ubifs-utils: Import UBIFS libs from linux kernel

Import UBIFS libs from linux kernel. Next patches will replace ubifs
related source code with implementation of linux kernel, which makes
userspace implementation be same with linux kernel, then fsck.ubifs
can resuse the code.

Notice: lpt.c is modified with [1] applied. ubifs.h and orphan.c are
modified with [2] applied, journal.c is modified with [3] reverted(
because fsck runs in a single thread, so waitqueue is not needed to
be implemented in userspace.).
[1] https://lore.kernel.org/linux-mtd/20231228014112.2836317-13-chengzhihao1@huawei.com/
[2] https://lore.kernel.org/linux-mtd/20240410073751.2522830-1-chengzhihao1@huawei.com/
[3] https://lore.kernel.org/linux-mtd/20240122063103.359501-1-chengzhihao1@huawei.com/

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 1744 insertions, 0 deletions

diff --git a/ubifs-utils/libubifs/dir.c b/ubifs-utils/libubifs/dir.c
new file mode 100644
index 0000000..c77ea57
--- /dev/null
+++ b/ubifs-utils/libubifs/dir.c
@@ -0,0 +1,1744 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ * Copyright (C) 2006, 2007 University of Szeged, Hungary
+ *
+ * Authors: Artem Bityutskiy (Битюцкий Артём)
+ *          Adrian Hunter
+ *          Zoltan Sogor
+ */
+
+/*
+ * This file implements directory operations.
+ *
+ * All FS operations in this file allocate budget before writing anything to the
+ * media. If they fail to allocate it, the error is returned. The only
+ * exceptions are 'ubifs_unlink()' and 'ubifs_rmdir()' which keep working even
+ * if they unable to allocate the budget, because deletion %-ENOSPC failure is
+ * not what users are usually ready to get. UBIFS budgeting subsystem has some
+ * space reserved for these purposes.
+ *
+ * All operations in this file write all inodes which they change straight
+ * away, instead of marking them dirty. For example, 'ubifs_link()' changes
+ * @i_size of the parent inode and writes the parent inode together with the
+ * target inode. This was done to simplify file-system recovery which would
+ * otherwise be very difficult to do. The only exception is rename which marks
+ * the re-named inode dirty (because its @i_ctime is updated) but does not
+ * write it, but just marks it as dirty.
+ */
+
+#include "ubifs.h"
+
+/**
+ * inherit_flags - inherit flags of the parent inode.
+ * @dir: parent inode
+ * @mode: new inode mode flags
+ *
+ * This is a helper function for 'ubifs_new_inode()' which inherits flag of the
+ * parent directory inode @dir. UBIFS inodes inherit the following flags:
+ * o %UBIFS_COMPR_FL, which is useful to switch compression on/of on
+ *   sub-directory basis;
+ * o %UBIFS_SYNC_FL - useful for the same reasons;
+ * o %UBIFS_DIRSYNC_FL - similar, but relevant only to directories.
+ *
+ * This function returns the inherited flags.
+ */
+static int inherit_flags(const struct inode *dir, umode_t mode)
+{
+	int flags;
+	const struct ubifs_inode *ui = ubifs_inode(dir);
+
+	if (!S_ISDIR(dir->i_mode))
+		/*
+		 * The parent is not a directory, which means that an extended
+		 * attribute inode is being created. No flags.
+		 */
+		return 0;
+
+	flags = ui->flags & (UBIFS_COMPR_FL | UBIFS_SYNC_FL | UBIFS_DIRSYNC_FL);
+	if (!S_ISDIR(mode))
+		/* The "DIRSYNC" flag only applies to directories */
+		flags &= ~UBIFS_DIRSYNC_FL;
+	return flags;
+}
+
+/**
+ * ubifs_new_inode - allocate new UBIFS inode object.
+ * @c: UBIFS file-system description object
+ * @dir: parent directory inode
+ * @mode: inode mode flags
+ * @is_xattr: whether the inode is xattr inode
+ *
+ * This function finds an unused inode number, allocates new inode and
+ * initializes it. Non-xattr new inode may be written with xattrs(selinux/
+ * encryption) before writing dentry, which could cause inconsistent problem
+ * when powercut happens between two operations. To deal with it, non-xattr
+ * new inode is initialized with zero-nlink and added into orphan list, caller
+ * should make sure that inode is relinked later, and make sure that orphan
+ * removing and journal writing into an committing atomic operation. Returns
+ * new inode in case of success and an error code in case of failure.
+ */
+struct inode *ubifs_new_inode(struct ubifs_info *c, struct inode *dir,
+			      umode_t mode, bool is_xattr)
+{
+	int err;
+	struct inode *inode;
+	struct ubifs_inode *ui;
+	bool encrypted = false;
+
+	inode = new_inode(c->vfs_sb);
+	ui = ubifs_inode(inode);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	/*
+	 * Set 'S_NOCMTIME' to prevent VFS form updating [mc]time of inodes and
+	 * marking them dirty in file write path (see 'file_update_time()').
+	 * UBIFS has to fully control "clean <-> dirty" transitions of inodes
+	 * to make budgeting work.
+	 */
+	inode->i_flags |= S_NOCMTIME;
+
+	inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
+	simple_inode_init_ts(inode);
+	inode->i_mapping->nrpages = 0;
+
+	if (!is_xattr) {
+		err = fscrypt_prepare_new_inode(dir, inode, &encrypted);
+		if (err) {
+			ubifs_err(c, "fscrypt_prepare_new_inode failed: %i", err);
+			goto out_iput;
+		}
+	}
+
+	switch (mode & S_IFMT) {
+	case S_IFREG:
+		inode->i_mapping->a_ops = &ubifs_file_address_operations;
+		inode->i_op = &ubifs_file_inode_operations;
+		inode->i_fop = &ubifs_file_operations;
+		break;
+	case S_IFDIR:
+		inode->i_op  = &ubifs_dir_inode_operations;
+		inode->i_fop = &ubifs_dir_operations;
+		inode->i_size = ui->ui_size = UBIFS_INO_NODE_SZ;
+		break;
+	case S_IFLNK:
+		inode->i_op = &ubifs_symlink_inode_operations;
+		break;
+	case S_IFSOCK:
+	case S_IFIFO:
+	case S_IFBLK:
+	case S_IFCHR:
+		inode->i_op  = &ubifs_file_inode_operations;
+		break;
+	default:
+		BUG();
+	}
+
+	ui->flags = inherit_flags(dir, mode);
+	ubifs_set_inode_flags(inode);
+	if (S_ISREG(mode))
+		ui->compr_type = c->default_compr;
+	else
+		ui->compr_type = UBIFS_COMPR_NONE;
+	ui->synced_i_size = 0;
+
+	spin_lock(&c->cnt_lock);
+	/* Inode number overflow is currently not supported */
+	if (c->highest_inum >= INUM_WARN_WATERMARK) {
+		if (c->highest_inum >= INUM_WATERMARK) {
+			spin_unlock(&c->cnt_lock);
+			ubifs_err(c, "out of inode numbers");
+			err = -EINVAL;
+			goto out_iput;
+		}
+		ubifs_warn(c, "running out of inode numbers (current %lu, max %u)",
+			   (unsigned long)c->highest_inum, INUM_WATERMARK);
+	}
+
+	inode->i_ino = ++c->highest_inum;
+	/*
+	 * The creation sequence number remains with this inode for its
+	 * lifetime. All nodes for this inode have a greater sequence number,
+	 * and so it is possible to distinguish obsolete nodes belonging to a
+	 * previous incarnation of the same inode number - for example, for the
+	 * purpose of rebuilding the index.
