scan.c

基于linux-2.6.28的mtd驱动

	INIT_LIST_HEAD(&si->corr);
	INIT_LIST_HEAD(&si->free);
	INIT_LIST_HEAD(&si->erase);
	INIT_LIST_HEAD(&si->alien);
	si->volumes = RB_ROOT;
	si->is_empty = 1;

	err = -ENOMEM;
	ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
	if (!ech)
		goto out_si;

	vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
	if (!vidh)
		goto out_ech;

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

		dbg_gen("process PEB %d", pnum);
		err = process_eb(ubi, si, pnum);
		if (err < 0)
			goto out_vidh;
	}

	dbg_msg("scanning is finished");

	/* Calculate mean erase counter */
	if (si->ec_count) {
		do_div(si->ec_sum, si->ec_count);
		si->mean_ec = si->ec_sum;
	}

	if (si->is_empty)
		ubi_msg("empty MTD device detected");

	/*
	 * In case of unknown erase counter we use the mean erase counter
	 * value.
	 */
	ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
		ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
			if (seb->ec == UBI_SCAN_UNKNOWN_EC)
				seb->ec = si->mean_ec;
	}

	list_for_each_entry(seb, &si->free, u.list) {
		if (seb->ec == UBI_SCAN_UNKNOWN_EC)
			seb->ec = si->mean_ec;
	}

	list_for_each_entry(seb, &si->corr, u.list)
		if (seb->ec == UBI_SCAN_UNKNOWN_EC)
			seb->ec = si->mean_ec;

	list_for_each_entry(seb, &si->erase, u.list)
		if (seb->ec == UBI_SCAN_UNKNOWN_EC)
			seb->ec = si->mean_ec;

	err = paranoid_check_si(ubi, si);
	if (err) {
		if (err > 0)
			err = -EINVAL;
		goto out_vidh;
	}

	ubi_free_vid_hdr(ubi, vidh);
	kfree(ech);

	return si;

out_vidh:
	ubi_free_vid_hdr(ubi, vidh);
out_ech:
	kfree(ech);
out_si:
	ubi_scan_destroy_si(si);
	return ERR_PTR(err);
}

/**
 * destroy_sv - free the scanning volume information
 * @sv: scanning volume information
 *
 * This function destroys the volume RB-tree (@sv->root) and the scanning
 * volume information.
 */
static void destroy_sv(struct ubi_scan_volume *sv)
{
	struct ubi_scan_leb *seb;
	struct rb_node *this = sv->root.rb_node;

	while (this) {
		if (this->rb_left)
			this = this->rb_left;
		else if (this->rb_right)
			this = this->rb_right;
		else {
			seb = rb_entry(this, struct ubi_scan_leb, u.rb);
			this = rb_parent(this);
			if (this) {
				if (this->rb_left == &seb->u.rb)
					this->rb_left = NULL;
				else
					this->rb_right = NULL;
			}

			kfree(seb);
		}
	}
	kfree(sv);
}

/**
 * ubi_scan_destroy_si - destroy scanning information.
 * @si: scanning information
 */
void ubi_scan_destroy_si(struct ubi_scan_info *si)
{
	struct ubi_scan_leb *seb, *seb_tmp;
	struct ubi_scan_volume *sv;
	struct rb_node *rb;

	list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) {
		list_del(&seb->u.list);
		kfree(seb);
	}
	list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) {
		list_del(&seb->u.list);
		kfree(seb);
	}
	list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) {
		list_del(&seb->u.list);
		kfree(seb);
	}
	list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) {
		list_del(&seb->u.list);
		kfree(seb);
	}

