2 files changed, 17 insertions, 1 deletions

diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 3477e16be1c8..b73720502433 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -479,6 +479,19 @@ static struct mtd_part *allocate_partition(struct mtd_info *master,
                                (unsigned long long)cur_offset, (unsigned long long)slave->offset);
                 }
         }
+        if (slave->offset == MTDPART_OFS_RETAIN) {
+                slave->offset = cur_offset;
+                if (master->size - slave->offset >= slave->mtd.size) {
+                        slave->mtd.size = master->size - slave->offset
+                                                        - slave->mtd.size;
+                } else {
+                        printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
+                                part->name, master->size - slave->offset,
+                                slave->mtd.size);
+                        /* register to preserve ordering */
+                        goto out_register;
+                }
+        }
         if (slave->mtd.size == MTDPART_SIZ_FULL)
                 slave->mtd.size = master->size - slave->offset;
 
diff --git a/include/linux/mtd/partitions.h b/include/linux/mtd/partitions.h
index 08c9c7b8b8e2..1431cf2609ed 100644
--- a/include/linux/mtd/partitions.h
+++ b/include/linux/mtd/partitions.h
@@ -24,7 +24,9 @@
  *      will extend to the end of the master MTD device.
  * offset: absolute starting position within the master MTD device; if
  *      defined as MTDPART_OFS_APPEND, the partition will start where the
- *      previous one ended; if MTDPART_OFS_NXTBLK, at the next erase block.
+ *      previous one ended; if MTDPART_OFS_NXTBLK, at the next erase block;
+ *      if MTDPART_OFS_RETAIN, consume as much as possible, leaving size
+ *      after the end of partition.
  * mask_flags: contains flags that have to be masked (removed) from the
  *      master MTD flag set for the corresponding MTD partition.
  *      For example, to force a read-only partition, simply adding
@@ -42,6 +44,7 @@ struct mtd_partition {
         struct nand_ecclayout *ecclayout;       /* out of band layout for this partition (NAND only) */
 };
 
+#define MTDPART_OFS_RETAIN      (-3)
 #define MTDPART_OFS_NXTBLK      (-2)
 #define MTDPART_OFS_APPEND      (-1)
 #define MTDPART_SIZ_FULL        (0)