+	 */
+	ui->creat_sqnum = ++c->max_sqnum;
+	spin_unlock(&c->cnt_lock);
+
+	if (!is_xattr) {
+		set_nlink(inode, 0);
+		err = ubifs_add_orphan(c, inode->i_ino);
+		if (err) {
+			ubifs_err(c, "ubifs_add_orphan failed: %i", err);
+			goto out_iput;
+		}
+		down_read(&c->commit_sem);
+		ui->del_cmtno = c->cmt_no;
+		up_read(&c->commit_sem);
+	}
+
+	if (encrypted) {
+		err = fscrypt_set_context(inode, NULL);
+		if (err) {
+			if (!is_xattr) {
+				set_nlink(inode, 1);
+				ubifs_delete_orphan(c, inode->i_ino);
+			}
+			ubifs_err(c, "fscrypt_set_context failed: %i", err);
+			goto out_iput;
+		}
+	}
+
+	return inode;
+
+out_iput:
+	make_bad_inode(inode);
+	iput(inode);
+	return ERR_PTR(err);
+}
+
+static int dbg_check_name(const struct ubifs_info *c,
+			  const struct ubifs_dent_node *dent,
+			  const struct fscrypt_name *nm)
+{
+	if (!dbg_is_chk_gen(c))
+		return 0;
+	if (le16_to_cpu(dent->nlen) != fname_len(nm))
+		return -EINVAL;
+	if (memcmp(dent->name, fname_name(nm), fname_len(nm)))
+		return -EINVAL;
+	return 0;
+}
+
+static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry,
+				   unsigned int flags)
+{
+	int err;
+	union ubifs_key key;
+	struct inode *inode = NULL;
+	struct ubifs_dent_node *dent = NULL;
+	struct ubifs_info *c = dir->i_sb->s_fs_info;
+	struct fscrypt_name nm;
+
+	dbg_gen("'%pd' in dir ino %lu", dentry, dir->i_ino);
+
+	err = fscrypt_prepare_lookup(dir, dentry, &nm);
+	if (err == -ENOENT)
+		return d_splice_alias(NULL, dentry);
+	if (err)
+		return ERR_PTR(err);
+
+	if (fname_len(&nm) > UBIFS_MAX_NLEN) {
+		inode = ERR_PTR(-ENAMETOOLONG);
+		goto done;
+	}
+
+	dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
+	if (!dent) {
+		inode = ERR_PTR(-ENOMEM);
+		goto done;
+	}
+
+	if (fname_name(&nm) == NULL) {
+		if (nm.hash & ~UBIFS_S_KEY_HASH_MASK)
+			goto done; /* ENOENT */
+		dent_key_init_hash(c, &key, dir->i_ino, nm.hash);
+		err = ubifs_tnc_lookup_dh(c, &key, dent, nm.minor_hash);
+	} else {
+		dent_key_init(c, &key, dir->i_ino, &nm);
+		err = ubifs_tnc_lookup_nm(c, &key, dent, &nm);
+	}
+
+	if (err) {
+		if (err == -ENOENT)
+			dbg_gen("not found");
+		else
+			inode = ERR_PTR(err);
+		goto done;
+	}
+
+	if (dbg_check_name(c, dent, &nm)) {
+		inode = ERR_PTR(-EINVAL);
+		goto done;
+	}
+
+	inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum));
+	if (IS_ERR(inode)) {
+		/*
+		 * This should not happen. Probably the file-system needs
+		 * checking.
+		 */
+		err = PTR_ERR(inode);
+		ubifs_err(c, "dead directory entry '%pd', error %d",
+			  dentry, err);
+		ubifs_ro_mode(c, err);
+		goto done;
+	}
+
+	if (IS_ENCRYPTED(dir) &&
+	    (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
+	    !fscrypt_has_permitted_context(dir, inode)) {
+		ubifs_warn(c, "Inconsistent encryption contexts: %lu/%lu",
+			   dir->i_ino, inode->i_ino);
+		iput(inode);
+		inode = ERR_PTR(-EPERM);
+	}
+
+done:
+	kfree(dent);
+	fscrypt_free_filename(&nm);
+	return d_splice_alias(inode, dentry);
+}
+
+static int ubifs_prepare_create(struct inode *dir, struct dentry *dentry,
+				struct fscrypt_name *nm)
+{
+	if (fscrypt_is_nokey_name(dentry))
+		return -ENOKEY;
+
+	return fscrypt_setup_filename(dir, &dentry->d_name, 0, nm);
+}
+
+static int ubifs_create(struct mnt_idmap *idmap, struct inode *dir,
+			struct dentry *dentry, umode_t mode, bool excl)
+{
+	struct inode *inode;
+	struct ubifs_info *c = dir->i_sb->s_fs_info;
+	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
+					.dirtied_ino = 1 };
+	struct ubifs_inode *dir_ui = ubifs_inode(dir);
+	struct fscrypt_name nm;
+	int err, sz_change;
+
+	/*
+	 * Budget request settings: new inode, new direntry, changing the
+	 * parent directory inode.
+	 */
+
+	dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
+		dentry, mode, dir->i_ino);
+
+	err = ubifs_budget_space(c, &req);
+	if (err)
+		return err;
+
+	err = ubifs_prepare_create(dir, dentry, &nm);
+	if (err)
+		goto out_budg;
+
+	sz_change = CALC_DENT_SIZE(fname_len(&nm));
+
+	inode = ubifs_new_inode(c, dir, mode, false);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto out_fname;
+	}
+
+	err = ubifs_init_security(dir, inode, &dentry->d_name);
+	if (err)
+		goto out_inode;
+
+	set_nlink(inode, 1);
+	mutex_lock(&dir_ui->ui_mutex);
+	dir->i_size += sz_change;
+	dir_ui->ui_size = dir->i_size;
+	inode_set_mtime_to_ts(dir,
+			      inode_set_ctime_to_ts(dir, inode_get_ctime(inode)));
+	err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 1);
+	if (err)
+		goto out_cancel;
+	mutex_unlock(&dir_ui->ui_mutex);
+
+	ubifs_release_budget(c, &req);
+	fscrypt_free_filename(&nm);
+	insert_inode_hash(inode);
+	d_instantiate(dentry, inode);
+	return 0;
+
+out_cancel:
+	dir->i_size -= sz_change;
+	dir_ui->ui_size = dir->i_size;
+	mutex_unlock(&dir_ui->ui_mutex);
+	set_nlink(inode, 0);
+out_inode:
+	iput(inode);
+out_fname:
+	fscrypt_free_filename(&nm);
+out_budg:
+	ubifs_release_budget(c, &req);
+	ubifs_err(c, "cannot create regular file, error %d", err);
+	return err;
+}
+
+static struct inode *create_whiteout(struct inode *dir, struct dentry *dentry)
+{
+	int err;
+	umode_t mode = S_IFCHR | WHITEOUT_MODE;
+	struct inode *inode;
+	struct ubifs_info *c = dir->i_sb->s_fs_info;
+
+	/*
+	 * Create an inode('nlink = 1') for whiteout without updating journal,
+	 * let ubifs_jnl_rename() store it on flash to complete rename whiteout
+	 * atomically.
