These tests revealed more bugs with delete (rewritten) and hash enlargement.
+ flist, F_WRLCK);
}
-#if 0
+/* Even if the entry isn't in this hash bucket, you'd have to lock this
+ * bucket to find it. */
static int chainlock(struct tdb_context *tdb, const TDB_DATA *key,
int ltype, enum tdb_lock_flags waitflag,
const char *func)
return chainlock(tdb, &key, F_WRLCK, TDB_LOCK_WAIT, "tdb_chainlock");
}
+int tdb_chainunlock(struct tdb_context *tdb, TDB_DATA key)
+{
+ uint64_t h = tdb_hash(tdb, key.dptr, key.dsize);
+ tdb_trace_1rec(tdb, "tdb_chainunlock", key);
+ return tdb_unlock_list(tdb, h, F_WRLCK);
+}
+
+#if 0
/* lock/unlock one hash chain, non-blocking. This is meant to be used
to reduce contention - it cannot guarantee how many records will be
locked */
"tdb_chainlock_nonblock");
}
-int tdb_chainunlock(struct tdb_context *tdb, TDB_DATA key)
-{
- uint64_t h = tdb_hash(tdb, key.dptr, key.dsize);
- tdb_trace_1rec(tdb, "tdb_chainunlock", key);
- return tdb_unlock_list(tdb, h & ((1ULL << tdb->header.v.hash_bits)-1),
- F_WRLCK);
-}
-
int tdb_chainlock_read(struct tdb_context *tdb, TDB_DATA key)
{
return chainlock(tdb, &key, F_RDLCK, TDB_LOCK_WAIT,
/* Hash random memory. */
uint64_t tdb_hash(struct tdb_context *tdb, const void *ptr, size_t len);
+/* offset of hash table entry for this list/hash value */
+tdb_off_t hash_off(struct tdb_context *tdb, uint64_t list);
+
/* free.c: */
void tdb_zone_init(struct tdb_context *tdb);
return NULL;
}
-static tdb_off_t hash_off(struct tdb_context *tdb, uint64_t list)
+tdb_off_t hash_off(struct tdb_context *tdb, uint64_t list)
{
return tdb->header.v.hash_off
+ ((list & ((1ULL << tdb->header.v.hash_bits) - 1))
if (unlikely(num == len)) {
/* We wrapped. Look through start of hash table. */
+ i = 0;
hoff = hash_off(tdb, 0);
len = (1ULL << tdb->header.v.hash_bits);
num = tdb_find_zero_off(tdb, hoff, len);
- if (i == len) {
+ if (num == len) {
tdb->ecode = TDB_ERR_CORRUPT;
tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
"hash_add: full hash table!\n");
return -1;
}
}
+ if (tdb_read_off(tdb, hash_off(tdb, i + num)) != 0) {
+ tdb->ecode = TDB_ERR_CORRUPT;
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
+ "hash_add: overwriting hash table?\n");
+ return -1;
+ }
+
/* FIXME: Encode extra hash bits! */
return tdb_write_off(tdb, hash_off(tdb, i + num), off);
}
tdb_len_t hlen;
uint64_t num = 1ULL << tdb->header.v.hash_bits;
struct tdb_used_record pad, *r;
+ unsigned int records = 0;
/* FIXME: We should do this without holding locks throughout. */
if (tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_WAIT, false) == -1)
goto oldheader;
if (off && hash_add(tdb, hash_record(tdb, off), off) == -1)
goto oldheader;
+ if (off)
+ records++;
}
+ tdb->log(tdb, TDB_DEBUG_TRACE, tdb->log_priv,
+ "enlarge_hash: moved %u records from %llu buckets.\n",
+ records, (long long)num);
+
/* Free up old hash. */
r = tdb_get(tdb, oldoff - sizeof(*r), &pad, sizeof(*r));
if (!r)
goto unlock;
}
+
+/* This is the slow version of the routine which searches the
+ * hashtable for an entry.
+ * We lock every hash bucket up to and including the next zero one.
