fs/buffer: Convert to hotplug state machine

Install the callbacks via the state machine.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-fsdevel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20161103145021.28528-2-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 6 insertions, 10 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index b205a629001d..1613656028d6 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -3403,7 +3403,7 @@ void free_buffer_head(struct buffer_head *bh)
 }
 EXPORT_SYMBOL(free_buffer_head);
 
-static void buffer_exit_cpu(int cpu)
+static int buffer_exit_cpu_dead(unsigned int cpu)
 {
         int i;
         struct bh_lru *b = &per_cpu(bh_lrus, cpu);
@@ -3414,14 +3414,7 @@ static void buffer_exit_cpu(int cpu)
         }
         this_cpu_add(bh_accounting.nr, per_cpu(bh_accounting, cpu).nr);
         per_cpu(bh_accounting, cpu).nr = 0;
-}
-
-static int buffer_cpu_notify(struct notifier_block *self,
-                              unsigned long action, void *hcpu)
-{
-        if (action == CPU_DEAD || action == CPU_DEAD_FROZEN)
-                buffer_exit_cpu((unsigned long)hcpu);
-        return NOTIFY_OK;
+        return 0;
 }
 
 /**
@@ -3471,6 +3464,7 @@ EXPORT_SYMBOL(bh_submit_read);
 void __init buffer_init(void)
 {
         unsigned long nrpages;
+        int ret;
 
         bh_cachep = kmem_cache_create("buffer_head",
                         sizeof(struct buffer_head), 0,
@@ -3483,5 +3477,7 @@ void __init buffer_init(void)
          */
         nrpages = (nr_free_buffer_pages() * 10) / 100;
         max_buffer_heads = nrpages * (PAGE_SIZE / sizeof(struct buffer_head));
-        hotcpu_notifier(buffer_cpu_notify, 0);
+        ret = cpuhp_setup_state_nocalls(CPUHP_FS_BUFF_DEAD, "fs/buffer:dead",
+                                        NULL, buffer_exit_cpu_dead);
+        WARN_ON(ret < 0);
 }