tdb2: update documentation
[ccan] / ccan / tdb2 / tdb.c
index 3cee472cfb0ac9990ef83848bbe0455708c18b5d..dfa68451e51a878d4be75f5431121ff1f012b9d4 100644 (file)
@@ -1,8 +1,7 @@
 #include "private.h"
 #include <ccan/tdb2/tdb2.h>
-#include <ccan/hash/hash.h>
-#include <ccan/likely/likely.h>
 #include <assert.h>
+#include <stdarg.h>
 
 /* The null return. */
 struct tdb_data tdb_null = { .dptr = NULL, .dsize = 0 };
@@ -10,52 +9,6 @@ struct tdb_data tdb_null = { .dptr = NULL, .dsize = 0 };
 /* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
 static struct tdb_context *tdbs = NULL;
 
-PRINTF_ATTRIBUTE(4, 5) static void
-null_log_fn(struct tdb_context *tdb,
-           enum tdb_debug_level level, void *priv,
-           const char *fmt, ...)
-{
-}
-
-/* We do a lot of work assuming our copy of the header volatile area
- * is uptodate, and usually it is.  However, once we grab a lock, we have to
- * re-check it. */
-bool update_header(struct tdb_context *tdb)
-{
-       struct tdb_header_volatile pad, *v;
-
-       if (tdb->header_uptodate) {
-               tdb->log(tdb, TDB_DEBUG_WARNING, tdb->log_priv,
-                        "warning: header uptodate already\n");
-       }
-
-       /* We could get a partial update if we're not holding any locks. */
-       assert(tdb_has_locks(tdb));
-
-       v = tdb_get(tdb, offsetof(struct tdb_header, v), &pad, sizeof(*v));
-       if (!v) {
-               /* On failure, imply we updated header so they retry. */
-               return true;
-       }
-       tdb->header_uptodate = true;
-       if (likely(memcmp(&tdb->header.v, v, sizeof(*v)) == 0)) {
-               return false;
-       }
-       tdb->header.v = *v;
-       return true;
-}
-
-static uint64_t jenkins_hash(const void *key, size_t length, uint64_t seed,
-                            void *arg)
-{
-       return hash64_any(key, length, seed);
-}
-
-uint64_t tdb_hash(struct tdb_context *tdb, const void *ptr, size_t len)
-{
-       return tdb->khash(ptr, len, tdb->header.hash_seed, tdb->hash_priv);
-}
-
 static bool tdb_already_open(dev_t device, ino_t ino)
 {
        struct tdb_context *i;
@@ -77,9 +30,9 @@ static uint64_t random_number(struct tdb_context *tdb)
 
        fd = open("/dev/urandom", O_RDONLY);
        if (fd >= 0) {
-               if (read(fd, &ret, sizeof(ret)) == sizeof(ret)) {
-                       tdb->log(tdb, TDB_DEBUG_TRACE, tdb->log_priv,
-                                "tdb_open: random from /dev/urandom\n");
+               if (tdb_read_all(fd, &ret, sizeof(ret))) {
+                       tdb_logerr(tdb, TDB_SUCCESS, TDB_DEBUG_TRACE,
+                                "tdb_open: random from /dev/urandom");
                        close(fd);
                        return ret;
                }
@@ -94,9 +47,9 @@ static uint64_t random_number(struct tdb_context *tdb)
                        char reply[1 + sizeof(uint64_t)];
                        int r = read(fd, reply, sizeof(reply));
                        if (r > 1) {
-                               tdb->log(tdb, TDB_DEBUG_TRACE, tdb->log_priv,
-                                        "tdb_open: %u random bytes from"
-                                        " /dev/egd-pool\n", r-1);
+                               tdb_logerr(tdb, TDB_SUCCESS, TDB_DEBUG_TRACE,
+                                          "tdb_open: %u random bytes from"
+                                          " /dev/egd-pool", r-1);
                                /* Copy at least some bytes. */
                                memcpy(&ret, reply+1, r - 1);
                                if (reply[0] == sizeof(uint64_t)
@@ -112,63 +65,68 @@ static uint64_t random_number(struct tdb_context *tdb)
        /* Fallback: pid and time. */
        gettimeofday(&now, NULL);
        ret = getpid() * 100132289ULL + now.tv_sec * 1000000ULL + now.tv_usec;
-       tdb->log(tdb, TDB_DEBUG_TRACE, tdb->log_priv,
-                "tdb_open: random from getpid and time\n");
+       tdb_logerr(tdb, TDB_SUCCESS, TDB_DEBUG_TRACE,
+                  "tdb_open: random from getpid and time");
        return ret;
 }
 
 struct new_database {
        struct tdb_header hdr;
-       struct tdb_used_record hrec;
-       tdb_off_t hash[1ULL << INITIAL_HASH_BITS];
-       struct tdb_used_record frec;
-       tdb_off_t free[INITIAL_FREE_BUCKETS + 1]; /* One overflow bucket */
+       struct tdb_freetable ftable;
 };
 
 /* initialise a new database */
-static int tdb_new_database(struct tdb_context *tdb)
+static int tdb_new_database(struct tdb_context *tdb,
+                           struct tdb_attribute_seed *seed,
+                           struct tdb_header *hdr)
 {
        /* We make it up in memory, then write it out if not internal */
        struct new_database newdb;
+       unsigned int magic_len;
 
