LXR qemu/scsi/pr-manager.c

   1/*
   2 * Persistent reservation manager abstract class
   3 *
   4 * Copyright (c) 2017 Red Hat, Inc.
   5 *
   6 * Author: Paolo Bonzini <pbonzini@redhat.com>
   7 *
   8 * This code is licensed under the LGPL.
   9 *
  10 */
  11
  12#include "qemu/osdep.h"
  13#include <scsi/sg.h>
  14
  15#include "qapi/error.h"
  16#include "block/aio.h"
  17#include "block/thread-pool.h"
  18#include "scsi/pr-manager.h"
  19#include "trace.h"
  20#include "qapi/qapi-types-block.h"
  21#include "qapi/qapi-commands-block.h"
  22
  23#define PR_MANAGER_PATH     "/objects"
  24
  25typedef struct PRManagerData {
  26    PRManager *pr_mgr;
  27    struct sg_io_hdr *hdr;
  28    int fd;
  29} PRManagerData;
  30
  31static int pr_manager_worker(void *opaque)
  32{
  33    PRManagerData *data = opaque;
  34    PRManager *pr_mgr = data->pr_mgr;
  35    PRManagerClass *pr_mgr_class =
  36        PR_MANAGER_GET_CLASS(pr_mgr);
  37    struct sg_io_hdr *hdr = data->hdr;
  38    int fd = data->fd;
  39    int r;
  40
  41    trace_pr_manager_run(fd, hdr->cmdp[0], hdr->cmdp[1]);
  42
  43    /* The reference was taken in pr_manager_execute.  */
  44    r = pr_mgr_class->run(pr_mgr, fd, hdr);
  45    object_unref(OBJECT(pr_mgr));
  46    return r;
  47}
  48
  49
  50int coroutine_fn pr_manager_execute(PRManager *pr_mgr, AioContext *ctx, int fd,
  51                                    struct sg_io_hdr *hdr)
  52{
  53    ThreadPool *pool = aio_get_thread_pool(ctx);
  54    PRManagerData data = {
  55        .pr_mgr = pr_mgr,
  56        .fd     = fd,
  57        .hdr    = hdr,
  58    };
  59
  60    trace_pr_manager_execute(fd, hdr->cmdp[0], hdr->cmdp[1]);
  61
  62    /* The matching object_unref is in pr_manager_worker.  */
  63    object_ref(OBJECT(pr_mgr));
  64    return thread_pool_submit_co(pool, pr_manager_worker, &data);
  65}
  66
  67bool pr_manager_is_connected(PRManager *pr_mgr)
  68{
  69    PRManagerClass *pr_mgr_class =
  70        PR_MANAGER_GET_CLASS(pr_mgr);
  71
  72    return !pr_mgr_class->is_connected || pr_mgr_class->is_connected(pr_mgr);
  73}
  74
  75static const TypeInfo pr_manager_info = {
  76    .parent = TYPE_OBJECT,
  77    .name = TYPE_PR_MANAGER,
  78    .class_size = sizeof(PRManagerClass),
  79    .abstract = true,
  80    .interfaces = (InterfaceInfo[]) {
  81        { TYPE_USER_CREATABLE },
  82        { }
  83    }
  84};
  85
  86PRManager *pr_manager_lookup(const char *id, Error **errp)
  87{
  88    Object *obj;
  89    PRManager *pr_mgr;
  90
  91    obj = object_resolve_path_component(object_get_objects_root(), id);
  92    if (!obj) {
  93        error_setg(errp, "No persistent reservation manager with id '%s'", id);
  94        return NULL;
  95    }
  96
  97    pr_mgr = (PRManager *)
  98        object_dynamic_cast(obj,
  99                            TYPE_PR_MANAGER);
 100    if (!pr_mgr) {
 101        error_setg(errp,
 102                   "Object with id '%s' is not a persistent reservation manager",
 103                   id);
 104        return NULL;
 105    }
 106
 107    return pr_mgr;
 108}
 109
 110static void
 111pr_manager_register_types(void)
 112{
 113    type_register_static(&pr_manager_info);
 114}
 115
 116static int query_one_pr_manager(Object *object, void *opaque)
 117{
 118    PRManagerInfoList ***prev = opaque;
 119    PRManagerInfoList *elem;
 120    PRManagerInfo *info;
 121    PRManager *pr_mgr;
 122
 123    pr_mgr = (PRManager *)object_dynamic_cast(object, TYPE_PR_MANAGER);
 124    if (!pr_mgr) {
 125        return 0;
 126    }
 127
 128    elem = g_new0(PRManagerInfoList, 1);
 129    info = g_new0(PRManagerInfo, 1);
 130    info->id = object_get_canonical_path_component(object);
 131    info->connected = pr_manager_is_connected(pr_mgr);
 132    elem->value = info;
 133    elem->next = NULL;
 134
 135    **prev = elem;
 136    *prev = &elem->next;
 137    return 0;
 138}
 139
 140PRManagerInfoList *qmp_query_pr_managers(Error **errp)
 141{
 142    PRManagerInfoList *head = NULL;
 143    PRManagerInfoList **prev = &head;
 144    Object *container = container_get(object_get_root(), PR_MANAGER_PATH);
 145
 146    object_child_foreach(container, query_one_pr_manager, &prev);
 147    return head;
 148}
 149
 150type_init(pr_manager_register_types);
 151