ext4 crypto: add ext4_mpage_readpages()

This takes code from fs/mpage.c and optimizes it for ext4.  Its
primary reason is to allow us to more easily add encryption to ext4's
read path in an efficient manner.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index f63c3d5805c4..f7f3f5871796 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2699,6 +2699,10 @@ static inline void ext4_set_de_type(struct super_block *sb,
 		de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
 }
 
+/* readpages.c */
+extern int ext4_mpage_readpages(struct address_space *mapping,
+				struct list_head *pages, struct page *page,
+				unsigned nr_pages);
 
 /* symlink.c */
 extern const struct inode_operations ext4_symlink_inode_operations;