smbd: Use dbwrap_do_locked() in smbXsrv_open_global_allocate()

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>

diff --git a/source3/smbd/smbXsrv_open.c b/source3/smbd/smbXsrv_open.c
index 95a59a75ff9bb60d853255ce2db7c7fd134cbe50..cba7107a88437e9e68c0184bbfd4b87eb983fb30 100644 (file)
--- a/source3/smbd/smbXsrv_open.c
+++ b/source3/smbd/smbXsrv_open.c
@@ -372,9 +372,77 @@ static NTSTATUS smbXsrv_open_global_store(
        return NT_STATUS_OK;
 }
 
+struct smbXsrv_open_global_allocate_state {
+       uint32_t id;
+       struct smbXsrv_open_global0 *global;
+       NTSTATUS status;
+};
+
+static void smbXsrv_open_global_allocate_fn(
+       struct db_record *rec, TDB_DATA oldval, void *private_data)
+{
+       struct smbXsrv_open_global_allocate_state *state = private_data;
+       struct smbXsrv_open_global0 *global = state->global;
+       struct smbXsrv_open_global0 *tmp_global0 = NULL;
+       TDB_DATA key = dbwrap_record_get_key(rec);
+
+       state->status = smbXsrv_open_global_verify_record(
+               key, oldval, talloc_tos(), &tmp_global0);
+
+       if (NT_STATUS_IS_OK(state->status)) {
+               /*
+                * Found an existing record
+                */
+               TALLOC_FREE(tmp_global0);
+               state->status = NT_STATUS_RETRY;
+               return;
+       }
+
+       if (NT_STATUS_EQUAL(state->status, NT_STATUS_NOT_FOUND)) {
+               /*
+                * Found an empty slot
+                */
+               global->open_global_id = state->id;
+               global->open_persistent_id = state->id;
+
+               state->status = smbXsrv_open_global_store(
+                       rec, key, (TDB_DATA) { .dsize = 0, }, state->global);
+               if (!NT_STATUS_IS_OK(state->status)) {
+                       DBG_WARNING("smbXsrv_open_global_store() for "
+                                   "id %"PRIu32" failed: %s\n",
+                                   state->id,
+                                   nt_errstr(state->status));
+               }
+               return;
+       }
+
+       if (NT_STATUS_EQUAL(state->status, NT_STATUS_FATAL_APP_EXIT)) {
+               NTSTATUS status;
+
+               TALLOC_FREE(tmp_global0);
+
+               /*
+                * smbd crashed
+                */
+               status = dbwrap_record_delete(rec);
+               if (!NT_STATUS_IS_OK(status)) {
+                       DBG_WARNING("dbwrap_record_delete() failed "
+                                   "for record %"PRIu32": %s\n",
+                                   state->id,
+                                   nt_errstr(status));
+                       state->status = NT_STATUS_INTERNAL_DB_CORRUPTION;
+                       return;
+               }
+               return;
+       }
+}
+
 static NTSTATUS smbXsrv_open_global_allocate(
        struct db_context *db, struct smbXsrv_open_global0 *global)
 {
+       struct smbXsrv_open_global_allocate_state state = {
+               .global = global,
+       };
        uint32_t i;
        uint32_t last_free = 0;
        const uint32_t min_tries = 3;
@@ -387,66 +455,38 @@ static NTSTATUS smbXsrv_open_global_allocate(
         */
        for (i = 0; i < UINT32_MAX; i++) {
                struct smbXsrv_open_global_key_buf key_buf;
-               struct smbXsrv_open_global0 *tmp_global0 = NULL;
-               TDB_DATA key, val;
-               uint32_t id;
+               TDB_DATA key;
                NTSTATUS status;
 
                if (i >= min_tries && last_free != 0) {
-                       id = last_free;
+                       state.id = last_free;
                } else {
-                       generate_nonce_buffer((uint8_t *)&id, sizeof(id));
-                       id = MAX(id, 1);
-                       id = MIN(id, UINT32_MAX-1);
+                       generate_nonce_buffer(
+                               (uint8_t *)&state.id, sizeof(state.id));
+                       state.id = MAX(state.id, 1);
+                       state.id = MIN(state.id, UINT32_MAX-1);
                }
 
