ubi: Fix race condition between ubi device creation and udev

commit 714fb87e8bc05ff78255afc0dca981e8c5242785 upstream.

Install the UBI device object before we arm sysfs.
Otherwise udev tries to read sysfs attributes before UBI is ready and
udev rules will not match.

Signed-off-by: Iosif Harutyunov <iharutyunov@sonicwall.com>
[rw: massaged commit message]
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 1f9c363..5c87c94 100644 (file)
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -974,6 +974,9 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
                        goto out_detach;
        }
 
                        goto out_detach;
        }
 

+       /* Make device "available" before it becomes accessible via sysfs */
+       ubi_devices[ubi_num] = ubi;
+

        err = uif_init(ubi, &ref);
        if (err)
                goto out_detach;
        err = uif_init(ubi, &ref);
        if (err)
                goto out_detach;


@@ -1017,7 +1020,6 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
        wake_up_process(ubi->bgt_thread);
        spin_unlock(&ubi->wl_lock);
 
        wake_up_process(ubi->bgt_thread);
        spin_unlock(&ubi->wl_lock);
 

-       ubi_devices[ubi_num] = ubi;

        ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
        return ubi_num;
 
        ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
        return ubi_num;
 


@@ -1028,6 +1030,7 @@ out_uif:
        ubi_assert(ref);
        uif_close(ubi);
 out_detach:
        ubi_assert(ref);
        uif_close(ubi);
 out_detach:

+       ubi_devices[ubi_num] = NULL;

        ubi_wl_close(ubi);
        free_internal_volumes(ubi);
        vfree(ubi->vtbl);
        ubi_wl_close(ubi);
        free_internal_volumes(ubi);
        vfree(ubi->vtbl);