File btrfs-progs-upstream-v0.19-35.patch of Package btrfs-progs

diff -aNur a/Makefile b/Makefile
--- a/Makefile	2009-06-12 00:56:15.000000000 +0800
+++ b/Makefile	2011-03-22 16:32:44.595948115 +0800
@@ -4,7 +4,7 @@
 objects = ctree.o disk-io.o radix-tree.o extent-tree.o print-tree.o \
 	  root-tree.o dir-item.o file-item.o inode-item.o \
 	  inode-map.o crc32c.o rbtree.o extent-cache.o extent_io.o \
-	  volumes.o utils.o
+	  volumes.o utils.o btrfs-list.o
 
 #
 CHECKFLAGS=-D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ -Wbitwise \
@@ -16,7 +16,9 @@
 bindir = $(prefix)/bin
 LIBS=-luuid
 
-progs = btrfsctl mkfs.btrfs btrfs-debug-tree btrfs-show btrfs-vol btrfsck
+progs = btrfsctl mkfs.btrfs btrfs-debug-tree btrfs-show btrfs-vol btrfsck \
+	btrfs \
+	btrfs-map-logical
 
 # make C=1 to enable sparse
 ifdef C
@@ -35,6 +37,10 @@
 version:
 	bash version.sh
 
+btrfs: $(objects) btrfs.o btrfs_cmds.o
+	gcc $(CFLAGS) -o btrfs btrfs.o btrfs_cmds.o \
+		$(objects) $(LDFLAGS) $(LIBS)
+
 btrfsctl: $(objects) btrfsctl.o
 	gcc $(CFLAGS) -o btrfsctl btrfsctl.o $(objects) $(LDFLAGS) $(LIBS)
 
@@ -53,9 +59,15 @@
 btrfs-debug-tree: $(objects) debug-tree.o
 	gcc $(CFLAGS) -o btrfs-debug-tree $(objects) debug-tree.o $(LDFLAGS) $(LIBS)
 
+btrfs-zero-log: $(objects) btrfs-zero-log.o
+	gcc $(CFLAGS) -o btrfs-zero-log $(objects) btrfs-zero-log.o $(LDFLAGS) $(LIBS)
+
 btrfstune: $(objects) btrfstune.o
 	gcc $(CFLAGS) -o btrfstune $(objects) btrfstune.o $(LDFLAGS) $(LIBS)
 
+btrfs-map-logical: $(objects) btrfs-map-logical.o
+	gcc $(CFLAGS) -o btrfs-map-logical $(objects) btrfs-map-logical.o $(LDFLAGS) $(LIBS)
+
 btrfs-image: $(objects) btrfs-image.o
 	gcc $(CFLAGS) -o btrfs-image $(objects) btrfs-image.o -lpthread -lz $(LDFLAGS) $(LIBS)
 
@@ -66,7 +78,10 @@
 	gcc $(CFLAGS) -o quick-test $(objects) quick-test.o $(LDFLAGS) $(LIBS)
 
 convert: $(objects) convert.o
-	gcc $(CFLAGS) -o btrfs-convert $(objects) convert.o -lext2fs $(LDFLAGS) $(LIBS)
+	gcc $(CFLAGS) -o btrfs-convert $(objects) convert.o -lext2fs -lcom_err $(LDFLAGS) $(LIBS)
+
+ioctl-test: $(objects) ioctl-test.o
+	gcc $(CFLAGS) -o ioctl-test $(objects) ioctl-test.o $(LDFLAGS) $(LIBS)
 
