- /*
+ /*
Unix SMB/CIFS implementation.
trivial database library
#include "tdb_private.h"
-TDB_DATA tdb_null;
+_PUBLIC_ TDB_DATA tdb_null;
/*
non-blocking increment of the tdb sequence number if the tdb has been opened using
the TDB_SEQNUM flag
*/
-void tdb_increment_seqnum_nonblock(struct tdb_context *tdb)
+_PUBLIC_ void tdb_increment_seqnum_nonblock(struct tdb_context *tdb)
{
tdb_off_t seqnum=0;
return;
}
+ if (tdb->transaction != NULL) {
+ tdb_increment_seqnum_nonblock(tdb);
+ return;
+ }
+
+#if defined(HAVE___ATOMIC_ADD_FETCH) && defined(HAVE___ATOMIC_ADD_LOAD)
+ if (tdb->map_ptr != NULL) {
+ uint32_t *pseqnum = (uint32_t *)(
+ TDB_SEQNUM_OFS + (char *)tdb->map_ptr);
+ __atomic_add_fetch(pseqnum, 1, __ATOMIC_SEQ_CST);
+ return;
+ }
+#endif
+
if (tdb_nest_lock(tdb, TDB_SEQNUM_OFS, F_WRLCK,
TDB_LOCK_WAIT|TDB_LOCK_PROBE) != 0) {
return;
return memcmp(data.dptr, key.dptr, data.dsize);
}
+void tdb_chainwalk_init(struct tdb_chainwalk_ctx *ctx, tdb_off_t ptr)
+{
+ *ctx = (struct tdb_chainwalk_ctx) { .slow_ptr = ptr };
+}
+
+bool tdb_chainwalk_check(struct tdb_context *tdb,
+ struct tdb_chainwalk_ctx *ctx,
+ tdb_off_t next_ptr)
+{
+ int ret;
+
+ if (ctx->slow_chase) {
+ ret = tdb_ofs_read(tdb, ctx->slow_ptr, &ctx->slow_ptr);
+ if (ret == -1) {
+ return false;
+ }
+ }
+ ctx->slow_chase = !ctx->slow_chase;
+
+ if (next_ptr == ctx->slow_ptr) {
+ tdb->ecode = TDB_ERR_CORRUPT;
+ TDB_LOG((tdb, TDB_DEBUG_ERROR,
+ "tdb_chainwalk_check: circular chain\n"));
+ return false;
+ }
+
+ return true;
+}
+
/* Returns 0 on fail. On success, return offset of record, and fills
in rec */
static tdb_off_t tdb_find(struct tdb_context *tdb, TDB_DATA key, uint32_t hash,
struct tdb_record *r)
{
tdb_off_t rec_ptr;
+ struct tdb_chainwalk_ctx chainwalk;
/* read in the hash top */
if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1)
return 0;
+ tdb_chainwalk_init(&chainwalk, rec_ptr);
+
/* keep looking until we find the right record */
while (rec_ptr) {
+ bool ok;
+
if (tdb_rec_read(tdb, rec_ptr, r) == -1)
return 0;
NULL) == 0) {
return rec_ptr;
}
- /* detect tight infinite loop */
- if (rec_ptr == r->next) {
- tdb->ecode = TDB_ERR_CORRUPT;
- TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_find: loop detected.\n"));
+ rec_ptr = r->next;
+
+ ok = tdb_chainwalk_check(tdb, &chainwalk, rec_ptr);
+ if (!ok) {
return 0;
}
- rec_ptr = r->next;
}
tdb->ecode = TDB_ERR_NOEXIST;
return 0;
static TDB_DATA _tdb_fetch(struct tdb_context *tdb, TDB_DATA key);
+struct tdb_update_hash_state {
+ const TDB_DATA *dbufs;
+ int num_dbufs;
+ tdb_len_t dbufs_len;
+};
+
+static int tdb_update_hash_cmp(TDB_DATA key, TDB_DATA data, void *private_data)
+{
+ struct tdb_update_hash_state *state = private_data;
+ unsigned char *dptr = data.dptr;
+ int i;
+
+ if (state->dbufs_len != data.dsize) {
+ return -1;
+ }
+
+ for (i=0; i<state->num_dbufs; i++) {
+ TDB_DATA dbuf = state->dbufs[i];
+ if( dbuf.dsize > 0) {
+ int ret;
+ ret = memcmp(dptr, dbuf.dptr, dbuf.dsize);
+ if (ret != 0) {
+ return -1;
+ }
+ dptr += dbuf.dsize;
+ }
+ }
+
+ return 0;
+}
+
/* update an entry in place - this only works if the new data size
is <= the old data size and the key exists.
on failure return -1.
*/
-static int tdb_update_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash, TDB_DATA dbuf)
+static int tdb_update_hash(struct tdb_context *tdb, TDB_DATA key,
+ uint32_t hash,
+ const TDB_DATA *dbufs, int num_dbufs,
+ tdb_len_t dbufs_len)
{
struct tdb_record rec;
- tdb_off_t rec_ptr;
+ tdb_off_t rec_ptr, ofs;
+ int i;
/* find entry */
if (!(rec_ptr = tdb_find(tdb, key, hash, &rec)))
/* it could be an exact duplicate of what is there - this is
* surprisingly common (eg. with a ldb re-index). */
- if (rec.key_len == key.dsize &&
- rec.data_len == dbuf.dsize &&
- rec.full_hash == hash) {
- TDB_DATA data = _tdb_fetch(tdb, key);
- if (data.dsize == dbuf.dsize &&
- memcmp(data.dptr, dbuf.dptr, data.dsize) == 0) {
- if (data.dptr) {
- free(data.dptr);
- }
+ if (rec.data_len == dbufs_len) {
+ struct tdb_update_hash_state state = {
+ .dbufs = dbufs, .num_dbufs = num_dbufs,
+ .dbufs_len = dbufs_len
+ };
+ int ret;
+
+ ret = tdb_parse_record(tdb, key, tdb_update_hash_cmp, &state);
+ if (ret == 0) {
return 0;
}
- if (data.dptr) {
- free(data.dptr);
- }
}
/* must be long enough key, data and tailer */
- if (rec.rec_len < key.dsize + dbuf.dsize + sizeof(tdb_off_t)) {
+ if (rec.rec_len < key.dsize + dbufs_len + sizeof(tdb_off_t)) {
tdb->ecode = TDB_SUCCESS; /* Not really an error */
return -1;
}
- if (tdb->methods->tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len,
- dbuf.dptr, dbuf.dsize) == -1)
- return -1;
+ ofs = rec_ptr + sizeof(rec) + rec.key_len;
+
+ for (i=0; i<num_dbufs; i++) {
+ TDB_DATA dbuf = dbufs[i];
+ int ret;
+
+ ret = tdb->methods->tdb_write(tdb, ofs, dbuf.dptr, dbuf.dsize);
+ if (ret == -1) {
+ return -1;
+ }
+ ofs += dbuf.dsize;
+ }
- if (dbuf.dsize != rec.data_len) {
+ if (dbufs_len != rec.data_len) {
/* update size */
- rec.data_len = dbuf.dsize;
+ rec.data_len = dbufs_len;
return tdb_rec_write(tdb, rec_ptr, &rec);
}
return ret;
}
-TDB_DATA tdb_fetch(struct tdb_context *tdb, TDB_DATA key)
+_PUBLIC_ TDB_DATA tdb_fetch(struct tdb_context *tdb, TDB_DATA key)
{
TDB_DATA ret = _tdb_fetch(tdb, key);
* Return -1 if the record was not found.
*/
-int tdb_parse_record(struct tdb_context *tdb, TDB_DATA key,
+_PUBLIC_ int tdb_parse_record(struct tdb_context *tdb, TDB_DATA key,
int (*parser)(TDB_DATA key, TDB_DATA data,
void *private_data),
void *private_data)
return ret;
}
-/* check if an entry in the database exists
+/* check if an entry in the database exists
note that 1 is returned if the key is found and 0 is returned if not found
this doesn't match the conventions in the rest of this module, but is
return 1;
}
-int tdb_exists(struct tdb_context *tdb, TDB_DATA key)
+_PUBLIC_ int tdb_exists(struct tdb_context *tdb, TDB_DATA key)
{
uint32_t hash = tdb->hash_fn(&key);
int ret;
return ret;
}
-/* actually delete an entry in the database given the offset */
-int tdb_do_delete(struct tdb_context *tdb, tdb_off_t rec_ptr, struct tdb_record *rec)
+/*
+ * Move a dead record to the freelist. The hash chain and freelist
+ * must be locked.
