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-rw-r--r--usr.sbin/makefs/zfs/zap.c567
1 files changed, 567 insertions, 0 deletions
diff --git a/usr.sbin/makefs/zfs/zap.c b/usr.sbin/makefs/zfs/zap.c
new file mode 100644
index 000000000000..316d1446cecf
--- /dev/null
+++ b/usr.sbin/makefs/zfs/zap.c
@@ -0,0 +1,567 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2022 The FreeBSD Foundation
+ *
+ * This software was developed by Mark Johnston under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/param.h>
+#include <sys/endian.h>
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <util.h>
+
+#include "makefs.h"
+#include "zfs.h"
+
+typedef struct zfs_zap_entry {
+ char *name; /* entry key, private copy */
+ uint64_t hash; /* key hash */
+ union {
+ uint8_t *valp;
+ uint16_t *val16p;
+ uint32_t *val32p;
+ uint64_t *val64p;
+ }; /* entry value, an integer array */
+ uint64_t val64; /* embedded value for a common case */
+ size_t intsz; /* array element size; 1, 2, 4 or 8 */
+ size_t intcnt; /* array size */
+ STAILQ_ENTRY(zfs_zap_entry) next;
+} zfs_zap_entry_t;
+
+struct zfs_zap {
+ STAILQ_HEAD(, zfs_zap_entry) kvps;
+ uint64_t hashsalt; /* key hash input */
+ unsigned long kvpcnt; /* number of key-value pairs */
+ unsigned long chunks; /* count of chunks needed for fat ZAP */
+ bool micro; /* can this be a micro ZAP? */
+
+ dnode_phys_t *dnode; /* backpointer */
+ zfs_objset_t *os; /* backpointer */
+};
+
+static uint16_t
+zap_entry_chunks(zfs_zap_entry_t *ent)
+{
+ return (1 + howmany(strlen(ent->name) + 1, ZAP_LEAF_ARRAY_BYTES) +
+ howmany(ent->intsz * ent->intcnt, ZAP_LEAF_ARRAY_BYTES));
+}
+
+static uint64_t
+zap_hash(uint64_t salt, const char *name)
+{
+ static uint64_t crc64_table[256];
+ const uint64_t crc64_poly = 0xC96C5795D7870F42UL;
+ const uint8_t *cp;
+ uint64_t crc;
+ uint8_t c;
+
+ assert(salt != 0);
+ if (crc64_table[128] == 0) {
+ for (int i = 0; i < 256; i++) {
+ uint64_t *t;
+
+ t = crc64_table + i;
+ *t = i;
+ for (int j = 8; j > 0; j--)
+ *t = (*t >> 1) ^ (-(*t & 1) & crc64_poly);
+ }
+ }
+ assert(crc64_table[128] == crc64_poly);
+
+ for (cp = (const uint8_t *)name, crc = salt; (c = *cp) != '\0'; cp++)
+ crc = (crc >> 8) ^ crc64_table[(crc ^ c) & 0xFF];
+
+ /*
+ * Only use 28 bits, since we need 4 bits in the cookie for the
+ * collision differentiator. We MUST use the high bits, since
+ * those are the ones that we first pay attention to when
+ * choosing the bucket.
+ */
+ crc &= ~((1ULL << (64 - ZAP_HASHBITS)) - 1);
+
+ return (crc);
+}
+
+zfs_zap_t *
+zap_alloc(zfs_objset_t *os, dnode_phys_t *dnode)
+{
+ zfs_zap_t *zap;
+
+ zap = ecalloc(1, sizeof(*zap));
+ STAILQ_INIT(&zap->kvps);
+ zap->hashsalt = ((uint64_t)random() << 32) | random();
+ zap->micro = true;
+ zap->kvpcnt = 0;
+ zap->chunks = 0;
+ zap->dnode = dnode;
+ zap->os = os;
+ return (zap);
+}
+
+void
+zap_add(zfs_zap_t *zap, const char *name, size_t intsz, size_t intcnt,
+ const uint8_t *val)
+{
+ zfs_zap_entry_t *ent;
+
+ assert(intsz == 1 || intsz == 2 || intsz == 4 || intsz == 8);
+ assert(strlen(name) + 1 <= ZAP_MAXNAMELEN);
+ assert(intcnt <= ZAP_MAXVALUELEN && intcnt * intsz <= ZAP_MAXVALUELEN);
+
+ ent = ecalloc(1, sizeof(*ent));
+ ent->name = estrdup(name);
+ ent->hash = zap_hash(zap->hashsalt, ent->name);
+ ent->intsz = intsz;
+ ent->intcnt = intcnt;
+ if (intsz == sizeof(uint64_t) && intcnt == 1) {
+ /*
+ * Micro-optimization to elide a memory allocation in that most
+ * common case where this is a directory entry.
+ */
+ ent->val64p = &ent->val64;
+ } else {
+ ent->valp = ecalloc(intcnt, intsz);
+ }
+ memcpy(ent->valp, val, intcnt * intsz);
+ zap->kvpcnt++;
+ zap->chunks += zap_entry_chunks(ent);
+ STAILQ_INSERT_TAIL(&zap->kvps, ent, next);
+
+ if (zap->micro && (intcnt != 1 || intsz != sizeof(uint64_t) ||
+ strlen(name) + 1 > MZAP_NAME_LEN || zap->kvpcnt > MZAP_ENT_MAX))
+ zap->micro = false;
+}
+
+void
+zap_add_uint64(zfs_zap_t *zap, const char *name, uint64_t val)
+{
+ zap_add(zap, name, sizeof(uint64_t), 1, (uint8_t *)&val);
+}
+
+void
+zap_add_uint64_self(zfs_zap_t *zap, uint64_t val)
+{
+ char name[32];
+
+ (void)snprintf(name, sizeof(name), "%jx", (uintmax_t)val);
+ zap_add(zap, name, sizeof(uint64_t), 1, (uint8_t *)&val);
+}
+
+void
+zap_add_string(zfs_zap_t *zap, const char *name, const char *val)
+{
+ zap_add(zap, name, 1, strlen(val) + 1, (const uint8_t *)val);
+}
+
+bool
+zap_entry_exists(zfs_zap_t *zap, const char *name)
+{
+ zfs_zap_entry_t *ent;
+
+ STAILQ_FOREACH(ent, &zap->kvps, next) {
+ if (strcmp(ent->name, name) == 0)
+ return (true);
+ }
+ return (false);
+}
+
+static void
+zap_micro_write(zfs_opt_t *zfs, zfs_zap_t *zap)
+{
+ dnode_phys_t *dnode;
+ zfs_zap_entry_t *ent;
+ mzap_phys_t *mzap;
+ mzap_ent_phys_t *ment;
+ off_t bytes, loc;
+ uint16_t cd;
+
+ _Static_assert(MZAP_ENT_MAX <= UINT16_MAX,
+ "micro ZAP collision differentiator must fit in 16 bits");
+
+ memset(zfs->filebuf, 0, sizeof(zfs->filebuf));
+ mzap = (mzap_phys_t *)&zfs->filebuf[0];
+ mzap->mz_block_type = ZBT_MICRO;
+ mzap->mz_salt = zap->hashsalt;
+ mzap->mz_normflags = 0;
+
+ bytes = sizeof(*mzap) + (zap->kvpcnt - 1) * sizeof(*ment);
+ assert(bytes <= (off_t)MZAP_MAX_BLKSZ);
+
+ cd = 0;
+ ment = &mzap->mz_chunk[0];
+ STAILQ_FOREACH(ent, &zap->kvps, next) {
+ memcpy(&ment->mze_value, ent->valp, ent->intsz * ent->intcnt);
+ ment->mze_cd = cd++;
+ (void)strlcpy(ment->mze_name, ent->name,
+ sizeof(ment->mze_name));
+ ment++;
+ }
+
+ loc = objset_space_alloc(zfs, zap->os, &bytes);
+
+ dnode = zap->dnode;
+ dnode->dn_maxblkid = 0;
+ dnode->dn_datablkszsec = bytes >> MINBLOCKSHIFT;
+
+ vdev_pwrite_dnode_data(zfs, dnode, zfs->filebuf, bytes, loc);
+}
+
+/*
+ * Write some data to the fat ZAP leaf chunk starting at index "li".
+ *
+ * Note that individual integers in the value may be split among consecutive
+ * leaves.
