tdb: don't use 'private' in headers.

[ccan] / ccan / tdb / lock.c

diff --git a/ccan/tdb/lock.c b/ccan/tdb/lock.c
index 3013b06af6ec855477b0991422a2948bf7b69359..dfcac7a540adc30482dcd86e0c299b36bfb52e0b 100644 (file)
--- a/ccan/tdb/lock.c
+++ b/ccan/tdb/lock.c
@@ -119,6 +119,12 @@ static int fcntl_unlock(struct tdb_context *tdb, int rw, off_t off, off_t len)
        return fcntl(tdb->fd, F_SETLKW, &fl);
 }
 
        return fcntl(tdb->fd, F_SETLKW, &fl);
 }
 

+/* list -1 is the alloc list, otherwise a hash chain. */
+static tdb_off_t lock_offset(int list)
+{
+       return FREELIST_TOP + 4*list;
+}
+

 /* a byte range locking function - return 0 on success
    this functions locks/unlocks 1 byte at the specified offset.
 
 /* a byte range locking function - return 0 on success
    this functions locks/unlocks 1 byte at the specified offset.
 


@@ -197,13 +203,29 @@ int tdb_brunlock(struct tdb_context *tdb,
   deadlock detection and claim a deadlock when progress can be
   made. For those OSes we may loop for a while.  
 */
   deadlock detection and claim a deadlock when progress can be
   made. For those OSes we may loop for a while.  
 */

-int tdb_brlock_upgrade(struct tdb_context *tdb, tdb_off_t offset, size_t len)
+int tdb_allrecord_upgrade(struct tdb_context *tdb)

 {
        int count = 1000;
 {
        int count = 1000;

+
+       if (tdb->allrecord_lock.count != 1) {
+               TDB_LOG((tdb, TDB_DEBUG_ERROR,
+                        "tdb_allrecord_upgrade failed: count %u too high\n",
+                        tdb->allrecord_lock.count));
+               return -1;
+       }
+
+       if (tdb->allrecord_lock.off != 1) {
+               TDB_LOG((tdb, TDB_DEBUG_ERROR,
+                        "tdb_allrecord_upgrade failed: already upgraded?\n"));
+               return -1;
+       }
+

        while (count--) {
                struct timeval tv;
        while (count--) {
                struct timeval tv;

-               if (tdb_brlock(tdb, F_WRLCK, offset, len,
+               if (tdb_brlock(tdb, F_WRLCK, FREELIST_TOP, 0,

                               TDB_LOCK_WAIT|TDB_LOCK_PROBE) == 0) {
                               TDB_LOCK_WAIT|TDB_LOCK_PROBE) == 0) {

+                       tdb->allrecord_lock.ltype = F_WRLCK;
+                       tdb->allrecord_lock.off = 0;

                        return 0;
                }
                if (errno != EDEADLK) {
                        return 0;
                }
                if (errno != EDEADLK) {


@@ -214,14 +236,21 @@ int tdb_brlock_upgrade(struct tdb_context *tdb, tdb_off_t offset, size_t len)
                tv.tv_usec = 1;
                select(0, NULL, NULL, NULL, &tv);
        }
                tv.tv_usec = 1;
                select(0, NULL, NULL, NULL, &tv);
        }

-       TDB_LOG((tdb, TDB_DEBUG_TRACE,"tdb_brlock_upgrade failed at offset %d\n", offset));
+       TDB_LOG((tdb, TDB_DEBUG_TRACE,"tdb_allrecord_upgrade failed\n"));

        return -1;
 }
 
        return -1;
 }
 

-/* list -1 is the alloc list, otherwise a hash chain. */
-static tdb_off_t lock_offset(int list)
+static struct tdb_lock_type *find_nestlock(struct tdb_context *tdb,
+                                          tdb_off_t offset)

 {
 {

-       return FREELIST_TOP + 4*list;
+       unsigned int i;
+
+       for (i=0; i<tdb->num_lockrecs; i++) {
+               if (tdb->lockrecs[i].off == offset) {
+                       return &tdb->lockrecs[i];
+               }
+       }
+       return NULL;

 }
 
 /* lock an offset in the database. */
 }
 
 /* lock an offset in the database. */


@@ -229,7 +258,6 @@ int tdb_nest_lock(struct tdb_context *tdb, uint32_t offset, int ltype,
                  enum tdb_lock_flags flags)
 {
        struct tdb_lock_type *new_lck;
                  enum tdb_lock_flags flags)
 {
        struct tdb_lock_type *new_lck;

-       int i;

 
        if (offset >= lock_offset(tdb->header.hash_size)) {
                tdb->ecode = TDB_ERR_LOCK;
 
        if (offset >= lock_offset(tdb->header.hash_size)) {
                tdb->ecode = TDB_ERR_LOCK;


@@ -240,24 +268,14 @@ int tdb_nest_lock(struct tdb_context *tdb, uint32_t offset, int ltype,
        if (tdb->flags & TDB_NOLOCK)
                return 0;
 
        if (tdb->flags & TDB_NOLOCK)
                return 0;
 

-       for (i=0; i<tdb->num_lockrecs; i++) {
-               if (tdb->lockrecs[i].off == offset) {
-                       if (tdb->lockrecs[i].count == 0) {
-                               /*
-                                * Can't happen, see tdb_unlock(). It should
-                                * be an assert.
-                                */
-                               TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_lock: "
-                                        "lck->count == 0 for offset %u",
-                                        offset));
-                       }
-                       /*
-                        * Just increment the in-memory struct, posix locks
-                        * don't stack.
-                        */
-                       tdb->lockrecs[i].count++;
-                       return 0;
-               }
+       new_lck = find_nestlock(tdb, offset);
+       if (new_lck) {
+               /*
+                * Just increment the in-memory struct, posix locks
+                * don't stack.
+                */
+               new_lck->count++;
+               return 0;

        }
 
        new_lck = (struct tdb_lock_type *)realloc(
        }
 
        new_lck = (struct tdb_lock_type *)realloc(


@@ -271,24 +289,56 @@ int tdb_nest_lock(struct tdb_context *tdb, uint32_t offset, int ltype,
 
        /* Since fcntl locks don't nest, we do a lock for the first one,
           and simply bump the count for future ones */
 
        /* Since fcntl locks don't nest, we do a lock for the first one,
           and simply bump the count for future ones */

-       if (tdb->methods->brlock(tdb, ltype, offset, 1, flags)) {
+       if (tdb_brlock(tdb, ltype, offset, 1, flags)) {

                return -1;
        }
 
                return -1;
        }
 

-       tdb->num_locks++;
-

        tdb->lockrecs[tdb->num_lockrecs].off = offset;
        tdb->lockrecs[tdb->num_lockrecs].count = 1;
        tdb->lockrecs[tdb->num_lockrecs].ltype = ltype;
        tdb->lockrecs[tdb->num_lockrecs].off = offset;
        tdb->lockrecs[tdb->num_lockrecs].count = 1;
        tdb->lockrecs[tdb->num_lockrecs].ltype = ltype;

-       tdb->num_lockrecs += 1;
+       tdb->num_lockrecs++;

 
        return 0;
 }
 
 
        return 0;
 }
 

-/* lock a list in the database. list -1 is the alloc list */
-int tdb_lock(struct tdb_context *tdb, int list, int ltype)
+static int tdb_lock_and_recover(struct tdb_context *tdb)
+{
+       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;
+}
+
+static bool have_data_locks(const struct tdb_context *tdb)
+{
+       unsigned int i;
+
+       for (i = 0; i < tdb->num_lockrecs; i++) {
+               if (tdb->lockrecs[i].off >= lock_offset(-1))
+                       return true;
+       }
+       return false;
+}
+
+static int tdb_lock_list(struct tdb_context *tdb, int list, int ltype,
+                        enum tdb_lock_flags waitflag)

 {
        int ret;
 {
        int ret;

+       bool check = false;

 
        /* a allrecord lock allows us to avoid per chain locks */
        if (tdb->allrecord_lock.count &&
 
        /* a allrecord lock allows us to avoid per chain locks */
        if (tdb->allrecord_lock.count &&


@@ -300,9 +350,28 @@ int tdb_lock(struct tdb_context *tdb, int list, int ltype)
                tdb->ecode = TDB_ERR_LOCK;
                ret = -1;
        } else {
                tdb->ecode = TDB_ERR_LOCK;
                ret = -1;
        } else {

-               ret = tdb_nest_lock(tdb, lock_offset(list), ltype,
-                                   TDB_LOCK_WAIT);
+               /* Only check when we grab first data lock. */
+               check = !have_data_locks(tdb);
+               ret = tdb_nest_lock(tdb, lock_offset(list), ltype, waitflag);
+
+               if (ret == 0 && check && tdb_needs_recovery(tdb)) {
+                       tdb_nest_unlock(tdb, lock_offset(list), ltype, false);
+
+                       if (tdb_lock_and_recover(tdb) == -1) {
+                               return -1;
+                       }
+                       return tdb_lock_list(tdb, list, ltype, waitflag);
+               }

        }
        }

+       return ret;
+}
+
+/* lock a list in the database. list -1 is the alloc list */
+int tdb_lock(struct tdb_context *tdb, int list, int ltype)
+{
+       int ret;
+
+       ret = tdb_lock_list(tdb, list, ltype, TDB_LOCK_WAIT);

        if (ret) {
                TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_lock failed on list %d "
                         "ltype=%d (%s)\n",  list, ltype, strerror(errno)));
        if (ret) {
                TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_lock failed on list %d "
                         "ltype=%d (%s)\n",  list, ltype, strerror(errno)));


@@ -313,18 +382,7 @@ int tdb_lock(struct tdb_context *tdb, int list, int ltype)
 /* lock a list in the database. list -1 is the alloc list. non-blocking lock */
 int tdb_lock_nonblock(struct tdb_context *tdb, int list, int ltype)
 {
 /* lock a list in the database. list -1 is the alloc list. non-blocking lock */
 int tdb_lock_nonblock(struct tdb_context *tdb, int list, int ltype)
 {

-       /* a allrecord lock allows us to avoid per chain locks */
-       if (tdb->allrecord_lock.count &&
-           (ltype == tdb->allrecord_lock.ltype || ltype == F_RDLCK)) {
-               return 0;
-       }
-
-       if (tdb->allrecord_lock.count) {
-               tdb->ecode = TDB_ERR_LOCK;
-               return -1;
-       }
-
-       return tdb_nest_lock(tdb, lock_offset(list), ltype, TDB_LOCK_NOWAIT);
+       return tdb_lock_list(tdb, list, ltype, TDB_LOCK_NOWAIT);

 }
 
 
 }
 
 


@@ -332,8 +390,7 @@ int tdb_nest_unlock(struct tdb_context *tdb, uint32_t offset, int ltype,
                    bool mark_lock)
 {
        int ret = -1;
                    bool mark_lock)
 {
        int ret = -1;

-       int i;
-       struct tdb_lock_type *lck = NULL;
+       struct tdb_lock_type *lck;

 
        if (tdb->flags & TDB_NOLOCK)
                return 0;
 
        if (tdb->flags & TDB_NOLOCK)
                return 0;


