Initial import

1 files changed, 3104 insertions, 0 deletions

diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
new file mode 100644
index 000000000..4c46a9865
--- /dev/null
+++ b/fs/ubifs/debug.c
@@ -0,0 +1,3104 @@
+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Authors: Artem Bityutskiy (Битюцкий Артём)
+ *          Adrian Hunter
+ */
+
+/*
+ * This file implements most of the debugging stuff which is compiled in only
+ * when it is enabled. But some debugging check functions are implemented in
+ * corresponding subsystem, just because they are closely related and utilize
+ * various local functions of those subsystems.
+ */
+
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <linux/math64.h>
+#include <linux/uaccess.h>
+#include <linux/random.h>
+#include "ubifs.h"
+
+static DEFINE_SPINLOCK(dbg_lock);
+
+static const char *get_key_fmt(int fmt)
+{
+	switch (fmt) {
+	case UBIFS_SIMPLE_KEY_FMT:
+		return "simple";
+	default:
+		return "unknown/invalid format";
+	}
+}
+
+static const char *get_key_hash(int hash)
+{
+	switch (hash) {
+	case UBIFS_KEY_HASH_R5:
+		return "R5";
+	case UBIFS_KEY_HASH_TEST:
+		return "test";
+	default:
+		return "unknown/invalid name hash";
+	}
+}
+
+static const char *get_key_type(int type)
+{
+	switch (type) {
+	case UBIFS_INO_KEY:
+		return "inode";
+	case UBIFS_DENT_KEY:
+		return "direntry";
+	case UBIFS_XENT_KEY:
+		return "xentry";
+	case UBIFS_DATA_KEY:
+		return "data";
+	case UBIFS_TRUN_KEY:
+		return "truncate";
+	default:
+		return "unknown/invalid key";
+	}
+}
+
+static const char *get_dent_type(int type)
+{
+	switch (type) {
+	case UBIFS_ITYPE_REG:
+		return "file";
+	case UBIFS_ITYPE_DIR:
+		return "dir";
+	case UBIFS_ITYPE_LNK:
+		return "symlink";
+	case UBIFS_ITYPE_BLK:
+		return "blkdev";
+	case UBIFS_ITYPE_CHR:
+		return "char dev";
+	case UBIFS_ITYPE_FIFO:
+		return "fifo";
+	case UBIFS_ITYPE_SOCK:
+		return "socket";
+	default:
+		return "unknown/invalid type";
+	}
+}
+
+const char *dbg_snprintf_key(const struct ubifs_info *c,
+			     const union ubifs_key *key, char *buffer, int len)
+{
+	char *p = buffer;
+	int type = key_type(c, key);
+
+	if (c->key_fmt == UBIFS_SIMPLE_KEY_FMT) {
+		switch (type) {
+		case UBIFS_INO_KEY:
+			len -= snprintf(p, len, "(%lu, %s)",
+					(unsigned long)key_inum(c, key),
+					get_key_type(type));
+			break;
+		case UBIFS_DENT_KEY:
+		case UBIFS_XENT_KEY:
+			len -= snprintf(p, len, "(%lu, %s, %#08x)",
+					(unsigned long)key_inum(c, key),
+					get_key_type(type), key_hash(c, key));
+			break;
+		case UBIFS_DATA_KEY:
+			len -= snprintf(p, len, "(%lu, %s, %u)",
+					(unsigned long)key_inum(c, key),
+					get_key_type(type), key_block(c, key));
+			break;
+		case UBIFS_TRUN_KEY:
+			len -= snprintf(p, len, "(%lu, %s)",
+					(unsigned long)key_inum(c, key),
+					get_key_type(type));
+			break;
+		default:
+			len -= snprintf(p, len, "(bad key type: %#08x, %#08x)",
+					key->u32[0], key->u32[1]);
+		}
+	} else
+		len -= snprintf(p, len, "bad key format %d", c->key_fmt);
+	ubifs_assert(len > 0);
+	return p;
+}
+
+const char *dbg_ntype(int type)
+{
+	switch (type) {
+	case UBIFS_PAD_NODE:
+		return "padding node";
+	case UBIFS_SB_NODE:
+		return "superblock node";
+	case UBIFS_MST_NODE:
+		return "master node";
+	case UBIFS_REF_NODE:
+		return "reference node";
+	case UBIFS_INO_NODE:
+		return "inode node";
+	case UBIFS_DENT_NODE:
+		return "direntry node";
+	case UBIFS_XENT_NODE:
+		return "xentry node";
+	case UBIFS_DATA_NODE:
+		return "data node";
+	case UBIFS_TRUN_NODE:
+		return "truncate node";
+	case UBIFS_IDX_NODE:
+		return "indexing node";
+	case UBIFS_CS_NODE:
+		return "commit start node";
+	case UBIFS_ORPH_NODE:
+		return "orphan node";
+	default:
+		return "unknown node";
+	}
+}
+
+static const char *dbg_gtype(int type)
+{
+	switch (type) {
+	case UBIFS_NO_NODE_GROUP:
+		return "no node group";
+	case UBIFS_IN_NODE_GROUP:
+		return "in node group";
+	case UBIFS_LAST_OF_NODE_GROUP:
+		return "last of node group";
+	default:
+		return "unknown";
+	}
+}
+
+const char *dbg_cstate(int cmt_state)
+{
+	switch (cmt_state) {
+	case COMMIT_RESTING:
+		return "commit resting";
+	case COMMIT_BACKGROUND:
+		return "background commit requested";
+	case COMMIT_REQUIRED:
+		return "commit required";
+	case COMMIT_RUNNING_BACKGROUND:
+		return "BACKGROUND commit running";
+	case COMMIT_RUNNING_REQUIRED:
+		return "commit running and required";
+	case COMMIT_BROKEN:
+		return "broken commit";
+	default:
+		return "unknown commit state";
+	}
+}
+
+const char *dbg_jhead(int jhead)
+{
+	switch (jhead) {
+	case GCHD:
+		return "0 (GC)";
+	case BASEHD:
+		return "1 (base)";
+	case DATAHD:
+		return "2 (data)";
+	default:
+		return "unknown journal head";
+	}
+}
+
+static void dump_ch(const struct ubifs_ch *ch)
+{
+	pr_err("\tmagic          %#x\n", le32_to_cpu(ch->magic));
+	pr_err("\tcrc            %#x\n", le32_to_cpu(ch->crc));
+	pr_err("\tnode_type      %d (%s)\n", ch->node_type,
+	       dbg_ntype(ch->node_type));
+	pr_err("\tgroup_type     %d (%s)\n", ch->group_type,
+	       dbg_gtype(ch->group_type));
+	pr_err("\tsqnum          %llu\n",
+	       (unsigned long long)le64_to_cpu(ch->sqnum));
+	pr_err("\tlen            %u\n", le32_to_cpu(ch->len));
+}
+
+void ubifs_dump_inode(struct ubifs_info *c, const struct inode *inode)
+{
+	const struct ubifs_inode *ui = ubifs_inode(inode);
+	struct qstr nm = { .name = NULL };
+	union ubifs_key key;
+	struct ubifs_dent_node *dent, *pdent = NULL;
+	int count = 2;
+
+	pr_err("Dump in-memory inode:");
+	pr_err("\tinode          %lu\n", inode->i_ino);
+	pr_err("\tsize           %llu\n",
+	       (unsigned long long)i_size_read(inode));
+	pr_err("\tnlink          %u\n", inode->i_nlink);
+	pr_err("\tuid            %u\n", (unsigned int)i_uid_read(inode));
+	pr_err("\tgid            %u\n", (unsigned int)i_gid_read(inode));
+	pr_err("\tatime          %u.%u\n",
+	       (unsigned int)inode->i_atime.tv_sec,
+	       (unsigned int)inode->i_atime.tv_nsec);
+	pr_err("\tmtime          %u.%u\n",
+	       (unsigned int)inode->i_mtime.tv_sec,
+	       (unsigned int)inode->i_mtime.tv_nsec);
+	pr_err("\tctime          %u.%u\n",
+	       (unsigned int)inode->i_ctime.tv_sec,
+	       (unsigned int)inode->i_ctime.tv_nsec);
+	pr_err("\tcreat_sqnum    %llu\n", ui->creat_sqnum);
+	pr_err("\txattr_size     %u\n", ui->xattr_size);
+	pr_err("\txattr_cnt      %u\n", ui->xattr_cnt);
+	pr_err("\txattr_names    %u\n", ui->xattr_names);
+	pr_err("\tdirty          %u\n", ui->dirty);
+	pr_err("\txattr          %u\n", ui->xattr);
+	pr_err("\tbulk_read      %u\n", ui->xattr);
+	pr_err("\tsynced_i_size  %llu\n",
+	       (unsigned long long)ui->synced_i_size);
+	pr_err("\tui_size        %llu\n",
+	       (unsigned long long)ui->ui_size);
+	pr_err("\tflags          %d\n", ui->flags);
+	pr_err("\tcompr_type     %d\n", ui->compr_type);
+	pr_err("\tlast_page_read %lu\n", ui->last_page_read);
+	pr_err("\tread_in_a_row  %lu\n", ui->read_in_a_row);
+	pr_err("\tdata_len       %d\n", ui->data_len);
+
+	if (!S_ISDIR(inode->i_mode))
+		return;
+
+	pr_err("List of directory entries:\n");
+	ubifs_assert(!mutex_is_locked(&c->tnc_mutex));
+
+	lowest_dent_key(c, &key, inode->i_ino);
+	while (1) {
+		dent = ubifs_tnc_next_ent(c, &key, &nm);
+		if (IS_ERR(dent)) {
+			if (PTR_ERR(dent) != -ENOENT)
+				pr_err("error %ld\n", PTR_ERR(dent));
+			break;
+		}
+
+		pr_err("\t%d: %s (%s)\n",
+		       count++, dent->name, get_dent_type(dent->type));
+
+		nm.name = dent->name;
+		nm.len = le16_to_cpu(dent->nlen);
+		kfree(pdent);
+		pdent = dent;
+		key_read(c, &dent->key, &key);
+	}
+	kfree(pdent);
+}
+
+void ubifs_dump_node(const struct ubifs_info *c, const void *node)
+{
+	int i, n;
+	union ubifs_key key;
+	const struct ubifs_ch *ch = node;
+	char key_buf[DBG_KEY_BUF_LEN];
+
+	/* If the magic is incorrect, just hexdump the first bytes */
+	if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC) {
+		pr_err("Not a node, first %zu bytes:", UBIFS_CH_SZ);
+		print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 32, 1,
+			       (void *)node, UBIFS_CH_SZ, 1);
+		return;
+	}
+
+	spin_lock(&dbg_lock);
+	dump_ch(node);
+
+	switch (ch->node_type) {
+	case UBIFS_PAD_NODE:
+	{
+		const struct ubifs_pad_node *pad = node;
+
+		pr_err("\tpad_len        %u\n", le32_to_cpu(pad->pad_len));
+		break;
+	}
+	case UBIFS_SB_NODE:
+	{
+		const struct ubifs_sb_node *sup = node;
+		unsigned int sup_flags = le32_to_cpu(sup->flags);
+
+		pr_err("\tkey_hash       %d (%s)\n",
+		       (int)sup->key_hash, get_key_hash(sup->key_hash));
+		pr_err("\tkey_fmt        %d (%s)\n",
+		       (int)sup->key_fmt, get_key_fmt(sup->key_fmt));
+		pr_err("\tflags          %#x\n", sup_flags);
+		pr_err("\tbig_lpt        %u\n",
+		       !!(sup_flags & UBIFS_FLG_BIGLPT));
+		pr_err("\tspace_fixup    %u\n",
+		       !!(sup_flags & UBIFS_FLG_SPACE_FIXUP));
+		pr_err("\tmin_io_size    %u\n", le32_to_cpu(sup->min_io_size));
+		pr_err("\tleb_size       %u\n", le32_to_cpu(sup->leb_size));
+		pr_err("\tleb_cnt        %u\n", le32_to_cpu(sup->leb_cnt));
+		pr_err("\tmax_leb_cnt    %u\n", le32_to_cpu(sup->max_leb_cnt));
+		pr_err("\tmax_bud_bytes  %llu\n",
+		       (unsigned long long)le64_to_cpu(sup->max_bud_bytes));
+		pr_err("\tlog_lebs       %u\n", le32_to_cpu(sup->log_lebs));
+		pr_err("\tlpt_lebs       %u\n", le32_to_cpu(sup->lpt_lebs));
+		pr_err("\torph_lebs      %u\n", le32_to_cpu(sup->orph_lebs));
+		pr_err("\tjhead_cnt      %u\n", le32_to_cpu(sup->jhead_cnt));
+		pr_err("\tfanout         %u\n", le32_to_cpu(sup->fanout));
+		pr_err("\tlsave_cnt      %u\n", le32_to_cpu(sup->lsave_cnt));
+		pr_err("\tdefault_compr  %u\n",
+		       (int)le16_to_cpu(sup->default_compr));
