ocfs2: Separate out dlm lock functions.

This is the first in a series of patches to isolate ocfs2 from the
underlying cluster stack. Here we wrap the dlm locking functions with
ocfs2-specific calls. Because ocfs2 always uses the same dlm lock status
callbacks, we can eliminate the callbacks from the filesystem visible
functions.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

6 files changed, 179 insertions, 49 deletions

diff --git a/fs/ocfs2/Makefile b/fs/ocfs2/Makefile
index 4d4ce48bb42c..3ba64af26951 100644
--- a/fs/ocfs2/Makefile
+++ b/fs/ocfs2/Makefile
@@ -24,6 +24,7 @@ ocfs2-objs := \
         namei.o                 \
         resize.o                \
         slot_map.o              \
+        stackglue.o             \
         suballoc.o              \
         super.o                 \
         symlink.o               \
diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 15a5167e0513..aea3bef19171 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -53,6 +53,7 @@
 #include "heartbeat.h"
 #include "inode.h"
 #include "journal.h"
+#include "stackglue.h"
 #include "slot_map.h"
 #include "super.h"
 #include "uptodate.h"
@@ -888,22 +889,21 @@ static int ocfs2_lock_create(struct ocfs2_super *osb,
         lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
         spin_unlock_irqrestore(&lockres->l_lock, flags);
 
-        status = dlmlock(osb->dlm,
-                         level,
-                         &lockres->l_lksb,
-                         dlm_flags,
-                         lockres->l_name,
-                         OCFS2_LOCK_ID_MAX_LEN - 1,
-                         ocfs2_locking_ast,
-                         lockres,
-                         ocfs2_blocking_ast);
+        status = ocfs2_dlm_lock(osb->dlm,
+                                level,
+                                &lockres->l_lksb,
+                                dlm_flags,
+                                lockres->l_name,
+                                OCFS2_LOCK_ID_MAX_LEN - 1,
+                                lockres);
         if (status != DLM_NORMAL) {
-                ocfs2_log_dlm_error("dlmlock", status, lockres);
+                ocfs2_log_dlm_error("ocfs2_dlm_lock", status, lockres);
                 ret = -EINVAL;
                 ocfs2_recover_from_dlm_error(lockres, 1);
         }
 
-        mlog(0, "lock %s, successfull return from dlmlock\n", lockres->l_name);
+        mlog(0, "lock %s, successfull return from ocfs2_dlm_lock\n",
+             lockres->l_name);
 
 bail:
         mlog_exit(ret);
@@ -1091,29 +1091,27 @@ again:
                      lockres->l_name, lockres->l_level, level);
 
                 /* call dlm_lock to upgrade lock now */
-                status = dlmlock(osb->dlm,
-                                 level,
-                                 &lockres->l_lksb,
-                                 lkm_flags,
-                                 lockres->l_name,
-                                 OCFS2_LOCK_ID_MAX_LEN - 1,
-                                 ocfs2_locking_ast,
-                                 lockres,
-                                 ocfs2_blocking_ast);
+                status = ocfs2_dlm_lock(osb->dlm,
+                                        level,
+                                        &lockres->l_lksb,
+                                        lkm_flags,
+                                        lockres->l_name,
+                                        OCFS2_LOCK_ID_MAX_LEN - 1,
+                                        lockres);
                 if (status != DLM_NORMAL) {
                         if ((lkm_flags & LKM_NOQUEUE) &&
                             (status == DLM_NOTQUEUED))
                                 ret = -EAGAIN;
                         else {
-                                ocfs2_log_dlm_error("dlmlock", status,
-                                                    lockres);
+                                ocfs2_log_dlm_error("ocfs2_dlm_lock",
+                                                    status, lockres);
                                 ret = -EINVAL;
                         }
                         ocfs2_recover_from_dlm_error(lockres, 1);
                         goto out;
                 }
 
-                mlog(0, "lock %s, successfull return from dlmlock\n",
+                mlog(0, "lock %s, successfull return from ocfs2_dlm_lock\n",
                      lockres->l_name);
 
                 /* At this point we've gone inside the dlm and need to
@@ -1503,14 +1501,14 @@ int ocfs2_file_lock(struct file *file, int ex, int trylock)
         lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
         spin_unlock_irqrestore(&lockres->l_lock, flags);
 
