Linux Audio

Check our new training course

Loading...
  1// SPDX-License-Identifier: GPL-2.0-only
  2/******************************************************************************
  3*******************************************************************************
  4**
  5**  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
  6**  Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
  7**
  8**
  9*******************************************************************************
 10******************************************************************************/
 11
 12#include "dlm_internal.h"
 13#include "lockspace.h"
 14#include "member.h"
 15#include "lowcomms.h"
 16#include "rcom.h"
 17#include "config.h"
 18#include "memory.h"
 19#include "recover.h"
 20#include "util.h"
 21#include "lock.h"
 22#include "dir.h"
 23
 24/*
 25 * We use the upper 16 bits of the hash value to select the directory node.
 26 * Low bits are used for distribution of rsb's among hash buckets on each node.
 27 *
 28 * To give the exact range wanted (0 to num_nodes-1), we apply a modulus of
 29 * num_nodes to the hash value.  This value in the desired range is used as an
 30 * offset into the sorted list of nodeid's to give the particular nodeid.
 31 */
 32
 33int dlm_hash2nodeid(struct dlm_ls *ls, uint32_t hash)
 34{
 35	uint32_t node;
 36
 37	if (ls->ls_num_nodes == 1)
 38		return dlm_our_nodeid();
 39	else {
 40		node = (hash >> 16) % ls->ls_total_weight;
 41		return ls->ls_node_array[node];
 42	}
 43}
 44
 45int dlm_dir_nodeid(struct dlm_rsb *r)
 46{
 47	return r->res_dir_nodeid;
 48}
 49
 50void dlm_recover_dir_nodeid(struct dlm_ls *ls)
 51{
 52	struct dlm_rsb *r;
 53
 54	down_read(&ls->ls_root_sem);
 55	list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
 56		r->res_dir_nodeid = dlm_hash2nodeid(ls, r->res_hash);
 57	}
 58	up_read(&ls->ls_root_sem);
 59}
 60
 61int dlm_recover_directory(struct dlm_ls *ls)
 62{
 63	struct dlm_member *memb;
 64	char *b, *last_name = NULL;
 65	int error = -ENOMEM, last_len, nodeid, result;
 66	uint16_t namelen;
 67	unsigned int count = 0, count_match = 0, count_bad = 0, count_add = 0;
 68
 69	log_rinfo(ls, "dlm_recover_directory");
 70
 71	if (dlm_no_directory(ls))
 72		goto out_status;
 73
 74	last_name = kmalloc(DLM_RESNAME_MAXLEN, GFP_NOFS);
 75	if (!last_name)
 76		goto out;
 77
 78	list_for_each_entry(memb, &ls->ls_nodes, list) {
 79		if (memb->nodeid == dlm_our_nodeid())
 80			continue;
 81
 82		memset(last_name, 0, DLM_RESNAME_MAXLEN);
 83		last_len = 0;
 84
 85		for (;;) {
 86			int left;
 87			error = dlm_recovery_stopped(ls);
 88			if (error)
 89				goto out_free;
 90
 91			error = dlm_rcom_names(ls, memb->nodeid,
 92					       last_name, last_len);
 93			if (error)
 94				goto out_free;
 95
 96			cond_resched();
 97
 98			/*
 99			 * pick namelen/name pairs out of received buffer
100			 */
101
102			b = ls->ls_recover_buf->rc_buf;
103			left = ls->ls_recover_buf->rc_header.h_length;
104			left -= sizeof(struct dlm_rcom);
105
106			for (;;) {
107				__be16 v;
108
109				error = -EINVAL;
110				if (left < sizeof(__be16))
111					goto out_free;
112
113				memcpy(&v, b, sizeof(__be16));
114				namelen = be16_to_cpu(v);
115				b += sizeof(__be16);
116				left -= sizeof(__be16);
117
118				/* namelen of 0xFFFFF marks end of names for
119				   this node; namelen of 0 marks end of the
120				   buffer */
121
122				if (namelen == 0xFFFF)
123					goto done;
124				if (!namelen)
125					break;
126
127				if (namelen > left)
128					goto out_free;
129
130				if (namelen > DLM_RESNAME_MAXLEN)
131					goto out_free;
132
133				error = dlm_master_lookup(ls, memb->nodeid,
134							  b, namelen,
135							  DLM_LU_RECOVER_DIR,
136							  &nodeid, &result);
137				if (error) {
138					log_error(ls, "recover_dir lookup %d",
139						  error);
140					goto out_free;
141				}
142
143				/* The name was found in rsbtbl, but the
144				 * master nodeid is different from
145				 * memb->nodeid which says it is the master.
