Merge branch 'akpm' (incoming from Andrew Morton)

Merge misc fixes from Andrew Morton:
 "21 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (21 commits)
  mm/balloon_compaction: fix deflation when compaction is disabled
  sh: fix sh770x SCIF memory regions
  zram: avoid NULL pointer access in concurrent situation
  mm/slab_common: don't check for duplicate cache names
  ocfs2: fix d_splice_alias() return code checking
  mm: rmap: split out page_remove_file_rmap()
  mm: memcontrol: fix missed end-writeback page accounting
  mm: page-writeback: inline account_page_dirtied() into single caller
  lib/bitmap.c: fix undefined shift in __bitmap_shift_{left|right}()
  drivers/rtc/rtc-bq32k.c: fix register value
  memory-hotplug: clear pgdat which is allocated by bootmem in try_offline_node()
  drivers/rtc/rtc-s3c.c: fix initialization failure without rtc source clock
  kernel/kmod: fix use-after-free of the sub_info structure
  drivers/rtc/rtc-pm8xxx.c: rework to support pm8941 rtc
  mm, thp: fix collapsing of hugepages on madvise
  drivers: of: add return value to of_reserved_mem_device_init()
  mm: free compound page with correct order
  gcov: add ARM64 to GCOV_PROFILE_ALL
  fsnotify: next_i is freed during fsnotify_unmount_inodes.
  mm/compaction.c: avoid premature range skip in isolate_migratepages_range
  ...

1 files changed, 11 insertions, 6 deletions

diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index 9ce062218de9..e8497144b323 100644
--- a/fs/notify/inode_mark.c
+++ b/fs/notify/inode_mark.c
@@ -288,20 +288,25 @@ void fsnotify_unmount_inodes(struct list_head *list)
                 spin_unlock(&inode->i_lock);
 
                 /* In case the dropping of a reference would nuke next_i. */
-                if ((&next_i->i_sb_list != list) &&
-                    atomic_read(&next_i->i_count)) {
+                while (&next_i->i_sb_list != list) {
                         spin_lock(&next_i->i_lock);
-                        if (!(next_i->i_state & (I_FREEING | I_WILL_FREE))) {
+                        if (!(next_i->i_state & (I_FREEING | I_WILL_FREE)) &&
+                                                atomic_read(&next_i->i_count)) {
                                 __iget(next_i);
                                 need_iput = next_i;
+                                spin_unlock(&next_i->i_lock);
+                                break;
                         }
                         spin_unlock(&next_i->i_lock);
+                        next_i = list_entry(next_i->i_sb_list.next,
+                                                struct inode, i_sb_list);
                 }
 
                 /*
-                 * We can safely drop inode_sb_list_lock here because we hold
-                 * references on both inode and next_i.  Also no new inodes
-                 * will be added since the umount has begun.
+                 * We can safely drop inode_sb_list_lock here because either
+                 * we actually hold references on both inode and next_i or
+                 * end of list.  Also no new inodes will be added since the
+                 * umount has begun.
                  */
                 spin_unlock(&inode_sb_list_lock);