[GFS2] An update of the GFS2 lock modules

This brings the lock modules uptodate and removes the stray
.mod.c file which accidently got included in the last check in.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 297 insertions, 0 deletions

diff --git a/fs/gfs2/locking/dlm/plock.c b/fs/gfs2/locking/dlm/plock.c
new file mode 100644
index 000000000000..382847205bc1
--- /dev/null
+++ b/fs/gfs2/locking/dlm/plock.c
@@ -0,0 +1,297 @@
+/*
+ * Copyright (C) 2005 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
+ * of the GNU General Public License v.2.
+ */
+
+#include <linux/miscdevice.h>
+#include <linux/lock_dlm_plock.h>
+
+#include "lock_dlm.h"
+
+
+static spinlock_t ops_lock;
+static struct list_head send_list;
+static struct list_head recv_list;
+static wait_queue_head_t send_wq;
+static wait_queue_head_t recv_wq;
+
+struct plock_op {
+	struct list_head list;
+	int done;
+	struct gdlm_plock_info info;
+};
+
+static inline void set_version(struct gdlm_plock_info *info)
+{
+	info->version[0] = GDLM_PLOCK_VERSION_MAJOR;
+	info->version[1] = GDLM_PLOCK_VERSION_MINOR;
+	info->version[2] = GDLM_PLOCK_VERSION_PATCH;
+}
+
+static int check_version(struct gdlm_plock_info *info)
+{
+	if ((GDLM_PLOCK_VERSION_MAJOR != info->version[0]) ||
+	    (GDLM_PLOCK_VERSION_MINOR < info->version[1])) {
+		log_error("plock device version mismatch: "
+			  "kernel (%u.%u.%u), user (%u.%u.%u)",
+			  GDLM_PLOCK_VERSION_MAJOR,
+			  GDLM_PLOCK_VERSION_MINOR,
+			  GDLM_PLOCK_VERSION_PATCH,
+			  info->version[0],
+			  info->version[1],
+			  info->version[2]);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static void send_op(struct plock_op *op)
+{
+	set_version(&op->info);
+	INIT_LIST_HEAD(&op->list);
+	spin_lock(&ops_lock);
+	list_add_tail(&op->list, &send_list);
+	spin_unlock(&ops_lock);
+	wake_up(&send_wq);
+}
+
+int gdlm_plock(lm_lockspace_t *lockspace, struct lm_lockname *name,
+	       struct file *file, int cmd, struct file_lock *fl)
+{
+	struct gdlm_ls *ls = (struct gdlm_ls *) lockspace;
+	struct plock_op *op;
+	int rv;
+
+	op = kzalloc(sizeof(*op), GFP_KERNEL);
+	if (!op)
+		return -ENOMEM;
+
+	op->info.optype		= GDLM_PLOCK_OP_LOCK;
+	op->info.pid		= (uint32_t) fl->fl_owner;
+	op->info.ex		= (fl->fl_type == F_WRLCK);
+	op->info.wait		= IS_SETLKW(cmd);
+	op->info.fsid		= ls->id;
+	op->info.number		= name->ln_number;
+	op->info.start		= fl->fl_start;
+	op->info.end		= fl->fl_end;
+
+	send_op(op);
+	wait_event(recv_wq, (op->done != 0));
+
+	spin_lock(&ops_lock);
+	if (!list_empty(&op->list)) {
+		printk("plock op on list\n");
+		list_del(&op->list);
+	}
+	spin_unlock(&ops_lock);
+
+	rv = op->info.rv;
+
+	if (!rv) {
+		if (posix_lock_file_wait(file, fl) < 0)
+			log_error("gdlm_plock: vfs lock error %x,%llx",
+				  name->ln_type, name->ln_number);
+	}
+
+	kfree(op);
+	return rv;
+}
+
+int gdlm_punlock(lm_lockspace_t *lockspace, struct lm_lockname *name,
+		 struct file *file, struct file_lock *fl)
+{
+	struct gdlm_ls *ls = (struct gdlm_ls *) lockspace;
+	struct plock_op *op;
+	int rv;
+
+	op = kzalloc(sizeof(*op), GFP_KERNEL);
+	if (!op)
+		return -ENOMEM;
+
+	if (posix_lock_file_wait(file, fl) < 0)
+		log_error("gdlm_punlock: vfs unlock error %x,%llx",
+			  name->ln_type, name->ln_number);
+
+	op->info.optype		= GDLM_PLOCK_OP_UNLOCK;
+	op->info.pid		= (uint32_t) fl->fl_owner;
+	op->info.fsid		= ls->id;
+	op->info.number		= name->ln_number;
+	op->info.start		= fl->fl_start;
+	op->info.end		= fl->fl_end;
+
+	send_op(op);
+	wait_event(recv_wq, (op->done != 0));
+
+	spin_lock(&ops_lock);
+	if (!list_empty(&op->list)) {
+		printk("punlock op on list\n");
