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Commit daef3dd1 authored by Richard Weinberger's avatar Richard Weinberger
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UBI: Fastmap: Add self check to detect absent PEBs 



This self check allows Fastmap to detect absent PEBs while
writing a new fastmap to the MTD device.
It will help to find implementation issues in Fastmap.

Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
parent ee59ba8b

drivers/mtd/ubi/fastmap.c

+84 −2
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2012 Linutronix GmbH

 * Copyright (c) 2014 sigma star gmbh

 * Author: Richard Weinberger <richard@nod.at>

 *

 * This program is free software; you can redistribute it and/or modify
@@ -16,6 +17,69 @@ 
#include <linux/crc32.h>

#include "ubi.h"



/**

 * init_seen - allocate memory for used for debugging.

 * @ubi: UBI device description object

 */

static inline int *init_seen(struct ubi_device *ubi)

{

	int *ret;



	if (!ubi_dbg_chk_fastmap(ubi))

		return NULL;



	ret = kcalloc(ubi->peb_count, sizeof(int), GFP_KERNEL);

	if (!ret)

		return ERR_PTR(-ENOMEM);



	return ret;

}



/**

 * free_seen - free the seen logic integer array.

 * @seen: integer array of @ubi->peb_count size

 */

static inline void free_seen(int *seen)

{

	kfree(seen);

}



/**

 * set_seen - mark a PEB as seen.

 * @ubi: UBI device description object

 * @pnum: The PEB to be makred as seen

 * @seen: integer array of @ubi->peb_count size

 */

static inline void set_seen(struct ubi_device *ubi, int pnum, int *seen)

{

	if (!ubi_dbg_chk_fastmap(ubi) || !seen)

		return;



	seen[pnum] = 1;

}



/**

 * self_check_seen - check whether all PEB have been seen by fastmap.

 * @ubi: UBI device description object

 * @seen: integer array of @ubi->peb_count size

 */

static int self_check_seen(struct ubi_device *ubi, int *seen)

{

	int pnum, ret = 0;



	if (!ubi_dbg_chk_fastmap(ubi) || !seen)

		return 0;



	for (pnum = 0; pnum < ubi->peb_count; pnum++) {

		if (!seen[pnum] && ubi->lookuptbl[pnum]) {

			ubi_err(ubi, "self-check failed for PEB %d, fastmap didn't see it", pnum);

			ret = -EINVAL;

		}

	}



	return ret;

}



/**

 * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.

 * @ubi: UBI device description object
@@ -1030,6 +1094,7 @@ static int ubi_write_fastmap(struct ubi_device *ubi, 
	struct ubi_work *ubi_wrk;

	int ret, i, j, free_peb_count, used_peb_count, vol_count;

	int scrub_peb_count, erase_peb_count;

	int *seen_pebs = NULL;



	fm_raw = ubi->fm_buf;

	memset(ubi->fm_buf, 0, ubi->fm_size);
@@ -1046,6 +1111,12 @@ static int ubi_write_fastmap(struct ubi_device *ubi, 
		goto out_kfree;

	}



	seen_pebs = init_seen(ubi);

	if (IS_ERR(seen_pebs)) {

		ret = PTR_ERR(seen_pebs);

		goto out_kfree;

	}



	spin_lock(&ubi->volumes_lock);

	spin_lock(&ubi->wl_lock);
@@ -1076,8 +1147,10 @@ static int ubi_write_fastmap(struct ubi_device *ubi, 
	fmpl1->size = cpu_to_be16(ubi->fm_pool.size);

	fmpl1->max_size = cpu_to_be16(ubi->fm_pool.max_size);



	for (i = 0; i < ubi->fm_pool.size; i++)

	for (i = 0; i < ubi->fm_pool.size; i++) {

		fmpl1->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);

		set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);

	}



	fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);

	fm_pos += sizeof(*fmpl2);
@@ -1085,14 +1158,17 @@ static int ubi_write_fastmap(struct ubi_device *ubi, 
	fmpl2->size = cpu_to_be16(ubi->fm_wl_pool.size);

	fmpl2->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);



	for (i = 0; i < ubi->fm_wl_pool.size; i++)

	for (i = 0; i < ubi->fm_wl_pool.size; i++) {

		fmpl2->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);

		set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);

	}



	for (node = rb_first(&ubi->free); node; node = rb_next(node)) {

		wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);

		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);



		fec->pnum = cpu_to_be32(wl_e->pnum);

		set_seen(ubi, wl_e->pnum, seen_pebs);

		fec->ec = cpu_to_be32(wl_e->ec);



		free_peb_count++;
@@ -1106,6 +1182,7 @@ static int ubi_write_fastmap(struct ubi_device *ubi, 
		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);



		fec->pnum = cpu_to_be32(wl_e->pnum);

		set_seen(ubi, wl_e->pnum, seen_pebs);

		fec->ec = cpu_to_be32(wl_e->ec);



		used_peb_count++;
@@ -1132,6 +1209,7 @@ static int ubi_write_fastmap(struct ubi_device *ubi, 
		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);



		fec->pnum = cpu_to_be32(wl_e->pnum);

		set_seen(ubi, wl_e->pnum, seen_pebs);

		fec->ec = cpu_to_be32(wl_e->ec);



		scrub_peb_count++;
@@ -1149,6 +1227,7 @@ static int ubi_write_fastmap(struct ubi_device *ubi, 
			fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);



			fec->pnum = cpu_to_be32(wl_e->pnum);

			set_seen(ubi, wl_e->pnum, seen_pebs);

			fec->ec = cpu_to_be32(wl_e->ec);



			erase_peb_count++;
@@ -1208,6 +1287,7 @@ static int ubi_write_fastmap(struct ubi_device *ubi, 


	for (i = 0; i < new_fm->used_blocks; i++) {

		fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);

		set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);

		fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);

	}
@@ -1241,11 +1321,13 @@ static int ubi_write_fastmap(struct ubi_device *ubi, 
	ubi_assert(new_fm);

	ubi->fm = new_fm;



	ret = self_check_seen(ubi, seen_pebs);

	dbg_bld("fastmap written!");



out_kfree:

	ubi_free_vid_hdr(ubi, avhdr);

	ubi_free_vid_hdr(ubi, dvhdr);

	free_seen(seen_pebs);

out:

	return ret;

}