Commit ed95b21a authored by Ilya Dryomov's avatar Ilya Dryomov

rbd: support for exclusive-lock feature

Add basic support for RBD_FEATURE_EXCLUSIVE_LOCK feature.  Maintenance
operations (resize, snapshot create, etc) are offloaded to librbd via
returning -EOPNOTSUPP - librbd should request the lock and execute the
operation.
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
Reviewed-by: default avatarMike Christie <mchristi@redhat.com>
Tested-by: default avatarMike Christie <mchristi@redhat.com>
parent 99d16943
......@@ -31,6 +31,7 @@
#include <linux/ceph/libceph.h>
#include <linux/ceph/osd_client.h>
#include <linux/ceph/mon_client.h>
#include <linux/ceph/cls_lock_client.h>
#include <linux/ceph/decode.h>
#include <linux/parser.h>
#include <linux/bsearch.h>
......@@ -114,14 +115,17 @@ static int atomic_dec_return_safe(atomic_t *v)
#define RBD_OBJ_PREFIX_LEN_MAX 64
#define RBD_NOTIFY_TIMEOUT 5 /* seconds */
#define RBD_RETRY_DELAY msecs_to_jiffies(1000)
/* Feature bits */
#define RBD_FEATURE_LAYERING (1<<0)
#define RBD_FEATURE_STRIPINGV2 (1<<1)
#define RBD_FEATURES_ALL \
(RBD_FEATURE_LAYERING | RBD_FEATURE_STRIPINGV2)
#define RBD_FEATURE_EXCLUSIVE_LOCK (1<<2)
#define RBD_FEATURES_ALL (RBD_FEATURE_LAYERING | \
RBD_FEATURE_STRIPINGV2 | \
RBD_FEATURE_EXCLUSIVE_LOCK)
/* Features supported by this (client software) implementation. */
......@@ -327,6 +331,18 @@ enum rbd_watch_state {
RBD_WATCH_STATE_ERROR,
};
enum rbd_lock_state {
RBD_LOCK_STATE_UNLOCKED,
RBD_LOCK_STATE_LOCKED,
RBD_LOCK_STATE_RELEASING,
};
/* WatchNotify::ClientId */
struct rbd_client_id {
u64 gid;
u64 handle;
};
struct rbd_mapping {
u64 size;
u64 features;
......@@ -366,6 +382,15 @@ struct rbd_device {
u64 watch_cookie;
struct delayed_work watch_dwork;
struct rw_semaphore lock_rwsem;
enum rbd_lock_state lock_state;
struct rbd_client_id owner_cid;
struct work_struct acquired_lock_work;
struct work_struct released_lock_work;
struct delayed_work lock_dwork;
struct work_struct unlock_work;
wait_queue_head_t lock_waitq;
struct workqueue_struct *task_wq;
struct rbd_spec *parent_spec;
......@@ -450,6 +475,29 @@ static int minor_to_rbd_dev_id(int minor)
return minor >> RBD_SINGLE_MAJOR_PART_SHIFT;
}
static bool rbd_is_lock_supported(struct rbd_device *rbd_dev)
{
return (rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK) &&
rbd_dev->spec->snap_id == CEPH_NOSNAP &&
!rbd_dev->mapping.read_only;
}
static bool __rbd_is_lock_owner(struct rbd_device *rbd_dev)
{
return rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED ||
rbd_dev->lock_state == RBD_LOCK_STATE_RELEASING;
}
static bool rbd_is_lock_owner(struct rbd_device *rbd_dev)
{
bool is_lock_owner;
down_read(&rbd_dev->lock_rwsem);
is_lock_owner = __rbd_is_lock_owner(rbd_dev);
up_read(&rbd_dev->lock_rwsem);
return is_lock_owner;
}
static BUS_ATTR(add, S_IWUSR, NULL, rbd_add);
static BUS_ATTR(remove, S_IWUSR, NULL, rbd_remove);
static BUS_ATTR(add_single_major, S_IWUSR, NULL, rbd_add_single_major);
......@@ -3095,31 +3143,690 @@ static void rbd_img_parent_read(struct rbd_obj_request *obj_request)
obj_request_done_set(obj_request);
}
static const struct rbd_client_id rbd_empty_cid;
static bool rbd_cid_equal(const struct rbd_client_id *lhs,
const struct rbd_client_id *rhs)
{
return lhs->gid == rhs->gid && lhs->handle == rhs->handle;
}
static struct rbd_client_id rbd_get_cid(struct rbd_device *rbd_dev)
{
struct rbd_client_id cid;
