fs/dlm/dir.c

   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
  33 int 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
  45 int dlm_dir_nodeid(struct dlm_rsb *r)
  46 {
  47         return r->res_dir_nodeid;
  48 }
  49
  50 void 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
  61 int 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
 198 static 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
 234 void 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