Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 762 insertions, 0 deletions

diff --git a/fs/ubifs/log.c b/fs/ubifs/log.c
new file mode 100644
index 000000000..c6edcbf35
--- /dev/null
+++ b/fs/ubifs/log.c
@@ -0,0 +1,762 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ *
+ * Authors: Artem Bityutskiy (Битюцкий Артём)
+ *          Adrian Hunter
+ */
+
+/*
+ * This file is a part of UBIFS journal implementation and contains various
+ * functions which manipulate the log. The log is a fixed area on the flash
+ * which does not contain any data but refers to buds. The log is a part of the
+ * journal.
+ */
+
+#include "ubifs.h"
+
+static int dbg_check_bud_bytes(struct ubifs_info *c);
+
+/**
+ * ubifs_search_bud - search bud LEB.
+ * @c: UBIFS file-system description object
+ * @lnum: logical eraseblock number to search
+ *
+ * This function searches bud LEB @lnum. Returns bud description object in case
+ * of success and %NULL if there is no bud with this LEB number.
+ */
+struct ubifs_bud *ubifs_search_bud(struct ubifs_info *c, int lnum)
+{
+	struct rb_node *p;
+	struct ubifs_bud *bud;
+
+	spin_lock(&c->buds_lock);
+	p = c->buds.rb_node;
+	while (p) {
+		bud = rb_entry(p, struct ubifs_bud, rb);
+		if (lnum < bud->lnum)
+			p = p->rb_left;
+		else if (lnum > bud->lnum)
+			p = p->rb_right;
+		else {
+			spin_unlock(&c->buds_lock);
+			return bud;
+		}
+	}
+	spin_unlock(&c->buds_lock);
+	return NULL;
+}
+
+/**
+ * ubifs_get_wbuf - get the wbuf associated with a LEB, if there is one.
+ * @c: UBIFS file-system description object
+ * @lnum: logical eraseblock number to search
+ *
+ * This functions returns the wbuf for @lnum or %NULL if there is not one.
+ */
+struct ubifs_wbuf *ubifs_get_wbuf(struct ubifs_info *c, int lnum)
+{
+	struct rb_node *p;
+	struct ubifs_bud *bud;
+	int jhead;
+
+	if (!c->jheads)
+		return NULL;
+
+	spin_lock(&c->buds_lock);
+	p = c->buds.rb_node;
+	while (p) {
+		bud = rb_entry(p, struct ubifs_bud, rb);
+		if (lnum < bud->lnum)
+			p = p->rb_left;
+		else if (lnum > bud->lnum)
+			p = p->rb_right;
+		else {
+			jhead = bud->jhead;
+			spin_unlock(&c->buds_lock);
+			return &c->jheads[jhead].wbuf;
+		}
+	}
+	spin_unlock(&c->buds_lock);
+	return NULL;
+}
+
+/**
+ * empty_log_bytes - calculate amount of empty space in the log.
+ * @c: UBIFS file-system description object
+ */
+static inline long long empty_log_bytes(const struct ubifs_info *c)
+{
+	long long h, t;
+
+	h = (long long)c->lhead_lnum * c->leb_size + c->lhead_offs;
+	t = (long long)c->ltail_lnum * c->leb_size;
+
+	if (h > t)
+		return c->log_bytes - h + t;
+	else if (h != t)
+		return t - h;
+	else if (c->lhead_lnum != c->ltail_lnum)
+		return 0;
+	else
+		return c->log_bytes;
+}
+
+/**
+ * ubifs_add_bud - add bud LEB to the tree of buds and its journal head list.
+ * @c: UBIFS file-system description object
+ * @bud: the bud to add
+ */
+void ubifs_add_bud(struct ubifs_info *c, struct ubifs_bud *bud)
+{
+	struct rb_node **p, *parent = NULL;
+	struct ubifs_bud *b;
+	struct ubifs_jhead *jhead;
+
+	spin_lock(&c->buds_lock);
+	p = &c->buds.rb_node;
+	while (*p) {
+		parent = *p;
+		b = rb_entry(parent, struct ubifs_bud, rb);
+		ubifs_assert(c, bud->lnum != b->lnum);
+		if (bud->lnum < b->lnum)
+			p = &(*p)->rb_left;
+		else
+			p = &(*p)->rb_right;
+	}
+
+	rb_link_node(&bud->rb, parent, p);
+	rb_insert_color(&bud->rb, &c->buds);
+	if (c->jheads) {
+		jhead = &c->jheads[bud->jhead];
+		list_add_tail(&bud->list, &jhead->buds_list);
+	} else
+		ubifs_assert(c, c->replaying && c->ro_mount);
+
+	/*
+	 * Note, although this is a new bud, we anyway account this space now,
+	 * before any data has been written to it, because this is about to
+	 * guarantee fixed mount time, and this bud will anyway be read and
+	 * scanned.