+		pr_err("\trp_size        %llu\n",
+		       (unsigned long long)le64_to_cpu(sup->rp_size));
+		pr_err("\trp_uid         %u\n", le32_to_cpu(sup->rp_uid));
+		pr_err("\trp_gid         %u\n", le32_to_cpu(sup->rp_gid));
+		pr_err("\tfmt_version    %u\n", le32_to_cpu(sup->fmt_version));
+		pr_err("\ttime_gran      %u\n", le32_to_cpu(sup->time_gran));
+		pr_err("\tUUID           %pUB\n", sup->uuid);
+		break;
+	}
+	case UBIFS_MST_NODE:
+	{
+		const struct ubifs_mst_node *mst = node;
+
+		pr_err("\thighest_inum   %llu\n",
+		       (unsigned long long)le64_to_cpu(mst->highest_inum));
+		pr_err("\tcommit number  %llu\n",
+		       (unsigned long long)le64_to_cpu(mst->cmt_no));
+		pr_err("\tflags          %#x\n", le32_to_cpu(mst->flags));
+		pr_err("\tlog_lnum       %u\n", le32_to_cpu(mst->log_lnum));
+		pr_err("\troot_lnum      %u\n", le32_to_cpu(mst->root_lnum));
+		pr_err("\troot_offs      %u\n", le32_to_cpu(mst->root_offs));
+		pr_err("\troot_len       %u\n", le32_to_cpu(mst->root_len));
+		pr_err("\tgc_lnum        %u\n", le32_to_cpu(mst->gc_lnum));
+		pr_err("\tihead_lnum     %u\n", le32_to_cpu(mst->ihead_lnum));
+		pr_err("\tihead_offs     %u\n", le32_to_cpu(mst->ihead_offs));
+		pr_err("\tindex_size     %llu\n",
+		       (unsigned long long)le64_to_cpu(mst->index_size));
+		pr_err("\tlpt_lnum       %u\n", le32_to_cpu(mst->lpt_lnum));
+		pr_err("\tlpt_offs       %u\n", le32_to_cpu(mst->lpt_offs));
+		pr_err("\tnhead_lnum     %u\n", le32_to_cpu(mst->nhead_lnum));
+		pr_err("\tnhead_offs     %u\n", le32_to_cpu(mst->nhead_offs));
+		pr_err("\tltab_lnum      %u\n", le32_to_cpu(mst->ltab_lnum));
+		pr_err("\tltab_offs      %u\n", le32_to_cpu(mst->ltab_offs));
+		pr_err("\tlsave_lnum     %u\n", le32_to_cpu(mst->lsave_lnum));
+		pr_err("\tlsave_offs     %u\n", le32_to_cpu(mst->lsave_offs));
+		pr_err("\tlscan_lnum     %u\n", le32_to_cpu(mst->lscan_lnum));
+		pr_err("\tleb_cnt        %u\n", le32_to_cpu(mst->leb_cnt));
+		pr_err("\tempty_lebs     %u\n", le32_to_cpu(mst->empty_lebs));
+		pr_err("\tidx_lebs       %u\n", le32_to_cpu(mst->idx_lebs));
+		pr_err("\ttotal_free     %llu\n",
+		       (unsigned long long)le64_to_cpu(mst->total_free));
+		pr_err("\ttotal_dirty    %llu\n",
+		       (unsigned long long)le64_to_cpu(mst->total_dirty));
+		pr_err("\ttotal_used     %llu\n",
+		       (unsigned long long)le64_to_cpu(mst->total_used));
+		pr_err("\ttotal_dead     %llu\n",
+		       (unsigned long long)le64_to_cpu(mst->total_dead));
+		pr_err("\ttotal_dark     %llu\n",
+		       (unsigned long long)le64_to_cpu(mst->total_dark));
+		break;
+	}
+	case UBIFS_REF_NODE:
+	{
+		const struct ubifs_ref_node *ref = node;
+
+		pr_err("\tlnum           %u\n", le32_to_cpu(ref->lnum));
+		pr_err("\toffs           %u\n", le32_to_cpu(ref->offs));
+		pr_err("\tjhead          %u\n", le32_to_cpu(ref->jhead));
+		break;
+	}
+	case UBIFS_INO_NODE:
+	{
+		const struct ubifs_ino_node *ino = node;
+
+		key_read(c, &ino->key, &key);
+		pr_err("\tkey            %s\n",
+		       dbg_snprintf_key(c, &key, key_buf, DBG_KEY_BUF_LEN));
+		pr_err("\tcreat_sqnum    %llu\n",
+		       (unsigned long long)le64_to_cpu(ino->creat_sqnum));
+		pr_err("\tsize           %llu\n",
+		       (unsigned long long)le64_to_cpu(ino->size));
+		pr_err("\tnlink          %u\n", le32_to_cpu(ino->nlink));
+		pr_err("\tatime          %lld.%u\n",
+		       (long long)le64_to_cpu(ino->atime_sec),
+		       le32_to_cpu(ino->atime_nsec));
+		pr_err("\tmtime          %lld.%u\n",
+		       (long long)le64_to_cpu(ino->mtime_sec),
+		       le32_to_cpu(ino->mtime_nsec));
+		pr_err("\tctime          %lld.%u\n",
+		       (long long)le64_to_cpu(ino->ctime_sec),
+		       le32_to_cpu(ino->ctime_nsec));
+		pr_err("\tuid            %u\n", le32_to_cpu(ino->uid));
+		pr_err("\tgid            %u\n", le32_to_cpu(ino->gid));
+		pr_err("\tmode           %u\n", le32_to_cpu(ino->mode));
+		pr_err("\tflags          %#x\n", le32_to_cpu(ino->flags));
+		pr_err("\txattr_cnt      %u\n", le32_to_cpu(ino->xattr_cnt));
+		pr_err("\txattr_size     %u\n", le32_to_cpu(ino->xattr_size));
+		pr_err("\txattr_names    %u\n", le32_to_cpu(ino->xattr_names));
+		pr_err("\tcompr_type     %#x\n",
+		       (int)le16_to_cpu(ino->compr_type));
+		pr_err("\tdata len       %u\n", le32_to_cpu(ino->data_len));
+		break;
+	}
+	case UBIFS_DENT_NODE:
+	case UBIFS_XENT_NODE:
+	{
+		const struct ubifs_dent_node *dent = node;
+		int nlen = le16_to_cpu(dent->nlen);
+
+		key_read(c, &dent->key, &key);
+		pr_err("\tkey            %s\n",
+		       dbg_snprintf_key(c, &key, key_buf, DBG_KEY_BUF_LEN));
+		pr_err("\tinum           %llu\n",
+		       (unsigned long long)le64_to_cpu(dent->inum));
+		pr_err("\ttype           %d\n", (int)dent->type);
+		pr_err("\tnlen           %d\n", nlen);
+		pr_err("\tname           ");
+
+		if (nlen > UBIFS_MAX_NLEN)
+			pr_err("(bad name length, not printing, bad or corrupted node)");
+		else {
+			for (i = 0; i < nlen && dent->name[i]; i++)
+				pr_cont("%c", dent->name[i]);
+		}
+		pr_cont("\n");
+
+		break;
+	}
+	case UBIFS_DATA_NODE:
+	{
+		const struct ubifs_data_node *dn = node;
+		int dlen = le32_to_cpu(ch->len) - UBIFS_DATA_NODE_SZ;
+
+		key_read(c, &dn->key, &key);
+		pr_err("\tkey            %s\n",
+		       dbg_snprintf_key(c, &key, key_buf, DBG_KEY_BUF_LEN));
+		pr_err("\tsize           %u\n", le32_to_cpu(dn->size));
+		pr_err("\tcompr_typ      %d\n",
+		       (int)le16_to_cpu(dn->compr_type));
+		pr_err("\tdata size      %d\n", dlen);
+		pr_err("\tdata:\n");
+		print_hex_dump(KERN_ERR, "\t", DUMP_PREFIX_OFFSET, 32, 1,
+			       (void *)&dn->data, dlen, 0);
+		break;
+	}
+	case UBIFS_TRUN_NODE:
+	{
+		const struct ubifs_trun_node *trun = node;
+
+		pr_err("\tinum           %u\n", le32_to_cpu(trun->inum));
+		pr_err("\told_size       %llu\n",
+		       (unsigned long long)le64_to_cpu(trun->old_size));
+		pr_err("\tnew_size       %llu\n",
+		       (unsigned long long)le64_to_cpu(trun->new_size));
+		break;
+	}
+	case UBIFS_IDX_NODE:
+	{
+		const struct ubifs_idx_node *idx = node;
+
+		n = le16_to_cpu(idx->child_cnt);
+		pr_err("\tchild_cnt      %d\n", n);
+		pr_err("\tlevel          %d\n", (int)le16_to_cpu(idx->level));
+		pr_err("\tBranches:\n");
+
+		for (i = 0; i < n && i < c->fanout - 1; i++) {
+			const struct ubifs_branch *br;
+
+			br = ubifs_idx_branch(c, idx, i);
+			key_read(c, &br->key, &key);
+			pr_err("\t%d: LEB %d:%d len %d key %s\n",
+			       i, le32_to_cpu(br->lnum), le32_to_cpu(br->offs),
+			       le32_to_cpu(br->len),
+			       dbg_snprintf_key(c, &key, key_buf,
+						DBG_KEY_BUF_LEN));
+		}
+		break;
+	}
+	case UBIFS_CS_NODE:
+		break;
+	case UBIFS_ORPH_NODE:
+	{
+		const struct ubifs_orph_node *orph = node;
+
+		pr_err("\tcommit number  %llu\n",
+		       (unsigned long long)
+				le64_to_cpu(orph->cmt_no) & LLONG_MAX);
+		pr_err("\tlast node flag %llu\n",
+		       (unsigned long long)(le64_to_cpu(orph->cmt_no)) >> 63);
+		n = (le32_to_cpu(ch->len) - UBIFS_ORPH_NODE_SZ) >> 3;
+		pr_err("\t%d orphan inode numbers:\n", n);
+		for (i = 0; i < n; i++)
+			pr_err("\t  ino %llu\n",
+			       (unsigned long long)le64_to_cpu(orph->inos[i]));
+		break;
+	}
+	default:
+		pr_err("node type %d was not recognized\n",
+		       (int)ch->node_type);
+	}
+	spin_unlock(&dbg_lock);
+}
+
+void ubifs_dump_budget_req(const struct ubifs_budget_req *req)
+{
+	spin_lock(&dbg_lock);
+	pr_err("Budgeting request: new_ino %d, dirtied_ino %d\n",
+	       req->new_ino, req->dirtied_ino);
+	pr_err("\tnew_ino_d   %d, dirtied_ino_d %d\n",
+	       req->new_ino_d, req->dirtied_ino_d);
+	pr_err("\tnew_page    %d, dirtied_page %d\n",
+	       req->new_page, req->dirtied_page);
+	pr_err("\tnew_dent    %d, mod_dent     %d\n",
+	       req->new_dent, req->mod_dent);
+	pr_err("\tidx_growth  %d\n", req->idx_growth);
+	pr_err("\tdata_growth %d dd_growth     %d\n",
+	       req->data_growth, req->dd_growth);
+	spin_unlock(&dbg_lock);
+}
+
+void ubifs_dump_lstats(const struct ubifs_lp_stats *lst)
+{
+	spin_lock(&dbg_lock);
+	pr_err("(pid %d) Lprops statistics: empty_lebs %d, idx_lebs  %d\n",
+	       current->pid, lst->empty_lebs, lst->idx_lebs);
+	pr_err("\ttaken_empty_lebs %d, total_free %lld, total_dirty %lld\n",
+	       lst->taken_empty_lebs, lst->total_free, lst->total_dirty);
+	pr_err("\ttotal_used %lld, total_dark %lld, total_dead %lld\n",
+	       lst->total_used, lst->total_dark, lst->total_dead);
+	spin_unlock(&dbg_lock);
+}
+
+void ubifs_dump_budg(struct ubifs_info *c, const struct ubifs_budg_info *bi)
+{
+	int i;
+	struct rb_node *rb;
+	struct ubifs_bud *bud;
+	struct ubifs_gced_idx_leb *idx_gc;
+	long long available, outstanding, free;
+
+	spin_lock(&c->space_lock);
+	spin_lock(&dbg_lock);
+	pr_err("(pid %d) Budgeting info: data budget sum %lld, total budget sum %lld\n",
+	       current->pid, bi->data_growth + bi->dd_growth,
+	       bi->data_growth + bi->dd_growth + bi->idx_growth);
+	pr_err("\tbudg_data_growth %lld, budg_dd_growth %lld, budg_idx_growth %lld\n",
+	       bi->data_growth, bi->dd_growth, bi->idx_growth);
+	pr_err("\tmin_idx_lebs %d, old_idx_sz %llu, uncommitted_idx %lld\n",
+	       bi->min_idx_lebs, bi->old_idx_sz, bi->uncommitted_idx);
+	pr_err("\tpage_budget %d, inode_budget %d, dent_budget %d\n",
+	       bi->page_budget, bi->inode_budget, bi->dent_budget);
+	pr_err("\tnospace %u, nospace_rp %u\n", bi->nospace, bi->nospace_rp);
+	pr_err("\tdark_wm %d, dead_wm %d, max_idx_node_sz %d\n",
+	       c->dark_wm, c->dead_wm, c->max_idx_node_sz);
+
+	if (bi != &c->bi)
+		/*
+		 * If we are dumping saved budgeting data, do not print
+		 * additional information which is about the current state, not
+		 * the old one which corresponded to the saved budgeting data.
