Merge branch 'for_linus' of git://git.infradead.org/~dedekind/ubifs-2.6

* 'for_linus' of git://git.infradead.org/~dedekind/ubifs-2.6:
  UBIFS: include to compilation
  UBIFS: add new flash file system
  UBIFS: add brief documentation
  MAINTAINERS: add UBIFS section
  do_mounts: allow UBI root device name
  VFS: export sync_sb_inodes
  VFS: move inode_lock into sync_sb_inodes

Documentation/filesystems/ubifs.txt

+Introduction
+=============
+
+UBIFS file-system stands for UBI File System. UBI stands for "Unsorted
+Block Images". UBIFS is a flash file system, which means it is designed
+to work with flash devices. It is important to understand, that UBIFS
+is completely different to any traditional file-system in Linux, like
+Ext2, XFS, JFS, etc. UBIFS represents a separate class of file-systems
+which work with MTD devices, not block devices. The other Linux
+file-system of this class is JFFS2.
+
+To make it more clear, here is a small comparison of MTD devices and
+block devices.
+
+1 MTD devices represent flash devices and they consist of eraseblocks of
+  rather large size, typically about 128KiB. Block devices consist of
+  small blocks, typically 512 bytes.
+2 MTD devices support 3 main operations - read from some offset within an
+  eraseblock, write to some offset within an eraseblock, and erase a whole
+  eraseblock. Block  devices support 2 main operations - read a whole
+  block and write a whole block.
+3 The whole eraseblock has to be erased before it becomes possible to
+  re-write its contents. Blocks may be just re-written.
+4 Eraseblocks become worn out after some number of erase cycles -
+  typically 100K-1G for SLC NAND and NOR flashes, and 1K-10K for MLC
+  NAND flashes. Blocks do not have the wear-out property.
+5 Eraseblocks may become bad (only on NAND flashes) and software should
+  deal with this. Blocks on hard drives typically do not become bad,
+  because hardware has mechanisms to substitute bad blocks, at least in
+  modern LBA disks.
+
+It should be quite obvious why UBIFS is very different to traditional
+file-systems.
+
+UBIFS works on top of UBI. UBI is a separate software layer which may be
+found in drivers/mtd/ubi. UBI is basically a volume management and
+wear-leveling layer. It provides so called UBI volumes which is a higher
+level abstraction than a MTD device. The programming model of UBI devices
+is very similar to MTD devices - they still consist of large eraseblocks,
+they have read/write/erase operations, but UBI devices are devoid of
+limitations like wear and bad blocks (items 4 and 5 in the above list).
+
+In a sense, UBIFS is a next generation of JFFS2 file-system, but it is
+very different and incompatible to JFFS2. The following are the main
+differences.
+
+* JFFS2 works on top of MTD devices, UBIFS depends on UBI and works on
+  top of UBI volumes.
+* JFFS2 does not have on-media index and has to build it while mounting,
+  which requires full media scan. UBIFS maintains the FS indexing
+  information on the flash media and does not require full media scan,
+  so it mounts many times faster than JFFS2.
+* JFFS2 is a write-through file-system, while UBIFS supports write-back,
+  which makes UBIFS much faster on writes.
+
+Similarly to JFFS2, UBIFS supports on-the-flight compression which makes
+it possible to fit quite a lot of data to the flash.
+
+Similarly to JFFS2, UBIFS is tolerant of unclean reboots and power-cuts.
+It does not need stuff like ckfs.ext2. UBIFS automatically replays its
+journal and recovers from crashes, ensuring that the on-flash data
+structures are consistent.
+
+UBIFS scales logarithmically (most of the data structures it uses are
+trees), so the mount time and memory consumption do not linearly depend
+on the flash size, like in case of JFFS2. This is because UBIFS
+maintains the FS index on the flash media. However, UBIFS depends on
+UBI, which scales linearly. So overall UBI/UBIFS stack scales linearly.
+Nevertheless, UBI/UBIFS scales considerably better than JFFS2.
+
+The authors of UBIFS believe, that it is possible to develop UBI2 which
+would scale logarithmically as well. UBI2 would support the same API as UBI,
+but it would be binary incompatible to UBI. So UBIFS would not need to be
+changed to use UBI2
+
+
+Mount options
+=============
+
+(*) == default.
+
+norm_unmount (*)	commit on unmount; the journal is committed
+			when the file-system is unmounted so that the
+			next mount does not have to replay the journal
+			and it becomes very fast;
+fast_unmount		do not commit on unmount; this option makes
+			unmount faster, but the next mount slower
+			because of the need to replay the journal.
+
+
+Quick usage instructions
+========================
+
+The UBI volume to mount is specified using "ubiX_Y" or "ubiX:NAME" syntax,
+where "X" is UBI device number, "Y" is UBI volume number, and "NAME" is
+UBI volume name.
+
+Mount volume 0 on UBI device 0 to /mnt/ubifs:
+$ mount -t ubifs ubi0_0 /mnt/ubifs
+
+Mount "rootfs" volume of UBI device 0 to /mnt/ubifs ("rootfs" is volume
+name):
+$ mount -t ubifs ubi0:rootfs /mnt/ubifs
+
+The following is an example of the kernel boot arguments to attach mtd0
+to UBI and mount volume "rootfs":
+ubi.mtd=0 root=ubi0:rootfs rootfstype=ubifs
+
+
+Module Parameters for Debugging
+===============================
+
+When UBIFS has been compiled with debugging enabled, there are 3 module
+parameters that are available to control aspects of testing and debugging.
+The parameters are unsigned integers where each bit controls an option.
+The parameters are:
+
+debug_msgs	Selects which debug messages to display, as follows:
+
+		Message Type				Flag value
+
+		General messages			1
+		Journal messages			2
+		Mount messages				4
+		Commit messages				8
+		LEB search messages			16
+		Budgeting messages			32
+		Garbage collection messages		64
+		Tree Node Cache (TNC) messages		128
+		LEB properties (lprops) messages	256
+		Input/output messages			512
+		Log messages				1024
+		Scan messages				2048
+		Recovery messages			4096
+
+debug_chks	Selects extra checks that UBIFS can do while running:
+
+		Check					Flag value
+
+		General checks				1
+		Check Tree Node Cache (TNC)		2
+		Check indexing tree size		4
+		Check orphan area			8
+		Check old indexing tree			16
+		Check LEB properties (lprops)		32
+		Check leaf nodes and inodes		64
+
+debug_tsts	Selects a mode of testing, as follows:
+
+		Test mode				Flag value
+
+		Force in-the-gaps method		2
+		Failure mode for recovery testing	4
+
+For example, set debug_msgs to 5 to display General messages and Mount
+messages.
+
+
+References
+==========
+
+UBIFS documentation and FAQ/HOWTO at the MTD web site:
+http://www.linux-mtd.infradead.org/doc/ubifs.html
+http://www.linux-mtd.infradead.org/faq/ubifs.html

MAINTAINERS

@@ -2336,6 +2336,16 @@ L:	linux-mtd@lists.infradead.org
 W:	http://www.linux-mtd.infradead.org/doc/jffs2.html
 S:	Maintained
 
+UBI FILE SYSTEM (UBIFS)
+P:	Artem Bityutskiy
+M:	dedekind@infradead.org
+P:	Adrian Hunter
+M:	ext-adrian.hunter@nokia.com
+L:	linux-mtd@lists.infradead.org
+T:	git git://git.infradead.org/~dedekind/ubifs-2.6.git
+W:	http://www.linux-mtd.infradead.org/doc/ubifs.html
+S:	Maintained
+
 JFS FILESYSTEM
 P:	Dave Kleikamp
 M:	shaggy@austin.ibm.com

fs/Kconfig

@@ -1375,6 +1375,9 @@ config JFFS2_CMODE_FAVOURLZO
 
 endchoice
 
+# UBIFS File system configuration
+source "fs/ubifs/Kconfig"
+
 config CRAMFS
 	tristate "Compressed ROM file system support (cramfs)"
 	depends on BLOCK

fs/Makefile

@@ -101,6 +101,7 @@ obj-$(CONFIG_NTFS_FS)		+= ntfs/
 obj-$(CONFIG_UFS_FS)		+= ufs/
 obj-$(CONFIG_EFS_FS)		+= efs/
 obj-$(CONFIG_JFFS2_FS)		+= jffs2/
+obj-$(CONFIG_UBIFS_FS)		+= ubifs/
 obj-$(CONFIG_AFFS_FS)		+= affs/
 obj-$(CONFIG_ROMFS_FS)		+= romfs/
 obj-$(CONFIG_QNX4FS_FS)		+= qnx4/

fs/fs-writeback.c

@@ -424,8 +424,6 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
  * WB_SYNC_HOLD is a hack for sys_sync(): reattach the inode to sb->s_dirty so
  * that it can be located for waiting on in __writeback_single_inode().
  *
- * Called under inode_lock.
- *
  * If `bdi' is non-zero then we're being asked to writeback a specific queue.
  * This function assumes that the blockdev superblock's inodes are backed by
  * a variety of queues, so all inodes are searched.  For other superblocks,
@@ -441,11 +439,12 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
  * on the writer throttling path, and we get decent balancing between many
  * throttled threads: we don't want them all piling up on inode_sync_wait.
  */
-static void
-sync_sb_inodes(struct super_block *sb, struct writeback_control *wbc)
+void generic_sync_sb_inodes(struct super_block *sb,
+				struct writeback_control *wbc)
 {
 	const unsigned long start = jiffies;	/* livelock avoidance */
 
+	spin_lock(&inode_lock);
 	if (!wbc->for_kupdate || list_empty(&sb->s_io))
 		queue_io(sb, wbc->older_than_this);
 
@@ -524,8 +523,16 @@ sync_sb_inodes(struct super_block *sb, struct writeback_control *wbc)
 		if (!list_empty(&sb->s_more_io))
 			wbc->more_io = 1;
 	}
+	spin_unlock(&inode_lock);
 	return;		/* Leave any unwritten inodes on s_io */
 }
+EXPORT_SYMBOL_GPL(generic_sync_sb_inodes);
+
+static void sync_sb_inodes(struct super_block *sb,
+				struct writeback_control *wbc)
+{
+	generic_sync_sb_inodes(sb, wbc);
+}
 
 /*
  * Start writeback of dirty pagecache data against all unlocked inodes.
@@ -565,11 +572,8 @@ writeback_inodes(struct writeback_control *wbc)
 			 * be unmounted by the time it is released.
 			 */
 			if (down_read_trylock(&sb->s_umount)) {
-				if (sb->s_root) {
-					spin_lock(&inode_lock);
+				if (sb->s_root)
 					sync_sb_inodes(sb, wbc);
-					spin_unlock(&inode_lock);
-				}
 				up_read(&sb->s_umount);
 			}
 			spin_lock(&sb_lock);
@@ -607,9 +611,7 @@ void sync_inodes_sb(struct super_block *sb, int wait)
 			(inodes_stat.nr_inodes - inodes_stat.nr_unused) +
 			nr_dirty + nr_unstable;
 	wbc.nr_to_write += wbc.nr_to_write / 2;		/* Bit more for luck */
-	spin_lock(&inode_lock);
 	sync_sb_inodes(sb, &wbc);
-	spin_unlock(&inode_lock);
 }
 
 /*

fs/ubifs/Kconfig

+config UBIFS_FS
+	tristate "UBIFS file system support"
+	select CRC16
+	select CRC32
+	select CRYPTO if UBIFS_FS_ADVANCED_COMPR
+	select CRYPTO if UBIFS_FS_LZO
+	select CRYPTO if UBIFS_FS_ZLIB
+	select CRYPTO_LZO if UBIFS_FS_LZO
+	select CRYPTO_DEFLATE if UBIFS_FS_ZLIB
+	depends on MTD_UBI
+	help
+	  UBIFS is a file system for flash devices which works on top of UBI.
+
+config UBIFS_FS_XATTR
+	bool "Extended attributes support"
+	depends on UBIFS_FS
+	help
+	  This option enables support of extended attributes.
+
+config UBIFS_FS_ADVANCED_COMPR
+	bool "Advanced compression options"
+	depends on UBIFS_FS
+	help
+	  This option allows to explicitly choose which compressions, if any,
+	  are enabled in UBIFS. Removing compressors means inbility to read
+	  existing file systems.
+
+	  If unsure, say 'N'.
+
+config UBIFS_FS_LZO
+	bool "LZO compression support" if UBIFS_FS_ADVANCED_COMPR
+	depends on UBIFS_FS
+	default y
+	help
+	   LZO compressor is generally faster then zlib but compresses worse.
+	   Say 'Y' if unsure.
+
+config UBIFS_FS_ZLIB
+	bool "ZLIB compression support" if UBIFS_FS_ADVANCED_COMPR
+	depends on UBIFS_FS
+	default y
+	help
+	  Zlib copresses better then LZO but it is slower. Say 'Y' if unsure.
+
+# Debugging-related stuff
+config UBIFS_FS_DEBUG
+	bool "Enable debugging"
+	depends on UBIFS_FS
+	select DEBUG_FS
+	select KALLSYMS_ALL
+	help
+	  This option enables UBIFS debugging.
+
+config UBIFS_FS_DEBUG_MSG_LVL
+	int "Default message level (0 = no extra messages, 3 = lots)"
+	depends on UBIFS_FS_DEBUG
+	default "0"
+	help
+	  This controls the amount of debugging messages produced by UBIFS.
+	  If reporting bugs, please try to have available a full dump of the
+	  messages at level 1 while the misbehaviour was occurring. Level 2
+	  may become necessary if level 1 messages were not enough to find the
+	  bug. Generally Level 3 should be avoided.
+
+config UBIFS_FS_DEBUG_CHKS
+	bool "Enable extra checks"
+	depends on UBIFS_FS_DEBUG
+	help
+	  If extra checks are enabled UBIFS will check the consistency of its
+	  internal data structures during operation. However, UBIFS performance
+	  is dramatically slower when this option is selected especially if the
+	  file system is large.

fs/ubifs/Makefile

+obj-$(CONFIG_UBIFS_FS) += ubifs.o
+
+ubifs-y += shrinker.o journal.o file.o dir.o super.o sb.o io.o
+ubifs-y += tnc.o master.o scan.o replay.o log.o commit.o gc.o orphan.o
+ubifs-y += budget.o find.o tnc_commit.o compress.o lpt.o lprops.o
+ubifs-y += recovery.o ioctl.o lpt_commit.o tnc_misc.o
+
+ubifs-$(CONFIG_UBIFS_FS_DEBUG) += debug.o
+ubifs-$(CONFIG_UBIFS_FS_XATTR) += xattr.o

fs/ubifs/commit.c

+/*
+ * This file is part of UBIFS.
+ *
+ * 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
+ *
+ * Authors: Adrian Hunter
+ *          Artem Bityutskiy (Битюцкий Артём)
+ */
+
+/*
+ * This file implements functions that manage the running of the commit process.
+ * Each affected module has its own functions to accomplish their part in the
+ * commit and those functions are called here.
+ *
+ * The commit is the process whereby all updates to the index and LEB properties
+ * are written out together and the journal becomes empty. This keeps the
+ * file system consistent - at all times the state can be recreated by reading
+ * the index and LEB properties and then replaying the journal.
+ *
+ * The commit is split into two parts named "commit start" and "commit end".
+ * During commit start, the commit process has exclusive access to the journal
+ * by holding the commit semaphore down for writing. As few I/O operations as
+ * possible are performed during commit start, instead the nodes that are to be
+ * written are merely identified. During commit end, the commit semaphore is no
+ * longer held and the journal is again in operation, allowing users to continue
+ * to use the file system while the bulk of the commit I/O is performed. The
+ * purpose of this two-step approach is to prevent the commit from causing any
+ * latency blips. Note that in any case, the commit does not prevent lookups
+ * (as permitted by the TNC mutex), or access to VFS data structures e.g. page
+ * cache.
+ */
+
+#include <linux/freezer.h>
+#include <linux/kthread.h>
+#include "ubifs.h"
+
+/**
+ * do_commit - commit the journal.
+ * @c: UBIFS file-system description object
+ *
+ * This function implements UBIFS commit. It has to be called with commit lock
+ * locked. Returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+static int do_commit(struct ubifs_info *c)
+{
+	int err, new_ltail_lnum, old_ltail_lnum, i;
+	struct ubifs_zbranch zroot;
+	struct ubifs_lp_stats lst;
+
+	dbg_cmt("start");
+	if (c->ro_media) {
+		err = -EROFS;
+		goto out_up;
+	}
+
+	/* Sync all write buffers (necessary for recovery) */
+	for (i = 0; i < c->jhead_cnt; i++) {
+		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
+		if (err)
+			goto out_up;
+	}
+
+	err = ubifs_gc_start_commit(c);
+	if (err)
+		goto out_up;
+	err = dbg_check_lprops(c);
+	if (err)
+		goto out_up;
+	err = ubifs_log_start_commit(c, &new_ltail_lnum);
+	if (err)
+		goto out_up;
+	err = ubifs_tnc_start_commit(c, &zroot);
+	if (err)
+		goto out_up;
+	err = ubifs_lpt_start_commit(c);
+	if (err)
+		goto out_up;
+	err = ubifs_orphan_start_commit(c);
+	if (err)
+		goto out_up;
+
+	ubifs_get_lp_stats(c, &lst);
+
+	up_write(&c->commit_sem);
+
+	err = ubifs_tnc_end_commit(c);
+	if (err)
+		goto out;
+	err = ubifs_lpt_end_commit(c);
+	if (err)
+		goto out;
+	err = ubifs_orphan_end_commit(c);
+	if (err)
+		goto out;
+	old_ltail_lnum = c->ltail_lnum;
+	err = ubifs_log_end_commit(c, new_ltail_lnum);
+	if (err)
+		goto out;
+	err = dbg_check_old_index(c, &zroot);
+	if (err)
+		goto out;
+
+	mutex_lock(&c->mst_mutex);
+	c->mst_node->cmt_no      = cpu_to_le64(++c->cmt_no);
+	c->mst_node->log_lnum    = cpu_to_le32(new_ltail_lnum);
+	c->mst_node->root_lnum   = cpu_to_le32(zroot.lnum);
+	c->mst_node->root_offs   = cpu_to_le32(zroot.offs);
+	c->mst_node->root_len    = cpu_to_le32(zroot.len);
+	c->mst_node->ihead_lnum  = cpu_to_le32(c->ihead_lnum);
+	c->mst_node->ihead_offs  = cpu_to_le32(c->ihead_offs);
+	c->mst_node->index_size  = cpu_to_le64(c->old_idx_sz);
+	c->mst_node->lpt_lnum    = cpu_to_le32(c->lpt_lnum);
+	c->mst_node->lpt_offs    = cpu_to_le32(c->lpt_offs);
+	c->mst_node->nhead_lnum  = cpu_to_le32(c->nhead_lnum);
+	c->mst_node->nhead_offs  = cpu_to_le32(c->nhead_offs);
+	c->mst_node->ltab_lnum   = cpu_to_le32(c->ltab_lnum);
+	c->mst_node->ltab_offs   = cpu_to_le32(c->ltab_offs);
+	c->mst_node->lsave_lnum  = cpu_to_le32(c->lsave_lnum);
+	c->mst_node->lsave_offs  = cpu_to_le32(c->lsave_offs);
+	c->mst_node->lscan_lnum  = cpu_to_le32(c->lscan_lnum);
+	c->mst_node->empty_lebs  = cpu_to_le32(lst.empty_lebs);
+	c->mst_node->idx_lebs    = cpu_to_le32(lst.idx_lebs);
+	c->mst_node->total_free  = cpu_to_le64(lst.total_free);
+	c->mst_node->total_dirty = cpu_to_le64(lst.total_dirty);
+	c->mst_node->total_used  = cpu_to_le64(lst.total_used);
+	c->mst_node->total_dead  = cpu_to_le64(lst.total_dead);
+	c->mst_node->total_dark  = cpu_to_le64(lst.total_dark);
+	if (c->no_orphs)
+		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
+	else
+		c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_NO_ORPHS);
+	err = ubifs_write_master(c);
+	mutex_unlock(&c->mst_mutex);
+	if (err)
+		goto out;
+
+	err = ubifs_log_post_commit(c, old_ltail_lnum);
+	if (err)
+		goto out;
+	err = ubifs_gc_end_commit(c);
+	if (err)
+		goto out;
+	err = ubifs_lpt_post_commit(c);
+	if (err)
+		goto out;
+
+	spin_lock(&c->cs_lock);
+	c->cmt_state = COMMIT_RESTING;
+	wake_up(&c->cmt_wq);
+	dbg_cmt("commit end");
+	spin_unlock(&c->cs_lock);
+
+	return 0;
+
+out_up:
+	up_write(&c->commit_sem);
+out:
+	ubifs_err("commit failed, error %d", err);
+	spin_lock(&c->cs_lock);
+	c->cmt_state = COMMIT_BROKEN;
+	wake_up(&c->cmt_wq);
+	spin_unlock(&c->cs_lock);
+	ubifs_ro_mode(c, err);
+	return err;
+}
+
+/**
+ * run_bg_commit - run background commit if it is needed.
+ * @c: UBIFS file-system description object
+ *
+ * This function runs background commit if it is needed. Returns zero in case
+ * of success and a negative error code in case of failure.
+ */
+static int run_bg_commit(struct ubifs_info *c)
+{
+	spin_lock(&c->cs_lock);
+	/*
+	 * Run background commit only if background commit was requested or if
+	 * commit is required.
+	 */
+	if (c->cmt_state != COMMIT_BACKGROUND &&
+	    c->cmt_state != COMMIT_REQUIRED)
+		goto out;
+	spin_unlock(&c->cs_lock);
+
+	down_write(&c->commit_sem);
+	spin_lock(&c->cs_lock);
+	if (c->cmt_state == COMMIT_REQUIRED)
+		c->cmt_state = COMMIT_RUNNING_REQUIRED;
+	else if (c->cmt_state == COMMIT_BACKGROUND)
+		c->cmt_state = COMMIT_RUNNING_BACKGROUND;
+	else
+		goto out_cmt_unlock;
+	spin_unlock(&c->cs_lock);
+
+	return do_commit(c);
+
+out_cmt_unlock:
+	up_write(&c->commit_sem);
+out:
+	spin_unlock(&c->cs_lock);
+	return 0;
+}
+
+/**
+ * ubifs_bg_thread - UBIFS background thread function.
+ * @info: points to the file-system description object
+ *
+ * This function implements various file-system background activities:
+ * o when a write-buffer timer expires it synchronizes the appropriate
+ *   write-buffer;
+ * o when the journal is about to be full, it starts in-advance commit.
+ *
+ * Note, other stuff like background garbage collection may be added here in
+ * future.
+ */
+int ubifs_bg_thread(void *info)
+{
+	int err;
+	struct ubifs_info *c = info;
+
+	ubifs_msg("background thread \"%s\" started, PID %d",
+		  c->bgt_name, current->pid);
+	set_freezable();
+
+	while (1) {
+		if (kthread_should_stop())
+			break;
+
+		if (try_to_freeze())
+			continue;
+
+		set_current_state(TASK_INTERRUPTIBLE);
+		/* Check if there is something to do */
+		if (!c->need_bgt) {
+			/*
+			 * Nothing prevents us from going sleep now and
+			 * be never woken up and block the task which
+			 * could wait in 'kthread_stop()' forever.
+			 */
+			if (kthread_should_stop())
+				break;
+			schedule();
+			continue;
+		} else
+			__set_current_state(TASK_RUNNING);
+
+		c->need_bgt = 0;
+		err = ubifs_bg_wbufs_sync(c);
+		if (err)
+			ubifs_ro_mode(c, err);
+
+		run_bg_commit(c);
+		cond_resched();
+	}
+
+	dbg_msg("background thread \"%s\" stops", c->bgt_name);
+	return 0;
+}
+
+/**
+ * ubifs_commit_required - set commit state to "required".
+ * @c: UBIFS file-system description object
+ *
+ * This function is called if a commit is required but cannot be done from the
+ * calling function, so it is just flagged instead.
+ */
+void ubifs_commit_required(struct ubifs_info *c)
+{
+	spin_lock(&c->cs_lock);
+	switch (c->cmt_state) {
+	case COMMIT_RESTING:
+	case COMMIT_BACKGROUND:
+		dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
+			dbg_cstate(COMMIT_REQUIRED));
+		c->cmt_state = COMMIT_REQUIRED;
+		break;
+	case COMMIT_RUNNING_BACKGROUND:
+		dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
+			dbg_cstate(COMMIT_RUNNING_REQUIRED));
+		c->cmt_state = COMMIT_RUNNING_REQUIRED;
+		break;
+	case COMMIT_REQUIRED:
+	case COMMIT_RUNNING_REQUIRED:
+	case COMMIT_BROKEN:
+		break;
+	}
+	spin_unlock(&c->cs_lock);
+}
+
+/**
+ * ubifs_request_bg_commit - notify the background thread to do a commit.
+ * @c: UBIFS file-system description object
+ *
+ * This function is called if the journal is full enough to make a commit
+ * worthwhile, so background thread is kicked to start it.
+ */
+void ubifs_request_bg_commit(struct ubifs_info *c)
+{
+	spin_lock(&c->cs_lock);
+	if (c->cmt_state == COMMIT_RESTING) {
+		dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
+			dbg_cstate(COMMIT_BACKGROUND));
+		c->cmt_state = COMMIT_BACKGROUND;
+		spin_unlock(&c->cs_lock);
+		ubifs_wake_up_bgt(c);
+	} else
+		spin_unlock(&c->cs_lock);
+}
+
+/**
+ * wait_for_commit - wait for commit.
+ * @c: UBIFS file-system description object
+ *
+ * This function sleeps until the commit operation is no longer running.
+ */
+static int wait_for_commit(struct ubifs_info *c)
+{
+	dbg_cmt("pid %d goes sleep", current->pid);
+
+	/*
+	 * The following sleeps if the condition is false, and will be woken
+	 * when the commit ends. It is possible, although very unlikely, that we
+	 * will wake up and see the subsequent commit running, rather than the
+	 * one we were waiting for, and go back to sleep.  However, we will be
+	 * woken again, so there is no danger of sleeping forever.
+	 */
+	wait_event(c->cmt_wq, c->cmt_state != COMMIT_RUNNING_BACKGROUND &&
+			      c->cmt_state != COMMIT_RUNNING_REQUIRED);
+	dbg_cmt("commit finished, pid %d woke up", current->pid);
+	return 0;
+}
+
+/**
+ * ubifs_run_commit - run or wait for commit.
+ * @c: UBIFS file-system description object
+ *
+ * This function runs commit and returns zero in case of success and a negative
+ * error code in case of failure.
+ */
+int ubifs_run_commit(struct ubifs_info *c)
+{
+	int err = 0;
+
+	spin_lock(&c->cs_lock);
+	if (c->cmt_state == COMMIT_BROKEN) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (c->cmt_state == COMMIT_RUNNING_BACKGROUND)
+		/*
+		 * We set the commit state to 'running required' to indicate
+		 * that we want it to complete as quickly as possible.
+		 */
+		c->cmt_state = COMMIT_RUNNING_REQUIRED;
+
+	if (c->cmt_state == COMMIT_RUNNING_REQUIRED) {
+		spin_unlock(&c->cs_lock);
+		return wait_for_commit(c);
+	}
+	spin_unlock(&c->cs_lock);
+
+	/* Ok, the commit is indeed needed */
+
+	down_write(&c->commit_sem);
+	spin_lock(&c->cs_lock);
+	/*
+	 * Since we unlocked 'c->cs_lock', the state may have changed, so
+	 * re-check it.
+	 */
+	if (c->cmt_state == COMMIT_BROKEN) {
+		err = -EINVAL;
+		goto out_cmt_unlock;
+	}
+
+	if (c->cmt_state == COMMIT_RUNNING_BACKGROUND)
+		c->cmt_state = COMMIT_RUNNING_REQUIRED;
+
+	if (c->cmt_state == COMMIT_RUNNING_REQUIRED) {
+		up_write(&c->commit_sem);
+		spin_unlock(&c->cs_lock);
+		return wait_for_commit(c);
+	}
+	c->cmt_state = COMMIT_RUNNING_REQUIRED;
+	spin_unlock(&c->cs_lock);
+
+	err = do_commit(c);
+	return err;
+
+out_cmt_unlock:
+	up_write(&c->commit_sem);
+out:
+	spin_unlock(&c->cs_lock);
+	return err;
+}
+
+/**
+ * ubifs_gc_should_commit - determine if it is time for GC to run commit.
+ * @c: UBIFS file-system description object
+ *
+ * This function is called by garbage collection to determine if commit should
+ * be run. If commit state is @COMMIT_BACKGROUND, which means that the journal
+ * is full enough to start commit, this function returns true. It is not
+ * absolutely necessary to commit yet, but it feels like this should be better
+ * then to keep doing GC. This function returns %1 if GC has to initiate commit
+ * and %0 if not.
+ */
+int ubifs_gc_should_commit(struct ubifs_info *c)
+{
+	int ret = 0;
+
+	spin_lock(&c->cs_lock);
+	if (c->cmt_state == COMMIT_BACKGROUND) {
+		dbg_cmt("commit required now");
+		c->cmt_state = COMMIT_REQUIRED;
+	} else
+		dbg_cmt("commit not requested");
+	if (c->cmt_state == COMMIT_REQUIRED)
+		ret = 1;
+	spin_unlock(&c->cs_lock);
+	return ret;
+}
+
+#ifdef CONFIG_UBIFS_FS_DEBUG
+
+/**
+ * struct idx_node - hold index nodes during index tree traversal.
+ * @list: list
+ * @iip: index in parent (slot number of this indexing node in the parent
+ *       indexing node)
+ * @upper_key: all keys in this indexing node have to be less or equivalent to
+ *             this key
+ * @idx: index node (8-byte aligned because all node structures must be 8-byte
+ *       aligned)
+ */
+struct idx_node {
+	struct list_head list;
+	int iip;
+	union ubifs_key upper_key;
+	struct ubifs_idx_node idx __attribute__((aligned(8)));
+};
+
+/**
+ * dbg_old_index_check_init - get information for the next old index check.
+ * @c: UBIFS file-system description object
+ * @zroot: root of the index
+ *
+ * This function records information about the index that will be needed for the
+ * next old index check i.e. 'dbg_check_old_index()'.
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int dbg_old_index_check_init(struct ubifs_info *c, struct ubifs_zbranch *zroot)
+{
+	struct ubifs_idx_node *idx;
+	int lnum, offs, len, err = 0;
+
+	c->old_zroot = *zroot;
+
+	lnum = c->old_zroot.lnum;
+	offs = c->old_zroot.offs;
+	len = c->old_zroot.len;
+
+	idx = kmalloc(c->max_idx_node_sz, GFP_NOFS);
+	if (!idx)
+		return -ENOMEM;
+
+	err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs);
+	if (err)
+		goto out;
+
+	c->old_zroot_level = le16_to_cpu(idx->level);
+	c->old_zroot_sqnum = le64_to_cpu(idx->ch.sqnum);
+out:
+	kfree(idx);
+	return err;
+}
+
+/**
+ * dbg_check_old_index - check the old copy of the index.
+ * @c: UBIFS file-system description object
+ * @zroot: root of the new index
+ *
+ * In order to be able to recover from an unclean unmount, a complete copy of
+ * the index must exist on flash. This is the "old" index. The commit process
+ * must write the "new" index to flash without overwriting or destroying any
+ * part of the old index. This function is run at commit end in order to check
+ * that the old index does indeed exist completely intact.
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot)
+{
+	int lnum, offs, len, err = 0, uninitialized_var(last_level), child_cnt;
+	int first = 1, iip;
+	union ubifs_key lower_key, upper_key, l_key, u_key;
+	unsigned long long uninitialized_var(last_sqnum);
+	struct ubifs_idx_node *idx;
+	struct list_head list;
+	struct idx_node *i;
+	size_t sz;
+
+	if (!(ubifs_chk_flags & UBIFS_CHK_OLD_IDX))
+		goto out;
+
+	INIT_LIST_HEAD(&list);
+
+	sz = sizeof(struct idx_node) + ubifs_idx_node_sz(c, c->fanout) -
+	     UBIFS_IDX_NODE_SZ;
+
+	/* Start at the old zroot */
+	lnum = c->old_zroot.lnum;
+	offs = c->old_zroot.offs;
+	len = c->old_zroot.len;
+	iip = 0;
+
+	/*
+	 * Traverse the index tree preorder depth-first i.e. do a node and then
+	 * its subtrees from left to right.
+	 */
+	while (1) {
+		struct ubifs_branch *br;
+
+		/* Get the next index node */
+		i = kmalloc(sz, GFP_NOFS);
+		if (!i) {
+			err = -ENOMEM;
+			goto out_free;
+		}
+		i->iip = iip;
+		/* Keep the index nodes on our path in a linked list */
+		list_add_tail(&i->list, &list);
+		/* Read the index node */
+		idx = &i->idx;
+		err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs);
+		if (err)
+			goto out_free;
+		/* Validate index node */
+		child_cnt = le16_to_cpu(idx->child_cnt);
+		if (child_cnt < 1 || child_cnt > c->fanout) {
+			err = 1;
+			goto out_dump;
+		}
+		if (first) {
+			first = 0;
+			/* Check root level and sqnum */
+			if (le16_to_cpu(idx->level) != c->old_zroot_level) {
+				err = 2;
+				goto out_dump;
+			}
+			if (le64_to_cpu(idx->ch.sqnum) != c->old_zroot_sqnum) {
+				err = 3;
+				goto out_dump;
+			}
+			/* Set last values as though root had a parent */
+			last_level = le16_to_cpu(idx->level) + 1;
+			last_sqnum = le64_to_cpu(idx->ch.sqnum) + 1;
+			key_read(c, ubifs_idx_key(c, idx), &lower_key);
+			highest_ino_key(c, &upper_key, INUM_WATERMARK);
+		}
+		key_copy(c, &upper_key, &i->upper_key);
+		if (le16_to_cpu(idx->level) != last_level - 1) {
+			err = 3;
+			goto out_dump;
+		}
+		/*
+		 * The index is always written bottom up hence a child's sqnum
+		 * is always less than the parents.
+		 */
+		if (le64_to_cpu(idx->ch.sqnum) >= last_sqnum) {
+			err = 4;
+			goto out_dump;
+		}
+		/* Check key range */
+		key_read(c, ubifs_idx_key(c, idx), &l_key);
+		br = ubifs_idx_branch(c, idx, child_cnt - 1);
+		key_read(c, &br->key, &u_key);
+		if (keys_cmp(c, &lower_key, &l_key) > 0) {
+			err = 5;
+			goto out_dump;
+		}
+		if (keys_cmp(c, &upper_key, &u_key) < 0) {
+			err = 6;
+			goto out_dump;
+		}
+		if (keys_cmp(c, &upper_key, &u_key) == 0)
+			if (!is_hash_key(c, &u_key)) {
+				err = 7;
+				goto out_dump;
+			}
+		/* Go to next index node */
+		if (le16_to_cpu(idx->level) == 0) {
+			/* At the bottom, so go up until can go right */
+			while (1) {
+				/* Drop the bottom of the list */
+				list_del(&i->list);
+				kfree(i);
+				/* No more list means we are done */
+				if (list_empty(&list))
+					goto out;
+				/* Look at the new bottom */
+				i = list_entry(list.prev, struct idx_node,
+					       list);
+				idx = &i->idx;
+				/* Can we go right */
+				if (iip + 1 < le16_to_cpu(idx->child_cnt)) {
+					iip = iip + 1;
+					break;
+				} else
+					/* Nope, so go up again */
+					iip = i->iip;
+			}
+		} else
+			/* Go down left */
+			iip = 0;
+		/*
+		 * We have the parent in 'idx' and now we set up for reading the
+		 * child pointed to by slot 'iip'.
+		 */
+		last_level = le16_to_cpu(idx->level);
+		last_sqnum = le64_to_cpu(idx->ch.sqnum);
+		br = ubifs_idx_branch(c, idx, iip);
+		lnum = le32_to_cpu(br->lnum);
+		offs = le32_to_cpu(br->offs);
+		len = le32_to_cpu(br->len);
+		key_read(c, &br->key, &lower_key);
+		if (iip + 1 < le16_to_cpu(idx->child_cnt)) {
+			br = ubifs_idx_branch(c, idx, iip + 1);
+			key_read(c, &br->key, &upper_key);
+		} else
+			key_copy(c, &i->upper_key, &upper_key);
+	}
+out:
+	err = dbg_old_index_check_init(c, zroot);
+	if (err)
+		goto out_free;
+
+	return 0;
+
+out_dump:
+	dbg_err("dumping index node (iip=%d)", i->iip);
+	dbg_dump_node(c, idx);
+	list_del(&i->list);
+	kfree(i);
+	if (!list_empty(&list)) {
+		i = list_entry(list.prev, struct idx_node, list);
+		dbg_err("dumping parent index node");
+		dbg_dump_node(c, &i->idx);
+	}
+out_free:
+	while (!list_empty(&list)) {
+		i = list_entry(list.next, struct idx_node, list);
+		list_del(&i->list);
+		kfree(i);
+	}
+	ubifs_err("failed, error %d", err);
+	if (err > 0)
+		err = -EINVAL;
+	return err;
+}
+
+#endif /* CONFIG_UBIFS_FS_DEBUG */

