Merge branch 'linux-next' of git://git.infradead.org/~dedekind/ubi-2.6

* 'linux-next' of git://git.infradead.org/~dedekind/ubi-2.6: (22 commits)
UBI: always start the background thread
UBI: fix gcc warning
UBI: remove pre-sqnum images support
UBI: fix kernel-doc errors and warnings
UBI: fix checkpatch.pl errors and warnings
UBI: bugfix - do not torture PEB needlessly
UBI: rework scrubbing messages
UBI: implement multiple volumes rename
UBI: fix and re-work debugging stuff
UBI: amend commentaries
UBI: fix error message
UBI: improve mkvol request validation
UBI: add ubi_sync() interface
UBI: fix 64-bit calculations
UBI: fix LEB locking
UBI: fix memory leak on error path
UBI: do not forget to free internal volumes
UBI: fix memory leak
UBI: avoid unnecessary division operations
UBI: fix buffer padding
...

drivers/mtd/ubi/build.c

···
  * @name: MTD device name or number string
  * @vid_hdr_offs: VID header offset
  */
-struct mtd_dev_param
-{
+struct mtd_dev_param {
 	char name[MTD_PARAM_LEN_MAX];
 	int vid_hdr_offs;
 };
 
 /* Numbers of elements set in the @mtd_dev_param array */
-static int mtd_devs = 0;
+static int mtd_devs;
 
 /* MTD devices specification parameters */
 static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
···
 }
 
 /**
- * ubi_get_by_major - get UBI device description object by character device
- *                    major number.
+ * ubi_get_by_major - get UBI device by character device major number.
  * @major: major number
  *
  * This function is similar to 'ubi_get_device()', but it searches the device
···
 }
 
 /**
+ * free_user_volumes - free all user volumes.
+ * @ubi: UBI device description object
+ *
+ * Normally the volumes are freed at the release function of the volume device
+ * objects. However, on error paths the volumes have to be freed before the
+ * device objects have been initialized.
+ */
+static void free_user_volumes(struct ubi_device *ubi)
+{
+	int i;
+
+	for (i = 0; i < ubi->vtbl_slots; i++)
+		if (ubi->volumes[i]) {
+			kfree(ubi->volumes[i]->eba_tbl);
+			kfree(ubi->volumes[i]);
+		}
+}
+
+/**
  * uif_init - initialize user interfaces for an UBI device.
  * @ubi: UBI device description object
  *
  * This function returns zero in case of success and a negative error code in
- * case of failure.
+ * case of failure. Note, this function destroys all volumes if it failes.
  */
 static int uif_init(struct ubi_device *ubi)
 {
-	int i, err;
+	int i, err, do_free = 0;
 	dev_t dev;
 
 	sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
···
 
 	ubi_assert(MINOR(dev) == 0);
 	cdev_init(&ubi->cdev, &ubi_cdev_operations);
-	dbg_msg("%s major is %u", ubi->ubi_name, MAJOR(dev));
+	dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
 	ubi->cdev.owner = THIS_MODULE;
 
 	err = cdev_add(&ubi->cdev, dev, 1);
···
 
 out_volumes:
 	kill_volumes(ubi);
+	do_free = 0;
 out_sysfs:
 	ubi_sysfs_close(ubi);
 	cdev_del(&ubi->cdev);
 out_unreg:
+	if (do_free)
+		free_user_volumes(ubi);
 	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
 	ubi_err("cannot initialize UBI %s, error %d", ubi->ubi_name, err);
 	return err;
···
 /**
  * uif_close - close user interfaces for an UBI device.
  * @ubi: UBI device description object
+ *
+ * Note, since this function un-registers UBI volume device objects (@vol->dev),
+ * the memory allocated voe the volumes is freed as well (in the release
+ * function).
  */
 static void uif_close(struct ubi_device *ubi)
 {
···
 	ubi_sysfs_close(ubi);
 	cdev_del(&ubi->cdev);
 	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
+}
+
+/**
+ * free_internal_volumes - free internal volumes.
+ * @ubi: UBI device description object
+ */
+static void free_internal_volumes(struct ubi_device *ubi)
+{
+	int i;
+
+	for (i = ubi->vtbl_slots;
+	     i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
+		kfree(ubi->volumes[i]->eba_tbl);
+		kfree(ubi->volumes[i]);
+	}
 }
 
 /**
···
 out_wl:
 	ubi_wl_close(ubi);
 out_vtbl:
+	free_internal_volumes(ubi);
 	vfree(ubi->vtbl);
 out_si:
 	ubi_scan_destroy_si(si);
···
 }
 
 /**
- * io_init - initialize I/O unit for a given UBI device.
+ * io_init - initialize I/O sub-system for a given UBI device.
  * @ubi: UBI device description object
  *
  * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
···
 	ubi->min_io_size = ubi->mtd->writesize;
 	ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
 
-	/* Make sure minimal I/O unit is power of 2 */
+	/*
+	 * Make sure minimal I/O unit is power of 2. Note, there is no
+	 * fundamental reason for this assumption. It is just an optimization
+	 * which allows us to avoid costly division operations.
+	 */
 	if (!is_power_of_2(ubi->min_io_size)) {
 		ubi_err("min. I/O unit (%d) is not power of 2",
 			ubi->min_io_size);
···
 	if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
 	    ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
 	    ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
-	    ubi->leb_start % ubi->min_io_size) {
+	    ubi->leb_start & (ubi->min_io_size - 1)) {
 		ubi_err("bad VID header (%d) or data offsets (%d)",
 			ubi->vid_hdr_offset, ubi->leb_start);
 		return -EINVAL;
···
 
 	/*
 	 * Clear the auto-resize flag in the volume in-memory copy of the
-	 * volume table, and 'ubi_resize_volume()' will propogate this change
+	 * volume table, and 'ubi_resize_volume()' will propagate this change
 	 * to the flash.
 	 */
 	ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
···
 		struct ubi_vtbl_record vtbl_rec;
 
 		/*
-		 * No avalilable PEBs to re-size the volume, clear the flag on
+		 * No available PEBs to re-size the volume, clear the flag on
 		 * flash and exit.
 		 */
 		memcpy(&vtbl_rec, &ubi->vtbl[vol_id],
···
 
 /**
  * ubi_attach_mtd_dev - attach an MTD device.
- * @mtd_dev: MTD device description object
+ * @mtd: MTD device description object
  * @ubi_num: number to assign to the new UBI device
  * @vid_hdr_offset: VID header offset
  *
  * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
  * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
- * which case this function finds a vacant device nubert and assings it
+ * which case this function finds a vacant device number and assigns it
  * automatically. Returns the new UBI device number in case of success and a
  * negative error code in case of failure.
  *
···
 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
 {
 	struct ubi_device *ubi;
-	int i, err;
+	int i, err, do_free = 1;
 
 	/*
 	 * Check if we already have the same MTD device attached.
···
 			if (!ubi_devices[ubi_num])
 				break;
 		if (ubi_num == UBI_MAX_DEVICES) {
-			dbg_err("only %d UBI devices may be created", UBI_MAX_DEVICES);
+			dbg_err("only %d UBI devices may be created",
+				UBI_MAX_DEVICES);
 			return -ENFILE;
 		}
 	} else {
···
 
 	mutex_init(&ubi->buf_mutex);
 	mutex_init(&ubi->ckvol_mutex);
+	mutex_init(&ubi->mult_mutex);
 	mutex_init(&ubi->volumes_mutex);
 	spin_lock_init(&ubi->volumes_lock);
 
···
 
 	err = uif_init(ubi);
 	if (err)
-		goto out_detach;
+		goto out_nofree;
 
 	ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
 	if (IS_ERR(ubi->bgt_thread)) {
···
 		ubi->beb_rsvd_pebs);
 	ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
 
-	/* Enable the background thread */
-	if (!DBG_DISABLE_BGT) {
+	if (!DBG_DISABLE_BGT)
 		ubi->thread_enabled = 1;
-		wake_up_process(ubi->bgt_thread);
-	}
+	wake_up_process(ubi->bgt_thread);
 
 	ubi_devices[ubi_num] = ubi;
 	return ubi_num;
 
 out_uif:
 	uif_close(ubi);
+out_nofree:
+	do_free = 0;
 out_detach:
-	ubi_eba_close(ubi);
 	ubi_wl_close(ubi);
+	if (do_free)
+		free_user_volumes(ubi);
+	free_internal_volumes(ubi);
 	vfree(ubi->vtbl);
 out_free:
 	vfree(ubi->peb_buf1);
···
 		kthread_stop(ubi->bgt_thread);
 
 	uif_close(ubi);
-	ubi_eba_close(ubi);
 	ubi_wl_close(ubi);
+	free_internal_volumes(ubi);
 	vfree(ubi->vtbl);
 	put_mtd_device(ubi->mtd);
 	vfree(ubi->peb_buf1);
···
 module_exit(ubi_exit);
 
 /**
- * bytes_str_to_int - convert a string representing number of bytes to an
- * integer.
+ * bytes_str_to_int - convert a number of bytes string into an integer.
  * @str: the string to convert
  *
  * This function returns positive resulting integer in case of success and a

drivers/mtd/ubi/cdev.c

···
 #include <linux/stat.h>
 #include <linux/ioctl.h>
 #include <linux/capability.h>
+#include <linux/uaccess.h>
 #include <linux/smp_lock.h>
 #include <mtd/ubi-user.h>
-#include <asm/uaccess.h>
 #include <asm/div64.h>
 #include "ubi.h"
 
···
 	else
 		mode = UBI_READONLY;
 
-	dbg_msg("open volume %d, mode %d", vol_id, mode);
+	dbg_gen("open volume %d, mode %d", vol_id, mode);
 
 	desc = ubi_open_volume(ubi_num, vol_id, mode);
 	unlock_kernel();
···
 	struct ubi_volume_desc *desc = file->private_data;
 	struct ubi_volume *vol = desc->vol;
 
-	dbg_msg("release volume %d, mode %d", vol->vol_id, desc->mode);
+	dbg_gen("release volume %d, mode %d", vol->vol_id, desc->mode);
 
 	if (vol->updating) {
 		ubi_warn("update of volume %d not finished, volume is damaged",
···
 		vol->updating = 0;
 		vfree(vol->upd_buf);
 	} else if (vol->changing_leb) {
-		dbg_msg("only %lld of %lld bytes received for atomic LEB change"
+		dbg_gen("only %lld of %lld bytes received for atomic LEB change"
 			" for volume %d:%d, cancel", vol->upd_received,
 			vol->upd_bytes, vol->ubi->ubi_num, vol->vol_id);
 		vol->changing_leb = 0;
···
 		return -EINVAL;
 	}
 
-	dbg_msg("seek volume %d, offset %lld, origin %d, new offset %lld",
+	dbg_gen("seek volume %d, offset %lld, origin %d, new offset %lld",
 		vol->vol_id, offset, origin, new_offset);
 
 	file->f_pos = new_offset;
···
 	void *tbuf;
 	uint64_t tmp;
 
-	dbg_msg("read %zd bytes from offset %lld of volume %d",
+	dbg_gen("read %zd bytes from offset %lld of volume %d",
 		count, *offp, vol->vol_id);
 
 	if (vol->updating) {
···
 		return 0;
 
 	if (vol->corrupted)
-		dbg_msg("read from corrupted volume %d", vol->vol_id);
+		dbg_gen("read from corrupted volume %d", vol->vol_id);
 
 	if (*offp + count > vol->used_bytes)
 		count_save = count = vol->used_bytes - *offp;
···
 	char *tbuf;
 	uint64_t tmp;
 
-	dbg_msg("requested: write %zd bytes to offset %lld of volume %u",
+	dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
 		count, *offp, vol->vol_id);
 
 	if (vol->vol_type == UBI_STATIC_VOLUME)
···
 	off = do_div(tmp, vol->usable_leb_size);
 	lnum = tmp;
 
-	if (off % ubi->min_io_size) {
+	if (off & (ubi->min_io_size - 1)) {
 		dbg_err("unaligned position");
 		return -EINVAL;
 	}
···
 		count_save = count = vol->used_bytes - *offp;
 
 	/* We can write only in fractions of the minimum I/O unit */
-	if (count % ubi->min_io_size) {
+	if (count & (ubi->min_io_size - 1)) {
 		dbg_err("unaligned write length");
 		return -EINVAL;
 	}
···
 }
 
 #else
-#define vol_cdev_direct_write(file, buf, count, offp) -EPERM
+#define vol_cdev_direct_write(file, buf, count, offp) (-EPERM)
 #endif /* CONFIG_MTD_UBI_DEBUG_USERSPACE_IO */
 
 static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
···
 			break;
 		}
 
-		rsvd_bytes = vol->reserved_pebs * (ubi->leb_size-vol->data_pad);
+		rsvd_bytes = (long long)vol->reserved_pebs *
+					ubi->leb_size-vol->data_pad;
 		if (bytes < 0 || bytes > rsvd_bytes) {
 			err = -EINVAL;
 			break;
···
 			break;
 		}
 
-		dbg_msg("erase LEB %d:%d", vol->vol_id, lnum);
+		dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
 		err = ubi_eba_unmap_leb(ubi, vol, lnum);
 		if (err)
 			break;
···
 	if (req->alignment > ubi->leb_size)
 		goto bad;
 
-	n = req->alignment % ubi->min_io_size;
+	n = req->alignment & (ubi->min_io_size - 1);
 	if (req->alignment != 1 && n)
 		goto bad;
 
···
 		err = -ENAMETOOLONG;
 		goto bad;
 	}
+
+	n = strnlen(req->name, req->name_len + 1);
+	if (n != req->name_len)
+		goto bad;
 
 	return 0;
 