@@ -344,13 +401,7 @@ int tdb_nest_unlock(struct tdb_context *tdb, uint32_t offset, int ltype,
                return ret;
        }
 
                return ret;
        }
 

-       for (i=0; i<tdb->num_lockrecs; i++) {
-               if (tdb->lockrecs[i].off == offset) {
-                       lck = &tdb->lockrecs[i];
-                       break;
-               }
-       }
-
+       lck = find_nestlock(tdb, offset);

        if ((lck == NULL) || (lck->count == 0)) {
                TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlock: count is 0\n"));
                return -1;
        if ((lck == NULL) || (lck->count == 0)) {
                TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlock: count is 0\n"));
                return -1;


@@ -371,19 +422,14 @@ int tdb_nest_unlock(struct tdb_context *tdb, uint32_t offset, int ltype,
        if (mark_lock) {
                ret = 0;
        } else {
        if (mark_lock) {
                ret = 0;
        } else {

-               ret = tdb->methods->brunlock(tdb, ltype, offset, 1);
+               ret = tdb_brunlock(tdb, ltype, offset, 1);

        }
        }

-       tdb->num_locks--;

 
        /*
         * Shrink the array by overwriting the element just unlocked with the
         * last array element.
         */
 
        /*
         * Shrink the array by overwriting the element just unlocked with the
         * last array element.
         */

-
-       if (tdb->num_lockrecs > 1) {
-               *lck = tdb->lockrecs[tdb->num_lockrecs-1];
-       }
-       tdb->num_lockrecs -= 1;
+       *lck = tdb->lockrecs[--tdb->num_lockrecs];

 
        /*
         * We don't bother with realloc when the array shrinks, but if we have
 
        /*
         * We don't bother with realloc when the array shrinks, but if we have


@@ -420,18 +466,7 @@ int tdb_unlock(struct tdb_context *tdb, int list, int ltype)
  */
 int tdb_transaction_lock(struct tdb_context *tdb, int ltype)
 {
  */
 int tdb_transaction_lock(struct tdb_context *tdb, int ltype)
 {

-       if (tdb->transaction_lock_count > 0) {
-               tdb->transaction_lock_count++;
-               return 0;
-       }
-
-       if (tdb->methods->brlock(tdb, ltype, TRANSACTION_LOCK, 1, TDB_LOCK_WAIT) == -1) {
-               TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_lock: failed to get transaction lock\n"));
-               tdb->ecode = TDB_ERR_LOCK;
-               return -1;
-       }
-       tdb->transaction_lock_count++;
-       return 0;
+       return tdb_nest_lock(tdb, TRANSACTION_LOCK, ltype, TDB_LOCK_WAIT);

 }
 
 /*
 }
 
 /*


@@ -439,24 +474,12 @@ int tdb_transaction_lock(struct tdb_context *tdb, int ltype)
  */
 int tdb_transaction_unlock(struct tdb_context *tdb, int ltype)
 {
  */
 int tdb_transaction_unlock(struct tdb_context *tdb, int ltype)
 {

-       int ret;
-       if (tdb->transaction_lock_count > 1) {
-               tdb->transaction_lock_count--;
-               return 0;
-       }
-       ret = tdb->methods->brunlock(tdb, ltype, TRANSACTION_LOCK, 1);
-       if (ret == 0) {
-               tdb->transaction_lock_count = 0;
-       }
-       return ret;
+       return tdb_nest_unlock(tdb, TRANSACTION_LOCK, ltype, false);

 }
 
 }
 

-
-
-
-/* lock/unlock entire database */
-static int _tdb_lockall(struct tdb_context *tdb, int ltype,
-                       enum tdb_lock_flags flags)
+/* Returns 0 if all done, -1 if error, 1 if ok. */
+static int tdb_allrecord_check(struct tdb_context *tdb, int ltype,
+                              enum tdb_lock_flags flags, bool upgradable)

 {
        /* There are no locks on read-only dbs */
        if (tdb->read_only || tdb->traverse_read) {
 {
        /* There are no locks on read-only dbs */
        if (tdb->read_only || tdb->traverse_read) {


