X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb%2Ftraverse.c;h=c605c8e6a3b5b02344a662d492ad31f3497043cf;hp=4b3a316229c2059ef1977b9466b2d5d5fe34473d;hb=8458811a4126c22635b974718bfbf2876c893c37;hpb=bcf7916c5d694858766869dfd570e525127154a6

diff --git a/ccan/tdb/traverse.c b/ccan/tdb/traverse.c
index 4b3a3162..c605c8e6 100644
--- a/ccan/tdb/traverse.c
+++ b/ccan/tdb/traverse.c
@@ -27,16 +27,19 @@
 
 #include "tdb_private.h"
 
-/* Uses traverse lock: 0 = finish, -1 = error, other = record offset */
-static int tdb_next_lock(struct tdb_context *tdb, struct tdb_traverse_lock *tlock,
-			 struct list_struct *rec)
+#define TDB_NEXT_LOCK_ERR ((tdb_off_t)-1)
+
+/* Uses traverse lock: 0 = finish, TDB_NEXT_LOCK_ERR = error,
+   other = record offset */
+static tdb_off_t tdb_next_lock(struct tdb_context *tdb, struct tdb_traverse_lock *tlock,
+			 struct tdb_record *rec)
 {
 	int want_next = (tlock->off != 0);
 
 	/* Lock each chain from the start one. */
 	for (; tlock->hash < tdb->header.hash_size; tlock->hash++) {
 		if (!tlock->off && tlock->hash != 0) {
-			/* this is an optimisation for the common case where
+			/* this is an optimization for the common case where
 			   the hash chain is empty, which is particularly
 			   common for the use of tdb with ldb, where large
 			   hashes are used. In that case we spend most of our
@@ -50,7 +53,7 @@ static int tdb_next_lock(struct tdb_context *tdb, struct tdb_traverse_lock *tloc
 			   lock, so instead we get the lock and re-fetch the
 			   value below.
 			   
-			   Notice that not doing this optimisation on the
+			   Notice that not doing this optimization on the
 			   first hash chain is critical. We must guarantee
 			   that we have done at least one fcntl lock at the
 			   start of a search to guarantee that memory is
@@ -71,7 +74,7 @@ static int tdb_next_lock(struct tdb_context *tdb, struct tdb_traverse_lock *tloc
 		}
 
 		if (tdb_lock(tdb, tlock->hash, tlock->lock_rw) == -1)
-			return -1;
+			return TDB_NEXT_LOCK_ERR;
 
 		/* No previous record?  Start at top of chain. */
 		if (!tlock->off) {
@@ -99,6 +102,7 @@ static int tdb_next_lock(struct tdb_context *tdb, struct tdb_traverse_lock *tloc
 
 			/* Detect infinite loops. From "Shlomi Yaakobovich" <Shlomi@exanet.com>. */
 			if (tlock->off == rec->next) {
+				tdb->ecode = TDB_ERR_CORRUPT;
 				TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_next_lock: loop detected.\n"));
 				goto fail;
 			}
@@ -128,7 +132,7 @@ static int tdb_next_lock(struct tdb_context *tdb, struct tdb_traverse_lock *tloc
 	tlock->off = 0;
 	if (tdb_unlock(tdb, tlock->hash, tlock->lock_rw) != 0)
 		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_next_lock: On error unlock failed!\n"));
-	return -1;
+	return TDB_NEXT_LOCK_ERR;
 }
 
 /* traverse the entire database - calling fn(tdb, key, data) on each element.
@@ -141,8 +145,9 @@ static int tdb_traverse_internal(struct tdb_context *tdb,
 				 struct tdb_traverse_lock *tl)
 {
 	TDB_DATA key, dbuf;
-	struct list_struct rec;
-	int ret, count = 0;
+	struct tdb_record rec;
+	int ret = 0, count = 0;
+	tdb_off_t off;
 
