Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/drivers/mtd/ubi/debug.c b/drivers/mtd/ubi/debug.c
index a1dff92..8a83072 100644
--- a/drivers/mtd/ubi/debug.c
+++ b/drivers/mtd/ubi/debug.c
@@ -392,9 +392,6 @@
 {
 	struct ubi_device *ubi = s->private;
 
-	if (*pos == 0)
-		return SEQ_START_TOKEN;
-
 	if (*pos < ubi->peb_count)
 		return pos;
 
@@ -408,8 +405,6 @@
 {
 	struct ubi_device *ubi = s->private;
 
-	if (v == SEQ_START_TOKEN)
-		return pos;
 	(*pos)++;
 
 	if (*pos < ubi->peb_count)
@@ -431,11 +426,8 @@
 	int err;
 
 	/* If this is the start, print a header */
-	if (iter == SEQ_START_TOKEN) {
-		seq_puts(s,
-			 "physical_block_number\terase_count\tblock_status\tread_status\n");
-		return 0;
-	}
+	if (*block_number == 0)
+		seq_puts(s, "physical_block_number\terase_count\n");
 
 	err = ubi_io_is_bad(ubi, *block_number);
 	if (err)
diff --git a/drivers/mtd/ubi/fastmap-wl.c b/drivers/mtd/ubi/fastmap-wl.c
index c44c847..b486250 100644
--- a/drivers/mtd/ubi/fastmap-wl.c
+++ b/drivers/mtd/ubi/fastmap-wl.c
@@ -39,6 +39,13 @@
 	return victim;
 }
 
+static inline void return_unused_peb(struct ubi_device *ubi,
+				     struct ubi_wl_entry *e)
+{
+	wl_tree_add(e, &ubi->free);
+	ubi->free_count++;
+}
+
 /**
  * return_unused_pool_pebs - returns unused PEB to the free tree.
  * @ubi: UBI device description object
@@ -52,23 +59,10 @@
 
 	for (i = pool->used; i < pool->size; i++) {
 		e = ubi->lookuptbl[pool->pebs[i]];
-		wl_tree_add(e, &ubi->free);
-		ubi->free_count++;
+		return_unused_peb(ubi, e);
 	}
 }
 
-static int anchor_pebs_available(struct rb_root *root)
-{
-	struct rb_node *p;
-	struct ubi_wl_entry *e;
-
-	ubi_rb_for_each_entry(p, e, root, u.rb)
-		if (e->pnum < UBI_FM_MAX_START)
-			return 1;
-
-	return 0;
-}
-
 /**
  * ubi_wl_get_fm_peb - find a physical erase block with a given maximal number.
  * @ubi: UBI device description object
@@ -277,8 +271,26 @@
 int ubi_ensure_anchor_pebs(struct ubi_device *ubi)
 {
 	struct ubi_work *wrk;
+	struct ubi_wl_entry *anchor;
 
 	spin_lock(&ubi->wl_lock);
+
+	/* Do we already have an anchor? */
+	if (ubi->fm_anchor) {
+		spin_unlock(&ubi->wl_lock);
+		return 0;
+	}
+
+	/* See if we can find an anchor PEB on the list of free PEBs */
+	anchor = ubi_wl_get_fm_peb(ubi, 1);
+	if (anchor) {
+		ubi->fm_anchor = anchor;
+		spin_unlock(&ubi->wl_lock);
+		return 0;
+	}
+
+	/* No luck, trigger wear leveling to produce a new anchor PEB */
+	ubi->fm_do_produce_anchor = 1;
 	if (ubi->wl_scheduled) {
 		spin_unlock(&ubi->wl_lock);
 		return 0;
@@ -294,7 +306,6 @@
 		return -ENOMEM;
 	}
 
-	wrk->anchor = 1;
 	wrk->func = &wear_leveling_worker;
 	__schedule_ubi_work(ubi, wrk);
 	return 0;
@@ -356,6 +367,11 @@
 	return_unused_pool_pebs(ubi, &ubi->fm_pool);
 	return_unused_pool_pebs(ubi, &ubi->fm_wl_pool);
 
