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

[Dan Carpenter]

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