+		 */
+		goto out_unlock;
+
+	pr_err("\tfreeable_cnt %d, calc_idx_sz %lld, idx_gc_cnt %d\n",
+	       c->freeable_cnt, c->calc_idx_sz, c->idx_gc_cnt);
+	pr_err("\tdirty_pg_cnt %ld, dirty_zn_cnt %ld, clean_zn_cnt %ld\n",
+	       atomic_long_read(&c->dirty_pg_cnt),
+	       atomic_long_read(&c->dirty_zn_cnt),
+	       atomic_long_read(&c->clean_zn_cnt));
+	pr_err("\tgc_lnum %d, ihead_lnum %d\n", c->gc_lnum, c->ihead_lnum);
+
+	/* If we are in R/O mode, journal heads do not exist */
+	if (c->jheads)
+		for (i = 0; i < c->jhead_cnt; i++)
+			pr_err("\tjhead %s\t LEB %d\n",
+			       dbg_jhead(c->jheads[i].wbuf.jhead),
+			       c->jheads[i].wbuf.lnum);
+	for (rb = rb_first(&c->buds); rb; rb = rb_next(rb)) {
+		bud = rb_entry(rb, struct ubifs_bud, rb);
+		pr_err("\tbud LEB %d\n", bud->lnum);
+	}
+	list_for_each_entry(bud, &c->old_buds, list)
+		pr_err("\told bud LEB %d\n", bud->lnum);
+	list_for_each_entry(idx_gc, &c->idx_gc, list)
+		pr_err("\tGC'ed idx LEB %d unmap %d\n",
+		       idx_gc->lnum, idx_gc->unmap);
+	pr_err("\tcommit state %d\n", c->cmt_state);
+
+	/* Print budgeting predictions */
+	available = ubifs_calc_available(c, c->bi.min_idx_lebs);
+	outstanding = c->bi.data_growth + c->bi.dd_growth;
+	free = ubifs_get_free_space_nolock(c);
+	pr_err("Budgeting predictions:\n");
+	pr_err("\tavailable: %lld, outstanding %lld, free %lld\n",
+	       available, outstanding, free);
+out_unlock:
+	spin_unlock(&dbg_lock);
+	spin_unlock(&c->space_lock);
+}
+
+void ubifs_dump_lprop(const struct ubifs_info *c, const struct ubifs_lprops *lp)
+{
+	int i, spc, dark = 0, dead = 0;
+	struct rb_node *rb;
+	struct ubifs_bud *bud;
+
+	spc = lp->free + lp->dirty;
+	if (spc < c->dead_wm)
+		dead = spc;
+	else
+		dark = ubifs_calc_dark(c, spc);
+
+	if (lp->flags & LPROPS_INDEX)
+		pr_err("LEB %-7d free %-8d dirty %-8d used %-8d free + dirty %-8d flags %#x (",
+		       lp->lnum, lp->free, lp->dirty, c->leb_size - spc, spc,
+		       lp->flags);
+	else
+		pr_err("LEB %-7d free %-8d dirty %-8d used %-8d free + dirty %-8d dark %-4d dead %-4d nodes fit %-3d flags %#-4x (",
+		       lp->lnum, lp->free, lp->dirty, c->leb_size - spc, spc,
+		       dark, dead, (int)(spc / UBIFS_MAX_NODE_SZ), lp->flags);
+
+	if (lp->flags & LPROPS_TAKEN) {
+		if (lp->flags & LPROPS_INDEX)
+			pr_cont("index, taken");
+		else
+			pr_cont("taken");
+	} else {
+		const char *s;
+
+		if (lp->flags & LPROPS_INDEX) {
+			switch (lp->flags & LPROPS_CAT_MASK) {
+			case LPROPS_DIRTY_IDX:
+				s = "dirty index";
+				break;
+			case LPROPS_FRDI_IDX:
+				s = "freeable index";
+				break;
+			default:
+				s = "index";
+			}
+		} else {
+			switch (lp->flags & LPROPS_CAT_MASK) {
+			case LPROPS_UNCAT:
+				s = "not categorized";
+				break;
+			case LPROPS_DIRTY:
+				s = "dirty";
+				break;
+			case LPROPS_FREE:
+				s = "free";
+				break;
+			case LPROPS_EMPTY:
+				s = "empty";
+				break;
+			case LPROPS_FREEABLE:
+				s = "freeable";
+				break;
+			default:
+				s = NULL;
+				break;
+			}
+		}
+		pr_cont("%s", s);
+	}
+
+	for (rb = rb_first((struct rb_root *)&c->buds); rb; rb = rb_next(rb)) {
+		bud = rb_entry(rb, struct ubifs_bud, rb);
+		if (bud->lnum == lp->lnum) {
+			int head = 0;
+			for (i = 0; i < c->jhead_cnt; i++) {
+				/*
+				 * Note, if we are in R/O mode or in the middle
+				 * of mounting/re-mounting, the write-buffers do
+				 * not exist.
+				 */
+				if (c->jheads &&
+				    lp->lnum == c->jheads[i].wbuf.lnum) {
+					pr_cont(", jhead %s", dbg_jhead(i));
+					head = 1;
+				}
+			}
+			if (!head)
+				pr_cont(", bud of jhead %s",
+				       dbg_jhead(bud->jhead));
+		}
+	}
+	if (lp->lnum == c->gc_lnum)
+		pr_cont(", GC LEB");
+	pr_cont(")\n");
+}
+
+void ubifs_dump_lprops(struct ubifs_info *c)
+{
+	int lnum, err;
+	struct ubifs_lprops lp;
+	struct ubifs_lp_stats lst;
+
+	pr_err("(pid %d) start dumping LEB properties\n", current->pid);
+	ubifs_get_lp_stats(c, &lst);
+	ubifs_dump_lstats(&lst);
+
+	for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) {
+		err = ubifs_read_one_lp(c, lnum, &lp);
+		if (err) {
+			ubifs_err(c, "cannot read lprops for LEB %d", lnum);
+			continue;
+		}
+
+		ubifs_dump_lprop(c, &lp);
+	}
+	pr_err("(pid %d) finish dumping LEB properties\n", current->pid);
+}
+
+void ubifs_dump_lpt_info(struct ubifs_info *c)
+{
+	int i;
+
+	spin_lock(&dbg_lock);
+	pr_err("(pid %d) dumping LPT information\n", current->pid);
+	pr_err("\tlpt_sz:        %lld\n", c->lpt_sz);
+	pr_err("\tpnode_sz:      %d\n", c->pnode_sz);
+	pr_err("\tnnode_sz:      %d\n", c->nnode_sz);
+	pr_err("\tltab_sz:       %d\n", c->ltab_sz);
+	pr_err("\tlsave_sz:      %d\n", c->lsave_sz);
+	pr_err("\tbig_lpt:       %d\n", c->big_lpt);
+	pr_err("\tlpt_hght:      %d\n", c->lpt_hght);
+	pr_err("\tpnode_cnt:     %d\n", c->pnode_cnt);
+	pr_err("\tnnode_cnt:     %d\n", c->nnode_cnt);
+	pr_err("\tdirty_pn_cnt:  %d\n", c->dirty_pn_cnt);
+	pr_err("\tdirty_nn_cnt:  %d\n", c->dirty_nn_cnt);
+	pr_err("\tlsave_cnt:     %d\n", c->lsave_cnt);
+	pr_err("\tspace_bits:    %d\n", c->space_bits);
+	pr_err("\tlpt_lnum_bits: %d\n", c->lpt_lnum_bits);
+	pr_err("\tlpt_offs_bits: %d\n", c->lpt_offs_bits);
+	pr_err("\tlpt_spc_bits:  %d\n", c->lpt_spc_bits);
+	pr_err("\tpcnt_bits:     %d\n", c->pcnt_bits);
+	pr_err("\tlnum_bits:     %d\n", c->lnum_bits);
+	pr_err("\tLPT root is at %d:%d\n", c->lpt_lnum, c->lpt_offs);
+	pr_err("\tLPT head is at %d:%d\n",
+	       c->nhead_lnum, c->nhead_offs);
+	pr_err("\tLPT ltab is at %d:%d\n", c->ltab_lnum, c->ltab_offs);
+	if (c->big_lpt)
+		pr_err("\tLPT lsave is at %d:%d\n",
+		       c->lsave_lnum, c->lsave_offs);
+	for (i = 0; i < c->lpt_lebs; i++)
+		pr_err("\tLPT LEB %d free %d dirty %d tgc %d cmt %d\n",
+		       i + c->lpt_first, c->ltab[i].free, c->ltab[i].dirty,
+		       c->ltab[i].tgc, c->ltab[i].cmt);
+	spin_unlock(&dbg_lock);
+}
+
+void ubifs_dump_sleb(const struct ubifs_info *c,
+		     const struct ubifs_scan_leb *sleb, int offs)
+{
+	struct ubifs_scan_node *snod;
+
+	pr_err("(pid %d) start dumping scanned data from LEB %d:%d\n",
+	       current->pid, sleb->lnum, offs);
+
+	list_for_each_entry(snod, &sleb->nodes, list) {
+		cond_resched();
+		pr_err("Dumping node at LEB %d:%d len %d\n",
+		       sleb->lnum, snod->offs, snod->len);
+		ubifs_dump_node(c, snod->node);
+	}
+}
+
+void ubifs_dump_leb(const struct ubifs_info *c, int lnum)
+{
+	struct ubifs_scan_leb *sleb;
+	struct ubifs_scan_node *snod;
+	void *buf;
+
+	pr_err("(pid %d) start dumping LEB %d\n", current->pid, lnum);
+
+	buf = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
+	if (!buf) {
+		ubifs_err(c, "cannot allocate memory for dumping LEB %d", lnum);
+		return;
+	}
+
+	sleb = ubifs_scan(c, lnum, 0, buf, 0);
+	if (IS_ERR(sleb)) {
+		ubifs_err(c, "scan error %d", (int)PTR_ERR(sleb));
+		goto out;
+	}
+
+	pr_err("LEB %d has %d nodes ending at %d\n", lnum,
+	       sleb->nodes_cnt, sleb->endpt);
+
+	list_for_each_entry(snod, &sleb->nodes, list) {
+		cond_resched();
+		pr_err("Dumping node at LEB %d:%d len %d\n", lnum,
+		       snod->offs, snod->len);
+		ubifs_dump_node(c, snod->node);
+	}
+
+	pr_err("(pid %d) finish dumping LEB %d\n", current->pid, lnum);
+	ubifs_scan_destroy(sleb);
+
+out:
+	vfree(buf);
+	return;
+}
+
+void ubifs_dump_znode(const struct ubifs_info *c,
+		      const struct ubifs_znode *znode)
+{
+	int n;
+	const struct ubifs_zbranch *zbr;
+	char key_buf[DBG_KEY_BUF_LEN];
+
+	spin_lock(&dbg_lock);
+	if (znode->parent)
+		zbr = &znode->parent->zbranch[znode->iip];
+	else
+		zbr = &c->zroot;
+
+	pr_err("znode %p, LEB %d:%d len %d parent %p iip %d level %d child_cnt %d flags %lx\n",
+	       znode, zbr->lnum, zbr->offs, zbr->len, znode->parent, znode->iip,
+	       znode->level, znode->child_cnt, znode->flags);
+
+	if (znode->child_cnt <= 0 || znode->child_cnt > c->fanout) {
+		spin_unlock(&dbg_lock);
+		return;
+	}
+
+	pr_err("zbranches:\n");
+	for (n = 0; n < znode->child_cnt; n++) {
+		zbr = &znode->zbranch[n];
+		if (znode->level > 0)
+			pr_err("\t%d: znode %p LEB %d:%d len %d key %s\n",
+			       n, zbr->znode, zbr->lnum, zbr->offs, zbr->len,
+			       dbg_snprintf_key(c, &zbr->key, key_buf,
+						DBG_KEY_BUF_LEN));
+		else
+			pr_err("\t%d: LNC %p LEB %d:%d len %d key %s\n",
+			       n, zbr->znode, zbr->lnum, zbr->offs, zbr->len,
+			       dbg_snprintf_key(c, &zbr->key, key_buf,
+						DBG_KEY_BUF_LEN));
+	}
+	spin_unlock(&dbg_lock);
+}
+
+void ubifs_dump_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, int cat)
+{
+	int i;
+
+	pr_err("(pid %d) start dumping heap cat %d (%d elements)\n",
+	       current->pid, cat, heap->cnt);
+	for (i = 0; i < heap->cnt; i++) {
+		struct ubifs_lprops *lprops = heap->arr[i];
+
+		pr_err("\t%d. LEB %d hpos %d free %d dirty %d flags %d\n",
+		       i, lprops->lnum, lprops->hpos, lprops->free,
+		       lprops->dirty, lprops->flags);
+	}
+	pr_err("(pid %d) finish dumping heap\n", current->pid);
+}
+
+void ubifs_dump_pnode(struct ubifs_info *c, struct ubifs_pnode *pnode,
+		      struct ubifs_nnode *parent, int iip)
+{
+	int i;
+
+	pr_err("(pid %d) dumping pnode:\n", current->pid);
+	pr_err("\taddress %zx parent %zx cnext %zx\n",
+	       (size_t)pnode, (size_t)parent, (size_t)pnode->cnext);
+	pr_err("\tflags %lu iip %d level %d num %d\n",
+	       pnode->flags, iip, pnode->level, pnode->num);
+	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
+		struct ubifs_lprops *lp = &pnode->lprops[i];
+
+		pr_err("\t%d: free %d dirty %d flags %d lnum %d\n",
+		       i, lp->free, lp->dirty, lp->flags, lp->lnum);
+	}
+}
+
+void ubifs_dump_tnc(struct ubifs_info *c)
+{
+	struct ubifs_znode *znode;
+	int level;
+
+	pr_err("\n");
+	pr_err("(pid %d) start dumping TNC tree\n", current->pid);
+	znode = ubifs_tnc_levelorder_next(c->zroot.znode, NULL);
+	level = znode->level;
+	pr_err("== Level %d ==\n", level);
+	while (znode) {
+		if (level != znode->level) {
+			level = znode->level;
+			pr_err("== Level %d ==\n", level);
+		}
+		ubifs_dump_znode(c, znode);
+		znode = ubifs_tnc_levelorder_next(c->zroot.znode, znode);
+	}
+	pr_err("(pid %d) finish dumping TNC tree\n", current->pid);
+}
+
+static int dump_znode(struct ubifs_info *c, struct ubifs_znode *znode,
+		      void *priv)
+{
+	ubifs_dump_znode(c, znode);
+	return 0;
+}
+
+/**
+ * ubifs_dump_index - dump the on-flash index.
+ * @c: UBIFS file-system description object
+ *
+ * This function dumps whole UBIFS indexing B-tree, unlike 'ubifs_dump_tnc()'
+ * which dumps only in-memory znodes and does not read znodes which from flash.
+ */
+void ubifs_dump_index(struct ubifs_info *c)
+{
+	dbg_walk_index(c, NULL, dump_znode, NULL);
+}
+
+/**
+ * dbg_save_space_info - save information about flash space.
+ * @c: UBIFS file-system description object
+ *
+ * This function saves information about UBIFS free space, dirty space, etc, in
+ * order to check it later.
+ */
+void dbg_save_space_info(struct ubifs_info *c)
+{
+	struct ubifs_debug_info *d = c->dbg;
+	int freeable_cnt;
+
+	spin_lock(&c->space_lock);
+	memcpy(&d->saved_lst, &c->lst, sizeof(struct ubifs_lp_stats));
+	memcpy(&d->saved_bi, &c->bi, sizeof(struct ubifs_budg_info));
+	d->saved_idx_gc_cnt = c->idx_gc_cnt;
+
+	/*
+	 * We use a dirty hack here and zero out @c->freeable_cnt, because it
+	 * affects the free space calculations, and UBIFS might not know about
+	 * all freeable eraseblocks. Indeed, we know about freeable eraseblocks
+	 * only when we read their lprops, and we do this only lazily, upon the
+	 * need. So at any given point of time @c->freeable_cnt might be not
+	 * exactly accurate.
+	 *
+	 * Just one example about the issue we hit when we did not zero
+	 * @c->freeable_cnt.
+	 * 1. The file-system is mounted R/O, c->freeable_cnt is %0. We save the
+	 *    amount of free space in @d->saved_free
+	 * 2. We re-mount R/W, which makes UBIFS to read the "lsave"
+	 *    information from flash, where we cache LEBs from various
+	 *    categories ('ubifs_remount_fs()' -> 'ubifs_lpt_init()'
+	 *    -> 'lpt_init_wr()' -> 'read_lsave()' -> 'ubifs_lpt_lookup()'
+	 *    -> 'ubifs_get_pnode()' -> 'update_cats()'
+	 *    -> 'ubifs_add_to_cat()').
