Since getting the address of the fsverity_info has gotten a bit more
expensive, make fsverity_cleanup_inode() check for IS_VERITY() instead.
This avoids adding more overhead to non-verity files.
This assumes that verity info is never set when !IS_VERITY(), which is
currently true, but add a VFS_WARN_ON_ONCE() that asserts that. (This
of course defeats the optimization, but only when CONFIG_VFS_DEBUG=y.)
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
include/linux/fsverity.h | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h
index 844f7b8b56bbc..5bc7280425a71 100644
--- a/include/linux/fsverity.h
+++ b/include/linux/fsverity.h
@@ -188,12 +188,19 @@ void __fsverity_cleanup_inode(struct inode *inode);
*
* Filesystems must call this on inode eviction to free the inode's verity info.
*/
static inline void fsverity_cleanup_inode(struct inode *inode)
{
- if (*fsverity_info_addr(inode))
+ /*
+ * Only IS_VERITY() inodes can have verity info, so start by checking
+ * for IS_VERITY() (which is faster than retrieving the pointer to the
+ * verity info). This minimizes overhead for non-verity inodes.
+ */
+ if (IS_VERITY(inode))
__fsverity_cleanup_inode(inode);
+ else
+ VFS_WARN_ON_ONCE(*fsverity_info_addr(inode) != NULL);
}
/* read_metadata.c */
int fsverity_ioctl_read_metadata(struct file *filp, const void __user *uarg);
--
2.50.1
