mtd, ubi, ubifs: resync with Linux-3.14

resync ubi subsystem with linux:

commit 455c6fdbd219161bd09b1165f11699d6d73de11c
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sun Mar 30 20:40:15 2014 -0700

    Linux 3.14

A nice side effect of this, is we introduce UBI Fastmap support
to U-Boot.

Signed-off-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Tom Rini <trini@ti.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Sergey Lapin <slapin@ossfans.org>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Joerg Krause <jkrause@posteo.de>

1 files changed, 1791 insertions, 298 deletions

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 748ab6792d..9c87db40d3 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -3,18 +3,7 @@
  *
  * Copyright (C) 2006-2008 Nokia Corporation.
  *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published by
- * the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 51
- * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ * SPDX-License-Identifier:	GPL-2.0+
  *
  * Authors: Artem Bityutskiy (Битюцкий Артём)
  *          Adrian Hunter
@@ -26,103 +15,45 @@
  * corresponding subsystems, but most of it is here.
  */
 
-#include "ubifs.h"
+#define __UBOOT__
+#ifndef __UBOOT__
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/ctype.h>
+#include <linux/kthread.h>
+#include <linux/parser.h>
+#include <linux/seq_file.h>
+#include <linux/mount.h>
 #include <linux/math64.h>
+#include <linux/writeback.h>
+#else
 
-#define INODE_LOCKED_MAX	64
+#include <linux/compat.h>
+#include <linux/stat.h>
+#include <linux/err.h>
+#include "ubifs.h"
+#include <ubi_uboot.h>
+#include <mtd/ubi-user.h>
 
-struct super_block *ubifs_sb;
-static struct inode *inodes_locked_down[INODE_LOCKED_MAX];
+struct dentry;
+struct file;
+struct iattr;
+struct kstat;
+struct vfsmount;
 
-/* shrinker.c */
+#define INODE_LOCKED_MAX	64
 
-/* List of all UBIFS file-system instances */
-struct list_head ubifs_infos;
+struct super_block *ubifs_sb;
+LIST_HEAD(super_blocks);
 
-/* linux/fs/super.c */
+static struct inode *inodes_locked_down[INODE_LOCKED_MAX];
 
-static int sb_set(struct super_block *sb, void *data)
+int set_anon_super(struct super_block *s, void *data)
 {
-	dev_t *dev = data;
-
-	sb->s_dev = *dev;
 	return 0;
 }
 
-/**
- *	sget	-	find or create a superblock
- *	@type:	filesystem type superblock should belong to
- *	@test:	comparison callback
- *	@set:	setup callback
- *	@data:	argument to each of them
- */
-struct super_block *sget(struct file_system_type *type,
-			int (*test)(struct super_block *,void *),
-			int (*set)(struct super_block *,void *),
-			void *data)
-{
-	struct super_block *s = NULL;
-	int err;
-
-	s = kzalloc(sizeof(struct super_block),  GFP_USER);
-	if (!s) {
-		err = -ENOMEM;
-		return ERR_PTR(err);
-	}
-
-	INIT_LIST_HEAD(&s->s_instances);
-	INIT_LIST_HEAD(&s->s_inodes);
-	s->s_time_gran = 1000000000;
-
-	err = set(s, data);
-	if (err) {
-		return ERR_PTR(err);
-	}
-	s->s_type = type;
-	strncpy(s->s_id, type->name, sizeof(s->s_id));
-	list_add(&s->s_instances, &type->fs_supers);
-	return s;
-}
-
-/**
- * validate_inode - validate inode.
- * @c: UBIFS file-system description object
- * @inode: the inode to validate
- *
- * This is a helper function for 'ubifs_iget()' which validates various fields
- * of a newly built inode to make sure they contain sane values and prevent
- * possible vulnerabilities. Returns zero if the inode is all right and
- * a non-zero error code if not.
- */
-static int validate_inode(struct ubifs_info *c, const struct inode *inode)
-{
-	int err;
-	const struct ubifs_inode *ui = ubifs_inode(inode);
-
-	if (inode->i_size > c->max_inode_sz) {
-		ubifs_err("inode is too large (%lld)",
-			  (long long)inode->i_size);
-		return 1;
-	}
-
-	if (ui->compr_type < 0 || ui->compr_type >= UBIFS_COMPR_TYPES_CNT) {
-		ubifs_err("unknown compression type %d", ui->compr_type);
-		return 2;
-	}
-
-	if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA)
-		return 4;
-
-	if (!ubifs_compr_present(ui->compr_type)) {
-		ubifs_warn("inode %lu uses '%s' compression, but it was not "
-			   "compiled in", inode->i_ino,
-			   ubifs_compr_name(ui->compr_type));
-	}
-
-	err = dbg_check_dir_size(c, inode);
-	return err;
-}
-
 struct inode *iget_locked(struct super_block *sb, unsigned long ino)
 {
 	struct inode *inode;
@@ -138,6 +69,10 @@ struct inode *iget_locked(struct super_block *sb, unsigned long ino)
 	return inode;
 }
 
+void iget_failed(struct inode *inode)
+{
+}
+
 int ubifs_iput(struct inode *inode)
 {
 	list_del_init(&inode->i_sb_list);
@@ -179,6 +114,125 @@ void iput(struct inode *inode)
 	inodes_locked_down[i] = ino;
 }
 
+/* from fs/inode.c */
+/**
+ * clear_nlink - directly zero an inode's link count
+ * @inode: inode
+ *
+ * This is a low-level filesystem helper to replace any
+ * direct filesystem manipulation of i_nlink.  See
+ * drop_nlink() for why we care about i_nlink hitting zero.
+ */
+void clear_nlink(struct inode *inode)
+{
+	if (inode->i_nlink) {
+		inode->__i_nlink = 0;
+		atomic_long_inc(&inode->i_sb->s_remove_count);
+	}
+}
+EXPORT_SYMBOL(clear_nlink);
+
+/**
+ * set_nlink - directly set an inode's link count
+ * @inode: inode
+ * @nlink: new nlink (should be non-zero)
+ *
+ * This is a low-level filesystem helper to replace any
+ * direct filesystem manipulation of i_nlink.
+ */
+void set_nlink(struct inode *inode, unsigned int nlink)
+{
+	if (!nlink) {
+		clear_nlink(inode);
+	} else {
+		/* Yes, some filesystems do change nlink from zero to one */
+		if (inode->i_nlink == 0)
+			atomic_long_dec(&inode->i_sb->s_remove_count);
+
+		inode->__i_nlink = nlink;
+	}
+}
+EXPORT_SYMBOL(set_nlink);
+
+/* from include/linux/fs.h */
+static inline void i_uid_write(struct inode *inode, uid_t uid)
+{
+	inode->i_uid.val = uid;
+}
+
+static inline void i_gid_write(struct inode *inode, gid_t gid)
+{
+	inode->i_gid.val = gid;
+}
+
+void unlock_new_inode(struct inode *inode)
+{
+	return;
+}
+#endif
+
+/*
+ * Maximum amount of memory we may 'kmalloc()' without worrying that we are
+ * allocating too much.
+ */
+#define UBIFS_KMALLOC_OK (128*1024)
+
+/* Slab cache for UBIFS inodes */
+struct kmem_cache *ubifs_inode_slab;
+
+#ifndef __UBOOT__
+/* UBIFS TNC shrinker description */
+static struct shrinker ubifs_shrinker_info = {
+	.scan_objects = ubifs_shrink_scan,
+	.count_objects = ubifs_shrink_count,
+	.seeks = DEFAULT_SEEKS,
+};
+#endif
+
+/**
+ * validate_inode - validate inode.
+ * @c: UBIFS file-system description object
+ * @inode: the inode to validate
+ *
+ * This is a helper function for 'ubifs_iget()' which validates various fields
+ * of a newly built inode to make sure they contain sane values and prevent
+ * possible vulnerabilities. Returns zero if the inode is all right and
+ * a non-zero error code if not.
+ */
+static int validate_inode(struct ubifs_info *c, const struct inode *inode)
+{
+	int err;
+	const struct ubifs_inode *ui = ubifs_inode(inode);
+
+	if (inode->i_size > c->max_inode_sz) {
+		ubifs_err("inode is too large (%lld)",
+			  (long long)inode->i_size);
+		return 1;
+	}
+
+	if (ui->compr_type < 0 || ui->compr_type >= UBIFS_COMPR_TYPES_CNT) {
+		ubifs_err("unknown compression type %d", ui->compr_type);
+		return 2;
+	}
+
+	if (ui->xattr_names + ui->xattr_cnt > XATTR_LIST_MAX)
+		return 3;
+
+	if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA)
+		return 4;
+
+	if (ui->xattr && !S_ISREG(inode->i_mode))
+		return 5;
+
+	if (!ubifs_compr_present(ui->compr_type)) {
+		ubifs_warn("inode %lu uses '%s' compression, but it was not compiled in",
+			   inode->i_ino, ubifs_compr_name(ui->compr_type));
+	}
+
+	err = dbg_check_dir(c, inode);
+	return err;
+}
+
 struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
 {
 	int err;
@@ -187,10 +241,13 @@ struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
 	struct ubifs_info *c = sb->s_fs_info;
 	struct inode *inode;
 	struct ubifs_inode *ui;
+#ifdef __UBOOT__
 	int i;
+#endif
 
 	dbg_gen("inode %lu", inum);
 
+#ifdef __UBOOT__
 	/*
 	 * U-Boot special handling of locked down inodes via recovery
 	 * e.g. ubifs_recover_size()
@@ -211,6 +268,7 @@ struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
 			return inodes_locked_down[i];
 		}
 	}
+#endif
 
 	inode = iget_locked(sb, inum);
 	if (!inode)
@@ -232,9 +290,9 @@ struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
 		goto out_ino;
 
 	inode->i_flags |= (S_NOCMTIME | S_NOATIME);
-	inode->i_nlink = le32_to_cpu(ino->nlink);
-	inode->i_uid   = le32_to_cpu(ino->uid);
-	inode->i_gid   = le32_to_cpu(ino->gid);
+	set_nlink(inode, le32_to_cpu(ino->nlink));
+	i_uid_write(inode, le32_to_cpu(ino->uid));
+	i_gid_write(inode, le32_to_cpu(ino->gid));
 	inode->i_atime.tv_sec  = (int64_t)le64_to_cpu(ino->atime_sec);
 	inode->i_atime.tv_nsec = le32_to_cpu(ino->atime_nsec);
 	inode->i_mtime.tv_sec  = (int64_t)le64_to_cpu(ino->mtime_sec);
@@ -248,12 +306,101 @@ struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
 	ui->flags       = le32_to_cpu(ino->flags);
 	ui->compr_type  = le16_to_cpu(ino->compr_type);
 	ui->creat_sqnum = le64_to_cpu(ino->creat_sqnum);
+	ui->xattr_cnt   = le32_to_cpu(ino->xattr_cnt);
+	ui->xattr_size  = le32_to_cpu(ino->xattr_size);
+	ui->xattr_names = le32_to_cpu(ino->xattr_names);
 	ui->synced_i_size = ui->ui_size = inode->i_size;
 
+	ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0;
+
 	err = validate_inode(c, inode);
 	if (err)
 		goto out_invalid;
 
+#ifndef __UBOOT__
+	/* Disable read-ahead */
+	inode->i_mapping->backing_dev_info = &c->bdi;
+
+	switch (inode->i_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;
+		if (ui->xattr) {
+			ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
+			if (!ui->data) {
+				err = -ENOMEM;
+				goto out_ino;
+			}
+			memcpy(ui->data, ino->data, ui->data_len);
+			((char *)ui->data)[ui->data_len] = '\0';
+		} else if (ui->data_len != 0) {
+			err = 10;
+			goto out_invalid;
+		}
+		break;
+	case S_IFDIR:
+		inode->i_op  = &ubifs_dir_inode_operations;
+		inode->i_fop = &ubifs_dir_operations;
+		if (ui->data_len != 0) {
+			err = 11;
+			goto out_invalid;
+		}
+		break;
+	case S_IFLNK:
+		inode->i_op = &ubifs_symlink_inode_operations;
+		if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) {
+			err = 12;
+			goto out_invalid;
+		}
+		ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
+		if (!ui->data) {
+			err = -ENOMEM;
+			goto out_ino;
+		}
+		memcpy(ui->data, ino->data, ui->data_len);
+		((char *)ui->data)[ui->data_len] = '\0';
+		break;
+	case S_IFBLK:
+	case S_IFCHR:
+	{
+		dev_t rdev;
+		union ubifs_dev_desc *dev;
+
+		ui->data = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
+		if (!ui->data) {
+			err = -ENOMEM;
+			goto out_ino;
+		}
+
+		dev = (union ubifs_dev_desc *)ino->data;
+		if (ui->data_len == sizeof(dev->new))
+			rdev = new_decode_dev(le32_to_cpu(dev->new));
+		else if (ui->data_len == sizeof(dev->huge))
+			rdev = huge_decode_dev(le64_to_cpu(dev->huge));
+		else {
+			err = 13;
+			goto out_invalid;
+		}
+		memcpy(ui->data, ino->data, ui->data_len);
+		inode->i_op = &ubifs_file_inode_operations;
+		init_special_inode(inode, inode->i_mode, rdev);
+		break;
+	}
+	case S_IFSOCK:
+	case S_IFIFO:
+		inode->i_op = &ubifs_file_inode_operations;
+		init_special_inode(inode, inode->i_mode, 0);
+		if (ui->data_len != 0) {
+			err = 14;
+			goto out_invalid;
+		}
+		break;
+	default:
+		err = 15;
+		goto out_invalid;
+	}
+#else
 	if ((inode->i_mode & S_IFMT) == S_IFLNK) {
 		if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) {
 			err = 12;
@@ -267,23 +414,258 @@ struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
 		memcpy(ui->data, ino->data, ui->data_len);
 		((char *)ui->data)[ui->data_len] = '\0';
 	}
+#endif
 
 	kfree(ino);
-	inode->i_state &= ~(I_LOCK | I_NEW);
+#ifndef __UBOOT__
+	ubifs_set_inode_flags(inode);
+#endif
+	unlock_new_inode(inode);
 	return inode;
 
 out_invalid:
 	ubifs_err("inode %lu validation failed, error %d", inode->i_ino, err);
-	dbg_dump_node(c, ino);
-	dbg_dump_inode(c, inode);
+	ubifs_dump_node(c, ino);
+	ubifs_dump_inode(c, inode);
 	err = -EINVAL;
 out_ino:
 	kfree(ino);
 out:
 	ubifs_err("failed to read inode %lu, error %d", inode->i_ino, err);
+	iget_failed(inode);
 	return ERR_PTR(err);
 }
 
+static struct inode *ubifs_alloc_inode(struct super_block *sb)
+{
+	struct ubifs_inode *ui;
+
+	ui = kmem_cache_alloc(ubifs_inode_slab, GFP_NOFS);
+	if (!ui)
+		return NULL;
+
+	memset((void *)ui + sizeof(struct inode), 0,
+	       sizeof(struct ubifs_inode) - sizeof(struct inode));
+	mutex_init(&ui->ui_mutex);
+	spin_lock_init(&ui->ui_lock);
+	return &ui->vfs_inode;
+};
+
+#ifndef __UBOOT__
+static void ubifs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	struct ubifs_inode *ui = ubifs_inode(inode);
+	kmem_cache_free(ubifs_inode_slab, ui);
+}
+
+static void ubifs_destroy_inode(struct inode *inode)
+{
+	struct ubifs_inode *ui = ubifs_inode(inode);
+
+	kfree(ui->data);
+	call_rcu(&inode->i_rcu, ubifs_i_callback);
+}
+
+/*
+ * Note, Linux write-back code calls this without 'i_mutex'.
+ */
+static int ubifs_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	int err = 0;
+	struct ubifs_info *c = inode->i_sb->s_fs_info;
+	struct ubifs_inode *ui = ubifs_inode(inode);
+
+	ubifs_assert(!ui->xattr);
+	if (is_bad_inode(inode))
+		return 0;
+
+	mutex_lock(&ui->ui_mutex);
+	/*
+	 * Due to races between write-back forced by budgeting
+	 * (see 'sync_some_inodes()') and background write-back, the inode may
+	 * have already been synchronized, do not do this again. This might
+	 * also happen if it was synchronized in an VFS operation, e.g.
+	 * 'ubifs_link()'.
+	 */
+	if (!ui->dirty) {
+		mutex_unlock(&ui->ui_mutex);
+		return 0;
+	}
+
+	/*
+	 * As an optimization, do not write orphan inodes to the media just
+	 * because this is not needed.
+	 */
+	dbg_gen("inode %lu, mode %#x, nlink %u",
+		inode->i_ino, (int)inode->i_mode, inode->i_nlink);
+	if (inode->i_nlink) {
+		err = ubifs_jnl_write_inode(c, inode);
+		if (err)
+			ubifs_err("can't write inode %lu, error %d",
+				  inode->i_ino, err);
+		else
+			err = dbg_check_inode_size(c, inode, ui->ui_size);
+	}
+
+	ui->dirty = 0;
+	mutex_unlock(&ui->ui_mutex);
+	ubifs_release_dirty_inode_budget(c, ui);
+	return err;
+}
+
+static void ubifs_evict_inode(struct inode *inode)
+{
+	int err;
+	struct ubifs_info *c = inode->i_sb->s_fs_info;
+	struct ubifs_inode *ui = ubifs_inode(inode);
+
+	if (ui->xattr)
+		/*
+		 * Extended attribute inode deletions are fully handled in
+		 * 'ubifs_removexattr()'. These inodes are special and have
+		 * limited usage, so there is nothing to do here.
+		 */
+		goto out;
+
+	dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode);
+	ubifs_assert(!atomic_read(&inode->i_count));
+
+	truncate_inode_pages(&inode->i_data, 0);
+
+	if (inode->i_nlink)
+		goto done;
+
+	if (is_bad_inode(inode))
+		goto out;
+
+	ui->ui_size = inode->i_size = 0;
+	err = ubifs_jnl_delete_inode(c, inode);
+	if (err)
+		/*
+		 * Worst case we have a lost orphan inode wasting space, so a
+		 * simple error message is OK here.
+		 */
+		ubifs_err("can't delete inode %lu, error %d",
+			  inode->i_ino, err);
+
+out:
+	if (ui->dirty)
+		ubifs_release_dirty_inode_budget(c, ui);
+	else {
+		/* We've deleted something - clean the "no space" flags */
+		c->bi.nospace = c->bi.nospace_rp = 0;
+		smp_wmb();
+	}
+done:
+	clear_inode(inode);
+}
+#endif
+
+static void ubifs_dirty_inode(struct inode *inode, int flags)
+{
+	struct ubifs_inode *ui = ubifs_inode(inode);
+
+	ubifs_assert(mutex_is_locked(&ui->ui_mutex));
+	if (!ui->dirty) {
+		ui->dirty = 1;
+		dbg_gen("inode %lu",  inode->i_ino);
+	}
+}
+
+#ifndef __UBOOT__
+static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct ubifs_info *c = dentry->d_sb->s_fs_info;
+	unsigned long long free;
+	__le32 *uuid = (__le32 *)c->uuid;
+
+	free = ubifs_get_free_space(c);
+	dbg_gen("free space %lld bytes (%lld blocks)",
+		free, free >> UBIFS_BLOCK_SHIFT);
+
+	buf->f_type = UBIFS_SUPER_MAGIC;
+	buf->f_bsize = UBIFS_BLOCK_SIZE;
+	buf->f_blocks = c->block_cnt;
+	buf->f_bfree = free >> UBIFS_BLOCK_SHIFT;
+	if (free > c->report_rp_size)
+		buf->f_bavail = (free - c->report_rp_size) >> UBIFS_BLOCK_SHIFT;
+	else
+		buf->f_bavail = 0;
+	buf->f_files = 0;
+	buf->f_ffree = 0;
+	buf->f_namelen = UBIFS_MAX_NLEN;
+	buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]);
+	buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]);
+	ubifs_assert(buf->f_bfree <= c->block_cnt);
+	return 0;
+}
+
+static int ubifs_show_options(struct seq_file *s, struct dentry *root)
+{
+	struct ubifs_info *c = root->d_sb->s_fs_info;
+
+	if (c->mount_opts.unmount_mode == 2)
+		seq_printf(s, ",fast_unmount");
+	else if (c->mount_opts.unmount_mode == 1)
+		seq_printf(s, ",norm_unmount");
+
+	if (c->mount_opts.bulk_read == 2)
+		seq_printf(s, ",bulk_read");
+	else if (c->mount_opts.bulk_read == 1)
+		seq_printf(s, ",no_bulk_read");
+
+	if (c->mount_opts.chk_data_crc == 2)
+		seq_printf(s, ",chk_data_crc");
+	else if (c->mount_opts.chk_data_crc == 1)
+		seq_printf(s, ",no_chk_data_crc");
+
+	if (c->mount_opts.override_compr) {
+		seq_printf(s, ",compr=%s",
+			   ubifs_compr_name(c->mount_opts.compr_type));
+	}
+
+	return 0;
+}
+
+static int ubifs_sync_fs(struct super_block *sb, int wait)
+{
+	int i, err;
+	struct ubifs_info *c = sb->s_fs_info;
+
+	/*
+	 * Zero @wait is just an advisory thing to help the file system shove
+	 * lots of data into the queues, and there will be the second
+	 * '->sync_fs()' call, with non-zero @wait.
+	 */
+	if (!wait)
+		return 0;
+
+	/*
+	 * Synchronize write buffers, because 'ubifs_run_commit()' does not
+	 * do this if it waits for an already running commit.
+	 */
+	for (i = 0; i < c->jhead_cnt; i++) {
+		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
+		if (err)
+			return err;
+	}
+
+	/*
+	 * Strictly speaking, it is not necessary to commit the journal here,
+	 * synchronizing write-buffers would be enough. But committing makes
+	 * UBIFS free space predictions much more accurate, so we want to let
+	 * the user be able to get more accurate results of 'statfs()' after
+	 * they synchronize the file system.
+	 */
+	err = ubifs_run_commit(c);
+	if (err)
+		return err;
+
+	return ubi_sync(c->vi.ubi_num);
+}
+#endif
+
 /**
  * init_constants_early - initialize UBIFS constants.
  * @c: UBIFS file-system description object
@@ -312,9 +694,12 @@ static int init_constants_early(struct ubifs_info *c)
 
 	c->leb_cnt = c->vi.size;
 	c->leb_size = c->vi.usable_leb_size;
+	c->leb_start = c->di.leb_start;
 	c->half_leb_size = c->leb_size / 2;
 	c->min_io_size = c->di.min_io_size;
 	c->min_io_shift = fls(c->min_io_size) - 1;
+	c->max_write_size = c->di.max_write_size;
+	c->max_write_shift = fls(c->max_write_size) - 1;
 
 	if (c->leb_size < UBIFS_MIN_LEB_SZ) {
 		ubifs_err("too small LEBs (%d bytes), min. is %d bytes",
@@ -334,6 +719,18 @@ static int init_constants_early(struct ubifs_info *c)
 	}
 
