Merge tag 'upstream-3.16-rc1-v2' of git://git.infradead.org/linux-ubifs

Pull UBIFS updates from Artem Bityutskiy:
 "This contains several UBIFS fixes.  One of them fixes a race condition
  between the mmap page fault path and fsync.  Another just removes a
  bogus assertion from the UBIFS memory shrinker.

  UBIFS also started honoring the MS_SILENT mount flag, so now it won't
  print many I/O errors when user-space just tries to probe for the FS.

  Rest of the changes are rather minor UBI/UBIFS fixes, improvements,
  and clean-ups"

* tag 'upstream-3.16-rc1-v2' of git://git.infradead.org/linux-ubifs:
  UBIFS: Add an assertion for clean_zn_cnt
  UBIFS: respect MS_SILENT mount flag
  UBIFS: Remove incorrect assertion in shrink_tnc()
  UBIFS: fix debugging check
  UBIFS: add missing ui pointer in debugging code
  UBI: block: Fix error path on alloc_workqueue failure
  UBIFS: Fix dump messages in ubifs_dump_lprops
  UBI: fix rb_tree node comparison in add_map
  UBIFS: Remove unused variables in ubifs_budget_space
  UBI: weaken the 'exclusive' constraint when opening volumes to rename
  UBIFS: fix an mmap and fsync race condition

8 files changed, 35 insertions, 16 deletions

diff --git a/fs/ubifs/budget.c b/fs/ubifs/budget.c
index e8e01d74dc05..eb997e9c4ab0 100644
--- a/fs/ubifs/budget.c
+++ b/fs/ubifs/budget.c
@@ -437,7 +437,6 @@ static int calc_dd_growth(const struct ubifs_info *c,
  */
 int ubifs_budget_space(struct ubifs_info *c, struct ubifs_budget_req *req)
 {
-        int uninitialized_var(cmt_retries), uninitialized_var(wb_retries);
         int err, idx_growth, data_growth, dd_growth, retried = 0;
 
         ubifs_assert(req->new_page <= 1);
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index 5157b866a853..177b0152fef4 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -745,8 +745,10 @@ void ubifs_dump_lprops(struct ubifs_info *c)
 
         for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) {
                 err = ubifs_read_one_lp(c, lnum, &lp);
-                if (err)
+                if (err) {
                         ubifs_err("cannot read lprops for LEB %d", lnum);
+                        continue;
+                }
 
                 ubifs_dump_lprop(c, &lp);
         }
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index 4f34dbae823d..0ab7f7dfb98b 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -903,8 +903,9 @@ static int do_writepage(struct page *page, int len)
         struct ubifs_info *c = inode->i_sb->s_fs_info;
 
 #ifdef UBIFS_DEBUG
+        struct ubifs_inode *ui = ubifs_inode(inode);
         spin_lock(&ui->ui_lock);
-        ubifs_assert(page->index <= ui->synced_i_size << PAGE_CACHE_SIZE);
+        ubifs_assert(page->index <= ui->synced_i_size >> PAGE_CACHE_SHIFT);
         spin_unlock(&ui->ui_lock);
 #endif
 
@@ -1525,8 +1526,7 @@ static int ubifs_vm_page_mkwrite(struct vm_area_struct *vma,
         }
 
         wait_for_stable_page(page);
-        unlock_page(page);
-        return 0;
+        return VM_FAULT_LOCKED;
 
 out_unlock:
         unlock_page(page);
diff --git a/fs/ubifs/io.c b/fs/ubifs/io.c
index e18b9889a51b..2290d5866725 100644
--- a/fs/ubifs/io.c
+++ b/fs/ubifs/io.c
@@ -988,30 +988,32 @@ int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len,
                 return err;
 
         if (type != ch->node_type) {
-                ubifs_err("bad node type (%d but expected %d)",
-                          ch->node_type, type);
+                ubifs_errc(c, "bad node type (%d but expected %d)",
+                           ch->node_type, type);
                 goto out;
         }
 
         err = ubifs_check_node(c, buf, lnum, offs, 0, 0);
         if (err) {
-                ubifs_err("expected node type %d", type);
+                ubifs_errc(c, "expected node type %d", type);
                 return err;
         }
 
         l = le32_to_cpu(ch->len);
         if (l != len) {
-                ubifs_err("bad node length %d, expected %d", l, len);
+                ubifs_errc(c, "bad node length %d, expected %d", l, len);
                 goto out;
         }
 
