mtd: Make sure mtd->erasesize is valid even if the partition is of size 0

bbrezillon · bbrezillon · commit ad4635153034 · 2019-02-06T00:02:51.000+01:00
Commit 33f45c4 ("mtd: Do not allow MTD devices with inconsistent erase properties") introduced a check to make sure ->erasesize and ->_erase values are consistent with the MTD_NO_ERASE flag. This patch did not take the 0 bytes partition case into account which can happen when the defined partition is outside the flash device memory range. Fix that by setting the partition erasesize to the parent erasesize. Fixes: 33f45c4 ("mtd: Do not allow MTD devices with inconsistent erase properties") Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: <stable@vger.kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Boris Brezillon <bbrezillon@kernel.org> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
@@ -480,6 +480,10 @@ static struct mtd_part *allocate_partition(struct mtd_info *parent,
 		/* let's register it anyway to preserve ordering */
 		slave->offset = 0;
 		slave->mtd.size = 0;
+
+		/* Initialize ->erasesize to make add_mtd_device() happy. */
+		slave->mtd.erasesize = parent->erasesize;
+
 		printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
 			part->name);
 		goto out_register;
