1 files changed, 88 insertions, 24 deletions

diff --git a/drivers/mtd/ubi/fastmap-wl.c b/drivers/mtd/ubi/fastmap-wl.c
index 863f571f1adb..2a9cc9413c42 100644
--- a/drivers/mtd/ubi/fastmap-wl.c
+++ b/drivers/mtd/ubi/fastmap-wl.c
@@ -76,7 +76,7 @@ struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor)
 {
 	struct ubi_wl_entry *e = NULL;
 
-	if (!ubi->free.rb_node || (ubi->free_count - ubi->beb_rsvd_pebs < 1))
+	if (!ubi->free.rb_node)
 		goto out;
 
 	if (anchor)
@@ -98,43 +98,104 @@ out:
 }
 
 /*
- * has_enough_free_count - whether ubi has enough free pebs to fill fm pools
+ * wait_free_pebs_for_pool - wait until there enough free pebs
+ * @ubi: UBI device description object
+ *
+ * Wait and execute do_work until there are enough free pebs, fill pool
+ * as much as we can. This will reduce pool refilling times, which can
+ * reduce the fastmap updating frequency.
+ */
+static void wait_free_pebs_for_pool(struct ubi_device *ubi)
+{
+	struct ubi_fm_pool *wl_pool = &ubi->fm_wl_pool;
+	struct ubi_fm_pool *pool = &ubi->fm_pool;
+	int free, expect_free, executed;
+	/*
+	 * There are at least following free pebs which reserved by UBI:
+	 * 1. WL_RESERVED_PEBS[1]
+	 * 2. EBA_RESERVED_PEBS[1]
+	 * 3. fm pebs - 1: Twice fastmap size deducted by fastmap and fm_anchor
+	 * 4. beb_rsvd_pebs: This value should be get under lock ubi->wl_lock
+	 */
+	int reserved = WL_RESERVED_PEBS + EBA_RESERVED_PEBS +
+		       ubi->fm_size / ubi->leb_size - 1 + ubi->fm_pool_rsv_cnt;
+
+	do {
+		spin_lock(&ubi->wl_lock);
+		free = ubi->free_count;
+		free += pool->size - pool->used + wl_pool->size - wl_pool->used;
+		expect_free = reserved + ubi->beb_rsvd_pebs;
+		spin_unlock(&ubi->wl_lock);
+
+		/*
+		 * Break out if there are no works or work is executed failure,
+		 * given the fact that erase_worker will schedule itself when
+		 * -EBUSY is returned from mtd layer caused by system shutdown.
+		 */
+		if (do_work(ubi, &executed) || !executed)
+			break;
+	} while (free < expect_free);
+}
+
+/*
+ * left_free_count - returns the number of free pebs to fill fm pools
  * @ubi: UBI device description object
- * @is_wl_pool: whether UBI is filling wear leveling pool
  *
- * This helper function checks whether there are enough free pebs (deducted
- * by fastmap pebs) to fill fm_pool and fm_wl_pool, above rule works after
- * there is at least one of free pebs is filled into fm_wl_pool.
- * For wear leveling pool, UBI should also reserve free pebs for bad pebs
- * handling, because there maybe no enough free pebs for user volumes after
- * producing new bad pebs.
+ * This helper function returns the number of free pebs (deducted
+ * by fastmap pebs) to fill fm_pool and fm_wl_pool.
  */
-static bool has_enough_free_count(struct ubi_device *ubi, bool is_wl_pool)
+static int left_free_count(struct ubi_device *ubi)
 {
 	int fm_used = 0;	// fastmap non anchor pebs.
-	int beb_rsvd_pebs;
 
 	if (!ubi->free.rb_node)
-		return false;
+		return 0;
 
-	beb_rsvd_pebs = is_wl_pool ? ubi->beb_rsvd_pebs : 0;
-	if (ubi->fm_wl_pool.size > 0 && !(ubi->ro_mode || ubi->fm_disabled))
+	if (!ubi->ro_mode && !ubi->fm_disabled)
 		fm_used = ubi->fm_size / ubi->leb_size - 1;
 
-	return ubi->free_count - beb_rsvd_pebs > fm_used;
+	return ubi->free_count - fm_used;
+}
+
+/*
+ * can_fill_pools - whether free PEBs will be left after filling pools
+ * @ubi: UBI device description object
+ * @free: current number of free PEBs
+ *
+ * Return %1 if there are still left free PEBs after filling pools,
+ * otherwise %0 is returned.
+ */
+static int can_fill_pools(struct ubi_device *ubi, int free)
+{
+	struct ubi_fm_pool *wl_pool = &ubi->fm_wl_pool;
+	struct ubi_fm_pool *pool = &ubi->fm_pool;
+	int pool_need = pool->max_size - pool->size +
+			wl_pool->max_size - wl_pool->size;
+
+	if (free - pool_need < 1)
+		return 0;
+
+	return 1;
 }
 
 /**
- * ubi_refill_pools - refills all fastmap PEB pools.
+ * ubi_refill_pools_and_lock - refills all fastmap PEB pools and takes fm locks.
  * @ubi: UBI device description object
  */
-void ubi_refill_pools(struct ubi_device *ubi)
+void ubi_refill_pools_and_lock(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;
 	int enough;
 
+	if (!ubi->ro_mode && !ubi->fm_disabled)
+		wait_free_pebs_for_pool(ubi);
+
+	down_write(&ubi->fm_protect);
+	down_write(&ubi->work_sem);
+	down_write(&ubi->fm_eba_sem);
+
 	spin_lock(&ubi->wl_lock);
 
 	return_unused_pool_pebs(ubi, wl_pool);
@@ -159,7 +220,7 @@ void ubi_refill_pools(struct ubi_device *ubi)
 	for (;;) {
 		enough = 0;
 		if (pool->size < pool->max_size) {
-			if (!has_enough_free_count(ubi, false))
+			if (left_free_count(ubi) <= 0)
 				break;
 
 			e = wl_get_wle(ubi);
@@ -172,10 +233,13 @@ void ubi_refill_pools(struct ubi_device *ubi)
 			enough++;
 
 		if (wl_pool->size < wl_pool->max_size) {
-			if (!has_enough_free_count(ubi, true))
+			int left_free = left_free_count(ubi);
+
+			if (left_free <= 0)
 				break;
 
-			e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
+			e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF,
+					  !can_fill_pools(ubi, left_free));
 			self_check_in_wl_tree(ubi, e, &ubi->free);
 			rb_erase(&e->u.rb, &ubi->free);
 			ubi->free_count--;
@@ -210,7 +274,7 @@ static int produce_free_peb(struct ubi_device *ubi)
 
 	while (!ubi->free.rb_node && ubi->works_count) {
 		dbg_wl("do one work synchronously");
-		err = do_work(ubi);
+		err = do_work(ubi, NULL);
 
 		if (err)
 			return err;
@@ -315,12 +379,12 @@ static bool need_wear_leveling(struct ubi_device *ubi)
 	if (!e) {
 		if (!ubi->free.rb_node)
 			return false;
-		e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
+		e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF, 0);
 		ec = e->ec;
 	} else {
 		ec = e->ec;
 		if (ubi->free.rb_node) {
-			e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
+			e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF, 0);
 			ec = max(ec, e->ec);
 		}
 	}
@@ -481,7 +545,7 @@ static void ubi_fastmap_close(struct ubi_device *ubi)
 static struct ubi_wl_entry *may_reserve_for_fm(struct ubi_device *ubi,
 					   struct ubi_wl_entry *e,
 					   struct rb_root *root) {
-	if (e && !ubi->fm_disabled && !ubi->fm &&
+	if (e && !ubi->fm_disabled && !ubi->fm && !ubi->fm_anchor &&
 	    e->pnum < UBI_FM_MAX_START)
 		e = rb_entry(rb_next(root->rb_node),
 			     struct ubi_wl_entry, u.rb);