Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 848 insertions, 0 deletions

diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
new file mode 100644
index 000000000..50192b95b
--- /dev/null
+++ b/drivers/mtd/ubi/vmt.c
@@ -0,0 +1,848 @@
+// 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 =
+	__ATTR(reserved_ebs, S_IRUGO, vol_attribute_show, NULL);
+static struct device_attribute attr_vol_type =
+	__ATTR(type, S_IRUGO, vol_attribute_show, NULL);
+static struct device_attribute attr_vol_name =
+	__ATTR(name, S_IRUGO, vol_attribute_show, NULL);
+static struct device_attribute attr_vol_corrupted =
+	__ATTR(corrupted, S_IRUGO, vol_attribute_show, NULL);
+static struct device_attribute attr_vol_alignment =
+	__ATTR(alignment, S_IRUGO, vol_attribute_show, NULL);
+static struct device_attribute attr_vol_usable_eb_size =
+	__ATTR(usable_eb_size, S_IRUGO, vol_attribute_show, NULL);
+static struct device_attribute attr_vol_data_bytes =
+	__ATTR(data_bytes, S_IRUGO, vol_attribute_show, NULL);
+static struct device_attribute attr_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;
+ *
+ * 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)
+{
+	int ret;
+	struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
+	struct ubi_device *ubi = vol->ubi;
+
+	spin_lock(&ubi->volumes_lock);
+	if (!ubi->volumes[vol->vol_id] || ubi->volumes[vol->vol_id]->is_dead) {
+		spin_unlock(&ubi->volumes_lock);
+		return -ENODEV;
+	}
+	/* Take a reference to prevent volume removal */
+	vol->ref_count += 1;
+	spin_unlock(&ubi->volumes_lock);
+
+	if (attr == &attr_vol_reserved_ebs)
+		ret = sprintf(buf, "%d\n", vol->reserved_pebs);
+	else if (attr == &attr_vol_type) {
+		const char *tp;
+
+		if (vol->vol_type == UBI_DYNAMIC_VOLUME)
+			tp = "dynamic";
+		else
+			tp = "static";
+		ret = sprintf(buf, "%s\n", tp);
+	} else if (attr == &attr_vol_name)
+		ret = sprintf(buf, "%s\n", vol->name);
+	else if (attr == &attr_vol_corrupted)
+		ret = sprintf(buf, "%d\n", vol->corrupted);
+	else if (attr == &attr_vol_alignment)
+		ret = sprintf(buf, "%d\n", vol->alignment);
+	else if (attr == &attr_vol_usable_eb_size)
+		ret = sprintf(buf, "%d\n", vol->usable_leb_size);
+	else if (attr == &attr_vol_data_bytes)
+		ret = sprintf(buf, "%lld\n", vol->used_bytes);
+	else if (attr == &attr_vol_upd_marker)
+		ret = sprintf(buf, "%d\n", vol->upd_marker);
+	else
+		/* This must be a bug */
+		ret = -EINVAL;
+
+	/* We've done the operation, drop volume and UBI device references */
+	spin_lock(&ubi->volumes_lock);
+	vol->ref_count -= 1;
+	ubi_assert(vol->ref_count >= 0);
+	spin_unlock(&ubi->volumes_lock);
+	return ret;
+}
+
+static struct attribute *volume_dev_attrs[] = {
+	&attr_vol_reserved_ebs.attr,
+	&attr_vol_type.attr,
+	&attr_vol_name.attr,
+	&attr_vol_corrupted.attr,
+	&attr_vol_alignment.attr,
+	&attr_vol_usable_eb_size.attr,
+	&attr_vol_data_bytes.attr,
+	&attr_vol_upd_marker.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(volume_dev);