+	 */
+
+	dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
+		dentry, mode, dir->i_ino);
+
+	inode = ubifs_new_inode(c, dir, mode, false);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto out_free;
+	}
+
+	init_special_inode(inode, inode->i_mode, WHITEOUT_DEV);
+	ubifs_assert(c, inode->i_op == &ubifs_file_inode_operations);
+
+	err = ubifs_init_security(dir, inode, &dentry->d_name);
+	if (err)
+		goto out_inode;
+
+	/* The dir size is updated by do_rename. */
+	insert_inode_hash(inode);
+
+	return inode;
+
+out_inode:
+	iput(inode);
+out_free:
+	ubifs_err(c, "cannot create whiteout file, error %d", err);
+	return ERR_PTR(err);
+}
+
+/**
+ * lock_2_inodes - a wrapper for locking two UBIFS inodes.
+ * @inode1: first inode
+ * @inode2: second inode
+ *
+ * We do not implement any tricks to guarantee strict lock ordering, because
+ * VFS has already done it for us on the @i_mutex. So this is just a simple
+ * wrapper function.
+ */
+static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
+{
+	mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
+	mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
+}
+
+/**
+ * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes.
+ * @inode1: first inode
+ * @inode2: second inode
+ */
+static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
+{
+	mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
+	mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
+}
+
+static int ubifs_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
+			 struct file *file, umode_t mode)
+{
+	struct dentry *dentry = file->f_path.dentry;
+	struct inode *inode;
+	struct ubifs_info *c = dir->i_sb->s_fs_info;
+	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
+					.dirtied_ino = 1};
+	struct ubifs_budget_req ino_req = { .dirtied_ino = 1 };
+	struct ubifs_inode *ui;
+	int err, instantiated = 0;
+	struct fscrypt_name nm;
+
+	/*
+	 * Budget request settings: new inode, new direntry, changing the
+	 * parent directory inode.
+	 * Allocate budget separately for new dirtied inode, the budget will
+	 * be released via writeback.
+	 */
+
+	dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
+		dentry, mode, dir->i_ino);
+
+	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
+	if (err)
+		return err;
+
+	err = ubifs_budget_space(c, &req);
+	if (err) {
+		fscrypt_free_filename(&nm);
+		return err;
+	}
+
+	err = ubifs_budget_space(c, &ino_req);
+	if (err) {
+		ubifs_release_budget(c, &req);
+		fscrypt_free_filename(&nm);
+		return err;
+	}
+
+	inode = ubifs_new_inode(c, dir, mode, false);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto out_budg;
+	}
+	ui = ubifs_inode(inode);
+
+	err = ubifs_init_security(dir, inode, &dentry->d_name);
+	if (err)
+		goto out_inode;
+
+	set_nlink(inode, 1);
+	mutex_lock(&ui->ui_mutex);
+	insert_inode_hash(inode);
+	d_tmpfile(file, inode);
+	ubifs_assert(c, ui->dirty);
+
+	instantiated = 1;
+	mutex_unlock(&ui->ui_mutex);
+
+	lock_2_inodes(dir, inode);
+	err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0, 1);
+	if (err)
+		goto out_cancel;
+	unlock_2_inodes(dir, inode);
+
+	ubifs_release_budget(c, &req);
+	fscrypt_free_filename(&nm);
+
+	return finish_open_simple(file, 0);
+
+out_cancel:
+	unlock_2_inodes(dir, inode);
+out_inode:
+	if (!instantiated)
+		iput(inode);
+out_budg:
+	ubifs_release_budget(c, &req);
+	if (!instantiated)
+		ubifs_release_budget(c, &ino_req);
+	fscrypt_free_filename(&nm);
+	ubifs_err(c, "cannot create temporary file, error %d", err);
+	return err;
+}
+
+/**
+ * vfs_dent_type - get VFS directory entry type.
+ * @type: UBIFS directory entry type
+ *
+ * This function converts UBIFS directory entry type into VFS directory entry
+ * type.
+ */
+static unsigned int vfs_dent_type(uint8_t type)
+{
+	switch (type) {
+	case UBIFS_ITYPE_REG:
+		return DT_REG;
+	case UBIFS_ITYPE_DIR:
+		return DT_DIR;
+	case UBIFS_ITYPE_LNK:
+		return DT_LNK;
+	case UBIFS_ITYPE_BLK:
+		return DT_BLK;
+	case UBIFS_ITYPE_CHR:
+		return DT_CHR;
+	case UBIFS_ITYPE_FIFO:
+		return DT_FIFO;
+	case UBIFS_ITYPE_SOCK:
+		return DT_SOCK;
+	default:
+		BUG();
+	}
+	return 0;
+}
+
+/*
+ * The classical Unix view for directory is that it is a linear array of
+ * (name, inode number) entries. Linux/VFS assumes this model as well.
+ * Particularly, 'readdir()' call wants us to return a directory entry offset
+ * which later may be used to continue 'readdir()'ing the directory or to
+ * 'seek()' to that specific direntry. Obviously UBIFS does not really fit this
+ * model because directory entries are identified by keys, which may collide.
+ *
+ * UBIFS uses directory entry hash value for directory offsets, so
+ * 'seekdir()'/'telldir()' may not always work because of possible key
+ * collisions. But UBIFS guarantees that consecutive 'readdir()' calls work
+ * properly by means of saving full directory entry name in the private field
+ * of the file description object.
+ *
+ * This means that UBIFS cannot support NFS which requires full
+ * 'seekdir()'/'telldir()' support.
+ */
+static int ubifs_readdir(struct file *file, struct dir_context *ctx)
+{
+	int fstr_real_len = 0, err = 0;
+	struct fscrypt_name nm;
+	struct fscrypt_str fstr = {0};
+	union ubifs_key key;
+	struct ubifs_dent_node *dent;
+	struct inode *dir = file_inode(file);
+	struct ubifs_info *c = dir->i_sb->s_fs_info;
+	bool encrypted = IS_ENCRYPTED(dir);
+
+	dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, ctx->pos);
+
+	if (ctx->pos > UBIFS_S_KEY_HASH_MASK || ctx->pos == 2)
+		/*
+		 * The directory was seek'ed to a senseless position or there
+		 * are no more entries.
+		 */
+		return 0;
+
+	if (encrypted) {
+		err = fscrypt_prepare_readdir(dir);
+		if (err)
+			return err;
+
+		err = fscrypt_fname_alloc_buffer(UBIFS_MAX_NLEN, &fstr);
+		if (err)
+			return err;
+
+		fstr_real_len = fstr.len;
+	}
+
+	if (file->f_version == 0) {
+		/*
+		 * The file was seek'ed, which means that @file->private_data
+		 * is now invalid. This may also be just the first
+		 * 'ubifs_readdir()' invocation, in which case
+		 * @file->private_data is NULL, and the below code is
+		 * basically a no-op.
+		 */
+		kfree(file->private_data);
+		file->private_data = NULL;
+	}
+
+	/*
+	 * 'generic_file_llseek()' unconditionally sets @file->f_version to
+	 * zero, and we use this for detecting whether the file was seek'ed.
+	 */
+	file->f_version = 1;
+
+	/* File positions 0 and 1 correspond to "." and ".." */
+	if (ctx->pos < 2) {
+		ubifs_assert(c, !file->private_data);
+		if (!dir_emit_dots(file, ctx)) {
+			if (encrypted)
+				fscrypt_fname_free_buffer(&fstr);
+			return 0;
+		}
+
+		/* Find the first entry in TNC and save it */
+		lowest_dent_key(c, &key, dir->i_ino);
+		fname_len(&nm) = 0;
+		dent = ubifs_tnc_next_ent(c, &key, &nm);
+		if (IS_ERR(dent)) {
+			err = PTR_ERR(dent);
+			goto out;
+		}
+
+		ctx->pos = key_hash_flash(c, &dent->key);
+		file->private_data = dent;
+	}
+
+	dent = file->private_data;
+	if (!dent) {
+		/*
+		 * The directory was seek'ed to and is now readdir'ed.
+		 * Find the entry corresponding to @ctx->pos or the closest one.
+		 */
+		dent_key_init_hash(c, &key, dir->i_ino, ctx->pos);
+		fname_len(&nm) = 0;
+		dent = ubifs_tnc_next_ent(c, &key, &nm);
+		if (IS_ERR(dent)) {
+			err = PTR_ERR(dent);
+			goto out;
+		}
+		ctx->pos = key_hash_flash(c, &dent->key);
+		file->private_data = dent;
+	}
+
+	while (1) {
+		dbg_gen("ino %llu, new f_pos %#x",
+			(unsigned long long)le64_to_cpu(dent->inum),
+			key_hash_flash(c, &dent->key));
+		ubifs_assert(c, le64_to_cpu(dent->ch.sqnum) >
+			     ubifs_inode(dir)->creat_sqnum);
+
+		fname_len(&nm) = le16_to_cpu(dent->nlen);
+		fname_name(&nm) = dent->name;
+
+		if (encrypted) {
+			fstr.len = fstr_real_len;
+
+			err = fscrypt_fname_disk_to_usr(dir, key_hash_flash(c,
+							&dent->key),
+							le32_to_cpu(dent->cookie),
+							&nm.disk_name, &fstr);
+			if (err)
+				goto out;
+		} else {
+			fstr.len = fname_len(&nm);
+			fstr.name = fname_name(&nm);
+		}
+
+		if (!dir_emit(ctx, fstr.name, fstr.len,
+			       le64_to_cpu(dent->inum),
+			       vfs_dent_type(dent->type))) {
+			if (encrypted)
+				fscrypt_fname_free_buffer(&fstr);
+			return 0;
+		}
+
+		/* Switch to the next entry */
+		key_read(c, &dent->key, &key);
+		dent = ubifs_tnc_next_ent(c, &key, &nm);
+		if (IS_ERR(dent)) {
+			err = PTR_ERR(dent);
+			goto out;
+		}
+
+		kfree(file->private_data);
+		ctx->pos = key_hash_flash(c, &dent->key);
+		file->private_data = dent;
+		cond_resched();
+	}
+
+out:
+	kfree(file->private_data);
+	file->private_data = NULL;
+
+	if (encrypted)
+		fscrypt_fname_free_buffer(&fstr);
+
+	if (err != -ENOENT)
+		ubifs_err(c, "cannot find next direntry, error %d", err);
+	else
+		/*
+		 * -ENOENT is a non-fatal error in this context, the TNC uses
+		 * it to indicate that the cursor moved past the current directory
+		 * and readdir() has to stop.
+		 */
+		err = 0;
+
+
+	/* 2 is a special value indicating that there are no more direntries */
+	ctx->pos = 2;
+	return err;
+}
+
+/* Free saved readdir() state when the directory is closed */
+static int ubifs_dir_release(struct inode *dir, struct file *file)
+{
+	kfree(file->private_data);
+	file->private_data = NULL;
+	return 0;
+}
+
+static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
+		      struct dentry *dentry)
+{
+	struct ubifs_info *c = dir->i_sb->s_fs_info;
+	struct inode *inode = d_inode(old_dentry);
+	struct ubifs_inode *ui = ubifs_inode(inode);
+	struct ubifs_inode *dir_ui = ubifs_inode(dir);
+	int err, sz_change;
+	struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2,
+				.dirtied_ino_d = ALIGN(ui->data_len, 8) };
+	struct fscrypt_name nm;
+
+	/*
+	 * Budget request settings: new direntry, changing the target inode,
+	 * changing the parent inode.
+	 */
+
+	dbg_gen("dent '%pd' to ino %lu (nlink %d) in dir ino %lu",
+		dentry, inode->i_ino,
+		inode->i_nlink, dir->i_ino);
+	ubifs_assert(c, inode_is_locked(dir));
+	ubifs_assert(c, inode_is_locked(inode));
+
+	err = fscrypt_prepare_link(old_dentry, dir, dentry);
+	if (err)
+		return err;
+
+	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
+	if (err)
+		return err;
+
+	sz_change = CALC_DENT_SIZE(fname_len(&nm));
+
+	err = dbg_check_synced_i_size(c, inode);
+	if (err)
+		goto out_fname;
+
+	err = ubifs_budget_space(c, &req);
+	if (err)
+		goto out_fname;
+
+	lock_2_inodes(dir, inode);
+
+	inc_nlink(inode);
+	ihold(inode);
+	inode_set_ctime_current(inode);
+	dir->i_size += sz_change;
+	dir_ui->ui_size = dir->i_size;
+	inode_set_mtime_to_ts(dir,
+			      inode_set_ctime_to_ts(dir, inode_get_ctime(inode)));
+	err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, inode->i_nlink == 1);
+	if (err)
+		goto out_cancel;
+	unlock_2_inodes(dir, inode);
+
+	ubifs_release_budget(c, &req);
+	d_instantiate(dentry, inode);
+	fscrypt_free_filename(&nm);
+	return 0;
+
+out_cancel:
+	dir->i_size -= sz_change;
+	dir_ui->ui_size = dir->i_size;
+	drop_nlink(inode);
+	unlock_2_inodes(dir, inode);
+	ubifs_release_budget(c, &req);
+	iput(inode);
+out_fname:
+	fscrypt_free_filename(&nm);
+	return err;
+}
+
+static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
+{
+	struct ubifs_info *c = dir->i_sb->s_fs_info;
+	struct inode *inode = d_inode(dentry);
+	struct ubifs_inode *dir_ui = ubifs_inode(dir);
+	int err, sz_change, budgeted = 1;
+	struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
+	unsigned int saved_nlink = inode->i_nlink;
+	struct fscrypt_name nm;
+
+	/*
+	 * Budget request settings: deletion direntry, deletion inode (+1 for
+	 * @dirtied_ino), changing the parent directory inode. If budgeting
+	 * fails, go ahead anyway because we have extra space reserved for
+	 * deletions.
+	 */
+
+	dbg_gen("dent '%pd' from ino %lu (nlink %d) in dir ino %lu",
+		dentry, inode->i_ino,
+		inode->i_nlink, dir->i_ino);
+
+	err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm);
+	if (err)
+		return err;
+
+	err = ubifs_purge_xattrs(inode);
+	if (err)
+		return err;
+
+	sz_change = CALC_DENT_SIZE(fname_len(&nm));
+
+	ubifs_assert(c, inode_is_locked(dir));
+	ubifs_assert(c, inode_is_locked(inode));
+	err = dbg_check_synced_i_size(c, inode);
+	if (err)
+		goto out_fname;
+
+	err = ubifs_budget_space(c, &req);
+	if (err) {
+		if (err != -ENOSPC)
+			goto out_fname;
+		budgeted = 0;
+	}
+
+	lock_2_inodes(dir, inode);
+	inode_set_ctime_current(inode);
+	drop_nlink(inode);
+	dir->i_size -= sz_change;
+	dir_ui->ui_size = dir->i_size;
+	inode_set_mtime_to_ts(dir,
+			      inode_set_ctime_to_ts(dir, inode_get_ctime(inode)));
+	err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0, 0);
+	if (err)
+		goto out_cancel;
+	unlock_2_inodes(dir, inode);
+
+	if (budgeted)
+		ubifs_release_budget(c, &req);
+	else {
+		/* We've deleted something - clean the "no space" flags */
+		c->bi.nospace = c->bi.nospace_rp = 0;
+		smp_wmb();
+	}
+	fscrypt_free_filename(&nm);
+	return 0;
+
+out_cancel:
+	dir->i_size += sz_change;
+	dir_ui->ui_size = dir->i_size;
+	set_nlink(inode, saved_nlink);
+	unlock_2_inodes(dir, inode);
+	if (budgeted)
+		ubifs_release_budget(c, &req);
+out_fname:
+	fscrypt_free_filename(&nm);
+	return err;
+}
+
+/**
+ * ubifs_check_dir_empty - check if a directory is empty or not.
+ * @dir: VFS inode object of the directory to check
+ *
+ * This function checks if directory @dir is empty. Returns zero if the
+ * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
+ * in case of errors.
+ */
+int ubifs_check_dir_empty(struct inode *dir)
+{
+	struct ubifs_info *c = dir->i_sb->s_fs_info;
+	struct fscrypt_name nm = { 0 };
+	struct ubifs_dent_node *dent;
+	union ubifs_key key;
+	int err;
+
+	lowest_dent_key(c, &key, dir->i_ino);
+	dent = ubifs_tnc_next_ent(c, &key, &nm);
+	if (IS_ERR(dent)) {
+		err = PTR_ERR(dent);
+		if (err == -ENOENT)
+			err = 0;
+	} else {
+		kfree(dent);
+		err = -ENOTEMPTY;
+	}
+	return err;
+}
+
+static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	struct ubifs_info *c = dir->i_sb->s_fs_info;
+	struct inode *inode = d_inode(dentry);
+	int err, sz_change, budgeted = 1;
+	struct ubifs_inode *dir_ui = ubifs_inode(dir);
+	struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
+	struct fscrypt_name nm;
+
+	/*
+	 * Budget request settings: deletion direntry, deletion inode and
+	 * changing the parent inode. If budgeting fails, go ahead anyway
+	 * because we have extra space reserved for deletions.
+	 */
+
+	dbg_gen("directory '%pd', ino %lu in dir ino %lu", dentry,
+		inode->i_ino, dir->i_ino);
+	ubifs_assert(c, inode_is_locked(dir));
+	ubifs_assert(c, inode_is_locked(inode));
+	err = ubifs_check_dir_empty(d_inode(dentry));
+	if (err)
+		return err;
+
+	err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm);
+	if (err)
+		return err;
+
+	err = ubifs_purge_xattrs(inode);
+	if (err)
+		return err;
+
+	sz_change = CALC_DENT_SIZE(fname_len(&nm));
+
+	err = ubifs_budget_space(c, &req);
+	if (err) {
+		if (err != -ENOSPC)
+			goto out_fname;
+		budgeted = 0;
+	}
+
+	lock_2_inodes(dir, inode);
+	inode_set_ctime_current(inode);
+	clear_nlink(inode);
+	drop_nlink(dir);
+	dir->i_size -= sz_change;
+	dir_ui->ui_size = dir->i_size;
+	inode_set_mtime_to_ts(dir,
+			      inode_set_ctime_to_ts(dir, inode_get_ctime(inode)));
+	err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0, 0);
+	if (err)
+		goto out_cancel;
+	unlock_2_inodes(dir, inode);
+
+	if (budgeted)
+		ubifs_release_budget(c, &req);
+	else {
+		/* We've deleted something - clean the "no space" flags */
+		c->bi.nospace = c->bi.nospace_rp = 0;
+		smp_wmb();
+	}
+	fscrypt_free_filename(&nm);
+	return 0;
+
+out_cancel:
+	dir->i_size += sz_change;
+	dir_ui->ui_size = dir->i_size;
+	inc_nlink(dir);
+	set_nlink(inode, 2);
+	unlock_2_inodes(dir, inode);
+	if (budgeted)
+		ubifs_release_budget(c, &req);
+out_fname:
+	fscrypt_free_filename(&nm);
+	return err;
+}
+
+static int ubifs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
+		       struct dentry *dentry, umode_t mode)
+{
+	struct inode *inode;
+	struct ubifs_inode *dir_ui = ubifs_inode(dir);
+	struct ubifs_info *c = dir->i_sb->s_fs_info;
+	int err, sz_change;
+	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
+					.dirtied_ino = 1};
+	struct fscrypt_name nm;
+
+	/*
+	 * Budget request settings: new inode, new direntry and changing parent
+	 * directory inode.
+	 */
+
+	dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
+		dentry, mode, dir->i_ino);
+
+	err = ubifs_budget_space(c, &req);
+	if (err)
+		return err;
+
+	err = ubifs_prepare_create(dir, dentry, &nm);
+	if (err)
+		goto out_budg;
+
+	sz_change = CALC_DENT_SIZE(fname_len(&nm));
+
+	inode = ubifs_new_inode(c, dir, S_IFDIR | mode, false);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto out_fname;
+	}
+
+	err = ubifs_init_security(dir, inode, &dentry->d_name);
+	if (err)
+		goto out_inode;
+
+	set_nlink(inode, 1);
+	mutex_lock(&dir_ui->ui_mutex);
+	insert_inode_hash(inode);
+	inc_nlink(inode);
+	inc_nlink(dir);
+	dir->i_size += sz_change;
+	dir_ui->ui_size = dir->i_size;
+	inode_set_mtime_to_ts(dir,
+			      inode_set_ctime_to_ts(dir, inode_get_ctime(inode)));
+	err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 1);
+	if (err) {
+		ubifs_err(c, "cannot create directory, error %d", err);
+		goto out_cancel;
+	}
+	mutex_unlock(&dir_ui->ui_mutex);
+
+	ubifs_release_budget(c, &req);
+	d_instantiate(dentry, inode);
+	fscrypt_free_filename(&nm);
+	return 0;
+
+out_cancel:
+	dir->i_size -= sz_change;
+	dir_ui->ui_size = dir->i_size;
+	drop_nlink(dir);
+	mutex_unlock(&dir_ui->ui_mutex);
+	set_nlink(inode, 0);
+out_inode:
+	iput(inode);
+out_fname:
+	fscrypt_free_filename(&nm);
+out_budg:
+	ubifs_release_budget(c, &req);
+	return err;
+}
+
+static int ubifs_mknod(struct mnt_idmap *idmap, struct inode *dir,
+		       struct dentry *dentry, umode_t mode, dev_t rdev)
+{
+	struct inode *inode;
+	struct ubifs_inode *ui;
+	struct ubifs_inode *dir_ui = ubifs_inode(dir);
+	struct ubifs_info *c = dir->i_sb->s_fs_info;
+	union ubifs_dev_desc *dev = NULL;
+	int sz_change;
+	int err, devlen = 0;
+	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
+					.dirtied_ino = 1 };
+	struct fscrypt_name nm;
+
+	/*
+	 * Budget request settings: new inode, new direntry and changing parent
+	 * directory inode.
