No preallocate is actually sent on the wire (other than creating the file) in the example you tried. Some servers do not support preallocate - do you know the expected behavior on a local file system that does not support preallocate whether it should 1) fail to create the file and return an error or 2) succeed in creating the file (even though couldn't preallocate the size). Looking at the code I am surprised it is not returning an error message though it looks like smb3_simple_falloc would return an EOPNOTSUPP error (at least if allocating more than a few pages beyond end of file) On Fri, Mar 22, 2019 at 7:26 AM Xiaoli Feng <xifeng@xxxxxxxxxx> wrote: > > Hello, > > Use xfs_io to test preallocate. It returns successfuly. But it's a empty file. And doesn't allocate space. > > # mount //localhost/cifs ~/cifs > # xfs_io -f -c "resvsp 4 4" cifs/file > # du -h cifs/file > 0 cifs/file > > > Test on xfs: > # rm -rf file > # xfs_io -f -c "resvsp 4 4" file > # du -h file > 4.0K file > > Is it expected for cifs? I think the size should be a block size(1M for cifs). > > Thanks. > > -- > Best regards! > XiaoLi Feng 冯小丽 > > Red Hat Software (Beijing) Co.,Ltd > filesystem-qe Team > IRC:xifeng，#channel: fs-qe > Tel:+86-10-8388112 > 9/F, Raycom -- Thanks, Steve