fs/ubifs/compress.c

+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ * Copyright (C) 2006, 2007 University of Szeged, Hungary
+ *
+ * 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
+ *
+ * Authors: Adrian Hunter
+ *          Artem Bityutskiy (Битюцкий Артём)
+ *          Zoltan Sogor
+ */
+
+/*
+ * This file provides a single place to access to compression and
+ * decompression.
+ */
+
+#include <linux/crypto.h>
+#include "ubifs.h"
+
+/* Fake description object for the "none" compressor */
+static struct ubifs_compressor none_compr = {
+	.compr_type = UBIFS_COMPR_NONE,
+	.name = "no compression",
+	.capi_name = "",
+};
+
+#ifdef CONFIG_UBIFS_FS_LZO
+static DEFINE_MUTEX(lzo_mutex);
+
+static struct ubifs_compressor lzo_compr = {
+	.compr_type = UBIFS_COMPR_LZO,
+	.comp_mutex = &lzo_mutex,
+	.name = "LZO",
+	.capi_name = "lzo",
+};
+#else
+static struct ubifs_compressor lzo_compr = {
+	.compr_type = UBIFS_COMPR_LZO,
+	.name = "LZO",
+};
+#endif
+
+#ifdef CONFIG_UBIFS_FS_ZLIB
+static DEFINE_MUTEX(deflate_mutex);
+static DEFINE_MUTEX(inflate_mutex);
+
+static struct ubifs_compressor zlib_compr = {
+	.compr_type = UBIFS_COMPR_ZLIB,
+	.comp_mutex = &deflate_mutex,
+	.decomp_mutex = &inflate_mutex,
+	.name = "zlib",
+	.capi_name = "deflate",
+};
+#else
+static struct ubifs_compressor zlib_compr = {
+	.compr_type = UBIFS_COMPR_ZLIB,
+	.name = "zlib",
+};
+#endif
+
+/* All UBIFS compressors */
+struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT];
+
+/**
+ * ubifs_compress - compress data.
+ * @in_buf: data to compress
+ * @in_len: length of the data to compress
+ * @out_buf: output buffer where compressed data should be stored
+ * @out_len: output buffer length is returned here
+ * @compr_type: type of compression to use on enter, actually used compression
+ *              type on exit
+ *
+ * This function compresses input buffer @in_buf of length @in_len and stores
+ * the result in the output buffer @out_buf and the resulting length in
+ * @out_len. If the input buffer does not compress, it is just copied to the
+ * @out_buf. The same happens if @compr_type is %UBIFS_COMPR_NONE or if
+ * compression error occurred.
+ *
+ * Note, if the input buffer was not compressed, it is copied to the output
+ * buffer and %UBIFS_COMPR_NONE is returned in @compr_type.
+ *
+ * This functions returns %0 on success or a negative error code on failure.
+ */
+void ubifs_compress(const void *in_buf, int in_len, void *out_buf, int *out_len,
+		    int *compr_type)
+{
+	int err;
+	struct ubifs_compressor *compr = ubifs_compressors[*compr_type];
+
+	if (*compr_type == UBIFS_COMPR_NONE)
+		goto no_compr;
+
+	/* If the input data is small, do not even try to compress it */
+	if (in_len < UBIFS_MIN_COMPR_LEN)
+		goto no_compr;
+
+	if (compr->comp_mutex)
+		mutex_lock(compr->comp_mutex);
+	err = crypto_comp_compress(compr->cc, in_buf, in_len, out_buf,
+				   out_len);
+	if (compr->comp_mutex)
+		mutex_unlock(compr->comp_mutex);
+	if (unlikely(err)) {
+		ubifs_warn("cannot compress %d bytes, compressor %s, "
+			   "error %d, leave data uncompressed",
+			   in_len, compr->name, err);
+		 goto no_compr;
+	}
+
+	/*
+	 * Presently, we just require that compression results in less data,
+	 * rather than any defined minimum compression ratio or amount.
+	 */
+	if (ALIGN(*out_len, 8) >= ALIGN(in_len, 8))
+		goto no_compr;
+
+	return;
+
+no_compr:
+	memcpy(out_buf, in_buf, in_len);
+	*out_len = in_len;
+	*compr_type = UBIFS_COMPR_NONE;
+}
+
+/**
+ * ubifs_decompress - decompress data.
+ * @in_buf: data to decompress
+ * @in_len: length of the data to decompress
+ * @out_buf: output buffer where decompressed data should
+ * @out_len: output length is returned here
+ * @compr_type: type of compression
+ *
+ * This function decompresses data from buffer @in_buf into buffer @out_buf.
+ * The length of the uncompressed data is returned in @out_len. This functions
+ * returns %0 on success or a negative error code on failure.
+ */
+int ubifs_decompress(const void *in_buf, int in_len, void *out_buf,
+		     int *out_len, int compr_type)
+{
+	int err;
+	struct ubifs_compressor *compr;
+
+	if (unlikely(compr_type < 0 || compr_type >= UBIFS_COMPR_TYPES_CNT)) {
+		ubifs_err("invalid compression type %d", compr_type);
+		return -EINVAL;
+	}
+
+	compr = ubifs_compressors[compr_type];
+
+	if (unlikely(!compr->capi_name)) {
+		ubifs_err("%s compression is not compiled in", compr->name);
+		return -EINVAL;
+	}
+
+	if (compr_type == UBIFS_COMPR_NONE) {
+		memcpy(out_buf, in_buf, in_len);
+		*out_len = in_len;
+		return 0;
+	}
+
+	if (compr->decomp_mutex)
+		mutex_lock(compr->decomp_mutex);
+	err = crypto_comp_decompress(compr->cc, in_buf, in_len, out_buf,
+				     out_len);
+	if (compr->decomp_mutex)
+		mutex_unlock(compr->decomp_mutex);
+	if (err)
+		ubifs_err("cannot decompress %d bytes, compressor %s, "
+			  "error %d", in_len, compr->name, err);
+
+	return err;
+}
+
+/**
+ * compr_init - initialize a compressor.
+ * @compr: compressor description object
+ *
+ * This function initializes the requested compressor and returns zero in case
+ * of success or a negative error code in case of failure.
+ */
+static int __init compr_init(struct ubifs_compressor *compr)
+{
+	if (compr->capi_name) {
+		compr->cc = crypto_alloc_comp(compr->capi_name, 0, 0);
+		if (IS_ERR(compr->cc)) {
+			ubifs_err("cannot initialize compressor %s, error %ld",
+				  compr->name, PTR_ERR(compr->cc));
+			return PTR_ERR(compr->cc);
+		}
+	}
+
+	ubifs_compressors[compr->compr_type] = compr;
+	return 0;
+}
+
+/**
+ * compr_exit - de-initialize a compressor.
+ * @compr: compressor description object
+ */
+static void compr_exit(struct ubifs_compressor *compr)
+{
+	if (compr->capi_name)
+		crypto_free_comp(compr->cc);
+	return;
+}
+
+/**
+ * ubifs_compressors_init - initialize UBIFS compressors.
+ *
+ * This function initializes the compressor which were compiled in. Returns
+ * zero in case of success and a negative error code in case of failure.
+ */
+int __init ubifs_compressors_init(void)
+{
+	int err;
+
+	err = compr_init(&lzo_compr);
+	if (err)
+		return err;
+
+	err = compr_init(&zlib_compr);
+	if (err)
+		goto out_lzo;
+
+	ubifs_compressors[UBIFS_COMPR_NONE] = &none_compr;
+	return 0;
+
+out_lzo:
+	compr_exit(&lzo_compr);
+	return err;
+}
+
+/**
+ * ubifs_compressors_exit - de-initialize UBIFS compressors.
+ */
+void __exit ubifs_compressors_exit(void)
+{
+	compr_exit(&lzo_compr);
+	compr_exit(&zlib_compr);
+}

fs/ubifs/debug.h

+/*
+ * This file is part of UBIFS.
+ *
+ * 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
+ *
+ * Authors: Artem Bityutskiy (Битюцкий Артём)
+ *          Adrian Hunter
+ */
+
+#ifndef __UBIFS_DEBUG_H__
+#define __UBIFS_DEBUG_H__
+
+#ifdef CONFIG_UBIFS_FS_DEBUG
+
+#define UBIFS_DBG(op) op
+
+#define ubifs_assert(expr)  do {                                               \
+	if (unlikely(!(expr))) {                                               \
+		printk(KERN_CRIT "UBIFS assert failed in %s at %u (pid %d)\n", \
+		       __func__, __LINE__, current->pid);                      \
+		dbg_dump_stack();                                              \
+	}                                                                      \
+} while (0)
+
+#define ubifs_assert_cmt_locked(c) do {                                        \
+	if (unlikely(down_write_trylock(&(c)->commit_sem))) {                  \
+		up_write(&(c)->commit_sem);                                    \
+		printk(KERN_CRIT "commit lock is not locked!\n");              \
+		ubifs_assert(0);                                               \
+	}                                                                      \
+} while (0)
+
+#define dbg_dump_stack() do {                                                  \
+	if (!dbg_failure_mode)                                                 \
+		dump_stack();                                                  \
+} while (0)
+
+/* Generic debugging messages */
+#define dbg_msg(fmt, ...) do {                                                 \
+	spin_lock(&dbg_lock);                                                  \
+	printk(KERN_DEBUG "UBIFS DBG (pid %d): %s: " fmt "\n", current->pid,   \
+	       __func__, ##__VA_ARGS__);                                       \
+	spin_unlock(&dbg_lock);                                                \
+} while (0)
+
+#define dbg_do_msg(typ, fmt, ...) do {                                         \
+	if (ubifs_msg_flags & typ)                                             \
+		dbg_msg(fmt, ##__VA_ARGS__);                                   \
+} while (0)
+
+#define dbg_err(fmt, ...) do {                                                 \
+	spin_lock(&dbg_lock);                                                  \
+	ubifs_err(fmt, ##__VA_ARGS__);                                         \
+	spin_unlock(&dbg_lock);                                                \
+} while (0)
+
+const char *dbg_key_str0(const struct ubifs_info *c,
+			 const union ubifs_key *key);
+const char *dbg_key_str1(const struct ubifs_info *c,
+			 const union ubifs_key *key);
+
+/*
+ * DBGKEY macros require dbg_lock to be held, which it is in the dbg message
+ * macros.
+ */
+#define DBGKEY(key) dbg_key_str0(c, (key))
+#define DBGKEY1(key) dbg_key_str1(c, (key))
+
+/* General messages */
+#define dbg_gen(fmt, ...)        dbg_do_msg(UBIFS_MSG_GEN, fmt, ##__VA_ARGS__)
+
+/* Additional journal messages */
+#define dbg_jnl(fmt, ...)        dbg_do_msg(UBIFS_MSG_JNL, fmt, ##__VA_ARGS__)
+
+/* Additional TNC messages */
+#define dbg_tnc(fmt, ...)        dbg_do_msg(UBIFS_MSG_TNC, fmt, ##__VA_ARGS__)
+
+/* Additional lprops messages */
+#define dbg_lp(fmt, ...)         dbg_do_msg(UBIFS_MSG_LP, fmt, ##__VA_ARGS__)
+
+/* Additional LEB find messages */
+#define dbg_find(fmt, ...)       dbg_do_msg(UBIFS_MSG_FIND, fmt, ##__VA_ARGS__)
+
+/* Additional mount messages */
+#define dbg_mnt(fmt, ...)        dbg_do_msg(UBIFS_MSG_MNT, fmt, ##__VA_ARGS__)
+
+/* Additional I/O messages */
+#define dbg_io(fmt, ...)         dbg_do_msg(UBIFS_MSG_IO, fmt, ##__VA_ARGS__)
+
+/* Additional commit messages */
+#define dbg_cmt(fmt, ...)        dbg_do_msg(UBIFS_MSG_CMT, fmt, ##__VA_ARGS__)
+
+/* Additional budgeting messages */
+#define dbg_budg(fmt, ...)       dbg_do_msg(UBIFS_MSG_BUDG, fmt, ##__VA_ARGS__)
+
+/* Additional log messages */
+#define dbg_log(fmt, ...)        dbg_do_msg(UBIFS_MSG_LOG, fmt, ##__VA_ARGS__)
+
+/* Additional gc messages */
+#define dbg_gc(fmt, ...)         dbg_do_msg(UBIFS_MSG_GC, fmt, ##__VA_ARGS__)
+
+/* Additional scan messages */
+#define dbg_scan(fmt, ...)       dbg_do_msg(UBIFS_MSG_SCAN, fmt, ##__VA_ARGS__)
+
+/* Additional recovery messages */
+#define dbg_rcvry(fmt, ...)      dbg_do_msg(UBIFS_MSG_RCVRY, fmt, ##__VA_ARGS__)
+
+/*
+ * Debugging message type flags (must match msg_type_names in debug.c).
+ *
+ * UBIFS_MSG_GEN: general messages
+ * UBIFS_MSG_JNL: journal messages
+ * UBIFS_MSG_MNT: mount messages
+ * UBIFS_MSG_CMT: commit messages
+ * UBIFS_MSG_FIND: LEB find messages
+ * UBIFS_MSG_BUDG: budgeting messages
+ * UBIFS_MSG_GC: garbage collection messages
+ * UBIFS_MSG_TNC: TNC messages
+ * UBIFS_MSG_LP: lprops messages
+ * UBIFS_MSG_IO: I/O messages
+ * UBIFS_MSG_LOG: log messages
+ * UBIFS_MSG_SCAN: scan messages
+ * UBIFS_MSG_RCVRY: recovery messages
+ */
+enum {
+	UBIFS_MSG_GEN   = 0x1,
+	UBIFS_MSG_JNL   = 0x2,
+	UBIFS_MSG_MNT   = 0x4,
+	UBIFS_MSG_CMT   = 0x8,
+	UBIFS_MSG_FIND  = 0x10,
+	UBIFS_MSG_BUDG  = 0x20,
+	UBIFS_MSG_GC    = 0x40,
+	UBIFS_MSG_TNC   = 0x80,
+	UBIFS_MSG_LP    = 0x100,
+	UBIFS_MSG_IO    = 0x200,
+	UBIFS_MSG_LOG   = 0x400,
+	UBIFS_MSG_SCAN  = 0x800,
+	UBIFS_MSG_RCVRY = 0x1000,
+};
+
+/* Debugging message type flags for each default debug message level */
+#define UBIFS_MSG_LVL_0 0
+#define UBIFS_MSG_LVL_1 0x1
+#define UBIFS_MSG_LVL_2 0x7f
+#define UBIFS_MSG_LVL_3 0xffff
+
+/*
+ * Debugging check flags (must match chk_names in debug.c).
+ *
+ * UBIFS_CHK_GEN: general checks
+ * UBIFS_CHK_TNC: check TNC
+ * UBIFS_CHK_IDX_SZ: check index size
+ * UBIFS_CHK_ORPH: check orphans
+ * UBIFS_CHK_OLD_IDX: check the old index
+ * UBIFS_CHK_LPROPS: check lprops
+ * UBIFS_CHK_FS: check the file-system
+ */
+enum {
+	UBIFS_CHK_GEN     = 0x1,
+	UBIFS_CHK_TNC     = 0x2,
+	UBIFS_CHK_IDX_SZ  = 0x4,
+	UBIFS_CHK_ORPH    = 0x8,
+	UBIFS_CHK_OLD_IDX = 0x10,
+	UBIFS_CHK_LPROPS  = 0x20,
+	UBIFS_CHK_FS      = 0x40,
+};
+
+/*
+ * Special testing flags (must match tst_names in debug.c).
+ *
+ * UBIFS_TST_FORCE_IN_THE_GAPS: force the use of in-the-gaps method
+ * UBIFS_TST_RCVRY: failure mode for recovery testing
+ */
+enum {
+	UBIFS_TST_FORCE_IN_THE_GAPS = 0x2,
+	UBIFS_TST_RCVRY             = 0x4,
+};
+
+#if CONFIG_UBIFS_FS_DEBUG_MSG_LVL == 1
+#define UBIFS_MSG_FLAGS_DEFAULT UBIFS_MSG_LVL_1
+#elif CONFIG_UBIFS_FS_DEBUG_MSG_LVL == 2
+#define UBIFS_MSG_FLAGS_DEFAULT UBIFS_MSG_LVL_2
+#elif CONFIG_UBIFS_FS_DEBUG_MSG_LVL == 3
+#define UBIFS_MSG_FLAGS_DEFAULT UBIFS_MSG_LVL_3
+#else
+#define UBIFS_MSG_FLAGS_DEFAULT UBIFS_MSG_LVL_0
+#endif
+
+#ifdef CONFIG_UBIFS_FS_DEBUG_CHKS
+#define UBIFS_CHK_FLAGS_DEFAULT 0xffffffff
+#else
+#define UBIFS_CHK_FLAGS_DEFAULT 0
+#endif
+
+extern spinlock_t dbg_lock;
+
+extern unsigned int ubifs_msg_flags;
+extern unsigned int ubifs_chk_flags;
+extern unsigned int ubifs_tst_flags;
+
+/* Dump functions */
+
+const char *dbg_ntype(int type);
+const char *dbg_cstate(int cmt_state);
+const char *dbg_get_key_dump(const struct ubifs_info *c,
+			     const union ubifs_key *key);
+void dbg_dump_inode(const struct ubifs_info *c, const struct inode *inode);
+void dbg_dump_node(const struct ubifs_info *c, const void *node);
+void dbg_dump_budget_req(const struct ubifs_budget_req *req);
+void dbg_dump_lstats(const struct ubifs_lp_stats *lst);
+void dbg_dump_budg(struct ubifs_info *c);
+void dbg_dump_lprop(const struct ubifs_info *c, const struct ubifs_lprops *lp);
+void dbg_dump_lprops(struct ubifs_info *c);
+void dbg_dump_leb(const struct ubifs_info *c, int lnum);
+void dbg_dump_znode(const struct ubifs_info *c,
+		    const struct ubifs_znode *znode);
+void dbg_dump_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, int cat);
+void dbg_dump_pnode(struct ubifs_info *c, struct ubifs_pnode *pnode,
+		    struct ubifs_nnode *parent, int iip);
+void dbg_dump_tnc(struct ubifs_info *c);
+void dbg_dump_index(struct ubifs_info *c);
+
+/* Checking helper functions */
+
+typedef int (*dbg_leaf_callback)(struct ubifs_info *c,
+				 struct ubifs_zbranch *zbr, void *priv);
+typedef int (*dbg_znode_callback)(struct ubifs_info *c,
+				  struct ubifs_znode *znode, void *priv);
+
+int dbg_walk_index(struct ubifs_info *c, dbg_leaf_callback leaf_cb,
+		   dbg_znode_callback znode_cb, void *priv);
+
+/* Checking functions */
+
+int dbg_check_lprops(struct ubifs_info *c);
+
+int dbg_old_index_check_init(struct ubifs_info *c, struct ubifs_zbranch *zroot);
+int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot);
+
+int dbg_check_cats(struct ubifs_info *c);
+
+int dbg_check_ltab(struct ubifs_info *c);
+
+int dbg_check_synced_i_size(struct inode *inode);
+
+int dbg_check_dir_size(struct ubifs_info *c, const struct inode *dir);
+
+int dbg_check_tnc(struct ubifs_info *c, int extra);
+
+int dbg_check_idx_size(struct ubifs_info *c, long long idx_size);
+
+int dbg_check_filesystem(struct ubifs_info *c);
+
+void dbg_check_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, int cat,
+		    int add_pos);
+
+int dbg_check_lprops(struct ubifs_info *c);
+int dbg_check_lpt_nodes(struct ubifs_info *c, struct ubifs_cnode *cnode,
+			int row, int col);
+
+/* Force the use of in-the-gaps method for testing */
+
+#define dbg_force_in_the_gaps_enabled \
+	(ubifs_tst_flags & UBIFS_TST_FORCE_IN_THE_GAPS)
+
+int dbg_force_in_the_gaps(void);
+
+/* Failure mode for recovery testing */
+
+#define dbg_failure_mode (ubifs_tst_flags & UBIFS_TST_RCVRY)
+
+void dbg_failure_mode_registration(struct ubifs_info *c);
+void dbg_failure_mode_deregistration(struct ubifs_info *c);
+
+#ifndef UBIFS_DBG_PRESERVE_UBI
+
+#define ubi_leb_read   dbg_leb_read
+#define ubi_leb_write  dbg_leb_write
+#define ubi_leb_change dbg_leb_change
+#define ubi_leb_erase  dbg_leb_erase
+#define ubi_leb_unmap  dbg_leb_unmap
+#define ubi_is_mapped  dbg_is_mapped
+#define ubi_leb_map    dbg_leb_map
+
+#endif
+
+int dbg_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
+		 int len, int check);
+int dbg_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
+		  int offset, int len, int dtype);
+int dbg_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
+		   int len, int dtype);
+int dbg_leb_erase(struct ubi_volume_desc *desc, int lnum);
+int dbg_leb_unmap(struct ubi_volume_desc *desc, int lnum);
+int dbg_is_mapped(struct ubi_volume_desc *desc, int lnum);
+int dbg_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype);
+
+static inline int dbg_read(struct ubi_volume_desc *desc, int lnum, char *buf,
+			   int offset, int len)
+{
+	return dbg_leb_read(desc, lnum, buf, offset, len, 0);
+}
+
+static inline int dbg_write(struct ubi_volume_desc *desc, int lnum,
+			    const void *buf, int offset, int len)
+{
+	return dbg_leb_write(desc, lnum, buf, offset, len, UBI_UNKNOWN);
+}
+
+static inline int dbg_change(struct ubi_volume_desc *desc, int lnum,
+				    const void *buf, int len)
+{
+	return dbg_leb_change(desc, lnum, buf, len, UBI_UNKNOWN);
+}
+
+#else /* !CONFIG_UBIFS_FS_DEBUG */
+
+#define UBIFS_DBG(op)
+#define ubifs_assert(expr)                         ({})
+#define ubifs_assert_cmt_locked(c)
+#define dbg_dump_stack()
+#define dbg_err(fmt, ...)                          ({})
+#define dbg_msg(fmt, ...)                          ({})
+#define dbg_key(c, key, fmt, ...)                  ({})
+
+#define dbg_gen(fmt, ...)                          ({})
+#define dbg_jnl(fmt, ...)                          ({})
+#define dbg_tnc(fmt, ...)                          ({})
+#define dbg_lp(fmt, ...)                           ({})
+#define dbg_find(fmt, ...)                         ({})
+#define dbg_mnt(fmt, ...)                          ({})
+#define dbg_io(fmt, ...)                           ({})
+#define dbg_cmt(fmt, ...)                          ({})
+#define dbg_budg(fmt, ...)                         ({})
+#define dbg_log(fmt, ...)                          ({})
+#define dbg_gc(fmt, ...)                           ({})
+#define dbg_scan(fmt, ...)                         ({})
+#define dbg_rcvry(fmt, ...)                        ({})
+
+#define dbg_ntype(type)                            ""
+#define dbg_cstate(cmt_state)                      ""
+#define dbg_get_key_dump(c, key)                   ({})
+#define dbg_dump_inode(c, inode)                   ({})
+#define dbg_dump_node(c, node)                     ({})
+#define dbg_dump_budget_req(req)                   ({})
+#define dbg_dump_lstats(lst)                       ({})
+#define dbg_dump_budg(c)                           ({})
+#define dbg_dump_lprop(c, lp)                      ({})
+#define dbg_dump_lprops(c)                         ({})
+#define dbg_dump_leb(c, lnum)                      ({})
+#define dbg_dump_znode(c, znode)                   ({})
+#define dbg_dump_heap(c, heap, cat)                ({})
+#define dbg_dump_pnode(c, pnode, parent, iip)      ({})
+#define dbg_dump_tnc(c)                            ({})
+#define dbg_dump_index(c)                          ({})
+
+#define dbg_walk_index(c, leaf_cb, znode_cb, priv) 0
+
+#define dbg_old_index_check_init(c, zroot)         0
+#define dbg_check_old_index(c, zroot)              0
+
+#define dbg_check_cats(c)                          0
+
+#define dbg_check_ltab(c)                          0
+
+#define dbg_check_synced_i_size(inode)             0
+
+#define dbg_check_dir_size(c, dir)                 0
+
+#define dbg_check_tnc(c, x)                        0
+
+#define dbg_check_idx_size(c, idx_size)            0
+
+#define dbg_check_filesystem(c)                    0
+
+#define dbg_check_heap(c, heap, cat, add_pos)      ({})
+
+#define dbg_check_lprops(c)                        0
+#define dbg_check_lpt_nodes(c, cnode, row, col)    0
+
+#define dbg_force_in_the_gaps_enabled              0
+#define dbg_force_in_the_gaps()                    0
+
+#define dbg_failure_mode                           0
+#define dbg_failure_mode_registration(c)           ({})
+#define dbg_failure_mode_deregistration(c)         ({})
+
+#endif /* !CONFIG_UBIFS_FS_DEBUG */
+
+#endif /* !__UBIFS_DEBUG_H__ */

fs/ubifs/ioctl.c

+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ * Copyright (C) 2006, 2007 University of Szeged, Hungary
+ *
+ * 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
+ *
+ * Authors: Zoltan Sogor
+ *          Artem Bityutskiy (Битюцкий Артём)
+ *          Adrian Hunter
+ */
+
+/* This file implements EXT2-compatible extended attribute ioctl() calls */
+
+#include <linux/compat.h>
+#include <linux/smp_lock.h>
+#include <linux/mount.h>
+#include "ubifs.h"
+
+/**
+ * ubifs_set_inode_flags - set VFS inode flags.
+ * @inode: VFS inode to set flags for
+ *
+ * This function propagates flags from UBIFS inode object to VFS inode object.
+ */
+void ubifs_set_inode_flags(struct inode *inode)
+{
+	unsigned int flags = ubifs_inode(inode)->flags;
+
+	inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_DIRSYNC);
+	if (flags & UBIFS_SYNC_FL)
+		inode->i_flags |= S_SYNC;
+	if (flags & UBIFS_APPEND_FL)
+		inode->i_flags |= S_APPEND;
+	if (flags & UBIFS_IMMUTABLE_FL)
+		inode->i_flags |= S_IMMUTABLE;
+	if (flags & UBIFS_DIRSYNC_FL)
+		inode->i_flags |= S_DIRSYNC;
+}
+
+/*
+ * ioctl2ubifs - convert ioctl inode flags to UBIFS inode flags.
+ * @ioctl_flags: flags to convert
+ *
+ * This function convert ioctl flags (@FS_COMPR_FL, etc) to UBIFS inode flags
+ * (@UBIFS_COMPR_FL, etc).
+ */
+static int ioctl2ubifs(int ioctl_flags)
+{
+	int ubifs_flags = 0;
+
+	if (ioctl_flags & FS_COMPR_FL)
+		ubifs_flags |= UBIFS_COMPR_FL;
+	if (ioctl_flags & FS_SYNC_FL)
+		ubifs_flags |= UBIFS_SYNC_FL;
+	if (ioctl_flags & FS_APPEND_FL)
+		ubifs_flags |= UBIFS_APPEND_FL;
+	if (ioctl_flags & FS_IMMUTABLE_FL)
+		ubifs_flags |= UBIFS_IMMUTABLE_FL;
+	if (ioctl_flags & FS_DIRSYNC_FL)
+		ubifs_flags |= UBIFS_DIRSYNC_FL;
+
+	return ubifs_flags;
+}
+
+/*
+ * ubifs2ioctl - convert UBIFS inode flags to ioctl inode flags.
+ * @ubifs_flags: flags to convert
+ *
+ * This function convert UBIFS (@UBIFS_COMPR_FL, etc) to ioctl flags
+ * (@FS_COMPR_FL, etc).
+ */
+static int ubifs2ioctl(int ubifs_flags)
+{
+	int ioctl_flags = 0;
+
+	if (ubifs_flags & UBIFS_COMPR_FL)
+		ioctl_flags |= FS_COMPR_FL;
+	if (ubifs_flags & UBIFS_SYNC_FL)
+		ioctl_flags |= FS_SYNC_FL;
+	if (ubifs_flags & UBIFS_APPEND_FL)
+		ioctl_flags |= FS_APPEND_FL;
+	if (ubifs_flags & UBIFS_IMMUTABLE_FL)
+		ioctl_flags |= FS_IMMUTABLE_FL;
+	if (ubifs_flags & UBIFS_DIRSYNC_FL)
+		ioctl_flags |= FS_DIRSYNC_FL;
+
+	return ioctl_flags;
+}
+
+static int setflags(struct inode *inode, int flags)
+{
+	int oldflags, err, release;
+	struct ubifs_inode *ui = ubifs_inode(inode);
+	struct ubifs_info *c = inode->i_sb->s_fs_info;
+	struct ubifs_budget_req req = { .dirtied_ino = 1,
+					.dirtied_ino_d = ui->data_len };
+
+	err = ubifs_budget_space(c, &req);
+	if (err)
+		return err;
+
+	/*
+	 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
+	 * the relevant capability.
+	 */
+	mutex_lock(&ui->ui_mutex);
+	oldflags = ubifs2ioctl(ui->flags);
+	if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
+		if (!capable(CAP_LINUX_IMMUTABLE)) {
+			err = -EPERM;
+			goto out_unlock;
+		}
+	}
+
+	ui->flags = ioctl2ubifs(flags);
+	ubifs_set_inode_flags(inode);
+	inode->i_ctime = ubifs_current_time(inode);
+	release = ui->dirty;
+	mark_inode_dirty_sync(inode);
+	mutex_unlock(&ui->ui_mutex);
+
+	if (release)
+		ubifs_release_budget(c, &req);
+	if (IS_SYNC(inode))
+		err = write_inode_now(inode, 1);
+	return err;
+
+out_unlock:
+	ubifs_err("can't modify inode %lu attributes", inode->i_ino);
+	mutex_unlock(&ui->ui_mutex);
+	ubifs_release_budget(c, &req);
+	return err;
+}
+
+long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	int flags, err;
+	struct inode *inode = file->f_path.dentry->d_inode;
+
+	switch (cmd) {
+	case FS_IOC_GETFLAGS:
+		flags = ubifs2ioctl(ubifs_inode(inode)->flags);
+
+		return put_user(flags, (int __user *) arg);
+
+	case FS_IOC_SETFLAGS: {
+		if (IS_RDONLY(inode))
+			return -EROFS;
+
+		if (!is_owner_or_cap(inode))
+			return -EACCES;
+
+		if (get_user(flags, (int __user *) arg))
+			return -EFAULT;
+
+		if (!S_ISDIR(inode->i_mode))
+			flags &= ~FS_DIRSYNC_FL;
+
+		/*
+		 * Make sure the file-system is read-write and make sure it
+		 * will not become read-only while we are changing the flags.
+		 */
+		err = mnt_want_write(file->f_path.mnt);
+		if (err)
+			return err;
+		err = setflags(inode, flags);
+		mnt_drop_write(file->f_path.mnt);
+		return err;
+	}
+
+	default:
+		return -ENOTTY;
+	}
+}
+
+#ifdef CONFIG_COMPAT
+long ubifs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case FS_IOC32_GETFLAGS:
+		cmd = FS_IOC_GETFLAGS;
+		break;
+	case FS_IOC32_SETFLAGS:
+		cmd = FS_IOC_SETFLAGS;
+		break;
+	default:
+		return -ENOIOCTLCMD;
+	}
+	return ubifs_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif

include/linux/fs.h

@@ -1729,6 +1729,8 @@ static inline void invalidate_remote_inode(struct inode *inode)
 extern int invalidate_inode_pages2(struct address_space *mapping);
 extern int invalidate_inode_pages2_range(struct address_space *mapping,
 					 pgoff_t start, pgoff_t end);
+extern void generic_sync_sb_inodes(struct super_block *sb,
+				struct writeback_control *wbc);
 extern int write_inode_now(struct inode *, int);
 extern int filemap_fdatawrite(struct address_space *);
 extern int filemap_flush(struct address_space *);

init/do_mounts.c

@@ -372,7 +372,8 @@ void __init prepare_namespace(void)
 
 	if (saved_root_name[0]) {
 		root_device_name = saved_root_name;
-		if (!strncmp(root_device_name, "mtd", 3)) {
+		if (!strncmp(root_device_name, "mtd", 3) ||
+		    !strncmp(root_device_name, "ubi", 3)) {
 			mount_block_root(root_device_name, root_mountflags);
 			goto out;
 		}