Merge git://git.infradead.org/~dedekind/ubi-2.6

drivers/mtd/ubi/build.c

@@ -66,9 +66,6 @@ static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
 struct class *ubi_class;
 
-/* Slab cache for lock-tree entries */
-struct kmem_cache *ubi_ltree_slab;
-
 /* Slab cache for wear-leveling entries */
 struct kmem_cache *ubi_wl_entry_slab;
 
@@ -369,9 +366,6 @@ static int uif_init(struct ubi_device *ubi)
 	int i, err;
 	dev_t dev;
 
-	mutex_init(&ubi->volumes_mutex);
-	spin_lock_init(&ubi->volumes_lock);
-
 	sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
 
 	/*
@@ -568,7 +562,7 @@ static int io_init(struct ubi_device *ubi)
 	}
 
 	/* Similar for the data offset */
-	ubi->leb_start = ubi->vid_hdr_offset + ubi->vid_hdr_alsize;
+	ubi->leb_start = ubi->vid_hdr_offset + UBI_EC_HDR_SIZE;
 	ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
 
 	dbg_msg("vid_hdr_offset   %d", ubi->vid_hdr_offset);
@@ -626,6 +620,58 @@ static int io_init(struct ubi_device *ubi)
 	return 0;
 }
 
+/**
+ * autoresize - re-size the volume which has the "auto-resize" flag set.
+ * @ubi: UBI device description object
+ * @vol_id: ID of the volume to re-size
+ *
+ * This function re-sizes the volume marked by the @UBI_VTBL_AUTORESIZE_FLG in
+ * the volume table to the largest possible size. See comments in ubi-header.h
+ * for more description of the flag. Returns zero in case of success and a
+ * negative error code in case of failure.
+ */
+static int autoresize(struct ubi_device *ubi, int vol_id)
+{
+	struct ubi_volume_desc desc;
+	struct ubi_volume *vol = ubi->volumes[vol_id];
+	int err, old_reserved_pebs = vol->reserved_pebs;
+
+	/*
+	 * Clear the auto-resize flag in the volume in-memory copy of the
+	 * volume table, and 'ubi_resize_volume()' will propogate this change
+	 * to the flash.
+	 */
+	ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
+
+	if (ubi->avail_pebs == 0) {
+		struct ubi_vtbl_record vtbl_rec;
+
+		/*
+		 * No avalilable PEBs to re-size the volume, clear the flag on
+		 * flash and exit.
+		 */
+		memcpy(&vtbl_rec, &ubi->vtbl[vol_id],
+		       sizeof(struct ubi_vtbl_record));
+		err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
+		if (err)
+			ubi_err("cannot clean auto-resize flag for volume %d",
+				vol_id);
+	} else {
+		desc.vol = vol;
+		err = ubi_resize_volume(&desc,
+					old_reserved_pebs + ubi->avail_pebs);
+		if (err)
+			ubi_err("cannot auto-resize volume %d", vol_id);
+	}
+
+	if (err)
+		return err;
+
+	ubi_msg("volume %d (\"%s\") re-sized from %d to %d LEBs", vol_id,
+		vol->name, old_reserved_pebs, vol->reserved_pebs);
+	return 0;
+}
+
 /**
  * ubi_attach_mtd_dev - attach an MTD device.
  * @mtd_dev: MTD device description object
@@ -702,6 +748,12 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
 	ubi->mtd = mtd;
 	ubi->ubi_num = ubi_num;
 	ubi->vid_hdr_offset = vid_hdr_offset;
+	ubi->autoresize_vol_id = -1;
+
+	mutex_init(&ubi->buf_mutex);
+	mutex_init(&ubi->ckvol_mutex);
+	mutex_init(&ubi->volumes_mutex);
+	spin_lock_init(&ubi->volumes_lock);
 
 	dbg_msg("attaching mtd%d to ubi%d: VID header offset %d",
 		mtd->index, ubi_num, vid_hdr_offset);
@@ -710,8 +762,6 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
 	if (err)
 		goto out_free;
 
-	mutex_init(&ubi->buf_mutex);
-	mutex_init(&ubi->ckvol_mutex);
 	ubi->peb_buf1 = vmalloc(ubi->peb_size);
 	if (!ubi->peb_buf1)
 		goto out_free;
@@ -733,6 +783,12 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
 		goto out_free;
 	}
 
+	if (ubi->autoresize_vol_id != -1) {
+		err = autoresize(ubi, ubi->autoresize_vol_id);
+		if (err)
+			goto out_detach;
+	}
+
 	err = uif_init(ubi);
 	if (err)
 		goto out_detach;
@@ -857,20 +913,6 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
 	return 0;
 }
 
-/**
- * ltree_entry_ctor - lock tree entries slab cache constructor.
- * @obj: the lock-tree entry to construct
- * @cache: the lock tree entry slab cache
- * @flags: constructor flags
- */
-static void ltree_entry_ctor(struct kmem_cache *cache, void *obj)
-{
-	struct ubi_ltree_entry *le = obj;
-
-	le->users = 0;
-	init_rwsem(&le->mutex);
-}
-
 /**
  * find_mtd_device - open an MTD device by its name or number.
  * @mtd_dev: name or number of the device
@@ -933,17 +975,11 @@ static int __init ubi_init(void)
 		goto out_version;
 	}
 
-	ubi_ltree_slab = kmem_cache_create("ubi_ltree_slab",
-					   sizeof(struct ubi_ltree_entry), 0,
-					   0, &ltree_entry_ctor);
-	if (!ubi_ltree_slab)
-		goto out_dev_unreg;
-
 	ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
 						sizeof(struct ubi_wl_entry),
 						0, 0, NULL);
 	if (!ubi_wl_entry_slab)
-		goto out_ltree;
+		goto out_dev_unreg;
 
 	/* Attach MTD devices */
 	for (i = 0; i < mtd_devs; i++) {
@@ -980,8 +1016,6 @@ out_detach:
 			mutex_unlock(&ubi_devices_mutex);
 		}
 	kmem_cache_destroy(ubi_wl_entry_slab);
-out_ltree:
-	kmem_cache_destroy(ubi_ltree_slab);
 out_dev_unreg:
 	misc_deregister(&ubi_ctrl_cdev);
 out_version:
@@ -1005,7 +1039,6 @@ static void __exit ubi_exit(void)
 			mutex_unlock(&ubi_devices_mutex);
 		}
 	kmem_cache_destroy(ubi_wl_entry_slab);
-	kmem_cache_destroy(ubi_ltree_slab);
 	misc_deregister(&ubi_ctrl_cdev);
 	class_remove_file(ubi_class, &ubi_version);
 	class_destroy(ubi_class);
@@ -1066,7 +1099,7 @@ static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
 	struct mtd_dev_param *p;
 	char buf[MTD_PARAM_LEN_MAX];
 	char *pbuf = &buf[0];
-	char *tokens[3] = {NULL, NULL, NULL};
+	char *tokens[2] = {NULL, NULL};
 
 	if (!val)
 		return -EINVAL;
@@ -1096,7 +1129,7 @@ static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
 	if (buf[len - 1] == '\n')
 		buf[len - 1] = '\0';
 
-	for (i = 0; i < 3; i++)
+	for (i = 0; i < 2; i++)
 		tokens[i] = strsep(&pbuf, ",");
 
 	if (pbuf) {

drivers/mtd/ubi/cdev.c

@@ -132,8 +132,15 @@ static int vol_cdev_release(struct inode *inode, struct file *file)
 	if (vol->updating) {
 		ubi_warn("update of volume %d not finished, volume is damaged",
 			 vol->vol_id);
+		ubi_assert(!vol->changing_leb);
 		vol->updating = 0;
 		vfree(vol->upd_buf);
+	} else if (vol->changing_leb) {
+		dbg_msg("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;
+		vfree(vol->upd_buf);
 	}
 
 	ubi_close_volume(desc);
@@ -184,13 +191,13 @@ static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
 	struct ubi_volume_desc *desc = file->private_data;
 	struct ubi_volume *vol = desc->vol;
 	struct ubi_device *ubi = vol->ubi;
-	int err, lnum, off, len,  vol_id = desc->vol->vol_id, tbuf_size;
+	int err, lnum, off, len,  tbuf_size;
 	size_t count_save = count;
 	void *tbuf;
 	uint64_t tmp;
 
 	dbg_msg("read %zd bytes from offset %lld of volume %d",
-		count, *offp, vol_id);
+		count, *offp, vol->vol_id);
 
 	if (vol->updating) {
 		dbg_err("updating");
@@ -204,7 +211,7 @@ static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
 		return 0;
 
 	if (vol->corrupted)
-		dbg_msg("read from corrupted volume %d", vol_id);
+		dbg_msg("read from corrupted volume %d", vol->vol_id);
 
 	if (*offp + count > vol->used_bytes)
 		count_save = count = vol->used_bytes - *offp;
@@ -274,7 +281,7 @@ static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
 	uint64_t tmp;
 
 	dbg_msg("requested: write %zd bytes to offset %lld of volume %u",
-		count, *offp, desc->vol->vol_id);
+		count, *offp, vol->vol_id);
 
 	if (vol->vol_type == UBI_STATIC_VOLUME)
 		return -EROFS;
@@ -351,23 +358,32 @@ static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
 	struct ubi_volume *vol = desc->vol;
 	struct ubi_device *ubi = vol->ubi;
 
-	if (!vol->updating)
+	if (!vol->updating && !vol->changing_leb)
 		return vol_cdev_direct_write(file, buf, count, offp);
 
-	err = ubi_more_update_data(ubi, vol->vol_id, buf, count);
+	if (vol->updating)
+		err = ubi_more_update_data(ubi, vol, buf, count);
+	else
+		err = ubi_more_leb_change_data(ubi, vol, buf, count);
+
 	if (err < 0) {
-		ubi_err("cannot write %zd bytes of update data, error %d",
+		ubi_err("cannot accept more %zd bytes of data, error %d",
 			count, err);
 		return err;
 	}
 
 	if (err) {
 		/*
-		 * Update is finished, @err contains number of actually written
-		 * bytes now.
+		 * The operation is finished, @err contains number of actually
+		 * written bytes.
 		 */
 		count = err;
 
+		if (vol->changing_leb) {
+			revoke_exclusive(desc, UBI_READWRITE);
+			return count;
+		}
+
 		err = ubi_check_volume(ubi, vol->vol_id);
 		if (err < 0)
 			return err;
@@ -382,7 +398,6 @@ static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
 		revoke_exclusive(desc, UBI_READWRITE);
 	}
 
-	*offp += count;
 	return count;
 }
 
@@ -427,11 +442,46 @@ static int vol_cdev_ioctl(struct inode *inode, struct file *file,
 		if (err < 0)
 			break;
 
-		err = ubi_start_update(ubi, vol->vol_id, bytes);
+		err = ubi_start_update(ubi, vol, bytes);
 		if (bytes == 0)
 			revoke_exclusive(desc, UBI_READWRITE);
+		break;
+	}
+
+	/* Atomic logical eraseblock change command */
+	case UBI_IOCEBCH:
+	{
+		struct ubi_leb_change_req req;
+
+		err = copy_from_user(&req, argp,
+				     sizeof(struct ubi_leb_change_req));
+		if (err) {
+			err = -EFAULT;
+			break;
+		}
+
+		if (desc->mode == UBI_READONLY ||
+		    vol->vol_type == UBI_STATIC_VOLUME) {
+			err = -EROFS;
+			break;
+		}
+
+		/* Validate the request */
+		err = -EINVAL;
+		if (req.lnum < 0 || req.lnum >= vol->reserved_pebs ||
+		    req.bytes < 0 || req.lnum >= vol->usable_leb_size)
+			break;
+		if (req.dtype != UBI_LONGTERM && req.dtype != UBI_SHORTTERM &&
+		    req.dtype != UBI_UNKNOWN)
+			break;
+
+		err = get_exclusive(desc);
+		if (err < 0)
+			break;
 
-		file->f_pos = 0;
+		err = ubi_start_leb_change(ubi, vol, &req);
+		if (req.bytes == 0)
+			revoke_exclusive(desc, UBI_READWRITE);
 		break;
 	}
 
@@ -447,7 +497,8 @@ static int vol_cdev_ioctl(struct inode *inode, struct file *file,
 			break;
 		}
 
-		if (desc->mode == UBI_READONLY) {
+		if (desc->mode == UBI_READONLY ||
+		    vol->vol_type == UBI_STATIC_VOLUME) {
 			err = -EROFS;
 			break;
 		}
@@ -457,11 +508,6 @@ static int vol_cdev_ioctl(struct inode *inode, struct file *file,
 			break;
 		}
 
-		if (vol->vol_type != UBI_DYNAMIC_VOLUME) {
-			err = -EROFS;
-			break;
-		}
-
 		dbg_msg("erase LEB %d:%d", vol->vol_id, lnum);
 		err = ubi_eba_unmap_leb(ubi, vol, lnum);
 		if (err)

drivers/mtd/ubi/eba.c

@@ -78,7 +78,7 @@ static unsigned long long next_sqnum(struct ubi_device *ubi)
  */
 static int ubi_get_compat(const struct ubi_device *ubi, int vol_id)
 {
-	if (vol_id == UBI_LAYOUT_VOL_ID)
+	if (vol_id == UBI_LAYOUT_VOLUME_ID)
 		return UBI_LAYOUT_VOLUME_COMPAT;
 	return 0;
 }
@@ -137,10 +137,12 @@ static struct ubi_ltree_entry *ltree_add_entry(struct ubi_device *ubi,
 {
 	struct ubi_ltree_entry *le, *le1, *le_free;
 
-	le = kmem_cache_alloc(ubi_ltree_slab, GFP_NOFS);
+	le = kmalloc(sizeof(struct ubi_ltree_entry), GFP_NOFS);
 	if (!le)
 		return ERR_PTR(-ENOMEM);
 
+	le->users = 0;
+	init_rwsem(&le->mutex);
 	le->vol_id = vol_id;
 	le->lnum = lnum;
 
@@ -188,7 +190,7 @@ static struct ubi_ltree_entry *ltree_add_entry(struct ubi_device *ubi,
 	spin_unlock(&ubi->ltree_lock);
 
 	if (le_free)
-		kmem_cache_free(ubi_ltree_slab, le_free);
+		kfree(le_free);
 
 	return le;
 }
@@ -236,7 +238,7 @@ static void leb_read_unlock(struct ubi_device *ubi, int vol_id, int lnum)
 
 	up_read(&le->mutex);
 	if (free)
-		kmem_cache_free(ubi_ltree_slab, le);
+		kfree(le);
 }
 
 /**
@@ -292,7 +294,7 @@ static int leb_write_trylock(struct ubi_device *ubi, int vol_id, int lnum)
 		free = 0;
 	spin_unlock(&ubi->ltree_lock);
 	if (free)
-		kmem_cache_free(ubi_ltree_slab, le);
+		kfree(le);
 
 	return 1;
 }
@@ -321,7 +323,7 @@ static void leb_write_unlock(struct ubi_device *ubi, int vol_id, int lnum)
 
 	up_write(&le->mutex);
 	if (free)
-		kmem_cache_free(ubi_ltree_slab, le);
+		kfree(le);
 }
 
 /**
@@ -339,9 +341,6 @@ int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
 {
 	int err, pnum, vol_id = vol->vol_id;
 
-	ubi_assert(ubi->ref_count > 0);
-	ubi_assert(vol->ref_count > 0);
-
 	if (ubi->ro_mode)
 		return -EROFS;
 
@@ -390,9 +389,6 @@ int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 	struct ubi_vid_hdr *vid_hdr;
 	uint32_t uninitialized_var(crc);
 
-	ubi_assert(ubi->ref_count > 0);
-	ubi_assert(vol->ref_count > 0);
-
 	err = leb_read_lock(ubi, vol_id, lnum);
 	if (err)
 		return err;
@@ -616,9 +612,6 @@ int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 	int err, pnum, tries = 0, vol_id = vol->vol_id;
 	struct ubi_vid_hdr *vid_hdr;
 
-	ubi_assert(ubi->ref_count > 0);
-	ubi_assert(vol->ref_count > 0);
-
 	if (ubi->ro_mode)
 		return -EROFS;
 
@@ -752,9 +745,6 @@ int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
 	struct ubi_vid_hdr *vid_hdr;
 	uint32_t crc;
 
-	ubi_assert(ubi->ref_count > 0);
-	ubi_assert(vol->ref_count > 0);
-
 	if (ubi->ro_mode)
 		return -EROFS;
 
@@ -869,12 +859,20 @@ int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 	struct ubi_vid_hdr *vid_hdr;
 	uint32_t crc;
 
-	ubi_assert(ubi->ref_count > 0);
-	ubi_assert(vol->ref_count > 0);
-
 	if (ubi->ro_mode)
 		return -EROFS;
 
+	if (len == 0) {
+		/*
+		 * Special case when data length is zero. In this case the LEB
+		 * has to be unmapped and mapped somewhere else.
+		 */
+		err = ubi_eba_unmap_leb(ubi, vol, lnum);
+		if (err)
+			return err;
+		return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0, dtype);
+	}
+
 	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
 	if (!vid_hdr)
 		return -ENOMEM;

drivers/mtd/ubi/kapi.c

@@ -480,9 +480,9 @@ int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum)
 {
 	struct ubi_volume *vol = desc->vol;
 	struct ubi_device *ubi = vol->ubi;
-	int err, vol_id = vol->vol_id;
+	int err;
 
-	dbg_msg("erase LEB %d:%d", vol_id, lnum);
+	dbg_msg("erase LEB %d:%d", vol->vol_id, lnum);
 
 	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
 		return -EROFS;
@@ -541,9 +541,8 @@ int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum)
 {
 	struct ubi_volume *vol = desc->vol;
 	struct ubi_device *ubi = vol->ubi;
-	int vol_id = vol->vol_id;
 
-	dbg_msg("unmap LEB %d:%d", vol_id, lnum);
+	dbg_msg("unmap LEB %d:%d", vol->vol_id, lnum);
 
 	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
 		return -EROFS;
@@ -579,9 +578,8 @@ int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype)
 {
 	struct ubi_volume *vol = desc->vol;
 	struct ubi_device *ubi = vol->ubi;
-	int vol_id = vol->vol_id;
 
-	dbg_msg("unmap LEB %d:%d", vol_id, lnum);
+	dbg_msg("unmap LEB %d:%d", vol->vol_id, lnum);
 
