Ocfs2 devel - Oct 2013 - [PATCH 6/6] Use the new DLM operation callbacks while requesting new lockspace

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 (wit o2cb as well), it could
simplify userspace tools to check if the filesystem is mounted
on other nodes.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn at suse.com>
---
 fs/ocfs2/stack_user.c | 97 ++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 73 insertions(+), 24 deletions(-)

diff --git a/fs/ocfs2/stack_user.c b/fs/ocfs2/stack_user.c
index f417d5e..c4466f5 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"
@@ -121,6 +122,7 @@ 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 {
@@ -217,7 +219,7 @@ static int ocfs2_live_connection_new(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
@@ -926,6 +928,7 @@ 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 = {
@@ -934,11 +937,21 @@ 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);
 
@@ -948,12 +961,65 @@ 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_new(conn, lc);
 	if (rc)
 		goto out;
 
+	if (lc->oc_type == NO_CONTROLD) {
+		int ret;
+		lc->oc_version_lksb.sb_lvbptr = lc->oc_lvb;
+		ret = version_lock(conn, DLM_LOCK_EX,
+				DLM_LKF_VALBLK|DLM_LKF_NOQUEUE);
+		running_proto.pv_major = 
+			ocfs2_user_plugin.sp_max_proto.pv_major;
+		running_proto.pv_minor +			ocfs2_user_plugin.sp_max_proto.pv_minor;
+		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) {
+			version_lock(conn, DLM_LOCK_PR, DLM_LKF_VALBLK);
+			ret = lvb_to_version(lc->oc_lvb, &conn->cc_version);
+			if (ret) {
+				rc = ret;
+				user_cluster_disconnect(conn);
+				goto out;
+			}
+		} else {
+			printk(KERN_ERR "ocfs2: Could not determine"
+					" locking version\n");
+			rc = ret;
+			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.
@@ -961,40 +1027,20 @@ 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)
@@ -1004,8 +1050,11 @@ 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;
 
-- 
1.8.1.4


-- 
Goldwyn

On Fri, Oct 18, 2013 at 09:46:31AM -0500, 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.
> 
> If this becomes the standard (wit o2cb as well), it could
> simplify userspace tools to check if the filesystem is mounted
> on other nodes.
> 
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn at suse.com>
> ---
>  fs/ocfs2/stack_user.c | 97
++++++++++++++++++++++++++++++++++++++-------------
>  1 file changed, 73 insertions(+), 24 deletions(-)
> @@ -948,12 +961,65 @@ 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_new(conn, lc);
>  	if (rc)
>  		goto out;
>  
> +	if (lc->oc_type == NO_CONTROLD) {
> +		int ret;
> +		lc->oc_version_lksb.sb_lvbptr = lc->oc_lvb;
> +		ret = version_lock(conn, DLM_LOCK_EX,
> +				DLM_LKF_VALBLK|DLM_LKF_NOQUEUE);
> +		running_proto.pv_major = 
> +			ocfs2_user_plugin.sp_max_proto.pv_major;
> +		running_proto.pv_minor > +			ocfs2_user_plugin.sp_max_proto.pv_minor;
> +		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) {
> +			version_lock(conn, DLM_LOCK_PR, DLM_LKF_VALBLK);
> +			ret = lvb_to_version(lc->oc_lvb, &conn->cc_version);
> +			if (ret) {
> +				rc = ret;
> +				user_cluster_disconnect(conn);
> +				goto out;
> +			}
> +		} else {
> +			printk(KERN_ERR "ocfs2: Could not determine"
> +					" locking version\n");
> +			rc = ret;
> +			user_cluster_disconnect(conn);
> +			goto out;
> +		}
> +		wait_event(lc->oc_wait, (atomic_read(&lc->oc_this_node) >
0));
> +	}
> +
Can we put this block in it's own function?
	--Mark


--
Mark Fasheh

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

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;
 
-- 
1.8.1.4


-- 
Goldwyn

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