X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb%2Fopen.c;h=aa32a45eda3957aa04e8c9444a9ba2bd749b1207;hp=b7aa6e745e0aa388b6162b63952137be3a047b2f;hb=233e3055c46ba2ed8fea326ac40ea0545eb0444f;hpb=d92b8a7d9a050eb9735e48a8d37a5833500242d3

diff --git a/ccan/tdb/open.c b/ccan/tdb/open.c
index b7aa6e74..aa32a45e 100644
--- a/ccan/tdb/open.c
+++ b/ccan/tdb/open.c
@@ -44,6 +44,25 @@ static unsigned int default_tdb_hash(TDB_DATA *key)
 	return (1103515243 * value + 12345);  
 }
 
+/* We use two hashes to double-check they're using the right hash function. */
+void tdb_header_hash(struct tdb_context *tdb,
+		     uint32_t *magic1_hash, uint32_t *magic2_hash)
+{
+	TDB_DATA hash_key;
+	uint32_t tdb_magic = TDB_MAGIC;
+
+	hash_key.dptr = (unsigned char *)TDB_MAGIC_FOOD;
+	hash_key.dsize = sizeof(TDB_MAGIC_FOOD);
+	*magic1_hash = tdb->hash_fn(&hash_key);
+
+	hash_key.dptr = CONVERT(tdb_magic);
+	hash_key.dsize = sizeof(tdb_magic);
+	*magic2_hash = tdb->hash_fn(&hash_key);
+
+	/* Make sure at least one hash is non-zero! */
+	if (*magic1_hash == 0 && *magic2_hash == 0)
+		*magic1_hash = 1;
+}
 
 /* initialise a new database with a specified hash size */
 static int tdb_new_database(struct tdb_context *tdb, int hash_size)
@@ -63,6 +82,9 @@ static int tdb_new_database(struct tdb_context *tdb, int hash_size)
 	/* Fill in the header */
 	newdb->version = TDB_VERSION;
 	newdb->hash_size = hash_size;
+
+	tdb_header_hash(tdb, &newdb->magic1_hash, &newdb->magic2_hash);
+
 	if (tdb->flags & TDB_INTERNAL) {
 		tdb->map_size = size;
 		tdb->map_ptr = (char *)newdb;
@@ -155,6 +177,9 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 	unsigned char *vp;
 	uint32_t vertest;
 	unsigned v;
+	uint32_t magic1_hash;
+	uint32_t magic2_hash;
+	const char *hash_alg;
 
 	if (!(tdb = (struct tdb_context *)calloc(1, sizeof *tdb))) {
 		/* Can't log this */
@@ -176,7 +201,14 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 		tdb->log.log_fn = null_log_fn;
 		tdb->log.log_private = NULL;
 	}
-	tdb->hash_fn = hash_fn ? hash_fn : default_tdb_hash;
+
+	if (hash_fn) {
+		tdb->hash_fn = hash_fn;
+		hash_alg = "user defined";
+	} else {
+		tdb->hash_fn = default_tdb_hash;
+		hash_alg = "default";
+	}
 
 	/* cache the page size */
 	tdb->page_size = getpagesize();
@@ -240,7 +272,7 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
         fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
 
 	/* ensure there is only one process initialising at once */
-	if (tdb->methods->brlock(tdb, F_WRLCK, OPEN_LOCK, 1, TDB_LOCK_WAIT) == -1) {
+	if (tdb_nest_lock(tdb, OPEN_LOCK, F_WRLCK, TDB_LOCK_WAIT) == -1) {
 		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to get open lock on %s: %s\n",
 			 name, strerror(errno)));
 		goto fail;	/* errno set by tdb_brlock */
@@ -249,7 +281,7 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 	/* we need to zero database if we are the only one with it open */
 	if ((tdb_flags & TDB_CLEAR_IF_FIRST) &&
 	    (!tdb->read_only) &&
-	    (locked = (tdb->methods->brlock(tdb, F_WRLCK, ACTIVE_LOCK, 1, TDB_LOCK_NOWAIT|TDB_LOCK_PROBE) == 0))) {
+	    (locked = (tdb_nest_lock(tdb, ACTIVE_LOCK, F_WRLCK, TDB_LOCK_NOWAIT|TDB_LOCK_PROBE) == 0))) {
 		open_flags |= O_CREAT;
 		if (ftruncate(tdb->fd, 0) == -1) {
 			TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
@@ -293,6 +325,27 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 		goto fail;
 	}
 
