Import base vinum lkm sources

1 files changed, 137 insertions, 0 deletions

diff --git a/sys/dev/vinum/vinumlock.c b/sys/dev/vinum/vinumlock.c
new file mode 100644
index 0000000..ed69649
--- /dev/null
+++ b/sys/dev/vinum/vinumlock.c
@@ -0,0 +1,137 @@
+/*-
+ * Copyright (c) 1997, 1998
+ *	Nan Yang Computer Services Limited.  All rights reserved.
+ *
+ *  This software is distributed under the so-called ``Berkeley
+ *  License'':
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by Nan Yang Computer
+ *      Services Limited.
+ * 4. Neither the name of the Company nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *  
+ * This software is provided ``as is'', and any express or implied
+ * warranties, including, but not limited to, the implied warranties of
+ * merchantability and fitness for a particular purpose are disclaimed.
+ * In no event shall the company or contributors be liable for any
+ * direct, indirect, incidental, special, exemplary, or consequential
+ * damages (including, but not limited to, procurement of substitute
+ * goods or services; loss of use, data, or profits; or business
+ * interruption) however caused and on any theory of liability, whether
+ * in contract, strict liability, or tort (including negligence or
+ * otherwise) arising in any way out of the use of this software, even if
+ * advised of the possibility of such damage.
+ *
+ * $Id: lock.c,v 1.6 1998/07/28 06:32:57 grog Exp grog $
+ */
+
+#define REALLYKERNEL
+#include "vinumhdr.h"
+
+/* Lock routines.  Currently, we lock either an individual volume
+ * or the global configuration.  I don't think tsleep and
+ * wakeup are SMP safe. FIXME XXX */
+
+/* Lock a volume, wait if it's in use */
+int 
+lockvol(struct volume *vol)
+{
+    int error;
+
+    while ((vol->flags & VF_LOCKED) != 0) {
+	vol->flags |= VF_LOCKING;
+	/* It would seem to make more sense to sleep on
+	 * the address 'vol'.  Unfortuntaly we can't
+	 * guarantee that this address won't change due to
+	 * table expansion.  The address we choose won't change. */
+	if ((error = tsleep(&vinum_conf.volume + vol->devno,
+		    PRIBIO | PCATCH,
+		    "volock",
+		    0)) != 0)
+	    return error;
+    }
+    vol->flags |= VF_LOCKED;
+    return 0;
+}
+
+/* Unlock a volume and let the next one at it */
+void 
+unlockvol(struct volume *vol)
+{
+    vol->flags &= ~VF_LOCKED;
+    if ((vol->flags & VF_LOCKING) != 0) {
+	vol->flags &= ~VF_LOCKING;
+	wakeup(&vinum_conf.volume + vol->devno);
+    }
+}
+
+/* Lock a plex, wait if it's in use */
+int 
+lockplex(struct plex *plex)
+{
+    int error;
+
+    while ((plex->flags & VF_LOCKED) != 0) {
+	plex->flags |= VF_LOCKING;
+	/* It would seem to make more sense to sleep on
+	 * the address 'plex'.  Unfortuntaly we can't
+	 * guarantee that this address won't change due to
+	 * table expansion.  The address we choose won't change. */
+	if ((error = tsleep(&vinum_conf.plex + plex->sdnos[0],
+		    PRIBIO | PCATCH,
+		    "plexlk",
+		    0)) != 0)
+	    return error;
+    }
+    plex->flags |= VF_LOCKED;
+    return 0;
+}
+
+/* Unlock a plex and let the next one at it */
+void 
+unlockplex(struct plex *plex)
+{
+    plex->flags &= ~VF_LOCKED;
+    if ((plex->flags & VF_LOCKING) != 0) {
+	plex->flags &= ~VF_LOCKING;
+	wakeup(&vinum_conf.plex + plex->plexno);
+    }
+}
+
+
+/* Get a lock for the global config, wait if it's not available */
+int 
+lock_config(void)
+{
+    int error;
+
+    while ((vinum_conf.flags & VF_LOCKED) != 0) {
+	vinum_conf.flags |= VF_LOCKING;
+	if ((error = tsleep(&vinum_conf, PRIBIO | PCATCH, "vincfg", 0)) != 0)
+	    return error;
+    }
+    vinum_conf.flags |= VF_LOCKED;
+    return 0;
+}
+
+/* Unlock and wake up any waiters  */
+void 
+unlock_config(void)
+{
+    vinum_conf.flags &= ~VF_LOCKED;
+    if ((vinum_conf.flags & VF_LOCKING) != 0) {
+	vinum_conf.flags &= ~VF_LOCKING;
+	wakeup(&vinum_conf);
+    }
+}