> Which API is used in other OS to query the offline bit? > Do they use SMB specific API, as Windows does? No it is not smb specific - a local fs can also report this. It is included in the attribute bits for files and directories, it also includes a few additional bits that are used by HSM software on local drives (e.g. FILE_ATTRIBUTE_PINNED when the file may not be taken offline by HSM software) ATTRIBUTE_HIDDEN ATTRIBUTE_SYSTEM ATTRIBUTE_DIRECTORY ATTRIGBUTE_ARCHIVE ATTRIBUTE_TEMPORARY ATTRIBUTE_SPARSE_FILE ATTRIBUTE_REPARE_POINT ATTRIBUTE_COMPRESSED ATTRIBUTE_NOT_CONTENT_INDEXED ATTRIBUTE_ENCRYPTED ATTRIBUTE_OFFLINE On Thu, Mar 7, 2024 at 2:54 AM Amir Goldstein <amir73il@xxxxxxxxx> wrote: > > 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 -- Thanks, Steve
