tdb: use tdb_nest_lock() for open lock.

[ccan] / ccan / tdb / open.c

diff --git a/ccan/tdb/open.c b/ccan/tdb/open.c
index 77c6936fc2f5bac28b6c421f3d61f730cba71129..54a8fe57ad11a460471785dbf370f7ae1f4a9b93 100644 (file)
--- a/ccan/tdb/open.c
+++ b/ccan/tdb/open.c
@@ -161,7 +161,6 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
                errno = ENOMEM;
                goto fail;
        }
                errno = ENOMEM;
                goto fail;
        }

-

        tdb_io_init(tdb);
        tdb->fd = -1;
 #ifdef TDB_TRACE
        tdb_io_init(tdb);
        tdb->fd = -1;
 #ifdef TDB_TRACE


@@ -203,6 +202,22 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
                tdb->flags &= ~TDB_CLEAR_IF_FIRST;
        }
 
                tdb->flags &= ~TDB_CLEAR_IF_FIRST;
        }
 

+       if ((tdb->flags & TDB_ALLOW_NESTING) &&
+           (tdb->flags & TDB_DISALLOW_NESTING)) {
+               tdb->ecode = TDB_ERR_NESTING;
+               TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
+                       "allow_nesting and disallow_nesting are not allowed together!"));
+               errno = EINVAL;
+               goto fail;
+       }
+
+       /*
+        * TDB_DISALLOW_NESTING is the default behavior.
+        */
+       if (!(tdb->flags & TDB_ALLOW_NESTING)) {
+               tdb->flags |= TDB_DISALLOW_NESTING;
+       }
+

        /* internal databases don't mmap or lock, and start off cleared */
        if (tdb->flags & TDB_INTERNAL) {
                tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
        /* internal databases don't mmap or lock, and start off cleared */
        if (tdb->flags & TDB_INTERNAL) {
                tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);


@@ -225,8 +240,8 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
         fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
 
        /* ensure there is only one process initialising at once */
         fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
 
        /* ensure there is only one process initialising at once */

-       if (tdb->methods->brlock(tdb, F_WRLCK, GLOBAL_LOCK, 1, TDB_LOCK_WAIT) == -1) {
-               TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to get global lock on %s: %s\n",
+       if (tdb_nest_lock(tdb, OPEN_LOCK, F_WRLCK, TDB_LOCK_WAIT) == -1) {
+               TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to get open lock on %s: %s\n",

                         name, strerror(errno)));
                goto fail;      /* errno set by tdb_brlock */
        }
                         name, strerror(errno)));
                goto fail;      /* errno set by tdb_brlock */
        }


@@ -325,7 +340,8 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
        {
                char tracefile[strlen(name) + 32];
 
        {
                char tracefile[strlen(name) + 32];
 

-               sprintf(tracefile, "%s.trace.%u", name, getpid());
+               snprintf(tracefile, sizeof(tracefile),
+                        "%s.trace.%li", name, (long)getpid());

                tdb->tracefd = open(tracefile, O_WRONLY|O_CREAT|O_EXCL, 0600);
                if (tdb->tracefd >= 0) {
                        tdb_enable_seqnum(tdb);
                tdb->tracefd = open(tracefile, O_WRONLY|O_CREAT|O_EXCL, 0600);
                if (tdb->tracefd >= 0) {
                        tdb_enable_seqnum(tdb);


@@ -339,9 +355,10 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
  internal:
        /* Internal (memory-only) databases skip all the code above to
         * do with disk files, and resume here by releasing their
  internal:
        /* Internal (memory-only) databases skip all the code above to
         * do with disk files, and resume here by releasing their

-        * global lock and hooking into the active list. */
-       if (tdb->methods->brunlock(tdb, F_WRLCK, GLOBAL_LOCK, 1) == -1)
+        * open lock and hooking into the active list. */
+       if (tdb_nest_unlock(tdb, OPEN_LOCK, F_WRLCK, false) == -1) {

                goto fail;
                goto fail;

+       }

        tdb->next = tdbs;
        tdbs = tdb;
        return tdb;
        tdb->next = tdbs;
        tdbs = tdb;
        return tdb;


