.. SPDX-License-Identifier: GPL-2.0 Large Extended Attribute Values ------------------------------- To enable ext4 to store extended attribute values that do not fit in the inode or in the single extended attribute block attached to an inode, the EA\_INODE feature allows us to store the value in the data blocks of a regular file inode. This “EA inode” is linked only from the extended attribute name index and must not appear in a directory entry. The inode's i\_atime field is used to store a checksum of the xattr value; and i\_ctime/i\_version store a 64-bit reference count, which enables sharing of large xattr values between multiple owning inodes. For backward compatibility with older versions of this feature, the i\_mtime/i\_generation *may* store a back-reference to the inode number and i\_generation of the **one** owning inode (in cases where the EA inode is not referenced by multiple inodes) to verify that the EA inode is the correct one being accessed.