···
 	return 0;
 }
 
+/**
+ * rename_volumes - rename UBI volumes.
+ * @ubi: UBI device description object
+ * @req: volumes re-name request
+ *
+ * This is a helper function for the volume re-name IOCTL which validates the
+ * the request, opens the volume and calls corresponding volumes management
+ * function. Returns zero in case of success and a negative error code in case
+ * of failure.
+ */
+static int rename_volumes(struct ubi_device *ubi,
+			  struct ubi_rnvol_req *req)
+{
+	int i, n, err;
+	struct list_head rename_list;
+	struct ubi_rename_entry *re, *re1;
+
+	if (req->count < 0 || req->count > UBI_MAX_RNVOL)
+		return -EINVAL;
+
+	if (req->count == 0)
+		return 0;
+
+	/* Validate volume IDs and names in the request */
+	for (i = 0; i < req->count; i++) {
+		if (req->ents[i].vol_id < 0 ||
+		    req->ents[i].vol_id >= ubi->vtbl_slots)
+			return -EINVAL;
+		if (req->ents[i].name_len < 0)
+			return -EINVAL;
+		if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
+			return -ENAMETOOLONG;
+		req->ents[i].name[req->ents[i].name_len] = '\0';
+		n = strlen(req->ents[i].name);
+		if (n != req->ents[i].name_len)
+			err = -EINVAL;
+	}
+
+	/* Make sure volume IDs and names are unique */
+	for (i = 0; i < req->count - 1; i++) {
+		for (n = i + 1; n < req->count; n++) {
+			if (req->ents[i].vol_id == req->ents[n].vol_id) {
+				dbg_err("duplicated volume id %d",
+					req->ents[i].vol_id);
+				return -EINVAL;
+			}
+			if (!strcmp(req->ents[i].name, req->ents[n].name)) {
+				dbg_err("duplicated volume name \"%s\"",
+					req->ents[i].name);
+				return -EINVAL;
+			}
+		}
+	}
+
+	/* Create the re-name list */
+	INIT_LIST_HEAD(&rename_list);
+	for (i = 0; i < req->count; i++) {
+		int vol_id = req->ents[i].vol_id;
+		int name_len = req->ents[i].name_len;
+		const char *name = req->ents[i].name;
+
+		re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
+		if (!re) {
+			err = -ENOMEM;
+			goto out_free;
+		}
+
+		re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
+		if (IS_ERR(re->desc)) {
+			err = PTR_ERR(re->desc);
+			dbg_err("cannot open volume %d, error %d", vol_id, err);
+			kfree(re);
+			goto out_free;
+		}
+
+		/* Skip this re-naming if the name does not really change */
+		if (re->desc->vol->name_len == name_len &&
+		    !memcmp(re->desc->vol->name, name, name_len)) {
+			ubi_close_volume(re->desc);
+			kfree(re);
+			continue;
+		}
+
+		re->new_name_len = name_len;
+		memcpy(re->new_name, name, name_len);
+		list_add_tail(&re->list, &rename_list);
+		dbg_msg("will rename volume %d from \"%s\" to \"%s\"",
+			vol_id, re->desc->vol->name, name);
+	}
+
+	if (list_empty(&rename_list))
+		return 0;
+
+	/* Find out the volumes which have to be removed */
+	list_for_each_entry(re, &rename_list, list) {
+		struct ubi_volume_desc *desc;
+		int no_remove_needed = 0;
+
+		/*
+		 * Volume @re->vol_id is going to be re-named to
+		 * @re->new_name, while its current name is @name. If a volume
+		 * with name @re->new_name currently exists, it has to be
+		 * removed, unless it is also re-named in the request (@req).
+		 */
+		list_for_each_entry(re1, &rename_list, list) {
+			if (re->new_name_len == re1->desc->vol->name_len &&
+			    !memcmp(re->new_name, re1->desc->vol->name,
+				    re1->desc->vol->name_len)) {
+				no_remove_needed = 1;
+				break;
+			}
+		}
+
+		if (no_remove_needed)
+			continue;
+
+		/*
+		 * It seems we need to remove volume with name @re->new_name,
+		 * if it exists.
+		 */
+		desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name, UBI_EXCLUSIVE);
+		if (IS_ERR(desc)) {
+			err = PTR_ERR(desc);
+			if (err == -ENODEV)
+				/* Re-naming into a non-existing volume name */
+				continue;
+
+			/* The volume exists but busy, or an error occurred */
+			dbg_err("cannot open volume \"%s\", error %d",
+				re->new_name, err);
+			goto out_free;
+		}
+
+		re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
+		if (!re) {
+			err = -ENOMEM;
+			ubi_close_volume(desc);
+			goto out_free;
+		}
+
+		re->remove = 1;
+		re->desc = desc;
+		list_add(&re->list, &rename_list);
+		dbg_msg("will remove volume %d, name \"%s\"",
+			re->desc->vol->vol_id, re->desc->vol->name);
+	}
+
+	mutex_lock(&ubi->volumes_mutex);
+	err = ubi_rename_volumes(ubi, &rename_list);
+	mutex_unlock(&ubi->volumes_mutex);
+
+out_free:
+	list_for_each_entry_safe(re, re1, &rename_list, list) {
+		ubi_close_volume(re->desc);
+		list_del(&re->list);
+		kfree(re);
+	}
+	return err;
+}
+
 static int ubi_cdev_ioctl(struct inode *inode, struct file *file,
 			  unsigned int cmd, unsigned long arg)
 {
···
 	{
 		struct ubi_mkvol_req req;
 
-		dbg_msg("create volume");
+		dbg_gen("create volume");
 		err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
 		if (err) {
 			err = -EFAULT;
 			break;
 		}
 
+		req.name[req.name_len] = '\0';
 		err = verify_mkvol_req(ubi, &req);
 		if (err)
 			break;
-
-		req.name[req.name_len] = '\0';
 
 		mutex_lock(&ubi->volumes_mutex);
 		err = ubi_create_volume(ubi, &req);
···
 	{
 		int vol_id;
 
-		dbg_msg("remove volume");
+		dbg_gen("remove volume");
 		err = get_user(vol_id, (__user int32_t *)argp);
 		if (err) {
 			err = -EFAULT;
···
 		}
 
 		mutex_lock(&ubi->volumes_mutex);
-		err = ubi_remove_volume(desc);
+		err = ubi_remove_volume(desc, 0);
 		mutex_unlock(&ubi->volumes_mutex);
 
 		/*
···
 		uint64_t tmp;
 		struct ubi_rsvol_req req;
 
-		dbg_msg("re-size volume");
+		dbg_gen("re-size volume");
 		err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
 		if (err) {
 			err = -EFAULT;
···
 		err = ubi_resize_volume(desc, pebs);
 		mutex_unlock(&ubi->volumes_mutex);
 		ubi_close_volume(desc);
+		break;
+	}
+
+	/* Re-name volumes command */
+	case UBI_IOCRNVOL:
+	{
+		struct ubi_rnvol_req *req;
+
+		dbg_msg("re-name volumes");
+		req = kmalloc(sizeof(struct ubi_rnvol_req), GFP_KERNEL);
+		if (!req) {
+			err = -ENOMEM;
+			break;
+		};
+
+		err = copy_from_user(req, argp, sizeof(struct ubi_rnvol_req));
+		if (err) {
+			err = -EFAULT;
+			kfree(req);
+			break;
+		}
+
+		mutex_lock(&ubi->mult_mutex);
+		err = rename_volumes(ubi, req);
+		mutex_unlock(&ubi->mult_mutex);
+		kfree(req);
 		break;
 	}
 
···
 		struct ubi_attach_req req;
 		struct mtd_info *mtd;
 
-		dbg_msg("attach MTD device");
+		dbg_gen("attach MTD device");
 		err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
 		if (err) {
 			err = -EFAULT;
···
 	{
 		int ubi_num;
 
-		dbg_msg("dettach MTD device");
+		dbg_gen("dettach MTD device");
 		err = get_user(ubi_num, (__user int32_t *)argp);
 		if (err) {
 			err = -EFAULT;

drivers/mtd/ubi/debug.c

···
  * changes.
  */
 
-#ifdef CONFIG_MTD_UBI_DEBUG_MSG
+#ifdef CONFIG_MTD_UBI_DEBUG
 
 #include "ubi.h"
 
···
  */
 void ubi_dbg_dump_ec_hdr(const struct ubi_ec_hdr *ec_hdr)
 {
-	dbg_msg("erase counter header dump:");
-	dbg_msg("magic          %#08x", be32_to_cpu(ec_hdr->magic));
-	dbg_msg("version        %d",    (int)ec_hdr->version);
-	dbg_msg("ec             %llu",  (long long)be64_to_cpu(ec_hdr->ec));
-	dbg_msg("vid_hdr_offset %d",    be32_to_cpu(ec_hdr->vid_hdr_offset));
-	dbg_msg("data_offset    %d",    be32_to_cpu(ec_hdr->data_offset));
-	dbg_msg("hdr_crc        %#08x", be32_to_cpu(ec_hdr->hdr_crc));
-	dbg_msg("erase counter header hexdump:");
+	printk(KERN_DEBUG "Erase counter header dump:\n");
+	printk(KERN_DEBUG "\tmagic          %#08x\n",
+	       be32_to_cpu(ec_hdr->magic));
+	printk(KERN_DEBUG "\tversion        %d\n", (int)ec_hdr->version);
+	printk(KERN_DEBUG "\tec             %llu\n",
+	       (long long)be64_to_cpu(ec_hdr->ec));
+	printk(KERN_DEBUG "\tvid_hdr_offset %d\n",
+	       be32_to_cpu(ec_hdr->vid_hdr_offset));
+	printk(KERN_DEBUG "\tdata_offset    %d\n",
+	       be32_to_cpu(ec_hdr->data_offset));
+	printk(KERN_DEBUG "\thdr_crc        %#08x\n",
+	       be32_to_cpu(ec_hdr->hdr_crc));
+	printk(KERN_DEBUG "erase counter header hexdump:\n");
 	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
 		       ec_hdr, UBI_EC_HDR_SIZE, 1);
 }
···
  */
 void ubi_dbg_dump_vid_hdr(const struct ubi_vid_hdr *vid_hdr)
 {
-	dbg_msg("volume identifier header dump:");
-	dbg_msg("magic     %08x", be32_to_cpu(vid_hdr->magic));
-	dbg_msg("version   %d",   (int)vid_hdr->version);
-	dbg_msg("vol_type  %d",   (int)vid_hdr->vol_type);
-	dbg_msg("copy_flag %d",   (int)vid_hdr->copy_flag);
-	dbg_msg("compat    %d",   (int)vid_hdr->compat);
-	dbg_msg("vol_id    %d",   be32_to_cpu(vid_hdr->vol_id));
-	dbg_msg("lnum      %d",   be32_to_cpu(vid_hdr->lnum));
-	dbg_msg("leb_ver   %u",   be32_to_cpu(vid_hdr->leb_ver));
-	dbg_msg("data_size %d",   be32_to_cpu(vid_hdr->data_size));
-	dbg_msg("used_ebs  %d",   be32_to_cpu(vid_hdr->used_ebs));
-	dbg_msg("data_pad  %d",   be32_to_cpu(vid_hdr->data_pad));
-	dbg_msg("sqnum     %llu",
+	printk(KERN_DEBUG "Volume identifier header dump:\n");
+	printk(KERN_DEBUG "\tmagic     %08x\n", be32_to_cpu(vid_hdr->magic));
+	printk(KERN_DEBUG "\tversion   %d\n",   (int)vid_hdr->version);
+	printk(KERN_DEBUG "\tvol_type  %d\n",   (int)vid_hdr->vol_type);
+	printk(KERN_DEBUG "\tcopy_flag %d\n",   (int)vid_hdr->copy_flag);
+	printk(KERN_DEBUG "\tcompat    %d\n",   (int)vid_hdr->compat);
+	printk(KERN_DEBUG "\tvol_id    %d\n",   be32_to_cpu(vid_hdr->vol_id));
+	printk(KERN_DEBUG "\tlnum      %d\n",   be32_to_cpu(vid_hdr->lnum));
+	printk(KERN_DEBUG "\tdata_size %d\n",   be32_to_cpu(vid_hdr->data_size));
+	printk(KERN_DEBUG "\tused_ebs  %d\n",   be32_to_cpu(vid_hdr->used_ebs));
+	printk(KERN_DEBUG "\tdata_pad  %d\n",   be32_to_cpu(vid_hdr->data_pad));
+	printk(KERN_DEBUG "\tsqnum     %llu\n",
 		(unsigned long long)be64_to_cpu(vid_hdr->sqnum));
-	dbg_msg("hdr_crc   %08x", be32_to_cpu(vid_hdr->hdr_crc));
-	dbg_msg("volume identifier header hexdump:");
+	printk(KERN_DEBUG "\thdr_crc   %08x\n", be32_to_cpu(vid_hdr->hdr_crc));
+	printk(KERN_DEBUG "Volume identifier header hexdump:\n");
+	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+		       vid_hdr, UBI_VID_HDR_SIZE, 1);
 }
 
 /**
···
  */
 void ubi_dbg_dump_vol_info(const struct ubi_volume *vol)
 {
-	dbg_msg("volume information dump:");
-	dbg_msg("vol_id          %d", vol->vol_id);
-	dbg_msg("reserved_pebs   %d", vol->reserved_pebs);
-	dbg_msg("alignment       %d", vol->alignment);
-	dbg_msg("data_pad        %d", vol->data_pad);
-	dbg_msg("vol_type        %d", vol->vol_type);
-	dbg_msg("name_len        %d", vol->name_len);
-	dbg_msg("usable_leb_size %d", vol->usable_leb_size);
-	dbg_msg("used_ebs        %d", vol->used_ebs);
-	dbg_msg("used_bytes      %lld", vol->used_bytes);
-	dbg_msg("last_eb_bytes   %d", vol->last_eb_bytes);
-	dbg_msg("corrupted       %d", vol->corrupted);
-	dbg_msg("upd_marker      %d", vol->upd_marker);
+	printk(KERN_DEBUG "Volume information dump:\n");
+	printk(KERN_DEBUG "\tvol_id          %d\n", vol->vol_id);
+	printk(KERN_DEBUG "\treserved_pebs   %d\n", vol->reserved_pebs);
+	printk(KERN_DEBUG "\talignment       %d\n", vol->alignment);
+	printk(KERN_DEBUG "\tdata_pad        %d\n", vol->data_pad);
+	printk(KERN_DEBUG "\tvol_type        %d\n", vol->vol_type);
+	printk(KERN_DEBUG "\tname_len        %d\n", vol->name_len);
+	printk(KERN_DEBUG "\tusable_leb_size %d\n", vol->usable_leb_size);
+	printk(KERN_DEBUG "\tused_ebs        %d\n", vol->used_ebs);
+	printk(KERN_DEBUG "\tused_bytes      %lld\n", vol->used_bytes);
+	printk(KERN_DEBUG "\tlast_eb_bytes   %d\n", vol->last_eb_bytes);
+	printk(KERN_DEBUG "\tcorrupted       %d\n", vol->corrupted);
+	printk(KERN_DEBUG "\tupd_marker      %d\n", vol->upd_marker);
 
 	if (vol->name_len <= UBI_VOL_NAME_MAX &&
 	    strnlen(vol->name, vol->name_len + 1) == vol->name_len) {
-		dbg_msg("name            %s", vol->name);
+		printk(KERN_DEBUG "\tname            %s\n", vol->name);
 	} else {
-		dbg_msg("the 1st 5 characters of the name: %c%c%c%c%c",
-			vol->name[0], vol->name[1], vol->name[2],
-			vol->name[3], vol->name[4]);
+		printk(KERN_DEBUG "\t1st 5 characters of name: %c%c%c%c%c\n",
+		       vol->name[0], vol->name[1], vol->name[2],
+		       vol->name[3], vol->name[4]);
 	}
 }
 
···
 {
 	int name_len = be16_to_cpu(r->name_len);
 
-	dbg_msg("volume table record %d dump:", idx);
-	dbg_msg("reserved_pebs   %d", be32_to_cpu(r->reserved_pebs));
-	dbg_msg("alignment       %d", be32_to_cpu(r->alignment));
-	dbg_msg("data_pad        %d", be32_to_cpu(r->data_pad));
-	dbg_msg("vol_type        %d", (int)r->vol_type);
-	dbg_msg("upd_marker      %d", (int)r->upd_marker);
-	dbg_msg("name_len        %d", name_len);
+	printk(KERN_DEBUG "Volume table record %d dump:\n", idx);
+	printk(KERN_DEBUG "\treserved_pebs   %d\n",
+	       be32_to_cpu(r->reserved_pebs));
+	printk(KERN_DEBUG "\talignment       %d\n", be32_to_cpu(r->alignment));
+	printk(KERN_DEBUG "\tdata_pad        %d\n", be32_to_cpu(r->data_pad));
+	printk(KERN_DEBUG "\tvol_type        %d\n", (int)r->vol_type);
+	printk(KERN_DEBUG "\tupd_marker      %d\n", (int)r->upd_marker);
+	printk(KERN_DEBUG "\tname_len        %d\n", name_len);
 
 	if (r->name[0] == '\0') {
-		dbg_msg("name            NULL");
+		printk(KERN_DEBUG "\tname            NULL\n");
 		return;
 	}
 
 	if (name_len <= UBI_VOL_NAME_MAX &&
 	    strnlen(&r->name[0], name_len + 1) == name_len) {
-		dbg_msg("name            %s", &r->name[0]);
+		printk(KERN_DEBUG "\tname            %s\n", &r->name[0]);
 	} else {
-		dbg_msg("1st 5 characters of the name: %c%c%c%c%c",
+		printk(KERN_DEBUG "\t1st 5 characters of name: %c%c%c%c%c\n",
 			r->name[0], r->name[1], r->name[2], r->name[3],
 			r->name[4]);
 	}
-	dbg_msg("crc             %#08x", be32_to_cpu(r->crc));
+	printk(KERN_DEBUG "\tcrc             %#08x\n", be32_to_cpu(r->crc));
 }
 
 /**
···
  */
 void ubi_dbg_dump_sv(const struct ubi_scan_volume *sv)
 {
-	dbg_msg("volume scanning information dump:");
-	dbg_msg("vol_id         %d", sv->vol_id);
-	dbg_msg("highest_lnum   %d", sv->highest_lnum);
-	dbg_msg("leb_count      %d", sv->leb_count);
-	dbg_msg("compat         %d", sv->compat);
-	dbg_msg("vol_type       %d", sv->vol_type);
-	dbg_msg("used_ebs       %d", sv->used_ebs);
-	dbg_msg("last_data_size %d", sv->last_data_size);
-	dbg_msg("data_pad       %d", sv->data_pad);
+	printk(KERN_DEBUG "Volume scanning information dump:\n");
+	printk(KERN_DEBUG "\tvol_id         %d\n", sv->vol_id);
+	printk(KERN_DEBUG "\thighest_lnum   %d\n", sv->highest_lnum);
+	printk(KERN_DEBUG "\tleb_count      %d\n", sv->leb_count);
+	printk(KERN_DEBUG "\tcompat         %d\n", sv->compat);
+	printk(KERN_DEBUG "\tvol_type       %d\n", sv->vol_type);
+	printk(KERN_DEBUG "\tused_ebs       %d\n", sv->used_ebs);
+	printk(KERN_DEBUG "\tlast_data_size %d\n", sv->last_data_size);
+	printk(KERN_DEBUG "\tdata_pad       %d\n", sv->data_pad);
 }
 
 /**
···
  */
 void ubi_dbg_dump_seb(const struct ubi_scan_leb *seb, int type)
 {
-	dbg_msg("eraseblock scanning information dump:");
-	dbg_msg("ec       %d", seb->ec);
-	dbg_msg("pnum     %d", seb->pnum);
+	printk(KERN_DEBUG "eraseblock scanning information dump:\n");
+	printk(KERN_DEBUG "\tec       %d\n", seb->ec);
+	printk(KERN_DEBUG "\tpnum     %d\n", seb->pnum);
 	if (type == 0) {
-		dbg_msg("lnum     %d", seb->lnum);
-		dbg_msg("scrub    %d", seb->scrub);
-		dbg_msg("sqnum    %llu", seb->sqnum);
-		dbg_msg("leb_ver  %u", seb->leb_ver);
+		printk(KERN_DEBUG "\tlnum     %d\n", seb->lnum);
+		printk(KERN_DEBUG "\tscrub    %d\n", seb->scrub);
+		printk(KERN_DEBUG "\tsqnum    %llu\n", seb->sqnum);
 	}
 }
 
···
 {
 	char nm[17];
 
-	dbg_msg("volume creation request dump:");
-	dbg_msg("vol_id    %d",   req->vol_id);
-	dbg_msg("alignment %d",   req->alignment);
-	dbg_msg("bytes     %lld", (long long)req->bytes);
-	dbg_msg("vol_type  %d",   req->vol_type);
-	dbg_msg("name_len  %d",   req->name_len);
+	printk(KERN_DEBUG "Volume creation request dump:\n");
+	printk(KERN_DEBUG "\tvol_id    %d\n",   req->vol_id);
+	printk(KERN_DEBUG "\talignment %d\n",   req->alignment);
+	printk(KERN_DEBUG "\tbytes     %lld\n", (long long)req->bytes);
+	printk(KERN_DEBUG "\tvol_type  %d\n",   req->vol_type);
+	printk(KERN_DEBUG "\tname_len  %d\n",   req->name_len);
 
 	memcpy(nm, req->name, 16);
 	nm[16] = 0;
-	dbg_msg("the 1st 16 characters of the name: %s", nm);
+	printk(KERN_DEBUG "\t1st 16 characters of name: %s\n", nm);
 }
 
-#endif /* CONFIG_MTD_UBI_DEBUG_MSG */
+#endif /* CONFIG_MTD_UBI_DEBUG */

drivers/mtd/ubi/debug.h

···
 #ifdef CONFIG_MTD_UBI_DEBUG
 #include <linux/random.h>
 
-#define ubi_assert(expr)  BUG_ON(!(expr))
 #define dbg_err(fmt, ...) ubi_err(fmt, ##__VA_ARGS__)
-#else
-#define ubi_assert(expr)  ({})
-#define dbg_err(fmt, ...) ({})
-#endif
 
-#ifdef CONFIG_MTD_UBI_DEBUG_DISABLE_BGT
-#define DBG_DISABLE_BGT 1
-#else
-#define DBG_DISABLE_BGT 0
-#endif
+#define ubi_assert(expr)  do {                                               \
+        if (unlikely(!(expr))) {                                             \
+                printk(KERN_CRIT "UBI assert failed in %s at %u (pid %d)\n", \
+                       __func__, __LINE__, current->pid);                    \
+                ubi_dbg_dump_stack();                                        \
+        }                                                                    \
+} while (0)
 
-#ifdef CONFIG_MTD_UBI_DEBUG_MSG
-/* Generic debugging message */
 #define dbg_msg(fmt, ...)                                    \
 	printk(KERN_DEBUG "UBI DBG (pid %d): %s: " fmt "\n", \
 	       current->pid, __func__, ##__VA_ARGS__)
···
 void ubi_dbg_dump_seb(const struct ubi_scan_leb *seb, int type);
 void ubi_dbg_dump_mkvol_req(const struct ubi_mkvol_req *req);
 
+#ifdef CONFIG_MTD_UBI_DEBUG_MSG
+/* General debugging messages */
+#define dbg_gen(fmt, ...) dbg_msg(fmt, ##__VA_ARGS__)
 #else
-
-#define dbg_msg(fmt, ...)    ({})
-#define ubi_dbg_dump_stack() ({})
-#define ubi_dbg_dump_ec_hdr(ec_hdr)      ({})
-#define ubi_dbg_dump_vid_hdr(vid_hdr)    ({})
-#define ubi_dbg_dump_vol_info(vol)       ({})
-#define ubi_dbg_dump_vtbl_record(r, idx) ({})
-#define ubi_dbg_dump_sv(sv)              ({})
-#define ubi_dbg_dump_seb(seb, type)      ({})
-#define ubi_dbg_dump_mkvol_req(req)      ({})
-
-#endif /* CONFIG_MTD_UBI_DEBUG_MSG */
+#define dbg_gen(fmt, ...) ({})
+#endif
 
 #ifdef CONFIG_MTD_UBI_DEBUG_MSG_EBA
-/* Messages from the eraseblock association unit */
+/* Messages from the eraseblock association sub-system */
 #define dbg_eba(fmt, ...) dbg_msg(fmt, ##__VA_ARGS__)
 #else
 #define dbg_eba(fmt, ...) ({})
 #endif
 
 #ifdef CONFIG_MTD_UBI_DEBUG_MSG_WL
-/* Messages from the wear-leveling unit */
+/* Messages from the wear-leveling sub-system */
 #define dbg_wl(fmt, ...) dbg_msg(fmt, ##__VA_ARGS__)
 #else
 #define dbg_wl(fmt, ...) ({})
 #endif
 
 #ifdef CONFIG_MTD_UBI_DEBUG_MSG_IO
-/* Messages from the input/output unit */
+/* Messages from the input/output sub-system */
 #define dbg_io(fmt, ...) dbg_msg(fmt, ##__VA_ARGS__)
 #else
 #define dbg_io(fmt, ...) ({})
···
 #else
 #define dbg_bld(fmt, ...) ({})
 #define UBI_IO_DEBUG 0
+#endif
+
+#ifdef CONFIG_MTD_UBI_DEBUG_DISABLE_BGT
+#define DBG_DISABLE_BGT 1
+#else
+#define DBG_DISABLE_BGT 0
 #endif
 
 #ifdef CONFIG_MTD_UBI_DEBUG_EMULATE_BITFLIPS
···
 #define ubi_dbg_is_erase_failure() 0
 #endif
 
+#else
+
+#define ubi_assert(expr)                 ({})
+#define dbg_err(fmt, ...)                ({})
+#define dbg_msg(fmt, ...)                ({})
+#define dbg_gen(fmt, ...)                ({})
+#define dbg_eba(fmt, ...)                ({})
+#define dbg_wl(fmt, ...)                 ({})
+#define dbg_io(fmt, ...)                 ({})
+#define dbg_bld(fmt, ...)                ({})
+#define ubi_dbg_dump_stack()             ({})
+#define ubi_dbg_dump_ec_hdr(ec_hdr)      ({})
+#define ubi_dbg_dump_vid_hdr(vid_hdr)    ({})
+#define ubi_dbg_dump_vol_info(vol)       ({})
+#define ubi_dbg_dump_vtbl_record(r, idx) ({})
+#define ubi_dbg_dump_sv(sv)              ({})
+#define ubi_dbg_dump_seb(seb, type)      ({})
+#define ubi_dbg_dump_mkvol_req(req)      ({})
+
+#define UBI_IO_DEBUG               0
+#define DBG_DISABLE_BGT            0
+#define ubi_dbg_is_bitflip()       0
+#define ubi_dbg_is_write_failure() 0
+#define ubi_dbg_is_erase_failure() 0
+
+#endif /* !CONFIG_MTD_UBI_DEBUG */
 #endif /* !__UBI_DEBUG_H__ */

drivers/mtd/ubi/eba.c

···
  */
 
 /*
- * The UBI Eraseblock Association (EBA) unit.
+ * The UBI Eraseblock Association (EBA) sub-system.
  *
- * This unit is responsible for I/O to/from logical eraseblock.
+ * This sub-system is responsible for I/O to/from logical eraseblock.
  *
  * Although in this implementation the EBA table is fully kept and managed in
  * RAM, which assumes poor scalability, it might be (partially) maintained on
  * flash in future implementations.
  *
- * The EBA unit implements per-logical eraseblock locking. Before accessing a
- * logical eraseblock it is locked for reading or writing. The per-logical
- * eraseblock locking is implemented by means of the lock tree. The lock tree
- * is an RB-tree which refers all the currently locked logical eraseblocks. The
- * lock tree elements are &struct ubi_ltree_entry objects. They are indexed by
- * (@vol_id, @lnum) pairs.
+ * The EBA sub-system implements per-logical eraseblock locking. Before
+ * accessing a logical eraseblock it is locked for reading or writing. The
+ * per-logical eraseblock locking is implemented by means of the lock tree. The
+ * lock tree is an RB-tree which refers all the currently locked logical
+ * eraseblocks. The lock tree elements are &struct ubi_ltree_entry objects.
+ * They are indexed by (@vol_id, @lnum) pairs.
  *
  * EBA also maintains the global sequence counter which is incremented each
  * time a logical eraseblock is mapped to a physical eraseblock and it is
···
 	le->users += 1;
 	spin_unlock(&ubi->ltree_lock);
 
-	if (le_free)
-		kfree(le_free);
-
+	kfree(le_free);
 	return le;
 }
 
···
  */
 static void leb_read_unlock(struct ubi_device *ubi, int vol_id, int lnum)
 {
-	int free = 0;
 	struct ubi_ltree_entry *le;
 
 	spin_lock(&ubi->ltree_lock);
 	le = ltree_lookup(ubi, vol_id, lnum);
 	le->users -= 1;
 	ubi_assert(le->users >= 0);
+	up_read(&le->mutex);
 	if (le->users == 0) {
 		rb_erase(&le->rb, &ubi->ltree);
-		free = 1;
+		kfree(le);
 	}
 	spin_unlock(&ubi->ltree_lock);
-
-	up_read(&le->mutex);
-	if (free)
-		kfree(le);
 }
 
 /**
···
  */
 static int leb_write_trylock(struct ubi_device *ubi, int vol_id, int lnum)
 {
-	int free;
 	struct ubi_ltree_entry *le;
 
 	le = ltree_add_entry(ubi, vol_id, lnum);
···
 	ubi_assert(le->users >= 0);
 	if (le->users == 0) {
 		rb_erase(&le->rb, &ubi->ltree);
-		free = 1;
-	} else
-		free = 0;
-	spin_unlock(&ubi->ltree_lock);
-	if (free)
 		kfree(le);
+	}
+	spin_unlock(&ubi->ltree_lock);
 
 	return 1;
 }
···
  */
 static void leb_write_unlock(struct ubi_device *ubi, int vol_id, int lnum)
 {
-	int free;
 	struct ubi_ltree_entry *le;
 
 	spin_lock(&ubi->ltree_lock);
 	le = ltree_lookup(ubi, vol_id, lnum);
 	le->users -= 1;
 	ubi_assert(le->users >= 0);
+	up_write(&le->mutex);
 	if (le->users == 0) {
 		rb_erase(&le->rb, &ubi->ltree);
-		free = 1;
-	} else
-		free = 0;
-	spin_unlock(&ubi->ltree_lock);
-
-	up_write(&le->mutex);
-	if (free)
 		kfree(le);
+	}
+	spin_unlock(&ubi->ltree_lock);
 }
 
 /**
···
 	struct ubi_vid_hdr *vid_hdr;
 
 	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
-	if (!vid_hdr) {
+	if (!vid_hdr)
 		return -ENOMEM;
-	}
 
 	mutex_lock(&ubi->buf_mutex);
 
···
 		/* If this is the last LEB @len may be unaligned */
 		len = ALIGN(data_size, ubi->min_io_size);
 	else
-		ubi_assert(len % ubi->min_io_size == 0);
+		ubi_assert(!(len & (ubi->min_io_size - 1)));
 
 	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
 	if (!vid_hdr)
···
 	}
 
 	if (vol->eba_tbl[lnum] >= 0) {
-		err = ubi_wl_put_peb(ubi, vol->eba_tbl[lnum], 1);
+		err = ubi_wl_put_peb(ubi, vol->eba_tbl[lnum], 0);
 		if (err)
 			goto out_leb_unlock;
 	}
···
 }
 
 /**
- * ubi_eba_init_scan - initialize the EBA unit using scanning information.
+ * ubi_eba_init_scan - initialize the EBA sub-system using scanning information.
  * @ubi: UBI device description object
  * @si: scanning information
  *
···
 	struct ubi_scan_leb *seb;
 	struct rb_node *rb;
 
-	dbg_eba("initialize EBA unit");
+	dbg_eba("initialize EBA sub-system");
 
 	spin_lock_init(&ubi->ltree_lock);
 	mutex_init(&ubi->alc_mutex);
···
 		ubi->rsvd_pebs  += ubi->beb_rsvd_pebs;
 	}
 
-	dbg_eba("EBA unit is initialized");
+	dbg_eba("EBA sub-system is initialized");
 	return 0;
 
 out_free:
···
 		kfree(ubi->volumes[i]->eba_tbl);
 	}
 	return err;
-}
-
-/**
- * ubi_eba_close - close EBA unit.
- * @ubi: UBI device description object
- */
-void ubi_eba_close(const struct ubi_device *ubi)
-{
-	int i, num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT;
-
-	dbg_eba("close EBA unit");
-
-	for (i = 0; i < num_volumes; i++) {
-		if (!ubi->volumes[i])
-			continue;
-		kfree(ubi->volumes[i]->eba_tbl);
-	}
 }

drivers/mtd/ubi/gluebi.c

···
 	struct ubi_device *ubi;
 	uint64_t tmp = from;
 
-	dbg_msg("read %zd bytes from offset %lld", len, from);
+	dbg_gen("read %zd bytes from offset %lld", len, from);
 
 	if (len < 0 || from < 0 || from + len > mtd->size)
 		return -EINVAL;
···
 	struct ubi_device *ubi;
 	uint64_t tmp = to;
 
-	dbg_msg("write %zd bytes to offset %lld", len, to);
+	dbg_gen("write %zd bytes to offset %lld", len, to);
 
 	if (len < 0 || to < 0 || len + to > mtd->size)
 		return -EINVAL;
···
 	struct ubi_volume *vol;
 	struct ubi_device *ubi;
 