 	/*
+	 * Maximum write size has to be greater or equivalent to min. I/O
+	 * size, and be multiple of min. I/O size.
+	 */
+	if (c->max_write_size < c->min_io_size ||
+	    c->max_write_size % c->min_io_size ||
+	    !is_power_of_2(c->max_write_size)) {
+		ubifs_err("bad write buffer size %d for %d min. I/O unit",
+			  c->max_write_size, c->min_io_size);
+		return -EINVAL;
+	}
+
+	/*
 	 * UBIFS aligns all node to 8-byte boundary, so to make function in
 	 * io.c simpler, assume minimum I/O unit size to be 8 bytes if it is
 	 * less than 8.
@@ -341,6 +738,10 @@ static int init_constants_early(struct ubifs_info *c)
 	if (c->min_io_size < 8) {
 		c->min_io_size = 8;
 		c->min_io_shift = 3;
+		if (c->max_write_size < c->min_io_size) {
+			c->max_write_size = c->min_io_size;
+			c->max_write_shift = c->min_io_shift;
+		}
 	}
 
 	c->ref_node_alsz = ALIGN(UBIFS_REF_NODE_SZ, c->min_io_size);
@@ -393,9 +794,33 @@ static int init_constants_early(struct ubifs_info *c)
 	 */
 	c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ;
 
+	/* Buffer size for bulk-reads */
+	c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ;
+	if (c->max_bu_buf_len > c->leb_size)
+		c->max_bu_buf_len = c->leb_size;
 	return 0;
 }
 
+/**
+ * bud_wbuf_callback - bud LEB write-buffer synchronization call-back.
+ * @c: UBIFS file-system description object
+ * @lnum: LEB the write-buffer was synchronized to
+ * @free: how many free bytes left in this LEB
+ * @pad: how many bytes were padded
+ *
+ * This is a callback function which is called by the I/O unit when the
+ * write-buffer is synchronized. We need this to correctly maintain space
+ * accounting in bud logical eraseblocks. This function returns zero in case of
+ * success and a negative error code in case of failure.
+ *
+ * This function actually belongs to the journal, but we keep it here because
+ * we want to keep it static.
+ */
+static int bud_wbuf_callback(struct ubifs_info *c, int lnum, int free, int pad)
+{
+	return ubifs_update_one_lp(c, lnum, free, pad, 0, 0);
+}
+
 /*
  * init_constants_sb - initialize UBIFS constants.
  * @c: UBIFS file-system description object
@@ -426,8 +851,8 @@ static int init_constants_sb(struct ubifs_info *c)
 	tmp = UBIFS_CS_NODE_SZ + UBIFS_REF_NODE_SZ * c->jhead_cnt;
 	tmp = ALIGN(tmp, c->min_io_size);
 	if (tmp > c->leb_size) {
-		dbg_err("too small LEB size %d, at least %d needed",
-			c->leb_size, tmp);
+		ubifs_err("too small LEB size %d, at least %d needed",
+			  c->leb_size, tmp);
 		return -EINVAL;
 	}
 
@@ -441,8 +866,8 @@ static int init_constants_sb(struct ubifs_info *c)
 	tmp /= c->leb_size;
 	tmp += 1;
 	if (c->log_lebs < tmp) {
-		dbg_err("too small log %d LEBs, required min. %d LEBs",
-			c->log_lebs, tmp);
+		ubifs_err("too small log %d LEBs, required min. %d LEBs",
+			  c->log_lebs, tmp);
 		return -EINVAL;
 	}
 
@@ -451,11 +876,11 @@ static int init_constants_sb(struct ubifs_info *c)
 	 * be compressed and direntries are of the maximum size.
 	 *
 	 * Note, data, which may be stored in inodes is budgeted separately, so
-	 * it is not included into 'c->inode_budget'.
+	 * it is not included into 'c->bi.inode_budget'.
 	 */
-	c->page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;
-	c->inode_budget = UBIFS_INO_NODE_SZ;
-	c->dent_budget = UBIFS_MAX_DENT_NODE_SZ;
+	c->bi.page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;
+	c->bi.inode_budget = UBIFS_INO_NODE_SZ;
+	c->bi.dent_budget = UBIFS_MAX_DENT_NODE_SZ;
 
 	/*
 	 * When the amount of flash space used by buds becomes
@@ -482,6 +907,8 @@ static int init_constants_sb(struct ubifs_info *c)
 	if (err)
 		return err;
 
+	/* Initialize effective LEB size used in budgeting calculations */
+	c->idx_leb_size = c->leb_size - c->max_idx_node_sz;
 	return 0;
 }
 
@@ -497,7 +924,8 @@ static void init_constants_master(struct ubifs_info *c)
 {
 	long long tmp64;
 
-	c->min_idx_lebs = ubifs_calc_min_idx_lebs(c);
+	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
+	c->report_rp_size = ubifs_reported_space(c, c->rp_size);
 
 	/*
 	 * Calculate total amount of FS blocks. This number is not used
@@ -515,6 +943,88 @@ static void init_constants_master(struct ubifs_info *c)
 }
 
 /**
+ * take_gc_lnum - reserve GC LEB.
+ * @c: UBIFS file-system description object
+ *
+ * This function ensures that the LEB reserved for garbage collection is marked
+ * as "taken" in lprops. We also have to set free space to LEB size and dirty
+ * space to zero, because lprops may contain out-of-date information if the
+ * file-system was un-mounted before it has been committed. This function
+ * returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+static int take_gc_lnum(struct ubifs_info *c)
+{
+	int err;
+
+	if (c->gc_lnum == -1) {
+		ubifs_err("no LEB for GC");
+		return -EINVAL;
+	}
+
+	/* And we have to tell lprops that this LEB is taken */
+	err = ubifs_change_one_lp(c, c->gc_lnum, c->leb_size, 0,
+				  LPROPS_TAKEN, 0, 0);
+	return err;
+}
+
+/**
+ * alloc_wbufs - allocate write-buffers.
+ * @c: UBIFS file-system description object
+ *
+ * This helper function allocates and initializes UBIFS write-buffers. Returns
+ * zero in case of success and %-ENOMEM in case of failure.
+ */
+static int alloc_wbufs(struct ubifs_info *c)
+{
+	int i, err;
+
+	c->jheads = kzalloc(c->jhead_cnt * sizeof(struct ubifs_jhead),
+			   GFP_KERNEL);
+	if (!c->jheads)
+		return -ENOMEM;
+
+	/* Initialize journal heads */
+	for (i = 0; i < c->jhead_cnt; i++) {
+		INIT_LIST_HEAD(&c->jheads[i].buds_list);
+		err = ubifs_wbuf_init(c, &c->jheads[i].wbuf);
+		if (err)
+			return err;
+
+		c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback;
+		c->jheads[i].wbuf.jhead = i;
+		c->jheads[i].grouped = 1;
+	}
+
+	/*
+	 * Garbage Collector head does not need to be synchronized by timer.
+	 * Also GC head nodes are not grouped.
+	 */
+	c->jheads[GCHD].wbuf.no_timer = 1;
+	c->jheads[GCHD].grouped = 0;
+
+	return 0;
+}
+
+/**
+ * free_wbufs - free write-buffers.
+ * @c: UBIFS file-system description object
+ */
+static void free_wbufs(struct ubifs_info *c)
+{
+	int i;
+
+	if (c->jheads) {
+		for (i = 0; i < c->jhead_cnt; i++) {
+			kfree(c->jheads[i].wbuf.buf);
+			kfree(c->jheads[i].wbuf.inodes);
+		}
+		kfree(c->jheads);
+		c->jheads = NULL;
+	}
+}
+
+/**
  * free_orphans - free orphans.
  * @c: UBIFS file-system description object
  */
@@ -533,13 +1043,27 @@ static void free_orphans(struct ubifs_info *c)
 		orph = list_entry(c->orph_list.next, struct ubifs_orphan, list);
 		list_del(&orph->list);
 		kfree(orph);
-		dbg_err("orphan list not empty at unmount");
+		ubifs_err("orphan list not empty at unmount");
 	}
 
 	vfree(c->orph_buf);
 	c->orph_buf = NULL;
 }
 
+#ifndef __UBOOT__
+/**
+ * free_buds - free per-bud objects.
+ * @c: UBIFS file-system description object
+ */
+static void free_buds(struct ubifs_info *c)
+{
+	struct ubifs_bud *bud, *n;
+
+	rbtree_postorder_for_each_entry_safe(bud, n, &c->buds, rb)
+		kfree(bud);
+}
+#endif
+
 /**
  * check_volume_empty - check if the UBI volume is empty.
  * @c: UBIFS file-system description object
@@ -555,7 +1079,7 @@ static int check_volume_empty(struct ubifs_info *c)
 
 	c->empty = 1;
 	for (lnum = 0; lnum < c->leb_cnt; lnum++) {
-		err = ubi_is_mapped(c->ubi, lnum);
+		err = ubifs_is_mapped(c, lnum);
 		if (unlikely(err < 0))
 			return err;
 		if (err == 1) {
@@ -569,23 +1093,258 @@ static int check_volume_empty(struct ubifs_info *c)
 	return 0;
 }
 