+ */
+static void
+zap_fat_write_array_chunk(zap_leaf_t *l, uint16_t li, size_t sz,
+ const uint8_t *val)
+{
+ struct zap_leaf_array *la;
+
+ assert(sz <= ZAP_MAXVALUELEN);
+ assert(sz > 0);
+
+ for (uint16_t n, resid = sz; resid > 0; resid -= n, val += n, li++) {
+ n = MIN(resid, ZAP_LEAF_ARRAY_BYTES);
+
+ la = &ZAP_LEAF_CHUNK(l, li).l_array;
+ assert(la->la_type == ZAP_CHUNK_FREE);
+ la->la_type = ZAP_CHUNK_ARRAY;
+ memcpy(la->la_array, val, n);
+ la->la_next = li + 1;
+ }
+ la->la_next = 0xffff;
+}
+
+/*
+ * Find the shortest hash prefix length which lets us distribute keys without
+ * overflowing a leaf block. This is not (space) optimal, but is simple, and
+ * directories large enough to overflow a single 128KB leaf block are uncommon.
+ */
+static unsigned int
+zap_fat_write_prefixlen(zfs_zap_t *zap, zap_leaf_t *l)
+{
+ zfs_zap_entry_t *ent;
+ unsigned int prefixlen;
+
+ if (zap->chunks <= ZAP_LEAF_NUMCHUNKS(l)) {
+ /*
+ * All chunks will fit in a single leaf block.
+ */
+ return (0);
+ }
+
+ for (prefixlen = 1; prefixlen < (unsigned int)l->l_bs; prefixlen++) {
+ uint32_t *leafchunks;
+
+ leafchunks = ecalloc(1u << prefixlen, sizeof(*leafchunks));
+ STAILQ_FOREACH(ent, &zap->kvps, next) {
+ uint64_t li;
+ uint16_t chunks;
+
+ li = ZAP_HASH_IDX(ent->hash, prefixlen);
+
+ chunks = zap_entry_chunks(ent);
+ if (ZAP_LEAF_NUMCHUNKS(l) - leafchunks[li] < chunks) {
+ /*
+ * Not enough space, grow the prefix and retry.
+ */
+ break;
+ }
+ leafchunks[li] += chunks;
+ }
+ free(leafchunks);
+
+ if (ent == NULL) {
+ /*
+ * Everything fits, we're done.
+ */
+ break;
+ }
+ }
+
+ /*
+ * If this fails, then we need to expand the pointer table. For now
+ * this situation is unhandled since it is hard to trigger.
+ */
+ assert(prefixlen < (unsigned int)l->l_bs);
+
+ return (prefixlen);
+}
+
+/*
+ * Initialize a fat ZAP leaf block.
+ */
+static void
+zap_fat_write_leaf_init(zap_leaf_t *l, uint64_t prefix, int prefixlen)
+{
+ zap_leaf_phys_t *leaf;
+
+ leaf = l->l_phys;
+
+ leaf->l_hdr.lh_block_type = ZBT_LEAF;
+ leaf->l_hdr.lh_magic = ZAP_LEAF_MAGIC;
+ leaf->l_hdr.lh_nfree = ZAP_LEAF_NUMCHUNKS(l);
+ leaf->l_hdr.lh_prefix = prefix;
+ leaf->l_hdr.lh_prefix_len = prefixlen;
+
+ /* Initialize the leaf hash table. */
+ assert(leaf->l_hdr.lh_nfree < 0xffff);
+ memset(leaf->l_hash, 0xff,
+ ZAP_LEAF_HASH_NUMENTRIES(l) * sizeof(*leaf->l_hash));
+
+ /* Initialize the leaf chunks. */
+ for (uint16_t i = 0; i < ZAP_LEAF_NUMCHUNKS(l); i++) {
+ struct zap_leaf_free *lf;
+
+ lf = &ZAP_LEAF_CHUNK(l, i).l_free;
+ lf->lf_type = ZAP_CHUNK_FREE;
+ if (i + 1 == ZAP_LEAF_NUMCHUNKS(l))
+ lf->lf_next = 0xffff;
+ else
+ lf->lf_next = i + 1;
+ }
+}
+
+static void
+zap_fat_write(zfs_opt_t *zfs, zfs_zap_t *zap)
+{
+ struct dnode_cursor *c;
+ zap_leaf_t l;
+ zap_phys_t *zaphdr;
+ struct zap_table_phys *zt;
+ zfs_zap_entry_t *ent;
+ dnode_phys_t *dnode;
+ uint8_t *leafblks;
+ uint64_t lblkcnt, *ptrhasht;
+ off_t loc, blksz;
+ size_t blkshift;
+ unsigned int prefixlen;
+ int ptrcnt;
+
+ /*
+ * For simplicity, always use the largest block size. This should be ok
+ * since most directories will be micro ZAPs, but it's space inefficient
+ * for small ZAPs and might need to be revisited.