+	 */
+
+	dbg_gen("dent '%pd' in dir ino %lu", dentry, dir->i_ino);
+
+	if (S_ISBLK(mode) || S_ISCHR(mode)) {
+		dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
+		if (!dev)
+			return -ENOMEM;
+		devlen = ubifs_encode_dev(dev, rdev);
+	}
+
+	req.new_ino_d = ALIGN(devlen, 8);
+	err = ubifs_budget_space(c, &req);
+	if (err) {
+		kfree(dev);
+		return err;
+	}
+
+	err = ubifs_prepare_create(dir, dentry, &nm);
+	if (err) {
+		kfree(dev);
+		goto out_budg;
+	}
+
+	sz_change = CALC_DENT_SIZE(fname_len(&nm));
+
+	inode = ubifs_new_inode(c, dir, mode, false);
+	if (IS_ERR(inode)) {
+		kfree(dev);
+		err = PTR_ERR(inode);
+		goto out_fname;
+	}
+
+	err = ubifs_init_security(dir, inode, &dentry->d_name);
+	if (err) {
+		kfree(dev);
+		goto out_inode;
+	}
+
+	init_special_inode(inode, inode->i_mode, rdev);
+	inode->i_size = ubifs_inode(inode)->ui_size = devlen;
+	ui = ubifs_inode(inode);
+	ui->data = dev;
+	ui->data_len = devlen;
+	set_nlink(inode, 1);
+
+	mutex_lock(&dir_ui->ui_mutex);
+	dir->i_size += sz_change;
+	dir_ui->ui_size = dir->i_size;
+	inode_set_mtime_to_ts(dir,
+			      inode_set_ctime_to_ts(dir, inode_get_ctime(inode)));
+	err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 1);
+	if (err)
+		goto out_cancel;
+	mutex_unlock(&dir_ui->ui_mutex);
+
+	ubifs_release_budget(c, &req);
+	insert_inode_hash(inode);
+	d_instantiate(dentry, inode);
+	fscrypt_free_filename(&nm);
+	return 0;
+
+out_cancel:
+	dir->i_size -= sz_change;
+	dir_ui->ui_size = dir->i_size;
+	mutex_unlock(&dir_ui->ui_mutex);
+	set_nlink(inode, 0);
+out_inode:
+	iput(inode);
+out_fname:
+	fscrypt_free_filename(&nm);
+out_budg:
+	ubifs_release_budget(c, &req);
+	return err;
+}
+
+static int ubifs_symlink(struct mnt_idmap *idmap, struct inode *dir,
+			 struct dentry *dentry, const char *symname)
+{
+	struct inode *inode;
+	struct ubifs_inode *ui;
+	struct ubifs_inode *dir_ui = ubifs_inode(dir);
+	struct ubifs_info *c = dir->i_sb->s_fs_info;
+	int err, sz_change, len = strlen(symname);
+	struct fscrypt_str disk_link;
+	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
+					.dirtied_ino = 1 };
+	struct fscrypt_name nm;
+
+	dbg_gen("dent '%pd', target '%s' in dir ino %lu", dentry,
+		symname, dir->i_ino);
+
+	err = fscrypt_prepare_symlink(dir, symname, len, UBIFS_MAX_INO_DATA,
+				      &disk_link);
+	if (err)
+		return err;
+
+	/*
+	 * Budget request settings: new inode, new direntry and changing parent
+	 * directory inode.
+	 */
+	req.new_ino_d = ALIGN(disk_link.len - 1, 8);
+	err = ubifs_budget_space(c, &req);
+	if (err)
+		return err;
+
+	err = ubifs_prepare_create(dir, dentry, &nm);
+	if (err)
+		goto out_budg;
+
+	sz_change = CALC_DENT_SIZE(fname_len(&nm));
+
+	inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO, false);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto out_fname;
+	}
+
+	err = ubifs_init_security(dir, inode, &dentry->d_name);
+	if (err)
+		goto out_inode;
+
+	ui = ubifs_inode(inode);
+	ui->data = kmalloc(disk_link.len, GFP_NOFS);
+	if (!ui->data) {
+		err = -ENOMEM;
+		goto out_inode;
+	}
+
+	if (IS_ENCRYPTED(inode)) {
+		disk_link.name = ui->data; /* encrypt directly into ui->data */
+		err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
+		if (err)
+			goto out_inode;
+	} else {
+		memcpy(ui->data, disk_link.name, disk_link.len);
+		inode->i_link = ui->data;
+	}
+
+	/*
+	 * The terminating zero byte is not written to the flash media and it
+	 * is put just to make later in-memory string processing simpler. Thus,
+	 * data length is @disk_link.len - 1, not @disk_link.len.
+	 */
+	ui->data_len = disk_link.len - 1;
+	inode->i_size = ubifs_inode(inode)->ui_size = disk_link.len - 1;
+	set_nlink(inode, 1);
+
+	mutex_lock(&dir_ui->ui_mutex);
+	dir->i_size += sz_change;
+	dir_ui->ui_size = dir->i_size;
+	inode_set_mtime_to_ts(dir,
+			      inode_set_ctime_to_ts(dir, inode_get_ctime(inode)));
+	err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 1);
+	if (err)
+		goto out_cancel;
+	mutex_unlock(&dir_ui->ui_mutex);
+
+	insert_inode_hash(inode);
+	d_instantiate(dentry, inode);
+	err = 0;
+	goto out_fname;
+
+out_cancel:
+	dir->i_size -= sz_change;
+	dir_ui->ui_size = dir->i_size;
+	mutex_unlock(&dir_ui->ui_mutex);
+	set_nlink(inode, 0);
+out_inode:
+	/* Free inode->i_link before inode is marked as bad. */
+	fscrypt_free_inode(inode);
+	iput(inode);
+out_fname:
+	fscrypt_free_filename(&nm);
+out_budg:
+	ubifs_release_budget(c, &req);
+	return err;
+}
+
+/**
+ * lock_4_inodes - a wrapper for locking three UBIFS inodes.
+ * @inode1: first inode
+ * @inode2: second inode
+ * @inode3: third inode
+ * @inode4: fourth inode
+ *
+ * This function is used for 'ubifs_rename()' and @inode1 may be the same as
+ * @inode2 whereas @inode3 and @inode4 may be %NULL.
+ *
+ * We do not implement any tricks to guarantee strict lock ordering, because
+ * VFS has already done it for us on the @i_mutex. So this is just a simple
+ * wrapper function.
+ */
+static void lock_4_inodes(struct inode *inode1, struct inode *inode2,
+			  struct inode *inode3, struct inode *inode4)
+{
+	mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
+	if (inode2 != inode1)
+		mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
+	if (inode3)
+		mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3);
+	if (inode4)
+		mutex_lock_nested(&ubifs_inode(inode4)->ui_mutex, WB_MUTEX_4);
+}
+
+/**
+ * unlock_4_inodes - a wrapper for unlocking three UBIFS inodes for rename.
+ * @inode1: first inode
+ * @inode2: second inode
+ * @inode3: third inode
+ * @inode4: fourth inode
+ */
+static void unlock_4_inodes(struct inode *inode1, struct inode *inode2,
+			    struct inode *inode3, struct inode *inode4)
+{
+	if (inode4)
+		mutex_unlock(&ubifs_inode(inode4)->ui_mutex);
+	if (inode3)
+		mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
+	if (inode1 != inode2)
+		mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
+	mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
+}
+
+static int do_rename(struct inode *old_dir, struct dentry *old_dentry,
+		     struct inode *new_dir, struct dentry *new_dentry,
+		     unsigned int flags)
+{
+	struct ubifs_info *c = old_dir->i_sb->s_fs_info;
+	struct inode *old_inode = d_inode(old_dentry);
+	struct inode *new_inode = d_inode(new_dentry);
+	struct inode *whiteout = NULL;
+	struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode);
+	struct ubifs_inode *whiteout_ui = NULL;
+	int err, release, sync = 0, move = (new_dir != old_dir);
+	int is_dir = S_ISDIR(old_inode->i_mode);
+	int unlink = !!new_inode, new_sz, old_sz;
+	struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
+					.dirtied_ino = 3 };
+	struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
+			.dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) };
+	struct ubifs_budget_req wht_req;
+	unsigned int saved_nlink;
+	struct fscrypt_name old_nm, new_nm;
+
+	/*
+	 * Budget request settings:
+	 *   req: deletion direntry, new direntry, removing the old inode,
+	 *   and changing old and new parent directory inodes.
