#define TDB_OFF_HASH_EXTRA_BIT 57
#define TDB_OFF_UPPER_STEAL_SUBHASH_BIT 56
+/* Additional features we understand. Currently: none. */
+#define TDB_FEATURE_MASK ((uint64_t)0)
+
/* The bit number where we store the extra hash bits. */
/* Convenience mask to get actual offset. */
#define TDB_OFF_MASK \
tdb_off_t free_table; /* (First) free table. */
tdb_off_t recovery; /* Transaction recovery area. */
- tdb_off_t reserved[26];
+ uint64_t features_used; /* Features all writers understand */
+ uint64_t features_offered; /* Features offered */
+
+ tdb_off_t reserved[24];
/* Top level hash table. */
tdb_off_t hashtable[1ULL << TDB_TOPLEVEL_HASH_BITS];
newdb.hdr.hash_seed,
tdb->hash_priv);
newdb.hdr.recovery = 0;
+ newdb.hdr.features_used = newdb.hdr.features_offered = TDB_FEATURE_MASK;
memset(newdb.hdr.reserved, 0, sizeof(newdb.hdr.reserved));
/* Initial hashes are empty. */
memset(newdb.hdr.hashtable, 0, sizeof(newdb.hdr.hashtable));
goto fail;
}
+ /* Clear any features we don't understand. */
+ if ((open_flags & O_ACCMODE) != O_RDONLY) {
+ hdr.features_used &= TDB_FEATURE_MASK;
+ if (tdb_write_convert(tdb, offsetof(struct tdb_header,
+ features_used),
+ &hdr.features_used,
+ sizeof(hdr.features_used)) == -1)
+ goto fail;
+ }
+
tdb->device = st.st_dev;
tdb->inode = st.st_ino;
tdb_unlock_open(tdb);
--- /dev/null
+#include <ccan/tdb2/tdb.c>
+#include <ccan/tdb2/free.c>
+#include <ccan/tdb2/lock.c>
+#include <ccan/tdb2/io.c>
+#include <ccan/tdb2/hash.c>
+#include <ccan/tdb2/check.c>
+#include <ccan/tdb2/summary.c>
+#include <ccan/tdb2/transaction.c>
+#include <ccan/tap/tap.h>
+#include "logging.h"
+
+int main(int argc, char *argv[])
+{
+ unsigned int i, j;
+ struct tdb_context *tdb;
+ int flags[] = { TDB_DEFAULT, TDB_NOMMAP,
+ TDB_CONVERT, TDB_NOMMAP|TDB_CONVERT };
+ struct tdb_data key = { (unsigned char *)&j, sizeof(j) };
+ struct tdb_data data = { (unsigned char *)&j, sizeof(j) };
+
+ plan_tests(sizeof(flags) / sizeof(flags[0]) * 8 + 1);
+ for (i = 0; i < sizeof(flags) / sizeof(flags[0]); i++) {
+ uint64_t features;
+ tdb = tdb_open("run-features.tdb", flags[i],
+ O_RDWR|O_CREAT|O_TRUNC, 0600, &tap_log_attr);
+ ok1(tdb);
+ if (!tdb)
+ continue;
+
+ /* Put some stuff in there. */
+ for (j = 0; j < 100; j++) {
+ if (tdb_store(tdb, key, data, TDB_REPLACE) != 0)
+ fail("Storing in tdb");
+ }
+
+ /* Mess with features fields in hdr. */
+ features = (~TDB_FEATURE_MASK ^ 1);
+ ok1(tdb_write_convert(tdb, offsetof(struct tdb_header,
+ features_used),
+ &features, sizeof(features)) == 0);
+ ok1(tdb_write_convert(tdb, offsetof(struct tdb_header,
+ features_offered),
+ &features, sizeof(features)) == 0);
+ tdb_close(tdb);
+
+ tdb = tdb_open("run-features.tdb", flags[i], O_RDWR, 0,
+ &tap_log_attr);
+ ok1(tdb);
+ if (!tdb)
+ continue;
+
+ /* Should not have changed features offered. */
+ ok1(tdb_read_convert(tdb, offsetof(struct tdb_header,
+ features_offered),
+ &features, sizeof(features)) == 0);
+ ok1(features == (~TDB_FEATURE_MASK ^ 1));
+
+ /* Should have cleared unknown bits in features_used. */
+ ok1(tdb_read_convert(tdb, offsetof(struct tdb_header,
+ features_used),
+ &features, sizeof(features)) == 0);
+ ok1(features == (1 & TDB_FEATURE_MASK));
+
+ tdb_close(tdb);
+ }
+
+ ok1(tap_log_messages == 0);
+ return exit_status();
+}
+
+