+	 */
+	c->bud_bytes += c->leb_size - bud->start;
+
+	dbg_log("LEB %d:%d, jhead %s, bud_bytes %lld", bud->lnum,
+		bud->start, dbg_jhead(bud->jhead), c->bud_bytes);
+	spin_unlock(&c->buds_lock);
+}
+
+/**
+ * ubifs_add_bud_to_log - add a new bud to the log.
+ * @c: UBIFS file-system description object
+ * @jhead: journal head the bud belongs to
+ * @lnum: LEB number of the bud
+ * @offs: starting offset of the bud
+ *
+ * This function writes a reference node for the new bud LEB @lnum to the log,
+ * and adds it to the buds trees. It also makes sure that log size does not
+ * exceed the 'c->max_bud_bytes' limit. Returns zero in case of success,
+ * %-EAGAIN if commit is required, and a negative error code in case of
+ * failure.
+ */
+int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs)
+{
+	int err;
+	struct ubifs_bud *bud;
+	struct ubifs_ref_node *ref;
+
+	bud = kmalloc_obj(struct ubifs_bud, GFP_NOFS);
+	if (!bud)
+		return -ENOMEM;
+	ref = kzalloc(c->ref_node_alsz, GFP_NOFS);
+	if (!ref) {
+		kfree(bud);
+		return -ENOMEM;
+	}
+
+	mutex_lock(&c->log_mutex);
+	ubifs_assert(c, !c->ro_media && !c->ro_mount);
+	if (c->ro_error) {
+		err = -EROFS;
+		goto out_unlock;
+	}
+
+	/* Make sure we have enough space in the log */
+	if (empty_log_bytes(c) - c->ref_node_alsz < c->min_log_bytes) {
+		dbg_log("not enough log space - %lld, required %d",
+			empty_log_bytes(c), c->min_log_bytes);
+		ubifs_commit_required(c);
+		err = -EAGAIN;
+		goto out_unlock;
+	}
+
+	/*
+	 * Make sure the amount of space in buds will not exceed the
+	 * 'c->max_bud_bytes' limit, because we want to guarantee mount time
+	 * limits.
+	 *
+	 * It is not necessary to hold @c->buds_lock when reading @c->bud_bytes
+	 * because we are holding @c->log_mutex. All @c->bud_bytes take place
+	 * when both @c->log_mutex and @c->bud_bytes are locked.
+	 */
+	if (c->bud_bytes + c->leb_size - offs > c->max_bud_bytes) {
+		dbg_log("bud bytes %lld (%lld max), require commit",
+			c->bud_bytes, c->max_bud_bytes);
+		ubifs_commit_required(c);
+		err = -EAGAIN;
+		goto out_unlock;
+	}
+
+	/*
+	 * If the journal is full enough - start background commit. Note, it is
+	 * OK to read 'c->cmt_state' without spinlock because integer reads
+	 * are atomic in the kernel.
+	 */
+	if (c->bud_bytes >= c->bg_bud_bytes &&
+	    c->cmt_state == COMMIT_RESTING) {
+		dbg_log("bud bytes %lld (%lld max), initiate BG commit",
+			c->bud_bytes, c->max_bud_bytes);
+		ubifs_request_bg_commit(c);
+	}
+
+	bud->lnum = lnum;
+	bud->start = offs;
+	bud->jhead = jhead;
+	bud->log_hash = NULL;
+
+	ref->ch.node_type = UBIFS_REF_NODE;
+	ref->lnum = cpu_to_le32(bud->lnum);
+	ref->offs = cpu_to_le32(bud->start);
+	ref->jhead = cpu_to_le32(jhead);
+
+	if (c->lhead_offs > c->leb_size - c->ref_node_alsz) {
+		c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
+		ubifs_assert(c, c->lhead_lnum != c->ltail_lnum);
+		c->lhead_offs = 0;
+	}
+
+	if (c->lhead_offs == 0) {
+		/* Must ensure next log LEB has been unmapped */
+		err = ubifs_leb_unmap(c, c->lhead_lnum);
+		if (err)
+			goto out_unlock;
+	}
+
+	if (bud->start == 0) {
+		/*
+		 * Before writing the LEB reference which refers an empty LEB
+		 * to the log, we have to make sure it is mapped, because
+		 * otherwise we'd risk to refer an LEB with garbage in case of
+		 * an unclean reboot, because the target LEB might have been
+		 * unmapped, but not yet physically erased.
+		 */
+		err = ubifs_leb_map(c, bud->lnum);
+		if (err)
+			goto out_unlock;
+	}
+
+	dbg_log("write ref LEB %d:%d",
+		c->lhead_lnum, c->lhead_offs);
+	err = ubifs_write_node(c, ref, UBIFS_REF_NODE_SZ, c->lhead_lnum,
+			       c->lhead_offs);
+	if (err)
+		goto out_unlock;
+
+	err = ubifs_shash_update(c, c->log_hash, ref, UBIFS_REF_NODE_SZ);
+	if (err)
+		goto out_unlock;
+
+	err = ubifs_shash_copy_state(c, c->log_hash, c->jheads[jhead].log_hash);
+	if (err)
+		goto out_unlock;
+
+	c->lhead_offs += c->ref_node_alsz;
+
+	ubifs_add_bud(c, bud);
+
+	mutex_unlock(&c->log_mutex);
+	kfree(ref);
+	return 0;
+
+out_unlock:
+	mutex_unlock(&c->log_mutex);
+	kfree(ref);
+	kfree(bud);
+	return err;
+}
+
+/**
+ * remove_buds - remove used buds.
+ * @c: UBIFS file-system description object
+ *
+ * This function removes use buds from the buds tree. It does not remove the
+ * buds which are pointed to by journal heads.
+ */
+static void remove_buds(struct ubifs_info *c)
+{
+	struct rb_node *p;
+
+	ubifs_assert(c, list_empty(&c->old_buds));
+	c->cmt_bud_bytes = 0;
+	spin_lock(&c->buds_lock);
+	p = rb_first(&c->buds);
+	while (p) {
+		struct rb_node *p1 = p;
+		struct ubifs_bud *bud;
+		struct ubifs_wbuf *wbuf;
+
+		p = rb_next(p);
+		bud = rb_entry(p1, struct ubifs_bud, rb);
+		wbuf = &c->jheads[bud->jhead].wbuf;
+
+		if (wbuf->lnum == bud->lnum) {
+			/*
+			 * Do not remove buds which are pointed to by journal
+			 * heads (non-closed buds).
+			 */
+			c->cmt_bud_bytes += wbuf->offs - bud->start;
+			dbg_log("preserve %d:%d, jhead %s, bud bytes %d, cmt_bud_bytes %lld",
+				bud->lnum, bud->start, dbg_jhead(bud->jhead),
+				wbuf->offs - bud->start, c->cmt_bud_bytes);
+			bud->start = wbuf->offs;
+		} else {
+			c->cmt_bud_bytes += c->leb_size - bud->start;
+			dbg_log("remove %d:%d, jhead %s, bud bytes %d, cmt_bud_bytes %lld",
+				bud->lnum, bud->start, dbg_jhead(bud->jhead),
+				c->leb_size - bud->start, c->cmt_bud_bytes);
+			rb_erase(p1, &c->buds);
+			/*
+			 * If the commit does not finish, the recovery will need
+			 * to replay the journal, in which case the old buds
+			 * must be unchanged. Do not release them until post
+			 * commit i.e. do not allow them to be garbage
+			 * collected.
+			 */
+			list_move(&bud->list, &c->old_buds);
+		}
+	}
+	spin_unlock(&c->buds_lock);
+}
+
+/**
+ * ubifs_log_start_commit - start commit.
