On Mon 23-10-23 16:55:40, Amir Goldstein wrote: > On Wed, Oct 18, 2023 at 1:00 PM Amir Goldstein <amir73il@xxxxxxxxx> wrote: > > > > AT_HANDLE_FID was added as an API for name_to_handle_at() that request > > the encoding of a file id, which is not intended to be decoded. > > > > This file id is used by fanotify to describe objects in events. > > > > So far, overlayfs is the only filesystem that supports encoding > > non-decodeable file ids, by providing export_operations with an > > ->encode_fh() method and without a ->decode_fh() method. > > > > Add support for encoding non-decodeable file ids to all the filesystems > > that do not provide export_operations, by encoding a file id of type > > FILEID_INO64_GEN from { i_ino, i_generation }. > > > > A filesystem may that does not support NFS export, can opt-out of > > encoding non-decodeable file ids for fanotify by defining an empty > > export_operations struct (i.e. with a NULL ->encode_fh() method). > > > > This allows the use of fanotify events with file ids on filesystems > > like 9p which do not support NFS export to bring fanotify in feature > > parity with inotify on those filesystems. > > > > Note that fanotify also requires that the filesystems report a non-null > > fsid. Currently, many simple filesystems that have support for inotify > > (e.g. debugfs, tracefs, sysfs) report a null fsid, so can still not be > > used with fanotify in file id reporting mode. > > > > Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> > > --- > > Hi Jan, > > Did you get a chance to look at this patch? > I saw your review comments on the rest of the series, so was waiting > for feedback on this last one before posting v2. Ah, sorry. I don't have any further comments regarding this patch besides what Chuck already wrote. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR