@@ -2554,6 +2554,43 @@ static bool finished_loading(const char *name)
return ret;
}
+/* Must be called with module_mutex held */
+static int module_patient_check_exists(const char *name)
+{
+ struct module *old;
+ int err = 0;
+
+ old = find_module_all(name, strlen(name), true);
+ if (old == NULL)
+ return 0;
+
+ if (old->state == MODULE_STATE_COMING
+ || old->state == MODULE_STATE_UNFORMED) {
+ /* Wait in case it fails to load. */
+ mutex_unlock(&module_mutex);
+ err = wait_event_interruptible(module_wq,
+ finished_loading(name));
+ if (err)
+ return err;
+
+ /* The module might have gone in the meantime. */
+ mutex_lock(&module_mutex);
+ old = find_module_all(name, strlen(name), true);
+ }
+
+ /*
+ * We are here only when the same module was being loaded. Do
+ * not try to load it again right now. It prevents long delays
+ * caused by serialized module load failures. It might happen
+ * when more devices of the same type trigger load of
+ * a particular module.
+ */
+ if (old && old->state == MODULE_STATE_LIVE)
+ return -EEXIST;
+ else
+ return -EBUSY;
+}
+
/*
* We try to place it in the list now to make sure it's unique before
* we dedicate too many resources. In particular, temporary percpu
@@ -2562,41 +2599,14 @@ static bool finished_loading(const char *name)
static int add_unformed_module(struct module *mod)
{
int err;
- struct module *old;
mod->state = MODULE_STATE_UNFORMED;
mutex_lock(&module_mutex);
- old = find_module_all(mod->name, strlen(mod->name), true);
- if (old != NULL) {
- if (old->state == MODULE_STATE_COMING
- || old->state == MODULE_STATE_UNFORMED) {
- /* Wait in case it fails to load. */
- mutex_unlock(&module_mutex);
- err = wait_event_interruptible(module_wq,
- finished_loading(mod->name));
- if (err)
- goto out_unlocked;
-
- /* The module might have gone in the meantime. */
- mutex_lock(&module_mutex);
- old = find_module_all(mod->name, strlen(mod->name),
- true);
- }
-
- /*
- * We are here only when the same module was being loaded. Do
- * not try to load it again right now. It prevents long delays
- * caused by serialized module load failures. It might happen
- * when more devices of the same type trigger load of
- * a particular module.
- */
- if (old && old->state == MODULE_STATE_LIVE)
- err = -EEXIST;
- else
- err = -EBUSY;
+ err = module_patient_check_exists(mod->name);
+ if (err)
goto out;
- }
+
mod_update_bounds(mod);
list_add_rcu(&mod->list, &modules);
mod_tree_insert(mod);
@@ -2604,7 +2614,6 @@ static int add_unformed_module(struct module *mod)
out:
mutex_unlock(&module_mutex);
-out_unlocked:
return err;
}
The patient module check inside add_unformed_module() is large enough as we need it. It is a bit hard to read too, so just move it to a helper and do the inverse checks first to help shift the code and make it easier to read. The new helper then is module_patient_check_exists(). Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> --- kernel/module/main.c | 71 +++++++++++++++++++++++++------------------- 1 file changed, 40 insertions(+), 31 deletions(-)