On Fri, Mar 10, 2017 at 04:48:52PM +0000, Ben Hutchings wrote:
> On Fri, 2017-03-10 at 10:08 +0100, Greg Kroah-Hartman wrote:
> > 4.4-stable review patch. If anyone has any objections, please let me
> > know.
> >
> > ------------------
> >
> > From: Theodore Ts'o <tytso@xxxxxxx>
> >
> > commit eb5efbcb762aee4b454b04f7115f73ccbcf8f0ef upstream.
> >
> > The write_end() function must always unlock the page and drop its ref
> > count, even on an error.
>
> This looks like a theoretical rather than a real issue, because I can't
> see how ext4_write_inline_data_end() ever returns an error code.
I'll leave that up to Ted to justify :)
> > Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> >
> > ---
> > fs/ext4/inline.c | 9 ++++++++-
> > fs/ext4/inode.c | 20 +++++++++++++++-----
> > 2 files changed, 23 insertions(+), 6 deletions(-)
> >
> > --- a/fs/ext4/inline.c
> > +++ b/fs/ext4/inline.c
> > @@ -933,8 +933,15 @@ int ext4_da_write_inline_data_end(struct
> > > struct page *page)
> > {
> > int i_size_changed = 0;
> > + int ret;
> >
> > - copied = ext4_write_inline_data_end(inode, pos, len, copied, page);
> > + ret = ext4_write_inline_data_end(inode, pos, len, copied, page);
> > + if (ret < 0) {
> > + unlock_page(page);
> > + put_page(page);
> [...]
>
> For 4.4 each put_page() should ideally be changed to
> page_cache_release(). It makes no practical difference but would be
> consistent with other paths.
As it's still the same logic, I'd prefer to stick to what newer kernels
do if at all possible.
thanks,
greg k-h