@@ -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 @@ out_err:
obj_request_done_set(obj_request);
}
-static void rbd_watch_cb(void *arg, u64 notify_id, u64 cookie,
- u64 notifier_id, void *data, size_t data_len)
+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 rbd_device *rbd_dev = arg;
struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ char cookie[32];
int ret;
- dout("%s rbd_dev %p cookie %llu notify_id %llu\n", __func__, rbd_dev,
- cookie, notify_id);
+ 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);
/*
- * Until adequate refresh error handling is in place, there is
- * not much we can do here, except warn.
+ * Ensure that all in-flight IO is flushed.
*
- * See http://tracker.ceph.com/issues/5040
+ * FIXME: ceph_osdc_sync() flushes the entire OSD client, which
+ * may be shared with other devices.
*/
- ret = rbd_dev_refresh(rbd_dev);
- if (ret)
- rbd_warn(rbd_dev, "refresh failed: %d", ret);
+ 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,
- NULL, 0);
+ buf, buf_size);
if (ret)
- rbd_warn(rbd_dev, "notify_ack ret %d", 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;
+ 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 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))
+ /*
+ * 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);
+
+ 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 @@ out:
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)
{
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: Ilya Dryomov <idryomov@gmail.com> --- drivers/block/rbd.c | 812 +++++++++++++++++++++++++++++++++++++++++++++- drivers/block/rbd_types.h | 11 + net/ceph/ceph_strings.c | 1 + 3 files changed, 808 insertions(+), 16 deletions(-)