mutex_lock(&rbd_dev->watch_mutex);
cid.gid = ceph_client_gid(rbd_dev->rbd_client->client);
cid.handle = rbd_dev->watch_cookie;
mutex_unlock(&rbd_dev->watch_mutex);
return cid;
}
/*
* lock_rwsem must be held for write
*/
static void rbd_set_owner_cid(struct rbd_device *rbd_dev,
const struct rbd_client_id *cid)
{
dout("%s rbd_dev %p %llu-%llu -> %llu-%llu\n", __func__, rbd_dev,
rbd_dev->owner_cid.gid, rbd_dev->owner_cid.handle,
cid->gid, cid->handle);
rbd_dev->owner_cid = *cid; /* struct */
}
static void format_lock_cookie(struct rbd_device *rbd_dev, char *buf)
{
mutex_lock(&rbd_dev->watch_mutex);
sprintf(buf, "%s %llu", RBD_LOCK_COOKIE_PREFIX, rbd_dev->watch_cookie);
mutex_unlock(&rbd_dev->watch_mutex);
}
/*
* lock_rwsem must be held for write
*/
static int rbd_lock(struct rbd_device *rbd_dev)
{
struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
struct rbd_client_id cid = rbd_get_cid(rbd_dev);
char cookie[32];
int ret;
WARN_ON(__rbd_is_lock_owner(rbd_dev));
format_lock_cookie(rbd_dev, cookie);
ret = ceph_cls_lock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
RBD_LOCK_NAME, CEPH_CLS_LOCK_EXCLUSIVE, cookie,
RBD_LOCK_TAG, "", 0);
if (ret)
return ret;
rbd_dev->lock_state = RBD_LOCK_STATE_LOCKED;
rbd_set_owner_cid(rbd_dev, &cid);
queue_work(rbd_dev->task_wq, &rbd_dev->acquired_lock_work);
return 0;
}
/*
* lock_rwsem must be held for write
*/
static int rbd_unlock(struct rbd_device *rbd_dev)
{
struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
char cookie[32];
int ret;
WARN_ON(!__rbd_is_lock_owner(rbd_dev));
rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
format_lock_cookie(rbd_dev, cookie);
ret = ceph_cls_unlock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
RBD_LOCK_NAME, cookie);
if (ret && ret != -ENOENT) {
rbd_warn(rbd_dev, "cls_unlock failed: %d", ret);
return ret;
}
rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
queue_work(rbd_dev->task_wq, &rbd_dev->released_lock_work);
return 0;
}
static int __rbd_notify_op_lock(struct rbd_device *rbd_dev,
enum rbd_notify_op notify_op,
struct page ***preply_pages,
size_t *preply_len)
{
struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
struct rbd_client_id cid = rbd_get_cid(rbd_dev);
int buf_size = 4 + 8 + 8 + CEPH_ENCODING_START_BLK_LEN;
char buf[buf_size];
void *p = buf;
dout("%s rbd_dev %p notify_op %d\n", __func__, rbd_dev, notify_op);
/* encode *LockPayload NotifyMessage (op + ClientId) */
ceph_start_encoding(&p, 2, 1, buf_size - CEPH_ENCODING_START_BLK_LEN);
ceph_encode_32(&p, notify_op);
ceph_encode_64(&p, cid.gid);
ceph_encode_64(&p, cid.handle);
return ceph_osdc_notify(osdc, &rbd_dev->header_oid,
&rbd_dev->header_oloc, buf, buf_size,
RBD_NOTIFY_TIMEOUT, preply_pages, preply_len);
}
static void rbd_notify_op_lock(struct rbd_device *rbd_dev,
enum rbd_notify_op notify_op)
{
struct page **reply_pages;
size_t reply_len;
__rbd_notify_op_lock(rbd_dev, notify_op, &reply_pages, &reply_len);
ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
}
static void rbd_notify_acquired_lock(struct work_struct *work)
{
struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
acquired_lock_work);
rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_ACQUIRED_LOCK);
}
static void rbd_notify_released_lock(struct work_struct *work)
{
struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
released_lock_work);
rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_RELEASED_LOCK);
}
