ubi: Fix race condition between ubi volume creation and udev

[ Upstream commit a51a0c8d213594bc094cb8e54aad0cb6d7f7b9a6 ]

Similar to commit 714fb87e8bc0 ("ubi: Fix race condition between ubi
device creation and udev"), we should make the volume active before
registering it.

Signed-off-by: Clay McClure <clay@daemons.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>

diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
index 812ecf2d253a3d32b660f19bc51ea0ec1943ef37..9965acb8aca0013c9b3fc2a4854c72499bad4844 100644 (file)
--- a/drivers/mtd/ubi/vmt.c
+++ b/drivers/mtd/ubi/vmt.c
@@ -310,6 +310,12 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
                        vol->last_eb_bytes = vol->usable_leb_size;
        }
 
+       /* Make volume "available" before it becomes accessible via sysfs */
+       spin_lock(&ubi->volumes_lock);
+       ubi->volumes[vol_id] = vol;
+       ubi->vol_count += 1;
+       spin_unlock(&ubi->volumes_lock);
+
        /* Register character device for the volume */
        cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
        vol->cdev.owner = THIS_MODULE;
@@ -352,11 +358,6 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
        if (err)
                goto out_sysfs;
 
-       spin_lock(&ubi->volumes_lock);
-       ubi->volumes[vol_id] = vol;
-       ubi->vol_count += 1;
-       spin_unlock(&ubi->volumes_lock);
-
        ubi_volume_notify(ubi, vol, UBI_VOLUME_ADDED);
        self_check_volumes(ubi);
        return err;
@@ -376,6 +377,10 @@ out_sysfs:
 out_cdev:
        cdev_del(&vol->cdev);
 out_mapping:
+       spin_lock(&ubi->volumes_lock);
+       ubi->volumes[vol_id] = NULL;
+       ubi->vol_count -= 1;
+       spin_unlock(&ubi->volumes_lock);
        if (do_free)
                kfree(vol->eba_tbl);
 out_acc: