ubi,ubifs: sync with linux v4.2

sync with linux v4.2

commit 64291f7db5bd8150a74ad2036f1037e6a0428df2
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sun Aug 30 11:34:09 2015 -0700

    Linux 4.2

This update is needed, as it turned out, that fastmap
was in experimental/broken state in kernel v3.15, which
was the last base for U-Boot.

Signed-off-by: Heiko Schocher <hs@denx.de>
Tested-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>

1 files changed, 210 insertions, 497 deletions

diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 6886f89df2..507b091720 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -96,6 +96,7 @@
 #endif
 
 #include "ubi.h"
+#include "wl.h"
 
 /* Number of physical eraseblocks reserved for wear-leveling purposes */
 #define WL_RESERVED_PEBS 1
@@ -133,44 +134,6 @@ static int self_check_in_wl_tree(const struct ubi_device *ubi,
 static int self_check_in_pq(const struct ubi_device *ubi,
 			    struct ubi_wl_entry *e);
 
-#ifdef CONFIG_MTD_UBI_FASTMAP
-#ifndef __UBOOT__
-/**
- * update_fastmap_work_fn - calls ubi_update_fastmap from a work queue
- * @wrk: the work description object
- */
-static void update_fastmap_work_fn(struct work_struct *wrk)
-{
-	struct ubi_device *ubi = container_of(wrk, struct ubi_device, fm_work);
-	ubi_update_fastmap(ubi);
-}
-#endif
-
-/**
- *  ubi_ubi_is_fm_block - returns 1 if a PEB is currently used in a fastmap.
- *  @ubi: UBI device description object
- *  @pnum: the to be checked PEB
- */
-static int ubi_is_fm_block(struct ubi_device *ubi, int pnum)
-{
-	int i;
-
-	if (!ubi->fm)
-		return 0;
-
-	for (i = 0; i < ubi->fm->used_blocks; i++)
-		if (ubi->fm->e[i]->pnum == pnum)
-			return 1;
-
-	return 0;
-}
-#else
-static int ubi_is_fm_block(struct ubi_device *ubi, int pnum)
-{
-	return 0;
-}
-#endif
-
 /**
  * wl_tree_add - add a wear-leveling entry to a WL RB-tree.
  * @e: the wear-leveling entry to add
@@ -208,13 +171,31 @@ static void wl_tree_add(struct ubi_wl_entry *e, struct rb_root *root)
 }
 
 /**
+ * wl_tree_destroy - destroy a wear-leveling entry.
+ * @ubi: UBI device description object
+ * @e: the wear-leveling entry to add
+ *
+ * This function destroys a wear leveling entry and removes
+ * the reference from the lookup table.
+ */
+static void wl_entry_destroy(struct ubi_device *ubi, struct ubi_wl_entry *e)
+{
+	ubi->lookuptbl[e->pnum] = NULL;
+	kmem_cache_free(ubi_wl_entry_slab, e);
+}
+
+/**
  * do_work - do one pending work.
  * @ubi: UBI device description object
  *
  * This function returns zero in case of success and a negative error code in
  * case of failure.
  */
+#ifndef __UBOOT__
 static int do_work(struct ubi_device *ubi)
+#else
+int do_work(struct ubi_device *ubi)
+#endif
 {
 	int err;
 	struct ubi_work *wrk;
@@ -248,40 +229,13 @@ static int do_work(struct ubi_device *ubi)
 	 */
 	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;
 }
 
