From: Howard Chu Date: Tue, 15 Nov 2022 15:33:48 +0000 (+0000) Subject: ITS#9916 liblmdb: use alternate MDB_page2 struct for some accesses X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8e3cab0f633f11eff800170b2d1ada2b53616ab9;p=thirdparty%2Fopenldap.git ITS#9916 liblmdb: use alternate MDB_page2 struct for some accesses fakepage pointers are only guaranteed to be 2-byte aligned. Use a 2-byte aligned struct definition when referencing 2-byte page members if a page pointer possibly points to a fakepage. --- diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c index 5c684afe6c..4c960fe87c 100644 --- a/libraries/liblmdb/mdb.c +++ b/libraries/liblmdb/mdb.c @@ -1046,9 +1046,26 @@ typedef struct MDB_page { #define mp_pad mp_hdr.mh_pad #define mp_flags mp_hdr.mh_flags #define mp_pb mp_hdr.mh_pb - indx_t mp_ptrs[1]; /**< dynamic size */ + indx_t mp_ptrs[0]; /**< dynamic size */ } MDB_page; +/** Alternate page header, for 2-byte aligned access */ +typedef struct MDB_page2 { + uint16_t mp2_p[(sizeof(pgno_t)+sizeof(txnid_t))/2]; + uint16_t mp2_pad; + uint16_t mp2_flags; + indx_t mp2_lower; + indx_t mp2_upper; + indx_t mp2_ptrs[0]; +} MDB_page2; + +#define MP_PGNO(p) (((MDB_page2 *)(void *)(p))->mp2_p) +#define MP_PAD(p) (((MDB_page2 *)(void *)(p))->mp2_pad) +#define MP_FLAGS(p) (((MDB_page2 *)(void *)(p))->mp2_flags) +#define MP_LOWER(p) (((MDB_page2 *)(void *)(p))->mp2_lower) +#define MP_UPPER(p) (((MDB_page2 *)(void *)(p))->mp2_upper) +#define MP_PTRS(p) (((MDB_page2 *)(void *)(p))->mp2_ptrs) + /** Size of the page header, excluding dynamic data at the end */ #define PAGEHDRSZ ((unsigned)sizeof(MDB_page_header)) @@ -1059,10 +1076,10 @@ typedef struct MDB_page { #define PAGEBASE PAGEHDRSZ /** Number of nodes on a page */ -#define NUMKEYS(p) (((p)->mp_lower - (PAGEHDRSZ-PAGEBASE)) >> 1) +#define NUMKEYS(p) ((MP_LOWER(p) - (PAGEHDRSZ-PAGEBASE)) >> 1) /** The amount of space remaining in the page */ -#define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower) +#define SIZELEFT(p) (indx_t)(MP_UPPER(p) - MP_LOWER(p)) /** The percentage of space used in the page, in tenths of a percent. */ #define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \ @@ -1073,15 +1090,15 @@ typedef struct MDB_page { #define FILL_THRESHOLD 250 /** Test if a page is a leaf page */ -#define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF) +#define IS_LEAF(p) F_ISSET(MP_FLAGS(p), P_LEAF) /** Test if a page is a LEAF2 page */ -#define IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2) +#define IS_LEAF2(p) F_ISSET(MP_FLAGS(p), P_LEAF2) /** Test if a page is a branch page */ -#define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH) +#define IS_BRANCH(p) F_ISSET(MP_FLAGS(p), P_BRANCH) /** Test if a page is an overflow page */ -#define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW) +#define IS_OVERFLOW(p) F_ISSET(MP_FLAGS(p), P_OVERFLOW) /** Test if a page is a sub page */ -#define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP) +#define IS_SUBP(p) F_ISSET(MP_FLAGS(p), P_SUBP) /** Test if (this non-sub page is dirty && env is non-#MDB_WRITEMAP) */ #define IS_DIRTY_NW(txn, p) ((p)->mp_txnid > (txn)->mt_txnid) @@ -1192,7 +1209,7 @@ typedef struct MDB_node { #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size) /** Address of node \b i in page \b p */ -#define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i] + PAGEBASE)) +#define NODEPTR(p, i) ((MDB_node *)((char *)(p) + MP_PTRS(p)[i] + PAGEBASE)) /** Address of the key for the node */ #define NODEKEY(node) (void *)((node)->mn_data) @@ -1220,6 +1237,8 @@ typedef struct MDB_node { /** Copy a page number from src to dst */ #ifdef MISALIGNED_OK #define COPY_PGNO(dst,src) dst = src +#undef MP_PGNO +#define MP_PGNO(p) ((p)->mp_pgno) #else #if MDB_SIZE_MAX > 0xffffffffU #define COPY_PGNO(dst,src) do { \ @@ -1923,7 +1942,7 @@ static pgno_t mdb_dbg_pgno(MDB_page *mp) { pgno_t ret; - COPY_PGNO(ret, mp->mp_pgno); + COPY_PGNO(ret, MP_PGNO(mp)); return ret; } @@ -1976,7 +1995,7 @@ mdb_page_list(MDB_page *mp) MDB_val key; DKBUF; - switch (mp->mp_flags & (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP)) { + switch (MP_FLAGS(mp) & (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP)) { case P_BRANCH: type = "Branch page"; break; case P_LEAF: type = "Leaf page"; break; case P_LEAF|P_SUBP: type = "Sub-page"; break; @@ -1990,7 +2009,7 @@ mdb_page_list(MDB_page *mp) pgno, ((MDB_meta *)METADATA(mp))->mm_txnid); return; default: - fprintf(stderr, "Bad page %"Yu" flags 0x%X\n", pgno, mp->mp_flags); + fprintf(stderr, "Bad page %"Yu" flags 0x%X\n", pgno, MP_FLAGS(mp)); return; } @@ -2026,7 +2045,7 @@ mdb_page_list(MDB_page *mp) total = EVEN(total); } fprintf(stderr, "Total: header %d + contents %d + unused %d\n", - IS_LEAF2(mp) ? PAGEHDRSZ : PAGEBASE + mp->mp_lower, total, SIZELEFT(mp)); + IS_LEAF2(mp) ? PAGEHDRSZ : PAGEBASE + MP_LOWER(mp), total, SIZELEFT(mp)); } void @@ -7744,7 +7763,7 @@ mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, mc->mc_ki[mc->mc_top] = 0; return MDB_NOTFOUND; } - if (mp->mp_flags & P_LEAF2) { + if (MP_FLAGS(mp) & P_LEAF2) { nodekey.mv_size = mc->mc_db->md_pad; nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size); } else { @@ -7765,7 +7784,7 @@ mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, unsigned int i; unsigned int nkeys = NUMKEYS(mp); if (nkeys > 1) { - if (mp->mp_flags & P_LEAF2) { + if (MP_FLAGS(mp) & P_LEAF2) { nodekey.mv_data = LEAF2KEY(mp, nkeys-1, nodekey.mv_size); } else { @@ -7783,7 +7802,7 @@ mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, if (rc < 0) { if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) { /* This is definitely the right page, skip search_page */ - if (mp->mp_flags & P_LEAF2) { + if (MP_FLAGS(mp) & P_LEAF2) { nodekey.mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], nodekey.mv_size); } else { @@ -8348,7 +8367,7 @@ mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data, *mc->mc_dbflag |= DB_DIRTY; if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED)) == MDB_DUPFIXED) - np->mp_flags |= P_LEAF2; + MP_FLAGS(np) |= P_LEAF2; mc->mc_flags |= C_INITIALIZED; } else { /* make sure all cursor pages are writable */ @@ -8370,7 +8389,7 @@ mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data, fp_flags = P_LEAF; fp = env->me_pbuf; fp->mp_pad = data->mv_size; /* used if MDB_DUPFIXED */ - fp->mp_lower = fp->mp_upper = (PAGEHDRSZ-PAGEBASE); + MP_LOWER(fp) = MP_UPPER(fp) = (PAGEHDRSZ-PAGEBASE); olddata.mv_size = PAGEHDRSZ; goto prep_subDB; } @@ -8445,18 +8464,18 @@ more: dkey.mv_data = memcpy(fp+1, olddata.mv_data, olddata.mv_size); /* Make sub-page header for the dup items, with dummy body */ - fp->mp_flags = P_LEAF|P_SUBP; - fp->mp_lower = (PAGEHDRSZ-PAGEBASE); + MP_FLAGS(fp) = P_LEAF|P_SUBP; + MP_LOWER(fp) = (PAGEHDRSZ-PAGEBASE); xdata.mv_size = PAGEHDRSZ + dkey.mv_size + data->mv_size; if (mc->mc_db->md_flags & MDB_DUPFIXED) { - fp->mp_flags |= P_LEAF2; + MP_FLAGS(fp) |= P_LEAF2; fp->mp_pad = data->mv_size; xdata.mv_size += 2 * data->mv_size; /* leave space for 2 more */ } else { xdata.mv_size += 2 * (sizeof(indx_t) + NODESIZE) + (dkey.mv_size & 1) + (data->mv_size & 1); } - fp->mp_upper = xdata.mv_size - PAGEBASE; + MP_UPPER(fp) = xdata.mv_size - PAGEBASE; olddata.mv_size = xdata.mv_size; /* pretend olddata is fp */ } else if (leaf->mn_flags & F_SUBDATA) { /* Data is on sub-DB, just store it */ @@ -8479,7 +8498,7 @@ more: } /* FALLTHRU */ /* Big enough MDB_DUPFIXED sub-page */ case MDB_CURRENT: - COPY_PGNO(fp->mp_pgno, mp->mp_pgno); + COPY_PGNO(MP_PGNO(fp), MP_PGNO(mp)); mc->mc_xcursor->mx_cursor.mc_pg[0] = fp; flags |= F_DUPDATA; goto put_sub; @@ -8487,7 +8506,7 @@ more: xdata.mv_size = olddata.mv_size + offset; } - fp_flags = fp->mp_flags; + fp_flags = MP_FLAGS(fp); if (NODESIZE + NODEKSZ(leaf) + xdata.mv_size > env->me_nodemax) { /* Too big for a sub-page, convert to sub-DB */ fp_flags &= ~P_SUBP; @@ -8518,16 +8537,16 @@ prep_subDB: sub_root = mp; } if (mp != fp) { - mp->mp_flags = fp_flags; - mp->mp_pad = fp->mp_pad; - mp->mp_lower = fp->mp_lower; - mp->mp_upper = fp->mp_upper + offset; + MP_FLAGS(mp) = fp_flags; + MP_PAD(mp) = MP_PAD(fp); + MP_LOWER(mp) = MP_LOWER(fp); + MP_UPPER(mp) = MP_UPPER(fp) + offset; if (fp_flags & P_LEAF2) { memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad); } else { - memcpy((char *)mp + mp->mp_upper + PAGEBASE, (char *)fp + fp->mp_upper + PAGEBASE, - olddata.mv_size - fp->mp_upper - PAGEBASE); - memcpy((char *)(&mp->mp_ptrs), (char *)(&fp->mp_ptrs), NUMKEYS(fp) * sizeof(mp->mp_ptrs[0])); + memcpy((char *)mp + MP_UPPER(mp) + PAGEBASE, (char *)fp + MP_UPPER(fp) + PAGEBASE, + olddata.mv_size - MP_UPPER(fp) - PAGEBASE); + memcpy((char *)MP_PTRS(mp), (char *)MP_PTRS(fp), NUMKEYS(fp) * sizeof(mp->mp_ptrs[0])); for (i=0; imp_ptrs[i] += offset; } @@ -8975,7 +8994,7 @@ mdb_node_add(MDB_cursor *mc, indx_t indx, void *ndata; DKBUF; - mdb_cassert(mc, mp->mp_upper >= mp->mp_lower); + mdb_cassert(mc, MP_UPPER(mp) >= MP_LOWER(mp)); DPRINTF(("add to %s %spage %"Yu" index %i, data size %"Z"u key size %"Z"u [%s]", IS_LEAF(mp) ? "leaf" : "branch", @@ -8994,8 +9013,8 @@ mdb_node_add(MDB_cursor *mc, indx_t indx, memcpy(ptr, key->mv_data, ksize); /* Just using these for counting */ - mp->mp_lower += sizeof(indx_t); - mp->mp_upper -= ksize - sizeof(indx_t); + MP_LOWER(mp) += sizeof(indx_t); + MP_UPPER(mp) -= ksize - sizeof(indx_t); return MDB_SUCCESS; } @@ -9032,14 +9051,14 @@ mdb_node_add(MDB_cursor *mc, indx_t indx, update: /* Move higher pointers up one slot. */ for (i = NUMKEYS(mp); i > indx; i--) - mp->mp_ptrs[i] = mp->mp_ptrs[i - 1]; + MP_PTRS(mp)[i] = MP_PTRS(mp)[i - 1]; /* Adjust free space offsets. */ - ofs = mp->mp_upper - node_size; - mdb_cassert(mc, ofs >= mp->mp_lower + sizeof(indx_t)); - mp->mp_ptrs[indx] = ofs; - mp->mp_upper = ofs; - mp->mp_lower += sizeof(indx_t); + ofs = MP_UPPER(mp) - node_size; + mdb_cassert(mc, ofs >= MP_LOWER(mp) + sizeof(indx_t)); + MP_PTRS(mp)[indx] = ofs; + MP_UPPER(mp) = ofs; + MP_LOWER(mp) += sizeof(indx_t); /* Write the node data. */ node = NODEPTR(mp, indx); @@ -9081,7 +9100,7 @@ update: full: DPRINTF(("not enough room in page %"Yu", got %u ptrs", mdb_dbg_pgno(mp), NUMKEYS(mp))); - DPRINTF(("upper-lower = %u - %u = %"Z"d", mp->mp_upper,mp->mp_lower,room)); + DPRINTF(("upper-lower = %u - %u = %"Z"d", MP_UPPER(mp),MP_LOWER(mp),room)); DPRINTF(("node size = %"Z"u", node_size)); mc->mc_txn->mt_flags |= MDB_TXN_ERROR; return MDB_PAGE_FULL; @@ -9112,8 +9131,8 @@ mdb_node_del(MDB_cursor *mc, int ksize) base = LEAF2KEY(mp, indx, ksize); if (x) memmove(base, base + ksize, x * ksize); - mp->mp_lower -= sizeof(indx_t); - mp->mp_upper += ksize - sizeof(indx_t); + MP_LOWER(mp) -= sizeof(indx_t); + MP_UPPER(mp) += ksize - sizeof(indx_t); return; } @@ -9127,21 +9146,21 @@ mdb_node_del(MDB_cursor *mc, int ksize) } sz = EVEN(sz); - ptr = mp->mp_ptrs[indx]; + ptr = MP_PTRS(mp)[indx]; for (i = j = 0; i < numkeys; i++) { if (i != indx) { - mp->mp_ptrs[j] = mp->mp_ptrs[i]; - if (mp->mp_ptrs[i] < ptr) - mp->mp_ptrs[j] += sz; + MP_PTRS(mp)[j] = MP_PTRS(mp)[i]; + if (MP_PTRS(mp)[i] < ptr) + MP_PTRS(mp)[j] += sz; j++; } } - base = (char *)mp + mp->mp_upper + PAGEBASE; - memmove(base + sz, base, ptr - mp->mp_upper); + base = (char *)mp + MP_UPPER(mp) + PAGEBASE; + memmove(base + sz, base, ptr - MP_UPPER(mp)); - mp->mp_lower -= sizeof(indx_t); - mp->mp_upper += sz; + MP_LOWER(mp) -= sizeof(indx_t); + MP_UPPER(mp) += sz; } /** Compact the main page after deleting a node on a subpage. @@ -9170,11 +9189,11 @@ mdb_node_shrink(MDB_page *mp, indx_t indx) } else { xp = (MDB_page *)((char *)sp + delta); /* destination subpage */ for (i = NUMKEYS(sp); --i >= 0; ) - xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta; + MP_PTRS(xp)[i] = MP_PTRS(sp)[i] - delta; len = PAGEHDRSZ; } - sp->mp_upper = sp->mp_lower; - COPY_PGNO(sp->mp_pgno, mp->mp_pgno); + MP_UPPER(sp) = MP_LOWER(sp); + COPY_PGNO(MP_PGNO(sp), mp->mp_pgno); SETDSZ(node, nsize); /* Shift upward */ @@ -9246,7 +9265,7 @@ mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node) mx->mx_db.md_leaf_pages = 1; mx->mx_db.md_overflow_pages = 0; mx->mx_db.md_entries = NUMKEYS(fp); - COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno); + COPY_PGNO(mx->mx_db.md_root, MP_PGNO(fp)); mx->mx_cursor.mc_snum = 1; mx->mx_cursor.mc_top = 0; mx->mx_cursor.mc_flags |= C_INITIALIZED;