[DLM] The core of the DLM for GFS2/CLVM

This is the core of the distributed lock manager which is required
to use GFS2 as a cluster filesystem. It is also used by CLVM and
can be used as a standalone lock manager independantly of either
of these two projects.

It implements VAX-style locking modes.

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

1 files changed, 310 insertions, 0 deletions

diff --git a/fs/dlm/debug_fs.c b/fs/dlm/debug_fs.c
new file mode 100644
index 000000000000..98b49a1ece47
--- /dev/null
+++ b/fs/dlm/debug_fs.c
@@ -0,0 +1,310 @@
+/******************************************************************************
+*******************************************************************************
+**
+**  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/pagemap.h>
+#include <linux/seq_file.h>
+#include <linux/module.h>
+#include <linux/ctype.h>
+#include <linux/debugfs.h>
+
+#include "dlm_internal.h"
+
+
+static struct dentry *dlm_root;
+
+struct rsb_iter {
+        int entry;
+        struct dlm_ls *ls;
+        struct list_head *next;
+        struct dlm_rsb *rsb;
+};
+
+static char *print_lockmode(int mode)
+{
+        switch (mode) {
+        case DLM_LOCK_IV:
+                return "--";
+        case DLM_LOCK_NL:
+                return "NL";
+        case DLM_LOCK_CR:
+                return "CR";
+        case DLM_LOCK_CW:
+                return "CW";
+        case DLM_LOCK_PR:
+                return "PR";
+        case DLM_LOCK_PW:
+                return "PW";
+        case DLM_LOCK_EX:
+                return "EX";
+        default:
+                return "??";
+        }
+}
+
+static void print_lock(struct seq_file *s, struct dlm_lkb *lkb,
+                       struct dlm_rsb *res)
+{
+        seq_printf(s, "%08x %s", lkb->lkb_id, print_lockmode(lkb->lkb_grmode));
+
+        if (lkb->lkb_status == DLM_LKSTS_CONVERT
+            || lkb->lkb_status == DLM_LKSTS_WAITING)
+                seq_printf(s, " (%s)", print_lockmode(lkb->lkb_rqmode));
+
+        if (lkb->lkb_range) {
+                /* FIXME: this warns on Alpha */
+                if (lkb->lkb_status == DLM_LKSTS_CONVERT
+                    || lkb->lkb_status == DLM_LKSTS_GRANTED)
+                        seq_printf(s, " %" PRIx64 "-%" PRIx64,
+                                   lkb->lkb_range[GR_RANGE_START],
+                                   lkb->lkb_range[GR_RANGE_END]);
+                if (lkb->lkb_status == DLM_LKSTS_CONVERT
+                    || lkb->lkb_status == DLM_LKSTS_WAITING)
+                        seq_printf(s, " (%" PRIx64 "-%" PRIx64 ")",
+                                   lkb->lkb_range[RQ_RANGE_START],
+                                   lkb->lkb_range[RQ_RANGE_END]);
+        }
+
+        if (lkb->lkb_nodeid) {
+                if (lkb->lkb_nodeid != res->res_nodeid)
+                        seq_printf(s, " Remote: %3d %08x", lkb->lkb_nodeid,
+                                   lkb->lkb_remid);
+                else
+                        seq_printf(s, " Master:     %08x", lkb->lkb_remid);
+        }
+
+        if (lkb->lkb_wait_type)
+                seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
+
+        seq_printf(s, "\n");
+}
+
+static int print_resource(struct dlm_rsb *res, struct seq_file *s)
+{
+        struct dlm_lkb *lkb;
+        int i, lvblen = res->res_ls->ls_lvblen;
+
+        seq_printf(s, "\nResource %p Name (len=%d) \"", res, res->res_length);
+        for (i = 0; i < res->res_length; i++) {
+                if (isprint(res->res_name[i]))
+                        seq_printf(s, "%c", res->res_name[i]);
+                else
+                        seq_printf(s, "%c", '.');
+        }
+        if (res->res_nodeid > 0)
+                seq_printf(s, "\"  \nLocal Copy, Master is node %d\n",
+                           res->res_nodeid);
+        else if (res->res_nodeid == 0)
+                seq_printf(s, "\"  \nMaster Copy\n");
+        else if (res->res_nodeid == -1)
+                seq_printf(s, "\"  \nLooking up master (lkid %x)\n",
+                           res->res_first_lkid);
+        else
+                seq_printf(s, "\"  \nInvalid master %d\n", res->res_nodeid);
+
+        /* Print the LVB: */
+        if (res->res_lvbptr) {
+                seq_printf(s, "LVB: ");
+                for (i = 0; i < lvblen; i++) {
+                        if (i == lvblen / 2)
+                                seq_printf(s, "\n     ");
+                        seq_printf(s, "%02x ",
+                                   (unsigned char) res->res_lvbptr[i]);
+                }
+                if (rsb_flag(res, RSB_VALNOTVALID))
+                        seq_printf(s, " (INVALID)");
+                seq_printf(s, "\n");
+        }
+
+        /* Print the locks attached to this resource */
