1 files changed, 89 insertions, 40 deletions

diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 8455f1d47f3c..fbd399cf6503 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -165,7 +165,7 @@ static void wl_tree_add(struct ubi_wl_entry *e, struct rb_root *root)
 }
 
 /**
- * wl_tree_destroy - destroy a wear-leveling entry.
+ * wl_entry_destroy - destroy a wear-leveling entry.
  * @ubi: UBI device description object
  * @e: the wear-leveling entry to add
  *
@@ -181,11 +181,13 @@ static void wl_entry_destroy(struct ubi_device *ubi, struct ubi_wl_entry *e)
 /**
  * do_work - do one pending work.
  * @ubi: UBI device description object
+ * @executed: whether there is one work is executed
  *
  * This function returns zero in case of success and a negative error code in
- * case of failure.
+ * case of failure. If @executed is not NULL and there is one work executed,
+ * @executed is set as %1, otherwise @executed is set as %0.
  */
-static int do_work(struct ubi_device *ubi)
+static int do_work(struct ubi_device *ubi, int *executed)
 {
 	int err;
 	struct ubi_work *wrk;
@@ -203,9 +205,13 @@ static int do_work(struct ubi_device *ubi)
 	if (list_empty(&ubi->works)) {
 		spin_unlock(&ubi->wl_lock);
 		up_read(&ubi->work_sem);
+		if (executed)
+			*executed = 0;
 		return 0;
 	}
 
+	if (executed)
+		*executed = 1;
 	wrk = list_entry(ubi->works.next, struct ubi_work, list);
 	list_del(&wrk->list);
 	ubi->works_count -= 1;
@@ -311,12 +317,14 @@ static void prot_queue_add(struct ubi_device *ubi, struct ubi_wl_entry *e)
  * @ubi: UBI device description object
  * @root: the RB-tree where to look for
  * @diff: maximum possible difference from the smallest erase counter
+ * @pick_max: pick PEB even its erase counter beyonds 'min_ec + @diff'
  *
  * This function looks for a wear leveling entry with erase counter closest to
  * min + @diff, where min is the smallest erase counter.
  */
 static struct ubi_wl_entry *find_wl_entry(struct ubi_device *ubi,
-					  struct rb_root *root, int diff)
+					  struct rb_root *root, int diff,
+					  int pick_max)
 {
 	struct rb_node *p;
 	struct ubi_wl_entry *e;
@@ -330,9 +338,11 @@ static struct ubi_wl_entry *find_wl_entry(struct ubi_device *ubi,
 		struct ubi_wl_entry *e1;
 
 		e1 = rb_entry(p, struct ubi_wl_entry, u.rb);
-		if (e1->ec >= max)
+		if (e1->ec >= max) {
+			if (pick_max)
+				e = e1;
 			p = p->rb_left;
-		else {
+		} else {
 			p = p->rb_right;
 			e = e1;
 		}
@@ -361,12 +371,15 @@ static struct ubi_wl_entry *find_mean_wl_entry(struct ubi_device *ubi,
 	if (last->ec - first->ec < WL_FREE_MAX_DIFF) {
 		e = rb_entry(root->rb_node, struct ubi_wl_entry, u.rb);
 
-		/* If no fastmap has been written and this WL entry can be used
-		 * as anchor PEB, hold it back and return the second best
-		 * WL entry such that fastmap can use the anchor PEB later. */
+		/*
+		 * If no fastmap has been written and fm_anchor is not
+		 * reserved and this WL entry can be used as anchor PEB
+		 * hold it back and return the second best WL entry such
+		 * that fastmap can use the anchor PEB later.
+		 */
 		e = may_reserve_for_fm(ubi, e, root);
 	} else
-		e = find_wl_entry(ubi, root, WL_FREE_MAX_DIFF/2);
+		e = find_wl_entry(ubi, root, WL_FREE_MAX_DIFF/2, 0);
 
 	return e;
 }
@@ -376,7 +389,7 @@ static struct ubi_wl_entry *find_mean_wl_entry(struct ubi_device *ubi,
  * refill_wl_user_pool().
  * @ubi: UBI device description object
  *
- * This function returns a a wear leveling entry in case of success and
+ * This function returns a wear leveling entry in case of success and
  * NULL in case of failure.
  */
 static struct ubi_wl_entry *wl_get_wle(struct ubi_device *ubi)
@@ -427,16 +440,15 @@ static int prot_queue_del(struct ubi_device *ubi, int pnum)
 }
 
