Merge branch 'for-3.9-async' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull async changes from Tejun Heo:
 "These are followups for the earlier deadlock issue involving async
  ending up waiting for itself through block requesting module[1].  The
  following changes are made by these commits.

   - Instead of requesting default elevator on each request_queue init,
     block now requests it once early during boot.

   - Kmod triggers warning if invoked from an async worker.

   - Async synchronization implementation has been reimplemented.  It's
     a lot simpler now."

* 'for-3.9-async' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  async: initialise list heads to fix crash
  async: replace list of active domains with global list of pending items
  async: keep pending tasks on async_domain and remove async_pending
  async: use ULLONG_MAX for infinity cookie value
  async: bring sanity to the use of words domain and running
  async, kmod: warn on synchronous request_module() from async workers
  block: don't request module during elevator init
  init, block: try to load default elevator module early during boot

3 files changed, 26 insertions, 1 deletions

diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c
index f9acf71b9810..a32ec1ce882b 100644
--- a/init/do_mounts_initrd.c
+++ b/init/do_mounts_initrd.c
@@ -61,6 +61,9 @@ static void __init handle_initrd(void)
         sys_mkdir("/old", 0700);
         sys_chdir("/old");
 
+        /* try loading default modules from initrd */
+        load_default_modules();
+
         /*
          * In case that a resume from disk is carried out by linuxrc or one of
          * its children, we need to tell the freezer not to wait for us.
diff --git a/init/initramfs.c b/init/initramfs.c
index 84c6bf111300..a67ef9dbda9d 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -592,7 +592,7 @@ static int __init populate_rootfs(void)
                         initrd_end - initrd_start);
                 if (!err) {
                         free_initrd();
-                        return 0;
+                        goto done;
                 } else {
                         clean_rootfs();
                         unpack_to_rootfs(__initramfs_start, __initramfs_size);
@@ -607,6 +607,7 @@ static int __init populate_rootfs(void)
                         sys_close(fd);
                         free_initrd();
                 }
+        done:
 #else
                 printk(KERN_INFO "Unpacking initramfs...\n");
                 err = unpack_to_rootfs((char *)initrd_start,
@@ -615,6 +616,11 @@ static int __init populate_rootfs(void)
                         printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
                 free_initrd();
 #endif
+                /*
+                 * Try loading default modules from initramfs.  This gives
+                 * us a chance to load before device_initcalls.
+                 */
+                load_default_modules();
         }
         return 0;
 }
diff --git a/init/main.c b/init/main.c
index cee4b5c66d81..63534a141b4e 100644
--- a/init/main.c
+++ b/init/main.c
@@ -70,6 +70,8 @@
 #include <linux/perf_event.h>
 #include <linux/file.h>
 #include <linux/ptrace.h>
+#include <linux/blkdev.h>
+#include <linux/elevator.h>
 
 #include <asm/io.h>
 #include <asm/bugs.h>
@@ -794,6 +796,17 @@ static void __init do_pre_smp_initcalls(void)
                 do_one_initcall(*fn);
 }
 
+/*
+ * This function requests modules which should be loaded by default and is
+ * called twice right after initrd is mounted and right before init is
+ * exec'd.  If such modules are on either initrd or rootfs, they will be
+ * loaded before control is passed to userland.
+ */
+void __init load_default_modules(void)
+{
+        load_default_elevator_module();
+}
+
 static int run_init_process(const char *init_filename)
 {
         argv_init[0] = init_filename;
@@ -900,4 +913,7 @@ static noinline void __init kernel_init_freeable(void)
          * we're essentially up and running. Get rid of the
          * initmem segments and start the user-mode stuff..
          */
+
+        /* rootfs is available now, try loading default modules */
+        load_default_modules();
 }