 	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
 		return -EROFS;

drivers/mtd/ubi/scan.c

@@ -286,9 +286,14 @@ static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
 		 * FIXME: but this is anyway obsolete and will be removed at
 		 * some point.
 		 */
-
 		dbg_bld("using old crappy leb_ver stuff");
 
+		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;
@@ -390,7 +395,6 @@ out_free_buf:
 	vfree(buf);
 out_free_vidh:
 	ubi_free_vid_hdr(ubi, vh);
-	ubi_assert(err < 0);
 	return err;
 }
 
@@ -854,7 +858,7 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, int pnum
 	}
 
 	vol_id = be32_to_cpu(vidh->vol_id);
-	if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOL_ID) {
+	if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
 		int lnum = be32_to_cpu(vidh->lnum);
 
 		/* Unsupported internal volume */

drivers/mtd/ubi/ubi.h

@@ -144,7 +144,6 @@ struct ubi_volume_desc;
  * @readers: number of users holding this volume in read-only mode
  * @writers: number of users holding this volume in read-write mode
  * @exclusive: whether somebody holds this volume in exclusive mode
- * @checked: if this static volume was checked
  *
  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
@@ -152,21 +151,30 @@ struct ubi_volume_desc;
  * @used_ebs: how many logical eraseblocks in this volume contain data
  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
  * @used_bytes: how many bytes of data this volume contains
- * @upd_marker: non-zero if the update marker is set for this volume
- * @corrupted: non-zero if the volume is corrupted (static volumes only)
  * @alignment: volume alignment
  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
  *            satisfy the requested alignment
  * @name_len: volume name length
  * @name: volume name
  *
- * @updating: whether the volume is being updated
  * @upd_ebs: how many eraseblocks are expected to be updated
- * @upd_bytes: how many bytes are expected to be received
- * @upd_received: how many update bytes were already received
- * @upd_buf: update buffer which is used to collect update data
+ * @ch_lnum: LEB number which is being changing by the atomic LEB change
+ *           operation
+ * @ch_dtype: data persistency type which is being changing by the atomic LEB
+ *            change operation
+ * @upd_bytes: how many bytes are expected to be received for volume update or
+ *             atomic LEB change
+ * @upd_received: how many bytes were already received for volume update or
+ *                atomic LEB change
+ * @upd_buf: update buffer which is used to collect update data or data for
+ *           atomic LEB change
  *
  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
+ * @checked: %1 if this static volume was checked
+ * @corrupted: %1 if the volume is corrupted (static volumes only)
+ * @upd_marker: %1 if the update marker is set for this volume
+ * @updating: %1 if the volume is being updated
+ * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
  *
  * @gluebi_desc: gluebi UBI volume descriptor
  * @gluebi_refcount: reference count of the gluebi MTD device
@@ -189,7 +197,6 @@ struct ubi_volume {
 	int readers;
 	int writers;
 	int exclusive;
-	int checked;
 
 	int reserved_pebs;
 	int vol_type;
@@ -197,23 +204,31 @@ struct ubi_volume {
 	int used_ebs;
 	int last_eb_bytes;
 	long long used_bytes;
-	int upd_marker;
-	int corrupted;
 	int alignment;
 	int data_pad;
 	int name_len;
 	char name[UBI_VOL_NAME_MAX+1];
 
-	int updating;
 	int upd_ebs;
+	int ch_lnum;
+	int ch_dtype;
 	long long upd_bytes;
 	long long upd_received;
 	void *upd_buf;
 
 	int *eba_tbl;
+	int checked:1;
+	int corrupted:1;
+	int upd_marker:1;
+	int updating:1;
+	int changing_leb:1;
 
 #ifdef CONFIG_MTD_UBI_GLUEBI
-	/* Gluebi-related stuff may be compiled out */
+	/*
+	 * Gluebi-related stuff may be compiled out.
+	 * TODO: 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;
 	int gluebi_refcount;
 	struct mtd_info gluebi_mtd;
@@ -250,9 +265,11 @@ struct ubi_wl_entry;
  * @rsvd_pebs: count of reserved physical eraseblocks
  * @avail_pebs: count of available physical eraseblocks
  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
- * handling
+ *                 handling
  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
  *
+ * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
+ *                     of UBI ititializetion
  * @vtbl_slots: how many slots are available in the volume table
  * @vtbl_size: size of the volume table in bytes
  * @vtbl: in-RAM volume table copy
@@ -333,12 +350,14 @@ struct ubi_device {
 	int beb_rsvd_pebs;
 	int beb_rsvd_level;
 
+	int autoresize_vol_id;
 	int vtbl_slots;
 	int vtbl_size;
 	struct ubi_vtbl_record *vtbl;
 	struct mutex volumes_mutex;
 
 	int max_ec;
+	/* TODO: mean_ec is not updated run-time, fix */
 	int mean_ec;
 
 	/* EBA unit's stuff */
@@ -399,7 +418,6 @@ struct ubi_device {
 #endif
 };
 
-extern struct kmem_cache *ubi_ltree_slab;
 extern struct kmem_cache *ubi_wl_entry_slab;
 extern struct file_operations ubi_ctrl_cdev_operations;
 extern struct file_operations ubi_cdev_operations;
@@ -420,9 +438,14 @@ int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
 
 /* upd.c */
-int ubi_start_update(struct ubi_device *ubi, int vol_id, long long bytes);
-int ubi_more_update_data(struct ubi_device *ubi, int vol_id,
+int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
+		     long long bytes);
+int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
 			 const void __user *buf, int count);
+int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
+			 const struct ubi_leb_change_req *req);
+int ubi_more_leb_change_data(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);

drivers/mtd/ubi/upd.c

@@ -22,7 +22,8 @@
  */
 
 /*
- * This file contains implementation of the volume update functionality.
+ * This file contains implementation of the volume update and atomic LEB change
+ * functionality.
  *
  * The update operation is based on the per-volume update marker which is
  * stored in the volume table. The update marker is set before the update
@@ -45,30 +46,30 @@
 /**
  * set_update_marker - set update marker.
  * @ubi: UBI device description object
- * @vol_id: volume ID
+ * @vol: volume description object
  *
- * This function sets the update marker flag for volume @vol_id. Returns zero
+ * This function sets the update marker flag for volume @vol. Returns zero
  * in case of success and a negative error code in case of failure.
  */
-static int set_update_marker(struct ubi_device *ubi, int vol_id)
+static int set_update_marker(struct ubi_device *ubi, struct ubi_volume *vol)
 {
 	int err;
 	struct ubi_vtbl_record vtbl_rec;
-	struct ubi_volume *vol = ubi->volumes[vol_id];
 
