diff mbox

[6/6] Use the new DLM operation callbacks while requesting new lockspace

Message ID 20131112140817.GA3955@shrek.lan (mailing list archive)
State New, archived
Headers show

Commit Message

Goldwyn Rodrigues Nov. 12, 2013, 2:08 p.m. UTC 
Attempt to use the new DLM operations. If it is not supported,
use the traditional ocfs2_controld.

To exchange ocfs2 versioning, we use the LVB of the version dlm lock.
It first attempts to take the lock in EX mode (non-blocking). If
successful (which means it is the first mount), it writes the
version number and downconverts to PR lock. If it is unsuccessful,
it reads the version from the lock.

If this becomes the standard (with o2cb as well), it could
simplify userspace tools to check if the filesystem is mounted
on other nodes.

Dan: Since ocfs2_protocol_version are two u8 values, the additional
checks with LONG* don't make sense.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
 fs/ocfs2/stack_user.c | 119 ++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 95 insertions(+), 24 deletions(-)

Comments

Mark Fasheh Dec. 8, 2013, 7:30 p.m. UTC | #1 
On Tue, Nov 12, 2013 at 08:08:22AM -0600, Goldwyn Rodrigues wrote:
> Attempt to use the new DLM operations. If it is not supported,
> use the traditional ocfs2_controld.
> 
> To exchange ocfs2 versioning, we use the LVB of the version dlm lock.
> It first attempts to take the lock in EX mode (non-blocking). If
> successful (which means it is the first mount), it writes the
> version number and downconverts to PR lock. If it is unsuccessful,
> it reads the version from the lock.

Can you take this description of the protocol and put it (as a comment) in
or above get_protocol_version(). I kind of had to look back to the patch
description to figure out exactly what it meant to do so I figure someone
reading this int he future will have  the same questions.

Otherwise this patch looks good, thanks!
	--Mark

--
Mark Fasheh
diff mbox

Patch

diff --git a/fs/ocfs2/stack_user.c b/fs/ocfs2/stack_user.c
index d33dd05..ec6f406 100644
--- a/fs/ocfs2/stack_user.c
+++ b/fs/ocfs2/stack_user.c
@@ -23,6 +23,7 @@ 
 #include <linux/mutex.h>
 #include <linux/slab.h>
 #include <linux/reboot.h>
+#include <linux/sched.h>
 #include <asm/uaccess.h>
 
 #include "stackglue.h"
@@ -122,6 +123,7 @@  struct ocfs2_live_connection {
 	struct dlm_lksb                 oc_version_lksb;
 	char                            oc_lvb[DLM_LVB_LEN];
 	struct completion               oc_sync_wait;
+	wait_queue_head_t		oc_wait;
 };
 
 struct ocfs2_control_private {
@@ -218,7 +220,7 @@  static int ocfs2_live_connection_attach(struct ocfs2_cluster_connection *conn,
 	mutex_lock(&ocfs2_control_lock);
 	c->oc_conn = conn;
 
-	if (atomic_read(&ocfs2_control_opened))
+	if ((c->oc_type == NO_CONTROLD) || atomic_read(&ocfs2_control_opened))
 		list_add(&c->oc_list, &ocfs2_live_connection_list);
 	else {
 		printk(KERN_ERR
@@ -897,6 +899,48 @@  static int version_unlock(struct ocfs2_cluster_connection *conn)
 	return sync_unlock(conn, &lc->oc_version_lksb, VERSION_LOCK);
 }
 
+static int get_protocol_version(struct ocfs2_cluster_connection *conn)
+{
+	int ret;
+	struct ocfs2_live_connection *lc = conn->cc_private;
+	struct ocfs2_protocol_version pv;
+	
+	running_proto.pv_major = 
+		ocfs2_user_plugin.sp_max_proto.pv_major;
+	running_proto.pv_minor =
+		ocfs2_user_plugin.sp_max_proto.pv_minor;
+
+	lc->oc_version_lksb.sb_lvbptr = lc->oc_lvb;
+	ret = version_lock(conn, DLM_LOCK_EX,
+			DLM_LKF_VALBLK|DLM_LKF_NOQUEUE);
+	if (!ret) {
+		conn->cc_version.pv_major = running_proto.pv_major;
+		conn->cc_version.pv_minor = running_proto.pv_minor;
+		version_to_lvb(&running_proto, lc->oc_lvb);
+		version_lock(conn, DLM_LOCK_PR, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
+	} else if (ret == -EAGAIN) {
+		ret = version_lock(conn, DLM_LOCK_PR, DLM_LKF_VALBLK);
+		if (ret)
+			goto out;
+		lvb_to_version(lc->oc_lvb, &pv);
+
+		if (pv.pv_minor < 0) {
+			ret = -ERANGE;
+			goto out;
+		}
+		if ((pv.pv_major != running_proto.pv_major) ||
+				(pv.pv_minor > running_proto.pv_minor)) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		conn->cc_version.pv_major = pv.pv_major;
+		conn->cc_version.pv_minor = pv.pv_minor;
+	}
+out:
+	return ret;
+}
+
 static void user_recover_prep(void *arg)
 {
 }
@@ -925,6 +969,7 @@  static void user_recover_done(void *arg, struct dlm_slot *slots,
 		}
 
 	lc->oc_our_slot = our_slot;
+	wake_up(&lc->oc_wait);
 }
 
 const struct dlm_lockspace_ops ocfs2_ls_ops = {
@@ -933,11 +978,21 @@  const struct dlm_lockspace_ops ocfs2_ls_ops = {
 	.recover_done = user_recover_done,
 };
 
+static int user_cluster_disconnect(struct ocfs2_cluster_connection *conn)
+{
+	version_unlock(conn);
+	dlm_release_lockspace(conn->cc_lockspace, 2);
+	conn->cc_lockspace = NULL;
+	ocfs2_live_connection_drop(conn->cc_private);
+	conn->cc_private = NULL;
+	return 0;
+}
+
 static int user_cluster_connect(struct ocfs2_cluster_connection *conn)
 {
 	dlm_lockspace_t *fsdlm;
 	struct ocfs2_live_connection *lc;
-	int rc;
+	int rc, ops_rv;
 
 	BUG_ON(conn == NULL);
 
@@ -947,11 +1002,44 @@  static int user_cluster_connect(struct ocfs2_cluster_connection *conn)
 		goto out;
 	}
 
-	lc->oc_type = WITH_CONTROLD;
+	init_waitqueue_head(&lc->oc_wait);
+	init_completion(&lc->oc_sync_wait);
+	atomic_set(&lc->oc_this_node, 0);
+	conn->cc_private = lc;
+	lc->oc_type = NO_CONTROLD;
+
+	rc = dlm_new_lockspace(conn->cc_name, conn->cc_cluster_name,
+			       DLM_LSFL_FS, DLM_LVB_LEN,
+			       &ocfs2_ls_ops, conn, &ops_rv, &fsdlm);
+	if (rc)
+		goto out;
+
+	if (ops_rv == -EOPNOTSUPP) {
+		lc->oc_type = WITH_CONTROLD;
+		printk(KERN_NOTICE "ocfs2: You seem to be using an older "
+				"version of dlm_controld and/or ocfs2-tools."
+				" Please consider upgrading.\n");
+	} else if (ops_rv) {
+		rc = ops_rv;
+		goto out;
+	}
+	conn->cc_lockspace = fsdlm;
+
 	rc = ocfs2_live_connection_attach(conn, lc);
 	if (rc)
 		goto out;
 
+	if (lc->oc_type == NO_CONTROLD) {
+		rc = get_protocol_version(conn);
+		if (rc) {
+			printk(KERN_ERR "ocfs2: Could not determine"
+					" locking version\n");
+			user_cluster_disconnect(conn);
+			goto out;
+		}
+		wait_event(lc->oc_wait, (atomic_read(&lc->oc_this_node) > 0));
+	}
+
 	/*
 	 * running_proto must have been set before we allowed any mounts
 	 * to proceed.
@@ -959,40 +1047,20 @@  static int user_cluster_connect(struct ocfs2_cluster_connection *conn)
 	if (fs_protocol_compare(&running_proto, &conn->cc_version)) {
 		printk(KERN_ERR
 		       "Unable to mount with fs locking protocol version "
-		       "%u.%u because the userspace control daemon has "
-		       "negotiated %u.%u\n",
+		       "%u.%u because negotiated protocol is %u.%u\n",
 		       conn->cc_version.pv_major, conn->cc_version.pv_minor,
 		       running_proto.pv_major, running_proto.pv_minor);
 		rc = -EPROTO;
 		ocfs2_live_connection_drop(lc);
 		lc = NULL;
-		goto out;
 	}
 
-	rc = dlm_new_lockspace(conn->cc_name, NULL, DLM_LSFL_FS, DLM_LVB_LEN,
-			       NULL, NULL, NULL, &fsdlm);
-	if (rc) {
-		ocfs2_live_connection_drop(lc);
-		lc = NULL;
-		goto out;
-	}
-
-	conn->cc_private = lc;
-	conn->cc_lockspace = fsdlm;
 out:
 	if (rc && lc)
 		kfree(lc);
 	return rc;
 }
 
-static int user_cluster_disconnect(struct ocfs2_cluster_connection *conn)
-{
-	dlm_release_lockspace(conn->cc_lockspace, 2);
-	conn->cc_lockspace = NULL;
-	ocfs2_live_connection_drop(conn->cc_private);
-	conn->cc_private = NULL;
-	return 0;
-}
 
 static int user_cluster_this_node(struct ocfs2_cluster_connection *conn,
 				  unsigned int *this_node)
@@ -1002,8 +1070,11 @@  static int user_cluster_this_node(struct ocfs2_cluster_connection *conn,
 
 	if (lc->oc_type == WITH_CONTROLD)
 		rc = ocfs2_control_get_this_node();
+	else if (lc->oc_type == NO_CONTROLD)
+		rc = atomic_read(&lc->oc_this_node);
 	else
 		rc = -EINVAL;
+
 	if (rc < 0)
 		return rc;