Commit 0f8e0d9a authored by David Teigland's avatar David Teigland
Browse files

dlm: allow multiple lockspace creates 



Add a count for lockspace create and release so that create can
be called multiple times to use the lockspace from different places.
Also add the new flag DLM_LSFL_NEWEXCL to create a lockspace with
the previous behavior of returning -EEXIST if the lockspace already
exists.

Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
parent 4c246edd

fs/dlm/dlm_internal.h

+4 −2
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ 
*******************************************************************************

**

**  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.

**  Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.

**  Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.

**

**  This copyrighted material is made available to anyone wishing to use,

**  modify, copy, or redistribute it subject to the terms and conditions
@@ -441,7 +441,9 @@ struct dlm_ls { 
	uint32_t		ls_global_id;	/* global unique lockspace ID */

	uint32_t		ls_exflags;

	int			ls_lvblen;

	int			ls_count;	/* reference count */

	int			ls_count;	/* refcount of processes in

						   the dlm using this ls */

	int			ls_create_count; /* create/release refcount */

	unsigned long		ls_flags;	/* LSFL_ */

	struct kobject		ls_kobj;

fs/dlm/lockspace.c

+70 −37
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ 
*******************************************************************************

**

**  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.

**  Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.

**  Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.

**

**  This copyrighted material is made available to anyone wishing to use,

**  modify, copy, or redistribute it subject to the terms and conditions
@@ -23,6 +23,7 @@ 
#include "lock.h"

#include "recover.h"

#include "requestqueue.h"

#include "user.h"



static int			ls_count;

static struct mutex		ls_lock;
@@ -246,23 +247,6 @@ static void dlm_scand_stop(void) 
	kthread_stop(scand_task);

}



static struct dlm_ls *dlm_find_lockspace_name(char *name, int namelen)

{

	struct dlm_ls *ls;



	spin_lock(&lslist_lock);



	list_for_each_entry(ls, &lslist, ls_list) {

		if (ls->ls_namelen == namelen &&

		    memcmp(ls->ls_name, name, namelen) == 0)

			goto out;

	}

	ls = NULL;

 out:

	spin_unlock(&lslist_lock);

	return ls;

}



struct dlm_ls *dlm_find_lockspace_global(uint32_t id)

{

	struct dlm_ls *ls;
@@ -327,6 +311,7 @@ static void remove_lockspace(struct dlm_ls *ls) 
	for (;;) {

		spin_lock(&lslist_lock);

		if (ls->ls_count == 0) {

			WARN_ON(ls->ls_create_count != 0);

			list_del(&ls->ls_list);

			spin_unlock(&lslist_lock);

			return;
@@ -381,7 +366,7 @@ static int new_lockspace(char *name, int namelen, void **lockspace, 
			 uint32_t flags, int lvblen)

{

	struct dlm_ls *ls;

	int i, size, error = -ENOMEM;

	int i, size, error;

	int do_unreg = 0;



	if (namelen > DLM_LOCKSPACE_LEN)
@@ -393,12 +378,32 @@ static int new_lockspace(char *name, int namelen, void **lockspace, 
	if (!try_module_get(THIS_MODULE))

		return -EINVAL;



	ls = dlm_find_lockspace_name(name, namelen);

	if (ls) {

		*lockspace = ls;

	error = 0;



	spin_lock(&lslist_lock);

	list_for_each_entry(ls, &lslist, ls_list) {

		WARN_ON(ls->ls_create_count <= 0);

		if (ls->ls_namelen != namelen)

			continue;

		if (memcmp(ls->ls_name, name, namelen))

			continue;

		if (flags & DLM_LSFL_NEWEXCL) {

			error = -EEXIST;

			break;

		}

		ls->ls_create_count++;

		module_put(THIS_MODULE);

		return -EEXIST;

		error = 1; /* not an error, return 0 */

		break;

