Unverified Commit ab90c2d2 authored by Eric Biggers's avatar Eric Biggers Committed by Christian Brauner
Browse files

fs: remove inode::i_crypt_info 



Now that all fscrypt-capable filesystems store the pointer to
fscrypt_inode_info in the filesystem-specific part of the inode
structure, inode::i_crypt_info is no longer needed.  Update
fscrypt_inode_info_addr() to no longer support the fallback to
inode::i_crypt_info.  Finally, remove inode::i_crypt_info itself along
with the now-unnecessary forward declaration of fscrypt_inode_info.

The end result of the migration to the filesystem-specific pointer is
memory savings on CONFIG_FS_ENCRYPTION=y kernels for all filesystems
that don't support fscrypt.  Specifically, their in-memory inodes are
now smaller by the size of a pointer: either 4 or 8 bytes.

Co-developed-by: default avatarChristian Brauner <brauner@kernel.org>
Signed-off-by: default avatarEric Biggers <ebiggers@kernel.org>
Link: https://lore.kernel.org/20250810075706.172910-8-ebiggers@kernel.org


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent bbe395de

include/linux/fs.h

+0 −5
Original line number Diff line number Diff line
@@ -72,7 +72,6 @@ struct swap_info_struct; 
struct seq_file;

struct workqueue_struct;

struct iov_iter;

struct fscrypt_inode_info;

struct fscrypt_operations;

struct fsverity_info;

struct fsverity_operations;
@@ -780,10 +779,6 @@ struct inode { 
	struct fsnotify_mark_connector __rcu	*i_fsnotify_marks;

#endif



#ifdef CONFIG_FS_ENCRYPTION

	struct fscrypt_inode_info	*i_crypt_info;

#endif



#ifdef CONFIG_FS_VERITY

	struct fsverity_info	*i_verity_info;

#endif

include/linux/fscrypt.h

+6 −2
Original line number Diff line number Diff line
@@ -201,11 +201,15 @@ struct fscrypt_operations { 
int fscrypt_d_revalidate(struct inode *dir, const struct qstr *name,

			 struct dentry *dentry, unsigned int flags);



/*

 * Returns the address of the fscrypt info pointer within the

 * filesystem-specific part of the inode.  (To save memory on filesystems that

 * don't support fscrypt, a field in 'struct inode' itself is no longer used.)

 */

static inline struct fscrypt_inode_info **

fscrypt_inode_info_addr(const struct inode *inode)

{

	if (inode->i_sb->s_cop->inode_info_offs == 0)

		return (struct fscrypt_inode_info **)&inode->i_crypt_info;

	VFS_WARN_ON_ONCE(inode->i_sb->s_cop->inode_info_offs == 0);

	return (void *)inode + inode->i_sb->s_cop->inode_info_offs;

}