[PATCH] xfs: reserve fields in inode for parent ptr and alloc policy

[Mark Tinguely <tinguely@xxxxxxx>]

Reserve fields in new inode layout for parent pointer and
allocation policy.
                ----
The inode will hold the parent information for the first
link to a file. Information for the other links will be
held in extended attribute entries.

The "di_parino" is the inode of the parent directory. The
directory information for this entry is located the parent
directory with "di_paroff" offset. 

The di_parino/di_paroff concept code is running.
                ----
The "di_allocpolicy" will be used to remember the allocation
policy associated with this inode.

Signed-off-by: Mark Tinguely <tinguely@xxxxxxx>
---
 fs/xfs/xfs_dinode.h |    3 +++
 fs/xfs/xfs_inode.c  |    6 ++++++
 fs/xfs/xfs_inode.h  |    3 +++
 3 files changed, 12 insertions(+)

Index: b/fs/xfs/xfs_dinode.h
===================================================================
--- a/fs/xfs/xfs_dinode.h
+++ b/fs/xfs/xfs_dinode.h
@@ -76,6 +76,9 @@ typedef struct xfs_dinode {
        __be64          di_changecount; /* number of attribute changes */
        __be64          di_lsn;         /* flush sequence */
        __be64          di_flags2;      /* more random flags */
+       __be64          di_parino;      /* parent inode */
+       __be32          di_paroff;      /* offset into parent directory */
+       __be32          di_allocpolicy; /* allocation policy number */
        __u8            di_pad2[16];    /* more padding for future expansion */
 
        /* fields only written to during inode creation */
Index: b/fs/xfs/xfs_inode.c
===================================================================
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -875,6 +875,9 @@ xfs_dinode_from_disk(
                to->di_flags2 = be64_to_cpu(from->di_flags2);
                to->di_ino = be64_to_cpu(from->di_ino);
                to->di_lsn = be64_to_cpu(from->di_lsn);
+               to->di_parino = be64_to_cpu(from->di_parino);
+               to->di_paroff = be32_to_cpu(from->di_paroff);
+               to->di_allocpolicy = be32_to_cpu(from->di_allocpolicy);
                memcpy(to->di_pad2, from->di_pad2, sizeof(to->di_pad2));
                uuid_copy(&to->di_uuid, &from->di_uuid);
        }
@@ -922,6 +925,9 @@ xfs_dinode_to_disk(
                to->di_flags2 = cpu_to_be64(from->di_flags2);
                to->di_ino = cpu_to_be64(from->di_ino);
                to->di_lsn = cpu_to_be64(from->di_lsn);
+               to->di_parino = cpu_to_be64(from->di_parino);
+               to->di_paroff = cpu_to_be32(from->di_paroff);
+               to->di_allocpolicy = cpu_to_be32(from->di_allocpolicy);
                memcpy(to->di_pad2, from->di_pad2, sizeof(to->di_pad2));
                uuid_copy(&to->di_uuid, &from->di_uuid);
        }
Index: b/fs/xfs/xfs_inode.h
===================================================================
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -159,6 +159,9 @@ typedef struct xfs_icdinode {
        __uint64_t      di_changecount; /* number of attribute changes */
        xfs_lsn_t       di_lsn;         /* flush sequence */
        __uint64_t      di_flags2;      /* more random flags */
+       xfs_ino_t       di_parino;      /* parent inode */
+       __uint32_t      di_paroff;      /* offset into parent directory */
+       __uint32_t      di_allocpolicy; /* allocation policy number */
        __uint8_t       di_pad2[16];    /* more padding for future expansion */
 
        /* fields only written to during inode creation */