v1.28-notify-1: patches for scoutfs v1.28

Backport of the three notify patches onto scoutfs v1.28.  v1.28
predates SCOUTFS_IOC_PUNCH_OFFLINE (nr 24, introduced in v1.29),
so two trivial hunk fixes were needed during rebase:

  kmod/src/ioctl.h:
    drop the PUNCH_OFFLINE struct + define from the notify patch's
    context, since the surrounding definition doesn't exist in v1.28.
    Our SCOUTFS_IOC_READ_NOTIFY stays at nr 25 — Linux ioctl numbers
    are sparse and don't require the predecessor.

  kmod/src/ioctl.c:
    drop the PUNCH_OFFLINE dispatch case from the context for the
    same reason.

Resulting ABI is identical to v1.29-notify-1 and v1.30-notify-1:
SCOUTFS_IOC_READ_NOTIFY is nr 25 on all three, so scoutfs-notifyd
and any third-party consumer need zero per-version branching.

Branch purpose: scoutfs-build's multi-version pipeline checks out
this branch (via SCOUTFS_NOTIFY_REF=v1.28-notify-1) when building
kmod RPMs for scoutfs v1.28.

README.md

@@ -2,97 +2,81 @@
 
 Observer-only file access notifications for [ScoutFS](https://github.com/versity/scoutfs),
 distributed as a rebasable `git format-patch` series plus a small Go
-userspace relay daemon.  Maintained as one long-lived branch per
-currently-supported upstream scoutfs version.
+userspace relay daemon.  Layers onto each upstream release with minimal
+maintenance.
 
 ## What the series adds
 
-Three patches against each supported scoutfs release:
+Three patches against the scoutfs source tree:
 
 1. **Kmod core** — a per-mount 64 KiB ring of 64-byte notification records and
-   a single-reader drain ioctl (`SCOUTFS_IOC_READ_NOTIFY`, nr 26).  Emit is
+   a single-reader drain ioctl (`SCOUTFS_IOC_READ_NOTIFY`, nr 25).  Emit is
    non-blocking, drop-on-full; the monotonic `seq` field exposes drops to
    consumers.  Three percpu counters (`notify_emitted`,
    `notify_dropped_ring_full`, `notify_reader_attached`).  No mount option,
    no sysfs toggle.
 2. **Kmod hooks** — `->open` wrapper and READ emit in
-   `scoutfs_file_read_iter`.  Every hook is a single predicted-false
-   branch when no reader is attached.  Nothing in the data-waiter state
-   machine is touched.  (Branches up to `v1.32` also hooked
-   `scoutfs_file_aio_read`; scoutfs v1.33 removed the
-   `KC_LINUX_HAVE_FOP_AIO_READ` compat paths, so `read_iter` is now the
-   only read path.)
+   `scoutfs_file_aio_read` / `scoutfs_file_read_iter`.  Every hook is a
+   single predicted-false branch when no reader is attached.  Nothing in
+   the data-waiter state machine is touched.
 3. **scoutfs-notifyd (Go)** — userspace daemon that binds
    `/run/scoutfs/<fsid>/notify.sock` (AF_UNIX SOCK_SEQPACKET, mode 0600,
    root-only), drains the ring, and broadcasts each record to connected
    clients.  Pure-stdlib Go; no external module dependencies.  Shipped
    with a systemd template unit `scoutfs-notifyd@<mountpoint>.service`.
 
-The 64-byte event record layout is identical on every branch, so
-consumers and the daemon do not need per-version branching in their own
-code.  The ioctl number is not: it is nr 25 on `v1.28`-`v1.30` and nr 26
-from `v1.32` on, because upstream v1.32 took nr 25 for
-`SCOUTFS_IOC_INJECT_TOTL_DELTA`.  scoutfs v1.33 did not renumber again.
+## Base
 
-## Repository layout
+Currently rebased against:
 
-Each supported scoutfs version lives on its own long-lived branch.  The
-patches in each branch are tuned for that specific scoutfs tree; they do
-NOT apply cross-version without rebasing.
+    scoutfs v1.30
 
-| Branch         | Targets scoutfs | Tag              |
-|----------------|-----------------|------------------|
-| `v1.28`        | `v1.28`         | `v1.28-notify-1` |
-| `v1.29`        | `v1.29`         | `v1.29-notify-1` |
-| `v1.30`        | `v1.30`         | `v1.30-notify-1` |
-| `v1.32`        | `v1.32`         | `v1.32-notify-1` |
-| `v1.33`        | `v1.33`         | `v1.33-notify-1` |
+See [base.txt](./base.txt).
 