 /**
- * produce_free_peb - produce a free physical eraseblock.
- * @ubi: UBI device description object
- *
- * This function tries to make a free PEB by means of synchronous execution of
- * pending works. This may be needed if, for example the background thread is
- * disabled. Returns zero in case of success and a negative error code in case
- * of failure.
- */
-static int produce_free_peb(struct ubi_device *ubi)
-{
-	int err;
-
-	while (!ubi->free.rb_node) {
-		spin_unlock(&ubi->wl_lock);
-
-		dbg_wl("do one work synchronously");
-		err = do_work(ubi);
-
-		spin_lock(&ubi->wl_lock);
-		if (err)
-			return err;
-	}
-
-	return 0;
-}
-
-/**
  * in_wl_tree - check if wear-leveling entry is present in a WL RB-tree.
  * @e: the wear-leveling entry to check
  * @root: the root of the tree
@@ -404,119 +358,32 @@ 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);
 
-#ifdef CONFIG_MTD_UBI_FASTMAP
 		/* 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 (e && !ubi->fm_disabled && !ubi->fm &&
-		    e->pnum < UBI_FM_MAX_START)
-			e = rb_entry(rb_next(root->rb_node),
-				     struct ubi_wl_entry, u.rb);
-#endif
+		e = may_reserve_for_fm(ubi, e, root);
 	} else
 		e = find_wl_entry(ubi, root, WL_FREE_MAX_DIFF/2);
 
 	return e;
 }
 
-#ifdef CONFIG_MTD_UBI_FASTMAP
-/**
- * find_anchor_wl_entry - find wear-leveling entry to used as anchor PEB.
- * @root: the RB-tree where to look for
- */
-static struct ubi_wl_entry *find_anchor_wl_entry(struct rb_root *root)
-{
-	struct rb_node *p;
-	struct ubi_wl_entry *e, *victim = NULL;
-	int max_ec = UBI_MAX_ERASECOUNTER;
-
-	ubi_rb_for_each_entry(p, e, root, u.rb) {
-		if (e->pnum < UBI_FM_MAX_START && e->ec < max_ec) {
-			victim = e;
-			max_ec = e->ec;
-		}
-	}
-
-	return victim;
-}
-
-static int anchor_pebs_avalible(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
- * @anchor: This PEB will be used as anchor PEB by fastmap
- *
- * The function returns a physical erase block with a given maximal number
- * and removes it from the wl subsystem.
- * Must be called with wl_lock held!
- */
-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))
-		goto out;
-
-	if (anchor)
-		e = find_anchor_wl_entry(&ubi->free);
-	else
-		e = find_mean_wl_entry(ubi, &ubi->free);
-
-	if (!e)
-		goto out;
-
-	self_check_in_wl_tree(ubi, e, &ubi->free);
-
-	/* remove it from the free list,
-	 * the wl subsystem does no longer know this erase block */
-	rb_erase(&e->u.rb, &ubi->free);
-	ubi->free_count--;
-out:
-	return e;
-}
-#endif
-
 /**
- * __wl_get_peb - get a physical eraseblock.
+ * wl_get_wle - get a mean wl entry to be used by ubi_wl_get_peb() or
+ * refill_wl_user_pool().
  * @ubi: UBI device description object
  *
- * This function returns a physical eraseblock in case of success and a
- * negative error code in case of failure.
+ * This function returns a a wear leveling entry in case of success and
+ * NULL in case of failure.
  */
-static int __wl_get_peb(struct ubi_device *ubi)
+static struct ubi_wl_entry *wl_get_wle(struct ubi_device *ubi)
 {
-	int err;
 	struct ubi_wl_entry *e;
 
-retry:
-	if (!ubi->free.rb_node) {
-		if (ubi->works_count == 0) {
-			ubi_err("no free eraseblocks");
-			ubi_assert(list_empty(&ubi->works));
-			return -ENOSPC;
-		}
-
-		err = produce_free_peb(ubi);
-		if (err < 0)
-			return err;
-		goto retry;
-	}
-
 	e = find_mean_wl_entry(ubi, &ubi->free);
 	if (!e) {
-		ubi_err("no free eraseblocks");
-		return -ENOSPC;
+		ubi_err(ubi, "no free eraseblocks");
+		return NULL;
 	}
 
