dm thin: initialize dm_thin_new_mapping returned by get_next_mapping

As additional members are added to the dm_thin_new_mapping structure
care should be taken to make sure they get initialized before use.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org

diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index ee29037ffc2e74633050b708718ccbe963bf20d1..da65febdb6c48fe59b03e2d34d40c77a9cd9b8bd 100644 (file)
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -751,13 +751,17 @@ static int ensure_next_mapping(struct pool *pool)
 
 static struct dm_thin_new_mapping *get_next_mapping(struct pool *pool)
 {
-       struct dm_thin_new_mapping *r = pool->next_mapping;
+       struct dm_thin_new_mapping *m = pool->next_mapping;
 
        BUG_ON(!pool->next_mapping);
 
+       memset(m, 0, sizeof(struct dm_thin_new_mapping));
+       INIT_LIST_HEAD(&m->list);
+       m->bio = NULL;
+
        pool->next_mapping = NULL;
 
-       return r;
+       return m;
 }
 
 static void schedule_copy(struct thin_c *tc, dm_block_t virt_block,
@@ -769,15 +773,10 @@ static void schedule_copy(struct thin_c *tc, dm_block_t virt_block,
        struct pool *pool = tc->pool;
        struct dm_thin_new_mapping *m = get_next_mapping(pool);
 
-       INIT_LIST_HEAD(&m->list);
-       m->quiesced = 0;
-       m->prepared = 0;
        m->tc = tc;
        m->virt_block = virt_block;
        m->data_block = data_dest;
        m->cell = cell;
-       m->err = 0;
-       m->bio = NULL;
 
        if (!dm_deferred_set_add_work(pool->shared_read_ds, &m->list))
                m->quiesced = 1;
@@ -840,15 +839,12 @@ static void schedule_zero(struct thin_c *tc, dm_block_t virt_block,
        struct pool *pool = tc->pool;
        struct dm_thin_new_mapping *m = get_next_mapping(pool);
 
-       INIT_LIST_HEAD(&m->list);
        m->quiesced = 1;
        m->prepared = 0;
        m->tc = tc;
        m->virt_block = virt_block;
        m->data_block = data_block;
        m->cell = cell;
-       m->err = 0;
-       m->bio = NULL;
 
        /*
         * If the whole block of data is being overwritten or we are not
@@ -1045,7 +1041,6 @@ static void process_discard(struct thin_c *tc, struct bio *bio)
                        m->data_block = lookup_result.block;
                        m->cell = cell;
                        m->cell2 = cell2;
-                       m->err = 0;
                        m->bio = bio;
 
                        if (!dm_deferred_set_add_work(pool->all_io_ds, &m->list)) {