/*
- * 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
#include <linux/poll.h>
#include <linux/signal.h>
#include <linux/spinlock.h>
+#include <linux/smp_lock.h>
#include <linux/dlm.h>
#include <linux/dlm_device.h>
static const char name_prefix[] = "dlm";
static const struct file_operations device_fops;
+static atomic_t dlm_monitor_opened;
+static int dlm_monitor_unused = 1;
#ifdef CONFIG_COMPAT
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;
}
k32buf = (struct dlm_write_request32 *)kbuf;
kbuf = kmalloc(count + 1 + (sizeof(struct dlm_write_request) -
sizeof(struct dlm_write_request32)), GFP_KERNEL);
- if (!kbuf)
+ if (!kbuf) {
+ kfree(k32buf);
return -ENOMEM;
+ }
if (proc)
set_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags);
/* do we really need this? can a write happen after a close? */
if ((kbuf->cmd == DLM_USER_LOCK || kbuf->cmd == DLM_USER_UNLOCK) &&
- test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))
- return -EINVAL;
+ (proc && test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))) {
+ error = -EINVAL;
+ goto out_free;
+ }
sigfillset(&allsigs);
sigprocmask(SIG_BLOCK, &allsigs, &tmpsig);
struct dlm_user_proc *proc;
struct dlm_ls *ls;
+ lock_kernel();
ls = dlm_find_lockspace_device(iminor(inode));
- if (!ls)
+ if (!ls) {
+ unlock_kernel();
return -ENOENT;
+ }
proc = kzalloc(sizeof(struct dlm_user_proc), GFP_KERNEL);
if (!proc) {
dlm_put_lockspace(ls);
+ unlock_kernel();
return -ENOMEM;
}
spin_lock_init(&proc->locks_spin);
init_waitqueue_head(&proc->wait);
file->private_data = proc;
+ unlock_kernel();
return 0;
}
return 0;
}
+int dlm_user_daemon_available(void)
+{
+ /* dlm_controld hasn't started (or, has started, but not
+ properly populated configfs) */
+
+ if (!dlm_our_nodeid())
+ return 0;
+
+ /* This is to deal with versions of dlm_controld that don't
+ know about the monitor device. We assume that if the
+ dlm_controld was started (above), but the monitor device
+ was never opened, that it's an old version. dlm_controld
+ should open the monitor device before populating configfs. */
+
+ if (dlm_monitor_unused)
+ return 1;
+
+ return atomic_read(&dlm_monitor_opened) ? 1 : 0;
+}
+
static int ctl_device_open(struct inode *inode, struct file *file)
{
+ cycle_kernel_lock();
file->private_data = NULL;
return 0;
}
return 0;
}
+static int monitor_device_open(struct inode *inode, struct file *file)
+{
+ atomic_inc(&dlm_monitor_opened);
+ dlm_monitor_unused = 0;
+ return 0;
+}
+
+static int monitor_device_close(struct inode *inode, struct file *file)
+{
+ if (atomic_dec_and_test(&dlm_monitor_opened))
+ dlm_stop_lockspaces();
+ return 0;
+}
+
static const struct file_operations device_fops = {
.open = device_open,
.release = device_close,
.minor = MISC_DYNAMIC_MINOR,
};
+static const struct file_operations monitor_device_fops = {
+ .open = monitor_device_open,
+ .release = monitor_device_close,
+ .owner = THIS_MODULE,
+};
+
+static struct miscdevice monitor_device = {
+ .name = "dlm-monitor",
+ .fops = &monitor_device_fops,
+ .minor = MISC_DYNAMIC_MINOR,
+};
+
int __init dlm_user_init(void)
{
int error;
+ atomic_set(&dlm_monitor_opened, 0);
+
error = misc_register(&ctl_device);
- if (error)
+ if (error) {
log_print("misc_register failed for control device");
+ goto out;
+ }
+ error = misc_register(&monitor_device);
+ if (error) {
+ log_print("misc_register failed for monitor device");
+ misc_deregister(&ctl_device);
+ }
+ out:
return error;
}
void dlm_user_exit(void)
{
misc_deregister(&ctl_device);
+ misc_deregister(&monitor_device);
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff