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     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(pr_manager_worker, &data);
  65 }
  66
  67 bool 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
  75 static 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
  86 PRManager *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
 110 static void
 111 pr_manager_register_types(void)
 112 {
 113     type_register_static(&pr_manager_info);
 114 }
 115
 116 static int query_one_pr_manager(Object *object, void *opaque)
 117 {
 118     PRManagerInfoList ***tail = opaque;
 119     PRManagerInfo *info;
 120     PRManager *pr_mgr;
 121
 122     pr_mgr = (PRManager *)object_dynamic_cast(object, TYPE_PR_MANAGER);
 123     if (!pr_mgr) {
 124         return 0;
 125     }
 126
 127     info = g_new0(PRManagerInfo, 1);
 128     info->id = g_strdup(object_get_canonical_path_component(object));
 129     info->connected = pr_manager_is_connected(pr_mgr);
 130     QAPI_LIST_APPEND(*tail, info);
 131     return 0;
 132 }
 133
 134 PRManagerInfoList *qmp_query_pr_managers(Error **errp)
 135 {
 136     PRManagerInfoList *head = NULL;
 137     PRManagerInfoList **prev = &head;
 138     Object *container = container_get(object_get_root(), PR_MANAGER_PATH);
 139
 140     object_child_foreach(container, query_one_pr_manager, &prev);
 141     return head;
 142 }
 143
 144 type_init(pr_manager_register_types);