On Mon, 16 Aug 2021, kreijack@xxxxxxxxx wrote: > On 8/15/21 9:35 PM, Roman Mamedov wrote: > > On Sun, 15 Aug 2021 09:39:08 +0200 > > Goffredo Baroncelli <kreijack@xxxxxxxxx> wrote: > > > >> I am sure that it was discussed already but I was unable to find any track > >> of this discussion. But if the problem is the collision between the inode > >> number of different subvolume in the nfd export, is it simpler if the export > >> is truncated to the subvolume boundary ? It would be more coherent with the > >> current behavior of vfs+nfsd. > > > > See this bugreport thread which started it all: > > https://www.spinics.net/lists/linux-btrfs/msg111172.html > > > > In there the reporting user replied that it is strongly not feasible for them > > to export each individual snapshot. > > Thanks for pointing that. > > However looking at the 'exports' man page, it seems that NFS has already an > option to cover these cases: 'crossmnt'. > > If NFSd detects a "child" filesystem (i.e. a filesystem mounted inside an already > exported one) and the "parent" filesystem is marked as 'crossmnt', the client mount > the parent AND the child filesystem with two separate mounts, so there is not problem of inode collision. As you acknowledged, you haven't read the whole back-story. Maybe you should. https://lore.kernel.org/linux-nfs/20210613115313.BC59.409509F4@xxxxxxxxxxxx/ https://lore.kernel.org/linux-nfs/162848123483.25823.15844774651164477866.stgit@noble.brown/ https://lore.kernel.org/linux-btrfs/162742539595.32498.13687924366155737575.stgit@noble.brown/ The flow of conversation does sometimes jump between threads. I'm very happy to respond you questions after you've absorbed all that. NeilBrown
