[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");
+}
+