xfs: introduce inode log format object

We currently carry around and log an entire inode core in the
struct xfs_inode. A lot of the information in the inode core is
duplicated in the VFS inode, but we cannot remove this duplication
of infomration because the inode core is logged directly in
xfs_inode_item_format().

Add a new function xfs_inode_item_format_core() that copies the
inode core data into a struct xfs_icdinode that is pulled directly
from the log vector buffer. This means we no longer directly
copy the inode core, but copy the structures one member at a time.
This will be slightly less efficient than copying, but will allow us
to remove duplicate and unnecessary items from the struct xfs_inode.

To enable us to do this, call the new structure a xfs_log_dinode,
so that we know it's different to the physical xfs_dinode and the
in-core xfs_icdinode.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 8 insertions, 7 deletions

diff --git a/fs/xfs/libxfs/xfs_log_format.h b/fs/xfs/libxfs/xfs_log_format.h
index 265314690415..d00ed639e0bc 100644
--- a/fs/xfs/libxfs/xfs_log_format.h
+++ b/fs/xfs/libxfs/xfs_log_format.h
@@ -290,6 +290,7 @@ typedef struct xfs_inode_log_format_64 {
 	__int32_t		ilf_boffset;	/* off of inode in buffer */
 } xfs_inode_log_format_64_t;
 
+
 /*
  * Flags for xfs_trans_log_inode flags field.
  */
@@ -360,10 +361,10 @@ typedef struct xfs_ictimestamp {
 } xfs_ictimestamp_t;
 
 /*
- * NOTE:  This structure must be kept identical to struct xfs_dinode
- *	  except for the endianness annotations.
+ * Define the format of the inode core that is logged. This structure must be
+ * kept identical to struct xfs_dinode except for the endianness annotations.
  */
-typedef struct xfs_icdinode {
+struct xfs_log_dinode {
 	__uint16_t	di_magic;	/* inode magic # = XFS_DINODE_MAGIC */
 	__uint16_t	di_mode;	/* mode and type of file */
 	__int8_t	di_version;	/* inode version */
@@ -407,13 +408,13 @@ typedef struct xfs_icdinode {
 	uuid_t		di_uuid;	/* UUID of the filesystem */
 
 	/* structure must be padded to 64 bit alignment */
-} xfs_icdinode_t;
+};
 
-static inline uint xfs_icdinode_size(int version)
+static inline uint xfs_log_dinode_size(int version)
 {
 	if (version == 3)
-		return sizeof(struct xfs_icdinode);
-	return offsetof(struct xfs_icdinode, di_next_unlinked);
+		return sizeof(struct xfs_log_dinode);
+	return offsetof(struct xfs_log_dinode, di_next_unlinked);
 }
 
 /*