/******************************************************************************
*******************************************************************************
**
** 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 "lockspace.h"
#include "member.h"
#include "lowcomms.h"
#include "rcom.h"
#include "config.h"
#include "memory.h"
#include "recover.h"
#include "util.h"
#include "lock.h"
#include "dir.h"
static void put_free_de(struct dlm_ls *ls, struct dlm_direntry *de)
{
spin_lock(&ls->ls_recover_list_lock);
list_add(&de->list, &ls->ls_recover_list);
spin_unlock(&ls->ls_recover_list_lock);
}
static struct dlm_direntry *get_free_de(struct dlm_ls *ls, int len)
{
int found = 0;
struct dlm_direntry *de;
spin_lock(&ls->ls_recover_list_lock);
list_for_each_entry(de, &ls->ls_recover_list, list) {
if (de->length == len) {
list_del(&de->list);
de->master_nodeid = 0;
memset(de->name, 0, len);
found = 1;
break;
}
}
spin_unlock(&ls->ls_recover_list_lock);
if (!found)
de = allocate_direntry(ls, len);
return de;
}
void dlm_clear_free_entries(struct dlm_ls *ls)
{
struct dlm_direntry *de;
spin_lock(&ls->ls_recover_list_lock);
while (!list_empty(&ls->ls_recover_list)) {
de = list_entry(ls->ls_recover_list.next, struct dlm_direntry,
list);
list_del(&de->list);
free_direntry(de);
}
spin_unlock(&ls->ls_recover_list_lock);
}
/*
* We use the upper 16 bits of the hash value to select the directory node.
* Low bits are used for distribution of rsb's among hash buckets on each node.
*
* To give the exact range wanted (0 to num_nodes-1), we apply a modulus of
* num_nodes to the hash value. This value in the desired range is used as an
* offset into the sorted list of nodeid's to give the particular nodeid.
*/
int dlm_hash2nodeid(struct dlm_ls *ls, uint32_t hash)
{
struct list_head *tmp;
struct dlm_member *memb = NULL;
uint32_t node, n = 0;
int nodeid;
if (ls->ls_num_nodes == 1) {
nodeid = dlm_our_nodeid();
goto out;
}
if (ls->ls_node_array) {
node = (hash >> 16) % ls->ls_total_weight;
nodeid = ls->ls_node_array[node];
goto out;
}
/* make_member_array() failed to kmalloc ls_node_array... */
node = (hash >> 16) % ls->ls_num_nodes;
list_for_each(tmp, &ls->ls_nodes) {
if (n++ != node)
continue;
memb = list_entry(tmp, struct dlm_member, list);
break;
}
DLM_ASSERT(memb , printk("num_nodes=%u n=%u node=%u\n",
ls->ls_num_nodes, n, node););
nodeid = memb->nodeid;
out:
return nodeid;
}
int dlm_dir_nodeid(struct dlm_rsb *r)
{
return dlm_hash2nodeid(r->res_ls, r->res_hash);
}
static inline uint32_t dir_hash(struct dlm_ls *ls, char *name, int len)
{
uint32_t val;
val = jhash(name, len, 0);
val &= (ls->ls_dirtbl_size - 1);
return val;
}
static void add_entry_to_hash(struct dlm_ls *ls, struct dlm_direntry *de)
{
uint32_t bucket;
bucket = dir_hash(ls, de->name, de->length);
list_add_tail(&de->list, &ls->ls_dirtbl[bucket].list);
}
static struct dlm_direntry *search_bucket(struct dlm_ls *ls, char *name,
int namelen, uint32_t bucket)
{
struct dlm_direntry *de;
list_for_each_entry(de, &ls->ls_dirtbl[bucket].list, list) {
if (de->length == namelen && !memcmp(name, de->name, namelen))
goto out;
}
de = NULL;
out:
return de;
}
void dlm_dir_remove_entry(struct dlm_ls *ls, int nodeid, char *name, int namelen)
{
struct dlm_direntry *de;
uint32_t bucket;
bucket = dir_hash(ls, name, namelen);
write_lock(&ls->ls_dirtbl[bucket].lock);
de = search_bucket(ls, name, namelen, bucket);
if (!de) {
log_error(ls, "remove fr %u none", nodeid);
goto out;
}
if (de->master_nodeid != nodeid) {
log_error(ls, "remove fr %u ID %u", nodeid, de->master_nodeid);
goto out;
}
list_del(&de->list);
free_direntry(de);
out:
write_unlock(&ls->ls_dirtbl[bucket].lock);
}
void dlm_dir_clear(struct dlm_ls *ls)
{
struct list_head *head;
struct dlm_direntry *de;
int i;
DLM_ASSERT(list_empty(&ls->ls_recover_list), );
for (i = 0; i < ls->ls_dirtbl_size; i++) {
write_lock(&ls->ls_dirtbl[i].lock);
head = &ls->ls_dirtbl[i].list;
while (!list_empty(head)) {
de = list_entry(head->next, struct dlm_direntry, list);
list_del(&de->list);
put_free_de(ls, de);
}
write_unlock(&ls->ls_dirtbl[i].lock);
}
}
int dlm_recover_directory(struct dlm_ls *ls)
{
struct dlm_member *memb;
struct dlm_direntry *de;
char *b, *last_name = NULL;
int error = -ENOMEM, last_len, count = 0;
uint16_t namelen;
log_debug(ls, "dlm_recover_directory");
if (dlm_no_directory(ls))
goto out_status;
dlm_dir_clear(ls);