+	 * 3. Lsave contains a freeable eraseblock, and @c->freeable_cnt
+	 *    becomes %1.
+	 * 4. We calculate the amount of free space when the re-mount is
+	 *    finished in 'dbg_check_space_info()' and it does not match
+	 *    @d->saved_free.
+	 */
+	freeable_cnt = c->freeable_cnt;
+	c->freeable_cnt = 0;
+	d->saved_free = ubifs_get_free_space_nolock(c);
+	c->freeable_cnt = freeable_cnt;
+	spin_unlock(&c->space_lock);
+}
+
+/**
+ * dbg_check_space_info - check flash space information.
+ * @c: UBIFS file-system description object
+ *
+ * This function compares current flash space information with the information
+ * which was saved when the 'dbg_save_space_info()' function was called.
+ * Returns zero if the information has not changed, and %-EINVAL it it has
+ * changed.
+ */
+int dbg_check_space_info(struct ubifs_info *c)
+{
+	struct ubifs_debug_info *d = c->dbg;
+	struct ubifs_lp_stats lst;
+	long long free;
+	int freeable_cnt;
+
+	spin_lock(&c->space_lock);
+	freeable_cnt = c->freeable_cnt;
+	c->freeable_cnt = 0;
+	free = ubifs_get_free_space_nolock(c);
+	c->freeable_cnt = freeable_cnt;
+	spin_unlock(&c->space_lock);
+
+	if (free != d->saved_free) {
+		ubifs_err(c, "free space changed from %lld to %lld",
+			  d->saved_free, free);
+		goto out;
+	}
+
+	return 0;
+
+out:
+	ubifs_msg(c, "saved lprops statistics dump");
+	ubifs_dump_lstats(&d->saved_lst);
+	ubifs_msg(c, "saved budgeting info dump");
+	ubifs_dump_budg(c, &d->saved_bi);
+	ubifs_msg(c, "saved idx_gc_cnt %d", d->saved_idx_gc_cnt);
+	ubifs_msg(c, "current lprops statistics dump");
+	ubifs_get_lp_stats(c, &lst);
+	ubifs_dump_lstats(&lst);
+	ubifs_msg(c, "current budgeting info dump");
+	ubifs_dump_budg(c, &c->bi);
+	dump_stack();
+	return -EINVAL;
+}
+
+/**
+ * dbg_check_synced_i_size - check synchronized inode size.
+ * @c: UBIFS file-system description object
+ * @inode: inode to check
+ *
+ * If inode is clean, synchronized inode size has to be equivalent to current
+ * inode size. This function has to be called only for locked inodes (@i_mutex
+ * has to be locked). Returns %0 if synchronized inode size if correct, and
+ * %-EINVAL if not.
+ */
+int dbg_check_synced_i_size(const struct ubifs_info *c, struct inode *inode)
+{
+	int err = 0;
+	struct ubifs_inode *ui = ubifs_inode(inode);
+
+	if (!dbg_is_chk_gen(c))
+		return 0;
+	if (!S_ISREG(inode->i_mode))
+		return 0;
+
+	mutex_lock(&ui->ui_mutex);
+	spin_lock(&ui->ui_lock);
+	if (ui->ui_size != ui->synced_i_size && !ui->dirty) {
+		ubifs_err(c, "ui_size is %lld, synced_i_size is %lld, but inode is clean",
+			  ui->ui_size, ui->synced_i_size);
+		ubifs_err(c, "i_ino %lu, i_mode %#x, i_size %lld", inode->i_ino,
+			  inode->i_mode, i_size_read(inode));
+		dump_stack();
+		err = -EINVAL;
+	}
+	spin_unlock(&ui->ui_lock);
+	mutex_unlock(&ui->ui_mutex);
+	return err;
+}
+
+/*
+ * dbg_check_dir - check directory inode size and link count.
+ * @c: UBIFS file-system description object
+ * @dir: the directory to calculate size for
+ * @size: the result is returned here
+ *
+ * This function makes sure that directory size and link count are correct.
+ * Returns zero in case of success and a negative error code in case of
+ * failure.
+ *
+ * Note, it is good idea to make sure the @dir->i_mutex is locked before
+ * calling this function.
+ */
+int dbg_check_dir(struct ubifs_info *c, const struct inode *dir)
+{
+	unsigned int nlink = 2;
+	union ubifs_key key;
+	struct ubifs_dent_node *dent, *pdent = NULL;
+	struct qstr nm = { .name = NULL };
+	loff_t size = UBIFS_INO_NODE_SZ;
+
+	if (!dbg_is_chk_gen(c))
+		return 0;
+
+	if (!S_ISDIR(dir->i_mode))
+		return 0;
+
+	lowest_dent_key(c, &key, dir->i_ino);
+	while (1) {
+		int err;
+
+		dent = ubifs_tnc_next_ent(c, &key, &nm);
+		if (IS_ERR(dent)) {
+			err = PTR_ERR(dent);
+			if (err == -ENOENT)
+				break;
+			return err;
+		}
+
+		nm.name = dent->name;
+		nm.len = le16_to_cpu(dent->nlen);
+		size += CALC_DENT_SIZE(nm.len);
+		if (dent->type == UBIFS_ITYPE_DIR)
+			nlink += 1;
+		kfree(pdent);
+		pdent = dent;
+		key_read(c, &dent->key, &key);
+	}
+	kfree(pdent);
+
+	if (i_size_read(dir) != size) {
+		ubifs_err(c, "directory inode %lu has size %llu, but calculated size is %llu",
+			  dir->i_ino, (unsigned long long)i_size_read(dir),
+			  (unsigned long long)size);
+		ubifs_dump_inode(c, dir);
+		dump_stack();
+		return -EINVAL;
+	}
+	if (dir->i_nlink != nlink) {
+		ubifs_err(c, "directory inode %lu has nlink %u, but calculated nlink is %u",
+			  dir->i_ino, dir->i_nlink, nlink);
+		ubifs_dump_inode(c, dir);
+		dump_stack();
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * dbg_check_key_order - make sure that colliding keys are properly ordered.
+ * @c: UBIFS file-system description object
+ * @zbr1: first zbranch
+ * @zbr2: following zbranch
+ *
+ * In UBIFS indexing B-tree colliding keys has to be sorted in binary order of
+ * names of the direntries/xentries which are referred by the keys. This
+ * function reads direntries/xentries referred by @zbr1 and @zbr2 and makes
+ * sure the name of direntry/xentry referred by @zbr1 is less than
+ * direntry/xentry referred by @zbr2. Returns zero if this is true, %1 if not,
+ * and a negative error code in case of failure.
+ */
+static int dbg_check_key_order(struct ubifs_info *c, struct ubifs_zbranch *zbr1,
+			       struct ubifs_zbranch *zbr2)
+{
+	int err, nlen1, nlen2, cmp;
+	struct ubifs_dent_node *dent1, *dent2;
+	union ubifs_key key;
+	char key_buf[DBG_KEY_BUF_LEN];
+
+	ubifs_assert(!keys_cmp(c, &zbr1->key, &zbr2->key));
+	dent1 = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
+	if (!dent1)
+		return -ENOMEM;
+	dent2 = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
+	if (!dent2) {
+		err = -ENOMEM;
+		goto out_free;
+	}
+
+	err = ubifs_tnc_read_node(c, zbr1, dent1);
+	if (err)
+		goto out_free;
+	err = ubifs_validate_entry(c, dent1);
+	if (err)
+		goto out_free;
+
+	err = ubifs_tnc_read_node(c, zbr2, dent2);
+	if (err)
+		goto out_free;
+	err = ubifs_validate_entry(c, dent2);
+	if (err)
+		goto out_free;
+
+	/* Make sure node keys are the same as in zbranch */
+	err = 1;
+	key_read(c, &dent1->key, &key);
+	if (keys_cmp(c, &zbr1->key, &key)) {
+		ubifs_err(c, "1st entry at %d:%d has key %s", zbr1->lnum,
+			  zbr1->offs, dbg_snprintf_key(c, &key, key_buf,
+						       DBG_KEY_BUF_LEN));
+		ubifs_err(c, "but it should have key %s according to tnc",
+			  dbg_snprintf_key(c, &zbr1->key, key_buf,
+					   DBG_KEY_BUF_LEN));
+		ubifs_dump_node(c, dent1);
+		goto out_free;
+	}
+
+	key_read(c, &dent2->key, &key);
+	if (keys_cmp(c, &zbr2->key, &key)) {
+		ubifs_err(c, "2nd entry at %d:%d has key %s", zbr1->lnum,
+			  zbr1->offs, dbg_snprintf_key(c, &key, key_buf,
+						       DBG_KEY_BUF_LEN));
+		ubifs_err(c, "but it should have key %s according to tnc",
+			  dbg_snprintf_key(c, &zbr2->key, key_buf,
+					   DBG_KEY_BUF_LEN));
+		ubifs_dump_node(c, dent2);
+		goto out_free;
+	}
+
+	nlen1 = le16_to_cpu(dent1->nlen);
+	nlen2 = le16_to_cpu(dent2->nlen);
+
+	cmp = memcmp(dent1->name, dent2->name, min_t(int, nlen1, nlen2));
+	if (cmp < 0 || (cmp == 0 && nlen1 < nlen2)) {
+		err = 0;
+		goto out_free;
+	}
+	if (cmp == 0 && nlen1 == nlen2)
+		ubifs_err(c, "2 xent/dent nodes with the same name");
+	else
+		ubifs_err(c, "bad order of colliding key %s",
+			  dbg_snprintf_key(c, &key, key_buf, DBG_KEY_BUF_LEN));
+
+	ubifs_msg(c, "first node at %d:%d\n", zbr1->lnum, zbr1->offs);
+	ubifs_dump_node(c, dent1);
+	ubifs_msg(c, "second node at %d:%d\n", zbr2->lnum, zbr2->offs);
+	ubifs_dump_node(c, dent2);
+
+out_free:
+	kfree(dent2);
+	kfree(dent1);
+	return err;
+}
+
+/**
+ * dbg_check_znode - check if znode is all right.
+ * @c: UBIFS file-system description object
+ * @zbr: zbranch which points to this znode
+ *
+ * This function makes sure that znode referred to by @zbr is all right.
+ * Returns zero if it is, and %-EINVAL if it is not.
+ */
+static int dbg_check_znode(struct ubifs_info *c, struct ubifs_zbranch *zbr)
+{
+	struct ubifs_znode *znode = zbr->znode;
+	struct ubifs_znode *zp = znode->parent;
+	int n, err, cmp;
+
+	if (znode->child_cnt <= 0 || znode->child_cnt > c->fanout) {
+		err = 1;
+		goto out;
+	}
+	if (znode->level < 0) {
+		err = 2;
+		goto out;
+	}
+	if (znode->iip < 0 || znode->iip >= c->fanout) {
+		err = 3;
+		goto out;
+	}
+
+	if (zbr->len == 0)
+		/* Only dirty zbranch may have no on-flash nodes */
+		if (!ubifs_zn_dirty(znode)) {
+			err = 4;
+			goto out;
+		}
+
+	if (ubifs_zn_dirty(znode)) {
+		/*
+		 * If znode is dirty, its parent has to be dirty as well. The
+		 * order of the operation is important, so we have to have
+		 * memory barriers.
+		 */
+		smp_mb();
+		if (zp && !ubifs_zn_dirty(zp)) {
+			/*
+			 * The dirty flag is atomic and is cleared outside the
+			 * TNC mutex, so znode's dirty flag may now have
+			 * been cleared. The child is always cleared before the
+			 * parent, so we just need to check again.
+			 */
+			smp_mb();
+			if (ubifs_zn_dirty(znode)) {
+				err = 5;
+				goto out;
+			}
+		}
+	}
+
+	if (zp) {
+		const union ubifs_key *min, *max;
+
+		if (znode->level != zp->level - 1) {
+			err = 6;
+			goto out;
+		}
+
+		/* Make sure the 'parent' pointer in our znode is correct */
+		err = ubifs_search_zbranch(c, zp, &zbr->key, &n);
+		if (!err) {
+			/* This zbranch does not exist in the parent */
+			err = 7;
+			goto out;
+		}
+
+		if (znode->iip >= zp->child_cnt) {
+			err = 8;
+			goto out;
+		}
+
+		if (znode->iip != n) {
+			/* This may happen only in case of collisions */
+			if (keys_cmp(c, &zp->zbranch[n].key,
+				     &zp->zbranch[znode->iip].key)) {
+				err = 9;
+				goto out;
+			}
+			n = znode->iip;
+		}
+
+		/*
+		 * Make sure that the first key in our znode is greater than or
+		 * equal to the key in the pointing zbranch.
+		 */
+		min = &zbr->key;
+		cmp = keys_cmp(c, min, &znode->zbranch[0].key);
+		if (cmp == 1) {
+			err = 10;
+			goto out;
+		}
+
+		if (n + 1 < zp->child_cnt) {
+			max = &zp->zbranch[n + 1].key;
+
+			/*
+			 * Make sure the last key in our znode is less or
+			 * equivalent than the key in the zbranch which goes
+			 * after our pointing zbranch.
+			 */
+			cmp = keys_cmp(c, max,
+				&znode->zbranch[znode->child_cnt - 1].key);
+			if (cmp == -1) {
+				err = 11;
+				goto out;
+			}
+		}
+	} else {
+		/* This may only be root znode */
+		if (zbr != &c->zroot) {
+			err = 12;
+			goto out;
+		}
+	}
+
+	/*
+	 * Make sure that next key is greater or equivalent then the previous
+	 * one.
+	 */
+	for (n = 1; n < znode->child_cnt; n++) {
+		cmp = keys_cmp(c, &znode->zbranch[n - 1].key,
+			       &znode->zbranch[n].key);
+		if (cmp > 0) {
+			err = 13;
+			goto out;
+		}
+		if (cmp == 0) {
+			/* This can only be keys with colliding hash */
+			if (!is_hash_key(c, &znode->zbranch[n].key)) {
+				err = 14;
+				goto out;
+			}
+
+			if (znode->level != 0 || c->replaying)
+				continue;
+
+			/*
+			 * Colliding keys should follow binary order of
+			 * corresponding xentry/dentry names.
+			 */
+			err = dbg_check_key_order(c, &znode->zbranch[n - 1],
+						  &znode->zbranch[n]);
+			if (err < 0)
+				return err;
+			if (err) {
+				err = 15;
+				goto out;
+			}
+		}
+	}
+
+	for (n = 0; n < znode->child_cnt; n++) {
+		if (!znode->zbranch[n].znode &&
+		    (znode->zbranch[n].lnum == 0 ||
+		     znode->zbranch[n].len == 0)) {
+			err = 16;
+			goto out;
+		}
+
+		if (znode->zbranch[n].lnum != 0 &&
+		    znode->zbranch[n].len == 0) {
+			err = 17;
+			goto out;
+		}
+
+		if (znode->zbranch[n].lnum == 0 &&
+		    znode->zbranch[n].len != 0) {
+			err = 18;
+			goto out;
+		}
+
+		if (znode->zbranch[n].lnum == 0 &&
+		    znode->zbranch[n].offs != 0) {
+			err = 19;
+			goto out;
+		}
+
+		if (znode->level != 0 && znode->zbranch[n].znode)
+			if (znode->zbranch[n].znode->parent != znode) {
+				err = 20;
+				goto out;
+			}
+	}
+
+	return 0;
+
+out:
+	ubifs_err(c, "failed, error %d", err);
+	ubifs_msg(c, "dump of the znode");
+	ubifs_dump_znode(c, znode);
+	if (zp) {
+		ubifs_msg(c, "dump of the parent znode");
+		ubifs_dump_znode(c, zp);
+	}
+	dump_stack();
+	return -EINVAL;
+}
+
+/**
+ * dbg_check_tnc - check TNC tree.
+ * @c: UBIFS file-system description object
+ * @extra: do extra checks that are possible at start commit
+ *
+ * This function traverses whole TNC tree and checks every znode. Returns zero
+ * if everything is all right and %-EINVAL if something is wrong with TNC.
+ */
+int dbg_check_tnc(struct ubifs_info *c, int extra)
+{
+	struct ubifs_znode *znode;
+	long clean_cnt = 0, dirty_cnt = 0;
+	int err, last;
+
+	if (!dbg_is_chk_index(c))
+		return 0;
+
+	ubifs_assert(mutex_is_locked(&c->tnc_mutex));
+	if (!c->zroot.znode)
+		return 0;
+
+	znode = ubifs_tnc_postorder_first(c->zroot.znode);
+	while (1) {
+		struct ubifs_znode *prev;
+		struct ubifs_zbranch *zbr;
+
+		if (!znode->parent)
+			zbr = &c->zroot;
+		else
+			zbr = &znode->parent->zbranch[znode->iip];
+
+		err = dbg_check_znode(c, zbr);
+		if (err)
+			return err;
+
+		if (extra) {
+			if (ubifs_zn_dirty(znode))
+				dirty_cnt += 1;
+			else
+				clean_cnt += 1;
+		}
+
+		prev = znode;
+		znode = ubifs_tnc_postorder_next(znode);
+		if (!znode)
+			break;
+
+		/*
+		 * If the last key of this znode is equivalent to the first key
+		 * of the next znode (collision), then check order of the keys.
+		 */
+		last = prev->child_cnt - 1;
+		if (prev->level == 0 && znode->level == 0 && !c->replaying &&
+		    !keys_cmp(c, &prev->zbranch[last].key,
+			      &znode->zbranch[0].key)) {
+			err = dbg_check_key_order(c, &prev->zbranch[last],
+						  &znode->zbranch[0]);
+			if (err < 0)
+				return err;
+			if (err) {
+				ubifs_msg(c, "first znode");
+				ubifs_dump_znode(c, prev);
+				ubifs_msg(c, "second znode");
+				ubifs_dump_znode(c, znode);
+				return -EINVAL;
+			}
+		}
+	}
+
+	if (extra) {
+		if (clean_cnt != atomic_long_read(&c->clean_zn_cnt)) {
+			ubifs_err(c, "incorrect clean_zn_cnt %ld, calculated %ld",
+				  atomic_long_read(&c->clean_zn_cnt),
+				  clean_cnt);
+			return -EINVAL;
+		}
+		if (dirty_cnt != atomic_long_read(&c->dirty_zn_cnt)) {
+			ubifs_err(c, "incorrect dirty_zn_cnt %ld, calculated %ld",
+				  atomic_long_read(&c->dirty_zn_cnt),
+				  dirty_cnt);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * dbg_walk_index - walk the on-flash index.
+ * @c: UBIFS file-system description object
+ * @leaf_cb: called for each leaf node
+ * @znode_cb: called for each indexing node
+ * @priv: private data which is passed to callbacks
+ *
+ * This function walks the UBIFS index and calls the @leaf_cb for each leaf
+ * node and @znode_cb for each indexing node. Returns zero in case of success
+ * and a negative error code in case of failure.
+ *
+ * It would be better if this function removed every znode it pulled to into
+ * the TNC, so that the behavior more closely matched the non-debugging
+ * behavior.
+ */
+int dbg_walk_index(struct ubifs_info *c, dbg_leaf_callback leaf_cb,
+		   dbg_znode_callback znode_cb, void *priv)
+{
+	int err;
+	struct ubifs_zbranch *zbr;
+	struct ubifs_znode *znode, *child;
+
+	mutex_lock(&c->tnc_mutex);
+	/* If the root indexing node is not in TNC - pull it */
+	if (!c->zroot.znode) {
+		c->zroot.znode = ubifs_load_znode(c, &c->zroot, NULL, 0);
+		if (IS_ERR(c->zroot.znode)) {
+			err = PTR_ERR(c->zroot.znode);
+			c->zroot.znode = NULL;
+			goto out_unlock;
+		}
+	}
+
+	/*
+	 * We are going to traverse the indexing tree in the postorder manner.
+	 * Go down and find the leftmost indexing node where we are going to
+	 * start from.
+	 */
+	znode = c->zroot.znode;
+	while (znode->level > 0) {
+		zbr = &znode->zbranch[0];
+		child = zbr->znode;
+		if (!child) {
+			child = ubifs_load_znode(c, zbr, znode, 0);
+			if (IS_ERR(child)) {
+				err = PTR_ERR(child);
+				goto out_unlock;
+			}
+			zbr->znode = child;
+		}
+
+		znode = child;
+	}
+
+	/* Iterate over all indexing nodes */
+	while (1) {
+		int idx;
+
+		cond_resched();
+
+		if (znode_cb) {
+			err = znode_cb(c, znode, priv);
+			if (err) {
+				ubifs_err(c, "znode checking function returned error %d",
+					  err);
+				ubifs_dump_znode(c, znode);
+				goto out_dump;
+			}
+		}
+		if (leaf_cb && znode->level == 0) {
+			for (idx = 0; idx < znode->child_cnt; idx++) {
+				zbr = &znode->zbranch[idx];
+				err = leaf_cb(c, zbr, priv);
+				if (err) {
+					ubifs_err(c, "leaf checking function returned error %d, for leaf at LEB %d:%d",
+						  err, zbr->lnum, zbr->offs);
+					goto out_dump;
+				}
+			}
+		}
+
+		if (!znode->parent)
+			break;
+
+		idx = znode->iip + 1;
+		znode = znode->parent;
+		if (idx < znode->child_cnt) {
+			/* Switch to the next index in the parent */
+			zbr = &znode->zbranch[idx];
+			child = zbr->znode;
+			if (!child) {
+				child = ubifs_load_znode(c, zbr, znode, idx);
+				if (IS_ERR(child)) {
+					err = PTR_ERR(child);
+					goto out_unlock;
+				}
+				zbr->znode = child;
+			}
+			znode = child;
+		} else
+			/*
+			 * This is the last child, switch to the parent and
+			 * continue.
+			 */
+			continue;
+
+		/* Go to the lowest leftmost znode in the new sub-tree */
+		while (znode->level > 0) {
+			zbr = &znode->zbranch[0];
+			child = zbr->znode;
+			if (!child) {
+				child = ubifs_load_znode(c, zbr, znode, 0);
+				if (IS_ERR(child)) {
+					err = PTR_ERR(child);
+					goto out_unlock;
+				}
+				zbr->znode = child;
+			}
+			znode = child;
+		}
+	}
+
+	mutex_unlock(&c->tnc_mutex);
+	return 0;
+
+out_dump:
+	if (znode->parent)
+		zbr = &znode->parent->zbranch[znode->iip];
+	else
+		zbr = &c->zroot;
+	ubifs_msg(c, "dump of znode at LEB %d:%d", zbr->lnum, zbr->offs);
+	ubifs_dump_znode(c, znode);
+out_unlock:
+	mutex_unlock(&c->tnc_mutex);
+	return err;
+}
+
+/**
+ * add_size - add znode size to partially calculated index size.
+ * @c: UBIFS file-system description object
+ * @znode: znode to add size for
+ * @priv: partially calculated index size
+ *
+ * This is a helper function for 'dbg_check_idx_size()' which is called for
+ * every indexing node and adds its size to the 'long long' variable pointed to
+ * by @priv.
+ */
+static int add_size(struct ubifs_info *c, struct ubifs_znode *znode, void *priv)
+{
+	long long *idx_size = priv;
+	int add;
+
+	add = ubifs_idx_node_sz(c, znode->child_cnt);
+	add = ALIGN(add, 8);
+	*idx_size += add;
+	return 0;
+}
+
+/**
+ * dbg_check_idx_size - check index size.
+ * @c: UBIFS file-system description object
+ * @idx_size: size to check
+ *
+ * This function walks the UBIFS index, calculates its size and checks that the
+ * size is equivalent to @idx_size. Returns zero in case of success and a
+ * negative error code in case of failure.
+ */
+int dbg_check_idx_size(struct ubifs_info *c, long long idx_size)
+{
+	int err;
+	long long calc = 0;
+
+	if (!dbg_is_chk_index(c))
+		return 0;
+
+	err = dbg_walk_index(c, NULL, add_size, &calc);
+	if (err) {
+		ubifs_err(c, "error %d while walking the index", err);
+		return err;
+	}
+
+	if (calc != idx_size) {
+		ubifs_err(c, "index size check failed: calculated size is %lld, should be %lld",
+			  calc, idx_size);
+		dump_stack();
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * struct fsck_inode - information about an inode used when checking the file-system.
+ * @rb: link in the RB-tree of inodes
+ * @inum: inode number
+ * @mode: inode type, permissions, etc
+ * @nlink: inode link count
+ * @xattr_cnt: count of extended attributes
+ * @references: how many directory/xattr entries refer this inode (calculated
+ *              while walking the index)
+ * @calc_cnt: for directory inode count of child directories
+ * @size: inode size (read from on-flash inode)
+ * @xattr_sz: summary size of all extended attributes (read from on-flash
+ *            inode)
+ * @calc_sz: for directories calculated directory size
+ * @calc_xcnt: count of extended attributes
+ * @calc_xsz: calculated summary size of all extended attributes
+ * @xattr_nms: sum of lengths of all extended attribute names belonging to this
+ *             inode (read from on-flash inode)
+ * @calc_xnms: calculated sum of lengths of all extended attribute names
+ */
+struct fsck_inode {
+	struct rb_node rb;
+	ino_t inum;
+	umode_t mode;
+	unsigned int nlink;
+	unsigned int xattr_cnt;
+	int references;
+	int calc_cnt;
+	long long size;
+	unsigned int xattr_sz;
+	long long calc_sz;
+	long long calc_xcnt;
+	long long calc_xsz;
+	unsigned int xattr_nms;
+	long long calc_xnms;
+};
+
+/**
+ * struct fsck_data - private FS checking information.
+ * @inodes: RB-tree of all inodes (contains @struct fsck_inode objects)
+ */
+struct fsck_data {
+	struct rb_root inodes;
+};
+
+/**
+ * add_inode - add inode information to RB-tree of inodes.
+ * @c: UBIFS file-system description object
+ * @fsckd: FS checking information
+ * @ino: raw UBIFS inode to add
+ *
+ * This is a helper function for 'check_leaf()' which adds information about
+ * inode @ino to the RB-tree of inodes. Returns inode information pointer in
+ * case of success and a negative error code in case of failure.
+ */
+static struct fsck_inode *add_inode(struct ubifs_info *c,
+				    struct fsck_data *fsckd,
+				    struct ubifs_ino_node *ino)
+{
+	struct rb_node **p, *parent = NULL;
+	struct fsck_inode *fscki;
+	ino_t inum = key_inum_flash(c, &ino->key);
+	struct inode *inode;
+	struct ubifs_inode *ui;
+
+	p = &fsckd->inodes.rb_node;
+	while (*p) {
+		parent = *p;
+		fscki = rb_entry(parent, struct fsck_inode, rb);
+		if (inum < fscki->inum)
+			p = &(*p)->rb_left;
+		else if (inum > fscki->inum)
+			p = &(*p)->rb_right;
+		else
+			return fscki;
+	}
+
+	if (inum > c->highest_inum) {
+		ubifs_err(c, "too high inode number, max. is %lu",
+			  (unsigned long)c->highest_inum);
+		return ERR_PTR(-EINVAL);
+	}
+
+	fscki = kzalloc(sizeof(struct fsck_inode), GFP_NOFS);
+	if (!fscki)
+		return ERR_PTR(-ENOMEM);
+
+	inode = ilookup(c->vfs_sb, inum);
+
+	fscki->inum = inum;
+	/*
+	 * If the inode is present in the VFS inode cache, use it instead of
+	 * the on-flash inode which might be out-of-date. E.g., the size might
+	 * be out-of-date. If we do not do this, the following may happen, for
+	 * example:
+	 *   1. A power cut happens
+	 *   2. We mount the file-system R/O, the replay process fixes up the
+	 *      inode size in the VFS cache, but on on-flash.
+	 *   3. 'check_leaf()' fails because it hits a data node beyond inode
+	 *      size.
