[PATCH][RFC]Ext4: Use get_cpu()/put_cpu() in preemptible context

[Mingming Cao <cmm@us.ibm.com>]

Fix the warning of:

printk: 369 messages suppressed.
BUG: using smp_processor_id() in preemptible [00000001] code: fsx-linux/31702
caller is ext4_mb_new_blocks+0x2aa/0x1319

Signed-off-by: Mingming Cao <cmm@us.ibm.com>

---
 fs/ext4/mballoc.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Index: linux-2.6.24-rc1/fs/ext4/mballoc.c
===================================================================
--- linux-2.6.24-rc1.orig/fs/ext4/mballoc.c	2007-11-02 17:22:18.000000000 -0700
+++ linux-2.6.24-rc1/fs/ext4/mballoc.c	2007-11-02 17:23:02.000000000 -0700
@@ -4006,7 +4006,8 @@ static void ext4_mb_group_or_file(struct
 		return;
 
 	BUG_ON(ac->ac_lg != NULL);
-	ac->ac_lg = &sbi->s_locality_groups[smp_processor_id()];
+	ac->ac_lg = &sbi->s_locality_groups[get_cpu()];
+	put_cpu();
 
 	/* we're going to use group allocation */
 	ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC;