Fixup metapage writes

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 7a9804dc5ec9eb64d19ea980557a8d3673b3012c..5715eac78c3d4f9e82cb086f0354a95532f735df 100644 (file)
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -229,7 +229,6 @@ typedef struct MDB_db {
 } MDB_db;
 
 struct MDB_txn {
-       pgno_t          mt_root;                /* current / new root page */
        pgno_t          mt_next_pgno;   /* next unallocated page */
        ULONG           mt_txnid;
        ULONG           mt_oldest;
@@ -241,6 +240,7 @@ struct MDB_txn {
        } mt_u;
        MDB_dbx         *mt_dbxs;               /* array */
        MDB_db          **mt_dbs;               /* array of ptrs */
+       MDB_db          mt_db0;                 /* just for write txns */
        unsigned int    mt_numdbs;
 
 #define MDB_TXN_RDONLY          0x01           /* read-only transaction */
@@ -520,13 +520,6 @@ mdb_txn_begin(MDB_env *env, int rdonly, MDB_txn **ret)
                }
                txn->mt_free_pgs[0] = 0;
        }
-       /* Copy the DB arrays */
-       txn->mt_numdbs = env->me_numdbs;
-       rc = (txn->mt_numdbs % DBX_CHUNK) + 1;
-       txn->mt_dbxs = malloc(rc * DBX_CHUNK * sizeof(MDB_dbx));
-       txn->mt_dbs = malloc(rc * DBX_CHUNK * sizeof(MDB_db *));
-       memcpy(txn->mt_dbxs, env->me_dbxs, txn->mt_numdbs * sizeof(MDB_dbx));
-       memcpy(txn->mt_dbs, env->me_dbs, txn->mt_numdbs * sizeof(MDB_db *));
 
        txn->mt_txnid = env->me_txns->mt_txnid;
        if (rdonly) {
@@ -563,13 +556,24 @@ mdb_txn_begin(MDB_env *env, int rdonly, MDB_txn **ret)
                return rc;
        }
 
-       if (toggle)
-               txn->mt_flags |= MDB_TXN_METOGGLE;
+       /* Copy the DB arrays */
+       txn->mt_numdbs = env->me_numdbs;
+       rc = (txn->mt_numdbs % DBX_CHUNK) + 1;
+       txn->mt_dbxs = malloc(rc * DBX_CHUNK * sizeof(MDB_dbx));
+       txn->mt_dbs = malloc(rc * DBX_CHUNK * sizeof(MDB_db *));
+       memcpy(txn->mt_dbxs, env->me_dbxs, txn->mt_numdbs * sizeof(MDB_dbx));
+       memcpy(txn->mt_dbs, env->me_dbs, txn->mt_numdbs * sizeof(MDB_db *));
+
+       if (!rdonly) {
+               memcpy(&txn->mt_db0, txn->mt_dbs[0], sizeof(txn->mt_db0));
+               txn->mt_dbs[0] = &txn->mt_db0;
+               if (toggle)
+                       txn->mt_flags |= MDB_TXN_METOGGLE;
+               txn->mt_next_pgno = env->me_meta.mm_last_pg+1;
+       }
 
-       txn->mt_next_pgno = env->me_meta.mm_last_pg+1;
-       txn->mt_root = env->me_meta.mm_root;
        DPRINTF("begin transaction %lu on mdbenv %p, root page %lu",
-               txn->mt_txnid, (void *) env, txn->mt_root);
+               txn->mt_txnid, (void *) env, txn->mt_dbs[0]->md_root);
 
        *ret = txn;
        return MDB_SUCCESS;
@@ -586,7 +590,7 @@ mdb_txn_abort(MDB_txn *txn)
 
        env = txn->mt_env;
        DPRINTF("abort transaction %lu on mdbenv %p, root page %lu",
-               txn->mt_txnid, (void *) env, txn->mt_root);
+               txn->mt_txnid, (void *) env, txn->mt_dbs[0]->md_root);
 
        free(txn->mt_dbs);
        free(txn->mt_dbxs);
@@ -667,7 +671,7 @@ mdb_txn_commit(MDB_txn *txn)
                goto done;
 
        DPRINTF("committing transaction %lu on mdbenv %p, root page %lu",
-           txn->mt_txnid, (void *) env, txn->mt_root);
+           txn->mt_txnid, (void *) env, txn->mt_dbs[0]->md_root);
 
        /* Commit up to MDB_COMMIT_PAGES dirty pages to disk until done.
         */
@@ -746,8 +750,10 @@ mdb_txn_commit(MDB_txn *txn)
                MDB_dbx *p1 = env->me_dbxs;
                MDB_db **p2 = env->me_dbs;
 
+               txn->mt_dbs[0] = env->me_dbs[0];
                env->me_dbxs = txn->mt_dbxs;
                env->me_dbs = txn->mt_dbs;
+               env->me_numdbs = txn->mt_numdbs;
 
                free(p2);
                free(p1);
@@ -876,23 +882,25 @@ mdbenv_write_meta(MDB_txn *txn)
        assert(txn != NULL);
        assert(txn->mt_env != NULL);
 
-       DPRINTF("writing meta page for root page %lu", txn->mt_root);
+       DPRINTF("writing meta page for root page %lu", txn->mt_dbs[0]->md_root);
 
        env = txn->mt_env;
 
        ptr = (char *)&meta;
-       off = offsetof(MDB_meta, mm_depth);
+       off = offsetof(MDB_meta, mm_last_pg);
        len = sizeof(MDB_meta) - off;
 
        ptr += off;
+       meta.mm_last_pg = txn->mt_next_pgno - 1;
+       meta.mm_txnid = txn->mt_txnid;
+       meta.mm_psize = env->me_meta.mm_psize;
+       meta.mm_flags = env->me_meta.mm_flags;
        meta.mm_depth = txn->mt_dbs[0]->md_depth;
        meta.mm_branch_pages = txn->mt_dbs[0]->md_branch_pages;
        meta.mm_leaf_pages = txn->mt_dbs[0]->md_leaf_pages;
        meta.mm_overflow_pages = txn->mt_dbs[0]->md_overflow_pages;
        meta.mm_entries = txn->mt_dbs[0]->md_entries;
-       meta.mm_root = txn->mt_root;
-       meta.mm_last_pg = txn->mt_next_pgno - 1;
-       meta.mm_txnid = txn->mt_txnid;
+       meta.mm_root = txn->mt_dbs[0]->md_root;
 
        if (!F_ISSET(txn->mt_flags, MDB_TXN_METOGGLE))
                off += env->me_meta.mm_psize;
@@ -1212,6 +1220,8 @@ mdbenv_close(MDB_env *env)
        if (env == NULL)
                return;
 
+       free(env->me_dbs);
+       free(env->me_dbxs);
        free(env->me_path);
 
        if (env->me_map) {
@@ -1440,7 +1450,7 @@ mdb_search_page(MDB_txn *txn, MDB_dbi dbi, MDB_val *key,
                DPRINTF("transaction has failed, must abort");
                return EINVAL;
        } else
-               root = txn->mt_root;
+               root = txn->mt_dbs[dbi]->md_root;
 
        if (root == P_INVALID) {                /* Tree is empty. */
                DPRINTF("tree is empty");
@@ -1457,7 +1467,7 @@ mdb_search_page(MDB_txn *txn, MDB_dbi dbi, MDB_val *key,
                mpp->mp_pi = 0;
                if ((rc = mdb_touch(txn, mpp)))
                        return rc;
-               txn->mt_root = mpp->mp_page->mp_pgno;
+               txn->mt_dbs[dbi]->md_root = mpp->mp_page->mp_pgno;
        }
 
        return mdb_search_page_root(txn, dbi, key, cursor, modify, mpp);
@@ -2313,8 +2323,6 @@ mdb_split(MDB_txn *txn, MDB_dbi dbi, MDB_page **mpp, unsigned int *newindxp,
                mdp->h.md_pi = 0;
                mdp->h.md_parent = &pdp->p;
                txn->mt_dbs[dbi]->md_root = pdp->p.mp_pgno;
-               if (!dbi)
-                       txn->mt_root = pdp->p.mp_pgno;
                DPRINTF("root split! new root = %lu", pdp->p.mp_pgno);
                txn->mt_dbs[dbi]->md_depth++;
 
@@ -2490,8 +2498,6 @@ mdb_put(MDB_txn *txn, MDB_dbi dbi,
                }
                mpp.mp_page = &dp->p;
                txn->mt_dbs[dbi]->md_root = mpp.mp_page->mp_pgno;
-               if (!dbi)
-                       txn->mt_root = mpp.mp_page->mp_pgno;
                txn->mt_dbs[dbi]->md_depth++;
                ki = 0;
        }