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-rw-r--r--fs/dlm/user.c61
1 files changed, 60 insertions, 1 deletions
diff --git a/fs/dlm/user.c b/fs/dlm/user.c
index 6542110c0da4..81627b502a56 100644
--- a/fs/dlm/user.c
+++ b/fs/dlm/user.c
@@ -27,6 +27,8 @@
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
@@ -890,6 +892,26 @@ static unsigned int device_poll(struct file *file, poll_table *wait)
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();
@@ -902,6 +924,20 @@ static int ctl_device_close(struct inode *inode, struct file *file)
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,
@@ -925,19 +961,42 @@ static struct miscdevice ctl_device = {
.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);
}