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Commit 286eaa95 authored by Joel Becker's avatar Joel Becker Committed by Mark Fasheh
Browse files

ocfs2: Break out stackglue into modules. 



We define the ocfs2_stack_plugin structure to represent a stack driver.
The o2cb stack code is split into stack_o2cb.c.  This becomes the
ocfs2_stack_o2cb.ko module.

The stackglue generic functions are similarly split into the
ocfs2_stackglue.ko module.  This module now provides an interface to
register drivers.  The ocfs2_stack_o2cb driver registers itself.  As
part of this interface, ocfs2_stackglue can load drivers on demand.
This is accomplished in ocfs2_cluster_connect().

ocfs2_cluster_disconnect() is now notified when a _hangup() is pending.
If a hangup is pending, it will not release the driver module and will
let _hangup() do that.

Signed-off-by: default avatarJoel Becker <joel.becker@oracle.com>
parent e3dad42b

fs/ocfs2/Makefile

+4 −3
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ EXTRA_CFLAGS += -Ifs/ocfs2 


EXTRA_CFLAGS += -DCATCH_BH_JBD_RACES



obj-$(CONFIG_OCFS2_FS) += ocfs2.o

obj-$(CONFIG_OCFS2_FS) += ocfs2.o ocfs2_stackglue.o ocfs2_stack_o2cb.o



ocfs2-objs := \

	alloc.o 		\
@@ -24,8 +24,6 @@ ocfs2-objs := \ 
	namei.o 		\

	resize.o		\

	slot_map.o 		\

	stackglue.o		\

	stack_o2cb.o		\

	suballoc.o 		\

	super.o 		\

	symlink.o 		\
@@ -33,5 +31,8 @@ ocfs2-objs := \ 
	uptodate.o		\

	ver.o



ocfs2_stackglue-objs := stackglue.o

ocfs2_stack_o2cb-objs := stack_o2cb.o



obj-$(CONFIG_OCFS2_FS) += cluster/

obj-$(CONFIG_OCFS2_FS) += dlm/

fs/ocfs2/dlmglue.c

+4 −3
Original line number Diff line number Diff line
@@ -2641,7 +2641,7 @@ int ocfs2_dlm_init(struct ocfs2_super *osb) 
		mlog_errno(status);

		mlog(ML_ERROR,

		     "could not find this host's node number\n");

		ocfs2_cluster_disconnect(conn);

		ocfs2_cluster_disconnect(conn, 0);

		goto bail;

	}
@@ -2663,7 +2663,8 @@ bail: 
	return status;

}



void ocfs2_dlm_shutdown(struct ocfs2_super *osb)

void ocfs2_dlm_shutdown(struct ocfs2_super *osb,

			int hangup_pending)

{

	mlog_entry_void();
@@ -2683,7 +2684,7 @@ void ocfs2_dlm_shutdown(struct ocfs2_super *osb) 
	ocfs2_lock_res_free(&osb->osb_super_lockres);

	ocfs2_lock_res_free(&osb->osb_rename_lockres);



	ocfs2_cluster_disconnect(osb->cconn);

	ocfs2_cluster_disconnect(osb->cconn, hangup_pending);

	osb->cconn = NULL;



	ocfs2_dlm_shutdown_debug(osb);

fs/ocfs2/dlmglue.h

+1 −1
Original line number Diff line number Diff line
@@ -58,7 +58,7 @@ struct ocfs2_meta_lvb { 
#define OCFS2_LOCK_NONBLOCK		(0x04)



int ocfs2_dlm_init(struct ocfs2_super *osb);

void ocfs2_dlm_shutdown(struct ocfs2_super *osb);

void ocfs2_dlm_shutdown(struct ocfs2_super *osb, int hangup_pending);

void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res);

void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,

			       enum ocfs2_lock_type type,

fs/ocfs2/stack_o2cb.c

+33 −8
Original line number Diff line number Diff line
@@ -18,7 +18,7 @@ 
 */



#include <linux/crc32.h>

#include <linux/kmod.h>

#include <linux/module.h>



/* Needed for AOP_TRUNCATED_PAGE in mlog_errno() */

#include <linux/fs.h>
@@ -33,6 +33,8 @@ struct o2dlm_private { 
	struct dlm_eviction_cb op_eviction_cb;

};



static struct ocfs2_stack_plugin o2cb_stack;



/* These should be identical */

#if (DLM_LOCK_IV != LKM_IVMODE)

# error Lock modes do not match
@@ -158,23 +160,23 @@ static int dlm_status_to_errno(enum dlm_status status) 


static void o2dlm_lock_ast_wrapper(void *astarg)

{

	BUG_ON(stack_glue_lproto == NULL);

	BUG_ON(o2cb_stack.sp_proto == NULL);



	stack_glue_lproto->lp_lock_ast(astarg);

	o2cb_stack.sp_proto->lp_lock_ast(astarg);

}



static void o2dlm_blocking_ast_wrapper(void *astarg, int level)

{

	BUG_ON(stack_glue_lproto == NULL);

	BUG_ON(o2cb_stack.sp_proto == NULL);



	stack_glue_lproto->lp_blocking_ast(astarg, level);

	o2cb_stack.sp_proto->lp_blocking_ast(astarg, level);

}



static void o2dlm_unlock_ast_wrapper(void *astarg, enum dlm_status status)

{

	int error = dlm_status_to_errno(status);



	BUG_ON(stack_glue_lproto == NULL);

	BUG_ON(o2cb_stack.sp_proto == NULL);



	/*

	 * In o2dlm, you can get both the lock_ast() for the lock being
@@ -190,7 +192,7 @@ static void o2dlm_unlock_ast_wrapper(void *astarg, enum dlm_status status) 
	if (status == DLM_CANCELGRANT)

		return;



	stack_glue_lproto->lp_unlock_ast(astarg, error);

	o2cb_stack.sp_proto->lp_unlock_ast(astarg, error);

}



static int o2cb_dlm_lock(struct ocfs2_cluster_connection *conn,
@@ -267,6 +269,7 @@ static int o2cb_cluster_connect(struct ocfs2_cluster_connection *conn) 
	struct dlm_protocol_version dlm_version;



	BUG_ON(conn == NULL);

	BUG_ON(o2cb_stack.sp_proto == NULL);



	/* for now we only have one cluster/node, make sure we see it

	 * in the heartbeat universe */
@@ -314,7 +317,8 @@ out: 
	return rc;

}



static int o2cb_cluster_disconnect(struct ocfs2_cluster_connection *conn)

static int o2cb_cluster_disconnect(struct ocfs2_cluster_connection *conn,

				   int hangup_pending)

{

	struct dlm_ctxt *dlm = conn->cc_lockspace;

	struct o2dlm_private *priv = conn->cc_private;
@@ -393,3 +397,24 @@ struct ocfs2_stack_operations o2cb_stack_ops = { 
	.dump_lksb	= o2cb_dump_lksb,

};



static struct ocfs2_stack_plugin o2cb_stack = {

	.sp_name	= "o2cb",

	.sp_ops		= &o2cb_stack_ops,

	.sp_owner	= THIS_MODULE,

};



static int __init o2cb_stack_init(void)

{

	return ocfs2_stack_glue_register(&o2cb_stack);

}



static void __exit o2cb_stack_exit(void)

{

	ocfs2_stack_glue_unregister(&o2cb_stack);

}



MODULE_AUTHOR("Oracle");

MODULE_DESCRIPTION("ocfs2 driver for the classic o2cb stack");

MODULE_LICENSE("GPL");

module_init(o2cb_stack_init);

module_exit(o2cb_stack_exit);

fs/ocfs2/stackglue.c

+214 −24
Original line number Diff line number Diff line
@@ -18,17 +18,176 @@ 
 * General Public License for more details.

 */



#include <linux/list.h>

#include <linux/spinlock.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <linux/kmod.h>



/* Needed for AOP_TRUNCATED_PAGE in mlog_errno() */

#include <linux/fs.h>

#include "stackglue.h"



#include "cluster/masklog.h"

static struct ocfs2_locking_protocol *lproto;

static DEFINE_SPINLOCK(ocfs2_stack_lock);

static LIST_HEAD(ocfs2_stack_list);



#include "stackglue.h"

/*

 * The stack currently in use.  If not null, active_stack->sp_count > 0,

 * the module is pinned, and the locking protocol cannot be changed.

 */

static struct ocfs2_stack_plugin *active_stack;



static struct ocfs2_stack_plugin *ocfs2_stack_lookup(const char *name)

{

	struct ocfs2_stack_plugin *p;



	assert_spin_locked(&ocfs2_stack_lock);



	list_for_each_entry(p, &ocfs2_stack_list, sp_list) {

		if (!strcmp(p->sp_name, name))

			return p;

	}



	return NULL;

}



static int ocfs2_stack_driver_request(const char *name)

{

	int rc;

	struct ocfs2_stack_plugin *p;



	spin_lock(&ocfs2_stack_lock);



	if (active_stack) {

		/*

		 * If the active stack isn't the one we want, it cannot

		 * be selected right now.

		 */

		if (!strcmp(active_stack->sp_name, name))

			rc = 0;

		else

			rc = -EBUSY;

		goto out;

	}



	p = ocfs2_stack_lookup(name);

	if (!p || !try_module_get(p->sp_owner)) {

		rc = -ENOENT;

		goto out;

	}



	/* Ok, the stack is pinned */

	p->sp_count++;

	active_stack = p;



	rc = 0;



out:

	spin_unlock(&ocfs2_stack_lock);

	return rc;

}



/*

 * This function looks up the appropriate stack and makes it active.  If

 * there is no stack, it tries to load it.  It will fail if the stack still

 * cannot be found.  It will also fail if a different stack is in use.

 */

static int ocfs2_stack_driver_get(const char *name)

{

	int rc;



	rc = ocfs2_stack_driver_request(name);

	if (rc == -ENOENT) {

		request_module("ocfs2_stack_%s", name);

		rc = ocfs2_stack_driver_request(name);

	}



	if (rc == -ENOENT) {

		printk(KERN_ERR

		       "ocfs2: Cluster stack driver \"%s\" cannot be found\n",

		       name);

	} else if (rc == -EBUSY) {

		printk(KERN_ERR

		       "ocfs2: A different cluster stack driver is in use\n");

	}



	return rc;

}



static void ocfs2_stack_driver_put(void)

{

	spin_lock(&ocfs2_stack_lock);

	BUG_ON(active_stack == NULL);

	BUG_ON(active_stack->sp_count == 0);



	active_stack->sp_count--;

	if (!active_stack->sp_count) {

		module_put(active_stack->sp_owner);

		active_stack = NULL;

	}

	spin_unlock(&ocfs2_stack_lock);

}



int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin)

{

	int rc;



	spin_lock(&ocfs2_stack_lock);

	if (!ocfs2_stack_lookup(plugin->sp_name)) {

		plugin->sp_count = 0;

		plugin->sp_proto = lproto;

		list_add(&plugin->sp_list, &ocfs2_stack_list);

		printk(KERN_INFO "ocfs2: Registered cluster interface %s\n",

		       plugin->sp_name);

		rc = 0;

	} else {

		printk(KERN_ERR "ocfs2: Stack \"%s\" already registered\n",

		       plugin->sp_name);

		rc = -EEXIST;

	}

	spin_unlock(&ocfs2_stack_lock);



struct ocfs2_locking_protocol *stack_glue_lproto;

	return rc;

}

EXPORT_SYMBOL_GPL(ocfs2_stack_glue_register);



void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin)

{

	struct ocfs2_stack_plugin *p;



	spin_lock(&ocfs2_stack_lock);

	p = ocfs2_stack_lookup(plugin->sp_name);

	if (p) {

		BUG_ON(p != plugin);

		BUG_ON(plugin == active_stack);

		BUG_ON(plugin->sp_count != 0);

		list_del_init(&plugin->sp_list);

		printk(KERN_INFO "ocfs2: Unregistered cluster interface %s\n",

		       plugin->sp_name);

	} else {

		printk(KERN_ERR "Stack \"%s\" is not registered\n",

		       plugin->sp_name);

	}

	spin_unlock(&ocfs2_stack_lock);

}

EXPORT_SYMBOL_GPL(ocfs2_stack_glue_unregister);



void ocfs2_stack_glue_set_locking_protocol(struct ocfs2_locking_protocol *proto)

{

	struct ocfs2_stack_plugin *p;



	BUG_ON(proto == NULL);



	spin_lock(&ocfs2_stack_lock);

	BUG_ON(active_stack != NULL);



	lproto = proto;

	list_for_each_entry(p, &ocfs2_stack_list, sp_list) {

		p->sp_proto = lproto;

	}



	spin_unlock(&ocfs2_stack_lock);

}

EXPORT_SYMBOL_GPL(ocfs2_stack_glue_set_locking_protocol);





int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn,
@@ -39,26 +198,29 @@ int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn, 
		   unsigned int namelen,

		   void *astarg)

{

	BUG_ON(stack_glue_lproto == NULL);

	BUG_ON(lproto == NULL);



	return o2cb_stack_ops.dlm_lock(conn, mode, lksb, flags,

	return active_stack->sp_ops->dlm_lock(conn, mode, lksb, flags,

					      name, namelen, astarg);

}

EXPORT_SYMBOL_GPL(ocfs2_dlm_lock);



int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,

		     union ocfs2_dlm_lksb *lksb,

		     u32 flags,

		     void *astarg)

{

	BUG_ON(stack_glue_lproto == NULL);

	BUG_ON(lproto == NULL);



	return o2cb_stack_ops.dlm_unlock(conn, lksb, flags, astarg);

	return active_stack->sp_ops->dlm_unlock(conn, lksb, flags, astarg);

}

EXPORT_SYMBOL_GPL(ocfs2_dlm_unlock);



int ocfs2_dlm_lock_status(union ocfs2_dlm_lksb *lksb)

{

	return o2cb_stack_ops.lock_status(lksb);

	return active_stack->sp_ops->lock_status(lksb);

}

EXPORT_SYMBOL_GPL(ocfs2_dlm_lock_status);



/*

 * Why don't we cast to ocfs2_meta_lvb?  The "clean" answer is that we
@@ -67,13 +229,15 @@ int ocfs2_dlm_lock_status(union ocfs2_dlm_lksb *lksb) 
 */

void *ocfs2_dlm_lvb(union ocfs2_dlm_lksb *lksb)

{

	return o2cb_stack_ops.lock_lvb(lksb);

	return active_stack->sp_ops->lock_lvb(lksb);

}

EXPORT_SYMBOL_GPL(ocfs2_dlm_lvb);



void ocfs2_dlm_dump_lksb(union ocfs2_dlm_lksb *lksb)

{

	o2cb_stack_ops.dump_lksb(lksb);

	active_stack->sp_ops->dump_lksb(lksb);

}

EXPORT_SYMBOL_GPL(ocfs2_dlm_dump_lksb);



int ocfs2_cluster_connect(const char *group,

			  int grouplen,
@@ -107,11 +271,16 @@ int ocfs2_cluster_connect(const char *group, 
	new_conn->cc_recovery_data = recovery_data;



	/* Start the new connection at our maximum compatibility level */

	new_conn->cc_version = stack_glue_lproto->lp_max_version;

	new_conn->cc_version = lproto->lp_max_version;



	rc = o2cb_stack_ops.connect(new_conn);

	/* This will pin the stack driver if successful */

	rc = ocfs2_stack_driver_get("o2cb");

	if (rc)

		goto out_free;



	rc = active_stack->sp_ops->connect(new_conn);

	if (rc) {

		mlog_errno(rc);

		ocfs2_stack_driver_put();

		goto out_free;

	}
@@ -124,39 +293,60 @@ out_free: 
out:

	return rc;

}

EXPORT_SYMBOL_GPL(ocfs2_cluster_connect);



int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn)

/* If hangup_pending is 0, the stack driver will be dropped */

int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn,

			     int hangup_pending)

{

	int ret;



	BUG_ON(conn == NULL);



	ret = o2cb_stack_ops.disconnect(conn);

	ret = active_stack->sp_ops->disconnect(conn, hangup_pending);



	/* XXX Should we free it anyway? */

	if (!ret)

	if (!ret) {

		kfree(conn);

		if (!hangup_pending)

			ocfs2_stack_driver_put();

	}



	return ret;

}

EXPORT_SYMBOL_GPL(ocfs2_cluster_disconnect);



void ocfs2_cluster_hangup(const char *group, int grouplen)

{

	BUG_ON(group == NULL);

	BUG_ON(group[grouplen] != '\0');



	o2cb_stack_ops.hangup(group, grouplen);

	active_stack->sp_ops->hangup(group, grouplen);



	/* cluster_disconnect() was called with hangup_pending==1 */

	ocfs2_stack_driver_put();

}

EXPORT_SYMBOL_GPL(ocfs2_cluster_hangup);



int ocfs2_cluster_this_node(unsigned int *node)

{

	return o2cb_stack_ops.this_node(node);

	return active_stack->sp_ops->this_node(node);

}

EXPORT_SYMBOL_GPL(ocfs2_cluster_this_node);



void ocfs2_stack_glue_set_locking_protocol(struct ocfs2_locking_protocol *proto)



static int __init ocfs2_stack_glue_init(void)

{

	BUG_ON(proto != NULL);

	return 0;

}



	stack_glue_lproto = proto;

static void __exit ocfs2_stack_glue_exit(void)

{

	lproto = NULL;

}



MODULE_AUTHOR("Oracle");

MODULE_DESCRIPTION("ocfs2 cluter stack glue layer");

MODULE_LICENSE("GPL");

module_init(ocfs2_stack_glue_init);

module_exit(ocfs2_stack_glue_exit);