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    g_free(data);
  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
  51BlockAIOCB *pr_manager_execute(PRManager *pr_mgr,
  52                               AioContext *ctx, int fd,
  53                               struct sg_io_hdr *hdr,
  54                               BlockCompletionFunc *complete,
  55                               void *opaque)
  56{
  57    PRManagerData *data = g_new(PRManagerData, 1);
  58    ThreadPool *pool = aio_get_thread_pool(ctx);
  59
  60    trace_pr_manager_execute(fd, hdr->cmdp[0], hdr->cmdp[1], opaque);
  61    data->pr_mgr = pr_mgr;
  62    data->fd = fd;
  63    data->hdr = hdr;
  64
  65    /* The matching object_unref is in pr_manager_worker.  */
  66    object_ref(OBJECT(pr_mgr));
  67    return thread_pool_submit_aio(pool, pr_manager_worker,
  68                                  data, complete, opaque);
  69}
  70
  71bool pr_manager_is_connected(PRManager *pr_mgr)
  72{
  73    PRManagerClass *pr_mgr_class =
  74        PR_MANAGER_GET_CLASS(pr_mgr);
  75
  76    return !pr_mgr_class->is_connected || pr_mgr_class->is_connected(pr_mgr);
  77}
  78
  79static const TypeInfo pr_manager_info = {
  80    .parent = TYPE_OBJECT,
  81    .name = TYPE_PR_MANAGER,
  82    .class_size = sizeof(PRManagerClass),
  83    .abstract = true,
  84    .interfaces = (InterfaceInfo[]) {
  85        { TYPE_USER_CREATABLE },
  86        { }
  87    }
  88};
  89
  90PRManager *pr_manager_lookup(const char *id, Error **errp)
  91{
  92    Object *obj;
  93    PRManager *pr_mgr;
  94
  95    obj = object_resolve_path_component(object_get_objects_root(), id);
  96    if (!obj) {
  97        error_setg(errp, "No persistent reservation manager with id '%s'", id);
  98        return NULL;
  99    }
 100
 101    pr_mgr = (PRManager *)
 102        object_dynamic_cast(obj,
 103                            TYPE_PR_MANAGER);
 104    if (!pr_mgr) {
 105        error_setg(errp,
 106                   "Object with id '%s' is not a persistent reservation manager",
 107                   id);
 108        return NULL;
 109    }
 110
 111    return pr_mgr;
 112}
 113
 114static void
 115pr_manager_register_types(void)
 116{
 117    type_register_static(&pr_manager_info);
 118}
 119
 120static int query_one_pr_manager(Object *object, void *opaque)
 121{
 122    PRManagerInfoList ***prev = opaque;
 123    PRManagerInfoList *elem;
 124    PRManagerInfo *info;
 125    PRManager *pr_mgr;
 126
 127    pr_mgr = (PRManager *)object_dynamic_cast(object, TYPE_PR_MANAGER);
 128    if (!pr_mgr) {
 129        return 0;
 130    }
 131
 132    elem = g_new0(PRManagerInfoList, 1);
 133    info = g_new0(PRManagerInfo, 1);
 134    info->id = object_get_canonical_path_component(object);
 135    info->connected = pr_manager_is_connected(pr_mgr);
 136    elem->value = info;
 137    elem->next = NULL;
 138
 139    **prev = elem;
 140    *prev = &elem->next;
 141    return 0;
 142}
 143
 144PRManagerInfoList *qmp_query_pr_managers(Error **errp)
 145{
 146    PRManagerInfoList *head = NULL;
 147    PRManagerInfoList **prev = &head;
 148    Object *container = container_get(object_get_root(), PR_MANAGER_PATH);
 149
 150    object_child_foreach(container, query_one_pr_manager, &prev);
 151    return head;
 152}
 153
 154type_init(pr_manager_register_types);
 155