fix-mmap-data-corruption-in-nodelalloc-mode-when-blocksize-lt-pagesize

   1 ext4: fix mmap data corruption in nodelalloc mode when blocksize < pagesize
   2
   3 From: Xiaoguang Wang <wangxg.fnst@cn.fujitsu.com>
   4
   5 Since commit 90a8020 and d6320cb, Jan Kara has fixed this issue partially.
   6 This mmap data corruption still exists in nodelalloc mode, fix this.
   7
   8 Signed-off-by: Xiaoguang Wang <wangxg.fnst@cn.fujitsu.com>
   9 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  10 Reviewed-by:   Jan Kara <jack@suse.cz>
  11 ---
  12  fs/ext4/inode.c | 7 +++++++
  13  1 file changed, 7 insertions(+)
  14
  15 diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
  16 index 9193ea1..0390e41 100644
  17 --- a/fs/ext4/inode.c
  18 +++ b/fs/ext4/inode.c
  19 @@ -1007,6 +1007,7 @@ static int ext4_write_end(struct file *file,
  20  {
  21         handle_t *handle = ext4_journal_current_handle();
  22         struct inode *inode = mapping->host;
  23 +       loff_t old_size = inode->i_size;
  24         int ret = 0, ret2;
  25         int i_size_changed = 0;
  26
  27 @@ -1037,6 +1038,8 @@ static int ext4_write_end(struct file *file,
  28         unlock_page(page);
  29         page_cache_release(page);
  30
  31 +       if (old_size < pos)
  32 +               pagecache_isize_extended(inode, old_size, pos);
  33         /*
  34          * Don't mark the inode dirty under page lock. First, it unnecessarily
  35          * makes the holding time of page lock longer. Second, it forces lock
  36 @@ -1078,6 +1081,7 @@ static int ext4_journalled_write_end(struct file *file,
  37  {
  38         handle_t *handle = ext4_journal_current_handle();
  39         struct inode *inode = mapping->host;
  40 +       loff_t old_size = inode->i_size;
  41         int ret = 0, ret2;
  42         int partial = 0;
  43         unsigned from, to;
  44 @@ -1110,6 +1114,9 @@ static int ext4_journalled_write_end(struct file *file,
  45         unlock_page(page);
  46         page_cache_release(page);
  47
  48 +       if (old_size < pos)
  49 +               pagecache_isize_extended(inode, old_size, pos);
  50 +
  51         if (size_changed) {
  52                 ret2 = ext4_mark_inode_dirty(handle, inode);
  53                 if (!ret)
  54 --
  55 1.8.3.1
  56
  57