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