On Mon, Oct 22, 2018 at 02:45:04PM -0400, Olga Kornievskaia wrote: > On Sat, Oct 20, 2018 at 4:54 AM Amir Goldstein <amir73il@xxxxxxxxx> wrote: > > Another thing is the commit message claims to: > > "Allow copy_file_range to copy between different superblocks but only > > of the same file system types" > > > > But what the patch actually does is: > > "Allow copy_file_range() syscall to copy between different filesystems > > AND allow calling the filesystems' copy_file_range() method > > between different superblocks but only of the same file system types" > > > > It's probably OK and quite useful to do the former, but maybe man page > > should be fixed to explicitly mention that the copy is expected to work > > across filesystems since kernel version XXX (?) > > > > If you don't wish to change cross filesystem type behavior and only > > relax cross super block limitation, then you should replace the > > same inode->i_sb check above with same inode->i_sb->s_type > > check instead of doing the check only for calling the filesystem > > copy_file_range() method. > > Thank you for the feedback. In the next version, I will remove the > check for the functions and instead check for the same file system > types. Jeff and I agree that this is the wrong way to go. Instead, the cross-device check should be in the individual instances, not the top level code.