[PATCH 2/1] xfs: use XFS_BMAP_BMDR_SPACE vs. XFS_BROOT_SIZE_ADJ

[Eric Sandeen <sandeen@xxxxxxxxxxx>]

XFS_BROOT_SIZE_ADJ is an undocumented macro which accounts for
the difference in size between the on-disk and in-core btree
root.  It's much clearer to just use the newly-added 
XFS_BMAP_BMDR_SPACE macro which gives us the on-disk size
directly.

In one case, we must test that the if_broot exists before
applying the macro, however.

Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
---

diff --git a/fs/xfs/xfs_dinode.h b/fs/xfs/xfs_dinode.h
index a372163..be76047 100644
--- a/fs/xfs/xfs_dinode.h
+++ b/fs/xfs/xfs_dinode.h
@@ -107,9 +107,6 @@ typedef enum xfs_dinode_fmt {
 #define XFS_LITINO(mp) \
        ((int)(((mp)->m_sb.sb_inodesize) - sizeof(struct xfs_dinode)))
 
-#define        XFS_BROOT_SIZE_ADJ      \
-       (XFS_BTREE_LBLOCK_LEN - sizeof(xfs_bmdr_block_t))
-
 /*
  * Inode data & attribute fork sizes, per inode.
  */
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index b210224..a1a6337 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1833,8 +1833,8 @@ xfs_iroot_realloc(
                np = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
                                                     (int)new_size);
                ifp->if_broot_bytes = (int)new_size;
-               ASSERT(ifp->if_broot_bytes <=
-                       XFS_IFORK_SIZE(ip, whichfork) + XFS_BROOT_SIZE_ADJ);
+               ASSERT(XFS_BMAP_BMDR_SPACE(ifp->if_broot) <=
+                       XFS_IFORK_SIZE(ip, whichfork));
                memmove(np, op, cur_max * (uint)sizeof(xfs_dfsbno_t));
                return;
        }
@@ -1886,8 +1886,9 @@ xfs_iroot_realloc(
        kmem_free(ifp->if_broot);
        ifp->if_broot = new_broot;
        ifp->if_broot_bytes = (int)new_size;
-       ASSERT(ifp->if_broot_bytes <=
-               XFS_IFORK_SIZE(ip, whichfork) + XFS_BROOT_SIZE_ADJ);
+       if (ifp->if_broot)
+               ASSERT(XFS_BMAP_BMDR_SPACE(ifp->if_broot) <=
+                       XFS_IFORK_SIZE(ip, whichfork));
        return;
 }
 
@@ -2201,9 +2202,8 @@ xfs_iflush_fork(
                if ((iip->ili_format.ilf_fields & brootflag[whichfork]) &&
                    (ifp->if_broot_bytes > 0)) {
                        ASSERT(ifp->if_broot != NULL);
-                       ASSERT(ifp->if_broot_bytes <=
-                              (XFS_IFORK_SIZE(ip, whichfork) +
-                               XFS_BROOT_SIZE_ADJ));
+                       ASSERT(XFS_BMAP_BMDR_SPACE(ifp->if_broot) <=
+                               XFS_IFORK_SIZE(ip, whichfork));
                        xfs_bmbt_to_bmdr(mp, ifp->if_broot, ifp->if_broot_bytes,
                                (xfs_bmdr_block_t *)cp,
                                XFS_DFORK_SIZE(dip, mp, whichfork));