7 files changed, 121 insertions, 26 deletions

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 8b4573559df..4e761e957de 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -366,9 +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);
 
         /*
@@ -624,6 +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
@@ -699,6 +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);
@@ -707,8 +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;
@@ -730,6 +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;
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 7c05c6e1abc..1f951e39c53 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -341,9 +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;
 
@@ -392,9 +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;
@@ -618,9 +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;
 
@@ -754,9 +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;
 
@@ -871,9 +859,6 @@ 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;
 
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 90cdcad83cb..a8cdbd0364f 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -250,9 +250,11 @@ 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 +335,14 @@ 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 */
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
index 221ce70be56..a3ca2257e60 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) {
diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c
index 7a1a8a1da61..2fd9cf4cea7 100644
--- a/drivers/mtd/ubi/vtbl.c
+++ b/drivers/mtd/ubi/vtbl.c
@@ -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;
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 1142aabcfc8..8bfb7434c99 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);
 
diff --git a/include/mtd/ubi-header.h b/include/mtd/ubi-header.h
index 74efa776347..69d5d7e2289 100644
--- a/include/mtd/ubi-header.h
+++ b/include/mtd/ubi-header.h
@@ -58,6 +58,43 @@ enum {
 };
 
 /*
+ * 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.
  *
  * @UBI_COMPAT_DELETE: delete this internal volume before anything is written
@@ -289,7 +326,8 @@ 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 +362,8 @@ 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));