-	dbg_msg("erase %u bytes at offset %u", instr->len, instr->addr);
+	dbg_gen("erase %u bytes at offset %u", instr->len, instr->addr);
 
 	if (instr->addr < 0 || instr->addr > mtd->size - mtd->erasesize)
 		return -EINVAL;
···
 	if (err)
 		goto out_err;
 
-        instr->state = MTD_ERASE_DONE;
-        mtd_erase_callback(instr);
+	instr->state = MTD_ERASE_DONE;
+	mtd_erase_callback(instr);
 	return 0;
 
 out_err:
···
 		mtd->size = vol->used_bytes;
 
 	if (add_mtd_device(mtd)) {
-		ubi_err("cannot not add MTD device\n");
+		ubi_err("cannot not add MTD device");
 		kfree(mtd->name);
 		return -ENFILE;
 	}
 
-	dbg_msg("added mtd%d (\"%s\"), size %u, EB size %u",
+	dbg_gen("added mtd%d (\"%s\"), size %u, EB size %u",
 		mtd->index, mtd->name, mtd->size, mtd->erasesize);
 	return 0;
 }
···
 	int err;
 	struct mtd_info *mtd = &vol->gluebi_mtd;
 
-	dbg_msg("remove mtd%d", mtd->index);
+	dbg_gen("remove mtd%d", mtd->index);
 	err = del_mtd_device(mtd);
 	if (err)
 		return err;

drivers/mtd/ubi/io.c

···
  */
 
 /*
- * UBI input/output unit.
+ * UBI input/output sub-system.
  *
- * This unit provides a uniform way to work with all kinds of the underlying
- * MTD devices. It also implements handy functions for reading and writing UBI
- * headers.
+ * This sub-system provides a uniform way to work with all kinds of the
+ * underlying MTD devices. It also implements handy functions for reading and
+ * writing UBI headers.
  *
  * We are trying to have a paranoid mindset and not to trust to what we read
- * from the flash media in order to be more secure and robust. So this unit
- * validates every single header it reads from the flash media.
+ * from the flash media in order to be more secure and robust. So this
+ * sub-system validates every single header it reads from the flash media.
  *
  * Some words about how the eraseblock headers are stored.
  *
···
  * 512-byte chunks, we have to allocate one more buffer and copy our VID header
  * to offset 448 of this buffer.
  *
- * The I/O unit does the following trick in order to avoid this extra copy.
- * It always allocates a @ubi->vid_hdr_alsize bytes buffer for the VID header
- * and returns a pointer to offset @ubi->vid_hdr_shift of this buffer. When the
- * VID header is being written out, it shifts the VID header pointer back and
- * writes the whole sub-page.
+ * The I/O sub-system does the following trick in order to avoid this extra
+ * copy. It always allocates a @ubi->vid_hdr_alsize bytes buffer for the VID
+ * header and returns a pointer to offset @ubi->vid_hdr_shift of this buffer.
+ * When the VID header is being written out, it shifts the VID header pointer
+ * back and writes the whole sub-page.
  */
 
 #include <linux/crc32.h>
···
 			/*
 			 * -EUCLEAN is reported if there was a bit-flip which
 			 * was corrected, so this is harmless.
+			 *
+			 * We do not report about it here unless debugging is
+			 * enabled. A corresponding message will be printed
+			 * later, when it is has been scrubbed.
 			 */
-			ubi_msg("fixable bit-flip detected at PEB %d", pnum);
+			dbg_msg("fixable bit-flip detected at PEB %d", pnum);
 			ubi_assert(len == read);
 			return UBI_IO_BITFLIPS;
 		}
 
 		if (read != len && retries++ < UBI_IO_RETRIES) {
-			dbg_io("error %d while reading %d bytes from PEB %d:%d, "
-			       "read only %zd bytes, retry",
+			dbg_io("error %d while reading %d bytes from PEB %d:%d,"
+			       " read only %zd bytes, retry",
 			       err, len, pnum, offset, read);
 			yield();
 			goto retry;
···
 		ubi_assert(len == read);
 
 		if (ubi_dbg_is_bitflip()) {
-			dbg_msg("bit-flip (emulated)");
+			dbg_gen("bit-flip (emulated)");
 			err = UBI_IO_BITFLIPS;
 		}
 	}
···
 {
 	int err, i, patt_count;
 
+	ubi_msg("run torture test for PEB %d", pnum);
 	patt_count = ARRAY_SIZE(patterns);
 	ubi_assert(patt_count > 0);
 
···
 	}
 
 	err = patt_count;
+	ubi_msg("PEB %d passed torture test, do not mark it a bad", pnum);
 
 out:
 	mutex_unlock(&ubi->buf_mutex);
···
 
 	if (hdr_crc != crc) {
 		if (verbose) {
-			ubi_warn("bad EC header CRC at PEB %d, calculated %#08x,"
-				 " read %#08x", pnum, crc, hdr_crc);
+			ubi_warn("bad EC header CRC at PEB %d, calculated "
+				 "%#08x, read %#08x", pnum, crc, hdr_crc);
 			ubi_dbg_dump_ec_hdr(ec_hdr);
 		}
 		return UBI_IO_BAD_EC_HDR;
···
 }
 
 /**
- * paranoid_check_peb_ec_hdr - check that the erase counter header of a
- * physical eraseblock is in-place and is all right.
+ * paranoid_check_peb_ec_hdr - check erase counter header.
  * @ubi: UBI device description object
  * @pnum: the physical eraseblock number to check
  *
···
 }
 
 /**
- * paranoid_check_peb_vid_hdr - check that the volume identifier header of a
- * physical eraseblock is in-place and is all right.
+ * paranoid_check_peb_vid_hdr - check volume identifier header.
  * @ubi: UBI device description object
  * @pnum: the physical eraseblock number to check
  *
···
 
 fail:
 	ubi_err("paranoid check failed for PEB %d", pnum);
-	dbg_msg("hex dump of the %d-%d region", offset, offset + len);
+	ubi_msg("hex dump of the %d-%d region", offset, offset + len);
 	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
 		       ubi->dbg_peb_buf, len, 1);
 	err = 1;

drivers/mtd/ubi/kapi.c

···
 	struct ubi_device *ubi;
 	struct ubi_volume *vol;
 
-	dbg_msg("open device %d volume %d, mode %d", ubi_num, vol_id, mode);
+	dbg_gen("open device %d volume %d, mode %d", ubi_num, vol_id, mode);
 
 	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
 		return ERR_PTR(-EINVAL);
···
 	struct ubi_device *ubi;
 	struct ubi_volume_desc *ret;
 
-	dbg_msg("open volume %s, mode %d", name, mode);
+	dbg_gen("open volume %s, mode %d", name, mode);
 
 	if (!name)
 		return ERR_PTR(-EINVAL);
···
 	struct ubi_volume *vol = desc->vol;
 	struct ubi_device *ubi = vol->ubi;
 
-	dbg_msg("close volume %d, mode %d", vol->vol_id, desc->mode);
+	dbg_gen("close volume %d, mode %d", vol->vol_id, desc->mode);
 
 	spin_lock(&ubi->volumes_lock);
 	switch (desc->mode) {
···
 	struct ubi_device *ubi = vol->ubi;
 	int err, vol_id = vol->vol_id;
 
-	dbg_msg("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset);
+	dbg_gen("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset);
 
 	if (vol_id < 0 || vol_id >= ubi->vtbl_slots || lnum < 0 ||
 	    lnum >= vol->used_ebs || offset < 0 || len < 0 ||
···
 	struct ubi_device *ubi = vol->ubi;
 	int vol_id = vol->vol_id;
 
-	dbg_msg("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset);
+	dbg_gen("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset);
 
 	if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
 		return -EINVAL;
···
 		return -EROFS;
 
 	if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 ||
-	    offset + len > vol->usable_leb_size || offset % ubi->min_io_size ||
-	    len % ubi->min_io_size)
+	    offset + len > vol->usable_leb_size ||
+	    offset & (ubi->min_io_size - 1) || len & (ubi->min_io_size - 1))
 		return -EINVAL;
 
 	if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
···
 	struct ubi_device *ubi = vol->ubi;
 	int vol_id = vol->vol_id;
 
-	dbg_msg("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum);
+	dbg_gen("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum);
 
 	if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
 		return -EINVAL;
···
 		return -EROFS;
 
 	if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 ||
-	    len > vol->usable_leb_size || len % ubi->min_io_size)
+	    len > vol->usable_leb_size || len & (ubi->min_io_size - 1))
 		return -EINVAL;
 
 	if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
···
 	struct ubi_device *ubi = vol->ubi;
 	int err;
 
-	dbg_msg("erase LEB %d:%d", vol->vol_id, lnum);
+	dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
 
 	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
 		return -EROFS;
···
 	struct ubi_volume *vol = desc->vol;
 	struct ubi_device *ubi = vol->ubi;
 
-	dbg_msg("unmap LEB %d:%d", vol->vol_id, lnum);
+	dbg_gen("unmap LEB %d:%d", vol->vol_id, lnum);
 
 	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
 		return -EROFS;
···
 	struct ubi_volume *vol = desc->vol;
 	struct ubi_device *ubi = vol->ubi;
 
-	dbg_msg("unmap LEB %d:%d", vol->vol_id, lnum);
+	dbg_gen("unmap LEB %d:%d", vol->vol_id, lnum);
 
 	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
 		return -EROFS;
···
 {
 	struct ubi_volume *vol = desc->vol;
 
-	dbg_msg("test LEB %d:%d", vol->vol_id, lnum);
+	dbg_gen("test LEB %d:%d", vol->vol_id, lnum);
 
 	if (lnum < 0 || lnum >= vol->reserved_pebs)
 		return -EINVAL;
···
 	return vol->eba_tbl[lnum] >= 0;
 }
 EXPORT_SYMBOL_GPL(ubi_is_mapped);
+
+/**
+ * ubi_sync - synchronize UBI device buffers.
+ * @ubi_num: UBI device to synchronize
+ *
+ * The underlying MTD device may cache data in hardware or in software. This
+ * function ensures the caches are flushed. Returns zero in case of success and
+ * a negative error code in case of failure.
+ */
+int ubi_sync(int ubi_num)
+{
+	struct ubi_device *ubi;
+
+	ubi = ubi_get_device(ubi_num);
+	if (!ubi)
+		return -ENODEV;
+
+	if (ubi->mtd->sync)
+		ubi->mtd->sync(ubi->mtd);
+
+	ubi_put_device(ubi);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ubi_sync);

drivers/mtd/ubi/misc.c

···
 {
 	int i;
 
-	ubi_assert(length % ubi->min_io_size == 0);
+	ubi_assert(!(length & (ubi->min_io_size - 1)));
 
 	for (i = length - 1; i >= 0; i--)
 		if (((const uint8_t *)buf)[i] != 0xFF)

drivers/mtd/ubi/scan.c

···
  */
 
 /*
- * UBI scanning unit.
+ * UBI scanning sub-system.
  *
- * This unit is responsible for scanning the flash media, checking UBI
+ * This sub-system is responsible for scanning the flash media, checking UBI
  * headers and providing complete information about the UBI flash image.
  *
  * The scanning information is represented by a &struct ubi_scan_info' object.
···
 }
 
 /**
- * validate_vid_hdr - check that volume identifier header is correct and
- * consistent.
+ * validate_vid_hdr - check volume identifier header.
  * @vid_hdr: the volume identifier header to check
  * @sv: information about the volume this logical eraseblock belongs to
  * @pnum: physical eraseblock number the VID header came from
···
  * non-zero if an inconsistency was found and zero if not.
  *
  * Note, UBI does sanity check of everything it reads from the flash media.
- * Most of the checks are done in the I/O unit. Here we check that the
+ * Most of the checks are done in the I/O sub-system. Here we check that the
  * information in the VID header is consistent to the information in other VID
  * headers of the same volume.
  */
···
 	struct ubi_vid_hdr *vh = NULL;
 	unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
 
-	if (seb->sqnum == 0 && sqnum2 == 0) {
-		long long abs, v1 = seb->leb_ver, v2 = be32_to_cpu(vid_hdr->leb_ver);
-
+	if (sqnum2 == seb->sqnum) {
 		/*
-		 * UBI constantly increases the logical eraseblock version
-		 * number and it can overflow. Thus, we have to bear in mind
-		 * that versions that are close to %0xFFFFFFFF are less then
-		 * versions that are close to %0.
-		 *
-		 * The UBI WL unit guarantees that the number of pending tasks
-		 * is not greater then %0x7FFFFFFF. So, if the difference
-		 * between any two versions is greater or equivalent to
-		 * %0x7FFFFFFF, there was an overflow and the logical
-		 * eraseblock with lower version is actually newer then the one
-		 * with higher version.
-		 *
-		 * FIXME: but this is anyway obsolete and will be removed at
-		 * some point.
+		 * This must be a really ancient UBI image which has been
+		 * created before sequence numbers support has been added. At
+		 * that times we used 32-bit LEB versions stored in logical
+		 * eraseblocks. That was before UBI got into mainline. We do not
+		 * support these images anymore. Well, those images will work
+		 * still work, but only if no unclean reboots happened.
 		 */
-		dbg_bld("using old crappy leb_ver stuff");
+		ubi_err("unsupported on-flash UBI format\n");
+		return -EINVAL;
+	}
 
-		if (v1 == v2) {
-			ubi_err("PEB %d and PEB %d have the same version %lld",
-				seb->pnum, pnum, v1);
-			return -EINVAL;
-		}
-
-		abs = v1 - v2;
-		if (abs < 0)
-			abs = -abs;
-
-		if (abs < 0x7FFFFFFF)
-			/* Non-overflow situation */
-			second_is_newer = (v2 > v1);
-		else
-			second_is_newer = (v2 < v1);
-	} else
-		/* Obviously the LEB with lower sequence counter is older */
-		second_is_newer = sqnum2 > seb->sqnum;
+	/* Obviously the LEB with lower sequence counter is older */
+	second_is_newer = !!(sqnum2 > seb->sqnum);
 
 	/*
 	 * Now we know which copy is newer. If the copy flag of the PEB with
···
 	 * check data CRC. For the second PEB we already have the VID header,
 	 * for the first one - we'll need to re-read it from flash.
 	 *
-	 * FIXME: this may be optimized so that we wouldn't read twice.
+	 * Note: this may be optimized so that we wouldn't read twice.
 	 */
 
 	if (second_is_newer) {
···
 }
 
 /**
- * ubi_scan_add_used - add information about a physical eraseblock to the
- * scanning information.
+ * ubi_scan_add_used - add physical eraseblock to the scanning information.
  * @ubi: UBI device description object
  * @si: scanning information
  * @pnum: the physical eraseblock number
···
 		      int bitflips)
 {
 	int err, vol_id, lnum;
-	uint32_t leb_ver;
 	unsigned long long sqnum;
 	struct ubi_scan_volume *sv;
 	struct ubi_scan_leb *seb;
···
 	vol_id = be32_to_cpu(vid_hdr->vol_id);
 	lnum = be32_to_cpu(vid_hdr->lnum);
 	sqnum = be64_to_cpu(vid_hdr->sqnum);
-	leb_ver = be32_to_cpu(vid_hdr->leb_ver);
 
-	dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, ver %u, bitflips %d",
-		pnum, vol_id, lnum, ec, sqnum, leb_ver, bitflips);
+	dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
+		pnum, vol_id, lnum, ec, sqnum, bitflips);
 
 	sv = add_volume(si, vol_id, pnum, vid_hdr);
 	if (IS_ERR(sv) < 0)
···
 		 */
 
 		dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
-			"LEB ver %u, EC %d", seb->pnum, seb->sqnum,
-			seb->leb_ver, seb->ec);
-
-		/*
-		 * Make sure that the logical eraseblocks have different
-		 * versions. Otherwise the image is bad.
-		 */
-		if (seb->leb_ver == leb_ver && leb_ver != 0) {
-			ubi_err("two LEBs with same version %u", leb_ver);
-			ubi_dbg_dump_seb(seb, 0);
-			ubi_dbg_dump_vid_hdr(vid_hdr);
-			return -EINVAL;
-		}
+			"EC %d", seb->pnum, seb->sqnum, seb->ec);
 
