[PATCH 1/9] metadump: clean up btree block region zeroing

[Dave Chinner <david@xxxxxxxxxxxxx>]

From: Dave Chinner <dchinner@xxxxxxxxxx>

Abstract out all the common operations in the btree block zeroing
so that we only have one copy of offset/len calculations and don't
require lots of casts for the pointer arithmetic.

Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
---
 db/metadump.c | 61 +++++++++++++++++++++++------------------------------------
 1 file changed, 24 insertions(+), 37 deletions(-)

diff --git a/db/metadump.c b/db/metadump.c
index 8455fdd..a185da5 100644
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -258,8 +258,8 @@ zero_btree_node(
        xfs_inobt_key_t         *ikp;
        xfs_alloc_ptr_t         *app;
        xfs_alloc_key_t         *akp;
-       void                    *zp1, *zp2;
-       int                     zlen1, zlen2;
+       char                    *zp1, *zp2;
+       char                    *key_end;
 
        nrecs = be16_to_cpu(block->bb_numrecs);
 
@@ -268,43 +268,36 @@ zero_btree_node(
        case TYP_BMAPBTD:
                bkp = XFS_BMBT_KEY_ADDR(mp, block, 1);
                bpp = XFS_BMBT_PTR_ADDR(mp, block, 1, mp->m_bmap_dmxr[1]);
-               zp1 = &bkp[nrecs];
-               zlen1 = (char *)&bpp[0] - (char *)&bkp[nrecs];
-               zp2 = &bpp[nrecs];
-               zlen2 = (char *)block + mp->m_sb.sb_blocksize -
-                                                       (char *)&bpp[nrecs];
+               zp1 = (char *)&bkp[nrecs];
+               zp2 = (char *)&bpp[nrecs];
+               key_end = (char *)bpp;
                break;
        case TYP_INOBT:
        case TYP_FINOBT:
                ikp = XFS_INOBT_KEY_ADDR(mp, block, 1);
                ipp = XFS_INOBT_PTR_ADDR(mp, block, 1, mp->m_inobt_mxr[1]);
-               zp1 = &ikp[nrecs];
-               zlen1 = (char *)&ipp[0] - (char *)&ikp[nrecs];
-               zp2 = &ipp[nrecs];
-               zlen2 = (char *)block + mp->m_sb.sb_blocksize -
-                                                       (char *)&ipp[nrecs];
+               zp1 = (char *)&ikp[nrecs];
+               zp2 = (char *)&ipp[nrecs];
+               key_end = (char *)ipp;
                break;
        case TYP_BNOBT:
        case TYP_CNTBT:
                akp = XFS_ALLOC_KEY_ADDR(mp, block, 1);
                app = XFS_ALLOC_PTR_ADDR(mp, block, 1, mp->m_alloc_mxr[1]);
-               zp1 = &akp[nrecs];
-               zlen1 = (char *)&app[0] - (char *)&akp[nrecs];
-               zp2 = &app[nrecs];
-               zlen2 = (char *)block + mp->m_sb.sb_blocksize -
-                                                       (char *)&app[nrecs];
+               zp1 = (char *)&akp[nrecs];
+               zp2 = (char *)&app[nrecs];
+               key_end = (char *)app;
                break;
        default:
-               zp1 = NULL;
-               break;
+               return;
        }
 
-       if (zp1 && zp2) {
-               /* Zero from end of keys to beginning of pointers */
-               memset(zp1, 0, zlen1);
-               /* Zero from end of pointers to end of block */
-               memset(zp2, 0, zlen2);
-       }
+
+       /* Zero from end of keys to beginning of pointers */
+       memset(zp1, 0, key_end - zp1);
+
+       /* Zero from end of pointers to end of block */
+       memset(zp2, 0, (char *)block + mp->m_sb.sb_blocksize - zp2);
 }
 
 static void
@@ -316,8 +309,7 @@ zero_btree_leaf(
        struct xfs_bmbt_rec     *brp;
        struct xfs_inobt_rec    *irp;
        struct xfs_alloc_rec    *arp;
-       void                    *zp;
-       int                     zlen;
+       char                    *zp;
 
        nrecs = be16_to_cpu(block->bb_numrecs);
 
@@ -325,29 +317,24 @@ zero_btree_leaf(
        case TYP_BMAPBTA:
        case TYP_BMAPBTD:
                brp = XFS_BMBT_REC_ADDR(mp, block, 1);
-               zp = &brp[nrecs];
-               zlen = (char *)block + mp->m_sb.sb_blocksize - (char 
*)&brp[nrecs];
+               zp = (char *)&brp[nrecs];
                break;
        case TYP_INOBT:
        case TYP_FINOBT:
                irp = XFS_INOBT_REC_ADDR(mp, block, 1);
-               zp = &irp[nrecs];
-               zlen = (char *)block + mp->m_sb.sb_blocksize - (char 
*)&irp[nrecs];
+               zp = (char *)&irp[nrecs];
                break;
        case TYP_BNOBT:
        case TYP_CNTBT:
                arp = XFS_ALLOC_REC_ADDR(mp, block, 1);
-               zp = &arp[nrecs];
-               zlen = (char *)block + mp->m_sb.sb_blocksize - (char 
*)&arp[nrecs];
+               zp = (char *)&arp[nrecs];
                break;
        default:
-               zp = NULL;
-               break;
+               return;
        }
 
        /* Zero from end of records to end of block */
-       if (zp && zlen < mp->m_sb.sb_blocksize)
-               memset(zp, 0, zlen);
+       memset(zp, 0, (char *)block + mp->m_sb.sb_blocksize - zp);
 }
 
 static void
-- 
2.5.0