 	self_check_in_wl_tree(ubi, e, &ubi->free);
@@ -528,178 +395,10 @@ retry:
 	rb_erase(&e->u.rb, &ubi->free);
 	ubi->free_count--;
 	dbg_wl("PEB %d EC %d", e->pnum, e->ec);
-#ifndef CONFIG_MTD_UBI_FASTMAP
-	/* We have to enqueue e only if fastmap is disabled,
-	 * is fastmap enabled prot_queue_add() will be called by
-	 * ubi_wl_get_peb() after removing e from the pool. */
-	prot_queue_add(ubi, e);
-#endif
-	return e->pnum;
-}
-
-#ifdef CONFIG_MTD_UBI_FASTMAP
-/**
- * return_unused_pool_pebs - returns unused PEB to the free tree.
- * @ubi: UBI device description object
- * @pool: fastmap pool description object
- */
-static void return_unused_pool_pebs(struct ubi_device *ubi,
-				    struct ubi_fm_pool *pool)
-{
-	int i;
-	struct ubi_wl_entry *e;
-
-	for (i = pool->used; i < pool->size; i++) {
-		e = ubi->lookuptbl[pool->pebs[i]];
-		wl_tree_add(e, &ubi->free);
-		ubi->free_count++;
-	}
-}
-
-/**
- * refill_wl_pool - refills all the fastmap pool used by the
- * WL sub-system.
- * @ubi: UBI device description object
- */
-static void refill_wl_pool(struct ubi_device *ubi)
-{
-	struct ubi_wl_entry *e;
-	struct ubi_fm_pool *pool = &ubi->fm_wl_pool;
-
-	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 < 5))
-			break;
-
-		e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
-		self_check_in_wl_tree(ubi, e, &ubi->free);
-		rb_erase(&e->u.rb, &ubi->free);
-		ubi->free_count--;
-
-		pool->pebs[pool->size] = e->pnum;
-	}
-	pool->used = 0;
-}
-
-/**
- * refill_wl_user_pool - refills all the fastmap pool used by ubi_wl_get_peb.
- * @ubi: UBI device description object
- */
-static void refill_wl_user_pool(struct ubi_device *ubi)
-{
-	struct ubi_fm_pool *pool = &ubi->fm_pool;
-
-	return_unused_pool_pebs(ubi, pool);
-
-	for (pool->size = 0; pool->size < pool->max_size; pool->size++) {
-		pool->pebs[pool->size] = __wl_get_peb(ubi);
-		if (pool->pebs[pool->size] < 0)
-			break;
-	}
-	pool->used = 0;
-}
-
-/**
- * ubi_refill_pools - refills all fastmap PEB pools.
- * @ubi: UBI device description object
- */
-void ubi_refill_pools(struct ubi_device *ubi)
-{
-	spin_lock(&ubi->wl_lock);
-	refill_wl_pool(ubi);
-	refill_wl_user_pool(ubi);
-	spin_unlock(&ubi->wl_lock);
-}
-
-/* ubi_wl_get_peb - works exaclty like __wl_get_peb but keeps track of
- * the fastmap pool.
- */
-int ubi_wl_get_peb(struct ubi_device *ubi)
-{
-	int ret;
-	struct ubi_fm_pool *pool = &ubi->fm_pool;
-	struct ubi_fm_pool *wl_pool = &ubi->fm_wl_pool;
-
-	if (!pool->size || !wl_pool->size || pool->used == pool->size ||
-	    wl_pool->used == wl_pool->size)
-		ubi_update_fastmap(ubi);
-
-	/* we got not a single free PEB */
-	if (!pool->size)
-		ret = -ENOSPC;
-	else {
-		spin_lock(&ubi->wl_lock);
-		ret = pool->pebs[pool->used++];
-		prot_queue_add(ubi, ubi->lookuptbl[ret]);
-		spin_unlock(&ubi->wl_lock);
-	}
-
-	return ret;
-}
-
-/* get_peb_for_wl - returns a PEB to be used internally by the WL sub-system.
- *
- * @ubi: UBI device description object
- */
-static struct ubi_wl_entry *get_peb_for_wl(struct ubi_device *ubi)
-{
-	struct ubi_fm_pool *pool = &ubi->fm_wl_pool;
-	int pnum;
-
-	if (pool->used == pool->size || !pool->size) {
-		/* We cannot update the fastmap here because this
-		 * function is called in atomic context.
-		 * Let's fail here and refill/update it as soon as possible. */
-#ifndef __UBOOT__
-		schedule_work(&ubi->fm_work);
-#else
-		/* In U-Boot we must call this directly */
-	        ubi_update_fastmap(ubi);
-#endif
-		return NULL;
-	} else {
-		pnum = pool->pebs[pool->used++];
-		return ubi->lookuptbl[pnum];
-	}
-}
-#else
-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);
-	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;
 }
 
-int ubi_wl_get_peb(struct ubi_device *ubi)
-{
-	int peb, err;
-
-	spin_lock(&ubi->wl_lock);
-	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);
-		return err;
-	}
-
-	return peb;
-}
-#endif
-
 /**
  * prot_queue_del - remove a physical eraseblock from the protection queue.
  * @ubi: UBI device description object
@@ -760,7 +459,7 @@ static int sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
 		 * 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;
@@ -835,7 +534,7 @@ repeat:
  * @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)
 {
@@ -847,11 +546,16 @@ static void __schedule_ubi_work(struct ubi_device *ubi, struct ubi_work *wrk)
 	if (ubi->thread_enabled && !ubi_dbg_is_bgt_disabled(ubi))
 		wake_up_process(ubi->bgt_thread);
 #else
+	int err;
 	/*
 	 * U-Boot special: We have no bgt_thread in U-Boot!
 	 * So just call do_work() here directly.
 	 */
-	do_work(ubi);
+	err = do_work(ubi);
+	if (err) {
+		ubi_err(ubi, "%s: work failed with error code %d",
+			ubi->bgt_name, err);
+	}
 #endif
 	spin_unlock(&ubi->wl_lock);
 }
@@ -872,18 +576,7 @@ static void schedule_ubi_work(struct ubi_device *ubi, struct ubi_work *wrk)
 }
 
 static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
-			int cancel);
-
-#ifdef CONFIG_MTD_UBI_FASTMAP
-/**
- * ubi_is_erase_work - checks whether a work is erase work.
- * @wrk: The work object to be checked
- */
-int ubi_is_erase_work(struct ubi_work *wrk)
-{
-	return wrk->func == erase_worker;
-}
-#endif
+			int shutdown);
 
 /**
  * schedule_erase - schedule an erase work.
@@ -902,7 +595,6 @@ static int schedule_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
 	struct ubi_work *wl_wrk;
 
 	ubi_assert(e);
-	ubi_assert(!ubi_is_fm_block(ubi, e->pnum));
 
 	dbg_wl("schedule erasure of PEB %d, EC %d, torture %d",
 	       e->pnum, e->ec, torture);
@@ -949,66 +641,22 @@ static int do_sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
 	return erase_worker(ubi, wl_wrk, 0);
 }
 
-#ifdef CONFIG_MTD_UBI_FASTMAP
-/**
- * ubi_wl_put_fm_peb - returns a PEB used in a fastmap to the wear-leveling
- * sub-system.
- * see: ubi_wl_put_peb()
- *
- * @ubi: UBI device description object
- * @fm_e: physical eraseblock to return
- * @lnum: the last used logical eraseblock number for the PEB
- * @torture: if this physical eraseblock has to be tortured
- */
-int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *fm_e,
-		      int lnum, int torture)
-{
-	struct ubi_wl_entry *e;
-	int vol_id, pnum = fm_e->pnum;
-
-	dbg_wl("PEB %d", pnum);
-
-	ubi_assert(pnum >= 0);
-	ubi_assert(pnum < ubi->peb_count);
-
-	spin_lock(&ubi->wl_lock);
-	e = ubi->lookuptbl[pnum];
-
-	/* This can happen if we recovered from a fastmap the very
-	 * first time and writing now a new one. In this case the wl system
-	 * has never seen any PEB used by the original fastmap.
-	 */
-	if (!e) {
-		e = fm_e;
-		ubi_assert(e->ec >= 0);
-		ubi->lookuptbl[pnum] = e;
-	} else {
-		e->ec = fm_e->ec;
-		kfree(fm_e);
-	}
-
-	spin_unlock(&ubi->wl_lock);
-
-	vol_id = lnum ? UBI_FM_DATA_VOLUME_ID : UBI_FM_SB_VOLUME_ID;
-	return schedule_erase(ubi, e, vol_id, lnum, torture);
-}
-#endif
-
 /**
  * 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, uninitialized_var(lnum);
+	int vol_id = -1, lnum = -1;
 #ifdef CONFIG_MTD_UBI_FASTMAP
 	int anchor = wrk->anchor;
 #endif
@@ -1016,7 +664,7 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 	struct ubi_vid_hdr *vid_hdr;
 
 	kfree(wrk);
-	if (cancel)
+	if (shutdown)
 		return 0;
 
 	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
@@ -1144,7 +792,7 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 			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;
 	}
@@ -1188,7 +836,7 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 			 * 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;
 			}
@@ -1204,7 +852,7 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 
 	/* 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);
 
@@ -1219,9 +867,8 @@ 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) {
-		kmem_cache_free(ubi_wl_entry_slab, e1);
 		if (e2)
-			kmem_cache_free(ubi_wl_entry_slab, e2);
+			wl_entry_destroy(ubi, e2);
 		goto out_ro;
 	}
 
@@ -1233,10 +880,8 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 		dbg_wl("PEB %d (LEB %d:%d) was put meanwhile, erase",
 		       e2->pnum, vol_id, lnum);
 		err = do_sync_erase(ubi, e2, vol_id, lnum, 0);
-		if (err) {
-			kmem_cache_free(ubi_wl_entry_slab, e2);
+		if (err)
 			goto out_ro;
-		}
 	}
 
 	dbg_wl("done");
@@ -1272,19 +917,18 @@ out_not_moved:
 
 	ubi_free_vid_hdr(ubi, vid_hdr);
 	err = do_sync_erase(ubi, e2, vol_id, lnum, torture);
-	if (err) {
-		kmem_cache_free(ubi_wl_entry_slab, e2);
+	if (err)
 		goto out_ro;
-	}
+
 	mutex_unlock(&ubi->move_mutex);
 	return 0;
 
 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;
@@ -1292,8 +936,8 @@ out_error:
 	spin_unlock(&ubi->wl_lock);
 
 	ubi_free_vid_hdr(ubi, vid_hdr);
-	kmem_cache_free(ubi_wl_entry_slab, e1);
-	kmem_cache_free(ubi_wl_entry_slab, e2);
+	wl_entry_destroy(ubi, e1);
+	wl_entry_destroy(ubi, e2);
 
