UBI: fix and cleanup volume opening functions

This patch fixes error codes of the functions - if the device number
is out of range, -EINVAL should be returned. It also removes unneeded
try_module_get call from the open by name function.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

1 files changed, 25 insertions, 36 deletions

diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c
index 96f5fef5f3fa..9c283768319f 100644
--- a/drivers/mtd/ubi/kapi.c
+++ b/drivers/mtd/ubi/kapi.c
@@ -104,37 +104,32 @@ struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
 
         dbg_msg("open device %d volume %d, mode %d", ubi_num, vol_id, mode);
 
-        err = -ENODEV;
-        if (ubi_num < 0)
-                return ERR_PTR(err);
-
-        ubi = ubi_devices[ubi_num];
+        if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
+                return ERR_PTR(-EINVAL);
 
-        if (!try_module_get(THIS_MODULE))
-                return ERR_PTR(err);
+        if (mode != UBI_READONLY && mode != UBI_READWRITE &&
+            mode != UBI_EXCLUSIVE)
+                return ERR_PTR(-EINVAL);
 
-        if (ubi_num >= UBI_MAX_DEVICES || !ubi)
-                goto out_put;
+        ubi = ubi_devices[ubi_num];
+        if (!ubi)
+                return ERR_PTR(-ENODEV);
 
-        err = -EINVAL;
         if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
-                goto out_put;
-        if (mode != UBI_READONLY && mode != UBI_READWRITE &&
-            mode != UBI_EXCLUSIVE)
-                goto out_put;
+                return ERR_PTR(-EINVAL);
 
         desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL);
-        if (!desc) {
-                err = -ENOMEM;
-                goto out_put;
-        }
+        if (!desc)
+                return ERR_PTR(-ENOMEM);
+
+        err = -ENODEV;
+        if (!try_module_get(THIS_MODULE))
+                goto out_free;
 
         spin_lock(&ubi->volumes_lock);
         vol = ubi->volumes[vol_id];
-        if (!vol) {
-                err = -ENODEV;
+        if (!vol)
                 goto out_unlock;
-        }
 
         err = -EBUSY;
         switch (mode) {
@@ -184,13 +179,14 @@ struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
                 vol->checked = 1;
         }
         mutex_unlock(&ubi->volumes_mutex);
+
         return desc;
 
 out_unlock:
         spin_unlock(&ubi->volumes_lock);
-        kfree(desc);
-out_put:
         module_put(THIS_MODULE);
+out_free:
+        kfree(desc);
         return ERR_PTR(err);
 }
 EXPORT_SYMBOL_GPL(ubi_open_volume);
@@ -207,7 +203,6 @@ struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
                                            int mode)
 {
         int i, vol_id = -1, len;
-        struct ubi_volume_desc *ret;
         struct ubi_device *ubi;
 
         dbg_msg("open volume %s, mode %d", name, mode);
@@ -219,14 +214,12 @@ struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
         if (len > UBI_VOL_NAME_MAX)
                 return ERR_PTR(-EINVAL);
 
-        ret = ERR_PTR(-ENODEV);
-        if (!try_module_get(THIS_MODULE))
-                return ret;
-
-        if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES || !ubi_devices[ubi_num])
-                goto out_put;
+        if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
+                return ERR_PTR(-EINVAL);
 
         ubi = ubi_devices[ubi_num];
+        if (!ubi)
+                return ERR_PTR(-ENODEV);
 
         spin_lock(&ubi->volumes_lock);
         /* Walk all volumes of this UBI device */
@@ -241,13 +234,9 @@ struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
         spin_unlock(&ubi->volumes_lock);
 
         if (vol_id < 0)
-                goto out_put;
-
-        ret = ubi_open_volume(ubi_num, vol_id, mode);
+                return ERR_PTR(-ENODEV);
 
-out_put:
-        module_put(THIS_MODULE);
-        return ret;
+        return ubi_open_volume(ubi_num, vol_id, mode);
 }
 EXPORT_SYMBOL_GPL(ubi_open_volume_nm);