Merge tag 'upstream-4.9-rc1' of git://git.infradead.org/linux-ubifs

Pull UBI/UBIFS updates from Richard Weinberger:
 "This pull request contains:

   - Fixes for both UBI and UBIFS
   - overlayfs support (O_TMPFILE, RENAME_WHITEOUT/EXCHANGE)
   - Code refactoring for the upcoming MLC support"

[ Ugh, we just got rid of the "rename2()" naming for the extended rename
  functionality. And this re-introduces it in ubifs with the cross-
  renaming and whiteout support.

  But rather than do any re-organizations in the merge itself, the
  naming can be cleaned up later ]

* tag 'upstream-4.9-rc1' of git://git.infradead.org/linux-ubifs: (27 commits)
  UBIFS: improve function-level documentation
  ubifs: fix host xattr_len when changing xattr
  ubifs: Use move variable in ubifs_rename()
  ubifs: Implement RENAME_EXCHANGE
  ubifs: Implement RENAME_WHITEOUT
  ubifs: Implement O_TMPFILE
  ubi: Fix Fastmap's update_vol()
  ubi: Fix races around ubi_refill_pools()
  ubi: Deal with interrupted erasures in WL
  UBI: introduce the VID buffer concept
  UBI: hide EBA internals
  UBI: provide an helper to query LEB information
  UBI: provide an helper to check whether a LEB is mapped or not
  UBI: add an helper to check lnum validity
  UBI: simplify LEB write and atomic LEB change code
  UBI: simplify recover_peb() code
  UBI: move the global ech and vidh variables into struct ubi_attach_info
  UBI: provide helpers to allocate and free aeb elements
  UBI: fastmap: use ubi_io_{read, write}_data() instead of ubi_io_{read, write}()
  UBI: fastmap: use ubi_rb_for_each_entry() in unmap_peb()
  ...

9 files changed, 411 insertions, 42 deletions

diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index 64902702b17d..c8f60df2733e 100644
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -301,6 +301,95 @@ out_budg:
 	return err;
 }
 
+static int do_tmpfile(struct inode *dir, struct dentry *dentry,
+		      umode_t mode, struct inode **whiteout)
+{
+	struct inode *inode;
+	struct ubifs_info *c = dir->i_sb->s_fs_info;
+	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1};
+	struct ubifs_budget_req ino_req = { .dirtied_ino = 1 };
+	struct ubifs_inode *ui, *dir_ui = ubifs_inode(dir);
+	int err, instantiated = 0;
+
+	/*
+	 * Budget request settings: new dirty inode, new direntry,
+	 * budget for dirtied inode will be released via writeback.
+	 */
+
+	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_budget_space(c, &ino_req);
+	if (err) {
+		ubifs_release_budget(c, &req);
+		return err;
+	}
+
+	inode = ubifs_new_inode(c, dir, mode);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto out_budg;
+	}
+	ui = ubifs_inode(inode);
+
+	if (whiteout) {
+		init_special_inode(inode, inode->i_mode, WHITEOUT_DEV);
+		ubifs_assert(inode->i_op == &ubifs_file_inode_operations);
+	}
+
+	err = ubifs_init_security(dir, inode, &dentry->d_name);
+	if (err)
+		goto out_inode;
+
+	mutex_lock(&ui->ui_mutex);
+	insert_inode_hash(inode);
+
+	if (whiteout) {
+		mark_inode_dirty(inode);
+		drop_nlink(inode);
+		*whiteout = inode;
+	} else {
+		d_tmpfile(dentry, inode);
+	}
+	ubifs_assert(ui->dirty);
+
+	instantiated = 1;
+	mutex_unlock(&ui->ui_mutex);
+
+	mutex_lock(&dir_ui->ui_mutex);
+	err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
+	if (err)
+		goto out_cancel;
+	mutex_unlock(&dir_ui->ui_mutex);
+
+	ubifs_release_budget(c, &req);
+
+	return 0;
+
+out_cancel:
+	mutex_unlock(&dir_ui->ui_mutex);
+out_inode:
+	make_bad_inode(inode);
+	if (!instantiated)
+		iput(inode);
+out_budg:
+	ubifs_release_budget(c, &req);
+	if (!instantiated)
+		ubifs_release_budget(c, &ino_req);
+	ubifs_err(c, "cannot create temporary file, error %d", err);
+	return err;
+}
+
+static int ubifs_tmpfile(struct inode *dir, struct dentry *dentry,
+			 umode_t mode)
+{
+	return do_tmpfile(dir, dentry, mode, NULL);
+}
+
 /**
  * vfs_dent_type - get VFS directory entry type.
  * @type: UBIFS directory entry type
@@ -927,37 +1016,43 @@ out_budg:
 }
 
