--- zzzz-none-000/linux-3.10.107/drivers/mtd/ubi/wl.c	2017-06-27 09:49:32.000000000 +0000
+++ vr9-7490-729/linux-3.10.107/drivers/mtd/ubi/wl.c	2021-11-10 11:53:55.000000000 +0000
@@ -253,7 +253,7 @@
 	 */
 	err = wrk->func(ubi, wrk, 0);
 	if (err)
-		ubi_err("work failed with error code %d", err);
+		ubi_err(ubi, "work failed with error code %d", err);
 	up_read(&ubi->work_sem);
 
 	return err;
@@ -272,7 +272,7 @@
 {
 	int err;
 
-	while (!ubi->free.rb_node) {
+	while (!ubi->free.rb_node && ubi->works_count) {
 		spin_unlock(&ubi->wl_lock);
 
 		dbg_wl("do one work synchronously");
@@ -470,8 +470,11 @@
 {
 	struct ubi_wl_entry *e = NULL;
 
-	if (!ubi->free.rb_node || (ubi->free_count - ubi->beb_rsvd_pebs < 1))
+	if (!ubi->free.rb_node || (ubi->free_count - ubi->beb_rsvd_pebs < 1)) {
+		ubi_warn(ubi, "Can't get peb for fastmap:anchor=%d, free_cnt=%d, reserved=%d",
+			 anchor, ubi->free_count, ubi->beb_rsvd_pebs);
 		goto out;
+	}
 
 	if (anchor)
 		e = find_anchor_wl_entry(&ubi->free);
@@ -507,7 +510,7 @@
 retry:
 	if (!ubi->free.rb_node) {
 		if (ubi->works_count == 0) {
-			ubi_err("no free eraseblocks");
+			ubi_err(ubi, "no free eraseblocks");
 			ubi_assert(list_empty(&ubi->works));
 			return -ENOSPC;
 		}
@@ -520,7 +523,7 @@
 
 	e = find_mean_wl_entry(ubi, &ubi->free);
 	if (!e) {
-		ubi_err("no free eraseblocks");
+		ubi_err(ubi, "no free eraseblocks");
 		return -ENOSPC;
 	}
 
@@ -599,10 +602,6 @@
 	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 < 1))
-			break;
-
 		pool->pebs[pool->size] = __wl_get_peb(ubi);
 		if (pool->pebs[pool->size] < 0)
 			break;
@@ -675,6 +674,8 @@
 
 	e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
 	self_check_in_wl_tree(ubi, e, &ubi->free);
+	ubi->free_count--;
+	ubi_assert(ubi->free_count >= 0);
 	rb_erase(&e->u.rb, &ubi->free);
 
 	return e;
@@ -688,10 +689,14 @@
 	peb = __wl_get_peb(ubi);
 	spin_unlock(&ubi->wl_lock);
 
+	if (peb < 0)
+		return peb;
+
 	err = ubi_self_check_all_ff(ubi, peb, ubi->vid_hdr_aloffset,
 				    ubi->peb_size - ubi->vid_hdr_aloffset);
 	if (err) {
-		ubi_err("new PEB %d does not contain all 0xFF bytes", peb);
+		ubi_err(ubi, "new PEB %d does not contain all 0xFF bytes",
+			peb);
 		return err;
 	}
 
@@ -759,7 +764,7 @@
 		 * Erase counter overflow. Upgrade UBI and use 64-bit
 		 * erase counters internally.
 		 */
-		ubi_err("erase counter overflow at PEB %d, EC %llu",
+		ubi_err(ubi, "erase counter overflow at PEB %d, EC %llu",
 			e->pnum, ec);
 		err = -EINVAL;
 		goto out_free;
@@ -834,7 +839,7 @@
  * @wrk: the work to schedule
  *
  * This function adds a work defined by @wrk to the tail of the pending works
- * list. Can only be used of ubi->work_sem is already held in read mode!
+ * list. Can only be used if ubi->work_sem is already held in read mode!
  */
 static void __schedule_ubi_work(struct ubi_device *ubi, struct ubi_work *wrk)
 {
@@ -863,7 +868,7 @@
 }
 
 static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
-			int cancel);
+			int shutdown);
 
