void *load_shared_library(struct cmd_context *cmd, const char *libname,
const char *desc, int silent)
{
char path[PATH_MAX];
void *library;
if (is_static()) {
log_error("Not loading shared %s library %s in static mode.",
desc, libname);
return NULL;
}
get_shared_library_path(cmd, libname, path, sizeof(path));
log_very_verbose("Opening shared %s library %s", desc, path);
if (!(library = dlopen(path, RTLD_LAZY | RTLD_GLOBAL))) {
if (silent && ignorelockingfailure())
log_verbose("Unable to open external %s library %s: %s",
desc, path, dlerror());
else
log_error("Unable to open external %s library %s: %s",
desc, path, dlerror());
}
return library;
}
/*
* Select a locking type
* type: locking type; if < 0, then read config tree value
*/
int init_locking(int type, struct cmd_context *cmd, int suppress_messages)
{
if (getenv("LVM_SUPPRESS_LOCKING_FAILURE_MESSAGES"))
suppress_messages = 1;
if (type < 0)
type = find_config_tree_int(cmd, global_locking_type_CFG, NULL);
_blocking_supported = find_config_tree_bool(cmd, global_wait_for_locks_CFG, NULL);
switch (type) {
case 0:
init_no_locking(&_locking, cmd, suppress_messages);
log_warn("WARNING: Locking disabled. Be careful! "
"This could corrupt your metadata.");
return 1;
case 1:
log_very_verbose("%sFile-based locking selected.",
_blocking_supported ? "" : "Non-blocking ");
if (!init_file_locking(&_locking, cmd, suppress_messages)) {
log_error_suppress(suppress_messages,
"File-based locking initialisation failed.");
break;
}
return 1;
#ifdef HAVE_LIBDL
case 2:
if (!is_static()) {
log_very_verbose("External locking selected.");
if (init_external_locking(&_locking, cmd, suppress_messages))
return 1;
}
if (!find_config_tree_bool(cmd, global_fallback_to_clustered_locking_CFG, NULL)) {
log_error_suppress(suppress_messages, "External locking initialisation failed.");
break;
}
#endif
#ifdef CLUSTER_LOCKING_INTERNAL
log_very_verbose("Falling back to internal clustered locking.");
/* Fall through */
case 3:
log_very_verbose("Cluster locking selected.");
if (!init_cluster_locking(&_locking, cmd, suppress_messages)) {
log_error_suppress(suppress_messages,
"Internal cluster locking initialisation failed.");
break;
}
return 1;
#endif
case 4:
log_verbose("Read-only locking selected. "
"Only read operations permitted.");
if (!init_readonly_locking(&_locking, cmd, suppress_messages))
break;
return 1;
default:
log_error("Unknown locking type requested.");
return 0;
}
if ((type == 2 || type == 3) &&
find_config_tree_bool(cmd, global_fallback_to_local_locking_CFG, NULL)) {
log_warn_suppress(suppress_messages, "WARNING: Falling back to local file-based locking.");
log_warn_suppress(suppress_messages,
"Volume Groups with the clustered attribute will "
"be inaccessible.");
if (init_file_locking(&_locking, cmd, suppress_messages))
return 1;
else
log_error_suppress(suppress_messages,
"File-based locking initialisation failed.");
}
if (!ignorelockingfailure())
return 0;
log_verbose("Locking disabled - only read operations permitted.");
init_readonly_locking(&_locking, cmd, suppress_messages);
return 1;
}
