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
  26 typedef struct PRManagerData {
  27     PRManager *pr_mgr;
  28     struct sg_io_hdr *hdr;
  29     int fd;
  30 } PRManagerData;
  31
  32 static 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
  51 int 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
  68 bool 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
  76 static 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
  87 PRManager *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
 111 static void
 112 pr_manager_register_types(void)
 113 {
 114     type_register_static(&pr_manager_info);
 115 }
 116
 117 static 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
 141 PRManagerInfoList *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
 151 type_init(pr_manager_register_types);