xref: /openbmc/qemu/scsi/pr-manager.c (revision 62aa1d88)
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 "qapi/qapi-commands-block.h"
22 
23 #define PR_MANAGER_PATH     "/objects"
24 
25 typedef struct PRManagerData {
26     PRManager *pr_mgr;
27     struct sg_io_hdr *hdr;
28     int fd;
29 } PRManagerData;
30 
31 static int pr_manager_worker(void *opaque)
32 {
33     PRManagerData *data = opaque;
34     PRManager *pr_mgr = data->pr_mgr;
35     PRManagerClass *pr_mgr_class =
36         PR_MANAGER_GET_CLASS(pr_mgr);
37     struct sg_io_hdr *hdr = data->hdr;
38     int fd = data->fd;
39     int r;
40 
41     g_free(data);
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 BlockAIOCB *pr_manager_execute(PRManager *pr_mgr,
52                                AioContext *ctx, int fd,
53                                struct sg_io_hdr *hdr,
54                                BlockCompletionFunc *complete,
55                                void *opaque)
56 {
57     PRManagerData *data = g_new(PRManagerData, 1);
58     ThreadPool *pool = aio_get_thread_pool(ctx);
59 
60     trace_pr_manager_execute(fd, hdr->cmdp[0], hdr->cmdp[1], opaque);
61     data->pr_mgr = pr_mgr;
62     data->fd = fd;
63     data->hdr = hdr;
64 
65     /* The matching object_unref is in pr_manager_worker.  */
66     object_ref(OBJECT(pr_mgr));
67     return thread_pool_submit_aio(pool, pr_manager_worker,
68                                   data, complete, opaque);
69 }
70 
71 bool pr_manager_is_connected(PRManager *pr_mgr)
72 {
73     PRManagerClass *pr_mgr_class =
74         PR_MANAGER_GET_CLASS(pr_mgr);
75 
76     return !pr_mgr_class->is_connected || pr_mgr_class->is_connected(pr_mgr);
77 }
78 
79 static const TypeInfo pr_manager_info = {
80     .parent = TYPE_OBJECT,
81     .name = TYPE_PR_MANAGER,
82     .class_size = sizeof(PRManagerClass),
83     .abstract = true,
84     .interfaces = (InterfaceInfo[]) {
85         { TYPE_USER_CREATABLE },
86         { }
87     }
88 };
89 
90 PRManager *pr_manager_lookup(const char *id, Error **errp)
91 {
92     Object *obj;
93     PRManager *pr_mgr;
94 
95     obj = object_resolve_path_component(object_get_objects_root(), id);
96     if (!obj) {
97         error_setg(errp, "No persistent reservation manager with id '%s'", id);
98         return NULL;
99     }
100 
101     pr_mgr = (PRManager *)
102         object_dynamic_cast(obj,
103                             TYPE_PR_MANAGER);
104     if (!pr_mgr) {
105         error_setg(errp,
106                    "Object with id '%s' is not a persistent reservation manager",
107                    id);
108         return NULL;
109     }
110 
111     return pr_mgr;
112 }
113 
114 static void
115 pr_manager_register_types(void)
116 {
117     type_register_static(&pr_manager_info);
118 }
119 
120 static int query_one_pr_manager(Object *object, void *opaque)
121 {
122     PRManagerInfoList ***prev = opaque;
123     PRManagerInfoList *elem;
124     PRManagerInfo *info;
125     PRManager *pr_mgr;
126 
127     pr_mgr = (PRManager *)object_dynamic_cast(object, TYPE_PR_MANAGER);
128     if (!pr_mgr) {
129         return 0;
130     }
131 
132     elem = g_new0(PRManagerInfoList, 1);
133     info = g_new0(PRManagerInfo, 1);
134     info->id = object_get_canonical_path_component(object);
135     info->connected = pr_manager_is_connected(pr_mgr);
136     elem->value = info;
137     elem->next = NULL;
138 
139     **prev = elem;
140     *prev = &elem->next;
141     return 0;
142 }
143 
144 PRManagerInfoList *qmp_query_pr_managers(Error **errp)
145 {
146     PRManagerInfoList *head = NULL;
147     PRManagerInfoList **prev = &head;
148     Object *container = container_get(object_get_root(), PR_MANAGER_PATH);
149 
150     object_child_foreach(container, query_one_pr_manager, &prev);
151     return head;
152 }
153 
154 type_init(pr_manager_register_types);
155