
 	.writepages		= ext2_dax_writepages,
 	.direct_IO		= noop_direct_IO,
 	.set_page_dirty		= __set_page_dirty_no_writeback,
-	.invalidatepage		= noop_invalidatepage,
 };
 
 /*

fs/ext4/inode.c

@@ -3632,7 +3632,6 @@ static const struct address_space_operations ext4_dax_aops = {
 	.direct_IO		= noop_direct_IO,
 	.set_page_dirty		= __set_page_dirty_no_writeback,
 	.bmap			= ext4_bmap,
-	.invalidatepage		= noop_invalidatepage,
 	.swap_activate		= ext4_iomap_swap_activate,
 };
 

fs/fuse/dax.c

@@ -1327,7 +1327,6 @@ static const struct address_space_operations fuse_dax_file_aops  = {
 	.writepages	= fuse_dax_writepages,
 	.direct_IO	= noop_direct_IO,
 	.set_page_dirty	= __set_page_dirty_no_writeback,
-	.invalidatepage	= noop_invalidatepage,
 };
 
 static bool fuse_should_enable_dax(struct inode *inode, unsigned int flags)

fs/libfs.c

@@ -1198,17 +1198,6 @@ int noop_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 }
 EXPORT_SYMBOL(noop_fsync);
 
-void noop_invalidatepage(struct page *page, unsigned int offset,
-		unsigned int length)
-{
-	/*
-	 * There is no page cache to invalidate in the dax case, however
-	 * we need this callback defined to prevent falling back to
-	 * block_invalidatepage() in do_invalidatepage().
-	 */
-}
-EXPORT_SYMBOL_GPL(noop_invalidatepage);
-
 ssize_t noop_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 {
 	/*

fs/xfs/xfs_aops.c

@@ -582,6 +582,5 @@ const struct address_space_operations xfs_dax_aops = {
 	.writepages		= xfs_dax_writepages,
 	.direct_IO		= noop_direct_IO,
 	.set_page_dirty		= __set_page_dirty_no_writeback,
-	.invalidatepage		= noop_invalidatepage,
 	.swap_activate		= xfs_iomap_swapfile_activate,
 };

include/linux/fs.h

@@ -3323,8 +3323,6 @@ extern int simple_rename(struct user_namespace *, struct inode *,
 extern void simple_recursive_removal(struct dentry *,
                               void (*callback)(struct dentry *));
 extern int noop_fsync(struct file *, loff_t, loff_t, int);
-extern void noop_invalidatepage(struct page *page, unsigned int offset,
-		unsigned int length);
 extern ssize_t noop_direct_IO(struct kiocb *iocb, struct iov_iter *iter);
 extern int simple_empty(struct dentry *);
 extern int simple_write_begin(struct file *file, struct address_space *mapping,