Merge branch 'linux-next' of git://git.infradead.org/ubifs-2.6

* 'linux-next' of git://git.infradead.org/ubifs-2.6:
  UBIFS: do not allocate unneeded scan buffer
  UBIFS: do not forget to cancel timers
  UBIFS: remove a bit of unneeded code
  UBIFS: add a commentary about log recovery
  UBIFS: avoid kernel error if ubifs superblock read fails
  UBIFS: introduce new flags for RO mounts
  UBIFS: introduce new flag for RO due to errors
  UBIFS: check return code of pnode_lookup
  UBIFS: check return code of ubifs_lpt_lookup
  UBIFS: improve error reporting when reading bad node
  UBIFS: introduce list sorting debugging checks
  UBIFS: fix assertion warnings in comparison function
  UBIFS: mark unused key objects as invalid
  UBIFS: do not write rubbish into truncation scanning node
  UBIFS: improve assertion in node comparison functions
  UBIFS: do not use key type in list_sort
  UBIFS: do not look up truncation nodes
  UBIFS: fix assertion warning
  UBIFS: do not treat ENOSPC specially
  UBIFS: switch to RO mode after synchronizing

fs/ubifs/commit.c

@@ -63,7 +63,9 @@ static int do_commit(struct ubifs_info *c)
 	struct ubifs_lp_stats lst;
 
 	dbg_cmt("start");
-	if (c->ro_media) {
+	ubifs_assert(!c->ro_media && !c->ro_mount);
+
+	if (c->ro_error) {
 		err = -EROFS;
 		goto out_up;
 	}

fs/ubifs/debug.c

@@ -2239,6 +2239,162 @@ out_free:
 	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 (!(ubifs_chk_flags & UBIFS_CHK_GEN))
+		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("bad node type %d", sa->type);
+			dbg_dump_node(c, sa->node);
+			return -EINVAL;
+		}
+		if (sb->type != UBIFS_DATA_NODE) {
+			ubifs_err("bad node type %d", sb->type);
+			dbg_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("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("larger block %u goes before %u", blka, blkb);
+			goto error_dump;
+		}
+		if (blka == blkb) {
+			ubifs_err("two data nodes for the same block");
+			goto error_dump;
+		}
+	}
+
+	return 0;
+
+error_dump:
+	dbg_dump_node(c, sa->node);
+	dbg_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 (!(ubifs_chk_flags & UBIFS_CHK_GEN))
+		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("bad node type %d", sa->type);
+			dbg_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("bad node type %d", sb->type);
+			dbg_dump_node(c, sb->node);
+			return -EINVAL;
+		}
+
+		if (sa->type != UBIFS_INO_NODE && sb->type == UBIFS_INO_NODE) {
+			ubifs_err("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("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("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("larger hash %u goes before %u", hasha, hashb);
+			goto error_dump;
+		}
+	}
+
+	return 0;
+
+error_dump:
+	ubifs_msg("dumping first node");
+	dbg_dump_node(c, sa->node);
+	ubifs_msg("dumping second node");
+	dbg_dump_node(c, sb->node);
+	return -EINVAL;
+	return 0;
+}
+
 static int invocation_cnt;
 
 int dbg_force_in_the_gaps(void)

fs/ubifs/debug.h

@@ -324,6 +324,8 @@ int dbg_check_lpt_nodes(struct ubifs_info *c, struct ubifs_cnode *cnode,
 			int row, int col);
 int dbg_check_inode_size(struct ubifs_info *c, const struct inode *inode,
 			 loff_t size);
+int dbg_check_data_nodes_order(struct ubifs_info *c, struct list_head *head);
+int dbg_check_nondata_nodes_order(struct ubifs_info *c, struct list_head *head);
 
 /* Force the use of in-the-gaps method for testing */
 
@@ -465,6 +467,8 @@ void dbg_debugfs_exit_fs(struct ubifs_info *c);
 #define dbg_check_lprops(c)                        0
 #define dbg_check_lpt_nodes(c, cnode, row, col)    0
 #define dbg_check_inode_size(c, inode, size)       0
+#define dbg_check_data_nodes_order(c, head)        0
+#define dbg_check_nondata_nodes_order(c, head)     0
 #define dbg_force_in_the_gaps_enabled              0
 #define dbg_force_in_the_gaps()                    0
 #define dbg_failure_mode                           0

fs/ubifs/file.c

@@ -433,8 +433,9 @@ static int ubifs_write_begin(struct file *file, struct address_space *mapping,
 	struct page *page;
 
 	ubifs_assert(ubifs_inode(inode)->ui_size == inode->i_size);
+	ubifs_assert(!c->ro_media && !c->ro_mount);
 
-	if (unlikely(c->ro_media))
+	if (unlikely(c->ro_error))
 		return -EROFS;
 
 	/* Try out the fast-path part first */
@@ -1439,9 +1440,9 @@ static int ubifs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vm
 
 	dbg_gen("ino %lu, pg %lu, i_size %lld",	inode->i_ino, page->index,
 		i_size_read(inode));
-	ubifs_assert(!(inode->i_sb->s_flags & MS_RDONLY));
+	ubifs_assert(!c->ro_media && !c->ro_mount);
 
-	if (unlikely(c->ro_media))
+	if (unlikely(c->ro_error))
 		return VM_FAULT_SIGBUS; /* -EROFS */
 