	/* Destroy the volume RB-tree */
	rb = si->volumes.rb_node;
	while (rb) {
		if (rb->rb_left)
			rb = rb->rb_left;
		else if (rb->rb_right)
			rb = rb->rb_right;
		else {
			sv = rb_entry(rb, struct ubi_scan_volume, rb);

			rb = rb_parent(rb);
			if (rb) {
				if (rb->rb_left == &sv->rb)
					rb->rb_left = NULL;
				else
					rb->rb_right = NULL;
			}

			destroy_sv(sv);
		}
	}

	kfree(si);
}

#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID

/**
 * paranoid_check_si - check the scanning information.
 * @ubi: UBI device description object
 * @si: scanning information
 *
 * This function returns zero if the scanning information is all right, %1 if
 * not and a negative error code if an error occurred.
 */
static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si)
{
	int pnum, err, vols_found = 0;
	struct rb_node *rb1, *rb2;
	struct ubi_scan_volume *sv;
	struct ubi_scan_leb *seb, *last_seb;
	uint8_t *buf;

	/*
	 * At first, check that scanning information is OK.
	 */
	ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
		int leb_count = 0;

		cond_resched();

		vols_found += 1;

		if (si->is_empty) {
			ubi_err("bad is_empty flag");
			goto bad_sv;
		}

		if (sv->vol_id < 0 || sv->highest_lnum < 0 ||
		    sv->leb_count < 0 || sv->vol_type < 0 || sv->used_ebs < 0 ||
		    sv->data_pad < 0 || sv->last_data_size < 0) {
			ubi_err("negative values");
			goto bad_sv;
		}

		if (sv->vol_id >= UBI_MAX_VOLUMES &&
		    sv->vol_id < UBI_INTERNAL_VOL_START) {
			ubi_err("bad vol_id");
			goto bad_sv;
		}

		if (sv->vol_id > si->highest_vol_id) {
			ubi_err("highest_vol_id is %d, but vol_id %d is there",
				si->highest_vol_id, sv->vol_id);
			goto out;
		}

		if (sv->vol_type != UBI_DYNAMIC_VOLUME &&
		    sv->vol_type != UBI_STATIC_VOLUME) {
			ubi_err("bad vol_type");
			goto bad_sv;
		}

		if (sv->data_pad > ubi->leb_size / 2) {
			ubi_err("bad data_pad");
			goto bad_sv;
		}

		last_seb = NULL;
		ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
			cond_resched();

			last_seb = seb;
			leb_count += 1;

			if (seb->pnum < 0 || seb->ec < 0) {
				ubi_err("negative values");
				goto bad_seb;
			}

			if (seb->ec < si->min_ec) {
				ubi_err("bad si->min_ec (%d), %d found",
					si->min_ec, seb->ec);
				goto bad_seb;
			}

			if (seb->ec > si->max_ec) {
				ubi_err("bad si->max_ec (%d), %d found",
					si->max_ec, seb->ec);
				goto bad_seb;
			}

			if (seb->pnum >= ubi->peb_count) {
				ubi_err("too high PEB number %d, total PEBs %d",
					seb->pnum, ubi->peb_count);
				goto bad_seb;
			}

			if (sv->vol_type == UBI_STATIC_VOLUME) {
				if (seb->lnum >= sv->used_ebs) {
					ubi_err("bad lnum or used_ebs");
					goto bad_seb;
				}
			} else {
				if (sv->used_ebs != 0) {
					ubi_err("non-zero used_ebs");
					goto bad_seb;
				}
			}

			if (seb->lnum > sv->highest_lnum) {
				ubi_err("incorrect highest_lnum or lnum");
				goto bad_seb;
			}
		}

		if (sv->leb_count != leb_count) {
			ubi_err("bad leb_count, %d objects in the tree",
				leb_count);
			goto bad_sv;
		}

		if (!last_seb)
			continue;

		seb = last_seb;

		if (seb->lnum != sv->highest_lnum) {
			ubi_err("bad highest_lnum");
			goto bad_seb;
		}
	}

	if (vols_found != si->vols_found) {
		ubi_err("bad si->vols_found %d, should be %d",
			si->vols_found, vols_found);
		goto out;
	}