+		list_del(&op->list);
+	}
+	spin_unlock(&ops_lock);
+
+	rv = op->info.rv;
+
+	kfree(op);
+	return rv;
+}
+
+int gdlm_plock_get(lm_lockspace_t *lockspace, struct lm_lockname *name,
+		   struct file *file, struct file_lock *fl)
+{
+	struct gdlm_ls *ls = (struct gdlm_ls *) lockspace;
+	struct plock_op *op;
+	int rv;
+
+	op = kzalloc(sizeof(*op), GFP_KERNEL);
+	if (!op)
+		return -ENOMEM;
+
+	op->info.optype		= GDLM_PLOCK_OP_GET;
+	op->info.pid		= (uint32_t) fl->fl_owner;
+	op->info.ex		= (fl->fl_type == F_WRLCK);
+	op->info.fsid		= ls->id;
+	op->info.number		= name->ln_number;
+	op->info.start		= fl->fl_start;
+	op->info.end		= fl->fl_end;
+
+	send_op(op);
+	wait_event(recv_wq, (op->done != 0));
+
+	spin_lock(&ops_lock);
+	if (!list_empty(&op->list)) {
+		printk("plock_get op on list\n");
+		list_del(&op->list);
+	}
+	spin_unlock(&ops_lock);
+
+	rv = op->info.rv;
+
+	if (rv == 0)
+		fl->fl_type = F_UNLCK;
+	else if (rv > 0) {
+		fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;
+		fl->fl_pid = op->info.pid;
+		fl->fl_start = op->info.start;
+		fl->fl_end = op->info.end;
+	}
+
+	kfree(op);
+	return rv;
+}
+
+/* a read copies out one plock request from the send list */
+static ssize_t dev_read(struct file *file, char __user *u, size_t count,
+			loff_t *ppos)
+{
+	struct gdlm_plock_info info;
+	struct plock_op *op = NULL;
+
+	if (count < sizeof(info))
+		return -EINVAL;
+
+	spin_lock(&ops_lock);
+	if (!list_empty(&send_list)) {
+		op = list_entry(send_list.next, struct plock_op, list);
+		list_move(&op->list, &recv_list);
+		memcpy(&info, &op->info, sizeof(info));
+	}
+	spin_unlock(&ops_lock);
+
+	if (!op)
+		return -EAGAIN;
+
+	if (copy_to_user(u, &info, sizeof(info)))
+		return -EFAULT;
+	return sizeof(info);
+}
+
+/* a write copies in one plock result that should match a plock_op
+   on the recv list */
+static ssize_t dev_write(struct file *file, const char __user *u, size_t count,
+			 loff_t *ppos)
+{
+	struct gdlm_plock_info info;
+	struct plock_op *op;
+	int found = 0;
+
+	if (count != sizeof(info))
+		return -EINVAL;
+
+	if (copy_from_user(&info, u, sizeof(info)))
+		return -EFAULT;
+
+	if (check_version(&info))
+		return -EINVAL;
+
+	spin_lock(&ops_lock);
+	list_for_each_entry(op, &recv_list, list) {
+		if (op->info.fsid == info.fsid &&
+		    op->info.number == info.number) {
+			list_del_init(&op->list);
+			found = 1;
+			op->done = 1;
+			memcpy(&op->info, &info, sizeof(info));
+			break;
+		}
+	}
+	spin_unlock(&ops_lock);
+
+	if (found)
+		wake_up(&recv_wq);
+	else
+		printk("gdlm dev_write no op %x %llx\n", info.fsid,
+			info.number);
+	return count;
+}
+
+static unsigned int dev_poll(struct file *file, poll_table *wait)
+{
+	poll_wait(file, &send_wq, wait);
+
+	spin_lock(&ops_lock);
+	if (!list_empty(&send_list)) {
+		spin_unlock(&ops_lock);
+		return POLLIN | POLLRDNORM;
+	}
+	spin_unlock(&ops_lock);
+	return 0;
+}
+
+static struct file_operations dev_fops = {
+	.read    = dev_read,
+	.write   = dev_write,
+	.poll    = dev_poll,
+	.owner   = THIS_MODULE
+};
+
+static struct miscdevice plock_dev_misc = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = GDLM_PLOCK_MISC_NAME,
+	.fops = &dev_fops
+};
+
+int gdlm_plock_init(void)
+{
+	int rv;
+
+	spin_lock_init(&ops_lock);
+	INIT_LIST_HEAD(&send_list);
+	INIT_LIST_HEAD(&recv_list);
+	init_waitqueue_head(&send_wq);
+	init_waitqueue_head(&recv_wq);
+
+	rv = misc_register(&plock_dev_misc);
+	if (rv)
+		printk("gdlm_plock_init: misc_register failed %d", rv);
+	return rv;
+}
+
+void gdlm_plock_exit(void)
+{
+	if (misc_deregister(&plock_dev_misc) < 0)
+		printk("gdlm_plock_exit: misc_deregister failed");
+}
+