+ */
+static tdb_off_t find_and_lock_slow(struct tdb_context *tdb,
+ struct tdb_data key,
+ uint64_t h,
+ int ltype,
+ tdb_off_t *start_lock,
+ tdb_len_t *num_locks,
+ tdb_off_t *bucket,
+ struct tdb_used_record *rec)
+{
+ /* Warning: this may drop the lock on *bucket! */
+ *num_locks = relock_hash_to_zero(tdb, *start_lock, ltype);
+ if (*num_locks == TDB_OFF_ERR)
+ return TDB_OFF_ERR;
+
+ for (*bucket = *start_lock;
+ *bucket < *start_lock + *num_locks;
+ (*bucket)++) {
+ tdb_off_t off = entry_matches(tdb, *bucket, h, &key, rec);
+ /* Empty entry or we found it? */
+ if (off == 0 || off != TDB_OFF_ERR)
+ return off;
+ }
+
+ /* We didn't find a zero entry? Something went badly wrong... */
+ unlock_lists(tdb, *start_lock, *start_lock + *num_locks, ltype);
+ tdb->ecode = TDB_ERR_CORRUPT;
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
+ "find_and_lock: expected to find an empty hash bucket!\n");
+ return TDB_OFF_ERR;
+}
+
/* This is the core routine which searches the hashtable for an entry.
* On error, no locks are held and TDB_OFF_ERR is returned.
* Otherwise, *num_locks locks of type ltype from *start_lock are held.
}
/* Slow path, need to grab more locks and search. */
-
- /* Warning: this may drop the lock on *bucket! */
- *num_locks = relock_hash_to_zero(tdb, *start_lock, ltype);
- if (*num_locks == TDB_OFF_ERR)
- return TDB_OFF_ERR;
-
- for (*bucket = *start_lock;
- *bucket < *start_lock + *num_locks;
- (*bucket)++) {
- off = entry_matches(tdb, *bucket, h, &key, rec);
- /* Empty entry or we found it? */
- if (off == 0 || off != TDB_OFF_ERR)
- return off;
- }
-
- /* We didn't find a zero entry? Something went badly wrong... */
- unlock_lists(tdb, *start_lock, *start_lock + *num_locks, ltype);
- tdb->ecode = TDB_ERR_CORRUPT;
- tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
- "find_and_lock: expected to find an empty hash bucket!\n");
- return TDB_OFF_ERR;
+ return find_and_lock_slow(tdb, key, h, ltype, start_lock, num_locks,
+ bucket, rec);
}
/* Returns -1 on error, 0 on OK, 1 on "expand and retry." */
/* Allocate a new record. */
new_off = alloc(tdb, key.dsize, dbuf.dsize, h, growing);
- if (new_off == 0)
+ if (unlikely(new_off == TDB_OFF_ERR))
+ return -1;
+
+ if (unlikely(new_off == 0))
return 1;
/* We didn't like the existing one: remove it. */
if (unlikely(num > 4 * tdb->header.v.hash_bits - 30))
enlarge_hash(tdb);
- return 0;
+ return ret;
fail:
unlock_lists(tdb, start, num, F_WRLCK);
uint64_t h;
h = tdb_hash(tdb, key.dptr, key.dsize);
- off = find_and_lock(tdb, key, h, F_WRLCK, &start, &num, &bucket, &rec);
+ start = tdb_lock_list(tdb, h, F_WRLCK, TDB_LOCK_WAIT);
+ if (unlikely(start == TDB_OFF_ERR))
+ return -1;
+
+ /* FIXME: Fastpath: if next is zero, we can delete without lock,
+ * since this lock protects us. */
+ off = find_and_lock_slow(tdb, key, h, F_WRLCK,
+ &start, &num, &bucket, &rec);
if (unlikely(off == TDB_OFF_ERR))
return -1;
if (!off) {
+ /* FIXME: We could optimize not found case if it mattered, by
+ * reading offset after first lock: if it's zero, goto here. */
unlock_lists(tdb, start, num, F_WRLCK);
tdb->ecode = TDB_ERR_NOEXIST;
return -1;
}
+ /* Since we found the entry, we must have locked it and a zero. */
+ assert(num >= 2);
/* This actually unlinks it. */
if (tdb_write_off(tdb, hash_off(tdb, bucket), 0) == -1)
goto unlock_err;
/* Rehash anything following. */
- for (i = hash_off(tdb, bucket+1);
- i != hash_off(tdb, h + num - 1);
- i += sizeof(tdb_off_t)) {
- tdb_off_t off2;
+ for (i = bucket+1; i != bucket + num - 1; i++) {
+ tdb_off_t hoff, off2;
uint64_t h2;
- off2 = tdb_read_off(tdb, i);
+ hoff = hash_off(tdb, i);
+ off2 = tdb_read_off(tdb, hoff);
if (unlikely(off2 == TDB_OFF_ERR))
goto unlock_err;
/* Maybe use a bit to indicate it is in ideal place? */
h2 = hash_record(tdb, off2);
/* Is it happy where it is? */
- if (hash_off(tdb, h2) == i)
+ if (hash_off(tdb, h2) == hoff)
continue;
/* Remove it. */
- if (tdb_write_off(tdb, i, 0) == -1)
+ if (tdb_write_off(tdb, hoff, 0) == -1)
goto unlock_err;
/* Rehash it. */
struct tdb_context;
/* FIXME: Make typesafe */
+typedef int (*tdb_traverse_func)(struct tdb_context *, TDB_DATA, TDB_DATA, void *);
typedef void (*tdb_logfn_t)(struct tdb_context *, enum tdb_debug_level, void *priv, const char *, ...) PRINTF_ATTRIBUTE(4, 5);
typedef uint64_t (*tdb_hashfn_t)(const void *key, size_t len, uint64_t seed,
void *priv);
int tdb_delete(struct tdb_context *tdb, struct tdb_data key);
int tdb_store(struct tdb_context *tdb, struct tdb_data key, struct tdb_data dbuf, int flag);
int tdb_append(struct tdb_context *tdb, struct tdb_data key, struct tdb_data dbuf);
+int tdb_chainlock(struct tdb_context *tdb, TDB_DATA key);
+int tdb_chainunlock(struct tdb_context *tdb, TDB_DATA key);
+int64_t tdb_traverse(struct tdb_context *tdb, tdb_traverse_func fn, void *p);
+int64_t tdb_traverse_read(struct tdb_context *tdb,
+ tdb_traverse_func fn, void *p);
int tdb_close(struct tdb_context *tdb);
int tdb_check(struct tdb_context *tdb,
int (*check)(TDB_DATA key, TDB_DATA data, void *private_data),
add_free_record(tdb, eoff, sizeof(struct tdb_used_record) + elen);
}
-static tdb_off_t hash_off(struct tdb_context *tdb, uint64_t list)
-{
- return tdb->header.v.hash_off
- + ((list & ((1ULL << tdb->header.v.hash_bits) - 1))
- * sizeof(tdb_off_t));
-}
-
static void add_to_hashtable(struct tdb_context *tdb,
tdb_off_t eoff,
struct tdb_data key)
--- /dev/null
+/* Another test revealed that we lost an entry. This reproduces it. */
+#include <ccan/tdb2/tdb.c>
+#include <ccan/tdb2/free.c>
+#include <ccan/tdb2/lock.c>
+#include <ccan/tdb2/io.c>
+#include <ccan/tdb2/check.c>
+#include <ccan/tdb2/traverse.c>
+#include <ccan/tap/tap.h>
+#include "logging.h"
+
+#define NUM_RECORDS 1189
+
+/* We use the same seed which we saw this failure on. */
+static uint64_t failhash(const void *key, size_t len, uint64_t seed, void *p)
+{
+ seed = 699537674708983027ULL;
+ return hash64_stable((const unsigned char *)key, len, seed);
+}
+
+int main(int argc, char *argv[])
+{
+ int i;
+ struct tdb_context *tdb;
+ struct tdb_data key = { (unsigned char *)&i, sizeof(i) };
+ struct tdb_data data = { (unsigned char *)&i, sizeof(i) };
+ union tdb_attribute hattr = { .hash = { .base = { TDB_ATTRIBUTE_HASH },
+ .hash_fn = failhash } };
+
+ hattr.base.next = &tap_log_attr;
+ plan_tests(1 + 2 * NUM_RECORDS + 1);
+
+ tdb = tdb_open("run-missing-entries.tdb", TDB_INTERNAL,
+ O_RDWR|O_CREAT|O_TRUNC, 0600, &hattr);
+ ok1(tdb);
+ if (tdb) {
+ for (i = 0; i < NUM_RECORDS; i++) {
+ ok1(tdb_store(tdb, key, data, TDB_REPLACE) == 0);
+ ok1(tdb_check(tdb, NULL, NULL) == 0);
+ }
+ tdb_close(tdb);
+ }
+
+ ok1(tap_log_messages == 0);
+ return exit_status();
+}
--- /dev/null
+ /*
+ Trivial Database 2: traverse function.
