From: Jonathan Brassow <jbrassow@redhat.com>
Subject: [PATCH RHEL 5.1] BZ 242069 - move fn call that could block outside 	spinlock
Date: Fri, 01 Jun 2007 13:43:17 -0500
Bugzilla: 242069
Message-Id: <1180723397.22889.2.camel@hydrogen.msp.redhat.com>
Changelog: [md] move fn call that could block outside spinlock


 brassow

>From drivers/md/dm-log.h:
        /*
         * Mark an area as clean or dirty.  These functions may
         * block, though for performance reasons blocking should
         * be extremely rare (eg, allocating another chunk of
         * memory for some reason).
         */
        void (*mark_region)(struct dirty_log *log, region_t region);
        void (*clear_region)(struct dirty_log *log, region_t region);

These function rarely block, but they could.  Would be a good idea
to move the clear_region call in rh_update_states outside the
spin lock.

Index: linux-rhel5/drivers/md/dm-raid1.c
===================================================================
--- linux-rhel5.orig/drivers/md/dm-raid1.c
+++ linux-rhel5/drivers/md/dm-raid1.c
@@ -396,10 +396,8 @@ static void rh_update_states(struct regi
 		list_splice(&rh->clean_regions, &clean);
 		INIT_LIST_HEAD(&rh->clean_regions);
 
-		list_for_each_entry (reg, &clean, list) {
-			rh->log->type->clear_region(rh->log, reg->key);
+		list_for_each_entry (reg, &clean, list)
 			list_del(&reg->hash_list);
-		}
 	}
 
 	if (!list_empty(&rh->recovered_regions)) {
@@ -437,14 +435,15 @@ static void rh_update_states(struct regi
 		mempool_free(reg, rh->region_pool);
 	}
 
+	list_for_each_entry_safe (reg, next, &clean, list) {
+		rh->log->type->clear_region(rh->log, reg->key);
+		mempool_free(reg, rh->region_pool);
+	}
 	/*
 	 * If the log implementation is good, it will only
 	 * flush (to disk) if it is necessary.
 	 */
 	rh->log->type->flush(rh->log);
-
-	list_for_each_entry_safe (reg, next, &clean, list)
-		mempool_free(reg, rh->region_pool);
 }
 
 static void rh_inc(struct region_hash *rh, region_t region)