X-Git-Url: http://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Ftdb2%2Fopen.c;h=02ec0eb68d7f4bf07702b26e2d16cc96e6345149;hb=bb2a75f445f408e43730fc55a1a978581ebe9b96;hp=3217a9b252ad7be2670733fc7b1930339f5b6968;hpb=c8c3b3568677e8b0105f84e4ab068c580faf4591;p=ccan

diff --git a/ccan/tdb2/open.c b/ccan/tdb2/open.c
index 3217a9b2..02ec0eb6 100644
--- a/ccan/tdb2/open.c
+++ b/ccan/tdb2/open.c
@@ -135,6 +135,7 @@ static enum TDB_ERROR tdb_new_database(struct tdb_context *tdb,
 	newdb.hdr.recovery = 0;
 	newdb.hdr.features_used = newdb.hdr.features_offered = TDB_FEATURE_MASK;
 	newdb.hdr.seqnum = 0;
+	newdb.hdr.capabilities = 0;
 	memset(newdb.hdr.reserved, 0, sizeof(newdb.hdr.reserved));
 	/* Initial hashes are empty. */
 	memset(newdb.hdr.hashtable, 0, sizeof(newdb.hdr.hashtable));
@@ -375,6 +376,54 @@ static bool is_tdb1(struct tdb1_header *hdr, const void *buf, ssize_t rlen)
 		|| hdr->version == TDB1_BYTEREV(TDB1_VERSION);
 }
 
+/* The top three bits of the capability tell us whether it matters. */
+enum TDB_ERROR unknown_capability(struct tdb_context *tdb, const char *caller,
+				  tdb_off_t type)
+{
+	if (type & TDB_CAP_NOOPEN) {
+		return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+				  "%s: file has unknown capability %llu",
+				  caller, type & TDB_CAP_NOOPEN);
+	}
+
+	if ((type & TDB_CAP_NOWRITE) && !(tdb->flags & TDB_RDONLY)) {
+		return tdb_logerr(tdb, TDB_ERR_RDONLY, TDB_LOG_ERROR,
+				  "%s: file has unknown capability %llu"
+				  " (cannot write to it)",
+				  caller, type & TDB_CAP_NOOPEN);
+	}
+
+	if (type & TDB_CAP_NOCHECK) {
+		tdb->flags |= TDB_CANT_CHECK;
+	}
+	return TDB_SUCCESS;
+}
+
+static enum TDB_ERROR capabilities_ok(struct tdb_context *tdb,
+				      tdb_off_t capabilities)
+{
+	tdb_off_t off, next;
+	enum TDB_ERROR ecode = TDB_SUCCESS;
+	const struct tdb_capability *cap;
+
+	/* Check capability list. */
+	for (off = capabilities; off && ecode == TDB_SUCCESS; off = next) {
+		cap = tdb_access_read(tdb, off, sizeof(*cap), true);
+		if (TDB_PTR_IS_ERR(cap)) {
+			return TDB_PTR_ERR(cap);
+		}
+
+		switch (cap->type & TDB_CAP_TYPE_MASK) {
+		/* We don't understand any capabilities (yet). */
+		default:
+			ecode = unknown_capability(tdb, "tdb_open", cap->type);
+		}
+		next = cap->next;
+		tdb_access_release(tdb, cap);
+	}
+	return ecode;
+}
+
 struct tdb_context *tdb_open(const char *name, int tdb_flags,
 			     int open_flags, mode_t mode,
 			     union tdb_attribute *attr)
@@ -388,6 +437,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 	struct tdb_header hdr;
 	struct tdb_attribute_seed *seed = NULL;
 	struct tdb_attribute_tdb1_hashsize *hsize_attr = NULL;
+	struct tdb_attribute_tdb1_max_dead *maxsize_attr = NULL;
 	tdb_bool_err berr;
 	enum TDB_ERROR ecode;
 	int openlock;
@@ -433,6 +483,9 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 		case TDB_ATTRIBUTE_TDB1_HASHSIZE:
 			hsize_attr = &attr->tdb1_hashsize;
 			break;
+		case TDB_ATTRIBUTE_TDB1_MAX_DEAD:
+			maxsize_attr = &attr->tdb1_max_dead;
+			break;
 		default:
 			/* These are set as normal. */
 			ecode = tdb_set_attribute(tdb, attr);
@@ -511,7 +564,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 		}
 		tdb->file->fd = -1;
 		if (tdb->flags & TDB_VERSION1)
-			ecode = tdb1_new_database(tdb, hsize_attr);
+			ecode = tdb1_new_database(tdb, hsize_attr, maxsize_attr);
 		else {
 			ecode = tdb_new_database(tdb, seed, &hdr);
 			if (ecode == TDB_SUCCESS) {
@@ -591,7 +644,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 	rlen = pread(tdb->file->fd, &hdr, sizeof(hdr), 0);
 	if (rlen == 0 && (open_flags & O_CREAT)) {
 		if (tdb->flags & TDB_VERSION1) {
-			ecode = tdb1_new_database(tdb, hsize_attr);
+			ecode = tdb1_new_database(tdb, hsize_attr, maxsize_attr);
 			if (ecode != TDB_SUCCESS)
 				goto fail;
 			goto finished;
@@ -608,7 +661,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 	} else if (rlen < sizeof(hdr)
 		   || strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0) {
 		if (is_tdb1(&tdb->tdb1.header, &hdr, rlen)) {
-			ecode = tdb1_open(tdb);
+			ecode = tdb1_open(tdb, maxsize_attr);
 			if (!ecode)
 				goto finished;
 			goto fail;
@@ -623,7 +676,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 			tdb->flags |= TDB_CONVERT;
 		else {
 			if (is_tdb1(&tdb->tdb1.header, &hdr, rlen)) {
-				ecode = tdb1_open(tdb);
+				ecode = tdb1_open(tdb, maxsize_attr);
 				if (!ecode)
 					goto finished;
 				goto fail;
@@ -643,12 +696,9 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 		goto fail;
 	}
 
