I know cross-posting is frowned upon, but I wanted everyone who might like to comment to see this.
Currently copy_file_range(2) only supports regular files, which is compatible with the Linux one, where EINVAL is returned when either file descriptor refers to a non-regular file. Alan Somers would like to extend the syscall to handle special files. I think he has a couple of reasons for this (he can correct me): - When integrating it into "cp", he needed to provide a fallback for special files and similar fallbacks would probably be needed for other utilities like "dd". - iSCSI provides a "copy" operation which could be implemented using copy_file_range(2)/VOP_COPY_FILE_RANGE() if it supported special files. kib@ was concerned that a copy from /dev/zero would fill a disk, but I think that issue can be dealt with by limiting the duration of the syscall to 1sec (so that the utility can be terminated via SIGTERM or similar). I am on the fence w.r.t. since I modelled it after the Linux one and keeping it Linux compatible would facilitate portable code, but I understand why Alan Somers wants to extend it (the iSCSI support seems particularily useful). Everyone, please comment on this, rick _______________________________________________ freebsd-current@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