 /**
- * lock_3_inodes - a wrapper for locking three UBIFS inodes.
+ * lock_4_inodes - a wrapper for locking three UBIFS inodes.
  * @inode1: first inode
  * @inode2: second inode
  * @inode3: third inode
+ * @inode4: fouth inode
  *
  * This function is used for 'ubifs_rename()' and @inode1 may be the same as
- * @inode2 whereas @inode3 may be %NULL.
+ * @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_3_inodes(struct inode *inode1, struct inode *inode2,
-			  struct inode *inode3)
+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_3_inodes - a wrapper for unlocking three UBIFS inodes for rename.
+ * unlock_4_inodes - a wrapper for unlocking three UBIFS inodes for rename.
  * @inode1: first inode
  * @inode2: second inode
  * @inode3: third inode
+ * @inode4: fouth inode
  */
-static void unlock_3_inodes(struct inode *inode1, struct inode *inode2,
-			    struct inode *inode3)
+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)
@@ -972,7 +1067,9 @@ static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	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;
@@ -997,15 +1094,13 @@ static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	 * separately.
 	 */
 
-	dbg_gen("dent '%pd' ino %lu in dir ino %lu to dent '%pd' in dir ino %lu",
+	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);
-	ubifs_assert(inode_is_locked(old_dir));
-	ubifs_assert(inode_is_locked(new_dir));
+		new_dentry, new_dir->i_ino, flags);
+
 	if (unlink)
 		ubifs_assert(inode_is_locked(new_inode));
 
-
 	if (unlink && is_dir) {
 		err = check_dir_empty(c, new_inode);
 		if (err)
@@ -1021,7 +1116,32 @@ static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		return err;
 	}
 
-	lock_3_inodes(old_dir, new_dir, new_inode);
+	if (flags & RENAME_WHITEOUT) {
+		union ubifs_dev_desc *dev = NULL;
+
+		dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
+		if (!dev) {
+			ubifs_release_budget(c, &req);
+			ubifs_release_budget(c, &ino_req);
+			return -ENOMEM;
+		}
+
+		err = do_tmpfile(old_dir, old_dentry, S_IFCHR | WHITEOUT_MODE, &whiteout);
+		if (err) {
+			ubifs_release_budget(c, &req);
+			ubifs_release_budget(c, &ino_req);
+			kfree(dev);
+			return err;
+		}
+
+		whiteout->i_state |= I_LINKABLE;
+		whiteout_ui = ubifs_inode(whiteout);
+		whiteout_ui->data = dev;
+		whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0));
+		ubifs_assert(!whiteout_ui->dirty);
+	}
+
+	lock_4_inodes(old_dir, new_dir, new_inode, whiteout);
 
 	/*
 	 * Like most other Unix systems, set the @i_ctime for inodes on a
@@ -1091,12 +1211,34 @@ static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		if (unlink && IS_SYNC(new_inode))
 			sync = 1;
 	}
-	err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry,
+
+	if (whiteout) {
+		struct ubifs_budget_req wht_req = { .dirtied_ino = 1,
+				.dirtied_ino_d = \
+				ALIGN(ubifs_inode(whiteout)->data_len, 8) };
+
+		err = ubifs_budget_space(c, &wht_req);
+		if (err) {
+			ubifs_release_budget(c, &req);
+			ubifs_release_budget(c, &ino_req);
+			kfree(whiteout_ui->data);
+			whiteout_ui->data_len = 0;
+			iput(whiteout);
+			return err;
+		}
+
+		inc_nlink(whiteout);
+		mark_inode_dirty(whiteout);
+		whiteout->i_state &= ~I_LINKABLE;
+		iput(whiteout);
+	}
+
+	err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry, whiteout,
 			       sync);
 	if (err)
 		goto out_cancel;
 
