X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb2%2Flock.c;h=0b30af54c52bb77ac5a42e1318580114c7ec364a;hp=c7c449abc1a37091824563475b7aa7558f89e759;hb=4e185ad8ab5a7e01edbbe12d11eb2f1577de7e8b;hpb=9faf17435f1f5ce3c7046a738c45b60597838c03

diff --git a/ccan/tdb2/lock.c b/ccan/tdb2/lock.c
index c7c449ab..0b30af54 100644
--- a/ccan/tdb2/lock.c
+++ b/ccan/tdb2/lock.c
@@ -26,6 +26,8 @@
 */
 
 #include "private.h"
+#include <assert.h>
+#include <ccan/build_assert/build_assert.h>
 
 static int fcntl_lock(struct tdb_context *tdb,
 		      int rw, off_t off, off_t len, bool waitflag)
@@ -38,10 +40,13 @@ static int fcntl_lock(struct tdb_context *tdb,
 	fl.l_len = len;
 	fl.l_pid = 0;
 
+	add_stat(tdb, lock_lowlevel, 1);
 	if (waitflag)
 		return fcntl(tdb->fd, F_SETLKW, &fl);
-	else
+	else {
+		add_stat(tdb, lock_nonblock, 1);
 		return fcntl(tdb->fd, F_SETLK, &fl);
+	}
 }
 
 static int fcntl_unlock(struct tdb_context *tdb, int rw, off_t off, off_t len)
@@ -97,7 +102,7 @@ static int fcntl_unlock(struct tdb_context *tdb, int rw, off_t off, off_t len)
 	}
 
 	if (!found) {
-		fprintf(stderr, "Unlock on %u@%u not found!\n",
+		fprintf(stderr, "Unlock on %u@%u not found!",
 			(int)off, (int)len);
 		abort();
 	}
@@ -130,16 +135,16 @@ static int tdb_brlock(struct tdb_context *tdb,
 	}
 
 	if (rw_type == F_WRLCK && tdb->read_only) {
-		tdb->ecode = TDB_ERR_RDONLY;
+		tdb_logerr(tdb, TDB_ERR_RDONLY, TDB_DEBUG_WARNING,
+			   "Write lock attempted on read-only database");
 		return -1;
 	}
 
 	/* A 32 bit system cannot open a 64-bit file, but it could have
 	 * expanded since then: check here. */
 	if ((size_t)(offset + len) != offset + len) {
-		tdb->ecode = TDB_ERR_IO;
-		tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-			 "tdb_brlock: lock on giant offset %llu\n",
+		tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_ERROR,
+			 "tdb_brlock: lock on giant offset %llu",
 			 (long long)(offset + len));
 		return -1;
 	}
@@ -155,11 +160,12 @@ static int tdb_brlock(struct tdb_context *tdb,
 		 * EAGAIN is an expected return from non-blocking
 		 * locks. */
 		if (!(flags & TDB_LOCK_PROBE) && errno != EAGAIN) {
-			tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-				 "tdb_brlock failed (fd=%d) at"
-				 " offset %llu rw_type=%d flags=%d len=%llu\n",
-				 tdb->fd, (long long)offset, rw_type,
-				 flags, (long long)len);
+			tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_ERROR,
+				   "tdb_brlock failed (fd=%d) at"
+				   " offset %zu rw_type=%d flags=%d len=%zu:"
+				   " %s",
+				   tdb->fd, (size_t)offset, rw_type,
+				   flags, (size_t)len, strerror(errno));
 		}
 		return -1;
 	}
@@ -180,15 +186,14 @@ static int tdb_brunlock(struct tdb_context *tdb,
 	} while (ret == -1 && errno == EINTR);
 
 	if (ret == -1) {
-		tdb->log(tdb, TDB_DEBUG_TRACE, tdb->log_priv,
-			 "tdb_brunlock failed (fd=%d) at offset %llu"
-			 " rw_type=%d len=%llu\n",
-			 tdb->fd, (long long)offset, rw_type, (long long)len);
+		tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_TRACE,
+			   "tdb_brunlock failed (fd=%d) at offset %zu"
+			   " rw_type=%d len=%zu",
+			   tdb->fd, (size_t)offset, rw_type, (size_t)len);
 	}
 	return ret;
 }
 
-#if 0
 /*
   upgrade a read lock to a write lock. This needs to be handled in a
   special way as some OSes (such as solaris) have too conservative
@@ -200,23 +205,22 @@ int tdb_allrecord_upgrade(struct tdb_context *tdb)
 	int count = 1000;
 
 	if (tdb->allrecord_lock.count != 1) {
-		tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-			 "tdb_allrecord_upgrade failed: count %u too high\n",
-			 tdb->allrecord_lock.count);
+		tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_ERROR,
+			   "tdb_allrecord_upgrade failed: count %u too high",
+			   tdb->allrecord_lock.count);
 		return -1;
 	}
 
 	if (tdb->allrecord_lock.off != 1) {
-		tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-			 "tdb_allrecord_upgrade failed: already upgraded?\n");
+		tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_ERROR,
+			   "tdb_allrecord_upgrade failed: already upgraded?");
 		return -1;
 	}
 
 	while (count--) {
 		struct timeval tv;
 		if (tdb_brlock(tdb, F_WRLCK,
-			       TDB_HASH_LOCK_START
-			       + (1ULL << tdb->header.v.hash_bits), 0,
+			       TDB_HASH_LOCK_START, 0,
 			       TDB_LOCK_WAIT|TDB_LOCK_PROBE) == 0) {
 			tdb->allrecord_lock.ltype = F_WRLCK;
 			tdb->allrecord_lock.off = 0;
@@ -230,11 +234,10 @@ int tdb_allrecord_upgrade(struct tdb_context *tdb)
 		tv.tv_usec = 1;
 		select(0, NULL, NULL, NULL, &tv);
 	}
-	tdb->log(tdb, TDB_DEBUG_WARNING, tdb->log_priv,
-		 "tdb_allrecord_upgrade failed\n");
+	tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_WARNING,
+		   "tdb_allrecord_upgrade failed");
 	return -1;
 }
-#endif
 
 static struct tdb_lock_type *find_nestlock(struct tdb_context *tdb,
 					   tdb_off_t offset)
@@ -249,46 +252,73 @@ static struct tdb_lock_type *find_nestlock(struct tdb_context *tdb,
 	return NULL;
 }
 
+int tdb_lock_and_recover(struct tdb_context *tdb)
+{
+	int ret;
+
+	if (tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK,
+			       false) == -1) {
+		return -1;
+	}
+
+	if (tdb_lock_open(tdb, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK) == -1) {
+		tdb_allrecord_unlock(tdb, F_WRLCK);
+		return -1;
+	}
+	ret = tdb_transaction_recover(tdb);
+
+	tdb_unlock_open(tdb);
+	tdb_allrecord_unlock(tdb, F_WRLCK);
+
+	return ret;
+}
+
 /* lock an offset in the database. */
 static int tdb_nest_lock(struct tdb_context *tdb, tdb_off_t offset, int ltype,
 			 enum tdb_lock_flags flags)
 {
 	struct tdb_lock_type *new_lck;
 
-	/* Header is not valid for open lock; valgrind complains. */
-	if (offset >= TDB_HASH_LOCK_START) {
-		if (offset > TDB_HASH_LOCK_START
-		    + (1ULL << tdb->header.v.hash_bits)
-		    + (tdb->header.v.num_zones
-		       * (tdb->header.v.free_buckets+1))) {
-			tdb->ecode = TDB_ERR_LOCK;
-			tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
-				 "tdb_lock: invalid offset %llu ltype=%d\n",
-				 (long long)offset, ltype);
-			return -1;
-		}
+	if (offset > TDB_HASH_LOCK_START + TDB_HASH_LOCK_RANGE + tdb->map_size / 8) {
+		tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_FATAL,
+			   "tdb_nest_lock: invalid offset %zu ltype=%d",
+			   (size_t)offset, ltype);
+		return -1;
 	}
+
 	if (tdb->flags & TDB_NOLOCK)
 		return 0;
 
+	add_stat(tdb, locks, 1);
+
 	new_lck = find_nestlock(tdb, offset);
 	if (new_lck) {
-		/*
-		 * Just increment the in-memory struct, posix locks
-		 * don't stack.
-		 */
+		if (new_lck->ltype == F_RDLCK && ltype == F_WRLCK) {
+			tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_FATAL,
+				   "tdb_nest_lock: offset %zu has read lock",
+				   (size_t)offset);
+			return -1;
+		}
+		/* Just increment the struct, posix locks don't stack. */
 		new_lck->count++;
 		return 0;
 	}
 
+	if (tdb->num_lockrecs
+	    && offset >= TDB_HASH_LOCK_START
+	    && offset < TDB_HASH_LOCK_START + TDB_HASH_LOCK_RANGE) {
+		tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_FATAL,
+			   "tdb_nest_lock: already have a hash lock?");
+		return -1;
+	}
+
 	new_lck = (struct tdb_lock_type *)realloc(
 		tdb->lockrecs,
 		sizeof(*tdb->lockrecs) * (tdb->num_lockrecs+1));
 	if (new_lck == NULL) {
-		tdb->ecode = TDB_ERR_OOM;
-		tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-			 "tdb_lock: unable to allocate %llu lock structure",
-			 (long long)(tdb->num_lockrecs + 1));
+		tdb_logerr(tdb, TDB_ERR_OOM, TDB_DEBUG_ERROR,
+			 "tdb_nest_lock: unable to allocate %zu lock struct",
+			 tdb->num_lockrecs + 1);
 		errno = ENOMEM;
 		return -1;
 	}
@@ -300,6 +330,21 @@ static int tdb_nest_lock(struct tdb_context *tdb, tdb_off_t offset, int ltype,
 		return -1;
 	}
 