+        seq_printf(s, "Granted Queue\n");
+        list_for_each_entry(lkb, &res->res_grantqueue, lkb_statequeue)
+                print_lock(s, lkb, res);
+
+        seq_printf(s, "Conversion Queue\n");
+        list_for_each_entry(lkb, &res->res_convertqueue, lkb_statequeue)
+                print_lock(s, lkb, res);
+
+        seq_printf(s, "Waiting Queue\n");
+        list_for_each_entry(lkb, &res->res_waitqueue, lkb_statequeue)
+                print_lock(s, lkb, res);
+
+        return 0;
+}
+
+static int rsb_iter_next(struct rsb_iter *ri)
+{
+        struct dlm_ls *ls = ri->ls;
+        int i;
+
+        if (!ri->next) {
+ top:
+                /* Find the next non-empty hash bucket */
+                for (i = ri->entry; i < ls->ls_rsbtbl_size; i++) {
+                        read_lock(&ls->ls_rsbtbl[i].lock);
+                        if (!list_empty(&ls->ls_rsbtbl[i].list)) {
+                                ri->next = ls->ls_rsbtbl[i].list.next;
+                                read_unlock(&ls->ls_rsbtbl[i].lock);
+                                break;
+                        }
+                        read_unlock(&ls->ls_rsbtbl[i].lock);
+                }
+                ri->entry = i;
+
+                if (ri->entry >= ls->ls_rsbtbl_size)
+                        return 1;
+        } else {
+                i = ri->entry;
+                read_lock(&ls->ls_rsbtbl[i].lock);
+                ri->next = ri->next->next;
+                if (ri->next->next == ls->ls_rsbtbl[i].list.next) {
+                        /* End of list - move to next bucket */
+                        ri->next = NULL;
+                        ri->entry++;
+                        read_unlock(&ls->ls_rsbtbl[i].lock);
+                        goto top;
+                }
+                read_unlock(&ls->ls_rsbtbl[i].lock);
+        }
+        ri->rsb = list_entry(ri->next, struct dlm_rsb, res_hashchain);
+
+        return 0;
+}
+
+static void rsb_iter_free(struct rsb_iter *ri)
+{
+        kfree(ri);
+}
+
+static struct rsb_iter *rsb_iter_init(struct dlm_ls *ls)
+{
+        struct rsb_iter *ri;
+
+        ri = kmalloc(sizeof *ri, GFP_KERNEL);
+        if (!ri)
+                return NULL;
+
+        ri->ls = ls;
+        ri->entry = 0;
+        ri->next = NULL;
+
+        if (rsb_iter_next(ri)) {
+                rsb_iter_free(ri);
+                return NULL;
+        }
+
+        return ri;
+}
+
+static void *seq_start(struct seq_file *file, loff_t *pos)
+{
+        struct rsb_iter *ri;
+        loff_t n = *pos;
+
+        ri = rsb_iter_init(file->private);
+        if (!ri)
+                return NULL;
+
+        while (n--) {
+                if (rsb_iter_next(ri)) {
+                        rsb_iter_free(ri);
+                        return NULL;
+                }
+        }
+
+        return ri;
+}
+
+static void *seq_next(struct seq_file *file, void *iter_ptr, loff_t *pos)
+{
+        struct rsb_iter *ri = iter_ptr;
+
+        (*pos)++;
+
+        if (rsb_iter_next(ri)) {
+                rsb_iter_free(ri);
+                return NULL;
+        }
+
+        return ri;
+}
+
+static void seq_stop(struct seq_file *file, void *iter_ptr)
+{
+        /* nothing for now */
+}
+
+static int seq_show(struct seq_file *file, void *iter_ptr)
+{
+        struct rsb_iter *ri = iter_ptr;
+
+        print_resource(ri->rsb, file);
+
+        return 0;
+}
+
+static struct seq_operations dlm_seq_ops = {
+        .start = seq_start,
+        .next  = seq_next,
+        .stop  = seq_stop,
+        .show  = seq_show,
+};
+
+static int do_open(struct inode *inode, struct file *file)
+{
+        struct seq_file *seq;
+        int ret;
+
+        ret = seq_open(file, &dlm_seq_ops);
+        if (ret)
+                return ret;
+
+        seq = file->private_data;
+        seq->private = inode->u.generic_ip;
+
+        return 0;
+}
+
+static struct file_operations dlm_fops = {
+        .owner   = THIS_MODULE,
+        .open    = do_open,
+        .read    = seq_read,
+        .llseek  = seq_lseek,
+        .release = seq_release
+};
+
+int dlm_create_debug_file(struct dlm_ls *ls)
+{
+        ls->ls_debug_dentry = debugfs_create_file(ls->ls_name,
+                                                  S_IFREG | S_IRUGO,
+                                                  dlm_root,
+                                                  ls,
+                                                  &dlm_fops);
+        return ls->ls_debug_dentry ? 0 : -ENOMEM;
+}
+
+void dlm_delete_debug_file(struct dlm_ls *ls)
+{
+        if (ls->ls_debug_dentry)
+                debugfs_remove(ls->ls_debug_dentry);
+}
+
+int dlm_register_debugfs(void)
+{
+        dlm_root = debugfs_create_dir("dlm", NULL);
+        return dlm_root ? 0 : -ENOMEM;
+}
+
+void dlm_unregister_debugfs(void)
+{
+        debugfs_remove(dlm_root);
+}
+