        /* Fill in the header */
        newdb.hdr.version = TDB_VERSION;
-       newdb.hdr.hash_seed = random_number(tdb);
+       if (seed)
+               newdb.hdr.hash_seed = seed->seed;
+       else
+               newdb.hdr.hash_seed = random_number(tdb);
        newdb.hdr.hash_test = TDB_HASH_MAGIC;
        newdb.hdr.hash_test = tdb->khash(&newdb.hdr.hash_test,
                                         sizeof(newdb.hdr.hash_test),
                                         newdb.hdr.hash_seed,
                                         tdb->hash_priv);
+       newdb.hdr.recovery = 0;
+       memset(newdb.hdr.reserved, 0, sizeof(newdb.hdr.reserved));
+       /* Initial hashes are empty. */
+       memset(newdb.hdr.hashtable, 0, sizeof(newdb.hdr.hashtable));
+
+       /* Free is empty. */
+       newdb.hdr.free_table = offsetof(struct new_database, ftable);
+       memset(&newdb.ftable, 0, sizeof(newdb.ftable));
+       set_header(NULL, &newdb.ftable.hdr, TDB_FTABLE_MAGIC, 0,
+                  sizeof(newdb.ftable) - sizeof(newdb.ftable.hdr),
+                  sizeof(newdb.ftable) - sizeof(newdb.ftable.hdr), 0);
 
-       newdb.hdr.v.generation = 0;
+       /* Magic food */
+       memset(newdb.hdr.magic_food, 0, sizeof(newdb.hdr.magic_food));
+       strcpy(newdb.hdr.magic_food, TDB_MAGIC_FOOD);
 
-       /* Free array has 1 zone, 10 buckets.  All buckets empty. */
-       newdb.hdr.v.num_zones = 1;
-       newdb.hdr.v.zone_bits = INITIAL_ZONE_BITS;
-       newdb.hdr.v.free_buckets = INITIAL_FREE_BUCKETS;
-       newdb.hdr.v.free_off = offsetof(struct new_database, free);
-       set_header(tdb, &newdb.frec, 0,
-                  sizeof(newdb.free), sizeof(newdb.free), 0);
-       memset(newdb.free, 0, sizeof(newdb.free));
+       /* This creates an endian-converted database, as if read from disk */
+       magic_len = sizeof(newdb.hdr.magic_food);
+       tdb_convert(tdb,
+                   (char *)&newdb.hdr + magic_len, sizeof(newdb) - magic_len);
 
-       /* Initial hashes are empty. */
-       newdb.hdr.v.hash_bits = INITIAL_HASH_BITS;
-       newdb.hdr.v.hash_off = offsetof(struct new_database, hash);
-       set_header(tdb, &newdb.hrec, 0,
-                  sizeof(newdb.hash), sizeof(newdb.hash), 0);
-       memset(newdb.hash, 0, sizeof(newdb.hash));
+       *hdr = newdb.hdr;
 
        if (tdb->flags & TDB_INTERNAL) {
                tdb->map_size = sizeof(newdb);
                tdb->map_ptr = malloc(tdb->map_size);
                if (!tdb->map_ptr) {
-                       tdb->ecode = TDB_ERR_OOM;
+                       tdb_logerr(tdb, TDB_ERR_OOM, TDB_DEBUG_FATAL,
+                                  "tdb_new_database: failed to allocate");
                        return -1;
                }
                memcpy(tdb->map_ptr, &newdb, tdb->map_size);
-               tdb->header = newdb.hdr;
-               /* Convert the `ondisk' version if asked. */
-               tdb_convert(tdb, tdb->map_ptr, sizeof(newdb));
                return 0;
        }
        if (lseek(tdb->fd, 0, SEEK_SET) == -1)
@@ -177,16 +135,10 @@ static int tdb_new_database(struct tdb_context *tdb)
        if (ftruncate(tdb->fd, 0) == -1)
                return -1;
 
-       /* This creates an endian-converted header, as if read from disk */
-       tdb->header = newdb.hdr;
-       tdb_convert(tdb, &tdb->header, sizeof(tdb->header));
-
-       /* Don't endian-convert the magic food! */
-       memset(newdb.hdr.magic_food, 0, sizeof(newdb.hdr.magic_food));
-       strcpy(newdb.hdr.magic_food, TDB_MAGIC_FOOD);
-
        if (!tdb_pwrite_all(tdb->fd, &newdb, sizeof(newdb), 0)) {
-               tdb->ecode = TDB_ERR_IO;
+               tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_FATAL,
+                          "tdb_new_database: failed to write: %s",
+                          strerror(errno));
                return -1;
        }
        return 0;
@@ -198,62 +150,96 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 {
        struct tdb_context *tdb;
        struct stat st;
-       int save_errno;
+       int saved_errno = 0;
        uint64_t hash_test;
        unsigned v;
+       struct tdb_header hdr;
+       struct tdb_attribute_seed *seed = NULL;
 
-       if (!(tdb = (struct tdb_context *)calloc(1, sizeof *tdb))) {
+       tdb = malloc(sizeof(*tdb));
+       if (!tdb) {
                /* Can't log this */
                errno = ENOMEM;
-               goto fail;
+               return NULL;
        }
-       tdb->fd = -1;
        tdb->name = NULL;
        tdb->map_ptr = NULL;
+       tdb->direct_access = 0;
+       tdb->fd = -1;
+       tdb->map_size = sizeof(struct tdb_header);
+       tdb->ecode = TDB_SUCCESS;
        tdb->flags = tdb_flags;
-       tdb->log = null_log_fn;
-       tdb->log_priv = NULL;
-       tdb->khash = jenkins_hash;
-       tdb->hash_priv = NULL;
-
-       /* FIXME */
-       if (attr) {
-               tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-                        "tdb_open: attributes not yet supported\n");
-               errno = EINVAL;
-               goto fail;
+       tdb->logfn = NULL;
+       tdb->transaction = NULL;
+       tdb->stats = NULL;
+       tdb->access = NULL;
+       tdb_hash_init(tdb);
+       tdb_io_init(tdb);
+       tdb_lock_init(tdb);
+
+       while (attr) {
+               switch (attr->base.attr) {
+               case TDB_ATTRIBUTE_LOG:
+                       tdb->logfn = attr->log.log_fn;
+                       tdb->log_private = attr->log.log_private;
+                       break;
+               case TDB_ATTRIBUTE_HASH:
+                       tdb->khash = attr->hash.hash_fn;
+                       tdb->hash_priv = attr->hash.hash_private;
+                       break;
+               case TDB_ATTRIBUTE_SEED:
+                       seed = &attr->seed;
+                       break;
+               case TDB_ATTRIBUTE_STATS:
+                       tdb->stats = &attr->stats;
+                       /* They have stats we don't know about?  Tell them. */
+                       if (tdb->stats->size > sizeof(attr->stats))
+                               tdb->stats->size = sizeof(attr->stats);
+                       break;
+               default:
+                       tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_DEBUG_ERROR,
+                                  "tdb_open: unknown attribute type %u",
+                                  attr->base.attr);
+                       goto fail;
+               }
+               attr = attr->base.next;
        }
 
        if ((open_flags & O_ACCMODE) == O_WRONLY) {
-               tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-                        "tdb_open: can't open tdb %s write-only\n", name);
-               errno = EINVAL;
+               tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_DEBUG_ERROR,
+                          "tdb_open: can't open tdb %s write-only", name);
                goto fail;
        }
 
        if ((open_flags & O_ACCMODE) == O_RDONLY) {
-               tdb->read_only = 1;
+               tdb->read_only = true;
                /* read only databases don't do locking */
                tdb->flags |= TDB_NOLOCK;
+               tdb->mmap_flags = PROT_READ;
+       } else {
+               tdb->read_only = false;
+               tdb->mmap_flags = PROT_READ | PROT_WRITE;
        }
 
-       /* internal databases don't mmap or lock */
+       /* internal databases don't need any of the rest. */
        if (tdb->flags & TDB_INTERNAL) {
                tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
-               if (tdb_new_database(tdb) != 0) {
-                       tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-                                "tdb_open: tdb_new_database failed!");
+               if (tdb_new_database(tdb, seed, &hdr) != 0) {
                        goto fail;
                }
-               TEST_IT(tdb->flags & TDB_CONVERT);
-               goto internal;
+               tdb_convert(tdb, &hdr.hash_seed, sizeof(hdr.hash_seed));
+               tdb->hash_seed = hdr.hash_seed;
+               tdb_ftable_init(tdb);
+               return tdb;
        }
 
        if ((tdb->fd = open(name, open_flags, mode)) == -1) {
-               tdb->log(tdb, TDB_DEBUG_WARNING, tdb->log_priv,
-                        "tdb_open: could not open file %s: %s\n",
-                        name, strerror(errno));
-               goto fail;      /* errno set by open(2) */
+               /* errno set by open(2) */
+               saved_errno = errno;
+               tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_ERROR,
+                          "tdb_open: could not open file %s: %s",
+                          name, strerror(errno));
+               goto fail;
        }
 
        /* on exec, don't inherit the fd */
@@ -261,88 +247,115 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
         fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
 
        /* ensure there is only one process initialising at once */
-       if (tdb_lock_open(tdb) == -1) {
-               tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-                        "tdb_open: failed to get open lock on %s: %s\n",
-                        name, strerror(errno));
-               goto fail;      /* errno set by tdb_brlock */
+       if (tdb_lock_open(tdb, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK) == -1) {
+               /* errno set by tdb_brlock */
+               saved_errno = errno;
+               goto fail;
        }
 
-       errno = 0;
-       if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
-           || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0) {
-               if (!(open_flags & O_CREAT) || tdb_new_database(tdb) == -1) {
-                       if (errno == 0) {
-                               errno = EIO; /* ie bad format or something */
-                       }
+       if (!tdb_pread_all(tdb->fd, &hdr, sizeof(hdr), 0)
+           || strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0) {
+               if (!(open_flags & O_CREAT)) {
+                       tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_ERROR,
+                                  "tdb_open: %s is not a tdb file", name);
                        goto fail;
                }
-       } else if (tdb->header.version != TDB_VERSION) {
-               if (tdb->header.version == bswap_64(TDB_VERSION))
+               if (tdb_new_database(tdb, seed, &hdr) == -1) {
+                       goto fail;
+               }
+       } else if (hdr.version != TDB_VERSION) {
+               if (hdr.version == bswap_64(TDB_VERSION))
                        tdb->flags |= TDB_CONVERT;
                else {
                        /* wrong version */
-                       tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-                                "tdb_open: %s is unknown version 0x%llx\n",
-                                name, (long long)tdb->header.version);
-                       errno = EIO;
+                       tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_ERROR,
+                                  "tdb_open: %s is unknown version 0x%llx",
+                                  name, (long long)hdr.version);
                        goto fail;
                }
        }
 
-       tdb_convert(tdb, &tdb->header, sizeof(tdb->header));
+       tdb_convert(tdb, &hdr, sizeof(hdr));
+       tdb->hash_seed = hdr.hash_seed;
        hash_test = TDB_HASH_MAGIC;
-       hash_test = tdb->khash(&hash_test, sizeof(hash_test),
-                              tdb->header.hash_seed, tdb->hash_priv);
-       if (tdb->header.hash_test != hash_test) {
+       hash_test = tdb_hash(tdb, &hash_test, sizeof(hash_test));
+       if (hdr.hash_test != hash_test) {
                /* wrong hash variant */
-               tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-                        "tdb_open: %s uses a different hash function\n",
-                        name);
-               errno = EIO;
+               tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_ERROR,
+                          "tdb_open: %s uses a different hash function",
+                          name);
                goto fail;
        }
 
-       if (fstat(tdb->fd, &st) == -1)
+       if (fstat(tdb->fd, &st) == -1) {
+               saved_errno = errno;
+               tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_ERROR,
+                          "tdb_open: could not stat open %s: %s",
+                          name, strerror(errno));
                goto fail;
+       }
 
        /* Is it already in the open list?  If so, fail. */
        if (tdb_already_open(st.st_dev, st.st_ino)) {
                /* FIXME */
-               tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-                        "tdb_open: %s (%d,%d) is already open in this process\n",
-                        name, (int)st.st_dev, (int)st.st_ino);
-               errno = EBUSY;
+               tdb_logerr(tdb, TDB_ERR_NESTING, TDB_DEBUG_ERROR,
+                          "tdb_open: %s (%d,%d) is already open in this"
+                          " process",
+                          name, (int)st.st_dev, (int)st.st_ino);
                goto fail;
        }
 
        tdb->name = strdup(name);
        if (!tdb->name) {
-               errno = ENOMEM;
+               tdb_logerr(tdb, TDB_ERR_OOM, TDB_DEBUG_ERROR,
+                          "tdb_open: failed to allocate name");
                goto fail;
        }
 
-       tdb->map_size = st.st_size;
        tdb->device = st.st_dev;
        tdb->inode = st.st_ino;
-       tdb_io_init(tdb);
-       tdb_mmap(tdb);
-
- internal:
-       /* Internal (memory-only) databases skip all the code above to
-        * do with disk files, and resume here by releasing their
-        * open lock and hooking into the active list. */
        tdb_unlock_open(tdb);
-       tdb->last_zone = random_free_zone(tdb);
+
+       /* This make sure we have current map_size and mmap. */
+       tdb->methods->oob(tdb, tdb->map_size + 1, true);
+
+       /* Now it's fully formed, recover if necessary. */
+       if (tdb_needs_recovery(tdb) && tdb_lock_and_recover(tdb) == -1) {
+               goto fail;
+       }
+
+       if (tdb_ftable_init(tdb) == -1)
+               goto fail;
+
        tdb->next = tdbs;
        tdbs = tdb;
        return tdb;
 
  fail:
-       save_errno = errno;
-
-       if (!tdb)
-               return NULL;
+       /* Map ecode to some logical errno. */
+       if (!saved_errno) {
+               switch (tdb->ecode) {
+               case TDB_ERR_CORRUPT:
+               case TDB_ERR_IO:
+                       saved_errno = EIO;
+                       break;
+               case TDB_ERR_LOCK:
+                       saved_errno = EWOULDBLOCK;
+                       break;
+               case TDB_ERR_OOM:
+                       saved_errno = ENOMEM;
+                       break;
+               case TDB_ERR_EINVAL:
+                       saved_errno = EINVAL;
+                       break;
+               case TDB_ERR_NESTING:
+                       saved_errno = EBUSY;
+                       break;
+               default:
+                       saved_errno = EINVAL;
+                       break;
+               }
+       }
 
 #ifdef TDB_TRACE
        close(tdb->tracefd);
@@ -356,224 +369,81 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
        free((char *)tdb->name);
        if (tdb->fd != -1)
                if (close(tdb->fd) != 0)
-                       tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-                                "tdb_open: failed to close tdb->fd"
-                                " on error!\n");
+                       tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_ERROR,
+                                  "tdb_open: failed to close tdb->fd"
+                                  " on error!");
        free(tdb);
-       errno = save_errno;
+       errno = saved_errno;
        return NULL;
 }
 
-static int tdb_key_compare(TDB_DATA key, TDB_DATA data, void *private_data)
-{
-       return memcmp(data.dptr, key.dptr, data.dsize) == 0;
-}
-
-static void unlock_lists(struct tdb_context *tdb,
-                        uint64_t start, uint64_t end, int ltype)
-{
-       do {
-               tdb_unlock_list(tdb, start, ltype);
-               start = (start + ((1ULL << tdb->header.v.hash_bits) - 1))
-                       & ((1ULL << tdb->header.v.hash_bits) - 1);
-       } while (start != end);
-}
-
-/* FIXME: Return header copy? */
-/* Returns -1 or offset of entry (0 if not found).
- * Locks hash entried from *start to *end (where the entry was found). */
-static tdb_off_t find_bucket_and_lock(struct tdb_context *tdb,
-                                     const struct tdb_data *key,
-                                     uint64_t hash,
-                                     uint64_t *start,
-                                     uint64_t *end,
-                                     uint64_t *room,
-                                     int ltype)
-{
-       uint64_t hextra;
-       tdb_off_t off;
-
-       /* hash_bits might be out of date... */
-again:
-       *start = *end = hash & ((1ULL << tdb->header.v.hash_bits) - 1);
-       hextra = hash >> tdb->header.v.hash_bits;
-
-       /* FIXME: can we avoid locks for some fast paths? */
-       if (tdb_lock_list(tdb, *end, ltype, TDB_LOCK_WAIT) == -1)
-               return TDB_OFF_ERR;
-
-       /* We only need to check this for first lock. */
-       if (unlikely(update_header(tdb))) {
-               tdb_unlock_list(tdb, *end, ltype);
-               goto again;
-       }
-
-       while ((off = tdb_read_off(tdb, tdb->header.v.hash_off
-                                  + *end * sizeof(tdb_off_t)))
-              != TDB_OFF_ERR) {
-               struct tdb_used_record pad, *r;
-               uint64_t keylen, next;
-
-               /* Didn't find it? */
-               if (!off)
-                       return 0;
-
-#if 0 /* FIXME: Check other bits. */
-               unsigned int bits, bitmask, hoffextra;
-               /* Bottom three bits show how many extra hash bits. */
-               bits = (off & ((1 << TDB_EXTRA_HASHBITS_NUM) - 1)) + 1;
-               bitmask = (1 << bits)-1;
-               hoffextra = ((off >> TDB_EXTRA_HASHBITS_NUM) & bitmask);
-               if ((hextra & bitmask) != hoffextra) 
-                       goto lock_next;
-#endif
-
-               r = tdb_get(tdb, off, &pad, sizeof(*r));
-               if (!r)
-                       goto unlock_err;
-
-               if (rec_magic(r) != TDB_MAGIC) {
-                       tdb->ecode = TDB_ERR_CORRUPT;
-                       tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
-                                "find_bucket_and_lock: bad magic 0x%llx"
-                                " at offset %llu!\n",
-                                (long long)rec_magic(r), (long long)off);
-                       goto unlock_err;
-               }
-
-               /* FIXME: check extra bits in header! */
-               keylen = rec_key_length(r);
-               if (keylen != key->dsize)
-                       goto lock_next;
-
-               switch (tdb_parse_data(tdb, *key, off + sizeof(*r), key->dsize,
-                                      tdb_key_compare, NULL)) {
-               case 1:
-                       /* Match! */
-                       *room = rec_data_length(r) + rec_extra_padding(r);
-                       return off >> TDB_EXTRA_HASHBITS_NUM;
-               case 0:
-                       break;
-               default:
-                       goto unlock_err;
-               }
-
-       lock_next:
-               /* Lock next bucket. */
-               /* FIXME: We can deadlock if this wraps! */
-               next = (*end + 1) & ((1ULL << tdb->header.v.hash_bits) - 1);
-               if (next == *start) {
-                       tdb->ecode = TDB_ERR_CORRUPT;
-                       tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
-                                "find_bucket_and_lock: full hash table!\n");
-                       goto unlock_err;
-               }
-               if (tdb_lock_list(tdb, next, ltype, TDB_LOCK_WAIT) == -1)
-                       goto unlock_err;
-               *end = next;
-       }
-
-unlock_err:
-       TEST_IT(*end < *start);
-       unlock_lists(tdb, *start, *end, ltype);
-       return TDB_OFF_ERR;
-}
-
 static int update_rec_hdr(struct tdb_context *tdb,
                          tdb_off_t off,
                          tdb_len_t keylen,
                          tdb_len_t datalen,
-                         tdb_len_t room,
+                         struct tdb_used_record *rec,
                          uint64_t h)
 {
-       struct tdb_used_record rec;
+       uint64_t dataroom = rec_data_length(rec) + rec_extra_padding(rec);
 
