3 files changed, 40 insertions, 2 deletions

diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 32045dd3d1db..f3ff8604b5e5 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -84,6 +84,23 @@ static int ubi_get_compat(const struct ubi_device *ubi, int vol_id)
 }
 
 /**
+ * ubi_eba_get_ldesc - get information about a LEB
+ * @vol: volume description object
+ * @lnum: logical eraseblock number
+ * @ldesc: the LEB descriptor to fill
+ *
+ * Used to query information about a specific LEB.
+ * It is currently only returning the physical position of the LEB, but will be
+ * extended to provide more information.
+ */
+void ubi_eba_get_ldesc(struct ubi_volume *vol, int lnum,
+		       struct ubi_eba_leb_desc *ldesc)
+{
+	ldesc->lnum = lnum;
+	ldesc->pnum = vol->eba_tbl[lnum];
+}
+
+/**
  * ltree_lookup - look up the lock tree.
  * @ubi: UBI device description object
  * @vol_id: volume ID
diff --git a/drivers/mtd/ubi/fastmap.c b/drivers/mtd/ubi/fastmap.c
index 25e80a749a52..27a94f28819b 100644
--- a/drivers/mtd/ubi/fastmap.c
+++ b/drivers/mtd/ubi/fastmap.c
@@ -1257,8 +1257,12 @@ static int ubi_write_fastmap(struct ubi_device *ubi,
 		fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
 		ubi_assert(fm_pos <= ubi->fm_size);
 
-		for (j = 0; j < vol->reserved_pebs; j++)
-			feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
+		for (j = 0; j < vol->reserved_pebs; j++) {
+			struct ubi_eba_leb_desc ldesc;
+
+			ubi_eba_get_ldesc(vol, j, &ldesc);
+			feba->pnum[j] = cpu_to_be32(ldesc.pnum);
+		}
 
 		feba->reserved_pebs = cpu_to_be32(j);
 		feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 37469805591d..98e5dac677ee 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -267,6 +267,21 @@ struct ubi_fm_pool {
 };
 
 /**
+ * struct ubi_eba_leb_desc - EBA logical eraseblock descriptor
+ * @lnum: the logical eraseblock number
+ * @pnum: the physical eraseblock where the LEB can be found
+ *
+ * This structure is here to hide EBA's internal from other part of the
+ * UBI implementation.
+ *
+ * One can query the position of a LEB by calling ubi_eba_get_ldesc().
+ */
+struct ubi_eba_leb_desc {
+	int lnum;
+	int pnum;
+};
+
+/**
  * struct ubi_volume - UBI volume description data structure.
  * @dev: device object to make use of the the Linux device model
  * @cdev: character device object to create character device
@@ -849,6 +864,8 @@ static inline bool ubi_leb_valid(struct ubi_volume *vol, int lnum)
 }
 
 /* eba.c */
+void ubi_eba_get_ldesc(struct ubi_volume *vol, int lnum,
+		       struct ubi_eba_leb_desc *ldesc);
 bool ubi_eba_is_mapped(struct ubi_volume *vol, int lnum);
 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
 		      int lnum);