> On May 2, 2022, at 6:46 PM, Steve Dickson <steved@xxxxxxxxxx> wrote: > > > > On 5/2/22 12:17 PM, J. Bruce Fields wrote: >> On Mon, May 02, 2022 at 10:50:40AM +0200, Richard Weinberger wrote: >>> This is the first non-RFC iteration of the NFS re-export >>> improvement series for nfs-utils. >>> While the kernel side[0] didn't change at all and is still small, >>> the userspace side saw much more changes. >>> >>> The core idea is adding new export option: reeport= >>> Using reexport= it is possible to mark an export entry in the exports >>> file explicitly as NFS re-export and select a strategy how unique >>> identifiers should be provided. >>> Currently two strategies are supported, "auto-fsidnum" and >>> "predefined-fsidnum", both use a SQLite database as backend to keep >>> track of generated ids. >>> For a more detailed description see patch "exports: Implement new export option reexport=". >>> I choose SQLite because nfs-utils already uses it and using SQL ids can nicely >>> generated and maintained. It will also scale for large setups where the amount >>> of subvolumes is high. >>> >>> Beside of id generation this series also addresses the reboot problem. >>> If the re-exporting NFS server reboots, uncovered NFS subvolumes are not yet >>> mounted and file handles become stale. >>> Now mountd/exportd keeps track of uncovered subvolumes and makes sure they get >>> uncovered while nfsd starts. >>> >>> The whole set of features is currently opt-in via --enable-reexport. >> Can we remove that option before upstreaming? Somehow I missed Bruce's comment, but I had the same thought. The cover letter does not explain why someone would want to build nfs-utils without re-export support. If there isn't a good reason for needing this switch, IMO it can be removed. >> For testing purposes it may makes sense to be able to turn the new code >> on and off quickly. But for something we're really going to support, >> it's just another hurdle for users to jump through, and another case we >> probably won't remember to test. The export options themselves should >> be enough configuration. >> Anyway, basically sounds reasonable to me. I'll try to give it a proper >> review sometime, feel free to bug me if I don't get to it in a week or >> so. > How about --disable-reexport? So it is on by default to help testing > but if there are issues we can turn it off... > > steved. > >> --b. >>> I'm also not sure about the rearrangement of the reexport code, >>> currently it is a helper library. >>> >>> A typical export entry on a re-exporting server looks like: >>> /nfs *(rw,no_root_squash,no_subtree_check,crossmnt,reexport=auto-fsidnum) >>> reexport=auto-fsidnum will automatically assign an fsid= to /nfs and all >>> uncovered subvolumes. >>> >>> Richard Weinberger (5): >>> Implement reexport helper library >>> exports: Implement new export option reexport= >>> export: Implement logic behind reexport= >>> export: Avoid fsid= conflicts >>> reexport: Make state database location configurable >>> >>> [0] https://git.kernel.org/pub/scm/linux/kernel/git/rw/misc.git/log/?h=nfs_reexport_clean >>> >>> configure.ac | 12 ++ >>> nfs.conf | 3 + >>> support/Makefile.am | 4 + >>> support/export/Makefile.am | 2 + >>> support/export/cache.c | 71 ++++++- >>> support/export/export.c | 27 ++- >>> support/include/nfslib.h | 1 + >>> support/nfs/Makefile.am | 1 + >>> support/nfs/exports.c | 68 +++++++ >>> support/reexport/Makefile.am | 6 + >>> support/reexport/reexport.c | 354 +++++++++++++++++++++++++++++++++ >>> support/reexport/reexport.h | 39 ++++ >>> systemd/Makefile.am | 4 + >>> systemd/nfs-server-generator.c | 14 +- >>> systemd/nfs.conf.man | 6 + >>> utils/exportd/Makefile.am | 8 +- >>> utils/exportd/exportd.c | 5 + >>> utils/exportfs/Makefile.am | 6 + >>> utils/exportfs/exportfs.c | 21 +- >>> utils/exportfs/exports.man | 31 +++ >>> utils/mount/Makefile.am | 7 + >>> utils/mountd/Makefile.am | 6 + >>> utils/mountd/mountd.c | 1 + >>> utils/mountd/svc_run.c | 6 + >>> 24 files changed, 690 insertions(+), 13 deletions(-) >>> create mode 100644 support/reexport/Makefile.am >>> create mode 100644 support/reexport/reexport.c >>> create mode 100644 support/reexport/reexport.h >>> >>> -- >>> 2.31.1 > -- Chuck Lever
