xref: /openbmc/qemu/scsi/pr-manager.c (revision 500eb6db)
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);
153