ext4: add fs-verity read support
Make ext4_mpage_readpages() verify data as it is read from fs-verity
files, using the helper functions from fs/verity/.
To support both encryption and verity simultaneously, this required
refactoring the decryption workflow into a generic "post-read
processing" workflow which can do decryption, verification, or both.
The case where the ext4 block size is not equal to the PAGE_SIZE is not
supported yet, since in that case ext4_mpage_readpages() sometimes falls
back to block_read_full_page(), which does not support fs-verity yet.
Co-developed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 736972f..9c7f403 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3191,6 +3191,8 @@ static inline void ext4_set_de_type(struct super_block *sb,
extern int ext4_mpage_readpages(struct address_space *mapping,
struct list_head *pages, struct page *page,
unsigned nr_pages, bool is_readahead);
+extern int __init ext4_init_post_read_processing(void);
+extern void ext4_exit_post_read_processing(void);
/* symlink.c */
extern const struct inode_operations ext4_encrypted_symlink_inode_operations;