@@ -481,17 +504,101 @@ static int _tdb_lockall(struct tdb_context *tdb, int ltype,
                return -1;
        }
 
                return -1;
        }
 

-       if (tdb->methods->brlock(tdb, ltype,
-                                FREELIST_TOP, 4*tdb->header.hash_size,
-                                flags)) {
-               if (flags & TDB_LOCK_WAIT) {
-                       TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_lockall failed (%s)\n", strerror(errno)));
-               }
+       if (upgradable && ltype != F_RDLCK) {
+               /* tdb error: you can't upgrade a write lock! */
+               tdb->ecode = TDB_ERR_LOCK;
+               return -1;
+       }
+       return 1;
+}
+
+/* We only need to lock individual bytes, but Linux merges consecutive locks
+ * so we lock in contiguous ranges. */
+static int tdb_chainlock_gradual(struct tdb_context *tdb,
+                                int ltype, enum tdb_lock_flags flags,
+                                size_t off, size_t len)
+{
+       int ret;
+       enum tdb_lock_flags nb_flags = (flags & ~TDB_LOCK_WAIT);
+
+       if (len <= 4) {
+               /* Single record.  Just do blocking lock. */
+               return tdb_brlock(tdb, ltype, off, len, flags);
+       }
+
+       /* First we try non-blocking. */
+       ret = tdb_brlock(tdb, ltype, off, len, nb_flags);
+       if (ret == 0) {
+               return 0;
+       }
+
+       /* Try locking first half, then second. */
+       ret = tdb_chainlock_gradual(tdb, ltype, flags, off, len / 2);
+       if (ret == -1)
+               return -1;
+
+       ret = tdb_chainlock_gradual(tdb, ltype, flags,
+                                   off + len / 2, len - len / 2);
+       if (ret == -1) {
+               tdb_brunlock(tdb, ltype, off, len / 2);
+               return -1;
+       }
+       return 0;
+}
+
+/* lock/unlock entire database.  It can only be upgradable if you have some
+ * other way of guaranteeing exclusivity (ie. transaction write lock).
+ * We do the locking gradually to avoid being starved by smaller locks. */
+int tdb_allrecord_lock(struct tdb_context *tdb, int ltype,
+                      enum tdb_lock_flags flags, bool upgradable)
+{
+       switch (tdb_allrecord_check(tdb, ltype, flags, upgradable)) {
+       case -1:
+               return -1;
+       case 0:
+               return 0;
+       }
+
+       /* We cover two kinds of locks:
+        * 1) Normal chain locks.  Taken for almost all operations.
+        * 3) Individual records locks.  Taken after normal or free
+        *    chain locks.
+        *
+        * It is (1) which cause the starvation problem, so we're only
+        * gradual for that. */
+       if (tdb_chainlock_gradual(tdb, ltype, flags, FREELIST_TOP,
+                                 tdb->header.hash_size * 4) == -1) {
+               return -1;
+       }
+
+       /* Grab individual record locks. */
+       if (tdb_brlock(tdb, ltype, lock_offset(tdb->header.hash_size), 0,
+                      flags) == -1) {
+               tdb_brunlock(tdb, ltype, FREELIST_TOP,
+                            tdb->header.hash_size * 4);

                return -1;
        }
 
        tdb->allrecord_lock.count = 1;
                return -1;
        }
 
        tdb->allrecord_lock.count = 1;

-       tdb->allrecord_lock.ltype = ltype;
+       /* If it's upgradable, it's actually exclusive so we can treat
+        * it as a write lock. */
+       tdb->allrecord_lock.ltype = upgradable ? F_WRLCK : ltype;
+       tdb->allrecord_lock.off = upgradable;
+
+       if (tdb_needs_recovery(tdb)) {
+               bool mark = flags & TDB_LOCK_MARK_ONLY;
+               tdb_allrecord_unlock(tdb, ltype, mark);
+               if (mark) {
+                       tdb->ecode = TDB_ERR_LOCK;
+                       TDB_LOG((tdb, TDB_DEBUG_ERROR,
+                                "tdb_lockall_mark cannot do recovery\n"));
+                       return -1;
+               }
+               if (tdb_lock_and_recover(tdb) == -1) {
+                       return -1;
+               }
+               return tdb_allrecord_lock(tdb, ltype, flags, upgradable);
+       }