+
+/* Release method for volume devices */
+static void vol_release(struct device *dev)
+{
+	struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
+
+	ubi_eba_replace_table(vol, NULL);
+	ubi_fastmap_destroy_checkmap(vol);
+	kfree(vol);
+}
+
+static struct fwnode_handle *find_volume_fwnode(struct ubi_volume *vol)
+{
+	struct fwnode_handle *fw_vols, *fw_vol;
+	const char *volname;
+	u32 volid;
+
+	fw_vols = device_get_named_child_node(vol->dev.parent->parent, "volumes");
+	if (!fw_vols)
+		return NULL;
+
+	fwnode_for_each_child_node(fw_vols, fw_vol) {
+		if (!fwnode_property_read_string(fw_vol, "volname", &volname) &&
+		    strncmp(volname, vol->name, vol->name_len))
+			continue;
+
+		if (!fwnode_property_read_u32(fw_vol, "volid", &volid) &&
+		    vol->vol_id != volid)
+			continue;
+
+		fwnode_handle_put(fw_vols);
+		return fw_vol;
+	}
+	fwnode_handle_put(fw_vols);
+
+	return NULL;
+}
+
+/**
+ * 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)
+{
+	int i, err, vol_id = req->vol_id;
+	struct ubi_volume *vol;
+	struct ubi_vtbl_record vtbl_rec;
+	struct ubi_eba_table *eba_tbl = NULL;
+
+	if (ubi->ro_mode)
+		return -EROFS;
+
+	vol = kzalloc_obj(struct ubi_volume);
+	if (!vol)
+		return -ENOMEM;
+
+	device_initialize(&vol->dev);
+	vol->dev.release = vol_release;
+	vol->dev.parent = &ubi->dev;
+	vol->dev.class = &ubi_class;
+	vol->dev.groups = volume_dev_groups;
+
+	if (req->flags & UBI_VOL_SKIP_CRC_CHECK_FLG)
+		vol->skip_check = 1;
+
+	spin_lock(&ubi->volumes_lock);
+	if (vol_id == UBI_VOL_NUM_AUTO) {
+		/* Find unused volume ID */
+		dbg_gen("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) {
+			ubi_err(ubi, "out of volume IDs");
+			err = -ENFILE;
+			goto out_unlock;
+		}
+		req->vol_id = vol_id;
+	}
+
+	dbg_gen("create device %d, volume %d, %llu bytes, type %d, name %s",
+		ubi->ubi_num, 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]) {
+		ubi_err(ubi, "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]->is_dead &&
+		    ubi->volumes[i]->name_len == req->name_len &&
+		    !strcmp(ubi->volumes[i]->name, req->name)) {
+			ubi_err(ubi, "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;
+	vol->reserved_pebs = div_u64(req->bytes + vol->usable_leb_size - 1,
+				     vol->usable_leb_size);
+
+	/* Reserve physical eraseblocks */
+	if (vol->reserved_pebs > ubi->avail_pebs) {
+		ubi_err(ubi, "not enough PEBs, only %d available",
+			ubi->avail_pebs);
+		if (ubi->corr_peb_count)
+			ubi_err(ubi, "%d PEBs are corrupted and not used",
+				ubi->corr_peb_count);
+		err = -ENOSPC;
+		goto out_unlock;
+	}
+	ubi->avail_pebs -= vol->reserved_pebs;
+	ubi->rsvd_pebs += vol->reserved_pebs;
+	spin_unlock(&ubi->volumes_lock);
+
+	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);
+	vol->ubi = ubi;
+	device_set_node(&vol->dev, find_volume_fwnode(vol));
+
+	/*
+	 * Finish all pending erases because there may be some LEBs belonging
+	 * to the same volume ID.