         return 0;
 
 out:
-        ubifs_err("bad node at LEB %d:%d, LEB mapping status %d", lnum, offs,
-                  ubi_is_mapped(c->ubi, lnum));
-        ubifs_dump_node(c, buf);
-        dump_stack();
+        ubifs_errc(c, "bad node at LEB %d:%d, LEB mapping status %d", lnum,
+                   offs, ubi_is_mapped(c->ubi, lnum));
+        if (!c->probing) {
+                ubifs_dump_node(c, buf);
+                dump_stack();
+        }
         return -EINVAL;
 }
 
diff --git a/fs/ubifs/shrinker.c b/fs/ubifs/shrinker.c
index f35135e28e96..9a9fb94a41c6 100644
--- a/fs/ubifs/shrinker.c
+++ b/fs/ubifs/shrinker.c
@@ -128,7 +128,6 @@ static int shrink_tnc(struct ubifs_info *c, int nr, int age, int *contention)
                         freed = ubifs_destroy_tnc_subtree(znode);
                         atomic_long_sub(freed, &ubifs_clean_zn_cnt);
                         atomic_long_sub(freed, &c->clean_zn_cnt);
-                        ubifs_assert(atomic_long_read(&c->clean_zn_cnt) >= 0);
                         total_freed += freed;
                         znode = zprev;
                 }
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index a81c7b556896..3904c8574ef9 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1149,6 +1149,9 @@ static int mount_ubifs(struct ubifs_info *c)
         size_t sz;
 
         c->ro_mount = !!(c->vfs_sb->s_flags & MS_RDONLY);
+        /* Suppress error messages while probing if MS_SILENT is set */
+        c->probing = !!(c->vfs_sb->s_flags & MS_SILENT);
+
         err = init_constants_early(c);
         if (err)
                 return err;
@@ -1214,6 +1217,8 @@ static int mount_ubifs(struct ubifs_info *c)
         if (err)
                 goto out_free;
 
+        c->probing = 0;
+
         /*
          * Make sure the compressor which is set as default in the superblock
          * or overridden by mount options is actually compiled in.
diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c
index 9083bc7ed4ae..8a40cf9c02d7 100644
--- a/fs/ubifs/tnc.c
+++ b/fs/ubifs/tnc.c
@@ -2859,10 +2859,11 @@ void ubifs_tnc_close(struct ubifs_info *c)
 {
         tnc_destroy_cnext(c);
         if (c->zroot.znode) {
-                long n;
+                long n, freed;
 
-                ubifs_destroy_tnc_subtree(c->zroot.znode);
                 n = atomic_long_read(&c->clean_zn_cnt);
+                freed = ubifs_destroy_tnc_subtree(c->zroot.znode);
+                ubifs_assert(freed == n);
                 atomic_long_sub(n, &ubifs_clean_zn_cnt);
         }
         kfree(c->gap_lebs);
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index e8c8cfe1435c..c1f71fe17cc0 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -51,6 +51,15 @@
 #define ubifs_warn(fmt, ...)                                        \
         pr_warn("UBIFS warning (pid %d): %s: " fmt "\n",            \
                 current->pid, __func__, ##__VA_ARGS__)
+/*
+ * A variant of 'ubifs_err()' which takes the UBIFS file-sytem description
+ * object as an argument.
+ */
+#define ubifs_errc(c, fmt, ...)                                     \
+        do {                                                        \
+                if (!(c)->probing)                                  \
+                        ubifs_err(fmt, ##__VA_ARGS__);              \
+        } while (0)
 
 /* UBIFS file system VFS magic number */
 #define UBIFS_SUPER_MAGIC 0x24051905
@@ -1209,6 +1218,7 @@ struct ubifs_debug_info;
  * @need_recovery: %1 if the file-system needs recovery
  * @replaying: %1 during journal replay
  * @mounting: %1 while mounting
+ * @probing: %1 while attempting to mount if MS_SILENT mount flag is set
  * @remounting_rw: %1 while re-mounting from R/O mode to R/W mode
  * @replay_list: temporary list used during journal replay
  * @replay_buds: list of buds to replay
@@ -1441,6 +1451,7 @@ struct ubifs_info {
         unsigned int replaying:1;
         unsigned int mounting:1;
         unsigned int remounting_rw:1;
+        unsigned int probing:1;
         struct list_head replay_list;
         struct list_head replay_buds;
         unsigned long long cs_sqnum;