-        ret = dlmlock(osb->dlm, level, &lockres->l_lksb, lkm_flags,
-                      lockres->l_name, OCFS2_LOCK_ID_MAX_LEN - 1,
-                      ocfs2_locking_ast, lockres, ocfs2_blocking_ast);
+        ret = ocfs2_dlm_lock(osb->dlm, level, &lockres->l_lksb, lkm_flags,
+                             lockres->l_name, OCFS2_LOCK_ID_MAX_LEN - 1,
+                             lockres);
         if (ret != DLM_NORMAL) {
                 if (trylock && ret == DLM_NOTQUEUED)
                         ret = -EAGAIN;
                 else {
-                        ocfs2_log_dlm_error("dlmlock", ret, lockres);
+                        ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
                         ret = -EINVAL;
                 }
 
@@ -2699,15 +2697,15 @@ static int ocfs2_drop_lock(struct ocfs2_super *osb,
 
         mlog(0, "lock %s\n", lockres->l_name);
 
-        status = dlmunlock(osb->dlm, &lockres->l_lksb, lkm_flags,
-                           ocfs2_unlock_ast, lockres);
+        status = ocfs2_dlm_unlock(osb->dlm, &lockres->l_lksb, lkm_flags,
+                                  lockres);
         if (status != DLM_NORMAL) {
-                ocfs2_log_dlm_error("dlmunlock", status, lockres);
+                ocfs2_log_dlm_error("ocfs2_dlm_unlock", status, lockres);
                 mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags);
                 dlm_print_one_lock(lockres->l_lksb.lockid);
                 BUG();
         }
-        mlog(0, "lock %s, successfull return from dlmunlock\n",
+        mlog(0, "lock %s, successfull return from ocfs2_dlm_unlock\n",
              lockres->l_name);
 
         ocfs2_wait_on_busy_lock(lockres);
@@ -2832,17 +2830,15 @@ static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
         if (lvb)
                 dlm_flags |= LKM_VALBLK;
 
-        status = dlmlock(osb->dlm,
-                         new_level,
-                         &lockres->l_lksb,
-                         dlm_flags,
-                         lockres->l_name,
-                         OCFS2_LOCK_ID_MAX_LEN - 1,
-                         ocfs2_locking_ast,
-                         lockres,
-                         ocfs2_blocking_ast);
+        status = ocfs2_dlm_lock(osb->dlm,
+                                new_level,
+                                &lockres->l_lksb,
+                                dlm_flags,
+                                lockres->l_name,
+                                OCFS2_LOCK_ID_MAX_LEN - 1,
+                                lockres);
         if (status != DLM_NORMAL) {
-                ocfs2_log_dlm_error("dlmlock", status, lockres);
+                ocfs2_log_dlm_error("ocfs2_dlm_lock", status, lockres);
                 ret = -EINVAL;
                 ocfs2_recover_from_dlm_error(lockres, 1);
                 goto bail;
@@ -2854,7 +2850,7 @@ bail:
         return ret;
 }
 
-/* returns 1 when the caller should unlock and call dlmunlock */
+/* returns 1 when the caller should unlock and call ocfs2_dlm_unlock */
 static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
                                         struct ocfs2_lock_res *lockres)
 {
@@ -2896,18 +2892,17 @@ static int ocfs2_cancel_convert(struct ocfs2_super *osb,
         mlog(0, "lock %s\n", lockres->l_name);
 
         ret = 0;
-        status = dlmunlock(osb->dlm,
-                           &lockres->l_lksb,
-                           LKM_CANCEL,
-                           ocfs2_unlock_ast,
-                           lockres);
+        status = ocfs2_dlm_unlock(osb->dlm,
+                                  &lockres->l_lksb,
+                                  LKM_CANCEL,
+                                  lockres);
         if (status != DLM_NORMAL) {
-                ocfs2_log_dlm_error("dlmunlock", status, lockres);
+                ocfs2_log_dlm_error("ocfs2_dlm_unlock", status, lockres);
                 ret = -EINVAL;
                 ocfs2_recover_from_dlm_error(lockres, 0);
         }
 
-        mlog(0, "lock %s return from dlmunlock\n", lockres->l_name);
+        mlog(0, "lock %s return from ocfs2_dlm_unlock\n", lockres->l_name);
 
         mlog_exit(ret);
         return ret;
@@ -3211,6 +3206,23 @@ static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
         return UNBLOCK_CONTINUE_POST;
 }
 