	}

	spin_unlock(&lslist_lock);



	if (error < 0)

		goto out;

	if (error)

		goto ret_zero;



	error = -ENOMEM;



	ls = kzalloc(sizeof(struct dlm_ls) + namelen, GFP_KERNEL);

	if (!ls)
@@ -418,8 +423,9 @@ static int new_lockspace(char *name, int namelen, void **lockspace, 
		ls->ls_allocation = GFP_KERNEL;



	/* ls_exflags are forced to match among nodes, and we don't

	   need to require all nodes to have TIMEWARN or FS set */

	ls->ls_exflags = (flags & ~(DLM_LSFL_TIMEWARN | DLM_LSFL_FS));

	   need to require all nodes to have some flags set */

	ls->ls_exflags = (flags & ~(DLM_LSFL_TIMEWARN | DLM_LSFL_FS |

				    DLM_LSFL_NEWEXCL));



	size = dlm_config.ci_rsbtbl_size;

	ls->ls_rsbtbl_size = size;
@@ -510,6 +516,7 @@ static int new_lockspace(char *name, int namelen, void **lockspace, 
	down_write(&ls->ls_in_recovery);



	spin_lock(&lslist_lock);

	ls->ls_create_count = 1;

	list_add(&ls->ls_list, &lslist);

	spin_unlock(&lslist_lock);
@@ -548,7 +555,7 @@ static int new_lockspace(char *name, int namelen, void **lockspace, 
	dlm_create_debug_file(ls);



	log_debug(ls, "join complete");



 ret_zero:

	*lockspace = ls;

	return 0;
@@ -635,11 +642,32 @@ static int release_lockspace(struct dlm_ls *ls, int force) 
	struct dlm_lkb *lkb;

	struct dlm_rsb *rsb;

	struct list_head *head;

	int i;

	int busy = lockspace_busy(ls);

	int i, busy, rv;



	busy = lockspace_busy(ls);



	spin_lock(&lslist_lock);

	if (ls->ls_create_count == 1) {

		if (busy > force)

		return -EBUSY;

			rv = -EBUSY;

		else {

			/* remove_lockspace takes ls off lslist */

			ls->ls_create_count = 0;

			rv = 0;

		}

	} else if (ls->ls_create_count > 1) {

		rv = --ls->ls_create_count;

	} else {

		rv = -EINVAL;

	}

	spin_unlock(&lslist_lock);



	if (rv) {

		log_debug(ls, "release_lockspace no remove %d", rv);

		return rv;

	}



	dlm_device_deregister(ls);



	if (force < 3)

		do_uevent(ls, 0);
@@ -720,15 +748,10 @@ static int release_lockspace(struct dlm_ls *ls, int force) 
	dlm_clear_members(ls);

	dlm_clear_members_gone(ls);

	kfree(ls->ls_node_array);

	log_debug(ls, "release_lockspace final free");

	kobject_put(&ls->ls_kobj);

	/* The ls structure will be freed when the kobject is done with */



	mutex_lock(&ls_lock);

	ls_count--;

	if (!ls_count)

		threads_stop();

	mutex_unlock(&ls_lock);



	module_put(THIS_MODULE);

	return 0;

}
@@ -750,11 +773,21 @@ static int release_lockspace(struct dlm_ls *ls, int force) 
int dlm_release_lockspace(void *lockspace, int force)

{

	struct dlm_ls *ls;

	int error;



	ls = dlm_find_lockspace_local(lockspace);

	if (!ls)

		return -EINVAL;

	dlm_put_lockspace(ls);

	return release_lockspace(ls, force);



	mutex_lock(&ls_lock);

	error = release_lockspace(ls, force);

	if (!error)

		ls_count--;

	else if (!ls_count)

		threads_stop();

	mutex_unlock(&ls_lock);



	return error;

}

fs/dlm/user.c

+33 −21
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2006-2007 Red Hat, Inc.  All rights reserved.

 * Copyright (C) 2006-2008 Red Hat, Inc.  All rights reserved.

 *

 * This copyrighted material is made available to anyone wishing to use,

 * modify, copy, or redistribute it subject to the terms and conditions
@@ -340,10 +340,15 @@ static int device_user_deadlock(struct dlm_user_proc *proc, 
	return error;

}



static int create_misc_device(struct dlm_ls *ls, char *name)

static int dlm_device_register(struct dlm_ls *ls, char *name)

{

	int error, len;



	/* The device is already registered.  This happens when the

	   lockspace is created multiple times from userspace. */

	if (ls->ls_device.name)

		return 0;



	error = -ENOMEM;

	len = strlen(name) + strlen(name_prefix) + 2;

	ls->ls_device.name = kzalloc(len, GFP_KERNEL);
@@ -363,6 +368,22 @@ fail: 
	return error;

}



int dlm_device_deregister(struct dlm_ls *ls)

{

	int error;



	/* The device is not registered.  This happens when the lockspace

	   was never used from userspace, or when device_create_lockspace()

	   calls dlm_release_lockspace() after the register fails. */

	if (!ls->ls_device.name)

		return 0;



	error = misc_deregister(&ls->ls_device);

	if (!error)

		kfree(ls->ls_device.name);

	return error;

}



static int device_user_purge(struct dlm_user_proc *proc,

			     struct dlm_purge_params *params)

{
@@ -397,7 +418,7 @@ static int device_create_lockspace(struct dlm_lspace_params *params) 
	if (!ls)

		return -ENOENT;



	error = create_misc_device(ls, params->name);

	error = dlm_device_register(ls, params->name);

	dlm_put_lockspace(ls);



	if (error)
@@ -421,31 +442,22 @@ static int device_remove_lockspace(struct dlm_lspace_params *params) 
	if (!ls)

		return -ENOENT;



	/* Deregister the misc device first, so we don't have

	 * a device that's not attached to a lockspace. If

	 * dlm_release_lockspace fails then we can recreate it

	 */

	error = misc_deregister(&ls->ls_device);

	if (error) {

		dlm_put_lockspace(ls);

		goto out;

	}

	kfree(ls->ls_device.name);



	if (params->flags & DLM_USER_LSFLG_FORCEFREE)

		force = 2;



	lockspace = ls->ls_local_handle;

	dlm_put_lockspace(ls);



	/* dlm_release_lockspace waits for references to go to zero,

	   so all processes will need to close their device for the ls

	   before the release will procede */

	/* The final dlm_release_lockspace waits for references to go to

	   zero, so all processes will need to close their device for the

	   ls before the release will proceed.  release also calls the

	   device_deregister above.  Converting a positive return value

	   from release to zero means that userspace won't know when its

	   release was the final one, but it shouldn't need to know. */



	dlm_put_lockspace(ls);

	error = dlm_release_lockspace(lockspace, force);

	if (error)

		create_misc_device(ls, ls->ls_name);

 out:

	if (error > 0)

		error = 0;

	return error;

}

fs/dlm/user.h

+2 −1
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.

 * Copyright (C) 2006-2008 Red Hat, Inc.  All rights reserved.

 *

 * This copyrighted material is made available to anyone wishing to use,

 * modify, copy, or redistribute it subject to the terms and conditions
@@ -12,5 +12,6 @@ 
void dlm_user_add_ast(struct dlm_lkb *lkb, int type);

int dlm_user_init(void);

void dlm_user_exit(void);

int dlm_device_deregister(struct dlm_ls *ls);



#endif

fs/gfs2/locking/dlm/mount.c

+2 −1
Original line number Diff line number Diff line
@@ -144,7 +144,8 @@ static int gdlm_mount(char *table_name, char *host_data, 


	error = dlm_new_lockspace(ls->fsname, strlen(ls->fsname),

				  &ls->dlm_lockspace,

				  DLM_LSFL_FS | (nodir ? DLM_LSFL_NODIR : 0),

				  DLM_LSFL_FS | DLM_LSFL_NEWEXCL |

				  (nodir ? DLM_LSFL_NODIR : 0),

				  GDLM_LVB_SIZE);

	if (error) {

		log_error("dlm_new_lockspace error %d", error);