TLS read_sock performance scalability

I'd like to encourage in-kernel kTLS consumers (i.e., NFS and
NVMe/TCP) to coalesce on the use of read_sock. When I suggested
this to Hannes, he reported a number of nagging performance
scalability issues with read_sock. This series is an attempt to
run these issues down and get them fixed before we convert the
above sock_recvmsg consumers over to read_sock.

Batch async decryption and its submit/deliver scaffolding were
dropped from this series because async_capable is always false
for TLS 1.3, which NFS and NVMe/TCP both require. Async crypto
support for TLS 1.3 is a prerequisite for revisiting that work.

---
Changes since v5:
- Patch 6: Set released = true when sk_flush_backlog() returns
  true, so tls_strp_msg_load() knows the socket lock was
  released (Sabrina)
- Patch 6: Drop Fixes tag; submit bug fix separately via net
  if warranted (Sabrina)
- Patch 6: Note redundant flush on cold path in commit message
  (Sabrina)

Changes since v4:
- Drop batch async decryption and submit/deliver restructure:
  async_capable is always false for TLS 1.3, so the new code
  was unreachable for NFS and NVMe/TCP
- Purge async_hold directly in tls_decrypt_async_wait() and drop
  the tls_decrypt_async_drain() wrapper
- Merge tls_strp_check_rcv_quiet() into tls_strp_check_rcv() with
  a bool wake parameter; fix lost wakeup on the recvmsg exit path

Changes since v3:
- Clarify why tls_decrypt_async_drain() is separate from _wait()
- Fold tls_err_abort() into tls_rx_one_record(), drop tls_rx_decrypt_record()
- Move backlog flush into tls_rx_rec_wait() so all RX paths benefit

Changes since v2:
- Fix short read self tests

Changes since v1:
- Add C11 reference
- Extend data_ready reduction to recvmsg and splice
- Restructure read_sock and recvmsg using shared helpers

---
- Link to v5: https://patch.msgid.link/20260324-tls-read-sock-v5-0-5408...

---
Chuck Lever (6):
      tls: Purge async_hold in tls_decrypt_async_wait()
      tls: Abort the connection on decrypt failure
      tls: Fix dangling skb pointer in tls_sw_read_sock()
      tls: Factor tls_strp_msg_release() from tls_strp_msg_done()
      tls: Suppress spurious saved_data_ready on all receive paths
      tls: Flush backlog before waiting for a new record

 net/tls/tls.h      |  4 ++--
 net/tls/tls_main.c |  2 +-
 net/tls/tls_strp.c | 42 +++++++++++++++++++++++++++++++-----------
 net/tls/tls_sw.c   | 52 +++++++++++++++++++++++++++++++---------------------
 4 files changed, 65 insertions(+), 35 deletions(-)
---
base-commit: fb78a629b4f0eb399b413f6c093a3da177b3a4eb
change-id: 20260317-tls-read-sock-a0022c9df265

Best regards,
--  
Chuck Lever