-	unlock_3_inodes(old_dir, new_dir, new_inode);
+	unlock_4_inodes(old_dir, new_dir, new_inode, whiteout);
 	ubifs_release_budget(c, &req);
 
 	mutex_lock(&old_inode_ui->ui_mutex);
@@ -1129,12 +1271,74 @@ out_cancel:
 				inc_nlink(old_dir);
 		}
 	}
-	unlock_3_inodes(old_dir, new_dir, new_inode);
+	if (whiteout) {
+		drop_nlink(whiteout);
+		iput(whiteout);
+	}
+	unlock_4_inodes(old_dir, new_dir, new_inode, whiteout);
 	ubifs_release_budget(c, &ino_req);
 	ubifs_release_budget(c, &req);
 	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);
+	struct timespec time;
+	int err;
+
+	ubifs_assert(fst_inode && snd_inode);
+
+	lock_4_inodes(old_dir, new_dir, NULL, NULL);
+
+	time = ubifs_current_time(old_dir);
+	fst_inode->i_ctime = time;
+	snd_inode->i_ctime = time;
+	old_dir->i_mtime = old_dir->i_ctime = time;
+	new_dir->i_mtime = new_dir->i_ctime = time;
+
+	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, old_dentry, new_dir, new_dentry,
+				sync);
+
+	unlock_4_inodes(old_dir, new_dir, NULL, NULL);
+	ubifs_release_budget(c, &req);
+
+	return err;
+}
+
+static int ubifs_rename2(struct inode *old_dir, struct dentry *old_dentry,
+			struct inode *new_dir, struct dentry *new_dentry,
+			unsigned int flags)
+{
+	if (flags & ~(RENAME_NOREPLACE | RENAME_WHITEOUT | RENAME_EXCHANGE))
+		return -EINVAL;
+
+	ubifs_assert(inode_is_locked(old_dir));
+	ubifs_assert(inode_is_locked(new_dir));
+
+	if (flags & RENAME_EXCHANGE)
+		return ubifs_xrename(old_dir, old_dentry, new_dir, new_dentry);
+
+	return ubifs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
+}
+
 int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 		  struct kstat *stat)
 {
@@ -1183,13 +1387,14 @@ const struct inode_operations ubifs_dir_inode_operations = {
 	.mkdir       = ubifs_mkdir,
 	.rmdir       = ubifs_rmdir,
 	.mknod       = ubifs_mknod,
-	.rename     = ubifs_rename,
+	.rename      = ubifs_rename2,
 	.setattr     = ubifs_setattr,
 	.getattr     = ubifs_getattr,
 	.listxattr   = ubifs_listxattr,
 #ifdef CONFIG_UBIFS_ATIME_SUPPORT
 	.update_time = ubifs_update_time,
 #endif
+	.tmpfile     = ubifs_tmpfile,
 };
 
 const struct file_operations ubifs_dir_operations = {
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index a746982fbcda..b4fbeefba246 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -1397,7 +1397,7 @@ int ubifs_update_time(struct inode *inode, struct timespec *time,
 #endif
 
 /**
- * update_ctime - update mtime and ctime of an inode.
+ * update_mctime - update mtime and ctime of an inode.
  * @inode: inode to update
  *
  * This function updates mtime and ctime of the inode if it is not equivalent to
diff --git a/fs/ubifs/gc.c b/fs/ubifs/gc.c
index 821b34816976..e845c64b6ce1 100644
--- a/fs/ubifs/gc.c
+++ b/fs/ubifs/gc.c
@@ -113,7 +113,7 @@ static int switch_gc_head(struct ubifs_info *c)
  * data_nodes_cmp - compare 2 data nodes.
  * @priv: UBIFS file-system description object
  * @a: first data node
- * @a: second data node
+ * @b: second data node
  *
  * This function compares data nodes @a and @b. Returns %1 if @a has greater
  * inode or block number, and %-1 otherwise.
diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c
index 0b9da5b6e0f9..91bc76dc559e 100644
--- a/fs/ubifs/journal.c
+++ b/fs/ubifs/journal.c
@@ -908,6 +908,147 @@ int ubifs_jnl_delete_inode(struct ubifs_info *c, const struct inode *inode)
 }
 
 /**
+ * ubifs_jnl_xrename - cross rename two directory entries.
+ * @c: UBIFS file-system description object
+ * @fst_dir: parent inode of 1st directory entry to exchange
+ * @fst_dentry: 1st directory entry to exchange
+ * @snd_dir: parent inode of 2nd directory entry to exchange
+ * @snd_dentry: 2nd directory entry to exchange
+ * @sync: non-zero if the write-buffer has to be synchronized
+ *
+ * This function implements the cross rename operation which may involve
+ * writing 2 inodes and 2 directory entries. It marks the written inodes as clean
+ * and returns zero on success. In case of failure, a negative error code is
+ * returned.
+ */
+int ubifs_jnl_xrename(struct ubifs_info *c, const struct inode *fst_dir,
+		      const struct dentry *fst_dentry,
+		      const struct inode *snd_dir,
+		      const struct dentry *snd_dentry, int sync)
+{
+	union ubifs_key key;
+	struct ubifs_dent_node *dent1, *dent2;
+	int err, dlen1, dlen2, lnum, offs, len, plen = UBIFS_INO_NODE_SZ;
+	int aligned_dlen1, aligned_dlen2;
+	int twoparents = (fst_dir != snd_dir);
+	const struct inode *fst_inode = d_inode(fst_dentry);
+	const struct inode *snd_inode = d_inode(snd_dentry);
+	void *p;
+
+	dbg_jnl("dent '%pd' in dir ino %lu between dent '%pd' in dir ino %lu",
+		fst_dentry, fst_dir->i_ino, snd_dentry, snd_dir->i_ino);
+
+	ubifs_assert(ubifs_inode(fst_dir)->data_len == 0);
+	ubifs_assert(ubifs_inode(snd_dir)->data_len == 0);
+	ubifs_assert(mutex_is_locked(&ubifs_inode(fst_dir)->ui_mutex));
+	ubifs_assert(mutex_is_locked(&ubifs_inode(snd_dir)->ui_mutex));
+
+	dlen1 = UBIFS_DENT_NODE_SZ + snd_dentry->d_name.len + 1;
+	dlen2 = UBIFS_DENT_NODE_SZ + fst_dentry->d_name.len + 1;
+	aligned_dlen1 = ALIGN(dlen1, 8);
+	aligned_dlen2 = ALIGN(dlen2, 8);
+
+	len = aligned_dlen1 + aligned_dlen2 + ALIGN(plen, 8);
+	if (twoparents)
+		len += plen;
+
+	dent1 = kmalloc(len, GFP_NOFS);
+	if (!dent1)
+		return -ENOMEM;
+
+	/* Make reservation before allocating sequence numbers */
+	err = make_reservation(c, BASEHD, len);
+	if (err)
+		goto out_free;
+
+	/* Make new dent for 1st entry */
+	dent1->ch.node_type = UBIFS_DENT_NODE;
+	dent_key_init_flash(c, &dent1->key, snd_dir->i_ino, &snd_dentry->d_name);
+	dent1->inum = cpu_to_le64(fst_inode->i_ino);
+	dent1->type = get_dent_type(fst_inode->i_mode);
+	dent1->nlen = cpu_to_le16(snd_dentry->d_name.len);
+	memcpy(dent1->name, snd_dentry->d_name.name, snd_dentry->d_name.len);
+	dent1->name[snd_dentry->d_name.len] = '\0';
+	zero_dent_node_unused(dent1);
+	ubifs_prep_grp_node(c, dent1, dlen1, 0);
+
+	/* Make new dent for 2nd entry */
+	dent2 = (void *)dent1 + aligned_dlen1;
+	dent2->ch.node_type = UBIFS_DENT_NODE;
+	dent_key_init_flash(c, &dent2->key, fst_dir->i_ino, &fst_dentry->d_name);
+	dent2->inum = cpu_to_le64(snd_inode->i_ino);
+	dent2->type = get_dent_type(snd_inode->i_mode);
+	dent2->nlen = cpu_to_le16(fst_dentry->d_name.len);
+	memcpy(dent2->name, fst_dentry->d_name.name, fst_dentry->d_name.len);
+	dent2->name[fst_dentry->d_name.len] = '\0';
+	zero_dent_node_unused(dent2);
+	ubifs_prep_grp_node(c, dent2, dlen2, 0);
+
+	p = (void *)dent2 + aligned_dlen2;
+	if (!twoparents)
+		pack_inode(c, p, fst_dir, 1);
+	else {
+		pack_inode(c, p, fst_dir, 0);
+		p += ALIGN(plen, 8);
+		pack_inode(c, p, snd_dir, 1);
+	}
+
+	err = write_head(c, BASEHD, dent1, len, &lnum, &offs, sync);
+	if (err)
+		goto out_release;
+	if (!sync) {
+		struct ubifs_wbuf *wbuf = &c->jheads[BASEHD].wbuf;
+
+		ubifs_wbuf_add_ino_nolock(wbuf, fst_dir->i_ino);
+		ubifs_wbuf_add_ino_nolock(wbuf, snd_dir->i_ino);
+	}
+	release_head(c, BASEHD);
+
+	dent_key_init(c, &key, snd_dir->i_ino, &snd_dentry->d_name);
+	err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen1, &snd_dentry->d_name);
+	if (err)
+		goto out_ro;
+
+	offs += aligned_dlen1;
+	dent_key_init(c, &key, fst_dir->i_ino, &fst_dentry->d_name);
+	err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen2, &fst_dentry->d_name);
+	if (err)
+		goto out_ro;
+
+	offs += aligned_dlen2;
+
+	ino_key_init(c, &key, fst_dir->i_ino);
+	err = ubifs_tnc_add(c, &key, lnum, offs, plen);
+	if (err)
+		goto out_ro;
+
+	if (twoparents) {
+		offs += ALIGN(plen, 8);
+		ino_key_init(c, &key, snd_dir->i_ino);
+		err = ubifs_tnc_add(c, &key, lnum, offs, plen);
+		if (err)
+			goto out_ro;
+	}
+
+	finish_reservation(c);
+
+	mark_inode_clean(c, ubifs_inode(fst_dir));
+	if (twoparents)
+		mark_inode_clean(c, ubifs_inode(snd_dir));
+	kfree(dent1);
+	return 0;
+
+out_release:
+	release_head(c, BASEHD);
+out_ro:
+	ubifs_ro_mode(c, err);
+	finish_reservation(c);
+out_free:
+	kfree(dent1);
+	return err;
+}
+
+/**
  * ubifs_jnl_rename - rename a directory entry.
  * @c: UBIFS file-system description object
  * @old_dir: parent inode of directory entry to rename
@@ -917,14 +1058,15 @@ int ubifs_jnl_delete_inode(struct ubifs_info *c, const struct inode *inode)
  * @sync: non-zero if the write-buffer has to be synchronized
  *
  * This function implements the re-name operation which may involve writing up
- * to 3 inodes and 2 directory entries. It marks the written inodes as clean
+ * to 4 inodes and 2 directory entries. It marks the written inodes as clean
  * and returns zero on success. In case of failure, a negative error code is
  * returned.
  */
 int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
 		     const struct dentry *old_dentry,
 		     const struct inode *new_dir,
-		     const struct dentry *new_dentry, int sync)
+		     const struct dentry *new_dentry,
+		     const struct inode *whiteout, int sync)
 {
 	void *p;
 	union ubifs_key key;
@@ -958,7 +1100,7 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
 	aligned_dlen1 = ALIGN(dlen1, 8);
 	aligned_dlen2 = ALIGN(dlen2, 8);
 	len = aligned_dlen1 + aligned_dlen2 + ALIGN(ilen, 8) + ALIGN(plen, 8);
-	if (old_dir != new_dir)
+	if (move)
 		len += plen;
 	dent = kmalloc(len, GFP_NOFS);
 	if (!dent)
@@ -980,13 +1122,19 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
 	zero_dent_node_unused(dent);
 	ubifs_prep_grp_node(c, dent, dlen1, 0);
 