+	if (ubi->fm_anchor) {
+		return_unused_peb(ubi, ubi->fm_anchor);
+		ubi->fm_anchor = NULL;
+	}
+
 	if (ubi->fm) {
 		for (i = 0; i < ubi->fm->used_blocks; i++)
 			kfree(ubi->fm->e[i]);
diff --git a/drivers/mtd/ubi/fastmap.c b/drivers/mtd/ubi/fastmap.c
index 30621c6..53f448e 100644
--- a/drivers/mtd/ubi/fastmap.c
+++ b/drivers/mtd/ubi/fastmap.c
@@ -64,7 +64,7 @@
 		return 0;
 
 	for (pnum = 0; pnum < ubi->peb_count; pnum++) {
-		if (test_bit(pnum, seen) && ubi->lookuptbl[pnum]) {
+		if (!test_bit(pnum, seen) && ubi->lookuptbl[pnum]) {
 			ubi_err(ubi, "self-check failed for PEB %d, fastmap didn't see it", pnum);
 			ret = -EINVAL;
 		}
@@ -1137,7 +1137,7 @@
 	struct rb_node *tmp_rb;
 	int ret, i, j, free_peb_count, used_peb_count, vol_count;
 	int scrub_peb_count, erase_peb_count;
-	unsigned long *seen_pebs = NULL;
+	unsigned long *seen_pebs;
 
 	fm_raw = ubi->fm_buf;
 	memset(ubi->fm_buf, 0, ubi->fm_size);
@@ -1151,7 +1151,7 @@
 	dvbuf = new_fm_vbuf(ubi, UBI_FM_DATA_VOLUME_ID);
 	if (!dvbuf) {
 		ret = -ENOMEM;
-		goto out_kfree;
+		goto out_free_avbuf;
 	}
 
 	avhdr = ubi_get_vid_hdr(avbuf);
@@ -1160,7 +1160,7 @@
 	seen_pebs = init_seen(ubi);
 	if (IS_ERR(seen_pebs)) {
 		ret = PTR_ERR(seen_pebs);
-		goto out_kfree;
+		goto out_free_dvbuf;
 	}
 
 	spin_lock(&ubi->volumes_lock);
@@ -1328,7 +1328,7 @@
 	ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avbuf);
 	if (ret) {
 		ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
-		goto out_kfree;
+		goto out_free_seen;
 	}
 
 	for (i = 0; i < new_fm->used_blocks; i++) {
@@ -1350,7 +1350,7 @@
 		if (ret) {
 			ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
 				new_fm->e[i]->pnum);
-			goto out_kfree;
+			goto out_free_seen;
 		}
 	}
 
@@ -1360,7 +1360,7 @@
 		if (ret) {
 			ubi_err(ubi, "unable to write fastmap to PEB %i!",
 				new_fm->e[i]->pnum);
-			goto out_kfree;
+			goto out_free_seen;
 		}
 	}
 
@@ -1370,10 +1370,13 @@
 	ret = self_check_seen(ubi, seen_pebs);
 	dbg_bld("fastmap written!");
 
-out_kfree:
-	ubi_free_vid_buf(avbuf);
-	ubi_free_vid_buf(dvbuf);
+out_free_seen:
 	free_seen(seen_pebs);
+out_free_dvbuf:
+	ubi_free_vid_buf(dvbuf);
+out_free_avbuf:
+	ubi_free_vid_buf(avbuf);
+
 out:
 	return ret;
 }
@@ -1540,14 +1543,6 @@
 		return 0;
 	}
 
-	ret = ubi_ensure_anchor_pebs(ubi);
-	if (ret) {
-		up_write(&ubi->fm_eba_sem);
-		up_write(&ubi->work_sem);
-		up_write(&ubi->fm_protect);
-		return ret;
-	}
-
 	new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
 	if (!new_fm) {
 		up_write(&ubi->fm_eba_sem);
@@ -1618,7 +1613,8 @@
 	}
 
 	spin_lock(&ubi->wl_lock);
-	tmp_e = ubi_wl_get_fm_peb(ubi, 1);
+	tmp_e = ubi->fm_anchor;
+	ubi->fm_anchor = NULL;
 	spin_unlock(&ubi->wl_lock);
 
 	if (old_fm) {
@@ -1670,6 +1666,9 @@
 	up_write(&ubi->work_sem);
 	up_write(&ubi->fm_protect);
 	kfree(old_fm);
+
+	ubi_ensure_anchor_pebs(ubi);
+
 	return ret;
 
 err:
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 721b6aa..a173eb7 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -491,6 +491,8 @@
  * @fm_work: fastmap work queue
  * @fm_work_scheduled: non-zero if fastmap work was scheduled
  * @fast_attach: non-zero if UBI was attached by fastmap
+ * @fm_anchor: The next anchor PEB to use for fastmap
+ * @fm_do_produce_anchor: If true produce an anchor PEB in wl
  *
  * @used: RB-tree of used physical eraseblocks
  * @erroneous: RB-tree of erroneous used physical eraseblocks
@@ -599,6 +601,8 @@
 	struct work_struct fm_work;
 	int fm_work_scheduled;
 	int fast_attach;
+	struct ubi_wl_entry *fm_anchor;
+	int fm_do_produce_anchor;
 