+	 */
+	err = ubi_wl_flush(ubi, vol_id, UBI_ALL);
+	if (err)
+		goto out_acc;
+
+	eba_tbl = ubi_eba_create_table(vol, vol->reserved_pebs);
+	if (IS_ERR(eba_tbl)) {
+		err = PTR_ERR(eba_tbl);
+		goto out_acc;
+	}
+
+	ubi_eba_replace_table(vol, eba_tbl);
+
+	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
+		vol->used_ebs = vol->reserved_pebs;
+		vol->last_eb_bytes = vol->usable_leb_size;
+		vol->used_bytes =
+			(long long)vol->used_ebs * vol->usable_leb_size;
+	} else {
+		vol->used_ebs = div_u64_rem(vol->used_bytes,
+					    vol->usable_leb_size,
+					    &vol->last_eb_bytes);
+		if (vol->last_eb_bytes != 0)
+			vol->used_ebs += 1;
+		else
+			vol->last_eb_bytes = vol->usable_leb_size;
+	}
+
+	/* Make volume "available" before it becomes accessible via sysfs */
+	spin_lock(&ubi->volumes_lock);
+	ubi->volumes[vol_id] = vol;
+	ubi->vol_count += 1;
+	spin_unlock(&ubi->volumes_lock);
+
+	/* Register character device for the volume */
+	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
+	vol->cdev.owner = THIS_MODULE;
+
+	vol->dev.devt = MKDEV(MAJOR(ubi->cdev.dev), vol_id + 1);
+	dev_set_name(&vol->dev, "%s_%d", ubi->ubi_name, vol->vol_id);
+	err = cdev_device_add(&vol->cdev, &vol->dev);
+	if (err) {
+		ubi_err(ubi, "cannot add device");
+		goto out_mapping;
+	}
+
+	/* Fill volume table record */
+	memset(&vtbl_rec, 0, sizeof(struct ubi_vtbl_record));
+	vtbl_rec.reserved_pebs = cpu_to_be32(vol->reserved_pebs);
+	vtbl_rec.alignment     = cpu_to_be32(vol->alignment);
+	vtbl_rec.data_pad      = cpu_to_be32(vol->data_pad);
+	vtbl_rec.name_len      = cpu_to_be16(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;
+
+	if (vol->skip_check)
+		vtbl_rec.flags |= UBI_VTBL_SKIP_CRC_CHECK_FLG;
+
+	memcpy(vtbl_rec.name, vol->name, vol->name_len);
+
+	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
+	if (err)
+		goto out_sysfs;
+
+	ubi_volume_notify(ubi, vol, UBI_VOLUME_ADDED);
+	self_check_volumes(ubi);
+	return err;
+
+out_sysfs:
+	/*
+	 * We have registered our device, we should not free the volume
+	 * description object in this function in case of an error - it is
+	 * freed by the release function.
+	 */
+	cdev_device_del(&vol->cdev, &vol->dev);
+out_mapping:
+	spin_lock(&ubi->volumes_lock);
+	ubi->volumes[vol_id] = NULL;
+	ubi->vol_count -= 1;
+	spin_unlock(&ubi->volumes_lock);
+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);
+	put_device(&vol->dev);
+	ubi_err(ubi, "cannot create volume %d, error %d", vol_id, err);
+	return err;
+}
+
+/**
+ * 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)
+{
+	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_gen("remove device %d, volume %d", ubi->ubi_num, vol_id);
+	ubi_assert(desc->mode == UBI_EXCLUSIVE);
+	ubi_assert(vol == ubi->volumes[vol_id]);
+
+	if (ubi->ro_mode)
+		return -EROFS;
+
+	spin_lock(&ubi->volumes_lock);
+	if (vol->ref_count > 1) {
+		/*
+		 * The volume is busy, probably someone is reading one of its
+		 * sysfs files.
+		 */
+		err = -EBUSY;
+		goto out_unlock;
+	}
+
+	/*
+	 * Mark volume as dead at this point to prevent that anyone
+	 * can take a reference to the volume from now on.
+	 * This is necessary as we have to release the spinlock before
+	 * calling ubi_volume_notify.
+	 */
+	vol->is_dead = true;
+	spin_unlock(&ubi->volumes_lock);
