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diff --git a/ccan/ntdb/doc/TDB_porting.txt b/ccan/ntdb/doc/TDB_porting.txt
deleted file mode 100644
index 5daf94b7..00000000
--- a/ccan/ntdb/doc/TDB_porting.txt
+++ /dev/null
@@ -1,483 +0,0 @@
-Interface differences between TDB and NTDB.
-
-- ntdb shares 'struct TDB_DATA' with tdb, but TDB defines the TDB_DATA
-  typedef, whereas ntdb defines NTDB_DATA (ie. both are compatible).
-  If you include both ntdb.h and tdb.h, #include tdb.h first,
-  otherwise you'll get a compile error when tdb.h re-defined struct
-  TDB_DATA.
-
-  Example:
-	#include <tdb.h>
-	#include <ntdb.h>
-
-- ntdb functions return NTDB_SUCCESS (ie 0) on success, and a negative
-  error on failure, whereas tdb functions returned 0 on success, and
-  -1 on failure.  tdb then used tdb_error() to determine the error;
-  this API is nasty if we ever want to support threads, so is not supported.
-
-  Example:
-	#include <tdb.h>
-	#include <ntdb.h>
-
-	void tdb_example(struct tdb_context *tdb, TDB_DATA key, TDB_DATA d)
-	{
-		if (tdb_store(tdb, key, d) == -1) {
-			printf("store failed: %s\n", tdb_errorstr(tdb));
-		}
-	}
-
-	void ntdb_example(struct ntdb_context *ntdb, NTDB_DATA key, NTDB_DATA d)
-	{
-		enum NTDB_ERROR e;
-
-		e = ntdb_store(ntdb, key, d);
-		if (e) {
-			printf("store failed: %s\n", ntdb_errorstr(e));
-		}
-	}
-
-- ntdb's ntdb_fetch() returns an error, tdb's returned the data directly
-  (or tdb_null, and you were supposed to check tdb_error() to find out why).
-
-  Example:
-	#include <tdb.h>
-	#include <ntdb.h>
-
-	void tdb_example(struct tdb_context *tdb, TDB_DATA key)
-	{
-		TDB_DATA data;
-
-		data = tdb_fetch(tdb, key);
-		if (!data.dptr) {
-			printf("fetch failed: %s\n", tdb_errorstr(tdb));
-		}
-	}
-
-	void ntdb_example(struct ntdb_context *ntdb, NTDB_DATA key)
-	{
-		NTDB_DATA data;
-		enum NTDB_ERROR e;
-
-		e = ntdb_fetch(ntdb, key, &data);
-		if (e) {
-			printf("fetch failed: %s\n", ntdb_errorstr(e));
-		}
-	}
-
-- ntdb's ntdb_nextkey() frees the old key's dptr, in tdb you needed to do
-  this manually.
-
-  Example:
-	#include <tdb.h>
-	#include <ntdb.h>
-
-	void tdb_example(struct tdb_context *tdb)
-	{
-		TDB_DATA key, next, data;
-
-		for (key = tdb_firstkey(tdb); key.dptr; key = next) {
-			printf("Got key!\n");
-			next = tdb_nextkey(tdb, key);
-			free(key.dptr);
-		}
-	}
-
-
-	void ntdb_example(struct ntdb_context *ntdb)
-	{
-		NTDB_DATA k, data;
-		enum NTDB_ERROR e;
-
-		for (e = ntdb_firstkey(ntdb,&k); !e; e = ntdb_nextkey(ntdb,&k))
-			printf("Got key!\n");
-	}
-
-- Unlike tdb_open/tdb_open_ex, ntdb_open does not allow NULL names,
-  even for NTDB_INTERNAL dbs, and thus ntdb_name() never returns NULL.
-
-  Example:
-	#include <tdb.h>
-	#include <ntdb.h>
-
-	struct tdb_context *tdb_example(void)
-	{
-		return tdb_open(NULL, 0, TDB_INTERNAL, O_RDWR, 0);
-	}
-
-	struct ntdb_context *ntdb_example(void)
-	{
-		return ntdb_open("example", NTDB_INTERNAL, O_RDWR, 0);
-	}
-
-- ntdb uses a linked list of attribute structures to implement logging and
-  alternate hashes.  tdb used tdb_open_ex, which was not extensible.
-
-  Example:
-	#include <tdb.h>
-	#include <ntdb.h>
-
-	/* Custom hash function */
-	static unsigned int my_tdb_hash_func(TDB_DATA *key)
-	{
-		return key->dsize;
-	}
-
-	struct tdb_context *tdb_example(void)
-	{
-		return tdb_open_ex("example.tdb", 0, TDB_DEFAULT,
-		                   O_CREAT|O_RDWR, 0600, NULL, my_hash_func);
-	}
-
-	/* Custom hash function */
-	static unsigned int my_ntdb_hash_func(const void *key, size_t len,
-					      uint32_t seed, void *data)
-	{
-		return len;
-	}
-
-	struct ntdb_context *ntdb_example(void)
-	{
-		union ntdb_attribute hash;
-
-		hash.base.attr = NTDB_ATTRIBUTE_HASH;
-		hash.base.next = NULL;
-		hash.hash.fn = my_ntdb_hash_func;
-		return ntdb_open("example.ntdb", NTDB_DEFAULT,
-		                   O_CREAT|O_RDWR, 0600, &hash);
-	}
-
-- tdb's tdb_open/tdb_open_ex took an explicit hash size, defaulting to
-  131.  ntdb's uses an attribute for this, defaulting to 8192.
-
-  Example:
-	#include <tdb.h>
-	#include <ntdb.h>
-
-	struct tdb_context *tdb_example(void)
-	{
-		return tdb_open("example.tdb", 10007, TDB_DEFAULT,
-		                O_CREAT|O_RDWR, 0600);
-	}
-
-	struct ntdb_context *ntdb_example(void)
-	{
-		union ntdb_attribute hashsize;
-
-		hashsize.base.attr = NTDB_ATTRIBUTE_HASHSIZE;
-		hashsize.base.next = NULL;
-		hashsize.hashsize.size = 16384;
-		return ntdb_open("example.ntdb", NTDB_DEFAULT,
-		                   O_CREAT|O_RDWR, 0600, &hashsize);
-	}
-
-- ntdb's log function is simpler than tdb's log function.  The string
-  is already formatted, is not terminated by a '\n', and it takes an
-  enum ntdb_log_level not a tdb_debug_level, and which has only three
-  values: NTDB_LOG_ERROR, NTDB_LOG_USE_ERROR and NTDB_LOG_WARNING.
-
-	#include <tdb.h>
-	#include <ntdb.h>
-
-	static void tdb_log(struct tdb_context *tdb,
-	                    enum tdb_debug_level level, const char *fmt, ...)
-	{
-		va_list ap;
-		const char *name;
-
-		switch (level) {
-		case TDB_DEBUG_FATAL:
-			fprintf(stderr, "FATAL: ");
-			break;
-		case TDB_DEBUG_ERROR:
-			fprintf(stderr, "ERROR: ");
-			break;
-		case TDB_DEBUG_WARNING:
-			fprintf(stderr, "WARNING: ");
-			break;
-		case TDB_DEBUG_TRACE:
-			/* Don't print out tracing. */
-			return;
-		}
-
-		name = tdb_name(tdb);
-		if (!name) {
-			name = "unnamed";
-		}
-
-		fprintf(stderr, "tdb(%s):", name);
-
-		va_start(ap, fmt);
-		vfprintf(stderr, fmt, ap);
-		va_end(ap);
-	}
-
-	struct tdb_context *tdb_example(void)
-	{
-		struct tdb_logging_context lctx;
-
-		lctx.log_fn = tdb_log;
-		return tdb_open_ex("example.tdb", 0, TDB_DEFAULT,
-		                   O_CREAT|O_RDWR, 0600, &lctx, NULL);
-	}
-
-	static void ntdb_log(struct ntdb_context *ntdb,
-			     enum ntdb_log_level level,
-			     enum NTDB_ERROR ecode,
-			     const char *message,
-			     void *data)
-	{
-		switch (level) {
-		case NTDB_LOG_ERROR:
-			fprintf(stderr, "ERROR: ");
-			break;
-		case NTDB_LOG_USE_ERROR:
-			/* We made a mistake, so abort. */
-			abort();
-			break;
-		case NTDB_LOG_WARNING:
-			fprintf(stderr, "WARNING: ");
-			break;
-		}
-
-		fprintf(stderr, "ntdb(%s):%s:%s\n",
-			ntdb_name(ntdb), ntdb_errorstr(ecode), message);
-	}
-
-	struct ntdb_context *ntdb_example(void)
-	{
-		union ntdb_attribute log;
-
-		log.base.attr = NTDB_ATTRIBUTE_LOG;
-		log.base.next = NULL;
-		log.log.fn = ntdb_log;
-		return ntdb_open("example.ntdb", NTDB_DEFAULT,
-		                 O_CREAT|O_RDWR, 0600, &log);
-	}
-
-- ntdb provides ntdb_deq() for comparing two NTDB_DATA, and ntdb_mkdata() for
-  creating an NTDB_DATA.
-
-	#include <tdb.h>
-	#include <ntdb.h>
-
-	void tdb_example(struct tdb_context *tdb)
-	{
-		TDB_DATA data, key;
-
-		key.dsize = strlen("hello");
-		key.dptr = "hello";
-		data = tdb_fetch(tdb, key);
-		if (data.dsize == key.dsize
-		    && !memcmp(data.dptr, key.dptr, key.dsize))
-			printf("key is same as data\n");
-		}
-		free(data.dptr);
-	}
-
-	void ntdb_example(struct ntdb_context *ntdb)
-	{
-		NTDB_DATA data, key;
-
-		key = ntdb_mkdata("hello", strlen("hello"));
-		if (ntdb_fetch(ntdb, key, &data) == NTDB_SUCCESS) {
-			if (ntdb_deq(key, data)) {
-				printf("key is same as data\n");
-			}
-			free(data.dptr);
-		}
-	}
-
-- ntdb's ntdb_parse_record() takes a type-checked callback data
-  pointer, not a void * (though a void * pointer still works).  The
-  callback function is allowed to do read operations on the database,
-  or write operations if you first call ntdb_lockall().  TDB's
-  tdb_parse_record() did not allow any database access within the
-  callback, could crash if you tried.
-
-  Example:
-	#include <tdb.h>
-	#include <ntdb.h>
-
-	static int tdb_parser(TDB_DATA key, TDB_DATA data, void *private_data)
-	{
-		TDB_DATA *expect = private_data;
-
-		return data.dsize == expect->dsize
-			&& !memcmp(data.dptr, expect->dptr, data.dsize);
-	}
-
-	void tdb_example(struct tdb_context *tdb, TDB_DATA key, NTDB_DATA d)
-	{
-		switch (tdb_parse_record(tdb, key, tdb_parser, &d)) {
-		case -1:
-			printf("parse failed: %s\n", tdb_errorstr(tdb));
-			break;
-		case 0:
-			printf("data was different!\n");
-			break;
-		case 1:
-			printf("data was same!\n");
-			break;
-		}
-	}
-
-	static int ntdb_parser(TDB_DATA key, TDB_DATA data, TDB_DATA *expect)
-	{
-		return ntdb_deq(data, *expect);
-	}
-
-	void ntdb_example(struct ntdb_context *ntdb, NTDB_DATA key, NTDB_DATA d)
-	{
-		enum NTDB_ERROR e;
-
-		e = tdb_parse_record(tdb, key, tdb_parser, &d);
-		switch (e) {
-		case 0:
-			printf("data was different!\n");
-			break;
-		case 1:
-			printf("data was same!\n");
-			break;
-		default:
-			printf("parse failed: %s\n", ntdb_errorstr(e));
-			break;
-		}
-	}
-
-- ntdb does locking on read-only databases (ie. O_RDONLY passed to ntdb_open).
-  tdb did not: use the NTDB_NOLOCK flag if you want to suppress locking.
-
-  Example:
-	#include <tdb.h>
-	#include <ntdb.h>
-
-	struct tdb_context *tdb_example(void)
-	{
-		return tdb_open("example.tdb", 0, TDB_DEFAULT, O_RDONLY, 0);
-	}
-
-	struct ntdb_context *ntdb_example(void)
-	{
-		return ntdb_open("example.ntdb", NTDB_NOLOCK, O_RDONLY, NULL);
-	}
-
-- Failure inside a transaction (such as a lock function failing) does
-  not implicitly cancel the transaction; you still need to call
-  ntdb_transaction_cancel().