 out_ro:
 	ubi_ro_mode(ubi);
@@ -1379,43 +1023,12 @@ out_unlock:
 	return err;
 }
 
-#ifdef CONFIG_MTD_UBI_FASTMAP
-/**
- * ubi_ensure_anchor_pebs - schedule wear-leveling to produce an anchor PEB.
- * @ubi: UBI device description object
- */
-int ubi_ensure_anchor_pebs(struct ubi_device *ubi)
-{
-	struct ubi_work *wrk;
-
-	spin_lock(&ubi->wl_lock);
-	if (ubi->wl_scheduled) {
-		spin_unlock(&ubi->wl_lock);
-		return 0;
-	}
-	ubi->wl_scheduled = 1;
-	spin_unlock(&ubi->wl_lock);
-
-	wrk = kmalloc(sizeof(struct ubi_work), GFP_NOFS);
-	if (!wrk) {
-		spin_lock(&ubi->wl_lock);
-		ubi->wl_scheduled = 0;
-		spin_unlock(&ubi->wl_lock);
-		return -ENOMEM;
-	}
-
-	wrk->anchor = 1;
-	wrk->func = &wear_leveling_worker;
-	schedule_ubi_work(ubi, wrk);
-	return 0;
-}
-#endif
-
 /**
  * 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
@@ -1423,7 +1036,7 @@ int ubi_ensure_anchor_pebs(struct ubi_device *ubi)
  * 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;
@@ -1431,18 +1044,16 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
 	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);
+		wl_entry_destroy(ubi, e);
 		return 0;
 	}
 
 	dbg_wl("erase PEB %d EC %d LEB %d:%d",
 	       pnum, e->ec, wl_wrk->vol_id, wl_wrk->lnum);
 
-	ubi_assert(!ubi_is_fm_block(ubi, e->pnum));
-
 	err = sync_erase(ubi, e, wl_wrk->torture);
 	if (!err) {
 		/* Fine, we've erased it successfully */
@@ -1464,7 +1075,7 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
 		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 ||
@@ -1480,7 +1091,7 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
 		return err;
 	}
 
-	kmem_cache_free(ubi_wl_entry_slab, e);
+	wl_entry_destroy(ubi, e);
 	if (err != -EIO)
 		/*
 		 * If this is not %-EIO, we have no idea what to do. Scheduling
@@ -1492,7 +1103,7 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
 	/* 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;
 	}
 
@@ -1500,7 +1111,7 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
 	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;
@@ -1508,7 +1119,7 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
 	}
 	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;
@@ -1529,11 +1140,12 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
 	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;
@@ -1571,6 +1183,8 @@ int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum,
 	ubi_assert(pnum >= 0);
 	ubi_assert(pnum < ubi->peb_count);
 
+	down_read(&ubi->fm_protect);
+
 retry:
 	spin_lock(&ubi->wl_lock);
 	e = ubi->lookuptbl[pnum];
@@ -1601,6 +1215,7 @@ retry:
 		ubi_assert(!ubi->move_to_put);
 		ubi->move_to_put = 1;
 		spin_unlock(&ubi->wl_lock);
+		up_read(&ubi->fm_protect);
 		return 0;
 	} else {
 		if (in_wl_tree(e, &ubi->used)) {
@@ -1619,9 +1234,10 @@ retry:
 		} 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);
+				up_read(&ubi->fm_protect);
 				return err;
 			}
 		}
@@ -1635,6 +1251,7 @@ retry:
 		spin_unlock(&ubi->wl_lock);
 	}
 
+	up_read(&ubi->fm_protect);
 	return err;
 }
 
@@ -1652,7 +1269,7 @@ int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum)
 {
 	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);
@@ -1684,7 +1301,7 @@ retry:
 
 		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;
@@ -1726,12 +1343,12 @@ int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum)
 	       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);
@@ -1766,9 +1383,10 @@ int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum)
 
 /**
  * tree_destroy - destroy an RB-tree.
+ * @ubi: UBI device description object
  * @root: the root of the tree to destroy
  */
-static void tree_destroy(struct rb_root *root)
+static void tree_destroy(struct ubi_device *ubi, struct rb_root *root)
 {
 	struct rb_node *rb;
 	struct ubi_wl_entry *e;
@@ -1790,7 +1408,7 @@ static void tree_destroy(struct rb_root *root)
 					rb->rb_right = NULL;
 			}
 
-			kmem_cache_free(ubi_wl_entry_slab, e);
+			wl_entry_destroy(ubi, e);
 		}
 	}
 }
@@ -1804,7 +1422,7 @@ int ubi_thread(void *u)
 	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();
@@ -1829,14 +1447,14 @@ int ubi_thread(void *u)
 
 		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;
@@ -1853,11 +1471,18 @@ int ubi_thread(void *u)
 }
 
 /**
- * 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)
 {
+#ifdef CONFIG_MTD_UBI_FASTMAP
+#ifndef __UBOOT__
+	flush_work(&ubi->fm_work);
+#else
+	/* in U-Boot, we have all work done */
+#endif
+#endif
 	while (!list_empty(&ubi->works)) {
 		struct ubi_work *wrk;
 
@@ -1891,11 +1516,6 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
 	init_rwsem(&ubi->work_sem);
 	ubi->max_ec = ai->max_ec;
 	INIT_LIST_HEAD(&ubi->works);
-#ifndef __UBOOT__
-#ifdef CONFIG_MTD_UBI_FASTMAP
-	INIT_WORK(&ubi->fm_work, update_fastmap_work_fn);
-#endif
-#endif
 
 	sprintf(ubi->bgt_name, UBI_BGT_NAME_PATTERN, ubi->ubi_num);
 
@@ -1917,10 +1537,9 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
 
 		e->pnum = aeb->pnum;
 		e->ec = aeb->ec;
-		ubi_assert(!ubi_is_fm_block(ubi, e->pnum));
 		ubi->lookuptbl[e->pnum] = e;
 		if (schedule_erase(ubi, e, aeb->vol_id, aeb->lnum, 0)) {
-			kmem_cache_free(ubi_wl_entry_slab, e);
+			wl_entry_destroy(ubi, e);
 			goto out_free;
 		}
 
@@ -1938,7 +1557,6 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
 		e->pnum = aeb->pnum;
 		e->ec = aeb->ec;
 		ubi_assert(e->ec >= 0);
-		ubi_assert(!ubi_is_fm_block(ubi, e->pnum));
 
 		wl_tree_add(e, &ubi->free);
 		ubi->free_count++;
@@ -1976,23 +1594,26 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
 
 	dbg_wl("found %i PEBs", found_pebs);
 
-	if (ubi->fm)
-		ubi_assert(ubi->good_peb_count == \
+	if (ubi->fm) {
+		ubi_assert(ubi->good_peb_count ==
 			   found_pebs + ubi->fm->used_blocks);
+
+		for (i = 0; i < ubi->fm->used_blocks; i++) {
+			e = ubi->fm->e[i];
+			ubi->lookuptbl[e->pnum] = e;
+		}
+	}
 	else
 		ubi_assert(ubi->good_peb_count == found_pebs);
 
 	reserved_pebs = WL_RESERVED_PEBS;
-#ifdef CONFIG_MTD_UBI_FASTMAP
-	/* Reserve enough LEBs to store two fastmaps. */
-	reserved_pebs += (ubi->fm_size / ubi->leb_size) * 2;
-#endif
+	ubi_fastmap_init(ubi, &reserved_pebs);
 
 	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);
 		goto out_free;
 	}
@@ -2007,10 +1628,10 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
 	return 0;
 
