xref: /qemu/scsi/pr-manager.c (revision 83ecdb18) 
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);
145