target/mips: Fix TCG temporary leak in gen_cache_operation()
[qemu/ar7.git] / scsi / pr-manager-helper.c
blob451c7631b76f36b60e581c3e7edc60c1853d7854
1 /*
2  * Persistent reservation manager that talks to qemu-pr-helper
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 v2.1 or later.
9  *
10  */
12 #include "qemu/osdep.h"
13 #include "qapi/error.h"
14 #include "scsi/constants.h"
15 #include "scsi/pr-manager.h"
16 #include "scsi/utils.h"
17 #include "io/channel.h"
18 #include "io/channel-socket.h"
19 #include "pr-helper.h"
20 #include "qapi/qapi-events-block.h"
21 #include "qemu/module.h"
23 #include <scsi/sg.h>
24 #include "qom/object.h"
26 #define PR_MAX_RECONNECT_ATTEMPTS 5
28 #define TYPE_PR_MANAGER_HELPER "pr-manager-helper"
30 OBJECT_DECLARE_SIMPLE_TYPE(PRManagerHelper, PR_MANAGER_HELPER)
32 struct PRManagerHelper {
33     /* <private> */
34     PRManager parent;
36     char *path;
38     QemuMutex lock;
39     QIOChannel *ioc;
42 static void pr_manager_send_status_changed_event(PRManagerHelper *pr_mgr)
44     const char *id = object_get_canonical_path_component(OBJECT(pr_mgr));
46     if (id) {
47         qapi_event_send_pr_manager_status_changed(id, !!pr_mgr->ioc);
48     }
51 /* Called with lock held.  */
52 static int pr_manager_helper_read(PRManagerHelper *pr_mgr,
53                                   void *buf, int sz, Error **errp)
55     ssize_t r = qio_channel_read_all(pr_mgr->ioc, buf, sz, errp);
57     if (r < 0) {
58         object_unref(OBJECT(pr_mgr->ioc));
59         pr_mgr->ioc = NULL;
60         pr_manager_send_status_changed_event(pr_mgr);
61         return -EINVAL;
62     }
64     return 0;
67 /* Called with lock held.  */
68 static int pr_manager_helper_write(PRManagerHelper *pr_mgr,
69                                    int fd,
70                                    const void *buf, int sz, Error **errp)
72     size_t nfds = (fd != -1);
73     while (sz > 0) {
74         struct iovec iov;
75         ssize_t n_written;
77         iov.iov_base = (void *)buf;
78         iov.iov_len = sz;
79         n_written = qio_channel_writev_full(QIO_CHANNEL(pr_mgr->ioc), &iov, 1,
80                                             nfds ? &fd : NULL, nfds, errp);
82         if (n_written <= 0) {
83             assert(n_written != QIO_CHANNEL_ERR_BLOCK);
84             object_unref(OBJECT(pr_mgr->ioc));
85             pr_mgr->ioc = NULL;
86             pr_manager_send_status_changed_event(pr_mgr);
87             return n_written < 0 ? -EINVAL : 0;
88         }
90         nfds = 0;
91         buf += n_written;
92         sz -= n_written;
93     }
95     return 0;
98 /* Called with lock held.  */
99 static int pr_manager_helper_initialize(PRManagerHelper *pr_mgr,
100                                         Error **errp)
102     char *path = g_strdup(pr_mgr->path);
103     SocketAddress saddr = {
104         .type = SOCKET_ADDRESS_TYPE_UNIX,
105         .u.q_unix.path = path
106     };
107     QIOChannelSocket *sioc = qio_channel_socket_new();
108     Error *local_err = NULL;
110     uint32_t flags;
111     int r;
113     assert(!pr_mgr->ioc);
114     qio_channel_set_name(QIO_CHANNEL(sioc), "pr-manager-helper");
115     qio_channel_socket_connect_sync(sioc,
116                                     &saddr,
117                                     &local_err);
118     g_free(path);
119     if (local_err) {
120         object_unref(OBJECT(sioc));
121         error_propagate(errp, local_err);
122         return -ENOTCONN;
123     }
125     qio_channel_set_delay(QIO_CHANNEL(sioc), false);
126     pr_mgr->ioc = QIO_CHANNEL(sioc);
128     /* A simple feature negotiation protocol, even though there is
129      * no optional feature right now.