 	/*

fs/ubifs/gc.c

@@ -125,10 +125,16 @@ int data_nodes_cmp(void *priv, struct list_head *a, struct list_head *b)
 	struct ubifs_scan_node *sa, *sb;
 
 	cond_resched();
+	if (a == b)
+		return 0;
+
 	sa = list_entry(a, struct ubifs_scan_node, list);
 	sb = list_entry(b, struct ubifs_scan_node, list);
+
 	ubifs_assert(key_type(c, &sa->key) == UBIFS_DATA_KEY);
 	ubifs_assert(key_type(c, &sb->key) == UBIFS_DATA_KEY);
+	ubifs_assert(sa->type == UBIFS_DATA_NODE);
+	ubifs_assert(sb->type == UBIFS_DATA_NODE);
 
 	inuma = key_inum(c, &sa->key);
 	inumb = key_inum(c, &sb->key);
@@ -157,28 +163,40 @@ int data_nodes_cmp(void *priv, struct list_head *a, struct list_head *b)
  */
 int nondata_nodes_cmp(void *priv, struct list_head *a, struct list_head *b)
 {
-	int typea, typeb;
 	ino_t inuma, inumb;
 	struct ubifs_info *c = priv;
 	struct ubifs_scan_node *sa, *sb;
 
 	cond_resched();
+	if (a == b)
+		return 0;
+
 	sa = list_entry(a, struct ubifs_scan_node, list);
 	sb = list_entry(b, struct ubifs_scan_node, list);
-	typea = key_type(c, &sa->key);
-	typeb = key_type(c, &sb->key);
-	ubifs_assert(typea != UBIFS_DATA_KEY && typeb != UBIFS_DATA_KEY);
+
+	ubifs_assert(key_type(c, &sa->key) != UBIFS_DATA_KEY &&
+		     key_type(c, &sb->key) != UBIFS_DATA_KEY);
+	ubifs_assert(sa->type != UBIFS_DATA_NODE &&
+		     sb->type != UBIFS_DATA_NODE);
 
 	/* Inodes go before directory entries */
-	if (typea == UBIFS_INO_KEY) {
-		if (typeb == UBIFS_INO_KEY)
+	if (sa->type == UBIFS_INO_NODE) {
+		if (sb->type == UBIFS_INO_NODE)
 			return sb->len - sa->len;
 		return -1;
 	}
-	if (typeb == UBIFS_INO_KEY)
+	if (sb->type == UBIFS_INO_NODE)
 		return 1;
 
-	ubifs_assert(typea == UBIFS_DENT_KEY && typeb == UBIFS_DENT_KEY);
+	ubifs_assert(key_type(c, &sa->key) == UBIFS_DENT_KEY ||
+		     key_type(c, &sa->key) == UBIFS_XENT_KEY);
+	ubifs_assert(key_type(c, &sb->key) == UBIFS_DENT_KEY ||
+		     key_type(c, &sb->key) == UBIFS_XENT_KEY);
+	ubifs_assert(sa->type == UBIFS_DENT_NODE ||
+		     sa->type == UBIFS_XENT_NODE);
+	ubifs_assert(sb->type == UBIFS_DENT_NODE ||
+		     sb->type == UBIFS_XENT_NODE);
+
 	inuma = key_inum(c, &sa->key);
 	inumb = key_inum(c, &sb->key);
 
@@ -224,17 +242,33 @@ int nondata_nodes_cmp(void *priv, struct list_head *a, struct list_head *b)
 static int sort_nodes(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
 		      struct list_head *nondata, int *min)
 {
+	int err;
 	struct ubifs_scan_node *snod, *tmp;
 
 	*min = INT_MAX;
 
 	/* Separate data nodes and non-data nodes */
 	list_for_each_entry_safe(snod, tmp, &sleb->nodes, list) {
-		int err;
+		ubifs_assert(snod->type == UBIFS_INO_NODE  ||
+			     snod->type == UBIFS_DATA_NODE ||
+			     snod->type == UBIFS_DENT_NODE ||
+			     snod->type == UBIFS_XENT_NODE ||
+			     snod->type == UBIFS_TRUN_NODE);
+
+		if (snod->type != UBIFS_INO_NODE  &&
+		    snod->type != UBIFS_DATA_NODE &&
+		    snod->type != UBIFS_DENT_NODE &&
+		    snod->type != UBIFS_XENT_NODE) {
+			/* Probably truncation node, zap it */
+			list_del(&snod->list);
+			kfree(snod);
+			continue;
+		}
 
-		ubifs_assert(snod->type != UBIFS_IDX_NODE);
-		ubifs_assert(snod->type != UBIFS_REF_NODE);
-		ubifs_assert(snod->type != UBIFS_CS_NODE);
+		ubifs_assert(key_type(c, &snod->key) == UBIFS_DATA_KEY ||
+			     key_type(c, &snod->key) == UBIFS_INO_KEY  ||
+			     key_type(c, &snod->key) == UBIFS_DENT_KEY ||
+			     key_type(c, &snod->key) == UBIFS_XENT_KEY);
 
 		err = ubifs_tnc_has_node(c, &snod->key, 0, sleb->lnum,
 					 snod->offs, 0);
@@ -258,6 +292,13 @@ static int sort_nodes(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
 	/* Sort data and non-data nodes */
 	list_sort(c, &sleb->nodes, &data_nodes_cmp);
 	list_sort(c, nondata, &nondata_nodes_cmp);
+
+	err = dbg_check_data_nodes_order(c, &sleb->nodes);
+	if (err)
+		return err;
+	err = dbg_check_nondata_nodes_order(c, nondata);
+	if (err)
+		return err;
 	return 0;
 }
 