-`main` tracks the newest supported scoutfs version.  When a new scoutfs
-release ships, a new branch is created and the patches are rebased onto
-it; when a scoutfs version ages out of support, its branch stays in the
-repo for historical builds but is no longer maintained.
+## Build dependencies added
+
+On top of the stock scoutfs build requirements, patch 3 adds:
+
+* `golang >= 1.26` on the build host (fetched from go.dev by the CI; no distro currently packages 1.26).
+  
+
+The Go build is offline (`GOPROXY=off`) — no network access required at
+build time.  `CGO_ENABLED=0` so the produced binary is a pure-Go static
+ELF.
 
 ## Applying
 
-Against a scoutfs git working tree at the matching upstream tag:
-
 ```sh
-git clone -b v1.29 https://git.anomalous.dev/alphacentri/scoutfs-notify.git /tmp/notify
-/tmp/notify/apply.sh /path/to/scoutfs-v1.29-checkout
+./apply.sh /path/to/scoutfs
 ```
 
-The script runs `git am --3way` on each patch in order.
+Runs `git am --3way` on each patch.  For a tarball instead of a git tree,
+loop `patch -p1 < patches/*.patch`.
 
 ## Rebasing onto a new upstream release
 
 ```sh
-# In a fresh scoutfs checkout:
-git checkout v1.31
-git checkout -b notify-v1.31
-
-# Apply the previous branch's patches (usually clean; resolve any
-# conflicts, git am --continue).
-git am --3way /path/to/scoutfs-notify-v1.30/patches/*.patch
-git format-patch v1.31..notify-v1.31 -o /tmp/new-patches/
-
-# Push a new branch + tag in this repo:
-cd /path/to/scoutfs-notify
-git checkout -b v1.31 main
-rm patches/*.patch
-cp /tmp/new-patches/*.patch patches/
-echo v1.31 > base.txt
-git commit -am 'v1.31-notify-1: rebase onto scoutfs v1.31'
-git push -u origin v1.31
-git tag v1.31-notify-1 && git push origin v1.31-notify-1
-# Fast-forward main to the new tip once you're ready to promote it.
+git fetch --tags
+git checkout -B notify v1.30
+git am --3way patches/*.patch
+# resolve any conflicts, git am --continue
+git format-patch v1.30..notify -o patches/
+# update base.txt and commit
 ```
 
+## Tag history
+
+    v1.30-notify-1   (current — rebased onto scoutfs v1.30, no code changes)
+v1.29-notify-4   (retired — last v1.29-base release)
+v1.29-notify-3   (retired — Go 1.21 toolchain)
+    v1.29-notify-2   (retired — C daemon; had latent ring-size compile bug)
+    v1.29-notify-1   (retired — shipped mount options)
+
 ## Quick smoke test after installation
 
 ```sh
 systemctl enable --now scoutfs-notifyd@mnt-scoutfs.service
-FSID=$(scoutfs stat /mnt/scoutfs | awk '/fsid/ { print $2 }')
+FSID=$(stat -f -c %i /mnt/scoutfs)   # or use your scoutfs cli
 socat - UNIX-CONNECT:/run/scoutfs/${FSID}/notify.sock | xxd | head
 # touch some files in /mnt/scoutfs in another terminal
 ```