-       if (set_header(tdb, &rec, keylen, datalen, room - datalen, h))
+       if (set_header(tdb, rec, TDB_USED_MAGIC, keylen, datalen,
+                      keylen + dataroom, h))
                return -1;
 
-       return tdb_write_convert(tdb, off, &rec, sizeof(rec));
+       return tdb_write_convert(tdb, off, rec, sizeof(*rec));
 }
 
-/* If we fail, others will try after us. */
-static void enlarge_hash(struct tdb_context *tdb)
+/* Returns -1 on error, 0 on OK */
+static int replace_data(struct tdb_context *tdb,
+                       struct hash_info *h,
+                       struct tdb_data key, struct tdb_data dbuf,
+                       tdb_off_t old_off, tdb_len_t old_room,
+                       bool growing)
 {
-       tdb_off_t newoff, i;
-       uint64_t h, num = 1ULL << tdb->header.v.hash_bits;
-       struct tdb_used_record pad, *r;
+       tdb_off_t new_off;
 
-       /* FIXME: We should do this without holding locks throughout. */
-       if (tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_WAIT, false) == -1)
-               return;
+       /* Allocate a new record. */
+       new_off = alloc(tdb, key.dsize, dbuf.dsize, h->h, TDB_USED_MAGIC,
+                       growing);
+       if (unlikely(new_off == TDB_OFF_ERR))
+               return -1;
 
-       if (unlikely(update_header(tdb))) {
-               /* Someone else enlarged for us?  Nothing to do. */
-               if ((1ULL << tdb->header.v.hash_bits) != num)
-                       goto unlock;
+       /* We didn't like the existing one: remove it. */
+       if (old_off) {
+               add_stat(tdb, frees, 1);
+               add_free_record(tdb, old_off,
+                               sizeof(struct tdb_used_record)
+                               + key.dsize + old_room);
+               if (replace_in_hash(tdb, h, new_off) == -1)
+                       return -1;
+       } else {
+               if (add_to_hash(tdb, h, new_off) == -1)
+                       return -1;
        }
 
-       newoff = alloc(tdb, 0, num * 2, 0, false);
-       if (unlikely(newoff == TDB_OFF_ERR))
-               goto unlock;
-       if (unlikely(newoff == 0)) {
-               if (tdb_expand(tdb, 0, num * 2, false) == -1)
-                       goto unlock;
-               newoff = alloc(tdb, 0, num * 2, 0, false);
-               if (newoff == TDB_OFF_ERR || newoff == 0)
-                       goto unlock;
-       }
+       new_off += sizeof(struct tdb_used_record);
+       if (tdb->methods->write(tdb, new_off, key.dptr, key.dsize) == -1)
+               return -1;
 
-       /* FIXME: If the space before is empty, we know this is in its ideal
-        * location.  We can steal a bit from the pointer to avoid rehash. */
-       for (i = tdb_find_nonzero_off(tdb, tdb->header.v.hash_off, num);
-            i < num;
-            i += tdb_find_nonzero_off(tdb, tdb->header.v.hash_off
-                                      + i*sizeof(tdb_off_t), num - i)) {
-               tdb_off_t off;
-               off = tdb_read_off(tdb, tdb->header.v.hash_off
-                                  + i*sizeof(tdb_off_t));
-               if (unlikely(off == TDB_OFF_ERR))
-                       goto unlock;
-               if (unlikely(!off)) {
-                       tdb->ecode = TDB_ERR_CORRUPT;
-                       tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
-                                "find_bucket_and_lock: zero hash bucket!\n");
-                       goto unlock;
-               }
-               h = hash_record(tdb, off);
-               /* FIXME: Encode extra hash bits! */
-               if (tdb_write_off(tdb, newoff
-                                 + (h & ((num * 2) - 1)) * sizeof(uint64_t),
-                                 off) == -1)
-                       goto unlock;
-       }
+       new_off += key.dsize;
+       if (tdb->methods->write(tdb, new_off, dbuf.dptr, dbuf.dsize) == -1)
+               return -1;
 
-       /* Free up old hash. */
-       r = tdb_get(tdb, tdb->header.v.hash_off, &pad, sizeof(*r));
-       if (!r)
-               goto unlock;
-       add_free_record(tdb, tdb->header.v.hash_off,
-                       rec_data_length(r) + rec_extra_padding(r));
-
-       /* Now we write the modified header. */
-       tdb->header.v.generation++;
-       tdb->header.v.hash_bits++;
-       tdb->header.v.hash_off = newoff;
-       tdb_write_convert(tdb, offsetof(struct tdb_header, v),
-                         &tdb->header.v, sizeof(tdb->header.v));
-unlock:
-       tdb_allrecord_unlock(tdb, F_WRLCK);
+       /* FIXME: tdb_increment_seqnum(tdb); */
+       return 0;
 }
 
 int tdb_store(struct tdb_context *tdb,
              struct tdb_data key, struct tdb_data dbuf, int flag)
 {
-       tdb_off_t new_off, off, start, end, room;
-       uint64_t h;
-       bool growing = false;
+       struct hash_info h;
+       tdb_off_t off;
+       tdb_len_t old_room = 0;
+       struct tdb_used_record rec;
+       int ret;
 
-       h = tdb_hash(tdb, key.dptr, key.dsize);
-       off = find_bucket_and_lock(tdb, &key, h, &start, &end, &room, F_WRLCK);
-       if (off == TDB_OFF_ERR)
+       off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
+       if (unlikely(off == TDB_OFF_ERR))
                return -1;
 
        /* Now we have lock on this hash bucket. */
@@ -584,17 +454,22 @@ int tdb_store(struct tdb_context *tdb,
                }
        } else {
                if (off) {
-                       if (room >= key.dsize + dbuf.dsize) {
-                               new_off = off;
+                       old_room = rec_data_length(&rec)
+                               + rec_extra_padding(&rec);
+                       if (old_room >= dbuf.dsize) {
+                               /* Can modify in-place.  Easy! */
                                if (update_rec_hdr(tdb, off,
                                                   key.dsize, dbuf.dsize,
-                                                  room, h))
+                                                  &rec, h.h))
                                        goto fail;
-                               goto write;
+                               if (tdb->methods->write(tdb, off + sizeof(rec)
+                                                       + key.dsize,
+                                                       dbuf.dptr, dbuf.dsize))
+                                       goto fail;
+                               tdb_unlock_hashes(tdb, h.hlock_start,
+                                                 h.hlock_range, F_WRLCK);
+                               return 0;
                        }
-                       /* FIXME: See if right record is free? */
-                       /* Hint to allocator that we've realloced. */
-                       growing = true;
                } else {
                        if (flag == TDB_MODIFY) {
                                /* if the record doesn't exist and we
@@ -606,244 +481,155 @@ int tdb_store(struct tdb_context *tdb,
                }
        }
 
-       /* Allocate a new record. */
-       new_off = alloc(tdb, key.dsize, dbuf.dsize, h, growing);
-       if (new_off == 0) {
-               unlock_lists(tdb, start, end, F_WRLCK);
-               /* Expand, then try again... */
-               if (tdb_expand(tdb, key.dsize, dbuf.dsize, growing) == -1)
-                       return -1;
-               return tdb_store(tdb, key, dbuf, flag);
-       }
+       /* If we didn't use the old record, this implies we're growing. */
+       ret = replace_data(tdb, &h, key, dbuf, off, old_room, off != 0);
+       tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
+       return ret;
+
+fail:
+       tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
+       return -1;
+}
+
+int tdb_append(struct tdb_context *tdb,
+              struct tdb_data key, struct tdb_data dbuf)
+{
+       struct hash_info h;
+       tdb_off_t off;
+       struct tdb_used_record rec;
+       tdb_len_t old_room = 0, old_dlen;
+       unsigned char *newdata;
+       struct tdb_data new_dbuf;
+       int ret;
+
+       off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
+       if (unlikely(off == TDB_OFF_ERR))
+               return -1;
 
-       /* We didn't like the existing one: remove it. */
        if (off) {
-               add_free_record(tdb, off, sizeof(struct tdb_used_record)
-                               + key.dsize + room);
-       }
+               old_dlen = rec_data_length(&rec);
+               old_room = old_dlen + rec_extra_padding(&rec);
 
-write:
-       off = tdb->header.v.hash_off + end * sizeof(tdb_off_t);
-       /* FIXME: Encode extra hash bits! */
-       if (tdb_write_off(tdb, off, new_off) == -1)
-               goto fail;
+               /* Fast path: can append in place. */
+               if (rec_extra_padding(&rec) >= dbuf.dsize) {
+                       if (update_rec_hdr(tdb, off, key.dsize,
+                                          old_dlen + dbuf.dsize, &rec, h.h))
+                               goto fail;
 
-       off = new_off + sizeof(struct tdb_used_record);
-       if (tdb->methods->write(tdb, off, key.dptr, key.dsize) == -1)
-               goto fail;
-       off += key.dsize;
-       if (tdb->methods->write(tdb, off, dbuf.dptr, dbuf.dsize) == -1)
-               goto fail;
+                       off += sizeof(rec) + key.dsize + old_dlen;
+                       if (tdb->methods->write(tdb, off, dbuf.dptr,
+                                               dbuf.dsize) == -1)
+                               goto fail;
 
-       /* FIXME: tdb_increment_seqnum(tdb); */
-       unlock_lists(tdb, start, end, F_WRLCK);
+                       /* FIXME: tdb_increment_seqnum(tdb); */
+                       tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range,
+                                         F_WRLCK);
+                       return 0;
+               }
 
-       /* By simple trial and error, this roughly approximates a 60%
-        * full measure. */
-       if (unlikely(end - start > 4 * tdb->header.v.hash_bits - 32))
-               enlarge_hash(tdb);
+               /* Slow path. */
+               newdata = malloc(key.dsize + old_dlen + dbuf.dsize);
+               if (!newdata) {
+                       tdb_logerr(tdb, TDB_ERR_OOM, TDB_DEBUG_FATAL,
+                                  "tdb_append: failed to allocate %zu bytes",
+                                  (size_t)(key.dsize+old_dlen+dbuf.dsize));
+                       goto fail;
+               }
+               if (tdb->methods->read(tdb, off + sizeof(rec) + key.dsize,
+                                      newdata, old_dlen) != 0) {
+                       free(newdata);
+                       goto fail;
+               }
+               memcpy(newdata + old_dlen, dbuf.dptr, dbuf.dsize);
+               new_dbuf.dptr = newdata;
+               new_dbuf.dsize = old_dlen + dbuf.dsize;
+       } else {
+               newdata = NULL;
+               new_dbuf = dbuf;
+       }
 
