ubi: fastmap: Fix add_vol() return value test in ubi_attach_fastmap()

Commit e96a8a3bb671 ("UBI: Fastmap: Do not add vol if it already
exists") introduced a bug by changing the possible error codes returned
by add_vol():
- this function no longer returns NULL in case of allocation failure
  but return ERR_PTR(-ENOMEM)
- when a duplicate entry in the volume RB tree is found it returns
  ERR_PTR(-EEXIST) instead of ERR_PTR(-EINVAL)

Fix the tests done on add_vol() return val to match this new behavior.

Fixes: e96a8a3bb671 ("UBI: Fastmap: Do not add vol if it already exists")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

diff --git a/drivers/mtd/ubi/fastmap.c b/drivers/mtd/ubi/fastmap.c
index 2ff62157d3bb0e6dfbe566ae0ffa898f3043a7ce..c1f5c29e458ef86305376fa7b404f9c5b8e05681 100644 (file)
--- a/drivers/mtd/ubi/fastmap.c
+++ b/drivers/mtd/ubi/fastmap.c
@@ -707,11 +707,11 @@ static int ubi_attach_fastmap(struct ubi_device *ubi,
                             fmvhdr->vol_type,
                             be32_to_cpu(fmvhdr->last_eb_bytes));
 
-               if (!av)
-                       goto fail_bad;
-               if (PTR_ERR(av) == -EINVAL) {
-                       ubi_err(ubi, "volume (ID %i) already exists",
-                               fmvhdr->vol_id);
+               if (IS_ERR(av)) {
+                       if (PTR_ERR(av) == -EEXIST)
+                               ubi_err(ubi, "volume (ID %i) already exists",
+                                       fmvhdr->vol_id);
+
                        goto fail_bad;
                }