xref: /openbmc/qemu/scsi/pr-manager.c (revision dc5bd18f)
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 
21 typedef struct PRManagerData {
22     PRManager *pr_mgr;
23     struct sg_io_hdr *hdr;
24     int fd;
25 } PRManagerData;
26 
27 static int pr_manager_worker(void *opaque)
28 {
29     PRManagerData *data = opaque;
30     PRManager *pr_mgr = data->pr_mgr;
31     PRManagerClass *pr_mgr_class =
32         PR_MANAGER_GET_CLASS(pr_mgr);
33     struct sg_io_hdr *hdr = data->hdr;
34     int fd = data->fd;
35     int r;
36 
37     g_free(data);
38     trace_pr_manager_run(fd, hdr->cmdp[0], hdr->cmdp[1]);
39 
40     /* The reference was taken in pr_manager_execute.  */
41     r = pr_mgr_class->run(pr_mgr, fd, hdr);
42     object_unref(OBJECT(pr_mgr));
43     return r;
44 }
45 
46 
47 BlockAIOCB *pr_manager_execute(PRManager *pr_mgr,
48                                AioContext *ctx, int fd,
49                                struct sg_io_hdr *hdr,
50                                BlockCompletionFunc *complete,
51                                void *opaque)
52 {
53     PRManagerData *data = g_new(PRManagerData, 1);
54     ThreadPool *pool = aio_get_thread_pool(ctx);
55 
56     trace_pr_manager_execute(fd, hdr->cmdp[0], hdr->cmdp[1], opaque);
57     data->pr_mgr = pr_mgr;
58     data->fd = fd;
59     data->hdr = hdr;
60 
61     /* The matching object_unref is in pr_manager_worker.  */
62     object_ref(OBJECT(pr_mgr));
63     return thread_pool_submit_aio(pool, pr_manager_worker,
64                                   data, complete, opaque);
65 }
66 
67 static const TypeInfo pr_manager_info = {
68     .parent = TYPE_OBJECT,
69     .name = TYPE_PR_MANAGER,
70     .class_size = sizeof(PRManagerClass),
71     .abstract = true,
72     .interfaces = (InterfaceInfo[]) {
73         { TYPE_USER_CREATABLE },
74         { }
75     }
76 };
77 
78 PRManager *pr_manager_lookup(const char *id, Error **errp)
79 {
80     Object *obj;
81     PRManager *pr_mgr;
82 
83     obj = object_resolve_path_component(object_get_objects_root(), id);
84     if (!obj) {
85         error_setg(errp, "No persistent reservation manager with id '%s'", id);
86         return NULL;
87     }
88 
89     pr_mgr = (PRManager *)
90         object_dynamic_cast(obj,
91                             TYPE_PR_MANAGER);
92     if (!pr_mgr) {
93         error_setg(errp,
94                    "Object with id '%s' is not a persistent reservation manager",
95                    id);
96         return NULL;
97     }
98 
99     return pr_mgr;
100 }
101 
102 static void
103 pr_manager_register_types(void)
104 {
105     type_register_static(&pr_manager_info);
106 }
107 
108 
109 type_init(pr_manager_register_types);
110