+/*
+ * UBIFS mount options.
+ *
+ * Opt_fast_unmount: do not run a journal commit before un-mounting
+ * Opt_norm_unmount: run a journal commit before un-mounting
+ * Opt_bulk_read: enable bulk-reads
+ * Opt_no_bulk_read: disable bulk-reads
+ * Opt_chk_data_crc: check CRCs when reading data nodes
+ * Opt_no_chk_data_crc: do not check CRCs when reading data nodes
+ * Opt_override_compr: override default compressor
+ * Opt_err: just end of array marker
+ */
+enum {
+	Opt_fast_unmount,
+	Opt_norm_unmount,
+	Opt_bulk_read,
+	Opt_no_bulk_read,
+	Opt_chk_data_crc,
+	Opt_no_chk_data_crc,
+	Opt_override_compr,
+	Opt_err,
+};
+
+#ifndef __UBOOT__
+static const match_table_t tokens = {
+	{Opt_fast_unmount, "fast_unmount"},
+	{Opt_norm_unmount, "norm_unmount"},
+	{Opt_bulk_read, "bulk_read"},
+	{Opt_no_bulk_read, "no_bulk_read"},
+	{Opt_chk_data_crc, "chk_data_crc"},
+	{Opt_no_chk_data_crc, "no_chk_data_crc"},
+	{Opt_override_compr, "compr=%s"},
+	{Opt_err, NULL},
+};
+
+/**
+ * parse_standard_option - parse a standard mount option.
+ * @option: the option to parse
+ *
+ * Normally, standard mount options like "sync" are passed to file-systems as
+ * flags. However, when a "rootflags=" kernel boot parameter is used, they may
+ * be present in the options string. This function tries to deal with this
+ * situation and parse standard options. Returns 0 if the option was not
+ * recognized, and the corresponding integer flag if it was.
+ *
+ * UBIFS is only interested in the "sync" option, so do not check for anything
+ * else.
+ */
+static int parse_standard_option(const char *option)
+{
+	ubifs_msg("parse %s", option);
+	if (!strcmp(option, "sync"))
+		return MS_SYNCHRONOUS;
+	return 0;
+}
+
+/**
+ * ubifs_parse_options - parse mount parameters.
+ * @c: UBIFS file-system description object
+ * @options: parameters to parse
+ * @is_remount: non-zero if this is FS re-mount
+ *
+ * This function parses UBIFS mount options and returns zero in case success
+ * and a negative error code in case of failure.
+ */
+static int ubifs_parse_options(struct ubifs_info *c, char *options,
+			       int is_remount)
+{
+	char *p;
+	substring_t args[MAX_OPT_ARGS];
+
+	if (!options)
+		return 0;
+
+	while ((p = strsep(&options, ","))) {
+		int token;
+
+		if (!*p)
+			continue;
+
+		token = match_token(p, tokens, args);
+		switch (token) {
+		/*
+		 * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.
+		 * We accept them in order to be backward-compatible. But this
+		 * should be removed at some point.
+		 */
+		case Opt_fast_unmount:
+			c->mount_opts.unmount_mode = 2;
+			break;
+		case Opt_norm_unmount:
+			c->mount_opts.unmount_mode = 1;
+			break;
+		case Opt_bulk_read:
+			c->mount_opts.bulk_read = 2;
+			c->bulk_read = 1;
+			break;
+		case Opt_no_bulk_read:
+			c->mount_opts.bulk_read = 1;
+			c->bulk_read = 0;
+			break;
+		case Opt_chk_data_crc:
+			c->mount_opts.chk_data_crc = 2;
+			c->no_chk_data_crc = 0;
+			break;
+		case Opt_no_chk_data_crc:
+			c->mount_opts.chk_data_crc = 1;
+			c->no_chk_data_crc = 1;
+			break;
+		case Opt_override_compr:
+		{
+			char *name = match_strdup(&args[0]);
+
+			if (!name)
+				return -ENOMEM;
+			if (!strcmp(name, "none"))
+				c->mount_opts.compr_type = UBIFS_COMPR_NONE;
+			else if (!strcmp(name, "lzo"))
+				c->mount_opts.compr_type = UBIFS_COMPR_LZO;
+			else if (!strcmp(name, "zlib"))
+				c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;
+			else {
+				ubifs_err("unknown compressor \"%s\"", name);
+				kfree(name);
+				return -EINVAL;
+			}
+			kfree(name);
+			c->mount_opts.override_compr = 1;
+			c->default_compr = c->mount_opts.compr_type;
+			break;
+		}
+		default:
+		{
+			unsigned long flag;
+			struct super_block *sb = c->vfs_sb;
+
+			flag = parse_standard_option(p);
+			if (!flag) {
+				ubifs_err("unrecognized mount option \"%s\" or missing value",
+					  p);
+				return -EINVAL;
+			}
+			sb->s_flags |= flag;
+			break;
+		}
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * destroy_journal - destroy journal data structures.
+ * @c: UBIFS file-system description object
+ *
+ * This function destroys journal data structures including those that may have
+ * been created by recovery functions.
+ */
+static void destroy_journal(struct ubifs_info *c)
+{
+	while (!list_empty(&c->unclean_leb_list)) {
+		struct ubifs_unclean_leb *ucleb;
+
+		ucleb = list_entry(c->unclean_leb_list.next,
+				   struct ubifs_unclean_leb, list);
+		list_del(&ucleb->list);
+		kfree(ucleb);
+	}
+	while (!list_empty(&c->old_buds)) {
+		struct ubifs_bud *bud;
+
+		bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
+		list_del(&bud->list);
+		kfree(bud);
+	}
+	ubifs_destroy_idx_gc(c);
+	ubifs_destroy_size_tree(c);
+	ubifs_tnc_close(c);
+	free_buds(c);
+}
+#endif
+
+/**
+ * bu_init - initialize bulk-read information.
+ * @c: UBIFS file-system description object
+ */
+static void bu_init(struct ubifs_info *c)
+{
+	ubifs_assert(c->bulk_read == 1);
+
+	if (c->bu.buf)
+		return; /* Already initialized */
+
+again:
+	c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN);
+	if (!c->bu.buf) {
+		if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {
+			c->max_bu_buf_len = UBIFS_KMALLOC_OK;
+			goto again;
+		}
+
+		/* Just disable bulk-read */
+		ubifs_warn("cannot allocate %d bytes of memory for bulk-read, disabling it",
+			   c->max_bu_buf_len);
+		c->mount_opts.bulk_read = 1;
+		c->bulk_read = 0;
+		return;
+	}
+}
+
+#ifndef __UBOOT__
+/**
+ * check_free_space - check if there is enough free space to mount.
+ * @c: UBIFS file-system description object
+ *
+ * This function makes sure UBIFS has enough free space to be mounted in
+ * read/write mode. UBIFS must always have some free space to allow deletions.
+ */
+static int check_free_space(struct ubifs_info *c)
+{
+	ubifs_assert(c->dark_wm > 0);
+	if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) {
+		ubifs_err("insufficient free space to mount in R/W mode");
+		ubifs_dump_budg(c, &c->bi);
+		ubifs_dump_lprops(c);
+		return -ENOSPC;
+	}
+	return 0;
+}
+#endif
+
 /**
  * mount_ubifs - mount UBIFS file-system.
  * @c: UBIFS file-system description object
  *
  * This function mounts UBIFS file system. Returns zero in case of success and
  * a negative error code in case of failure.
- *
- * Note, the function does not de-allocate resources it it fails half way
- * through, and the caller has to do this instead.
  */
 static int mount_ubifs(struct ubifs_info *c)
 {
-	struct super_block *sb = c->vfs_sb;
-	int err, mounted_read_only = (sb->s_flags & MS_RDONLY);
-	long long x;
+	int err;
+	long long x, y;
 	size_t sz;
 
+	c->ro_mount = !!(c->vfs_sb->s_flags & MS_RDONLY);
+#ifdef __UBOOT__
+	if (!c->ro_mount) {
+		printf("UBIFS: only ro mode in U-Boot allowed.\n");
+		return -EACCES;
+	}
+#endif
+
 	err = init_constants_early(c);
 	if (err)
 		return err;
@@ -598,7 +1357,7 @@ static int mount_ubifs(struct ubifs_info *c)
 	if (err)
 		goto out_free;
 
-	if (c->empty && (mounted_read_only || c->ro_media)) {
+	if (c->empty && (c->ro_mount || c->ro_media)) {
 		/*
 		 * This UBI volume is empty, and read-only, or the file system
 		 * is mounted read-only - we cannot format it.
@@ -609,7 +1368,7 @@ static int mount_ubifs(struct ubifs_info *c)
 		goto out_free;
 	}
 
-	if (c->ro_media && !mounted_read_only) {
+	if (c->ro_media && !c->ro_mount) {
 		ubifs_err("cannot mount read-write - read-only media");
 		err = -EROFS;
 		goto out_free;
@@ -629,11 +1388,27 @@ static int mount_ubifs(struct ubifs_info *c)
 	if (!c->sbuf)
 		goto out_free;
 
-	/*
-	 * We have to check all CRCs, even for data nodes, when we mount the FS
-	 * (specifically, when we are replaying).
-	 */
-	c->always_chk_crc = 1;
+#ifndef __UBOOT__
+	if (!c->ro_mount) {
+		c->ileb_buf = vmalloc(c->leb_size);
+		if (!c->ileb_buf)
+			goto out_free;
+	}
+#endif
+
+	if (c->bulk_read == 1)
+		bu_init(c);
+
+#ifndef __UBOOT__
+	if (!c->ro_mount) {
+		c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ,
+					       GFP_KERNEL);
+		if (!c->write_reserve_buf)
+			goto out_free;
+	}
+#endif
+
+	c->mounting = 1;
 
 	err = ubifs_read_superblock(c);
 	if (err)
@@ -646,11 +1421,10 @@ static int mount_ubifs(struct ubifs_info *c)
 	if (!ubifs_compr_present(c->default_compr)) {
 		ubifs_err("'compressor \"%s\" is not compiled in",
 			  ubifs_compr_name(c->default_compr));
+		err = -ENOTSUPP;
 		goto out_free;
 	}
 
-	dbg_failure_mode_registration(c);
-
 	err = init_constants_sb(c);
 	if (err)
 		goto out_free;
@@ -663,7 +1437,25 @@ static int mount_ubifs(struct ubifs_info *c)
 		goto out_free;
 	}
 
+	err = alloc_wbufs(c);
+	if (err)
+		goto out_cbuf;
+
 	sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
+#ifndef __UBOOT__
+	if (!c->ro_mount) {
+		/* Create background thread */
+		c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
+		if (IS_ERR(c->bgt)) {
+			err = PTR_ERR(c->bgt);
+			c->bgt = NULL;
+			ubifs_err("cannot spawn \"%s\", error %d",
+				  c->bgt_name, err);
+			goto out_wbufs;
+		}
+		wake_up_process(c->bgt);
+	}
+#endif
 
 	err = ubifs_read_master(c);
 	if (err)
@@ -676,118 +1468,208 @@ static int mount_ubifs(struct ubifs_info *c)
 		c->need_recovery = 1;
 	}
 
-	err = ubifs_lpt_init(c, 1, !mounted_read_only);
+#ifndef __UBOOT__
+	if (c->need_recovery && !c->ro_mount) {
+		err = ubifs_recover_inl_heads(c, c->sbuf);
+		if (err)
+			goto out_master;
+	}
+#endif
+
+	err = ubifs_lpt_init(c, 1, !c->ro_mount);
 	if (err)
-		goto out_lpt;
+		goto out_master;
+
+#ifndef __UBOOT__
+	if (!c->ro_mount && c->space_fixup) {
+		err = ubifs_fixup_free_space(c);
+		if (err)
+			goto out_lpt;
+	}
+
+	if (!c->ro_mount) {
+		/*
+		 * Set the "dirty" flag so that if we reboot uncleanly we
+		 * will notice this immediately on the next mount.
+		 */
+		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
+		err = ubifs_write_master(c);
+		if (err)
+			goto out_lpt;
+	}
+#endif
 