+	 *
+	 *   wht_req: new whiteout inode for RENAME_WHITEOUT.
+	 *
+	 *   ino_req: marks the target inode as dirty and does not write it.
+	 */
+
+	dbg_gen("dent '%pd' ino %lu in dir ino %lu to dent '%pd' in dir ino %lu flags 0x%x",
+		old_dentry, old_inode->i_ino, old_dir->i_ino,
+		new_dentry, new_dir->i_ino, flags);
+
+	if (unlink) {
+		ubifs_assert(c, inode_is_locked(new_inode));
+
+		/* Budget for old inode's data when its nlink > 1. */
+		req.dirtied_ino_d = ALIGN(ubifs_inode(new_inode)->data_len, 8);
+		err = ubifs_purge_xattrs(new_inode);
+		if (err)
+			return err;
+	}
+
+	if (unlink && is_dir) {
+		err = ubifs_check_dir_empty(new_inode);
+		if (err)
+			return err;
+	}
+
+	err = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &old_nm);
+	if (err)
+		return err;
+
+	err = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &new_nm);
+	if (err) {
+		fscrypt_free_filename(&old_nm);
+		return err;
+	}
+
+	new_sz = CALC_DENT_SIZE(fname_len(&new_nm));
+	old_sz = CALC_DENT_SIZE(fname_len(&old_nm));
+
+	err = ubifs_budget_space(c, &req);
+	if (err) {
+		fscrypt_free_filename(&old_nm);
+		fscrypt_free_filename(&new_nm);
+		return err;
+	}
+	err = ubifs_budget_space(c, &ino_req);
+	if (err) {
+		fscrypt_free_filename(&old_nm);
+		fscrypt_free_filename(&new_nm);
+		ubifs_release_budget(c, &req);
+		return err;
+	}
+
+	if (flags & RENAME_WHITEOUT) {
+		union ubifs_dev_desc *dev = NULL;
+
+		dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
+		if (!dev) {
+			err = -ENOMEM;
+			goto out_release;
+		}
+
+		/*
+		 * The whiteout inode without dentry is pinned in memory,
+		 * umount won't happen during rename process because we
+		 * got parent dentry.
+		 */
+		whiteout = create_whiteout(old_dir, old_dentry);
+		if (IS_ERR(whiteout)) {
+			err = PTR_ERR(whiteout);
+			kfree(dev);
+			goto out_release;
+		}
+
+		whiteout_ui = ubifs_inode(whiteout);
+		whiteout_ui->data = dev;
+		whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0));
+		ubifs_assert(c, !whiteout_ui->dirty);
+
+		memset(&wht_req, 0, sizeof(struct ubifs_budget_req));
+		wht_req.new_ino = 1;
+		wht_req.new_ino_d = ALIGN(whiteout_ui->data_len, 8);
+		/*
+		 * To avoid deadlock between space budget (holds ui_mutex and
+		 * waits wb work) and writeback work(waits ui_mutex), do space
+		 * budget before ubifs inodes locked.
+		 */
+		err = ubifs_budget_space(c, &wht_req);
+		if (err) {
+			iput(whiteout);
+			goto out_release;
+		}
+		set_nlink(whiteout, 1);
+
+		/* Add the old_dentry size to the old_dir size. */
+		old_sz -= CALC_DENT_SIZE(fname_len(&old_nm));
+	}
+
+	lock_4_inodes(old_dir, new_dir, new_inode, whiteout);
+
+	/*
+	 * Like most other Unix systems, set the @i_ctime for inodes on a
+	 * rename.
+	 */
+	simple_rename_timestamp(old_dir, old_dentry, new_dir, new_dentry);
+
+	/* We must adjust parent link count when renaming directories */
+	if (is_dir) {
+		if (move) {
+			/*
+			 * @old_dir loses a link because we are moving
+			 * @old_inode to a different directory.
+			 */
+			drop_nlink(old_dir);
+			/*
+			 * @new_dir only gains a link if we are not also
+			 * overwriting an existing directory.
+			 */
+			if (!unlink)
+				inc_nlink(new_dir);
+		} else {
+			/*
+			 * @old_inode is not moving to a different directory,
+			 * but @old_dir still loses a link if we are
+			 * overwriting an existing directory.
+			 */
+			if (unlink)
+				drop_nlink(old_dir);
+		}
+	}
+
+	old_dir->i_size -= old_sz;
+	ubifs_inode(old_dir)->ui_size = old_dir->i_size;
+
+	/*
+	 * And finally, if we unlinked a direntry which happened to have the
+	 * same name as the moved direntry, we have to decrement @i_nlink of
+	 * the unlinked inode.
+	 */
+	if (unlink) {
+		/*
+		 * Directories cannot have hard-links, so if this is a
+		 * directory, just clear @i_nlink.
+		 */
+		saved_nlink = new_inode->i_nlink;
+		if (is_dir)
+			clear_nlink(new_inode);
+		else
+			drop_nlink(new_inode);
+	} else {
+		new_dir->i_size += new_sz;
+		ubifs_inode(new_dir)->ui_size = new_dir->i_size;
+	}
+
+	/*
+	 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode
+	 * is dirty, because this will be done later on at the end of
+	 * 'ubifs_rename()'.
+	 */
+	if (IS_SYNC(old_inode)) {
+		sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
+		if (unlink && IS_SYNC(new_inode))
+			sync = 1;
+		/*
+		 * S_SYNC flag of whiteout inherits from the old_dir, and we
+		 * have already checked the old dir inode. So there is no need
+		 * to check whiteout.
+		 */
+	}
+
+	err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir,
+			       new_inode, &new_nm, whiteout, sync, !!whiteout);
+	if (err)
+		goto out_cancel;
+
+	unlock_4_inodes(old_dir, new_dir, new_inode, whiteout);
+	ubifs_release_budget(c, &req);
+
+	if (whiteout) {
+		ubifs_release_budget(c, &wht_req);
+		iput(whiteout);
+	}
+
+	mutex_lock(&old_inode_ui->ui_mutex);
+	release = old_inode_ui->dirty;
+	mark_inode_dirty_sync(old_inode);
+	mutex_unlock(&old_inode_ui->ui_mutex);
+
+	if (release)
+		ubifs_release_budget(c, &ino_req);
+	if (IS_SYNC(old_inode))
+		/*
+		 * Rename finished here. Although old inode cannot be updated
+		 * on flash, old ctime is not a big problem, don't return err
+		 * code to userspace.
