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 "qemu/module.h"
  22#include "qapi/qapi-commands-block.h"
  23
  24#define PR_MANAGER_PATH     "/objects"
  25
  26typedef struct PRManagerData {
  27    PRManager *pr_mgr;
  28    struct sg_io_hdr *hdr;
  29    int fd;
  30} PRManagerData;
  31
  32static int pr_manager_worker(void *opaque)
  33{
  34    PRManagerData *data = opaque;
  35    PRManager *pr_mgr = data->pr_mgr;
  36    PRManagerClass *pr_mgr_class =
  37        PR_MANAGER_GET_CLASS(pr_mgr);
  38    struct sg_io_hdr *hdr = data->hdr;
  39    int fd = data->fd;
  40    int r;
  41
  42    trace_pr_manager_run(fd, hdr->cmdp[0], hdr->cmdp[1]);
  43
  44    /* The reference was taken in pr_manager_execute.  */
  45    r = pr_mgr_class->run(pr_mgr, fd, hdr);
  46    object_unref(OBJECT(pr_mgr));
  47    return r;
  48}
  49
  50
  51int coroutine_fn pr_manager_execute(PRManager *pr_mgr, AioContext *ctx, int fd,
  52                                    struct sg_io_hdr *hdr)
  53{
  54    ThreadPool *pool = aio_get_thread_pool(ctx);
  55    PRManagerData data = {
  56        .pr_mgr = pr_mgr,
  57        .fd     = fd,
  58        .hdr    = hdr,
  59    };
  60
  61    trace_pr_manager_execute(fd, hdr->cmdp[0], hdr->cmdp[1]);
  62
  63    /* The matching object_unref is in pr_manager_worker.  */
  64    object_ref(OBJECT(pr_mgr));
  65    return thread_pool_submit_co(pool, pr_manager_worker, &data);
  66}
  67
  68bool pr_manager_is_connected(PRManager *pr_mgr)
  69{
  70    PRManagerClass *pr_mgr_class =
  71        PR_MANAGER_GET_CLASS(pr_mgr);
  72
  73    return !pr_mgr_class->is_connected || pr_mgr_class->is_connected(pr_mgr);
  74}
  75
  76static const TypeInfo pr_manager_info = {
  77    .parent = TYPE_OBJECT,
  78    .name = TYPE_PR_MANAGER,
  79    .class_size = sizeof(PRManagerClass),
  80    .abstract = true,
  81    .interfaces = (InterfaceInfo[]) {
  82        { TYPE_USER_CREATABLE },
  83        { }
  84    }
  85};
  86
  87PRManager *pr_manager_lookup(const char *id, Error **errp)
  88{
  89    Object *obj;
  90    PRManager *pr_mgr;
  91
  92    obj = object_resolve_path_component(object_get_objects_root(), id);
  93    if (!obj) {
  94        error_setg(errp, "No persistent reservation manager with id '%s'", id);
  95        return NULL;
  96    }
  97
  98    pr_mgr = (PRManager *)
  99        object_dynamic_cast(obj,
 100                            TYPE_PR_MANAGER);
 101    if (!pr_mgr) {
 102        error_setg(errp,
 103                   "Object with id '%s' is not a persistent reservation manager",
 104                   id);
 105        return NULL;
 106    }
 107
 108    return pr_mgr;
 109}
 110
 111static void
 112pr_manager_register_types(void)
 113{
 114    type_register_static(&pr_manager_info);
 115}
 116
 117static int query_one_pr_manager(Object *object, void *opaque)
 118{
 119    PRManagerInfoList ***prev = opaque;
 120    PRManagerInfoList *elem;
 121    PRManagerInfo *info;
 122    PRManager *pr_mgr;
 123
 124    pr_mgr = (PRManager *)object_dynamic_cast(object, TYPE_PR_MANAGER);
 125    if (!pr_mgr) {
 126        return 0;
 127    }
 128
 129    elem = g_new0(PRManagerInfoList, 1);
 130    info = g_new0(PRManagerInfo, 1);
 131    info->id = object_get_canonical_path_component(object);
 132    info->connected = pr_manager_is_connected(pr_mgr);
 133    elem->value = info;
 134    elem->next = NULL;
 135
 136    **prev = elem;
 137    *prev = &elem->next;
 138    return 0;
 139}
 140
 141PRManagerInfoList *qmp_query_pr_managers(Error **errp)
 142{
 143    PRManagerInfoList *head = NULL;
 144    PRManagerInfoList **prev = &head;
 145    Object *container = container_get(object_get_root(), PR_MANAGER_PATH);
 146
 147    object_child_foreach(container, query_one_pr_manager, &prev);
 148    return head;
 149}
 150
 151type_init(pr_manager_register_types);
 152