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>
diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
index 499e167..56eae4e 100644
--- a/fs/dlm/lockspace.c
+++ b/fs/dlm/lockspace.c
@@ -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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
dlm_create_debug_file(ls);
log_debug(ls, "join complete");
-
+ ret_zero:
*lockspace = ls;
return 0;
@@ -635,11 +642,32 @@
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 @@
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 @@
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;
}