[LU-10810] SEEK_HOLE and SEEK_DATA support for lseek

• Type: Improvement
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.14.0
• Labels: medium
• Assignee: Mikhail Pershin
• Reporter: Lokesh N J (Inactive)

Description

lseek with SEEK_HOLE and SEEK_DATA are really helpful  and easy to use tools for any usersapce applications like copy and backup. Currently lustre has min support implementation as per the man page which is not that useful however lustre does support fiemap ioctl which can be used for mapping data in the file.
As we already have support for fiemap I guess with some implementation lustre can support SEEK_HOLE and SEEK_DATA flags. I guess having this support will be helpful to deal with sparse files. Any feedback about the implementation will be really helpful.

Issue Links

• duplicates: LU-13397 lfs migrate/mirror extend/resync does not preserve sparse file
• is related to: LU-14143 SEEK_HOLE returns -ENXIO if file ends at components boundary
• is related to: LU-11621 Add copy_file_range() API and use it for lfs migrate and mirror resync
• is related to: LU-14217 better SEEK_HOLE/DATA support in OSD-ZFS
• is related to: LU-1941 ZFS FIEMAP support
• is related to: LU-3606 Implement fallocate() support for ldiskfs Lustre
• is related to: LU-13155 "lfs migrate" and "lfs mirror" should fallocate() the target file