Ocfs2 devel - Sep 2018 - [bug report] ocfs2: fix a static checker warning

Sorry, Gang He,

The error message is still there.

The patch 8c4d5a438716: "ocfs2: fix a static checker warning" from
Jul 6, 2017, leads to the following static checker warning:

	fs/ocfs2/export.c:127 ocfs2_get_dentry()
	warn: 'inode' can also be NULL

fs/ocfs2/inode.c
   161          args.fi_sysfile_type = sysfile_type;
   162  
   163          inode = iget5_locked(sb, args.fi_ino, ocfs2_find_actor,
   164                               ocfs2_init_locked_inode, &args);
   165          /* inode was *not* in the inode cache. 2.6.x requires
   166           * us to do our own read_inode call and unlock it
   167           * afterwards. */
   168          if (inode == NULL) {
   169                  inode = ERR_PTR(-ENOMEM);
   170                  mlog_errno(PTR_ERR(inode));
   171                  goto bail;
   172          }
   173          trace_ocfs2_iget5_locked(inode->i_state);
   174          if (inode->i_state & I_NEW) {
   175                  rc = ocfs2_read_locked_inode(inode, &args);
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Imagine this succeeds.

   176                  unlock_new_inode(inode);
   177          }
   178          if (is_bad_inode(inode)) {
   179                  iput(inode);
   180                  inode = ERR_PTR(rc);
                        ^^^^^^^^^^^^^^^^^^^
We're returning ERR_PTR(0) which is NULL which leads to a NULL
dereference in the caller.

   181                  goto bail;
   182          }
   183  

regards,
dan carpenter

Hello Dan,

Thank for your finding, I will fix this warning.

-Gang
>>> On 2018/9/25 at 14:53, in message <20180925125347.GA1300 at
mwanda>, Dan Carpenter
<dan.carpenter at oracle.com> wrote:
> Sorry, Gang He,
> 
> The error message is still there.
> 
> The patch 8c4d5a438716: "ocfs2: fix a static checker warning"
from
> Jul 6, 2017, leads to the following static checker warning:
> 
> 	fs/ocfs2/export.c:127 ocfs2_get_dentry()
> 	warn: 'inode' can also be NULL
> 
> fs/ocfs2/inode.c
>    161          args.fi_sysfile_type = sysfile_type;
>    162  
>    163          inode = iget5_locked(sb, args.fi_ino, ocfs2_find_actor,
>    164                               ocfs2_init_locked_inode, &args);
>    165          /* inode was *not* in the inode cache. 2.6.x requires
>    166           * us to do our own read_inode call and unlock it
>    167           * afterwards. */
>    168          if (inode == NULL) {
>    169                  inode = ERR_PTR(-ENOMEM);
>    170                  mlog_errno(PTR_ERR(inode));
>    171                  goto bail;
>    172          }
>    173          trace_ocfs2_iget5_locked(inode->i_state);
>    174          if (inode->i_state & I_NEW) {
>    175                  rc = ocfs2_read_locked_inode(inode, &args);
>                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> Imagine this succeeds.
> 
>    176                  unlock_new_inode(inode);
>    177          }
>    178          if (is_bad_inode(inode)) {
>    179                  iput(inode);
>    180                  inode = ERR_PTR(rc);
>                         ^^^^^^^^^^^^^^^^^^^
> We're returning ERR_PTR(0) which is NULL which leads to a NULL
> dereference in the caller.
> 
>    181                  goto bail;
>    182          }
>    183  
> 
> regards,
> dan carpenter