root/fs/dlm/requestqueue.c

DEFINITIONS

1. dlm_add_requestqueue
2. dlm_process_requestqueue
3. dlm_wait_requestqueue
4. purge_request
5. dlm_purge_requestqueue

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