-	err = dbg_check_idx_size(c, c->old_idx_sz);
+	err = dbg_check_idx_size(c, c->bi.old_idx_sz);
 	if (err)
 		goto out_lpt;
 
+#ifndef __UBOOT__
 	err = ubifs_replay_journal(c);
 	if (err)
 		goto out_journal;
+#endif
+
+	/* Calculate 'min_idx_lebs' after journal replay */
+	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
 
-	err = ubifs_mount_orphans(c, c->need_recovery, mounted_read_only);
+	err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);
 	if (err)
 		goto out_orphans;
 
-	if (c->need_recovery) {
+	if (!c->ro_mount) {
+#ifndef __UBOOT__
+		int lnum;
+
+		err = check_free_space(c);
+		if (err)
+			goto out_orphans;
+
+		/* Check for enough log space */
+		lnum = c->lhead_lnum + 1;
+		if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
+			lnum = UBIFS_LOG_LNUM;
+		if (lnum == c->ltail_lnum) {
+			err = ubifs_consolidate_log(c);
+			if (err)
+				goto out_orphans;
+		}
+
+		if (c->need_recovery) {
+			err = ubifs_recover_size(c);
+			if (err)
+				goto out_orphans;
+			err = ubifs_rcvry_gc_commit(c);
+			if (err)
+				goto out_orphans;
+		} else {
+			err = take_gc_lnum(c);
+			if (err)
+				goto out_orphans;
+
+			/*
+			 * GC LEB may contain garbage if there was an unclean
+			 * reboot, and it should be un-mapped.
+			 */
+			err = ubifs_leb_unmap(c, c->gc_lnum);
+			if (err)
+				goto out_orphans;
+		}
+
+		err = dbg_check_lprops(c);
+		if (err)
+			goto out_orphans;
+#endif
+	} else if (c->need_recovery) {
 		err = ubifs_recover_size(c);
 		if (err)
 			goto out_orphans;
+	} else {
+		/*
+		 * Even if we mount read-only, we have to set space in GC LEB
+		 * to proper value because this affects UBIFS free space
+		 * reporting. We do not want to have a situation when
+		 * re-mounting from R/O to R/W changes amount of free space.
+		 */
+		err = take_gc_lnum(c);
+		if (err)
+			goto out_orphans;
 	}
 
+#ifndef __UBOOT__
 	spin_lock(&ubifs_infos_lock);
 	list_add_tail(&c->infos_list, &ubifs_infos);
 	spin_unlock(&ubifs_infos_lock);
+#endif
 
 	if (c->need_recovery) {
-		if (mounted_read_only)
+		if (c->ro_mount)
 			ubifs_msg("recovery deferred");
 		else {
 			c->need_recovery = 0;
 			ubifs_msg("recovery completed");
+			/*
+			 * GC LEB has to be empty and taken at this point. But
+			 * the journal head LEBs may also be accounted as
+			 * "empty taken" if they are empty.
+			 */
+			ubifs_assert(c->lst.taken_empty_lebs > 0);
 		}
-	}
+	} else
+		ubifs_assert(c->lst.taken_empty_lebs > 0);
 
 	err = dbg_check_filesystem(c);
 	if (err)
 		goto out_infos;
 
-	c->always_chk_crc = 0;
+	err = dbg_debugfs_init_fs(c);
+	if (err)
+		goto out_infos;
+
+	c->mounting = 0;
 
-	ubifs_msg("mounted UBI device %d, volume %d, name \"%s\"",
-		  c->vi.ubi_num, c->vi.vol_id, c->vi.name);
-	if (mounted_read_only)
-		ubifs_msg("mounted read-only");
+	ubifs_msg("mounted UBI device %d, volume %d, name \"%s\"%s",
+		  c->vi.ubi_num, c->vi.vol_id, c->vi.name,
+		  c->ro_mount ? ", R/O mode" : "");
 	x = (long long)c->main_lebs * c->leb_size;
-	ubifs_msg("file system size:   %lld bytes (%lld KiB, %lld MiB, %d "
-		  "LEBs)", x, x >> 10, x >> 20, c->main_lebs);
-	x = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;
-	ubifs_msg("journal size:       %lld bytes (%lld KiB, %lld MiB, %d "
-		  "LEBs)", x, x >> 10, x >> 20, c->log_lebs + c->max_bud_cnt);
-	ubifs_msg("media format:       w%d/r%d (latest is w%d/r%d)",
+	y = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;
+	ubifs_msg("LEB size: %d bytes (%d KiB), min./max. I/O unit sizes: %d bytes/%d bytes",
+		  c->leb_size, c->leb_size >> 10, c->min_io_size,
+		  c->max_write_size);
+	ubifs_msg("FS size: %lld bytes (%lld MiB, %d LEBs), journal size %lld bytes (%lld MiB, %d LEBs)",
+		  x, x >> 20, c->main_lebs,
+		  y, y >> 20, c->log_lebs + c->max_bud_cnt);
+	ubifs_msg("reserved for root: %llu bytes (%llu KiB)",
+		  c->report_rp_size, c->report_rp_size >> 10);
+	ubifs_msg("media format: w%d/r%d (latest is w%d/r%d), UUID %pUB%s",
 		  c->fmt_version, c->ro_compat_version,
-		  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION);
-	ubifs_msg("default compressor: %s", ubifs_compr_name(c->default_compr));
-	ubifs_msg("reserved for root:  %llu bytes (%llu KiB)",
-		c->report_rp_size, c->report_rp_size >> 10);
-
-	dbg_msg("min. I/O unit size:  %d bytes", c->min_io_size);
-	dbg_msg("LEB size:            %d bytes (%d KiB)",
-		c->leb_size, c->leb_size >> 10);
-	dbg_msg("data journal heads:  %d",
+		  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION, c->uuid,
+		  c->big_lpt ? ", big LPT model" : ", small LPT model");
+
+	dbg_gen("default compressor:  %s", ubifs_compr_name(c->default_compr));
+	dbg_gen("data journal heads:  %d",
 		c->jhead_cnt - NONDATA_JHEADS_CNT);
-	dbg_msg("UUID:                %02X%02X%02X%02X-%02X%02X"
-	       "-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X",
-	       c->uuid[0], c->uuid[1], c->uuid[2], c->uuid[3],
-	       c->uuid[4], c->uuid[5], c->uuid[6], c->uuid[7],
-	       c->uuid[8], c->uuid[9], c->uuid[10], c->uuid[11],
-	       c->uuid[12], c->uuid[13], c->uuid[14], c->uuid[15]);
-	dbg_msg("big_lpt              %d", c->big_lpt);
-	dbg_msg("log LEBs:            %d (%d - %d)",
+	dbg_gen("log LEBs:            %d (%d - %d)",
 		c->log_lebs, UBIFS_LOG_LNUM, c->log_last);
-	dbg_msg("LPT area LEBs:       %d (%d - %d)",
+	dbg_gen("LPT area LEBs:       %d (%d - %d)",
 		c->lpt_lebs, c->lpt_first, c->lpt_last);
-	dbg_msg("orphan area LEBs:    %d (%d - %d)",
+	dbg_gen("orphan area LEBs:    %d (%d - %d)",
 		c->orph_lebs, c->orph_first, c->orph_last);
-	dbg_msg("main area LEBs:      %d (%d - %d)",
+	dbg_gen("main area LEBs:      %d (%d - %d)",
 		c->main_lebs, c->main_first, c->leb_cnt - 1);
-	dbg_msg("index LEBs:          %d", c->lst.idx_lebs);
-	dbg_msg("total index bytes:   %lld (%lld KiB, %lld MiB)",
-		c->old_idx_sz, c->old_idx_sz >> 10, c->old_idx_sz >> 20);
-	dbg_msg("key hash type:       %d", c->key_hash_type);
-	dbg_msg("tree fanout:         %d", c->fanout);
-	dbg_msg("reserved GC LEB:     %d", c->gc_lnum);
-	dbg_msg("first main LEB:      %d", c->main_first);
-	dbg_msg("max. znode size      %d", c->max_znode_sz);
-	dbg_msg("max. index node size %d", c->max_idx_node_sz);
-	dbg_msg("node sizes:          data %zu, inode %zu, dentry %zu",
+	dbg_gen("index LEBs:          %d", c->lst.idx_lebs);
+	dbg_gen("total index bytes:   %lld (%lld KiB, %lld MiB)",
+		c->bi.old_idx_sz, c->bi.old_idx_sz >> 10,
+		c->bi.old_idx_sz >> 20);
+	dbg_gen("key hash type:       %d", c->key_hash_type);
+	dbg_gen("tree fanout:         %d", c->fanout);
+	dbg_gen("reserved GC LEB:     %d", c->gc_lnum);
+	dbg_gen("max. znode size      %d", c->max_znode_sz);
+	dbg_gen("max. index node size %d", c->max_idx_node_sz);
+	dbg_gen("node sizes:          data %zu, inode %zu, dentry %zu",
 		UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ);
-	dbg_msg("node sizes:          trun %zu, sb %zu, master %zu",
+	dbg_gen("node sizes:          trun %zu, sb %zu, master %zu",
 		UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ);
-	dbg_msg("node sizes:          ref %zu, cmt. start %zu, orph %zu",
+	dbg_gen("node sizes:          ref %zu, cmt. start %zu, orph %zu",
 		UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ);
-	dbg_msg("max. node sizes:     data %zu, inode %zu dentry %zu",
+	dbg_gen("max. node sizes:     data %zu, inode %zu dentry %zu, idx %d",
 		UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ,
-		UBIFS_MAX_DENT_NODE_SZ);
-	dbg_msg("dead watermark:      %d", c->dead_wm);
-	dbg_msg("dark watermark:      %d", c->dark_wm);
-	dbg_msg("LEB overhead:        %d", c->leb_overhead);
+		UBIFS_MAX_DENT_NODE_SZ, ubifs_idx_node_sz(c, c->fanout));
+	dbg_gen("dead watermark:      %d", c->dead_wm);
+	dbg_gen("dark watermark:      %d", c->dark_wm);
+	dbg_gen("LEB overhead:        %d", c->leb_overhead);
 	x = (long long)c->main_lebs * c->dark_wm;
-	dbg_msg("max. dark space:     %lld (%lld KiB, %lld MiB)",
+	dbg_gen("max. dark space:     %lld (%lld KiB, %lld MiB)",
 		x, x >> 10, x >> 20);
-	dbg_msg("maximum bud bytes:   %lld (%lld KiB, %lld MiB)",
+	dbg_gen("maximum bud bytes:   %lld (%lld KiB, %lld MiB)",
 		c->max_bud_bytes, c->max_bud_bytes >> 10,
 		c->max_bud_bytes >> 20);
-	dbg_msg("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",
+	dbg_gen("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",
 		c->bg_bud_bytes, c->bg_bud_bytes >> 10,
 		c->bg_bud_bytes >> 20);
-	dbg_msg("current bud bytes    %lld (%lld KiB, %lld MiB)",
+	dbg_gen("current bud bytes    %lld (%lld KiB, %lld MiB)",
 		c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20);
-	dbg_msg("max. seq. number:    %llu", c->max_sqnum);
-	dbg_msg("commit number:       %llu", c->cmt_no);
+	dbg_gen("max. seq. number:    %llu", c->max_sqnum);
+	dbg_gen("commit number:       %llu", c->cmt_no);
 
 	return 0;
 
@@ -797,7 +1679,10 @@ out_infos:
 	spin_unlock(&ubifs_infos_lock);
 out_orphans:
 	free_orphans(c);
+#ifndef __UBOOT__
 out_journal:
+	destroy_journal(c);
+#endif
 out_lpt:
 	ubifs_lpt_free(c, 0);
 out_master:
@@ -805,8 +1690,15 @@ out_master:
 	kfree(c->rcvrd_mst_node);
 	if (c->bgt)
 		kthread_stop(c->bgt);
+#ifndef __UBOOT__
+out_wbufs:
+#endif
+	free_wbufs(c);
+out_cbuf:
 	kfree(c->cbuf);
 out_free:
+	kfree(c->write_reserve_buf);
+	kfree(c->bu.buf);
 	vfree(c->ileb_buf);
 	vfree(c->sbuf);
 	kfree(c->bottom_up_buf);
@@ -823,57 +1715,447 @@ out_free:
  * through mounting (error path cleanup function). So it has to make sure the
  * resource was actually allocated before freeing it.
  */
+#ifndef __UBOOT__
+static void ubifs_umount(struct ubifs_info *c)
+#else
 void ubifs_umount(struct ubifs_info *c)
+#endif
 {
 	dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,
 		c->vi.vol_id);
 
+	dbg_debugfs_exit_fs(c);
 	spin_lock(&ubifs_infos_lock);
 	list_del(&c->infos_list);
 	spin_unlock(&ubifs_infos_lock);
 
+#ifndef __UBOOT__
 	if (c->bgt)
 		kthread_stop(c->bgt);
 
+	destroy_journal(c);
+#endif
+	free_wbufs(c);
 	free_orphans(c);
 	ubifs_lpt_free(c, 0);
 
 	kfree(c->cbuf);
 	kfree(c->rcvrd_mst_node);
 	kfree(c->mst_node);
+	kfree(c->write_reserve_buf);
+	kfree(c->bu.buf);
 	vfree(c->ileb_buf);
 	vfree(c->sbuf);
 	kfree(c->bottom_up_buf);
 	ubifs_debugging_exit(c);
-
+#ifdef __UBOOT__
 	/* Finally free U-Boot's global copy of superblock */
 	if (ubifs_sb != NULL) {
 		free(ubifs_sb->s_fs_info);
 		free(ubifs_sb);
 	}
+#endif
+}
+
+#ifndef __UBOOT__
+/**
+ * ubifs_remount_rw - re-mount in read-write mode.
+ * @c: UBIFS file-system description object
+ *
+ * UBIFS avoids allocating many unnecessary resources when mounted in read-only
+ * mode. This function allocates the needed resources and re-mounts UBIFS in
+ * read-write mode.
+ */
+static int ubifs_remount_rw(struct ubifs_info *c)
+{
+	int err, lnum;
+
+	if (c->rw_incompat) {
+		ubifs_err("the file-system is not R/W-compatible");
+		ubifs_msg("on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
+			  c->fmt_version, c->ro_compat_version,
+			  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION);
+		return -EROFS;
+	}
+
+	mutex_lock(&c->umount_mutex);
+	dbg_save_space_info(c);
+	c->remounting_rw = 1;
+	c->ro_mount = 0;
+
+	if (c->space_fixup) {
+		err = ubifs_fixup_free_space(c);
+		if (err)
+			return err;
+	}
+
+	err = check_free_space(c);
+	if (err)
+		goto out;
+
+	if (c->old_leb_cnt != c->leb_cnt) {
+		struct ubifs_sb_node *sup;
+
+		sup = ubifs_read_sb_node(c);
+		if (IS_ERR(sup)) {
+			err = PTR_ERR(sup);
+			goto out;
+		}
+		sup->leb_cnt = cpu_to_le32(c->leb_cnt);
+		err = ubifs_write_sb_node(c, sup);
+		kfree(sup);
+		if (err)
+			goto out;
+	}
+
+	if (c->need_recovery) {
+		ubifs_msg("completing deferred recovery");
+		err = ubifs_write_rcvrd_mst_node(c);
+		if (err)
+			goto out;
+		err = ubifs_recover_size(c);
+		if (err)
+			goto out;
+		err = ubifs_clean_lebs(c, c->sbuf);
+		if (err)
+			goto out;
+		err = ubifs_recover_inl_heads(c, c->sbuf);
+		if (err)
+			goto out;
+	} else {
+		/* A readonly mount is not allowed to have orphans */
+		ubifs_assert(c->tot_orphans == 0);
+		err = ubifs_clear_orphans(c);
+		if (err)
+			goto out;
+	}
+
+	if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {
+		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
+		err = ubifs_write_master(c);
+		if (err)
+			goto out;
+	}
+
+	c->ileb_buf = vmalloc(c->leb_size);
+	if (!c->ileb_buf) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ, GFP_KERNEL);
+	if (!c->write_reserve_buf) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	err = ubifs_lpt_init(c, 0, 1);
+	if (err)
+		goto out;
+
+	/* Create background thread */
+	c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
+	if (IS_ERR(c->bgt)) {
+		err = PTR_ERR(c->bgt);
+		c->bgt = NULL;
+		ubifs_err("cannot spawn \"%s\", error %d",
+			  c->bgt_name, err);
+		goto out;
+	}
+	wake_up_process(c->bgt);
+
+	c->orph_buf = vmalloc(c->leb_size);
+	if (!c->orph_buf) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	/* Check for enough log space */
+	lnum = c->lhead_lnum + 1;
+	if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
+		lnum = UBIFS_LOG_LNUM;
+	if (lnum == c->ltail_lnum) {
+		err = ubifs_consolidate_log(c);
+		if (err)
+			goto out;
+	}
+
+	if (c->need_recovery)
+		err = ubifs_rcvry_gc_commit(c);
+	else
+		err = ubifs_leb_unmap(c, c->gc_lnum);
+	if (err)
+		goto out;
+
+	dbg_gen("re-mounted read-write");
+	c->remounting_rw = 0;
+
+	if (c->need_recovery) {
+		c->need_recovery = 0;
+		ubifs_msg("deferred recovery completed");
+	} else {
+		/*
+		 * Do not run the debugging space check if the were doing
+		 * recovery, because when we saved the information we had the
+		 * file-system in a state where the TNC and lprops has been
+		 * modified in memory, but all the I/O operations (including a
+		 * commit) were deferred. So the file-system was in
+		 * "non-committed" state. Now the file-system is in committed
+		 * state, and of course the amount of free space will change
+		 * because, for example, the old index size was imprecise.
+		 */
+		err = dbg_check_space_info(c);
+	}
+
+	mutex_unlock(&c->umount_mutex);
+	return err;
+
+out:
+	c->ro_mount = 1;
+	vfree(c->orph_buf);
+	c->orph_buf = NULL;
+	if (c->bgt) {
+		kthread_stop(c->bgt);
+		c->bgt = NULL;
+	}
+	free_wbufs(c);
+	kfree(c->write_reserve_buf);
+	c->write_reserve_buf = NULL;
+	vfree(c->ileb_buf);
+	c->ileb_buf = NULL;
+	ubifs_lpt_free(c, 1);
+	c->remounting_rw = 0;
+	mutex_unlock(&c->umount_mutex);
+	return err;
+}
+
+/**
+ * ubifs_remount_ro - re-mount in read-only mode.
+ * @c: UBIFS file-system description object
+ *
+ * We assume VFS has stopped writing. Possibly the background thread could be
+ * running a commit, however kthread_stop will wait in that case.
+ */
+static void ubifs_remount_ro(struct ubifs_info *c)
+{
+	int i, err;
+
+	ubifs_assert(!c->need_recovery);
+	ubifs_assert(!c->ro_mount);
+
+	mutex_lock(&c->umount_mutex);
+	if (c->bgt) {
+		kthread_stop(c->bgt);
+		c->bgt = NULL;
+	}
+
+	dbg_save_space_info(c);
+
+	for (i = 0; i < c->jhead_cnt; i++)
+		ubifs_wbuf_sync(&c->jheads[i].wbuf);
+
+	c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
+	c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
+	c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
+	err = ubifs_write_master(c);
+	if (err)
+		ubifs_ro_mode(c, err);
+
+	vfree(c->orph_buf);
+	c->orph_buf = NULL;
+	kfree(c->write_reserve_buf);
+	c->write_reserve_buf = NULL;
+	vfree(c->ileb_buf);
+	c->ileb_buf = NULL;
+	ubifs_lpt_free(c, 1);
+	c->ro_mount = 1;
+	err = dbg_check_space_info(c);
+	if (err)
+		ubifs_ro_mode(c, err);
+	mutex_unlock(&c->umount_mutex);
+}
+
+static void ubifs_put_super(struct super_block *sb)
+{
+	int i;
+	struct ubifs_info *c = sb->s_fs_info;
+
+	ubifs_msg("un-mount UBI device %d, volume %d", c->vi.ubi_num,
+		  c->vi.vol_id);
+
+	/*
+	 * The following asserts are only valid if there has not been a failure
+	 * of the media. For example, there will be dirty inodes if we failed
+	 * to write them back because of I/O errors.
+	 */
+	if (!c->ro_error) {
+		ubifs_assert(c->bi.idx_growth == 0);
+		ubifs_assert(c->bi.dd_growth == 0);
+		ubifs_assert(c->bi.data_growth == 0);
+	}
+
+	/*
+	 * The 'c->umount_lock' prevents races between UBIFS memory shrinker
+	 * and file system un-mount. Namely, it prevents the shrinker from
+	 * picking this superblock for shrinking - it will be just skipped if
+	 * the mutex is locked.
+	 */
+	mutex_lock(&c->umount_mutex);
+	if (!c->ro_mount) {
+		/*
+		 * First of all kill the background thread to make sure it does
+		 * not interfere with un-mounting and freeing resources.
+		 */
+		if (c->bgt) {
+			kthread_stop(c->bgt);
+			c->bgt = NULL;
+		}
+
+		/*
+		 * On fatal errors c->ro_error is set to 1, in which case we do
+		 * not write the master node.
+		 */
+		if (!c->ro_error) {
+			int err;
+
+			/* Synchronize write-buffers */
+			for (i = 0; i < c->jhead_cnt; i++)
+				ubifs_wbuf_sync(&c->jheads[i].wbuf);
+
+			/*
+			 * We are being cleanly unmounted which means the
+			 * orphans were killed - indicate this in the master
+			 * node. Also save the reserved GC LEB number.
+			 */
+			c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
+			c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
+			c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
+			err = ubifs_write_master(c);
+			if (err)
+				/*
+				 * Recovery will attempt to fix the master area
+				 * next mount, so we just print a message and
+				 * continue to unmount normally.
+				 */
+				ubifs_err("failed to write master node, error %d",
+					  err);
+		} else {
+#ifndef __UBOOT__
+			for (i = 0; i < c->jhead_cnt; i++)
+				/* Make sure write-buffer timers are canceled */
+				hrtimer_cancel(&c->jheads[i].wbuf.timer);
+#endif
+		}
+	}
+
+	ubifs_umount(c);
+#ifndef __UBOOT__
+	bdi_destroy(&c->bdi);
+#endif
+	ubi_close_volume(c->ubi);
+	mutex_unlock(&c->umount_mutex);
+}
+#endif
+
+#ifndef __UBOOT__
+static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
+{
+	int err;
+	struct ubifs_info *c = sb->s_fs_info;
+
+	dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
+
+	err = ubifs_parse_options(c, data, 1);
+	if (err) {
+		ubifs_err("invalid or unknown remount parameter");
+		return err;
+	}
+
+	if (c->ro_mount && !(*flags & MS_RDONLY)) {
+		if (c->ro_error) {
+			ubifs_msg("cannot re-mount R/W due to prior errors");
+			return -EROFS;
+		}
+		if (c->ro_media) {
+			ubifs_msg("cannot re-mount R/W - UBI volume is R/O");
+			return -EROFS;
+		}
+		err = ubifs_remount_rw(c);
+		if (err)
+			return err;
+	} else if (!c->ro_mount && (*flags & MS_RDONLY)) {
+		if (c->ro_error) {
+			ubifs_msg("cannot re-mount R/O due to prior errors");
+			return -EROFS;
+		}
+		ubifs_remount_ro(c);
+	}
+
+	if (c->bulk_read == 1)
+		bu_init(c);
+	else {
+		dbg_gen("disable bulk-read");
+		kfree(c->bu.buf);
+		c->bu.buf = NULL;
+	}
+
+	ubifs_assert(c->lst.taken_empty_lebs > 0);
+	return 0;
 }
+#endif
+
+const struct super_operations ubifs_super_operations = {
+	.alloc_inode   = ubifs_alloc_inode,
+#ifndef __UBOOT__
+	.destroy_inode = ubifs_destroy_inode,
+	.put_super     = ubifs_put_super,
+	.write_inode   = ubifs_write_inode,
+	.evict_inode   = ubifs_evict_inode,
+	.statfs        = ubifs_statfs,
+#endif
+	.dirty_inode   = ubifs_dirty_inode,
+#ifndef __UBOOT__
+	.remount_fs    = ubifs_remount_fs,
+	.show_options  = ubifs_show_options,
+	.sync_fs       = ubifs_sync_fs,
+#endif
+};
 
 /**
  * open_ubi - parse UBI device name string and open the UBI device.
  * @name: UBI volume name
  * @mode: UBI volume open mode
  *
- * There are several ways to specify UBI volumes when mounting UBIFS:
- * o ubiX_Y    - UBI device number X, volume Y;
- * o ubiY      - UBI device number 0, volume Y;
+ * The primary method of mounting UBIFS is by specifying the UBI volume
+ * character device node path. However, UBIFS may also be mounted withoug any
+ * character device node using one of the following methods:
+ *
+ * o ubiX_Y    - mount UBI device number X, volume Y;
+ * o ubiY      - mount UBI device number 0, volume Y;
  * o ubiX:NAME - mount UBI device X, volume with name NAME;
  * o ubi:NAME  - mount UBI device 0, volume with name NAME.
  *
  * Alternative '!' separator may be used instead of ':' (because some shells
  * like busybox may interpret ':' as an NFS host name separator). This function
- * returns ubi volume object in case of success and a negative error code in
- * case of failure.
+ * returns UBI volume description object in case of success and a negative
+ * error code in case of failure.
  */
 static struct ubi_volume_desc *open_ubi(const char *name, int mode)
 {
+#ifndef __UBOOT__
+	struct ubi_volume_desc *ubi;
+#endif
 	int dev, vol;
 	char *endptr;
 
+#ifndef __UBOOT__
+	/* First, try to open using the device node path method */
+	ubi = ubi_open_volume_path(name, mode);
+	if (!IS_ERR(ubi))
+		return ubi;
+#endif
+
+	/* Try the "nodev" method */
 	if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
 		return ERR_PTR(-EINVAL);
 
@@ -905,78 +2187,100 @@ static struct ubi_volume_desc *open_ubi(const char *name, int mode)
 	return ERR_PTR(-EINVAL);
 }
 
-static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
+static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)
 {
-	struct ubi_volume_desc *ubi = sb->s_fs_info;
 	struct ubifs_info *c;
-	struct inode *root;
-	int err;
 
 	c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
-	if (!c)
-		return -ENOMEM;
+	if (c) {
+		spin_lock_init(&c->cnt_lock);
+		spin_lock_init(&c->cs_lock);
+		spin_lock_init(&c->buds_lock);
+		spin_lock_init(&c->space_lock);
+		spin_lock_init(&c->orphan_lock);
+		init_rwsem(&c->commit_sem);
+		mutex_init(&c->lp_mutex);
+		mutex_init(&c->tnc_mutex);
+		mutex_init(&c->log_mutex);
+		mutex_init(&c->mst_mutex);
+		mutex_init(&c->umount_mutex);
+		mutex_init(&c->bu_mutex);
+		mutex_init(&c->write_reserve_mutex);
+		init_waitqueue_head(&c->cmt_wq);
+		c->buds = RB_ROOT;
+		c->old_idx = RB_ROOT;
+		c->size_tree = RB_ROOT;
+		c->orph_tree = RB_ROOT;
+		INIT_LIST_HEAD(&c->infos_list);
+		INIT_LIST_HEAD(&c->idx_gc);
+		INIT_LIST_HEAD(&c->replay_list);
+		INIT_LIST_HEAD(&c->replay_buds);
+		INIT_LIST_HEAD(&c->uncat_list);
+		INIT_LIST_HEAD(&c->empty_list);
+		INIT_LIST_HEAD(&c->freeable_list);
+		INIT_LIST_HEAD(&c->frdi_idx_list);
+		INIT_LIST_HEAD(&c->unclean_leb_list);
+		INIT_LIST_HEAD(&c->old_buds);
+		INIT_LIST_HEAD(&c->orph_list);
+		INIT_LIST_HEAD(&c->orph_new);
+		c->no_chk_data_crc = 1;
+
+		c->highest_inum = UBIFS_FIRST_INO;
+		c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
+
+		ubi_get_volume_info(ubi, &c->vi);
+		ubi_get_device_info(c->vi.ubi_num, &c->di);
+	}
+	return c;
+}
 
-	spin_lock_init(&c->cnt_lock);
-	spin_lock_init(&c->cs_lock);
-	spin_lock_init(&c->buds_lock);
-	spin_lock_init(&c->space_lock);
-	spin_lock_init(&c->orphan_lock);
-	init_rwsem(&c->commit_sem);
-	mutex_init(&c->lp_mutex);
-	mutex_init(&c->tnc_mutex);
-	mutex_init(&c->log_mutex);
-	mutex_init(&c->mst_mutex);
-	mutex_init(&c->umount_mutex);
-	init_waitqueue_head(&c->cmt_wq);
-	c->buds = RB_ROOT;
-	c->old_idx = RB_ROOT;
-	c->size_tree = RB_ROOT;
-	c->orph_tree = RB_ROOT;
-	INIT_LIST_HEAD(&c->infos_list);
-	INIT_LIST_HEAD(&c->idx_gc);
-	INIT_LIST_HEAD(&c->replay_list);
-	INIT_LIST_HEAD(&c->replay_buds);
-	INIT_LIST_HEAD(&c->uncat_list);
-	INIT_LIST_HEAD(&c->empty_list);
-	INIT_LIST_HEAD(&c->freeable_list);
-	INIT_LIST_HEAD(&c->frdi_idx_list);
-	INIT_LIST_HEAD(&c->unclean_leb_list);
-	INIT_LIST_HEAD(&c->old_buds);
-	INIT_LIST_HEAD(&c->orph_list);
-	INIT_LIST_HEAD(&c->orph_new);
-
-	c->highest_inum = UBIFS_FIRST_INO;
-	c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
-
-	ubi_get_volume_info(ubi, &c->vi);
-	ubi_get_device_info(c->vi.ubi_num, &c->di);
+static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
+{
+	struct ubifs_info *c = sb->s_fs_info;
+	struct inode *root;
+	int err;
 
+	c->vfs_sb = sb;
 	/* Re-open the UBI device in read-write mode */
-	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY);
+	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE);
 	if (IS_ERR(c->ubi)) {
 		err = PTR_ERR(c->ubi);
-		goto out_free;
+		goto out;
 	}
 
-	c->vfs_sb = sb;
+#ifndef __UBOOT__
+	/*
+	 * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For
+	 * UBIFS, I/O is not deferred, it is done immediately in readpage,
+	 * which means the user would have to wait not just for their own I/O
+	 * but the read-ahead I/O as well i.e. completely pointless.
+	 *
+	 * Read-ahead will be disabled because @c->bdi.ra_pages is 0.
+	 */
+	co>bdi.name = "ubifs",
+	c->bdi.capabilities = BDI_CAP_MAP_COPY;
+	err  = bdi_init(&c->bdi);
+	if (err)
+		goto out_close;
+	err = bdi_register(&c->bdi, NULL, "ubifs_%d_%d",
+			   c->vi.ubi_num, c->vi.vol_id);
+	if (err)
+		goto out_bdi;
+
+	err = ubifs_parse_options(c, data, 0);
+	if (err)
+		goto out_bdi;
 
+	sb->s_bdi = &c->bdi;
+#endif
 	sb->s_fs_info = c;
 	sb->s_magic = UBIFS_SUPER_MAGIC;
 	sb->s_blocksize = UBIFS_BLOCK_SIZE;
 	sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT;
-	sb->s_dev = c->vi.cdev;
 	sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);
 	if (c->max_inode_sz > MAX_LFS_FILESIZE)
 		sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
-
-	if (c->rw_incompat) {
-		ubifs_err("the file-system is not R/W-compatible");
-		ubifs_msg("on-flash format version is w%d/r%d, but software "
-			  "only supports up to version w%d/r%d", c->fmt_version,
-			  c->ro_compat_version, UBIFS_FORMAT_VERSION,
-			  UBIFS_RO_COMPAT_VERSION);
-		return -EROFS;
-	}
+	sb->s_op = &ubifs_super_operations;
 
 	mutex_lock(&c->umount_mutex);
 	err = mount_ubifs(c);
@@ -992,7 +2296,15 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
 		goto out_umount;
 	}
 
+#ifndef __UBOOT__
+	sb->s_root = d_make_root(root);
+	if (!sb->s_root) {
+		err = -ENOMEM;
+		goto out_umount;
+	}
+#else
 	sb->s_root = NULL;
+#endif
 
 	mutex_unlock(&c->umount_mutex);
 	return 0;
@@ -1001,24 +2313,130 @@ out_umount:
 	ubifs_umount(c);
 out_unlock:
 	mutex_unlock(&c->umount_mutex);
+#ifndef __UBOOT__
+out_bdi:
+	bdi_destroy(&c->bdi);
+out_close:
+#endif
 	ubi_close_volume(c->ubi);
-out_free:
-	kfree(c);
+out:
 	return err;
 }
 
 static int sb_test(struct super_block *sb, void *data)
 {
-	dev_t *dev = data;
+	struct ubifs_info *c1 = data;
+	struct ubifs_info *c = sb->s_fs_info;
 
-	return sb->s_dev == *dev;
+	return c->vi.cdev == c1->vi.cdev;
 }
 
-static int ubifs_get_sb(struct file_system_type *fs_type, int flags,
-			const char *name, void *data, struct vfsmount *mnt)
+static int sb_set(struct super_block *sb, void *data)
+{
+	sb->s_fs_info = data;
+	return set_anon_super(sb, NULL);
+}
+
+static struct super_block *alloc_super(struct file_system_type *type, int flags)
+{
+	struct super_block *s;
+	int err;
+
+	s = kzalloc(sizeof(struct super_block),  GFP_USER);
+	if (!s) {
+		err = -ENOMEM;
+		return ERR_PTR(err);
+	}
+
+	INIT_HLIST_NODE(&s->s_instances);
+	INIT_LIST_HEAD(&s->s_inodes);
+	s->s_time_gran = 1000000000;
+	s->s_flags = flags;
+
+	return s;
+}
+
+/**
+ *	sget	-	find or create a superblock
+ *	@type:	filesystem type superblock should belong to
+ *	@test:	comparison callback
+ *	@set:	setup callback
+ *	@flags:	mount flags
+ *	@data:	argument to each of them
+ */
+struct super_block *sget(struct file_system_type *type,
+			int (*test)(struct super_block *,void *),
+			int (*set)(struct super_block *,void *),
+			int flags,
+			void *data)
+{
+	struct super_block *s = NULL;
+#ifndef __UBOOT__
+	struct super_block *old;
+#endif
+	int err;
+
+#ifndef __UBOOT__
+retry:
+	spin_lock(&sb_lock);
+	if (test) {
+		hlist_for_each_entry(old, &type->fs_supers, s_instances) {
+			if (!test(old, data))
+				continue;
+			if (!grab_super(old))
+				goto retry;
+			if (s) {
+				up_write(&s->s_umount);
+				destroy_super(s);
+				s = NULL;
+			}
+			return old;
+		}
+	}
+#endif
+	if (!s) {
+		spin_unlock(&sb_lock);
+		s = alloc_super(type, flags);
+		if (!s)
+			return ERR_PTR(-ENOMEM);
+#ifndef __UBOOT__
+		goto retry;
+#endif
+	}
+		
+	err = set(s, data);
+	if (err) {
+#ifndef __UBOOT__
+		spin_unlock(&sb_lock);
+		up_write(&s->s_umount);
+		destroy_super(s);
+#endif
+		return ERR_PTR(err);
+	}
+	s->s_type = type;
+#ifndef __UBOOT__
+	strlcpy(s->s_id, type->name, sizeof(s->s_id));
+#else
+	strncpy(s->s_id, type->name, sizeof(s->s_id));
+#endif
+	list_add_tail(&s->s_list, &super_blocks);
+	hlist_add_head(&s->s_instances, &type->fs_supers);
+#ifndef __UBOOT__
+	spin_unlock(&sb_lock);
+	get_filesystem(type);
+	register_shrinker(&s->s_shrink);
+#endif
+	return s;
+}
+
+EXPORT_SYMBOL(sget);
+
+
+static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
+			const char *name, void *data)
 {
 	struct ubi_volume_desc *ubi;
-	struct ubi_volume_info vi;
+	struct ubifs_info *c;
 	struct super_block *sb;
 	int err;
 
@@ -1033,32 +2451,34 @@ static int ubifs_get_sb(struct file_system_type *fs_type, int flags,
 	if (IS_ERR(ubi)) {
 		ubifs_err("cannot open \"%s\", error %d",
 			  name, (int)PTR_ERR(ubi));
-		return PTR_ERR(ubi);
+		return ERR_CAST(ubi);
+	}
+
+	c = alloc_ubifs_info(ubi);
+	if (!c) {
+		err = -ENOMEM;
+		goto out_close;
 	}
-	ubi_get_volume_info(ubi, &vi);
 
-	dbg_gen("opened ubi%d_%d", vi.ubi_num, vi.vol_id);
+	dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
 
-	sb = sget(fs_type, &sb_test, &sb_set, &vi.cdev);
+	sb = sget(fs_type, sb_test, sb_set, flags, c);
 	if (IS_ERR(sb)) {
 		err = PTR_ERR(sb);
+		kfree(c);
 		goto out_close;
 	}
 
 	if (sb->s_root) {
+		struct ubifs_info *c1 = sb->s_fs_info;
+		kfree(c);
 		/* A new mount point for already mounted UBIFS */
 		dbg_gen("this ubi volume is already mounted");
-		if ((flags ^ sb->s_flags) & MS_RDONLY) {
+		if (!!(flags & MS_RDONLY) != c1->ro_mount) {
 			err = -EBUSY;
 			goto out_deact;
 		}
 	} else {
-		sb->s_flags = flags;
-		/*
-		 * Pass 'ubi' to 'fill_super()' in sb->s_fs_info where it is
-		 * replaced by 'c'.
-		 */
-		sb->s_fs_info = ubi;
 		err = ubifs_fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
 		if (err)
 			goto out_deact;
@@ -1069,17 +2489,53 @@ static int ubifs_get_sb(struct file_system_type *fs_type, int flags,
 	/* 'fill_super()' opens ubi again so we must close it here */
 	ubi_close_volume(ubi);
 
+#ifdef __UBOOT__
 	ubifs_sb = sb;
 	return 0;
+#else
+	return dget(sb->s_root);
+#endif
 
 out_deact:
-	up_write(&sb->s_umount);
+#ifndef __UBOOT__
+	deactivate_locked_super(sb);
+#endif
 out_close:
 	ubi_close_volume(ubi);
-	return err;
+	return ERR_PTR(err);
+}
+
+static void kill_ubifs_super(struct super_block *s)
+{
+	struct ubifs_info *c = s->s_fs_info;
+#ifndef __UBOOT__
+	kill_anon_super(s);
+#endif
+	kfree(c);
+}
+
+static struct file_system_type ubifs_fs_type = {
+	.name    = "ubifs",
+	.owner   = THIS_MODULE,
+	.mount   = ubifs_mount,
+	.kill_sb = kill_ubifs_super,
+};
+#ifndef __UBOOT__
+MODULE_ALIAS_FS("ubifs");
+
+/*
+ * Inode slab cache constructor.
+ */
+static void inode_slab_ctor(void *obj)
+{
+	struct ubifs_inode *ui = obj;
+	inode_init_once(&ui->vfs_inode);
 }
 
-int __init ubifs_init(void)
+static int __init ubifs_init(void)
+#else
+int ubifs_init(void)
+#endif
 {
 	int err;
 
@@ -1135,41 +2591,84 @@ int __init ubifs_init(void)
 	 * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2.
 	 */
 	if (PAGE_CACHE_SIZE < UBIFS_BLOCK_SIZE) {
-		ubifs_err("VFS page cache size is %u bytes, but UBIFS requires"
-			  " at least 4096 bytes",
+		ubifs_err("VFS page cache size is %u bytes, but UBIFS requires at least 4096 bytes",
 			  (unsigned int)PAGE_CACHE_SIZE);
 		return -EINVAL;
 	}
 
-	err = -ENOMEM;
+#ifndef __UBOOT__
+	ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab",
+				sizeof(struct ubifs_inode), 0,
+				SLAB_MEM_SPREAD | SLAB_RECLAIM_ACCOUNT,
+				&inode_slab_ctor);
+	if (!ubifs_inode_slab)
+		return -ENOMEM;
+
+	register_shrinker(&ubifs_shrinker_info);
+#endif
 
 	err = ubifs_compressors_init();
 	if (err)
 		goto out_shrinker;
 
+#ifndef __UBOOT__
+	err = dbg_debugfs_init();
+	if (err)
+		goto out_compr;
+
+	err = register_filesystem(&ubifs_fs_type);
+	if (err) {
+		ubifs_err("cannot register file system, error %d", err);
+		goto out_dbg;
+	}
+#endif
 	return 0;
 
+#ifndef __UBOOT__
+out_dbg:
+	dbg_debugfs_exit();
+out_compr:
+	ubifs_compressors_exit();
+#endif
 out_shrinker:
+#ifndef __UBOOT__
+	unregister_shrinker(&ubifs_shrinker_info);
+#endif
+	kmem_cache_destroy(ubifs_inode_slab);
 	return err;
 }
+/* late_initcall to let compressors initialize first */
+late_initcall(ubifs_init);
 
-/*
- * ubifsmount...
- */
+#ifndef __UBOOT__
+static void __exit ubifs_exit(void)
+{
+	ubifs_assert(list_empty(&ubifs_infos));
+	ubifs_assert(atomic_long_read(&ubifs_clean_zn_cnt) == 0);
 
-static struct file_system_type ubifs_fs_type = {
-	.name    = "ubifs",
-	.owner   = THIS_MODULE,
-	.get_sb  = ubifs_get_sb,
-};
+	dbg_debugfs_exit();
+	ubifs_compressors_exit();
+	unregister_shrinker(&ubifs_shrinker_info);
 
-int ubifs_mount(char *name)
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(ubifs_inode_slab);
+	unregister_filesystem(&ubifs_fs_type);
+}
+module_exit(ubifs_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_VERSION(__stringify(UBIFS_VERSION));
+MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter");
+MODULE_DESCRIPTION("UBIFS - UBI File System");
+#else
+int uboot_ubifs_mount(char *vol_name)
 {
+	struct dentry *ret;
 	int flags;
-	void *data;
-	struct vfsmount *mnt;
-	int ret;
-	struct ubifs_info *c;
 
 	/*
 	 * First unmount if allready mounted
@@ -1177,23 +2676,17 @@ int ubifs_mount(char *name)
 	if (ubifs_sb)
 		ubifs_umount(ubifs_sb->s_fs_info);
 
-	INIT_LIST_HEAD(&ubifs_infos);
-	INIT_LIST_HEAD(&ubifs_fs_type.fs_supers);
-
 	/*
 	 * Mount in read-only mode
 	 */
 	flags = MS_RDONLY;
-	data = NULL;
-	mnt = NULL;
-	ret = ubifs_get_sb(&ubifs_fs_type, flags, name, data, mnt);
-	if (ret) {
-		ubifs_err("Error reading superblock on volume '%s' errno=%d!\n", name, ret);
+	ret = ubifs_mount(&ubifs_fs_type, flags, vol_name, NULL);
+	if (IS_ERR(ret)) {
+		printf("Error reading superblock on volume '%s' " \
+			"errno=%d!\n", vol_name, (int)PTR_ERR(ret));
 		return -1;
 	}
 
-	c = ubifs_sb->s_fs_info;
-	ubi_close_volume(c->ubi);
-
 	return 0;
 }
+#endif