static int rbd_request_lock(struct rbd_device *rbd_dev)
{
struct page **reply_pages;
size_t reply_len;
bool lock_owner_responded = false;
int ret;
dout("%s rbd_dev %p\n", __func__, rbd_dev);
ret = __rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_REQUEST_LOCK,
&reply_pages, &reply_len);
if (ret && ret != -ETIMEDOUT) {
rbd_warn(rbd_dev, "failed to request lock: %d", ret);
goto out;
}
if (reply_len > 0 && reply_len <= PAGE_SIZE) {
void *p = page_address(reply_pages[0]);
void *const end = p + reply_len;
u32 n;
ceph_decode_32_safe(&p, end, n, e_inval); /* num_acks */
while (n--) {
u8 struct_v;
u32 len;
ceph_decode_need(&p, end, 8 + 8, e_inval);
p += 8 + 8; /* skip gid and cookie */
ceph_decode_32_safe(&p, end, len, e_inval);
if (!len)
continue;
if (lock_owner_responded) {
rbd_warn(rbd_dev,
"duplicate lock owners detected");
ret = -EIO;
goto out;
}
lock_owner_responded = true;
ret = ceph_start_decoding(&p, end, 1, "ResponseMessage",
&struct_v, &len);
if (ret) {
rbd_warn(rbd_dev,
"failed to decode ResponseMessage: %d",
ret);
goto e_inval;
}
ret = ceph_decode_32(&p);
}
}
if (!lock_owner_responded) {
rbd_warn(rbd_dev, "no lock owners detected");
ret = -ETIMEDOUT;
}
out:
ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
return ret;
e_inval:
ret = -EINVAL;
goto out;
}
static void wake_requests(struct rbd_device *rbd_dev, bool wake_all)
{
dout("%s rbd_dev %p wake_all %d\n", __func__, rbd_dev, wake_all);
cancel_delayed_work(&rbd_dev->lock_dwork);
if (wake_all)
wake_up_all(&rbd_dev->lock_waitq);
else
wake_up(&rbd_dev->lock_waitq);
}
static int get_lock_owner_info(struct rbd_device *rbd_dev,
struct ceph_locker **lockers, u32 *num_lockers)
{
struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
u8 lock_type;
char *lock_tag;
int ret;
dout("%s rbd_dev %p\n", __func__, rbd_dev);
ret = ceph_cls_lock_info(osdc, &rbd_dev->header_oid,
&rbd_dev->header_oloc, RBD_LOCK_NAME,
&lock_type, &lock_tag, lockers, num_lockers);
if (ret)
return ret;
if (*num_lockers == 0) {
dout("%s rbd_dev %p no lockers detected\n", __func__, rbd_dev);
goto out;
}
if (strcmp(lock_tag, RBD_LOCK_TAG)) {
rbd_warn(rbd_dev, "locked by external mechanism, tag %s",
lock_tag);
ret = -EBUSY;
goto out;
}
if (lock_type == CEPH_CLS_LOCK_SHARED) {
rbd_warn(rbd_dev, "shared lock type detected");
ret = -EBUSY;
goto out;
}
if (strncmp((*lockers)[0].id.cookie, RBD_LOCK_COOKIE_PREFIX,
strlen(RBD_LOCK_COOKIE_PREFIX))) {
rbd_warn(rbd_dev, "locked by external mechanism, cookie %s",
(*lockers)[0].id.cookie);
ret = -EBUSY;
goto out;
}
out:
kfree(lock_tag);
return ret;
}
static int find_watcher(struct rbd_device *rbd_dev,
const struct ceph_locker *locker)
{
struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
struct ceph_watch_item *watchers;
u32 num_watchers;
u64 cookie;
int i;
int ret;
ret = ceph_osdc_list_watchers(osdc, &rbd_dev->header_oid,
&rbd_dev->header_oloc, &watchers,
&num_watchers);
if (ret)
return ret;
sscanf(locker->id.cookie, RBD_LOCK_COOKIE_PREFIX " %llu", &cookie);
for (i = 0; i < num_watchers; i++) {
if (!memcmp(&watchers[i].addr, &locker->info.addr,
sizeof(locker->info.addr)) &&
watchers[i].cookie == cookie) {
struct rbd_client_id cid = {
.gid = le64_to_cpu(watchers[i].name.num),
.handle = cookie,
};
dout("%s rbd_dev %p found cid %llu-%llu\n", __func__,
rbd_dev, cid.gid, cid.handle);
rbd_set_owner_cid(rbd_dev, &cid);
ret = 1;
goto out;
}
}
dout("%s rbd_dev %p no watchers\n", __func__, rbd_dev);
ret = 0;
