scsi: add persistent reservation manager using qemu-pr-helper
This adds a concrete subclass of pr-manager that talks to qemu-pr-helper. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini
parent
fe8fc5ae5c
commit
9bad2a6b9d
@ -1,3 +1,3 @@
|
||||
block-obj-y += utils.o
|
||||
|
||||
block-obj-$(CONFIG_LINUX) += pr-manager.o
|
||||
block-obj-$(CONFIG_LINUX) += pr-manager.o pr-manager-helper.o
|
||||
|
||||
302
scsi/pr-manager-helper.c
Normal file
302
scsi/pr-manager-helper.c
Normal file
@ -0,0 +1,302 @@
|
||||
/*
|
||||
* Persistent reservation manager that talks to qemu-pr-helper
|
||||
*
|
||||
* Copyright (c) 2017 Red Hat, Inc.
|
||||
*
|
||||
* Author: Paolo Bonzini <pbonzini@redhat.com>
|
||||
*
|
||||
* This code is licensed under the LGPL v2.1 or later.
|
||||
*
|
||||
*/
|
||||
|
||||
#include "qemu/osdep.h"
|
||||
#include "qapi/error.h"
|
||||
#include "scsi/constants.h"
|
||||
#include "scsi/pr-manager.h"
|
||||
#include "scsi/utils.h"
|
||||
#include "io/channel.h"
|
||||
#include "io/channel-socket.h"
|
||||
#include "pr-helper.h"
|
||||
|
||||
#include <scsi/sg.h>
|
||||
|
||||
#define PR_MAX_RECONNECT_ATTEMPTS 5
|
||||
|
||||
#define TYPE_PR_MANAGER_HELPER "pr-manager-helper"
|
||||
|
||||
#define PR_MANAGER_HELPER(obj) \
|
||||
OBJECT_CHECK(PRManagerHelper, (obj), \
|
||||
TYPE_PR_MANAGER_HELPER)
|
||||
|
||||
typedef struct PRManagerHelper {
|
||||
/* <private> */
|
||||
PRManager parent;
|
||||
|
||||
char *path;
|
||||
|
||||
QemuMutex lock;
|
||||
QIOChannel *ioc;
|
||||
} PRManagerHelper;
|
||||
|
||||
/* Called with lock held. */
|
||||
static int pr_manager_helper_read(PRManagerHelper *pr_mgr,
|
||||
void *buf, int sz, Error **errp)
|
||||
{
|
||||
ssize_t r = qio_channel_read_all(pr_mgr->ioc, buf, sz, errp);
|
||||
|
||||
if (r < 0) {
|
||||
object_unref(OBJECT(pr_mgr->ioc));
|
||||
pr_mgr->ioc = NULL;
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Called with lock held. */
|
||||
static int pr_manager_helper_write(PRManagerHelper *pr_mgr,
|
||||
int fd,
|
||||
const void *buf, int sz, Error **errp)
|
||||
{
|
||||
size_t nfds = (fd != -1);
|
||||
while (sz > 0) {
|
||||
struct iovec iov;
|
||||
ssize_t n_written;
|
||||
|
||||
iov.iov_base = (void *)buf;
|
||||
iov.iov_len = sz;
|
||||
n_written = qio_channel_writev_full(QIO_CHANNEL(pr_mgr->ioc), &iov, 1,
|
||||
nfds ? &fd : NULL, nfds, errp);
|
||||
|
||||
if (n_written <= 0) {
|
||||
assert(n_written != QIO_CHANNEL_ERR_BLOCK);
|
||||
object_unref(OBJECT(pr_mgr->ioc));
|
||||
return n_written < 0 ? -EINVAL : 0;
|
||||
}
|
||||
|
||||
nfds = 0;
|
||||
buf += n_written;
|
||||
sz -= n_written;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Called with lock held. */
|
||||
static int pr_manager_helper_initialize(PRManagerHelper *pr_mgr,
|
||||
Error **errp)
|
||||
{
|
||||
char *path = g_strdup(pr_mgr->path);
|
||||
SocketAddress saddr = {
|
||||
.type = SOCKET_ADDRESS_TYPE_UNIX,
|
||||
.u.q_unix.path = path
|
||||
};
|
||||
QIOChannelSocket *sioc = qio_channel_socket_new();
|
||||
Error *local_err = NULL;
|
||||
|
||||
uint32_t flags;
|
||||
int r;
|
||||
|
||||
assert(!pr_mgr->ioc);
|
||||
qio_channel_set_name(QIO_CHANNEL(sioc), "pr-manager-helper");
|
||||
qio_channel_socket_connect_sync(sioc,
|
||||
&saddr,
|
||||
&local_err);
|
||||
g_free(path);
|
||||
if (local_err) {
|
||||
object_unref(OBJECT(sioc));
|
||||
error_propagate(errp, local_err);
|
||||
return -ENOTCONN;
|
||||
}
|
||||
|
||||
qio_channel_set_delay(QIO_CHANNEL(sioc), false);
|
||||
pr_mgr->ioc = QIO_CHANNEL(sioc);
|
||||
|
||||
/* A simple feature negotation protocol, even though there is
|
||||
* no optional feature right now.
