diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 754b337..540f721 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -43,17 +43,18 @@
 
 /* Normal UBI messages */
 #ifdef CONFIG_UBI_SILENCE_MSG
-#define ubi_msg(fmt, ...)
+#define ubi_msg(ubi, fmt, ...)
 #else
-#define ubi_msg(fmt, ...) printk(KERN_NOTICE "UBI: " fmt "\n", ##__VA_ARGS__)
+#define ubi_msg(ubi, fmt, ...) printk(UBI_NAME_STR "%d: " fmt "\n", \
+					 ubi->ubi_num, ##__VA_ARGS__)
 #endif
 
 /* UBI warning messages */
-#define ubi_warn(fmt, ...) pr_warn("UBI warning: %s: " fmt "\n",  \
-				   __func__, ##__VA_ARGS__)
+#define ubi_warn(ubi, fmt, ...) pr_warn(UBI_NAME_STR "%d warning: %s: " fmt "\n", \
+					ubi->ubi_num, __func__, ##__VA_ARGS__)
 /* UBI error messages */
-#define ubi_err(fmt, ...) pr_err("UBI error: %s: " fmt "\n",      \
-				 __func__, ##__VA_ARGS__)
+#define ubi_err(ubi, fmt, ...) pr_err(UBI_NAME_STR "%d error: %s: " fmt "\n", \
+				      ubi->ubi_num, __func__, ##__VA_ARGS__)
 
 /* Background thread name pattern */
 #define UBI_BGT_NAME_PATTERN "ubi_bgt%dd"
@@ -147,6 +148,17 @@
 	UBI_BAD_FASTMAP,
 };
 
+/*
+ * Flags for emulate_power_cut in ubi_debug_info
+ *
+ * POWER_CUT_EC_WRITE: Emulate a power cut when writing an EC header
+ * POWER_CUT_VID_WRITE: Emulate a power cut when writing a VID header
+ */
+enum {
+	POWER_CUT_EC_WRITE = 0x01,
+	POWER_CUT_VID_WRITE = 0x02,
+};
+
 /**
  * struct ubi_wl_entry - wear-leveling entry.
  * @u.rb: link in the corresponding (free/used) RB-tree
@@ -257,6 +269,7 @@
  * @readers: number of users holding this volume in read-only mode
  * @writers: number of users holding this volume in read-write mode
  * @exclusive: whether somebody holds this volume in exclusive mode
+ * @metaonly: whether somebody is altering only meta data of this volume
  *
  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
@@ -305,6 +318,7 @@
 	int readers;
 	int writers;
 	int exclusive;
+	int metaonly;
 
 	int reserved_pebs;
 	int vol_type;
@@ -339,7 +353,8 @@
 /**
  * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
  * @vol: reference to the corresponding volume description object
- * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
+ * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, %UBI_EXCLUSIVE
+ * or %UBI_METAONLY)
  */
 struct ubi_volume_desc {
 	struct ubi_volume *vol;
@@ -353,30 +368,48 @@
  *
  * @chk_gen: if UBI general extra checks are enabled
  * @chk_io: if UBI I/O extra checks are enabled
+ * @chk_fastmap: if UBI fastmap extra checks are enabled
  * @disable_bgt: disable the background task for testing purposes
  * @emulate_bitflips: emulate bit-flips for testing purposes
  * @emulate_io_failures: emulate write/erase failures for testing purposes
+ * @emulate_power_cut: emulate power cut for testing purposes
+ * @power_cut_counter: count down for writes left until emulated power cut
+ * @power_cut_min: minimum number of writes before emulating a power cut
+ * @power_cut_max: maximum number of writes until emulating a power cut
  * @dfs_dir_name: name of debugfs directory containing files of this UBI device
  * @dfs_dir: direntry object of the UBI device debugfs directory
  * @dfs_chk_gen: debugfs knob to enable UBI general extra checks
  * @dfs_chk_io: debugfs knob to enable UBI I/O extra checks
+ * @dfs_chk_fastmap: debugfs knob to enable UBI fastmap extra checks
  * @dfs_disable_bgt: debugfs knob to disable the background task
  * @dfs_emulate_bitflips: debugfs knob to emulate bit-flips
  * @dfs_emulate_io_failures: debugfs knob to emulate write/erase failures
+ * @dfs_emulate_power_cut: debugfs knob to emulate power cuts
+ * @dfs_power_cut_min: debugfs knob for minimum writes before power cut
+ * @dfs_power_cut_max: debugfs knob for maximum writes until power cut
  */
 struct ubi_debug_info {
 	unsigned int chk_gen:1;
 	unsigned int chk_io:1;
+	unsigned int chk_fastmap:1;
 	unsigned int disable_bgt:1;
 	unsigned int emulate_bitflips:1;
 	unsigned int emulate_io_failures:1;
+	unsigned int emulate_power_cut:2;
+	unsigned int power_cut_counter;
+	unsigned int power_cut_min;
+	unsigned int power_cut_max;
 	char dfs_dir_name[UBI_DFS_DIR_LEN + 1];
 	struct dentry *dfs_dir;
 	struct dentry *dfs_chk_gen;
 	struct dentry *dfs_chk_io;
+	struct dentry *dfs_chk_fastmap;
 	struct dentry *dfs_disable_bgt;
 	struct dentry *dfs_emulate_bitflips;
 	struct dentry *dfs_emulate_io_failures;
+	struct dentry *dfs_emulate_power_cut;
+	struct dentry *dfs_power_cut_min;
+	struct dentry *dfs_power_cut_max;
 };
 
 /**
@@ -390,7 +423,8 @@
  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
  *                @vol->readers, @vol->writers, @vol->exclusive,
- *                @vol->ref_count, @vol->mapping and @vol->eba_tbl.
+ *                @vol->metaonly, @vol->ref_count, @vol->mapping and
+ *                @vol->eba_tbl.
  * @ref_count: count of references on the UBI device
  * @image_seq: image sequence number recorded on EC headers
  *
@@ -422,11 +456,13 @@
  * @fm_pool: in-memory data structure of the fastmap pool
  * @fm_wl_pool: in-memory data structure of the fastmap pool used by the WL
  *		sub-system
- * @fm_mutex: serializes ubi_update_fastmap() and protects @fm_buf
+ * @fm_protect: serializes ubi_update_fastmap(), protects @fm_buf and makes sure
+ * that critical sections cannot be interrupted by ubi_update_fastmap()
  * @fm_buf: vmalloc()'d buffer which holds the raw fastmap
  * @fm_size: fastmap size in bytes
- * @fm_sem: allows ubi_update_fastmap() to block EBA table changes
+ * @fm_eba_sem: allows ubi_update_fastmap() to block EBA table changes
  * @fm_work: fastmap work queue
+ * @fm_work_scheduled: non-zero if fastmap work was scheduled
  *
  * @used: RB-tree of used physical eraseblocks
  * @erroneous: RB-tree of erroneous used physical eraseblocks
@@ -438,9 +474,11 @@
  * @pq_head: protection queue head
  * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
  *	     @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
- *	     @erroneous, and @erroneous_peb_count fields
+ *	     @erroneous, @erroneous_peb_count, @fm_work_scheduled, @fm_pool,
+ *	     and @fm_wl_pool fields
  * @move_mutex: serializes eraseblock moves
- * @work_sem: synchronizes the WL worker with use tasks
+ * @work_sem: used to wait for all the scheduled works to finish and prevent
+ * new works from being submitted
  * @wl_scheduled: non-zero if the wear-leveling was scheduled
  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
  *             physical eraseblock
@@ -474,7 +512,7 @@
  * @vid_hdr_offset: starting offset of the volume identifier header (might be
  *                  unaligned)
  * @vid_hdr_aloffset: starting offset of the VID header aligned to
- * @hdrs_min_io_size
+ *                    @hdrs_min_io_size
  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
  *               not
@@ -527,13 +565,14 @@
 	struct ubi_fastmap_layout *fm;
 	struct ubi_fm_pool fm_pool;
 	struct ubi_fm_pool fm_wl_pool;
-	struct rw_semaphore fm_sem;
-	struct mutex fm_mutex;
+	struct rw_semaphore fm_eba_sem;
+	struct rw_semaphore fm_protect;
 	void *fm_buf;
 	size_t fm_size;
 #ifndef __UBOOT__
 	struct work_struct fm_work;
 #endif
+	int fm_work_scheduled;
 
