Unverified Commit 818c659a authored by Eric Biggers's avatar Eric Biggers Committed by Christian Brauner
Browse files

fs: remove inode::i_verity_info 



Now that all fsverity-capable filesystems store the pointer to
fsverity_info in the filesystem-specific part of the inode structure,
inode::i_verity_info is no longer needed.  Update fsverity_info_addr()
to no longer support the fallback to inode::i_verity_info.  Finally,
remove inode::i_verity_info itself, and move the forward declaration of
struct fsverity_info from fs.h (which no longer needs it) to fsverity.h.

The end result of the migration to the filesystem-specific pointer is
memory savings on CONFIG_FS_VERITY=y kernels for all filesystems that
don't support fsverity.  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/20250810075706.172910-13-ebiggers@kernel.org


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent fcafdd42

include/linux/fs.h

+0 −5
Original line number Diff line number Diff line
@@ -73,7 +73,6 @@ struct seq_file; 
struct workqueue_struct;

struct iov_iter;

struct fscrypt_operations;

struct fsverity_info;

struct fsverity_operations;

struct fsnotify_mark_connector;

struct fsnotify_sb_info;
@@ -779,10 +778,6 @@ struct inode { 
	struct fsnotify_mark_connector __rcu	*i_fsnotify_marks;

#endif



#ifdef CONFIG_FS_VERITY

	struct fsverity_info	*i_verity_info;

#endif



	void			*i_private; /* fs or device private pointer */

} __randomize_layout;

include/linux/fsverity.h

+8 −2
Original line number Diff line number Diff line
@@ -26,6 +26,8 @@ 
/* Arbitrary limit to bound the kmalloc() size.  Can be changed. */

#define FS_VERITY_MAX_DESCRIPTOR_SIZE	16384



struct fsverity_info;



/* Verity operations for filesystems */

struct fsverity_operations {

	/**
@@ -130,11 +132,15 @@ struct fsverity_operations { 


#ifdef CONFIG_FS_VERITY



/*

 * Returns the address of the verity info pointer within the filesystem-specific

 * part of the inode.  (To save memory on filesystems that don't support

 * fsverity, a field in 'struct inode' itself is no longer used.)

 */

static inline struct fsverity_info **

fsverity_info_addr(const struct inode *inode)

{

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

		return (struct fsverity_info **)&inode->i_verity_info;

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

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

}