+ */
+static int tdb_del_dead(struct tdb_context *tdb,
+ uint32_t last_ptr,
+ uint32_t rec_ptr,
+ struct tdb_record *rec,
+ bool *deleted)
{
- tdb_off_t last_ptr, i;
- struct tdb_record lastrec;
-
- if (tdb->read_only || tdb->traverse_read) return -1;
+ int ret;
- if (((tdb->traverse_write != 0) && (!TDB_DEAD(rec))) ||
- tdb_write_lock_record(tdb, rec_ptr) == -1) {
- /* Someone traversing here: mark it as dead */
- rec->magic = TDB_DEAD_MAGIC;
- return tdb_rec_write(tdb, rec_ptr, rec);
+ ret = tdb_write_lock_record(tdb, rec_ptr);
+ if (ret == -1) {
+ /* Someone traversing here: Just leave it dead */
+ return 0;
}
- if (tdb_write_unlock_record(tdb, rec_ptr) != 0)
- return -1;
-
- /* find previous record in hash chain */
- if (tdb_ofs_read(tdb, TDB_HASH_TOP(rec->full_hash), &i) == -1)
- return -1;
- for (last_ptr = 0; i != rec_ptr; last_ptr = i, i = lastrec.next)
- if (tdb_rec_read(tdb, i, &lastrec) == -1)
- return -1;
-
- /* unlink it: next ptr is at start of record. */
- if (last_ptr == 0)
- last_ptr = TDB_HASH_TOP(rec->full_hash);
- if (tdb_ofs_write(tdb, last_ptr, &rec->next) == -1)
+ ret = tdb_write_unlock_record(tdb, rec_ptr);
+ if (ret == -1) {
return -1;
-
- /* recover the space */
- if (tdb_free(tdb, rec_ptr, rec) == -1)
+ }
+ ret = tdb_ofs_write(tdb, last_ptr, &rec->next);
+ if (ret == -1) {
return -1;
- return 0;
-}
-
-static int tdb_count_dead(struct tdb_context *tdb, uint32_t hash)
-{
- int res = 0;
- tdb_off_t rec_ptr;
- struct tdb_record rec;
-
- /* read in the hash top */
- if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1)
- return 0;
+ }
- while (rec_ptr) {
- if (tdb_rec_read(tdb, rec_ptr, &rec) == -1)
- return 0;
+ *deleted = true;
- if (rec.magic == TDB_DEAD_MAGIC) {
- res += 1;
- }
- rec_ptr = rec.next;
- }
- return res;
+ ret = tdb_free(tdb, rec_ptr, rec);
+ return ret;
}
/*
- * Purge all DEAD records from a hash chain
+ * Walk the hash chain and leave tdb->max_dead_records around. Move
+ * the rest of dead records to the freelist.
*/
-static int tdb_purge_dead(struct tdb_context *tdb, uint32_t hash)
+int tdb_trim_dead(struct tdb_context *tdb, uint32_t hash)
{
- int res = -1;
+ struct tdb_chainwalk_ctx chainwalk;
struct tdb_record rec;
- tdb_off_t rec_ptr;
+ tdb_off_t last_ptr, rec_ptr;
+ bool locked_freelist = false;
+ int num_dead = 0;
+ int ret;
+
+ last_ptr = TDB_HASH_TOP(hash);
+
+ /*
+ * Init chainwalk with the pointer to the hash top. It might
+ * be that the very first record in the chain is a dead one
+ * that we have to delete.
+ */
+ tdb_chainwalk_init(&chainwalk, last_ptr);
- if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
+ ret = tdb_ofs_read(tdb, last_ptr, &rec_ptr);
+ if (ret == -1) {
return -1;
}
- /* read in the hash top */
- if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1)
- goto fail;
+ while (rec_ptr != 0) {
+ bool deleted = false;
+ uint32_t next;
- while (rec_ptr) {
- tdb_off_t next;
-
- if (tdb_rec_read(tdb, rec_ptr, &rec) == -1) {
+ ret = tdb_rec_read(tdb, rec_ptr, &rec);
+ if (ret == -1) {
goto fail;
}
+ /*
+ * Make a copy of rec.next: Further down we might
+ * delete and put the record on the freelist. Make
+ * sure that modifications in that code path can't
+ * break the chainwalk here.
+ */
next = rec.next;
- if (rec.magic == TDB_DEAD_MAGIC
- && tdb_do_delete(tdb, rec_ptr, &rec) == -1) {
- goto fail;
+ if (rec.magic == TDB_DEAD_MAGIC) {
+ num_dead += 1;
+
+ if (num_dead > tdb->max_dead_records) {
+
+ if (!locked_freelist) {
+ /*
+ * Lock the freelist only if
+ * it's really required.
+ */
+ ret = tdb_lock(tdb, -1, F_WRLCK);
+ if (ret == -1) {
+ goto fail;
+ };
+ locked_freelist = true;
+ }
+
+ ret = tdb_del_dead(
+ tdb,
+ last_ptr,
+ rec_ptr,
+ &rec,
+ &deleted);
+
+ if (ret == -1) {
+ goto fail;
+ }
+ }
+ }
+
+ /*
+ * Don't do the chainwalk check if "rec_ptr" was
+ * deleted. We reduced the chain, and the chainwalk
+ * check might catch up early. Imagine a valid chain
+ * with just dead records: We never can bump the
+ * "slow" pointer in chainwalk_check, as there isn't
+ * anything left to jump to and compare.
