fs/dlm/requestqueue.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /******************************************************************************
   3 *******************************************************************************
   4 **
   5 **  Copyright (C) 2005-2007 Red Hat, Inc.  All rights reserved.
   6 **
   7 **
   8 *******************************************************************************
   9 ******************************************************************************/
  10
  11 #include "dlm_internal.h"
  12 #include "member.h"
  13 #include "lock.h"
  14 #include "dir.h"
  15 #include "config.h"
  16 #include "requestqueue.h"
  17 #include "util.h"
  18
  19 struct rq_entry {
  20         struct list_head list;
  21         uint32_t recover_seq;
  22         int nodeid;
  23         struct dlm_message request;
  24 };
  25
  26 /*
  27  * Requests received while the lockspace is in recovery get added to the
  28  * request queue and processed when recovery is complete.  This happens when
  29  * the lockspace is suspended on some nodes before it is on others, or the
  30  * lockspace is enabled on some while still suspended on others.
  31  */
  32
  33 void dlm_add_requestqueue(struct dlm_ls *ls, int nodeid, struct dlm_message *ms)
  34 {
  35         struct rq_entry *e;
  36         int length = le16_to_cpu(ms->m_header.h_length) -
  37                 sizeof(struct dlm_message);
  38
  39         e = kmalloc(sizeof(struct rq_entry) + length, GFP_NOFS);
  40         if (!e) {
  41                 log_print("dlm_add_requestqueue: out of memory len %d", length);
  42                 return;
  43         }
  44
  45         e->recover_seq = ls->ls_recover_seq & 0xFFFFFFFF;
  46         e->nodeid = nodeid;
  47         memcpy(&e->request, ms, le16_to_cpu(ms->m_header.h_length));
  48
  49         atomic_inc(&ls->ls_requestqueue_cnt);
  50         mutex_lock(&ls->ls_requestqueue_mutex);
  51         list_add_tail(&e->list, &ls->ls_requestqueue);
  52         mutex_unlock(&ls->ls_requestqueue_mutex);
  53 }
  54
  55 /*
  56  * Called by dlm_recoverd to process normal messages saved while recovery was
  57  * happening.  Normal locking has been enabled before this is called.  dlm_recv
  58  * upon receiving a message, will wait for all saved messages to be drained
  59  * here before processing the message it got.  If a new dlm_ls_stop() arrives
  60  * while we're processing these saved messages, it may block trying to suspend
  61  * dlm_recv if dlm_recv is waiting for us in dlm_wait_requestqueue.  In that
  62  * case, we don't abort since locking_stopped is still 0.  If dlm_recv is not
  63  * waiting for us, then this processing may be aborted due to locking_stopped.
  64  */
  65
  66 int dlm_process_requestqueue(struct dlm_ls *ls)
  67 {
  68         struct rq_entry *e;
  69         struct dlm_message *ms;
  70         int error = 0;
  71
  72         mutex_lock(&ls->ls_requestqueue_mutex);
  73
  74         for (;;) {
  75                 if (list_empty(&ls->ls_requestqueue)) {
  76                         mutex_unlock(&ls->ls_requestqueue_mutex);
  77                         error = 0;
  78                         break;
  79                 }
  80                 e = list_entry(ls->ls_requestqueue.next, struct rq_entry, list);
  81                 mutex_unlock(&ls->ls_requestqueue_mutex);
  82
  83                 ms = &e->request;
  84
  85                 log_limit(ls, "dlm_process_requestqueue msg %d from %d "
  86                           "lkid %x remid %x result %d seq %u",
  87                           le32_to_cpu(ms->m_type),
  88                           le32_to_cpu(ms->m_header.h_nodeid),
  89                           le32_to_cpu(ms->m_lkid), le32_to_cpu(ms->m_remid),
  90                           from_dlm_errno(le32_to_cpu(ms->m_result)),
  91                           e->recover_seq);
  92
  93                 dlm_receive_message_saved(ls, &e->request, e->recover_seq);
  94
  95                 mutex_lock(&ls->ls_requestqueue_mutex);
  96                 list_del(&e->list);
  97                 if (atomic_dec_and_test(&ls->ls_requestqueue_cnt))
  98                         wake_up(&ls->ls_requestqueue_wait);
  99                 kfree(e);
 100
 101                 if (dlm_locking_stopped(ls)) {
 102                         log_debug(ls, "process_requestqueue abort running");
 103                         mutex_unlock(&ls->ls_requestqueue_mutex);
 104                         error = -EINTR;
 105                         break;
 106                 }
 107                 schedule();
 108         }
 109
 110         return error;
 111 }
 112
 113 /*
 114  * After recovery is done, locking is resumed and dlm_recoverd takes all the
 115  * saved requests and processes them as they would have been by dlm_recv.  At
 116  * the same time, dlm_recv will start receiving new requests from remote nodes.
 117  * We want to delay dlm_recv processing new requests until dlm_recoverd has
 118  * finished processing the old saved requests.  We don't check for locking
 119  * stopped here because dlm_ls_stop won't stop locking until it's suspended us
 120  * (dlm_recv).
 121  */
 122
 123 void dlm_wait_requestqueue(struct dlm_ls *ls)
 124 {
 125         wait_event(ls->ls_requestqueue_wait,
 126                    atomic_read(&ls->ls_requestqueue_cnt) == 0);
 127 }
 128
 129 static int purge_request(struct dlm_ls *ls, struct dlm_message *ms, int nodeid)
 130 {
 131         __le32 type = ms->m_type;
 132
 133         /* the ls is being cleaned up and freed by release_lockspace */
 134         if (!atomic_read(&ls->ls_count))
 135                 return 1;
 136
 137         if (dlm_is_removed(ls, nodeid))
 138                 return 1;
 139
 140         /* directory operations are always purged because the directory is
 141            always rebuilt during recovery and the lookups resent */
 142
 143         if (type == cpu_to_le32(DLM_MSG_REMOVE) ||
 144             type == cpu_to_le32(DLM_MSG_LOOKUP) ||
 145             type == cpu_to_le32(DLM_MSG_LOOKUP_REPLY))
 146                 return 1;
 147
 148         if (!dlm_no_directory(ls))
 149                 return 0;
 150
 151         return 1;
 152 }
 153
 154 void dlm_purge_requestqueue(struct dlm_ls *ls)
 155 {
 156         struct dlm_message *ms;
 157         struct rq_entry *e, *safe;
 158
 159         mutex_lock(&ls->ls_requestqueue_mutex);
 160         list_for_each_entry_safe(e, safe, &ls->ls_requestqueue, list) {
 161                 ms =  &e->request;
 162
 163                 if (purge_request(ls, ms, e->nodeid)) {
 164                         list_del(&e->list);
 165                         if (atomic_dec_and_test(&ls->ls_requestqueue_cnt))
 166                                 wake_up(&ls->ls_requestqueue_wait);
 167                         kfree(e);
 168                 }
 169         }
 170         mutex_unlock(&ls->ls_requestqueue_mutex);
 171 }
 172