 		/*
 		 * Make sure that the logical eraseblocks have different
 		 * sequence numbers. Otherwise the image is bad.
 		 *
-		 * FIXME: remove 'sqnum != 0' check when leb_ver is removed.
+		 * However, if the sequence number is zero, we assume it must
+		 * be an ancient UBI image from the era when UBI did not have
+		 * sequence numbers. We still can attach these images, unless
+		 * there is a need to distinguish between old and new
+		 * eraseblocks, in which case we'll refuse the image in
+		 * 'compare_lebs()'. In other words, we attach old clean
+		 * images, but refuse attaching old images with duplicated
+		 * logical eraseblocks because there was an unclean reboot.
 		 */
 		if (seb->sqnum == sqnum && sqnum != 0) {
 			ubi_err("two LEBs with same sequence number %llu",
···
 			seb->pnum = pnum;
 			seb->scrub = ((cmp_res & 2) || bitflips);
 			seb->sqnum = sqnum;
-			seb->leb_ver = leb_ver;
 
 			if (sv->highest_lnum == lnum)
 				sv->last_data_size =
···
 	seb->lnum = lnum;
 	seb->sqnum = sqnum;
 	seb->scrub = bitflips;
-	seb->leb_ver = leb_ver;
 
 	if (sv->highest_lnum <= lnum) {
 		sv->highest_lnum = lnum;
···
 }
 
 /**
- * ubi_scan_find_sv - find information about a particular volume in the
- * scanning information.
+ * ubi_scan_find_sv - find volume in the scanning information.
  * @si: scanning information
  * @vol_id: the requested volume ID
  *
···
 }
 
 /**
- * ubi_scan_find_seb - find information about a particular logical
- * eraseblock in the volume scanning information.
+ * ubi_scan_find_seb - find LEB in the volume scanning information.
  * @sv: a pointer to the volume scanning information
  * @lnum: the requested logical eraseblock
  *
···
  *
  * This function erases physical eraseblock 'pnum', and writes the erase
  * counter header to it. This function should only be used on UBI device
- * initialization stages, when the EBA unit had not been yet initialized. This
- * function returns zero in case of success and a negative error code in case
- * of failure.
+ * initialization stages, when the EBA sub-system had not been yet initialized.
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
  */
 int ubi_scan_erase_peb(struct ubi_device *ubi, const struct ubi_scan_info *si,
 		       int pnum, int ec)
···
  * @si: scanning information
  *
  * This function returns a free physical eraseblock. It is supposed to be
- * called on the UBI initialization stages when the wear-leveling unit is not
- * initialized yet. This function picks a physical eraseblocks from one of the
- * lists, writes the EC header if it is needed, and removes it from the list.
+ * called on the UBI initialization stages when the wear-leveling sub-system is
+ * not initialized yet. This function picks a physical eraseblocks from one of
+ * the lists, writes the EC header if it is needed, and removes it from the
+ * list.
  *
  * This function returns scanning physical eraseblock information in case of
  * success and an error code in case of failure.
···
 }
 
 /**
- * process_eb - read UBI headers, check them and add corresponding data
- * to the scanning information.
+ * process_eb - read, check UBI headers, and add them to scanning information.
  * @ubi: UBI device description object
  * @si: scanning information
  * @pnum: the physical eraseblock number
···
  * This function returns a zero if the physical eraseblock was successfully
  * handled and a negative error code in case of failure.
  */
-static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, int pnum)
+static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
+		      int pnum)
 {
 	long long uninitialized_var(ec);
 	int err, bitflips = 0, vol_id, ec_corr = 0;
···
 		return err;
 	else if (err) {
 		/*
-		 * FIXME: this is actually duty of the I/O unit to initialize
-		 * this, but MTD does not provide enough information.
+		 * FIXME: this is actually duty of the I/O sub-system to
+		 * initialize this, but MTD does not provide enough
+		 * information.
 		 */
 		si->bad_peb_count += 1;
 		return 0;
···
 	for (pnum = 0; pnum < ubi->peb_count; pnum++) {
 		cond_resched();
 
-		dbg_msg("process PEB %d", pnum);
+		dbg_gen("process PEB %d", pnum);
 		err = process_eb(ubi, si, pnum);
 		if (err < 0)
 			goto out_vidh;
···
 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
 
 /**
- * paranoid_check_si - check if the scanning information is correct and
- * consistent.
+ * paranoid_check_si - check the scanning information.
  * @ubi: UBI device description object
  * @si: scanning information
  *
···
 				ubi_err("bad data_pad %d", sv->data_pad);
 				goto bad_vid_hdr;
 			}
-
-			if (seb->leb_ver != be32_to_cpu(vidh->leb_ver)) {
-				ubi_err("bad leb_ver %u", seb->leb_ver);
-				goto bad_vid_hdr;
-			}
 		}
 
 		if (!last_seb)
···
 		if (err < 0) {
 			kfree(buf);
 			return err;
-		}
-		else if (err)
+		} else if (err)
 			buf[pnum] = 1;
 	}
 

drivers/mtd/ubi/scan.h

···
  * @u: unions RB-tree or @list links
  * @u.rb: link in the per-volume RB-tree of &struct ubi_scan_leb objects
  * @u.list: link in one of the eraseblock lists
- * @leb_ver: logical eraseblock version (obsolete)
  *
  * One object of this type is allocated for each physical eraseblock during
  * scanning.
···
 		struct rb_node rb;
 		struct list_head list;
 	} u;
-	uint32_t leb_ver;
 };
 
 /**
···
  * @leb_count: number of logical eraseblocks in this volume
  * @vol_type: volume type
  * @used_ebs: number of used logical eraseblocks in this volume (only for
- * static volumes)
+ *            static volumes)
  * @last_data_size: amount of data in the last logical eraseblock of this
- * volume (always equivalent to the usable logical eraseblock size in case of
- * dynamic volumes)
+ *                  volume (always equivalent to the usable logical eraseblock
+ *                  size in case of dynamic volumes)
  * @data_pad: how many bytes at the end of logical eraseblocks of this volume
- * are not used (due to volume alignment)
+ *            are not used (due to volume alignment)
  * @compat: compatibility flags of this volume
  * @rb: link in the volume RB-tree
  * @root: root of the RB-tree containing all the eraseblock belonging to this
- * volume (&struct ubi_scan_leb objects)
+ *        volume (&struct ubi_scan_leb objects)
  *
  * One object of this type is allocated for each volume during scanning.
  */
···
  * @free: list of free physical eraseblocks
  * @erase: list of physical eraseblocks which have to be erased
  * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
+ *         those belonging to "preserve"-compatible internal volumes)
  * @bad_peb_count: count of bad physical eraseblocks
- * those belonging to "preserve"-compatible internal volumes)
  * @vols_found: number of volumes found during scanning
  * @highest_vol_id: highest volume ID
  * @alien_peb_count: count of physical eraseblocks in the @alien list
···
  * @ec_count: a temporary variable used when calculating @mean_ec
  *
  * This data structure contains the result of scanning and may be used by other
- * UBI units to build final UBI data structures, further error-recovery and so
- * on.
+ * UBI sub-systems to build final UBI data structures, further error-recovery
+ * and so on.
  */
 struct ubi_scan_info {
 	struct rb_root volumes;
···
 struct ubi_vid_hdr;
 
 /*
- * ubi_scan_move_to_list - move a physical eraseblock from the volume tree to a
- * list.
+ * ubi_scan_move_to_list - move a PEB from the volume tree to a list.
  *
  * @sv: volume scanning information
  * @seb: scanning eraseblock infprmation

drivers/mtd/ubi/ubi-media.h

···
  * Compatibility constants used by internal volumes.
  *
  * @UBI_COMPAT_DELETE: delete this internal volume before anything is written
- * to the flash
+ *                     to the flash
  * @UBI_COMPAT_RO: attach this device in read-only mode
  * @UBI_COMPAT_PRESERVE: preserve this internal volume - do not touch its
- * physical eraseblocks, don't allow the wear-leveling unit to move them
+ *                       physical eraseblocks, don't allow the wear-leveling
+ *                       sub-system to move them
  * @UBI_COMPAT_REJECT: reject this UBI image
  */
 enum {
···
  * struct ubi_ec_hdr - UBI erase counter header.
  * @magic: erase counter header magic number (%UBI_EC_HDR_MAGIC)
  * @version: version of UBI implementation which is supposed to accept this
- * UBI image
+ *           UBI image
  * @padding1: reserved for future, zeroes
  * @ec: the erase counter
  * @vid_hdr_offset: where the VID header starts
···
  * struct ubi_vid_hdr - on-flash UBI volume identifier header.
  * @magic: volume identifier header magic number (%UBI_VID_HDR_MAGIC)
  * @version: UBI implementation version which is supposed to accept this UBI
- * image (%UBI_VERSION)
+ *           image (%UBI_VERSION)
  * @vol_type: volume type (%UBI_VID_DYNAMIC or %UBI_VID_STATIC)
  * @copy_flag: if this logical eraseblock was copied from another physical
- * eraseblock (for wear-leveling reasons)
+ *             eraseblock (for wear-leveling reasons)
  * @compat: compatibility of this volume (%0, %UBI_COMPAT_DELETE,
- * %UBI_COMPAT_IGNORE, %UBI_COMPAT_PRESERVE, or %UBI_COMPAT_REJECT)
+ *          %UBI_COMPAT_IGNORE, %UBI_COMPAT_PRESERVE, or %UBI_COMPAT_REJECT)
  * @vol_id: ID of this volume
  * @lnum: logical eraseblock number
- * @leb_ver: version of this logical eraseblock (IMPORTANT: obsolete, to be
- * removed, kept only for not breaking older UBI users)
+ * @padding1: reserved for future, zeroes
  * @data_size: how many bytes of data this logical eraseblock contains
  * @used_ebs: total number of used logical eraseblocks in this volume
  * @data_pad: how many bytes at the end of this physical eraseblock are not
- * used
+ *            used
  * @data_crc: CRC checksum of the data stored in this logical eraseblock
- * @padding1: reserved for future, zeroes
- * @sqnum: sequence number
  * @padding2: reserved for future, zeroes
+ * @sqnum: sequence number
+ * @padding3: reserved for future, zeroes
  * @hdr_crc: volume identifier header CRC checksum
  *
  * The @sqnum is the value of the global sequence counter at the time when this
···
  * checksum is correct, this physical eraseblock is selected (P1). Otherwise
  * the older one (P) is selected.
  *
- * Note, there is an obsolete @leb_ver field which was used instead of @sqnum
- * in the past. But it is not used anymore and we keep it in order to be able
- * to deal with old UBI images. It will be removed at some point.
- *
  * There are 2 sorts of volumes in UBI: user volumes and internal volumes.
  * Internal volumes are not seen from outside and are used for various internal
  * UBI purposes. In this implementation there is only one internal volume - the
···
  * The @data_crc field contains the CRC checksum of the contents of the logical
  * eraseblock if this is a static volume. In case of dynamic volumes, it does
  * not contain the CRC checksum as a rule. The only exception is when the
- * data of the physical eraseblock was moved by the wear-leveling unit, then
- * the wear-leveling unit calculates the data CRC and stores it in the
- * @data_crc field. And of course, the @copy_flag is %in this case.
+ * data of the physical eraseblock was moved by the wear-leveling sub-system,
+ * then the wear-leveling sub-system calculates the data CRC and stores it in
+ * the @data_crc field. And of course, the @copy_flag is %in this case.
  *
  * The @data_size field is used only for static volumes because UBI has to know
  * how many bytes of data are stored in this eraseblock. For dynamic volumes,
···
 	__u8    compat;
 	__be32  vol_id;
 	__be32  lnum;
-	__be32  leb_ver; /* obsolete, to be removed, don't use */
+	__u8    padding1[4];
 	__be32  data_size;
 	__be32  used_ebs;
 	__be32  data_pad;
 	__be32  data_crc;
-	__u8    padding1[4];
+	__u8    padding2[4];
 	__be64  sqnum;
-	__u8    padding2[12];
+	__u8    padding3[12];
 	__be32  hdr_crc;
 } __attribute__ ((packed));
 

drivers/mtd/ubi/ubi.h

···
 #define UBI_IO_RETRIES 3
 
 /*
- * Error codes returned by the I/O unit.
+ * Error codes returned by the I/O sub-system.
  *
  * UBI_IO_PEB_EMPTY: the physical eraseblock is empty, i.e. it contains only
- * 0xFF bytes
+ *                   %0xFF bytes
  * UBI_IO_PEB_FREE: the physical eraseblock is free, i.e. it contains only a
- * valid erase counter header, and the rest are %0xFF bytes
+ *                  valid erase counter header, and the rest are %0xFF bytes
  * UBI_IO_BAD_EC_HDR: the erase counter header is corrupted (bad magic or CRC)
  * UBI_IO_BAD_VID_HDR: the volume identifier header is corrupted (bad magic or
- * CRC)
+ *                     CRC)
  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
  */
 enum {
···
  * @ec: erase counter
  * @pnum: physical eraseblock number
  *
- * This data structure is used in the WL unit. Each physical eraseblock has a
- * corresponding &struct wl_entry object which may be kept in different
- * RB-trees. See WL unit for details.
+ * This data structure is used in the WL sub-system. Each physical eraseblock
+ * has a corresponding &struct wl_entry object which may be kept in different
+ * RB-trees. See WL sub-system for details.
  */
 struct ubi_wl_entry {
 	struct rb_node rb;
···
  * @mutex: read/write mutex to implement read/write access serialization to
  *         the (@vol_id, @lnum) logical eraseblock
  *
- * This data structure is used in the EBA unit to implement per-LEB locking.
- * When a logical eraseblock is being locked - corresponding
+ * This data structure is used in the EBA sub-system to implement per-LEB
+ * locking. When a logical eraseblock is being locked - corresponding
  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
- * See EBA unit for details.
+ * See EBA sub-system for details.
  */
 struct ubi_ltree_entry {
 	struct rb_node rb;
···
 	int lnum;
 	int users;
 	struct rw_semaphore mutex;
+};
+
+/**
+ * struct ubi_rename_entry - volume re-name description data structure.
+ * @new_name_len: new volume name length
+ * @new_name: new volume name
+ * @remove: if not zero, this volume should be removed, not re-named
+ * @desc: descriptor of the volume
+ * @list: links re-name entries into a list
+ *
+ * This data structure is utilized in the multiple volume re-name code. Namely,
+ * UBI first creates a list of &struct ubi_rename_entry objects from the
+ * &struct ubi_rnvol_req request object, and then utilizes this list to do all
+ * the job.
+ */
+struct ubi_rename_entry {
+	int new_name_len;
+	char new_name[UBI_VOL_NAME_MAX + 1];
+	int remove;
+	struct ubi_volume_desc *desc;
+	struct list_head list;
 };
 
 struct ubi_volume_desc;
···
 	int alignment;
 	int data_pad;
 	int name_len;
-	char name[UBI_VOL_NAME_MAX+1];
+	char name[UBI_VOL_NAME_MAX + 1];
 
 	int upd_ebs;
 	int ch_lnum;
···
 #ifdef CONFIG_MTD_UBI_GLUEBI
 	/*
 	 * Gluebi-related stuff may be compiled out.
-	 * TODO: this should not be built into UBI but should be a separate
+	 * Note: this should not be built into UBI but should be a separate
 	 * ubimtd driver which works on top of UBI and emulates MTD devices.
 	 */
 	struct ubi_volume_desc *gluebi_desc;
···
 };
 