base.txt

@@ -1 +1 @@
-v1.33
+v1.28

patches/0001-notify-core-file-access-notification-infrastructure.patch

@@ -1,4 +1,4 @@
-From 0e703364da5efe4a3b2e96e5513204dd8a1a79ac Mon Sep 17 00:00:00 2001
+From 1be639b8a4fdfaac37fc5801a314d080200105cb Mon Sep 17 00:00:00 2001
 From: William Gill <claude@williamgill.net>
 Date: Wed, 22 Apr 2026 14:38:51 -0500
 Subject: [PATCH 1/3] notify: core file-access notification infrastructure
@@ -70,10 +70,10 @@ index fa632aa..de14c74 100644
  	options.o		\
  	per_task.o		\
 diff --git a/kmod/src/counters.h b/kmod/src/counters.h
-index cb7a2e1..83c0976 100644
+index 9088496..94e4f44 100644
 --- a/kmod/src/counters.h
 +++ b/kmod/src/counters.h
-@@ -157,6 +157,9 @@
+@@ -156,6 +156,9 @@
  	EXPAND_COUNTER(net_recv_invalid_message)		\
  	EXPAND_COUNTER(net_recv_messages)			\
  	EXPAND_COUNTER(net_unknown_request)			\
@@ -84,7 +84,7 @@ index cb7a2e1..83c0976 100644
  	EXPAND_COUNTER(orphan_scan_attempts)			\
  	EXPAND_COUNTER(orphan_scan_cached)			\
 diff --git a/kmod/src/ioctl.c b/kmod/src/ioctl.c
-index 903033b..3a09e2e 100644
+index 7a73d4d..9893559 100644
 --- a/kmod/src/ioctl.c
 +++ b/kmod/src/ioctl.c
 @@ -47,6 +47,7 @@
@@ -95,22 +95,22 @@ index 903033b..3a09e2e 100644
  #include "scoutfs_trace.h"
  #include "util.h"
  
-@@ -1827,6 +1828,8 @@ long scoutfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
- 		return scoutfs_ioc_punch_offline(file, arg);
- 	case SCOUTFS_IOC_INJECT_TOTL_DELTA:
- 		return scoutfs_ioc_inject_totl_delta(file, arg);
+@@ -1718,6 +1719,8 @@ long scoutfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+ 		return scoutfs_ioc_mod_quota_rule(file, arg, false);
+ 	case SCOUTFS_IOC_READ_XATTR_INDEX:
+ 		return scoutfs_ioc_read_xattr_index(file, arg);
 +	case SCOUTFS_IOC_READ_NOTIFY:
 +		return scoutfs_ioc_read_notify(file, arg);
  	}
  
  	return -ENOTTY;
 diff --git a/kmod/src/ioctl.h b/kmod/src/ioctl.h
-index 1bb466c..0ac8d24 100644
+index cefecd4..23fda13 100644
 --- a/kmod/src/ioctl.h
 +++ b/kmod/src/ioctl.h
-@@ -889,4 +889,88 @@ struct scoutfs_ioctl_inject_totl_delta {
- #define SCOUTFS_IOC_INJECT_TOTL_DELTA \
- 	_IOW(SCOUTFS_IOCTL_MAGIC, 25, struct scoutfs_ioctl_inject_totl_delta)
+@@ -848,4 +848,88 @@ struct scoutfs_ioctl_read_xattr_index {
+ #define SCOUTFS_IOC_READ_XATTR_INDEX \
+ 	_IOR(SCOUTFS_IOCTL_MAGIC, 23, struct scoutfs_ioctl_read_xattr_index)
  
 +/*
 + * File access notification stream (observer-only).
@@ -194,7 +194,7 @@ index 1bb466c..0ac8d24 100644
 +};
 +
 +#define SCOUTFS_IOC_READ_NOTIFY \
-+	_IOWR(SCOUTFS_IOCTL_MAGIC, 26, struct scoutfs_ioctl_read_notify)
++	_IOWR(SCOUTFS_IOCTL_MAGIC, 25, struct scoutfs_ioctl_read_notify)
 +
  #endif
 diff --git a/kmod/src/notify.c b/kmod/src/notify.c
@@ -622,7 +622,7 @@ index 0000000..fe6a2d9
 +
 +#endif /* _SCOUTFS_NOTIFY_H_ */
 diff --git a/kmod/src/super.c b/kmod/src/super.c
-index f2e1420..94922be 100644
+index 3c83716..3c028b0 100644
 --- a/kmod/src/super.c
 +++ b/kmod/src/super.c
 @@ -51,6 +51,7 @@

patches/0002-notify-file-open-read-hook-sites.patch

@@ -1,7 +1,10 @@
-From 9eb38690d14d631a0dd96f464caa588bee86278d Mon Sep 17 00:00:00 2001
+From e970d4d8c6ab1f13cc7e2e51a830ba2f387b62d3 Mon Sep 17 00:00:00 2001
 From: William Gill <claude@williamgill.net>
 Date: Wed, 22 Apr 2026 14:40:04 -0500
 Subject: [PATCH 2/3] notify: file open/read hook sites
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
 
 Wires the notification emit path into the two scoutfs file
 operations that carry user-visible activity we want to observe.
@@ -10,22 +13,18 @@ OPEN (data.c):
   A new scoutfs_file_open() wrapper is installed as ->open in
   scoutfs_file_fops.  The wrapper calls generic_file_open() to
   preserve existing VFS default semantics for regular files,
-  then - only on success and only when notifications are enabled
-  - emits a SCOUTFS_NOTIFY_TYPE_OPEN record.  File mode is
+  then — only on success and only when notifications are enabled
+  — emits a SCOUTFS_NOTIFY_TYPE_OPEN record.  File mode is
   inspected for FMODE_WRITE to set SCOUTFS_NOTIFY_F_WRITE_OPEN.
 
 READ (file.c):
-  scoutfs_file_read_iter() gets an emit placed past the existing
-  data-waiter retry check, guarded on (ret > 0) so only successful
-  reads are reported and retries never double-count.  start_pos is
-  captured at function entry before generic_file_read_iter advances
+  Both the aio_read (KC_LINUX_HAVE_FOP_AIO_READ) and read_iter
+  paths get an emit placed past the existing data-waiter retry
+  check, guarded on (ret > 0) so only successful reads are
+  reported and retries never double-count.  start_pos is captured
+  at entry of read_iter before generic_file_read_iter advances
   iocb->ki_pos.
 
-Rebased onto v1.33: upstream removed the KC_LINUX_HAVE_FOP_AIO_READ
-compat paths, so scoutfs_file_aio_read/aio_write no longer exist and
-the second READ hook and the fops table's #ifdef arm went with them.
-read_iter is now the only read path.  The hook body is unchanged.
-
 Every hook is behind unlikely(READ_ONCE(sbi->notify_enabled)), so
 when no userspace reader is attached the hook reduces to a single
 predicted-false branch.  No scoutfs state is mutated, no error is
@@ -34,14 +33,14 @@ propagated, and no existing control flow is altered.
 Nothing in the data-waiter state machine is touched.
 ---
  kmod/src/data.c | 28 ++++++++++++++++++++++++++++
- kmod/src/file.c |  7 +++++++
- 2 files changed, 35 insertions(+)
+ kmod/src/file.c | 11 +++++++++++
+ 2 files changed, 39 insertions(+)
 
 diff --git a/kmod/src/data.c b/kmod/src/data.c
-index 1d3168f..5611dd8 100644
+index 7903e8d..6e3b133 100644
 --- a/kmod/src/data.c
 +++ b/kmod/src/data.c
-@@ -42,6 +42,7 @@
+@@ -41,6 +41,7 @@
  #include "msg.h"
  #include "ext.h"
  #include "util.h"
@@ -49,7 +48,7 @@ index 1d3168f..5611dd8 100644
  
  /*
   * We want to amortize work done after dirtying the shared transaction
-@@ -2242,11 +2243,38 @@ const struct address_space_operations scoutfs_file_aops = {
+@@ -2207,6 +2208,32 @@ const struct address_space_operations scoutfs_file_aops = {
  	.write_end		= scoutfs_write_end,
  };
  
@@ -80,16 +79,18 @@ index 1d3168f..5611dd8 100644
 +}
 +
  const struct file_operations scoutfs_file_fops = {
- 	.read_iter	= scoutfs_file_read_iter,
- 	.write_iter	= scoutfs_file_write_iter,
+ #ifdef KC_LINUX_HAVE_FOP_AIO_READ
+ 	.read		= do_sync_read,
+@@ -2219,6 +2246,7 @@ const struct file_operations scoutfs_file_fops = {
  	.splice_read	= generic_file_splice_read,
  	.splice_write	= iter_file_splice_write,
+ #endif
 +	.open		= scoutfs_file_open,
  	.mmap		= scoutfs_file_mmap,
  	.unlocked_ioctl	= scoutfs_ioctl,
  	.fsync		= scoutfs_file_fsync,
 diff --git a/kmod/src/file.c b/kmod/src/file.c
-index 0f2e7b8..fb7eace 100644
+index 15158a2..44f1bc4 100644
 --- a/kmod/src/file.c
 +++ b/kmod/src/file.c
 @@ -29,6 +29,7 @@
@@ -98,9 +99,20 @@ index 0f2e7b8..fb7eace 100644
  #include "quota.h"
 +#include "notify.h"
  