130      */
131     r = pr_manager_helper_read(pr_mgr, &flags, sizeof(flags), errp);
132     if (r < 0) {
133         goto out_close;
134     }
136     flags = 0;
137     r = pr_manager_helper_write(pr_mgr, -1, &flags, sizeof(flags), errp);
138     if (r < 0) {
139         goto out_close;
140     }
142     pr_manager_send_status_changed_event(pr_mgr);
143     return 0;
145 out_close:
146     object_unref(OBJECT(pr_mgr->ioc));
147     pr_mgr->ioc = NULL;
148     return r;
151 static int pr_manager_helper_run(PRManager *p,
152                                  int fd, struct sg_io_hdr *io_hdr)
154     PRManagerHelper *pr_mgr = PR_MANAGER_HELPER(p);
156     uint32_t len;
157     PRHelperResponse resp;
158     int ret;
159     int expected_dir;
160     int attempts;
161     uint8_t cdb[PR_HELPER_CDB_SIZE] = { 0 };
163     if (!io_hdr->cmd_len || io_hdr->cmd_len > PR_HELPER_CDB_SIZE) {
164         return -EINVAL;
165     }
167     memcpy(cdb, io_hdr->cmdp, io_hdr->cmd_len);
168     assert(cdb[0] == PERSISTENT_RESERVE_OUT || cdb[0] == PERSISTENT_RESERVE_IN);
169     expected_dir =
170         (cdb[0] == PERSISTENT_RESERVE_OUT ? SG_DXFER_TO_DEV : SG_DXFER_FROM_DEV);
171     if (io_hdr->dxfer_direction != expected_dir) {
172         return -EINVAL;
173     }
175     len = scsi_cdb_xfer(cdb);
176     if (io_hdr->dxfer_len < len || len > PR_HELPER_DATA_SIZE) {
177         return -EINVAL;
178     }
180     qemu_mutex_lock(&pr_mgr->lock);
182     /* Try to reconnect while sending the CDB.  */
183     for (attempts = 0; attempts < PR_MAX_RECONNECT_ATTEMPTS; attempts++) {
184         if (!pr_mgr->ioc) {
185             ret = pr_manager_helper_initialize(pr_mgr, NULL);
186             if (ret < 0) {
187                 qemu_mutex_unlock(&pr_mgr->lock);
188                 g_usleep(G_USEC_PER_SEC);
189                 qemu_mutex_lock(&pr_mgr->lock);
190                 continue;
191             }
192         }
194         ret = pr_manager_helper_write(pr_mgr, fd, cdb, ARRAY_SIZE(cdb), NULL);
195         if (ret >= 0) {
196             break;
197         }
198     }
199     if (ret < 0) {
200         goto out;
201     }
203     /* After sending the CDB, any communications failure causes the
204      * command to fail.  The failure is transient, retrying the command
205      * will invoke pr_manager_helper_initialize again.
