[PATCH nfs-utils v3 00/11] mountd: bugfixes for up/downcall interfaces

[Jeff Layton <jlayton@kernel.org>]

The main difference in this version is some cleanup to the warning
messages, so that we don't warn about internal events. Mantas, if you're
able to test this version too, that would be great.

Mantas reported a problem with his configuration that was using crossmnt
and autofs to export a number of btrfs filesystems. Some analysis with
Claude also uncovered a few other bugs. This version also fixes a
number of problems that Sashiko flagged. Some of them were preexisting
but seemed like good things to fix.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
Changes in v3:
- Stop warning twice per unexportable path
- Keep a warning for the ip_map and unix_gid answers, which have no fallback
- Don't warn about a submount nobody asked to export
- Quieten the same message on the pipefs downcall (preexisting)
- Link to v2: https://lore.kernel.org/r/20260911-nl-crossmnt-v2-0-f4d869951c5e@kernel.org

Changes in v2:
- Retry instead of caching a negative when the failure may be transient:
  kernel errno, statfs, fsidd, and an undelivered negative fallback
- Drop a deferred request once it has been answered
- Bound the junction path copied into exportent.e_path (preexisting)
- Give each worker its own netlink command socket (preexisting)
- Bound the retry queues (preexisting)
- Link to v1: https://lore.kernel.org/r/20260909-nl-crossmnt-v1-0-4064b5a3bd85@kernel.org

---
Jeff Layton (11):
      mountd: factor out the per-path export attribute computation
      mountd: handle unmountable paths and junctions in the netlink downcall
      mountd: answer requests the kernel rejects on the netlink downcall
      mountd: don't leak the parent export's fsid onto crossmnt submounts
      mountd: retry unresolvable fsid lookups on the netlink downcall
      mountd: bound the junction path before copying it into e_path
      mountd: give each worker its own netlink command socket
      mountd: retry export attributes that fail to resolve for a passing reason
      mountd: drop a deferred fsid lookup once it has been answered
      mountd: bound the retry queues
      mountd: don't warn about pipefs submounts nobody asked to export

 support/export/cache.c | 1391 +++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 1084 insertions(+), 307 deletions(-)
---
base-commit: 630393e9c73667b3fda6a7507cb5171ec0ec38dc
change-id: 20260908-nl-crossmnt-85584b71c721

Best regards,
-- 
Jeff Layton <jlayton@kernel.org>