146				 * This should not happen. */
147
148				if (result == DLM_LU_MATCH &&
149				    nodeid != memb->nodeid) {
150					count_bad++;
151					log_error(ls, "recover_dir lookup %d "
152						  "nodeid %d memb %d bad %u",
153						  result, nodeid, memb->nodeid,
154						  count_bad);
155					print_hex_dump_bytes("dlm_recover_dir ",
156							     DUMP_PREFIX_NONE,
157							     b, namelen);
158				}
159
160				/* The name was found in rsbtbl, and the
161				 * master nodeid matches memb->nodeid. */
162
163				if (result == DLM_LU_MATCH &&
164				    nodeid == memb->nodeid) {
165					count_match++;
166				}
167
168				/* The name was not found in rsbtbl and was
169				 * added with memb->nodeid as the master. */
170
171				if (result == DLM_LU_ADD) {
172					count_add++;
173				}
174
175				last_len = namelen;
176				memcpy(last_name, b, namelen);
177				b += namelen;
178				left -= namelen;
179				count++;
180			}
181		}
182	 done:
183		;
184	}
185
186 out_status:
187	error = 0;
188	dlm_set_recover_status(ls, DLM_RS_DIR);
189
190	log_rinfo(ls, "dlm_recover_directory %u in %u new",
191		  count, count_add);
192 out_free:
193	kfree(last_name);
194 out:
195	return error;
196}
197
198static struct dlm_rsb *find_rsb_root(struct dlm_ls *ls, char *name, int len)
199{
200	struct dlm_rsb *r;
201	uint32_t hash, bucket;
202	int rv;
203
204	hash = jhash(name, len, 0);
205	bucket = hash & (ls->ls_rsbtbl_size - 1);
206
207	spin_lock(&ls->ls_rsbtbl[bucket].lock);
208	rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[bucket].keep, name, len, &r);
209	if (rv)
210		rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[bucket].toss,
211					 name, len, &r);
212	spin_unlock(&ls->ls_rsbtbl[bucket].lock);
213
214	if (!rv)
215		return r;
216
217	down_read(&ls->ls_root_sem);
218	list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
219		if (len == r->res_length && !memcmp(name, r->res_name, len)) {
220			up_read(&ls->ls_root_sem);
221			log_debug(ls, "find_rsb_root revert to root_list %s",
222				  r->res_name);
223			return r;
224		}
225	}
226	up_read(&ls->ls_root_sem);
227	return NULL;
228}
229
230/* Find the rsb where we left off (or start again), then send rsb names
231   for rsb's we're master of and whose directory node matches the requesting
232   node.  inbuf is the rsb name last sent, inlen is the name's length */
233
234void dlm_copy_master_names(struct dlm_ls *ls, char *inbuf, int inlen,
235 			   char *outbuf, int outlen, int nodeid)
236{
237	struct list_head *list;
238	struct dlm_rsb *r;
239	int offset = 0, dir_nodeid;
240	__be16 be_namelen;
241
242	down_read(&ls->ls_root_sem);
243
244	if (inlen > 1) {
245		r = find_rsb_root(ls, inbuf, inlen);
246		if (!r) {
247			inbuf[inlen - 1] = '\0';
248			log_error(ls, "copy_master_names from %d start %d %s",
249				  nodeid, inlen, inbuf);
250			goto out;
251		}
252		list = r->res_root_list.next;
253	} else {
254		list = ls->ls_root_list.next;
255	}
256
257	for (offset = 0; list != &ls->ls_root_list; list = list->next) {
258		r = list_entry(list, struct dlm_rsb, res_root_list);
259		if (r->res_nodeid)
260			continue;
261
262		dir_nodeid = dlm_dir_nodeid(r);
263		if (dir_nodeid != nodeid)
264			continue;
265
266		/*
267		 * The block ends when we can't fit the following in the
268		 * remaining buffer space:
269		 * namelen (uint16_t) +
270		 * name (r->res_length) +
271		 * end-of-block record 0x0000 (uint16_t)
272		 */
273
274		if (offset + sizeof(uint16_t)*2 + r->res_length > outlen) {
275			/* Write end-of-block record */
276			be_namelen = cpu_to_be16(0);
277			memcpy(outbuf + offset, &be_namelen, sizeof(__be16));
278			offset += sizeof(__be16);
279			ls->ls_recover_dir_sent_msg++;
280			goto out;
281		}
282
283		be_namelen = cpu_to_be16(r->res_length);
284		memcpy(outbuf + offset, &be_namelen, sizeof(__be16));
285		offset += sizeof(__be16);
286		memcpy(outbuf + offset, r->res_name, r->res_length);
287		offset += r->res_length;
288		ls->ls_recover_dir_sent_res++;
289	}
290
291	/*
292	 * If we've reached the end of the list (and there's room) write a
293	 * terminating record.
294	 */
295
296	if ((list == &ls->ls_root_list) &&
297	    (offset + sizeof(uint16_t) <= outlen)) {
298		be_namelen = cpu_to_be16(0xFFFF);
299		memcpy(outbuf + offset, &be_namelen, sizeof(__be16));
300		offset += sizeof(__be16);
301		ls->ls_recover_dir_sent_msg++;
302	}
303 out:
304	up_read(&ls->ls_root_sem);
305}
306