Merge branch 'for-2.6.28' of git://linux-nfs.org/~bfields/linux

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

diff --git a/fs/dlm/user.c b/fs/dlm/user.c
index 6542110c0da4cf98fa5d8ce76daad4c8474a6b77..b3832c67194af2573849df32b337d2096994a082 100644 (file)
--- a/fs/dlm/user.c
+++ b/fs/dlm/user.c
@@ -15,7 +15,6 @@
 #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>
 
@@ -27,6 +26,8 @@
 
 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
 
@@ -635,17 +636,13 @@ static int device_open(struct inode *inode, struct file *file)
        struct dlm_user_proc *proc;
        struct dlm_ls *ls;
 
-       lock_kernel();
        ls = dlm_find_lockspace_device(iminor(inode));
-       if (!ls) {
-               unlock_kernel();
+       if (!ls)
                return -ENOENT;
-       }
 
        proc = kzalloc(sizeof(struct dlm_user_proc), GFP_KERNEL);
        if (!proc) {
                dlm_put_lockspace(ls);
-               unlock_kernel();
                return -ENOMEM;
        }
 
@@ -657,7 +654,6 @@ static int device_open(struct inode *inode, struct file *file)
        spin_lock_init(&proc->locks_spin);
        init_waitqueue_head(&proc->wait);
        file->private_data = proc;
-       unlock_kernel();
 
        return 0;
 }
@@ -890,9 +886,28 @@ 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();
        file->private_data = NULL;
        return 0;
 }
@@ -902,6 +917,20 @@ 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 +954,42 @@ 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);
 }