UBI: kill debugging buffer

This patch kills the 'ubi->dbg_peb_buf' debugging buffer and the
associated mutex, because all users of this buffer are now gone.
We are killing this buffer because we are going to switch to
dynamic debugging control, just like in UBIFS, which means that
CONFIG_MTD_UBI_DEBUG_PARANOID will be removed. In this case we'd
end up always allocating 'ubi->dbg_peb_buf', which is rather large
(128KiB or more), and this would be wasteful. Thus, we are just
killing it.

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

drivers/mtd/ubi/build.c

@@ -939,13 +939,6 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
 	if (!ubi->peb_buf2)
 		goto out_free;
 
-#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
-	mutex_init(&ubi->dbg_buf_mutex);
-	ubi->dbg_peb_buf = vmalloc(ubi->peb_size);
-	if (!ubi->dbg_peb_buf)
-		goto out_free;
-#endif
-
 	err = attach_by_scanning(ubi);
 	if (err) {
 		dbg_err("failed to attach by scanning, error %d", err);
@@ -1011,9 +1004,6 @@ out_detach:
 out_free:
 	vfree(ubi->peb_buf1);
 	vfree(ubi->peb_buf2);
-#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
-	vfree(ubi->dbg_peb_buf);
-#endif
 	if (ref)
 		put_device(&ubi->dev);
 	else
@@ -1084,9 +1074,6 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
 	put_mtd_device(ubi->mtd);
 	vfree(ubi->peb_buf1);
 	vfree(ubi->peb_buf2);
-#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
-	vfree(ubi->dbg_peb_buf);
-#endif
 	ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
 	put_device(&ubi->dev);
 	return 0;

drivers/mtd/ubi/ubi.h

@@ -388,8 +388,6 @@ struct ubi_wl_entry;
  * @peb_buf2: another buffer of PEB size used for different purposes
  * @buf_mutex: protects @peb_buf1 and @peb_buf2
  * @ckvol_mutex: serializes static volume checking when opening
- * @dbg_peb_buf: buffer of PEB size used for debugging
- * @dbg_buf_mutex: protects @dbg_peb_buf
  */
 struct ubi_device {
 	struct cdev cdev;
@@ -471,10 +469,6 @@ struct ubi_device {
 	void *peb_buf2;
 	struct mutex buf_mutex;
 	struct mutex ckvol_mutex;
-#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
-	void *dbg_peb_buf;
-	struct mutex dbg_buf_mutex;
-#endif
 };
 
 extern struct kmem_cache *ubi_wl_entry_slab;