last_name = kmalloc(DLM_RESNAME_MAXLEN, GFP_KERNEL);
if (!last_name)
goto out;
list_for_each_entry(memb, &ls->ls_nodes, list) {
memset(last_name, 0, DLM_RESNAME_MAXLEN);
last_len = 0;
for (;;) {
error = dlm_recovery_stopped(ls);
if (error)
goto out_free;
error = dlm_rcom_names(ls, memb->nodeid,
last_name, last_len);
if (error)
goto out_free;
schedule();
/*
* pick namelen/name pairs out of received buffer
*/
b = ls->ls_recover_buf + sizeof(struct dlm_rcom);
for (;;) {
memcpy(&namelen, b, sizeof(uint16_t));
namelen = be16_to_cpu(namelen);
b += sizeof(uint16_t);
/* namelen of 0xFFFFF marks end of names for
this node; namelen of 0 marks end of the
buffer */
if (namelen == 0xFFFF)
goto done;
if (!namelen)
break;
error = -ENOMEM;
de = get_free_de(ls, namelen);
if (!de)
goto out_free;
de->master_nodeid = memb->nodeid;
de->length = namelen;
last_len = namelen;
memcpy(de->name, b, namelen);
memcpy(last_name, b, namelen);
b += namelen;
add_entry_to_hash(ls, de);
count++;
}
}
done:
;
}
out_status:
error = 0;
dlm_set_recover_status(ls, DLM_RS_DIR);
log_debug(ls, "dlm_recover_directory %d entries", count);
out_free:
kfree(last_name);
out:
dlm_clear_free_entries(ls);
return error;
}
static int get_entry(struct dlm_ls *ls, int nodeid, char *name,
int namelen, int *r_nodeid)
{
struct dlm_direntry *de, *tmp;
uint32_t bucket;
bucket = dir_hash(ls, name, namelen);
write_lock(&ls->ls_dirtbl[bucket].lock);
de = search_bucket(ls, name, namelen, bucket);
if (de) {
*r_nodeid = de->master_nodeid;
write_unlock(&ls->ls_dirtbl[bucket].lock);
if (*r_nodeid == nodeid)
return -EEXIST;
return 0;
}
write_unlock(&ls->ls_dirtbl[bucket].lock);
de = allocate_direntry(ls, namelen);
if (!de)
return -ENOMEM;
de->master_nodeid = nodeid;
de->length = namelen;
memcpy(de->name, name, namelen);
write_lock(&ls->ls_dirtbl[bucket].lock);
tmp = search_bucket(ls, name, namelen, bucket);
if (tmp) {
free_direntry(de);
de = tmp;
} else {
list_add_tail(&de->list, &ls->ls_dirtbl[bucket].list);
}
*r_nodeid = de->master_nodeid;
write_unlock(&ls->ls_dirtbl[bucket].lock);
return 0;
}
int dlm_dir_lookup(struct dlm_ls *ls, int nodeid, char *name, int namelen,
int *r_nodeid)
{
return get_entry(ls, nodeid, name, namelen, r_nodeid);
}
/* Copy the names of master rsb's into the buffer provided.
Only select names whose dir node is the given nodeid. */
void dlm_copy_master_names(struct dlm_ls *ls, char *inbuf, int inlen,
char *outbuf, int outlen, int nodeid)
{
struct list_head *list;
struct dlm_rsb *start_r = NULL, *r = NULL;
int offset = 0, start_namelen, error, dir_nodeid;
char *start_name;
uint16_t be_namelen;
/*
* Find the rsb where we left off (or start again)
*/
start_namelen = inlen;
start_name = inbuf;
if (start_namelen > 1) {
/*
* We could also use a find_rsb_root() function here that
* searched the ls_root_list.
*/
error = dlm_find_rsb(ls, start_name, start_namelen, R_MASTER,
&start_r);
DLM_ASSERT(!error && start_r,
printk("error %d\n", error););
DLM_ASSERT(!list_empty(&start_r->res_root_list),
dlm_print_rsb(start_r););
dlm_put_rsb(start_r);
}
/*
* Send rsb names for rsb's we're master of and whose directory node
* matches the requesting node.
*/
down_read(&ls->ls_root_sem);
if (start_r)
list = start_r->res_root_list.next;
else
list = ls->ls_root_list.next;
for (offset = 0; list != &ls->ls_root_list; list = list->next) {
r = list_entry(list, struct dlm_rsb, res_root_list);
if (r->res_nodeid)
continue;
dir_nodeid = dlm_dir_nodeid(r);
if (dir_nodeid != nodeid)
continue;
/*
* The block ends when we can't fit the following in the
* remaining buffer space:
* namelen (uint16_t) +
* name (r->res_length) +
* end-of-block record 0x0000 (uint16_t)
*/
if (offset + sizeof(uint16_t)*2 + r->res_length > outlen) {
/* Write end-of-block record */
be_namelen = 0;
memcpy(outbuf + offset, &be_namelen, sizeof(uint16_t));
offset += sizeof(uint16_t);
goto out;
}
be_namelen = cpu_to_be16(r->res_length);
memcpy(outbuf + offset, &be_namelen, sizeof(uint16_t));
offset += sizeof(uint16_t);
memcpy(outbuf + offset, r->res_name, r->res_length);
offset += r->res_length;
}
/*
* If we've reached the end of the list (and there's room) write a
* terminating record.
*/
if ((list == &ls->ls_root_list) &&
(offset + sizeof(uint16_t) <= outlen)) {
be_namelen = 0xFFFF;
memcpy(outbuf + offset, &be_namelen, sizeof(uint16_t));
offset += sizeof(uint16_t);
}
out:
up_read(&ls->ls_root_sem);
}
