tdb: use tdb_nest_lock() for active lock.

Use our newly-generic nested lock tracking for the active lock.

Note that the tdb_have_extra_locks() and tdb_release_extra_locks()
functions have to skip over this lock now it is tracked.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
(Imported from commit 4738d474c412cc59d26fcea64007e99094e8b675)

diff --git a/lib/tdb/common/lock.c b/lib/tdb/common/lock.c
index 6f5799a8198f13dd06851aae03869c635035200e..19b92d9ae09c63152b87d10062b1363a8c063516 100644 (file)
--- a/lib/tdb/common/lock.c
+++ b/lib/tdb/common/lock.c
@@ -675,6 +675,11 @@ bool tdb_have_extra_locks(struct tdb_context *tdb)
                return true;
        }
 
+       /* We always hold the active lock if CLEAR_IF_FIRST. */
+       if (find_nestlock(tdb, ACTIVE_LOCK)) {
+               extra--;
+       }
+
        /* In a transaction, we expect to hold the transaction lock */
        if (tdb->transaction && find_nestlock(tdb, TRANSACTION_LOCK)) {
                extra--;
@@ -698,8 +703,11 @@ void tdb_release_extra_locks(struct tdb_context *tdb)
        for (i=0;i<tdb->num_lockrecs;i++) {
                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);
                }

diff --git a/lib/tdb/common/open.c b/lib/tdb/common/open.c
index 1f948ff158f5efc48dd8239882ea263d7193dfc4..afea5544f98579de5d9b127aa4f94c145a1feb9a 100644 (file)
--- a/lib/tdb/common/open.c
+++ b/lib/tdb/common/open.c
@@ -250,7 +250,7 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
        /* we need to zero database if we are the only one with it open */
        if ((tdb_flags & TDB_CLEAR_IF_FIRST) &&
            (!tdb->read_only) &&
-           (locked = (tdb->methods->brlock(tdb, F_WRLCK, ACTIVE_LOCK, 1, TDB_LOCK_NOWAIT|TDB_LOCK_PROBE) == 0))) {
+           (locked = (tdb_nest_lock(tdb, ACTIVE_LOCK, F_WRLCK, TDB_LOCK_NOWAIT|TDB_LOCK_PROBE) == 0))) {
                open_flags |= O_CREAT;
                if (ftruncate(tdb->fd, 0) == -1) {
                        TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
@@ -313,7 +313,7 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
        tdb->inode = st.st_ino;
        tdb_mmap(tdb);
        if (locked) {
-               if (tdb->methods->brunlock(tdb, F_WRLCK, ACTIVE_LOCK, 1) == -1) {
+               if (tdb_nest_unlock(tdb, ACTIVE_LOCK, F_WRLCK, false) == -1) {
                        TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
                                 "failed to release ACTIVE_LOCK on %s: %s\n",
                                 name, strerror(errno)));
@@ -328,8 +328,9 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
 
        if (tdb_flags & TDB_CLEAR_IF_FIRST) {
                /* leave this lock in place to indicate it's in use */
-               if (tdb->methods->brlock(tdb, F_RDLCK, ACTIVE_LOCK, 1, TDB_LOCK_WAIT) == -1)
+               if (tdb_nest_lock(tdb, ACTIVE_LOCK, F_RDLCK, TDB_LOCK_WAIT) == -1) {
                        goto fail;
+               }
        }
 
        /* if needed, run recovery */
@@ -383,6 +384,7 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
        if (tdb->fd != -1)
                if (close(tdb->fd) != 0)
                        TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to close tdb->fd on error!\n"));
+       SAFE_FREE(tdb->lockrecs);
        SAFE_FREE(tdb);
        errno = save_errno;
        return NULL;
@@ -501,8 +503,11 @@ static int tdb_reopen_internal(struct tdb_context *tdb, bool active_lock)
        tdb_mmap(tdb);
 #endif /* fake pread or pwrite */
 
-       if (active_lock &&
-           (tdb->methods->brlock(tdb, F_RDLCK, ACTIVE_LOCK, 1, TDB_LOCK_WAIT) == -1)) {
+       /* We may still think we hold the active lock. */
+       tdb->num_lockrecs = 0;
+       SAFE_FREE(tdb->lockrecs);
+
+       if (active_lock && tdb_nest_lock(tdb, ACTIVE_LOCK, F_RDLCK, TDB_LOCK_WAIT) == -1) {
                TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: failed to obtain active lock\n"));
                goto fail;
        }