xref: /openbmc/qemu/scsi/pr-manager.c (revision a68694cd)
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 = g_strdup(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);
152