@@ -575,13 +616,14 @@ int ubifs_garbage_collect(struct ubifs_info *c, int anyway)
 	struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf;
 
 	ubifs_assert_cmt_locked(c);
+	ubifs_assert(!c->ro_media && !c->ro_mount);
 
 	if (ubifs_gc_should_commit(c))
 		return -EAGAIN;
 
 	mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
 
-	if (c->ro_media) {
+	if (c->ro_error) {
 		ret = -EROFS;
 		goto out_unlock;
 	}
@@ -677,14 +719,12 @@ int ubifs_garbage_collect(struct ubifs_info *c, int anyway)
 
 		ret = ubifs_garbage_collect_leb(c, &lp);
 		if (ret < 0) {
-			if (ret == -EAGAIN || ret == -ENOSPC) {
+			if (ret == -EAGAIN) {
 				/*
-				 * These codes are not errors, so we have to
-				 * return the LEB to lprops. But if the
-				 * 'ubifs_return_leb()' function fails, its
-				 * failure code is propagated to the caller
-				 * instead of the original '-EAGAIN' or
-				 * '-ENOSPC'.
+				 * This is not error, so we have to return the
+				 * LEB to lprops. But if 'ubifs_return_leb()'
+				 * fails, its failure code is propagated to the
+				 * caller instead of the original '-EAGAIN'.
 				 */
 				err = ubifs_return_leb(c, lp.lnum);
 				if (err)
@@ -774,8 +814,8 @@ out_unlock:
 out:
 	ubifs_assert(ret < 0);
 	ubifs_assert(ret != -ENOSPC && ret != -EAGAIN);
-	ubifs_ro_mode(c, ret);
 	ubifs_wbuf_sync_nolock(wbuf);
+	ubifs_ro_mode(c, ret);
 	mutex_unlock(&wbuf->io_mutex);
 	ubifs_return_leb(c, lp.lnum);
 	return ret;

fs/ubifs/io.c

@@ -61,8 +61,8 @@
  */
 void ubifs_ro_mode(struct ubifs_info *c, int err)
 {
-	if (!c->ro_media) {
-		c->ro_media = 1;
+	if (!c->ro_error) {
+		c->ro_error = 1;
 		c->no_chk_data_crc = 0;
 		c->vfs_sb->s_flags |= MS_RDONLY;
 		ubifs_warn("switched to read-only mode, error %d", err);
@@ -356,11 +356,11 @@ int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf)
 
 	dbg_io("LEB %d:%d, %d bytes, jhead %s",
 	       wbuf->lnum, wbuf->offs, wbuf->used, dbg_jhead(wbuf->jhead));
-	ubifs_assert(!(c->vfs_sb->s_flags & MS_RDONLY));
 	ubifs_assert(!(wbuf->avail & 7));
 	ubifs_assert(wbuf->offs + c->min_io_size <= c->leb_size);
+	ubifs_assert(!c->ro_media && !c->ro_mount);
 
-	if (c->ro_media)
+	if (c->ro_error)
 		return -EROFS;
 
 	ubifs_pad(c, wbuf->buf + wbuf->used, wbuf->avail);
@@ -440,11 +440,12 @@ int ubifs_bg_wbufs_sync(struct ubifs_info *c)
 {
 	int err, i;
 
+	ubifs_assert(!c->ro_media && !c->ro_mount);
 	if (!c->need_wbuf_sync)
 		return 0;
 	c->need_wbuf_sync = 0;
 
-	if (c->ro_media) {
+	if (c->ro_error) {
 		err = -EROFS;
 		goto out_timers;
 	}
@@ -519,6 +520,7 @@ int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len)
 	ubifs_assert(!(wbuf->offs & 7) && wbuf->offs <= c->leb_size);
 	ubifs_assert(wbuf->avail > 0 && wbuf->avail <= c->min_io_size);
 	ubifs_assert(mutex_is_locked(&wbuf->io_mutex));
+	ubifs_assert(!c->ro_media && !c->ro_mount);
 
 	if (c->leb_size - wbuf->offs - wbuf->used < aligned_len) {
 		err = -ENOSPC;
@@ -527,7 +529,7 @@ int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len)
 
 	cancel_wbuf_timer_nolock(wbuf);
 
-	if (c->ro_media)
+	if (c->ro_error)
 		return -EROFS;
 
 	if (aligned_len <= wbuf->avail) {
@@ -663,8 +665,9 @@ int ubifs_write_node(struct ubifs_info *c, void *buf, int len, int lnum,
 	       buf_len);
 	ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
 	ubifs_assert(offs % c->min_io_size == 0 && offs < c->leb_size);
+	ubifs_assert(!c->ro_media && !c->ro_mount);
 
-	if (c->ro_media)
+	if (c->ro_error)
 		return -EROFS;
 
 	ubifs_prepare_node(c, buf, len, 1);
@@ -815,7 +818,8 @@ int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len,
 	return 0;
 
 out:
-	ubifs_err("bad node at LEB %d:%d", lnum, offs);
+	ubifs_err("bad node at LEB %d:%d, LEB mapping status %d", lnum, offs,
+		  ubi_is_mapped(c->ubi, lnum));
 	dbg_dump_node(c, buf);
 	dbg_dump_stack();
 	return -EINVAL;

fs/ubifs/journal.c

@@ -122,11 +122,12 @@ static int reserve_space(struct ubifs_info *c, int jhead, int len)
 	 * better to try to allocate space at the ends of eraseblocks. This is
 	 * what the squeeze parameter does.
 	 */
+	ubifs_assert(!c->ro_media && !c->ro_mount);
 	squeeze = (jhead == BASEHD);
 again:
 	mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
 
-	if (c->ro_media) {
+	if (c->ro_error) {
 		err = -EROFS;
 		goto out_unlock;
 	}

fs/ubifs/key.h

@@ -305,6 +305,20 @@ static inline void trun_key_init(const struct ubifs_info *c,
 	key->u32[1] = UBIFS_TRUN_KEY << UBIFS_S_KEY_BLOCK_BITS;
 }
 
+/**
+ * invalid_key_init - initialize invalid node key.
+ * @c: UBIFS file-system description object
+ * @key: key to initialize
+ *
+ * This is a helper function which marks a @key object as invalid.
+ */
+static inline void invalid_key_init(const struct ubifs_info *c,
+				    union ubifs_key *key)
+{
+	key->u32[0] = 0xDEADBEAF;
+	key->u32[1] = UBIFS_INVALID_KEY;
+}
+
 /**
  * key_type - get key type.
  * @c: UBIFS file-system description object

fs/ubifs/log.c

@@ -159,7 +159,7 @@ void ubifs_add_bud(struct ubifs_info *c, struct ubifs_bud *bud)
 		jhead = &c->jheads[bud->jhead];
 		list_add_tail(&bud->list, &jhead->buds_list);
 	} else
-		ubifs_assert(c->replaying && (c->vfs_sb->s_flags & MS_RDONLY));
+		ubifs_assert(c->replaying && c->ro_mount);
 
 	/*
 	 * Note, although this is a new bud, we anyway account this space now,
@@ -223,8 +223,8 @@ int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs)
 	}
 
 	mutex_lock(&c->log_mutex);
-
-	if (c->ro_media) {
+	ubifs_assert(!c->ro_media && !c->ro_mount);
+	if (c->ro_error) {
 		err = -EROFS;
 		goto out_unlock;
 	}

fs/ubifs/lpt.c

@@ -1363,6 +1363,7 @@ static int read_lsave(struct ubifs_info *c)
 		goto out;
 	for (i = 0; i < c->lsave_cnt; i++) {
 		int lnum = c->lsave[i];
+		struct ubifs_lprops *lprops;
 
 		/*
 		 * Due to automatic resizing, the values in the lsave table
@@ -1370,7 +1371,11 @@ static int read_lsave(struct ubifs_info *c)
 		 */
 		if (lnum >= c->leb_cnt)
 			continue;
-		ubifs_lpt_lookup(c, lnum);
+		lprops = ubifs_lpt_lookup(c, lnum);
+		if (IS_ERR(lprops)) {
+			err = PTR_ERR(lprops);
+			goto out;
+		}
 	}
 out:
 	vfree(buf);

fs/ubifs/lpt_commit.c

@@ -705,6 +705,9 @@ static int make_tree_dirty(struct ubifs_info *c)
 	struct ubifs_pnode *pnode;
 
 	pnode = pnode_lookup(c, 0);
+	if (IS_ERR(pnode))
+		return PTR_ERR(pnode);
+
 	while (pnode) {
 		do_make_pnode_dirty(c, pnode);
 		pnode = next_pnode_to_dirty(c, pnode);

fs/ubifs/master.c

@@ -361,7 +361,8 @@ int ubifs_write_master(struct ubifs_info *c)
 {
 	int err, lnum, offs, len;
 
-	if (c->ro_media)
+	ubifs_assert(!c->ro_media && !c->ro_mount);
+	if (c->ro_error)
 		return -EROFS;
 
 	lnum = UBIFS_MST_LNUM;

fs/ubifs/misc.h

@@ -132,7 +132,8 @@ static inline int ubifs_leb_unmap(const struct ubifs_info *c, int lnum)
 {
 	int err;
 
-	if (c->ro_media)
+	ubifs_assert(!c->ro_media && !c->ro_mount);
+	if (c->ro_error)
 		return -EROFS;
 	err = ubi_leb_unmap(c->ubi, lnum);
 	if (err) {
@@ -159,7 +160,8 @@ static inline int ubifs_leb_write(const struct ubifs_info *c, int lnum,
 {
 	int err;
 
-	if (c->ro_media)
+	ubifs_assert(!c->ro_media && !c->ro_mount);
+	if (c->ro_error)
 		return -EROFS;
 	err = ubi_leb_write(c->ubi, lnum, buf, offs, len, dtype);
 	if (err) {
@@ -186,7 +188,8 @@ static inline int ubifs_leb_change(const struct ubifs_info *c, int lnum,
 {
 	int err;
 
-	if (c->ro_media)
+	ubifs_assert(!c->ro_media && !c->ro_mount);
+	if (c->ro_error)
 		return -EROFS;
 	err = ubi_leb_change(c->ubi, lnum, buf, len, dtype);
 	if (err) {

fs/ubifs/recovery.c

@@ -292,7 +292,7 @@ int ubifs_recover_master_node(struct ubifs_info *c)
 
 	memcpy(c->mst_node, mst, UBIFS_MST_NODE_SZ);
 
-	if ((c->vfs_sb->s_flags & MS_RDONLY)) {
+	if (c->ro_mount) {
 		/* Read-only mode. Keep a copy for switching to rw mode */
 		c->rcvrd_mst_node = kmalloc(sz, GFP_KERNEL);
 		if (!c->rcvrd_mst_node) {
@@ -469,7 +469,7 @@ static int fix_unclean_leb(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
 		endpt = snod->offs + snod->len;
 	}
 
-	if ((c->vfs_sb->s_flags & MS_RDONLY) && !c->remounting_rw) {
+	if (c->ro_mount && !c->remounting_rw) {
 		/* Add to recovery list */
 		struct ubifs_unclean_leb *ucleb;
 
@@ -772,7 +772,8 @@ out_free:
  * @sbuf: LEB-sized buffer to use
  *
  * This function does a scan of a LEB, but caters for errors that might have
- * been caused by the unclean unmount from which we are attempting to recover.
+ * been caused by unclean reboots from which we are attempting to recover
+ * (assume that only the last log LEB can be corrupted by an unclean reboot).
  *
  * This function returns %0 on success and a negative error code on failure.
  */
@@ -883,7 +884,7 @@ int ubifs_recover_inl_heads(const struct ubifs_info *c, void *sbuf)
 {
 	int err;
 
-	ubifs_assert(!(c->vfs_sb->s_flags & MS_RDONLY) || c->remounting_rw);
+	ubifs_assert(!c->ro_mount || c->remounting_rw);
 
 	dbg_rcvry("checking index head at %d:%d", c->ihead_lnum, c->ihead_offs);
 	err = recover_head(c, c->ihead_lnum, c->ihead_offs, sbuf);
@@ -1461,7 +1462,7 @@ int ubifs_recover_size(struct ubifs_info *c)
 			}
 		}
 		if (e->exists && e->i_size < e->d_size) {
-			if (!e->inode && (c->vfs_sb->s_flags & MS_RDONLY)) {
+			if (!e->inode && c->ro_mount) {
 				/* Fix the inode size and pin it in memory */
 				struct inode *inode;
 

fs/ubifs/replay.c

@@ -627,8 +627,7 @@ static int replay_bud(struct ubifs_info *c, int lnum, int offs, int jhead,
 	ubifs_assert(sleb->endpt - offs >= used);
 	ubifs_assert(sleb->endpt % c->min_io_size == 0);
 
-	if (sleb->endpt + c->min_io_size <= c->leb_size &&
-	    !(c->vfs_sb->s_flags & MS_RDONLY))
+	if (sleb->endpt + c->min_io_size <= c->leb_size && !c->ro_mount)
 		err = ubifs_wbuf_seek_nolock(&c->jheads[jhead].wbuf, lnum,
 					     sleb->endpt, UBI_SHORTTERM);
 
@@ -840,6 +839,11 @@ static int replay_log_leb(struct ubifs_info *c, int lnum, int offs, void *sbuf)
 	if (IS_ERR(sleb)) {
 		if (PTR_ERR(sleb) != -EUCLEAN || !c->need_recovery)
 			return PTR_ERR(sleb);
+		/*
+		 * Note, the below function will recover this log LEB only if
+		 * it is the last, because unclean reboots can possibly corrupt
+		 * only the tail of the log.
+		 */
 		sleb = ubifs_recover_log_leb(c, lnum, offs, sbuf);
 		if (IS_ERR(sleb))
 			return PTR_ERR(sleb);
@@ -851,7 +855,6 @@ static int replay_log_leb(struct ubifs_info *c, int lnum, int offs, void *sbuf)
 	}
 
 	node = sleb->buf;
-
 	snod = list_entry(sleb->nodes.next, struct ubifs_scan_node, list);
 	if (c->cs_sqnum == 0) {
 		/*
@@ -898,7 +901,6 @@ static int replay_log_leb(struct ubifs_info *c, int lnum, int offs, void *sbuf)
 	}
 
 	list_for_each_entry(snod, &sleb->nodes, list) {
-
 		cond_resched();
 
 		if (snod->sqnum >= SQNUM_WATERMARK) {
@@ -1011,7 +1013,6 @@ out:
 int ubifs_replay_journal(struct ubifs_info *c)
 {
 	int err, i, lnum, offs, free;
-	void *sbuf = NULL;
 
 	BUILD_BUG_ON(UBIFS_TRUN_KEY > 5);
 
@@ -1026,14 +1027,8 @@ int ubifs_replay_journal(struct ubifs_info *c)
 		return -EINVAL;
 	}
 
-	sbuf = vmalloc(c->leb_size);
-	if (!sbuf)
-		return -ENOMEM;
-
 	dbg_mnt("start replaying the journal");
-
 	c->replaying = 1;
-
 	lnum = c->ltail_lnum = c->lhead_lnum;
 	offs = c->lhead_offs;
 
@@ -1046,7 +1041,7 @@ int ubifs_replay_journal(struct ubifs_info *c)
 			lnum = UBIFS_LOG_LNUM;
 			offs = 0;
 		}
-		err = replay_log_leb(c, lnum, offs, sbuf);
+		err = replay_log_leb(c, lnum, offs, c->sbuf);
 		if (err == 1)
 			/* We hit the end of the log */
 			break;
@@ -1079,7 +1074,6 @@ int ubifs_replay_journal(struct ubifs_info *c)
 out:
 	destroy_replay_tree(c);
 	destroy_bud_list(c);
-	vfree(sbuf);
 	c->replaying = 0;
 	return err;
 }

fs/ubifs/sb.c

@@ -542,11 +542,8 @@ int ubifs_read_superblock(struct ubifs_info *c)
 	 * due to the unavailability of time-travelling equipment.
 	 */
 	if (c->fmt_version > UBIFS_FORMAT_VERSION) {
-		struct super_block *sb = c->vfs_sb;
-		int mounting_ro = sb->s_flags & MS_RDONLY;
-
-		ubifs_assert(!c->ro_media || mounting_ro);
-		if (!mounting_ro ||
+		ubifs_assert(!c->ro_media || c->ro_mount);
+		if (!c->ro_mount ||
 		    c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) {
 			ubifs_err("on-flash format version is w%d/r%d, but "
 				  "software only supports up to version "
@@ -624,7 +621,7 @@ int ubifs_read_superblock(struct ubifs_info *c)
 	c->old_leb_cnt = c->leb_cnt;
 	if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) {
 		c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size);
-		if (c->vfs_sb->s_flags & MS_RDONLY)
+		if (c->ro_mount)
 			dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs",
 				c->old_leb_cnt,	c->leb_cnt);
 		else {

fs/ubifs/scan.c

@@ -197,7 +197,7 @@ int ubifs_add_snod(const struct ubifs_info *c, struct ubifs_scan_leb *sleb,
 	struct ubifs_ino_node *ino = buf;
 	struct ubifs_scan_node *snod;
 
-	snod = kzalloc(sizeof(struct ubifs_scan_node), GFP_NOFS);
+	snod = kmalloc(sizeof(struct ubifs_scan_node), GFP_NOFS);
 	if (!snod)
 		return -ENOMEM;
 
@@ -212,13 +212,15 @@ int ubifs_add_snod(const struct ubifs_info *c, struct ubifs_scan_leb *sleb,
 	case UBIFS_DENT_NODE:
 	case UBIFS_XENT_NODE:
 	case UBIFS_DATA_NODE:
-	case UBIFS_TRUN_NODE:
 		/*
 		 * The key is in the same place in all keyed
 		 * nodes.
 		 */
 		key_read(c, &ino->key, &snod->key);
 		break;
+	default:
+		invalid_key_init(c, &snod->key);
+		break;
 	}
 	list_add_tail(&snod->list, &sleb->nodes);
 	sleb->nodes_cnt += 1;

fs/ubifs/shrinker.c

@@ -250,7 +250,7 @@ static int kick_a_thread(void)
 			dirty_zn_cnt = atomic_long_read(&c->dirty_zn_cnt);
 
 			if (!dirty_zn_cnt || c->cmt_state == COMMIT_BROKEN ||
-			    c->ro_media) {
+			    c->ro_mount || c->ro_error) {
 				mutex_unlock(&c->umount_mutex);
 				continue;
 			}

fs/ubifs/super.c

@@ -1137,11 +1137,11 @@ static int check_free_space(struct ubifs_info *c)
  */
 static int mount_ubifs(struct ubifs_info *c)
 {
-	struct super_block *sb = c->vfs_sb;
-	int err, mounted_read_only = (sb->s_flags & MS_RDONLY);
+	int err;
 	long long x;
 	size_t sz;
 
+	c->ro_mount = !!(c->vfs_sb->s_flags & MS_RDONLY);
 	err = init_constants_early(c);
 	if (err)
 		return err;
@@ -1154,7 +1154,7 @@ static int mount_ubifs(struct ubifs_info *c)
 	if (err)
 		goto out_free;
 
-	if (c->empty && (mounted_read_only || c->ro_media)) {
+	if (c->empty && (c->ro_mount || c->ro_media)) {
 		/*
 		 * This UBI volume is empty, and read-only, or the file system
 		 * is mounted read-only - we cannot format it.
@@ -1165,7 +1165,7 @@ static int mount_ubifs(struct ubifs_info *c)
 		goto out_free;
 	}
 
-	if (c->ro_media && !mounted_read_only) {
+	if (c->ro_media && !c->ro_mount) {
 		ubifs_err("cannot mount read-write - read-only media");
 		err = -EROFS;
 		goto out_free;
@@ -1185,7 +1185,7 @@ static int mount_ubifs(struct ubifs_info *c)
 	if (!c->sbuf)
 		goto out_free;
 
-	if (!mounted_read_only) {
+	if (!c->ro_mount) {
 		c->ileb_buf = vmalloc(c->leb_size);
 		if (!c->ileb_buf)
 			goto out_free;
@@ -1228,7 +1228,7 @@ static int mount_ubifs(struct ubifs_info *c)
 	}
 
 	sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
-	if (!mounted_read_only) {
+	if (!c->ro_mount) {
 		err = alloc_wbufs(c);
 		if (err)
 			goto out_cbuf;
@@ -1254,12 +1254,12 @@ static int mount_ubifs(struct ubifs_info *c)
 	if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) {
 		ubifs_msg("recovery needed");
 		c->need_recovery = 1;
-		if (!mounted_read_only) {
+		if (!c->ro_mount) {
 			err = ubifs_recover_inl_heads(c, c->sbuf);
 			if (err)
 				goto out_master;
 		}
-	} else if (!mounted_read_only) {
+	} else if (!c->ro_mount) {
 		/*
 		 * Set the "dirty" flag so that if we reboot uncleanly we
 		 * will notice this immediately on the next mount.
@@ -1270,7 +1270,7 @@ static int mount_ubifs(struct ubifs_info *c)
 			goto out_master;
 	}
 
-	err = ubifs_lpt_init(c, 1, !mounted_read_only);
+	err = ubifs_lpt_init(c, 1, !c->ro_mount);
 	if (err)
 		goto out_lpt;
 
@@ -1285,11 +1285,11 @@ static int mount_ubifs(struct ubifs_info *c)
 	/* Calculate 'min_idx_lebs' after journal replay */
 	c->min_idx_lebs = ubifs_calc_min_idx_lebs(c);
 
-	err = ubifs_mount_orphans(c, c->need_recovery, mounted_read_only);
+	err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);
 	if (err)
 		goto out_orphans;
 
-	if (!mounted_read_only) {
+	if (!c->ro_mount) {
 		int lnum;
 
 		err = check_free_space(c);
@@ -1351,7 +1351,7 @@ static int mount_ubifs(struct ubifs_info *c)
 	spin_unlock(&ubifs_infos_lock);
 
 	if (c->need_recovery) {
-		if (mounted_read_only)
+		if (c->ro_mount)
 			ubifs_msg("recovery deferred");
 		else {
 			c->need_recovery = 0;
@@ -1378,7 +1378,7 @@ static int mount_ubifs(struct ubifs_info *c)
 
 	ubifs_msg("mounted UBI device %d, volume %d, name \"%s\"",
 		  c->vi.ubi_num, c->vi.vol_id, c->vi.name);
-	if (mounted_read_only)
+	if (c->ro_mount)
 		ubifs_msg("mounted read-only");
 	x = (long long)c->main_lebs * c->leb_size;
 	ubifs_msg("file system size:   %lld bytes (%lld KiB, %lld MiB, %d "
@@ -1640,7 +1640,7 @@ static int ubifs_remount_rw(struct ubifs_info *c)
 	}
 
 	dbg_gen("re-mounted read-write");
-	c->vfs_sb->s_flags &= ~MS_RDONLY;
+	c->ro_mount = 0;
 	c->remounting_rw = 0;
 	c->always_chk_crc = 0;
 	err = dbg_check_space_info(c);
@@ -1676,7 +1676,7 @@ static void ubifs_remount_ro(struct ubifs_info *c)
 	int i, err;
 
 	ubifs_assert(!c->need_recovery);
-	ubifs_assert(!(c->vfs_sb->s_flags & MS_RDONLY));
+	ubifs_assert(!c->ro_mount);
 
 	mutex_lock(&c->umount_mutex);
 	if (c->bgt) {
@@ -1686,10 +1686,8 @@ static void ubifs_remount_ro(struct ubifs_info *c)
 
 	dbg_save_space_info(c);
 
-	for (i = 0; i < c->jhead_cnt; i++) {
+	for (i = 0; i < c->jhead_cnt; i++)
 		ubifs_wbuf_sync(&c->jheads[i].wbuf);
-		hrtimer_cancel(&c->jheads[i].wbuf.timer);
-	}
 
 	c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
 	c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
@@ -1704,6 +1702,7 @@ static void ubifs_remount_ro(struct ubifs_info *c)
 	vfree(c->ileb_buf);
 	c->ileb_buf = NULL;
 	ubifs_lpt_free(c, 1);
+	c->ro_mount = 1;
 	err = dbg_check_space_info(c);
 	if (err)
 		ubifs_ro_mode(c, err);
@@ -1735,7 +1734,7 @@ static void ubifs_put_super(struct super_block *sb)
 	 * the mutex is locked.
 	 */
 	mutex_lock(&c->umount_mutex);
-	if (!(c->vfs_sb->s_flags & MS_RDONLY)) {
+	if (!c->ro_mount) {
 		/*
 		 * First of all kill the background thread to make sure it does
 		 * not interfere with un-mounting and freeing resources.
@@ -1745,23 +1744,22 @@ static void ubifs_put_super(struct super_block *sb)
 			c->bgt = NULL;
 		}
 
-		/* Synchronize write-buffers */
-		if (c->jheads)
-			for (i = 0; i < c->jhead_cnt; i++)
-				ubifs_wbuf_sync(&c->jheads[i].wbuf);
-
 		/*
-		 * On fatal errors c->ro_media is set to 1, in which case we do
+		 * On fatal errors c->ro_error is set to 1, in which case we do
 		 * not write the master node.
 		 */
-		if (!c->ro_media) {
+		if (!c->ro_error) {
+			int err;
+
+			/* Synchronize write-buffers */
+			for (i = 0; i < c->jhead_cnt; i++)
+				ubifs_wbuf_sync(&c->jheads[i].wbuf);
+
 			/*
 			 * We are being cleanly unmounted which means the
 			 * orphans were killed - indicate this in the master
 			 * node. Also save the reserved GC LEB number.
 			 */
-			int err;
-
 			c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
 			c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
 			c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
@@ -1774,6 +1772,10 @@ static void ubifs_put_super(struct super_block *sb)
 				 */
 				ubifs_err("failed to write master node, "
 					  "error %d", err);
+		} else {
+			for (i = 0; i < c->jhead_cnt; i++)
+				/* Make sure write-buffer timers are canceled */
+				hrtimer_cancel(&c->jheads[i].wbuf.timer);
 		}
 	}
 
@@ -1797,17 +1799,21 @@ static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
 		return err;
 	}
 