-               key = smbXsrv_open_global_id_to_key(id, &key_buf);
+               key = smbXsrv_open_global_id_to_key(state.id, &key_buf);
 
-               global->db_rec = dbwrap_fetch_locked(db, global, key);
-               if (global->db_rec == NULL) {
-                       return NT_STATUS_INSUFFICIENT_RESOURCES;
-               }
-               val = dbwrap_record_get_value(global->db_rec);
+               status = dbwrap_do_locked(
+                       db, key, smbXsrv_open_global_allocate_fn, &state);
 
-               status = smbXsrv_open_global_verify_record(
-                       key, val, talloc_tos(), &tmp_global0);
+               if (!NT_STATUS_IS_OK(status)) {
+                       DBG_WARNING("dbwrap_do_locked() failed: %s\n",
+                                   nt_errstr(status));
+                       return NT_STATUS_INTERNAL_DB_ERROR;
+               }
 
-               if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
+               if (NT_STATUS_IS_OK(state.status)) {
                        /*
-                        * Found an empty slot
+                        * Found an empty slot, done.
                         */
-                       global->open_global_id = id;
-                       global->open_persistent_id = id;
-
-                       status = smbXsrv_open_global_store(
-                               global->db_rec,
-                               key,
-                               (TDB_DATA) { .dsize = 0, },
-                               global);
-                       if (!NT_STATUS_IS_OK(status)) {
-                               DBG_WARNING("smbXsrv_open_global_store() for "
-                                           "id %"PRIu32" failed: %s\n",
-                                           id,
-                                           nt_errstr(status));
-                       }
-                       TALLOC_FREE(global->db_rec);
-                       return status;
+                       DBG_DEBUG("Found slot %"PRIu32"\n", state.id);
+                       return NT_STATUS_OK;
                }
 
-               TALLOC_FREE(tmp_global0);
-
-               if (NT_STATUS_EQUAL(status, NT_STATUS_FATAL_APP_EXIT)) {
-                       /*
-                        * smbd crashed
-                        */
-                       status = dbwrap_record_delete(global->db_rec);
-                       if (!NT_STATUS_IS_OK(status)) {
-                               DBG_WARNING("dbwrap_record_delete() failed "
-                                           "for record %"PRIu32": %s\n",
-                                           id,
-                                           nt_errstr(status));
-                               return NT_STATUS_INTERNAL_DB_CORRUPTION;
-                       }
+               if (NT_STATUS_EQUAL(state.status, NT_STATUS_FATAL_APP_EXIT)) {
 
                        if ((i < min_tries) && (last_free == 0)) {
                                /*
@@ -454,18 +494,23 @@ static NTSTATUS smbXsrv_open_global_allocate(
                                 * others to not recycle ids too
                                 * quickly.
                                 */
-                               last_free = id;
+                               last_free = state.id;
                        }
+                       continue;
                }
 
-               if (!NT_STATUS_IS_OK(status)) {
-                       DBG_WARNING("smbXsrv_open_global_verify_record() "
-                                   "failed for %s: %s, ignoring\n",
-                                   tdb_data_dbg(key),
-                                   nt_errstr(status));
+               if (NT_STATUS_EQUAL(state.status, NT_STATUS_RETRY)) {
+                       /*
+                        * Normal collision, try next
+                        */
+                       DBG_DEBUG("Found record for id %"PRIu32"\n",
+                                 state.id);
+                       continue;
                }
 
-               TALLOC_FREE(global->db_rec);
+               DBG_WARNING("smbXsrv_open_global_allocate_fn() failed: %s\n",
+                           nt_errstr(state.status));
+               return state.status;
        }
 
        /* should not be reached */