 #ifdef CONFIG_MTD_UBI_FASTMAP
 /**
@@ -989,14 +994,15 @@
  * wear_leveling_worker - wear-leveling worker function.
  * @ubi: UBI device description object
  * @wrk: the work object
- * @cancel: non-zero if the worker has to free memory and exit
+ * @shutdown: non-zero if the worker has to free memory and exit
+ * because the WL-subsystem is shutting down
  *
  * This function copies a more worn out physical eraseblock to a less worn out
  * one. Returns zero in case of success and a negative error code in case of
  * failure.
  */
 static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
-				int cancel)
+				int shutdown)
 {
 	int err, scrubbing = 0, torture = 0, protect = 0, erroneous = 0;
 	int vol_id = -1, lnum = -1;
@@ -1007,7 +1013,7 @@
 	struct ubi_vid_hdr *vid_hdr;
 
 	kfree(wrk);
-	if (cancel)
+	if (shutdown)
 		return 0;
 
 	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
@@ -1072,6 +1078,7 @@
 
 			/* Give the unused PEB back */
 			wl_tree_add(e2, &ubi->free);
+			ubi->free_count++;
 			goto out_cancel;
 		}
 		self_check_in_wl_tree(ubi, e1, &ubi->used);
@@ -1134,7 +1141,7 @@
 			goto out_not_moved;
 		}
 
-		ubi_err("error %d while reading VID header from PEB %d",
+		ubi_err(ubi, "error %d while reading VID header from PEB %d",
 			err, e1->pnum);
 		goto out_error;
 	}
@@ -1178,7 +1185,7 @@
 			 * UBI from trying to move it over and over again.
 			 */
 			if (ubi->erroneous_peb_count > ubi->max_erroneous) {
-				ubi_err("too many erroneous eraseblocks (%d)",
+				ubi_err(ubi, "too many erroneous eraseblocks (%d)",
 					ubi->erroneous_peb_count);
 				goto out_error;
 			}
@@ -1194,7 +1201,7 @@
 
 	/* The PEB has been successfully moved */
 	if (scrubbing)
-		ubi_msg("scrubbed PEB %d (LEB %d:%d), data moved to PEB %d",
+		ubi_msg(ubi, "scrubbed PEB %d (LEB %d:%d), data moved to PEB %d",
 			e1->pnum, vol_id, lnum, e2->pnum);
 	ubi_free_vid_hdr(ubi, vid_hdr);
 
@@ -1267,10 +1274,10 @@
 
 out_error:
 	if (vol_id != -1)
-		ubi_err("error %d while moving PEB %d to PEB %d",
+		ubi_err(ubi, "error %d while moving PEB %d to PEB %d",
 			err, e1->pnum, e2->pnum);
 	else
-		ubi_err("error %d while moving PEB %d (LEB %d:%d) to PEB %d",
+		ubi_err(ubi, "error %d while moving PEB %d (LEB %d:%d) to PEB %d",
 			err, e1->pnum, vol_id, lnum, e2->pnum);
 	spin_lock(&ubi->wl_lock);
 	ubi->move_from = ubi->move_to = NULL;
@@ -1401,7 +1408,8 @@
  * erase_worker - physical eraseblock erase worker function.
  * @ubi: UBI device description object
  * @wl_wrk: the work object
- * @cancel: non-zero if the worker has to free memory and exit
+ * @shutdown: non-zero if the worker has to free memory and exit
+ * because the WL sub-system is shutting down
  *
  * This function erases a physical eraseblock and perform torture testing if
  * needed. It also takes care about marking the physical eraseblock bad if
@@ -1409,7 +1417,7 @@
  * failure.
  */
 static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
-			int cancel)
+			int shutdown)
 {
 	struct ubi_wl_entry *e = wl_wrk->e;
 	int pnum = e->pnum;
@@ -1417,7 +1425,7 @@
 	int lnum = wl_wrk->lnum;
 	int err, available_consumed = 0;
 
-	if (cancel) {
+	if (shutdown) {
 		dbg_wl("cancel erasure of PEB %d EC %d", pnum, e->ec);
 		kfree(wl_wrk);
 		kmem_cache_free(ubi_wl_entry_slab, e);
@@ -1450,7 +1458,7 @@
 		return err;
 	}
 