+ */
+ if (!deleted) {
+ bool ok;
+
+ last_ptr = rec_ptr;
+
+ ok = tdb_chainwalk_check(tdb, &chainwalk, next);
+ if (!ok) {
+ ret = -1;
+ goto fail;
+ }
}
rec_ptr = next;
}
- res = 0;
- fail:
- tdb_unlock(tdb, -1, F_WRLCK);
- return res;
+ ret = 0;
+fail:
+ if (locked_freelist) {
+ tdb_unlock(tdb, -1, F_WRLCK);
+ }
+ return ret;
}
/* delete an entry in the database given a key */
struct tdb_record rec;
int ret;
- if (tdb->max_dead_records != 0) {
-
- /*
- * Allow for some dead records per hash chain, mainly for
- * tdb's with a very high create/delete rate like locking.tdb.
- */
-
- if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1)
- return -1;
-
- if (tdb_count_dead(tdb, hash) >= tdb->max_dead_records) {
- /*
- * Don't let the per-chain freelist grow too large,
- * delete all existing dead records
- */
- tdb_purge_dead(tdb, hash);
- }
-
- if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) {
- tdb_unlock(tdb, BUCKET(hash), F_WRLCK);
- return -1;
- }
-
- /*
- * Just mark the record as dead.
- */
- rec.magic = TDB_DEAD_MAGIC;
- ret = tdb_rec_write(tdb, rec_ptr, &rec);
+ if (tdb->read_only || tdb->traverse_read) {
+ tdb->ecode = TDB_ERR_RDONLY;
+ return -1;
}
- else {
- if (!(rec_ptr = tdb_find_lock_hash(tdb, key, hash, F_WRLCK,
- &rec)))
- return -1;
- ret = tdb_do_delete(tdb, rec_ptr, &rec);
+ rec_ptr = tdb_find_lock_hash(tdb, key, hash, F_WRLCK, &rec);
+ if (rec_ptr == 0) {
+ return -1;
}
- if (ret == 0) {
- tdb_increment_seqnum(tdb);
+ /*
+ * Mark the record dead
+ */
+ rec.magic = TDB_DEAD_MAGIC;
+ ret = tdb_rec_write(tdb, rec_ptr, &rec);
+ if (ret == -1) {
+ goto done;
}
- if (tdb_unlock(tdb, BUCKET(rec.full_hash), F_WRLCK) != 0)
+ tdb_increment_seqnum(tdb);
+
+ ret = tdb_trim_dead(tdb, hash);
+done:
+ if (tdb_unlock(tdb, BUCKET(hash), F_WRLCK) != 0)
TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_delete: WARNING tdb_unlock failed!\n"));
return ret;
}
-int tdb_delete(struct tdb_context *tdb, TDB_DATA key)
+_PUBLIC_ int tdb_delete(struct tdb_context *tdb, TDB_DATA key)
{
uint32_t hash = tdb->hash_fn(&key);
int ret;
/*
* See if we have a dead record around with enough space
*/
-static tdb_off_t tdb_find_dead(struct tdb_context *tdb, uint32_t hash,
- struct tdb_record *r, tdb_len_t length)
+tdb_off_t tdb_find_dead(struct tdb_context *tdb, uint32_t hash,
+ struct tdb_record *r, tdb_len_t length,
+ tdb_off_t *p_last_ptr)
{
- tdb_off_t rec_ptr;
+ tdb_off_t rec_ptr, last_ptr;
+ struct tdb_chainwalk_ctx chainwalk;
+ tdb_off_t best_rec_ptr = 0;
+ tdb_off_t best_last_ptr = 0;
+ struct tdb_record best = { .rec_len = UINT32_MAX };
+
+ length += sizeof(tdb_off_t); /* tailer */
+
+ last_ptr = TDB_HASH_TOP(hash);
/* read in the hash top */
- if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1)
+ if (tdb_ofs_read(tdb, last_ptr, &rec_ptr) == -1)
return 0;
+ tdb_chainwalk_init(&chainwalk, rec_ptr);
+
/* keep looking until we find the right record */
while (rec_ptr) {
+ bool ok;
+
if (tdb_rec_read(tdb, rec_ptr, r) == -1)
return 0;
- if (TDB_DEAD(r) && r->rec_len >= length) {
- /*
- * First fit for simple coding, TODO: change to best
- * fit
- */
- return rec_ptr;
+ if (TDB_DEAD(r) && (r->rec_len >= length) &&
+ (r->rec_len < best.rec_len)) {
+ best_rec_ptr = rec_ptr;
+ best_last_ptr = last_ptr;
+ best = *r;
}
+ last_ptr = rec_ptr;
rec_ptr = r->next;
+
+ ok = tdb_chainwalk_check(tdb, &chainwalk, rec_ptr);
+ if (!ok) {
+ return 0;
+ }
}
- return 0;
+
+ if (best.rec_len == UINT32_MAX) {
+ return 0;
+ }
+
+ *r = best;
+ *p_last_ptr = best_last_ptr;
+ return best_rec_ptr;
}
-static int _tdb_store(struct tdb_context *tdb, TDB_DATA key,
- TDB_DATA dbuf, int flag, uint32_t hash)
+static int _tdb_storev(struct tdb_context *tdb, TDB_DATA key,
+ const TDB_DATA *dbufs, int num_dbufs,
+ int flag, uint32_t hash)
{
struct tdb_record rec;
- tdb_off_t rec_ptr;
- char *p = NULL;
+ tdb_off_t rec_ptr, ofs;
+ tdb_len_t rec_len, dbufs_len;
+ int i;
int ret = -1;
+ dbufs_len = 0;
+
+ for (i=0; i<num_dbufs; i++) {
+ size_t dsize = dbufs[i].dsize;
+
+ if ((dsize != 0) && (dbufs[i].dptr == NULL)) {
+ tdb->ecode = TDB_ERR_EINVAL;
+ goto fail;
+ }
+
+ dbufs_len += dsize;
+ if (dbufs_len < dsize) {
+ tdb->ecode = TDB_ERR_OOM;
+ goto fail;
+ }
+ }
+
+ rec_len = key.dsize + dbufs_len;
+ if ((rec_len < key.dsize) || (rec_len < dbufs_len)) {
+ tdb->ecode = TDB_ERR_OOM;
+ goto fail;
+ }
+
/* check for it existing, on insert. */
if (flag == TDB_INSERT) {
if (tdb_exists_hash(tdb, key, hash)) {
}
} else {
/* first try in-place update, on modify or replace. */
- if (tdb_update_hash(tdb, key, hash, dbuf) == 0) {
+ if (tdb_update_hash(tdb, key, hash, dbufs, num_dbufs,
+ dbufs_len) == 0) {
goto done;
}
if (tdb->ecode == TDB_ERR_NOEXIST &&
goto fail;
}
}
- /* reset the error code potentially set by the tdb_update() */
+ /* reset the error code potentially set by the tdb_update_hash() */
tdb->ecode = TDB_SUCCESS;
/* delete any existing record - if it doesn't exist we don't
if (flag != TDB_INSERT)
tdb_delete_hash(tdb, key, hash);
- /* Copy key+value *before* allocating free space in case malloc
- fails and we are left with a dead spot in the tdb. */
+ /* we have to allocate some space */
+ rec_ptr = tdb_allocate(tdb, hash, rec_len, &rec);
- if (!(p = (char *)malloc(key.dsize + dbuf.dsize))) {
- tdb->ecode = TDB_ERR_OOM;
+ if (rec_ptr == 0) {
goto fail;
}
- memcpy(p, key.dptr, key.dsize);
- if (dbuf.dsize)
- memcpy(p+key.dsize, dbuf.dptr, dbuf.dsize);
+ /* Read hash top into next ptr */
+ if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1)
+ goto fail;
- if (tdb->max_dead_records != 0) {
- /*
- * Allow for some dead records per hash chain, look if we can
- * find one that can hold the new record. We need enough space
- * for key, data and tailer. If we find one, we don't have to
- * consult the central freelist.
- */
- rec_ptr = tdb_find_dead(
- tdb, hash, &rec,
- key.dsize + dbuf.dsize + sizeof(tdb_off_t));
-
- if (rec_ptr != 0) {
- rec.key_len = key.dsize;
- rec.data_len = dbuf.dsize;
- rec.full_hash = hash;
- rec.magic = TDB_MAGIC;
- if (tdb_rec_write(tdb, rec_ptr, &rec) == -1
- || tdb->methods->tdb_write(
- tdb, rec_ptr + sizeof(rec),
- p, key.dsize + dbuf.dsize) == -1) {
- goto fail;
- }
- goto done;
- }
- }
+ rec.key_len = key.dsize;
+ rec.data_len = dbufs_len;
+ rec.full_hash = hash;
+ rec.magic = TDB_MAGIC;
- /*
- * We have to allocate some space from the freelist, so this means we
- * have to lock it. Use the chance to purge all the DEAD records from
- * the hash chain under the freelist lock.