out:
kfree(watchers);
return ret;
}
/*
* lock_rwsem must be held for write
*/
static int rbd_try_lock(struct rbd_device *rbd_dev)
{
struct ceph_client *client = rbd_dev->rbd_client->client;
struct ceph_locker *lockers;
u32 num_lockers;
int ret;
for (;;) {
ret = rbd_lock(rbd_dev);
if (ret != -EBUSY)
return ret;
/* determine if the current lock holder is still alive */
ret = get_lock_owner_info(rbd_dev, &lockers, &num_lockers);
if (ret)
return ret;
if (num_lockers == 0)
goto again;
ret = find_watcher(rbd_dev, lockers);
if (ret) {
if (ret > 0)
ret = 0; /* have to request lock */
goto out;
}
rbd_warn(rbd_dev, "%s%llu seems dead, breaking lock",
ENTITY_NAME(lockers[0].id.name));
ret = ceph_monc_blacklist_add(&client->monc,
&lockers[0].info.addr);
if (ret) {
rbd_warn(rbd_dev, "blacklist of %s%llu failed: %d",
ENTITY_NAME(lockers[0].id.name), ret);
goto out;
}
ret = ceph_cls_break_lock(&client->osdc, &rbd_dev->header_oid,
&rbd_dev->header_oloc, RBD_LOCK_NAME,
lockers[0].id.cookie,
&lockers[0].id.name);
if (ret && ret != -ENOENT)
goto out;
again:
ceph_free_lockers(lockers, num_lockers);
}
out:
ceph_free_lockers(lockers, num_lockers);
return ret;
}
/*
* ret is set only if lock_state is RBD_LOCK_STATE_UNLOCKED
*/
static enum rbd_lock_state rbd_try_acquire_lock(struct rbd_device *rbd_dev,
int *pret)
{
enum rbd_lock_state lock_state;
down_read(&rbd_dev->lock_rwsem);
dout("%s rbd_dev %p read lock_state %d\n", __func__, rbd_dev,
rbd_dev->lock_state);
if (__rbd_is_lock_owner(rbd_dev)) {
lock_state = rbd_dev->lock_state;
up_read(&rbd_dev->lock_rwsem);
return lock_state;
}
up_read(&rbd_dev->lock_rwsem);
down_write(&rbd_dev->lock_rwsem);
dout("%s rbd_dev %p write lock_state %d\n", __func__, rbd_dev,
rbd_dev->lock_state);
if (!__rbd_is_lock_owner(rbd_dev)) {
*pret = rbd_try_lock(rbd_dev);
if (*pret)
rbd_warn(rbd_dev, "failed to acquire lock: %d", *pret);
}
lock_state = rbd_dev->lock_state;
up_write(&rbd_dev->lock_rwsem);
return lock_state;
}
static void rbd_acquire_lock(struct work_struct *work)
{
struct rbd_device *rbd_dev = container_of(to_delayed_work(work),
struct rbd_device, lock_dwork);
enum rbd_lock_state lock_state;
int ret;
dout("%s rbd_dev %p\n", __func__, rbd_dev);
again:
lock_state = rbd_try_acquire_lock(rbd_dev, &ret);
if (lock_state != RBD_LOCK_STATE_UNLOCKED || ret == -EBLACKLISTED) {
if (lock_state == RBD_LOCK_STATE_LOCKED)
wake_requests(rbd_dev, true);
dout("%s rbd_dev %p lock_state %d ret %d - done\n", __func__,
rbd_dev, lock_state, ret);
return;
}
ret = rbd_request_lock(rbd_dev);
if (ret == -ETIMEDOUT) {
goto again; /* treat this as a dead client */
} else if (ret < 0) {
rbd_warn(rbd_dev, "error requesting lock: %d", ret);
mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork,
RBD_RETRY_DELAY);
} else {
/*
* lock owner acked, but resend if we don't see them
* release the lock
*/
dout("%s rbd_dev %p requeueing lock_dwork\n", __func__,
rbd_dev);
mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork,
msecs_to_jiffies(2 * RBD_NOTIFY_TIMEOUT * MSEC_PER_SEC));
}
}
/*
* lock_rwsem must be held for write
*/
static bool rbd_release_lock(struct rbd_device *rbd_dev)
{
dout("%s rbd_dev %p read lock_state %d\n", __func__, rbd_dev,
rbd_dev->lock_state);
if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED)
return false;
rbd_dev->lock_state = RBD_LOCK_STATE_RELEASING;
downgrade_write(&rbd_dev->lock_rwsem);
/*
* Ensure that all in-flight IO is flushed.