 manpages:
 	cd man; make
diff -aNur a/btrfs-defrag.c b/btrfs-defrag.c
--- a/btrfs-defrag.c	1970-01-01 07:00:00.000000000 +0700
+++ b/btrfs-defrag.c	2011-03-22 16:32:44.598948115 +0800
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2010 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 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., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __CHECKER__
+#include <sys/ioctl.h>
+#include <sys/mount.h>
+#include "ioctl.h"
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <libgen.h>
+#include <getopt.h>
+#include "kerncompat.h"
+#include "ctree.h"
+#include "transaction.h"
+#include "utils.h"
+#include "version.h"
+
diff -aNur a/btrfs-list.c b/btrfs-list.c
--- a/btrfs-list.c	1970-01-01 07:00:00.000000000 +0700
+++ b/btrfs-list.c	2011-03-22 16:32:44.599948115 +0800
@@ -0,0 +1,835 @@
+/*
+ * Copyright (C) 2010 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 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., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#define _GNU_SOURCE
+#ifndef __CHECKER__
+#include <sys/ioctl.h>
+#include <sys/mount.h>
+#include "ioctl.h"
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <libgen.h>
+#include "kerncompat.h"
+#include "ctree.h"
+#include "transaction.h"
+#include "utils.h"
+#include "version.h"
+
+/* we store all the roots we find in an rbtree so that we can
+ * search for them later.
+ */
+struct root_lookup {
+	struct rb_root root;
+};
+
+/*
+ * one of these for each root we find.
+ */
+struct root_info {
+	struct rb_node rb_node;
+
+	/* this root's id */
+	u64 root_id;
+
+	/* the id of the root that references this one */
+	u64 ref_tree;
+
+	/* the dir id we're in from ref_tree */
+	u64 dir_id;
+
+	/* path from the subvol we live in to this root, including the
+	 * root's name.  This is null until we do the extra lookup ioctl.
+	 */
+	char *path;
+
+	/* the name of this root in the directory it lives in */
+	char name[];
+};
+
+static void root_lookup_init(struct root_lookup *tree)
+{
+	tree->root.rb_node = NULL;
+}
+
+static int comp_entry(struct root_info *entry, u64 root_id, u64 ref_tree)
+{
+	if (entry->root_id > root_id)
+		return 1;
+	if (entry->root_id < root_id)
+		return -1;
+	if (entry->ref_tree > ref_tree)
+		return 1;
+	if (entry->ref_tree < ref_tree)
+		return -1;
+	return 0;
+}
+
+/*
+ * insert a new root into the tree.  returns the existing root entry
+ * if one is already there.  Both root_id and ref_tree are used
+ * as the key
+ */
+static struct rb_node *tree_insert(struct rb_root *root, u64 root_id,
+				   u64 ref_tree, struct rb_node *node)
+{
+	struct rb_node ** p = &root->rb_node;
+	struct rb_node * parent = NULL;
+	struct root_info *entry;
+	int comp;
+
+	while(*p) {
+		parent = *p;
+		entry = rb_entry(parent, struct root_info, rb_node);
+
+		comp = comp_entry(entry, root_id, ref_tree);
+
+		if (comp < 0)
+			p = &(*p)->rb_left;
+		else if (comp > 0)
+			p = &(*p)->rb_right;
+		else
+			return parent;
+	}
+
+	entry = rb_entry(parent, struct root_info, rb_node);
+	rb_link_node(node, parent, p);
+	rb_insert_color(node, root);
+	return NULL;
+}
+
+/*
+ * find a given root id in the tree.  We return the smallest one,
+ * rb_next can be used to move forward looking for more if required
+ */
+static struct root_info *tree_search(struct rb_root *root, u64 root_id)
+{
+	struct rb_node * n = root->rb_node;
+	struct root_info *entry;
+
+	while(n) {
+		entry = rb_entry(n, struct root_info, rb_node);
+
+		if (entry->root_id < root_id)
+			n = n->rb_left;
+		else if (entry->root_id > root_id)
+			n = n->rb_right;
+		else {
+			struct root_info *prev;
+			struct rb_node *prev_n;
+			while (1) {
+				prev_n = rb_prev(n);
+				if (!prev_n)
+					break;
+				prev = rb_entry(prev_n, struct root_info,
+						      rb_node);
+				if (prev->root_id != root_id)
+					break;
+				entry = prev;
+				n = prev_n;
+			}
+			return entry;
+		}
+	}
+	return NULL;
+}
+
+/*
+ * this allocates a new root in the lookup tree.
+ *
+ * root_id should be the object id of the root
+ *
+ * ref_tree is the objectid of the referring root.
+ *
+ * dir_id is the directory in ref_tree where this root_id can be found.
+ *
+ * name is the name of root_id in that directory
+ *
+ * name_len is the length of name
+ */
+static int add_root(struct root_lookup *root_lookup,
+		    u64 root_id, u64 ref_tree, u64 dir_id, char *name,
+		    int name_len)
+{
+	struct root_info *ri;
+	struct rb_node *ret;
+	ri = malloc(sizeof(*ri) + name_len + 1);
+	if (!ri) {
+		printf("memory allocation failed\n");
+		exit(1);
+	}
+	memset(ri, 0, sizeof(*ri) + name_len + 1);
+	ri->path = NULL;
+	ri->dir_id = dir_id;
+	ri->root_id = root_id;
+	ri->ref_tree = ref_tree;
+	strncpy(ri->name, name, name_len);
+
+	ret = tree_insert(&root_lookup->root, root_id, ref_tree, &ri->rb_node);
+	if (ret) {
+		printf("failed to insert tree %llu\n", (unsigned long long)root_id);
+		exit(1);
+	}
+	return 0;
+}
+
+/*
+ * for a given root_info, search through the root_lookup tree to construct
+ * the full path name to it.
+ *
+ * This can't be called until all the root_info->path fields are filled
+ * in by lookup_ino_path
+ */
+static int resolve_root(struct root_lookup *rl, struct root_info *ri)
+{
+	u64 top_id;
+	char *full_path = NULL;
+	int len = 0;
+	struct root_info *found;
+
+	/*
+	 * we go backwards from the root_info object and add pathnames
+	 * from parent directories as we go.
+	 */
+	found = ri;
+	while (1) {
+		char *tmp;
+		u64 next;
+		int add_len = strlen(found->path);
+
+		/* room for / and for null */
+		tmp = malloc(add_len + 2 + len);
+		if (full_path) {
+			memcpy(tmp + add_len + 1, full_path, len);
+			tmp[add_len] = '/';
+			memcpy(tmp, found->path, add_len);
+			tmp [add_len + len + 1] = '\0';
+			free(full_path);
+			full_path = tmp;
+			len += add_len + 1;
+		} else {
+			full_path = strdup(found->path);
+			len = add_len;
+		}
+
+		next = found->ref_tree;
+		/* if the ref_tree refers to ourselves, we're at the top */
+		if (next == found->root_id) {
+			top_id = next;
+			break;
+		}
+
+		/*
+		 * if the ref_tree wasn't in our tree of roots, we're
+		 * at the top
+		 */
+		found = tree_search(&rl->root, next);
+		if (!found) {
+			top_id = next;
+			break;
+		}
+	}
+	printf("ID %llu top level %llu path %s\n", ri->root_id, top_id,
+	       full_path);
+	free(full_path);
+	return 0;
+}
+
+/*
+ * for a single root_info, ask the kernel to give us a path name
+ * inside it's ref_root for the dir_id where it lives.
+ *
+ * This fills in root_info->path with the path to the directory and and
+ * appends this root's name.
+ */
+static int lookup_ino_path(int fd, struct root_info *ri)
+{
+	struct btrfs_ioctl_ino_lookup_args args;
+	int ret;
+
+	if (ri->path)
+		return 0;
+
+	memset(&args, 0, sizeof(args));
+	args.treeid = ri->ref_tree;
+	args.objectid = ri->dir_id;
+
+	ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args);
+	if (ret) {
+		fprintf(stderr, "ERROR: Failed to lookup path for root %llu\n",
+			(unsigned long long)ri->ref_tree);
+		return ret;
+	}
+
+	if (args.name[0]) {
+		/*
+		 * we're in a subdirectory of ref_tree, the kernel ioctl
+		 * puts a / in there for us
+		 */
+		ri->path = malloc(strlen(ri->name) + strlen(args.name) + 1);
+		if (!ri->path) {
+			perror("malloc failed");
+			exit(1);
+		}
+		strcpy(ri->path, args.name);
+		strcat(ri->path, ri->name);
+	} else {
+		/* we're at the root of ref_tree */
+		ri->path = strdup(ri->name);
+		if (!ri->path) {
+			perror("strdup failed");
+			exit(1);
+		}
+	}
+	return 0;
+}
+
+/* finding the generation for a given path is a two step process.
+ * First we use the inode loookup routine to find out the root id
+ *
+ * Then we use the tree search ioctl to scan all the root items for a
+ * given root id and spit out the latest generation we can find
+ */
+static u64 find_root_gen(int fd)
+{
+	struct btrfs_ioctl_ino_lookup_args ino_args;
+	int ret;
+	struct btrfs_ioctl_search_args args;
+	struct btrfs_ioctl_search_key *sk = &args.key;
+	struct btrfs_ioctl_search_header *sh;
+	unsigned long off = 0;
+	u64 max_found = 0;
+	int i;
+
+	memset(&ino_args, 0, sizeof(ino_args));
+	ino_args.objectid = BTRFS_FIRST_FREE_OBJECTID;
+
+	/* this ioctl fills in ino_args->treeid */
+	ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &ino_args);
+	if (ret) {
+		fprintf(stderr, "ERROR: Failed to lookup path for dirid %llu\n",
+			(unsigned long long)BTRFS_FIRST_FREE_OBJECTID);
+		return 0;
+	}
+
+	memset(&args, 0, sizeof(args));
+
+	sk->tree_id = 1;
+
+	/*
+	 * there may be more than one ROOT_ITEM key if there are
+	 * snapshots pending deletion, we have to loop through
+	 * them.
+	 */
+	sk->min_objectid = ino_args.treeid;
+	sk->max_objectid = ino_args.treeid;
+	sk->max_type = BTRFS_ROOT_ITEM_KEY;
+	sk->min_type = BTRFS_ROOT_ITEM_KEY;
+	sk->max_offset = (u64)-1;
+	sk->max_transid = (u64)-1;
+	sk->nr_items = 4096;
+
+	while (1) {
+		ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
+		if (ret < 0) {
+			fprintf(stderr, "ERROR: can't perform the search\n");
+			return 0;
+		}
+		/* the ioctl returns the number of item it found in nr_items */
+		if (sk->nr_items == 0)
+			break;
+
+		off = 0;
+		for (i = 0; i < sk->nr_items; i++) {
+			struct btrfs_root_item *item;
+			sh = (struct btrfs_ioctl_search_header *)(args.buf +
+								  off);
+
+			off += sizeof(*sh);
+			item = (struct btrfs_root_item *)(args.buf + off);
+			off += sh->len;
+
+			sk->min_objectid = sh->objectid;
+			sk->min_type = sh->type;
+			sk->min_offset = sh->offset;
+
+			if (sh->objectid > ino_args.treeid)
+				break;
+
+			if (sh->objectid == ino_args.treeid &&
+			    sh->type == BTRFS_ROOT_ITEM_KEY) {
+				max_found = max(max_found,
+						btrfs_root_generation(item));
+			}
+		}
+		if (sk->min_offset < (u64)-1)
+			sk->min_offset++;
+		else
+			break;
+
+		if (sk->min_type != BTRFS_ROOT_ITEM_KEY)
+			break;
+		if (sk->min_objectid != BTRFS_ROOT_ITEM_KEY)
+			break;
+	}
+	return max_found;
+}
+
+/* pass in a directory id and this will return
+ * the full path of the parent directory inside its
+ * subvolume root.
+ *
+ * It may return NULL if it is in the root, or an ERR_PTR if things
+ * go badly.
+ */
+static char *__ino_resolve(int fd, u64 dirid)
+{
+	struct btrfs_ioctl_ino_lookup_args args;
+	int ret;
+	char *full;
+
+	memset(&args, 0, sizeof(args));
+	args.objectid = dirid;
+
+	ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args);
+	if (ret) {
+		fprintf(stderr, "ERROR: Failed to lookup path for dirid %llu\n",
+			(unsigned long long)dirid);
+		return ERR_PTR(ret);
+	}
+
+	if (args.name[0]) {
+		/*
+		 * we're in a subdirectory of ref_tree, the kernel ioctl
+		 * puts a / in there for us
+		 */
+		full = strdup(args.name);
+		if (!full) {
+			perror("malloc failed");
+			return ERR_PTR(-ENOMEM);
+		}
+	} else {
+		/* we're at the root of ref_tree */
+		full = NULL;
+	}
+	return full;
+}
+
+/*
+ * simple string builder, returning a new string with both
+ * dirid and name
+ */
+char *build_name(char *dirid, char *name)
+{
+	char *full;
+	if (!dirid)
+		return strdup(name);
+
+	full = malloc(strlen(dirid) + strlen(name) + 1);
+	if (!full)
+		return NULL;
+	strcpy(full, dirid);
+	strcat(full, name);
+	return full;
+}
+
+/*
+ * given an inode number, this returns the full path name inside the subvolume
+ * to that file/directory.  cache_dirid and cache_name are used to
+ * cache the results so we can avoid tree searches if a later call goes
+ * to the same directory or file name
+ */
+static char *ino_resolve(int fd, u64 ino, u64 *cache_dirid, char **cache_name)
+
+{
+	u64 dirid;
+	char *dirname;
+	char *name;
+	char *full;
+	int ret;
+	struct btrfs_ioctl_search_args args;
+	struct btrfs_ioctl_search_key *sk = &args.key;
+	struct btrfs_ioctl_search_header *sh;
+	unsigned long off = 0;
+	int namelen;
+
+	memset(&args, 0, sizeof(args));
+
+	sk->tree_id = 0;
+
+	/*
+	 * step one, we search for the inode back ref.  We just use the first
+	 * one
+	 */
+	sk->min_objectid = ino;
+	sk->max_objectid = ino;
+	sk->max_type = BTRFS_INODE_REF_KEY;
+	sk->max_offset = (u64)-1;
+	sk->min_type = BTRFS_INODE_REF_KEY;
+	sk->max_transid = (u64)-1;
+	sk->nr_items = 1;
+
+	ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
+	if (ret < 0) {
+		fprintf(stderr, "ERROR: can't perform the search\n");
+		return NULL;
+	}
+	/* the ioctl returns the number of item it found in nr_items */
+	if (sk->nr_items == 0)
+		return NULL;
+
+	off = 0;
+	sh = (struct btrfs_ioctl_search_header *)(args.buf + off);
+
+	if (sh->type == BTRFS_INODE_REF_KEY) {
+		struct btrfs_inode_ref *ref;
+		dirid = sh->offset;
+
+		ref = (struct btrfs_inode_ref *)(sh + 1);
+		namelen = btrfs_stack_inode_ref_name_len(ref);
+
+		name = (char *)(ref + 1);
+		name = strndup(name, namelen);
+
+		/* use our cached value */
+		if (dirid == *cache_dirid && *cache_name) {
+			dirname = *cache_name;
+			goto build;
+		}
+	} else {
+		return NULL;
+	}
+	/*
+	 * the inode backref gives us the file name and the parent directory id.
+	 * From here we use __ino_resolve to get the path to the parent
+	 */
+	dirname = __ino_resolve(fd, dirid);
+build:
+	full = build_name(dirname, name);
+	if (*cache_name && dirname != *cache_name)
+		free(*cache_name);
+
+	*cache_name = dirname;
+	*cache_dirid = dirid;
+	free(name);
+
+	return full;
+}
+
+int list_subvols(int fd)
+{
+	struct root_lookup root_lookup;
+	struct rb_node *n;
+	int ret;
+	struct btrfs_ioctl_search_args args;
+	struct btrfs_ioctl_search_key *sk = &args.key;
+	struct btrfs_ioctl_search_header *sh;
+	struct btrfs_root_ref *ref;
+	unsigned long off = 0;
+	int name_len;
+	char *name;
+	u64 dir_id;
+	int i;
+
+	root_lookup_init(&root_lookup);
+
+	memset(&args, 0, sizeof(args));
+
+	/* search in the tree of tree roots */
+	sk->tree_id = 1;
+
+	/*
+	 * set the min and max to backref keys.  The search will
+	 * only send back this type of key now.
+	 */
+	sk->max_type = BTRFS_ROOT_BACKREF_KEY;
+	sk->min_type = BTRFS_ROOT_BACKREF_KEY;
+
+	/*
+	 * set all the other params to the max, we'll take any objectid
+	 * and any trans
+	 */
+	sk->max_objectid = (u64)-1;
+	sk->max_offset = (u64)-1;
+	sk->max_transid = (u64)-1;
+
+	/* just a big number, doesn't matter much */
+	sk->nr_items = 4096;
+
+	while(1) {
+		ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
+		if (ret < 0) {
+			fprintf(stderr, "ERROR: can't perform the search\n");
+			return ret;
+		}
+		/* the ioctl returns the number of item it found in nr_items */
+		if (sk->nr_items == 0)
+			break;
+
+		off = 0;
+
+		/*
+		 * for each item, pull the key out of the header and then
+		 * read the root_ref item it contains
+		 */
+		for (i = 0; i < sk->nr_items; i++) {
+			sh = (struct btrfs_ioctl_search_header *)(args.buf +
+								  off);
+			off += sizeof(*sh);
+			if (sh->type == BTRFS_ROOT_BACKREF_KEY) {
+				ref = (struct btrfs_root_ref *)(args.buf + off);
+				name_len = btrfs_stack_root_ref_name_len(ref);
+				name = (char *)(ref + 1);
+				dir_id = btrfs_stack_root_ref_dirid(ref);
+
+				add_root(&root_lookup, sh->objectid, sh->offset,
+					 dir_id, name, name_len);
+			}
+
+			off += sh->len;
+
+			/*
+			 * record the mins in sk so we can make sure the
+			 * next search doesn't repeat this root
+			 */
+			sk->min_objectid = sh->objectid;
+			sk->min_type = sh->type;
+			sk->min_offset = sh->offset;
+		}
+		sk->nr_items = 4096;
+		/* this iteration is done, step forward one root for the next
+		 * ioctl
+		 */
+		if (sk->min_objectid < (u64)-1) {
+			sk->min_objectid++;
+			sk->min_type = BTRFS_ROOT_BACKREF_KEY;
+			sk->min_offset = 0;
+		} else
+			break;
+	}
+	/*
+	 * now we have an rbtree full of root_info objects, but we need to fill
+	 * in their path names within the subvol that is referencing each one.
+	 */
+	n = rb_first(&root_lookup.root);
+	while (n) {
+		struct root_info *entry;
+		int ret;
+		entry = rb_entry(n, struct root_info, rb_node);
+		ret = lookup_ino_path(fd, entry);
+		if(ret < 0)
+			return ret;
+		n = rb_next(n);
+	}
+
+	/* now that we have all the subvol-relative paths filled in,
+	 * we have to string the subvols together so that we can get
+	 * a path all the way back to the FS root
+	 */
+	n = rb_last(&root_lookup.root);
+	while (n) {
+		struct root_info *entry;
+		entry = rb_entry(n, struct root_info, rb_node);
+		resolve_root(&root_lookup, entry);
+		n = rb_prev(n);
+	}
+
+	return ret;
+}
+
+static int print_one_extent(int fd, struct btrfs_ioctl_search_header *sh,
+			    struct btrfs_file_extent_item *item,
+			    u64 found_gen, u64 *cache_dirid,
+			    char **cache_dir_name, u64 *cache_ino,
+			    char **cache_full_name)
+{
+	u64 len = 0;
+	u64 disk_start = 0;
+	u64 disk_offset = 0;
+	u8 type;
+	int compressed = 0;
+	int flags = 0;
+	char *name = NULL;
+
+	if (sh->objectid == *cache_ino) {
+		name = *cache_full_name;
+	} else if (*cache_full_name) {
+		free(*cache_full_name);
+		*cache_full_name = NULL;
+	}
+	if (!name) {
+		name = ino_resolve(fd, sh->objectid, cache_dirid,
+				   cache_dir_name);
+		*cache_full_name = name;
+		*cache_ino = sh->objectid;
+	}
+	if (!name)
+		return -EIO;
+
+	type = btrfs_stack_file_extent_type(item);
+	compressed = btrfs_stack_file_extent_compression(item);
+
+	if (type == BTRFS_FILE_EXTENT_REG ||
+	    type == BTRFS_FILE_EXTENT_PREALLOC) {
+		disk_start = btrfs_stack_file_extent_disk_bytenr(item);
+		disk_offset = btrfs_stack_file_extent_offset(item);
+		len = btrfs_stack_file_extent_num_bytes(item);
+	} else if (type == BTRFS_FILE_EXTENT_INLINE) {
+		disk_start = 0;
+		disk_offset = 0;
+		len = btrfs_stack_file_extent_ram_bytes(item);
+	} else {
+		printf("unhandled extent type %d for inode %llu "
+		       "file offset %llu gen %llu\n",
+			type,
+			(unsigned long long)sh->objectid,
+			(unsigned long long)sh->offset,
+			(unsigned long long)found_gen);
+
+		return -EIO;
+	}
+	printf("inode %llu file offset %llu len %llu disk start %llu "
+	       "offset %llu gen %llu flags ",
+	       (unsigned long long)sh->objectid,
+	       (unsigned long long)sh->offset,
+	       (unsigned long long)len,
+	       (unsigned long long)disk_start,
+	       (unsigned long long)disk_offset,
+	       (unsigned long long)found_gen);
+
+	if (compressed) {
+		printf("COMPRESS");
+		flags++;
+	}
+	if (type == BTRFS_FILE_EXTENT_PREALLOC) {
+		printf("%sPREALLOC", flags ? "|" : "");
+		flags++;
+	}
+	if (type == BTRFS_FILE_EXTENT_INLINE) {
+		printf("%sINLINE", flags ? "|" : "");
+		flags++;
+	}
+	if (!flags)
+		printf("NONE");
+
+	printf(" %s\n", name);
+	return 0;
+}
+
+int find_updated_files(int fd, u64 root_id, u64 oldest_gen)
+{
+	int ret;
+	struct btrfs_ioctl_search_args args;
+	struct btrfs_ioctl_search_key *sk = &args.key;
+	struct btrfs_ioctl_search_header *sh;
+	struct btrfs_file_extent_item *item;
+	unsigned long off = 0;
+	u64 found_gen;
+	u64 max_found = 0;
+	int i;
+	u64 cache_dirid = 0;
+	u64 cache_ino = 0;
+	char *cache_dir_name = NULL;
+	char *cache_full_name = NULL;
+	struct btrfs_file_extent_item backup;
+
+	memset(&backup, 0, sizeof(backup));
+	memset(&args, 0, sizeof(args));
+
+	sk->tree_id = root_id;
+
+	/*
+	 * set all the other params to the max, we'll take any objectid
+	 * and any trans
+	 */
+	sk->max_objectid = (u64)-1;
+	sk->max_offset = (u64)-1;
+	sk->max_transid = (u64)-1;
+	sk->max_type = BTRFS_EXTENT_DATA_KEY;
+	sk->min_transid = oldest_gen;
+	/* just a big number, doesn't matter much */
