UBI: Fastmap: Make ubi_refill_pools() fair

Currently ubi_refill_pools() first fills the first and then
the second one.
If only very few free PEBs are available the second pool can get
zero PEBs.
Change ubi_refill_pools() to distribute free PEBs fair between
all pools.

Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Guido Martínez <guido@vanguardiasur.com.ar>

diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 9f57d6b7579b2c73d6588144c83d15c095b3627a..227ca641f700a98a44967e2667b6c90b49169e08 100644 (file)
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -580,59 +580,62 @@ static void return_unused_pool_pebs(struct ubi_device *ubi,
 }
 
 /**
- * refill_wl_pool - refills all the fastmap pool used by the
- * WL sub-system.
+ * ubi_refill_pools - refills all fastmap PEB pools.
  * @ubi: UBI device description object
  */
-static void refill_wl_pool(struct ubi_device *ubi)
+void ubi_refill_pools(struct ubi_device *ubi)
 {
+       struct ubi_fm_pool *wl_pool = &ubi->fm_wl_pool;
+       struct ubi_fm_pool *pool = &ubi->fm_pool;
        struct ubi_wl_entry *e;
-       struct ubi_fm_pool *pool = &ubi->fm_wl_pool;
+       int enough;
 
+       spin_lock(&ubi->wl_lock);
+
+       return_unused_pool_pebs(ubi, wl_pool);
        return_unused_pool_pebs(ubi, pool);
 
-       for (pool->size = 0; pool->size < pool->max_size; pool->size++) {
-               if (!ubi->free.rb_node ||
-                  (ubi->free_count - ubi->beb_rsvd_pebs < 5))
-                       break;
+       wl_pool->size = 0;
+       pool->size = 0;
 
-               e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
-               self_check_in_wl_tree(ubi, e, &ubi->free);
-               rb_erase(&e->u.rb, &ubi->free);
-               ubi->free_count--;
+       for (;;) {
+               enough = 0;
+               if (pool->size < pool->max_size) {
+                       if (!ubi->free.rb_node ||
+                          (ubi->free_count - ubi->beb_rsvd_pebs < 5))
+                               break;
 
-               pool->pebs[pool->size] = e->pnum;
-       }
-       pool->used = 0;
-}
+                       e = wl_get_wle(ubi);
+                       if (!e)
+                               break;
 
-/**
- * refill_wl_user_pool - refills all the fastmap pool used by ubi_wl_get_peb.
- * @ubi: UBI device description object
- */
-static void refill_wl_user_pool(struct ubi_device *ubi)
-{
-       struct ubi_fm_pool *pool = &ubi->fm_pool;
+                       pool->pebs[pool->size] = e->pnum;
+                       pool->size++;
+               } else
+                       enough++;
 
-       return_unused_pool_pebs(ubi, pool);
+               if (wl_pool->size < wl_pool->max_size) {
+                       if (!ubi->free.rb_node ||
+                          (ubi->free_count - ubi->beb_rsvd_pebs < 5))
+                               break;
+
+                       e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
+                       self_check_in_wl_tree(ubi, e, &ubi->free);
+                       rb_erase(&e->u.rb, &ubi->free);
+                       ubi->free_count--;
+
+                       wl_pool->pebs[wl_pool->size] = e->pnum;
+                       wl_pool->size++;
+               } else
+                       enough++;
 
-       for (pool->size = 0; pool->size < pool->max_size; pool->size++) {
-               pool->pebs[pool->size] = __wl_get_peb(ubi);
-               if (pool->pebs[pool->size] < 0)
+               if (enough == 2)
                        break;
        }
+
+       wl_pool->used = 0;
        pool->used = 0;
-}
 
-/**
- * ubi_refill_pools - refills all fastmap PEB pools.
- * @ubi: UBI device description object
- */
-void ubi_refill_pools(struct ubi_device *ubi)
-{
-       spin_lock(&ubi->wl_lock);
-       refill_wl_pool(ubi);
-       refill_wl_user_pool(ubi);
        spin_unlock(&ubi->wl_lock);
 }
 
@@ -2002,9 +2005,15 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
 
        dbg_wl("found %i PEBs", found_pebs);
 
-       if (ubi->fm)
+       if (ubi->fm) {
                ubi_assert(ubi->good_peb_count == \
                           found_pebs + ubi->fm->used_blocks);
+
+               for (i = 0; i < ubi->fm->used_blocks; i++) {
+                       e = ubi->fm->e[i];
+                       ubi->lookuptbl[e->pnum] = e;
+               }
+       }
        else
                ubi_assert(ubi->good_peb_count == found_pebs);