-       return 0;
+       /* If they're using tdb_append(), it implies they're growing record. */
+       ret = replace_data(tdb, &h, key, new_dbuf, off, old_room, true);
+       tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
+       free(newdata);
+
+       return ret;
 
 fail:
-       unlock_lists(tdb, start, end, F_WRLCK);
+       tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
        return -1;
 }
 
 struct tdb_data tdb_fetch(struct tdb_context *tdb, struct tdb_data key)
 {
-       tdb_off_t off, start, end, room;
-       uint64_t h;
-       struct tdb_used_record pad, *r;
+       tdb_off_t off;
+       struct tdb_used_record rec;
+       struct hash_info h;
        struct tdb_data ret;
 
-       h = tdb_hash(tdb, key.dptr, key.dsize);
-       off = find_bucket_and_lock(tdb, &key, h, &start, &end, &room, F_RDLCK);
-       if (off == TDB_OFF_ERR)
+       off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
+       if (unlikely(off == TDB_OFF_ERR))
                return tdb_null;
 
        if (!off) {
-               unlock_lists(tdb, start, end, F_RDLCK);
-               tdb->ecode = TDB_SUCCESS;
-               return tdb_null;
-       }
-
-       r = tdb_get(tdb, off, &pad, sizeof(*r));
-       if (!r) {
-               unlock_lists(tdb, start, end, F_RDLCK);
-               return tdb_null;
+               tdb->ecode = TDB_ERR_NOEXIST;
+               ret = tdb_null;
+       } else {
+               ret.dsize = rec_data_length(&rec);
+               ret.dptr = tdb_alloc_read(tdb, off + sizeof(rec) + key.dsize,
+                                         ret.dsize);
        }
 
-       ret.dsize = rec_data_length(r);
-       ret.dptr = tdb_alloc_read(tdb, off + sizeof(*r) + key.dsize,
-                                 ret.dsize);
-       unlock_lists(tdb, start, end, F_RDLCK);
+       tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
        return ret;
 }
 
-static int hash_add(struct tdb_context *tdb, uint64_t h, tdb_off_t off)
+int tdb_delete(struct tdb_context *tdb, struct tdb_data key)
 {
-       tdb_off_t i, hoff, len, num;
-
-       i = (h & ((1ULL << tdb->header.v.hash_bits) - 1));
-       hoff = tdb->header.v.hash_off + i * sizeof(tdb_off_t);
-       len = (1ULL << tdb->header.v.hash_bits) - i;
-
-       /* Look for next space. */
-       num = tdb_find_zero_off(tdb, hoff, len);
-       if (unlikely(num == len)) {
-               hoff = tdb->header.v.hash_off;
-               len = (1ULL << tdb->header.v.hash_bits);
-               num = tdb_find_zero_off(tdb, hoff, len);
-               if (i == len)
-                       return -1;
-       }
-       /* FIXME: Encode extra hash bits! */
-       return tdb_write_off(tdb, hoff + num * sizeof(tdb_off_t), off);
-}
+       tdb_off_t off;
+       struct tdb_used_record rec;
+       struct hash_info h;
 
-static int unlink_used_record(struct tdb_context *tdb, tdb_off_t chain,
-                             uint64_t *extra_locks)
-{
-       tdb_off_t num, len, i, hoff;
-
-       /* FIXME: Maybe lock more in search?  Maybe don't lock if scan
-        * finds none? */
-again:
-       len = (1ULL << tdb->header.v.hash_bits) - (chain + 1);
-       hoff = tdb->header.v.hash_off + (chain + 1) * sizeof(tdb_off_t);
-       num = tdb_find_zero_off(tdb, hoff, len);
-
-       /* We want to lock the zero entry, too.  In the wrap case,
-        * this locks one extra.  That's harmless. */
-       num++;
-
-       for (i = chain + 1; i < chain + 1 + num; i++) {
-               if (tdb_lock_list(tdb, i, F_WRLCK, TDB_LOCK_WAIT) == -1) {
-                       if (i != chain + 1)
-                               unlock_lists(tdb, chain + 1, i-1, F_WRLCK);
-                       return -1;
-               }
-       }
+       off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
+       if (unlikely(off == TDB_OFF_ERR))
+               return -1;
 
-       /* The wrap case: we need those locks out of order! */
-       if (unlikely(num == len + 1)) {
-               *extra_locks = tdb_find_zero_off(tdb, tdb->header.v.hash_off,
-                                                1ULL << tdb->header.v.hash_bits);
-               (*extra_locks)++;
-               for (i = 0; i < *extra_locks; i++) {
-                       if (tdb_lock_list(tdb, i, F_WRLCK, TDB_LOCK_NOWAIT)) {
-                               /* Failed.  Caller must lock in order. */
-                               if (i)
-                                       unlock_lists(tdb, 0, i-1, F_WRLCK);
-                               unlock_lists(tdb, chain + 1, chain + num,
-                                            F_WRLCK);
-                               return 1;
-                       }
-               }
-               num += *extra_locks;
+       if (!off) {
+               tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
+               tdb->ecode = TDB_ERR_NOEXIST;
+               return -1;
        }
 
-       /* Now we have the locks, be certain that offset is still 0! */
-       hoff = tdb->header.v.hash_off
-               + (((chain + num) * sizeof(tdb_off_t))
-                  & ((1ULL << tdb->header.v.hash_bits) - 1));
-
-       if (unlikely(tdb_read_off(tdb, hoff) != 0)) {
-               unlock_lists(tdb, chain + 1, chain + num, F_WRLCK);
-               goto again;
-       }
+       if (delete_from_hash(tdb, &h) == -1)
+               goto unlock_err;
 
