[bug report] fuse: Add posix ACL support

[Dan Carpenter <dan.carpenter@oracle.com>]

Hello Seth Forshee,

The patch 60bcc88ad185: "fuse: Add posix ACL support" from Aug 29,
2016, leads to the following static checker warning:

	fs/fuse/acl.c:39 fuse_get_acl()
	warn: we tested 'fc->no_getxattr' before and it was 'false'

fs/fuse/acl.c
    13  
    14  struct posix_acl *fuse_get_acl(struct inode *inode, int type)
    15  {
    16          struct fuse_conn *fc = get_fuse_conn(inode);
    17          int size;
    18          const char *name;
    19          void *value = NULL;
    20          struct posix_acl *acl;
    21  
    22          if (!fc->posix_acl || fc->no_getxattr)
                                      ^^^^^^^^^^^^^^^

If this is set we return NULL.

    23                  return NULL;
    24  
    25          if (type == ACL_TYPE_ACCESS)
    26                  name = XATTR_NAME_POSIX_ACL_ACCESS;
    27          else if (type == ACL_TYPE_DEFAULT)
    28                  name = XATTR_NAME_POSIX_ACL_DEFAULT;
    29          else
    30                  return ERR_PTR(-EOPNOTSUPP);
    31  
    32          value = kmalloc(PAGE_SIZE, GFP_KERNEL);
    33          if (!value)
    34                  return ERR_PTR(-ENOMEM);
    35          size = fuse_getxattr(inode, name, value, PAGE_SIZE);
    36          if (size > 0)
    37                  acl = posix_acl_from_xattr(&init_user_ns, value, size);
    38          else if ((size == 0) || (size == -ENODATA) ||
    39                   (size == -EOPNOTSUPP && fc->no_getxattr))
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
So this can't happen.

    40                  acl = NULL;
    41          else if (size == -ERANGE)
    42                  acl = ERR_PTR(-E2BIG);
    43          else
    44                  acl = ERR_PTR(size);
    45  
    46          kfree(value);
    47          return acl;
    48  }

regards,
dan carpenter