21 files changed, 363 insertions, 112 deletions

diff --git a/fs/ubifs/commit.c b/fs/ubifs/commit.c
index 37fa7ed062d..02429d81ca3 100644
--- a/fs/ubifs/commit.c
+++ b/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;
         }
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index c2a68baa782..0bee4dbffc3 100644
--- a/fs/ubifs/debug.c
+++ b/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)
@@ -2625,6 +2781,7 @@ static const struct file_operations dfs_fops = {
         .open = open_debugfs_file,
         .write = write_debugfs_file,
         .owner = THIS_MODULE,
+        .llseek = default_llseek,
 };
 
 /**
diff --git a/fs/ubifs/debug.h b/fs/ubifs/debug.h
index 29d960101ea..69ebe472915 100644
--- a/fs/ubifs/debug.h
+++ b/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
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index 03ae894c45d..d77db7e3648 100644
--- a/fs/ubifs/file.c
+++ b/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 */
 
         /*
diff --git a/fs/ubifs/gc.c b/fs/ubifs/gc.c
index 918d1582ca0..151f1088282 100644
--- a/fs/ubifs/gc.c
+++ b/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;
diff --git a/fs/ubifs/io.c b/fs/ubifs/io.c
index bcf5a16f30b..d82173182ee 100644
--- a/fs/ubifs/io.c
+++ b/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;
diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c
index d321baeca68..914f1bd89e5 100644
--- a/fs/ubifs/journal.c
+++ b/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;
         }
diff --git a/fs/ubifs/key.h b/fs/ubifs/key.h
index 0f530c684f0..92a8491a8f8 100644
--- a/fs/ubifs/key.h
+++ b/fs/ubifs/key.h
@@ -306,6 +306,20 @@ static inline void trun_key_init(const struct ubifs_info *c,
 }
 
 /**
+ * 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
  * @key: key to get type of
diff --git a/fs/ubifs/log.c b/fs/ubifs/log.c
index c345e125f42..4d0cb124146 100644
--- a/fs/ubifs/log.c
+++ b/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;
         }
diff --git a/fs/ubifs/lpt.c b/fs/ubifs/lpt.c
index 0084a33c4c6..72775d35b99 100644
--- a/fs/ubifs/lpt.c
+++ b/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);
diff --git a/fs/ubifs/lpt_commit.c b/fs/ubifs/lpt_commit.c
index d12535b7fc7..5c90dec5db0 100644
--- a/fs/ubifs/lpt_commit.c
+++ b/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);
diff --git a/fs/ubifs/master.c b/fs/ubifs/master.c
index 28beaeedadc..21f47afdacf 100644
--- a/fs/ubifs/master.c
+++ b/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;
diff --git a/fs/ubifs/misc.h b/fs/ubifs/misc.h
index 4fa81d867e4..c3de04dc952 100644
--- a/fs/ubifs/misc.h
+++ b/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) {
diff --git a/fs/ubifs/recovery.c b/fs/ubifs/recovery.c
index daae9e1f538..77e9b874b6c 100644
--- a/fs/ubifs/recovery.c
+++ b/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;
 
diff --git a/fs/ubifs/replay.c b/fs/ubifs/replay.c
index 5c2d6d759a3..eed0fcff8d7 100644
--- a/fs/ubifs/replay.c
+++ b/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;
 }
diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c
index 96cb62c8a9d..bf31b4729e5 100644
--- a/fs/ubifs/sb.c
+++ b/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 {
diff --git a/fs/ubifs/scan.c b/fs/ubifs/scan.c
index 96c52538419..3e1ee57dbea 100644
--- a/fs/ubifs/scan.c
+++ b/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;
diff --git a/fs/ubifs/shrinker.c b/fs/ubifs/shrinker.c
index 0b201114a5a..46961c00323 100644
--- a/fs/ubifs/shrinker.c
+++ b/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;
                         }
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index cd5900b85d3..9a47c9f0ad0 100644
--- a/fs/ubifs/super.c
+++ b/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;
                 }
diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c
index 2194915220e..ad9cf013362 100644
--- a/fs/ubifs/tnc.c
+++ b/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.
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index 0c9876b396d..381d6b207a5 100644
--- a/fs/ubifs/ubifs.h
+++ b/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;