+ * @c: UBIFS file-system description object
+ * @ltail_lnum: return new log tail LEB number
+ *
+ * The commit operation starts with writing "commit start" node to the log and
+ * reference nodes for all journal heads which will define new journal after
+ * the commit has been finished. The commit start and reference nodes are
+ * written in one go to the nearest empty log LEB (hence, when commit is
+ * finished UBIFS may safely unmap all the previous log LEBs). This function
+ * returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum)
+{
+	void *buf;
+	struct ubifs_cs_node *cs;
+	struct ubifs_ref_node *ref;
+	int err, i, max_len, len;
+
+	err = dbg_check_bud_bytes(c);
+	if (err)
+		return err;
+
+	max_len = UBIFS_CS_NODE_SZ + c->jhead_cnt * UBIFS_REF_NODE_SZ;
+	max_len = ALIGN(max_len, c->min_io_size);
+	buf = cs = kmalloc(max_len, GFP_NOFS);
+	if (!buf)
+		return -ENOMEM;
+
+	cs->ch.node_type = UBIFS_CS_NODE;
+	cs->cmt_no = cpu_to_le64(c->cmt_no);
+	ubifs_prepare_node(c, cs, UBIFS_CS_NODE_SZ, 0);
+
+	err = ubifs_shash_init(c, c->log_hash);
+	if (err)
+		goto out;
+
+	err = ubifs_shash_update(c, c->log_hash, cs, UBIFS_CS_NODE_SZ);
+	if (err < 0)
+		goto out;
+
+	/*
+	 * Note, we do not lock 'c->log_mutex' because this is the commit start
+	 * phase and we are exclusively using the log. And we do not lock
+	 * write-buffer because nobody can write to the file-system at this
+	 * phase.
+	 */
+
+	len = UBIFS_CS_NODE_SZ;
+	for (i = 0; i < c->jhead_cnt; i++) {
+		int lnum = c->jheads[i].wbuf.lnum;
+		int offs = c->jheads[i].wbuf.offs;
+
+		if (lnum == -1 || offs == c->leb_size)
+			continue;
+
+		dbg_log("add ref to LEB %d:%d for jhead %s",
+			lnum, offs, dbg_jhead(i));
+		ref = buf + len;
+		ref->ch.node_type = UBIFS_REF_NODE;
+		ref->lnum = cpu_to_le32(lnum);
+		ref->offs = cpu_to_le32(offs);
+		ref->jhead = cpu_to_le32(i);
+
+		ubifs_prepare_node(c, ref, UBIFS_REF_NODE_SZ, 0);
+		len += UBIFS_REF_NODE_SZ;
+
+		err = ubifs_shash_update(c, c->log_hash, ref,
+					 UBIFS_REF_NODE_SZ);
+		if (err)
+			goto out;
+		ubifs_shash_copy_state(c, c->log_hash, c->jheads[i].log_hash);
+	}
+
+	ubifs_pad(c, buf + len, ALIGN(len, c->min_io_size) - len);
+
+	/* Switch to the next log LEB */
+	if (c->lhead_offs) {
+		c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
+		ubifs_assert(c, c->lhead_lnum != c->ltail_lnum);
+		c->lhead_offs = 0;
+	}
+
+	/* Must ensure next LEB has been unmapped */
+	err = ubifs_leb_unmap(c, c->lhead_lnum);
+	if (err)
+		goto out;
+
+	len = ALIGN(len, c->min_io_size);
+	dbg_log("writing commit start at LEB %d:0, len %d", c->lhead_lnum, len);
+	err = ubifs_leb_write(c, c->lhead_lnum, cs, 0, len);
+	if (err)
+		goto out;
+
+	*ltail_lnum = c->lhead_lnum;
+
+	c->lhead_offs += len;
+	ubifs_assert(c, c->lhead_offs < c->leb_size);
+
+	remove_buds(c);
+
+	/*
+	 * We have started the commit and now users may use the rest of the log
+	 * for new writes.
+	 */
+	c->min_log_bytes = 0;
+
+out:
+	kfree(buf);
+	return err;
+}
+
+/**
+ * ubifs_log_end_commit - end commit.
+ * @c: UBIFS file-system description object
+ * @ltail_lnum: new log tail LEB number
+ *
+ * This function is called on when the commit operation was finished. It
+ * moves log tail to new position and updates the master node so that it stores
+ * the new log tail LEB number. Returns zero in case of success and a negative
+ * error code in case of failure.
+ */
+int ubifs_log_end_commit(struct ubifs_info *c, int ltail_lnum)
+{
+	int err;
+
+	/*
+	 * At this phase we have to lock 'c->log_mutex' because UBIFS allows FS
+	 * writes during commit. Its only short "commit" start phase when
+	 * writers are blocked.
+	 */
+	mutex_lock(&c->log_mutex);
+
+	dbg_log("old tail was LEB %d:0, new tail is LEB %d:0",
+		c->ltail_lnum, ltail_lnum);
+
+	c->ltail_lnum = ltail_lnum;
+	/*
+	 * The commit is finished and from now on it must be guaranteed that
+	 * there is always enough space for the next commit.
+	 */
+	c->min_log_bytes = c->leb_size;
+
+	spin_lock(&c->buds_lock);
+	c->bud_bytes -= c->cmt_bud_bytes;
+	spin_unlock(&c->buds_lock);
+
+	err = dbg_check_bud_bytes(c);
+	if (err)
+		goto out;
+
+	err = ubifs_write_master(c);
+
+out:
+	mutex_unlock(&c->log_mutex);
+	return err;
+}
+
+/**
+ * ubifs_log_post_commit - things to do after commit is completed.
+ * @c: UBIFS file-system description object
+ * @old_ltail_lnum: old log tail LEB number
+ *
+ * Release buds only after commit is completed, because they must be unchanged
+ * if recovery is needed.
+ *
+ * Unmap log LEBs only after commit is completed, because they may be needed for
+ * recovery.
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int ubifs_log_post_commit(struct ubifs_info *c, int old_ltail_lnum)
+{
+	int lnum, err = 0;
+
+	while (!list_empty(&c->old_buds)) {
+		struct ubifs_bud *bud;
+
+		bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
+		err = ubifs_return_leb(c, bud->lnum);
+		if (err)
+			return err;
+		list_del(&bud->list);
+		kfree(bud->log_hash);
+		kfree(bud);
+	}
+	mutex_lock(&c->log_mutex);
+	for (lnum = old_ltail_lnum; lnum != c->ltail_lnum;
+	     lnum = ubifs_next_log_lnum(c, lnum)) {
+		dbg_log("unmap log LEB %d", lnum);
+		err = ubifs_leb_unmap(c, lnum);
+		if (err)
+			goto out;
+	}
+out:
+	mutex_unlock(&c->log_mutex);
+	return err;
+}
+
+/**
+ * struct done_ref - references that have been done.
+ * @rb: rb-tree node
+ * @lnum: LEB number
+ */
+struct done_ref {
+	struct rb_node rb;
+	int lnum;
+};
+
+/**
+ * done_already - determine if a reference has been done already.
+ * @done_tree: rb-tree to store references that have been done
+ * @lnum: LEB number of reference
+ *
+ * This function returns %1 if the reference has been done, %0 if not, otherwise
+ * a negative error code is returned.
+ */
+static int done_already(struct rb_root *done_tree, int lnum)
+{
+	struct rb_node **p = &done_tree->rb_node, *parent = NULL;
+	struct done_ref *dr;
+
+	while (*p) {
+		parent = *p;
+		dr = rb_entry(parent, struct done_ref, rb);
+		if (lnum < dr->lnum)
+			p = &(*p)->rb_left;
+		else if (lnum > dr->lnum)
+			p = &(*p)->rb_right;
+		else
+			return 1;
+	}
+
+	dr = kzalloc_obj(struct done_ref, GFP_NOFS);
+	if (!dr)
+		return -ENOMEM;
+
+	dr->lnum = lnum;
+
+	rb_link_node(&dr->rb, parent, p);
+	rb_insert_color(&dr->rb, done_tree);
+
+	return 0;
+}
+
+/**
+ * destroy_done_tree - destroy the done tree.
+ * @done_tree: done tree to destroy
+ */
+static void destroy_done_tree(struct rb_root *done_tree)
+{
+	struct done_ref *dr, *n;
+
+	rbtree_postorder_for_each_entry_safe(dr, n, done_tree, rb)
+		kfree(dr);
+}
+
+/**
+ * add_node - add a node to the consolidated log.
+ * @c: UBIFS file-system description object
+ * @buf: buffer to which to add
+ * @lnum: LEB number to which to write is passed and returned here
+ * @offs: offset to where to write is passed and returned here
+ * @node: node to add
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+static int add_node(struct ubifs_info *c, void *buf, int *lnum, int *offs,
+		    void *node)
+{
+	struct ubifs_ch *ch = node;
+	int len = le32_to_cpu(ch->len), remains = c->leb_size - *offs;
+
+	if (len > remains) {
+		int sz = ALIGN(*offs, c->min_io_size), err;
+
+		ubifs_pad(c, buf + *offs, sz - *offs);
+		err = ubifs_leb_change(c, *lnum, buf, sz);
+		if (err)
+			return err;
+		*lnum = ubifs_next_log_lnum(c, *lnum);
+		*offs = 0;
+	}
+	memcpy(buf + *offs, node, len);
+	*offs += ALIGN(len, 8);
+	return 0;
+}
+
+/**
+ * ubifs_consolidate_log - consolidate the log.
+ * @c: UBIFS file-system description object
+ *
+ * Repeated failed commits could cause the log to be full, but at least 1 LEB is
+ * needed for commit. This function rewrites the reference nodes in the log
+ * omitting duplicates, and failed CS nodes, and leaving no gaps.
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int ubifs_consolidate_log(struct ubifs_info *c)
+{
+	struct ubifs_scan_leb *sleb;
+	struct ubifs_scan_node *snod;
+	struct rb_root done_tree = RB_ROOT;
+	int lnum, err, first = 1, write_lnum, offs = 0;
+	void *buf;
+
+	dbg_rcvry("log tail LEB %d, log head LEB %d", c->ltail_lnum,
+		  c->lhead_lnum);
+	buf = vmalloc(c->leb_size);
+	if (!buf)
+		return -ENOMEM;
+	lnum = c->ltail_lnum;
+	write_lnum = lnum;
+	while (1) {
+		sleb = ubifs_scan(c, lnum, 0, c->sbuf, 0);
+		if (IS_ERR(sleb)) {
+			err = PTR_ERR(sleb);
+			goto out_free;
+		}
+		list_for_each_entry(snod, &sleb->nodes, list) {
+			switch (snod->type) {
+			case UBIFS_REF_NODE: {
+				struct ubifs_ref_node *ref = snod->node;
+				int ref_lnum = le32_to_cpu(ref->lnum);
+
+				err = done_already(&done_tree, ref_lnum);
+				if (err < 0)
+					goto out_scan;
+				if (err != 1) {
+					err = add_node(c, buf, &write_lnum,
+						       &offs, snod->node);
+					if (err)
+						goto out_scan;
+				}
+				break;
+			}
+			case UBIFS_CS_NODE:
+				if (!first)
+					break;
+				err = add_node(c, buf, &write_lnum, &offs,
+					       snod->node);
+				if (err)
+					goto out_scan;
+				first = 0;
+				break;
+			}
+		}
+		ubifs_scan_destroy(sleb);
+		if (lnum == c->lhead_lnum)
+			break;
+		lnum = ubifs_next_log_lnum(c, lnum);
+	}
+	if (offs) {
+		int sz = ALIGN(offs, c->min_io_size);
+
+		ubifs_pad(c, buf + offs, sz - offs);
+		err = ubifs_leb_change(c, write_lnum, buf, sz);
+		if (err)
+			goto out_free;
+		offs = ALIGN(offs, c->min_io_size);
+	}
+	destroy_done_tree(&done_tree);
+	vfree(buf);
+	if (write_lnum == c->lhead_lnum) {
+		ubifs_err(c, "log is too full");
+		return -EINVAL;
+	}
+	/* Unmap remaining LEBs */
+	lnum = write_lnum;
+	do {
+		lnum = ubifs_next_log_lnum(c, lnum);
+		err = ubifs_leb_unmap(c, lnum);
+		if (err)
+			return err;
+	} while (lnum != c->lhead_lnum);
+	c->lhead_lnum = write_lnum;
+	c->lhead_offs = offs;
+	dbg_rcvry("new log head at %d:%d", c->lhead_lnum, c->lhead_offs);
+	return 0;
+
+out_scan:
+	ubifs_scan_destroy(sleb);
+out_free:
+	destroy_done_tree(&done_tree);
+	vfree(buf);
+	return err;
+}
+
+/**
+ * dbg_check_bud_bytes - make sure bud bytes calculation are all right.
+ * @c: UBIFS file-system description object
+ *
+ * This function makes sure the amount of flash space used by closed buds
+ * ('c->bud_bytes' is correct). Returns zero in case of success and %-EINVAL in
+ * case of failure.
+ */
+static int dbg_check_bud_bytes(struct ubifs_info *c)
+{
+	int i, err = 0;
+	struct ubifs_bud *bud;
+	long long bud_bytes = 0;
+
+	if (!dbg_is_chk_gen(c))
+		return 0;
+
+	spin_lock(&c->buds_lock);
+	for (i = 0; i < c->jhead_cnt; i++)
+		list_for_each_entry(bud, &c->jheads[i].buds_list, list)
+			bud_bytes += c->leb_size - bud->start;
+
+	if (c->bud_bytes != bud_bytes) {
+		ubifs_err(c, "bad bud_bytes %lld, calculated %lld",
+			  c->bud_bytes, bud_bytes);
+		err = -EINVAL;
+	}
+	spin_unlock(&c->buds_lock);
+
+	return err;
+}