[PATCH v4 07/36] fs: Add a filesystem flag for large pages

[Matthew Wilcox]

From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>

The page cache needs to know whether the filesystem supports pages >
PAGE_SIZE.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 include/linux/fs.h      | 1 +
 include/linux/pagemap.h | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 55c743925c40..777783c8760b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2241,6 +2241,7 @@ struct file_system_type {
 #define FS_HAS_SUBTYPE		4
 #define FS_USERNS_MOUNT		8	/* Can be mounted by userns root */
 #define FS_DISALLOW_NOTIFY_PERM	16	/* Disable fanotify permission events */
+#define FS_LARGE_PAGES		8192	/* Remove once all fs converted */
 #define FS_RENAME_DOES_D_MOVE	32768	/* FS will handle d_move() during rename() internally. */
 	int (*init_fs_context)(struct fs_context *);
 	const struct fs_parameter_spec *parameters;
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 36bfc9d855bb..c6db74b5e62f 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -116,6 +116,11 @@ static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask)
 	m->gfp_mask = mask;
 }
 
+static inline bool mapping_large_pages(struct address_space *mapping)
+{
+	return mapping->host->i_sb->s_type->fs_flags & FS_LARGE_PAGES;
+}
+
 void release_pages(struct page **pages, int nr);
 
 /*
-- 
2.26.2