X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb%2Fopen.c;h=437a5fc38d1706e9b5f3e846876f8aa4e8d9da75;hp=677b23d84de3baf0a8f8b812cdc74db40578cf68;hb=a1ace0cd114e0c588d6ce1b9e7386af11716e0bd;hpb=23dbdf06c4521b11f7eb0f341af987d8fd92474c

diff --git a/ccan/tdb/open.c b/ccan/tdb/open.c
index 677b23d8..437a5fc3 100644
--- a/ccan/tdb/open.c
+++ b/ccan/tdb/open.c
@@ -63,6 +63,7 @@ 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;
+	newdb->hashcheck = hashcheck(tdb);
 	if (tdb->flags & TDB_INTERNAL) {
 		tdb->map_size = size;
 		tdb->map_ptr = (char *)newdb;
@@ -143,6 +144,18 @@ static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, con
 {
 }
 
+uint32_t hashcheck(struct tdb_context *tdb)
+{
+	uint32_t vals[] = { TDB_VERSION, TDB_MAGIC };
+	TDB_DATA hashkey = { (unsigned char *)vals, sizeof(vals) };
+
+	/* If we're using the default hash, let old code still open the db. */
+	if (tdb->hash_fn == default_tdb_hash)
+		return 0;
+
+	/* Only let new hash-aware TDB code open it (must not be zero!) */
+	return (tdb->hash_fn(&hashkey) | 1);
+}
 
 struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 				int open_flags, mode_t mode,
@@ -161,9 +174,11 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 		errno = ENOMEM;
 		goto fail;
 	}
-
 	tdb_io_init(tdb);
 	tdb->fd = -1;
+#ifdef TDB_TRACE
+	tdb->tracefd = -1;
+#endif
 	tdb->name = NULL;
 	tdb->map_ptr = NULL;
 	tdb->flags = tdb_flags;
@@ -200,6 +215,22 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 		tdb->flags &= ~TDB_CLEAR_IF_FIRST;
 	}
 
+	if ((tdb->flags & TDB_ALLOW_NESTING) &&
+	    (tdb->flags & TDB_DISALLOW_NESTING)) {
+		tdb->ecode = TDB_ERR_NESTING;
+		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
+			"allow_nesting and disallow_nesting are not allowed together!"));
+		errno = EINVAL;
+		goto fail;
+	}
+
+	/*
+	 * TDB_DISALLOW_NESTING is the default behavior.
+	 */
+	if (!(tdb->flags & TDB_ALLOW_NESTING)) {
+		tdb->flags |= TDB_DISALLOW_NESTING;
+	}
+
 	/* internal databases don't mmap or lock, and start off cleared */
 	if (tdb->flags & TDB_INTERNAL) {
 		tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
@@ -208,10 +239,6 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 			TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: tdb_new_database failed!"));
 			goto fail;
 		}
-#ifdef TDB_TRACE
-		/* All tracing will fail.  That's ok. */
-		tdb->tracefd = -1;
-#endif
 		goto internal;
 	}
 
@@ -226,8 +253,8 @@ 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->tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0, 1) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to get global lock on %s: %s\n",
+	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 */
 	}
@@ -235,7 +262,7 @@ 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->tdb_brlock(tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0, 1) == 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: "
@@ -274,8 +301,8 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 	if (fstat(tdb->fd, &st) == -1)
 		goto fail;
 
-	if (tdb->header.rwlocks != 0) {
-		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: spinlocks no longer supported\n"));
+	if (tdb->header.hashcheck != hashcheck(tdb)) {
+		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: wrong hash?\n"));
 		goto fail;
 	}
 
@@ -298,7 +325,7 @@ 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->tdb_brlock(tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK, 0, 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)));
@@ -313,8 +340,9 @@ 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->tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0, 1) == -1)
+		if (tdb_nest_lock(tdb, ACTIVE_LOCK, F_RDLCK, TDB_LOCK_WAIT) == -1) {
 			goto fail;
+		}
 	}
 
 	/* if needed, run recovery */
@@ -326,7 +354,8 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 	{
 		char tracefile[strlen(name) + 32];
 