-	if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
+	if (c->ro_mount && !(*flags & MS_RDONLY)) {
+		if (c->ro_error) {
+			ubifs_msg("cannot re-mount R/W due to prior errors");
+			return -EROFS;
+		}
 		if (c->ro_media) {
-			ubifs_msg("cannot re-mount due to prior errors");
+			ubifs_msg("cannot re-mount R/W - UBI volume is R/O");
 			return -EROFS;
 		}
 		err = ubifs_remount_rw(c);
 		if (err)
 			return err;
-	} else if (!(sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY)) {
-		if (c->ro_media) {
-			ubifs_msg("cannot re-mount due to prior errors");
+	} else if (!c->ro_mount && (*flags & MS_RDONLY)) {
+		if (c->ro_error) {
+			ubifs_msg("cannot re-mount R/O due to prior errors");
 			return -EROFS;
 		}
 		ubifs_remount_ro(c);
@@ -2049,8 +2055,8 @@ static int ubifs_get_sb(struct file_system_type *fs_type, int flags,
 	 */
 	ubi = open_ubi(name, UBI_READONLY);
 	if (IS_ERR(ubi)) {
-		ubifs_err("cannot open \"%s\", error %d",
-			  name, (int)PTR_ERR(ubi));
+		dbg_err("cannot open \"%s\", error %d",
+			name, (int)PTR_ERR(ubi));
 		return PTR_ERR(ubi);
 	}
 	ubi_get_volume_info(ubi, &vi);
@@ -2064,9 +2070,11 @@ static int ubifs_get_sb(struct file_system_type *fs_type, int flags,
 	}
 
 	if (sb->s_root) {
+		struct ubifs_info *c1 = sb->s_fs_info;
+
 		/* A new mount point for already mounted UBIFS */
 		dbg_gen("this ubi volume is already mounted");
-		if ((flags ^ sb->s_flags) & MS_RDONLY) {
+		if (!!(flags & MS_RDONLY) != c1->ro_mount) {
 			err = -EBUSY;
 			goto out_deact;
 		}

fs/ubifs/tnc.c

@@ -1177,6 +1177,7 @@ int ubifs_lookup_level0(struct ubifs_info *c, const union ubifs_key *key,
 	unsigned long time = get_seconds();
 
 	dbg_tnc("search key %s", DBGKEY(key));
+	ubifs_assert(key_type(c, key) < UBIFS_INVALID_KEY);
 
 	znode = c->zroot.znode;
 	if (unlikely(!znode)) {
@@ -2966,7 +2967,7 @@ static struct ubifs_znode *right_znode(struct ubifs_info *c,
  *
  * This function searches an indexing node by its first key @key and its
  * address @lnum:@offs. It looks up the indexing tree by pulling all indexing
- * nodes it traverses to TNC. This function is called fro indexing nodes which
+ * nodes it traverses to TNC. This function is called for indexing nodes which
  * were found on the media by scanning, for example when garbage-collecting or
  * when doing in-the-gaps commit. This means that the indexing node which is
  * looked for does not have to have exactly the same leftmost key @key, because
@@ -2988,6 +2989,8 @@ static struct ubifs_znode *lookup_znode(struct ubifs_info *c,
 	struct ubifs_znode *znode, *zn;
 	int n, nn;
 
+	ubifs_assert(key_type(c, key) < UBIFS_INVALID_KEY);
+
 	/*
 	 * The arguments have probably been read off flash, so don't assume
 	 * they are valid.

fs/ubifs/ubifs.h

@@ -119,8 +119,12 @@
  * in TNC. However, when replaying, it is handy to introduce fake "truncation"
  * keys for truncation nodes because the code becomes simpler. So we define
  * %UBIFS_TRUN_KEY type.
+ *
+ * But otherwise, out of the journal reply scope, the truncation keys are
+ * invalid.
  */
-#define UBIFS_TRUN_KEY UBIFS_KEY_TYPES_CNT
+#define UBIFS_TRUN_KEY    UBIFS_KEY_TYPES_CNT
+#define UBIFS_INVALID_KEY UBIFS_KEY_TYPES_CNT
 
 /*
  * How much a directory entry/extended attribute entry adds to the parent/host
@@ -1028,6 +1032,8 @@ struct ubifs_debug_info;
  * @max_leb_cnt: maximum count of logical eraseblocks
  * @old_leb_cnt: count of logical eraseblocks before re-size
  * @ro_media: the underlying UBI volume is read-only
+ * @ro_mount: the file-system was mounted as read-only
+ * @ro_error: UBIFS switched to R/O mode because an error happened
  *
  * @dirty_pg_cnt: number of dirty pages (not used)
  * @dirty_zn_cnt: number of dirty znodes
@@ -1168,11 +1174,14 @@ struct ubifs_debug_info;
  * @replay_sqnum: sequence number of node currently being replayed
  * @need_recovery: file-system needs recovery
  * @replaying: set to %1 during journal replay
- * @unclean_leb_list: LEBs to recover when mounting ro to rw
- * @rcvrd_mst_node: recovered master node to write when mounting ro to rw
+ * @unclean_leb_list: LEBs to recover when re-mounting R/O mounted FS to R/W
+ *                    mode
+ * @rcvrd_mst_node: recovered master node to write when re-mounting R/O mounted
+ *                  FS to R/W mode
  * @size_tree: inode size information for recovery
- * @remounting_rw: set while remounting from ro to rw (sb flags have MS_RDONLY)
- * @always_chk_crc: always check CRCs (while mounting and remounting rw)
+ * @remounting_rw: set while re-mounting from R/O mode to R/W mode
+ * @always_chk_crc: always check CRCs (while mounting and remounting to R/W
+ *                  mode)
  * @mount_opts: UBIFS-specific mount options
  *
  * @dbg: debugging-related information
@@ -1268,7 +1277,9 @@ struct ubifs_info {
 	int leb_cnt;
 	int max_leb_cnt;
 	int old_leb_cnt;
-	int ro_media;
+	unsigned int ro_media:1;
+	unsigned int ro_mount:1;
+	unsigned int ro_error:1;
 
 	atomic_long_t dirty_pg_cnt;
 	atomic_long_t dirty_zn_cnt;