 /**
- * struct ubi_volume_desc - descriptor of the UBI volume returned when it is
- * opened.
+ * 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)
  */
···
  * @vtbl_size: size of the volume table in bytes
  * @vtbl: in-RAM volume table copy
  * @volumes_mutex: protects on-flash volume table and serializes volume
- *                 changes, like creation, deletion, update, resize
+ *                 changes, like creation, deletion, update, re-size and re-name
  *
  * @max_ec: current highest erase counter value
  * @mean_ec: current mean erase counter value
···
  *           @move_to, @move_to_put @erase_pending, @wl_scheduled, and @works
  *           fields
  * @move_mutex: serializes eraseblock moves
+ * @work_sem: sycnhronizes the WL worker with use tasks
  * @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
···
  * @ro_mode: if the UBI device is in read-only mode
  * @leb_size: logical eraseblock size
  * @leb_start: starting offset of logical eraseblocks within physical
- * eraseblocks
+ *             eraseblocks
  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
  * @vid_hdr_offset: starting offset of the volume identifier header (might be
- * unaligned)
+ *                  unaligned)
  * @vid_hdr_aloffset: starting offset of the VID header aligned to
  * @hdrs_min_io_size
  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
···
  * @peb_buf1: a buffer of PEB size used for different purposes
  * @peb_buf2: another buffer of PEB size used for different purposes
  * @buf_mutex: proptects @peb_buf1 and @peb_buf2
+ * @ckvol_mutex: serializes static volume checking when opening
+ * @mult_mutex: serializes operations on multiple volumes, like re-nameing
  * @dbg_peb_buf: buffer of PEB size used for debugging
  * @dbg_buf_mutex: proptects @dbg_peb_buf
  */
···
 	struct mutex volumes_mutex;
 
 	int max_ec;
-	/* TODO: mean_ec is not updated run-time, fix */
+	/* Note, mean_ec is not updated run-time - should be fixed */
 	int mean_ec;
 
-	/* EBA unit's stuff */
+	/* EBA sub-system's stuff */
 	unsigned long long global_sqnum;
 	spinlock_t ltree_lock;
 	struct rb_root ltree;
 	struct mutex alc_mutex;
 
-	/* Wear-leveling unit's stuff */
+	/* Wear-leveling sub-system's stuff */
 	struct rb_root used;
 	struct rb_root free;
 	struct rb_root scrub;
···
 	int thread_enabled;
 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
 
-	/* I/O unit's stuff */
+	/* I/O sub-system's stuff */
 	long long flash_size;
 	int peb_count;
 	int peb_size;
···
 	void *peb_buf2;
 	struct mutex buf_mutex;
 	struct mutex ckvol_mutex;
+	struct mutex mult_mutex;
 #ifdef CONFIG_MTD_UBI_DEBUG
 	void *dbg_peb_buf;
 	struct mutex dbg_buf_mutex;
···
 /* vtbl.c */
 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
 			   struct ubi_vtbl_record *vtbl_rec);
+int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
+			    struct list_head *rename_list);
 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si);
 
 /* vmt.c */
 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
-int ubi_remove_volume(struct ubi_volume_desc *desc);
+int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
+int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
 
···
 			     const void __user *buf, int count);
 
 /* misc.c */
-int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf, int length);
+int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
+		      int length);
 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
 void ubi_calculate_reserved(struct ubi_device *ubi);
 
···
 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 		     struct ubi_vid_hdr *vid_hdr);
 int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
-void ubi_eba_close(const struct ubi_device *ubi);
 
 /* wl.c */
 int ubi_wl_get_peb(struct ubi_device *ubi, int dtype);

drivers/mtd/ubi/upd.c

···
  */
 
 #include <linux/err.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 #include <asm/div64.h>
 #include "ubi.h"
 
···
 	int err;
 	struct ubi_vtbl_record vtbl_rec;
 
-	dbg_msg("set update marker for volume %d", vol->vol_id);
+	dbg_gen("set update marker for volume %d", vol->vol_id);
 
 	if (vol->upd_marker) {
 		ubi_assert(ubi->vtbl[vol->vol_id].upd_marker);
-		dbg_msg("already set");
+		dbg_gen("already set");
 		return 0;
 	}
 
···
 	uint64_t tmp;
 	struct ubi_vtbl_record vtbl_rec;
 
-	dbg_msg("clear update marker for volume %d", vol->vol_id);
+	dbg_gen("clear update marker for volume %d", vol->vol_id);
 
 	memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id],
 	       sizeof(struct ubi_vtbl_record));
···
 	int i, err;
 	uint64_t tmp;
 
-	dbg_msg("start update of volume %d, %llu bytes", vol->vol_id, bytes);
+	dbg_gen("start update of volume %d, %llu bytes", vol->vol_id, bytes);
 	ubi_assert(!vol->updating && !vol->changing_leb);
 	vol->updating = 1;
 
···
 {
 	ubi_assert(!vol->updating && !vol->changing_leb);
 
-	dbg_msg("start changing LEB %d:%d, %u bytes",
+	dbg_gen("start changing LEB %d:%d, %u bytes",
 		vol->vol_id, req->lnum, req->bytes);
 	if (req->bytes == 0)
 		return ubi_eba_atomic_leb_change(ubi, vol, req->lnum, NULL, 0,
···
 	int err;
 
 	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
-		len = ALIGN(len, ubi->min_io_size);
-		memset(buf + len, 0xFF, len - len);
+		int l = ALIGN(len, ubi->min_io_size);
 
-		len = ubi_calc_data_len(ubi, buf, len);
+		memset(buf + len, 0xFF, l - len);
+		len = ubi_calc_data_len(ubi, buf, l);
 		if (len == 0) {
-			dbg_msg("all %d bytes contain 0xFF - skip", len);
+			dbg_gen("all %d bytes contain 0xFF - skip", len);
 			return 0;
 		}
 
-		err = ubi_eba_write_leb(ubi, vol, lnum, buf, 0, len, UBI_UNKNOWN);
+		err = ubi_eba_write_leb(ubi, vol, lnum, buf, 0, len,
+					UBI_UNKNOWN);
 	} else {
 		/*
 		 * When writing static volume, and this is the last logical
···
 
 /**
  * ubi_more_update_data - write more update data.
+ * @ubi: UBI device description object
  * @vol: volume description object
  * @buf: write data (user-space memory buffer)
  * @count: how much bytes to write
···
 	uint64_t tmp;
 	int lnum, offs, err = 0, len, to_write = count;
 
-	dbg_msg("write %d of %lld bytes, %lld already passed",
+	dbg_gen("write %d of %lld bytes, %lld already passed",
 		count, vol->upd_bytes, vol->upd_received);
 
 	if (ubi->ro_mode)
···
 
 /**
  * ubi_more_leb_change_data - accept more data for atomic LEB change.
+ * @ubi: UBI device description object
  * @vol: volume description object
  * @buf: write data (user-space memory buffer)
  * @count: how much bytes to write
···
 {
 	int err;
 
-	dbg_msg("write %d of %lld bytes, %lld already passed",
+	dbg_gen("write %d of %lld bytes, %lld already passed",
 		count, vol->upd_bytes, vol->upd_received);
 
 	if (ubi->ro_mode)
···
 	if (vol->upd_received == vol->upd_bytes) {
 		int len = ALIGN((int)vol->upd_bytes, ubi->min_io_size);
 
-		memset(vol->upd_buf + vol->upd_bytes, 0xFF, len - vol->upd_bytes);
+		memset(vol->upd_buf + vol->upd_bytes, 0xFF,
+		       len - vol->upd_bytes);
 		len = ubi_calc_data_len(ubi, vol->upd_buf, len);
 		err = ubi_eba_atomic_leb_change(ubi, vol, vol->ch_lnum,
 						vol->upd_buf, len, UBI_UNKNOWN);

drivers/mtd/ubi/vmt.c

···
 #include "ubi.h"
 
 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
-static void paranoid_check_volumes(struct ubi_device *ubi);
+static int paranoid_check_volumes(struct ubi_device *ubi);
 #else
-#define paranoid_check_volumes(ubi)
+#define paranoid_check_volumes(ubi) 0
 #endif
 
 static ssize_t vol_attribute_show(struct device *dev,
···
 {
 	struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
 
+	kfree(vol->eba_tbl);
 	kfree(vol);
 }
 
···
  */
 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
 {
-	int i, err, vol_id = req->vol_id, dont_free = 0;
+	int i, err, vol_id = req->vol_id, do_free = 1;
 	struct ubi_volume *vol;
 	struct ubi_vtbl_record vtbl_rec;
 	uint64_t bytes;
···
 	spin_lock(&ubi->volumes_lock);
 	if (vol_id == UBI_VOL_NUM_AUTO) {
 		/* Find unused volume ID */
-		dbg_msg("search for vacant volume ID");
+		dbg_gen("search for vacant volume ID");
 		for (i = 0; i < ubi->vtbl_slots; i++)
 			if (!ubi->volumes[i]) {
 				vol_id = i;
···
 		req->vol_id = vol_id;
 	}
 
-	dbg_msg("volume ID %d, %llu bytes, type %d, name %s",
+	dbg_gen("volume ID %d, %llu bytes, type %d, name %s",
 		vol_id, (unsigned long long)req->bytes,
 		(int)req->vol_type, req->name);
 
···
 			goto out_unlock;
 		}
 
-        /* Calculate how many eraseblocks are requested */
+	/* Calculate how many eraseblocks are requested */
 	vol->usable_leb_size = ubi->leb_size - ubi->leb_size % req->alignment;
 	bytes = req->bytes;
 	if (do_div(bytes, vol->usable_leb_size))
···
 	vol->data_pad  = ubi->leb_size % vol->alignment;
 	vol->vol_type  = req->vol_type;
 	vol->name_len  = req->name_len;
-	memcpy(vol->name, req->name, vol->name_len + 1);
+	memcpy(vol->name, req->name, vol->name_len);
 	vol->ubi = ubi;
 
 	/*
···
 		vtbl_rec.vol_type = UBI_VID_DYNAMIC;
 	else
 		vtbl_rec.vol_type = UBI_VID_STATIC;
-	memcpy(vtbl_rec.name, vol->name, vol->name_len + 1);
+	memcpy(vtbl_rec.name, vol->name, vol->name_len);
 
 	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
 	if (err)
···
 	ubi->vol_count += 1;
 	spin_unlock(&ubi->volumes_lock);
 
-	paranoid_check_volumes(ubi);
-	return 0;
+	err = paranoid_check_volumes(ubi);
+	return err;
 
 out_sysfs:
 	/*
-	 * We have registered our device, we should not free the volume*
+	 * We have registered our device, we should not free the volume
 	 * description object in this function in case of an error - it is
 	 * freed by the release function.
 	 *
 	 * Get device reference to prevent the release function from being
 	 * called just after sysfs has been closed.
 	 */
-	dont_free = 1;
+	do_free = 0;
 	get_device(&vol->dev);
 	volume_sysfs_close(vol);
 out_gluebi:
···
 out_cdev:
 	cdev_del(&vol->cdev);
 out_mapping:
-	kfree(vol->eba_tbl);
+	if (do_free)
+		kfree(vol->eba_tbl);
 out_acc:
 	spin_lock(&ubi->volumes_lock);
 	ubi->rsvd_pebs -= vol->reserved_pebs;
 	ubi->avail_pebs += vol->reserved_pebs;
 out_unlock:
 	spin_unlock(&ubi->volumes_lock);
-	if (dont_free)
-		put_device(&vol->dev);
-	else
+	if (do_free)
 		kfree(vol);
+	else
+		put_device(&vol->dev);
 	ubi_err("cannot create volume %d, error %d", vol_id, err);
 	return err;
 }
···
 /**
  * ubi_remove_volume - remove volume.
  * @desc: volume descriptor
+ * @no_vtbl: do not change volume table if not zero
  *
  * This function removes volume described by @desc. The volume has to be opened
  * in "exclusive" mode. Returns zero in case of success and a negative error
  * code in case of failure. The caller has to have the @ubi->volumes_mutex
  * locked.
  */
-int ubi_remove_volume(struct ubi_volume_desc *desc)
+int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl)
 {
 	struct ubi_volume *vol = desc->vol;
 	struct ubi_device *ubi = vol->ubi;
 	int i, err, vol_id = vol->vol_id, reserved_pebs = vol->reserved_pebs;
 
-	dbg_msg("remove UBI volume %d", vol_id);
+	dbg_gen("remove UBI volume %d", vol_id);
 	ubi_assert(desc->mode == UBI_EXCLUSIVE);
 	ubi_assert(vol == ubi->volumes[vol_id]);
 
···
 	if (err)
 		goto out_err;
 
-	err = ubi_change_vtbl_record(ubi, vol_id, NULL);
-	if (err)
-		goto out_err;
+	if (!no_vtbl) {
+		err = ubi_change_vtbl_record(ubi, vol_id, NULL);
+		if (err)
+			goto out_err;
+	}
 
 	for (i = 0; i < vol->reserved_pebs; i++) {
 		err = ubi_eba_unmap_leb(ubi, vol, i);
···
 			goto out_err;
 	}
 
-	kfree(vol->eba_tbl);
-	vol->eba_tbl = NULL;
 	cdev_del(&vol->cdev);
 	volume_sysfs_close(vol);
 
···
 	ubi->vol_count -= 1;
 	spin_unlock(&ubi->volumes_lock);
 
-	paranoid_check_volumes(ubi);
-	return 0;
+	if (!no_vtbl)
+		err = paranoid_check_volumes(ubi);
+	return err;
 
 out_err:
 	ubi_err("cannot remove volume %d, error %d", vol_id, err);
···
 	if (ubi->ro_mode)
 		return -EROFS;
 
-	dbg_msg("re-size volume %d to from %d to %d PEBs",
+	dbg_gen("re-size volume %d to from %d to %d PEBs",
 		vol_id, vol->reserved_pebs, reserved_pebs);
 
 	if (vol->vol_type == UBI_STATIC_VOLUME &&
···
 			(long long)vol->used_ebs * vol->usable_leb_size;
 	}
 
-	paranoid_check_volumes(ubi);
-	return 0;
+	err = paranoid_check_volumes(ubi);
+	return err;
 
 out_acc:
 	if (pebs > 0) {
···
 	}
 out_free:
 	kfree(new_mapping);
+	return err;
+}
+
+/**
+ * ubi_rename_volumes - re-name UBI volumes.
+ * @ubi: UBI device description object
+ * @rename_list: list of &struct ubi_rename_entry objects
+ *
+ * This function re-names or removes volumes specified in the re-name list.
+ * Returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list)
+{
+	int err;
+	struct ubi_rename_entry *re;
+
+	err = ubi_vtbl_rename_volumes(ubi, rename_list);
+	if (err)
+		return err;
+
+	list_for_each_entry(re, rename_list, list) {
+		if (re->remove) {
+			err = ubi_remove_volume(re->desc, 1);
+			if (err)
+				break;
+		} else {
+			struct ubi_volume *vol = re->desc->vol;
+
+			spin_lock(&ubi->volumes_lock);
+			vol->name_len = re->new_name_len;
+			memcpy(vol->name, re->new_name, re->new_name_len + 1);
+			spin_unlock(&ubi->volumes_lock);
+		}
+	}
+
+	if (!err)
+		err = paranoid_check_volumes(ubi);
 	return err;
 }
 
···
 	int err, vol_id = vol->vol_id;
 	dev_t dev;
 
-	dbg_msg("add volume %d", vol_id);
-	ubi_dbg_dump_vol_info(vol);
+	dbg_gen("add volume %d", vol_id);
 
 	/* Register character device for the volume */
 	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
···
 		return err;
 	}
 
-	paranoid_check_volumes(ubi);
-	return 0;
+	err = paranoid_check_volumes(ubi);
+	return err;
 
 out_gluebi:
 	err = ubi_destroy_gluebi(vol);
···
 {
 	int err;
 