+ */
+ blkshift = MAXBLOCKSHIFT;
+ blksz = (off_t)1 << blkshift;
+
+ /*
+ * Embedded pointer tables give up to 8192 entries. This ought to be
+ * enough for anything except massive directories.
+ */
+ ptrcnt = (blksz / 2) / sizeof(uint64_t);
+
+ memset(zfs->filebuf, 0, sizeof(zfs->filebuf));
+ zaphdr = (zap_phys_t *)&zfs->filebuf[0];
+ zaphdr->zap_block_type = ZBT_HEADER;
+ zaphdr->zap_magic = ZAP_MAGIC;
+ zaphdr->zap_num_entries = zap->kvpcnt;
+ zaphdr->zap_salt = zap->hashsalt;
+
+ l.l_bs = blkshift;
+ l.l_phys = NULL;
+
+ zt = &zaphdr->zap_ptrtbl;
+ zt->zt_blk = 0;
+ zt->zt_numblks = 0;
+ zt->zt_shift = flsll(ptrcnt) - 1;
+ zt->zt_nextblk = 0;
+ zt->zt_blks_copied = 0;
+
+ /*
+ * How many leaf blocks do we need? Initialize them and update the
+ * header.
+ */
+ prefixlen = zap_fat_write_prefixlen(zap, &l);
+ lblkcnt = (uint64_t)1 << prefixlen;
+ leafblks = ecalloc(lblkcnt, blksz);
+ for (unsigned int li = 0; li < lblkcnt; li++) {
+ l.l_phys = (zap_leaf_phys_t *)(leafblks + li * blksz);
+ zap_fat_write_leaf_init(&l, li, prefixlen);
+ }
+ zaphdr->zap_num_leafs = lblkcnt;
+ zaphdr->zap_freeblk = lblkcnt + 1;
+
+ /*
+ * For each entry, figure out which leaf block it belongs to based on
+ * the upper bits of its hash, allocate chunks from that leaf, and fill
+ * them out.
+ */
+ ptrhasht = (uint64_t *)(&zfs->filebuf[0] + blksz / 2);
+ STAILQ_FOREACH(ent, &zap->kvps, next) {
+ struct zap_leaf_entry *le;
+ uint16_t *lptr;
+ uint64_t hi, li;
+ uint16_t namelen, nchunks, nnamechunks, nvalchunks;
+
+ hi = ZAP_HASH_IDX(ent->hash, zt->zt_shift);
+ li = ZAP_HASH_IDX(ent->hash, prefixlen);
+ assert(ptrhasht[hi] == 0 || ptrhasht[hi] == li + 1);
+ ptrhasht[hi] = li + 1;
+ l.l_phys = (zap_leaf_phys_t *)(leafblks + li * blksz);
+
+ namelen = strlen(ent->name) + 1;
+
+ /*
+ * How many leaf chunks do we need for this entry?
+ */
+ nnamechunks = howmany(namelen, ZAP_LEAF_ARRAY_BYTES);
+ nvalchunks = howmany(ent->intcnt,
+ ZAP_LEAF_ARRAY_BYTES / ent->intsz);
+ nchunks = 1 + nnamechunks + nvalchunks;
+
+ /*
+ * Allocate a run of free leaf chunks for this entry,
+ * potentially extending a hash chain.
+ */
+ assert(l.l_phys->l_hdr.lh_nfree >= nchunks);
+ l.l_phys->l_hdr.lh_nfree -= nchunks;
+ l.l_phys->l_hdr.lh_nentries++;
+ lptr = ZAP_LEAF_HASH_ENTPTR(&l, ent->hash);
+ while (*lptr != 0xffff) {
+ assert(*lptr < ZAP_LEAF_NUMCHUNKS(&l));
+ le = ZAP_LEAF_ENTRY(&l, *lptr);
+ assert(le->le_type == ZAP_CHUNK_ENTRY);
+ le->le_cd++;
+ lptr = &le->le_next;
+ }
+ *lptr = l.l_phys->l_hdr.lh_freelist;
+ l.l_phys->l_hdr.lh_freelist += nchunks;
+ assert(l.l_phys->l_hdr.lh_freelist <=
+ ZAP_LEAF_NUMCHUNKS(&l));
+ if (l.l_phys->l_hdr.lh_freelist ==
+ ZAP_LEAF_NUMCHUNKS(&l))
+ l.l_phys->l_hdr.lh_freelist = 0xffff;
+
+ /*
+ * Integer values must be stored in big-endian format.
