[Cluster-devel] [PATCH dlm/next 4/5] fs: dlm: add API deprecation warning

[Alexander Aring]

This patch adds a deprecation config to DLM for API which will be removed
in kernel v5.22. This deprecation warning will occur if somebody enables
the deprecation API Kconfig entry and using the actual feature which
will get deprecated as a notification to update their user space.

Note that the timeout feature for kernel locks was never been supported.

Signed-off-by: Alexander Aring <aahringo at redhat.com>
---
 fs/dlm/Kconfig     |  9 +++++++++
 fs/dlm/lockspace.c | 11 ++++++++++-
 fs/dlm/netlink.c   |  8 ++++++++
 fs/dlm/user.c      |  8 ++++++++
 4 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/fs/dlm/Kconfig b/fs/dlm/Kconfig
index ee92634196a8..cae58f21da08 100644
--- a/fs/dlm/Kconfig
+++ b/fs/dlm/Kconfig
@@ -9,6 +9,15 @@ menuconfig DLM
 	A general purpose distributed lock manager for kernel or userspace
 	applications.
 
+config DLM_DEPRECATED_API
+	bool "DLM deprecated API"
+	depends on DLM
+	help
+	Enables DLM deprecated API which will be removed in later Linux
+	kernel releases.
+
+	If you are unsure, say N.
+
 config DLM_DEBUG
 	bool "DLM debugging"
 	depends on DLM
diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
index f9cbf35b3db1..ac227a30141c 100644
--- a/fs/dlm/lockspace.c
+++ b/fs/dlm/lockspace.c
@@ -489,8 +489,17 @@ static int new_lockspace(const char *name, const char *cluster,
 		ls->ls_ops_arg = ops_arg;
 	}
 
-	if (flags & DLM_LSFL_TIMEWARN)
+	if (flags & DLM_LSFL_TIMEWARN) {
+#ifdef CONFIG_DLM_DEPRECATED_API
+		pr_warn_once("===============================================================\n"
+			     "WARNING: the dlm DLM_LSFL_TIMEWARN flag is being deprecated and\n"
+			     "         will be removed in v5.22!\n"
+			     "         Inclusive DLM_LSFL_TIMEWARN define in UAPI header!\n"
+			     "===============================================================\n");
+#endif
+
 		set_bit(LSFL_TIMEWARN, &ls->ls_flags);
+	}
 
 	/* ls_exflags are forced to match among nodes, and we don't
 	   need to require all nodes to have some flags set */
diff --git a/fs/dlm/netlink.c b/fs/dlm/netlink.c
index 67f68d48d60c..fed04860e550 100644
--- a/fs/dlm/netlink.c
+++ b/fs/dlm/netlink.c
@@ -57,6 +57,14 @@ static int send_data(struct sk_buff *skb)
 
 static int user_cmd(struct sk_buff *skb, struct genl_info *info)
 {
+#ifdef CONFIG_DLM_DEPRECATED_API
+	pr_warn_once("====================================================\n"
+		     "WARNING: the dlm netlink API is being deprecated and\n"
+		     "         will be removed in v5.22!\n"
+		     "         Inclusive DLM netlink UAPI header!\n"
+		     "====================================================\n");
+#endif
+
 	listener_nlportid = info->snd_portid;
 	printk("user_cmd nlpid %u\n", listener_nlportid);
 	return 0;
diff --git a/fs/dlm/user.c b/fs/dlm/user.c
index 4b2a24a6a15d..1fccb08bd825 100644
--- a/fs/dlm/user.c
+++ b/fs/dlm/user.c
@@ -250,6 +250,14 @@ static int device_user_lock(struct dlm_user_proc *proc,
 		goto out;
 	}
 
+#ifdef CONFIG_DLM_DEPRECATED_API
+	if (params->timeout)
+		pr_warn_once("========================================================\n"
+			     "WARNING: the lkb timeout feature is being deprecated and\n"
+			     "         will be removed in v5.22!\n"
+			     "========================================================\n");
+#endif
+
 	ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
 	if (!ua)
 		goto out;
-- 
2.31.1