+
+	ubi_volume_notify(ubi, vol, UBI_VOLUME_SHUTDOWN);
+
+	spin_lock(&ubi->volumes_lock);
+	ubi->volumes[vol_id] = NULL;
+	spin_unlock(&ubi->volumes_lock);
+
+	if (!no_vtbl) {
+		err = ubi_change_vtbl_record(ubi, vol_id, NULL);
+		if (err)
+			goto out_err;
+	}
+
+	for (i = 0; i < vol->reserved_pebs; i++) {
+		err = ubi_eba_unmap_leb(ubi, vol, i);
+		if (err)
+			goto out_err;
+	}
+
+	cdev_device_del(&vol->cdev, &vol->dev);
+	put_device(&vol->dev);
+
+	spin_lock(&ubi->volumes_lock);
+	ubi->rsvd_pebs -= reserved_pebs;
+	ubi->avail_pebs += reserved_pebs;
+	ubi_update_reserved(ubi);
+	ubi->vol_count -= 1;
+	spin_unlock(&ubi->volumes_lock);
+
+	ubi_volume_notify(ubi, vol, UBI_VOLUME_REMOVED);
+	if (!no_vtbl)
+		self_check_volumes(ubi);
+
+	return 0;
+
+out_err:
+	ubi_err(ubi, "cannot remove volume %d, error %d", vol_id, err);
+	spin_lock(&ubi->volumes_lock);
+	ubi->volumes[vol_id] = vol;
+out_unlock:
+	spin_unlock(&ubi->volumes_lock);
+	return err;
+}
+
+/**
+ * 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)
+{
+	int i, err, pebs;
+	struct ubi_volume *vol = desc->vol;
+	struct ubi_device *ubi = vol->ubi;
+	struct ubi_vtbl_record vtbl_rec;
+	struct ubi_eba_table *new_eba_tbl = NULL;
+	struct ubi_eba_table *old_eba_tbl = NULL;
+	int vol_id = vol->vol_id;
+
+	if (ubi->ro_mode)
+		return -EROFS;
+
+	dbg_gen("re-size device %d, volume %d to from %d to %d PEBs",
+		ubi->ubi_num, vol_id, vol->reserved_pebs, reserved_pebs);
+
+	if (vol->vol_type == UBI_STATIC_VOLUME &&
+	    reserved_pebs < vol->used_ebs) {
+		ubi_err(ubi, "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_eba_tbl = ubi_eba_create_table(vol, reserved_pebs);
+	if (IS_ERR(new_eba_tbl))
+		return PTR_ERR(new_eba_tbl);
+
+	spin_lock(&ubi->volumes_lock);
+	if (vol->ref_count > 1) {
+		spin_unlock(&ubi->volumes_lock);
+		err = -EBUSY;
+		goto out_free;
+	}
+	spin_unlock(&ubi->volumes_lock);
+
+	/* Reserve physical eraseblocks */
+	pebs = reserved_pebs - vol->reserved_pebs;
+	if (pebs > 0) {
+		spin_lock(&ubi->volumes_lock);
+		if (pebs > ubi->avail_pebs) {
+			ubi_err(ubi, "not enough PEBs: requested %d, available %d",
+				pebs, ubi->avail_pebs);
+			if (ubi->corr_peb_count)
+				ubi_err(ubi, "%d PEBs are corrupted and not used",
+					ubi->corr_peb_count);
+			spin_unlock(&ubi->volumes_lock);
+			err = -ENOSPC;
+			goto out_free;
+		}
+
+		ubi->avail_pebs -= pebs;
+		ubi->rsvd_pebs += pebs;
+		ubi_eba_copy_table(vol, new_eba_tbl, vol->reserved_pebs);
+		old_eba_tbl = vol->eba_tbl;
+		vol->eba_tbl = new_eba_tbl;
+		vol->reserved_pebs = reserved_pebs;
+		spin_unlock(&ubi->volumes_lock);
+	}
+
+	if (pebs < 0) {
+		for (i = 0; i < -pebs; i++) {
+			err = ubi_eba_unmap_leb(ubi, vol, reserved_pebs + i);
+			if (err)
+				goto out_free;
+		}
+		spin_lock(&ubi->volumes_lock);
+		ubi->rsvd_pebs += pebs;
+		ubi->avail_pebs -= pebs;
+		ubi_update_reserved(ubi);
+		ubi_eba_copy_table(vol, new_eba_tbl, reserved_pebs);
+		old_eba_tbl = vol->eba_tbl;
+		vol->eba_tbl = new_eba_tbl;
+		vol->reserved_pebs = reserved_pebs;
+		spin_unlock(&ubi->volumes_lock);
+	}
+
+	/*
+	 * When we shrink a volume we have to flush all pending (erase) work.
+	 * Otherwise it can happen that upon next attach UBI finds a LEB with
+	 * lnum > highest_lnum and refuses to attach.
+	 */
+	if (pebs < 0) {
+		err = ubi_wl_flush(ubi, vol_id, UBI_ALL);
+		if (err)
+			goto out_acc;
+	}
+
+	/* Change volume table record */
+	vtbl_rec = ubi->vtbl[vol_id];
+	vtbl_rec.reserved_pebs = cpu_to_be32(reserved_pebs);
+	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
+	if (err)
+		goto out_acc;
+
+	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
+		vol->used_ebs = reserved_pebs;
+		vol->last_eb_bytes = vol->usable_leb_size;
+		vol->used_bytes =
+			(long long)vol->used_ebs * vol->usable_leb_size;
+	}
+
+	/* destroy old table */
+	ubi_eba_destroy_table(old_eba_tbl);
+	ubi_volume_notify(ubi, vol, UBI_VOLUME_RESIZED);
+	self_check_volumes(ubi);
+	return err;
+
+out_acc:
+	spin_lock(&ubi->volumes_lock);
+	vol->reserved_pebs = reserved_pebs - pebs;
+	ubi->rsvd_pebs -= pebs;
+	ubi->avail_pebs += pebs;
+	if (pebs > 0)
+		ubi_eba_copy_table(vol, old_eba_tbl, vol->reserved_pebs);
+	else
+		ubi_eba_copy_table(vol, old_eba_tbl, reserved_pebs);
+	vol->eba_tbl = old_eba_tbl;
+	spin_unlock(&ubi->volumes_lock);
+out_free:
+	ubi_eba_destroy_table(new_eba_tbl);
+	return err;
+}
+
+/**
+ * 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)
+{
+	int err;
+	struct ubi_rename_entry *re;
+
+	err = ubi_vtbl_rename_volumes(ubi, rename_list);
+	if (err)
+		return err;
+
+	list_for_each_entry(re, rename_list, list) {
+		if (re->remove) {
+			err = ubi_remove_volume(re->desc, 1);
+			if (err)
+				break;
+		} else {
+			struct ubi_volume *vol = re->desc->vol;
+
+			spin_lock(&ubi->volumes_lock);
+			vol->name_len = re->new_name_len;
+			memcpy(vol->name, re->new_name, re->new_name_len + 1);
+			spin_unlock(&ubi->volumes_lock);
+			ubi_volume_notify(ubi, vol, UBI_VOLUME_RENAMED);
+		}
+	}
+
+	if (!err)
+		self_check_volumes(ubi);
+	return err;
+}
+
+/**
+ * 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)
+{
+	int err, vol_id = vol->vol_id;
+	dev_t dev;
+
+	dbg_gen("add volume %d", vol_id);
+
+	/* Register character device for the volume */
+	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
+	vol->cdev.owner = THIS_MODULE;
+	dev = MKDEV(MAJOR(ubi->cdev.dev), vol->vol_id + 1);
+	err = cdev_add(&vol->cdev, dev, 1);
+	if (err) {
+		ubi_err(ubi, "cannot add character device for volume %d, error %d",
+			vol_id, err);
+		vol_release(&vol->dev);
+		return err;
+	}
+
+	vol->dev.release = vol_release;
+	vol->dev.parent = &ubi->dev;
+	vol->dev.devt = dev;
+	vol->dev.class = &ubi_class;
+	vol->dev.groups = volume_dev_groups;
+	dev_set_name(&vol->dev, "%s_%d", ubi->ubi_name, vol->vol_id);
+	device_set_node(&vol->dev, find_volume_fwnode(vol));
+	err = device_register(&vol->dev);
+	if (err) {
+		cdev_del(&vol->cdev);
+		put_device(&vol->dev);
+		return err;
+	}
+
+	self_check_volumes(ubi);
+	return err;
+}
+
+/**
+ * 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)
+{
+	dbg_gen("free volume %d", vol->vol_id);
+
+	ubi->volumes[vol->vol_id] = NULL;
+	cdev_del(&vol->cdev);
+	device_unregister(&vol->dev);
+}
+
+/**
+ * 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)
+{
+	int idx = vol_id2idx(ubi, vol_id);
+	int reserved_pebs, alignment, data_pad, vol_type, name_len, upd_marker;
+	const struct ubi_volume *vol;
+	long long n;
+	const char *name;
+
+	spin_lock(&ubi->volumes_lock);
+	reserved_pebs = be32_to_cpu(ubi->vtbl[vol_id].reserved_pebs);
+	vol = ubi->volumes[idx];
+
+	if (!vol) {