-	dbg_msg("set update marker for volume %d", vol_id);
+	dbg_msg("set update marker for volume %d", vol->vol_id);
 
 	if (vol->upd_marker) {
-		ubi_assert(ubi->vtbl[vol_id].upd_marker);
+		ubi_assert(ubi->vtbl[vol->vol_id].upd_marker);
 		dbg_msg("already set");
 		return 0;
 	}
 
-	memcpy(&vtbl_rec, &ubi->vtbl[vol_id], sizeof(struct ubi_vtbl_record));
+	memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id],
+	       sizeof(struct ubi_vtbl_record));
 	vtbl_rec.upd_marker = 1;
 
 	mutex_lock(&ubi->volumes_mutex);
-	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
+	err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
 	mutex_unlock(&ubi->volumes_mutex);
 	vol->upd_marker = 1;
 	return err;
@@ -77,23 +78,24 @@ static int set_update_marker(struct ubi_device *ubi, int vol_id)
 /**
  * clear_update_marker - clear update marker.
  * @ubi: UBI device description object
- * @vol_id: volume ID
+ * @vol: volume description object
  * @bytes: new data size in bytes
  *
- * This function clears the update marker for volume @vol_id, sets new volume
+ * This function clears the update marker for volume @vol, sets new volume
  * data size and clears the "corrupted" flag (static volumes only). Returns
  * zero in case of success and a negative error code in case of failure.
  */
-static int clear_update_marker(struct ubi_device *ubi, int vol_id, long long bytes)
+static int clear_update_marker(struct ubi_device *ubi, struct ubi_volume *vol,
+			       long long bytes)
 {
 	int err;
 	uint64_t tmp;
 	struct ubi_vtbl_record vtbl_rec;
-	struct ubi_volume *vol = ubi->volumes[vol_id];
 
-	dbg_msg("clear update marker for volume %d", vol_id);
+	dbg_msg("clear update marker for volume %d", vol->vol_id);
 
-	memcpy(&vtbl_rec, &ubi->vtbl[vol_id], sizeof(struct ubi_vtbl_record));
+	memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id],
+	       sizeof(struct ubi_vtbl_record));
 	ubi_assert(vol->upd_marker && vtbl_rec.upd_marker);
 	vtbl_rec.upd_marker = 0;
 
@@ -109,7 +111,7 @@ static int clear_update_marker(struct ubi_device *ubi, int vol_id, long long byt
 	}
 
 	mutex_lock(&ubi->volumes_mutex);
-	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
+	err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
 	mutex_unlock(&ubi->volumes_mutex);
 	vol->upd_marker = 0;
 	return err;
@@ -118,23 +120,24 @@ static int clear_update_marker(struct ubi_device *ubi, int vol_id, long long byt
 /**
  * ubi_start_update - start volume update.
  * @ubi: UBI device description object
- * @vol_id: volume ID
+ * @vol: volume description object
  * @bytes: update bytes
  *
  * This function starts volume update operation. If @bytes is zero, the volume
  * is just wiped out. Returns zero in case of success and a negative error code
  * in case of failure.
  */
-int ubi_start_update(struct ubi_device *ubi, int vol_id, long long bytes)
+int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
+		     long long bytes)
 {
 	int i, err;
 	uint64_t tmp;
-	struct ubi_volume *vol = ubi->volumes[vol_id];
 
-	dbg_msg("start update of volume %d, %llu bytes", vol_id, bytes);
+	dbg_msg("start update of volume %d, %llu bytes", vol->vol_id, bytes);
+	ubi_assert(!vol->updating && !vol->changing_leb);
 	vol->updating = 1;
 
-	err = set_update_marker(ubi, vol_id);
+	err = set_update_marker(ubi, vol);
 	if (err)
 		return err;
 
@@ -146,7 +149,7 @@ int ubi_start_update(struct ubi_device *ubi, int vol_id, long long bytes)
 	}
 
 	if (bytes == 0) {
-		err = clear_update_marker(ubi, vol_id, 0);
+		err = clear_update_marker(ubi, vol, 0);
 		if (err)
 			return err;
 		err = ubi_wl_flush(ubi);
@@ -166,10 +169,43 @@ int ubi_start_update(struct ubi_device *ubi, int vol_id, long long bytes)
 	return 0;
 }
 
+/**
+ * ubi_start_leb_change - start atomic LEB change.
+ * @ubi: UBI device description object
+ * @vol: volume description object
+ * @req: operation request
+ *
+ * This function starts atomic LEB change operation. Returns zero in case of
+ * success and a negative error code in case of failure.
+ */
+int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
+			 const struct ubi_leb_change_req *req)
+{
+	ubi_assert(!vol->updating && !vol->changing_leb);
+
+	dbg_msg("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,
+						 req->dtype);
+
+	vol->upd_bytes = req->bytes;
+	vol->upd_received = 0;
+	vol->changing_leb = 1;
+	vol->ch_lnum = req->lnum;
+	vol->ch_dtype = req->dtype;
+
+	vol->upd_buf = vmalloc(req->bytes);
+	if (!vol->upd_buf)
+		return -ENOMEM;
+
+	return 0;
+}
+
 /**
  * write_leb - write update data.
  * @ubi: UBI device description object
- * @vol_id: volume ID
+ * @vol: volume description object
  * @lnum: logical eraseblock number
  * @buf: data to write
  * @len: data size
@@ -195,25 +231,22 @@ int ubi_start_update(struct ubi_device *ubi, int vol_id, long long bytes)
  * This function returns zero in case of success and a negative error code in
  * case of failure.
  */
-static int write_leb(struct ubi_device *ubi, int vol_id, int lnum, void *buf,
-		     int len, int used_ebs)
+static int write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
+		     void *buf, int len, int used_ebs)
 {
-	int err, l;
-	struct ubi_volume *vol = ubi->volumes[vol_id];
+	int err;
 
 	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
-		l = ALIGN(len, ubi->min_io_size);
-		memset(buf + len, 0xFF, l - len);
+		len = ALIGN(len, ubi->min_io_size);
+		memset(buf + len, 0xFF, len - len);
 
-		l = ubi_calc_data_len(ubi, buf, l);
-		if (l == 0) {
+		len = ubi_calc_data_len(ubi, buf, len);
+		if (len == 0) {
 			dbg_msg("all %d bytes contain 0xFF - skip", len);
 			return 0;
 		}
-		if (len != l)
-			dbg_msg("skip last %d bytes (0xFF)", len - l);
 
-		err = ubi_eba_write_leb(ubi, vol, lnum, buf, 0, l, 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
@@ -239,16 +272,15 @@ static int write_leb(struct ubi_device *ubi, int vol_id, int lnum, void *buf,
  * @count: how much bytes to write
  *
  * This function writes more data to the volume which is being updated. It may
- * be called arbitrary number of times until all of the update data arrive.
- * This function returns %0 in case of success, number of bytes written during
- * the last call if the whole volume update was successfully finished, and a
+ * be called arbitrary number of times until all the update data arriveis. This
+ * function returns %0 in case of success, number of bytes written during the
+ * last call if the whole volume update has been successfully finished, and a
  * negative error code in case of failure.
  */
-int ubi_more_update_data(struct ubi_device *ubi, int vol_id,
+int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
 			 const void __user *buf, int count)
 {
 	uint64_t tmp;
-	struct ubi_volume *vol = ubi->volumes[vol_id];
 	int lnum, offs, err = 0, len, to_write = count;
 
 	dbg_msg("write %d of %lld bytes, %lld already passed",
@@ -293,8 +325,8 @@ int ubi_more_update_data(struct ubi_device *ubi, int vol_id,
 			 * is the last chunk, it's time to flush the buffer.
 			 */
 			ubi_assert(flush_len <= vol->usable_leb_size);
-			err = write_leb(ubi, vol_id, lnum, vol->upd_buf,
-					flush_len, vol->upd_ebs);
+			err = write_leb(ubi, vol, lnum, vol->upd_buf, flush_len,
+					vol->upd_ebs);
 			if (err)
 				return err;
 		}
@@ -321,8 +353,8 @@ int ubi_more_update_data(struct ubi_device *ubi, int vol_id,
 
 		if (len == vol->usable_leb_size ||
 		    vol->upd_received + len == vol->upd_bytes) {
-			err = write_leb(ubi, vol_id, lnum, vol->upd_buf, len,
-					vol->upd_ebs);
+			err = write_leb(ubi, vol, lnum, vol->upd_buf,
+					len, vol->upd_ebs);
 			if (err)
 				break;
 		}
@@ -336,16 +368,70 @@ int ubi_more_update_data(struct ubi_device *ubi, int vol_id,
 	ubi_assert(vol->upd_received <= vol->upd_bytes);
 	if (vol->upd_received == vol->upd_bytes) {
 		/* The update is finished, clear the update marker */
-		err = clear_update_marker(ubi, vol_id, vol->upd_bytes);
+		err = clear_update_marker(ubi, vol, vol->upd_bytes);
 		if (err)
 			return err;
 		err = ubi_wl_flush(ubi);
 		if (err == 0) {
+			vol->updating = 0;
 			err = to_write;
 			vfree(vol->upd_buf);
-			vol->updating = 0;
 		}
 	}
 
 	return err;
 }
+
+/**
+ * ubi_more_leb_change_data - accept more data for atomic LEB change.
+ * @vol: volume description object
+ * @buf: write data (user-space memory buffer)
+ * @count: how much bytes to write
+ *
+ * This function accepts more data to the volume which is being under the
+ * "atomic LEB change" operation. It may be called arbitrary number of times
+ * until all data arrives. This function returns %0 in case of success, number
+ * of bytes written during the last call if the whole "atomic LEB change"
+ * operation has been successfully finished, and a negative error code in case
+ * of failure.
+ */
+int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
+			     const void __user *buf, int count)
+{
+	int err;
+
+	dbg_msg("write %d of %lld bytes, %lld already passed",
+		count, vol->upd_bytes, vol->upd_received);
+
+	if (ubi->ro_mode)
+		return -EROFS;
+
+	if (vol->upd_received + count > vol->upd_bytes)
+		count = vol->upd_bytes - vol->upd_received;
+
+	err = copy_from_user(vol->upd_buf + vol->upd_received, buf, count);
+	if (err)
+		return -EFAULT;
+
+	vol->upd_received += count;
+
+	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);
+		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);
+		if (err)
+			return err;
+	}
+
+	ubi_assert(vol->upd_received <= vol->upd_bytes);
+	if (vol->upd_received == vol->upd_bytes) {
+		vol->changing_leb = 0;
+		err = count;
+		vfree(vol->upd_buf);
+	}
+
+	return err;
+}

drivers/mtd/ubi/vmt.c

@@ -497,8 +497,6 @@ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs)
 
 	dbg_msg("re-size volume %d to from %d to %d PEBs",
 		vol_id, vol->reserved_pebs, reserved_pebs);
-	ubi_assert(desc->mode == UBI_EXCLUSIVE);
-	ubi_assert(vol == ubi->volumes[vol_id]);
 
 	if (vol->vol_type == UBI_STATIC_VOLUME &&
 	    reserved_pebs < vol->used_ebs) {
@@ -526,7 +524,6 @@ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs)
 	}
 	spin_unlock(&ubi->volumes_lock);
 
-
 	/* Reserve physical eraseblocks */
 	pebs = reserved_pebs - vol->reserved_pebs;
 	if (pebs > 0) {
@@ -746,11 +743,6 @@ static void paranoid_check_volume(struct ubi_device *ubi, int vol_id)
 		goto fail;
 	}
 
