md/raid5: new alloc_stripe() to allocate an initialize a stripe.

The new batch_lock and batch_list fields are being initialized in
grow_one_stripe() but not in resize_stripes().  This causes a crash
on resize.

So separate the core initialization into a new function and call it
from both allocation sites.

Signed-off-by: NeilBrown <neilb@suse.de>
Fixes: 0a082b77715a ("RAID5: batch adjacent full stripe write")

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 77dfd720aaa00ebc55d14234cd40b6e9b65bae5f..91a1e8b26b521a59f93a5d325b2df7607f270b09 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -1971,17 +1971,30 @@ static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
        put_cpu();
 }
 
+static struct stripe_head *alloc_stripe(struct kmem_cache *sc, gfp_t gfp)
+{
+       struct stripe_head *sh;
+
+       sh = kmem_cache_zalloc(sc, gfp);
+       if (sh) {
+               spin_lock_init(&sh->stripe_lock);
+               spin_lock_init(&sh->batch_lock);
+               INIT_LIST_HEAD(&sh->batch_list);
+               INIT_LIST_HEAD(&sh->lru);
+               atomic_set(&sh->count, 1);
+       }
+       return sh;
+}
 static int grow_one_stripe(struct r5conf *conf, gfp_t gfp)
 {
        struct stripe_head *sh;
-       sh = kmem_cache_zalloc(conf->slab_cache, gfp);
+
+       sh = alloc_stripe(conf->slab_cache, gfp);
        if (!sh)
                return 0;
 
        sh->raid_conf = conf;
 
-       spin_lock_init(&sh->stripe_lock);
-
        if (grow_buffers(sh, gfp)) {
                shrink_buffers(sh);
                kmem_cache_free(conf->slab_cache, sh);
@@ -1990,13 +2003,8 @@ static int grow_one_stripe(struct r5conf *conf, gfp_t gfp)
        sh->hash_lock_index =
                conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS;
        /* we just created an active stripe so... */
-       atomic_set(&sh->count, 1);
        atomic_inc(&conf->active_stripes);
-       INIT_LIST_HEAD(&sh->lru);
 
-       spin_lock_init(&sh->batch_lock);
-       INIT_LIST_HEAD(&sh->batch_list);
-       sh->batch_head = NULL;
        release_stripe(sh);
        conf->max_nr_stripes++;
        return 1;
@@ -2109,13 +2117,11 @@ static int resize_stripes(struct r5conf *conf, int newsize)
                return -ENOMEM;
 
        for (i = conf->max_nr_stripes; i; i--) {
-               nsh = kmem_cache_zalloc(sc, GFP_KERNEL);
+               nsh = alloc_stripe(sc, GFP_KERNEL);
                if (!nsh)
                        break;
 
                nsh->raid_conf = conf;
-               spin_lock_init(&nsh->stripe_lock);
-
                list_add(&nsh->lru, &newstripes);
        }
        if (i) {
@@ -2142,13 +2148,11 @@ static int resize_stripes(struct r5conf *conf, int newsize)
                                    lock_device_hash_lock(conf, hash));
                osh = get_free_stripe(conf, hash);
                unlock_device_hash_lock(conf, hash);
-               atomic_set(&nsh->count, 1);
+
                for(i=0; i<conf->pool_size; i++) {
                        nsh->dev[i].page = osh->dev[i].page;
                        nsh->dev[i].orig_page = osh->dev[i].page;
                }
-               for( ; i<newsize; i++)
-                       nsh->dev[i].page = NULL;
                nsh->hash_lock_index = hash;
                kmem_cache_free(conf->slab_cache, osh);
                cnt++;