 /**
- * sync_erase - synchronously erase a physical eraseblock.
+ * ubi_sync_erase - synchronously erase a physical eraseblock.
  * @ubi: UBI device description object
- * @e: the the physical eraseblock to erase
+ * @e: the physical eraseblock to erase
  * @torture: if the physical eraseblock has to be tortured
  *
  * This function returns zero in case of success and a negative error code in
  * case of failure.
  */
-static int sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
-		      int torture)
+int ubi_sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e, int torture)
 {
 	int err;
 	struct ubi_ec_hdr *ec_hdr;
@@ -575,7 +587,7 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
  * @vol_id: the volume ID that last used this PEB
  * @lnum: the last used logical eraseblock number for the PEB
  * @torture: if the physical eraseblock has to be tortured
- * @nested: denotes whether the work_sem is already held in read mode
+ * @nested: denotes whether the work_sem is already held
  *
  * This function returns zero in case of success and a %-ENOMEM in case of
  * failure.
@@ -670,7 +682,11 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 	ubi_assert(!ubi->move_from && !ubi->move_to);
 	ubi_assert(!ubi->move_to_put);
 
+#ifdef CONFIG_MTD_UBI_FASTMAP
+	if (!next_peb_for_wl(ubi, true) ||
+#else
 	if (!ubi->free.rb_node ||
+#endif
 	    (!ubi->used.rb_node && !ubi->scrub.rb_node)) {
 		/*
 		 * No free physical eraseblocks? Well, they must be waiting in
@@ -689,16 +705,16 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 
 #ifdef CONFIG_MTD_UBI_FASTMAP
 	e1 = find_anchor_wl_entry(&ubi->used);
-	if (e1 && ubi->fm_next_anchor &&
-	    (ubi->fm_next_anchor->ec - e1->ec >= UBI_WL_THRESHOLD)) {
+	if (e1 && ubi->fm_anchor &&
+	    (ubi->fm_anchor->ec - e1->ec >= UBI_WL_THRESHOLD)) {
 		ubi->fm_do_produce_anchor = 1;
-		/* fm_next_anchor is no longer considered a good anchor
-		 * candidate.
+		/*
+		 * fm_anchor is no longer considered a good anchor.
 		 * NULL assignment also prevents multiple wear level checks
 		 * of this PEB.
 		 */
-		wl_tree_add(ubi->fm_next_anchor, &ubi->free);
-		ubi->fm_next_anchor = NULL;
+		wl_tree_add(ubi->fm_anchor, &ubi->free);
+		ubi->fm_anchor = NULL;
 		ubi->free_count++;
 	}
 
@@ -830,7 +846,14 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 			goto out_not_moved;
 		}
 		if (err == MOVE_RETRY) {
-			scrubbing = 1;
+			/*
+			 * For source PEB:
+			 * 1. The scrubbing is set for scrub type PEB, it will
+			 *    be put back into ubi->scrub list.
+			 * 2. Non-scrub type PEB will be put back into ubi->used
+			 *    list.
+			 */
+			keep = 1;
 			dst_leb_clean = 1;
 			goto out_not_moved;
 		}
@@ -886,8 +909,11 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 
 	err = do_sync_erase(ubi, e1, vol_id, lnum, 0);
 	if (err) {
-		if (e2)
+		if (e2) {
+			spin_lock(&ubi->wl_lock);
 			wl_entry_destroy(ubi, e2);
+			spin_unlock(&ubi->wl_lock);
+		}
 		goto out_ro;
 	}
 
@@ -969,11 +995,11 @@ out_error:
 	spin_lock(&ubi->wl_lock);
 	ubi->move_from = ubi->move_to = NULL;
 	ubi->move_to_put = ubi->wl_scheduled = 0;
+	wl_entry_destroy(ubi, e1);
+	wl_entry_destroy(ubi, e2);
 	spin_unlock(&ubi->wl_lock);
 
 	ubi_free_vid_buf(vidb);
-	wl_entry_destroy(ubi, e1);
-	wl_entry_destroy(ubi, e2);
 
 out_ro:
 	ubi_ro_mode(ubi);
@@ -1003,8 +1029,6 @@ out_cancel:
 static int ensure_wear_leveling(struct ubi_device *ubi, int nested)
 {
 	int err = 0;
-	struct ubi_wl_entry *e1;
-	struct ubi_wl_entry *e2;
 	struct ubi_work *wrk;
 
 	spin_lock(&ubi->wl_lock);
@@ -1014,9 +1038,16 @@ static int ensure_wear_leveling(struct ubi_device *ubi, int nested)
 
 	/*
 	 * If the ubi->scrub tree is not empty, scrubbing is needed, and the
-	 * the WL worker has to be scheduled anyway.
+	 * WL worker has to be scheduled anyway.
 	 */
 	if (!ubi->scrub.rb_node) {
+#ifdef CONFIG_MTD_UBI_FASTMAP
+		if (!need_wear_leveling(ubi))
+			goto out_unlock;
+#else
+		struct ubi_wl_entry *e1;
+		struct ubi_wl_entry *e2;
+
 		if (!ubi->used.rb_node || !ubi->free.rb_node)
 			/* No physical eraseblocks - no deal */
 			goto out_unlock;
@@ -1028,10 +1059,11 @@ static int ensure_wear_leveling(struct ubi_device *ubi, int nested)
 		 * %UBI_WL_THRESHOLD.
 		 */
 		e1 = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, u.rb);
-		e2 = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
+		e2 = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF, 0);
 
 		if (!(e2->ec - e1->ec >= UBI_WL_THRESHOLD))
 			goto out_unlock;
+#endif
 		dbg_wl("schedule wear-leveling");
 	} else
 		dbg_wl("schedule scrubbing");
@@ -1081,16 +1113,17 @@ static int __erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk)
 	dbg_wl("erase PEB %d EC %d LEB %d:%d",
 	       pnum, e->ec, wl_wrk->vol_id, wl_wrk->lnum);
 