-	if (vol->upd_marker != 0 && vol->upd_marker != 1) {
-		ubi_err("bad upd_marker");
-		goto fail;
-	}
-
 	if (vol->upd_marker && vol->corrupted) {
 		dbg_err("update marker and corrupted simultaneously");
 		goto fail;
@@ -785,7 +777,7 @@ static void paranoid_check_volume(struct ubi_device *ubi, int vol_id)
 
 	n = (long long)vol->used_ebs * vol->usable_leb_size;
 	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
-		if (vol->corrupted != 0) {
+		if (vol->corrupted) {
 			ubi_err("corrupted dynamic volume");
 			goto fail;
 		}
@@ -802,10 +794,6 @@ static void paranoid_check_volume(struct ubi_device *ubi, int vol_id)
 			goto fail;
 		}
 	} else {
-		if (vol->corrupted != 0 && vol->corrupted != 1) {
-			ubi_err("bad corrupted");
-			goto fail;
-		}
 		if (vol->used_ebs < 0 || vol->used_ebs > vol->reserved_pebs) {
 			ubi_err("bad used_ebs");
 			goto fail;

drivers/mtd/ubi/vtbl.c

@@ -89,7 +89,7 @@ int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
 	struct ubi_volume *layout_vol;
 
 	ubi_assert(idx >= 0 && idx < ubi->vtbl_slots);
-	layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOL_ID)];
+	layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)];
 
 	if (!vtbl_rec)
 		vtbl_rec = &empty_vtbl_record;
@@ -111,7 +111,7 @@ int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
 	}
 
 	paranoid_vtbl_check(ubi);
-	return ubi_wl_flush(ubi);
+	return 0;
 }
 
 /**
@@ -269,7 +269,7 @@ static int create_vtbl(struct ubi_device *ubi, struct ubi_scan_info *si,
 	 * this volume table copy was found during scanning. It has to be wiped
 	 * out.
 	 */
-	sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOL_ID);
+	sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOLUME_ID);
 	if (sv)
 		old_seb = ubi_scan_find_seb(sv, copy);
 
@@ -281,7 +281,7 @@ retry:
 	}
 
 	vid_hdr->vol_type = UBI_VID_DYNAMIC;
-	vid_hdr->vol_id = cpu_to_be32(UBI_LAYOUT_VOL_ID);
+	vid_hdr->vol_id = cpu_to_be32(UBI_LAYOUT_VOLUME_ID);
 	vid_hdr->compat = UBI_LAYOUT_VOLUME_COMPAT;
 	vid_hdr->data_size = vid_hdr->used_ebs =
 			     vid_hdr->data_pad = cpu_to_be32(0);
@@ -514,6 +514,17 @@ static int init_volumes(struct ubi_device *ubi, const struct ubi_scan_info *si,
 		vol->name[vol->name_len] = '\0';
 		vol->vol_id = i;
 
+		if (vtbl[i].flags & UBI_VTBL_AUTORESIZE_FLG) {
+			/* Auto re-size flag may be set only for one volume */
+			if (ubi->autoresize_vol_id != -1) {
+				ubi_err("more then one auto-resize volume (%d "
+					"and %d)", ubi->autoresize_vol_id, i);
+				return -EINVAL;
+			}
+
+			ubi->autoresize_vol_id = i;
+		}
+
 		ubi_assert(!ubi->volumes[i]);
 		ubi->volumes[i] = vol;
 		ubi->vol_count += 1;
@@ -579,7 +590,7 @@ static int init_volumes(struct ubi_device *ubi, const struct ubi_scan_info *si,
 	vol->last_eb_bytes = vol->reserved_pebs;
 	vol->used_bytes =
 		(long long)vol->used_ebs * (ubi->leb_size - vol->data_pad);
-	vol->vol_id = UBI_LAYOUT_VOL_ID;
+	vol->vol_id = UBI_LAYOUT_VOLUME_ID;
 	vol->ref_count = 1;
 
 	ubi_assert(!ubi->volumes[i]);
@@ -732,7 +743,7 @@ int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si)
 	ubi->vtbl_size = ubi->vtbl_slots * UBI_VTBL_RECORD_SIZE;
 	ubi->vtbl_size = ALIGN(ubi->vtbl_size, ubi->min_io_size);
 
-	sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOL_ID);
+	sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOLUME_ID);
 	if (!sv) {
 		/*
 		 * No logical eraseblocks belonging to the layout volume were

drivers/mtd/ubi/wl.c

@@ -1303,7 +1303,6 @@ int ubi_wl_flush(struct ubi_device *ubi)
 	 * Make sure all the works which have been done in parallel are
 	 * finished.
 	 */
-	ubi_assert(ubi->ref_count > 0);
 	down_write(&ubi->work_sem);
 	up_write(&ubi->work_sem);
 

include/linux/mtd/ubi.h

@@ -25,23 +25,6 @@
 #include <linux/types.h>
 #include <mtd/ubi-user.h>
 
-/*
- * UBI data type hint constants.
- *
- * UBI_LONGTERM: long-term data
- * UBI_SHORTTERM: short-term data
- * UBI_UNKNOWN: data persistence is unknown
- *
- * These constants are used when data is written to UBI volumes in order to
- * help the UBI wear-leveling unit to find more appropriate physical
- * eraseblocks.
- */
-enum {
-	UBI_LONGTERM = 1,
-	UBI_SHORTTERM,
-	UBI_UNKNOWN
-};
-
 /*
  * enum ubi_open_mode - UBI volume open mode constants.
  *

include/mtd/ubi-header.h

@@ -57,6 +57,43 @@ enum {
 	UBI_VID_STATIC  = 2
 };
 
+/*
+ * Volume flags used in the volume table record.
+ *
+ * @UBI_VTBL_AUTORESIZE_FLG: auto-resize this volume
+ *
+ * %UBI_VTBL_AUTORESIZE_FLG flag can be set only for one volume in the volume
+ * table. UBI automatically re-sizes the volume which has this flag and makes
+ * the volume to be of largest possible size. This means that if after the
+ * initialization UBI finds out that there are available physical eraseblocks
+ * present on the device, it automatically appends all of them to the volume
+ * (the physical eraseblocks reserved for bad eraseblocks handling and other
+ * reserved physical eraseblocks are not taken). So, if there is a volume with
+ * the %UBI_VTBL_AUTORESIZE_FLG flag set, the amount of available logical
+ * eraseblocks will be zero after UBI is loaded, because all of them will be
+ * reserved for this volume. Note, the %UBI_VTBL_AUTORESIZE_FLG bit is cleared
+ * after the volume had been initialized.
+ *
+ * The auto-resize feature is useful for device production purposes. For
+ * example, different NAND flash chips may have different amount of initial bad
+ * eraseblocks, depending of particular chip instance. Manufacturers of NAND
+ * chips usually guarantee that the amount of initial bad eraseblocks does not
+ * exceed certain percent, e.g. 2%. When one creates an UBI image which will be
+ * flashed to the end devices in production, he does not know the exact amount
+ * of good physical eraseblocks the NAND chip on the device will have, but this
+ * number is required to calculate the volume sized and put them to the volume
+ * table of the UBI image. In this case, one of the volumes (e.g., the one
+ * which will store the root file system) is marked as "auto-resizable", and
+ * UBI will adjust its size on the first boot if needed.
+ *
+ * Note, first UBI reserves some amount of physical eraseblocks for bad
+ * eraseblock handling, and then re-sizes the volume, not vice-versa. This
+ * means that the pool of reserved physical eraseblocks will always be present.
+ */
+enum {
+	UBI_VTBL_AUTORESIZE_FLG = 0x01,
+};
+
 /*
  * Compatibility constants used by internal volumes.
  *
@@ -262,7 +299,9 @@ struct ubi_vid_hdr {
 