- */
+ ofs = rec_ptr;
- if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
+ /* write out and point the top of the hash chain at it */
+ ret = tdb_rec_write(tdb, ofs, &rec);
+ if (ret == -1) {
goto fail;
}
+ ofs += sizeof(rec);
- if ((tdb->max_dead_records != 0)
- && (tdb_purge_dead(tdb, hash) == -1)) {
- tdb_unlock(tdb, -1, F_WRLCK);
+ ret = tdb->methods->tdb_write(tdb, ofs, key.dptr, key.dsize);
+ if (ret == -1) {
goto fail;
}
+ ofs += key.dsize;
- /* we have to allocate some space */
- rec_ptr = tdb_allocate(tdb, key.dsize + dbuf.dsize, &rec);
-
- tdb_unlock(tdb, -1, F_WRLCK);
+ for (i=0; i<num_dbufs; i++) {
+ if (dbufs[i].dsize == 0) {
+ continue;
+ }
- if (rec_ptr == 0) {
- goto fail;
+ ret = tdb->methods->tdb_write(tdb, ofs, dbufs[i].dptr,
+ dbufs[i].dsize);
+ if (ret == -1) {
+ goto fail;
+ }
+ ofs += dbufs[i].dsize;
}
- /* Read hash top into next ptr */
- if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1)
- goto fail;
-
- rec.key_len = key.dsize;
- rec.data_len = dbuf.dsize;
- rec.full_hash = hash;
- rec.magic = TDB_MAGIC;
-
- /* write out and point the top of the hash chain at it */
- if (tdb_rec_write(tdb, rec_ptr, &rec) == -1
- || tdb->methods->tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+dbuf.dsize)==-1
- || tdb_ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) {
+ ret = tdb_ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr);
+ if (ret == -1) {
/* Need to tdb_unallocate() here */
goto fail;
}
if (ret == 0) {
tdb_increment_seqnum(tdb);
}
-
- SAFE_FREE(p);
return ret;
}
+static int _tdb_store(struct tdb_context *tdb, TDB_DATA key,
+ TDB_DATA dbuf, int flag, uint32_t hash)
+{
+ return _tdb_storev(tdb, key, &dbuf, 1, flag, hash);
+}
+
/* store an element in the database, replacing any existing element
with the same key
return 0 on success, -1 on failure
*/
-int tdb_store(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf, int flag)
+_PUBLIC_ int tdb_store(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf, int flag)
{
uint32_t hash;
int ret;
return ret;
}
-/* Append to an entry. Create if not exist. */
-int tdb_append(struct tdb_context *tdb, TDB_DATA key, TDB_DATA new_dbuf)
+_PUBLIC_ int tdb_storev(struct tdb_context *tdb, TDB_DATA key,
+ const TDB_DATA *dbufs, int num_dbufs, int flag)
{
uint32_t hash;
- TDB_DATA dbuf;
- int ret = -1;
+ int ret;
+
+ if (tdb->read_only || tdb->traverse_read) {
+ tdb->ecode = TDB_ERR_RDONLY;
+ tdb_trace_1plusn_rec_flag_ret(tdb, "tdb_storev", key,
+ dbufs, num_dbufs, flag, -1);
+ return -1;
+ }
/* find which hash bucket it is in */
hash = tdb->hash_fn(&key);
if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1)
return -1;
- dbuf = _tdb_fetch(tdb, key);
+ ret = _tdb_storev(tdb, key, dbufs, num_dbufs, flag, hash);
+ tdb_trace_1plusn_rec_flag_ret(tdb, "tdb_storev", key,
+ dbufs, num_dbufs, flag, -1);
+ tdb_unlock(tdb, BUCKET(hash), F_WRLCK);
+ return ret;
+}
- if (dbuf.dptr == NULL) {
- dbuf.dptr = (unsigned char *)malloc(new_dbuf.dsize);
- } else {
- unsigned int new_len = dbuf.dsize + new_dbuf.dsize;
- unsigned char *new_dptr;
-
- /* realloc '0' is special: don't do that. */
- if (new_len == 0)
- new_len = 1;
- new_dptr = (unsigned char *)realloc(dbuf.dptr, new_len);
- if (new_dptr == NULL) {
- free(dbuf.dptr);
- }
- dbuf.dptr = new_dptr;
- }
+/* Append to an entry. Create if not exist. */
+_PUBLIC_ int tdb_append(struct tdb_context *tdb, TDB_DATA key, TDB_DATA new_dbuf)
+{
+ uint32_t hash;
+ TDB_DATA dbufs[2];
+ int ret = -1;
- if (dbuf.dptr == NULL) {
- tdb->ecode = TDB_ERR_OOM;
- goto failed;
- }
+ /* find which hash bucket it is in */
+ hash = tdb->hash_fn(&key);
+ if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1)
+ return -1;
- memcpy(dbuf.dptr + dbuf.dsize, new_dbuf.dptr, new_dbuf.dsize);
- dbuf.dsize += new_dbuf.dsize;
+ dbufs[0] = _tdb_fetch(tdb, key);
+ dbufs[1] = new_dbuf;
- ret = _tdb_store(tdb, key, dbuf, 0, hash);
- tdb_trace_2rec_retrec(tdb, "tdb_append", key, new_dbuf, dbuf);
+ ret = _tdb_storev(tdb, key, dbufs, 2, 0, hash);
+ tdb_trace_2rec_retrec(tdb, "tdb_append", key, dbufs[0], dbufs[1]);
-failed:
tdb_unlock(tdb, BUCKET(hash), F_WRLCK);
- SAFE_FREE(dbuf.dptr);
+ SAFE_FREE(dbufs[0].dptr);
return ret;
}
return the name of the current tdb file
useful for external logging functions
*/
-const char *tdb_name(struct tdb_context *tdb)
+_PUBLIC_ const char *tdb_name(struct tdb_context *tdb)
{
return tdb->name;
}
useful for external routines that want to check the device/inode
of the fd
*/
-int tdb_fd(struct tdb_context *tdb)
+_PUBLIC_ int tdb_fd(struct tdb_context *tdb)
{
return tdb->fd;
}
return the current logging function
useful for external tdb routines that wish to log tdb errors
*/
-tdb_log_func tdb_log_fn(struct tdb_context *tdb)
+_PUBLIC_ tdb_log_func tdb_log_fn(struct tdb_context *tdb)
{
return tdb->log.log_fn;
}
The aim of this sequence number is to allow for a very lightweight
test of a possible tdb change.