+ */
+ switch (ent->intsz) {
+ case 1:
+ break;
+ case 2:
+ for (uint16_t *v = ent->val16p;
+ v - ent->val16p < (ptrdiff_t)ent->intcnt;
+ v++)
+ *v = htobe16(*v);
+ break;
+ case 4:
+ for (uint32_t *v = ent->val32p;
+ v - ent->val32p < (ptrdiff_t)ent->intcnt;
+ v++)
+ *v = htobe32(*v);
+ break;
+ case 8:
+ for (uint64_t *v = ent->val64p;
+ v - ent->val64p < (ptrdiff_t)ent->intcnt;
+ v++)
+ *v = htobe64(*v);
+ break;
+ default:
+ assert(0);
+ }
+
+ /*
+ * Finally, write out the leaf chunks for this entry.
+ */
+ le = ZAP_LEAF_ENTRY(&l, *lptr);
+ assert(le->le_type == ZAP_CHUNK_FREE);
+ le->le_type = ZAP_CHUNK_ENTRY;
+ le->le_next = 0xffff;
+ le->le_name_chunk = *lptr + 1;
+ le->le_name_numints = namelen;
+ le->le_value_chunk = *lptr + 1 + nnamechunks;
+ le->le_value_intlen = ent->intsz;
+ le->le_value_numints = ent->intcnt;
+ le->le_hash = ent->hash;
+ zap_fat_write_array_chunk(&l, *lptr + 1, namelen,
+ (uint8_t *)ent->name);
+ zap_fat_write_array_chunk(&l, *lptr + 1 + nnamechunks,
+ ent->intcnt * ent->intsz, ent->valp);
+ }
+
+ /*
+ * Initialize unused slots of the pointer table.
+ */
+ for (int i = 0; i < ptrcnt; i++)
+ if (ptrhasht[i] == 0)
+ ptrhasht[i] = (i >> (zt->zt_shift - prefixlen)) + 1;
+
+ /*
+ * Write the whole thing to disk.
+ */
+ dnode = zap->dnode;
+ dnode->dn_datablkszsec = blksz >> MINBLOCKSHIFT;
+ dnode->dn_maxblkid = lblkcnt + 1;
+
+ c = dnode_cursor_init(zfs, zap->os, zap->dnode,
+ (lblkcnt + 1) * blksz, blksz);
+
+ loc = objset_space_alloc(zfs, zap->os, &blksz);
+ vdev_pwrite_dnode_indir(zfs, dnode, 0, 1, zfs->filebuf, blksz, loc,
+ dnode_cursor_next(zfs, c, 0));
+
+ for (uint64_t i = 0; i < lblkcnt; i++) {
+ loc = objset_space_alloc(zfs, zap->os, &blksz);
+ vdev_pwrite_dnode_indir(zfs, dnode, 0, 1, leafblks + i * blksz,
+ blksz, loc, dnode_cursor_next(zfs, c, (i + 1) * blksz));
+ }
+
+ dnode_cursor_finish(zfs, c);
+
+ free(leafblks);
+}
+
+void
+zap_write(zfs_opt_t *zfs, zfs_zap_t *zap)
+{
+ zfs_zap_entry_t *ent;
+
+ if (zap->micro) {
+ zap_micro_write(zfs, zap);
+ } else {
+ assert(!STAILQ_EMPTY(&zap->kvps));
+ assert(zap->kvpcnt > 0);
+ zap_fat_write(zfs, zap);
+ }
+
+ while ((ent = STAILQ_FIRST(&zap->kvps)) != NULL) {
+ STAILQ_REMOVE_HEAD(&zap->kvps, next);
+ if (ent->val64p != &ent->val64)
+ free(ent->valp);
+ free(ent->name);
+ free(ent);
+ }
+ free(zap);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2025-11-04 11:51:04 +0000