[PATCH] md: tidy up daemon stop/start code in md/bitmap.c

The bitmap code used to have two daemons, so there is some 'common' start/stop
code.  But now there is only one, so the common code is just noise.

This patch tidies this up somewhat.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 87145fa..2fba2bb 100644 (file)
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -626,7 +626,7 @@ static void bitmap_file_unmap(struct bitmap *bitmap)
                page_cache_release(sb_page);
 }
 
-static void bitmap_stop_daemons(struct bitmap *bitmap);
+static void bitmap_stop_daemon(struct bitmap *bitmap);
 
 /* dequeue the next item in a page list -- don't call from irq context */
 static struct page_list *dequeue_page(struct bitmap *bitmap)
@@ -668,7 +668,7 @@ static void bitmap_file_put(struct bitmap *bitmap)
        bitmap->file = NULL;
        spin_unlock_irqrestore(&bitmap->lock, flags);
 
-       bitmap_stop_daemons(bitmap);
+       bitmap_stop_daemon(bitmap);
 
        drain_write_queues(bitmap);
 
@@ -1188,21 +1188,12 @@ static void bitmap_writeback_daemon(mddev_t *mddev)
        }
 }
 
-static int bitmap_start_daemon(struct bitmap *bitmap, mdk_thread_t **ptr,
+static mdk_thread_t *bitmap_start_daemon(struct bitmap *bitmap,
                                void (*func)(mddev_t *), char *name)
 {
        mdk_thread_t *daemon;
-       unsigned long flags;
        char namebuf[32];
 
-       spin_lock_irqsave(&bitmap->lock, flags);
-       *ptr = NULL;
-
-       if (!bitmap->file) /* no need for daemon if there's no backing file */
-               goto out_unlock;
-
-       spin_unlock_irqrestore(&bitmap->lock, flags);
-
 #ifdef INJECT_FATAL_FAULT_2
        daemon = NULL;
 #else
@@ -1212,47 +1203,32 @@ static int bitmap_start_daemon(struct bitmap *bitmap, mdk_thread_t **ptr,
        if (!daemon) {
                printk(KERN_ERR "%s: failed to start bitmap daemon\n",
                        bmname(bitmap));
-               return -ECHILD;
+               return ERR_PTR(-ECHILD);
        }
 
-       spin_lock_irqsave(&bitmap->lock, flags);
-       *ptr = daemon;
-
        md_wakeup_thread(daemon); /* start it running */
 
        PRINTK("%s: %s daemon (pid %d) started...\n",
                bmname(bitmap), name, daemon->tsk->pid);
-out_unlock:
-       spin_unlock_irqrestore(&bitmap->lock, flags);
-       return 0;
-}
 
-static int bitmap_start_daemons(struct bitmap *bitmap)
-{
-       int err = bitmap_start_daemon(bitmap, &bitmap->writeback_daemon,
-                                       bitmap_writeback_daemon, "bitmap_wb");
-       return err;
+       return daemon;
 }
 
-static void bitmap_stop_daemon(struct bitmap *bitmap, mdk_thread_t **ptr)
+static void bitmap_stop_daemon(struct bitmap *bitmap)
 {
-       mdk_thread_t *daemon;
-       unsigned long flags;
-
-       spin_lock_irqsave(&bitmap->lock, flags);
-       daemon = *ptr;
-       *ptr = NULL;
-       spin_unlock_irqrestore(&bitmap->lock, flags);
-       if (daemon)
-               md_unregister_thread(daemon); /* destroy the thread */
-}
+       /* the daemon can't stop itself... it'll just exit instead... */
+       if (bitmap->writeback_daemon && ! IS_ERR(bitmap->writeback_daemon) &&
+           current->pid != bitmap->writeback_daemon->tsk->pid) {
+               mdk_thread_t *daemon;
+               unsigned long flags;
 
-static void bitmap_stop_daemons(struct bitmap *bitmap)
-{
-       /* the daemons can't stop themselves... they'll just exit instead... */
-       if (bitmap->writeback_daemon &&
-           current->pid != bitmap->writeback_daemon->tsk->pid)
-               bitmap_stop_daemon(bitmap, &bitmap->writeback_daemon);
+               spin_lock_irqsave(&bitmap->lock, flags);
+               daemon = bitmap->writeback_daemon;
+               bitmap->writeback_daemon = NULL;
+               spin_unlock_irqrestore(&bitmap->lock, flags);
+               if (daemon && ! IS_ERR(daemon))
+                       md_unregister_thread(daemon); /* destroy the thread */
+       }
 }
 
 static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
@@ -1637,10 +1613,15 @@ int bitmap_create(mddev_t *mddev)
 
        mddev->bitmap = bitmap;
 
-       /* kick off the bitmap daemons */
-       err = bitmap_start_daemons(bitmap);
-       if (err)
-               return err;
+       if (file)
+               /* kick off the bitmap writeback daemon */
+               bitmap->writeback_daemon =
+                       bitmap_start_daemon(bitmap,
+                                           bitmap_writeback_daemon,
+                                           "bitmap_wb");
+
+       if (IS_ERR(bitmap->writeback_daemon))
+               return PTR_ERR(bitmap->writeback_daemon);
        return bitmap_update_sb(bitmap);
 
  error:

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index bfe7857..a93ca47 100644 (file)
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1703,7 +1703,7 @@ static int raid1_reshape(mddev_t *mddev, int raid_disks)
        return 0;
 }
 
-void raid1_quiesce(mddev_t *mddev, int state)
+static void raid1_quiesce(mddev_t *mddev, int state)
 {
        conf_t *conf = mddev_to_conf(mddev);