X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb%2Fcheck.c;h=4fbbb92c5a4ae62902d14b7ccffa697df0ccbde8;hp=b3b8c23104e5a4d770672d15f68acc6e8d7f875a;hb=63e80faf9b42fbe73e25c804dd734b6179e42c24;hpb=735980539f488d6f6299ec710f4045abbb104d46

diff --git a/ccan/tdb/check.c b/ccan/tdb/check.c
index b3b8c231..4fbbb92c 100644
--- a/ccan/tdb/check.c
+++ b/ccan/tdb/check.c
@@ -29,8 +29,9 @@
 static bool tdb_check_header(struct tdb_context *tdb, tdb_off_t *recovery)
 {
 	struct tdb_header hdr;
+	uint32_t h1, h2;
 
-	if (tdb->methods->tdb_read(tdb, 0, &hdr, sizeof(hdr), DOCONV()) == -1)
+	if (tdb->methods->tdb_read(tdb, 0, &hdr, sizeof(hdr), 0) == -1)
 		return false;
 	if (strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0)
 		goto corrupt;
@@ -39,7 +40,12 @@ static bool tdb_check_header(struct tdb_context *tdb, tdb_off_t *recovery)
 	if (hdr.version != TDB_VERSION)
 		goto corrupt;
 
-	if (hdr.hashcheck != hashcheck(tdb))
+	if (hdr.rwlocks != 0 && hdr.rwlocks != TDB_HASH_RWLOCK_MAGIC)
+		goto corrupt;
+
+	tdb_header_hash(tdb, &h1, &h2);
+	if (hdr.magic1_hash && hdr.magic2_hash &&
+	    (hdr.magic1_hash != h1 || hdr.magic2_hash != h2))
 		goto corrupt;
 
 	if (hdr.hash_size == 0)
@@ -303,7 +309,7 @@ static bool tdb_check_free_record(struct tdb_context *tdb,
 }
 
 /* Slow, but should be very rare. */
-static size_t dead_space(struct tdb_context *tdb, tdb_off_t off)
+size_t tdb_dead_space(struct tdb_context *tdb, tdb_off_t off)
 {
 	size_t len;
 
@@ -327,9 +333,17 @@ int tdb_check(struct tdb_context *tdb,
 	struct tdb_record rec;
 	bool found_recovery = false;
 	tdb_len_t dead;
-
-	if (tdb_lockall(tdb) == -1)
-		return -1;
+	bool locked;
+
+	/* Read-only databases use no locking at all: it's best-effort.
+	 * We may have a write lock already, so skip that case too. */
+	if (tdb->read_only || tdb->allrecord_lock.count != 0) {
+		locked = false;
+	} else {
+		if (tdb_lockall_read(tdb) == -1)
+			return -1;
+		locked = true;
+	}
 
 	/* Make sure we know true size of the underlying file. */
 	tdb->methods->tdb_oob(tdb, tdb->map_size + 1, 1);
@@ -393,7 +407,7 @@ int tdb_check(struct tdb_context *tdb,
 				found_recovery = true;
 				break;
 			}
-			dead = dead_space(tdb, off);
+			dead = tdb_dead_space(tdb, off);
 			if (dead < sizeof(rec))
 				goto corrupt;
 
@@ -444,12 +458,16 @@ int tdb_check(struct tdb_context *tdb,
 	}
 
 	free(hashes);
-	tdb_unlockall(tdb);
+	if (locked) {
+		tdb_unlockall_read(tdb);
+	}
 	return 0;
 
 free:
 	free(hashes);
 unlock:
-	tdb_unlockall(tdb);
+	if (locked) {
+		tdb_unlockall_read(tdb);
+	}
 	return -1;
 }