-	/* Make deletion dent */
 	dent2 = (void *)dent + aligned_dlen1;
 	dent2->ch.node_type = UBIFS_DENT_NODE;
 	dent_key_init_flash(c, &dent2->key, old_dir->i_ino,
 			    &old_dentry->d_name);
-	dent2->inum = 0;
-	dent2->type = DT_UNKNOWN;
+
+	if (whiteout) {
+		dent2->inum = cpu_to_le64(whiteout->i_ino);
+		dent2->type = get_dent_type(whiteout->i_mode);
+	} else {
+		/* Make deletion dent */
+		dent2->inum = 0;
+		dent2->type = DT_UNKNOWN;
+	}
 	dent2->nlen = cpu_to_le16(old_dentry->d_name.len);
 	memcpy(dent2->name, old_dentry->d_name.name, old_dentry->d_name.len);
 	dent2->name[old_dentry->d_name.len] = '\0';
@@ -1035,16 +1183,26 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
 	if (err)
 		goto out_ro;
 
-	err = ubifs_add_dirt(c, lnum, dlen2);
-	if (err)
-		goto out_ro;
+	offs += aligned_dlen1;
+	if (whiteout) {
+		dent_key_init(c, &key, old_dir->i_ino, &old_dentry->d_name);
+		err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen2, &old_dentry->d_name);
+		if (err)
+			goto out_ro;
 
-	dent_key_init(c, &key, old_dir->i_ino, &old_dentry->d_name);
-	err = ubifs_tnc_remove_nm(c, &key, &old_dentry->d_name);
-	if (err)
-		goto out_ro;
+		ubifs_delete_orphan(c, whiteout->i_ino);
+	} else {
+		err = ubifs_add_dirt(c, lnum, dlen2);
+		if (err)
+			goto out_ro;
+
+		dent_key_init(c, &key, old_dir->i_ino, &old_dentry->d_name);
+		err = ubifs_tnc_remove_nm(c, &key, &old_dentry->d_name);
+		if (err)
+			goto out_ro;
+	}
 
-	offs += aligned_dlen1 + aligned_dlen2;
+	offs += aligned_dlen2;
 	if (new_inode) {
 		ino_key_init(c, &key, new_inode->i_ino);
 		err = ubifs_tnc_add(c, &key, lnum, offs, ilen);
@@ -1058,7 +1216,7 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
 	if (err)
 		goto out_ro;
 
-	if (old_dir != new_dir) {
+	if (move) {
 		offs += ALIGN(plen, 8);
 		ino_key_init(c, &key, new_dir->i_ino);
 		err = ubifs_tnc_add(c, &key, lnum, offs, plen);
diff --git a/fs/ubifs/lprops.c b/fs/ubifs/lprops.c
index a0011aa3a779..6c3a1abd0e22 100644
--- a/fs/ubifs/lprops.c
+++ b/fs/ubifs/lprops.c
@@ -636,7 +636,7 @@ const struct ubifs_lprops *ubifs_change_lp(struct ubifs_info *c,
 /**
  * ubifs_get_lp_stats - get lprops statistics.
  * @c: UBIFS file-system description object
- * @st: return statistics
+ * @lst: return statistics
  */
 void ubifs_get_lp_stats(struct ubifs_info *c, struct ubifs_lp_stats *lst)
 {
diff --git a/fs/ubifs/lpt_commit.c b/fs/ubifs/lpt_commit.c
index ce89bdc3eb02..235654c2fe89 100644
--- a/fs/ubifs/lpt_commit.c
+++ b/fs/ubifs/lpt_commit.c
@@ -34,7 +34,6 @@ static int dbg_populate_lsave(struct ubifs_info *c);
 
 /**
  * first_dirty_cnode - find first dirty cnode.
- * @c: UBIFS file-system description object
  * @nnode: nnode at which to start
  *
  * This function returns the first dirty cnode or %NULL if there is not one.
@@ -1623,7 +1622,6 @@ static int dbg_is_node_dirty(struct ubifs_info *c, int node_type, int lnum,
  * dbg_check_ltab_lnum - check the ltab for a LPT LEB number.
  * @c: the UBIFS file-system description object
  * @lnum: LEB number where node was written
- * @offs: offset where node was written
  *
  * This function returns %0 on success and a negative error code on failure.
  */
@@ -1870,7 +1868,7 @@ int dbg_chk_lpt_sz(struct ubifs_info *c, int action, int len)
 }
 
 /**
- * ubifs_dump_lpt_leb - dump an LPT LEB.
+ * dump_lpt_leb - dump an LPT LEB.
  * @c: UBIFS file-system description object
  * @lnum: LEB number to dump
  *
diff --git a/fs/ubifs/replay.c b/fs/ubifs/replay.c
index 3ca4540130b5..fb0f44cd1e28 100644
--- a/fs/ubifs/replay.c
+++ b/fs/ubifs/replay.c
@@ -267,7 +267,7 @@ static int apply_replay_entry(struct ubifs_info *c, struct replay_entry *r)
  * replay_entries_cmp - compare 2 replay entries.
  * @priv: UBIFS file-system description object
  * @a: first replay entry
- * @a: second replay entry
+ * @b: second replay entry
  *
  * This is a comparios function for 'list_sort()' which compares 2 replay
  * entries @a and @b by comparing their sequence numer.  Returns %1 if @a has
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index 4617d459022a..096035eb29d0 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -157,6 +157,7 @@ enum {
 	WB_MUTEX_1 = 0,
 	WB_MUTEX_2 = 1,
 	WB_MUTEX_3 = 2,
+	WB_MUTEX_4 = 3,
 };
 
 /*
@@ -1520,10 +1521,15 @@ int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode,
 			 const union ubifs_key *key, const void *buf, int len);
 int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode);
 int ubifs_jnl_delete_inode(struct ubifs_info *c, const struct inode *inode);
+int ubifs_jnl_xrename(struct ubifs_info *c, const struct inode *fst_dir,
+		      const struct dentry *fst_dentry,
+		      const struct inode *snd_dir,
+		      const struct dentry *snd_dentry, int sync);
 int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
 		     const struct dentry *old_dentry,
 		     const struct inode *new_dir,
-		     const struct dentry *new_dentry, int sync);
+		     const struct dentry *new_dentry,
+		     const struct inode *whiteout, int sync);
 int ubifs_jnl_truncate(struct ubifs_info *c, const struct inode *inode,
 		       loff_t old_size, loff_t new_size);
 int ubifs_jnl_delete_xattr(struct ubifs_info *c, const struct inode *host,
diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c
index 11a004114eba..6c2f4d41ed73 100644
--- a/fs/ubifs/xattr.c
+++ b/fs/ubifs/xattr.c
@@ -200,6 +200,7 @@ static int change_xattr(struct ubifs_info *c, struct inode *host,
 	struct ubifs_inode *host_ui = ubifs_inode(host);
 	struct ubifs_inode *ui = ubifs_inode(inode);
 	void *buf = NULL;
+	int old_size;
 	struct ubifs_budget_req req = { .dirtied_ino = 2,
 		.dirtied_ino_d = ALIGN(size, 8) + ALIGN(host_ui->data_len, 8) };
 
@@ -217,12 +218,13 @@ static int change_xattr(struct ubifs_info *c, struct inode *host,
 	kfree(ui->data);
 	ui->data = buf;
 	inode->i_size = ui->ui_size = size;
+	old_size = ui->data_len;
 	ui->data_len = size;
 	mutex_unlock(&ui->ui_mutex);
 
 	mutex_lock(&host_ui->ui_mutex);
 	host->i_ctime = ubifs_current_time(host);
-	host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len);
+	host_ui->xattr_size -= CALC_XATTR_BYTES(old_size);
 	host_ui->xattr_size += CALC_XATTR_BYTES(size);
 
 	/*
@@ -241,7 +243,7 @@ static int change_xattr(struct ubifs_info *c, struct inode *host,
 
 out_cancel:
 	host_ui->xattr_size -= CALC_XATTR_BYTES(size);
-	host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len);
+	host_ui->xattr_size += CALC_XATTR_BYTES(old_size);
 	mutex_unlock(&host_ui->ui_mutex);
 	make_bad_inode(inode);
 out_free: