[PATCH v5 05/13] ubifs: move crypt info pointer to fs-specific part of inode

[Eric Biggers]

Move the fscrypt_inode_info pointer into the filesystem-specific part of
the inode by adding the field ubifs_inode::i_crypt_info and configuring
fscrypt_operations::inode_info_offs accordingly.

This is a prerequisite for a later commit that removes
inode::i_crypt_info, saving memory and improving cache efficiency with
filesystems that don't support fscrypt.

Note that the initialization of ubifs_inode::i_crypt_info to NULL on
inode allocation is handled by the memset() in ubifs_alloc_inode().

Co-developed-by: Christian Brauner <brauner at kernel.org>
Signed-off-by: Christian Brauner <brauner at kernel.org>
Signed-off-by: Eric Biggers <ebiggers at kernel.org>
---
 fs/ubifs/crypto.c | 2 ++
 fs/ubifs/ubifs.h  | 4 ++++
 2 files changed, 6 insertions(+)

diff --git a/fs/ubifs/crypto.c b/fs/ubifs/crypto.c
index fb5ac358077b1..0b14d004a095b 100644
--- a/fs/ubifs/crypto.c
+++ b/fs/ubifs/crypto.c
@@ -86,10 +86,12 @@ int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn,
 
 	return 0;
 }
 
 const struct fscrypt_operations ubifs_crypt_operations = {
+	.inode_info_offs	= (int)offsetof(struct ubifs_inode, i_crypt_info) -
+				  (int)offsetof(struct ubifs_inode, vfs_inode),
 	.legacy_key_prefix	= "ubifs:",
 	.get_context		= ubifs_crypt_get_context,
 	.set_context		= ubifs_crypt_set_context,
 	.empty_dir		= ubifs_crypt_empty_dir,
 };
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index 5db45c9e26ee0..49e50431741cd 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -363,10 +363,11 @@ struct ubifs_gced_idx_leb {
  * @compr_type: default compression type used for this inode
  * @last_page_read: page number of last page read (for bulk read)
  * @read_in_a_row: number of consecutive pages read in a row (for bulk read)
  * @data_len: length of the data attached to the inode
  * @data: inode's data
+ * @i_crypt_info: inode's fscrypt information
  *
  * @ui_mutex exists for two main reasons. At first it prevents inodes from
  * being written back while UBIFS changing them, being in the middle of an VFS
  * operation. This way UBIFS makes sure the inode fields are consistent. For
  * example, in 'ubifs_rename()' we change 4 inodes simultaneously, and
@@ -414,10 +415,13 @@ struct ubifs_inode {
 	int flags;
 	pgoff_t last_page_read;
 	pgoff_t read_in_a_row;
 	int data_len;
 	void *data;
+#ifdef CONFIG_FS_ENCRYPTION
+	struct fscrypt_inode_info *i_crypt_info;
+#endif
 };
 
 /**
  * struct ubifs_unclean_leb - records a LEB recovered under read-only mode.
  * @list: list
-- 
2.50.1