[XFS] implement generic xfs_btree_lshift

Make the btree left shift code generic. Based on a patch from David
Chinner with lots of changes to follow the original btree implementations
more closely. While this loses some of the generic helper routines for
inserting/moving/removing records it also solves some of the one off bugs
in the original code and makes it easier to verify.

SGI-PV: 985583

SGI-Modid: xfs-linux-melb:xfs-kern:32197a

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, 2 insertions, 136 deletions

diff --git a/fs/xfs/xfs_bmap_btree.c b/fs/xfs/xfs_bmap_btree.c
index 9d18fa8aa1da..809bd6ee177e 100644
--- a/fs/xfs/xfs_bmap_btree.c
+++ b/fs/xfs/xfs_bmap_btree.c
@@ -52,7 +52,6 @@
 STATIC int xfs_bmbt_killroot(xfs_btree_cur_t *);
 STATIC void xfs_bmbt_log_keys(xfs_btree_cur_t *, xfs_buf_t *, int, int);
 STATIC void xfs_bmbt_log_ptrs(xfs_btree_cur_t *, xfs_buf_t *, int, int);
-STATIC int xfs_bmbt_lshift(xfs_btree_cur_t *, int, int *);
 STATIC int xfs_bmbt_split(xfs_btree_cur_t *, int, xfs_fsblock_t *,
                 __uint64_t *, xfs_btree_cur_t **, int *);
 
@@ -270,7 +269,7 @@ xfs_bmbt_delrec(
                 bno = be64_to_cpu(right->bb_leftsib);
                 if (be16_to_cpu(right->bb_numrecs) - 1 >=
                     XFS_BMAP_BLOCK_IMINRECS(level, cur)) {
-                        if ((error = xfs_bmbt_lshift(tcur, level, &i))) {
+                        if ((error = xfs_btree_lshift(tcur, level, &i))) {
                                 XFS_BMBT_TRACE_CURSOR(cur, ERROR);
                                 goto error0;
                         }
@@ -544,7 +543,7 @@ xfs_bmbt_insrec(
                         if (i) {
                                 /* nothing */
                         } else {
-                                if ((error = xfs_bmbt_lshift(cur, level, &i))) {
+                                if ((error = xfs_btree_lshift(cur, level, &i))) {
                                         XFS_BMBT_TRACE_CURSOR(cur, ERROR);
                                         return error;
                                 }
@@ -811,139 +810,6 @@ xfs_bmbt_log_ptrs(
 }
 
 /*
- * Move 1 record left from cur/level if possible.
- * Update cur to reflect the new path.
- */
-STATIC int                                      /* error */
-xfs_bmbt_lshift(
-        xfs_btree_cur_t         *cur,
-        int                     level,
-        int                     *stat)          /* success/failure */
-{
-        int                     error;          /* error return value */
-#ifdef DEBUG
-        int                     i;              /* loop counter */
-#endif
-        xfs_bmbt_key_t          key;            /* bmap btree key */
-        xfs_buf_t               *lbp;           /* left buffer pointer */
-        xfs_bmbt_block_t        *left;          /* left btree block */
-        xfs_bmbt_key_t          *lkp=NULL;      /* left btree key */
-        xfs_bmbt_ptr_t          *lpp;           /* left address pointer */
-        int                     lrecs;          /* left record count */
-        xfs_bmbt_rec_t          *lrp=NULL;      /* left record pointer */
-        xfs_mount_t             *mp;            /* file system mount point */
-        xfs_buf_t               *rbp;           /* right buffer pointer */
-        xfs_bmbt_block_t        *right;         /* right btree block */
-        xfs_bmbt_key_t          *rkp=NULL;      /* right btree key */
-        xfs_bmbt_ptr_t          *rpp=NULL;      /* right address pointer */
-        xfs_bmbt_rec_t          *rrp=NULL;      /* right record pointer */
-        int                     rrecs;          /* right record count */
-
-        XFS_BMBT_TRACE_CURSOR(cur, ENTRY);
-        XFS_BMBT_TRACE_ARGI(cur, level);
-        if (level == cur->bc_nlevels - 1) {
-                XFS_BMBT_TRACE_CURSOR(cur, EXIT);
-                *stat = 0;
-                return 0;
-        }
-        rbp = cur->bc_bufs[level];
-        right = XFS_BUF_TO_BMBT_BLOCK(rbp);
-#ifdef DEBUG
-        if ((error = xfs_btree_check_lblock(cur, right, level, rbp))) {
-                XFS_BMBT_TRACE_CURSOR(cur, ERROR);
-                return error;
-        }
-#endif
-        if (be64_to_cpu(right->bb_leftsib) == NULLDFSBNO) {
-                XFS_BMBT_TRACE_CURSOR(cur, EXIT);
-                *stat = 0;
-                return 0;
-        }
-        if (cur->bc_ptrs[level] <= 1) {
-                XFS_BMBT_TRACE_CURSOR(cur, EXIT);
-                *stat = 0;
-                return 0;
-        }
-        mp = cur->bc_mp;
-        if ((error = xfs_btree_read_bufl(mp, cur->bc_tp, be64_to_cpu(right->bb_leftsib), 0,
-                        &lbp, XFS_BMAP_BTREE_REF))) {
-                XFS_BMBT_TRACE_CURSOR(cur, ERROR);
-                return error;
-        }
-        left = XFS_BUF_TO_BMBT_BLOCK(lbp);
-        if ((error = xfs_btree_check_lblock(cur, left, level, lbp))) {
-                XFS_BMBT_TRACE_CURSOR(cur, ERROR);
-                return error;
-        }
-        if (be16_to_cpu(left->bb_numrecs) == XFS_BMAP_BLOCK_IMAXRECS(level, cur)) {
-                XFS_BMBT_TRACE_CURSOR(cur, EXIT);
-                *stat = 0;
-                return 0;
-        }
-        lrecs = be16_to_cpu(left->bb_numrecs) + 1;
-        if (level > 0) {
-                lkp = XFS_BMAP_KEY_IADDR(left, lrecs, cur);
-                rkp = XFS_BMAP_KEY_IADDR(right, 1, cur);
-                *lkp = *rkp;
-                xfs_bmbt_log_keys(cur, lbp, lrecs, lrecs);
-                lpp = XFS_BMAP_PTR_IADDR(left, lrecs, cur);
-                rpp = XFS_BMAP_PTR_IADDR(right, 1, cur);
-#ifdef DEBUG
-                if ((error = xfs_btree_check_lptr_disk(cur, *rpp, level))) {
-                        XFS_BMBT_TRACE_CURSOR(cur, ERROR);
-                        return error;
-                }
-#endif
-                *lpp = *rpp;
-                xfs_bmbt_log_ptrs(cur, lbp, lrecs, lrecs);
-        } else {
-                lrp = XFS_BMAP_REC_IADDR(left, lrecs, cur);
-                rrp = XFS_BMAP_REC_IADDR(right, 1, cur);
-                *lrp = *rrp;
-                xfs_bmbt_log_recs(cur, lbp, lrecs, lrecs);
-        }
-        left->bb_numrecs = cpu_to_be16(lrecs);
-        xfs_bmbt_log_block(cur, lbp, XFS_BB_NUMRECS);
-#ifdef DEBUG
-        if (level > 0)
-                xfs_btree_check_key(XFS_BTNUM_BMAP, lkp - 1, lkp);
-        else
-                xfs_btree_check_rec(XFS_BTNUM_BMAP, lrp - 1, lrp);
-#endif
-        rrecs = be16_to_cpu(right->bb_numrecs) - 1;
-        right->bb_numrecs = cpu_to_be16(rrecs);
-        xfs_bmbt_log_block(cur, rbp, XFS_BB_NUMRECS);
-        if (level > 0) {
-#ifdef DEBUG
-                for (i = 0; i < rrecs; i++) {
-                        if ((error = xfs_btree_check_lptr_disk(cur, rpp[i + 1],
-                                        level))) {
-                                XFS_BMBT_TRACE_CURSOR(cur, ERROR);
-                                return error;
-                        }
-                }
-#endif
-                memmove(rkp, rkp + 1, rrecs * sizeof(*rkp));
-                memmove(rpp, rpp + 1, rrecs * sizeof(*rpp));
-                xfs_bmbt_log_keys(cur, rbp, 1, rrecs);
-                xfs_bmbt_log_ptrs(cur, rbp, 1, rrecs);
-        } else {
-                memmove(rrp, rrp + 1, rrecs * sizeof(*rrp));
-                xfs_bmbt_log_recs(cur, rbp, 1, rrecs);
-                key.br_startoff = cpu_to_be64(xfs_bmbt_disk_get_startoff(rrp));
-                rkp = &key;
-        }
-        if ((error = xfs_btree_updkey(cur, (union xfs_btree_key *)rkp, level + 1))) {
-                XFS_BMBT_TRACE_CURSOR(cur, ERROR);
-                return error;
-        }
-        cur->bc_ptrs[level]--;
-        XFS_BMBT_TRACE_CURSOR(cur, EXIT);
-        *stat = 1;
-        return 0;
-}
-
-/*
  * Determine the extent state.
  */
 /* ARGSUSED */