+	/* First time we grab a lock, perhaps someone died in commit? */
+	if (!(flags & TDB_LOCK_NOCHECK)
+	    && tdb->num_lockrecs == 0
+	    && unlikely(tdb_needs_recovery(tdb))) {
+		tdb_brunlock(tdb, ltype, offset, 1);
+
+		if (tdb_lock_and_recover(tdb) == -1) {
+			return -1;
+		}
+
+		if (tdb_brlock(tdb, ltype, offset, 1, flags)) {
+			return -1;
+		}
+	}
+
 	tdb->lockrecs[tdb->num_lockrecs].off = offset;
 	tdb->lockrecs[tdb->num_lockrecs].count = 1;
 	tdb->lockrecs[tdb->num_lockrecs].ltype = ltype;
@@ -308,40 +353,6 @@ static int tdb_nest_lock(struct tdb_context *tdb, tdb_off_t offset, int ltype,
 	return 0;
 }
 
-static int tdb_lock_and_recover(struct tdb_context *tdb)
-{
-#if 0 /* FIXME */
-
-	int ret;
-
-	/* We need to match locking order in transaction commit. */
-	if (tdb_brlock(tdb, F_WRLCK, FREELIST_TOP, 0, TDB_LOCK_WAIT)) {
-		return -1;
-	}
-
-	if (tdb_brlock(tdb, F_WRLCK, OPEN_LOCK, 1, TDB_LOCK_WAIT)) {
-		tdb_brunlock(tdb, F_WRLCK, FREELIST_TOP, 0);
-		return -1;
-	}
-
-	ret = tdb_transaction_recover(tdb);
-
-	tdb_brunlock(tdb, F_WRLCK, OPEN_LOCK, 1);
-	tdb_brunlock(tdb, F_WRLCK, FREELIST_TOP, 0);
-
-	return ret;
-#else
-	abort();
-	return -1;
-#endif
-}
-
-static bool tdb_needs_recovery(struct tdb_context *tdb)
-{
-	/* FIXME */
-	return false;
-}
-
 static int tdb_nest_unlock(struct tdb_context *tdb, tdb_off_t off, int ltype)
 {
 	int ret = -1;
@@ -352,9 +363,8 @@ static int tdb_nest_unlock(struct tdb_context *tdb, tdb_off_t off, int ltype)
 
 	lck = find_nestlock(tdb, off);
 	if ((lck == NULL) || (lck->count == 0)) {
-		tdb->ecode = TDB_ERR_LOCK;
-		tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-			 "tdb_unlock: no lock for %llu\n", (long long)off);
+		tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_ERROR,
+			   "tdb_nest_unlock: no lock for %zu", (size_t)off);
 		return -1;
 	}
 
@@ -377,22 +387,15 @@ static int tdb_nest_unlock(struct tdb_context *tdb, tdb_off_t off, int ltype)
 	 */
 	*lck = tdb->lockrecs[--tdb->num_lockrecs];
 
-	if (tdb->num_lockrecs == 0) {
-		/* If we're not holding any locks, header can change. */
-		tdb->header_uptodate = false;
-	}
-
 	return ret;
 }
 
-#if 0
 /*
   get the transaction lock
  */
-int tdb_transaction_lock(struct tdb_context *tdb, int ltype,
-			 enum tdb_lock_flags lockflags)
+int tdb_transaction_lock(struct tdb_context *tdb, int ltype)
 {
-	return tdb_nest_lock(tdb, TRANSACTION_LOCK, ltype, lockflags);
+	return tdb_nest_lock(tdb, TDB_TRANSACTION_LOCK, ltype, TDB_LOCK_WAIT);
 }
 
 /*
@@ -400,9 +403,8 @@ int tdb_transaction_lock(struct tdb_context *tdb, int ltype,
  */
 int tdb_transaction_unlock(struct tdb_context *tdb, int ltype)
 {
-	return tdb_nest_unlock(tdb, TRANSACTION_LOCK, ltype, false);
+	return tdb_nest_unlock(tdb, TDB_TRANSACTION_LOCK, ltype);
 }
-#endif
 
 /* We only need to lock individual bytes, but Linux merges consecutive locks
  * so we lock in contiguous ranges. */
@@ -413,8 +415,10 @@ static int tdb_lock_gradual(struct tdb_context *tdb,
 	int ret;
 	enum tdb_lock_flags nb_flags = (flags & ~TDB_LOCK_WAIT);
 
-	if (len <= 4) {
-		/* Single record.  Just do blocking lock. */
+	if (len <= 1) {
+		/* 0 would mean to end-of-file... */
+		assert(len != 0);
+		/* Single hash.  Just do blocking lock. */
 		return tdb_brlock(tdb, ltype, off, len, flags);
 	}
 
@@ -439,64 +443,67 @@ static int tdb_lock_gradual(struct tdb_context *tdb,
 }
 
 /* lock/unlock entire database.  It can only be upgradable if you have some
- * other way of guaranteeing exclusivity (ie. transaction write lock).
- * Note that we don't lock the free chains: noone can get those locks
- * without a hash chain lock first.
- * The header *will be* up to date once this returns success. */
+ * other way of guaranteeing exclusivity (ie. transaction write lock). */
 int tdb_allrecord_lock(struct tdb_context *tdb, int ltype,
 		       enum tdb_lock_flags flags, bool upgradable)
 {
-	tdb_off_t hash_size;
-
 	/* FIXME: There are no locks on read-only dbs */
 	if (tdb->read_only) {
-		tdb->ecode = TDB_ERR_LOCK;
-		tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-			 "tdb_allrecord_lock: read-only\n");
+		tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_ERROR,
+			   "tdb_allrecord_lock: read-only");
 		return -1;
 	}
 
-	if (tdb->allrecord_lock.count && tdb->allrecord_lock.ltype == ltype) {
+	if (tdb->allrecord_lock.count
+	    && (ltype == F_RDLCK || tdb->allrecord_lock.ltype == F_WRLCK)) {
 		tdb->allrecord_lock.count++;
 		return 0;
 	}
 
 	if (tdb->allrecord_lock.count) {
 		/* a global lock of a different type exists */
-		tdb->ecode = TDB_ERR_LOCK;
-		tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-			 "tdb_allrecord_lock: already have %s lock\n",
-			 tdb->allrecord_lock.ltype == F_RDLCK
-			 ? "read" : "write");
+		tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_ERROR,
+			   "tdb_allrecord_lock: already have %s lock",
+			   tdb->allrecord_lock.ltype == F_RDLCK
+			   ? "read" : "write");
 		return -1;
 	}
 
-	if (tdb_has_locks(tdb)) {
+	if (tdb_has_hash_locks(tdb)) {
 		/* can't combine global and chain locks */
-		tdb->ecode = TDB_ERR_LOCK;
-		tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-			 "tdb_allrecord_lock: already have chain lock\n");
+		tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_ERROR,
+			 "tdb_allrecord_lock: already have chain lock");
 		return -1;
 	}
 
 	if (upgradable && ltype != F_RDLCK) {
 		/* tdb error: you can't upgrade a write lock! */
-		tdb->ecode = TDB_ERR_LOCK;
-		tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-			 "tdb_allrecord_lock: can't upgrade a write lock\n");
+		tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_ERROR,
+			   "tdb_allrecord_lock: can't upgrade a write lock");
 		return -1;
 	}
 
-	/* Lock all the hash buckets. */
+	add_stat(tdb, locks, 1);
 again:
-	hash_size = (1ULL << tdb->header.v.hash_bits);
+	/* Lock hashes, gradually. */
 	if (tdb_lock_gradual(tdb, ltype, flags, TDB_HASH_LOCK_START,
-			     hash_size)) {
+			     TDB_HASH_LOCK_RANGE)) {
+		if (!(flags & TDB_LOCK_PROBE)) {
+			tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_ERROR,
+				   "tdb_allrecord_lock hashes failed");
+		}
+		return -1;
+	}
+
+	/* Lock free lists: there to end of file. */
+	if (tdb_brlock(tdb, ltype, TDB_HASH_LOCK_START + TDB_HASH_LOCK_RANGE,
+		       0, flags)) {
 		if (!(flags & TDB_LOCK_PROBE)) {
-			tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-				 "tdb_lockall hashes failed (%s)\n",
-				 strerror(errno));
+			tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_ERROR,
+				 "tdb_allrecord_lock freelist failed");
 		}
+		tdb_brunlock(tdb, ltype, TDB_HASH_LOCK_START, 
+			     TDB_HASH_LOCK_RANGE);
 		return -1;
 	}
 
@@ -506,14 +513,8 @@ again:
 	tdb->allrecord_lock.ltype = upgradable ? F_WRLCK : ltype;
 	tdb->allrecord_lock.off = upgradable;
 
