releases/4.4.120/f2fs-fix-a-bug-caused-by-null-extent-tree.patch

   1 From dad48e73127ba10279ea33e6dbc8d3905c4d31c0 Mon Sep 17 00:00:00 2001
   2 From: Yunlei He <heyunlei@huawei.com>
   3 Date: Fri, 19 May 2017 15:06:12 +0800
   4 Subject: f2fs: fix a bug caused by NULL extent tree
   5
   6 From: Yunlei He <heyunlei@huawei.com>
   7
   8 commit dad48e73127ba10279ea33e6dbc8d3905c4d31c0 upstream.
   9
  10 Thread A:                                       Thread B:
  11
  12 -f2fs_remount
  13     -sbi->mount_opt.opt = 0;
  14                                                 <--- -f2fs_iget
  15                                                          -do_read_inode
  16                                                              -f2fs_init_extent_tree
  17                                                                  -F2FS_I(inode)->extent_tree is NULL
  18         -default_options && parse_options
  19             -remount return
  20                                                 <---  -f2fs_map_blocks
  21                                                           -f2fs_lookup_extent_tree
  22                                                               -f2fs_bug_on(sbi, !et);
  23
  24 The same problem with f2fs_new_inode.
  25
  26 Signed-off-by: Yunlei He <heyunlei@huawei.com>
  27 Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
  28 Signed-off-by: Nikolay Borisov <nborisov@suse.com>
  29 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  30
  31 ---
  32  fs/f2fs/extent_cache.c |   10 +++++++++-
  33  1 file changed, 9 insertions(+), 1 deletion(-)
  34
  35 --- a/fs/f2fs/extent_cache.c
  36 +++ b/fs/f2fs/extent_cache.c
  37 @@ -172,7 +172,7 @@ void f2fs_drop_largest_extent(struct ino
  38         __drop_largest_extent(inode, fofs, 1);
  39  }
  40
  41 -void f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
  42 +static void __f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
  43  {
  44         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
  45         struct extent_tree *et;
  46 @@ -204,6 +204,14 @@ out:
  47         write_unlock(&et->lock);
  48  }
  49
  50 +void f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
  51 +{
  52 +       __f2fs_init_extent_tree(inode, i_ext);
  53 +
  54 +       if (!F2FS_I(inode)->extent_tree)
  55 +               set_inode_flag(F2FS_I(inode), FI_NO_EXTENT);
  56 +}
  57 +
  58  static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
  59                                                         struct extent_info *ei)
  60  {