disable FB

hc

2024-01-04 1543e317f1da31b75942316931e8f491a8920811

 kernel/drivers/mtd/ubi/fastmap-wl.c
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@@ -1,17 +1,8 @@
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+// SPDX-License-Identifier: GPL-2.0-only
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 /*
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  * Copyright (c) 2012 Linutronix GmbH
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  * Copyright (c) 2014 sigma star gmbh
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  * Author: Richard Weinberger <richard@nod.at>
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- *
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- * This program is free software; you can redistribute it and/or modify
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- * it under the terms of the GNU General Public License as published by
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- * the Free Software Foundation; version 2.
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- *
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- * This program is distributed in the hope that it will be useful,
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- * but WITHOUT ANY WARRANTY; without even the implied warranty of
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- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
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- * the GNU General Public License for more details.
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- *
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  */
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 /**
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@@ -106,6 +97,33 @@
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 	return e;
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 }
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99
 
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+/*
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+ * has_enough_free_count - whether ubi has enough free pebs to fill fm pools
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+ * @ubi: UBI device description object
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+ * @is_wl_pool: whether UBI is filling wear leveling pool
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+ *
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+ * This helper function checks whether there are enough free pebs (deducted
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+ * by fastmap pebs) to fill fm_pool and fm_wl_pool, above rule works after
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+ * there is at least one of free pebs is filled into fm_wl_pool.
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+ * For wear leveling pool, UBI should also reserve free pebs for bad pebs
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+ * handling, because there maybe no enough free pebs for user volumes after
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+ * producing new bad pebs.
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+ */
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+static bool has_enough_free_count(struct ubi_device *ubi, bool is_wl_pool)
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+{
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+	int fm_used = 0;	// fastmap non anchor pebs.
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+	int beb_rsvd_pebs;
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+
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+	if (!ubi->free.rb_node)
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+		return false;
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+
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+	beb_rsvd_pebs = is_wl_pool ? ubi->beb_rsvd_pebs : 0;
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+	if (ubi->fm_wl_pool.size > 0 && !(ubi->ro_mode || ubi->fm_disabled))
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+		fm_used = ubi->fm_size / ubi->leb_size - 1;
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+
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+	return ubi->free_count - beb_rsvd_pebs > fm_used;
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+}
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+
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 /**
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  * ubi_refill_pools - refills all fastmap PEB pools.
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  * @ubi: UBI device description object
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@@ -125,10 +143,23 @@
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 	wl_pool->size = 0;
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 	pool->size = 0;
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+	if (ubi->fm_anchor) {
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+		wl_tree_add(ubi->fm_anchor, &ubi->free);
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+		ubi->free_count++;
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+		ubi->fm_anchor = NULL;
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+	}
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+
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+	if (!ubi->fm_disabled)
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+		/*
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+		 * All available PEBs are in ubi->free, now is the time to get
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+		 * the best anchor PEBs.
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+		 */
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+		ubi->fm_anchor = ubi_wl_get_fm_peb(ubi, 1);
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+
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 	for (;;) {
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 		enough = 0;
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 		if (pool->size < pool->max_size) {
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-			if (!ubi->free.rb_node)
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+			if (!has_enough_free_count(ubi, false))
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 				break;
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 			e = wl_get_wle(ubi);
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@@ -141,8 +172,7 @@
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 			enough++;
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 		if (wl_pool->size < wl_pool->max_size) {
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-			if (!ubi->free.rb_node ||
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-			   (ubi->free_count - ubi->beb_rsvd_pebs < 5))
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+			if (!has_enough_free_count(ubi, true))
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 				break;
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 			e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
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@@ -199,7 +229,7 @@
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  */
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 int ubi_wl_get_peb(struct ubi_device *ubi)
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 {
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-	int ret, retried = 0;
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+	int ret, attempts = 0;
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 	struct ubi_fm_pool *pool = &ubi->fm_pool;
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 	struct ubi_fm_pool *wl_pool = &ubi->fm_wl_pool;
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@@ -224,12 +254,12 @@
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 	if (pool->used == pool->size) {
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 		spin_unlock(&ubi->wl_lock);
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-		if (retried) {
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+		attempts++;
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+		if (attempts == 10) {
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 			ubi_err(ubi, "Unable to get a free PEB from user WL pool");
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 			ret = -ENOSPC;
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 			goto out;
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 		}
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-		retried = 1;
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 		up_read(&ubi->fm_eba_sem);
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 		ret = produce_free_peb(ubi);
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 		if (ret < 0) {
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@@ -298,8 +328,8 @@
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 		return 0;
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 	}
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-	/* No luck, trigger wear leveling to produce a new anchor PEB */
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 	ubi->fm_do_produce_anchor = 1;
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+	/* No luck, trigger wear leveling to produce a new anchor PEB. */
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 	if (ubi->wl_scheduled) {
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 		spin_unlock(&ubi->wl_lock);
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 		return 0;