+	sk->nr_items = 4096;
+
+	max_found = find_root_gen(fd);
+	while(1) {
+		ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
+		if (ret < 0) {
+			fprintf(stderr, "ERROR: can't perform the search\n");
+			return ret;
+		}
+		/* the ioctl returns the number of item it found in nr_items */
+		if (sk->nr_items == 0)
+			break;
+
+		off = 0;
+
+		/*
+		 * for each item, pull the key out of the header and then
+		 * read the root_ref item it contains
+		 */
+		for (i = 0; i < sk->nr_items; i++) {
+			sh = (struct btrfs_ioctl_search_header *)(args.buf +
+								  off);
+			off += sizeof(*sh);
+
+			/*
+			 * just in case the item was too big, pass something other
+			 * than garbage
+			 */
+			if (sh->len == 0)
+				item = &backup;
+			else
+				item = (struct btrfs_file_extent_item *)(args.buf +
+								 off);
+			found_gen = btrfs_stack_file_extent_generation(item);
+			if (sh->type == BTRFS_EXTENT_DATA_KEY &&
+			    found_gen >= oldest_gen) {
+				print_one_extent(fd, sh, item, found_gen,
+						 &cache_dirid, &cache_dir_name,
+						 &cache_ino, &cache_full_name);
+			}
+			off += sh->len;
+
+			/*
+			 * record the mins in sk so we can make sure the
+			 * next search doesn't repeat this root
+			 */
+			sk->min_objectid = sh->objectid;
+			sk->min_offset = sh->offset;
+			sk->min_type = sh->type;
+		}
+		sk->nr_items = 4096;
+		if (sk->min_offset < (u64)-1)
+			sk->min_offset++;
+		else if (sk->min_objectid < (u64)-1) {
+			sk->min_objectid++;
+			sk->min_offset = 0;
+			sk->min_type = 0;
+		} else
+			break;
+	}
+	free(cache_dir_name);
+	free(cache_full_name);
+	printf("transid marker was %llu\n", (unsigned long long)max_found);
+	return ret;
+}
diff -aNur a/btrfs-map-logical.c b/btrfs-map-logical.c
--- a/btrfs-map-logical.c	1970-01-01 07:00:00.000000000 +0700
+++ b/btrfs-map-logical.c	2011-03-22 16:32:44.600948115 +0800
@@ -0,0 +1,221 @@
+/*
+ * Copyright (C) 2009 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 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., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#define _XOPEN_SOURCE 500
+#define _GNU_SOURCE 1
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <getopt.h>
+#include "kerncompat.h"
+#include "ctree.h"
+#include "volumes.h"
+#include "disk-io.h"
+#include "print-tree.h"
+#include "transaction.h"
+#include "list.h"
+#include "version.h"
+
+/* we write the mirror info to stdout unless they are dumping the data
+ * to stdout
+ * */
+static FILE *info_file;
+
+struct extent_buffer *debug_read_block(struct btrfs_root *root, u64 bytenr,
+				     u32 blocksize, int copy)
+{
+	int ret;
+	int dev_nr;
+	struct extent_buffer *eb;
+	u64 length;
+	struct btrfs_multi_bio *multi = NULL;
+	struct btrfs_device *device;
+	int num_copies;
+	int mirror_num = 1;
+
+	eb = btrfs_find_create_tree_block(root, bytenr, blocksize);
+	if (!eb)
+		return NULL;
+
+	dev_nr = 0;
+	length = blocksize;
+	while (1) {
+		ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
+				      eb->start, &length, &multi, mirror_num);
+		BUG_ON(ret);
+		device = multi->stripes[0].dev;
+		eb->fd = device->fd;
+		device->total_ios++;
+		eb->dev_bytenr = multi->stripes[0].physical;
+
+		fprintf(info_file, "mirror %d logical %Lu physical %Lu "
+			"device %s\n", mirror_num, bytenr, eb->dev_bytenr,
+			device->name);
+		kfree(multi);
+
+		if (!copy || mirror_num == copy)
+			ret = read_extent_from_disk(eb);
+
+		num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
+					      eb->start, eb->len);
+		if (num_copies == 1)
+			break;
+
+		mirror_num++;
+		if (mirror_num > num_copies)
+			break;
+	}
+	return eb;
+}
+
+static void print_usage(void)
+{
+	fprintf(stderr, "usage: btrfs-map-logical [options] mount_point\n");
+	fprintf(stderr, "\t-l Logical extent to map\n");
+	fprintf(stderr, "\t-c Copy of the extent to read (usually 1 or 2)\n");
+	fprintf(stderr, "\t-o Output file to hold the extent\n");
+	fprintf(stderr, "\t-s Number of bytes to read\n");
+	exit(1);
+}
+
+static struct option long_options[] = {
+	/* { "byte-count", 1, NULL, 'b' }, */
+	{ "logical", 1, NULL, 'l' },
+	{ "copy", 1, NULL, 'c' },
+	{ "output", 1, NULL, 'c' },
+	{ "bytes", 1, NULL, 'b' },
+	{ 0, 0, 0, 0}
+};
+
+int main(int ac, char **av)
+{
+	struct cache_tree root_cache;
+	struct btrfs_root *root;
+	struct extent_buffer *eb;
+	char *dev;
+	char *output_file = NULL;
+	u64 logical = 0;
+	int ret = 0;
+	int option_index = 0;
+	int copy = 0;
+	u64 bytes = 0;
+	int out_fd = 0;
+	int err;
+
+	while(1) {
+		int c;
+		c = getopt_long(ac, av, "l:c:o:b:", long_options,
+				&option_index);
+		if (c < 0)
+			break;
+		switch(c) {
+			case 'l':
+				logical = atoll(optarg);
+				if (logical == 0) {
+					fprintf(stderr,
+						"invalid extent number\n");
+					print_usage();
+				}
+				break;
+			case 'c':
+				copy = atoi(optarg);
+				if (copy == 0) {
+					fprintf(stderr,
+						"invalid copy number\n");
+					print_usage();
+				}
+				break;
+			case 'b':
+				bytes = atoll(optarg);
+				if (bytes == 0) {
+					fprintf(stderr,
+						"invalid byte count\n");
+					print_usage();
+				}
+				break;
+			case 'o':
+				output_file = strdup(optarg);
+				break;
+			default:
+				print_usage();
+		}
+	}
+	ac = ac - optind;
+	if (ac == 0)
+		print_usage();
+	if (logical == 0)
+		print_usage();
+	if (copy < 0)
+		print_usage();
+
+	dev = av[optind];
+
+	radix_tree_init();
+	cache_tree_init(&root_cache);
+
+	root = open_ctree(dev, 0, 0);
+	if (!root) {
+		fprintf(stderr, "Open ctree failed\n");
+		exit(1);
+	}
+
+	if (output_file) {
+		if (strcmp(output_file, "-") == 0) {
+			out_fd = 1;
+			info_file = stderr;
+		} else {
+			out_fd = open(output_file, O_RDWR | O_CREAT, 0600);
+			if (out_fd < 0)
+				goto close;
+			err = ftruncate(out_fd, 0);
+			if (err) {
+				close(out_fd);
+				goto close;
+			}
+			info_file = stdout;
+		}
+	}
+
+	if (bytes == 0)
+		bytes = root->sectorsize;
+
+	bytes = (bytes + root->sectorsize - 1) / root->sectorsize;
+	bytes *= root->sectorsize;
+
+	while (bytes > 0) {
+		eb = debug_read_block(root, logical, root->sectorsize, copy);
+		if (eb && output_file) {
+			err = write(out_fd, eb->data, eb->len);
+			if (err < 0 || err != eb->len) {
+				fprintf(stderr, "output file write failed\n");
+				goto out_close_fd;
+			}
+		}
+		free_extent_buffer(eb);
+		logical += root->sectorsize;
+		bytes -= root->sectorsize;
+	}
+
+out_close_fd:
+	if (output_file && out_fd != 1)
+		close(out_fd);
+close:
+	close_ctree(root);
+	return ret;
+}
diff -aNur a/btrfs-vol.c b/btrfs-vol.c
--- a/btrfs-vol.c	2009-06-12 00:56:15.000000000 +0800
+++ b/btrfs-vol.c	2011-03-22 16:32:44.601948115 +0800
@@ -108,10 +108,24 @@
 	if (device && strcmp(device, "missing") == 0 &&
 	    cmd == BTRFS_IOC_RM_DEV) {
 		fprintf(stderr, "removing missing devices from %s\n", mnt);
-	} else if (device) {
+	} else if (cmd != BTRFS_IOC_BALANCE) {
+		if (cmd == BTRFS_IOC_ADD_DEV) {
+			ret = check_mounted(device);
+			if (ret < 0) {
+				fprintf(stderr,
+					"error checking %s mount status\n",
+					device);
+				exit(1);
+			}
+			if (ret == 1) {
+				fprintf(stderr, "%s is mounted\n", device);
+				exit(1);
+			}
+		}
 		devfd = open(device, O_RDWR);
-		if (!devfd) {
+		if (devfd < 0) {
 			fprintf(stderr, "Unable to open device %s\n", device);
+			exit(1);
 		}
 		ret = fstat(devfd, &st);
 		if (ret) {
diff -aNur a/btrfs-zero-log.c b/btrfs-zero-log.c
--- a/btrfs-zero-log.c	1970-01-01 07:00:00.000000000 +0700
+++ b/btrfs-zero-log.c	2011-03-22 16:32:44.604948115 +0800
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2007 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 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., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#define _XOPEN_SOURCE 500
+#define _GNU_SOURCE 1
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include "kerncompat.h"
+#include "ctree.h"
+#include "disk-io.h"
+#include "print-tree.h"
+#include "transaction.h"
+#include "list.h"
+#include "version.h"
+#include "utils.h"
+
+static void print_usage(void)
+{
+	fprintf(stderr, "usage: btrfs-zero-log dev\n");
+	fprintf(stderr, "%s\n", BTRFS_BUILD_VERSION);
+	exit(1);
+}
+
+int main(int ac, char **av)
+{
+	struct btrfs_root *root;
+	int ret;
+
+	if (ac != 2)
+		print_usage();
+
+	radix_tree_init();
+
+	if((ret = check_mounted(av[1])) < 0) {
+		fprintf(stderr, "Could not check mount status: %s\n", strerror(ret));
+		return ret;
+	} else if(ret) {
+		fprintf(stderr, "%s is currently mounted. Aborting.\n", av[1]);
+		return -EBUSY;
+	}
+
+	root = open_ctree(av[1], 0, 1);
+
+	if (root == NULL)
+		return 1;
+
+	btrfs_set_super_log_root(&root->fs_info->super_copy, 0);
+	btrfs_set_super_log_root_level(&root->fs_info->super_copy, 0);
+	close_ctree(root);
+	return ret;
+}
diff -aNur a/btrfs.c b/btrfs.c
--- a/btrfs.c	1970-01-01 07:00:00.000000000 +0700
+++ b/btrfs.c	2011-03-22 16:32:44.605948115 +0800
@@ -0,0 +1,387 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 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., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "kerncompat.h"
+#include "btrfs_cmds.h"
+#include "version.h"
+
+typedef int (*CommandFunction)(int argc, char **argv);
+
+struct Command {
+	CommandFunction	func;	/* function which implements the command */
+	int	nargs;		/* if == 999, any number of arguments
+				   if >= 0, number of arguments,
+				   if < 0, _minimum_ number of arguments */
+	char	*verb;		/* verb */
+	char	*help;		/* help lines; form the 2nd onward they are
+				   indented */
+
+	/* the following fields are run-time filled by the program */
+	char	**cmds;		/* array of subcommands */
+	int	ncmds;		/* number of subcommand */
+};
+
+static struct Command commands[] = {
+
+	/*
+		avoid short commands different for the case only
+	*/
+	{ do_clone, 2,
+	  "subvolume snapshot", "<source> [<dest>/]<name>\n"
+		"Create a writable snapshot of the subvolume <source> with\n"
+		"the name <name> in the <dest> directory."
+	},
+	{ do_delete_subvolume, 1,
+	  "subvolume delete", "<subvolume>\n"
+		"Delete the subvolume <subvolume>."
+	},
+	{ do_create_subvol, 1,
+	  "subvolume create", "[<dest>/]<name>\n"
+		"Create a subvolume in <dest> (or the current directory if\n"
+		"not passed)."
+	},
+	{ do_subvol_list, 1, "subvolume list", "<path>\n"
+		"List the snapshot/subvolume of a filesystem."
+	},
+	{ do_find_newer, 2, "subvolume find-new", "<path> <last_gen>\n"
+		"List the recently modified files in a filesystem."
+	},
+	{ do_defrag, -1,
+	  "filesystem defragment", "[-vcf] [-s start] [-l len] [-t size] <file>|<dir> [<file>|<dir>...]\n"
+		"Defragment a file or a directory."
+	},
+	{ do_set_default_subvol, 2,
+	  "subvolume set-default", "<id> <path>\n"
+		"Set the subvolume of the filesystem <path> which will be mounted\n"
+		"as default."
+	},
+	{ do_fssync, 1,
+	  "filesystem sync", "<path>\n"
+		"Force a sync on the filesystem <path>."
+	},
+	{ do_resize, 2,
+	  "filesystem resize", "[+/-]<newsize>[gkm]|max <filesystem>\n"
+		"Resize the file system. If 'max' is passed, the filesystem\n"
+		"will occupe all available space on the device."
+	},
+	{ do_show_filesystem, 999,
+	  "filesystem show", "[<uuid>|<label>]\n"
+		"Show the info of a btrfs filesystem. If no <uuid> or <label>\n"
+		"is passed, info of all the btrfs filesystem are shown."
+	},
+	{ do_df_filesystem, 1,
+	  "filesystem df", "<path>\n"
+		"Show space usage information for a mount point\n."
+	},
+	{ do_balance, 1,
+	  "filesystem balance", "<path>\n"
+		"Balance the chunks across the device."
+	},
+	{ do_scan,
+	  999, "device scan", "[<device> [<device>..]\n"
+		"Scan all device for or the passed device for a btrfs\n"
+		"filesystem."
+	},
+	{ do_add_volume, -2,
+	  "device add", "<dev> [<dev>..] <path>\n"
+		"Add a device to a filesystem."
+	},
+	{ do_remove_volume, -2,
+	  "device delete", "<dev> [<dev>..] <path>\n"
+		"Remove a device from a filesystem."
+	},
+	/* coming soon
+	{ 2, "filesystem label", "<label> <path>\n"
+		"Set the label of a filesystem"
+	}
+	*/
+	{ 0, 0 , 0 }
+};
+
+static char *get_prgname(char *programname)
+{
+	char	*np;
+	np = strrchr(programname,'/');
+	if(!np)
+		np = programname;
+	else
+		np++;
+
+	return np;
+}
+
+static void print_help(char *programname, struct Command *cmd)
+{
+	char	*pc;
+
+	printf("\t%s %s ", programname, cmd->verb );
+
+	for(pc = cmd->help; *pc; pc++){
+		putchar(*pc);
+		if(*pc == '\n')
+			printf("\t\t");
+	}
+	putchar('\n');
+}
+
+static void help(char *np)
+{
+	struct Command *cp;
+
+	printf("Usage:\n");
+	for( cp = commands; cp->verb; cp++ )
+		print_help(np, cp);
+
+	printf("\n\t%s help|--help|-h\n\t\tShow the help.\n",np);
+	printf("\n%s\n", BTRFS_BUILD_VERSION);
+}
+
+static int split_command(char *cmd, char ***commands)
+{
+	int	c, l;
+	char	*p, *s;
+
+	for( *commands = 0, l = c = 0, p = s = cmd ; ; p++, l++ ){
+		if ( *p && *p != ' ' )
+			continue;
+
+		/* c + 2 so that we have room for the null */
+		(*commands) = realloc( (*commands), sizeof(char *)*(c + 2));
+		(*commands)[c] = strndup(s, l);
+		c++;
+		l = 0;
+		s = p+1;
+		if( !*p ) break;
+	}
+
+	(*commands)[c] = 0;
+	return c;
+}
+
+/*
+	This function checks if the passed command is ambiguous
+*/
+static int check_ambiguity(struct Command *cmd, char **argv){
+	int		i;
+	struct Command	*cp;
+	/* check for ambiguity */
+	for( i = 0 ; i < cmd->ncmds ; i++ ){
+		int match;
+		for( match = 0, cp = commands; cp->verb; cp++ ){
+			int	j, skip;
+			char	*s1, *s2;
+
+			if( cp->ncmds < i )
+				continue;
+
+			for( skip = 0, j = 0 ; j < i ; j++ )
+				if( strcmp(cmd->cmds[j], cp->cmds[j])){
+					skip=1;
+					break;
+				}
+			if(skip)
+				continue;
+
+			if( !strcmp(cmd->cmds[i], cp->cmds[i]))
+				continue;
+			for(s2 = cp->cmds[i], s1 = argv[i+1];
+				*s1 == *s2 && *s1; s1++, s2++ ) ;
+			if( !*s1 )
+				match++;
+		}
+		if(match){
+			int j;
+			fprintf(stderr, "ERROR: in command '");
+			for( j = 0 ; j <= i ; j++ )
+				fprintf(stderr, "%s%s",j?" ":"", argv[j+1]);
+			fprintf(stderr, "', '%s' is ambiguous\n",argv[j]);
+			return -2;
+		}
+	}
+	return 0;
+}
+
+/*
+ * This function, compacts the program name and the command in the first
+ * element of the '*av' array
+ */
+static int prepare_args(int *ac, char ***av, char *prgname, struct Command *cmd ){
+
+	char	**ret;
+	int	i;
+	char	*newname;
+
+	ret = (char **)malloc(sizeof(char*)*(*ac+1));
+	newname = (char*)malloc(strlen(prgname)+strlen(cmd->verb)+2);
+	if( !ret || !newname ){
+		free(ret);
+		free(newname);
+		return -1;
+	}
+
+	ret[0] = newname;
+	for(i=0; i < *ac ; i++ )
+		ret[i+1] = (*av)[i];
+
+	strcpy(newname, prgname);
+	strcat(newname, " ");
+	strcat(newname, cmd->verb);
+
+	(*ac)++;
+	*av = ret;
+
+	return 0;
+
+}
+
+
+
+/*
+
+	This function perform the following jobs:
+	- show the help if '--help' or 'help' or '-h' are passed
+	- verify that a command is not ambiguous, otherwise show which
+	  part of the command is ambiguous
+	- if after a (even partial) command there is '--help' show the help
+	  for all the matching commands
+	- if the command doesn't' match show an error
+	- finally, if a command match, they return which command is matched and
+	  the arguments
+
+	The function return 0 in case of help is requested; <0 in case
+	of uncorrect command; >0 in case of matching commands
+	argc, argv are the arg-counter and arg-vector (input)
+	*nargs_ is the number of the arguments after the command (output)
+	**cmd_  is the invoked command (output)
+	***args_ are the arguments after the command
+
+*/
+static int parse_args(int argc, char **argv,
+		      CommandFunction *func_,
+		      int *nargs_, char **cmd_, char ***args_ )
+{
+	struct Command	*cp;
+	struct Command	*matchcmd=0;
+	char		*prgname = get_prgname(argv[0]);
+	int		i=0, helprequested=0;
+
+	if( argc < 2 || !strcmp(argv[1], "help") ||
+		!strcmp(argv[1], "-h") || !strcmp(argv[1], "--help")){
+		help(prgname);
+		return 0;
+	}
+
+	for( cp = commands; cp->verb; cp++ )
+		if( !cp->ncmds)
+			cp->ncmds = split_command(cp->verb, &(cp->cmds));
+
+	for( cp = commands; cp->verb; cp++ ){
+		int     match;
+
+		if( argc-1 < cp->ncmds )
+			continue;
+		for( match = 1, i = 0 ; i < cp->ncmds ; i++ ){
+			char	*s1, *s2;
+			s1 = cp->cmds[i];
+			s2 = argv[i+1];
+
+			for(s2 = cp->cmds[i], s1 = argv[i+1];
+				*s1 == *s2 && *s1;
+				s1++, s2++ ) ;
+			if( *s1 ){
+				match=0;
+				break;
+			}
+		}
+
+		/* If you understand why this code works ...
+			you are a genious !! */
+		if(argc>i+1 && !strcmp(argv[i+1],"--help")){
+			if(!helprequested)
+				printf("Usage:\n");
+			print_help(prgname, cp);
+			helprequested=1;
+			continue;
+		}
+
+		if(!match)
+			continue;
+
+		matchcmd = cp;
+		*nargs_  = argc-matchcmd->ncmds-1;
+		*cmd_ = matchcmd->verb;
+		*args_ = argv+matchcmd->ncmds+1;
+		*func_ = cp->func;
+
+		break;
+	}
+
+	if(helprequested){
+		printf("\n%s\n", BTRFS_BUILD_VERSION);
+		return 0;
+	}
+
+	if(!matchcmd){
+		fprintf( stderr, "ERROR: unknown command '%s'\n",argv[1]);
+		help(prgname);
+		return -1;
+	}
+
+	if(check_ambiguity(matchcmd, argv))
+		return -2;
+
+	/* check the number of argument */
+	if (matchcmd->nargs < 0 && matchcmd->nargs < -*nargs_ ){
+		fprintf(stderr, "ERROR: '%s' requires minimum %d arg(s)\n",
+			matchcmd->verb, -matchcmd->nargs);
+			return -2;
+	}
+	if(matchcmd->nargs >= 0 && matchcmd->nargs != *nargs_ && matchcmd->nargs != 999){
+		fprintf(stderr, "ERROR: '%s' requires %d arg(s)\n",
+			matchcmd->verb, matchcmd->nargs);
+			return -2;
+	}
+	
+        if (prepare_args( nargs_, args_, prgname, matchcmd )){
+                fprintf(stderr, "ERROR: not enough memory\\n");
+		return -20;
+        }
+
+
+	return 1;
+}
+int main(int ac, char **av )
+{
+
+	char		*cmd=0, **args=0;
+	int		nargs=0, r;
+	CommandFunction func=0;
+
+	r = parse_args(ac, av, &func, &nargs, &cmd, &args);
+	if( r <= 0 ){
+		/* error or no command to parse*/
+		exit(-r);
+	}
+
+	exit(func(nargs, args));
+
+}
+
diff -aNur a/btrfs_cmds.c b/btrfs_cmds.c
--- a/btrfs_cmds.c	1970-01-01 07:00:00.000000000 +0700
+++ b/btrfs_cmds.c	2011-03-22 16:32:44.605948115 +0800
@@ -0,0 +1,924 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 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., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <libgen.h>
+#include <limits.h>
+#include <uuid/uuid.h>
+#include <ctype.h>
+
+#undef ULONG_MAX
+
+#include "kerncompat.h"
+#include "ctree.h"
+#include "transaction.h"
+#include "utils.h"
+#include "version.h"
+#include "ioctl.h"
+#include "volumes.h"
+
+#include "btrfs_cmds.h"
+
+#ifdef __CHECKER__
+#define BLKGETSIZE64 0
+#define BTRFS_IOC_SNAP_CREATE 0
+#define BTRFS_VOL_NAME_MAX 255
+struct btrfs_ioctl_vol_args { char name[BTRFS_VOL_NAME_MAX]; };
+static inline int ioctl(int fd, int define, void *arg) { return 0; }
+#endif
+
+/*
+ * test if path is a subvolume:
+ * this function return
+ * 0-> path exists but it is not a subvolume
+ * 1-> path exists and it is  a subvolume
+ * -1 -> path is unaccessible
+ */
+static int test_issubvolume(char *path)
+{
+
+	struct stat	st;
+	int		res;
+
+	res = stat(path, &st);
+	if(res < 0 )
+		return -1;
+
+	return (st.st_ino == 256) && S_ISDIR(st.st_mode);
+
+}
+
+/*
+ * test if path is a directory
+ * this function return
+ * 0-> path exists but it is not a directory
+ * 1-> path exists and it is  a directory
+ * -1 -> path is unaccessible
+ */
+static int test_isdir(char *path)
+{
+	struct stat	st;
+	int		res;
+
+	res = stat(path, &st);
+	if(res < 0 )
+		return -1;
+
+	return S_ISDIR(st.st_mode);
+
+}
+
+static int open_file_or_dir(const char *fname)
+{
+	int ret;
+	struct stat st;
+	DIR *dirstream;
+	int fd;
+
+	ret = stat(fname, &st);
+	if (ret < 0) {
+		return -1;
+	}
+	if (S_ISDIR(st.st_mode)) {
+		dirstream = opendir(fname);
+		if (!dirstream) {
+			return -2;
+		}
+		fd = dirfd(dirstream);
+	} else {
+		fd = open(fname, O_RDWR);
+	}
+	if (fd < 0) {
+		return -3;
+	}
+	return fd;
+}
+
+static u64 parse_size(char *s)
+{
+	int len = strlen(s);
+	char c;
+	u64 mult = 1;
+
+	if (!isdigit(s[len - 1])) {
+		c = tolower(s[len - 1]);
+		switch (c) {
+		case 'g':
+			mult *= 1024;
+		case 'm':
+			mult *= 1024;
+		case 'k':
+			mult *= 1024;
+		case 'b':
+			break;
+		default:
+			fprintf(stderr, "Unknown size descriptor %c\n", c);
+			exit(1);
+		}
+		s[len - 1] = '\0';
+	}
+	return atoll(s) * mult;
+}
+
+int do_defrag(int ac, char **av)
+{
+	int fd;
+	int compress = 0;
+	int flush = 0;
+	u64 start = 0;
+	u64 len = (u64)-1;
+	u32 thresh = 0;
+	int i;
+	int errors = 0;
+	int ret = 0;
+	int verbose = 0;
+	int fancy_ioctl = 0;
+	struct btrfs_ioctl_defrag_range_args range;
+
+	optind = 1;
+	while(1) {
+		int c = getopt(ac, av, "vcfs:l:t:");
+		if (c < 0)
+			break;
+		switch(c) {
+		case 'c':
+			compress = 1;
+			fancy_ioctl = 1;
+			break;
+		case 'f':
+			flush = 1;
+			fancy_ioctl = 1;
+			break;
+		case 'v':
+			verbose = 1;
+			break;
+		case 's':
+			start = parse_size(optarg);
+			fancy_ioctl = 1;
+			break;
+		case 'l':
+			len = parse_size(optarg);
+			fancy_ioctl = 1;
+			break;
+		case 't':
+			thresh = parse_size(optarg);
+			fancy_ioctl = 1;
+			break;
+		default:
+			fprintf(stderr, "Invalid arguments for defragment\n");
+			free(av);
+			return 1;
+		}
+	}
+	if (ac - optind == 0) {
+		fprintf(stderr, "Invalid arguments for defragment\n");
+		free(av);
+		return 1;
+	}
+
+	memset(&range, 0, sizeof(range));
+	range.start = start;
+	range.len = len;
+	range.extent_thresh = thresh;
+	if (compress)
+		range.flags |= BTRFS_DEFRAG_RANGE_COMPRESS;
+	if (flush)
+		range.flags |= BTRFS_DEFRAG_RANGE_START_IO;
+
+	for (i = optind; i < ac; i++) {
+		if (verbose)
+			printf("%s\n", av[i]);
+		fd = open_file_or_dir(av[i]);
+		if (fd < 0) {
+			fprintf(stderr, "failed to open %s\n", av[i]);
+			perror("open:");
+			errors++;
+			continue;
+		}
+		if (!fancy_ioctl) {
+			ret = ioctl(fd, BTRFS_IOC_DEFRAG, NULL);
+		} else {
+			ret = ioctl(fd, BTRFS_IOC_DEFRAG_RANGE, &range);
+			if (ret && errno == ENOTTY) {
+				fprintf(stderr, "defrag range ioctl not "
+					"supported in this kernel, please try "
+					"without any options.\n");
+				errors++;
+				break;
+			}
+		}
+		if (ret) {
+			fprintf(stderr, "ioctl failed on %s ret %d errno %d\n",
+				av[i], ret, errno);
+			errors++;
+		}
+		close(fd);
+	}
+	if (verbose)
+		printf("%s\n", BTRFS_BUILD_VERSION);
+	if (errors) {
+		fprintf(stderr, "total %d failures\n", errors);
+		exit(1);
+	}
+
+	free(av);
+	return errors + 20;
+}
+
+int do_find_newer(int argc, char **argv)
+{
+	int fd;
+	int ret;
+	char *subvol;
+	u64 last_gen;
+
+	subvol = argv[1];
+	last_gen = atoll(argv[2]);
+
+	ret = test_issubvolume(subvol);
+	if (ret < 0) {
+		fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
+		return 12;
+	}
+	if (!ret) {
+		fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
+		return 13;
+	}
+
+	fd = open_file_or_dir(subvol);
+	if (fd < 0) {
+		fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
+		return 12;
+	}
+	ret = find_updated_files(fd, 0, last_gen);
+	if (ret)
+		return 19;
+	return 0;
+}
+
+int do_subvol_list(int argc, char **argv)
+{
+	int fd;
+	int ret;
+	char *subvol;
+
+	subvol = argv[1];
+
+	ret = test_issubvolume(subvol);
+	if (ret < 0) {
+		fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
+		return 12;
+	}
+	if (!ret) {
+		fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
+		return 13;
+	}
+
+	fd = open_file_or_dir(subvol);
+	if (fd < 0) {
+		fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
+		return 12;
+	}
+	ret = list_subvols(fd);
+	if (ret)
+		return 19;
+	return 0;
+}
+
+int do_clone(int argc, char **argv)
+{
+	char	*subvol, *dst;
+	int	res, fd, fddst, len;
+	char	*newname;
+	char	*dstdir;
+
+	subvol = argv[1];
+	dst = argv[2];
+	struct btrfs_ioctl_vol_args	args;
+
+	res = test_issubvolume(subvol);
+	if(res<0){
+		fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
+		return 12;
+	}
+	if(!res){
+		fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
+		return 13;
+	}
+
+	res = test_isdir(dst);
+	if(res == 0 ){
+		fprintf(stderr, "ERROR: '%s' exists and it is not a directory\n", dst);
+		return 12;
+	}
+
+	if(res>0){
+		newname = strdup(subvol);
+		newname = basename(newname);
+		dstdir = dst;
+	}else{
+		newname = strdup(dst);
+		newname = basename(newname);
+		dstdir = strdup(dst);
+		dstdir = dirname(dstdir);
+	}
+
+	if( !strcmp(newname,".") || !strcmp(newname,"..") ||
+	     strchr(newname, '/') ){
+		fprintf(stderr, "ERROR: incorrect snapshot name ('%s')\n",
+			newname);
+		return 14;
+	}
+
+	len = strlen(newname);
+	if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
+		fprintf(stderr, "ERROR: snapshot name too long ('%s)\n",
+			newname);
+		return 14;
+	}
+
+	fddst = open_file_or_dir(dstdir);
+	if (fddst < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", dstdir);
+		return 12;
+	}
+
+	fd = open_file_or_dir(subvol);
+	if (fd < 0) {
+		close(fddst);
+		fprintf(stderr, "ERROR: can't access to '%s'\n", dstdir);
+		return 12;
+	}
+
+	printf("Create a snapshot of '%s' in '%s/%s'\n",
+	       subvol, dstdir, newname);
+	args.fd = fd;
+	strcpy(args.name, newname);
+	res = ioctl(fddst, BTRFS_IOC_SNAP_CREATE, &args);
+
+	close(fd);
+	close(fddst);
+
+	if(res < 0 ){
+		fprintf( stderr, "ERROR: cannot snapshot '%s'\n",subvol);
+		return 11;
+	}
+
+	return 0;
+
+}
+
+int do_delete_subvolume(int argc, char **argv)
+{
+	int	res, fd, len;
+	struct btrfs_ioctl_vol_args	args;
+	char	*dname, *vname, *cpath;
+	char	*path = argv[1];
+
+	res = test_issubvolume(path);
+	if(res<0){
+		fprintf(stderr, "ERROR: error accessing '%s'\n", path);
+		return 12;
+	}
+	if(!res){
+		fprintf(stderr, "ERROR: '%s' is not a subvolume\n", path);
+		return 13;
+	}
+
+	cpath = realpath(path, 0);
+	dname = strdup(cpath);
+	dname = dirname(dname);
+	vname = strdup(cpath);
+	vname = basename(vname);
+	free(cpath);
+
+	if( !strcmp(vname,".") || !strcmp(vname,"..") ||
+	     strchr(vname, '/') ){
+		fprintf(stderr, "ERROR: incorrect subvolume name ('%s')\n",
+			vname);
+		return 14;
+	}
+
+	len = strlen(vname);
+	if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
+		fprintf(stderr, "ERROR: snapshot name too long ('%s)\n",
+			vname);
+		return 14;
+	}
+
+	fd = open_file_or_dir(dname);
+	if (fd < 0) {
+		close(fd);
+		fprintf(stderr, "ERROR: can't access to '%s'\n", dname);
+		return 12;
+	}
+
+	printf("Delete subvolume '%s/%s'\n", dname, vname);
+	strcpy(args.name, vname);
+	res = ioctl(fd, BTRFS_IOC_SNAP_DESTROY, &args);
+
+	close(fd);
+
+	if(res < 0 ){
+		fprintf( stderr, "ERROR: cannot delete '%s/%s'\n",dname, vname);
+		return 11;
+	}
+
+	return 0;
+
+}
+
+int do_create_subvol(int argc, char **argv)
+{
+	int	res, fddst, len;
+	char	*newname;
+	char	*dstdir;
+	struct btrfs_ioctl_vol_args	args;
+	char	*dst = argv[1];
+
+	res = test_isdir(dst);
+	if(res >= 0 ){
+		fprintf(stderr, "ERROR: '%s' exists\n", dst);
+		return 12;
+	}
+
+	newname = strdup(dst);
+	newname = basename(newname);
+	dstdir = strdup(dst);
+	dstdir = dirname(dstdir);
+
+	if( !strcmp(newname,".") || !strcmp(newname,"..") ||
+	     strchr(newname, '/') ){
+		fprintf(stderr, "ERROR: uncorrect subvolume name ('%s')\n",
+			newname);
+		return 14;
+	}
+
+	len = strlen(newname);
+	if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
+		fprintf(stderr, "ERROR: subvolume name too long ('%s)\n",
+			newname);
+		return 14;
+	}
+
+	fddst = open_file_or_dir(dstdir);
+	if (fddst < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", dstdir);
+		return 12;
+	}
+
+	printf("Create subvolume '%s/%s'\n", dstdir, newname);
+	strcpy(args.name, newname);
+	res = ioctl(fddst, BTRFS_IOC_SUBVOL_CREATE, &args);
+
+	close(fddst);
+
+	if(res < 0 ){
+		fprintf( stderr, "ERROR: cannot create subvolume\n");
+		return 11;
+	}
+
+	return 0;
+
+}
+
+int do_fssync(int argc, char **argv)
+{
+	int fd, res;
+	char	*path = argv[1];
+
+	fd = open_file_or_dir(path);
+	if (fd < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", path);
+		return 12;
+	}
+
+	printf("FSSync '%s'\n", path);
+	res = ioctl(fd, BTRFS_IOC_SYNC);
+	close(fd);
+	if( res < 0 ){
+		fprintf(stderr, "ERROR: unable to fs-syncing '%s'\n", path);
+		return 16;
+	}
+
+	return 0;
+}
+
+int do_scan(int argc, char **argv)
+{
+	int	i, fd;
+	if(argc<=1){
+		int ret;
+
+		printf("Scanning for Btrfs filesystems\n");
+		ret = btrfs_scan_one_dir("/dev", 1);
+		if (ret){
+			fprintf(stderr, "ERROR: error %d while scanning\n", ret);
+			return 18;
+		}
+		return 0;
+	}
+
+	fd = open("/dev/btrfs-control", O_RDWR);
+	if (fd < 0) {
+		perror("failed to open /dev/btrfs-control");
+		return 10;
+	}
+
+	for( i = 1 ; i < argc ; i++ ){
+		struct btrfs_ioctl_vol_args args;
+		int ret;
+
+		printf("Scanning for Btrfs filesystems in '%s'\n", argv[i]);
+
+		strcpy(args.name, argv[i]);
+		/*
+		 * FIXME: which are the error code returned by this ioctl ?
+		 * it seems that is impossible to understand if there no is
+		 * a btrfs filesystem from an I/O error !!!
+		 */
+		ret = ioctl(fd, BTRFS_IOC_SCAN_DEV, &args);
+
+		if( ret < 0 ){
+			close(fd);
+			fprintf(stderr, "ERROR: unable to scan the device '%s'\n", argv[i]);
+			return 11;
+		}
+	}
+
+	close(fd);
+	return 0;
+
+}
+
+int do_resize(int argc, char **argv)
+{
+
+	struct btrfs_ioctl_vol_args	args;
+	int	fd, res, len;
+	char	*amount=argv[1], *path=argv[2];
+
+	fd = open_file_or_dir(path);
+	if (fd < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", path);
+		return 12;
+	}
+	len = strlen(amount);
+	if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
+		fprintf(stderr, "ERROR: size value too long ('%s)\n",
+			amount);
+		return 14;
+	}
+
+	printf("Resize '%s' of '%s'\n", path, amount);
+	strcpy(args.name, amount);
+	res = ioctl(fd, BTRFS_IOC_RESIZE, &args);
+	close(fd);
+	if( res < 0 ){
+		fprintf(stderr, "ERROR: unable to resize '%s'\n", path);
+		return 30;
+	}
+	return 0;
+}
+
+static int uuid_search(struct btrfs_fs_devices *fs_devices, char *search)
+{
+	struct list_head *cur;
+	struct btrfs_device *device;
+
+	list_for_each(cur, &fs_devices->devices) {
+		device = list_entry(cur, struct btrfs_device, dev_list);
+		if ((device->label && strcmp(device->label, search) == 0) ||
+		    strcmp(device->name, search) == 0)
+			return 1;
+	}
+	return 0;
+}
+
+static void print_one_uuid(struct btrfs_fs_devices *fs_devices)
+{
+	char uuidbuf[37];
+	struct list_head *cur;
+	struct btrfs_device *device;
+	char *super_bytes_used;
+	u64 devs_found = 0;
+	u64 total;
+
+	uuid_unparse(fs_devices->fsid, uuidbuf);
+	device = list_entry(fs_devices->devices.next, struct btrfs_device,
+			    dev_list);
+	if (device->label && device->label[0])
+		printf("Label: '%s' ", device->label);
+	else
+		printf("Label: none ");
+
+	super_bytes_used = pretty_sizes(device->super_bytes_used);
+
+	total = device->total_devs;
+	printf(" uuid: %s\n\tTotal devices %llu FS bytes used %s\n", uuidbuf,
+	       (unsigned long long)total, super_bytes_used);
+
+	free(super_bytes_used);
+
+	list_for_each(cur, &fs_devices->devices) {
+		char *total_bytes;
+		char *bytes_used;
+		device = list_entry(cur, struct btrfs_device, dev_list);
+		total_bytes = pretty_sizes(device->total_bytes);
+		bytes_used = pretty_sizes(device->bytes_used);
+		printf("\tdevid %4llu size %s used %s path %s\n",
+		       (unsigned long long)device->devid,
+		       total_bytes, bytes_used, device->name);
+		free(total_bytes);
+		free(bytes_used);
+		devs_found++;
+	}
+	if (devs_found < total) {
+		printf("\t*** Some devices missing\n");
+	}
+	printf("\n");
+}
+
+int do_show_filesystem(int argc, char **argv)
+{
+	struct list_head *all_uuids;
+	struct btrfs_fs_devices *fs_devices;
+	struct list_head *cur_uuid;
+	char *search = argv[1];
+	int ret;
+
+	ret = btrfs_scan_one_dir("/dev", 0);
+	if (ret){
+		fprintf(stderr, "ERROR: error %d while scanning\n", ret);
+		return 18;
+	}
+
+	all_uuids = btrfs_scanned_uuids();
+	list_for_each(cur_uuid, all_uuids) {
+		fs_devices = list_entry(cur_uuid, struct btrfs_fs_devices,
+					list);
+		if (search && uuid_search(fs_devices, search) == 0)
+			continue;
+		print_one_uuid(fs_devices);
+	}
+	printf("%s\n", BTRFS_BUILD_VERSION);
+	return 0;
+}
+
+int do_add_volume(int nargs, char **args)
+{
+
+	char	*mntpnt = args[nargs-1];
+	int	i, fdmnt, ret=0;
+
+
+	fdmnt = open_file_or_dir(mntpnt);
+	if (fdmnt < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", mntpnt);
+		return 12;
+	}
+
+	for(i=1 ; i < (nargs-1) ; i++ ){
+		struct btrfs_ioctl_vol_args ioctl_args;
+		int	devfd, res;
+		u64 dev_block_count = 0;
+		struct stat st;
+
+		devfd = open(args[i], O_RDWR);
+		if (!devfd) {
+			fprintf(stderr, "ERROR: Unable to open device '%s'\n", args[i]);
+			close(devfd);
+			ret++;
+			continue;
+		}
+		ret = fstat(devfd, &st);
+		if (ret) {
+			fprintf(stderr, "ERROR: Unable to stat '%s'\n", args[i]);
+			close(devfd);
+			ret++;
+			continue;
+		}
+		if (!S_ISBLK(st.st_mode)) {
+			fprintf(stderr, "ERROR: '%s' is not a block device\n", args[i]);
+			close(devfd);
+			ret++;
+			continue;
+		}
+
+		res = btrfs_prepare_device(devfd, args[i], 1, &dev_block_count);
+		if (res) {
+			fprintf(stderr, "ERROR: Unable to init '%s'\n", args[i]);
+			close(devfd);
+			ret++;
+			continue;
+		}
+		close(devfd);
+
+		strcpy(ioctl_args.name, args[i]);
+		res = ioctl(fdmnt, BTRFS_IOC_ADD_DEV, &ioctl_args);
+		if(res<0){
+			fprintf(stderr, "ERROR: error adding the device '%s'\n", args[i]);
+			ret++;
+		}
+
+	}
+
+	close(fdmnt);
+	if( ret)
+		return ret+20;
+	else
+		return 0;
+
+}
+
+int do_balance(int argc, char **argv)
+{
+
+	int	fdmnt, ret=0;
+	struct btrfs_ioctl_vol_args args;
+	char	*path = argv[1];
+
+	fdmnt = open_file_or_dir(path);
+	if (fdmnt < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", path);
+		return 12;
+	}
+
+	memset(&args, 0, sizeof(args));
+	ret = ioctl(fdmnt, BTRFS_IOC_BALANCE, &args);
+	close(fdmnt);
+	if(ret<0){
+		fprintf(stderr, "ERROR: balancing '%s'\n", path);
+
+		return 19;
+	}
+	return 0;
+}
+int do_remove_volume(int nargs, char **args)
+{
+
+	char	*mntpnt = args[nargs-1];
+	int	i, fdmnt, ret=0;
+
+	fdmnt = open_file_or_dir(mntpnt);
+	if (fdmnt < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", mntpnt);
+		return 12;
+	}
+
+	for(i=1 ; i < (nargs-1) ; i++ ){
+		struct	btrfs_ioctl_vol_args arg;
+		int	res;
+
+		strcpy(arg.name, args[i]);
+		res = ioctl(fdmnt, BTRFS_IOC_RM_DEV, &arg);
+		if(res<0){
+			fprintf(stderr, "ERROR: error removing the device '%s'\n", args[i]);
+			ret++;
+		}
+	}
+
+	close(fdmnt);
+	if( ret)
+		return ret+20;
+	else
+		return 0;
+}
+
+int do_set_default_subvol(int nargs, char **argv)
+{
+	int	ret=0, fd;
+	u64	objectid;
+	char	*path = argv[2];
+	char	*subvolid = argv[1];
+
+	fd = open_file_or_dir(path);
+	if (fd < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", path);
+		return 12;
+	}
+
+	objectid = (unsigned long long)strtoll(subvolid, NULL, 0);
+	if (errno == ERANGE) {
+		fprintf(stderr, "ERROR: invalid tree id (%s)\n",subvolid);
+		return 30;
+	}
+	ret = ioctl(fd, BTRFS_IOC_DEFAULT_SUBVOL, &objectid);
+	close(fd);
+	if( ret < 0 ){
+		fprintf(stderr, "ERROR: unable to set a new default subvolume\n");
+		return 30;
+	}
+	return 0;
+}
+
+int do_df_filesystem(int nargs, char **argv)
+{
+	struct btrfs_ioctl_space_args *sargs;
+	u64 count = 0, i;
+	int ret;
+	int fd;
+	char *path = argv[1];
+
+	fd = open_file_or_dir(path);
+	if (fd < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", path);
+		return 12;
+	}
+
+	sargs = malloc(sizeof(struct btrfs_ioctl_space_args));
+	if (!sargs)
+		return -ENOMEM;
+
+	sargs->space_slots = 0;
+	sargs->total_spaces = 0;
+
+	ret = ioctl(fd, BTRFS_IOC_SPACE_INFO, sargs);
+	if (ret) {
+		free(sargs);
+		return ret;
+	}
+	if (!sargs->total_spaces)
+		return 0;
+
+	count = sargs->total_spaces;
+
+	sargs = realloc(sargs, sizeof(struct btrfs_ioctl_space_args) +
+			(count * sizeof(struct btrfs_ioctl_space_info)));
+	if (!sargs)
+		return -ENOMEM;
+
+	sargs->space_slots = count;
+	sargs->total_spaces = 0;
+
+	ret = ioctl(fd, BTRFS_IOC_SPACE_INFO, sargs);
+	if (ret) {
+		free(sargs);
+		return ret;
+	}
+
+	for (i = 0; i < sargs->total_spaces; i++) {
+		char description[80];
+		char *total_bytes;
+		char *used_bytes;
+		int written = 0;
+		u64 flags = sargs->spaces[i].flags;
+
+		memset(description, 0, 80);
+
+		if (flags & BTRFS_BLOCK_GROUP_DATA) {
+			snprintf(description, 5, "%s", "Data");
+			written += 4;
+		} else if (flags & BTRFS_BLOCK_GROUP_SYSTEM) {
+			snprintf(description, 7, "%s", "System");
+			written += 6;
+		} else if (flags & BTRFS_BLOCK_GROUP_METADATA) {
+			snprintf(description, 9, "%s", "Metadata");
+			written += 8;
+		}
+
+		if (flags & BTRFS_BLOCK_GROUP_RAID0) {
+			snprintf(description+written, 8, "%s", ", RAID0");
+			written += 7;
+		} else if (flags & BTRFS_BLOCK_GROUP_RAID1) {
+			snprintf(description+written, 8, "%s", ", RAID1");
+			written += 7;
+		} else if (flags & BTRFS_BLOCK_GROUP_DUP) {
+			snprintf(description+written, 6, "%s", ", DUP");
+			written += 5;
+		} else if (flags & BTRFS_BLOCK_GROUP_RAID10) {
+			snprintf(description+written, 9, "%s", ", RAID10");
+			written += 8;
+		}
+
+		total_bytes = pretty_sizes(sargs->spaces[i].total_bytes);
+		used_bytes = pretty_sizes(sargs->spaces[i].used_bytes);
+		printf("%s: total=%s, used=%s\n", description, total_bytes,
+		       used_bytes);
+	}
+	free(sargs);
+
+	return 0;
+}
diff -aNur a/btrfs_cmds.h b/btrfs_cmds.h
--- a/btrfs_cmds.h	1970-01-01 07:00:00.000000000 +0700
+++ b/btrfs_cmds.h	2011-03-22 16:32:44.605948115 +0800
@@ -0,0 +1,34 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 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., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+/* btrfs_cmds.c*/
+int do_clone(int nargs, char **argv);
+int do_delete_subvolume(int nargs, char **argv);
+int do_create_subvol(int nargs, char **argv);
+int do_fssync(int nargs, char **argv);
+int do_defrag(int argc, char **argv);
+int do_show_filesystem(int nargs, char **argv);
+int do_add_volume(int nargs, char **args);
+int do_balance(int nargs, char **argv);
+int do_remove_volume(int nargs, char **args);
+int do_scan(int nargs, char **argv);
+int do_resize(int nargs, char **argv);
+int do_subvol_list(int nargs, char **argv);
+int do_set_default_subvol(int nargs, char **argv);
+int list_subvols(int fd);
+int do_df_filesystem(int nargs, char **argv);
+int find_updated_files(int fd, u64 root_id, u64 oldest_gen);
+int do_find_newer(int argc, char **argv);
diff -aNur a/btrfsck.c b/btrfsck.c
--- a/btrfsck.c	2009-06-12 00:56:15.000000000 +0800
+++ b/btrfsck.c	2011-03-22 16:32:44.606948115 +0800
@@ -20,7 +20,9 @@
 #define _GNU_SOURCE 1
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include <fcntl.h>
+#include <sys/stat.h>
 #include "kerncompat.h"
 #include "ctree.h"
 #include "disk-io.h"
@@ -28,6 +30,7 @@
 #include "transaction.h"
 #include "list.h"
 #include "version.h"
+#include "utils.h"
 
 static u64 bytes_used = 0;
 static u64 total_csum_bytes = 0;
@@ -36,7 +39,7 @@
 static u64 btree_space_waste = 0;
 static u64 data_bytes_allocated = 0;
 static u64 data_bytes_referenced = 0;
-int found_old_backref = 0;
+static int found_old_backref = 0;
 
 struct extent_backref {
 	struct list_head list;
@@ -100,7 +103,11 @@
 #define REF_ERR_DUP_INODE_REF		(1 << 5)
 #define REF_ERR_INDEX_UNMATCH		(1 << 6)
 #define REF_ERR_FILETYPE_UNMATCH	(1 << 7)
-#define REF_ERR_NAME_TOO_LONG		(1 << 8)
+#define REF_ERR_NAME_TOO_LONG		(1 << 8) // 100
+#define REF_ERR_NO_ROOT_REF		(1 << 9)
+#define REF_ERR_NO_ROOT_BACKREF		(1 << 10)
+#define REF_ERR_DUP_ROOT_REF		(1 << 11)
+#define REF_ERR_DUP_ROOT_BACKREF	(1 << 12)
 
 struct inode_record {
 	struct list_head backrefs;
@@ -144,6 +151,29 @@
 #define I_ERR_SOME_CSUM_MISSING		(1 << 12)
 #define I_ERR_LINK_COUNT_WRONG		(1 << 13)
 
+struct root_backref {
+	struct list_head list;
+	unsigned int found_dir_item:1;
+	unsigned int found_dir_index:1;
+	unsigned int found_back_ref:1;
+	unsigned int found_forward_ref:1;
+	unsigned int reachable:1;
+	int errors;
+	u64 ref_root;
+	u64 dir;
+	u64 index;
+	u16 namelen;
+	char name[0];
+};
+
+struct root_record {
+	struct list_head backrefs;
+	struct cache_extent cache;
+	unsigned int found_root_item:1;
+	u64 objectid;
+	u32 found_ref;
+};
+
 struct ptr_node {
 	struct cache_extent cache;
 	void *data;
@@ -151,6 +181,7 @@
 
 struct shared_node {
 	struct cache_extent cache;
+	struct cache_tree root_cache;
 	struct cache_tree inode_cache;
 	struct inode_record *current;
 	u32 refs;
@@ -258,6 +289,14 @@
 	free(rec);
 }
 
+static int can_free_inode_rec(struct inode_record *rec)
+{
+	if (!rec->errors && rec->checked && rec->found_inode_item &&
+	    rec->nlink == rec->found_link && list_empty(&rec->backrefs))
+		return 1;
+	return 0;
+}
+
 static void maybe_free_inode_rec(struct cache_tree *inode_cache,
 				 struct inode_record *rec)
 {
@@ -309,8 +348,7 @@
 	}
 
 	BUG_ON(rec->refs != 1);
-	if (!rec->errors && rec->nlink == rec->found_link &&
-	    list_empty(&rec->backrefs)) {
+	if (can_free_inode_rec(rec)) {
 		cache = find_cache_extent(inode_cache, rec->ino, 1);
 		node = container_of(cache, struct ptr_node, cache);
 		BUG_ON(node->data != rec);
@@ -338,14 +376,12 @@
 	return ret;
 }
 
-static int process_inode_item(struct btrfs_root *root,
-			      struct extent_buffer *eb,
+static int process_inode_item(struct extent_buffer *eb,
 			      int slot, struct btrfs_key *key,
 			      struct shared_node *active_node)
 {
 	struct inode_record *rec;
 	struct btrfs_inode_item *item;
-	int ret;
 
 	rec = active_node->current;
 	BUG_ON(rec->ino != key->objectid || rec->refs > 1);
@@ -361,11 +397,8 @@
 	if (btrfs_inode_flags(eb, item) & BTRFS_INODE_NODATASUM)
 		rec->nodatasum = 1;
 	rec->found_inode_item = 1;
-	if (rec->nlink == 0) {
-		ret = check_orphan_item(root, rec->ino);
-		if (ret == -ENOENT)
-			rec->errors |= I_ERR_NO_ORPHAN_ITEM;
-	}
+	if (rec->nlink == 0)
+		rec->errors |= I_ERR_NO_ORPHAN_ITEM;
 	maybe_free_inode_rec(&active_node->inode_cache, rec);
 	return 0;
 }
@@ -391,7 +424,6 @@
 	memcpy(backref->name, name, namelen);
 	backref->name[namelen] = '\0';
 	list_add_tail(&backref->list, &rec->backrefs);
-	rec->found_link++;
 	return backref;
 }
 
@@ -419,6 +451,7 @@
 		backref->filetype = filetype;
 		backref->found_dir_index = 1;
 	} else if (itemtype == BTRFS_DIR_ITEM_KEY) {
+		rec->found_link++;
 		if (backref->found_dir_item)
 			backref->errors |= REF_ERR_DUP_DIR_ITEM;
 		if (backref->found_dir_index && backref->filetype != filetype)
@@ -443,10 +476,10 @@
 }
 
 static int merge_inode_recs(struct inode_record *src, struct inode_record *dst,
-			    struct shared_node *dst_node)
+			    struct cache_tree *dst_cache)
 {
 	struct inode_backref *backref;
-	struct cache_tree *dst_cache = &dst_node->inode_cache;
+	u32 dir_count = 0;
 
 	dst->merging = 1;
 	list_for_each_entry(backref, &src->backrefs, list) {
@@ -457,6 +490,7 @@
 					BTRFS_DIR_INDEX_KEY, backref->errors);
 		}
 		if (backref->found_dir_item) {
+			dir_count++;
 			add_inode_backref(dst_cache, dst->ino,
 					backref->dir, 0, backref->name,
 					backref->namelen, backref->filetype,
@@ -481,6 +515,8 @@
 	if (dst->first_extent_gap > src->first_extent_gap)
 		dst->first_extent_gap = src->first_extent_gap;
 
+	BUG_ON(src->found_link < dir_count);
+	dst->found_link += src->found_link - dir_count;
 	dst->found_size += src->found_size;
 	if (src->extent_start != (u64)-1) {
 		if (dst->extent_start == (u64)-1) {
@@ -510,14 +546,8 @@
 			dst->errors |= I_ERR_DUP_INODE_ITEM;
 		}
 	}
-
-	if (src->checked) {
-		dst->checked = 1;
-		if (dst_node->current == dst)
-			dst_node->current = NULL;
-	}
 	dst->merging = 0;
-	maybe_free_inode_rec(dst_cache, dst);
+
 	return 0;
 }
 
@@ -537,8 +567,9 @@
 	if (src_node->current)
 		current_ino = src_node->current->ino;
 
-	src = &src_node->inode_cache;
-	dst = &dst_node->inode_cache;
+	src = &src_node->root_cache;
+	dst = &dst_node->root_cache;
+again:
 	cache = find_first_cache_extent(src, 0);
 	while (cache) {
 		node = container_of(cache, struct ptr_node, cache);
@@ -558,13 +589,26 @@
 		ret = insert_existing_cache_extent(dst, &ins->cache);
 		if (ret == -EEXIST) {
 			conflict = get_inode_rec(dst, rec->ino, 1);
-			merge_inode_recs(rec, conflict, dst_node);
+			merge_inode_recs(rec, conflict, dst);
+			if (rec->checked) {
+				conflict->checked = 1;
+				if (dst_node->current == conflict)
+					dst_node->current = NULL;
+			}
+			maybe_free_inode_rec(dst, conflict);
 			free_inode_rec(rec);
 			free(ins);
 		} else {
 			BUG_ON(ret);
 		}
 	}
+
+	if (src == &src_node->root_cache) {
+		src = &src_node->inode_cache;
+		dst = &dst_node->inode_cache;
+		goto again;
+	}
+
 	if (current_ino > 0 && (!dst_node->current ||
 	    current_ino > dst_node->current->ino)) {
 		if (dst_node->current) {
@@ -616,6 +660,7 @@
 	node = calloc(1, sizeof(*node));
 	node->cache.start = bytenr;
 	node->cache.size = 1;
+	cache_tree_init(&node->root_cache);
 	cache_tree_init(&node->inode_cache);
 	node->refs = refs;
 
@@ -646,6 +691,7 @@
 	if (wc->root_level == wc->active_node &&
 	    btrfs_root_refs(&root->root_item) == 0) {
 		if (--node->refs == 0) {
+			free_inode_recs(&node->root_cache);
 			free_inode_recs(&node->inode_cache);
 			remove_cache_extent(&wc->shared, &node->cache);
 			free(node);
@@ -708,10 +754,12 @@
 	int filetype;
 	struct btrfs_dir_item *di;
 	struct inode_record *rec;
+	struct cache_tree *root_cache;
 	struct cache_tree *inode_cache;
 	struct btrfs_key location;
 	char namebuf[BTRFS_NAME_LEN];
 
+	root_cache = &active_node->root_cache;
 	inode_cache = &active_node->inode_cache;
 	rec = active_node->current;
 	rec->found_dir_item = 1;
@@ -740,7 +788,9 @@
 					  key->objectid, key->offset, namebuf,
 					  len, filetype, key->type, error);
 		} else if (location.type == BTRFS_ROOT_ITEM_KEY) {
-			/* fixme: check root back & forward references */
+			add_inode_backref(root_cache, location.objectid,
+					  key->objectid, key->offset, namebuf,
+					  len, filetype, key->type, error);
 		} else {
 			fprintf(stderr, "warning line %d\n", __LINE__);
 		}
@@ -977,8 +1027,7 @@
 			ret = process_inode_ref(eb, i, &key, active_node);
 			break;
 		case BTRFS_INODE_ITEM_KEY:
-			ret = process_inode_item(root, eb, i, &key,
-						 active_node);
+			ret = process_inode_item(eb, i, &key, active_node);
 			break;
 		case BTRFS_EXTENT_DATA_KEY:
 			ret = process_file_extent(root, eb, i, &key,
@@ -1120,7 +1169,7 @@
 
 	if (!rec->found_inode_item || rec->errors)
 		goto out;
-	if (rec->nlink != 1 || rec->found_link != 1)
+	if (rec->nlink != 1 || rec->found_link != 0)
 		goto out;
 	if (list_empty(&rec->backrefs))
 		goto out;
@@ -1176,13 +1225,23 @@
 		node = container_of(cache, struct ptr_node, cache);
 		rec = node->data;
 		remove_cache_extent(inode_cache, &node->cache);
+		free(node);
 		if (rec->ino == root_dirid ||
 		    rec->ino == BTRFS_ORPHAN_OBJECTID) {
-			free(node);
 			free_inode_rec(rec);
 			continue;
 		}
 
+		if (rec->errors & I_ERR_NO_ORPHAN_ITEM) {
+			ret = check_orphan_item(root, rec->ino);
+			if (ret == 0)
+				rec->errors &= ~I_ERR_NO_ORPHAN_ITEM;
+			if (can_free_inode_rec(rec)) {
+				free_inode_rec(rec);
+				continue;
+			}
+		}
+
 		error++;
 		if (!rec->found_inode_item)
 			rec->errors |= I_ERR_NO_INODE_ITEM;
@@ -1205,13 +1264,314 @@
 				backref->namelen, backref->name,
 				backref->filetype, backref->errors);
 		}
-		free(node);
 		free_inode_rec(rec);
 	}
 	return (error > 0) ? -1 : 0;
 }
 
+static struct root_record *get_root_rec(struct cache_tree *root_cache,
+					u64 objectid)
+{
+	struct cache_extent *cache;
+	struct root_record *rec = NULL;
+	int ret;
+
+	cache = find_cache_extent(root_cache, objectid, 1);
+	if (cache) {
+		rec = container_of(cache, struct root_record, cache);
+	} else {
+		rec = calloc(1, sizeof(*rec));
+		rec->objectid = objectid;
+		INIT_LIST_HEAD(&rec->backrefs);
+		rec->cache.start = objectid;
+		rec->cache.size = 1;
+
+		ret = insert_existing_cache_extent(root_cache, &rec->cache);
+		BUG_ON(ret);
+	}
+	return rec;
+}
+
+static struct root_backref *get_root_backref(struct root_record *rec,
+					     u64 ref_root, u64 dir, u64 index,
+					     const char *name, int namelen)
+{
+	struct root_backref *backref;
+
+	list_for_each_entry(backref, &rec->backrefs, list) {
+		if (backref->ref_root != ref_root || backref->dir != dir ||
+		    backref->namelen != namelen)
+			continue;
+		if (memcmp(name, backref->name, namelen))
+			continue;
+		return backref;
+	}
+
+	backref = malloc(sizeof(*backref) + namelen + 1);
+	memset(backref, 0, sizeof(*backref));
+	backref->ref_root = ref_root;
+	backref->dir = dir;
+	backref->index = index;
+	backref->namelen = namelen;
+	memcpy(backref->name, name, namelen);
+	backref->name[namelen] = '\0';
+	list_add_tail(&backref->list, &rec->backrefs);
+	return backref;
+}
+
+static void free_root_recs(struct cache_tree *root_cache)
+{
+	struct cache_extent *cache;
+	struct root_record *rec;
+	struct root_backref *backref;
+
+	while (1) {
+		cache = find_first_cache_extent(root_cache, 0);
+		if (!cache)
+			break;
+		rec = container_of(cache, struct root_record, cache);
+		remove_cache_extent(root_cache, &rec->cache);
+
+		while (!list_empty(&rec->backrefs)) {
+			backref = list_entry(rec->backrefs.next,
+					     struct root_backref, list);
+			list_del(&backref->list);
+			free(backref);
+		}
+		kfree(rec);
+	}
+}
+
+static int add_root_backref(struct cache_tree *root_cache,
+			    u64 root_id, u64 ref_root, u64 dir, u64 index,
+			    const char *name, int namelen,
+			    int item_type, int errors)
+{
+	struct root_record *rec;
+	struct root_backref *backref;
+
+	rec = get_root_rec(root_cache, root_id);
+	backref = get_root_backref(rec, ref_root, dir, index, name, namelen);
+
+	backref->errors |= errors;
+
+	if (item_type != BTRFS_DIR_ITEM_KEY) {
+		if (backref->found_dir_index || backref->found_back_ref ||
+		    backref->found_forward_ref) {
+			if (backref->index != index)
+				backref->errors |= REF_ERR_INDEX_UNMATCH;
+		} else {
+			backref->index = index;
+		}
+	}
+
+	if (item_type == BTRFS_DIR_ITEM_KEY) {
+		backref->found_dir_item = 1;
+		backref->reachable = 1;
+		rec->found_ref++;
+	} else if (item_type == BTRFS_DIR_INDEX_KEY) {
+		backref->found_dir_index = 1;
+	} else if (item_type == BTRFS_ROOT_REF_KEY) {
+		if (backref->found_forward_ref)
+			backref->errors |= REF_ERR_DUP_ROOT_REF;
+		backref->found_forward_ref = 1;
+	} else if (item_type == BTRFS_ROOT_BACKREF_KEY) {
+		if (backref->found_back_ref)
+			backref->errors |= REF_ERR_DUP_ROOT_BACKREF;
+		backref->found_back_ref = 1;
+	} else {
+		BUG_ON(1);
+	}
+
+	return 0;
+}
+
+static int merge_root_recs(struct btrfs_root *root,
+			   struct cache_tree *src_cache,
+			   struct cache_tree *dst_cache)
+{
+	struct cache_extent *cache;
+	struct ptr_node *node;
+	struct inode_record *rec;
+	struct inode_backref *backref;
+
+	if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
+		free_inode_recs(src_cache);
+		return 0;
+	}
+
+	while (1) {
+		cache = find_first_cache_extent(src_cache, 0);
+		if (!cache)
+			break;
+		node = container_of(cache, struct ptr_node, cache);
+		rec = node->data;
+		remove_cache_extent(src_cache, &node->cache);
+		free(node);
+
+		list_for_each_entry(backref, &rec->backrefs, list) {
+			BUG_ON(backref->found_inode_ref);
+			if (backref->found_dir_item)
+				add_root_backref(dst_cache, rec->ino,
+					root->root_key.objectid, backref->dir,
+					backref->index, backref->name,
+					backref->namelen, BTRFS_DIR_ITEM_KEY,
+					backref->errors);
+			if (backref->found_dir_index)
+				add_root_backref(dst_cache, rec->ino,
+					root->root_key.objectid, backref->dir,
+					backref->index, backref->name,
+					backref->namelen, BTRFS_DIR_INDEX_KEY,
+					backref->errors);
+		}
+		free_inode_rec(rec);
+	}
+	return 0;
+}
+
+static int check_root_refs(struct btrfs_root *root,
+			   struct cache_tree *root_cache)
+{
+	struct root_record *rec;
+	struct root_record *ref_root;
+	struct root_backref *backref;
+	struct cache_extent *cache;
+	int loop = 1;
+	int ret;
+	int error;
+	int errors = 0;
+
+	rec = get_root_rec(root_cache, BTRFS_FS_TREE_OBJECTID);
+	rec->found_ref = 1;
+
+	/* fixme: this can not detect circular references */
+	while (loop) {
+		loop = 0;
+		cache = find_first_cache_extent(root_cache, 0);
+		while (1) {
+			if (!cache)
+				break;
+			rec = container_of(cache, struct root_record, cache);
+			cache = next_cache_extent(cache);
+
+			if (rec->found_ref == 0)
+				continue;
+
+			list_for_each_entry(backref, &rec->backrefs, list) {
+				if (!backref->reachable)
+					continue;
+
+				ref_root = get_root_rec(root_cache,
+							backref->ref_root);
+				if (ref_root->found_ref > 0)
+					continue;
+
+				backref->reachable = 0;
+				rec->found_ref--;
+				if (rec->found_ref == 0)
+					loop = 1;
+			}
+		}
+	}
+
+	cache = find_first_cache_extent(root_cache, 0);
+	while (1) {
+		if (!cache)
+			break;
+		rec = container_of(cache, struct root_record, cache);
+		cache = next_cache_extent(cache);
+
+		if (rec->found_ref == 0 &&
+		    rec->objectid >= BTRFS_FIRST_FREE_OBJECTID &&
+		    rec->objectid <= BTRFS_LAST_FREE_OBJECTID) {
+			ret = check_orphan_item(root->fs_info->tree_root,
+						rec->objectid);
+			if (ret == 0)
+				continue;
+			errors++;
+			fprintf(stderr, "fs tree %llu not referenced\n",
+				(unsigned long long)rec->objectid);
+		}
+
+		error = 0;
+		if (rec->found_ref > 0 && !rec->found_root_item)
+			error = 1;
+		list_for_each_entry(backref, &rec->backrefs, list) {
+			if (!backref->found_dir_item)
+				backref->errors |= REF_ERR_NO_DIR_ITEM;
+			if (!backref->found_dir_index)
+				backref->errors |= REF_ERR_NO_DIR_INDEX;
+			if (!backref->found_back_ref)
+				backref->errors |= REF_ERR_NO_ROOT_BACKREF;
+			if (!backref->found_forward_ref)
+				backref->errors |= REF_ERR_NO_ROOT_REF;
+			if (backref->reachable && backref->errors)
+				error = 1;
+		}
+		if (!error)
+			continue;
+
+		errors++;
+		fprintf(stderr, "fs tree %llu refs %u %s\n",
+			(unsigned long long)rec->objectid, rec->found_ref,
+			 rec->found_root_item ? "" : "not found");
+
+		list_for_each_entry(backref, &rec->backrefs, list) {
+			if (!backref->reachable)
+				continue;
+			if (!backref->errors && rec->found_root_item)
+				continue;
+			fprintf(stderr, "\tunresolved ref root %llu dir %llu"
+				" index %llu namelen %u name %s error %x\n",
+				(unsigned long long)backref->ref_root,
+				(unsigned long long)backref->dir,
+				(unsigned long long)backref->index,
+				backref->namelen, backref->name,
+				backref->errors);
+		}
+	}
+	return errors > 0 ? 1 : 0;
+}
+
+static int process_root_ref(struct extent_buffer *eb, int slot,
+			    struct btrfs_key *key,
+			    struct cache_tree *root_cache)
+{
+	u64 dirid;
+	u64 index;
+	u32 len;
+	u32 name_len;
+	struct btrfs_root_ref *ref;
+	char namebuf[BTRFS_NAME_LEN];
+	int error;
+
+	ref = btrfs_item_ptr(eb, slot, struct btrfs_root_ref);
+
+	dirid = btrfs_root_ref_dirid(eb, ref);
+	index = btrfs_root_ref_sequence(eb, ref);
+	name_len = btrfs_root_ref_name_len(eb, ref);
+
+	if (name_len <= BTRFS_NAME_LEN) {
+		len = name_len;
+		error = 0;
+	} else {
+		len = BTRFS_NAME_LEN;
+		error = REF_ERR_NAME_TOO_LONG;
+	}
+	read_extent_buffer(eb, namebuf, (unsigned long)(ref + 1), len);
+
+	if (key->type == BTRFS_ROOT_REF_KEY) {
+		add_root_backref(root_cache, key->offset, key->objectid, dirid,
+				 index, namebuf, len, key->type, error);
+	} else {
+		add_root_backref(root_cache, key->objectid, key->offset, dirid,
+				 index, namebuf, len, key->type, error);
+	}
+	return 0;
+}
+
 static int check_fs_root(struct btrfs_root *root,
+			 struct cache_tree *root_cache,
 			 struct walk_control *wc)
 {
 	int ret = 0;
@@ -1219,10 +1579,18 @@
 	int level;
 	struct btrfs_path path;
 	struct shared_node root_node;
+	struct root_record *rec;
 	struct btrfs_root_item *root_item = &root->root_item;
 
+	if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
+		rec = get_root_rec(root_cache, root->root_key.objectid);
+		if (btrfs_root_refs(root_item) > 0)
+			rec->found_root_item = 1;
+	}
+
 	btrfs_init_path(&path);
 	memset(&root_node, 0, sizeof(root_node));
+	cache_tree_init(&root_node.root_cache);
 	cache_tree_init(&root_node.inode_cache);
 
 	level = btrfs_header_level(root->node);
@@ -1266,6 +1634,8 @@
 	}
 	btrfs_release_path(root, &path);
 
+	merge_root_recs(root, &root_node.root_cache, root_cache);
+
 	if (root_node.current) {
 		root_node.current->checked = 1;
 		maybe_free_inode_rec(&root_node.inode_cache,
@@ -1280,13 +1650,15 @@
 {
 	if (objectid == BTRFS_FS_TREE_OBJECTID ||
 	    objectid == BTRFS_TREE_RELOC_OBJECTID ||
+	    objectid == BTRFS_DATA_RELOC_TREE_OBJECTID ||
 	    (objectid >= BTRFS_FIRST_FREE_OBJECTID &&
-	     objectid < BTRFS_LAST_FREE_OBJECTID))
+	     objectid <= BTRFS_LAST_FREE_OBJECTID))
 		return 1;
 	return 0;
 }
 
-static int check_fs_roots(struct btrfs_root *root)
+static int check_fs_roots(struct btrfs_root *root,
+			  struct cache_tree *root_cache)
 {
 	struct btrfs_path path;
 	struct btrfs_key key;
@@ -1319,10 +1691,14 @@
 		    fs_root_objectid(key.objectid)) {
 			tmp_root = btrfs_read_fs_root_no_cache(root->fs_info,
 							       &key);
-			ret = check_fs_root(tmp_root, &wc);
+			ret = check_fs_root(tmp_root, root_cache, &wc);
 			if (ret)
 				err = 1;
 			btrfs_free_fs_root(root->fs_info, tmp_root);
+		} else if (key.type == BTRFS_ROOT_REF_KEY ||
+			   key.type == BTRFS_ROOT_BACKREF_KEY) {
+			process_root_ref(leaf, path.slots[0], &key,
+					 root_cache);
 		}
 		path.slots[0]++;
 	}
@@ -1895,7 +2271,6 @@
 	return 0;
 }
 
-
 static int add_pending(struct cache_tree *pending,
 		       struct cache_tree *seen, u64 bytenr, u32 size)
 {
@@ -2443,14 +2818,45 @@
 
 int main(int ac, char **av)
 {
+	struct cache_tree root_cache;
 	struct btrfs_root *root;
+	u64 bytenr = 0;
 	int ret;
+	int num;
 
-	if (ac < 2)
+	while(1) {
+		int c;
+		c = getopt(ac, av, "s:");
+		if (c < 0)
+			break;
+		switch(c) {
+			case 's':
+				num = atol(optarg);
+				bytenr = btrfs_sb_offset(num);
+				printf("using SB copy %d, bytenr %llu\n", num,
+				       (unsigned long long)bytenr);
+				break;
+			default:
+				print_usage();
+		}
+	}
+	ac = ac - optind;
+
+	if (ac != 1)
 		print_usage();
 
 	radix_tree_init();
-	root = open_ctree(av[1], 0, 0);
+	cache_tree_init(&root_cache);
+
+	if((ret = check_mounted(av[optind])) < 0) {
+		fprintf(stderr, "Could not check mount status: %s\n", strerror(ret));
+		return ret;
+	} else if(ret) {
+		fprintf(stderr, "%s is currently mounted. Aborting.\n", av[optind]);
+		return -EBUSY;
+	}
+
+	root = open_ctree(av[optind], bytenr, 0);
 
 	if (root == NULL)
 		return 1;
@@ -2458,10 +2864,15 @@
 	ret = check_extents(root);
 	if (ret)
 		goto out;
-	ret = check_fs_roots(root);
+	ret = check_fs_roots(root, &root_cache);
+	if (ret)
+		goto out;
 
+	ret = check_root_refs(root, &root_cache);
 out:
+	free_root_recs(&root_cache);
 	close_ctree(root);
+
 	if (found_old_backref) {
 		/*
 		 * there was a disk format change when mixed
diff -aNur a/btrfsctl.c b/btrfsctl.c
--- a/btrfsctl.c	2009-06-12 00:56:15.000000000 +0800
+++ b/btrfsctl.c	2011-03-22 16:32:44.607948115 +0800
@@ -29,6 +29,7 @@
 #include <unistd.h>
 #include <dirent.h>
 #include <libgen.h>
+#include <stdlib.h>
 #include "kerncompat.h"
 #include "ctree.h"
 #include "transaction.h"
@@ -46,7 +47,7 @@
 static void print_usage(void)
 {
 	printf("usage: btrfsctl [ -d file|dir] [ -s snap_name subvol|tree ]\n");
-	printf("                [-r size] [-A device] [-a] [-c]\n");
+	printf("                [-r size] [-A device] [-a] [-c] [-D dir .]\n");
 	printf("\t-d filename: defragments one file\n");
 	printf("\t-d directory: defragments the entire Btree\n");
 	printf("\t-s snap_name dir: creates a new snapshot of dir\n");
@@ -55,6 +56,9 @@
 	printf("\t-A device: scans the device file for a Btrfs filesystem\n");
 	printf("\t-a: scans all devices for Btrfs filesystems\n");
 	printf("\t-c: forces a single FS sync\n");
+	printf("\t-D: delete snapshot\n");
+	printf("\t-m [tree id] directory: set the default mounted subvolume"
+	       " to the [tree id] or the directory\n");
 	printf("%s\n", BTRFS_BUILD_VERSION);
 	exit(1);
 }
@@ -99,7 +103,9 @@
 	int i;
 	unsigned long command = 0;
 	int len;
+	char *pos;
 	char *fullpath;
+	u64 objectid = 0;
 
 	if (ac == 2 && strcmp(av[1], "-a") == 0) {
 		fprintf(stderr, "Scanning for Btrfs filesystems\n");
@@ -158,6 +164,28 @@
 				print_usage();
 			}
 			command = BTRFS_IOC_DEFRAG;
+		} else if (strcmp(av[i], "-D") == 0) {
+			if (i >= ac - 1) {
+				fprintf(stderr, "-D requires an arg\n");
+				print_usage();
+			}
+			command = BTRFS_IOC_SNAP_DESTROY;
+			name = av[i + 1];
+			len = strlen(name);
+			pos = strchr(name, '/');
+			if (pos) {
+				if (*(pos + 1) == '\0')
+					*(pos) = '\0';
+				else {
+					fprintf(stderr,
+						"error: / not allowed in names\n");
+					exit(1);
+				}
+			}
+			if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
+				fprintf(stderr, "-D size too long\n");
+				exit(1);
+			}
 		} else if (strcmp(av[i], "-A") == 0) {
 			if (i >= ac - 1) {
 				fprintf(stderr, "-A requires an arg\n");
@@ -178,6 +206,16 @@
 			command = BTRFS_IOC_RESIZE;
 		} else if (strcmp(av[i], "-c") == 0) {
 			command = BTRFS_IOC_SYNC;
+		} else if (strcmp(av[i], "-m") == 0) {
+			command = BTRFS_IOC_DEFAULT_SUBVOL;
+			if (i == ac - 3) {
+				objectid = (unsigned long long)
+					    strtoll(av[i + 1], NULL, 0);
+				if (errno == ERANGE) {
+					fprintf(stderr, "invalid tree id\n");
+					exit(1);
+				}
+			}
 		}
 	}
 	if (command == 0) {
@@ -206,6 +244,9 @@
 	if (command == BTRFS_IOC_SNAP_CREATE) {
 		args.fd = fd;
 		ret = ioctl(snap_fd, command, &args);
+	} else if (command == BTRFS_IOC_DEFAULT_SUBVOL) {
+		printf("objectid is %llu\n", objectid);
+		ret = ioctl(fd, command, &objectid);
 	} else
 		ret = ioctl(fd, command, &args);
 	if (ret < 0) {
@@ -219,8 +260,8 @@
 	}
 	printf("%s\n", BTRFS_BUILD_VERSION);
 	if (ret)
-		exit(0);
-	else
 		exit(1);
+
+	return 0;
 }
 
diff -aNur a/convert.c b/convert.c
--- a/convert.c	2009-06-12 00:56:15.000000000 +0800
+++ b/convert.c	2011-03-22 16:32:44.608948115 +0800
@@ -370,7 +370,6 @@
 	struct btrfs_extent_item *ei;
 	u32 blocksize = root->sectorsize;
 	u64 nbytes;
-	u64 bytes_used;
 
 	if (disk_bytenr == 0) {
 		ret = btrfs_insert_file_extent(trans, root, objectid,
@@ -432,9 +431,6 @@
 	nbytes = btrfs_stack_inode_nbytes(inode) + num_bytes;
 	btrfs_set_stack_inode_nbytes(inode, nbytes);
 
-	bytes_used = btrfs_root_used(&root->root_item);
-	btrfs_set_root_used(&root->root_item, bytes_used + num_bytes);
-
 	btrfs_release_path(root, &path);
 
 	ins_key.objectid = disk_bytenr;
@@ -454,9 +450,6 @@
 
 		btrfs_mark_buffer_dirty(leaf);
 
-		bytes_used = btrfs_super_bytes_used(&info->super_copy);
-		btrfs_set_super_bytes_used(&info->super_copy, bytes_used +
-					   num_bytes);
 		ret = btrfs_update_block_group(trans, root, disk_bytenr,
 					       num_bytes, 1, 0);
 		if (ret)
diff -aNur a/ctree.h b/ctree.h
--- a/ctree.h	2009-06-12 00:56:15.000000000 +0800
+++ b/ctree.h	2011-03-22 16:32:44.614948115 +0800
@@ -350,11 +350,13 @@
  * ones specified below then we will fail to mount
  */
 #define BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF	(1ULL << 0)
+#define BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL	(2ULL << 0)
 
 #define BTRFS_FEATURE_COMPAT_SUPP		0ULL
 #define BTRFS_FEATURE_COMPAT_RO_SUPP		0ULL
 #define BTRFS_FEATURE_INCOMPAT_SUPP		\
-	BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF
+	(BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF |	\
+	 BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)
 
 /*
  * A leaf is full of items. offset and size tell us where to find
@@ -1047,6 +1049,7 @@
 
 /* struct btrfs_inode_ref */
 BTRFS_SETGET_FUNCS(inode_ref_name_len, struct btrfs_inode_ref, name_len, 16);
+BTRFS_SETGET_STACK_FUNCS(stack_inode_ref_name_len, struct btrfs_inode_ref, name_len, 16);
 BTRFS_SETGET_FUNCS(inode_ref_index, struct btrfs_inode_ref, index, 64);
 
 /* struct btrfs_inode_item */
@@ -1325,6 +1328,10 @@
 BTRFS_SETGET_FUNCS(root_ref_sequence, struct btrfs_root_ref, sequence, 64);
 BTRFS_SETGET_FUNCS(root_ref_name_len, struct btrfs_root_ref, name_len, 16);
 
+BTRFS_SETGET_STACK_FUNCS(stack_root_ref_dirid, struct btrfs_root_ref, dirid, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_root_ref_sequence, struct btrfs_root_ref, sequence, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_root_ref_name_len, struct btrfs_root_ref, name_len, 16);
+
 /* struct btrfs_dir_item */
 BTRFS_SETGET_FUNCS(dir_data_len, struct btrfs_dir_item, data_len, 16);
 BTRFS_SETGET_FUNCS(dir_type, struct btrfs_dir_item, type, 8);
@@ -1572,6 +1579,7 @@
 