 
        return 0;
 }
 
        return 0;
 }


@@ -499,7 +606,7 @@ static int _tdb_lockall(struct tdb_context *tdb, int ltype,
 
 
 /* unlock entire db */
 
 
 /* unlock entire db */

-static int _tdb_unlockall(struct tdb_context *tdb, int ltype, bool mark_lock)
+int tdb_allrecord_unlock(struct tdb_context *tdb, int ltype, bool mark_lock)

 {
        /* There are no locks on read-only dbs */
        if (tdb->read_only || tdb->traverse_read) {
 {
        /* There are no locks on read-only dbs */
        if (tdb->read_only || tdb->traverse_read) {


@@ -507,7 +614,14 @@ static int _tdb_unlockall(struct tdb_context *tdb, int ltype, bool mark_lock)
                return -1;
        }
 
                return -1;
        }
 

-       if (tdb->allrecord_lock.ltype != ltype || tdb->allrecord_lock.count == 0) {
+       if (tdb->allrecord_lock.count == 0) {
+               tdb->ecode = TDB_ERR_LOCK;
+               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;
                return -1;
        }
                tdb->ecode = TDB_ERR_LOCK;
                return -1;
        }


@@ -517,9 +631,7 @@ static int _tdb_unlockall(struct tdb_context *tdb, int ltype, bool mark_lock)
                return 0;
        }
 
                return 0;
        }
 

-       if (!mark_lock &&
-           tdb->methods->brunlock(tdb, ltype,
-                                  FREELIST_TOP, 4*tdb->header.hash_size)) {
+       if (!mark_lock && tdb_brunlock(tdb, ltype, FREELIST_TOP, 0)) {

                TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlockall failed (%s)\n", strerror(errno)));
                return -1;
        }
                TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlockall failed (%s)\n", strerror(errno)));
                return -1;
        }


@@ -534,27 +646,27 @@ static int _tdb_unlockall(struct tdb_context *tdb, int ltype, bool mark_lock)
 int tdb_lockall(struct tdb_context *tdb)
 {
        tdb_trace(tdb, "tdb_lockall");
 int tdb_lockall(struct tdb_context *tdb)
 {
        tdb_trace(tdb, "tdb_lockall");

-       return _tdb_lockall(tdb, F_WRLCK, TDB_LOCK_WAIT);
+       return tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_WAIT, false);

 }
 
 /* lock entire database with write lock - mark only */
 int tdb_lockall_mark(struct tdb_context *tdb)
 {
        tdb_trace(tdb, "tdb_lockall_mark");
 }
 
 /* lock entire database with write lock - mark only */
 int tdb_lockall_mark(struct tdb_context *tdb)
 {
        tdb_trace(tdb, "tdb_lockall_mark");

-       return _tdb_lockall(tdb, F_WRLCK, TDB_LOCK_MARK_ONLY);
+       return tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_MARK_ONLY, false);

 }
 
 /* unlock entire database with write lock - unmark only */
 int tdb_lockall_unmark(struct tdb_context *tdb)
 {
        tdb_trace(tdb, "tdb_lockall_unmark");
 }
 
 /* unlock entire database with write lock - unmark only */
 int tdb_lockall_unmark(struct tdb_context *tdb)
 {
        tdb_trace(tdb, "tdb_lockall_unmark");

-       return _tdb_unlockall(tdb, F_WRLCK, true);
+       return tdb_allrecord_unlock(tdb, F_WRLCK, true);

 }
 
 /* lock entire database with write lock - nonblocking varient */
 int tdb_lockall_nonblock(struct tdb_context *tdb)
 {
 }
 
 /* lock entire database with write lock - nonblocking varient */
 int tdb_lockall_nonblock(struct tdb_context *tdb)
 {

-       int ret = _tdb_lockall(tdb, F_WRLCK, TDB_LOCK_NOWAIT);
+       int ret = tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_NOWAIT, false);

        tdb_trace_ret(tdb, "tdb_lockall_nonblock", ret);
        return ret;
 }
        tdb_trace_ret(tdb, "tdb_lockall_nonblock", ret);
        return ret;
 }


@@ -563,20 +675,20 @@ int tdb_lockall_nonblock(struct tdb_context *tdb)
 int tdb_unlockall(struct tdb_context *tdb)
 {
        tdb_trace(tdb, "tdb_unlockall");
 int tdb_unlockall(struct tdb_context *tdb)
 {
        tdb_trace(tdb, "tdb_unlockall");

-       return _tdb_unlockall(tdb, F_WRLCK, false);
+       return tdb_allrecord_unlock(tdb, F_WRLCK, false);

 }
 
 /* lock entire database with read lock */
 int tdb_lockall_read(struct tdb_context *tdb)
 {
        tdb_trace(tdb, "tdb_lockall_read");
 }
 
 /* lock entire database with read lock */
 int tdb_lockall_read(struct tdb_context *tdb)
 {
        tdb_trace(tdb, "tdb_lockall_read");

-       return _tdb_lockall(tdb, F_RDLCK, TDB_LOCK_WAIT);
+       return tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, false);

 }
 
 /* lock entire database with read lock - nonblock varient */
 int tdb_lockall_read_nonblock(struct tdb_context *tdb)
 {
 }
 
 /* lock entire database with read lock - nonblock varient */
 int tdb_lockall_read_nonblock(struct tdb_context *tdb)
 {

-       int ret = _tdb_lockall(tdb, F_RDLCK, TDB_LOCK_NOWAIT);
+       int ret = tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_NOWAIT, false);

        tdb_trace_ret(tdb, "tdb_lockall_read_nonblock", ret);
        return ret;
 }
        tdb_trace_ret(tdb, "tdb_lockall_read_nonblock", ret);
        return ret;
 }


@@ -585,7 +697,7 @@ int tdb_lockall_read_nonblock(struct tdb_context *tdb)
 int tdb_unlockall_read(struct tdb_context *tdb)
 {
        tdb_trace(tdb, "tdb_unlockall_read");
 int tdb_unlockall_read(struct tdb_context *tdb)
 {
        tdb_trace(tdb, "tdb_unlockall_read");

-       return _tdb_unlockall(tdb, F_RDLCK, false);
+       return tdb_allrecord_unlock(tdb, F_RDLCK, false);

 }
 
 /* lock/unlock one hash chain. This is meant to be used to reduce
 }
 
 /* lock/unlock one hash chain. This is meant to be used to reduce


@@ -652,7 +764,7 @@ int tdb_lock_record(struct tdb_context *tdb, tdb_off_t off)
        if (tdb->allrecord_lock.count) {
                return 0;
        }
        if (tdb->allrecord_lock.count) {
                return 0;
        }

-       return off ? tdb->methods->brlock(tdb, F_RDLCK, off, 1, TDB_LOCK_WAIT) : 0;
+       return off ? tdb_brlock(tdb, F_RDLCK, off, 1, TDB_LOCK_WAIT) : 0;

 }
 
 /*
 }
 
 /*


@@ -666,12 +778,21 @@ int tdb_write_lock_record(struct tdb_context *tdb, tdb_off_t off)
        for (i = &tdb->travlocks; i; i = i->next)
                if (i->off == off)
                        return -1;
        for (i = &tdb->travlocks; i; i = i->next)
                if (i->off == off)
                        return -1;

