fix gfs2_stuffed_write_end() on short copies

a) the page is uptodate - ->write_begin() would either fail (in which
case we don't reach ->write_end()), or unstuff the inode, or find the
page already uptodate, or do a successful call of stuffed_readpage(),
which would've made it uptodate

b) zeroing the tail in pagecache is wrong.  kill -9 at the right time
while writing unmodified file contents to the same file should _not_
leave us in a situation when read() from the file will be reporting
it full of zeroes.  Especially since that effect will be transient -
at some later point the page will be evicted and then we'll be back
to the real file contents.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
index 5a6f52ea272282b0c695372f11c8f8512c7ace12..6b039d7ce160fce7677c3e5d702cd27a6299bb59 100644 (file)
--- a/fs/gfs2/aops.c
+++ b/fs/gfs2/aops.c
@@ -839,12 +839,10 @@ static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh,
        BUG_ON((pos + len) > (dibh->b_size - sizeof(struct gfs2_dinode)));
        kaddr = kmap_atomic(page);
        memcpy(buf + pos, kaddr + pos, copied);
-       memset(kaddr + pos + copied, 0, len - copied);
        flush_dcache_page(page);
        kunmap_atomic(kaddr);
 
-       if (!PageUptodate(page))
-               SetPageUptodate(page);
+       WARN_ON(!PageUptodate(page));
        unlock_page(page);
        put_page(page);