@@ -437,9 +454,7 @@ void *tdb_get_logging_private(struct tdb_context *tdb)
        return tdb->log.log_private;
 }
 
        return tdb->log.log_private;
 }
 

-/* reopen a tdb - this can be used after a fork to ensure that we have an independent
-   seek pointer from our parent and to re-establish locks */
-int tdb_reopen(struct tdb_context *tdb)
+static int tdb_reopen_internal(struct tdb_context *tdb, bool active_lock)

 {
        struct stat st;
 
 {
        struct stat st;
 


@@ -447,7 +462,7 @@ int tdb_reopen(struct tdb_context *tdb)
                return 0; /* Nothing to do. */
        }
 
                return 0; /* Nothing to do. */
        }
 

-       if (tdb->num_locks != 0 || tdb->global_lock.count) {
+       if (tdb_have_extra_locks(tdb)) {

                TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed with locks held\n"));
                goto fail;
        }
                TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed with locks held\n"));
                goto fail;
        }


@@ -468,11 +483,6 @@ int tdb_reopen(struct tdb_context *tdb)
                TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: open failed (%s)\n", strerror(errno)));
                goto fail;
        }
                TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: open failed (%s)\n", strerror(errno)));
                goto fail;
        }

-       if ((tdb->flags & TDB_CLEAR_IF_FIRST) && 
-           (tdb->methods->brlock(tdb, F_RDLCK, ACTIVE_LOCK, 1, TDB_LOCK_WAIT) == -1)) {
-               TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: failed to obtain active lock\n"));
-               goto fail;
-       }

        if (fstat(tdb->fd, &st) != 0) {
                TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: fstat failed (%s)\n", strerror(errno)));
                goto fail;
        if (fstat(tdb->fd, &st) != 0) {
                TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: fstat failed (%s)\n", strerror(errno)));
                goto fail;


@@ -483,6 +493,12 @@ int tdb_reopen(struct tdb_context *tdb)
        }
        tdb_mmap(tdb);
 
        }
        tdb_mmap(tdb);
 

+       if (active_lock &&
+           (tdb->methods->brlock(tdb, F_RDLCK, ACTIVE_LOCK, 1, TDB_LOCK_WAIT) == -1)) {
+               TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: failed to obtain active lock\n"));
+               goto fail;
+       }
+

        return 0;
 
 fail:
        return 0;
 
 fail:


@@ -490,12 +506,21 @@ fail:
        return -1;
 }
 
        return -1;
 }
 

+/* reopen a tdb - this can be used after a fork to ensure that we have an independent
+   seek pointer from our parent and to re-establish locks */
+int tdb_reopen(struct tdb_context *tdb)
+{
+       return tdb_reopen_internal(tdb, tdb->flags & TDB_CLEAR_IF_FIRST);
+}
+

 /* reopen all tdb's */
 int tdb_reopen_all(int parent_longlived)
 {
        struct tdb_context *tdb;
 
        for (tdb=tdbs; tdb; tdb = tdb->next) {
 /* reopen all tdb's */
 int tdb_reopen_all(int parent_longlived)
 {
        struct tdb_context *tdb;
 
        for (tdb=tdbs; tdb; tdb = tdb->next) {

+               bool active_lock = (tdb->flags & TDB_CLEAR_IF_FIRST);
+

                /*
                 * If the parent is longlived (ie. a
                 * parent daemon architecture), we know
                /*
                 * If the parent is longlived (ie. a
                 * parent daemon architecture), we know


@@ -509,10 +534,10 @@ int tdb_reopen_all(int parent_longlived)
                 */
                if (parent_longlived) {
                        /* Ensure no clear-if-first. */
                 */
                if (parent_longlived) {
                        /* Ensure no clear-if-first. */

-                       tdb->flags &= ~TDB_CLEAR_IF_FIRST;
+                       active_lock = false;

                }
 
                }
 

-               if (tdb_reopen(tdb) != 0)
+               if (tdb_reopen_internal(tdb, active_lock) != 0)

                        return -1;
        }
 
                        return -1;
        }