 	/* Wear-leveling sub-system's stuff */
 	struct rb_root used;
@@ -716,14 +755,15 @@
  * @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 @cancel argument is
- * not zero, the worker has to free the resources and exit immediately. The
- * worker has to return zero in case of success and a negative error code in
+ * 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
+ * WL sub-system is shutting down.
+ * The worker has to return zero in case of success and a negative error code in
  * case of failure.
  */
 struct ubi_work {
 	struct list_head list;
-	int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int cancel);
+	int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int shutdown);
 	/* The below fields are only relevant to erasure works */
 	struct ubi_wl_entry *e;
 	int vol_id;
@@ -738,7 +778,7 @@
 extern const struct file_operations ubi_ctrl_cdev_operations;
 extern const struct file_operations ubi_cdev_operations;
 extern const struct file_operations ubi_vol_cdev_operations;
-extern struct class *ubi_class;
+extern struct class ubi_class;
 extern struct mutex ubi_devices_mutex;
 extern struct blocking_notifier_head ubi_notifiers;
 
@@ -807,6 +847,9 @@
 		      int lnum);
 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 		     void *buf, int offset, int len, int check);
+int ubi_eba_read_leb_sg(struct ubi_device *ubi, struct ubi_volume *vol,
+			struct ubi_sgl *sgl, int lnum, int offset, int len,
+			int check);
 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 		      const void *buf, int offset, int len);
 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
@@ -877,10 +920,14 @@
 		      int pnum, const struct ubi_vid_hdr *vid_hdr);
 
 /* fastmap.c */
+#ifdef CONFIG_MTD_UBI_FASTMAP
 size_t ubi_calc_fm_size(struct ubi_device *ubi);
 int ubi_update_fastmap(struct ubi_device *ubi);
 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 		     int fm_anchor);
+#else
+static inline int ubi_update_fastmap(struct ubi_device *ubi) { return 0; }
+#endif
 
 /* block.c */
 #ifdef CONFIG_MTD_UBI_BLOCK
@@ -901,6 +948,42 @@
 }
 #endif
 
+/*
+ * ubi_for_each_free_peb - walk the UBI free RB tree.
+ * @ubi: UBI device description object
+ * @e: a pointer to a ubi_wl_entry to use as cursor
+ * @pos: a pointer to RB-tree entry type to use as a loop counter
+ */
+#define ubi_for_each_free_peb(ubi, e, tmp_rb)	\
+	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->free, u.rb)
+
+/*
+ * ubi_for_each_used_peb - walk the UBI used RB tree.
+ * @ubi: UBI device description object
+ * @e: a pointer to a ubi_wl_entry to use as cursor
+ * @pos: a pointer to RB-tree entry type to use as a loop counter
+ */
+#define ubi_for_each_used_peb(ubi, e, tmp_rb)	\
+	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->used, u.rb)
+
+/*
+ * ubi_for_each_scub_peb - walk the UBI scub RB tree.
+ * @ubi: UBI device description object
+ * @e: a pointer to a ubi_wl_entry to use as cursor
+ * @pos: a pointer to RB-tree entry type to use as a loop counter
+ */
+#define ubi_for_each_scrub_peb(ubi, e, tmp_rb)	\
+	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->scrub, u.rb)
+
+/*
+ * ubi_for_each_protected_peb - walk the UBI protection queue.
+ * @ubi: UBI device description object
+ * @i: a integer used as counter
+ * @e: a pointer to a ubi_wl_entry to use as cursor
+ */
+#define ubi_for_each_protected_peb(ubi, i, e)	\
+	for ((i) = 0; (i) < UBI_PROT_QUEUE_LEN; (i)++)	\
+		list_for_each_entry((e), &(ubi->pq[(i)]), u.list)
 
 /*
  * ubi_rb_for_each_entry - walk an RB-tree.
@@ -1004,7 +1087,7 @@
 {
 	if (!ubi->ro_mode) {
 		ubi->ro_mode = 1;
-		ubi_warn("switch to read-only mode");
+		ubi_warn(ubi, "switch to read-only mode");
 		dump_stack();
 	}
 }
@@ -1035,4 +1118,7 @@
 		return idx;
 }
 
+#ifdef __UBOOT__
+int do_work(struct ubi_device *ubi);
+#endif
 #endif /* !__UBI_UBI_H__ */