-	dbg_msg("free volume %d", vol->vol_id);
+	dbg_gen("free volume %d", vol->vol_id);
 
 	ubi->volumes[vol->vol_id] = NULL;
 	err = ubi_destroy_gluebi(vol);
···
  * paranoid_check_volume - check volume information.
  * @ubi: UBI device description object
  * @vol_id: volume ID
+ *
+ * Returns zero if volume is all right and a a negative error code if not.
  */
-static void paranoid_check_volume(struct ubi_device *ubi, int vol_id)
+static int paranoid_check_volume(struct ubi_device *ubi, int vol_id)
 {
 	int idx = vol_id2idx(ubi, vol_id);
 	int reserved_pebs, alignment, data_pad, vol_type, name_len, upd_marker;
···
 			goto fail;
 		}
 		spin_unlock(&ubi->volumes_lock);
-		return;
-	}
-
-	if (vol->exclusive) {
-		/*
-		 * The volume may be being created at the moment, do not check
-		 * it (e.g., it may be in the middle of ubi_create_volume().
-		 */
-		spin_unlock(&ubi->volumes_lock);
-		return;
+		return 0;
 	}
 
 	if (vol->reserved_pebs < 0 || vol->alignment < 0 || vol->data_pad < 0 ||
···
 		goto fail;
 	}
 
-	n = vol->alignment % ubi->min_io_size;
+	n = vol->alignment & (ubi->min_io_size - 1);
 	if (vol->alignment != 1 && n) {
 		ubi_err("alignment is not multiple of min I/O unit");
 		goto fail;
···
 
 	if (alignment != vol->alignment || data_pad != vol->data_pad ||
 	    upd_marker != vol->upd_marker || vol_type != vol->vol_type ||
-	    name_len!= vol->name_len || strncmp(name, vol->name, name_len)) {
+	    name_len != vol->name_len || strncmp(name, vol->name, name_len)) {
 		ubi_err("volume info is different");
 		goto fail;
 	}
 
 	spin_unlock(&ubi->volumes_lock);
-	return;
+	return 0;
 
 fail:
 	ubi_err("paranoid check failed for volume %d", vol_id);
-	ubi_dbg_dump_vol_info(vol);
+	if (vol)
+		ubi_dbg_dump_vol_info(vol);
 	ubi_dbg_dump_vtbl_record(&ubi->vtbl[vol_id], vol_id);
 	spin_unlock(&ubi->volumes_lock);
-	BUG();
+	return -EINVAL;
 }
 
 /**
  * paranoid_check_volumes - check information about all volumes.
  * @ubi: UBI device description object
+ *
+ * Returns zero if volumes are all right and a a negative error code if not.
  */
-static void paranoid_check_volumes(struct ubi_device *ubi)
+static int paranoid_check_volumes(struct ubi_device *ubi)
 {
-	int i;
+	int i, err = 0;
 
-	for (i = 0; i < ubi->vtbl_slots; i++)
-		paranoid_check_volume(ubi, i);
+	for (i = 0; i < ubi->vtbl_slots; i++) {
+		err = paranoid_check_volume(ubi, i);
+		if (err)
+			break;
+	}
+
+	return err;
 }
 #endif

drivers/mtd/ubi/vtbl.c

···
 }
 
 /**
- * vtbl_check - check if volume table is not corrupted and contains sensible
- *              data.
+ * ubi_vtbl_rename_volumes - rename UBI volumes in the volume table.
+ * @ubi: UBI device description object
+ * @rename_list: list of &struct ubi_rename_entry objects
+ *
+ * This function re-names multiple volumes specified in @req in the volume
+ * table. Returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
+			    struct list_head *rename_list)
+{
+	int i, err;
+	struct ubi_rename_entry *re;
+	struct ubi_volume *layout_vol;
+
+	list_for_each_entry(re, rename_list, list) {
+		uint32_t crc;
+		struct ubi_volume *vol = re->desc->vol;
+		struct ubi_vtbl_record *vtbl_rec = &ubi->vtbl[vol->vol_id];
+
+		if (re->remove) {
+			memcpy(vtbl_rec, &empty_vtbl_record,
+			       sizeof(struct ubi_vtbl_record));
+			continue;
+		}
+
+		vtbl_rec->name_len = cpu_to_be16(re->new_name_len);
+		memcpy(vtbl_rec->name, re->new_name, re->new_name_len);
+		memset(vtbl_rec->name + re->new_name_len, 0,
+		       UBI_VOL_NAME_MAX + 1 - re->new_name_len);
+		crc = crc32(UBI_CRC32_INIT, vtbl_rec,
+			    UBI_VTBL_RECORD_SIZE_CRC);
+		vtbl_rec->crc = cpu_to_be32(crc);
+	}
+
+	layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)];
+	for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) {
+		err = ubi_eba_unmap_leb(ubi, layout_vol, i);
+		if (err)
+			return err;
+
+		err = ubi_eba_write_leb(ubi, layout_vol, i, ubi->vtbl, 0,
+					ubi->vtbl_size, UBI_LONGTERM);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+/**
+ * vtbl_check - check if volume table is not corrupted and sensible.
  * @ubi: UBI device description object
  * @vtbl: volume table
  *
···
 		      const struct ubi_vtbl_record *vtbl)
 {
 	int i, n, reserved_pebs, alignment, data_pad, vol_type, name_len;
-	int upd_marker;
+	int upd_marker, err;
 	uint32_t crc;
 	const char *name;
 
···
 		if (reserved_pebs == 0) {
 			if (memcmp(&vtbl[i], &empty_vtbl_record,
 						UBI_VTBL_RECORD_SIZE)) {
-				dbg_err("bad empty record");
+				err = 2;
 				goto bad;
 			}
 			continue;
···
 
 		if (reserved_pebs < 0 || alignment < 0 || data_pad < 0 ||
 		    name_len < 0) {
-			dbg_err("negative values");
+			err = 3;
 			goto bad;
 		}
 
 		if (alignment > ubi->leb_size || alignment == 0) {
-			dbg_err("bad alignment");
+			err = 4;
 			goto bad;
 		}
 
-		n = alignment % ubi->min_io_size;
+		n = alignment & (ubi->min_io_size - 1);
 		if (alignment != 1 && n) {
-			dbg_err("alignment is not multiple of min I/O unit");
+			err = 5;
 			goto bad;
 		}
 
 		n = ubi->leb_size % alignment;
 		if (data_pad != n) {
 			dbg_err("bad data_pad, has to be %d", n);
+			err = 6;
 			goto bad;
 		}
 
 		if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
-			dbg_err("bad vol_type");
+			err = 7;
 			goto bad;
 		}
 
 		if (upd_marker != 0 && upd_marker != 1) {
-			dbg_err("bad upd_marker");
+			err = 8;
 			goto bad;
 		}
 
 		if (reserved_pebs > ubi->good_peb_count) {
 			dbg_err("too large reserved_pebs, good PEBs %d",
 				ubi->good_peb_count);
+			err = 9;
 			goto bad;
 		}
 
 		if (name_len > UBI_VOL_NAME_MAX) {
-			dbg_err("too long volume name, max %d",
-				UBI_VOL_NAME_MAX);
+			err = 10;
 			goto bad;
 		}
 
 		if (name[0] == '\0') {
-			dbg_err("NULL volume name");
+			err = 11;
 			goto bad;
 		}
 
 		if (name_len != strnlen(name, name_len + 1)) {
-			dbg_err("bad name_len");
+			err = 12;
 			goto bad;
 		}
 	}
···
 	return 0;
 
 bad:
-	ubi_err("volume table check failed, record %d", i);
+	ubi_err("volume table check failed: record %d, error %d", i, err);
 	ubi_dbg_dump_vtbl_record(&vtbl[i], i);
 	return -EINVAL;
 }
···
 			     vid_hdr->data_pad = cpu_to_be32(0);
 	vid_hdr->lnum = cpu_to_be32(copy);
 	vid_hdr->sqnum = cpu_to_be64(++si->max_sqnum);
-	vid_hdr->leb_ver = cpu_to_be32(old_seb ? old_seb->leb_ver + 1: 0);
 
 	/* The EC header is already there, write the VID header */
 	err = ubi_io_write_vid_hdr(ubi, new_seb->pnum, vid_hdr);
···
 	 *    to LEB 0.
 	 */
 
-	dbg_msg("check layout volume");
+	dbg_gen("check layout volume");
 
 	/* Read both LEB 0 and LEB 1 into memory */
 	ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) {
···
 		err = ubi_io_read_data(ubi, leb[seb->lnum], seb->pnum, 0,
 				       ubi->vtbl_size);
 		if (err == UBI_IO_BITFLIPS || err == -EBADMSG)
-			/* Scrub the PEB later */
+			/*
+			 * Scrub the PEB later. Note, -EBADMSG indicates an
+			 * uncorrectable ECC error, but we have our own CRC and
+			 * the data will be checked later. If the data is OK,
+			 * the PEB will be scrubbed (because we set
+			 * seb->scrub). If the data is not OK, the contents of
+			 * the PEB will be recovered from the second copy, and
+			 * seb->scrub will be cleared in
+			 * 'ubi_scan_add_used()'.
+			 */
 			seb->scrub = 1;
 		else if (err)
 			goto out_free;
···
 	if (!leb_corrupted[0]) {
 		/* LEB 0 is OK */
 		if (leb[1])
-			leb_corrupted[1] = memcmp(leb[0], leb[1], ubi->vtbl_size);
+			leb_corrupted[1] = memcmp(leb[0], leb[1],
+						  ubi->vtbl_size);
 		if (leb_corrupted[1]) {
 			ubi_warn("volume table copy #2 is corrupted");
 			err = create_vtbl(ubi, si, 1, leb[0]);
···
 static int check_sv(const struct ubi_volume *vol,
 		    const struct ubi_scan_volume *sv)
 {
+	int err;
+
 	if (sv->highest_lnum >= vol->reserved_pebs) {
-		dbg_err("bad highest_lnum");
+		err = 1;
 		goto bad;
 	}
 	if (sv->leb_count > vol->reserved_pebs) {
-		dbg_err("bad leb_count");
+		err = 2;
 		goto bad;
 	}
 	if (sv->vol_type != vol->vol_type) {
-		dbg_err("bad vol_type");
+		err = 3;
 		goto bad;
 	}
 	if (sv->used_ebs > vol->reserved_pebs) {
-		dbg_err("bad used_ebs");
+		err = 4;
 		goto bad;
 	}
 	if (sv->data_pad != vol->data_pad) {
-		dbg_err("bad data_pad");
+		err = 5;
 		goto bad;
 	}
 	return 0;
 
 bad:
-	ubi_err("bad scanning information");
+	ubi_err("bad scanning information, error %d", err);
 	ubi_dbg_dump_sv(sv);
 	ubi_dbg_dump_vol_info(vol);
 	return -EINVAL;
···
 		return -EINVAL;
 	}
 
-	if (si->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT&&
+	if (si->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT &&
 	    si->highest_vol_id < UBI_INTERNAL_VOL_START) {
 		ubi_err("too large volume ID %d found by scanning",
 			si->highest_vol_id);
 		return -EINVAL;
 	}
-
 
 	for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
 		cond_resched();
···
 }
 
 /**
- * ubi_read_volume_table - read volume table.
- * information.
+ * ubi_read_volume_table - read the volume table.
  * @ubi: UBI device description object
  * @si: scanning information
  *
···
 
 out_free:
 	vfree(ubi->vtbl);
-	for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++)
-		if (ubi->volumes[i]) {
-			kfree(ubi->volumes[i]);
-			ubi->volumes[i] = NULL;
-		}
+	for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
+		kfree(ubi->volumes[i]);
+		ubi->volumes[i] = NULL;
+	}
 	return err;
 }
 

drivers/mtd/ubi/wl.c

···
  */
 
 /*
- * UBI wear-leveling unit.
+ * UBI wear-leveling sub-system.
  *
- * This unit is responsible for wear-leveling. It works in terms of physical
- * eraseblocks and erase counters and knows nothing about logical eraseblocks,
- * volumes, etc. From this unit's perspective all physical eraseblocks are of
- * two types - used and free. Used physical eraseblocks are those that were
- * "get" by the 'ubi_wl_get_peb()' function, and free physical eraseblocks are
- * those that were put by the 'ubi_wl_put_peb()' function.
+ * This sub-system is responsible for wear-leveling. It works in terms of
+ * physical* eraseblocks and erase counters and knows nothing about logical
+ * eraseblocks, volumes, etc. From this sub-system's perspective all physical
+ * eraseblocks are of two types - used and free. Used physical eraseblocks are
+ * those that were "get" by the 'ubi_wl_get_peb()' function, and free physical
+ * eraseblocks are those that were put by the 'ubi_wl_put_peb()' function.
  *
  * Physical eraseblocks returned by 'ubi_wl_get_peb()' have only erase counter
- * header. The rest of the physical eraseblock contains only 0xFF bytes.
+ * header. The rest of the physical eraseblock contains only %0xFF bytes.
  *
- * When physical eraseblocks are returned to the WL unit by means of the
+ * When physical eraseblocks are returned to the WL sub-system by means of the
  * 'ubi_wl_put_peb()' function, they are scheduled for erasure. The erasure is
  * done asynchronously in context of the per-UBI device background thread,
- * which is also managed by the WL unit.
+ * which is also managed by the WL sub-system.
  *
  * The wear-leveling is ensured by means of moving the contents of used
  * physical eraseblocks with low erase counter to free physical eraseblocks
···
  * The 'ubi_wl_get_peb()' function accepts data type hints which help to pick
  * an "optimal" physical eraseblock. For example, when it is known that the
  * physical eraseblock will be "put" soon because it contains short-term data,
- * the WL unit may pick a free physical eraseblock with low erase counter, and
- * so forth.
+ * the WL sub-system may pick a free physical eraseblock with low erase
+ * counter, and so forth.
  *
- * If the WL unit fails to erase a physical eraseblock, it marks it as bad.
+ * If the WL sub-system fails to erase a physical eraseblock, it marks it as
+ * bad.
  *
- * This unit is also responsible for scrubbing. If a bit-flip is detected in a
- * physical eraseblock, it has to be moved. Technically this is the same as
- * moving it for wear-leveling reasons.
+ * This sub-system is also responsible for scrubbing. If a bit-flip is detected
+ * in a physical eraseblock, it has to be moved. Technically this is the same
+ * as moving it for wear-leveling reasons.
  *
- * As it was said, for the UBI unit all physical eraseblocks are either "free"
- * or "used". Free eraseblock are kept in the @wl->free RB-tree, while used
- * eraseblocks are kept in a set of different RB-trees: @wl->used,
+ * As it was said, for the UBI sub-system all physical eraseblocks are either
+ * "free" or "used". Free eraseblock are kept in the @wl->free RB-tree, while
+ * used eraseblocks are kept in a set of different RB-trees: @wl->used,
  * @wl->prot.pnum, @wl->prot.aec, and @wl->scrub.
  *
  * Note, in this implementation, we keep a small in-RAM object for each physical
  * eraseblock. This is surely not a scalable solution. But it appears to be good
  * enough for moderately large flashes and it is simple. In future, one may
- * re-work this unit and make it more scalable.
+ * re-work this sub-system and make it more scalable.
  *
- * At the moment this unit does not utilize the sequence number, which was
- * introduced relatively recently. But it would be wise to do this because the
- * sequence number of a logical eraseblock characterizes how old is it. For
+ * At the moment this sub-system does not utilize the sequence number, which
+ * was introduced relatively recently. But it would be wise to do this because
+ * the sequence number of a logical eraseblock characterizes how old is it. For
  * example, when we move a PEB with low erase counter, and we need to pick the
  * target PEB, we pick a PEB with the highest EC if our PEB is "old" and we
  * pick target PEB with an average EC if our PEB is not very "old". This is a
- * room for future re-works of the WL unit.
+ * room for future re-works of the WL sub-system.
  *
- * FIXME: looks too complex, should be simplified (later).
+ * Note: the stuff with protection trees looks too complex and is difficult to
+ * understand. Should be fixed.
  */
 
 #include <linux/slab.h>
···
 
 /*
  * Maximum difference between two erase counters. If this threshold is
- * exceeded, the WL unit starts moving data from used physical eraseblocks with
- * low erase counter to free physical eraseblocks with high erase counter.
+ * exceeded, the WL sub-system starts moving data from used physical
+ * eraseblocks with low erase counter to free physical eraseblocks with high
+ * erase counter.
  */
 #define UBI_WL_THRESHOLD CONFIG_MTD_UBI_WL_THRESHOLD
 
 /*
- * When a physical eraseblock is moved, the WL unit has to pick the target
+ * When a physical eraseblock is moved, the WL sub-system has to pick the target
  * physical eraseblock to move to. The simplest way would be just to pick the
  * one with the highest erase counter. But in certain workloads this could lead
  * to an unlimited wear of one or few physical eraseblock. Indeed, imagine a
  * situation when the picked physical eraseblock is constantly erased after the
  * data is written to it. So, we have a constant which limits the highest erase
- * counter of the free physical eraseblock to pick. Namely, the WL unit does
- * not pick eraseblocks with erase counter greater then the lowest erase
+ * counter of the free physical eraseblock to pick. Namely, the WL sub-system
+ * does not pick eraseblocks with erase counter greater then the lowest erase
  * counter plus %WL_FREE_MAX_DIFF.
  */
 #define WL_FREE_MAX_DIFF (2*UBI_WL_THRESHOLD)
···
  * @abs_ec: the absolute erase counter value when the protection ends
  * @e: the wear-leveling entry of the physical eraseblock under protection
  *
- * When the WL unit returns a physical eraseblock, the physical eraseblock is
- * protected from being moved for some "time". For this reason, the physical
- * eraseblock is not directly moved from the @wl->free tree to the @wl->used
- * tree. There is one more tree in between where this physical eraseblock is
- * temporarily stored (@wl->prot).
+ * When the WL sub-system returns a physical eraseblock, the physical
+ * eraseblock is protected from being moved for some "time". For this reason,
+ * the physical eraseblock is not directly moved from the @wl->free tree to the
+ * @wl->used tree. There is one more tree in between where this physical
+ * eraseblock is temporarily stored (@wl->prot).
  *
  * All this protection stuff is needed because:
  *  o we don't want to move physical eraseblocks just after we have given them
···
  * @list: a link in the list of pending works
  * @func: worker function
  * @priv: private data of the worker function
- *
  * @e: physical eraseblock to erase
  * @torture: if the physical eraseblock has to be tortured
  *
···
 	}
 
 	switch (dtype) {
-		case UBI_LONGTERM:
-			/*
-			 * For long term data we pick a physical eraseblock
-			 * with high erase counter. But the highest erase
-			 * counter we can pick is bounded by the the lowest
-			 * erase counter plus %WL_FREE_MAX_DIFF.
-			 */
-			e = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF);
-			protect = LT_PROTECTION;
-			break;
-		case UBI_UNKNOWN:
-			/*
-			 * For unknown data we pick a physical eraseblock with
-			 * medium erase counter. But we by no means can pick a
-			 * physical eraseblock with erase counter greater or
-			 * equivalent than the lowest erase counter plus
-			 * %WL_FREE_MAX_DIFF.
-			 */
-			first = rb_entry(rb_first(&ubi->free),
-					 struct ubi_wl_entry, rb);
-			last = rb_entry(rb_last(&ubi->free),
-					struct ubi_wl_entry, rb);
+	case UBI_LONGTERM:
+		/*
+		 * For long term data we pick a physical eraseblock with high
+		 * erase counter. But the highest erase counter we can pick is
+		 * bounded by the the lowest erase counter plus
+		 * %WL_FREE_MAX_DIFF.
+		 */
+		e = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF);
+		protect = LT_PROTECTION;
+		break;
+	case UBI_UNKNOWN:
+		/*
+		 * For unknown data we pick a physical eraseblock with medium
+		 * erase counter. But we by no means can pick a physical
+		 * eraseblock with erase counter greater or equivalent than the
+		 * lowest erase counter plus %WL_FREE_MAX_DIFF.
+		 */
+		first = rb_entry(rb_first(&ubi->free), struct ubi_wl_entry, rb);
+		last = rb_entry(rb_last(&ubi->free), struct ubi_wl_entry, rb);
 
-			if (last->ec - first->ec < WL_FREE_MAX_DIFF)
-				e = rb_entry(ubi->free.rb_node,
-						struct ubi_wl_entry, rb);
-			else {
-				medium_ec = (first->ec + WL_FREE_MAX_DIFF)/2;
-				e = find_wl_entry(&ubi->free, medium_ec);
-			}
-			protect = U_PROTECTION;
-			break;
-		case UBI_SHORTTERM:
-			/*
-			 * For short term data we pick a physical eraseblock
-			 * with the lowest erase counter as we expect it will
-			 * be erased soon.
-			 */
-			e = rb_entry(rb_first(&ubi->free),
-				     struct ubi_wl_entry, rb);
-			protect = ST_PROTECTION;
-			break;
-		default:
-			protect = 0;
-			e = NULL;
-			BUG();
+		if (last->ec - first->ec < WL_FREE_MAX_DIFF)
+			e = rb_entry(ubi->free.rb_node,
+					struct ubi_wl_entry, rb);
+		else {
+			medium_ec = (first->ec + WL_FREE_MAX_DIFF)/2;
+			e = find_wl_entry(&ubi->free, medium_ec);
+		}
+		protect = U_PROTECTION;
+		break;
+	case UBI_SHORTTERM:
+		/*
+		 * For short term data we pick a physical eraseblock with the
+		 * lowest erase counter as we expect it will be erased soon.
+		 */
+		e = rb_entry(rb_first(&ubi->free), struct ubi_wl_entry, rb);
+		protect = ST_PROTECTION;
+		break;
+	default:
+		protect = 0;
+		e = NULL;
+		BUG();
 	}
 
 	/*
···
  * This function returns zero in case of success and a negative error code in
  * case of failure.
  */
-static int sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e, int torture)
+static int sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
+		      int torture)
 {
 	int err;
 	struct ubi_ec_hdr *ec_hdr;
···
 }
 
 /**
- * check_protection_over - check if it is time to stop protecting some
- * physical eraseblocks.
+ * check_protection_over - check if it is time to stop protecting some PEBs.
  * @ubi: UBI device description object
  *
  * This function is called after each erase operation, when the absolute erase
···
 	}
 
 	ubi_free_vid_hdr(ubi, vid_hdr);
+	if (scrubbing && !protect)
+		ubi_msg("scrubbed PEB %d, data moved to PEB %d",
+			e1->pnum, e2->pnum);
+
 	spin_lock(&ubi->wl_lock);
 	if (protect)
 		prot_tree_add(ubi, e1, pe, protect);
···
 		spin_unlock(&ubi->wl_lock);
 
 		/*
-		 * One more erase operation has happened, take care about protected
-		 * physical eraseblocks.
+		 * One more erase operation has happened, take care about
+		 * protected physical eraseblocks.
 		 */
 		check_protection_over(ubi);
 
···
 }
 
 /**
- * ubi_wl_put_peb - return a physical eraseblock to the wear-leveling unit.
+ * ubi_wl_put_peb - return a PEB to the wear-leveling sub-system.
  * @ubi: UBI device description object
  * @pnum: physical eraseblock to return
  * @torture: if this physical eraseblock has to be tortured
···
 		/*
 		 * User is putting the physical eraseblock which was selected
 		 * as the target the data is moved to. It may happen if the EBA
-		 * unit already re-mapped the LEB in 'ubi_eba_copy_leb()' but
-		 * the WL unit has not put the PEB to the "used" tree yet, but
-		 * it is about to do this. So we just set a flag which will
-		 * tell the WL worker that the PEB is not needed anymore and
-		 * should be scheduled for erasure.
+		 * sub-system already re-mapped the LEB in 'ubi_eba_copy_leb()'
+		 * but the WL sub-system has not put the PEB to the "used" tree
+		 * yet, but it is about to do this. So we just set a flag which
+		 * will tell the WL worker that the PEB is not needed anymore
+		 * and should be scheduled for erasure.
 		 */
 		dbg_wl("PEB %d is the target of data moving", pnum);
 		ubi_assert(!ubi->move_to_put);
···
 {
 	struct ubi_wl_entry *e;
 
-	ubi_msg("schedule PEB %d for scrubbing", pnum);
+	dbg_msg("schedule PEB %d for scrubbing", pnum);
 
 retry:
 	spin_lock(&ubi->wl_lock);
···
 		int err;
 
 		if (kthread_should_stop())
-			goto out;
+			break;
 
 		if (try_to_freeze())
 			continue;
···
 		cond_resched();
 	}
 
-out:
 	dbg_wl("background thread \"%s\" is killed", ubi->bgt_name);
 	return 0;
 }
···
 }
 
 /**
- * ubi_wl_init_scan - initialize the wear-leveling unit using scanning
- * information.
+ * ubi_wl_init_scan - initialize the WL sub-system using scanning information.
  * @ubi: UBI device description object
  * @si: scanning information
  *
···
 }
 
 /**
- * ubi_wl_close - close the wear-leveling unit.
+ * ubi_wl_close - close the wear-leveling sub-system.
  * @ubi: UBI device description object
  */
 void ubi_wl_close(struct ubi_device *ubi)
 {
-	dbg_wl("close the UBI wear-leveling unit");
-
+	dbg_wl("close the WL sub-system");
 	cancel_pending(ubi);
 	protection_trees_destroy(ubi);
 	tree_destroy(&ubi->used);
···
 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
 
 /**
- * paranoid_check_ec - make sure that the erase counter of a physical eraseblock
- * is correct.
+ * paranoid_check_ec - make sure that the erase counter of a PEB is correct.
  * @ubi: UBI device description object
  * @pnum: the physical eraseblock number to check
  * @ec: the erase counter to check
···
 }
 
 /**
- * paranoid_check_in_wl_tree - make sure that a wear-leveling entry is present
- * in a WL RB-tree.
+ * paranoid_check_in_wl_tree - check that wear-leveling entry is in WL RB-tree.
  * @e: the wear-leveling entry to check
  * @root: the root of the tree
  *
- * This function returns zero if @e is in the @root RB-tree and %1 if it
- * is not.
+ * This function returns zero if @e is in the @root RB-tree and %1 if it is
+ * not.
  */
 static int paranoid_check_in_wl_tree(struct ubi_wl_entry *e,
 				     struct rb_root *root)

include/linux/mtd/ubi.h

···
  * @size: how many physical eraseblocks are reserved for this volume
  * @used_bytes: how many bytes of data this volume contains
  * @used_ebs: how many physical eraseblocks of this volume actually contain any
- * data
+ *            data
  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
  * @corrupted: non-zero if the volume is corrupted (static volumes only)
  * @upd_marker: non-zero if the volume has update marker set
  * @alignment: volume alignment
  * @usable_leb_size: how many bytes are available in logical eraseblocks of
- * this volume
+ *                   this volume
  * @name_len: volume name length
  * @name: volume name
  * @cdev: UBI volume character device major and minor numbers
···
 int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum);
 int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype);
 int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum);
+int ubi_sync(int ubi_num);
 
 /*
  * This function is the same as the 'ubi_leb_read()' function, but it does not

include/mtd/ubi-user.h

···
  * device should be used. A &struct ubi_rsvol_req object has to be properly
  * filled and a pointer to it has to be passed to the IOCTL.
  *
+ * UBI volumes re-name
+ * ~~~~~~~~~~~~~~~~~~~
+ *
+ * To re-name several volumes atomically at one go, the %UBI_IOCRNVOL command
+ * of the UBI character device should be used. A &struct ubi_rnvol_req object
+ * has to be properly filled and a pointer to it has to be passed to the IOCTL.
+ *
  * UBI volume update
  * ~~~~~~~~~~~~~~~~~
  *
···
 #define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, int32_t)
 /* Re-size an UBI volume */
 #define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req)
+/* Re-name volumes */
+#define UBI_IOCRNVOL _IOW(UBI_IOC_MAGIC, 3, struct ubi_rnvol_req)
 
 /* IOCTL commands of the UBI control character device */
 
···
 
 /* Maximum MTD device name length supported by UBI */
 #define MAX_UBI_MTD_NAME_LEN 127
+
+/* Maximum amount of UBI volumes that can be re-named at one go */
+#define UBI_MAX_RNVOL 32
 
 /*
  * UBI data type hint constants.
···
  * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages.
  *
  * But in rare cases, if this optimizes things, the VID header may be placed to
- * a different offset. For example, the boot-loader might do things faster if the
- * VID header sits at the end of the first 2KiB NAND page with 4 sub-pages. As
- * the boot-loader would not normally need to read EC headers (unless it needs
- * UBI in RW mode), it might be faster to calculate ECC. This is weird example,
- * but it real-life example. So, in this example, @vid_hdr_offer would be
- * 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes
- * aligned, which is OK, as UBI is clever enough to realize this is 4th sub-page
- * of the first page and add needed padding.
+ * a different offset. For example, the boot-loader might do things faster if
+ * the VID header sits at the end of the first 2KiB NAND page with 4 sub-pages.
+ * As the boot-loader would not normally need to read EC headers (unless it
+ * needs UBI in RW mode), it might be faster to calculate ECC. This is weird
+ * example, but it real-life example. So, in this example, @vid_hdr_offer would
+ * be 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes
+ * aligned, which is OK, as UBI is clever enough to realize this is 4th
+ * sub-page of the first page and add needed padding.
  */
 struct ubi_attach_req {
 	int32_t ubi_num;
 	int32_t mtd_num;
 	int32_t vid_hdr_offset;
-	uint8_t padding[12];
+	int8_t padding[12];
 };
 
 /**
···
 } __attribute__ ((packed));
 
 /**
+ * struct ubi_rnvol_req - volumes re-name request.
+ * @count: count of volumes to re-name
+ * @padding1:  reserved for future, not used, has to be zeroed
+ * @vol_id: ID of the volume to re-name
+ * @name_len: name length
+ * @padding2:  reserved for future, not used, has to be zeroed
+ * @name: new volume name
+ *
+ * UBI allows to re-name up to %32 volumes at one go. The count of volumes to
+ * re-name is specified in the @count field. The ID of the volumes to re-name
+ * and the new names are specified in the @vol_id and @name fields.
+ *
+ * The UBI volume re-name operation is atomic, which means that should power cut
+ * happen, the volumes will have either old name or new name. So the possible
+ * use-cases of this command is atomic upgrade. Indeed, to upgrade, say, volumes
+ * A and B one may create temporary volumes %A1 and %B1 with the new contents,
+ * then atomically re-name A1->A and B1->B, in which case old %A and %B will
+ * be removed.
+ *
+ * If it is not desirable to remove old A and B, the re-name request has to
+ * contain 4 entries: A1->A, A->A1, B1->B, B->B1, in which case old A1 and B1
+ * become A and B, and old A and B will become A1 and B1.
+ *
+ * It is also OK to request: A1->A, A1->X, B1->B, B->Y, in which case old A1
+ * and B1 become A and B, and old A and B become X and Y.
+ *
+ * In other words, in case of re-naming into an existing volume name, the
+ * existing volume is removed, unless it is re-named as well at the same
+ * re-name request.
+ */
+struct ubi_rnvol_req {
+	int32_t count;
+	int8_t padding1[12];
+	struct {
+		int32_t vol_id;
+		int16_t name_len;
+		int8_t  padding2[2];
+		char    name[UBI_MAX_VOLUME_NAME + 1];
+	} ents[UBI_MAX_RNVOL];
+} __attribute__ ((packed));
+
+/**
  * struct ubi_leb_change_req - a data structure used in atomic logical
  *                             eraseblock change requests.
  * @lnum: logical eraseblock number to change
···
 struct ubi_leb_change_req {
 	int32_t lnum;
 	int32_t bytes;
-	uint8_t dtype;
-	uint8_t padding[7];
+	int8_t  dtype;
+	int8_t  padding[7];
 } __attribute__ ((packed));
 
 #endif /* __UBI_USER_H__ */