+		if (reserved_pebs) {
+			ubi_err(ubi, "no volume info, but volume exists");
+			goto fail;
+		}
+		spin_unlock(&ubi->volumes_lock);
+		return 0;
+	}
+
+	if (vol->reserved_pebs < 0 || vol->alignment < 0 || vol->data_pad < 0 ||
+	    vol->name_len < 0) {
+		ubi_err(ubi, "negative values");
+		goto fail;
+	}
+	if (vol->alignment > ubi->leb_size || vol->alignment == 0) {
+		ubi_err(ubi, "bad alignment");
+		goto fail;
+	}
+
+	n = vol->alignment & (ubi->min_io_size - 1);
+	if (vol->alignment != 1 && n) {
+		ubi_err(ubi, "alignment is not multiple of min I/O unit");
+		goto fail;
+	}
+
+	n = ubi->leb_size % vol->alignment;
+	if (vol->data_pad != n) {
+		ubi_err(ubi, "bad data_pad, has to be %lld", n);
+		goto fail;
+	}
+
+	if (vol->vol_type != UBI_DYNAMIC_VOLUME &&
+	    vol->vol_type != UBI_STATIC_VOLUME) {
+		ubi_err(ubi, "bad vol_type");
+		goto fail;
+	}
+
+	if (vol->upd_marker && vol->corrupted) {
+		ubi_err(ubi, "update marker and corrupted simultaneously");
+		goto fail;
+	}
+
+	if (vol->reserved_pebs > ubi->good_peb_count) {
+		ubi_err(ubi, "too large reserved_pebs");
+		goto fail;
+	}
+
+	n = ubi->leb_size - vol->data_pad;
+	if (vol->usable_leb_size != ubi->leb_size - vol->data_pad) {
+		ubi_err(ubi, "bad usable_leb_size, has to be %lld", n);
+		goto fail;
+	}
+
+	if (vol->name_len > UBI_VOL_NAME_MAX) {
+		ubi_err(ubi, "too long volume name, max is %d",
+			UBI_VOL_NAME_MAX);
+		goto fail;
+	}
+
+	n = strnlen(vol->name, vol->name_len + 1);
+	if (n != vol->name_len) {
+		ubi_err(ubi, "bad name_len %lld", n);
+		goto fail;
+	}
+
+	n = (long long)vol->used_ebs * vol->usable_leb_size;
+	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
+		if (vol->corrupted) {
+			ubi_err(ubi, "corrupted dynamic volume");
+			goto fail;
+		}
+		if (vol->used_ebs != vol->reserved_pebs) {
+			ubi_err(ubi, "bad used_ebs");
+			goto fail;
+		}
+		if (vol->last_eb_bytes != vol->usable_leb_size) {
+			ubi_err(ubi, "bad last_eb_bytes");
+			goto fail;
+		}
+		if (vol->used_bytes != n) {
+			ubi_err(ubi, "bad used_bytes");
+			goto fail;
+		}
+
+		if (vol->skip_check) {
+			ubi_err(ubi, "bad skip_check");
+			goto fail;
+		}
+	} else {
+		if (vol->used_ebs < 0 || vol->used_ebs > vol->reserved_pebs) {
+			ubi_err(ubi, "bad used_ebs");
+			goto fail;
+		}
+		if (vol->last_eb_bytes < 0 ||
+		    vol->last_eb_bytes > vol->usable_leb_size) {
+			ubi_err(ubi, "bad last_eb_bytes");
+			goto fail;
+		}
+		if (vol->used_bytes < 0 || vol->used_bytes > n ||
+		    vol->used_bytes < n - vol->usable_leb_size) {
+			ubi_err(ubi, "bad used_bytes");
+			goto fail;
+		}
+	}
+
+	alignment  = be32_to_cpu(ubi->vtbl[vol_id].alignment);
+	data_pad   = be32_to_cpu(ubi->vtbl[vol_id].data_pad);
+	name_len   = be16_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(ubi, "volume info is different");
+		goto fail;
+	}
+
+	spin_unlock(&ubi->volumes_lock);
+	return 0;
+
+fail:
+	ubi_err(ubi, "self-check failed for volume %d", vol_id);
+	if (vol)
+		ubi_dump_vol_info(vol);
+	ubi_dump_vtbl_record(&ubi->vtbl[vol_id], vol_id);
+	dump_stack();
+	spin_unlock(&ubi->volumes_lock);
+	return -EINVAL;
+}
+
+/**
+ * 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)
+{
+	int i, err = 0;
+
+	if (!ubi_dbg_chk_gen(ubi))
+		return 0;
+
+	for (i = 0; i < ubi->vtbl_slots; i++) {
+		err = self_check_volume(ubi, i);
+		if (err)
+			break;
+	}
+
+	return err;
+}