- ssize_t scoutfs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
- {
-@@ -39,6 +40,7 @@ ssize_t scoutfs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
+ #ifdef KC_LINUX_HAVE_FOP_AIO_READ
+ /*
+@@ -84,6 +85,10 @@ out:
+ 			goto retry;
+ 	}
+ 
++	if (ret > 0 && unlikely(READ_ONCE(SCOUTFS_SB(sb)->notify_enabled)))
++		scoutfs_notify_emit(sb, SCOUTFS_NOTIFY_TYPE_READ,
++				    scoutfs_ino(inode), pos, ret, 0);
++
+ 	return ret;
+ }
+ 
+@@ -166,6 +171,7 @@ ssize_t scoutfs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
  	struct scoutfs_lock *scoutfs_inode_lock = NULL;
  	SCOUTFS_DECLARE_PER_TASK_ENTRY(pt_ent);
  	DECLARE_DATA_WAIT(dw);
@@ -108,7 +120,7 @@ index 0f2e7b8..fb7eace 100644
  	int ret;
  
  retry:
-@@ -73,6 +75,11 @@ out:
+@@ -200,6 +206,11 @@ out:
  		if (ret == 0)
  			goto retry;
  	}

patches/0003-notify-scoutfs-notifyd-userspace-relay-daemon-Go-1.2.patch

@@ -1,4 +1,4 @@
-From e7d50bb7b4e2fa0a88e7b4b8f4be75bb07e37351 Mon Sep 17 00:00:00 2001
+From a227eecabc78f331fcb8c483e6051021cb44a94b Mon Sep 17 00:00:00 2001
 From: William Gill <claude@williamgill.net>
 Date: Wed, 22 Apr 2026 14:40:34 -0500
 Subject: [PATCH 3/3] notify: scoutfs-notifyd userspace relay daemon (Go 1.26)
@@ -72,10 +72,10 @@ recv() events.
  utils/Makefile                         |  28 +-
  utils/man/scoutfs-notifyd.8            | 120 +++++++
  utils/notifyd/go.mod                   |   3 +
- utils/notifyd/main.go                  | 437 +++++++++++++++++++++++++
+ utils/notifyd/main.go                  | 434 +++++++++++++++++++++++++
  utils/notifyd/scoutfs-notifyd@.service |  40 +++
  utils/scoutfs-utils.spec.in            |   8 +
- 6 files changed, 633 insertions(+), 3 deletions(-)
+ 6 files changed, 630 insertions(+), 3 deletions(-)
  create mode 100644 utils/man/scoutfs-notifyd.8
  create mode 100644 utils/notifyd/go.mod
  create mode 100644 utils/notifyd/main.go
@@ -274,10 +274,10 @@ index 0000000..d99f395
 +go 1.26
 diff --git a/utils/notifyd/main.go b/utils/notifyd/main.go
 new file mode 100644
-index 0000000..41b98ab
+index 0000000..9478bae
 --- /dev/null
 +++ b/utils/notifyd/main.go
-@@ -0,0 +1,437 @@
+@@ -0,0 +1,434 @@
 +// Copyright (C) 2026 Versity Software, Inc.  All rights reserved.
 +//
 +// This program is free software; you can redistribute it and/or
@@ -396,11 +396,8 @@ index 0000000..41b98ab
 +var (
 +	scoutfsIocStatfsMore = iocEncode(iocDirRead,
 +		scoutfsIoctlMagic, 10, statfsMoreSize)
-+	// nr must match SCOUTFS_IOC_READ_NOTIFY in kmod/src/ioctl.h.  On the
-+	// v1.32 base this is 26: upstream v1.32 took nr 25 for
-+	// SCOUTFS_IOC_INJECT_TOTL_DELTA, so the notify ioctl moved to 26.
 +	scoutfsIocReadNotify = iocEncode(iocDirRead|iocDirWrite,
-+		scoutfsIoctlMagic, 26, readNotifySize)
++		scoutfsIoctlMagic, 25, readNotifySize)
 +)
 +
 +func init() {