-
-	#include <tdb.h>
-	#include <ntdb.h>
-
-	void tdb_example(struct tdb_context *tdb, TDB_DATA key, TDB_DATA d)
-	{
-		if (tdb_transaction_start(tdb) == -1) {
-			printf("transaction failed: %s\n", tdb_errorstr(tdb));
-			return;
-		}
-
-		if (tdb_store(tdb, key, d) == -1) {
-			printf("store failed: %s\n", tdb_errorstr(tdb));
-			return;
-		}
-		if (tdb_transaction_commit(tdb) == -1) {
-			printf("commit failed: %s\n", tdb_errorstr(tdb));
-		}
-	}
-
-	void ntdb_example(struct ntdb_context *ntdb, NTDB_DATA key, NTDB_DATA d)
-	{
-		enum NTDB_ERROR e;
-
-		e = ntdb_transaction_start(ntdb);
-		if (e) {
-			printf("transaction failed: %s\n", ntdb_errorstr(e));
-			return;
-		}
-
-		e = ntdb_store(ntdb, key, d);
-		if (e) {
-			printf("store failed: %s\n", ntdb_errorstr(e));
-			ntdb_transaction_cancel(ntdb);
-		}
-
-		e = ntdb_transaction_commit(ntdb);
-		if (e) {
-			printf("commit failed: %s\n", ntdb_errorstr(e));
-		}
-	}
-
-- There is no NTDB_CLEAR_IF_FIRST flag; it has severe scalability and
-  API problems.  If necessary, you can emulate this by using the open
-  hook and placing a 1-byte lock at offset 4.  If your program forks
-  and exits, you will need to place this lock again in the child before
-  the parent exits.
-
-  Example:
-
-	#include <tdb.h>
-	#include <ntdb.h>
-
-	struct tdb_context *tdb_example(void)
-	{
-		return tdb_open("example.tdb", 0, TDB_CLEAR_IF_FIRST,
-		                   O_CREAT|O_RDWR, 0600);
-	}
-
-	static enum NTDB_ERROR clear_if_first(int fd, void *unused)
-	{
-		/* We hold a lock offset 4 always, so we can tell if
-		 * anyone else is. */
-		struct flock fl;
-
-		fl.l_type = F_WRLCK;
-		fl.l_whence = SEEK_SET;
-		fl.l_start = 4; /* ACTIVE_LOCK */
-		fl.l_len = 1;
-
-		if (fcntl(fd, F_SETLK, &fl) == 0) {
-			/* We must be first ones to open it!  Clear it. */
-			if (ftruncate(fd, 0) != 0) {
-				return NTDB_ERR_IO;
-			}
-		}
-		fl.l_type = F_RDLCK;
-		if (fcntl(fd, F_SETLKW, &fl) != 0) {
-			return NTDB_ERR_IO;
-		}
-		return NTDB_SUCCESS;
-	}
-
-	struct ntdb_context *ntdb_example(void)
-	{
-		union ntdb_attribute open_attr;
-
-		open_attr.openhook.base.attr = NTDB_ATTRIBUTE_OPENHOOK;
-		open_attr.openhook.base.next = NULL;
-		open_attr.openhook.fn = clear_if_first;
-
-		return ntdb_open("example.ntdb", NTDB_DEFAULT,
-		                 O_CREAT|O_RDWR, 0600, &open_attr);
-	}
-
-- ntdb traversals are not reliable if the database is changed during
-  the traversal, ie your traversal may not cover all elements, or may
-  cover elements multiple times.  As a special exception, deleting the
-  current record within ntdb_traverse() is reliable.
-
-- There is no ntdb_traverse_read, since ntdb_traverse does not hold
-  a lock across the entire traversal anyway.  If you want to make sure
-  that your traversal function does not write to the database, you can
-  set and clear the NTDB_RDONLY flag around the traversal.
-
-- ntdb does not need tdb_reopen() or tdb_reopen_all().  If you call
-  fork() after during certain operations the child should close the
-  ntdb, or complete the operations before continuing to use the tdb:
-
-	ntdb_transaction_start(): child must ntdb_transaction_cancel()
-	ntdb_lockall(): child must call ntdb_unlockall()
-	ntdb_lockall_read(): child must call ntdb_unlockall_read()
-	ntdb_chainlock(): child must call ntdb_chainunlock()
-	ntdb_parse() callback: child must return from ntdb_parse()
-
-- ntdb will not open a non-ntdb file, even if O_CREAT is specified.  tdb
-  will overwrite an unknown file in that case.