[PATCH v5 07/13] fs: remove inode::i_crypt_info
From: Eric Biggers <ebiggers@kernel.org>
Date: 2025-08-10 08:00:10
Also in:
ceph-devel, linux-btrfs, linux-f2fs-devel, linux-fscrypt, linux-fsdevel
Subsystem:
filesystems (vfs and infrastructure), fscrypt: file system level encryption support, the rest · Maintainers:
Alexander Viro, Christian Brauner, Eric Biggers, Theodore Y. Ts'o, Jaegeuk Kim, Linus Torvalds
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: Christian Brauner <brauner@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Eric Biggers <ebiggers@kernel.org> --- include/linux/fs.h | 5 ----- include/linux/fscrypt.h | 8 ++++++-- 2 files changed, 6 insertions(+), 7 deletions(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index d7ab4f96d7051..1dafa18169be6 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h@@ -70,11 +70,10 @@ struct vfsmount; struct cred; 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; struct fsnotify_mark_connector; struct fsnotify_sb_info;
@@ -778,14 +777,10 @@ struct inode { __u32 i_fsnotify_mask; /* all events this inode cares about */ /* 32-bit hole reserved for expanding i_fsnotify_mask */ 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 void *i_private; /* fs or device private pointer */
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index d7ff53accbfef..516aba5b858b5 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h@@ -199,15 +199,19 @@ 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; } /* * Load the inode's fscrypt info pointer, using a raw dereference. Since this
--
2.50.1