*
* FIXME: ceph_osdc_sync() flushes the entire OSD client, which
* may be shared with other devices.
*/
ceph_osdc_sync(&rbd_dev->rbd_client->client->osdc);
up_read(&rbd_dev->lock_rwsem);
down_write(&rbd_dev->lock_rwsem);
dout("%s rbd_dev %p write lock_state %d\n", __func__, rbd_dev,
rbd_dev->lock_state);
if (rbd_dev->lock_state != RBD_LOCK_STATE_RELEASING)
return false;
if (!rbd_unlock(rbd_dev))
/*
* Give others a chance to grab the lock - we would re-acquire
* almost immediately if we got new IO during ceph_osdc_sync()
* otherwise. We need to ack our own notifications, so this
* lock_dwork will be requeued from rbd_wait_state_locked()
* after wake_requests() in rbd_handle_released_lock().
*/
cancel_delayed_work(&rbd_dev->lock_dwork);
return true;
}
static void rbd_release_lock_work(struct work_struct *work)
{
struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
unlock_work);
down_write(&rbd_dev->lock_rwsem);
rbd_release_lock(rbd_dev);
up_write(&rbd_dev->lock_rwsem);
}
static void rbd_handle_acquired_lock(struct rbd_device *rbd_dev, u8 struct_v,
void **p)
{
struct rbd_client_id cid = { 0 };
if (struct_v >= 2) {
cid.gid = ceph_decode_64(p);
cid.handle = ceph_decode_64(p);
}
dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
cid.handle);
if (!rbd_cid_equal(&cid, &rbd_empty_cid)) {
down_write(&rbd_dev->lock_rwsem);
if (rbd_cid_equal(&cid, &rbd_dev->owner_cid)) {
/*
* we already know that the remote client is
* the owner
*/
up_write(&rbd_dev->lock_rwsem);
return;
}
rbd_set_owner_cid(rbd_dev, &cid);
downgrade_write(&rbd_dev->lock_rwsem);
} else {
down_read(&rbd_dev->lock_rwsem);
}
if (!__rbd_is_lock_owner(rbd_dev))
wake_requests(rbd_dev, false);
up_read(&rbd_dev->lock_rwsem);
}
static void rbd_handle_released_lock(struct rbd_device *rbd_dev, u8 struct_v,
void **p)
{
struct rbd_client_id cid = { 0 };
if (struct_v >= 2) {
cid.gid = ceph_decode_64(p);
cid.handle = ceph_decode_64(p);
}
dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
cid.handle);
if (!rbd_cid_equal(&cid, &rbd_empty_cid)) {
down_write(&rbd_dev->lock_rwsem);
if (!rbd_cid_equal(&cid, &rbd_dev->owner_cid)) {
dout("%s rbd_dev %p unexpected owner, cid %llu-%llu != owner_cid %llu-%llu\n",
__func__, rbd_dev, cid.gid, cid.handle,
rbd_dev->owner_cid.gid, rbd_dev->owner_cid.handle);
up_write(&rbd_dev->lock_rwsem);
return;
}
rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
downgrade_write(&rbd_dev->lock_rwsem);
} else {
down_read(&rbd_dev->lock_rwsem);
}
if (!__rbd_is_lock_owner(rbd_dev))
wake_requests(rbd_dev, false);
up_read(&rbd_dev->lock_rwsem);
}
static bool rbd_handle_request_lock(struct rbd_device *rbd_dev, u8 struct_v,
void **p)
{
struct rbd_client_id my_cid = rbd_get_cid(rbd_dev);
struct rbd_client_id cid = { 0 };
bool need_to_send;
if (struct_v >= 2) {
cid.gid = ceph_decode_64(p);
cid.handle = ceph_decode_64(p);
}
dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