*/
-int tdb_get_seqnum(struct tdb_context *tdb)
+_PUBLIC_ int tdb_get_seqnum(struct tdb_context *tdb)
{
tdb_off_t seqnum=0;
+ if (tdb->transaction != NULL) {
+ tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &seqnum);
+ return seqnum;
+ }
+
+#if defined(HAVE___ATOMIC_ADD_FETCH) && defined(HAVE___ATOMIC_ADD_LOAD)
+ if (tdb->map_ptr != NULL) {
+ uint32_t *pseqnum = (uint32_t *)(
+ TDB_SEQNUM_OFS + (char *)tdb->map_ptr);
+ uint32_t ret;
+ __atomic_load(pseqnum, &ret,__ATOMIC_SEQ_CST);
+ return ret;
+ }
+#endif
+
tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &seqnum);
return seqnum;
}
-int tdb_hash_size(struct tdb_context *tdb)
+_PUBLIC_ int tdb_hash_size(struct tdb_context *tdb)
{
- return tdb->header.hash_size;
+ return tdb->hash_size;
}
-size_t tdb_map_size(struct tdb_context *tdb)
+_PUBLIC_ size_t tdb_map_size(struct tdb_context *tdb)
{
return tdb->map_size;
}
-int tdb_get_flags(struct tdb_context *tdb)
+_PUBLIC_ int tdb_get_flags(struct tdb_context *tdb)
{
return tdb->flags;
}
-void tdb_add_flags(struct tdb_context *tdb, unsigned flags)
+_PUBLIC_ void tdb_add_flags(struct tdb_context *tdb, unsigned flags)
{
if ((flags & TDB_ALLOW_NESTING) &&
(flags & TDB_DISALLOW_NESTING)) {
tdb->flags |= flags;
}
-void tdb_remove_flags(struct tdb_context *tdb, unsigned flags)
+_PUBLIC_ void tdb_remove_flags(struct tdb_context *tdb, unsigned flags)
{
if ((flags & TDB_ALLOW_NESTING) &&
(flags & TDB_DISALLOW_NESTING)) {
return;
}
+ if ((flags & TDB_NOLOCK) &&
+ (tdb->feature_flags & TDB_FEATURE_FLAG_MUTEX) &&
+ (tdb->mutexes == NULL)) {
+ tdb->ecode = TDB_ERR_LOCK;
+ TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_remove_flags: "
+ "Can not remove NOLOCK flag on mutexed databases"));
+ return;
+ }
+
if (flags & TDB_ALLOW_NESTING) {
tdb->flags |= TDB_DISALLOW_NESTING;
}
/*
enable sequence number handling on an open tdb
*/
-void tdb_enable_seqnum(struct tdb_context *tdb)
+_PUBLIC_ void tdb_enable_seqnum(struct tdb_context *tdb)
{
tdb->flags |= TDB_SEQNUM;
}
/*
- add a region of the file to the freelist. Length is the size of the region in bytes,
+ add a region of the file to the freelist. Length is the size of the region in bytes,
which includes the free list header that needs to be added
*/
static int tdb_free_region(struct tdb_context *tdb, tdb_off_t offset, ssize_t length)
}
if (length + offset > tdb->map_size) {
TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_free_region: adding region beyond end of file\n"));
- return -1;
+ return -1;
}
memset(&rec,'\0',sizeof(rec));
rec.rec_len = length - sizeof(rec);
This code carefully steps around the recovery area, leaving it alone
*/
-int tdb_wipe_all(struct tdb_context *tdb)
+_PUBLIC_ int tdb_wipe_all(struct tdb_context *tdb)
{
- int i;
+ uint32_t i;
tdb_off_t offset = 0;
ssize_t data_len;
tdb_off_t recovery_head;
if (tdb->methods->tdb_read(tdb, recovery_head, &rec, sizeof(rec), DOCONV()) == -1) {
TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_wipe_all: failed to read recovery record\n"));
return -1;
- }
+ }
recovery_size = rec.rec_len + sizeof(rec);
}
/* wipe the hashes */
- for (i=0;i<tdb->header.hash_size;i++) {
+ for (i=0;i<tdb->hash_size;i++) {
if (tdb_ofs_write(tdb, TDB_HASH_TOP(i), &offset) == -1) {
TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_wipe_all: failed to write hash %d\n", i));
goto failed;
