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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: David Teigland <teigland@redhat.com>
This commit is contained in:
David Teigland 2008-08-06 13:30:24 -05:00
parent 4c246edd25
commit 0f8e0d9a31
7 changed files with 117 additions and 65 deletions
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6
fs/dlm/dlm_internal.h
View File

@ -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;

107
fs/dlm/lockspace.c
View File

@ -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;
if (busy > force)
return -EBUSY;
busy = lockspace_busy(ls);
spin_lock(&lslist_lock);
if (ls->ls_create_count == 1) {
if (busy > force)
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;
}

56
fs/dlm/user.c
View File

@ -1,5 +1,5 @@
/*
* 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_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 */
dlm_put_lockspace(ls);
/* 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. */
error = dlm_release_lockspace(lockspace, force);
if (error)
create_misc_device(ls, ls->ls_name);
out:
if (error > 0)
error = 0;
return error;
}

3
fs/dlm/user.h
View File

@ -1,5 +1,5 @@
/*
* 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

3
fs/gfs2/locking/dlm/mount.c
View File

@ -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);

5
include/linux/dlm.h
View File

@ -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
@ -65,9 +65,12 @@ struct dlm_lksb {
char * sb_lvbptr;
};
/* dlm_new_lockspace() flags */
#define DLM_LSFL_NODIR 0x00000001
#define DLM_LSFL_TIMEWARN 0x00000002
#define DLM_LSFL_FS 0x00000004
#define DLM_LSFL_NEWEXCL 0x00000008
#ifdef __KERNEL__

2
include/linux/dlm_device.h
View File

@ -26,7 +26,7 @@
/* Version of the device interface */
#define DLM_DEVICE_VERSION_MAJOR 6
#define DLM_DEVICE_VERSION_MINOR 0
#define DLM_DEVICE_VERSION_PATCH 0
#define DLM_DEVICE_VERSION_PATCH 1
/* struct passed to the lock write */
struct dlm_lock_params {