-	err = sync_erase(ubi, e, wl_wrk->torture);
+	err = ubi_sync_erase(ubi, e, wl_wrk->torture);
 	if (!err) {
 		spin_lock(&ubi->wl_lock);
 
-		if (!ubi->fm_disabled && !ubi->fm_next_anchor &&
+		if (!ubi->fm_disabled && !ubi->fm_anchor &&
 		    e->pnum < UBI_FM_MAX_START) {
-			/* Abort anchor production, if needed it will be
+			/*
+			 * Abort anchor production, if needed it will be
 			 * enabled again in the wear leveling started below.
 			 */
-			ubi->fm_next_anchor = e;
+			ubi->fm_anchor = e;
 			ubi->fm_do_produce_anchor = 0;
 		} else {
 			wl_tree_add(e, &ubi->free);
@@ -1117,16 +1150,20 @@ static int __erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk)
 		int err1;
 
 		/* Re-schedule the LEB for erasure */
-		err1 = schedule_erase(ubi, e, vol_id, lnum, 0, false);
+		err1 = schedule_erase(ubi, e, vol_id, lnum, 0, true);
 		if (err1) {
+			spin_lock(&ubi->wl_lock);
 			wl_entry_destroy(ubi, e);
+			spin_unlock(&ubi->wl_lock);
 			err = err1;
 			goto out_ro;
 		}
 		return err;
 	}
 
+	spin_lock(&ubi->wl_lock);
 	wl_entry_destroy(ubi, e);
+	spin_unlock(&ubi->wl_lock);
 	if (err != -EIO)
 		/*
 		 * If this is not %-EIO, we have no idea what to do. Scheduling
@@ -1242,6 +1279,18 @@ int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum,
 retry:
 	spin_lock(&ubi->wl_lock);
 	e = ubi->lookuptbl[pnum];
+	if (!e) {
+		/*
+		 * This wl entry has been removed for some errors by other
+		 * process (eg. wear leveling worker), corresponding process
+		 * (except __erase_worker, which cannot concurrent with
+		 * ubi_wl_put_peb) will set ubi ro_mode at the same time,
+		 * just ignore this wl entry.
+		 */
+		spin_unlock(&ubi->wl_lock);
+		up_read(&ubi->fm_protect);
+		return 0;
+	}
 	if (e == ubi->move_from) {
 		/*
 		 * User is putting the physical eraseblock which was selected to
@@ -1453,7 +1502,7 @@ static bool scrub_possible(struct ubi_device *ubi, struct ubi_wl_entry *e)
  * ubi_bitflip_check - Check an eraseblock for bitflips and scrub it if needed.
  * @ubi: UBI device description object
  * @pnum: the physical eraseblock to schedule
- * @force: dont't read the block, assume bitflips happened and take action.
+ * @force: don't read the block, assume bitflips happened and take action.
  *
  * This function reads the given eraseblock and checks if bitflips occured.
  * In case of bitflips, the eraseblock is scheduled for scrubbing.
@@ -1656,7 +1705,7 @@ int ubi_thread(void *u)
 		}
 		spin_unlock(&ubi->wl_lock);
 
-		err = do_work(ubi);
+		err = do_work(ubi, NULL);
 		if (err) {
 			ubi_err(ubi, "%s: work failed with error code %d",
 				ubi->bgt_name, err);
@@ -1719,7 +1768,7 @@ static int erase_aeb(struct ubi_device *ubi, struct ubi_ainf_peb *aeb, bool sync
 	ubi->lookuptbl[e->pnum] = e;
 
 	if (sync) {
-		err = sync_erase(ubi, e, false);
+		err = ubi_sync_erase(ubi, e, false);
 		if (err)
 			goto out_free;
 
@@ -2041,7 +2090,7 @@ static struct ubi_wl_entry *get_peb_for_wl(struct ubi_device *ubi)
 {
 	struct ubi_wl_entry *e;
 
-	e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
+	e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF, 0);
 	self_check_in_wl_tree(ubi, e, &ubi->free);
 	ubi->free_count--;
 	ubi_assert(ubi->free_count >= 0);
@@ -2067,7 +2116,7 @@ static int produce_free_peb(struct ubi_device *ubi)
 		spin_unlock(&ubi->wl_lock);
 
 		dbg_wl("do one work synchronously");
-		err = do_work(ubi);
+		err = do_work(ubi, NULL);
 
 		spin_lock(&ubi->wl_lock);
 		if (err)