goto failed;
}
- /* add all the rest of the file to the freelist, possibly leaving a gap
+ /* add all the rest of the file to the freelist, possibly leaving a gap
for the recovery area */
if (recovery_size == 0) {
/* the simple case - the whole file can be used as a freelist */
- data_len = (tdb->map_size - TDB_DATA_START(tdb->header.hash_size));
- if (tdb_free_region(tdb, TDB_DATA_START(tdb->header.hash_size), data_len) != 0) {
+ data_len = (tdb->map_size - TDB_DATA_START(tdb->hash_size));
+ if (tdb_free_region(tdb, TDB_DATA_START(tdb->hash_size), data_len) != 0) {
goto failed;
}
} else {
/* we need to add two freelist entries - one on either
- side of the recovery area
+ side of the recovery area
Note that we cannot shift the recovery area during
this operation. Only the transaction.c code may
move the recovery area or we risk subtle data
corruption
*/
- data_len = (recovery_head - TDB_DATA_START(tdb->header.hash_size));
- if (tdb_free_region(tdb, TDB_DATA_START(tdb->header.hash_size), data_len) != 0) {
+ data_len = (recovery_head - TDB_DATA_START(tdb->hash_size));
+ if (tdb_free_region(tdb, TDB_DATA_START(tdb->hash_size), data_len) != 0) {
goto failed;
}
/* and the 2nd free list entry after the recovery area - if any */
}
}
+ tdb_increment_seqnum_nonblock(tdb);
+
if (tdb_unlockall(tdb) != 0) {
TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_wipe_all: failed to unlock\n"));
goto failed;
/*
repack a tdb
*/
-int tdb_repack(struct tdb_context *tdb)
+_PUBLIC_ int tdb_repack(struct tdb_context *tdb)
{
struct tdb_context *tmp_db;
struct traverse_state state;
TDB_LOG((tdb, TDB_DEBUG_FATAL, __location__ " Failed to traverse copying out\n"));
tdb_transaction_cancel(tdb);
tdb_close(tmp_db);
- return -1;
+ return -1;
}
if (state.error) {
TDB_LOG((tdb, TDB_DEBUG_FATAL, __location__ " Failed to traverse copying back\n"));
tdb_transaction_cancel(tdb);
tdb_close(tmp_db);
- return -1;
+ return -1;
}
if (state.error) {
return 0;
}
+/* Even on files, we can get partial writes due to signals. */
+bool tdb_write_all(int fd, const void *buf, size_t count)
+{
+ while (count) {
+ ssize_t ret;
+ ret = write(fd, buf, count);
+ if (ret < 0)
+ return false;
+ buf = (const char *)buf + ret;
+ count -= ret;
+ }
+ return true;
+}
+
+bool tdb_add_off_t(tdb_off_t a, tdb_off_t b, tdb_off_t *pret)
+{
+ tdb_off_t ret = a + b;
+
+ if ((ret < a) || (ret < b)) {
+ return false;
+ }
+ *pret = ret;
+ return true;
+}
+
#ifdef TDB_TRACE
static void tdb_trace_write(struct tdb_context *tdb, const char *str)
{
- if (write(tdb->tracefd, str, strlen(str)) != strlen(str)) {
+ if (!tdb_write_all(tdb->tracefd, str, strlen(str))) {
close(tdb->tracefd);
tdb->tracefd = -1;
}
tdb_trace_end_ret(tdb, ret);
}
+void tdb_trace_1plusn_rec_flag_ret(struct tdb_context *tdb, const char *op,
+ TDB_DATA rec,
+ const TDB_DATA *recs, int num_recs,
+ unsigned flag, int ret)
+{
+ char msg[1 + sizeof(ret) * 4];
+ int i;
+
+ snprintf(msg, sizeof(msg), " %#x", flag);
+ tdb_trace_start(tdb);
+ tdb_trace_write(tdb, op);
+ tdb_trace_record(tdb, rec);
+ for (i=0; i<num_recs; i++) {
+ tdb_trace_record(tdb, recs[i]);
+ }
+ tdb_trace_write(tdb, msg);
+ tdb_trace_end_ret(tdb, ret);
+}
+
void tdb_trace_2rec_retrec(struct tdb_context *tdb, const char *op,
TDB_DATA rec1, TDB_DATA rec2, TDB_DATA ret)
{
git.samba.org / samba.git / blobdiff