dlm: allow multiple lockspace creates

[linux-2.6-omap-h63xx.git] / fs / dlm / lockspace.c

diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
index 499e16759e96fea13329dc05d5408194fa96e4e9..56eae4e4a954f54289501552f2b0be841b5265d6 100644 (file)
--- 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 @@ 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)
+                       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);
@@ -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;
 }