 /* The layout volume contains the volume table */
 
-#define UBI_LAYOUT_VOL_ID        UBI_INTERNAL_VOL_START
+#define UBI_LAYOUT_VOLUME_ID     UBI_INTERNAL_VOL_START
+#define UBI_LAYOUT_VOLUME_TYPE   UBI_VID_DYNAMIC
+#define UBI_LAYOUT_VOLUME_ALIGN  1
 #define UBI_LAYOUT_VOLUME_EBS    2
 #define UBI_LAYOUT_VOLUME_NAME   "layout volume"
 #define UBI_LAYOUT_VOLUME_COMPAT UBI_COMPAT_REJECT
@@ -289,7 +328,8 @@ struct ubi_vid_hdr {
  * @upd_marker: if volume update was started but not finished
  * @name_len: volume name length
  * @name: the volume name
- * @padding2: reserved, zeroes
+ * @flags: volume flags (%UBI_VTBL_AUTORESIZE_FLG)
+ * @padding: reserved, zeroes
  * @crc: a CRC32 checksum of the record
  *
  * The volume table records are stored in the volume table, which is stored in
@@ -324,7 +364,8 @@ struct ubi_vtbl_record {
 	__u8    upd_marker;
 	__be16  name_len;
 	__u8    name[UBI_VOL_NAME_MAX+1];
-	__u8    padding2[24];
+	__u8    flags;
+	__u8    padding[23];
 	__be32  crc;
 } __attribute__ ((packed));
 

include/mtd/ubi-user.h

@@ -63,7 +63,7 @@
  *
  * Volume update should be done via the %UBI_IOCVOLUP IOCTL command of the
  * corresponding UBI volume character device. A pointer to a 64-bit update
- * size should be passed to the IOCTL. After then, UBI expects user to write
+ * size should be passed to the IOCTL. After this, UBI expects user to write
  * this number of bytes to the volume character device. The update is finished
  * when the claimed number of bytes is passed. So, the volume update sequence
  * is something like:
@@ -72,6 +72,15 @@
  * ioctl(fd, UBI_IOCVOLUP, &image_size);
  * write(fd, buf, image_size);
  * close(fd);
+ *
+ * Atomic eraseblock change
+ * ~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * Atomic eraseblock change operation is done via the %UBI_IOCEBCH IOCTL
+ * command of the corresponding UBI volume character device. A pointer to
+ * &struct ubi_leb_change_req has to be passed to the IOCTL. Then the user is
+ * expected to write the requested amount of bytes. This is similar to the
+ * "volume update" IOCTL.
  */
 
 /*
@@ -113,10 +122,29 @@
 #define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, int64_t)
 /* An eraseblock erasure command, used for debugging, disabled by default */
 #define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, int32_t)
+/* An atomic eraseblock change command */
+#define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, int32_t)
 
 /* Maximum MTD device name length supported by UBI */
 #define MAX_UBI_MTD_NAME_LEN 127
 
+/*
+ * UBI data type hint constants.
+ *
+ * UBI_LONGTERM: long-term data
+ * UBI_SHORTTERM: short-term data
+ * UBI_UNKNOWN: data persistence is unknown
+ *
+ * These constants are used when data is written to UBI volumes in order to
+ * help the UBI wear-leveling unit to find more appropriate physical
+ * eraseblocks.
+ */
+enum {
+	UBI_LONGTERM  = 1,
+	UBI_SHORTTERM = 2,
+	UBI_UNKNOWN   = 3,
+};
+
 /*
  * UBI volume type constants.
  *
@@ -125,7 +153,7 @@
  */
 enum {
 	UBI_DYNAMIC_VOLUME = 3,
-	UBI_STATIC_VOLUME = 4,
+	UBI_STATIC_VOLUME  = 4,
 };
 
 /**
@@ -137,7 +165,7 @@ enum {
  *
  * This data structure is used to specify MTD device UBI has to attach and the
  * parameters it has to use. The number which should be assigned to the new UBI
- * device is passed in @ubi_num. UBI may automatically assing the number if
+ * device is passed in @ubi_num. UBI may automatically assign the number if
  * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in
  * @ubi_num.
  *
@@ -176,7 +204,7 @@ struct ubi_attach_req {
  * @padding2: reserved for future, not used, has to be zeroed
  * @name: volume name
  *
- * This structure is used by userspace programs when creating new volumes. The
+ * This structure is used by user-space programs when creating new volumes. The
  * @used_bytes field is only necessary when creating static volumes.
  *
  * The @alignment field specifies the required alignment of the volume logical
@@ -222,4 +250,19 @@ struct ubi_rsvol_req {
 	int32_t vol_id;
 } __attribute__ ((packed));
 
+/**
+ * struct ubi_leb_change_req - a data structure used in atomic logical
+ *                             eraseblock change requests.
+ * @lnum: logical eraseblock number to change
+ * @bytes: how many bytes will be written to the logical eraseblock
+ * @dtype: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN)
+ * @padding: reserved for future, not used, has to be zeroed
+ */
+struct ubi_leb_change_req {
+	int32_t lnum;
+	int32_t bytes;
+	uint8_t dtype;
+	uint8_t padding[7];
+} __attribute__ ((packed));
+
 #endif /* __UBI_USER_H__ */