 out_free:
-	cancel_pending(ubi);
-	tree_destroy(&ubi->used);
-	tree_destroy(&ubi->free);
-	tree_destroy(&ubi->scrub);
+	shutdown_work(ubi);
+	tree_destroy(ubi, &ubi->used);
+	tree_destroy(ubi, &ubi->free);
+	tree_destroy(ubi, &ubi->scrub);
 	kfree(ubi->lookuptbl);
 	return err;
 }
@@ -2027,7 +1648,7 @@ static void protection_queue_destroy(struct ubi_device *ubi)
 	for (i = 0; i < UBI_PROT_QUEUE_LEN; ++i) {
 		list_for_each_entry_safe(e, tmp, &ubi->pq[i], u.list) {
 			list_del(&e->u.list);
-			kmem_cache_free(ubi_wl_entry_slab, e);
+			wl_entry_destroy(ubi, e);
 		}
 	}
 }
@@ -2039,12 +1660,13 @@ static void protection_queue_destroy(struct ubi_device *ubi)
 void ubi_wl_close(struct ubi_device *ubi)
 {
 	dbg_wl("close the WL sub-system");
-	cancel_pending(ubi);
+	ubi_fastmap_close(ubi);
+	shutdown_work(ubi);
 	protection_queue_destroy(ubi);
-	tree_destroy(&ubi->used);
-	tree_destroy(&ubi->erroneous);
-	tree_destroy(&ubi->free);
-	tree_destroy(&ubi->scrub);
+	tree_destroy(ubi, &ubi->used);
+	tree_destroy(ubi, &ubi->erroneous);
+	tree_destroy(ubi, &ubi->free);
+	tree_destroy(ubi, &ubi->scrub);
 	kfree(ubi->lookuptbl);
 }
 
@@ -2080,8 +1702,8 @@ static int self_check_ec(struct ubi_device *ubi, int pnum, int ec)
 
 	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
@@ -2110,7 +1732,7 @@ static int self_check_in_wl_tree(const struct ubi_device *ubi,
 	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;
@@ -2138,8 +1760,99 @@ static int self_check_in_pq(const struct ubi_device *ubi,
 			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;
 }
+#ifndef CONFIG_MTD_UBI_FASTMAP
+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);
+	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;
+}
+
+/**
+ * produce_free_peb - produce a free physical eraseblock.
+ * @ubi: UBI device description object
+ *
+ * This function tries to make a free PEB by means of synchronous execution of
+ * pending works. This may be needed if, for example the background thread is
+ * disabled. Returns zero in case of success and a negative error code in case
+ * of failure.
+ */
+static int produce_free_peb(struct ubi_device *ubi)
+{
+	int err;
+
+	while (!ubi->free.rb_node && ubi->works_count) {
+		spin_unlock(&ubi->wl_lock);
+
+		dbg_wl("do one work synchronously");
+		err = do_work(ubi);
+
+		spin_lock(&ubi->wl_lock);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+/**
+ * ubi_wl_get_peb - get a physical eraseblock.
+ * @ubi: UBI device description object
+ *
+ * This function returns a physical eraseblock in case of success and a
+ * negative error code in case of failure.
+ * Returns with ubi->fm_eba_sem held in read mode!
+ */
+int ubi_wl_get_peb(struct ubi_device *ubi)
+{
+	int err;
+	struct ubi_wl_entry *e;
+
+retry:
+	down_read(&ubi->fm_eba_sem);
+	spin_lock(&ubi->wl_lock);
+	if (!ubi->free.rb_node) {
+		if (ubi->works_count == 0) {
+			ubi_err(ubi, "no free eraseblocks");
+			ubi_assert(list_empty(&ubi->works));
+			spin_unlock(&ubi->wl_lock);
+			return -ENOSPC;
+		}
+
+		err = produce_free_peb(ubi);
+		if (err < 0) {
+			spin_unlock(&ubi->wl_lock);
+			return err;
+		}
+		spin_unlock(&ubi->wl_lock);
+		up_read(&ubi->fm_eba_sem);
+		goto retry;
+
+	}
+	e = wl_get_wle(ubi);
+	prot_queue_add(ubi, e);
+	spin_unlock(&ubi->wl_lock);
+
+	err = ubi_self_check_all_ff(ubi, e->pnum, ubi->vid_hdr_aloffset,
+				    ubi->peb_size - ubi->vid_hdr_aloffset);
+	if (err) {
+		ubi_err(ubi, "new PEB %d does not contain all 0xFF bytes", e->pnum);
+		return err;
+	}
+
+	return e->pnum;
+}
+#else
+#include "fastmap-wl.c"
+#endif