On 05.04.23 04:26, Luis Chamberlain wrote:
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@xxxxxxxxxx>
---
kernel/module/main.c | 71 +++++++++++++++++++++++++-------------------
1 file changed, 40 insertions(+), 31 deletions(-)
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 98c261928325..8f382580195b 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2638,6 +2638,43 @@ 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) {
I never understood why people prefer to prefix the || on a newline. But
it seems to be a thing in the module/ world :)
+ /* Wait in case it fails to load. */
+ mutex_unlock(&module_mutex);
+ err = wait_event_interruptible(module_wq,
+ finished_loading(name));
+ if (err)
+ return err;
You return with the mutex unlocked. The caller will unlock again ...
+
+ /* 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;
You can drop the else and return right away.
+}
+
/*
* We try to place it in the list now to make sure it's unique before
Besides, LGTM.
--
Thanks,
David / dhildenb