cid.handle);
if (rbd_cid_equal(&cid, &my_cid))
return false;
down_read(&rbd_dev->lock_rwsem);
need_to_send = __rbd_is_lock_owner(rbd_dev);
if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED) {
if (!rbd_cid_equal(&rbd_dev->owner_cid, &rbd_empty_cid)) {
dout("%s rbd_dev %p queueing unlock_work\n", __func__,
rbd_dev);
queue_work(rbd_dev->task_wq, &rbd_dev->unlock_work);
}
}
up_read(&rbd_dev->lock_rwsem);
return need_to_send;
}
static void __rbd_acknowledge_notify(struct rbd_device *rbd_dev,
u64 notify_id, u64 cookie, s32 *result)
{
struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
int buf_size = 4 + CEPH_ENCODING_START_BLK_LEN;
char buf[buf_size];
int ret;
if (result) {
void *p = buf;
/* encode ResponseMessage */
ceph_start_encoding(&p, 1, 1,
buf_size - CEPH_ENCODING_START_BLK_LEN);
ceph_encode_32(&p, *result);
} else {
buf_size = 0;
}
ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
&rbd_dev->header_oloc, notify_id, cookie,
buf, buf_size);
if (ret)
rbd_warn(rbd_dev, "acknowledge_notify failed: %d", ret);
}
static void rbd_acknowledge_notify(struct rbd_device *rbd_dev, u64 notify_id,
u64 cookie)
{
dout("%s rbd_dev %p\n", __func__, rbd_dev);
__rbd_acknowledge_notify(rbd_dev, notify_id, cookie, NULL);
}
static void rbd_acknowledge_notify_result(struct rbd_device *rbd_dev,
u64 notify_id, u64 cookie, s32 result)
{
dout("%s rbd_dev %p result %d\n", __func__, rbd_dev, result);
__rbd_acknowledge_notify(rbd_dev, notify_id, cookie, &result);
}
static void rbd_watch_cb(void *arg, u64 notify_id, u64 cookie,
u64 notifier_id, void *data, size_t data_len)
{
struct rbd_device *rbd_dev = arg;
struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
void *p = data;
void *const end = p + data_len;
u8 struct_v;
u32 len;
u32 notify_op;
int ret;
dout("%s rbd_dev %p cookie %llu notify_id %llu\n", __func__, rbd_dev,
cookie, notify_id);
dout("%s rbd_dev %p cookie %llu notify_id %llu data_len %zu\n",
__func__, rbd_dev, cookie, notify_id, data_len);
if (data_len) {
ret = ceph_start_decoding(&p, end, 1, "NotifyMessage",
&struct_v, &len);
if (ret) {
rbd_warn(rbd_dev, "failed to decode NotifyMessage: %d",
ret);
return;
}
notify_op = ceph_decode_32(&p);
} else {
/* legacy notification for header updates */
notify_op = RBD_NOTIFY_OP_HEADER_UPDATE;
len = 0;
}
dout("%s rbd_dev %p notify_op %u\n", __func__, rbd_dev, notify_op);
switch (notify_op) {
case RBD_NOTIFY_OP_ACQUIRED_LOCK:
rbd_handle_acquired_lock(rbd_dev, struct_v, &p);
rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
break;
case RBD_NOTIFY_OP_RELEASED_LOCK:
rbd_handle_released_lock(rbd_dev, struct_v, &p);
rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
break;
case RBD_NOTIFY_OP_REQUEST_LOCK:
if (rbd_handle_request_lock(rbd_dev, struct_v, &p))
/*
* Until adequate refresh error handling is in place, there is
* not much we can do here, except warn.
*
* See http://tracker.ceph.com/issues/5040
* send ResponseMessage(0) back so the client
* can detect a missing owner
*/
rbd_acknowledge_notify_result(rbd_dev, notify_id,
cookie, 0);
else
rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
break;
case RBD_NOTIFY_OP_HEADER_UPDATE:
ret = rbd_dev_refresh(rbd_dev);
if (ret)
rbd_warn(rbd_dev, "refresh failed: %d", ret);
ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
&rbd_dev->header_oloc, notify_id, cookie,
NULL, 0);
if (ret)
rbd_warn(rbd_dev, "notify_ack ret %d", ret);
rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
break;
default:
if (rbd_is_lock_owner(rbd_dev))
rbd_acknowledge_notify_result(rbd_dev, notify_id,
cookie, -EOPNOTSUPP);
else
rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
break;
}
}
static void __rbd_unregister_watch(struct rbd_device *rbd_dev);
......@@ -3130,6 +3837,10 @@ static void rbd_watch_errcb(void *arg, u64 cookie, int err)
rbd_warn(rbd_dev, "encountered watch error: %d", err);
down_write(&rbd_dev->lock_rwsem);
rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
up_write(&rbd_dev->lock_rwsem);
mutex_lock(&rbd_dev->watch_mutex);
if (rbd_dev->watch_state == RBD_WATCH_STATE_REGISTERED) {
__rbd_unregister_watch(rbd_dev);
......@@ -3202,10 +3913,15 @@ static void cancel_tasks_sync(struct rbd_device *rbd_dev)
dout("%s rbd_dev %p\n", __func__, rbd_dev);
cancel_delayed_work_sync(&rbd_dev->watch_dwork);
cancel_work_sync(&rbd_dev->acquired_lock_work);
cancel_work_sync(&rbd_dev->released_lock_work);
cancel_delayed_work_sync(&rbd_dev->lock_dwork);
cancel_work_sync(&rbd_dev->unlock_work);
}
static void rbd_unregister_watch(struct rbd_device *rbd_dev)
{
WARN_ON(waitqueue_active(&rbd_dev->lock_waitq));
cancel_tasks_sync(rbd_dev);
mutex_lock(&rbd_dev->watch_mutex);
......@@ -3221,10 +3937,15 @@ static void rbd_reregister_watch(struct work_struct *work)
{
struct rbd_device *rbd_dev = container_of(to_delayed_work(work),
struct rbd_device, watch_dwork);
bool was_lock_owner = false;
int ret;
dout("%s rbd_dev %p\n", __func__, rbd_dev);
down_write(&rbd_dev->lock_rwsem);
if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED)
was_lock_owner = rbd_release_lock(rbd_dev);
mutex_lock(&rbd_dev->watch_mutex);
if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR)
goto fail_unlock;
......@@ -3247,10 +3968,20 @@ static void rbd_reregister_watch(struct work_struct *work)
if (ret)
rbd_warn(rbd_dev, "reregisteration refresh failed: %d", ret);
if (was_lock_owner) {
ret = rbd_try_lock(rbd_dev);
if (ret)
rbd_warn(rbd_dev, "reregisteration lock failed: %d",
ret);
}
up_write(&rbd_dev->lock_rwsem);
wake_requests(rbd_dev, true);
return;
fail_unlock:
mutex_unlock(&rbd_dev->watch_mutex);
up_write(&rbd_dev->lock_rwsem);
}
/*
......@@ -3340,6 +4071,29 @@ static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
return ret;
}
/*
* lock_rwsem must be held for read
*/
static void rbd_wait_state_locked(struct rbd_device *rbd_dev)
{
DEFINE_WAIT(wait);
do {
/*
* Note the use of mod_delayed_work() in rbd_acquire_lock()
* and cancel_delayed_work() in wake_requests().
*/
dout("%s rbd_dev %p queueing lock_dwork\n", __func__, rbd_dev);
queue_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
prepare_to_wait_exclusive(&rbd_dev->lock_waitq, &wait,
TASK_UNINTERRUPTIBLE);
up_read(&rbd_dev->lock_rwsem);
schedule();
down_read(&rbd_dev->lock_rwsem);
} while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED);
finish_wait(&rbd_dev->lock_waitq, &wait);
}
static void rbd_queue_workfn(struct work_struct *work)
{
struct request *rq = blk_mq_rq_from_pdu(work);
......@@ -3350,6 +4104,7 @@ static void rbd_queue_workfn(struct work_struct *work)
u64 length = blk_rq_bytes(rq);
enum obj_operation_type op_type;
u64 mapping_size;
bool must_be_locked = false;
int result;
if (rq->cmd_type != REQ_TYPE_FS) {
......@@ -3411,6 +4166,7 @@ static void rbd_queue_workfn(struct work_struct *work)
if (op_type != OBJ_OP_READ) {
snapc = rbd_dev->header.snapc;
ceph_get_snap_context(snapc);
must_be_locked = rbd_is_lock_supported(rbd_dev);
}
up_read(&rbd_dev->header_rwsem);
......@@ -3421,11 +4177,17 @@ static void rbd_queue_workfn(struct work_struct *work)
goto err_rq;
}
if (must_be_locked) {
down_read(&rbd_dev->lock_rwsem);
if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED)
rbd_wait_state_locked(rbd_dev);
}
img_request = rbd_img_request_create(rbd_dev, offset, length, op_type,
snapc);
if (!img_request) {
result = -ENOMEM;
goto err_rq;
goto err_unlock;
}
img_request->rq = rq;
snapc = NULL; /* img_request consumes a ref */
......@@ -3443,10 +4205,15 @@ static void rbd_queue_workfn(struct work_struct *work)
if (result)
goto err_img_request;
if (must_be_locked)
up_read(&rbd_dev->lock_rwsem);
return;
err_img_request:
rbd_img_request_put(img_request);
err_unlock:
if (must_be_locked)
up_read(&rbd_dev->lock_rwsem);
err_rq:
if (result)
rbd_warn(rbd_dev, "%s %llx at %llx result %d",
......@@ -4020,6 +4787,7 @@ static void rbd_spec_free(struct kref *kref)
static void rbd_dev_free(struct rbd_device *rbd_dev)
{
WARN_ON(rbd_dev->watch_state != RBD_WATCH_STATE_UNREGISTERED);
WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_UNLOCKED);
ceph_oid_destroy(&rbd_dev->header_oid);
ceph_oloc_destroy(&rbd_dev->header_oloc);
......@@ -4071,6 +4839,14 @@ static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
INIT_DELAYED_WORK(&rbd_dev->watch_dwork, rbd_reregister_watch);
init_rwsem(&rbd_dev->lock_rwsem);
rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
INIT_WORK(&rbd_dev->acquired_lock_work, rbd_notify_acquired_lock);
INIT_WORK(&rbd_dev->released_lock_work, rbd_notify_released_lock);
INIT_DELAYED_WORK(&rbd_dev->lock_dwork, rbd_acquire_lock);
INIT_WORK(&rbd_dev->unlock_work, rbd_release_lock_work);
init_waitqueue_head(&rbd_dev->lock_waitq);
rbd_dev->dev.bus = &rbd_bus_type;
rbd_dev->dev.type = &rbd_device_type;
rbd_dev->dev.parent = &rbd_root_dev;
......@@ -5553,6 +6329,10 @@ static ssize_t do_rbd_remove(struct bus_type *bus,
if (ret < 0 || already)
return ret;
down_write(&rbd_dev->lock_rwsem);
if (__rbd_is_lock_owner(rbd_dev))
rbd_unlock(rbd_dev);
up_write(&rbd_dev->lock_rwsem);
rbd_unregister_watch(rbd_dev);
/*
......
......@@ -28,6 +28,17 @@
#define RBD_DATA_PREFIX "rbd_data."
#define RBD_ID_PREFIX "rbd_id."
#define RBD_LOCK_NAME "rbd_lock"
#define RBD_LOCK_TAG "internal"
#define RBD_LOCK_COOKIE_PREFIX "auto"
enum rbd_notify_op {
RBD_NOTIFY_OP_ACQUIRED_LOCK = 0,
RBD_NOTIFY_OP_RELEASED_LOCK = 1,
RBD_NOTIFY_OP_REQUEST_LOCK = 2,
RBD_NOTIFY_OP_HEADER_UPDATE = 3,
};
/*
* For format version 1, rbd image 'foo' consists of objects
* foo.rbd - image metadata
......
......@@ -15,6 +15,7 @@ const char *ceph_entity_type_name(int type)
default: return "unknown";
}
}
EXPORT_SYMBOL(ceph_entity_type_name);
const char *ceph_osd_op_name(int op)
{
......
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