-		sprintf(tracefile, "%s.trace.%u", name, getpid());
+		snprintf(tracefile, sizeof(tracefile),
+			 "%s.trace.%li", name, (long)getpid());
 		tdb->tracefd = open(tracefile, O_WRONLY|O_CREAT|O_EXCL, 0600);
 		if (tdb->tracefd >= 0) {
 			tdb_enable_seqnum(tdb);
@@ -340,9 +369,10 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
  internal:
 	/* Internal (memory-only) databases skip all the code above to
 	 * do with disk files, and resume here by releasing their
-	 * global lock and hooking into the active list. */
-	if (tdb->methods->tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1) == -1)
+	 * open lock and hooking into the active list. */
+	if (tdb_nest_unlock(tdb, OPEN_LOCK, F_WRLCK, false) == -1) {
 		goto fail;
+	}
 	tdb->next = tdbs;
 	tdbs = tdb;
 	return tdb;
@@ -366,6 +396,7 @@ 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;
@@ -391,10 +422,10 @@ int tdb_close(struct tdb_context *tdb)
 	struct tdb_context **i;
 	int ret = 0;
 
-	tdb_trace(tdb, "tdb_close");
 	if (tdb->transaction) {
-		tdb_transaction_cancel_internal(tdb);
+		tdb_transaction_cancel(tdb);
 	}
+	tdb_trace(tdb, "tdb_close");
 
 	if (tdb->map_ptr) {
 		if (tdb->flags & TDB_INTERNAL)
@@ -403,8 +434,10 @@ int tdb_close(struct tdb_context *tdb)
 			tdb_munmap(tdb);
 	}
 	SAFE_FREE(tdb->name);
-	if (tdb->fd != -1)
+	if (tdb->fd != -1) {
 		ret = close(tdb->fd);
+		tdb->fd = -1;
+	}
 	SAFE_FREE(tdb->lockrecs);
 
 	/* Remove from contexts list */
@@ -436,9 +469,7 @@ void *tdb_get_logging_private(struct tdb_context *tdb)
 	return tdb->log.log_private;
 }
 
-/* reopen a tdb - this can be used after a fork to ensure that we have an independent
-   seek pointer from our parent and to re-establish locks */
-int tdb_reopen(struct tdb_context *tdb)
+static int tdb_reopen_internal(struct tdb_context *tdb, bool active_lock)
 {
 	struct stat st;
 
@@ -446,7 +477,7 @@ int tdb_reopen(struct tdb_context *tdb)
 		return 0; /* Nothing to do. */
 	}
 
-	if (tdb->num_locks != 0 || tdb->global_lock.count) {
+	if (tdb_have_extra_locks(tdb)) {
 		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed with locks held\n"));
 		goto fail;
 	}
@@ -467,11 +498,6 @@ int tdb_reopen(struct tdb_context *tdb)
 		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: open failed (%s)\n", strerror(errno)));
 		goto fail;
 	}
-	if ((tdb->flags & TDB_CLEAR_IF_FIRST) && 
-	    (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0, 1) == -1)) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: failed to obtain active lock\n"));
-		goto fail;
-	}
 	if (fstat(tdb->fd, &st) != 0) {
 		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: fstat failed (%s)\n", strerror(errno)));
 		goto fail;
@@ -482,6 +508,15 @@ int tdb_reopen(struct tdb_context *tdb)
 	}
 	tdb_mmap(tdb);
 
+	/* 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;
+	}
+
 	return 0;
 
 fail:
@@ -489,12 +524,21 @@ fail:
 	return -1;
 }
 
+/* reopen a tdb - this can be used after a fork to ensure that we have an independent
+   seek pointer from our parent and to re-establish locks */
+int tdb_reopen(struct tdb_context *tdb)
+{
+	return tdb_reopen_internal(tdb, tdb->flags & TDB_CLEAR_IF_FIRST);
+}
+
 /* reopen all tdb's */
 int tdb_reopen_all(int parent_longlived)
 {
 	struct tdb_context *tdb;
 
 	for (tdb=tdbs; tdb; tdb = tdb->next) {
+		bool active_lock = (tdb->flags & TDB_CLEAR_IF_FIRST);
+
 		/*
 		 * If the parent is longlived (ie. a
 		 * parent daemon architecture), we know
@@ -508,10 +552,10 @@ int tdb_reopen_all(int parent_longlived)
 		 */
 		if (parent_longlived) {
 			/* Ensure no clear-if-first. */
-			tdb->flags &= ~TDB_CLEAR_IF_FIRST;
+			active_lock = false;
 		}
 
-		if (tdb_reopen(tdb) != 0)
+		if (tdb_reopen_internal(tdb, active_lock) != 0)
 			return -1;
 	}