Commit e7fd4179 authored by David Teigland's avatar David Teigland Committed by Steven Whitehouse

[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: 's avatarDavid Teigland <teigland@redhat.com>
Signed-off-by: 's avatarSteve Whitehouse <swhiteho@redhat.com>
parent e4731420
......@@ -1831,6 +1831,7 @@ source "fs/partitions/Kconfig"
endmenu
source "fs/nls/Kconfig"
source "fs/dlm/Kconfig"
endmenu
......@@ -48,6 +48,7 @@ obj-$(CONFIG_SYSFS) += sysfs/
obj-y += devpts/
obj-$(CONFIG_PROFILING) += dcookies.o
obj-$(CONFIG_DLM) += dlm/
# Do not add any filesystems before this line
obj-$(CONFIG_REISERFS_FS) += reiserfs/
......
menu "Distributed Lock Manager"
depends on INET && EXPERIMENTAL
config DLM
tristate "Distributed Lock Manager (DLM)"
depends on SYSFS
depends on IPV6 || IPV6=n
select IP_SCTP
select CONFIGFS_FS
help
A general purpose distributed lock manager for kernel or userspace
applications.
config DLM_DEVICE
tristate "DLM device for userspace access"
depends on DLM
help
This module creates a misc device through which the dlm lockspace
and locking functions become available to userspace applications
(usually through the libdlm library).
config DLM_DEBUG
bool "DLM debugging"
depends on DLM
help
Under the debugfs mount point, the name of each lockspace will
appear as a file in the "dlm" directory. The output is the
list of resource and locks the local node knows about.
endmenu
obj-$(CONFIG_DLM) += dlm.o
obj-$(CONFIG_DLM_DEVICE) += dlm_device.o
dlm-y := ast.o \
config.o \
dir.o \
lock.o \
lockspace.o \
lowcomms.o \
main.o \
member.o \
memory.o \
midcomms.o \
rcom.o \
recover.o \
recoverd.o \
requestqueue.o \
util.o
dlm-$(CONFIG_DLM_DEBUG) += debug_fs.o
dlm_device-y := device.o
/******************************************************************************
*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
** Copyright (C) 2004-2005 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 "dlm_internal.h"
#include "lock.h"
#include "ast.h"
#define WAKE_ASTS 0
static struct list_head ast_queue;
static spinlock_t ast_queue_lock;
static struct task_struct * astd_task;
static unsigned long astd_wakeflags;
static struct semaphore astd_running;
void dlm_del_ast(struct dlm_lkb *lkb)
{
spin_lock(&ast_queue_lock);
if (lkb->lkb_ast_type & (AST_COMP | AST_BAST))
list_del(&lkb->lkb_astqueue);
spin_unlock(&ast_queue_lock);
}
void dlm_add_ast(struct dlm_lkb *lkb, int type)
{
spin_lock(&ast_queue_lock);
if (!(lkb->lkb_ast_type & (AST_COMP | AST_BAST))) {
kref_get(&lkb->lkb_ref);
list_add_tail(&lkb->lkb_astqueue, &ast_queue);
}
lkb->lkb_ast_type |= type;
spin_unlock(&ast_queue_lock);
set_bit(WAKE_ASTS, &astd_wakeflags);
wake_up_process(astd_task);
}
static void process_asts(void)
{
struct dlm_ls *ls = NULL;
struct dlm_rsb *r = NULL;
struct dlm_lkb *lkb;
void (*cast) (long param);
void (*bast) (long param, int mode);
int type = 0, found, bmode;
for (;;) {
found = FALSE;
spin_lock(&ast_queue_lock);
list_for_each_entry(lkb, &ast_queue, lkb_astqueue) {
r = lkb->lkb_resource;
ls = r->res_ls;
if (dlm_locking_stopped(ls))
continue;
list_del(&lkb->lkb_astqueue);
type = lkb->lkb_ast_type;
lkb->lkb_ast_type = 0;
found = TRUE;
break;
}
spin_unlock(&ast_queue_lock);
if (!found)
break;
cast = lkb->lkb_astaddr;
bast = lkb->lkb_bastaddr;
bmode = lkb->lkb_bastmode;
if ((type & AST_COMP) && cast)
cast(lkb->lkb_astparam);
/* FIXME: Is it safe to look at lkb_grmode here
without doing a lock_rsb() ?
Look at other checks in v1 to avoid basts. */
if ((type & AST_BAST) && bast)
if (!dlm_modes_compat(lkb->lkb_grmode, bmode))
bast(lkb->lkb_astparam, bmode);
/* this removes the reference added by dlm_add_ast
and may result in the lkb being freed */
dlm_put_lkb(lkb);
schedule();
}
}
static inline int no_asts(void)
{
int ret;
spin_lock(&ast_queue_lock);
ret = list_empty(&ast_queue);
spin_unlock(&ast_queue_lock);
return ret;
}
static int dlm_astd(void *data)
{
while (!kthread_should_stop()) {
set_current_state(TASK_INTERRUPTIBLE);
if (!test_bit(WAKE_ASTS, &astd_wakeflags))
schedule();
set_current_state(TASK_RUNNING);
down(&astd_running);
if (test_and_clear_bit(WAKE_ASTS, &astd_wakeflags))
process_asts();
up(&astd_running);
}
return 0;
}
void dlm_astd_wake(void)
{
if (!no_asts()) {
set_bit(WAKE_ASTS, &astd_wakeflags);
wake_up_process(astd_task);
}
}
int dlm_astd_start(void)
{
struct task_struct *p;
int error = 0;
INIT_LIST_HEAD(&ast_queue);
spin_lock_init(&ast_queue_lock);
init_MUTEX(&astd_running);
p = kthread_run(dlm_astd, NULL, "dlm_astd");
if (IS_ERR(p))
error = PTR_ERR(p);
else
astd_task = p;
return error;
}
void dlm_astd_stop(void)
{
kthread_stop(astd_task);
}
void dlm_astd_suspend(void)
{
down(&astd_running);
}
void dlm_astd_resume(void)
{
up(&astd_running);
}
/******************************************************************************
*******************************************************************************
**
** 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.
**
*******************************************************************************
******************************************************************************/
#ifndef __ASTD_DOT_H__
#define __ASTD_DOT_H__
void dlm_add_ast(struct dlm_lkb *lkb, int type);
void dlm_del_ast(struct dlm_lkb *lkb);
void dlm_astd_wake(void);
int dlm_astd_start(void);
void dlm_astd_stop(void);
void dlm_astd_suspend(void);
void dlm_astd_resume(void);
#endif
This diff is collapsed.
/******************************************************************************
*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
** Copyright (C) 2004-2005 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.
**
*******************************************************************************
******************************************************************************/
#ifndef __CONFIG_DOT_H__
#define __CONFIG_DOT_H__
#define DLM_MAX_ADDR_COUNT 3
struct dlm_config_info {
int tcp_port;
int buffer_size;
int rsbtbl_size;
int lkbtbl_size;
int dirtbl_size;
int recover_timer;
int toss_secs;
int scan_secs;
};
extern struct dlm_config_info dlm_config;
int dlm_config_init(void);
void dlm_config_exit(void);
int dlm_node_weight(char *lsname, int nodeid);
int dlm_nodeid_list(char *lsname, int **ids_out);
int dlm_nodeid_to_addr(int nodeid, struct sockaddr_storage *addr);
int dlm_addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid);
int dlm_our_nodeid(void);
int dlm_our_addr(struct sockaddr_storage *addr, int num);
#endif /* __CONFIG_DOT_H__ */
/******************************************************************************
*******************************************************************************
**
** 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);
}
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/******************************************************************************
*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
** Copyright (C) 2004-2005 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.
**
*******************************************************************************
******************************************************************************/
#ifndef __DIR_DOT_H__
#define __DIR_DOT_H__
int dlm_dir_nodeid(struct dlm_rsb *rsb);
int dlm_hash2nodeid(struct dlm_ls *ls, uint32_t hash);
void dlm_dir_remove_entry(struct dlm_ls *ls, int nodeid, char *name, int len);
void dlm_dir_clear(struct dlm_ls *ls);
void dlm_clear_free_entries(struct dlm_ls *ls);
int dlm_recover_directory(struct dlm_ls *ls);
int dlm_dir_lookup(struct dlm_ls *ls, int nodeid, char *name, int namelen,
int *r_nodeid);
void dlm_copy_master_names(struct dlm_ls *ls, char *inbuf, int inlen,
char *outbuf, int outlen, int nodeid);
#endif /* __DIR_DOT_H__ */
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/******************************************************************************
*******************************************************************************
**
** 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.
**
*******************************************************************************
******************************************************************************/
#ifndef __LOCK_DOT_H__
#define __LOCK_DOT_H__
void dlm_print_rsb(struct dlm_rsb *r);
int dlm_receive_message(struct dlm_header *hd, int nodeid, int recovery);
int dlm_modes_compat(int mode1, int mode2);
int dlm_find_rsb(struct dlm_ls *ls, char *name, int namelen,
unsigned int flags, struct dlm_rsb **r_ret);
void dlm_put_rsb(struct dlm_rsb *r);
void dlm_hold_rsb(struct dlm_rsb *r);
int dlm_put_lkb(struct dlm_lkb *lkb);
void dlm_scan_rsbs(struct dlm_ls *ls);
int dlm_purge_locks(struct dlm_ls *ls);
void dlm_purge_mstcpy_locks(struct dlm_rsb *r);
int dlm_grant_after_purge(struct dlm_ls *ls);
int dlm_recover_waiters_post(struct dlm_ls *ls);
void dlm_recover_waiters_pre(struct dlm_ls *ls);
int dlm_recover_master_copy(struct dlm_ls *ls, struct dlm_rcom *rc);
int dlm_recover_process_copy(struct dlm_ls *ls, struct dlm_rcom *rc);
static inline int is_master(struct dlm_rsb *r)
{
return !r->res_nodeid;
}
static inline void lock_rsb(struct dlm_rsb *r)
{
down(&r->res_sem);
}
static inline void unlock_rsb(struct dlm_rsb *r)
{
up(&r->res_sem);
}
#endif
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/******************************************************************************
*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
** Copyright (C) 2004-2005 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.
**
*******************************************************************************
******************************************************************************/
#ifndef __LOCKSPACE_DOT_H__
#define __LOCKSPACE_DOT_H__
int dlm_lockspace_init(void);
void dlm_lockspace_exit(void);
struct dlm_ls *dlm_find_lockspace_global(uint32_t id);
struct dlm_ls *dlm_find_lockspace_local(void *id);
void dlm_put_lockspace(struct dlm_ls *ls);
#endif /* __LOCKSPACE_DOT_H__ */
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/******************************************************************************
*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
** Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.