+	tdb_header_hash(tdb, &magic1_hash, &magic2_hash);
+
+	if ((tdb->header.magic1_hash == 0) && (tdb->header.magic2_hash == 0)) {
+		/* older TDB without magic hash references */
+	} else if ((tdb->header.magic1_hash != magic1_hash) ||
+		   (tdb->header.magic2_hash != magic2_hash)) {
+		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
+			 "%s was not created with the %s hash function we are using\n"
+			 "magic1_hash[0x%08X %s 0x%08X] "
+			 "magic2_hash[0x%08X %s 0x%08X]\n",
+			 name, hash_alg,
+			 tdb->header.magic1_hash,
+			 (tdb->header.magic1_hash == magic1_hash) ? "==" : "!=",
+			 magic1_hash,
+			 tdb->header.magic2_hash,
+			 (tdb->header.magic2_hash == magic2_hash) ? "==" : "!=",
+			 magic2_hash));
+		errno = EINVAL;
+		goto fail;
+	}
+
 	/* Is it already in the open list?  If so, fail. */
 	if (tdb_already_open(st.st_dev, st.st_ino)) {
 		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
@@ -312,7 +365,7 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 	tdb->inode = st.st_ino;
 	tdb_mmap(tdb);
 	if (locked) {
-		if (tdb->methods->brunlock(tdb, F_WRLCK, ACTIVE_LOCK, 1) == -1) {
+		if (tdb_nest_unlock(tdb, ACTIVE_LOCK, F_WRLCK, false) == -1) {
 			TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
 				 "failed to take ACTIVE_LOCK on %s: %s\n",
 				 name, strerror(errno)));
@@ -327,8 +380,9 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 
 	if (tdb_flags & TDB_CLEAR_IF_FIRST) {
 		/* leave this lock in place to indicate it's in use */
-		if (tdb->methods->brlock(tdb, F_RDLCK, ACTIVE_LOCK, 1, TDB_LOCK_WAIT) == -1)
+		if (tdb_nest_lock(tdb, ACTIVE_LOCK, F_RDLCK, TDB_LOCK_WAIT) == -1) {
 			goto fail;
+		}
 	}
 
 	/* if needed, run recovery */
@@ -356,8 +410,9 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 	/* 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. */
-	if (tdb->methods->brunlock(tdb, F_WRLCK, OPEN_LOCK, 1) == -1)
+	if (tdb_nest_unlock(tdb, OPEN_LOCK, F_WRLCK, false) == -1) {
 		goto fail;
+	}
 	tdb->next = tdbs;
 	tdbs = tdb;
 	return tdb;
@@ -381,6 +436,7 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 	if (tdb->fd != -1)
 		if (close(tdb->fd) != 0)
 			TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to close tdb->fd on error!\n"));
+	SAFE_FREE(tdb->lockrecs);
 	SAFE_FREE(tdb);
 	errno = save_errno;
 	return NULL;
@@ -492,8 +548,11 @@ static int tdb_reopen_internal(struct tdb_context *tdb, bool active_lock)
 	}
 	tdb_mmap(tdb);
 
-	if (active_lock &&
-	    (tdb->methods->brlock(tdb, F_RDLCK, ACTIVE_LOCK, 1, TDB_LOCK_WAIT) == -1)) {
+	/* We may still think we hold the active lock. */
+	tdb->num_lockrecs = 0;
+	SAFE_FREE(tdb->lockrecs);
+
+	if (active_lock && tdb_nest_lock(tdb, ACTIVE_LOCK, F_RDLCK, TDB_LOCK_WAIT) == -1) {
 		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: failed to obtain active lock\n"));
 		goto fail;
 	}