*******************************************************************************
**
** 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
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;
*******************************************************************************
**
** 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
#include "lock.h"
#include "recover.h"
#include "requestqueue.h"
+#include "user.h"
static int ls_count;
static struct mutex ls_lock;
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;
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;
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)
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)
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;
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);
dlm_create_debug_file(ls);
log_debug(ls, "join complete");
-
+ ret_zero:
*lockspace = ls;
return 0;
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)
+ 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;
+ }
- if (busy > force)
- return -EBUSY;
+ dlm_device_deregister(ls);
if (force < 3)
do_uevent(ls, 0);
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;
}
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;
}
/*
- * 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
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);
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)
{
if (!ls)
return -ENOENT;
- error = create_misc_device(ls, params->name);
+ error = dlm_device_register(ls, params->name);
dlm_put_lockspace(ls);
if (error)
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;
}
/*
- * 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
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
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);
*******************************************************************************
**
** 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
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__
/* 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 {
projects / linux-2.6-omap-h63xx.git / commitdiff