-       /* OK, all locked.  Unlink first one. */
-       hoff = tdb->header.v.hash_off + chain * sizeof(tdb_off_t);
-       if (tdb_write_off(tdb, hoff, 0) == -1)
+       /* Free the deleted entry. */
+       add_stat(tdb, frees, 1);
+       if (add_free_record(tdb, off,
+                           sizeof(struct tdb_used_record)
+                           + rec_key_length(&rec)
+                           + rec_data_length(&rec)
+                           + rec_extra_padding(&rec)) != 0)
                goto unlock_err;
 
-       /* Rehash the rest. */
-       for (i = 1; i < num; i++) {
-               tdb_off_t off;
-               uint64_t h;
-
-               hoff = tdb->header.v.hash_off
-                       + (((chain + i) * sizeof(tdb_off_t))
-                          & ((1ULL << tdb->header.v.hash_bits) - 1));
-               off = tdb_read_off(tdb, hoff);
-               if (unlikely(off == TDB_OFF_ERR))
-                       goto unlock_err;
-
-               /* Maybe use a bit to indicate it is in ideal place? */
-               h = hash_record(tdb, off);
-               /* Is it happy where it is? */
-               if ((h & ((1ULL << tdb->header.v.hash_bits)-1)) == (chain + i))
-                       continue;
-
-               /* Remove it. */
-               if (tdb_write_off(tdb, hoff, 0) == -1)
-                       goto unlock_err;
-
-               /* Rehash it. */
-               if (hash_add(tdb, h, off) == -1)
-                       goto unlock_err;
-       }
-       unlock_lists(tdb, chain + 1, chain + num, F_WRLCK);
+       tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
        return 0;
 
 unlock_err:
-       unlock_lists(tdb, chain + 1, chain + num, F_WRLCK);
+       tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
        return -1;
 }
 
-int tdb_delete(struct tdb_context *tdb, struct tdb_data key)
-{
-       tdb_off_t off, start, end, room, extra_locks = 0;
-       uint64_t h;
-       int ret;
-
-       h = tdb_hash(tdb, key.dptr, key.dsize);
-       off = find_bucket_and_lock(tdb, &key, h, &start, &end, &room, F_WRLCK);
-       if (off == TDB_OFF_ERR)
-               return -1;
-
-       if (off == 0) {
-               unlock_lists(tdb, start, end, F_WRLCK);
-               tdb->ecode = TDB_ERR_NOEXIST;
-               return -1;
-       }
-
-       ret = unlink_used_record(tdb, end, &extra_locks);
-       if (unlikely(ret == 1)) {
-               unsigned int i;
-
-               unlock_lists(tdb, start, end, F_WRLCK);
-
-               /* We need extra locks at the start. */
-               for (i = 0; i < extra_locks; i++) {
-                       if (tdb_lock_list(tdb, i, F_WRLCK, TDB_LOCK_WAIT)) {
-                               if (i)
-                                       unlock_lists(tdb, 0, i-1, F_WRLCK);
-                               return -1;
-                       }
-               }
-               /* Try again now we're holding more locks. */
-               ret = tdb_delete(tdb, key);
-               unlock_lists(tdb, 0, i, F_WRLCK);
-               return ret;
-       }
-       unlock_lists(tdb, start, end, F_WRLCK);
-       return ret;
-}
-
 int tdb_close(struct tdb_context *tdb)
 {
        struct tdb_context **i;
        int ret = 0;
 
-       /* FIXME:
+       tdb_trace(tdb, "tdb_close");
+
        if (tdb->transaction) {
                tdb_transaction_cancel(tdb);
        }
-       */
-       tdb_trace(tdb, "tdb_close");
 
        if (tdb->map_ptr) {
                if (tdb->flags & TDB_INTERNAL)
@@ -873,3 +659,61 @@ int tdb_close(struct tdb_context *tdb)
 
        return ret;
 }
+
+enum TDB_ERROR tdb_error(const struct tdb_context *tdb)
+{
+       return tdb->ecode;
+}
+
+const char *tdb_errorstr(const struct tdb_context *tdb)
+{
+       /* Gcc warns if you miss a case in the switch, so use that. */
+       switch (tdb->ecode) {
+       case TDB_SUCCESS: return "Success";
+       case TDB_ERR_CORRUPT: return "Corrupt database";
+       case TDB_ERR_IO: return "IO Error";
+       case TDB_ERR_LOCK: return "Locking error";
+       case TDB_ERR_OOM: return "Out of memory";
+       case TDB_ERR_EXISTS: return "Record exists";
+       case TDB_ERR_NESTING: return "Transaction already started";
+       case TDB_ERR_EINVAL: return "Invalid parameter";
+       case TDB_ERR_NOEXIST: return "Record does not exist";
+       case TDB_ERR_RDONLY: return "write not permitted";
+       }
+       return "Invalid error code";
+}
+
+void COLD tdb_logerr(struct tdb_context *tdb,
+                    enum TDB_ERROR ecode,
+                    enum tdb_debug_level level,
+                    const char *fmt, ...)
+{
+       char *message;
+       va_list ap;
+       size_t len;
+       /* tdb_open paths care about errno, so save it. */
+       int saved_errno = errno;
+
+       tdb->ecode = ecode;
+
+       if (!tdb->logfn)
+               return;
+
+       /* FIXME: Doesn't assume asprintf. */
+       va_start(ap, fmt);
+       len = vsnprintf(NULL, 0, fmt, ap);
+       va_end(ap);
+
+       message = malloc(len + 1);
+       if (!message) {
+               tdb->logfn(tdb, level, tdb->log_private,
+                          "out of memory formatting message");
+               return;
+       }
+       va_start(ap, fmt);
+       len = vsprintf(message, fmt, ap);
+       va_end(ap);
+       tdb->logfn(tdb, level, tdb->log_private, message);
+       free(message);
+       errno = saved_errno;
+}