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, uint64_t seq)
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			if (dlm_recovery_stopped(ls)) {
88				error = -EINTR;
89				goto out_free;
90			}
91
92			error = dlm_rcom_names(ls, memb->nodeid,
93					       last_name, last_len, seq);
94			if (error)
95				goto out_free;
96
97			cond_resched();
98
99			/*
100			 * pick namelen/name pairs out of received buffer
101			 */
102
103			b = ls->ls_recover_buf->rc_buf;
104			left = le16_to_cpu(ls->ls_recover_buf->rc_header.h_length);
105			left -= sizeof(struct dlm_rcom);
106
107			for (;;) {
108				__be16 v;
109
110				error = -EINVAL;
111				if (left < sizeof(__be16))
112					goto out_free;
113
114				memcpy(&v, b, sizeof(__be16));
115				namelen = be16_to_cpu(v);
116				b += sizeof(__be16);
117				left -= sizeof(__be16);
118
119				/* namelen of 0xFFFFF marks end of names for
120				   this node; namelen of 0 marks end of the
121				   buffer */
122
123				if (namelen == 0xFFFF)
124					goto done;
125				if (!namelen)
126					break;
127
128				if (namelen > left)
129					goto out_free;
130
131				if (namelen > DLM_RESNAME_MAXLEN)
132					goto out_free;
133
134				error = dlm_master_lookup(ls, memb->nodeid,
135							  b, namelen,
136							  DLM_LU_RECOVER_DIR,
137							  &nodeid, &result);
138				if (error) {
139					log_error(ls, "recover_dir lookup %d",
140						  error);
141					goto out_free;
142				}
143
144				/* The name was found in rsbtbl, but the
145				 * master nodeid is different from
146				 * memb->nodeid which says it is the master.
147				 * This should not happen. */
148
149				if (result == DLM_LU_MATCH &&
150				    nodeid != memb->nodeid) {
151					count_bad++;
152					log_error(ls, "recover_dir lookup %d "
153						  "nodeid %d memb %d bad %u",
154						  result, nodeid, memb->nodeid,
155						  count_bad);
156					print_hex_dump_bytes("dlm_recover_dir ",
157							     DUMP_PREFIX_NONE,
158							     b, namelen);
159				}
160
161				/* The name was found in rsbtbl, and the
162				 * master nodeid matches memb->nodeid. */
163
164				if (result == DLM_LU_MATCH &&
165				    nodeid == memb->nodeid) {
166					count_match++;
167				}
168
169				/* The name was not found in rsbtbl and was
170				 * added with memb->nodeid as the master. */
171
172				if (result == DLM_LU_ADD) {
173					count_add++;
174				}
175
176				last_len = namelen;
177				memcpy(last_name, b, namelen);
178				b += namelen;
179				left -= namelen;
180				count++;
181			}
182		}
183	 done:
184		;
185	}
186
187 out_status:
188	error = 0;
189	dlm_set_recover_status(ls, DLM_RS_DIR);
190
191	log_rinfo(ls, "dlm_recover_directory %u in %u new",
192		  count, count_add);
193 out_free:
194	kfree(last_name);
195 out:
196	return error;
197}
198
199static struct dlm_rsb *find_rsb_root(struct dlm_ls *ls, const char *name,
200				     int len)
201{
202	struct dlm_rsb *r;
203	uint32_t hash, bucket;
204	int rv;
205
206	hash = jhash(name, len, 0);
207	bucket = hash & (ls->ls_rsbtbl_size - 1);
208
209	spin_lock(&ls->ls_rsbtbl[bucket].lock);
210	rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[bucket].keep, name, len, &r);
211	if (rv)
212		rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[bucket].toss,
213					 name, len, &r);
214	spin_unlock(&ls->ls_rsbtbl[bucket].lock);
215
216	if (!rv)
217		return r;
218
219	down_read(&ls->ls_root_sem);
220	list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
221		if (len == r->res_length && !memcmp(name, r->res_name, len)) {
222			up_read(&ls->ls_root_sem);
223			log_debug(ls, "find_rsb_root revert to root_list %s",
224				  r->res_name);
225			return r;
226		}
227	}
228	up_read(&ls->ls_root_sem);
229	return NULL;
230}
231
232/* Find the rsb where we left off (or start again), then send rsb names
233   for rsb's we're master of and whose directory node matches the requesting
234   node.  inbuf is the rsb name last sent, inlen is the name's length */
235
236void dlm_copy_master_names(struct dlm_ls *ls, const char *inbuf, int inlen,
237 			   char *outbuf, int outlen, int nodeid)
238{
239	struct list_head *list;
240	struct dlm_rsb *r;
241	int offset = 0, dir_nodeid;
242	__be16 be_namelen;
243
244	down_read(&ls->ls_root_sem);
245
246	if (inlen > 1) {
247		r = find_rsb_root(ls, inbuf, inlen);
248		if (!r) {
249			log_error(ls, "copy_master_names from %d start %d %.*s",
250				  nodeid, inlen, inlen, inbuf);
251			goto out;
252		}
253		list = r->res_root_list.next;
254	} else {
255		list = ls->ls_root_list.next;
256	}
257
258	for (offset = 0; list != &ls->ls_root_list; list = list->next) {
259		r = list_entry(list, struct dlm_rsb, res_root_list);
260		if (r->res_nodeid)
261			continue;
262
263		dir_nodeid = dlm_dir_nodeid(r);
264		if (dir_nodeid != nodeid)
265			continue;
266
267		/*
268		 * The block ends when we can't fit the following in the
269		 * remaining buffer space:
270		 * namelen (uint16_t) +
271		 * name (r->res_length) +
272		 * end-of-block record 0x0000 (uint16_t)
273		 */
274
275		if (offset + sizeof(uint16_t)*2 + r->res_length > outlen) {
276			/* Write end-of-block record */
277			be_namelen = cpu_to_be16(0);
278			memcpy(outbuf + offset, &be_namelen, sizeof(__be16));
279			offset += sizeof(__be16);
280			ls->ls_recover_dir_sent_msg++;
281			goto out;
282		}
283
284		be_namelen = cpu_to_be16(r->res_length);
285		memcpy(outbuf + offset, &be_namelen, sizeof(__be16));
286		offset += sizeof(__be16);
287		memcpy(outbuf + offset, r->res_name, r->res_length);
288		offset += r->res_length;
289		ls->ls_recover_dir_sent_res++;
290	}
291
292	/*
293	 * If we've reached the end of the list (and there's room) write a
294	 * terminating record.
295	 */
296
297	if ((list == &ls->ls_root_list) &&
298	    (offset + sizeof(uint16_t) <= outlen)) {
299		be_namelen = cpu_to_be16(0xFFFF);
300		memcpy(outbuf + offset, &be_namelen, sizeof(__be16));
301		offset += sizeof(__be16);
302		ls->ls_recover_dir_sent_msg++;
303	}
304 out:
305	up_read(&ls->ls_root_sem);
306}
307
308