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

10 files changed, 350 insertions, 164 deletions

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 8f1f9feb2d60..6ac81e35355c 100644
--- a/drivers/mtd/ubi/build.c
+++ b/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);
@@ -627,6 +621,58 @@ static int io_init(struct ubi_device *ubi)
 }
 
 /**
+ * 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
  * @ubi_num: number to assign to the new UBI device
@@ -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;
@@ -858,20 +914,6 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
 }
 
 /**
- * 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) {
diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c
index 5ec13dc4705b..9d6aae5449b6 100644
--- a/drivers/mtd/ubi/cdev.c
+++ b/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)
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 85297cde4ac5..7ce91ca742b1 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/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;
diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c
index 146957c3380d..a70d58823f8d 100644
--- a/drivers/mtd/ubi/kapi.c
+++ b/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;
diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c
index c57e8eff9866..05aa3e7daba1 100644
--- a/drivers/mtd/ubi/scan.c
+++ b/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 */
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index ef22f922f580..457710615261 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/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);
diff --git a/drivers/mtd/ubi/upd.c b/drivers/mtd/ubi/upd.c
index e32b04d2e048..ddaa1a56cc69 100644
--- a/drivers/mtd/ubi/upd.c
+++ b/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);
@@ -167,9 +170,42 @@ int ubi_start_update(struct ubi_device *ubi, int vol_id, long long bytes)
 }
 
 /**
+ * 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;
+}
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
index 177227e1f80d..a3ca2257e601 100644
--- a/drivers/mtd/ubi/vmt.c
+++ b/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;
diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c
index 7a1a8a1da610..56fc3fbce838 100644
--- a/drivers/mtd/ubi/vtbl.c
+++ b/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
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 0d44ad95ab84..a471a491f0ab 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/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);