+		 */
+		old_inode->i_sb->s_op->write_inode(old_inode, NULL);
+
+	fscrypt_free_filename(&old_nm);
+	fscrypt_free_filename(&new_nm);
+	return 0;
+
+out_cancel:
+	if (unlink) {
+		set_nlink(new_inode, saved_nlink);
+	} else {
+		new_dir->i_size -= new_sz;
+		ubifs_inode(new_dir)->ui_size = new_dir->i_size;
+	}
+	old_dir->i_size += old_sz;
+	ubifs_inode(old_dir)->ui_size = old_dir->i_size;
+	if (is_dir) {
+		if (move) {
+			inc_nlink(old_dir);
+			if (!unlink)
+				drop_nlink(new_dir);
+		} else {
+			if (unlink)
+				inc_nlink(old_dir);
+		}
+	}
+	unlock_4_inodes(old_dir, new_dir, new_inode, whiteout);
+	if (whiteout) {
+		ubifs_release_budget(c, &wht_req);
+		set_nlink(whiteout, 0);
+		iput(whiteout);
+	}
+out_release:
+	ubifs_release_budget(c, &ino_req);
+	ubifs_release_budget(c, &req);
+	fscrypt_free_filename(&old_nm);
+	fscrypt_free_filename(&new_nm);
+	return err;
+}
+
+static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry,
+			struct inode *new_dir, struct dentry *new_dentry)
+{
+	struct ubifs_info *c = old_dir->i_sb->s_fs_info;
+	struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
+				.dirtied_ino = 2 };
+	int sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
+	struct inode *fst_inode = d_inode(old_dentry);
+	struct inode *snd_inode = d_inode(new_dentry);
+	int err;
+	struct fscrypt_name fst_nm, snd_nm;
+
+	ubifs_assert(c, fst_inode && snd_inode);
+
+	/*
+	 * Budget request settings: changing two direntries, changing the two
+	 * parent directory inodes.
+	 */
+
+	dbg_gen("dent '%pd' ino %lu in dir ino %lu exchange dent '%pd' ino %lu in dir ino %lu",
+		old_dentry, fst_inode->i_ino, old_dir->i_ino,
+		new_dentry, snd_inode->i_ino, new_dir->i_ino);
+
+	err = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &fst_nm);
+	if (err)
+		return err;
+
+	err = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &snd_nm);
+	if (err) {
+		fscrypt_free_filename(&fst_nm);
+		return err;
+	}
+
+	err = ubifs_budget_space(c, &req);
+	if (err)
+		goto out;
+
+	lock_4_inodes(old_dir, new_dir, NULL, NULL);
+
+	simple_rename_timestamp(old_dir, old_dentry, new_dir, new_dentry);
+
+	if (old_dir != new_dir) {
+		if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) {
+			inc_nlink(new_dir);
+			drop_nlink(old_dir);
+		}
+		else if (!S_ISDIR(fst_inode->i_mode) && S_ISDIR(snd_inode->i_mode)) {
+			drop_nlink(new_dir);
+			inc_nlink(old_dir);
+		}
+	}
+
+	err = ubifs_jnl_xrename(c, old_dir, fst_inode, &fst_nm, new_dir,
+				snd_inode, &snd_nm, sync);
+
+	unlock_4_inodes(old_dir, new_dir, NULL, NULL);
+	ubifs_release_budget(c, &req);
+
+out:
+	fscrypt_free_filename(&fst_nm);
+	fscrypt_free_filename(&snd_nm);
+	return err;
+}
+
+static int ubifs_rename(struct mnt_idmap *idmap,
+			struct inode *old_dir, struct dentry *old_dentry,
+			struct inode *new_dir, struct dentry *new_dentry,
+			unsigned int flags)
+{
+	int err;
+	struct ubifs_info *c = old_dir->i_sb->s_fs_info;
+
+	if (flags & ~(RENAME_NOREPLACE | RENAME_WHITEOUT | RENAME_EXCHANGE))
+		return -EINVAL;
+
+	ubifs_assert(c, inode_is_locked(old_dir));
+	ubifs_assert(c, inode_is_locked(new_dir));
+
+	err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
+				     flags);
+	if (err)
+		return err;
+
+	if (flags & RENAME_EXCHANGE)
+		return ubifs_xrename(old_dir, old_dentry, new_dir, new_dentry);
+
+	return do_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
+}
+
+int ubifs_getattr(struct mnt_idmap *idmap, const struct path *path,
+		  struct kstat *stat, u32 request_mask, unsigned int flags)
+{
+	loff_t size;
+	struct inode *inode = d_inode(path->dentry);
+	struct ubifs_inode *ui = ubifs_inode(inode);
+
+	mutex_lock(&ui->ui_mutex);
+
+	if (ui->flags & UBIFS_APPEND_FL)
+		stat->attributes |= STATX_ATTR_APPEND;
+	if (ui->flags & UBIFS_COMPR_FL)
+		stat->attributes |= STATX_ATTR_COMPRESSED;
+	if (ui->flags & UBIFS_CRYPT_FL)
+		stat->attributes |= STATX_ATTR_ENCRYPTED;
+	if (ui->flags & UBIFS_IMMUTABLE_FL)
+		stat->attributes |= STATX_ATTR_IMMUTABLE;
+
+	stat->attributes_mask |= (STATX_ATTR_APPEND |
+				STATX_ATTR_COMPRESSED |
+				STATX_ATTR_ENCRYPTED |
+				STATX_ATTR_IMMUTABLE);
+
+	generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
+	stat->blksize = UBIFS_BLOCK_SIZE;
+	stat->size = ui->ui_size;
+
+	/*
+	 * Unfortunately, the 'stat()' system call was designed for block
+	 * device based file systems, and it is not appropriate for UBIFS,
+	 * because UBIFS does not have notion of "block". For example, it is
+	 * difficult to tell how many block a directory takes - it actually
+	 * takes less than 300 bytes, but we have to round it to block size,
+	 * which introduces large mistake. This makes utilities like 'du' to
+	 * report completely senseless numbers. This is the reason why UBIFS
+	 * goes the same way as JFFS2 - it reports zero blocks for everything
+	 * but regular files, which makes more sense than reporting completely
+	 * wrong sizes.
+	 */
+	if (S_ISREG(inode->i_mode)) {
+		size = ui->xattr_size;
+		size += stat->size;
+		size = ALIGN(size, UBIFS_BLOCK_SIZE);
+		/*
+		 * Note, user-space expects 512-byte blocks count irrespectively
+		 * of what was reported in @stat->size.
+		 */
+		stat->blocks = size >> 9;
+	} else
+		stat->blocks = 0;
+	mutex_unlock(&ui->ui_mutex);
+	return 0;
+}
+
+const struct inode_operations ubifs_dir_inode_operations = {
+	.lookup      = ubifs_lookup,
+	.create      = ubifs_create,
+	.link        = ubifs_link,
+	.symlink     = ubifs_symlink,
+	.unlink      = ubifs_unlink,
+	.mkdir       = ubifs_mkdir,
+	.rmdir       = ubifs_rmdir,
+	.mknod       = ubifs_mknod,
+	.rename      = ubifs_rename,
+	.setattr     = ubifs_setattr,
+	.getattr     = ubifs_getattr,
+	.listxattr   = ubifs_listxattr,
+	.update_time = ubifs_update_time,
+	.tmpfile     = ubifs_tmpfile,
+	.fileattr_get = ubifs_fileattr_get,
+	.fileattr_set = ubifs_fileattr_set,
+};
+
+const struct file_operations ubifs_dir_operations = {
+	.llseek         = generic_file_llseek,
+	.release        = ubifs_dir_release,
+	.read           = generic_read_dir,
+	.iterate_shared = ubifs_readdir,
+	.fsync          = ubifs_fsync,
+	.unlocked_ioctl = ubifs_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl   = ubifs_compat_ioctl,
+#endif
+};