On Thu, Mar 7, 2024 at 7:36 AM Steve French <smfrench@xxxxxxxxx> wrote: > > Following up on a discussion a few years ago about missing STATX > attributes, I noticed a case recently where some tools on other OS > have an option to skip offline files (e.g. the Windows equivalent of > grep, "findstr", and some Mac tools also seem to do this). > Which API is used in other OS to query the offline bit? Do they use SMB specific API, as Windows does? > This reminded me that there are a few additional STATX attribute flags > that could be helpful beyond the 8 that are currently defined (e.g. > STATX_ATTR_COMPRESSED, STATX_ATTR_ENCRYPTED, STATX_ATTR_NO_DUMP, > STATX_ATTR_VERITY) and that it be worthwhile revisiting which > additional STATX attribute flags would be most useful. I agree that it would be interesting to talk about new STATX_ attributes, but it should already be covered by this talk: https://lore.kernel.org/linux-fsdevel/2uvhm6gweyl7iyyp2xpfryvcu2g3padagaeqcbiavjyiis6prl@yjm725bizncq/ We have a recent example of what I see as a good process of introducing new STATX_ attributes: https://lore.kernel.org/linux-fsdevel/20240302220203.623614-1-kent.overstreet@xxxxxxxxx/ 1. Kent needed stx_subvol_id for bcachefs, so he proposed a patch 2. The minimum required bikeshedding on the name ;) 3. Buy in by at least one other filesystem (btrfs) w.r.t attributes that only serve one filesystem, certainly a requirement from general purpose userspace tools will go a long way to help when introducing new attributes such as STATX_ATTR_OFFLINE, so if you get userspace projects to request this functionality I think you should be good to go. > > "offline" could be helpful for fuse and cifs.ko and probably multiple > fs to be able to report, I am not sure why you think that "offline" will be useful to fuse? Is there any other network fs that already has the concept of "offline" attribute? > but there are likely other examples that could help various filesystems. Maybe interesting for network fs that are integrated with fscache/netfs? It may be useful for netfs to be able to raise the STATX_ATTR_OFFLINE attribute for a certain cached file in some scenarios? As a developer of HSM API [1], where files on any fs could have an "offline" status, STATX_ATTR_OFFLINE is interesting to me, but only if local disk fs will map it to persistent inode flags. When I get to it, I may pick a victim local fs and write a patch for it. Thanks, Amir. [1] https://github.com/amir73il/fsnotify-utils/wiki/Hierarchical-Storage-Management-API