	/* Check that scanning information is correct */
	ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
		last_seb = NULL;
		ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
			int vol_type;

			cond_resched();

			last_seb = seb;

			err = ubi_io_read_vid_hdr(ubi, seb->pnum, vidh, 1);
			if (err && err != UBI_IO_BITFLIPS) {
				ubi_err("VID header is not OK (%d)", err);
				if (err > 0)
					err = -EIO;
				return err;
			}

			vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
				   UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
			if (sv->vol_type != vol_type) {
				ubi_err("bad vol_type");
				goto bad_vid_hdr;
			}

			if (seb->sqnum != be64_to_cpu(vidh->sqnum)) {
				ubi_err("bad sqnum %llu", seb->sqnum);
				goto bad_vid_hdr;
			}

			if (sv->vol_id != be32_to_cpu(vidh->vol_id)) {
				ubi_err("bad vol_id %d", sv->vol_id);
				goto bad_vid_hdr;
			}

			if (sv->compat != vidh->compat) {
				ubi_err("bad compat %d", vidh->compat);
				goto bad_vid_hdr;
			}

			if (seb->lnum != be32_to_cpu(vidh->lnum)) {
				ubi_err("bad lnum %d", seb->lnum);
				goto bad_vid_hdr;
			}

			if (sv->used_ebs != be32_to_cpu(vidh->used_ebs)) {
				ubi_err("bad used_ebs %d", sv->used_ebs);
				goto bad_vid_hdr;
			}

			if (sv->data_pad != be32_to_cpu(vidh->data_pad)) {
				ubi_err("bad data_pad %d", sv->data_pad);
				goto bad_vid_hdr;
			}
		}

		if (!last_seb)
			continue;

		if (sv->highest_lnum != be32_to_cpu(vidh->lnum)) {
			ubi_err("bad highest_lnum %d", sv->highest_lnum);
			goto bad_vid_hdr;
		}

		if (sv->last_data_size != be32_to_cpu(vidh->data_size)) {
			ubi_err("bad last_data_size %d", sv->last_data_size);
			goto bad_vid_hdr;
		}
	}

	/*
	 * Make sure that all the physical eraseblocks are in one of the lists
	 * or trees.
	 */
	buf = kzalloc(ubi->peb_count, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	for (pnum = 0; pnum < ubi->peb_count; pnum++) {
		err = ubi_io_is_bad(ubi, pnum);
		if (err < 0) {
			kfree(buf);
			return err;
		} else if (err)
			buf[pnum] = 1;
	}

	ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb)
		ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
			buf[seb->pnum] = 1;

	list_for_each_entry(seb, &si->free, u.list)
		buf[seb->pnum] = 1;

	list_for_each_entry(seb, &si->corr, u.list)
		buf[seb->pnum] = 1;

	list_for_each_entry(seb, &si->erase, u.list)
		buf[seb->pnum] = 1;

	list_for_each_entry(seb, &si->alien, u.list)
		buf[seb->pnum] = 1;

	err = 0;
	for (pnum = 0; pnum < ubi->peb_count; pnum++)
		if (!buf[pnum]) {
			ubi_err("PEB %d is not referred", pnum);
			err = 1;
		}

	kfree(buf);
	if (err)
		goto out;
	return 0;

bad_seb:
	ubi_err("bad scanning information about LEB %d", seb->lnum);
	ubi_dbg_dump_seb(seb, 0);
	ubi_dbg_dump_sv(sv);
	goto out;

bad_sv:
	ubi_err("bad scanning information about volume %d", sv->vol_id);
	ubi_dbg_dump_sv(sv);
	goto out;

bad_vid_hdr:
	ubi_err("bad scanning information about volume %d", sv->vol_id);
	ubi_dbg_dump_sv(sv);
	ubi_dbg_dump_vid_hdr(vidh);

out:
	ubi_dbg_dump_stack();
	return 1;
}

#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */