diff --git a/Documentation/ABI/stable/sysfs-class-ubi b/Documentation/ABI/stable/sysfs-class-ubi
index 18d471d9faea..a6b324014692 100644
--- a/Documentation/ABI/stable/sysfs-class-ubi
+++ b/Documentation/ABI/stable/sysfs-class-ubi
@@ -107,6 +107,15 @@ Contact:	Artem Bityutskiy <dedekind@infradead.org>
 Description:
 		Number of physical eraseblocks reserved for bad block handling.
 
+What:		/sys/class/ubi/ubiX/ro_mode
+Date:		April 2016
+KernelVersion:	4.7
+Contact:	linux-mtd@lists.infradead.org
+Description:
+		Contains ASCII "1\n" if the read-only flag is set on this
+		device, and "0\n" if it is cleared. UBI devices mark themselves
+		as read-only when they detect an unrecoverable error.
+
 What:		/sys/class/ubi/ubiX/total_eraseblocks
 Date:		July 2006
 KernelVersion:	2.6.22
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index a7d1febf667a..16baeb51b2bd 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -149,6 +149,8 @@ static struct device_attribute dev_bgt_enabled =
 	__ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
 static struct device_attribute dev_mtd_num =
 	__ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_ro_mode =
+	__ATTR(ro_mode, S_IRUGO, dev_attribute_show, NULL);
 
 /**
  * ubi_volume_notify - send a volume change notification.
@@ -385,6 +387,8 @@ static ssize_t dev_attribute_show(struct device *dev,
 		ret = sprintf(buf, "%d\n", ubi->thread_enabled);
 	else if (attr == &dev_mtd_num)
 		ret = sprintf(buf, "%d\n", ubi->mtd->index);
+	else if (attr == &dev_ro_mode)
+		ret = sprintf(buf, "%d\n", ubi->ro_mode);
 	else
 		ret = -EINVAL;
 
@@ -404,6 +408,7 @@ static struct attribute *ubi_dev_attrs[] = {
 	&dev_min_io_size.attr,
 	&dev_bgt_enabled.attr,
 	&dev_mtd_num.attr,
+	&dev_ro_mode.attr,
 	NULL
 };
 ATTRIBUTE_GROUPS(ubi_dev);
diff --git a/drivers/mtd/ubi/debug.c b/drivers/mtd/ubi/debug.c
index c4cb15a3098c..f101a4985a7c 100644
--- a/drivers/mtd/ubi/debug.c
+++ b/drivers/mtd/ubi/debug.c
@@ -352,7 +352,8 @@ static ssize_t dfs_file_write(struct file *file, const char __user *user_buf,
 	} else if (dent == d->dfs_emulate_power_cut) {
 		if (kstrtoint(buf, 0, &val) != 0)
 			count = -EINVAL;
-		d->emulate_power_cut = val;
+		else
+			d->emulate_power_cut = val;
 		goto out;
 	}
 
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 5b9834cf2820..5780dd1ba79d 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -426,8 +426,25 @@ retry:
 						 pnum, vol_id, lnum);
 					err = -EBADMSG;
 				} else {
-					err = -EINVAL;
-					ubi_ro_mode(ubi);
+					/*
+					 * Ending up here in the non-Fastmap case
+					 * is a clear bug as the VID header had to
+					 * be present at scan time to have it referenced.
+					 * With fastmap the story is more complicated.
+					 * Fastmap has the mapping info without the need
+					 * of a full scan. So the LEB could have been
+					 * unmapped, Fastmap cannot know this and keeps
+					 * the LEB referenced.
+					 * This is valid and works as the layer above UBI
+					 * has to do bookkeeping about used/referenced
+					 * LEBs in any case.
+					 */
+					if (ubi->fast_attach) {
+						err = -EBADMSG;
+					} else {
+						err = -EINVAL;
+						ubi_ro_mode(ubi);
+					}
 				}
 			}
 			goto out_free;
@@ -1202,32 +1219,6 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 		}
 
 		cond_resched();
-
-		/*
-		 * We've written the data and are going to read it back to make
-		 * sure it was written correctly.
-		 */
-		memset(ubi->peb_buf, 0xFF, aldata_size);
-		err = ubi_io_read_data(ubi, ubi->peb_buf, to, 0, aldata_size);
-		if (err) {
-			if (err != UBI_IO_BITFLIPS) {
-				ubi_warn(ubi, "error %d while reading data back from PEB %d",
-					 err, to);
-				if (is_error_sane(err))
-					err = MOVE_TARGET_RD_ERR;
-			} else
-				err = MOVE_TARGET_BITFLIPS;
-			goto out_unlock_buf;
-		}
-
-		cond_resched();
-
-		if (crc != crc32(UBI_CRC32_INIT, ubi->peb_buf, data_size)) {
-			ubi_warn(ubi, "read data back from PEB %d and it is different",
-				 to);
-			err = -EINVAL;
-			goto out_unlock_buf;
-		}
 	}
 
 	ubi_assert(vol->eba_tbl[lnum] == from);
diff --git a/drivers/mtd/ubi/fastmap.c b/drivers/mtd/ubi/fastmap.c
index 263b439e21a8..990898b9dc72 100644
--- a/drivers/mtd/ubi/fastmap.c
+++ b/drivers/mtd/ubi/fastmap.c
@@ -1058,6 +1058,7 @@ int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 	ubi_msg(ubi, "fastmap WL pool size: %d",
 		ubi->fm_wl_pool.max_size);
 	ubi->fm_disabled = 0;
+	ubi->fast_attach = 1;
 
 	ubi_free_vid_hdr(ubi, vh);
 	kfree(ech);
diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c
index 437757c89b9e..348dbbcbedc8 100644
--- a/drivers/mtd/ubi/kapi.c
+++ b/drivers/mtd/ubi/kapi.c
@@ -705,7 +705,7 @@ int ubi_leb_map(struct ubi_volume_desc *desc, int lnum)
 	struct ubi_volume *vol = desc->vol;
 	struct ubi_device *ubi = vol->ubi;
 
-	dbg_gen("unmap LEB %d:%d", vol->vol_id, lnum);
+	dbg_gen("map LEB %d:%d", vol->vol_id, lnum);
 
 	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
 		return -EROFS;
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index dadc6a9d5755..61d4e99755a4 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -466,6 +466,7 @@ struct ubi_debug_info {
  * @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
+ * @fast_attach: non-zero if UBI was attached by fastmap
  *
  * @used: RB-tree of used physical eraseblocks
  * @erroneous: RB-tree of erroneous used physical eraseblocks
@@ -574,6 +575,7 @@ struct ubi_device {
 	size_t fm_size;
 	struct work_struct fm_work;
 	int fm_work_scheduled;
+	int fast_attach;
 
 	/* Wear-leveling sub-system's stuff */
 	struct rb_root used;
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
index 1ae17bb9b889..10059dfdc1b6 100644
--- a/drivers/mtd/ubi/vmt.c
+++ b/drivers/mtd/ubi/vmt.c
@@ -405,7 +405,7 @@ int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl)
 	if (!no_vtbl)
 		self_check_volumes(ubi);
 
-	return err;
+	return 0;
 
 out_err:
 	ubi_err(ubi, "cannot remove volume %d, error %d", vol_id, err);
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 17ec948ac40e..959c7b12e0b1 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -1534,6 +1534,7 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
 		INIT_LIST_HEAD(&ubi->pq[i]);
 	ubi->pq_head = 0;
 
+	ubi->free_count = 0;
 	list_for_each_entry_safe(aeb, tmp, &ai->erase, u.list) {
 		cond_resched();
 
@@ -1552,7 +1553,6 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
 		found_pebs++;
 	}
 
-	ubi->free_count = 0;
 	list_for_each_entry(aeb, &ai->free, u.list) {
 		cond_resched();
 
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index 595ca0debe11..69e287e20732 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -260,7 +260,7 @@ void ubifs_dump_inode(struct ubifs_info *c, const struct inode *inode)
 	pr_err("\txattr_names    %u\n", ui->xattr_names);
 	pr_err("\tdirty          %u\n", ui->dirty);
 	pr_err("\txattr          %u\n", ui->xattr);
-	pr_err("\tbulk_read      %u\n", ui->xattr);
+	pr_err("\tbulk_read      %u\n", ui->bulk_read);
 	pr_err("\tsynced_i_size  %llu\n",
 	       (unsigned long long)ui->synced_i_size);
 	pr_err("\tui_size        %llu\n",