fs: dlm: add deprecation Kconfig and warnings for timeouts

This patch adds a CONFIG_DLM_DEPRECATED_API Kconfig option
that must be enabled to use two timeout-related features
that we intend to remove in kernel v6.2.  Warnings are
printed if either is enabled and used.  Neither has ever
been used as far as we know.

. The DLM_LSFL_TIMEWARN lockspace creation flag will be
  removed, along with the associated configfs entry for
  setting the timeout.  Setting the flag and configfs file
  would cause dlm to track how long locks were waiting
  for reply messages.  After a timeout, a kernel message
  would be logged, and a netlink message would be sent
  to userspace.  Recently, midcomms messages have been
  added that produce much better logging about actual
  problems with messages.  No use has ever been found
  for the netlink messages.

. The userspace libdlm API has allowed the DLM_LKF_TIMEOUT
  flag with a timeout value to be set in lock requests.
  The lock request would be cancelled after the timeout.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

diff --git a/fs/dlm/Kconfig b/fs/dlm/Kconfig
index ee92634196a8e7809465f57a678f6390424e17e9..1105ce3c80cbddf5dc27eeae0dee77006bf29780 100644 (file)
--- 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 deprecated DLM timeout features that 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 ca1eca0809d416fda93ffd70590ce164baf64c49..d6af6186f05550721dc4c66e85dc9d236254cf44 100644 (file)
--- 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 v6.2!\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/user.c b/fs/dlm/user.c
index 4b2a24a6a15da37595356d9412f9146e47163efe..32452d7a466c63b171431cab7a7306d763f45b00 100644 (file)
--- 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 v6.2!\n"
+                            "========================================================\n");
+#endif
+
        ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
        if (!ua)
                goto out;