 /* struct btrfs_file_extent_item */
 BTRFS_SETGET_FUNCS(file_extent_type, struct btrfs_file_extent_item, type, 8);
+BTRFS_SETGET_STACK_FUNCS(stack_file_extent_type, struct btrfs_file_extent_item, type, 8);
 
 static inline unsigned long btrfs_file_extent_inline_start(struct
 						   btrfs_file_extent_item *e)
@@ -1588,18 +1596,30 @@
 
 BTRFS_SETGET_FUNCS(file_extent_disk_bytenr, struct btrfs_file_extent_item,
 		   disk_bytenr, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_file_extent_disk_bytenr, struct btrfs_file_extent_item,
+		   disk_bytenr, 64);
 BTRFS_SETGET_FUNCS(file_extent_generation, struct btrfs_file_extent_item,
 		   generation, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_file_extent_generation, struct btrfs_file_extent_item,
+		   generation, 64);
 BTRFS_SETGET_FUNCS(file_extent_disk_num_bytes, struct btrfs_file_extent_item,
 		   disk_num_bytes, 64);
 BTRFS_SETGET_FUNCS(file_extent_offset, struct btrfs_file_extent_item,
 		  offset, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_file_extent_offset, struct btrfs_file_extent_item,
+		  offset, 64);
 BTRFS_SETGET_FUNCS(file_extent_num_bytes, struct btrfs_file_extent_item,
 		   num_bytes, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_file_extent_num_bytes, struct btrfs_file_extent_item,
+		   num_bytes, 64);
 BTRFS_SETGET_FUNCS(file_extent_ram_bytes, struct btrfs_file_extent_item,
 		   ram_bytes, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_file_extent_ram_bytes, struct btrfs_file_extent_item,
+		   ram_bytes, 64);
 BTRFS_SETGET_FUNCS(file_extent_compression, struct btrfs_file_extent_item,
 		   compression, 8);
+BTRFS_SETGET_STACK_FUNCS(stack_file_extent_compression, struct btrfs_file_extent_item,
+		   compression, 8);
 BTRFS_SETGET_FUNCS(file_extent_encryption, struct btrfs_file_extent_item,
 		   encryption, 8);
 BTRFS_SETGET_FUNCS(file_extent_other_encoding, struct btrfs_file_extent_item,
diff -aNur a/debug-tree.c b/debug-tree.c
--- a/debug-tree.c	2009-06-12 00:56:15.000000000 +0800
+++ b/debug-tree.c	2011-03-22 16:32:44.614948115 +0800
@@ -116,19 +116,27 @@
 	int ret;
 	int slot;
 	int extent_only = 0;
+	int device_only = 0;
+	u64 block_only = 0;
 	struct btrfs_root *tree_root_scan;
 
 	radix_tree_init();
 
 	while(1) {
 		int c;
-		c = getopt(ac, av, "e");
+		c = getopt(ac, av, "deb:");
 		if (c < 0)
 			break;
 		switch(c) {
 			case 'e':
 				extent_only = 1;
 				break;
+			case 'd':
+				device_only = 1;
+				break;
+			case 'b':
+				block_only = atoll(optarg);
+				break;
 			default:
 				print_usage();
 		}
@@ -142,14 +150,37 @@
 		fprintf(stderr, "unable to open %s\n", av[optind]);
 		exit(1);
 	}
+	if (block_only) {
+		leaf = read_tree_block(root,
+				      block_only,
+				      root->leafsize, 0);
+
+		if (leaf && btrfs_header_level(leaf) != 0) {
+			free_extent_buffer(leaf);
+			leaf = NULL;
+		}
+
+		if (!leaf) {
+			leaf = read_tree_block(root,
+					      block_only,
+					      root->nodesize, 0);
+		}
+		if (!leaf) {
+			fprintf(stderr, "failed to read %llu\n", block_only);
+			return 0;
+		}
+		btrfs_print_tree(root, leaf, 0);
+		return 0;
+	}
+
 	if (!extent_only) {
 		printf("root tree\n");
 		btrfs_print_tree(root->fs_info->tree_root,
-				 root->fs_info->tree_root->node);
+				 root->fs_info->tree_root->node, 1);
 
 		printf("chunk tree\n");
 		btrfs_print_tree(root->fs_info->chunk_root,
-				 root->fs_info->chunk_root->node);
+				 root->fs_info->chunk_root->node, 1);
 	}
 	tree_root_scan = root->fs_info->tree_root;
 
@@ -175,7 +206,7 @@
 		if (btrfs_key_type(&found_key) == BTRFS_ROOT_ITEM_KEY) {
 			unsigned long offset;
 			struct extent_buffer *buf;
-			int skip = extent_only;
+			int skip = extent_only | device_only;
 
 			offset = btrfs_item_ptr_offset(leaf, slot);
 			read_extent_buffer(leaf, &ri, offset, sizeof(ri));
@@ -188,8 +219,9 @@
 					printf("root");
 				break;
 			case BTRFS_EXTENT_TREE_OBJECTID:
-				skip = 0;
-				if (!extent_only)
+				if (!device_only)
+					skip = 0;
+				if (!extent_only && !device_only)
 					printf("extent");
 				break;
 			case BTRFS_CHUNK_TREE_OBJECTID:
@@ -198,9 +230,8 @@
 				}
 				break;
 			case BTRFS_DEV_TREE_OBJECTID:
-				if (!skip) {
-					printf("device");
-				}
+				skip = 0;
+				printf("device");
 				break;
 			case BTRFS_FS_TREE_OBJECTID:
 				if (!skip) {
@@ -208,9 +239,8 @@
 				}
 				break;
 			case BTRFS_ROOT_TREE_DIR_OBJECTID:
-				if (!skip) {
-					printf("directory");
-				}
+				skip = 0;
+				printf("directory");
 				break;
 			case BTRFS_CSUM_TREE_OBJECTID:
 				if (!skip) {
@@ -256,13 +286,13 @@
 					printf("file");
 				}
 			}
-			if (!skip && !extent_only) {
+			if (extent_only && !skip) {
+				print_extents(tree_root_scan, buf);
+			} else if (!skip) {
 				printf(" tree ");
 				btrfs_print_key(&disk_key);
 				printf(" \n");
-				btrfs_print_tree(tree_root_scan, buf);
-			} else if (extent_only && !skip) {
-				print_extents(tree_root_scan, buf);
+				btrfs_print_tree(tree_root_scan, buf, 1);
 			}
 		}
 		path.slots[0]++;
@@ -275,7 +305,7 @@
 		goto again;
 	}
 
-	if (extent_only)
+	if (extent_only || device_only)
 		return 0;
 
 	printf("total bytes %llu\n",
diff -aNur a/dir-test.c b/dir-test.c
--- a/dir-test.c	2009-06-12 00:56:15.000000000 +0800
+++ b/dir-test.c	2011-03-22 16:32:44.615948115 +0800
@@ -485,7 +485,7 @@
 			if (ret) {
 				fprintf(stderr, "op %d failed %d:%d\n",
 					op, i, iterations);
-				btrfs_print_tree(root, root->node);
+				btrfs_print_tree(root, root->node, 1);
 				fprintf(stderr, "op %d failed %d:%d\n",
 					op, i, iterations);
 				err = ret;
diff -aNur a/disk-io.c b/disk-io.c
--- a/disk-io.c	2009-06-12 00:56:15.000000000 +0800
+++ b/disk-io.c	2011-03-22 16:32:44.616948115 +0800
@@ -86,7 +86,7 @@
 		if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
 			printk("checksum verify failed on %llu wanted %X "
 			       "found %X\n", (unsigned long long)buf->start,
-			       *((int *)result), *((int *)buf));
+			       *((int *)result), *((char *)buf->data));
 			free(result);
 			return 1;
 		}
@@ -970,13 +970,13 @@
 	if (fs_info->csum_root->node)
 		free_extent_buffer(fs_info->csum_root->node);
 
-	if (root->fs_info->log_root_tree) {
-		if (root->fs_info->log_root_tree->node)
-			free_extent_buffer(root->fs_info->log_root_tree->node);
-		free(root->fs_info->log_root_tree);
+	if (fs_info->log_root_tree) {
+		if (fs_info->log_root_tree->node)
+			free_extent_buffer(fs_info->log_root_tree->node);
+		free(fs_info->log_root_tree);
 	}
 
-	close_all_devices(root->fs_info);
+	close_all_devices(fs_info);
 	extent_io_tree_cleanup(&fs_info->extent_cache);
 	extent_io_tree_cleanup(&fs_info->free_space_cache);
 	extent_io_tree_cleanup(&fs_info->block_group_cache);
diff -aNur a/ioctl-test.c b/ioctl-test.c
--- a/ioctl-test.c	1970-01-01 07:00:00.000000000 +0700
+++ b/ioctl-test.c	2011-03-22 16:32:44.626948115 +0800
@@ -0,0 +1,36 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "kerncompat.h"
+#include "ioctl.h"
+
+unsigned long ioctls[] = {
+	BTRFS_IOC_SNAP_CREATE,
+	BTRFS_IOC_DEFRAG,
+	BTRFS_IOC_RESIZE,
+	BTRFS_IOC_SCAN_DEV,
+	BTRFS_IOC_TRANS_START,
+	BTRFS_IOC_TRANS_END,
+	BTRFS_IOC_SYNC,
+	BTRFS_IOC_CLONE,
+	BTRFS_IOC_ADD_DEV,
+	BTRFS_IOC_RM_DEV,
+	BTRFS_IOC_BALANCE,
+	BTRFS_IOC_SUBVOL_CREATE,
+	BTRFS_IOC_SNAP_DESTROY,
+	BTRFS_IOC_DEFRAG_RANGE,
+	BTRFS_IOC_TREE_SEARCH,
+	BTRFS_IOC_INO_LOOKUP,
+	BTRFS_IOC_DEFAULT_SUBVOL,
+	BTRFS_IOC_SPACE_INFO,
+	0 };
+
+int main(int ac, char **av)
+{
+	int i = 0;
+	while(ioctls[i]) {
+		printf("%lu\n" ,ioctls[i]);
+		i++;
+	}
+	return 0;
+}
+
diff -aNur a/ioctl.h b/ioctl.h
--- a/ioctl.h	2009-06-12 00:56:15.000000000 +0800
+++ b/ioctl.h	2011-03-22 16:32:44.627948115 +0800
@@ -30,6 +30,108 @@
 	char name[BTRFS_PATH_NAME_MAX + 1];
 };
 
+struct btrfs_ioctl_search_key {
+	/* which root are we searching.  0 is the tree of tree roots */
+	__u64 tree_id;
+
+	/* keys returned will be >= min and <= max */
+	__u64 min_objectid;
+	__u64 max_objectid;
+
+	/* keys returned will be >= min and <= max */
+	__u64 min_offset;
+	__u64 max_offset;
+
+	/* max and min transids to search for */
+	__u64 min_transid;
+	__u64 max_transid;
+
+	/* keys returned will be >= min and <= max */
+	__u32 min_type;
+	__u32 max_type;
+
+	/*
+	 * how many items did userland ask for, and how many are we
+	 * returning
+	 */
+	__u32 nr_items;
+
+	/* align to 64 bits */
+	__u32 unused;
+
+	/* some extra for later */
+	__u64 unused1;
+	__u64 unused2;
+	__u64 unused3;
+	__u64 unused4;
+};
+
+struct btrfs_ioctl_search_header {
+	__u64 transid;
+	__u64 objectid;
+	__u64 offset;
+	__u32 type;
+	__u32 len;
+} __attribute__((may_alias));
+
+#define BTRFS_SEARCH_ARGS_BUFSIZE (4096 - sizeof(struct btrfs_ioctl_search_key))
+/*
+ * the buf is an array of search headers where
+ * each header is followed by the actual item
+ * the type field is expanded to 32 bits for alignment
+ */
+struct btrfs_ioctl_search_args {
+	struct btrfs_ioctl_search_key key;
+	char buf[BTRFS_SEARCH_ARGS_BUFSIZE];
+};
+
+#define BTRFS_INO_LOOKUP_PATH_MAX 4080
+struct btrfs_ioctl_ino_lookup_args {
+	__u64 treeid;
+	__u64 objectid;
+	char name[BTRFS_INO_LOOKUP_PATH_MAX];
+};
+
+/* flags for the defrag range ioctl */
+#define BTRFS_DEFRAG_RANGE_COMPRESS 1
+#define BTRFS_DEFRAG_RANGE_START_IO 2
+
+struct btrfs_ioctl_defrag_range_args {
+	/* start of the defrag operation */
+	__u64 start;
+
+	/* number of bytes to defrag, use (u64)-1 to say all */
+	__u64 len;
+
+	/*
+	 * flags for the operation, which can include turning
+	 * on compression for this one defrag
+	 */
+	__u64 flags;
+
+	/*
+	 * any extent bigger than this will be considered
+	 * already defragged.  Use 0 to take the kernel default
+	 * Use 1 to say every single extent must be rewritten
+	 */
+	__u32 extent_thresh;
+
+	/* spare for later */
+	__u32 unused[5];
+};
+
+struct btrfs_ioctl_space_info {
+	__u64 flags;
+	__u64 total_bytes;
+	__u64 used_bytes;
+};
+
+struct btrfs_ioctl_space_args {
+	__u64 space_slots;
+	__u64 total_spaces;
+	struct btrfs_ioctl_space_info spaces[0];
+};
+
 #define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
 				   struct btrfs_ioctl_vol_args)
 #define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \
@@ -56,4 +158,15 @@
 /* 13 is for CLONE_RANGE */
 #define BTRFS_IOC_SUBVOL_CREATE _IOW(BTRFS_IOCTL_MAGIC, 14, \
 				   struct btrfs_ioctl_vol_args)
+#define BTRFS_IOC_SNAP_DESTROY _IOW(BTRFS_IOCTL_MAGIC, 15, \
+				   struct btrfs_ioctl_vol_args)
+#define BTRFS_IOC_DEFRAG_RANGE _IOW(BTRFS_IOCTL_MAGIC, 16, \
+				struct btrfs_ioctl_defrag_range_args)
+#define BTRFS_IOC_TREE_SEARCH _IOWR(BTRFS_IOCTL_MAGIC, 17, \
+				   struct btrfs_ioctl_search_args)
+#define BTRFS_IOC_INO_LOOKUP _IOWR(BTRFS_IOCTL_MAGIC, 18, \
+				   struct btrfs_ioctl_ino_lookup_args)
+#define BTRFS_IOC_DEFAULT_SUBVOL _IOW(BTRFS_IOCTL_MAGIC, 19, u64)
+#define BTRFS_IOC_SPACE_INFO _IOWR(BTRFS_IOCTL_MAGIC, 20, \
+				    struct btrfs_ioctl_space_args)
 #endif
diff -aNur a/kerncompat.h b/kerncompat.h
--- a/kerncompat.h	2009-06-12 00:56:15.000000000 +0800
+++ b/kerncompat.h	2011-03-22 16:32:44.627948115 +0800
@@ -42,7 +42,11 @@
 #define GFP_NOFS 0
 #define __read_mostly
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+
+#ifndef ULONG_MAX
 #define ULONG_MAX       (~0UL)
+#endif
+
 #define BUG() abort()
 #ifdef __CHECKER__
 #define __force    __attribute__((force))
diff -aNur a/man/Makefile b/man/Makefile
--- a/man/Makefile	2009-06-12 00:56:15.000000000 +0800
+++ b/man/Makefile	2011-03-22 16:32:44.630948115 +0800
@@ -7,13 +7,16 @@
 man8dir = $(mandir)/man8
 
 MANPAGES = mkfs.btrfs.8.gz btrfsctl.8.gz btrfsck.8.gz btrfs-image.8.gz \
-	   btrfs-show.8.gz
+	   btrfs-show.8.gz btrfs.8.gz
 
 all: $(MANPAGES)
 
 mkfs.btrfs.8.gz: mkfs.btrfs.8.in
 	$(GZIP) -n -c mkfs.btrfs.8.in > mkfs.btrfs.8.gz
 
+btrfs.8.gz: btrfs.8.in
+	$(GZIP) -n -c btrfs.8.in > btrfs.8.gz
+
 btrfsctl.8.gz: btrfsctl.8.in
 	$(GZIP) -n -c btrfsctl.8.in > btrfsctl.8.gz
 
diff -aNur a/man/btrfs.8.in b/man/btrfs.8.in
--- a/man/btrfs.8.in	1970-01-01 07:00:00.000000000 +0700
+++ b/man/btrfs.8.in	2011-03-22 16:32:44.632948115 +0800
@@ -0,0 +1,170 @@
+.TH BTRFS 8 "" "btrfs" "btrfs"
+.\"
+.\" Man page written by Goffredo Baroncelli <kreijack@inwind.it> (Feb 2010)
+.\"
+.SH NAME
+btrfs \- control a btrfs filesystem
+.SH SYNOPSIS
+\fBbtrfs\fP \fBsubvolume snapshot\fP\fI <source> [<dest>/]<name>\fP
+.PP
+\fBbtrfs\fP \fBsubvolume delete\fP\fI <subvolume>\fP
+.PP
+\fBbtrfs\fP \fBsubvolume create\fP\fI [<dest>/]<name>\fP
+.PP
+\fBbtrfs\fP \fBsubvolume list\fP\fI <path>\fP
+.PP
+\fBbtrfs\fP \fBsubvolume set-default\fP\fI <id> <path>\fP
+.PP
+\fBbtrfs\fP \fBfilesystem defrag\fP\fI <file>|<dir> [<file>|<dir>...]\fP
+.PP
+\fBbtrfs\fP \fBfilesystem sync\fP\fI <path> \fP
+.PP
+\fBbtrfs\fP \fBfilesystem resize\fP\fI [+/\-]<size>[gkm]|max <filesystem>\fP
+.PP
+\fBbtrfs\fP \fBdevice scan\fP\fI [<device> [<device>..]]\fP
+.PP
+\fBbtrfs\fP \fBdevice show\fP\fI <dev>|<label> [<dev>|<label>...]\fP
+.PP
+\fBbtrfs\fP \fBdevice balance\fP\fI <path> \fP
+.PP
+\fBbtrfs\fP \fBdevice add\fP\fI <dev> [<dev>..] <path> \fP
+.PP
+\fBbtrfs\fP \fBdevice delete\fP\fI <dev> [<dev>..] <path> \fP]
+
+.PP
+\fBbtrfs\fP \fBhelp|\-\-help|\-h \fP\fI\fP
+.PP
+.SH DESCRIPTION
+.B btrfs
+is used to control the filesystem and the files and directories stored. It is
+the tool to create or destroy a snapshot or a subvolume for the
+filesystem, to defrag a file or a directory, flush the data to the disk,
+to resize the filesystem, to scan the device.
+
+It is possible to abbreviate the commands unless the commands  are ambiguous.
+For example: it is possible to run
+.I btrfs sub snaps
+instead of
+.I btrfs subvolume snapshot.
+But
+.I btrfs dev s
+is not allowed, because
+.I dev s
+may be interpreted both as
+.I device show
+and as
+.I device scan.
+In this case
+.I btrfs
+returns an error.
+
+If a command is terminated by
+.I --help
+, the relevant help is showed. If the passed command matches more commands,
+the help of all the matched commands are showed. For example
+.I btrfs dev --help
+shows the help of all
+.I device*
+command.
+
+.SH COMMANDS
+.TP
+
+\fBsubvolume snapshot\fR\fI <source> [<dest>/]<name>\fR
+Create a writable snapshot of the subvolume \fI<source>\fR with the name
+\fI<name>\fR in the \fI<dest>\fR directory. If \fI<source>\fR is not a
+subvolume, \fBbtrfs\fR returns an error.
+.TP
+
+\fBsubvolume delete\fR\fI <subvolume>\fR
+Delete the subvolume \fI<subvolume>\fR. If \fI<subvolume>\fR is not a
+subvolume, \fBbtrfs\fR returns an error.
+.TP
+
+\fBsubvolume create\fR\fI [<dest>/]<name>\fR
+Create a subvolume in \fI<dest>\fR (or in the current directory if
+\fI<dest>\fR is omitted).
+.TP
+
+\fBsubvolume list\fR\fI <path>\fR
+List the subvolumes present in the filesystem \fI<path>\fR. For every
+subvolume is showed the subvolume ID (second column), 
+the ID of the \fItop level\fR 
+subvolume (fifth column), and the path (seventh column) relative to the
+\fItop level\fR subvolume.
+These <ID> may be used by the \fBsubvolume set-default\fR command, or at
+mount time via the \fIsubvol=\fR option.
+.TP
+
+\fBsubvolume set-default\fR\fI <id> <path>\fR
+Set the subvolume of the filesystem \fI<path>\fR which is mounted as 
+\fIdefault\fR. The subvolume is identified by \fB<id>\fR, which 
+is returned by the \fBsubvolume list\fR command.
+.TP
+
+\fBfilesystem defragment\fP\fI <file>|<dir> [<file>|<dir>...]\fR
+Defragment files and/or directories.
+.TP
+
+\fBdevice scan\fR \fI[<device> [<device>..]]\fR
+Scan devices for a btrfs filesystem. If no devices are passed, \fBbtrfs\fR scans
+all the block devices.
+.TP
+
+\fBfilesystem sync\fR\fI <path> \fR
+Force a sync for the filesystem identified by \fI<path>\fR.
+.TP
+
+.\"
+.\" Some wording are extracted by the resize2fs man page
+.\"
+
+\fBfilesystem resize\fR\fI [+/\-]<size>[gkm]|max <path>\fR
+Resize a filesystem identified by \fI<path>\fR.
+The \fI<size>\fR parameter specifies the new size of the filesystem.
+If the prefix \fI+\fR or \fI\-\fR is present the size is increased or decreased
+by the quantity \fI<size>\fR.
+If no units are specified, the unit of the \fI<size>\fR parameter defaults to
+bytes. Optionally, the size parameter may be suffixed by one of the following
+the units designators: 'K', 'M', or 'G', kilobytes, megabytes, or gigabytes,
+respectively.
+
+If 'max' is passed, the filesystem will occupy all available space on the
+volume(s).
+
+The \fBresize\fR command \fBdoes not\fR manipulate the size of underlying
+partition.  If you wish to enlarge/reduce a filesystem, you must make sure you
+can expand the partition before enlarging the filesystem and shrink the
+partition after reducing the size of the filesystem.
+.TP
+
+\fBfilesystem show\fR [<uuid>|<label>]\fR
+Show the btrfs filesystem with some additional info. If no UUID or label is
+passed, \fBbtrfs\fR show info of all the btrfs filesystem.
+.TP
+
+\fBdevice balance\fR \fI<path>\fR
+Balance the chunks of the filesystem identified by \fI<path>\fR
+across the devices.
+.TP
+
+\fBdevice add\fR\fI <dev> [<dev>..] <path>\fR
+Add device(s) to the filesystem identified by \fI<path>\fR.
+.TP
+
+\fBdevice delete\fR\fI <dev> [<dev>..] <path>\fR
+Remove device(s) from a filesystem identified by \fI<path>\fR.
+.PP
+
+.SH EXIT STATUS
+\fBbtrfs\fR returns a zero exist status if it succeeds. Non zero is returned in
+case of failure.
+
+.SH AVAILABILITY
+.B btrfs
+is part of btrfs-progs. Btrfs filesystem is currently under heavy development,
+and not suitable for any uses other than benchmarking and review.
+Please refer to the btrfs wiki http://btrfs.wiki.kernel.org for
+further details.
+.SH SEE ALSO
+.BR mkfs.btrfs (8)
diff -aNur a/print-tree.c b/print-tree.c
--- a/print-tree.c	2009-06-12 00:56:15.000000000 +0800
+++ b/print-tree.c	2011-03-22 16:32:44.639948115 +0800
@@ -413,8 +413,11 @@
 		printf("MULTIPLE");
 		break;
 	case BTRFS_FIRST_CHUNK_TREE_OBJECTID:
-		printf("FIRST_CHUNK_TREE");
-		break;
+		if (type == BTRFS_CHUNK_ITEM_KEY) {
+			printf("FIRST_CHUNK_TREE");
+			break;
+		}
+		/* fall-thru */
 	default:
 		printf("%llu", objectid);
 	}
@@ -607,7 +610,7 @@
 	}
 }
 
-void btrfs_print_tree(struct btrfs_root *root, struct extent_buffer *eb)
+void btrfs_print_tree(struct btrfs_root *root, struct extent_buffer *eb, int follow)
 {
 	int i;
 	u32 nr;
@@ -643,6 +646,9 @@
 		       (unsigned long long)btrfs_node_ptr_generation(eb, i));
 		fflush(stdout);
 	}
+	if (!follow)
+		return;
+
 	for (i = 0; i < nr; i++) {
 		struct extent_buffer *next = read_tree_block(root,
 					     btrfs_node_blockptr(eb, i),
@@ -660,8 +666,7 @@
 		if (btrfs_header_level(next) !=
 			btrfs_header_level(eb) - 1)
 			BUG();
-		btrfs_print_tree(root, next);
+		btrfs_print_tree(root, next, 1);
 		free_extent_buffer(next);
 	}
 }
-
diff -aNur a/print-tree.h b/print-tree.h
--- a/print-tree.h	2009-06-12 00:56:15.000000000 +0800
+++ b/print-tree.h	2011-03-22 16:32:44.640948115 +0800
@@ -19,6 +19,6 @@
 #ifndef __PRINT_TREE_
 #define __PRINT_TREE_
 void btrfs_print_leaf(struct btrfs_root *root, struct extent_buffer *l);
-void btrfs_print_tree(struct btrfs_root *root, struct extent_buffer *t);
+void btrfs_print_tree(struct btrfs_root *root, struct extent_buffer *t, int follow);
 void btrfs_print_key(struct btrfs_disk_key *disk_key);
 #endif
diff -aNur a/quick-test.c b/quick-test.c
--- a/quick-test.c	2009-06-12 00:56:15.000000000 +0800
+++ b/quick-test.c	2011-03-22 16:32:44.640948115 +0800
@@ -85,7 +85,7 @@
 			fprintf(stderr, "search %d:%d\n", num, i);
 		ret = btrfs_search_slot(NULL, root, &ins, &path, 0, 0);
 		if (ret) {
-			btrfs_print_tree(root, root->node);
+			btrfs_print_tree(root, root->node, 1);
 			printf("unable to find %d\n", num);
 			exit(1);
 		}
@@ -148,7 +148,7 @@
 			fprintf(stderr, "search %d:%d\n", num, i);
 		ret = btrfs_search_slot(NULL, root, &ins, &path, 0, 0);
 		if (ret) {
-			btrfs_print_tree(root, root->node);
+			btrfs_print_tree(root, root->node, 1);
 			printf("unable to find %d\n", num);
 			exit(1);
 		}
@@ -196,7 +196,7 @@
 	btrfs_commit_transaction(trans, root);
 	printf("tree size is now %d\n", tree_size);
 	printf("root %p commit root %p\n", root->node, root->commit_root);
-	btrfs_print_tree(root, root->node);
+	btrfs_print_tree(root, root->node, 1);
 	close_ctree(root);
 	return 0;
 }
diff -aNur a/random-test.c b/random-test.c
--- a/random-test.c	2009-06-12 00:56:15.000000000 +0800
+++ b/random-test.c	2011-03-22 16:32:44.642948115 +0800
@@ -404,7 +404,7 @@
 			if (ret) {
 				fprintf(stderr, "op %d failed %d:%d\n",
 					op, i, iterations);
-				btrfs_print_tree(root, root->node);
+				btrfs_print_tree(root, root->node, 1);
 				fprintf(stderr, "op %d failed %d:%d\n",
 					op, i, iterations);
 				err = ret;
diff -aNur a/utils.c b/utils.c
--- a/utils.c	2009-06-12 00:56:15.000000000 +0800
+++ b/utils.c	2011-03-22 16:32:44.646948115 +0800
@@ -31,6 +31,10 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <mntent.h>
+#include <linux/loop.h>
+#include <linux/major.h>
+#include <linux/kdev_t.h>
+#include <limits.h>
 #include "kerncompat.h"
 #include "radix-tree.h"
 #include "ctree.h"
@@ -586,55 +590,224 @@
 	return ret;
 }
 
+/* checks if a device is a loop device */
+int is_loop_device (const char* device) {
+	struct stat statbuf;
+
+	if(stat(device, &statbuf) < 0)
+		return -errno;
+
+	return (S_ISBLK(statbuf.st_mode) &&
+		MAJOR(statbuf.st_rdev) == LOOP_MAJOR);
+}
+
+
+/* Takes a loop device path (e.g. /dev/loop0) and returns
+ * the associated file (e.g. /images/my_btrfs.img) */
+int resolve_loop_device(const char* loop_dev, char* loop_file, int max_len)
+{
+	int loop_fd;
+	int ret_ioctl;
+	struct loop_info loopinfo;
+
+	if ((loop_fd = open(loop_dev, O_RDONLY)) < 0)
+		return -errno;
+
+	ret_ioctl = ioctl(loop_fd, LOOP_GET_STATUS, &loopinfo);
+	close(loop_fd);
+
+	if (ret_ioctl == 0)
+		strncpy(loop_file, loopinfo.lo_name, max_len);
+	else
+		return -errno;
+
+	return 0;
+}
+
+/* Checks whether a and b are identical or device
+ * files associated with the same block device
+ */
+int is_same_blk_file(const char* a, const char* b)
+{
+	struct stat st_buf_a, st_buf_b;
+	char real_a[PATH_MAX];
+	char real_b[PATH_MAX];
+
+	if(!realpath(a, real_a) ||
+	   !realpath(b, real_b))
+	{
+		return -errno;
+	}
+
+	/* Identical path? */
+	if(strcmp(real_a, real_b) == 0)
+		return 1;
+
+	if(stat(a, &st_buf_a) < 0 ||
+	   stat(b, &st_buf_b) < 0)
+	{
+		return -errno;
+	}
+
+	/* Same blockdevice? */
+	if(S_ISBLK(st_buf_a.st_mode) &&
+	   S_ISBLK(st_buf_b.st_mode) &&
+	   st_buf_a.st_rdev == st_buf_b.st_rdev)
+	{
+		return 1;
+	}
+
+	/* Hardlink? */
+	if (st_buf_a.st_dev == st_buf_b.st_dev &&
+	    st_buf_a.st_ino == st_buf_b.st_ino)
+	{
+		return 1;
+	}
+
+	return 0;
+}
+
+/* checks if a and b are identical or device
+ * files associated with the same block device or
+ * if one file is a loop device that uses the other
+ * file.
+ */
+int is_same_loop_file(const char* a, const char* b)
+{
+	char res_a[PATH_MAX];
+	char res_b[PATH_MAX];
+	const char* final_a;
+	const char* final_b;
+	int ret;
+
+	/* Resolve a if it is a loop device */
+	if((ret = is_loop_device(a)) < 0) {
+	   return ret;
+	} else if(ret) {
+		if((ret = resolve_loop_device(a, res_a, sizeof(res_a))) < 0)
+			return ret;
+
+		final_a = res_a;
+	} else {
+		final_a = a;
+	}
+
+	/* Resolve b if it is a loop device */
+	if((ret = is_loop_device(b)) < 0) {
+	   return ret;
+	} else if(ret) {
+		if((ret = resolve_loop_device(b, res_b, sizeof(res_b))) < 0)
+			return ret;
+
+		final_b = res_b;
+	} else {
+		final_b = b;
+	}
+
+	return is_same_blk_file(final_a, final_b);
+}
+
+/* Checks if a file exists and is a block or regular file*/
+int is_existing_blk_or_reg_file(const char* filename)
+{
+	struct stat st_buf;
+
+	if(stat(filename, &st_buf) < 0) {
+		if(errno == ENOENT)
+			return 0;
+		else
+			return -errno;
+	}
+
+	return (S_ISBLK(st_buf.st_mode) || S_ISREG(st_buf.st_mode));
+}
+
+/* Checks if a file is used (directly or indirectly via a loop device)
+ * by a device in fs_devices
+ */
+int blk_file_in_dev_list(struct btrfs_fs_devices* fs_devices, const char* file)
+{
+	int ret;
+	struct list_head *head;
+	struct list_head *cur;
+	struct btrfs_device *device;
+
+	head = &fs_devices->devices;
+	list_for_each(cur, head) {
+		device = list_entry(cur, struct btrfs_device, dev_list);
+
+		if((ret = is_same_loop_file(device->name, file)))
+			return ret;
+	}
+
+	return 0;
+}
+
 /*
  * returns 1 if the device was mounted, < 0 on error or 0 if everything
- * is safe to continue.  TODO, this should also scan multi-device filesystems
+ * is safe to continue.
  */
-int check_mounted(char *file)
+int check_mounted(const char* file)
 {
-	struct mntent *mnt;
-	struct stat st_buf;
-	dev_t file_dev = 0;
-	dev_t file_rdev = 0;
-	ino_t file_ino = 0;
+	int ret;
+	int fd;
+	u64 total_devs = 1;
+	int is_btrfs;
+	struct btrfs_fs_devices* fs_devices_mnt = NULL;
 	FILE *f;
-	int ret = 0;
+	struct mntent *mnt;
 
-	if ((f = setmntent ("/proc/mounts", "r")) == NULL)
+	fd = open(file, O_RDONLY);
+	if (fd < 0) {
+		fprintf (stderr, "check_mounted(): Could not open %s\n", file);
 		return -errno;
+	}
 
-	if (stat(file, &st_buf) < 0) {
-		return -errno;
-	} else {
-		if (S_ISBLK(st_buf.st_mode)) {
-			file_rdev = st_buf.st_rdev;
-		} else {
-			file_dev = st_buf.st_dev;
-			file_ino = st_buf.st_ino;
-		}
+	/* scan the initial device */
+	ret = btrfs_scan_one_device(fd, file, &fs_devices_mnt,
+				    &total_devs, BTRFS_SUPER_INFO_OFFSET);
+	is_btrfs = (ret >= 0);
+	close(fd);
+
+	/* scan other devices */
+	if (is_btrfs && total_devs > 1) {
+		if((ret = btrfs_scan_for_fsid(fs_devices_mnt, total_devs, 1)))
+			return ret;
 	}
 
+	/* iterate over the list of currently mountes filesystems */
+	if ((f = setmntent ("/proc/mounts", "r")) == NULL)
+		return -errno;
+
 	while ((mnt = getmntent (f)) != NULL) {
-		if (strcmp(file, mnt->mnt_fsname) == 0)
-			break;
+		if(is_btrfs) {
+			if(strcmp(mnt->mnt_type, "btrfs") != 0)
+				continue;
 
-		if (stat(mnt->mnt_fsname, &st_buf) == 0) {
-			if (S_ISBLK(st_buf.st_mode)) {
-				if (file_rdev && (file_rdev == st_buf.st_rdev))
-					break;
-			} else if (file_dev && ((file_dev == st_buf.st_dev) &&
-						(file_ino == st_buf.st_ino))) {
-					break;
-			}
+			ret = blk_file_in_dev_list(fs_devices_mnt, mnt->mnt_fsname);
+		} else {
+			/* ignore entries in the mount table that are not
+			   associated with a file*/
+			if((ret = is_existing_blk_or_reg_file(mnt->mnt_fsname)) < 0)
+				goto out_mntloop_err;
+			else if(!ret)
+				continue;
+
+			ret = is_same_loop_file(file, mnt->mnt_fsname);
 		}
-	}
 
-	if (mnt) {
-		/* found an entry in mnt table */
-		ret = 1;
+		if(ret < 0)
+			goto out_mntloop_err;
+		else if(ret)
+			break;
 	}
 
+	/* Did we find an entry in mnt table? */
+	ret = (mnt != NULL);
+
+out_mntloop_err:
 	endmntent (f);
+
 	return ret;
 }
 
diff -aNur a/utils.h b/utils.h
--- a/utils.h	2009-06-12 00:56:15.000000000 +0800
+++ b/utils.h	2011-03-22 16:32:44.646948115 +0800
@@ -36,7 +36,7 @@
 			int run_ioctls);
 void btrfs_register_one_device(char *fname);
 int btrfs_scan_one_dir(char *dirname, int run_ioctl);
-int check_mounted(char *devicename);
+int check_mounted(const char *devicename);
 int btrfs_device_already_in_root(struct btrfs_root *root, int fd,
 				 int super_offset);
 char *pretty_sizes(u64 size);