Message-Id: <20070323164402.8958.997.sendpatchset@localhost.localdomain>
Date:	Fri, 23 Mar 2007 18:44:02 +0200
From:	Artem Bityutskiy <dedekind@...radead.org>
To:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Cc:	Frank Haverkamp <haver@...t.ibm.com>,
	David Woodhouse <dwmw2@...radead.org>,
	Josh Boyer <jwboyer@...ux.vnet.ibm.com>,
	Artem Bityutskiy <dedekind@...radead.org>
Subject: [PATCH 13/20 take 4] UBI: volume management functionality

diff -auNrp tmp-from/drivers/mtd/ubi/vmt.c tmp-to/drivers/mtd/ubi/vmt.c
--- tmp-from/drivers/mtd/ubi/vmt.c	1970-01-01 02:00:00.000000000 +0200
+++ tmp-to/drivers/mtd/ubi/vmt.c	2007-03-23 18:20:02.000000000 +0200
@@ -0,0 +1,811 @@
+/*
+ * Copyright (c) International Business Machines Corp., 2006
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation;  either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Artem Bityutskiy (Битюцкий Артём)
+ */
+
+/*
+ * This file contains implementation of volume creation, deletion, updating and
+ * resizing.
+ */
+
+#include <linux/err.h>
+#include <asm/div64.h>
+#include "ubi.h"
+
+#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
+static void paranoid_check_volumes(struct ubi_device *ubi);
+#else
+#define paranoid_check_volumes(ubi)
+#endif
+
+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 vol_reserved_ebs =
+	__ATTR(reserved_ebs, S_IRUGO, vol_attribute_show, NULL);
+static struct device_attribute vol_type =
+	__ATTR(type, S_IRUGO, vol_attribute_show, NULL);
+static struct device_attribute vol_name =
+	__ATTR(name, S_IRUGO, vol_attribute_show, NULL);
+static struct device_attribute vol_corrupted =
+	__ATTR(corrupted, S_IRUGO, vol_attribute_show, NULL);
+static struct device_attribute vol_alignment =
+	__ATTR(alignment, S_IRUGO, vol_attribute_show, NULL);
+static struct device_attribute vol_usable_eb_size =
+	__ATTR(usable_eb_size, S_IRUGO, vol_attribute_show, NULL);
+static struct device_attribute vol_data_bytes =
+	__ATTR(data_bytes, S_IRUGO, vol_attribute_show, NULL);
+static struct device_attribute vol_upd_marker =
+	__ATTR(upd_marker, S_IRUGO, vol_attribute_show, NULL);
+
+/*
+ * "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;
+ *
+ * What we want to do in a situation like that is to return error when the file
+ * is read. This is done by means of the 'removed' flag and the 'vol_lock' of
+ * the UBI volume description object.
+ */
+static ssize_t vol_attribute_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	int ret;
+	struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
+
+	spin_lock(&vol->ubi->volumes_lock);
+	if (vol->removed) {
+		spin_unlock(&vol->ubi->volumes_lock);
+		return -ENODEV;
+	}
+	if (attr == &vol_reserved_ebs)
+		ret = sprintf(buf, "%d\n", vol->reserved_pebs);
+	else if (attr == &vol_type) {
+		const char *tp;
+		tp = vol->vol_type == UBI_DYNAMIC_VOLUME ? "dynamic" : "static";
+		ret = sprintf(buf, "%s\n", tp);
+	} else if (attr == &vol_name)
+		ret = sprintf(buf, "%s\n", vol->name);
+	else if (attr == &vol_corrupted)
+		ret = sprintf(buf, "%d\n", vol->corrupted);
+	else if (attr == &vol_alignment)
+		ret = sprintf(buf, "%d\n", vol->alignment);
+	else if (attr == &vol_usable_eb_size) {
+		ret = sprintf(buf, "%d\n", vol->usable_leb_size);
+	} else if (attr == &vol_data_bytes)
+		ret = sprintf(buf, "%lld\n", vol->used_bytes);
+	else if (attr == &vol_upd_marker)
+		ret = sprintf(buf, "%d\n", vol->upd_marker);
+	else
+		BUG();
+	spin_unlock(&vol->ubi->volumes_lock);
+	return ret;
+}
+
+/* Release method for volume devices */
+static void vol_release(struct device *dev)
+{
+	struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
+	ubi_assert(vol->removed);
+	kfree(vol);
+}
+
+/**
+ * volume_sysfs_init - initialize sysfs for new volume.