|
||||
*/
|
||||
r = pr_manager_helper_read(pr_mgr, &flags, sizeof(flags), errp);
|
||||
if (r < 0) {
|
||||
goto out_close;
|
||||
}
|
||||
|
||||
flags = 0;
|
||||
r = pr_manager_helper_write(pr_mgr, -1, &flags, sizeof(flags), errp);
|
||||
if (r < 0) {
|
||||
goto out_close;
|
||||
}
|
||||
|
||||
return 0;
|
||||
|
||||
out_close:
|
||||
object_unref(OBJECT(pr_mgr->ioc));
|
||||
pr_mgr->ioc = NULL;
|
||||
return r;
|
||||
}
|
||||
|
||||
static int pr_manager_helper_run(PRManager *p,
|
||||
int fd, struct sg_io_hdr *io_hdr)
|
||||
{
|
||||
PRManagerHelper *pr_mgr = PR_MANAGER_HELPER(p);
|
||||
|
||||
uint32_t len;
|
||||
PRHelperResponse resp;
|
||||
int ret;
|
||||
int expected_dir;
|
||||
int attempts;
|
||||
uint8_t cdb[PR_HELPER_CDB_SIZE] = { 0 };
|
||||
|
||||
if (!io_hdr->cmd_len || io_hdr->cmd_len > PR_HELPER_CDB_SIZE) {
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
memcpy(cdb, io_hdr->cmdp, io_hdr->cmd_len);
|
||||
assert(cdb[0] == PERSISTENT_RESERVE_OUT || cdb[0] == PERSISTENT_RESERVE_IN);
|
||||
expected_dir =
|
||||
(cdb[0] == PERSISTENT_RESERVE_OUT ? SG_DXFER_TO_DEV : SG_DXFER_FROM_DEV);
|
||||
if (io_hdr->dxfer_direction != expected_dir) {
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
len = scsi_cdb_xfer(cdb);
|
||||
if (io_hdr->dxfer_len < len || len > PR_HELPER_DATA_SIZE) {
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
qemu_mutex_lock(&pr_mgr->lock);
|
||||
|
||||
/* Try to reconnect while sending the CDB. */
|
||||
for (attempts = 0; attempts < PR_MAX_RECONNECT_ATTEMPTS; attempts++) {
|
||||
if (!pr_mgr->ioc) {
|
||||
ret = pr_manager_helper_initialize(pr_mgr, NULL);
|
||||
if (ret < 0) {
|
||||
qemu_mutex_unlock(&pr_mgr->lock);
|
||||
g_usleep(G_USEC_PER_SEC);
|
||||
qemu_mutex_lock(&pr_mgr->lock);
|
||||
continue;
|
||||
}
|
||||
}
|
||||
|
||||
ret = pr_manager_helper_write(pr_mgr, fd, cdb, ARRAY_SIZE(cdb), NULL);
|
||||
if (ret >= 0) {
|
||||
break;
|
||||
}
|
||||
}
|
||||
if (ret < 0) {
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* After sending the CDB, any communications failure causes the
|
||||
* command to fail. The failure is transient, retrying the command
|
||||
* will invoke pr_manager_helper_initialize again.