 	/* This was in the initializaton, above, but the IRIX compiler
 	 * did not like it.  crh
@@ -153,7 +158,11 @@ static int tdb_traverse_internal(struct tdb_context *tdb,
 	tdb->travlocks.next = tl;
 
 	/* tdb_next_lock places locks on the record returned, and its chain */
-	while ((ret = tdb_next_lock(tdb, tl, &rec)) > 0) {
+	while ((off = tdb_next_lock(tdb, tl, &rec)) != 0) {
+		if (off == TDB_NEXT_LOCK_ERR) {
+			ret = -1;
+			goto out;
+		}
 		count++;
 		/* now read the full record */
 		key.dptr = tdb_alloc_read(tdb, tl->off + sizeof(rec), 
@@ -181,7 +190,6 @@ static int tdb_traverse_internal(struct tdb_context *tdb,
 		if (fn && fn(tdb, key, dbuf, private_data)) {
 			/* They want us to terminate traversal */
 			tdb_trace_ret(tdb, "tdb_traverse_end", count);
-			ret = count;
 			if (tdb_unlock_record(tdb, tl->off) != 0) {
 				TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_traverse: unlock_record failed!\n"));;
 				ret = -1;
@@ -221,7 +229,7 @@ int tdb_traverse_read(struct tdb_context *tdb,
 	ret = tdb_traverse_internal(tdb, fn, private_data, &tl);
 	tdb->traverse_read--;
 
-	tdb_transaction_unlock(tdb);
+	tdb_transaction_unlock(tdb, F_RDLCK);
 
 	return ret;
 }
@@ -252,7 +260,7 @@ int tdb_traverse(struct tdb_context *tdb,
 	ret = tdb_traverse_internal(tdb, fn, private_data, &tl);
 	tdb->traverse_write--;
 
-	tdb_transaction_unlock(tdb);
+	tdb_transaction_unlock(tdb, F_WRLCK);
 
 	return ret;
 }
@@ -262,7 +270,8 @@ int tdb_traverse(struct tdb_context *tdb,
 TDB_DATA tdb_firstkey(struct tdb_context *tdb)
 {
 	TDB_DATA key;
-	struct list_struct rec;
+	struct tdb_record rec;
+	tdb_off_t off;
 
 	/* release any old lock */
 	if (tdb_unlock_record(tdb, tdb->travlocks.off) != 0)
@@ -271,7 +280,8 @@ TDB_DATA tdb_firstkey(struct tdb_context *tdb)
 	tdb->travlocks.lock_rw = F_RDLCK;
 
 	/* Grab first record: locks chain and returned record. */
-	if (tdb_next_lock(tdb, &tdb->travlocks, &rec) <= 0) {
+	off = tdb_next_lock(tdb, &tdb->travlocks, &rec);
+	if (off == 0 || off == TDB_NEXT_LOCK_ERR) {
 		tdb_trace_retrec(tdb, "tdb_firstkey", tdb_null);
 		return tdb_null;
 	}
@@ -292,8 +302,9 @@ TDB_DATA tdb_nextkey(struct tdb_context *tdb, TDB_DATA oldkey)
 {
 	uint32_t oldhash;
 	TDB_DATA key = tdb_null;
-	struct list_struct rec;
+	struct tdb_record rec;
 	unsigned char *k = NULL;
+	tdb_off_t off;
 
 	/* Is locked key the old key?  If so, traverse will be reliable. */
 	if (tdb->travlocks.off) {
@@ -337,7 +348,8 @@ TDB_DATA tdb_nextkey(struct tdb_context *tdb, TDB_DATA oldkey)
 
 	/* Grab next record: locks chain and returned record,
 	   unlocks old record */
-	if (tdb_next_lock(tdb, &tdb->travlocks, &rec) > 0) {
+	off = tdb_next_lock(tdb, &tdb->travlocks, &rec);
+	if (off != TDB_NEXT_LOCK_ERR && off != 0) {
 		key.dsize = rec.key_len;
 		key.dptr = tdb_alloc_read(tdb, tdb->travlocks.off+sizeof(rec),
 					  key.dsize);