From 7dfc32681affa6f0696bec78bd3b9e61ddc19562 Mon Sep 17 00:00:00 2001 From: barter-simsum Date: Tue, 12 Dec 2023 22:22:48 -0500 Subject: [PATCH] pma: more mmap changes. WIP --- rust/ares_pma/c-src/btree.c | 45 ++++++++++++++++++++++++++++--------- 1 file changed, 34 insertions(+), 11 deletions(-) diff --git a/rust/ares_pma/c-src/btree.c b/rust/ares_pma/c-src/btree.c index b1878ec..9641082 100644 --- a/rust/ares_pma/c-src/btree.c +++ b/rust/ares_pma/c-src/btree.c @@ -88,7 +88,7 @@ STATIC_ASSERT(0, "debugger break instruction unimplemented"); #define SUCC(x) ((x) == BT_SUCC) -#define BT_MAPADDR ((void *) S(0x1000,0000,0000)) +#define BT_MAPADDR ((BYTE *) S(0x1000,0000,0000)) static inline vaof_t addr2off(void *p) @@ -111,6 +111,7 @@ off2addr(vaof_t off) #define BT_PAGEWORD 32ULL #define BT_NUMMETAS 2 /* 2 metapages */ +#define BT_META_SECTION_WIDTH (BT_NUMMETAS * BT_PAGESIZE) #define BT_ADDRSIZE (BT_PAGESIZE << BT_PAGEWORD) #define PMA_GROW_SIZE (BT_PAGESIZE * 1024 * 64) @@ -235,7 +236,7 @@ static_assert(BT_DAT_MAXBYTES % sizeof(BT_dat) == 0); a meta page is like any other page, but the data section is used to store additional information */ -#define BLK_BASE_LEN0 (MBYTES(2) - (BT_PAGESIZE * BT_NUMMETAS)) +#define BLK_BASE_LEN0 (MBYTES(2) - BT_META_SECTION_WIDTH) #define BLK_BASE_LEN1 (BLK_BASE_LEN0 * 4) #define BLK_BASE_LEN2 (BLK_BASE_LEN1 * 4) #define BLK_BASE_LEN3 (BLK_BASE_LEN2 * 4) @@ -409,8 +410,10 @@ _bt_nalloc(BT_state *state) } } - /* make node writeable */ + /* make node writable */ mprotect(ret, sizeof(BT_page), PROT_READ | PROT_WRITE); + + return ret; } static int @@ -1498,7 +1501,7 @@ _flist_grow(BT_state *state, BT_flistnode *space) static int _flist_new(BT_state *state) -#define FLIST_PG_START (((BT_PAGESIZE * BT_NUMMETAS) + BLK_BASE_LEN0) / BT_PAGESIZE) +#define FLIST_PG_START ((BT_META_SECTION_WIDTH + BLK_BASE_LEN0) / BT_PAGESIZE) { BT_meta *meta = state->meta_pages[state->which]; BT_page *root = _node_get(state, meta->root); @@ -2189,6 +2192,13 @@ _bt_state_meta_new(BT_state *state) TRACE(); + /* open the metapage region for writing */ + if (mprotect(BT_MAPADDR, BT_META_SECTION_WIDTH, + PROT_READ | PROT_WRITE) != 0) { + DPRINTF("mprotect of metapage section failed with %s", strerror(errno)); + abort(); + } + /* initialize the block base array */ meta.blk_base[0] = BT_PAGESIZE * BT_NUMMETAS; @@ -2219,6 +2229,17 @@ _bt_state_meta_new(BT_state *state) first?? */ memcpy(METADATA(p2), &meta, sizeof meta); + /* only the active metapage should be writable (first page) */ + if (mprotect(BT_MAPADDR, BT_META_SECTION_WIDTH, PROT_READ) != 0) { + DPRINTF("mprotect of metapage section failed with %s", strerror(errno)); + abort(); + } + if (mprotect(BT_MAPADDR, BT_PAGESIZE, + PROT_READ | PROT_WRITE) != 0) { + DPRINTF("mprotect of current metapage failed with %s", strerror(errno)); + abort(); + } + return BT_SUCC; } @@ -2242,11 +2263,10 @@ _bt_state_load(BT_state *state) } } + /* map first node stripe (along with metapages) as read only */ state->map = mmap(BT_MAPADDR, - BT_ADDRSIZE, /* should actually just be first 2M - stripe. and then from there - should map like it's freespace. */ - PROT_READ | PROT_WRITE, /* ;;: PROT_READ */ + BT_META_SECTION_WIDTH + BLK_BASE_LEN0, + PROT_READ, MAP_FIXED | MAP_SHARED, state->data_fd, 0); @@ -2420,7 +2440,7 @@ _bt_sync_meta(BT_state *state) newwhich = state->which ? 0 : 1; newmeta = state->meta_pages[newwhich]; - /* make new metapage writeable */ + /* make new metapage writable */ if (mprotect(newmeta, sizeof(BT_page), PROT_READ | PROT_WRITE) != 0) { DPRINTF("mprotect of new metapage failed with %s", strerror(errno)); abort(); @@ -2527,6 +2547,9 @@ bt_state_open(BT_state *state, const char *path, ULONG flags, mode_t mode) if (!dpath) return ENOMEM; sprintf(dpath, "%s" DATANAME, path); + if (mkdir(path, 0774) == -1) + return errno; + if ((state->data_fd = open(dpath, oflags, mode)) == -1) return errno; @@ -2596,7 +2619,7 @@ bt_malloc(BT_state *state, size_t pages) addr2off(ret) + pages, pgno); - DPRINTF("map %p to offset %lld bytes (%lld pages)\n", ret, P2BYTES(pgno), pgno); + DPRINTF("map %p to offset 0x%zx bytes (0x%x pages)\n", ret, P2BYTES(pgno), pgno); if (ret != mmap(ret, P2BYTES(pages), @@ -2929,7 +2952,7 @@ int bt_inbounds(BT_state *state, void *p) /* 1: if in the bounds of the PMA, 0 otherwise */ { - return p >= BT_MAPADDR + return p >= (void *)BT_MAPADDR && p < (void *)((uintptr_t)BT_MAPADDR + BT_ADDRSIZE); }