-       return tdb->methods->brlock(tdb, F_WRLCK, off, 1, TDB_LOCK_NOWAIT|TDB_LOCK_PROBE);
+       if (tdb->allrecord_lock.count) {
+               if (tdb->allrecord_lock.ltype == F_WRLCK) {
+                       return 0;
+               }
+               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)
 {
 }
 
 int tdb_write_unlock_record(struct tdb_context *tdb, tdb_off_t off)
 {

-       return tdb->methods->brunlock(tdb, F_WRLCK, off, 1);
+       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 */
 }
 
 /* fcntl locks don't stack: avoid unlocking someone else's */


@@ -689,36 +810,56 @@ int tdb_unlock_record(struct tdb_context *tdb, tdb_off_t off)
        for (i = &tdb->travlocks; i; i = i->next)
                if (i->off == off)
                        count++;
        for (i = &tdb->travlocks; i; i = i->next)
                if (i->off == off)
                        count++;

-       return (count == 1 ? tdb->methods->brunlock(tdb, F_RDLCK, off, 1) : 0);
+       return (count == 1 ? tdb_brunlock(tdb, F_RDLCK, off, 1) : 0);

 }
 
 bool tdb_have_extra_locks(struct tdb_context *tdb)
 {
 }
 
 bool tdb_have_extra_locks(struct tdb_context *tdb)
 {

-       if (tdb->allrecord_lock.count) {
+       unsigned int extra = tdb->num_lockrecs;
+
+       /* A transaction holds the lock for all records. */
+       if (!tdb->transaction && tdb->allrecord_lock.count) {

                return true;
        }
                return true;
        }

-       if (tdb->num_lockrecs) {
-               return true;
+
+       /* We always hold the active lock if CLEAR_IF_FIRST. */
+       if (find_nestlock(tdb, ACTIVE_LOCK)) {
+               extra--;

        }
        }

-       return false;
+
+       /* In a transaction, we expect to hold the transaction lock */
+       if (tdb->transaction && find_nestlock(tdb, TRANSACTION_LOCK)) {
+               extra--;
+       }
+
+       return extra;

 }
 
 }
 

-/* The transaction code uses this to remove all locks. */
+/* The transaction code uses this to remove all locks.  Note that this
+   may include OPEN_LOCK. */

 void tdb_release_extra_locks(struct tdb_context *tdb)
 {
 void tdb_release_extra_locks(struct tdb_context *tdb)
 {

-       unsigned int i;
+       unsigned int i, extra = 0;

 
        if (tdb->allrecord_lock.count != 0) {
 
        if (tdb->allrecord_lock.count != 0) {

-               tdb_brunlock(tdb, tdb->allrecord_lock.ltype,
-                            FREELIST_TOP, 4*tdb->header.hash_size);
+               tdb_brunlock(tdb, tdb->allrecord_lock.ltype, FREELIST_TOP, 0);

                tdb->allrecord_lock.count = 0;
        }
 
        for (i=0;i<tdb->num_lockrecs;i++) {
                tdb->allrecord_lock.count = 0;
        }
 
        for (i=0;i<tdb->num_lockrecs;i++) {

-               tdb_brunlock(tdb, tdb->lockrecs[i].ltype,
-                            tdb->lockrecs[i].off, 1);
+               struct tdb_lock_type *lck = &tdb->lockrecs[i];
+
+               /* Don't release transaction or active locks! */
+               if (tdb->transaction && lck->off == TRANSACTION_LOCK) {
+                       tdb->lockrecs[extra++] = *lck;
+               } else if (lck->off == ACTIVE_LOCK) {
+                       tdb->lockrecs[extra++] = *lck;
+               } else {
+                       tdb_brunlock(tdb, lck->ltype, lck->off, 1);
+               }
+       }
+       tdb->num_lockrecs = extra;
+       if (tdb->num_lockrecs == 0) {
+               SAFE_FREE(tdb->lockrecs);

        }
        }

-       tdb->num_locks = 0;
-       tdb->num_lockrecs = 0;
-       SAFE_FREE(tdb->lockrecs);

 }
 }