+	/* This is a version2 tdb. */
 	if (tdb->flags & TDB_VERSION1) {
-		ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
-				   "tdb_open:"
-				   " %s does not need TDB_VERSION1",
-				   name);
-		goto fail;
+		tdb->flags &= ~TDB_VERSION1;
 	}
 
 	tdb2_context_init(tdb);
@@ -666,6 +716,11 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 		goto fail;
 	}
 
+	ecode = capabilities_ok(tdb, hdr.capabilities);
+	if (ecode != TDB_SUCCESS) {
+		goto fail;
+	}
+
 	/* Clear any features we don't understand. */
  	if ((open_flags & O_ACCMODE) != O_RDONLY) {
 		hdr.features_used &= TDB_FEATURE_MASK;
@@ -702,7 +757,7 @@ finished:
 		berr = tdb_needs_recovery(tdb);
 		if (unlikely(berr != false)) {
 			if (berr < 0) {
-				ecode = berr;
+				ecode = TDB_OFF_TO_ERR(berr);
 				goto fail;
 			}
 			ecode = tdb_lock_and_recover(tdb);
@@ -723,18 +778,18 @@ finished:
 
  fail:
 	/* Map ecode to some logical errno. */
-	switch (ecode) {
-	case TDB_ERR_CORRUPT:
-	case TDB_ERR_IO:
+	switch (TDB_ERR_TO_OFF(ecode)) {
+	case TDB_ERR_TO_OFF(TDB_ERR_CORRUPT):
+	case TDB_ERR_TO_OFF(TDB_ERR_IO):
 		saved_errno = EIO;
 		break;
-	case TDB_ERR_LOCK:
+	case TDB_ERR_TO_OFF(TDB_ERR_LOCK):
 		saved_errno = EWOULDBLOCK;
 		break;
-	case TDB_ERR_OOM:
+	case TDB_ERR_TO_OFF(TDB_ERR_OOM):
 		saved_errno = ENOMEM;
 		break;
-	case TDB_ERR_EINVAL:
+	case TDB_ERR_TO_OFF(TDB_ERR_EINVAL):
 		saved_errno = EINVAL;
 		break;
 	default: