mzatko@redhat.com
2014-May-15 15:39 UTC
[Libguestfs] [PATCH] Add global mutex around each C call
From: Maros Zatko <mzatko@redhat.com> Patch adds recursive mutex around C calls, which tries to fix potential race condition in guestfs_umount_local (see [1]). [1] - https://bugzilla.redhat.com/show_bug.cgi?id=917706 Maros Zatko (1): generator: c.ml - wrap non deamon function with recursive mutex generator/c.ml | 12 ++++++++++++ 1 file changed, 12 insertions(+) -- 1.8.5.3
mzatko@redhat.com
2014-May-15 15:39 UTC
[Libguestfs] [PATCH] generator: c.ml - wrap non deamon function with recursive mutex
From: Maros Zatko <mzatko@redhat.com>
---
generator/c.ml | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/generator/c.ml b/generator/c.ml
index ee276dc..4333bb8 100644
--- a/generator/c.ml
+++ b/generator/c.ml
@@ -788,6 +788,9 @@ and generate_internal_actions_h () pr "#define
GUESTFS_INTERNAL_ACTIONS_H_\n";
pr "\n";
+ pr "#include \"glthread/lock.h\"\n";
+ pr "\n";
+
List.iter (
fun { c_name = c_name; style = style } ->
generate_prototype ~single_line:true ~newline:true ~handle:"g"
@@ -796,6 +799,10 @@ and generate_internal_actions_h () )
non_daemon_functions;
pr "\n";
+
+ pr "gl_recursive_lock_define_initialized(static, global_lock)\n";
+ pr "\n";
+
pr "#endif /* GUESTFS_INTERNAL_ACTIONS_H_ */\n"
(* Generate guestfs-internal-frontend-cleanups.h file. *)
@@ -1567,6 +1574,8 @@ and generate_client_actions hash () c_name style;
pr "{\n";
+ pr " gl_recursive_lock_lock (global_lock);\n";
+
handle_null_optargs optargs c_name;
pr " int trace_flag = g->trace;\n";
@@ -1617,6 +1626,9 @@ and generate_client_actions hash () trace_return
name style "r";
);
pr "\n";
+
+ pr " gl_recursive_lock_unlock (global_lock);\n";
+
pr " return r;\n";
pr "}\n";
pr "\n"
--
1.8.5.3
Richard W.M. Jones
2014-May-16 15:44 UTC
Re: [Libguestfs] [PATCH] generator: c.ml - wrap non deamon function with recursive mutex
On Thu, May 15, 2014 at 05:39:08PM +0200, mzatko@redhat.com wrote:> + > + pr "gl_recursive_lock_define_initialized(static, global_lock)\n";static? I suspect this only allows one libguestfs handle per process into the critical section at once. I think the lock needs to be per-handle unless I'm misunderstanding what this is for. Rich.> + pr "\n"; > + > pr "#endif /* GUESTFS_INTERNAL_ACTIONS_H_ */\n" > > (* Generate guestfs-internal-frontend-cleanups.h file. *) > @@ -1567,6 +1574,8 @@ and generate_client_actions hash () > c_name style; > pr "{\n"; > > + pr " gl_recursive_lock_lock (global_lock);\n"; > + > handle_null_optargs optargs c_name; > > pr " int trace_flag = g->trace;\n"; > @@ -1617,6 +1626,9 @@ and generate_client_actions hash () > trace_return name style "r"; > ); > pr "\n"; > + > + pr " gl_recursive_lock_unlock (global_lock);\n"; > + > pr " return r;\n"; > pr "}\n"; > pr "\n" > -- > 1.8.5.3 > > _______________________________________________ > Libguestfs mailing list > Libguestfs@redhat.com > https://www.redhat.com/mailman/listinfo/libguestfs-- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-builder quickly builds VMs from scratch http://libguestfs.org/virt-builder.1.html