aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorRusty Russell <rusty@rustcorp.com.au>2013-09-17 05:48:51 +0930
committerRusty Russell <rusty@rustcorp.com.au>2013-09-23 15:44:58 +0930
commit3f2b9c9cdf389e303b2273679af08aab5f153517 (patch)
tree915b06441005e02d02c6e9f9549bd6449b70d501
parentd8524ae9d6f492a9c6db9f4d89c5f9b8782fa2d5 (diff)
module: remove rmmod --wait option.
The option to wait for a module reference count to reach zero was in the initial module implementation, but it was never supported in modprobe (you had to use rmmod --wait). After discussion with Lucas, It has been deprecated (with a 10 second sleep) in kmod for the last year. This finally removes it: the flag will evoke a printk warning and a normal (non-blocking) remove attempt. Cc: Lucas De Marchi <lucas.de.marchi@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
-rw-r--r--include/linux/module.h3
-rw-r--r--kernel/module.c46
2 files changed, 8 insertions, 41 deletions
diff --git a/include/linux/module.h b/include/linux/module.h
index 05f2447f8c1..15cd6b1b211 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -367,9 +367,6 @@ struct module
/* What modules do I depend on? */
struct list_head target_list;
- /* Who is waiting for us to be unloaded */
- struct task_struct *waiter;
-
/* Destruction function. */
void (*exit)(void);
diff --git a/kernel/module.c b/kernel/module.c
index dc582749fa1..947105fd4ca 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -644,8 +644,6 @@ static int module_unload_init(struct module *mod)
/* Hold reference count during initialization. */
__this_cpu_write(mod->refptr->incs, 1);
- /* Backwards compatibility macros put refcount during init. */
- mod->waiter = current;
return 0;
}
@@ -771,16 +769,9 @@ static int __try_stop_module(void *_sref)
static int try_stop_module(struct module *mod, int flags, int *forced)
{
- if (flags & O_NONBLOCK) {
- struct stopref sref = { mod, flags, forced };
+ struct stopref sref = { mod, flags, forced };
- return stop_machine(__try_stop_module, &sref, NULL);
- } else {
- /* We don't need to stop the machine for this. */
- mod->state = MODULE_STATE_GOING;
- synchronize_sched();
- return 0;
- }
+ return stop_machine(__try_stop_module, &sref, NULL);
}
unsigned long module_refcount(struct module *mod)
@@ -813,21 +804,6 @@ EXPORT_SYMBOL(module_refcount);
/* This exists whether we can unload or not */
static void free_module(struct module *mod);
-static void wait_for_zero_refcount(struct module *mod)
-{
- /* Since we might sleep for some time, release the mutex first */
- mutex_unlock(&module_mutex);
- for (;;) {
- pr_debug("Looking at refcount...\n");
- set_current_state(TASK_UNINTERRUPTIBLE);
- if (module_refcount(mod) == 0)
- break;
- schedule();
- }
- current->state = TASK_RUNNING;
- mutex_lock(&module_mutex);
-}
-
SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
unsigned int, flags)
{
@@ -842,6 +818,11 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
return -EFAULT;
name[MODULE_NAME_LEN-1] = '\0';
+ if (!(flags & O_NONBLOCK)) {
+ printk(KERN_WARNING
+ "waiting module removal not supported: please upgrade");
+ }
+
if (mutex_lock_interruptible(&module_mutex) != 0)
return -EINTR;
@@ -859,8 +840,7 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
/* Doing init or already dying? */
if (mod->state != MODULE_STATE_LIVE) {
- /* FIXME: if (force), slam module count and wake up
- waiter --RR */
+ /* FIXME: if (force), slam module count damn the torpedoes */
pr_debug("%s already dying\n", mod->name);
ret = -EBUSY;
goto out;
@@ -876,18 +856,11 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
}
}
- /* Set this up before setting mod->state */
- mod->waiter = current;
-
/* Stop the machine so refcounts can't move and disable module. */
ret = try_stop_module(mod, flags, &forced);
if (ret != 0)
goto out;
- /* Never wait if forced. */
- if (!forced && module_refcount(mod) != 0)
- wait_for_zero_refcount(mod);
-
mutex_unlock(&module_mutex);
/* Final destruction now no one is using it. */
if (mod->exit != NULL)
@@ -1005,9 +978,6 @@ void module_put(struct module *module)
__this_cpu_inc(module->refptr->decs);
trace_module_put(module, _RET_IP_);
- /* Maybe they're waiting for us to drop reference? */
- if (unlikely(!module_is_live(module)))
- wake_up_process(module->waiter);
preempt_enable();
}
}