+static struct ocfs2_locking_protocol lproto = {
+        .lp_lock_ast            = ocfs2_locking_ast,
+        .lp_blocking_ast        = ocfs2_blocking_ast,
+        .lp_unlock_ast          = ocfs2_unlock_ast,
+};
+
+/* This interface isn't the final one, hence the less-than-perfect names */
+void dlmglue_init_stack(void)
+{
+        o2cb_get_stack(&lproto);
+}
+
+void dlmglue_exit_stack(void)
+{
+        o2cb_put_stack();
+}
+
 static void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
                                        struct ocfs2_lock_res *lockres)
 {
diff --git a/fs/ocfs2/dlmglue.h b/fs/ocfs2/dlmglue.h
index e3cf902404b4..32380439401f 100644
--- a/fs/ocfs2/dlmglue.h
+++ b/fs/ocfs2/dlmglue.h
@@ -114,5 +114,8 @@ void ocfs2_wake_downconvert_thread(struct ocfs2_super *osb);
 struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void);
 void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug);
 
+void dlmglue_init_stack(void);
+void dlmglue_exit_stack(void);
+
 extern const struct dlm_protocol_version ocfs2_locking_protocol;
 #endif  /* DLMGLUE_H */
diff --git a/fs/ocfs2/stackglue.c b/fs/ocfs2/stackglue.c
new file mode 100644
index 000000000000..4f44f23795f0
--- /dev/null
+++ b/fs/ocfs2/stackglue.c
@@ -0,0 +1,65 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * stackglue.c
+ *
+ * Code which implements an OCFS2 specific interface to underlying
+ * cluster stacks.
+ *
+ * Copyright (C) 2007 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/types.h>
+#include <linux/list.h>
+
+#include "dlm/dlmapi.h"
+
+#include "stackglue.h"
+
+static struct ocfs2_locking_protocol *lproto;
+
+enum dlm_status ocfs2_dlm_lock(struct dlm_ctxt *dlm,
+                   int mode,
+                   struct dlm_lockstatus *lksb,
+                   u32 flags,
+                   void *name,
+                   unsigned int namelen,
+                   void *astarg)
+{
+        BUG_ON(lproto == NULL);
+        return dlmlock(dlm, mode, lksb, flags, name, namelen,
+                       lproto->lp_lock_ast, astarg,
+                       lproto->lp_blocking_ast);
+}
+
+enum dlm_status ocfs2_dlm_unlock(struct dlm_ctxt *dlm,
+                     struct dlm_lockstatus *lksb,
+                     u32 flags,
+                     void *astarg)
+{
+        BUG_ON(lproto == NULL);
+
+        return dlmunlock(dlm, lksb, flags, lproto->lp_unlock_ast, astarg);
+}
+
+
+void o2cb_get_stack(struct ocfs2_locking_protocol *proto)
+{
+        BUG_ON(proto == NULL);
+
+        lproto = proto;
+}
+
+void o2cb_put_stack(void)
+{
+        lproto = NULL;
+}
diff --git a/fs/ocfs2/stackglue.h b/fs/ocfs2/stackglue.h
new file mode 100644
index 000000000000..40a002413404
--- /dev/null
+++ b/fs/ocfs2/stackglue.h
@@ -0,0 +1,45 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * stackglue.h
+ *
+ * Glue to the underlying cluster stack.
+ *
+ * Copyright (C) 2007 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+
+#ifndef STACKGLUE_H
+#define STACKGLUE_H
+
+struct ocfs2_locking_protocol {
+        void (*lp_lock_ast)(void *astarg);
+        void (*lp_blocking_ast)(void *astarg, int level);
+        void (*lp_unlock_ast)(void *astarg, enum dlm_status status);
+};
+
+enum dlm_status ocfs2_dlm_lock(struct dlm_ctxt *dlm,
+                   int mode,
+                   struct dlm_lockstatus *lksb,
+                   u32 flags,
+                   void *name,
+                   unsigned int namelen,
+                   void *astarg);
+enum dlm_status ocfs2_dlm_unlock(struct dlm_ctxt *dlm,
+                     struct dlm_lockstatus *lksb,
+                     u32 flags,
+                     void *astarg);
+
+void o2cb_get_stack(struct ocfs2_locking_protocol *proto);
+void o2cb_put_stack(void);
+
+#endif  /* STACKGLUE_H */
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 1a4c7c7850f2..c8675464e299 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -933,6 +933,8 @@ static int __init ocfs2_init(void)
 
         ocfs2_print_version();
 
+        dlmglue_init_stack();
+
         status = init_ocfs2_uptodate_cache();
         if (status < 0) {
                 mlog_errno(status);
@@ -988,6 +990,8 @@ static void __exit ocfs2_exit(void)
 
         exit_ocfs2_uptodate_cache();
 
+        dlmglue_exit_stack();
+
         mlog_exit_void();
 }