e7fd41792f
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>
311 lines
6.7 KiB
C
311 lines
6.7 KiB
C
/******************************************************************************
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*******************************************************************************
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**
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** Copyright (C) 2005 Red Hat, Inc. All rights reserved.
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**
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** This copyrighted material is made available to anyone wishing to use,
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** modify, copy, or redistribute it subject to the terms and conditions
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** of the GNU General Public License v.2.
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**
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*******************************************************************************
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******************************************************************************/
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#include <linux/pagemap.h>
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#include <linux/seq_file.h>
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#include <linux/module.h>
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#include <linux/ctype.h>
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#include <linux/debugfs.h>
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#include "dlm_internal.h"
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static struct dentry *dlm_root;
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struct rsb_iter {
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int entry;
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struct dlm_ls *ls;
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struct list_head *next;
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struct dlm_rsb *rsb;
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};
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static char *print_lockmode(int mode)
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{
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switch (mode) {
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case DLM_LOCK_IV:
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return "--";
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case DLM_LOCK_NL:
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return "NL";
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case DLM_LOCK_CR:
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return "CR";
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case DLM_LOCK_CW:
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return "CW";
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case DLM_LOCK_PR:
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return "PR";
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case DLM_LOCK_PW:
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return "PW";
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case DLM_LOCK_EX:
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return "EX";
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default:
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return "??";
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}
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}
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static void print_lock(struct seq_file *s, struct dlm_lkb *lkb,
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struct dlm_rsb *res)
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{
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seq_printf(s, "%08x %s", lkb->lkb_id, print_lockmode(lkb->lkb_grmode));
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if (lkb->lkb_status == DLM_LKSTS_CONVERT
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|| lkb->lkb_status == DLM_LKSTS_WAITING)
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seq_printf(s, " (%s)", print_lockmode(lkb->lkb_rqmode));
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if (lkb->lkb_range) {
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/* FIXME: this warns on Alpha */
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if (lkb->lkb_status == DLM_LKSTS_CONVERT
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|| lkb->lkb_status == DLM_LKSTS_GRANTED)
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seq_printf(s, " %" PRIx64 "-%" PRIx64,
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lkb->lkb_range[GR_RANGE_START],
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lkb->lkb_range[GR_RANGE_END]);
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if (lkb->lkb_status == DLM_LKSTS_CONVERT
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|| lkb->lkb_status == DLM_LKSTS_WAITING)
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seq_printf(s, " (%" PRIx64 "-%" PRIx64 ")",
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lkb->lkb_range[RQ_RANGE_START],
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lkb->lkb_range[RQ_RANGE_END]);
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}
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if (lkb->lkb_nodeid) {
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if (lkb->lkb_nodeid != res->res_nodeid)
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seq_printf(s, " Remote: %3d %08x", lkb->lkb_nodeid,
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lkb->lkb_remid);
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else
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seq_printf(s, " Master: %08x", lkb->lkb_remid);
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}
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if (lkb->lkb_wait_type)
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seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
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seq_printf(s, "\n");
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}
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static int print_resource(struct dlm_rsb *res, struct seq_file *s)
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{
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struct dlm_lkb *lkb;
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int i, lvblen = res->res_ls->ls_lvblen;
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seq_printf(s, "\nResource %p Name (len=%d) \"", res, res->res_length);
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for (i = 0; i < res->res_length; i++) {
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if (isprint(res->res_name[i]))
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seq_printf(s, "%c", res->res_name[i]);
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else
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seq_printf(s, "%c", '.');
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}
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if (res->res_nodeid > 0)
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seq_printf(s, "\" \nLocal Copy, Master is node %d\n",
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res->res_nodeid);
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else if (res->res_nodeid == 0)
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seq_printf(s, "\" \nMaster Copy\n");
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else if (res->res_nodeid == -1)
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seq_printf(s, "\" \nLooking up master (lkid %x)\n",
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res->res_first_lkid);
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else
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seq_printf(s, "\" \nInvalid master %d\n", res->res_nodeid);
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/* Print the LVB: */
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if (res->res_lvbptr) {
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seq_printf(s, "LVB: ");
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for (i = 0; i < lvblen; i++) {
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if (i == lvblen / 2)
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seq_printf(s, "\n ");
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seq_printf(s, "%02x ",
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(unsigned char) res->res_lvbptr[i]);
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}
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if (rsb_flag(res, RSB_VALNOTVALID))
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seq_printf(s, " (INVALID)");
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seq_printf(s, "\n");
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}
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/* Print the locks attached to this resource */
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seq_printf(s, "Granted Queue\n");
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list_for_each_entry(lkb, &res->res_grantqueue, lkb_statequeue)
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print_lock(s, lkb, res);
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seq_printf(s, "Conversion Queue\n");
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list_for_each_entry(lkb, &res->res_convertqueue, lkb_statequeue)
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print_lock(s, lkb, res);
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seq_printf(s, "Waiting Queue\n");
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list_for_each_entry(lkb, &res->res_waitqueue, lkb_statequeue)
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print_lock(s, lkb, res);
