linux/drivers/mtd/ubi/vmt.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) International Business Machines Corp., 2006
 *
 * Author: Artem Bityutskiy (Битюцкий Артём)
 */

/*
 * This file contains implementation of volume creation, deletion, updating and
 * resizing.
 */

#include <linux/err.h>
#include <linux/math64.h>
#include <linux/slab.h>
#include <linux/export.h>
#include "ubi.h"

static int self_check_volumes(struct ubi_device *ubi);

static ssize_t vol_attribute_show(struct device *dev,
				  struct device_attribute *attr, char *buf);

/* Device attributes corresponding to files in '/<sysfs>/class/ubi/ubiX_Y' */
static struct device_attribute attr_vol_reserved_ebs = …;
static struct device_attribute attr_vol_type = …;
static struct device_attribute attr_vol_name = …;
static struct device_attribute attr_vol_corrupted = …;
static struct device_attribute attr_vol_alignment = …;
static struct device_attribute attr_vol_usable_eb_size = …;
static struct device_attribute attr_vol_data_bytes = …;
static struct device_attribute attr_vol_upd_marker = …;

/*
 * "Show" method for files in '/<sysfs>/class/ubi/ubiX_Y/'.
 *
 * Consider a situation:
 * A. process 1 opens a sysfs file related to volume Y, say
 *    /<sysfs>/class/ubi/ubiX_Y/reserved_ebs;
 * B. process 2 removes volume Y;
 * C. process 1 starts reading the /<sysfs>/class/ubi/ubiX_Y/reserved_ebs file;
 *
 * In this situation, this function will return %-ENODEV because it will find
 * out that the volume was removed from the @ubi->volumes array.
 */
static ssize_t vol_attribute_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
{ … }

static struct attribute *volume_dev_attrs[] = …;
ATTRIBUTE_GROUPS(…);

/* Release method for volume devices */
static void vol_release(struct device *dev)
{ … }

static struct fwnode_handle *find_volume_fwnode(struct ubi_volume *vol)
{ … }

/**
 * ubi_create_volume - create volume.
 * @ubi: UBI device description object
 * @req: volume creation request
 *
 * This function creates volume described by @req. If @req->vol_id id
 * %UBI_VOL_NUM_AUTO, this function automatically assign ID to the new volume
 * and saves it in @req->vol_id. Returns zero in case of success and a negative
 * error code in case of failure. Note, the caller has to have the
 * @ubi->device_mutex locked.
 */
int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
{ … }

/**
 * ubi_remove_volume - remove volume.
 * @desc: volume descriptor
 * @no_vtbl: do not change volume table if not zero
 *
 * This function removes volume described by @desc. The volume has to be opened
 * in "exclusive" mode. Returns zero in case of success and a negative error
 * code in case of failure. The caller has to have the @ubi->device_mutex
 * locked.
 */
int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl)
{ … }

/**
 * ubi_resize_volume - re-size volume.
 * @desc: volume descriptor
 * @reserved_pebs: new size in physical eraseblocks
 *
 * This function re-sizes the volume and returns zero in case of success, and a
 * negative error code in case of failure. The caller has to have the
 * @ubi->device_mutex locked.
 */
int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs)
{ … }

/**
 * ubi_rename_volumes - re-name UBI volumes.
 * @ubi: UBI device description object
 * @rename_list: list of &struct ubi_rename_entry objects
 *
 * This function re-names or removes volumes specified in the re-name list.
 * Returns zero in case of success and a negative error code in case of
 * failure.
 */
int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list)
{ … }

/**
 * ubi_add_volume - add volume.
 * @ubi: UBI device description object
 * @vol: volume description object
 *
 * This function adds an existing volume and initializes all its data
 * structures. Returns zero in case of success and a negative error code in
 * case of failure.
 */
int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol)
{ … }

/**
 * ubi_free_volume - free volume.
 * @ubi: UBI device description object
 * @vol: volume description object
 *
 * This function frees all resources for volume @vol but does not remove it.
 * Used only when the UBI device is detached.
 */
void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol)
{ … }

/**
 * self_check_volume - check volume information.
 * @ubi: UBI device description object
 * @vol_id: volume ID
 *
 * Returns zero if volume is all right and a negative error code if not.
 */
static int self_check_volume(struct ubi_device *ubi, int vol_id)
{ … }

/**
 * self_check_volumes - check information about all volumes.
 * @ubi: UBI device description object
 *
 * Returns zero if volumes are all right and a negative error code if not.
 */
static int self_check_volumes(struct ubi_device *ubi)
{ … }