+ * @ubi: UBI device description object
+ * @vol: volume description object
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ *
+ * Note, this function does not free allocated resources in case of failure -
+ * the caller does it. This is because this would cause release() here and the
+ * caller would oops.
+ */
+static int volume_sysfs_init(struct ubi_device *ubi, struct ubi_volume *vol)
+{
+	int err;
+
+	err = device_create_file(&vol->dev, &vol_reserved_ebs);
+	if (err)
+		return err;
+	err = device_create_file(&vol->dev, &vol_type);
+	if (err)
+		return err;
+	err = device_create_file(&vol->dev, &vol_name);
+	if (err)
+		return err;
+	err = device_create_file(&vol->dev, &vol_corrupted);
+	if (err)
+		return err;
+	err = device_create_file(&vol->dev, &vol_alignment);
+	if (err)
+		return err;
+	err = device_create_file(&vol->dev, &vol_usable_eb_size);
+	if (err)
+		return err;
+	err = device_create_file(&vol->dev, &vol_data_bytes);
+	if (err)
+		return err;
+	err = device_create_file(&vol->dev, &vol_upd_marker);
+	if (err)
+		return err;
+	return 0;
+}
+
+/**
+ * volume_sysfs_close - close sysfs for a volume.
+ * @vol: volume description object
+ */
+static void volume_sysfs_close(struct ubi_volume *vol)
+{
+	device_remove_file(&vol->dev, &vol_upd_marker);
+	device_remove_file(&vol->dev, &vol_data_bytes);
+	device_remove_file(&vol->dev, &vol_usable_eb_size);
+	device_remove_file(&vol->dev, &vol_alignment);
+	device_remove_file(&vol->dev, &vol_corrupted);
+	device_remove_file(&vol->dev, &vol_name);
+	device_remove_file(&vol->dev, &vol_type);
+	device_remove_file(&vol->dev, &vol_reserved_ebs);
+	device_unregister(&vol->dev);
+}
+
+/**
+ * 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 assigne 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.
+ */
+int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
+{
+	int i, err, vol_id = req->vol_id;
+	struct ubi_volume *vol;
+	struct ubi_vtbl_record vtbl_rec;
+	uint64_t bytes;
+
+	if (ubi->ro_mode)
+		return -EROFS;
+
+	vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL);
+	if (!vol)
+		return -ENOMEM;
+
+	spin_lock(&ubi->volumes_lock);
+
+	if (vol_id == UBI_VOL_NUM_AUTO) {
+ 		/* Find unused volume ID */
+		dbg_msg("search for vacant volume ID");
+		for (i = 0; i < ubi->vtbl_slots; i++)
+			if (!ubi->volumes[i]) {
+				vol_id = i;
+				break;
+			}
+
+		if (vol_id == UBI_VOL_NUM_AUTO) {
+			dbg_err("out of volume IDs");
+			err = -ENOSPC;
+			goto out_unlock;
+		}
+		req->vol_id = vol_id;
+	}
+
+	dbg_msg("volume ID %d, %llu bytes, type %d, name %s",
+		vol_id, (unsigned long long)req->bytes,
+		(int)req->vol_type, req->name);
+
+	/* Ensure that this volume does not exist */
+	err = -EEXIST;
+	if (ubi->volumes[vol_id]) {
+		dbg_err("volume %d already exists", vol_id);
+		goto out_unlock;
+	}
+
+	/* Ensure that the name is unique */
+	for (i = 0; i < ubi->vtbl_slots; i++)
+		if (ubi->volumes[i] &&
+		    ubi->volumes[i]->name_len == req->name_len &&
+		    strcmp(ubi->volumes[i]->name, req->name) == 0) {
+			dbg_err("volume \"%s\" exists (ID %d)", req->name, i);
+			goto out_unlock;
+		}
+
+        /* Calculate how many eraseblocks are requested */
+	vol->usable_leb_size = ubi->leb_size - ubi->leb_size % req->alignment;
+	bytes = req->bytes;
+	if (do_div(bytes, vol->usable_leb_size))
+		vol->reserved_pebs = 1;
+	vol->reserved_pebs += bytes;
+
+	/* Reserve physical eraseblocks */
+	if (vol->reserved_pebs > ubi->avail_pebs) {
+		dbg_err("not enough PEBs, only %d available", ubi->avail_pebs);
+		spin_unlock(&ubi->volumes_lock);
+		err = -ENOSPC;
+		goto out_unlock;
+	}
+	ubi->avail_pebs -= vol->reserved_pebs;
+	ubi->rsvd_pebs += vol->reserved_pebs;
+
+	vol->vol_id    = vol_id;
+	vol->alignment = req->alignment;
+	vol->data_pad  = ubi->leb_size % vol->alignment;
+	vol->vol_type  = req->vol_type;
+	vol->name_len  = req->name_len;
+	memcpy(vol->name, req->name, vol->name_len + 1);
+	vol->exclusive = 1;
+	vol->ubi = ubi;
+	ubi->volumes[vol_id] = vol;
+	spin_unlock(&ubi->volumes_lock);
+
+	/*
+	 * Finish all pending erases because there may be some LEBs belonging
+	 * to the same volume ID.
+	 */
+	err = ubi_wl_flush(ubi);
+	if (err)
+		goto out_acc;
+
+	vol->eba_tbl = kmalloc(vol->reserved_pebs * sizeof(int), GFP_KERNEL);
+	if (!vol->eba_tbl) {
+		err = -ENOMEM;
+		goto out_acc;
+	}
+
+	for (i = 0; i < vol->reserved_pebs; i++)
+		vol->eba_tbl[i] = UBI_LEB_UNMAPPED;
+
+	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
+		vol->used_ebs = vol->reserved_pebs;
+		vol->last_eb_bytes = vol->usable_leb_size;
+		vol->used_bytes = vol->used_ebs * vol->usable_leb_size;
+	} else {
+		bytes = vol->used_bytes;
+		vol->last_eb_bytes = do_div(bytes, vol->usable_leb_size);
+		vol->used_ebs = bytes;
+		if (vol->last_eb_bytes)
+			vol->used_ebs += 1;
+		else
+			vol->last_eb_bytes = vol->usable_leb_size;
+	}
+
+	/* Register character device for the volume */
+	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
+	vol->cdev.owner = THIS_MODULE;
+	err = cdev_add(&vol->cdev, MKDEV(ubi->major, vol_id + 1), 1);
+	if (err) {
+		ubi_err("cannot add character device for volume %d", vol_id);
+		goto out_mapping;
+	}
+
+	err = ubi_create_gluebi(ubi, vol);
+	if (err)
+		goto out_cdev;
+
+	vol->dev.release = vol_release;
+	vol->dev.parent = &ubi->dev;
+	vol->dev.devt = MKDEV(ubi->major, vol->vol_id + 1);
+	vol->dev.class = ubi_class;
+	sprintf(&vol->dev.bus_id[0], "%s_%d", ubi->ubi_name, vol->vol_id);
+	err = device_register(&vol->dev);
+	if (err)
+		goto out_gluebi;
+
+	err = volume_sysfs_init(ubi, vol);
+	if (err)
+		goto out_sysfs;
+
+	/* Fill volume table record */
+	memset(&vtbl_rec, 0, sizeof(struct ubi_vtbl_record));
+	vtbl_rec.reserved_pebs = cpu_to_ubi32(vol->reserved_pebs);
+	vtbl_rec.alignment     = cpu_to_ubi32(vol->alignment);
+	vtbl_rec.data_pad      = cpu_to_ubi32(vol->data_pad);
+	vtbl_rec.name_len      = cpu_to_ubi16(vol->name_len);
+	if (vol->vol_type == UBI_DYNAMIC_VOLUME)
+		vtbl_rec.vol_type = UBI_VID_DYNAMIC;
+	else
+		vtbl_rec.vol_type = UBI_VID_STATIC;
+	memcpy(vtbl_rec.name, vol->name, vol->name_len + 1);
+
+	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
+	if (err)
+		goto out_sysfs;
+
+	spin_lock(&ubi->volumes_lock);
+	ubi->vol_count += 1;
+	vol->exclusive = 0;
+	spin_unlock(&ubi->volumes_lock);
+
+	paranoid_check_volumes(ubi);
+	return 0;
+
+out_gluebi:
+	err = ubi_destroy_gluebi(vol);
+out_cdev:
+	cdev_del(&vol->cdev);
+out_mapping:
+	kfree(vol->eba_tbl);
+out_acc:
+	spin_lock(&ubi->volumes_lock);
+	ubi->rsvd_pebs -= vol->reserved_pebs;
+	ubi->avail_pebs += vol->reserved_pebs;
+out_unlock:
+	spin_unlock(&ubi->volumes_lock);
+	kfree(vol);
+	return err;
+
+	/*
+	 * We are registered, so @vol is destroyed in the release function and
+	 * we have to de-initialize differently.
+	 */
+out_sysfs:
+	err = ubi_destroy_gluebi(vol);
+	cdev_del(&vol->cdev);
+	kfree(vol->eba_tbl);
+	spin_lock(&ubi->volumes_lock);
+	ubi->rsvd_pebs -= vol->reserved_pebs;
+	ubi->avail_pebs += vol->reserved_pebs;
+	spin_unlock(&ubi->volumes_lock);
+	volume_sysfs_close(vol);
+	return err;
+}
+
+/**
+ * ubi_remove_volume - remove volume.
+ * @desc: volume descriptor
+ *
+ * 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.
+ */
+int ubi_remove_volume(struct ubi_volume_desc *desc)
+{
+	struct ubi_volume *vol = desc->vol;
+	struct ubi_device *ubi = vol->ubi;
+	int i, err, vol_id = vol->vol_id, reserved_pebs = vol->reserved_pebs;
+
+	dbg_msg("remove UBI volume %d", vol_id);
+	ubi_assert(desc->mode == UBI_EXCLUSIVE);
+	ubi_assert(vol == ubi->volumes[vol_id]);
+
+	if (ubi->ro_mode)
+		return -EROFS;
+
+	err = ubi_destroy_gluebi(vol);
+	if (err)
+		return err;
+
+	err = ubi_change_vtbl_record(ubi, vol_id, NULL);
+	if (err)
+		return err;
+
+	for (i = 0; i < vol->reserved_pebs; i++) {
+		err = ubi_eba_unmap_leb(ubi, vol_id, i);
+		if (err)
+			return err;
+	}
+
+	spin_lock(&ubi->volumes_lock);
+	vol->removed = 1;
+	ubi->volumes[vol_id] = NULL;
+	spin_unlock(&ubi->volumes_lock);
+
+	kfree(vol->eba_tbl);
+	vol->eba_tbl = NULL;
+	cdev_del(&vol->cdev);
+	volume_sysfs_close(vol);
+	kfree(desc);
+
+	spin_lock(&ubi->volumes_lock);
+	ubi->rsvd_pebs -= reserved_pebs;
+	ubi->avail_pebs += reserved_pebs;
+	i = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs;
+	if (i > 0) {
+		i = ubi->avail_pebs >= i ? i : ubi->avail_pebs;
+		ubi->avail_pebs -= i;
+		ubi->rsvd_pebs += i;
+		ubi->beb_rsvd_pebs += i;
+		if (i > 0)
+			ubi_msg("reserve more %d PEBs", i);
+	}
+	ubi->vol_count -= 1;
+	spin_unlock(&ubi->volumes_lock);
+
+	paranoid_check_volumes(ubi);
+	module_put(THIS_MODULE);
+	return 0;
+}
+
+/**
+ * ubi_resize_volume - re-size volume.
+ * @desc: volume descriptor
+ * @reserved_pebs: new size in physical eraseblocks
+ *
+ * This function returns zero in case of success, and a negative error code in
+ * case of failure.
+ */
+int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs)
+{
+	int i, err, pebs, *new_mapping;
+	struct ubi_volume *vol = desc->vol;
+	struct ubi_device *ubi = vol->ubi;
+	struct ubi_vtbl_record vtbl_rec;
+	int vol_id = vol->vol_id;
+
+	if (ubi->ro_mode)
+		return -EROFS;
+
+	dbg_msg("re-size volume %d to from %d to %d PEBs",
+		vol_id, vol->reserved_pebs, reserved_pebs);
+	ubi_assert(desc->mode == UBI_EXCLUSIVE);
+	ubi_assert(vol == ubi->volumes[vol_id]);
+
+	if (vol->vol_type == UBI_STATIC_VOLUME &&
+	    reserved_pebs < vol->used_ebs) {
+		dbg_err("too small size %d, %d LEBs contain data",
+			reserved_pebs, vol->used_ebs);
+		return -EINVAL;
+	}
+
+	/* If the size is the same, we have nothing to do */
+	if (reserved_pebs == vol->reserved_pebs)
+		return 0;
+
+	new_mapping = kmalloc(reserved_pebs * sizeof(int), GFP_KERNEL);
+	if (!new_mapping)
+		return -ENOMEM;
+
+	for (i = 0; i < reserved_pebs; i++)
+		new_mapping[i] = UBI_LEB_UNMAPPED;
+
+	/* Reserve physical eraseblocks */
+	pebs = reserved_pebs - vol->reserved_pebs;
+	if (pebs > 0) {
+		spin_lock(&ubi->volumes_lock);
+		if (pebs > ubi->avail_pebs) {
+			dbg_err("not enough PEBs: requested %d, available %d",
+				pebs, ubi->avail_pebs);
+			spin_unlock(&ubi->volumes_lock);
+			err = -ENOSPC;
+			goto out_free;
+		}
+		ubi->avail_pebs -= pebs;
+		ubi->rsvd_pebs += pebs;
+		for (i = 0; i < vol->reserved_pebs; i++)
+			new_mapping[i] = vol->eba_tbl[i];
+		kfree(vol->eba_tbl);
+		vol->eba_tbl = new_mapping;
+		spin_unlock(&ubi->volumes_lock);
+	}
+
+	/* Change volume table record */
+	memcpy(&vtbl_rec, &ubi->vtbl[vol_id], sizeof(struct ubi_vtbl_record));
+	vtbl_rec.reserved_pebs = cpu_to_ubi32(reserved_pebs);
+	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
+	if (err)
+		goto out_acc;
+
+	if (pebs < 0) {
+		for (i = 0; i < -pebs; i++) {
+			err = ubi_eba_unmap_leb(ubi, vol_id, reserved_pebs + i);
+			if (err)
+				goto out_acc;
+		}
+		spin_lock(&ubi->volumes_lock);
+		ubi->rsvd_pebs += pebs;
+		ubi->avail_pebs -= pebs;
+		pebs = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs;
+		if (pebs > 0) {
+			pebs = ubi->avail_pebs >= pebs ? pebs : ubi->avail_pebs;
+			ubi->avail_pebs -= pebs;
+			ubi->rsvd_pebs += pebs;
+			ubi->beb_rsvd_pebs += pebs;
+			if (pebs > 0)
+				ubi_msg("reserve more %d PEBs", pebs);
+		}
+		for (i = 0; i < reserved_pebs; i++)
+			new_mapping[i] = vol->eba_tbl[i];
+		kfree(vol->eba_tbl);
+		vol->eba_tbl = new_mapping;
+		spin_unlock(&ubi->volumes_lock);
+	}
+
+	vol->reserved_pebs = reserved_pebs;
+	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
+		vol->used_ebs = reserved_pebs;
+		vol->last_eb_bytes = vol->usable_leb_size;
+		vol->used_bytes = vol->used_ebs * vol->usable_leb_size;
+	}
+
+	paranoid_check_volumes(ubi);
+	return 0;
+
+out_acc:
+	if (pebs > 0) {
+		spin_lock(&ubi->volumes_lock);
+		ubi->rsvd_pebs -= pebs;
+		ubi->avail_pebs += pebs;
+		spin_unlock(&ubi->volumes_lock);
+	}
+out_free:
+	kfree(new_mapping);
+	return err;
+}
+
+/**
+ * ubi_add_volume - add volume.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ *
+ * This function adds an existin volume and initializes all its data
+ * structures. Returnes zero in case of success and a negative error code in
+ * case of failure.