-	/* Now we re-check header, holding lock. */
-	if (unlikely(header_changed(tdb))) {
-		tdb_allrecord_unlock(tdb, ltype);
-		goto again;
-	}
-
 	/* Now check for needing recovery. */
-	if (unlikely(tdb_needs_recovery(tdb))) {
+	if (!(flags & TDB_LOCK_NOCHECK) && unlikely(tdb_needs_recovery(tdb))) {
 		tdb_allrecord_unlock(tdb, ltype);
 		if (tdb_lock_and_recover(tdb) == -1) {
 			return -1;
@@ -524,9 +525,9 @@ again:
 	return 0;
 }
 
-int tdb_lock_open(struct tdb_context *tdb)
+int tdb_lock_open(struct tdb_context *tdb, enum tdb_lock_flags flags)
 {
-	return tdb_nest_lock(tdb, TDB_OPEN_LOCK, F_WRLCK, TDB_LOCK_WAIT);
+	return tdb_nest_lock(tdb, TDB_OPEN_LOCK, F_WRLCK, flags);
 }
 
 void tdb_unlock_open(struct tdb_context *tdb)
@@ -534,34 +535,39 @@ void tdb_unlock_open(struct tdb_context *tdb)
 	tdb_nest_unlock(tdb, TDB_OPEN_LOCK, F_WRLCK);
 }
 
-/* unlock entire db */
-int tdb_allrecord_unlock(struct tdb_context *tdb, int ltype)
+bool tdb_has_open_lock(struct tdb_context *tdb)
 {
-	tdb_off_t hash_size;
+	return find_nestlock(tdb, TDB_OPEN_LOCK) != NULL;
+}
 
-	/* FIXME: There are no locks on read-only dbs */
-	if (tdb->read_only) {
-		tdb->ecode = TDB_ERR_LOCK;
-		tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-			 "tdb_allrecord_unlock: read-only\n");
-		return -1;
-	}
+int tdb_lock_expand(struct tdb_context *tdb, int ltype)
+{
+	/* Lock doesn't protect data, so don't check (we recurse if we do!) */
+	return tdb_nest_lock(tdb, TDB_EXPANSION_LOCK, ltype,
+			     TDB_LOCK_WAIT | TDB_LOCK_NOCHECK);
+}
+
+void tdb_unlock_expand(struct tdb_context *tdb, int ltype)
+{
+	tdb_nest_unlock(tdb, TDB_EXPANSION_LOCK, ltype);
+}
 
+/* unlock entire db */
+int tdb_allrecord_unlock(struct tdb_context *tdb, int ltype)
+{
 	if (tdb->allrecord_lock.count == 0) {
-		tdb->ecode = TDB_ERR_LOCK;
-		tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-			 "tdb_allrecord_unlock: not locked!\n");
+		tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_ERROR,
+			   "tdb_allrecord_unlock: not locked!");
 		return -1;
 	}
 
 	/* Upgradable locks are marked as write locks. */
 	if (tdb->allrecord_lock.ltype != ltype
 	    && (!tdb->allrecord_lock.off || ltype != F_RDLCK)) {
-		tdb->ecode = TDB_ERR_LOCK;
-		tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-			 "tdb_allrecord_unlock: have %s lock\n",
-			 tdb->allrecord_lock.ltype == F_RDLCK
-			 ? "read" : "write");
+		tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_ERROR,
+			 "tdb_allrecord_unlock: have %s lock",
+			   tdb->allrecord_lock.ltype == F_RDLCK
+			   ? "read" : "write");
 		return -1;
 	}
 
@@ -572,296 +578,142 @@ int tdb_allrecord_unlock(struct tdb_context *tdb, int ltype)
 
 	tdb->allrecord_lock.count = 0;
 	tdb->allrecord_lock.ltype = 0;
-	tdb->header_uptodate = false;
-
-	hash_size = (1ULL << tdb->header.v.hash_bits);
 
-	return tdb_brunlock(tdb, ltype, TDB_HASH_LOCK_START, hash_size);
-}
-
-bool tdb_has_locks(struct tdb_context *tdb)
-{
-	return tdb->allrecord_lock.count || tdb->num_lockrecs;
-}
-
-#if 0
-/* lock entire database with write lock */
-int tdb_lockall(struct tdb_context *tdb)
-{
-	tdb_trace(tdb, "tdb_lockall");
-	return tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_WAIT, false);
+	return tdb_brunlock(tdb, ltype, TDB_HASH_LOCK_START, 0);
 }
 
-/* lock entire database with write lock - nonblocking varient */
-int tdb_lockall_nonblock(struct tdb_context *tdb)
+bool tdb_has_expansion_lock(struct tdb_context *tdb)
 {
-	int ret = tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_NOWAIT, false);
-	tdb_trace_ret(tdb, "tdb_lockall_nonblock", ret);
-	return ret;
+	return find_nestlock(tdb, TDB_EXPANSION_LOCK) != NULL;
 }
 