 	/* Wear-leveling sub-system's stuff */
 	struct rb_root used;
@@ -789,7 +793,6 @@
  * @vol_id: the volume ID on which this erasure is being performed
  * @lnum: the logical eraseblock number
  * @torture: if the physical eraseblock has to be tortured
- * @anchor: produce a anchor PEB to by used by fastmap
  *
  * The @func pointer points to the worker function. If the @shutdown argument is
  * not zero, the worker has to free the resources and exit immediately as the
@@ -805,7 +808,6 @@
 	int vol_id;
 	int lnum;
 	int torture;
-	int anchor;
 };
 
 #include "debug.h"
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 3fcdefe..7def041 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -339,13 +339,6 @@
 		}
 	}
 
-	/* 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 (prev_e && !ubi->fm_disabled &&
-	    !ubi->fm && e->pnum < UBI_FM_MAX_START)
-		return prev_e;
-
 	return e;
 }
 
@@ -656,9 +649,6 @@
 {
 	int err, scrubbing = 0, torture = 0, protect = 0, erroneous = 0;
 	int erase = 0, keep = 0, vol_id = -1, lnum = -1;
-#ifdef CONFIG_MTD_UBI_FASTMAP
-	int anchor = wrk->anchor;
-#endif
 	struct ubi_wl_entry *e1, *e2;
 	struct ubi_vid_io_buf *vidb;
 	struct ubi_vid_hdr *vid_hdr;
@@ -698,11 +688,7 @@
 	}
 
 #ifdef CONFIG_MTD_UBI_FASTMAP
-	/* Check whether we need to produce an anchor PEB */
-	if (!anchor)
-		anchor = !anchor_pebs_available(&ubi->free);
-
-	if (anchor) {
+	if (ubi->fm_do_produce_anchor) {
 		e1 = find_anchor_wl_entry(&ubi->used);
 		if (!e1)
 			goto out_cancel;
@@ -719,6 +705,7 @@
 		self_check_in_wl_tree(ubi, e1, &ubi->used);
 		rb_erase(&e1->u.rb, &ubi->used);
 		dbg_wl("anchor-move PEB %d to PEB %d", e1->pnum, e2->pnum);
+		ubi->fm_do_produce_anchor = 0;
 	} else if (!ubi->scrub.rb_node) {
 #else
 	if (!ubi->scrub.rb_node) {
@@ -1051,7 +1038,6 @@
 		goto out_cancel;
 	}
 
-	wrk->anchor = 0;
 	wrk->func = &wear_leveling_worker;
 	if (nested)
 		__schedule_ubi_work(ubi, wrk);
@@ -1093,8 +1079,15 @@
 	err = sync_erase(ubi, e, wl_wrk->torture);
 	if (!err) {
 		spin_lock(&ubi->wl_lock);
-		wl_tree_add(e, &ubi->free);
-		ubi->free_count++;
+
+		if (!ubi->fm_anchor && e->pnum < UBI_FM_MAX_START) {
+			ubi->fm_anchor = e;
+			ubi->fm_do_produce_anchor = 0;
+		} else {
+			wl_tree_add(e, &ubi->free);
+			ubi->free_count++;
+		}
+
 		spin_unlock(&ubi->wl_lock);
 
 		/*
@@ -1636,6 +1629,19 @@
 		    !ubi->thread_enabled || ubi_dbg_is_bgt_disabled(ubi)) {
 			set_current_state(TASK_INTERRUPTIBLE);
 			spin_unlock(&ubi->wl_lock);
+
+			/*
+			 * Check kthread_should_stop() after we set the task
+			 * state to guarantee that we either see the stop bit
+			 * and exit or the task state is reset to runnable such
+			 * that it's not scheduled out indefinitely and detects
+			 * the stop bit at kthread_should_stop().
+			 */
+			if (kthread_should_stop()) {
+				set_current_state(TASK_RUNNING);
+				break;
+			}
+
 			schedule();
 			continue;
 		}
@@ -1882,6 +1888,9 @@
 	if (err)
 		goto out_free;
 
+#ifdef CONFIG_MTD_UBI_FASTMAP
+	ubi_ensure_anchor_pebs(ubi);
+#endif
 	return 0;
 
 out_free:
diff --git a/drivers/mtd/ubi/wl.h b/drivers/mtd/ubi/wl.h
index a9e2d66..c93a532 100644
--- a/drivers/mtd/ubi/wl.h
+++ b/drivers/mtd/ubi/wl.h
@@ -2,7 +2,6 @@
 #ifndef UBI_WL_H
 #define UBI_WL_H
 #ifdef CONFIG_MTD_UBI_FASTMAP
-static int anchor_pebs_available(struct rb_root *root);
 static void update_fastmap_work_fn(struct work_struct *wrk);
 static struct ubi_wl_entry *find_anchor_wl_entry(struct rb_root *root);
 static struct ubi_wl_entry *get_peb_for_wl(struct ubi_device *ubi);