+ */
+int ubi_add_volume(struct ubi_device *ubi, int vol_id)
+{
+	int err;
+	struct ubi_volume *vol = ubi->volumes[vol_id];
+
+	dbg_msg("add volume %d", vol_id);
+	ubi_dbg_dump_vol_info(vol);
+	ubi_assert(vol);
+
+	/* Register character device for the volume */
+	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
+	vol->cdev.owner = THIS_MODULE;
+	err = cdev_add(&vol->cdev, MKDEV(ubi->major, vol->vol_id + 1), 1);
+	if (err) {
+		ubi_err("cannot add character device for volume %d", vol_id);
+		return err;
+	}
+
+	err = ubi_create_gluebi(ubi, vol);
+	if (err)
+		goto out_cdev;
+
+	vol->dev.release = vol_release;
+	vol->dev.parent = &ubi->dev;
+	vol->dev.devt = MKDEV(ubi->major, vol->vol_id + 1);
+	vol->dev.class = ubi_class;
+	sprintf(&vol->dev.bus_id[0], "%s_%d", ubi->ubi_name, vol->vol_id);
+	err = device_register(&vol->dev);
+	if (err)
+		goto out_gluebi;
+
+	err = volume_sysfs_init(ubi, vol);
+	if (err) {
+		cdev_del(&vol->cdev);
+		err = ubi_destroy_gluebi(vol);
+		volume_sysfs_close(vol);
+		return err;
+	}
+
+	paranoid_check_volumes(ubi);
+	return 0;
+
+out_gluebi:
+	err = ubi_destroy_gluebi(vol);
+out_cdev:
+	cdev_del(&vol->cdev);
+	return err;
+}
+
+/**
+ * ubi_free_volume - free volume.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ *
+ * This function frees all resources for volume @vol_id but does not remove it.
+ * Used only when the UBI device is detached.
+ */
+void ubi_free_volume(struct ubi_device *ubi, int vol_id)
+{
+	int err;
+	struct ubi_volume *vol = ubi->volumes[vol_id];
+
+	dbg_msg("free volume %d", vol_id);
+	ubi_assert(vol);
+
+	vol->removed = 1;
+	err = ubi_destroy_gluebi(vol);
+	ubi->volumes[vol_id] = NULL;
+	cdev_del(&vol->cdev);
+	volume_sysfs_close(vol);
+}
+
+#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
+
+/**
+ * paranoid_check_volume - check volume information.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ */
+static void paranoid_check_volume(const struct ubi_device *ubi, int vol_id)
+{
+	int idx = vol_id2idx(ubi, vol_id);
+	int reserved_pebs, alignment, data_pad, vol_type, name_len, upd_marker;
+	const struct ubi_volume *vol = ubi->volumes[idx];
+	long long n;
+	const char *name;
+
+	reserved_pebs = ubi32_to_cpu(ubi->vtbl[vol_id].reserved_pebs);
+
+	if (!vol) {
+		if (reserved_pebs) {
+			ubi_err("no volume info, but volume exists");
+			goto fail;
+		}
+		return;
+	}
+
+	if (unlikely(vol->reserved_pebs < 0 || vol->alignment < 0 ||
+		     vol->data_pad < 0 || vol->name_len < 0)) {
+		ubi_err("negative values");
+		goto fail;
+	}
+	if (unlikely(vol->alignment > ubi->leb_size ||
+		     vol->alignment == 0)) {
+		ubi_err("bad alignment");
+		goto fail;
+	}
+
+	n = vol->alignment % ubi->min_io_size;
+	if (vol->alignment != 1 && unlikely(n)) {
+		ubi_err("alignment is not multiple of min I/O unit");
+		goto fail;
+	}
+
+	n = ubi->leb_size % vol->alignment;
+	if (unlikely(vol->data_pad != n)) {
+		ubi_err("bad data_pad, has to be %lld", n);
+		goto fail;
+	}
+
+	if (unlikely(vol->vol_type != UBI_DYNAMIC_VOLUME &&
+		     vol->vol_type != UBI_STATIC_VOLUME)) {
+		ubi_err("bad vol_type");
+		goto fail;
+	}
+
+	if (unlikely(vol->upd_marker != 0 && vol->upd_marker != 1)) {
+		ubi_err("bad upd_marker");
