[Ocfs2-devel] ocfs2: fix sparse file & data ordering issue in direct io

[Dan Carpenter]

Ryan's email is dead.  But this is buggy.  Someone please fix it.

regards,
dan carpenter

On Tue, Nov 15, 2016 at 01:33:30PM +0300, Dan Carpenter wrote:
> I never got a response on this.  I was looking at it today and it still
> looks buggy to me.
> 
> regards,
> dan carpenter
> 
> On Wed, Mar 09, 2016 at 01:25:05PM +0300, Dan Carpenter wrote:
> > Hello Ryan Ding,
> > 
> > The patch fbe25fb91af5: "ocfs2: fix sparse file & data ordering issue
> > in direct io" from Feb 25, 2016, leads to the following static
> > checker warning:
> > 
> > 	fs/ocfs2/aops.c:2242 ocfs2_dio_get_block()
> > 	error: potentially dereferencing uninitialized 'wc'.
> > 
> > fs/ocfs2/aops.c
> >   2235  
> >   2236          ret = ocfs2_write_begin_nolock(inode->i_mapping, pos, len,
> >   2237                                         OCFS2_WRITE_DIRECT, NULL,
> >   2238                                         (void **)&wc, di_bh, NULL);
> >                                                ^^^^^^^^^^^^
> > 
> > See commit 5cffff9e2986 ('ocfs2: Fix ocfs2_page_mkwrite()') for an
> > explanation why a zero return here does not imply that "wc" has been
> > initialized.
> > 
> >   2239          if (ret) {
> >   2240                  mlog_errno(ret);
> >   2241                  goto unlock;
> >   2242          }
> >   2243  
> >   2244          desc = &wc->w_desc[0];
> >   2245  
> >   2246          p_blkno = ocfs2_clusters_to_blocks(inode->i_sb, desc->c_phys);
> > 
> > regards,
> > dan carpenter