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return 0;
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}
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static int rsb_iter_next(struct rsb_iter *ri)
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{
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struct dlm_ls *ls = ri->ls;
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int i;
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if (!ri->next) {
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top:
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/* Find the next non-empty hash bucket */
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for (i = ri->entry; i < ls->ls_rsbtbl_size; i++) {
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read_lock(&ls->ls_rsbtbl[i].lock);
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if (!list_empty(&ls->ls_rsbtbl[i].list)) {
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ri->next = ls->ls_rsbtbl[i].list.next;
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read_unlock(&ls->ls_rsbtbl[i].lock);
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break;
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}
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read_unlock(&ls->ls_rsbtbl[i].lock);
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}
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ri->entry = i;
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if (ri->entry >= ls->ls_rsbtbl_size)
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return 1;
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} else {
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i = ri->entry;
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read_lock(&ls->ls_rsbtbl[i].lock);
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ri->next = ri->next->next;
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if (ri->next->next == ls->ls_rsbtbl[i].list.next) {
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/* End of list - move to next bucket */
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ri->next = NULL;
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ri->entry++;
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read_unlock(&ls->ls_rsbtbl[i].lock);
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goto top;
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}
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read_unlock(&ls->ls_rsbtbl[i].lock);
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}
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ri->rsb = list_entry(ri->next, struct dlm_rsb, res_hashchain);
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return 0;
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}
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static void rsb_iter_free(struct rsb_iter *ri)
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{
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kfree(ri);
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}
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static struct rsb_iter *rsb_iter_init(struct dlm_ls *ls)
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{
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struct rsb_iter *ri;
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ri = kmalloc(sizeof *ri, GFP_KERNEL);
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if (!ri)
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return NULL;
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ri->ls = ls;
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ri->entry = 0;
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ri->next = NULL;
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if (rsb_iter_next(ri)) {
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rsb_iter_free(ri);
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return NULL;
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}
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return ri;
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}
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static void *seq_start(struct seq_file *file, loff_t *pos)
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{
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struct rsb_iter *ri;
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loff_t n = *pos;
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ri = rsb_iter_init(file->private);
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if (!ri)
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return NULL;
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while (n--) {
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if (rsb_iter_next(ri)) {
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rsb_iter_free(ri);
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return NULL;
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}
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}
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return ri;
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}
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static void *seq_next(struct seq_file *file, void *iter_ptr, loff_t *pos)
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{
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struct rsb_iter *ri = iter_ptr;
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(*pos)++;
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if (rsb_iter_next(ri)) {
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rsb_iter_free(ri);
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return NULL;
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}
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return ri;
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}
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static void seq_stop(struct seq_file *file, void *iter_ptr)
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{
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/* nothing for now */
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}
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static int seq_show(struct seq_file *file, void *iter_ptr)
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{
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struct rsb_iter *ri = iter_ptr;
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print_resource(ri->rsb, file);
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return 0;
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}
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static struct seq_operations dlm_seq_ops = {
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.start = seq_start,
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.next = seq_next,
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.stop = seq_stop,
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.show = seq_show,
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};
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static int do_open(struct inode *inode, struct file *file)
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{
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struct seq_file *seq;
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int ret;
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ret = seq_open(file, &dlm_seq_ops);
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if (ret)
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return ret;
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seq = file->private_data;
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seq->private = inode->u.generic_ip;
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return 0;
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}
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static struct file_operations dlm_fops = {
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.owner = THIS_MODULE,
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.open = do_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = seq_release
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};
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int dlm_create_debug_file(struct dlm_ls *ls)
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{
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ls->ls_debug_dentry = debugfs_create_file(ls->ls_name,
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S_IFREG | S_IRUGO,
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dlm_root,
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ls,
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&dlm_fops);
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return ls->ls_debug_dentry ? 0 : -ENOMEM;
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}
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void dlm_delete_debug_file(struct dlm_ls *ls)
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{
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if (ls->ls_debug_dentry)
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debugfs_remove(ls->ls_debug_dentry);
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}
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int dlm_register_debugfs(void)
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{
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dlm_root = debugfs_create_dir("dlm", NULL);
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return dlm_root ? 0 : -ENOMEM;
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}
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void dlm_unregister_debugfs(void)
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{
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debugfs_remove(dlm_root);
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}
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