+		goto fail;
+	}
+
+	if (unlikely(vol->upd_marker && vol->corrupted)) {
+		dbg_err("update marker and corrupted simultaneously");
+		goto fail;
+	}
+
+	if (unlikely(vol->reserved_pebs > ubi->good_peb_count)) {
+		ubi_err("too large reserved_pebs");
+		goto fail;
+	}
+
+	n = ubi->leb_size - vol->data_pad;
+	if (unlikely(vol->usable_leb_size != ubi->leb_size - vol->data_pad)) {
+		ubi_err("bad usable_leb_size, has to be %lld", n);
+		goto fail;
+	}
+
+	if (unlikely(vol->name_len > UBI_VOL_NAME_MAX)) {
+		ubi_err("too long volume name, max is %d", UBI_VOL_NAME_MAX);
+		goto fail;
+	}
+
+	if (unlikely(!vol->name)) {
+		ubi_err("NULL volume name");
+		goto fail;
+	}
+
+	n = strnlen(vol->name, vol->name_len + 1);
+	if (unlikely(n != vol->name_len)) {
+		ubi_err("bad name_len %lld", n);
+		goto fail;
+	}
+
+	n = vol->used_ebs * vol->usable_leb_size;
+	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
+		if (unlikely(vol->corrupted != 0)) {
+			ubi_err("corrupted dynamic volume");
+			goto fail;
+		}
+		if (unlikely(vol->used_ebs != vol->reserved_pebs)) {
+			ubi_err("bad used_ebs");
+			goto fail;
+		}
+		if (unlikely(vol->last_eb_bytes != vol->usable_leb_size)) {
+			ubi_err("bad last_eb_bytes");
+			goto fail;
+		}
+		if (unlikely(vol->used_bytes != n)) {
+			ubi_err("bad used_bytes");
+			goto fail;
+		}
+	} else {
+		if (unlikely(vol->corrupted != 0 && vol->corrupted != 1)) {
+			ubi_err("bad corrupted");
+			goto fail;
+		}
+		if (unlikely(vol->used_ebs < 0 ||
+			     vol->used_ebs > vol->reserved_pebs)) {
+			ubi_err("bad used_ebs");
+			goto fail;
+		}
+		if (unlikely(vol->last_eb_bytes < 0 ||
+			     vol->last_eb_bytes > vol->usable_leb_size)) {
+			ubi_err("bad last_eb_bytes");
+			goto fail;
+		}
+		if (unlikely(vol->used_bytes < 0 || vol->used_bytes > n ||
+			     vol->used_bytes < n - vol->usable_leb_size)) {
+			ubi_err("bad used_bytes");
+			goto fail;
+		}
+	}
+
+	alignment  = ubi32_to_cpu(ubi->vtbl[vol_id].alignment);
+	data_pad   = ubi32_to_cpu(ubi->vtbl[vol_id].data_pad);
+	name_len   = ubi16_to_cpu(ubi->vtbl[vol_id].name_len);
+	upd_marker = ubi->vtbl[vol_id].upd_marker;
+	name       = &ubi->vtbl[vol_id].name[0];
+	if (ubi->vtbl[vol_id].vol_type == UBI_VID_DYNAMIC)
+		vol_type = UBI_DYNAMIC_VOLUME;
+	else
+		vol_type = UBI_STATIC_VOLUME;
+
+	if (alignment != vol->alignment || data_pad != vol->data_pad ||
+	    upd_marker != vol->upd_marker || vol_type != vol->vol_type ||
+	    name_len!= vol->name_len || strncmp(name, vol->name, name_len)) {
+		ubi_err("volume info is different");
+		goto fail;
+	}
+
+	return;
+
+fail:
+	ubi_err("paranoid check failed");
+	ubi_dbg_dump_vol_info(vol);
+	ubi_dbg_dump_vtbl_record(&ubi->vtbl[vol_id], vol_id);
+	BUG();
+}
+
+/**
+ * paranoid_check_volumes - check information about all volumes.
+ * @ubi: UBI device description object
+ */
+static void paranoid_check_volumes(struct ubi_device *ubi)
+{
+	int i;
+
+	mutex_lock(&ubi->vtbl_mutex);
+	spin_lock(&ubi->volumes_lock);
+	for (i = 0; i < ubi->vtbl_slots; i++)
+		paranoid_check_volume(ubi, i);
+	spin_unlock(&ubi->volumes_lock);
+	mutex_unlock(&ubi->vtbl_mutex);
+}
+#endif
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