-/* unlock entire database with write lock */
-int tdb_unlockall(struct tdb_context *tdb)
+bool tdb_has_hash_locks(struct tdb_context *tdb)
 {
-	tdb_trace(tdb, "tdb_unlockall");
-	return tdb_allrecord_unlock(tdb, F_WRLCK);
-}
+	unsigned int i;
 
-/* lock entire database with read lock */
-int tdb_lockall_read(struct tdb_context *tdb)
-{
-	tdb_trace(tdb, "tdb_lockall_read");
-	return tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, false);
+	for (i=0; i<tdb->num_lockrecs; i++) {
+		if (tdb->lockrecs[i].off >= TDB_HASH_LOCK_START
+		    && tdb->lockrecs[i].off < (TDB_HASH_LOCK_START
+					       + TDB_HASH_LOCK_RANGE))
+			return true;
+	}
+	return false;
 }
 
-/* lock entire database with read lock - nonblock varient */
-int tdb_lockall_read_nonblock(struct tdb_context *tdb)
+static bool tdb_has_free_lock(struct tdb_context *tdb)
 {
-	int ret = tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_NOWAIT, false);
-	tdb_trace_ret(tdb, "tdb_lockall_read_nonblock", ret);
-	return ret;
-}
+	unsigned int i;
 
-/* unlock entire database with read lock */
-int tdb_unlockall_read(struct tdb_context *tdb)
-{
-	tdb_trace(tdb, "tdb_unlockall_read");
-	return tdb_allrecord_unlock(tdb, F_RDLCK);
+	for (i=0; i<tdb->num_lockrecs; i++) {
+		if (tdb->lockrecs[i].off
+		    > TDB_HASH_LOCK_START + TDB_HASH_LOCK_RANGE)
+			return true;
+	}
+	return false;
 }
-#endif
 
-/* Returns the list we actually locked. */
-tdb_off_t tdb_lock_list(struct tdb_context *tdb, uint64_t hash,
-			int ltype, enum tdb_lock_flags waitflag)
+int tdb_lock_hashes(struct tdb_context *tdb,
+		    tdb_off_t hash_lock,
+		    tdb_len_t hash_range,
+		    int ltype, enum tdb_lock_flags waitflag)
 {
-	tdb_off_t list = hash & ((1ULL << tdb->header.v.hash_bits) - 1);
-	/* Header can change ONLY if we had no locks before. */
-	bool can_change = tdb->num_lockrecs == 0;
+	/* FIXME: Do this properly, using hlock_range */
+	unsigned lock = TDB_HASH_LOCK_START
+		+ (hash_lock >> (64 - TDB_HASH_LOCK_RANGE_BITS));
 
 	/* a allrecord lock allows us to avoid per chain locks */
 	if (tdb->allrecord_lock.count &&
 	    (ltype == tdb->allrecord_lock.ltype || ltype == F_RDLCK)) {
-		return list;
+		return 0;
 	}
 
 	if (tdb->allrecord_lock.count) {
-		tdb->ecode = TDB_ERR_LOCK;
-		tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
-			 "tdb_lock_list: have %s allrecordlock\n",
-			 tdb->allrecord_lock.ltype == F_RDLCK
-			 ? "read" : "write");
-		return TDB_OFF_ERR;
+		tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_ERROR,
+			   "tdb_lock_hashes: already have %s allrecordlock",
+			   tdb->allrecord_lock.ltype == F_RDLCK
+			   ? "read" : "write");
+		return -1;
 	}
 
-again:
-	if (tdb_nest_lock(tdb, TDB_HASH_LOCK_START + list, ltype, waitflag))
-		return TDB_OFF_ERR;
-
-	if (can_change && unlikely(header_changed(tdb))) {
-		tdb_off_t new = hash & ((1ULL << tdb->header.v.hash_bits) - 1);
-		if (new != list) {
-			tdb_nest_unlock(tdb, TDB_HASH_LOCK_START+list, ltype);
-			list = new;
-			goto again;
-		}
+	if (tdb_has_free_lock(tdb)) {
+		tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_ERROR,
+			   "tdb_lock_hashes: already have free lock");
+		return -1;
+	}
+
+	if (tdb_has_expansion_lock(tdb)) {
+		tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_ERROR,
+			   "tdb_lock_hashes: already have expansion lock");
+		return -1;
 	}
-	return list;
+
+	return tdb_nest_lock(tdb, lock, ltype, waitflag);
 }
 
-int tdb_unlock_list(struct tdb_context *tdb, tdb_off_t list, int ltype)
+int tdb_unlock_hashes(struct tdb_context *tdb,
+		      tdb_off_t hash_lock,
+		      tdb_len_t hash_range, int ltype)
 {
-	list &= ((1ULL << tdb->header.v.hash_bits) - 1);
+	unsigned lock = TDB_HASH_LOCK_START
+		+ (hash_lock >> (64 - TDB_HASH_LOCK_RANGE_BITS));
 
