On Wed, Jun 21, 2017 at 02:21:11PM -0700, Tahsin Erdogan wrote:
> From: Andreas Dilger <andreas.dilger@xxxxxxxxx>
>
> Large xattr support is implemented for EXT4_FEATURE_INCOMPAT_EA_INODE.
>
> If the size of an xattr value is larger than will fit in a single
> external block, then the xattr value will be saved into the body
> of an external xattr inode.
>
> The also helps support a larger number of xattr, since only the headers
> will be stored in the in-inode space or the single external block.
>
> The inode is referenced from the xattr header via "e_value_inum",
> which was formerly "e_value_block", but that field was never used.
> The e_value_size still contains the xattr size so that listing
> xattrs does not need to look up the inode if the data is not accessed.
>
> struct ext4_xattr_entry {
> __u8 e_name_len; /* length of name */
> __u8 e_name_index; /* attribute name index */
> __le16 e_value_offs; /* offset in disk block of value */
> __le32 e_value_inum; /* inode in which value is stored */
> __le32 e_value_size; /* size of attribute value */
> __le32 e_hash; /* hash value of name and value */
> char e_name[0]; /* attribute name */
> };
>
> The xattr inode is marked with the EXT4_EA_INODE_FL flag and also
> holds a back-reference to the owning inode in its i_mtime field,
> allowing the ext4/e2fsck to verify the correct inode is accessed.
>
> Lustre-Jira: https://jira.hpdd.intel.com/browse/LU-80
> Lustre-bugzilla: https://bugzilla.lustre.org/show_bug.cgi?id=4424
> Signed-off-by: Kalpak Shah <kalpak.shah@xxxxxxx>
> Signed-off-by: James Simmons <uja.ornl@xxxxxxxxx>
> Signed-off-by: Andreas Dilger <andreas.dilger@xxxxxxxxx>
> Signed-off-by: Tahsin Erdogan <tahsin@xxxxxxxxxx>
Applied, thanks.
- Ted
