Fix MDB_txninfo.mt2 padding on Windows/Apple

[openldap] / libraries / libmdb / mdb.c

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 1249e58596d50560e50f79cb147086b5b7878fdd..b714119c1069933f1e8b1254982cddca1e44e23f 100644 (file)
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -202,6 +202,8 @@
 
 #if defined(_WIN32) || defined(__APPLE__)
 #define MNAME_LEN      32
+#else
+#define MNAME_LEN      (sizeof(pthread_mutex_t))
 #endif
 
 /** @} */
@@ -543,7 +545,7 @@ typedef struct MDB_txninfo {
                pthread_mutex_t mt2_wmutex;
 #define mti_wmutex     mt2.mt2_wmutex
 #endif
-               char pad[(sizeof(pthread_mutex_t)+CACHELINE-1) & ~(CACHELINE-1)];
+               char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];
        } mt2;
        MDB_reader      mti_readers[1];
 } MDB_txninfo;
@@ -764,6 +766,20 @@ typedef struct MDB_meta {
        txnid_t         mm_txnid;                       /**< txnid that committed this page */
 } MDB_meta;
 
+       /** Buffer for a stack-allocated dirty page.
+        *      The members define size and alignment, and silence type
+        *      aliasing warnings.  They are not used directly; that could
+        *      mean incorrectly using several union members in parallel.
+        */
+typedef union MDB_pagebuf {
+       char            mb_raw[MDB_PAGESIZE];
+       MDB_page        mb_page;
+       struct {
+               char            mm_pad[PAGEHDRSZ];
+               MDB_meta        mm_meta;
+       } mb_metabuf;
+} MDB_pagebuf;
+
        /** Auxiliary DB info.
         *      The information here is mostly static/read-only. There is
         *      only a single copy of this record in the environment.
@@ -1112,13 +1128,11 @@ static MDB_page *
 mdb_page_malloc(MDB_cursor *mc) {
        MDB_page *ret;
        size_t sz = mc->mc_txn->mt_env->me_psize;
-       if (mc->mc_txn->mt_env->me_dpages) {
-               ret = mc->mc_txn->mt_env->me_dpages;
+       if ((ret = mc->mc_txn->mt_env->me_dpages) != NULL) {
                VGMEMP_ALLOC(mc->mc_txn->mt_env, ret, sz);
                VGMEMP_DEFINED(ret, sizeof(ret->mp_next));
                mc->mc_txn->mt_env->me_dpages = ret->mp_next;
-       } else {
-               ret = malloc(sz);
+       } else if ((ret = malloc(sz)) != NULL) {
                VGMEMP_ALLOC(mc->mc_txn->mt_env, ret, sz);
        }
        return ret;
@@ -2050,7 +2064,7 @@ done:
 static int
 mdb_env_read_header(MDB_env *env, MDB_meta *meta)
 {
-       char             page[MDB_PAGESIZE];
+       MDB_pagebuf     pbuf;
        MDB_page        *p;
        MDB_meta        *m;
        int              rc, err;
@@ -2059,9 +2073,9 @@ mdb_env_read_header(MDB_env *env, MDB_meta *meta)
         */
 
 #ifdef _WIN32
-       if (!ReadFile(env->me_fd, page, MDB_PAGESIZE, (DWORD *)&rc, NULL) || rc == 0)
+       if (!ReadFile(env->me_fd, &pbuf, MDB_PAGESIZE, (DWORD *)&rc, NULL) || rc == 0)
 #else
-       if ((rc = read(env->me_fd, page, MDB_PAGESIZE)) == 0)
+       if ((rc = read(env->me_fd, &pbuf, MDB_PAGESIZE)) == 0)
 #endif
        {
                return ENOENT;
@@ -2074,7 +2088,7 @@ mdb_env_read_header(MDB_env *env, MDB_meta *meta)
                return err;
        }
 
