[XFS] implement generic xfs_btree_decrement

From: Dave Chinner <dgc@sgi.com>

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

SGI-PV: 985583

SGI-Modid: xfs-linux-melb:xfs-kern:32191a

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, 8 insertions, 82 deletions

diff --git a/fs/xfs/xfs_bmap_btree.c b/fs/xfs/xfs_bmap_btree.c
index 2d29a4980cf7..7b5181d34a5b 100644
--- a/fs/xfs/xfs_bmap_btree.c
+++ b/fs/xfs/xfs_bmap_btree.c
@@ -203,7 +203,7 @@ xfs_bmbt_delrec(
                         XFS_BMBT_TRACE_CURSOR(cur, ERROR);
                         goto error0;
                 }
-                if (level > 0 && (error = xfs_bmbt_decrement(cur, level, &j))) {
+                if (level > 0 && (error = xfs_btree_decrement(cur, level, &j))) {
                         XFS_BMBT_TRACE_CURSOR(cur, ERROR);
                         goto error0;
                 }
@@ -216,7 +216,7 @@ xfs_bmbt_delrec(
                 goto error0;
         }
         if (numrecs >= XFS_BMAP_BLOCK_IMINRECS(level, cur)) {
-                if (level > 0 && (error = xfs_bmbt_decrement(cur, level, &j))) {
+                if (level > 0 && (error = xfs_btree_decrement(cur, level, &j))) {
                         XFS_BMBT_TRACE_CURSOR(cur, ERROR);
                         goto error0;
                 }
@@ -237,7 +237,7 @@ xfs_bmbt_delrec(
                         XFS_BMBT_TRACE_CURSOR(cur, ERROR);
                         goto error0;
                 }
-                if (level > 0 && (error = xfs_bmbt_decrement(cur, level, &i))) {
+                if (level > 0 && (error = xfs_btree_decrement(cur, level, &i))) {
                         XFS_BMBT_TRACE_CURSOR(cur, ERROR);
                         goto error0;
                 }
@@ -282,7 +282,7 @@ xfs_bmbt_delrec(
                                 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
                                 tcur = NULL;
                                 if (level > 0) {
-                                        if ((error = xfs_bmbt_decrement(cur,
+                                        if ((error = xfs_btree_decrement(cur,
                                                         level, &i))) {
                                                 XFS_BMBT_TRACE_CURSOR(cur,
                                                         ERROR);
@@ -298,7 +298,7 @@ xfs_bmbt_delrec(
                 if (lbno != NULLFSBLOCK) {
                         i = xfs_btree_firstrec(tcur, level);
                         XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
-                        if ((error = xfs_bmbt_decrement(tcur, level, &i))) {
+                        if ((error = xfs_btree_decrement(tcur, level, &i))) {
                                 XFS_BMBT_TRACE_CURSOR(cur, ERROR);
                                 goto error0;
                         }
@@ -311,7 +311,7 @@ xfs_bmbt_delrec(
                 /*
                  * decrement to last in block
                  */
-                if ((error = xfs_bmbt_decrement(tcur, level, &i))) {
+                if ((error = xfs_btree_decrement(tcur, level, &i))) {
                         XFS_BMBT_TRACE_CURSOR(cur, ERROR);
                         goto error0;
                 }
@@ -383,7 +383,7 @@ xfs_bmbt_delrec(
                 }
                 lrecs = be16_to_cpu(left->bb_numrecs);
         } else {
-                if (level > 0 && (error = xfs_bmbt_decrement(cur, level, &i))) {
+                if (level > 0 && (error = xfs_btree_decrement(cur, level, &i))) {
                         XFS_BMBT_TRACE_CURSOR(cur, ERROR);
                         goto error0;
                 }
@@ -1487,80 +1487,6 @@ xfs_bmdr_to_bmbt(
 }
 
 /*
- * Decrement cursor by one record at the level.
- * For nonzero levels the leaf-ward information is untouched.
- */
-int                                             /* error */
-xfs_bmbt_decrement(
-        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_LEFTRA);
-
-        if (--cur->bc_ptrs[level] > 0) {
-                XFS_BMBT_TRACE_CURSOR(cur, EXIT);
-                *stat = 1;
-                return 0;
-        }
-        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 (be64_to_cpu(block->bb_leftsib) == NULLDFSBNO) {
-                XFS_BMBT_TRACE_CURSOR(cur, EXIT);
-                *stat = 0;
-                return 0;
-        }
-        for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
-                if (--cur->bc_ptrs[lev] > 0)
-                        break;
-                xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
-        }
-        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] = be16_to_cpu(block->bb_numrecs);
-        }
-        XFS_BMBT_TRACE_CURSOR(cur, EXIT);
-        *stat = 1;
-        return 0;
-}
-
-/*
  * Delete the record pointed to by cur.
  */
 int                                     /* error */
@@ -1582,7 +1508,7 @@ xfs_bmbt_delete(
         if (i == 0) {
                 for (level = 1; level < cur->bc_nlevels; level++) {
                         if (cur->bc_ptrs[level] == 0) {
-                                if ((error = xfs_bmbt_decrement(cur, level,
+                                if ((error = xfs_btree_decrement(cur, level,
                                                 &i))) {
                                         XFS_BMBT_TRACE_CURSOR(cur, ERROR);
                                         return error;