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: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
include/linux/fs.h | 5 -----
include/linux/fsverity.h | 10 ++++++++--
2 files changed, 8 insertions(+), 7 deletions(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 1dafa18169be6..12ecc6b0e6f96 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -71,11 +71,10 @@ struct cred;
struct swap_info_struct;
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;
struct fs_context;
struct fs_parameter_spec;
@@ -777,14 +776,10 @@ 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_VERITY
- struct fsverity_info *i_verity_info;
-#endif
-
void *i_private; /* fs or device private pointer */
} __randomize_layout;
static inline void inode_set_cached_link(struct inode *inode, char *link, int linklen)
{
diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h
index e0f132cb78393..844f7b8b56bbc 100644
--- a/include/linux/fsverity.h
+++ b/include/linux/fsverity.h
@@ -24,10 +24,12 @@
#define FS_VERITY_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE
/* 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 {
/**
* The offset of the pointer to struct fsverity_info in the
* filesystem-specific part of the inode, relative to the beginning of
@@ -128,15 +130,19 @@ struct fsverity_operations {
u64 pos, unsigned int size);
};
#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;
}
static inline struct fsverity_info *fsverity_get_info(const struct inode *inode)
{
--
2.50.1