-       p = (MDB_page *)page;
+       p = (MDB_page *)&pbuf;
 
        if (!F_ISSET(p->mp_flags, P_META)) {
                DPRINTF("page %zu not a meta page", p->mp_pgno);
@@ -2375,8 +2389,10 @@ mdb_env_open2(MDB_env *env, unsigned int flags)
                i |= MAP_FIXED;
        env->me_map = mmap(meta.mm_address, env->me_mapsize, PROT_READ, i,
                env->me_fd, 0);
-       if (env->me_map == MAP_FAILED)
+       if (env->me_map == MAP_FAILED) {
+               env->me_map = NULL;
                return ErrCode();
+       }
 #endif
 
        if (newenv) {
@@ -2625,8 +2641,8 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
                size = rsize - sizeof(MDB_txninfo);
                env->me_maxreaders = size/sizeof(MDB_reader) + 1;
        }
-#ifdef _WIN32
        {
+#ifdef _WIN32
                HANDLE mh;
                mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
                        0, 0, NULL);
@@ -2640,15 +2656,17 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
                        rc = ErrCode();
                        goto fail;
                }
-       }
 #else
-       env->me_txns = (MDB_txninfo *)mmap(0, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
-               env->me_lfd, 0);
-       if (env->me_txns == MAP_FAILED) {
-               rc = ErrCode();
-               goto fail;
-       }
+               void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
+                       env->me_lfd, 0);
+               if (m == MAP_FAILED) {
+                       env->me_txns = NULL;
+                       rc = ErrCode();
+                       goto fail;
+               }
+               env->me_txns = m;
 #endif
+       }
        if (*excl) {
 #ifdef _WIN32
                char hexbuf[17];
@@ -3996,7 +4014,7 @@ mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
        unsigned int mcount = 0;
        size_t nsize;
        int rc, rc2;
-       char pbuf[MDB_PAGESIZE];
+       MDB_pagebuf pbuf;
        char dbuf[MAXKEYSIZE+1];
        unsigned int nflags;
        DKBUF;
@@ -4092,7 +4110,7 @@ more:
                                /* create a fake page for the dup items */
                                memcpy(dbuf, dkey.mv_data, dkey.mv_size);
                                dkey.mv_data = dbuf;
-                               fp = (MDB_page *)pbuf;
+                               fp = (MDB_page *)&pbuf;
                                fp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
                                fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;
                                fp->mp_lower = PAGEHDRSZ;
@@ -4108,7 +4126,7 @@ more:
                                do_sub = 1;
                                rdata = &xdata;
                                xdata.mv_size = fp->mp_upper;
-                               xdata.mv_data = pbuf;
+                               xdata.mv_data = fp;
                                flags |= F_DUPDATA;
                                goto new_sub;
                        }
@@ -4161,8 +4179,8 @@ more:
                                        /* no, just grow it */
                                        rdata = &xdata;
                                        xdata.mv_size = NODEDSZ(leaf) + offset;
-                                       xdata.mv_data = pbuf;
-                                       mp = (MDB_page *)pbuf;
+                                       xdata.mv_data = &pbuf;
+                                       mp = (MDB_page *)&pbuf;
                                        mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
                                        flags |= F_DUPDATA;
                                }
@@ -4245,7 +4263,6 @@ new_sub:
                 * DB are all zero size.
                 */
                if (do_sub) {
-                       MDB_db *db;
                        int xflags;
 put_sub:
                        xdata.mv_size = 0;
@@ -4279,7 +4296,7 @@ put_sub:
                        xflags |= (flags & MDB_APPEND);
                        rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);
                        if (flags & F_SUBDATA) {
-                               db = NODEDATA(leaf);
+                               void *db = NODEDATA(leaf);
                                memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
                        }
                }
@@ -4329,7 +4346,7 @@ mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
                        if (mc->mc_xcursor->mx_db.md_entries) {
                                if (leaf->mn_flags & F_SUBDATA) {
                                        /* update subDB info */
-                                       MDB_db *db = NODEDATA(leaf);
+                                       void *db = NODEDATA(leaf);
                                        memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
                                } else {
                                        /* shrink fake page */