[bug report] xfs: Add xfs_has_attr and subroutines

[<dan.carpenter@oracle.com>]

Hello Allison Collins,

The patch cfe3d8821c6f: "xfs: Add xfs_has_attr and subroutines" from
Jul 20, 2020, leads to the following Smatch warning:

	fs/xfs/libxfs/xfs_attr.c:1431 xfs_attr_node_get()
	warn: variable dereferenced before check 'state' (see line 1426)

fs/xfs/libxfs/xfs_attr.c
  1398  STATIC int
  1399  xfs_attr_node_get(
  1400          struct xfs_da_args      *args)
  1401  {
  1402          struct xfs_da_state     *state;
  1403          struct xfs_da_state_blk *blk;
  1404          int                     i;
  1405          int                     error;
  1406  
  1407          trace_xfs_attr_node_get(args);
  1408  
  1409          /*
  1410           * Search to see if name exists, and get back a pointer to it.
  1411           */
  1412          error = xfs_attr_node_hasname(args, &state);
  1413          if (error != -EEXIST)
  1414                  goto out_release;
                        ^^^^^^^^^^^^^^^^
state can be NULL.

  1415  
  1416          /*
  1417           * Get the value, local or "remote"
  1418           */
  1419          blk = &state->path.blk[state->path.active - 1];
  1420          error = xfs_attr3_leaf_getvalue(blk->bp, args);
  1421  
  1422          /*
  1423           * If not in a transaction, we have to release all the buffers.
  1424           */
  1425  out_release:
  1426          for (i = 0; i < state->path.active; i++) {
                                ^^^^^^^^^^^^^^^^^^
Dereference

  1427                  xfs_trans_brelse(args->trans, state->path.blk[i].bp);
  1428                  state->path.blk[i].bp = NULL;
  1429          }
  1430  
  1431          if (state)
                    ^^^^^
To late.

  1432                  xfs_da_state_free(state);
  1433          return error;
  1434  }

regards,
dan carpenter