[XFS] implement generic xfs_btree_increment

From: Dave Chinner <dgc@sgi.com>

Because this is the first major generic btree routine this patch includes
some infrastrucure, first a few routines to deal with a btree block that
can be either in short or long form, second xfs_btree_read_buf_block,
which is the new central routine to read a btree block given a cursor, and
third the new xfs_btree_ptr_addr routine to calculate the address for a
given btree pointer record.

[hch: split out from bigger patch and minor adaptions]

SGI-PV: 985583

SGI-Modid: xfs-linux-melb:xfs-kern:32190a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Bill O'Donnell <billodo@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>

1 files changed, 4 insertions, 84 deletions

diff --git a/fs/xfs/xfs_bmap_btree.c b/fs/xfs/xfs_bmap_btree.c
index a71010abf6ec..2d29a4980cf7 100644
--- a/fs/xfs/xfs_bmap_btree.c
+++ b/fs/xfs/xfs_bmap_btree.c
@@ -254,7 +254,7 @@ xfs_bmbt_delrec(
         if (rbno != NULLFSBLOCK) {
                 i = xfs_btree_lastrec(tcur, level);
                 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
-                if ((error = xfs_bmbt_increment(tcur, level, &i))) {
+                if ((error = xfs_btree_increment(tcur, level, &i))) {
                         XFS_BMBT_TRACE_CURSOR(cur, ERROR);
                         goto error0;
                 }
@@ -445,7 +445,7 @@ xfs_bmbt_delrec(
                 cur->bc_bufs[level] = lbp;
                 cur->bc_ptrs[level] += lrecs;
                 cur->bc_ra[level] = 0;
-        } else if ((error = xfs_bmbt_increment(cur, level + 1, &i))) {
+        } else if ((error = xfs_btree_increment(cur, level + 1, &i))) {
                 XFS_BMBT_TRACE_CURSOR(cur, ERROR);
                 goto error0;
         }
@@ -929,7 +929,7 @@ xfs_bmbt_lookup(
                 if (dir == XFS_LOOKUP_GE && keyno > be16_to_cpu(block->bb_numrecs) &&
                     be64_to_cpu(block->bb_rightsib) != NULLDFSBNO) {
                         cur->bc_ptrs[0] = keyno;
-                        if ((error = xfs_bmbt_increment(cur, 0, &i))) {
+                        if ((error = xfs_btree_increment(cur, 0, &i))) {
                                 XFS_BMBT_TRACE_CURSOR(cur, ERROR);
                                 return error;
                         }
@@ -1202,7 +1202,7 @@ xfs_bmbt_rshift(
         }
         i = xfs_btree_lastrec(tcur, level);
         XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
-        if ((error = xfs_bmbt_increment(tcur, level, &i))) {
+        if ((error = xfs_btree_increment(tcur, level, &i))) {
                 XFS_BMBT_TRACE_CURSOR(tcur, ERROR);
                 goto error1;
         }
@@ -1761,86 +1761,6 @@ xfs_bmbt_disk_get_startoff(
 }
 
 /*
- * Increment cursor by one record at the level.
- * For nonzero levels the leaf-ward information is untouched.
- */
-int                                             /* error */
-xfs_bmbt_increment(
-        xfs_btree_cur_t         *cur,
-        int                     level,
-        int                     *stat)          /* success/failure */
-{
-        xfs_bmbt_block_t        *block;
-        xfs_buf_t               *bp;
-        int                     error;          /* error return value */
-        xfs_fsblock_t           fsbno;
-        int                     lev;
-        xfs_mount_t             *mp;
-        xfs_trans_t             *tp;
-
-        XFS_BMBT_TRACE_CURSOR(cur, ENTRY);
-        XFS_BMBT_TRACE_ARGI(cur, level);
-        ASSERT(level < cur->bc_nlevels);
-
-        xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
-        block = xfs_bmbt_get_block(cur, level, &bp);
-#ifdef DEBUG
-        if ((error = xfs_btree_check_lblock(cur, block, level, bp))) {
-                XFS_BMBT_TRACE_CURSOR(cur, ERROR);
-                return error;
-        }
-#endif
-        if (++cur->bc_ptrs[level] <= be16_to_cpu(block->bb_numrecs)) {
-                XFS_BMBT_TRACE_CURSOR(cur, EXIT);
-                *stat = 1;
-                return 0;
-        }
-        if (be64_to_cpu(block->bb_rightsib) == NULLDFSBNO) {
-                XFS_BMBT_TRACE_CURSOR(cur, EXIT);
-                *stat = 0;
-                return 0;
-        }
-        for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
-                block = xfs_bmbt_get_block(cur, lev, &bp);
-#ifdef DEBUG
-                if ((error = xfs_btree_check_lblock(cur, block, lev, bp))) {
-                        XFS_BMBT_TRACE_CURSOR(cur, ERROR);
-                        return error;
-                }
-#endif
-                if (++cur->bc_ptrs[lev] <= be16_to_cpu(block->bb_numrecs))
-                        break;
-                xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
-        }
-        if (lev == cur->bc_nlevels) {
-                XFS_BMBT_TRACE_CURSOR(cur, EXIT);
-                *stat = 0;
-                return 0;
-        }
-        tp = cur->bc_tp;
-        mp = cur->bc_mp;
-        for (block = xfs_bmbt_get_block(cur, lev, &bp); lev > level; ) {
-                fsbno = be64_to_cpu(*XFS_BMAP_PTR_IADDR(block, cur->bc_ptrs[lev], cur));
-                if ((error = xfs_btree_read_bufl(mp, tp, fsbno, 0, &bp,
-                                XFS_BMAP_BTREE_REF))) {
-                        XFS_BMBT_TRACE_CURSOR(cur, ERROR);
-                        return error;
-                }
-                lev--;
-                xfs_btree_setbuf(cur, lev, bp);
-                block = XFS_BUF_TO_BMBT_BLOCK(bp);
-                if ((error = xfs_btree_check_lblock(cur, block, lev, bp))) {
-                        XFS_BMBT_TRACE_CURSOR(cur, ERROR);
-                        return error;
-                }
-                cur->bc_ptrs[lev] = 1;
-        }
-        XFS_BMBT_TRACE_CURSOR(cur, EXIT);
-        *stat = 1;
-        return 0;
-}
-
-/*
  * Insert the current record at the point referenced by cur.
  *
  * A multi-level split of the tree on insert will invalidate the original