X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb2%2Fio.c;h=8c5f45f30827c9e722227e3787797288713e056e;hp=7e5dcb73160f4a441e6e978349e04c2bca5cbaa4;hb=18fe5ef012a96014b9e61e48616e682b4a5708a2;hpb=41e027e11e0b15100e50c14e49aaa4c2b418f431

diff --git a/ccan/tdb2/io.c b/ccan/tdb2/io.c
index 7e5dcb73..8c5f45f3 100644
--- a/ccan/tdb2/io.c
+++ b/ccan/tdb2/io.c
@@ -48,8 +48,13 @@ void tdb_mmap(struct tdb_context *tdb)
 	if (tdb->flags & TDB_NOMMAP)
 		return;
 
-	tdb->file->map_ptr = mmap(NULL, tdb->file->map_size, tdb->mmap_flags,
-				  MAP_SHARED, tdb->file->fd, 0);
+	/* size_t can be smaller than off_t. */
+	if ((size_t)tdb->file->map_size == tdb->file->map_size) {
+		tdb->file->map_ptr = mmap(NULL, tdb->file->map_size,
+					  tdb->mmap_flags,
+					  MAP_SHARED, tdb->file->fd, 0);
+	} else
+		tdb->file->map_ptr = MAP_FAILED;
 
 	/*
 	 * NB. When mmap fails it returns MAP_FAILED *NOT* NULL !!!!
@@ -125,6 +130,7 @@ static enum TDB_ERROR tdb_oob(struct tdb_context *tdb, tdb_off_t len,
 /* Endian conversion: we only ever deal with 8 byte quantities */
 void *tdb_convert(const struct tdb_context *tdb, void *buf, tdb_len_t size)
 {
+	assert(size % 8 == 0);
 	if (unlikely((tdb->flags & TDB_CONVERT)) && buf) {
 		uint64_t i, *p = (uint64_t *)buf;
 		for (i = 0; i < size / 8; i++)
@@ -342,7 +348,7 @@ enum TDB_ERROR tdb_write_off(struct tdb_context *tdb,
 static void *_tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset,
 			     tdb_len_t len, unsigned int prefix)
 {
-	void *buf;
+	unsigned char *buf;
 	enum TDB_ERROR ecode;
 
 	/* some systems don't like zero length malloc */
@@ -439,7 +445,7 @@ static enum TDB_ERROR tdb_expand_file(struct tdb_context *tdb,
 const void *tdb_access_read(struct tdb_context *tdb,
 			    tdb_off_t off, tdb_len_t len, bool convert)
 {
-	const void *ret = NULL;
+	void *ret = NULL;
 
 	if (likely(!(tdb->flags & TDB_CONVERT))) {
 		ret = tdb->methods->direct(tdb, off, len, false);
@@ -563,10 +569,33 @@ static void *tdb_direct(struct tdb_context *tdb, tdb_off_t off, size_t len,
 	return (char *)tdb->file->map_ptr + off;
 }
 
-void add_stat_(struct tdb_context *tdb, uint64_t *s, size_t val)
+void tdb_inc_seqnum(struct tdb_context *tdb)
 {
-	if ((uintptr_t)s < (uintptr_t)tdb->stats + tdb->stats->size)
-		*s += val;
+	tdb_off_t seq;
+
+	if (likely(!(tdb->flags & TDB_CONVERT))) {
+		int64_t *direct;
+
+		direct = tdb->methods->direct(tdb,
+					      offsetof(struct tdb_header,
+						       seqnum),
+					      sizeof(*direct), true);
+		if (likely(direct)) {
+			/* Don't let it go negative, even briefly */
+			if (unlikely((*direct) + 1) < 0)
+				*direct = 0;
+			(*direct)++;
+			return;
+		}
+	}
+
+	seq = tdb_read_off(tdb, offsetof(struct tdb_header, seqnum));
+	if (!TDB_OFF_IS_ERR(seq)) {
+		seq++;
+		if (unlikely((int64_t)seq < 0))
+			seq = 0;
+		tdb_write_off(tdb, offsetof(struct tdb_header, seqnum), seq);
+	}
 }
 
 static const struct tdb_methods io_methods = {