11 files changed, 44 insertions, 24 deletions

diff --git a/fs/ubifs/commit.c b/fs/ubifs/commit.c
index 37fa7ed062d8..712432789fb8 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);
+
+        if (c->ro_error) {
                 err = -EROFS;
                 goto out_up;
         }
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index 03ae894c45de..c6bc51c9f07c 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);
 
-        if (unlikely(c->ro_media))
+        if (unlikely(c->ro_error))
                 return -EROFS;
 
         /* Try out the fast-path part first */
@@ -1440,8 +1441,9 @@ 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);
 
-        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 396f24a30af9..d927196d730b 100644
--- a/fs/ubifs/gc.c
+++ b/fs/ubifs/gc.c
@@ -616,13 +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);
 
         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;
         }
diff --git a/fs/ubifs/io.c b/fs/ubifs/io.c
index 9432431bf595..18a4b8d7c844 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);
@@ -359,8 +359,9 @@ int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf)
         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);
 
-        if (c->ro_media)
+        if (c->ro_error)
                 return -EROFS;
 
         ubifs_pad(c, wbuf->buf + wbuf->used, wbuf->avail);
@@ -440,11 +441,12 @@ int ubifs_bg_wbufs_sync(struct ubifs_info *c)
 {
         int err, i;
 
+        ubifs_assert(!c->ro_media);
         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 +521,7 @@ 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);
 
         if (c->leb_size - wbuf->offs - wbuf->used < aligned_len) {
                 err = -ENOSPC;
@@ -527,7 +530,7 @@ 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 +666,9 @@ 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);
 
-        if (c->ro_media)
+        if (c->ro_error)
                 return -EROFS;
 
         ubifs_prepare_node(c, buf, len, 1);
diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c
index d321baeca68d..a6da8aa68f37 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);
         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/log.c b/fs/ubifs/log.c
index c345e125f42c..a41713e2fbb3 100644
--- a/fs/ubifs/log.c
+++ b/fs/ubifs/log.c
@@ -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);
+        if (c->ro_error) {
                 err = -EROFS;
                 goto out_unlock;
         }
diff --git a/fs/ubifs/master.c b/fs/ubifs/master.c
index 28beaeedadc0..0c818e855f59 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);
+        if (c->ro_error)
                 return -EROFS;
 
         lnum = UBIFS_MST_LNUM;
diff --git a/fs/ubifs/misc.h b/fs/ubifs/misc.h
index 4fa81d867e41..5d476ba184e6 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);
+        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);
+        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);
+        if (c->ro_error)
                 return -EROFS;
         err = ubi_leb_change(c->ubi, lnum, buf, len, dtype);
         if (err) {
diff --git a/fs/ubifs/shrinker.c b/fs/ubifs/shrinker.c
index 0b201114a5ad..10eec8778438 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_media || c->ro_error) {
                                 mutex_unlock(&c->umount_mutex);
                                 continue;
                         }
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index cd5900b85d38..1cfeec56df91 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1751,10 +1751,10 @@ static void ubifs_put_super(struct super_block *sb)
                                 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) {
                         /*
                          * We are being cleanly unmounted which means the
                          * orphans were killed - indicate this in the master
@@ -1798,16 +1798,20 @@ static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
         }
 
         if ((sb->s_flags & MS_RDONLY) && !(*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");
+                if (c->ro_error) {
+                        ubifs_msg("cannot re-mount R/O due to prior errors");
                         return -EROFS;
                 }
                 ubifs_remount_ro(c);
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index c4dc9b18f73e..f47ebb442d1c 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -1032,6 +1032,7 @@ 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_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
@@ -1272,7 +1273,8 @@ 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_error:1;
 
         atomic_long_t dirty_pg_cnt;
         atomic_long_t dirty_zn_cnt;