xfs: introduce directory geometry structure

The directory code has a dependency on the struct xfs_mount to
supply the directory block geometry. Block size, block log size,
and other parameters are pre-caclulated in the struct xfs_mount or
access directly from the superblock embedded in the struct
xfs_mount.

Extract all of this geometry information out of the struct xfs_mount
and superblock and place it into a new struct xfs_da_geometry
defined by the directory code. Allocate and initialise it at mount
time, and attach it to the struct xfs_mount so it canbe passed back
into the directory code appropriately rather than using the struct
xfs_mount.

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

1 files changed, 18 insertions, 0 deletions

diff --git a/fs/xfs/xfs_da_btree.h b/fs/xfs/xfs_da_btree.h
index c824a0a..0ac63ad 100644
--- a/fs/xfs/xfs_da_btree.h
+++ b/fs/xfs/xfs_da_btree.h
@@ -25,6 +25,23 @@ struct xfs_trans;
 struct zone;
 struct xfs_dir_ops;
 
+/*
+ * Directory/attribute geometry information. There will be one of these for each
+ * data fork type, and it will be passed around via the xfs_da_args. Global
+ * structures will be attached to the xfs_mount.
+ */
+struct xfs_da_geometry {
+	int		blksize;	/* da block size in bytes */
+	int		fsbcount;	/* da block size in filesystem blocks */
+	uint8_t		fsblog;		/* log2 of _filesystem_ block size */
+	uint8_t		blklog;		/* log2 of da block size */
+	uint		node_ents;	/* # of entries in a danode */
+	int		magicpct;	/* 37% of block size in bytes */
+	xfs_dablk_t	datablk;	/* blockno of dir data v2 */
+	xfs_dablk_t	leafblk;	/* blockno of leaf data v2 */
+	xfs_dablk_t	freeblk;	/* blockno of free data v2 */
+};
+
 /*========================================================================
  * Btree searching and modification structure definitions.
  *========================================================================*/
@@ -42,6 +59,7 @@ enum xfs_dacmp {
  * Structure to ease passing around component names.
  */
 typedef struct xfs_da_args {
+	struct xfs_da_geometry *geo;	/* da block geometry */
 	const __uint8_t	*name;		/* string (maybe not NULL terminated) */
 	int		namelen;	/* length of string (maybe no NULL) */
 	__uint8_t	filetype;	/* filetype of inode for directories */