+	 */
+	if (!inode) {
+		fscki->nlink = le32_to_cpu(ino->nlink);
+		fscki->size = le64_to_cpu(ino->size);
+		fscki->xattr_cnt = le32_to_cpu(ino->xattr_cnt);
+		fscki->xattr_sz = le32_to_cpu(ino->xattr_size);
+		fscki->xattr_nms = le32_to_cpu(ino->xattr_names);
+		fscki->mode = le32_to_cpu(ino->mode);
+	} else {
+		ui = ubifs_inode(inode);
+		fscki->nlink = inode->i_nlink;
+		fscki->size = inode->i_size;
+		fscki->xattr_cnt = ui->xattr_cnt;
+		fscki->xattr_sz = ui->xattr_size;
+		fscki->xattr_nms = ui->xattr_names;
+		fscki->mode = inode->i_mode;
+		iput(inode);
+	}
+
+	if (S_ISDIR(fscki->mode)) {
+		fscki->calc_sz = UBIFS_INO_NODE_SZ;
+		fscki->calc_cnt = 2;
+	}
+
+	rb_link_node(&fscki->rb, parent, p);
+	rb_insert_color(&fscki->rb, &fsckd->inodes);
+
+	return fscki;
+}
+
+/**
+ * search_inode - search inode in the RB-tree of inodes.
+ * @fsckd: FS checking information
+ * @inum: inode number to search
+ *
+ * This is a helper function for 'check_leaf()' which searches inode @inum in
+ * the RB-tree of inodes and returns an inode information pointer or %NULL if
+ * the inode was not found.
+ */
+static struct fsck_inode *search_inode(struct fsck_data *fsckd, ino_t inum)
+{
+	struct rb_node *p;
+	struct fsck_inode *fscki;
+
+	p = fsckd->inodes.rb_node;
+	while (p) {
+		fscki = rb_entry(p, struct fsck_inode, rb);
+		if (inum < fscki->inum)
+			p = p->rb_left;
+		else if (inum > fscki->inum)
+			p = p->rb_right;
+		else
+			return fscki;
+	}
+	return NULL;
+}
+
+/**
+ * read_add_inode - read inode node and add it to RB-tree of inodes.
+ * @c: UBIFS file-system description object
+ * @fsckd: FS checking information
+ * @inum: inode number to read
+ *
+ * This is a helper function for 'check_leaf()' which finds inode node @inum in
+ * the index, reads it, and adds it to the RB-tree of inodes. Returns inode
+ * information pointer in case of success and a negative error code in case of
+ * failure.
+ */
+static struct fsck_inode *read_add_inode(struct ubifs_info *c,
+					 struct fsck_data *fsckd, ino_t inum)
+{
+	int n, err;
+	union ubifs_key key;
+	struct ubifs_znode *znode;
+	struct ubifs_zbranch *zbr;
+	struct ubifs_ino_node *ino;
+	struct fsck_inode *fscki;
+
+	fscki = search_inode(fsckd, inum);
+	if (fscki)
+		return fscki;
+
+	ino_key_init(c, &key, inum);
+	err = ubifs_lookup_level0(c, &key, &znode, &n);
+	if (!err) {
+		ubifs_err(c, "inode %lu not found in index", (unsigned long)inum);
+		return ERR_PTR(-ENOENT);
+	} else if (err < 0) {
+		ubifs_err(c, "error %d while looking up inode %lu",
+			  err, (unsigned long)inum);
+		return ERR_PTR(err);
+	}
+
+	zbr = &znode->zbranch[n];
+	if (zbr->len < UBIFS_INO_NODE_SZ) {
+		ubifs_err(c, "bad node %lu node length %d",
+			  (unsigned long)inum, zbr->len);
+		return ERR_PTR(-EINVAL);
+	}
+
+	ino = kmalloc(zbr->len, GFP_NOFS);
+	if (!ino)
+		return ERR_PTR(-ENOMEM);
+
+	err = ubifs_tnc_read_node(c, zbr, ino);
+	if (err) {
+		ubifs_err(c, "cannot read inode node at LEB %d:%d, error %d",
+			  zbr->lnum, zbr->offs, err);
+		kfree(ino);
+		return ERR_PTR(err);
+	}
+
+	fscki = add_inode(c, fsckd, ino);
+	kfree(ino);
+	if (IS_ERR(fscki)) {
+		ubifs_err(c, "error %ld while adding inode %lu node",
+			  PTR_ERR(fscki), (unsigned long)inum);
+		return fscki;
+	}
+
+	return fscki;
+}
+
+/**
+ * check_leaf - check leaf node.
+ * @c: UBIFS file-system description object
+ * @zbr: zbranch of the leaf node to check
+ * @priv: FS checking information
+ *
+ * This is a helper function for 'dbg_check_filesystem()' which is called for
+ * every single leaf node while walking the indexing tree. It checks that the
+ * leaf node referred from the indexing tree exists, has correct CRC, and does
+ * some other basic validation. This function is also responsible for building
+ * an RB-tree of inodes - it adds all inodes into the RB-tree. It also
+ * calculates reference count, size, etc for each inode in order to later
+ * compare them to the information stored inside the inodes and detect possible
+ * inconsistencies. Returns zero in case of success and a negative error code
+ * in case of failure.
+ */
+static int check_leaf(struct ubifs_info *c, struct ubifs_zbranch *zbr,
+		      void *priv)
+{
+	ino_t inum;
+	void *node;
+	struct ubifs_ch *ch;
+	int err, type = key_type(c, &zbr->key);
+	struct fsck_inode *fscki;
+
+	if (zbr->len < UBIFS_CH_SZ) {
+		ubifs_err(c, "bad leaf length %d (LEB %d:%d)",
+			  zbr->len, zbr->lnum, zbr->offs);
+		return -EINVAL;
+	}
+
+	node = kmalloc(zbr->len, GFP_NOFS);
+	if (!node)
+		return -ENOMEM;
+
+	err = ubifs_tnc_read_node(c, zbr, node);
+	if (err) {
+		ubifs_err(c, "cannot read leaf node at LEB %d:%d, error %d",
+			  zbr->lnum, zbr->offs, err);
+		goto out_free;
+	}
+
+	/* If this is an inode node, add it to RB-tree of inodes */
+	if (type == UBIFS_INO_KEY) {
+		fscki = add_inode(c, priv, node);
+		if (IS_ERR(fscki)) {
+			err = PTR_ERR(fscki);
+			ubifs_err(c, "error %d while adding inode node", err);
+			goto out_dump;
+		}
+		goto out;
+	}
+
+	if (type != UBIFS_DENT_KEY && type != UBIFS_XENT_KEY &&
+	    type != UBIFS_DATA_KEY) {
+		ubifs_err(c, "unexpected node type %d at LEB %d:%d",
+			  type, zbr->lnum, zbr->offs);
+		err = -EINVAL;
+		goto out_free;
+	}
+
+	ch = node;
+	if (le64_to_cpu(ch->sqnum) > c->max_sqnum) {
+		ubifs_err(c, "too high sequence number, max. is %llu",
+			  c->max_sqnum);
+		err = -EINVAL;
+		goto out_dump;
+	}
+
+	if (type == UBIFS_DATA_KEY) {
+		long long blk_offs;
+		struct ubifs_data_node *dn = node;
+
+		ubifs_assert(zbr->len >= UBIFS_DATA_NODE_SZ);
+
+		/*
+		 * Search the inode node this data node belongs to and insert
+		 * it to the RB-tree of inodes.
+		 */
+		inum = key_inum_flash(c, &dn->key);
+		fscki = read_add_inode(c, priv, inum);
+		if (IS_ERR(fscki)) {
+			err = PTR_ERR(fscki);
+			ubifs_err(c, "error %d while processing data node and trying to find inode node %lu",
+				  err, (unsigned long)inum);
+			goto out_dump;
+		}
+
+		/* Make sure the data node is within inode size */
+		blk_offs = key_block_flash(c, &dn->key);
+		blk_offs <<= UBIFS_BLOCK_SHIFT;
+		blk_offs += le32_to_cpu(dn->size);
+		if (blk_offs > fscki->size) {
+			ubifs_err(c, "data node at LEB %d:%d is not within inode size %lld",
+				  zbr->lnum, zbr->offs, fscki->size);
+			err = -EINVAL;
+			goto out_dump;
+		}
+	} else {
+		int nlen;
+		struct ubifs_dent_node *dent = node;
+		struct fsck_inode *fscki1;
+
+		ubifs_assert(zbr->len >= UBIFS_DENT_NODE_SZ);
+
+		err = ubifs_validate_entry(c, dent);
+		if (err)
+			goto out_dump;
+
+		/*
+		 * Search the inode node this entry refers to and the parent
+		 * inode node and insert them to the RB-tree of inodes.
+		 */
+		inum = le64_to_cpu(dent->inum);
+		fscki = read_add_inode(c, priv, inum);
+		if (IS_ERR(fscki)) {
+			err = PTR_ERR(fscki);
+			ubifs_err(c, "error %d while processing entry node and trying to find inode node %lu",
+				  err, (unsigned long)inum);
+			goto out_dump;
+		}
+
+		/* Count how many direntries or xentries refers this inode */
+		fscki->references += 1;
+
+		inum = key_inum_flash(c, &dent->key);
+		fscki1 = read_add_inode(c, priv, inum);
+		if (IS_ERR(fscki1)) {
+			err = PTR_ERR(fscki1);
+			ubifs_err(c, "error %d while processing entry node and trying to find parent inode node %lu",
+				  err, (unsigned long)inum);
+			goto out_dump;
+		}
+
+		nlen = le16_to_cpu(dent->nlen);
+		if (type == UBIFS_XENT_KEY) {
+			fscki1->calc_xcnt += 1;
+			fscki1->calc_xsz += CALC_DENT_SIZE(nlen);
+			fscki1->calc_xsz += CALC_XATTR_BYTES(fscki->size);
+			fscki1->calc_xnms += nlen;
+		} else {
+			fscki1->calc_sz += CALC_DENT_SIZE(nlen);
+			if (dent->type == UBIFS_ITYPE_DIR)
+				fscki1->calc_cnt += 1;
+		}
+	}
+
+out:
+	kfree(node);
+	return 0;
+
+out_dump:
+	ubifs_msg(c, "dump of node at LEB %d:%d", zbr->lnum, zbr->offs);
+	ubifs_dump_node(c, node);
+out_free:
+	kfree(node);
+	return err;
+}
+
+/**
+ * free_inodes - free RB-tree of inodes.
+ * @fsckd: FS checking information
+ */
+static void free_inodes(struct fsck_data *fsckd)
+{
+	struct fsck_inode *fscki, *n;
+
+	rbtree_postorder_for_each_entry_safe(fscki, n, &fsckd->inodes, rb)
+		kfree(fscki);
+}
+
+/**
+ * check_inodes - checks all inodes.
+ * @c: UBIFS file-system description object
+ * @fsckd: FS checking information
+ *
+ * This is a helper function for 'dbg_check_filesystem()' which walks the
+ * RB-tree of inodes after the index scan has been finished, and checks that
+ * inode nlink, size, etc are correct. Returns zero if inodes are fine,
+ * %-EINVAL if not, and a negative error code in case of failure.
+ */
+static int check_inodes(struct ubifs_info *c, struct fsck_data *fsckd)
+{
+	int n, err;
+	union ubifs_key key;
+	struct ubifs_znode *znode;
+	struct ubifs_zbranch *zbr;
+	struct ubifs_ino_node *ino;
+	struct fsck_inode *fscki;
+	struct rb_node *this = rb_first(&fsckd->inodes);
+
+	while (this) {
+		fscki = rb_entry(this, struct fsck_inode, rb);
+		this = rb_next(this);
+
+		if (S_ISDIR(fscki->mode)) {
+			/*
+			 * Directories have to have exactly one reference (they
+			 * cannot have hardlinks), although root inode is an
+			 * exception.
+			 */
+			if (fscki->inum != UBIFS_ROOT_INO &&
+			    fscki->references != 1) {
+				ubifs_err(c, "directory inode %lu has %d direntries which refer it, but should be 1",
+					  (unsigned long)fscki->inum,
+					  fscki->references);
+				goto out_dump;
+			}
+			if (fscki->inum == UBIFS_ROOT_INO &&
+			    fscki->references != 0) {
+				ubifs_err(c, "root inode %lu has non-zero (%d) direntries which refer it",
+					  (unsigned long)fscki->inum,
+					  fscki->references);
+				goto out_dump;
+			}
+			if (fscki->calc_sz != fscki->size) {
+				ubifs_err(c, "directory inode %lu size is %lld, but calculated size is %lld",
+					  (unsigned long)fscki->inum,
+					  fscki->size, fscki->calc_sz);
+				goto out_dump;
+			}
+			if (fscki->calc_cnt != fscki->nlink) {
+				ubifs_err(c, "directory inode %lu nlink is %d, but calculated nlink is %d",
+					  (unsigned long)fscki->inum,
+					  fscki->nlink, fscki->calc_cnt);
+				goto out_dump;
+			}
+		} else {
+			if (fscki->references != fscki->nlink) {
+				ubifs_err(c, "inode %lu nlink is %d, but calculated nlink is %d",
+					  (unsigned long)fscki->inum,
+					  fscki->nlink, fscki->references);
+				goto out_dump;
+			}
+		}
+		if (fscki->xattr_sz != fscki->calc_xsz) {
+			ubifs_err(c, "inode %lu has xattr size %u, but calculated size is %lld",
+				  (unsigned long)fscki->inum, fscki->xattr_sz,
+				  fscki->calc_xsz);
+			goto out_dump;
+		}
+		if (fscki->xattr_cnt != fscki->calc_xcnt) {
+			ubifs_err(c, "inode %lu has %u xattrs, but calculated count is %lld",
+				  (unsigned long)fscki->inum,
+				  fscki->xattr_cnt, fscki->calc_xcnt);
+			goto out_dump;
+		}
+		if (fscki->xattr_nms != fscki->calc_xnms) {
+			ubifs_err(c, "inode %lu has xattr names' size %u, but calculated names' size is %lld",
+				  (unsigned long)fscki->inum, fscki->xattr_nms,
+				  fscki->calc_xnms);
+			goto out_dump;
+		}
+	}
+
+	return 0;
+
+out_dump:
+	/* Read the bad inode and dump it */
+	ino_key_init(c, &key, fscki->inum);
+	err = ubifs_lookup_level0(c, &key, &znode, &n);
+	if (!err) {
+		ubifs_err(c, "inode %lu not found in index",
+			  (unsigned long)fscki->inum);
+		return -ENOENT;
+	} else if (err < 0) {
+		ubifs_err(c, "error %d while looking up inode %lu",
+			  err, (unsigned long)fscki->inum);
+		return err;
+	}
+
+	zbr = &znode->zbranch[n];
+	ino = kmalloc(zbr->len, GFP_NOFS);
+	if (!ino)
+		return -ENOMEM;
+
+	err = ubifs_tnc_read_node(c, zbr, ino);
+	if (err) {
+		ubifs_err(c, "cannot read inode node at LEB %d:%d, error %d",
+			  zbr->lnum, zbr->offs, err);
+		kfree(ino);
+		return err;
+	}
+
+	ubifs_msg(c, "dump of the inode %lu sitting in LEB %d:%d",
+		  (unsigned long)fscki->inum, zbr->lnum, zbr->offs);
+	ubifs_dump_node(c, ino);
+	kfree(ino);
+	return -EINVAL;
+}
+
+/**
+ * dbg_check_filesystem - check the file-system.
+ * @c: UBIFS file-system description object
+ *
+ * This function checks the file system, namely:
+ * o makes sure that all leaf nodes exist and their CRCs are correct;
+ * o makes sure inode nlink, size, xattr size/count are correct (for all
+ *   inodes).
+ *
+ * The function reads whole indexing tree and all nodes, so it is pretty
+ * heavy-weight. Returns zero if the file-system is consistent, %-EINVAL if
+ * not, and a negative error code in case of failure.
+ */
+int dbg_check_filesystem(struct ubifs_info *c)
+{
+	int err;
+	struct fsck_data fsckd;
+
+	if (!dbg_is_chk_fs(c))
+		return 0;
+
+	fsckd.inodes = RB_ROOT;
+	err = dbg_walk_index(c, check_leaf, NULL, &fsckd);
+	if (err)
+		goto out_free;
+
+	err = check_inodes(c, &fsckd);
+	if (err)
+		goto out_free;
+
+	free_inodes(&fsckd);
+	return 0;
+
+out_free:
+	ubifs_err(c, "file-system check failed with error %d", err);
+	dump_stack();
+	free_inodes(&fsckd);
+	return err;
+}
+
+/**
+ * dbg_check_data_nodes_order - check that list of data nodes is sorted.
+ * @c: UBIFS file-system description object
+ * @head: the list of nodes ('struct ubifs_scan_node' objects)
+ *
+ * This function returns zero if the list of data nodes is sorted correctly,
+ * and %-EINVAL if not.
+ */
+int dbg_check_data_nodes_order(struct ubifs_info *c, struct list_head *head)
+{
+	struct list_head *cur;
+	struct ubifs_scan_node *sa, *sb;
+
+	if (!dbg_is_chk_gen(c))
+		return 0;
+
+	for (cur = head->next; cur->next != head; cur = cur->next) {
+		ino_t inuma, inumb;
+		uint32_t blka, blkb;
+
+		cond_resched();
+		sa = container_of(cur, struct ubifs_scan_node, list);
+		sb = container_of(cur->next, struct ubifs_scan_node, list);
+
+		if (sa->type != UBIFS_DATA_NODE) {
+			ubifs_err(c, "bad node type %d", sa->type);
+			ubifs_dump_node(c, sa->node);
+			return -EINVAL;
+		}
+		if (sb->type != UBIFS_DATA_NODE) {
+			ubifs_err(c, "bad node type %d", sb->type);
+			ubifs_dump_node(c, sb->node);
+			return -EINVAL;
+		}
+
+		inuma = key_inum(c, &sa->key);
+		inumb = key_inum(c, &sb->key);
+
+		if (inuma < inumb)
+			continue;
+		if (inuma > inumb) {
+			ubifs_err(c, "larger inum %lu goes before inum %lu",
+				  (unsigned long)inuma, (unsigned long)inumb);
+			goto error_dump;
+		}
+
+		blka = key_block(c, &sa->key);
+		blkb = key_block(c, &sb->key);
+
+		if (blka > blkb) {
+			ubifs_err(c, "larger block %u goes before %u", blka, blkb);
+			goto error_dump;
+		}
+		if (blka == blkb) {
+			ubifs_err(c, "two data nodes for the same block");
+			goto error_dump;
+		}
+	}
+
+	return 0;
+
+error_dump:
+	ubifs_dump_node(c, sa->node);
+	ubifs_dump_node(c, sb->node);
+	return -EINVAL;
+}
+
+/**
+ * dbg_check_nondata_nodes_order - check that list of data nodes is sorted.
+ * @c: UBIFS file-system description object
+ * @head: the list of nodes ('struct ubifs_scan_node' objects)
+ *
+ * This function returns zero if the list of non-data nodes is sorted correctly,
+ * and %-EINVAL if not.
+ */
+int dbg_check_nondata_nodes_order(struct ubifs_info *c, struct list_head *head)
+{
+	struct list_head *cur;
+	struct ubifs_scan_node *sa, *sb;
+
+	if (!dbg_is_chk_gen(c))
+		return 0;
+
+	for (cur = head->next; cur->next != head; cur = cur->next) {
+		ino_t inuma, inumb;
+		uint32_t hasha, hashb;
+
+		cond_resched();
+		sa = container_of(cur, struct ubifs_scan_node, list);
+		sb = container_of(cur->next, struct ubifs_scan_node, list);
+
+		if (sa->type != UBIFS_INO_NODE && sa->type != UBIFS_DENT_NODE &&
+		    sa->type != UBIFS_XENT_NODE) {
+			ubifs_err(c, "bad node type %d", sa->type);
+			ubifs_dump_node(c, sa->node);
+			return -EINVAL;
+		}
+		if (sa->type != UBIFS_INO_NODE && sa->type != UBIFS_DENT_NODE &&
+		    sa->type != UBIFS_XENT_NODE) {
+			ubifs_err(c, "bad node type %d", sb->type);
+			ubifs_dump_node(c, sb->node);
+			return -EINVAL;
+		}
+
+		if (sa->type != UBIFS_INO_NODE && sb->type == UBIFS_INO_NODE) {
+			ubifs_err(c, "non-inode node goes before inode node");
+			goto error_dump;
+		}
+
+		if (sa->type == UBIFS_INO_NODE && sb->type != UBIFS_INO_NODE)
+			continue;
+
+		if (sa->type == UBIFS_INO_NODE && sb->type == UBIFS_INO_NODE) {
+			/* Inode nodes are sorted in descending size order */
+			if (sa->len < sb->len) {
+				ubifs_err(c, "smaller inode node goes first");
+				goto error_dump;
+			}
+			continue;
+		}
+
+		/*
+		 * This is either a dentry or xentry, which should be sorted in
+		 * ascending (parent ino, hash) order.
+		 */
+		inuma = key_inum(c, &sa->key);
+		inumb = key_inum(c, &sb->key);
+
+		if (inuma < inumb)
+			continue;
+		if (inuma > inumb) {
+			ubifs_err(c, "larger inum %lu goes before inum %lu",
+				  (unsigned long)inuma, (unsigned long)inumb);
+			goto error_dump;
+		}
+
+		hasha = key_block(c, &sa->key);
+		hashb = key_block(c, &sb->key);
+
+		if (hasha > hashb) {
+			ubifs_err(c, "larger hash %u goes before %u",
+				  hasha, hashb);
+			goto error_dump;
+		}
+	}
+
+	return 0;
+
+error_dump:
+	ubifs_msg(c, "dumping first node");
+	ubifs_dump_node(c, sa->node);
+	ubifs_msg(c, "dumping second node");
+	ubifs_dump_node(c, sb->node);
+	return -EINVAL;
+	return 0;
+}
+
+static inline int chance(unsigned int n, unsigned int out_of)
+{
+	return !!((prandom_u32() % out_of) + 1 <= n);
+
+}
+
+static int power_cut_emulated(struct ubifs_info *c, int lnum, int write)
+{
+	struct ubifs_debug_info *d = c->dbg;
+
+	ubifs_assert(dbg_is_tst_rcvry(c));
+
+	if (!d->pc_cnt) {
+		/* First call - decide delay to the power cut */
+		if (chance(1, 2)) {
+			unsigned long delay;
+
+			if (chance(1, 2)) {
+				d->pc_delay = 1;
+				/* Fail within 1 minute */
+				delay = prandom_u32() % 60000;
+				d->pc_timeout = jiffies;
+				d->pc_timeout += msecs_to_jiffies(delay);
+				ubifs_warn(c, "failing after %lums", delay);
+			} else {
+				d->pc_delay = 2;
+				delay = prandom_u32() % 10000;
+				/* Fail within 10000 operations */
+				d->pc_cnt_max = delay;
+				ubifs_warn(c, "failing after %lu calls", delay);
+			}
+		}
+
+		d->pc_cnt += 1;
+	}
+
+	/* Determine if failure delay has expired */
+	if (d->pc_delay == 1 && time_before(jiffies, d->pc_timeout))
+			return 0;
+	if (d->pc_delay == 2 && d->pc_cnt++ < d->pc_cnt_max)
+			return 0;
+
+	if (lnum == UBIFS_SB_LNUM) {
+		if (write && chance(1, 2))
+			return 0;
+		if (chance(19, 20))
+			return 0;
+		ubifs_warn(c, "failing in super block LEB %d", lnum);
+	} else if (lnum == UBIFS_MST_LNUM || lnum == UBIFS_MST_LNUM + 1) {
+		if (chance(19, 20))
+			return 0;
+		ubifs_warn(c, "failing in master LEB %d", lnum);
+	} else if (lnum >= UBIFS_LOG_LNUM && lnum <= c->log_last) {
+		if (write && chance(99, 100))
+			return 0;
+		if (chance(399, 400))
+			return 0;
+		ubifs_warn(c, "failing in log LEB %d", lnum);
+	} else if (lnum >= c->lpt_first && lnum <= c->lpt_last) {
+		if (write && chance(7, 8))
+			return 0;
+		if (chance(19, 20))
+			return 0;
+		ubifs_warn(c, "failing in LPT LEB %d", lnum);
+	} else if (lnum >= c->orph_first && lnum <= c->orph_last) {
+		if (write && chance(1, 2))
+			return 0;
+		if (chance(9, 10))
+			return 0;
+		ubifs_warn(c, "failing in orphan LEB %d", lnum);
+	} else if (lnum == c->ihead_lnum) {
+		if (chance(99, 100))
+			return 0;
+		ubifs_warn(c, "failing in index head LEB %d", lnum);
+	} else if (c->jheads && lnum == c->jheads[GCHD].wbuf.lnum) {
+		if (chance(9, 10))
+			return 0;
+		ubifs_warn(c, "failing in GC head LEB %d", lnum);
+	} else if (write && !RB_EMPTY_ROOT(&c->buds) &&
+		   !ubifs_search_bud(c, lnum)) {
+		if (chance(19, 20))
+			return 0;
+		ubifs_warn(c, "failing in non-bud LEB %d", lnum);
+	} else if (c->cmt_state == COMMIT_RUNNING_BACKGROUND ||
+		   c->cmt_state == COMMIT_RUNNING_REQUIRED) {
+		if (chance(999, 1000))
+			return 0;
+		ubifs_warn(c, "failing in bud LEB %d commit running", lnum);
+	} else {
+		if (chance(9999, 10000))
+			return 0;
+		ubifs_warn(c, "failing in bud LEB %d commit not running", lnum);
+	}
+
+	d->pc_happened = 1;
+	ubifs_warn(c, "========== Power cut emulated ==========");
+	dump_stack();
+	return 1;
+}
+
+static int corrupt_data(const struct ubifs_info *c, const void *buf,
+			unsigned int len)
+{
+	unsigned int from, to, ffs = chance(1, 2);
+	unsigned char *p = (void *)buf;
+
+	from = prandom_u32() % len;
+	/* Corruption span max to end of write unit */
+	to = min(len, ALIGN(from + 1, c->max_write_size));
+
+	ubifs_warn(c, "filled bytes %u-%u with %s", from, to - 1,
+		   ffs ? "0xFFs" : "random data");
+
+	if (ffs)
+		memset(p + from, 0xFF, to - from);
+	else
+		prandom_bytes(p + from, to - from);
+
+	return to;
+}
+
+int dbg_leb_write(struct ubifs_info *c, int lnum, const void *buf,
+		  int offs, int len)
+{
+	int err, failing;
+
+	if (c->dbg->pc_happened)
+		return -EROFS;
+
+	failing = power_cut_emulated(c, lnum, 1);
+	if (failing) {
+		len = corrupt_data(c, buf, len);
+		ubifs_warn(c, "actually write %d bytes to LEB %d:%d (the buffer was corrupted)",
+			   len, lnum, offs);
+	}
+	err = ubi_leb_write(c->ubi, lnum, buf, offs, len);
+	if (err)
+		return err;
+	if (failing)
+		return -EROFS;
+	return 0;
+}
+
+int dbg_leb_change(struct ubifs_info *c, int lnum, const void *buf,
+		   int len)
+{
+	int err;
+
+	if (c->dbg->pc_happened)
+		return -EROFS;
+	if (power_cut_emulated(c, lnum, 1))
+		return -EROFS;
+	err = ubi_leb_change(c->ubi, lnum, buf, len);
+	if (err)
+		return err;
+	if (power_cut_emulated(c, lnum, 1))
+		return -EROFS;
+	return 0;
+}
+
+int dbg_leb_unmap(struct ubifs_info *c, int lnum)
+{
+	int err;
+
+	if (c->dbg->pc_happened)
+		return -EROFS;
+	if (power_cut_emulated(c, lnum, 0))
+		return -EROFS;
+	err = ubi_leb_unmap(c->ubi, lnum);
+	if (err)
+		return err;
+	if (power_cut_emulated(c, lnum, 0))
+		return -EROFS;
+	return 0;
+}
+
+int dbg_leb_map(struct ubifs_info *c, int lnum)
+{
+	int err;
+
+	if (c->dbg->pc_happened)
+		return -EROFS;
+	if (power_cut_emulated(c, lnum, 0))
+		return -EROFS;
+	err = ubi_leb_map(c->ubi, lnum);
+	if (err)
+		return err;
+	if (power_cut_emulated(c, lnum, 0))
+		return -EROFS;
+	return 0;
+}
+
+/*
+ * Root directory for UBIFS stuff in debugfs. Contains sub-directories which
+ * contain the stuff specific to particular file-system mounts.
+ */
+static struct dentry *dfs_rootdir;
+
+static int dfs_file_open(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+	return nonseekable_open(inode, file);
+}
+
+/**
+ * provide_user_output - provide output to the user reading a debugfs file.
+ * @val: boolean value for the answer
+ * @u: the buffer to store the answer at
+ * @count: size of the buffer
+ * @ppos: position in the @u output buffer
+ *
+ * This is a simple helper function which stores @val boolean value in the user
+ * buffer when the user reads one of UBIFS debugfs files. Returns amount of
+ * bytes written to @u in case of success and a negative error code in case of
+ * failure.
+ */
+static int provide_user_output(int val, char __user *u, size_t count,
+			       loff_t *ppos)
+{
+	char buf[3];
+
+	if (val)
+		buf[0] = '1';
+	else
+		buf[0] = '0';
+	buf[1] = '\n';
+	buf[2] = 0x00;
+
+	return simple_read_from_buffer(u, count, ppos, buf, 2);
+}
+
+static ssize_t dfs_file_read(struct file *file, char __user *u, size_t count,
+			     loff_t *ppos)
+{
+	struct dentry *dent = file->f_path.dentry;
+	struct ubifs_info *c = file->private_data;
+	struct ubifs_debug_info *d = c->dbg;
+	int val;
+
+	if (dent == d->dfs_chk_gen)
+		val = d->chk_gen;
+	else if (dent == d->dfs_chk_index)
+		val = d->chk_index;
+	else if (dent == d->dfs_chk_orph)
+		val = d->chk_orph;
+	else if (dent == d->dfs_chk_lprops)
+		val = d->chk_lprops;
+	else if (dent == d->dfs_chk_fs)
+		val = d->chk_fs;
+	else if (dent == d->dfs_tst_rcvry)
+		val = d->tst_rcvry;
+	else if (dent == d->dfs_ro_error)
+		val = c->ro_error;
+	else
+		return -EINVAL;
+
+	return provide_user_output(val, u, count, ppos);
+}
+
+/**
+ * interpret_user_input - interpret user debugfs file input.
+ * @u: user-provided buffer with the input
+ * @count: buffer size
+ *
+ * This is a helper function which interpret user input to a boolean UBIFS
+ * debugfs file. Returns %0 or %1 in case of success and a negative error code
+ * in case of failure.
+ */
+static int interpret_user_input(const char __user *u, size_t count)
+{
+	size_t buf_size;
+	char buf[8];
+
+	buf_size = min_t(size_t, count, (sizeof(buf) - 1));
+	if (copy_from_user(buf, u, buf_size))
+		return -EFAULT;
+
+	if (buf[0] == '1')
+		return 1;
+	else if (buf[0] == '0')
+		return 0;
+
+	return -EINVAL;
+}
+
+static ssize_t dfs_file_write(struct file *file, const char __user *u,
+			      size_t count, loff_t *ppos)
+{
+	struct ubifs_info *c = file->private_data;
+	struct ubifs_debug_info *d = c->dbg;
+	struct dentry *dent = file->f_path.dentry;
+	int val;
+
+	/*
+	 * TODO: this is racy - the file-system might have already been
+	 * unmounted and we'd oops in this case. The plan is to fix it with
+	 * help of 'iterate_supers_type()' which we should have in v3.0: when
+	 * a debugfs opened, we rember FS's UUID in file->private_data. Then
+	 * whenever we access the FS via a debugfs file, we iterate all UBIFS
+	 * superblocks and fine the one with the same UUID, and take the
+	 * locking right.
+	 *
+	 * The other way to go suggested by Al Viro is to create a separate
+	 * 'ubifs-debug' file-system instead.
+	 */
+	if (file->f_path.dentry == d->dfs_dump_lprops) {
+		ubifs_dump_lprops(c);
+		return count;
+	}
+	if (file->f_path.dentry == d->dfs_dump_budg) {
+		ubifs_dump_budg(c, &c->bi);
+		return count;
+	}
+	if (file->f_path.dentry == d->dfs_dump_tnc) {
+		mutex_lock(&c->tnc_mutex);
+		ubifs_dump_tnc(c);
+		mutex_unlock(&c->tnc_mutex);
+		return count;
+	}
+
+	val = interpret_user_input(u, count);
+	if (val < 0)
+		return val;
+
+	if (dent == d->dfs_chk_gen)
+		d->chk_gen = val;
+	else if (dent == d->dfs_chk_index)
+		d->chk_index = val;
+	else if (dent == d->dfs_chk_orph)
+		d->chk_orph = val;
+	else if (dent == d->dfs_chk_lprops)
+		d->chk_lprops = val;
+	else if (dent == d->dfs_chk_fs)
+		d->chk_fs = val;
+	else if (dent == d->dfs_tst_rcvry)
+		d->tst_rcvry = val;
+	else if (dent == d->dfs_ro_error)
+		c->ro_error = !!val;
+	else
+		return -EINVAL;
+
+	return count;
+}
+
+static const struct file_operations dfs_fops = {
+	.open = dfs_file_open,
+	.read = dfs_file_read,
+	.write = dfs_file_write,
+	.owner = THIS_MODULE,
+	.llseek = no_llseek,
+};
+
+/**
+ * dbg_debugfs_init_fs - initialize debugfs for UBIFS instance.
+ * @c: UBIFS file-system description object
+ *
+ * This function creates all debugfs files for this instance of UBIFS. Returns
+ * zero in case of success and a negative error code in case of failure.
+ *
+ * Note, the only reason we have not merged this function with the
+ * 'ubifs_debugging_init()' function is because it is better to initialize
+ * debugfs interfaces at the very end of the mount process, and remove them at
+ * the very beginning of the mount process.
+ */
+int dbg_debugfs_init_fs(struct ubifs_info *c)
+{
+	int err, n;
+	const char *fname;
+	struct dentry *dent;
+	struct ubifs_debug_info *d = c->dbg;
+
+	if (!IS_ENABLED(CONFIG_DEBUG_FS))
+		return 0;
+
+	n = snprintf(d->dfs_dir_name, UBIFS_DFS_DIR_LEN + 1, UBIFS_DFS_DIR_NAME,
+		     c->vi.ubi_num, c->vi.vol_id);
+	if (n == UBIFS_DFS_DIR_LEN) {
+		/* The array size is too small */
+		fname = UBIFS_DFS_DIR_NAME;
+		dent = ERR_PTR(-EINVAL);
+		goto out;
+	}
+
+	fname = d->dfs_dir_name;
+	dent = debugfs_create_dir(fname, dfs_rootdir);
+	if (IS_ERR_OR_NULL(dent))
+		goto out;
+	d->dfs_dir = dent;
+
+	fname = "dump_lprops";
+	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, c, &dfs_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	d->dfs_dump_lprops = dent;
+
+	fname = "dump_budg";
+	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, c, &dfs_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	d->dfs_dump_budg = dent;
+
+	fname = "dump_tnc";
+	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, c, &dfs_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	d->dfs_dump_tnc = dent;
+
+	fname = "chk_general";
+	dent = debugfs_create_file(fname, S_IRUSR | S_IWUSR, d->dfs_dir, c,
+				   &dfs_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	d->dfs_chk_gen = dent;
+
+	fname = "chk_index";
+	dent = debugfs_create_file(fname, S_IRUSR | S_IWUSR, d->dfs_dir, c,
+				   &dfs_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	d->dfs_chk_index = dent;
+
+	fname = "chk_orphans";
+	dent = debugfs_create_file(fname, S_IRUSR | S_IWUSR, d->dfs_dir, c,
+				   &dfs_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	d->dfs_chk_orph = dent;
+
+	fname = "chk_lprops";
+	dent = debugfs_create_file(fname, S_IRUSR | S_IWUSR, d->dfs_dir, c,
+				   &dfs_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	d->dfs_chk_lprops = dent;
+
+	fname = "chk_fs";
+	dent = debugfs_create_file(fname, S_IRUSR | S_IWUSR, d->dfs_dir, c,
+				   &dfs_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	d->dfs_chk_fs = dent;
+
+	fname = "tst_recovery";
+	dent = debugfs_create_file(fname, S_IRUSR | S_IWUSR, d->dfs_dir, c,
+				   &dfs_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	d->dfs_tst_rcvry = dent;
+
+	fname = "ro_error";
+	dent = debugfs_create_file(fname, S_IRUSR | S_IWUSR, d->dfs_dir, c,
+				   &dfs_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	d->dfs_ro_error = dent;
+
+	return 0;
+
+out_remove:
+	debugfs_remove_recursive(d->dfs_dir);
+out:
+	err = dent ? PTR_ERR(dent) : -ENODEV;
+	ubifs_err(c, "cannot create \"%s\" debugfs file or directory, error %d\n",
+		  fname, err);
+	return err;
+}
+
+/**
+ * dbg_debugfs_exit_fs - remove all debugfs files.
+ * @c: UBIFS file-system description object
+ */
+void dbg_debugfs_exit_fs(struct ubifs_info *c)
+{
+	if (IS_ENABLED(CONFIG_DEBUG_FS))
+		debugfs_remove_recursive(c->dbg->dfs_dir);
+}
+
+struct ubifs_global_debug_info ubifs_dbg;
+
+static struct dentry *dfs_chk_gen;
+static struct dentry *dfs_chk_index;
+static struct dentry *dfs_chk_orph;
+static struct dentry *dfs_chk_lprops;
+static struct dentry *dfs_chk_fs;
+static struct dentry *dfs_tst_rcvry;
+
+static ssize_t dfs_global_file_read(struct file *file, char __user *u,
+				    size_t count, loff_t *ppos)
+{
+	struct dentry *dent = file->f_path.dentry;
+	int val;
+
+	if (dent == dfs_chk_gen)
+		val = ubifs_dbg.chk_gen;
+	else if (dent == dfs_chk_index)
+		val = ubifs_dbg.chk_index;
+	else if (dent == dfs_chk_orph)
+		val = ubifs_dbg.chk_orph;
+	else if (dent == dfs_chk_lprops)
+		val = ubifs_dbg.chk_lprops;
+	else if (dent == dfs_chk_fs)
+		val = ubifs_dbg.chk_fs;
+	else if (dent == dfs_tst_rcvry)
+		val = ubifs_dbg.tst_rcvry;
+	else
+		return -EINVAL;
+
+	return provide_user_output(val, u, count, ppos);
+}
+
+static ssize_t dfs_global_file_write(struct file *file, const char __user *u,
+				     size_t count, loff_t *ppos)
+{
+	struct dentry *dent = file->f_path.dentry;
+	int val;
+
+	val = interpret_user_input(u, count);
+	if (val < 0)
+		return val;
+
+	if (dent == dfs_chk_gen)
+		ubifs_dbg.chk_gen = val;
+	else if (dent == dfs_chk_index)
+		ubifs_dbg.chk_index = val;
+	else if (dent == dfs_chk_orph)
+		ubifs_dbg.chk_orph = val;
+	else if (dent == dfs_chk_lprops)
+		ubifs_dbg.chk_lprops = val;
+	else if (dent == dfs_chk_fs)
+		ubifs_dbg.chk_fs = val;
+	else if (dent == dfs_tst_rcvry)
+		ubifs_dbg.tst_rcvry = val;
+	else
+		return -EINVAL;
+
+	return count;
+}
+
+static const struct file_operations dfs_global_fops = {
+	.read = dfs_global_file_read,
+	.write = dfs_global_file_write,
+	.owner = THIS_MODULE,
+	.llseek = no_llseek,
+};
+
+/**
+ * dbg_debugfs_init - initialize debugfs file-system.
+ *
+ * UBIFS uses debugfs file-system to expose various debugging knobs to
+ * user-space. This function creates "ubifs" directory in the debugfs
+ * file-system. Returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+int dbg_debugfs_init(void)
+{
+	int err;
+	const char *fname;
+	struct dentry *dent;
+
+	if (!IS_ENABLED(CONFIG_DEBUG_FS))
+		return 0;
+
+	fname = "ubifs";
+	dent = debugfs_create_dir(fname, NULL);
+	if (IS_ERR_OR_NULL(dent))
+		goto out;
+	dfs_rootdir = dent;
+
+	fname = "chk_general";
+	dent = debugfs_create_file(fname, S_IRUSR | S_IWUSR, dfs_rootdir, NULL,
+				   &dfs_global_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	dfs_chk_gen = dent;
+
+	fname = "chk_index";
+	dent = debugfs_create_file(fname, S_IRUSR | S_IWUSR, dfs_rootdir, NULL,
+				   &dfs_global_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	dfs_chk_index = dent;
+
+	fname = "chk_orphans";
+	dent = debugfs_create_file(fname, S_IRUSR | S_IWUSR, dfs_rootdir, NULL,
+				   &dfs_global_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	dfs_chk_orph = dent;
+
+	fname = "chk_lprops";
+	dent = debugfs_create_file(fname, S_IRUSR | S_IWUSR, dfs_rootdir, NULL,
+				   &dfs_global_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	dfs_chk_lprops = dent;
+
+	fname = "chk_fs";
+	dent = debugfs_create_file(fname, S_IRUSR | S_IWUSR, dfs_rootdir, NULL,
+				   &dfs_global_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	dfs_chk_fs = dent;
+
+	fname = "tst_recovery";
+	dent = debugfs_create_file(fname, S_IRUSR | S_IWUSR, dfs_rootdir, NULL,
+				   &dfs_global_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	dfs_tst_rcvry = dent;
+
+	return 0;
+
+out_remove:
+	debugfs_remove_recursive(dfs_rootdir);
+out:
+	err = dent ? PTR_ERR(dent) : -ENODEV;
+	pr_err("UBIFS error (pid %d): cannot create \"%s\" debugfs file or directory, error %d\n",
+	       current->pid, fname, err);
+	return err;
+}
+
+/**
+ * dbg_debugfs_exit - remove the "ubifs" directory from debugfs file-system.
+ */
+void dbg_debugfs_exit(void)
+{
+	if (IS_ENABLED(CONFIG_DEBUG_FS))
+		debugfs_remove_recursive(dfs_rootdir);
+}
+
+/**
+ * ubifs_debugging_init - initialize UBIFS debugging.
+ * @c: UBIFS file-system description object
+ *
+ * This function initializes debugging-related data for the file system.
+ * Returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+int ubifs_debugging_init(struct ubifs_info *c)
+{
+	c->dbg = kzalloc(sizeof(struct ubifs_debug_info), GFP_KERNEL);
+	if (!c->dbg)
+		return -ENOMEM;
+
+	return 0;
+}
+
+/**
+ * ubifs_debugging_exit - free debugging data.
+ * @c: UBIFS file-system description object
+ */
+void ubifs_debugging_exit(struct ubifs_info *c)
+{
+	kfree(c->dbg);
+}