|
||||
*/
|
||||
if (expected_dir == SG_DXFER_TO_DEV) {
|
||||
io_hdr->resid = io_hdr->dxfer_len - len;
|
||||
ret = pr_manager_helper_write(pr_mgr, -1, io_hdr->dxferp, len, NULL);
|
||||
if (ret < 0) {
|
||||
goto out;
|
||||
}
|
||||
}
|
||||
ret = pr_manager_helper_read(pr_mgr, &resp, sizeof(resp), NULL);
|
||||
if (ret < 0) {
|
||||
goto out;
|
||||
}
|
||||
|
||||
resp.result = be32_to_cpu(resp.result);
|
||||
resp.sz = be32_to_cpu(resp.sz);
|
||||
if (io_hdr->dxfer_direction == SG_DXFER_FROM_DEV) {
|
||||
assert(resp.sz <= io_hdr->dxfer_len);
|
||||
ret = pr_manager_helper_read(pr_mgr, io_hdr->dxferp, resp.sz, NULL);
|
||||
if (ret < 0) {
|
||||
goto out;
|
||||
}
|
||||
io_hdr->resid = io_hdr->dxfer_len - resp.sz;
|
||||
} else {
|
||||
assert(resp.sz == 0);
|
||||
}
|
||||
|
||||
io_hdr->status = resp.result;
|
||||
if (resp.result == CHECK_CONDITION) {
|
||||
io_hdr->driver_status = SG_ERR_DRIVER_SENSE;
|
||||
io_hdr->sb_len_wr = MIN(io_hdr->mx_sb_len, PR_HELPER_SENSE_SIZE);
|
||||
memcpy(io_hdr->sbp, resp.sense, io_hdr->sb_len_wr);
|
||||
}
|
||||
|
||||
out:
|
||||
if (ret < 0) {
|
||||
int sense_len = scsi_build_sense(io_hdr->sbp,
|
||||
SENSE_CODE(LUN_COMM_FAILURE));
|
||||
io_hdr->driver_status = SG_ERR_DRIVER_SENSE;
|
||||
io_hdr->sb_len_wr = MIN(io_hdr->mx_sb_len, sense_len);
|
||||
io_hdr->status = CHECK_CONDITION;
|
||||
}
|
||||
qemu_mutex_unlock(&pr_mgr->lock);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static void pr_manager_helper_complete(UserCreatable *uc, Error **errp)
|
||||
{
|
||||
PRManagerHelper *pr_mgr = PR_MANAGER_HELPER(uc);
|
||||
|
||||
qemu_mutex_lock(&pr_mgr->lock);
|
||||
pr_manager_helper_initialize(pr_mgr, errp);
|
||||
qemu_mutex_unlock(&pr_mgr->lock);
|
||||
}
|
||||
|
||||
static char *get_path(Object *obj, Error **errp)
|
||||
{
|
||||
PRManagerHelper *pr_mgr = PR_MANAGER_HELPER(obj);
|
||||
|
||||
return g_strdup(pr_mgr->path);
|
||||
}
|
||||
|
||||
static void set_path(Object *obj, const char *str, Error **errp)
|
||||
{
|
||||
PRManagerHelper *pr_mgr = PR_MANAGER_HELPER(obj);
|
||||
|
||||
g_free(pr_mgr->path);
|
||||
pr_mgr->path = g_strdup(str);
|
||||
}
|
||||
|
||||
static void pr_manager_helper_instance_finalize(Object *obj)
|
||||
{
|
||||
PRManagerHelper *pr_mgr = PR_MANAGER_HELPER(obj);
|
||||
|
||||
object_unref(OBJECT(pr_mgr->ioc));
|
||||
qemu_mutex_destroy(&pr_mgr->lock);
|
||||
}
|
||||
|
||||
static void pr_manager_helper_instance_init(Object *obj)
|
||||
{
|
||||
PRManagerHelper *pr_mgr = PR_MANAGER_HELPER(obj);
|
||||
|
||||
qemu_mutex_init(&pr_mgr->lock);
|
||||
}
|
||||
|
||||
static void pr_manager_helper_class_init(ObjectClass *klass,
|
||||
void *class_data G_GNUC_UNUSED)
|
||||
{
|
||||
PRManagerClass *prmgr_klass = PR_MANAGER_CLASS(klass);
|
||||
UserCreatableClass *uc_klass = USER_CREATABLE_CLASS(klass);
|
||||
|
||||
object_class_property_add_str(klass, "path", get_path, set_path,
|
||||
&error_abort);
|
||||
uc_klass->complete = pr_manager_helper_complete;
|
||||
prmgr_klass->run = pr_manager_helper_run;
|
||||
}
|
||||
|
||||
static const TypeInfo pr_manager_helper_info = {
|
||||
.parent = TYPE_PR_MANAGER,
|
||||
.name = TYPE_PR_MANAGER_HELPER,
|
||||
.instance_size = sizeof(PRManagerHelper),
|
||||
.instance_init = pr_manager_helper_instance_init,
|
||||
.instance_finalize = pr_manager_helper_instance_finalize,
|
||||
.class_init = pr_manager_helper_class_init,
|
||||
};
|
||||
|
||||
static void pr_manager_helper_register_types(void)
|
||||
{
|
||||
type_register_static(&pr_manager_helper_info);
|
||||
}
|
||||
|
||||
type_init(pr_manager_helper_register_types);
|
||||
Loading…
Reference in New Issue
Block a user