206      */
207     if (expected_dir == SG_DXFER_TO_DEV) {
208         io_hdr->resid = io_hdr->dxfer_len - len;
209         ret = pr_manager_helper_write(pr_mgr, -1, io_hdr->dxferp, len, NULL);
210         if (ret < 0) {
211             goto out;
212         }
213     }
214     ret = pr_manager_helper_read(pr_mgr, &resp, sizeof(resp), NULL);
215     if (ret < 0) {
216         goto out;
217     }
219     resp.result = be32_to_cpu(resp.result);
220     resp.sz = be32_to_cpu(resp.sz);
221     if (io_hdr->dxfer_direction == SG_DXFER_FROM_DEV) {
222         assert(resp.sz <= io_hdr->dxfer_len);
223         ret = pr_manager_helper_read(pr_mgr, io_hdr->dxferp, resp.sz, NULL);
224         if (ret < 0) {
225             goto out;
226         }
227         io_hdr->resid = io_hdr->dxfer_len - resp.sz;
228     } else {
229         assert(resp.sz == 0);
230     }
232     io_hdr->status = resp.result;
233     if (resp.result == CHECK_CONDITION) {
234         io_hdr->driver_status = SG_ERR_DRIVER_SENSE;
235         io_hdr->sb_len_wr = MIN(io_hdr->mx_sb_len, PR_HELPER_SENSE_SIZE);
236         memcpy(io_hdr->sbp, resp.sense, io_hdr->sb_len_wr);
237     }
239 out:
240     if (ret < 0) {
241         int sense_len = scsi_build_sense(io_hdr->sbp,
242                                          SENSE_CODE(LUN_COMM_FAILURE));
243         io_hdr->driver_status = SG_ERR_DRIVER_SENSE;
244         io_hdr->sb_len_wr = MIN(io_hdr->mx_sb_len, sense_len);
245         io_hdr->status = CHECK_CONDITION;
246     }
247     qemu_mutex_unlock(&pr_mgr->lock);
248     return ret;
251 static bool pr_manager_helper_is_connected(PRManager *p)
253     PRManagerHelper *pr_mgr = PR_MANAGER_HELPER(p);
254     bool result;
256     qemu_mutex_lock(&pr_mgr->lock);
257     result = (pr_mgr->ioc != NULL);
258     qemu_mutex_unlock(&pr_mgr->lock);
260     return result;
263 static void pr_manager_helper_complete(UserCreatable *uc, Error **errp)
265     PRManagerHelper *pr_mgr = PR_MANAGER_HELPER(uc);
267     qemu_mutex_lock(&pr_mgr->lock);
268     pr_manager_helper_initialize(pr_mgr, errp);
269     qemu_mutex_unlock(&pr_mgr->lock);
272 static char *get_path(Object *obj, Error **errp)
274     PRManagerHelper *pr_mgr = PR_MANAGER_HELPER(obj);
276     return g_strdup(pr_mgr->path);
279 static void set_path(Object *obj, const char *str, Error **errp)
281     PRManagerHelper *pr_mgr = PR_MANAGER_HELPER(obj);
283     g_free(pr_mgr->path);
284     pr_mgr->path = g_strdup(str);
287 static void pr_manager_helper_instance_finalize(Object *obj)
289     PRManagerHelper *pr_mgr = PR_MANAGER_HELPER(obj);
291     object_unref(OBJECT(pr_mgr->ioc));
292     qemu_mutex_destroy(&pr_mgr->lock);
295 static void pr_manager_helper_instance_init(Object *obj)
297     PRManagerHelper *pr_mgr = PR_MANAGER_HELPER(obj);
299     qemu_mutex_init(&pr_mgr->lock);
302 static void pr_manager_helper_class_init(ObjectClass *klass,
303                                          void *class_data G_GNUC_UNUSED)
305     PRManagerClass *prmgr_klass = PR_MANAGER_CLASS(klass);
306     UserCreatableClass *uc_klass = USER_CREATABLE_CLASS(klass);
308     object_class_property_add_str(klass, "path", get_path, set_path);
309     uc_klass->complete = pr_manager_helper_complete;
310     prmgr_klass->run = pr_manager_helper_run;
311     prmgr_klass->is_connected = pr_manager_helper_is_connected;
314 static const TypeInfo pr_manager_helper_info = {
315     .parent = TYPE_PR_MANAGER,
316     .name = TYPE_PR_MANAGER_HELPER,
317     .instance_size = sizeof(PRManagerHelper),
318     .instance_init = pr_manager_helper_instance_init,
319     .instance_finalize = pr_manager_helper_instance_finalize,
320     .class_init = pr_manager_helper_class_init,
323 static void pr_manager_helper_register_types(void)
325     type_register_static(&pr_manager_helper_info);
328 type_init(pr_manager_helper_register_types);