Merge branch 'modules' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

* 'modules' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  module: drop the lock while waiting for module to complete initialization.
  MODULE_DEVICE_TABLE(isapnp, ...) does nothing
  hisax_fcpcipnp: fix broken isapnp device table.
  isapnp: move definitions to mod_devicetable.h so file2alias can reach them.

1 files changed, 37 insertions, 22 deletions

diff --git a/kernel/module.c b/kernel/module.c
index 3c4fc4bb4b82..a8014bfb5a4e 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -565,33 +565,26 @@ int use_module(struct module *a, struct module *b)
         struct module_use *use;
         int no_warn, err;
 
-        if (b == NULL || already_uses(a, b)) return 1;
-
-        /* If we're interrupted or time out, we fail. */
-        if (wait_event_interruptible_timeout(
-                    module_wq, (err = strong_try_module_get(b)) != -EBUSY,
-                    30 * HZ) <= 0) {
-                printk("%s: gave up waiting for init of module %s.\n",
-                       a->name, b->name);
+        if (b == NULL || already_uses(a, b))
                 return 0;
-        }
 
-        /* If strong_try_module_get() returned a different error, we fail. */
+        /* If we're interrupted or time out, we fail. */
+        err = strong_try_module_get(b);
         if (err)
-                return 0;
+                return err;
 
         DEBUGP("Allocating new usage for %s.\n", a->name);
         use = kmalloc(sizeof(*use), GFP_ATOMIC);
         if (!use) {
                 printk("%s: out of memory loading\n", a->name);
                 module_put(b);
-                return 0;
+                return -ENOMEM;
         }
 
         use->module_which_uses = a;
         list_add(&use->list, &b->modules_which_use_me);
         no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name);
-        return 1;
+        return 0;
 }
 EXPORT_SYMBOL_GPL(use_module);
 
@@ -884,7 +877,7 @@ static inline void module_unload_free(struct module *mod)
 
 int use_module(struct module *a, struct module *b)
 {
-        return strong_try_module_get(b) == 0;
+        return strong_try_module_get(b);
 }
 EXPORT_SYMBOL_GPL(use_module);
 
@@ -1055,17 +1048,39 @@ static const struct kernel_symbol *resolve_symbol(Elf_Shdr *sechdrs,
         struct module *owner;
         const struct kernel_symbol *sym;
         const unsigned long *crc;
+        DEFINE_WAIT(wait);
+        int err;
+        long timeleft = 30 * HZ;
 
+again:
         sym = find_symbol(name, &owner, &crc,
                           !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
-        /* use_module can fail due to OOM,
-           or module initialization or unloading */
-        if (sym) {
-                if (!check_version(sechdrs, versindex, name, mod, crc, owner)
-                    || !use_module(mod, owner))
-                        sym = NULL;
-        }
-        return sym;
+        if (!sym)
+                return NULL;
+
+        if (!check_version(sechdrs, versindex, name, mod, crc, owner))
+                return NULL;
+
+        prepare_to_wait(&module_wq, &wait, TASK_INTERRUPTIBLE);
+        err = use_module(mod, owner);
+        if (likely(!err) || err != -EBUSY || signal_pending(current)) {
+                finish_wait(&module_wq, &wait);
+                return err ? NULL : sym;
+        }
+
+        /* Module is still loading.  Drop lock and wait. */
+        mutex_unlock(&module_mutex);
+        timeleft = schedule_timeout(timeleft);
+        mutex_lock(&module_mutex);
+        finish_wait(&module_wq, &wait);
+
+        /* Module might be gone entirely, or replaced.  Re-lookup. */
+        if (timeleft)
+                goto again;
+
+        printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
+               mod->name, owner->name);
+        return NULL;
 }
 
 /*