+ Copyright (C) Rusty Russell 2010
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 3 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+#include "private.h"
+#include <ccan/likely/likely.h>
+
+static int64_t traverse(struct tdb_context *tdb, int ltype,
+ tdb_traverse_func fn, void *p)
+{
+ uint64_t i, num, count = 0;
+ tdb_off_t off, prev_bucket;
+ struct tdb_used_record rec;
+ struct tdb_data k, d;
+ bool finish = false;
+
+ /* FIXME: Do we need to start at 0? */
+ prev_bucket = tdb_lock_list(tdb, 0, ltype, TDB_LOCK_WAIT);
+ if (prev_bucket != 0)
+ return -1;
+
+ num = (1ULL << tdb->header.v.hash_bits);
+
+ for (i = tdb_find_nonzero_off(tdb, hash_off(tdb, 0), num);
+ i != num && !finish;
+ i += tdb_find_nonzero_off(tdb, hash_off(tdb, i), num - i)) {
+ if (tdb_lock_list(tdb, i, ltype, TDB_LOCK_WAIT) != i)
+ goto fail;
+
+ off = tdb_read_off(tdb, hash_off(tdb, i));
+ if (off == TDB_OFF_ERR) {
+ tdb_unlock_list(tdb, i, ltype);
+ goto fail;
+ }
+
+ /* This race can happen, but look again. */
+ if (off == 0) {
+ tdb_unlock_list(tdb, i, ltype);
+ continue;
+ }
+
+ /* Drop previous lock. */
+ tdb_unlock_list(tdb, prev_bucket, ltype);
+ prev_bucket = i;
+
+ if (tdb_read_convert(tdb, off, &rec, sizeof(rec)) != 0)
+ goto fail;
+
+ k.dsize = rec_key_length(&rec);
+ d.dsize = rec_data_length(&rec);
+ if (ltype == F_RDLCK) {
+ /* Read traverses can keep the lock. */
+ k.dptr = (void *)tdb_access_read(tdb,
+ off + sizeof(rec),
+ k.dsize + d.dsize,
+ false);
+ } else {
+ k.dptr = tdb_alloc_read(tdb, off + sizeof(rec),
+ k.dsize + d.dsize);
+ }
+ if (!k.dptr)
+ goto fail;
+ d.dptr = k.dptr + k.dsize;
+ count++;
+
+ if (ltype == F_WRLCK) {
+ /* Drop lock before calling out. */
+ tdb_unlock_list(tdb, i, ltype);
+ }
+
+ if (fn && fn(tdb, k, d, p))
+ finish = true;
+
+ if (ltype == F_WRLCK) {
+ free(k.dptr);
+ /* Regain lock. FIXME: Is this necessary? */
+ if (tdb_lock_list(tdb, i, ltype, TDB_LOCK_WAIT) != i)
+ return -1;
+
+ /* This makes deleting under ourselves a bit nicer. */
+ if (tdb_read_off(tdb, hash_off(tdb, i)) == off)
+ i++;
+ } else {
+ tdb_access_release(tdb, k.dptr);
+ i++;
+ }
+ }
+
+ /* Drop final lock. */
+ tdb_unlock_list(tdb, prev_bucket, ltype);
+ return count;
+
+fail:
+ tdb_unlock_list(tdb, prev_bucket, ltype);
+ return -1;
+}
+
+int64_t tdb_traverse(struct tdb_context *tdb, tdb_traverse_func fn, void *p)
+{
+ return traverse(tdb, F_WRLCK, fn, p);
+}
+
+int64_t tdb_traverse_read(struct tdb_context *tdb,
+ tdb_traverse_func fn, void *p)
+{
+ int64_t ret;
+ bool was_ro = tdb->read_only;
+ tdb->read_only = true;
+ ret = traverse(tdb, F_RDLCK, fn, p);
+ tdb->read_only = was_ro;
+ return ret;
+}
projects / ccan / commitdiff