Add OCaml 5 support

0001-ocaml-Release-runtime-lock-around-call-to-nbd_close.patch

@@ -0,0 +1,75 @@
+From 2c909bc3b8594943c4306ec78e8c13327ca16284 Mon Sep 17 00:00:00 2001
+From: "Richard W.M. Jones" <rjones@redhat.com>
+Date: Wed, 21 Jun 2023 22:41:43 +0100
+Subject: [PATCH] ocaml: Release runtime lock around call to nbd_close
+
+OCaml 5 is stricter than earlier versions about correct locking.
+
+We must release the OCaml runtime lock when calling nbd_close since it
+may do some long-running operations and we want to allow concurrent
+threads to run.
+
+However specifically if there are callbacks (eg. a debug callback)
+then we would end up trying to re-acquire the lock in the callback,
+resulting in a crash:
+
+  (gdb) bt
+  #0  __pthread_kill_implementation (threadid=<optimized out>,
+      signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
+  #1  0x00007f47ffc8f773 in __pthread_kill_internal (signo=6,
+      threadid=<optimized out>) at pthread_kill.c:78
+  #2  0x00007f47ffc3e71e in __GI_raise (sig=sig@entry=6)
+      at ../sysdeps/posix/raise.c:26
+  #3  0x00007f47ffc2687f in __GI_abort () at abort.c:79
+  #4  0x0000560c9eb62779 in caml_fatal_error ()
+  #5  0x0000560c9eb63238 in caml_plat_fatal_error ()
+  #6  0x0000560c9eb4ea77 in caml_acquire_domain_lock ()
+  #7  0x0000560c9eb65cdc in caml_leave_blocking_section ()
+  #8  0x0000560c9eaf8a87 in debug_wrapper (user_data=0x560ca0af2670,
+      context=0x7f47fff8ca60 "nbd_close", msg=0x560ca0af28b0 "closing handle")
+      at ../nbd-c.c:187
+  #9  0x00007f47fff7072f in nbd_internal_debug (h=h@entry=0x560ca0b57db0,
+      context=0x7f47fff8ca60 "nbd_close", context@entry=0x0,
+      fs=fs@entry=0x7f47fff8ca6a "closing handle")
+      at /home/rjones/d/libnbd/lib/debug.c:90
+  #10 0x00007f47fff73f23 in nbd_close (h=0x560ca0b57db0)
+      at /home/rjones/d/libnbd/lib/handle.c:127
+  #11 0x0000560c9eae8dbe in nbd_internal_ocaml_handle_finalize (
+      hv=<optimized out>) at ../handle.c:39
+  #12 nbd_internal_ocaml_nbd_close (hv=<optimized out>) at ../handle.c:62
+  #13 <signal handler called>
+  #14 0x0000560c9eae84dc in camlTest_140_explicit_close__entry () at NBD.ml:148
+  #15 0x0000560c9eae5c5b in caml_program ()
+  #16 <signal handler called>
+  #17 0x0000560c9eb6cb77 in caml_startup_common ()
+  #18 0x0000560c9eb6cbef in caml_main ()
+  #19 0x0000560c9eae5910 in main ()
+---
+ ocaml/handle.c | 3 +++
+ 1 file changed, 3 insertions(+)
+
+diff --git a/ocaml/handle.c b/ocaml/handle.c
+index fb45b30102..b3e5a0fc33 100644
+--- a/ocaml/handle.c
++++ b/ocaml/handle.c
+@@ -26,6 +26,7 @@
+ #include <caml/fail.h>
+ #include <caml/memory.h>
+ #include <caml/mlvalues.h>
++#include <caml/threads.h>
+ 
+ #include <libnbd.h>
+ 
+@@ -36,7 +37,9 @@ nbd_internal_ocaml_handle_finalize (value hv)
+ {
+   struct nbd_handle *h = NBD_val (hv);
+ 
++  caml_enter_blocking_section ();
+   nbd_close (h);
++  caml_leave_blocking_section ();
+ }
+ 
+ value
+-- 
+2.41.0
+

libnbd.spec

@@ -5,14 +5,14 @@
 %global verify_tarball_signature 1
 
 # If there are patches which touch autotools files, set this to 1.
-%global patches_touch_autotools %{nil}
+%global patches_touch_autotools 1
 
 # The source directory.
 %global source_directory 1.17-development
 
 Name:           libnbd
 Version:        1.17.1
-Release:        1%{?dist}
+Release:        2%{?dist}
 Summary:        NBD client library in userspace
 
 License:        LGPL-2.0-or-later AND BSD-3-Clause
@@ -28,6 +28,9 @@ Source2:       libguestfs.keyring
 # Maintainer script which helps with handling patches.
 Source3:        copy-patches.sh
 
+# Upstream patch to fix OCaml 5 support.
+Patch:          0001-ocaml-Release-runtime-lock-around-call-to-nbd_close.patch
+
 %if 0%{patches_touch_autotools}
 BuildRequires: autoconf, automake, libtool
 %endif
@@ -356,6 +359,9 @@ make %{?_smp_mflags} check || {
 
 
 %changelog
+* Thu Jun 22 2023 Richard W.M. Jones <rjones@redhat.com> - 1.17.1-2
+- Add OCaml 5 support
+
 * Mon Jun 19 2023 Richard W.M. Jones <rjones@redhat.com> - 1.17.1-1
 - New upstream development version 1.17.1