The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From a51a0c8d213594bc094cb8e54aad0cb6d7f7b9a6 Mon Sep 17 00:00:00 2001
From: Clay McClure <clay@xxxxxxxxxxx>
Date: Thu, 21 Sep 2017 19:01:34 -0700
Subject: [PATCH] ubi: Fix race condition between ubi volume creation and udev
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@xxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Richard Weinberger <richard@xxxxxx>
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
index 85237cf661f9..3fd8d7ff7a02 100644
--- a/drivers/mtd/ubi/vmt.c
+++ b/drivers/mtd/ubi/vmt.c
@@ -270,6 +270,12 @@ 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;
@@ -298,11 +304,6 @@ 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;
@@ -315,6 +316,10 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
*/
cdev_device_del(&vol->cdev, &vol->dev);
out_mapping:
+ spin_lock(&ubi->volumes_lock);
+ ubi->volumes[vol_id] = NULL;
+ ubi->vol_count -= 1;
+ spin_unlock(&ubi->volumes_lock);
ubi_eba_destroy_table(eba_tbl);
out_acc:
spin_lock(&ubi->volumes_lock);