 	/* a allrecord lock allows us to avoid per chain locks */
 	if (tdb->allrecord_lock.count) {
 		if (tdb->allrecord_lock.ltype == F_RDLCK
 		    && ltype == F_WRLCK) {
-			tdb->ecode = TDB_ERR_LOCK;
-			tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
-				 "tdb_unlock_list RO allrecord!\n");
+			tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_FATAL,
+				   "tdb_unlock_hashes RO allrecord!");
 			return -1;
 		}
 		return 0;
-	} else {
-		return tdb_nest_unlock(tdb, TDB_HASH_LOCK_START + list, ltype);
 	}
-}
 
-/* Free list locks come after hash locks */
-int tdb_lock_free_list(struct tdb_context *tdb, tdb_off_t flist,
-		       enum tdb_lock_flags waitflag)
-{
-	/* You're supposed to have a hash lock first! */
-	if (!(tdb->flags & TDB_NOLOCK) && !tdb_has_locks(tdb)) {
-		tdb->ecode = TDB_ERR_LOCK;
-		tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
-			 "tdb_lock_free_list without lock!\n");
-		return -1;
-	}
-
-	/* a allrecord lock allows us to avoid per chain locks */
-	if (tdb->allrecord_lock.count) {
-		if (tdb->allrecord_lock.ltype == F_WRLCK)
-			return 0;
-		tdb->ecode = TDB_ERR_LOCK;
-		tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
-			 "tdb_lock_free_list with RO allrecordlock!\n");
-		return -1;
-	}
-
-	return tdb_nest_lock(tdb, TDB_HASH_LOCK_START
-			     + (1ULL << tdb->header.v.hash_bits)
-			     + flist, F_WRLCK, waitflag);
-}
-
-void tdb_unlock_free_list(struct tdb_context *tdb, tdb_off_t flist)
-{
-	if (tdb->allrecord_lock.count)
-		return;
-
-	tdb_nest_unlock(tdb, TDB_HASH_LOCK_START
-			+ (1ULL << tdb->header.v.hash_bits)
-			+ flist, F_WRLCK);
-}
-
-/* Even if the entry isn't in this hash bucket, you'd have to lock this
- * bucket to find it. */
-static int chainlock(struct tdb_context *tdb, const TDB_DATA *key,
-		     int ltype, enum tdb_lock_flags waitflag,
-		     const char *func)
-{
-	int ret;
-	uint64_t h = tdb_hash(tdb, key->dptr, key->dsize);
-
-	ret = tdb_lock_list(tdb, h, ltype, waitflag) == TDB_OFF_ERR ? -1 : 0;
-	tdb_trace_1rec(tdb, func, *key);
-	return ret;
+	return tdb_nest_unlock(tdb, lock, ltype);
 }
 
-/* lock/unlock one hash chain. This is meant to be used to reduce
-   contention - it cannot guarantee how many records will be locked */
-int tdb_chainlock(struct tdb_context *tdb, TDB_DATA key)
-{
-	return chainlock(tdb, &key, F_WRLCK, TDB_LOCK_WAIT, "tdb_chainlock");
-}
-
-int tdb_chainunlock(struct tdb_context *tdb, TDB_DATA key)
-{
-	uint64_t h = tdb_hash(tdb, key.dptr, key.dsize);
-	tdb_trace_1rec(tdb, "tdb_chainunlock", key);
-	return tdb_unlock_list(tdb, h, F_WRLCK);
-}
-
-#if 0
-/* lock/unlock one hash chain, non-blocking. This is meant to be used
-   to reduce contention - it cannot guarantee how many records will be
-   locked */
-int tdb_chainlock_nonblock(struct tdb_context *tdb, TDB_DATA key)
-{
-	return chainlock(tdb, &key, F_WRLCK, TDB_LOCK_NOWAIT,
-			 "tdb_chainlock_nonblock");
-}
-
-int tdb_chainlock_read(struct tdb_context *tdb, TDB_DATA key)
+/* Hash locks use TDB_HASH_LOCK_START + the next 30 bits.
+ * Then we begin; bucket offsets are sizeof(tdb_len_t) apart, so we divide.
+ * The result is that on 32 bit systems we don't use lock values > 2^31 on
+ * files that are less than 4GB.
+ */
+static tdb_off_t free_lock_off(tdb_off_t b_off)
 {
-	return chainlock(tdb, &key, F_RDLCK, TDB_LOCK_WAIT,
-			 "tdb_chainlock_read");
+	return TDB_HASH_LOCK_START + TDB_HASH_LOCK_RANGE
+		+ b_off / sizeof(tdb_off_t);
 }
 
-int tdb_chainunlock_read(struct tdb_context *tdb, TDB_DATA key)
+int tdb_lock_free_bucket(struct tdb_context *tdb, tdb_off_t b_off,
+			 enum tdb_lock_flags waitflag)
 {
-	uint64_t h = tdb_hash(tdb, key.dptr, key.dsize);
-	tdb_trace_1rec(tdb, "tdb_chainunlock_read", key);
-	return tdb_unlock_list(tdb, h & ((1ULL << tdb->header.v.hash_bits)-1),
-			       F_RDLCK);
-}
+	assert(b_off >= sizeof(struct tdb_header));
 
-/* record lock stops delete underneath */
-int tdb_lock_record(struct tdb_context *tdb, tdb_off_t off)
-{
-	if (tdb->allrecord_lock.count) {
-		return 0;
-	}
-	return off ? tdb_brlock(tdb, F_RDLCK, off, 1, TDB_LOCK_WAIT) : 0;
-}
-
-/*
-  Write locks override our own fcntl readlocks, so check it here.
-  Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not
-  an error to fail to get the lock here.
-*/
-int tdb_write_lock_record(struct tdb_context *tdb, tdb_off_t off)
-{
-	struct tdb_traverse_lock *i;
-	for (i = &tdb->travlocks; i; i = i->next)
-		if (i->off == off)
-			return -1;
+	/* a allrecord lock allows us to avoid per chain locks */
 	if (tdb->allrecord_lock.count) {
-		if (tdb->allrecord_lock.ltype == F_WRLCK) {
+		if (tdb->allrecord_lock.ltype == F_WRLCK)
 			return 0;
-		}
+		tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_FATAL,
+			 "tdb_lock_free_bucket with RO allrecordlock!");
 		return -1;
 	}
-	return tdb_brlock(tdb, F_WRLCK, off, 1, TDB_LOCK_NOWAIT|TDB_LOCK_PROBE);
-}
-
-int tdb_write_unlock_record(struct tdb_context *tdb, tdb_off_t off)
-{
-	if (tdb->allrecord_lock.count) {
-		return 0;
-	}
-	return tdb_brunlock(tdb, F_WRLCK, off, 1);
-}
 
-/* fcntl locks don't stack: avoid unlocking someone else's */
-int tdb_unlock_record(struct tdb_context *tdb, tdb_off_t off)
-{
-	struct tdb_traverse_lock *i;
-	uint32_t count = 0;
-
-	if (tdb->allrecord_lock.count) {
-		return 0;
+#if 0 /* FIXME */
+	if (tdb_has_expansion_lock(tdb)) {
+		tdb_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_ERROR,
+			   "tdb_lock_free_bucket: already have expansion lock");
+		return -1;
 	}
+#endif
 
-	if (off == 0)
-		return 0;
-	for (i = &tdb->travlocks; i; i = i->next)
-		if (i->off == off)
-			count++;
-	return (count == 1 ? tdb_brunlock(tdb, F_RDLCK, off, 1) : 0);
+	return tdb_nest_lock(tdb, free_lock_off(b_off), F_WRLCK, waitflag);
 }
 
-/* The transaction code uses this to remove all locks. */
-void tdb_release_transaction_locks(struct tdb_context *tdb)
+void tdb_unlock_free_bucket(struct tdb_context *tdb, tdb_off_t b_off)
 {
-	unsigned int i;
-
-	if (tdb->allrecord_lock.count != 0) {
-		tdb_off_t hash_size, free_size;
-
-		hash_size = (1ULL << tdb->header.v.hash_bits)
-			* sizeof(tdb_off_t);
-		free_size = tdb->header.v.free_zones 
-			* (tdb->header.v.free_buckets + 1) * sizeof(tdb_off_t);
-
-		tdb_brunlock(tdb, tdb->allrecord_lock.ltype,
-			     tdb->header.v.hash_off, hash_size);
-		tdb_brunlock(tdb, tdb->allrecord_lock.ltype,
-			     tdb->header.v.free_off, free_size);
-		tdb->allrecord_lock.count = 0;
-		tdb->allrecord_lock.ltype = 0;
-	}
-
-	for (i = 0; i<tdb->num_lockrecs; i++) {
-		struct tdb_lock_type *lck = &tdb->lockrecs[i];
+	if (tdb->allrecord_lock.count)
+		return;
 
-		tdb_brunlock(tdb, lck->ltype, lck->off, 1);
-	}
-	tdb->num_lockrecs = 0;
-	SAFE_FREE(tdb->lockrecs);
-	tdb->header_uptodate = false;
+	tdb_nest_unlock(tdb, free_lock_off(b_off), F_WRLCK);
 }
-#endif
 
 void tdb_lock_init(struct tdb_context *tdb)
 {