-	ubi_err("failed to erase PEB %d, error %d", pnum, err);
+	ubi_err(ubi, "failed to erase PEB %d, error %d", pnum, err);
 	kfree(wl_wrk);
 
 	if (err == -EINTR || err == -ENOMEM || err == -EAGAIN ||
@@ -1478,7 +1486,7 @@
 	/* It is %-EIO, the PEB went bad */
 
 	if (!ubi->bad_allowed) {
-		ubi_err("bad physical eraseblock %d detected", pnum);
+		ubi_err(ubi, "bad physical eraseblock %d detected", pnum);
 		goto out_ro;
 	}
 
@@ -1486,7 +1494,7 @@
 	if (ubi->beb_rsvd_pebs == 0) {
 		if (ubi->avail_pebs == 0) {
 			spin_unlock(&ubi->volumes_lock);
-			ubi_err("no reserved/available physical eraseblocks");
+			ubi_err(ubi, "no reserved/available physical eraseblocks");
 			goto out_ro;
 		}
 		ubi->avail_pebs -= 1;
@@ -1494,7 +1502,7 @@
 	}
 	spin_unlock(&ubi->volumes_lock);
 
-	ubi_msg("mark PEB %d as bad", pnum);
+	ubi_msg(ubi, "mark PEB %d as bad", pnum);
 	err = ubi_io_mark_bad(ubi, pnum);
 	if (err)
 		goto out_ro;
@@ -1515,11 +1523,12 @@
 	ubi->good_peb_count -= 1;
 	ubi_calculate_reserved(ubi);
 	if (available_consumed)
-		ubi_warn("no PEBs in the reserved pool, used an available PEB");
+		ubi_warn(ubi, "no PEBs in the reserved pool, used an available PEB");
 	else if (ubi->beb_rsvd_pebs)
-		ubi_msg("%d PEBs left in the reserve", ubi->beb_rsvd_pebs);
+		ubi_msg(ubi, "%d PEBs left in the reserve",
+			ubi->beb_rsvd_pebs);
 	else
-		ubi_warn("last PEB from the reserve was used");
+		ubi_warn(ubi, "last PEB from the reserve was used");
 	spin_unlock(&ubi->volumes_lock);
 
 	return err;
@@ -1605,7 +1614,7 @@
 		} else {
 			err = prot_queue_del(ubi, e->pnum);
 			if (err) {
-				ubi_err("PEB %d not found", pnum);
+				ubi_err(ubi, "PEB %d not found", pnum);
 				ubi_ro_mode(ubi);
 				spin_unlock(&ubi->wl_lock);
 				return err;
@@ -1638,7 +1647,7 @@
 {
 	struct ubi_wl_entry *e;
 
-	ubi_msg("schedule PEB %d for scrubbing", pnum);
+	ubi_msg(ubi, "schedule PEB %d for scrubbing", pnum);
 
 retry:
 	spin_lock(&ubi->wl_lock);
@@ -1670,7 +1679,7 @@
 
 		err = prot_queue_del(ubi, e->pnum);
 		if (err) {
-			ubi_err("PEB %d not found", pnum);
+			ubi_err(ubi, "PEB %d not found", pnum);
 			ubi_ro_mode(ubi);
 			spin_unlock(&ubi->wl_lock);
 			return err;
@@ -1712,12 +1721,12 @@
 	       vol_id, lnum, ubi->works_count);
 
 	while (found) {
-		struct ubi_work *wrk;
+		struct ubi_work *wrk, *tmp;
 		found = 0;
 
 		down_read(&ubi->work_sem);
 		spin_lock(&ubi->wl_lock);
-		list_for_each_entry(wrk, &ubi->works, list) {
+		list_for_each_entry_safe(wrk, tmp, &ubi->works, list) {
 			if ((vol_id == UBI_ALL || wrk->vol_id == vol_id) &&
 			    (lnum == UBI_ALL || wrk->lnum == lnum)) {
 				list_del(&wrk->list);
@@ -1790,15 +1799,18 @@
 	int failures = 0;
 	struct ubi_device *ubi = u;
 
-	ubi_msg("background thread \"%s\" started, PID %d",
+	ubi_msg(ubi, "background thread \"%s\" started, PID %d",
 		ubi->bgt_name, task_pid_nr(current));
 
 	set_freezable();
 	for (;;) {
 		int err;
 
-		if (kthread_should_stop())
+		if (kthread_should_stop()) {
+			ubi_msg(ubi, "background thread \"%s\" should stop, PID %d",
+				ubi->bgt_name, task_pid_nr(current));
 			break;
+		}
 
 		if (try_to_freeze())
 			continue;
@@ -1815,14 +1827,14 @@
 
 		err = do_work(ubi);
 		if (err) {
-			ubi_err("%s: work failed with error code %d",
+			ubi_err(ubi, "%s: work failed with error code %d",
 				ubi->bgt_name, err);
 			if (failures++ > WL_MAX_FAILURES) {
 				/*
 				 * Too many failures, disable the thread and
 				 * switch to read-only mode.
 				 */
-				ubi_msg("%s: %d consecutive failures",
+				ubi_msg(ubi, "%s: %d consecutive failures",
 					ubi->bgt_name, WL_MAX_FAILURES);
 				ubi_ro_mode(ubi);
 				ubi->thread_enabled = 0;
@@ -1839,10 +1851,10 @@
 }
 
 /**
- * cancel_pending - cancel all pending works.
+ * shutdown_work - shutdown all pending works.
  * @ubi: UBI device description object
  */
-static void cancel_pending(struct ubi_device *ubi)
+static void shutdown_work(struct ubi_device *ubi)
 {
 	while (!list_empty(&ubi->works)) {
 		struct ubi_work *wrk;
@@ -1973,10 +1985,10 @@
 #endif
 
 	if (ubi->avail_pebs < reserved_pebs) {
-		ubi_err("no enough physical eraseblocks (%d, need %d)",
+		ubi_err(ubi, "no enough physical eraseblocks (%d, need %d)",
 			ubi->avail_pebs, reserved_pebs);
 		if (ubi->corr_peb_count)
-			ubi_err("%d PEBs are corrupted and not used",
+			ubi_err(ubi, "%d PEBs are corrupted and not used",
 				ubi->corr_peb_count);
 		err = -ENOSPC;
 		goto out_free;
@@ -1992,7 +2004,7 @@
 	return 0;
 
 out_free:
-	cancel_pending(ubi);
+	shutdown_work(ubi);
 	tree_destroy(&ubi->used);
 	tree_destroy(&ubi->free);
 	tree_destroy(&ubi->scrub);
@@ -2024,7 +2036,7 @@
 void ubi_wl_close(struct ubi_device *ubi)
 {
 	dbg_wl("close the WL sub-system");
-	cancel_pending(ubi);
+	shutdown_work(ubi);
 	protection_queue_destroy(ubi);
 	tree_destroy(&ubi->used);
 	tree_destroy(&ubi->erroneous);
@@ -2065,8 +2077,8 @@
 
 	read_ec = be64_to_cpu(ec_hdr->ec);
 	if (ec != read_ec && read_ec - ec > 1) {
-		ubi_err("self-check failed for PEB %d", pnum);
-		ubi_err("read EC is %lld, should be %d", read_ec, ec);
+		ubi_err(ubi, "self-check failed for PEB %d", pnum);
+		ubi_err(ubi, "read EC is %lld, should be %d", read_ec, ec);
 		dump_stack();
 		err = 1;
 	} else
@@ -2095,7 +2107,7 @@
 	if (in_wl_tree(e, root))
 		return 0;
 
-	ubi_err("self-check failed for PEB %d, EC %d, RB-tree %p ",
+	ubi_err(ubi, "self-check failed for PEB %d, EC %d, RB-tree %p ",
 		e->pnum, e->ec, root);
 	dump_stack();
 	return -EINVAL;
@@ -2123,7 +2135,7 @@
 			if (p == e)
 				return 0;
 
-	ubi_err("self-check failed for PEB %d, EC %d, Protect queue",
+	ubi_err(ubi, "self-check failed for PEB %d, EC %d, Protect queue",
 		e->pnum, e->ec);
 	dump_stack();
 	return -EINVAL;