Unionfs: clear partial read in readpage

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>

diff --git a/fs/unionfs/mmap.c b/fs/unionfs/mmap.c
index cb45e856484393cec43f3a54c9dce7bc3c33a20d..4cec2b5e85939c0a6330d0feb6d874fc3b251a86 100644 (file)
--- a/fs/unionfs/mmap.c
+++ b/fs/unionfs/mmap.c
@@ -211,7 +211,8 @@ static int unionfs_do_readpage(struct file *file, struct page *page)
        err = vfs_read(lower_file, page_data, PAGE_CACHE_SIZE,
                       &lower_file->f_pos);
        set_fs(old_fs);
-
+       if (err >= 0 && err < PAGE_CACHE_SIZE)
+               memset(page_data + err, 0, PAGE_CACHE_SIZE - err);
        kunmap(page);
 
        if (err < 0)