libceph: async MON client generic requests
For map check, we are going to need to send CEPH_MSG_MON_GET_VERSION
messages asynchronously and get a callback on completion. Refactor MON
client to allow firing off generic requests asynchronously and add an
async variant of ceph_monc_get_version(). ceph_monc_do_statfs() is
switched over and remains sync.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c
index 98bfbe1..4e49b22 100644
--- a/net/ceph/mon_client.c
+++ b/net/ceph/mon_client.c
@@ -493,6 +493,10 @@
struct ceph_mon_generic_request *req =
container_of(kref, struct ceph_mon_generic_request, kref);
+ dout("%s greq %p request %p reply %p\n", __func__, req, req->request,
+ req->reply);
+ WARN_ON(!RB_EMPTY_NODE(&req->node));
+
if (req->reply)
ceph_msg_put(req->reply);
if (req->request)
@@ -503,7 +507,8 @@
static void put_generic_request(struct ceph_mon_generic_request *req)
{
- kref_put(&req->kref, release_generic_request);
+ if (req)
+ kref_put(&req->kref, release_generic_request);
}
static void get_generic_request(struct ceph_mon_generic_request *req)
@@ -511,6 +516,103 @@
kref_get(&req->kref);
}
+static struct ceph_mon_generic_request *
+alloc_generic_request(struct ceph_mon_client *monc, gfp_t gfp)
+{
+ struct ceph_mon_generic_request *req;
+
+ req = kzalloc(sizeof(*req), gfp);
+ if (!req)
+ return NULL;
+
+ req->monc = monc;
+ kref_init(&req->kref);
+ RB_CLEAR_NODE(&req->node);
+ init_completion(&req->completion);
+
+ dout("%s greq %p\n", __func__, req);
+ return req;
+}
+
+static void register_generic_request(struct ceph_mon_generic_request *req)
+{
+ struct ceph_mon_client *monc = req->monc;
+
+ WARN_ON(req->tid);
+
+ get_generic_request(req);
+ req->tid = ++monc->last_tid;
+ insert_generic_request(&monc->generic_request_tree, req);
+}
+
+static void send_generic_request(struct ceph_mon_client *monc,
+ struct ceph_mon_generic_request *req)
+{
+ WARN_ON(!req->tid);
+
+ dout("%s greq %p tid %llu\n", __func__, req, req->tid);
+ req->request->hdr.tid = cpu_to_le64(req->tid);
+ ceph_con_send(&monc->con, ceph_msg_get(req->request));
+}
+
+static void __finish_generic_request(struct ceph_mon_generic_request *req)
+{
+ struct ceph_mon_client *monc = req->monc;
+
+ dout("%s greq %p tid %llu\n", __func__, req, req->tid);
+ erase_generic_request(&monc->generic_request_tree, req);
+
+ ceph_msg_revoke(req->request);
+ ceph_msg_revoke_incoming(req->reply);
+}
+
+static void finish_generic_request(struct ceph_mon_generic_request *req)
+{
+ __finish_generic_request(req);
+ put_generic_request(req);
+}
+
+static void complete_generic_request(struct ceph_mon_generic_request *req)
+{
+ if (req->complete_cb)
+ req->complete_cb(req);
+ else
+ complete_all(&req->completion);
+ put_generic_request(req);
+}
+
+void cancel_generic_request(struct ceph_mon_generic_request *req)
+{
+ struct ceph_mon_client *monc = req->monc;
+ struct ceph_mon_generic_request *lookup_req;
+
+ dout("%s greq %p tid %llu\n", __func__, req, req->tid);
+
+ mutex_lock(&monc->mutex);
+ lookup_req = lookup_generic_request(&monc->generic_request_tree,
+ req->tid);
+ if (lookup_req) {
+ WARN_ON(lookup_req != req);
+ finish_generic_request(req);
+ }
+
+ mutex_unlock(&monc->mutex);
+}
+
+static int wait_generic_request(struct ceph_mon_generic_request *req)
+{
+ int ret;
+
+ dout("%s greq %p tid %llu\n", __func__, req, req->tid);
+ ret = wait_for_completion_interruptible(&req->completion);
+ if (ret)
+ cancel_generic_request(req);
+ else
+ ret = req->result; /* completed */
+
+ return ret;
+}
+
static struct ceph_msg *get_generic_reply(struct ceph_connection *con,
struct ceph_msg_header *hdr,
int *skip)
@@ -540,40 +642,6 @@
return m;
}
-static int __do_generic_request(struct ceph_mon_client *monc, u64 tid,
- struct ceph_mon_generic_request *req)
-{
- int err;
-
- /* register request */
- req->tid = tid != 0 ? tid : ++monc->last_tid;
- req->request->hdr.tid = cpu_to_le64(req->tid);
- insert_generic_request(&monc->generic_request_tree, req);
- ceph_con_send(&monc->con, ceph_msg_get(req->request));
- mutex_unlock(&monc->mutex);
-
- err = wait_for_completion_interruptible(&req->completion);
-
- mutex_lock(&monc->mutex);
- erase_generic_request(&monc->generic_request_tree, req);
-
- if (!err)
- err = req->result;
- return err;
-}
-
-static int do_generic_request(struct ceph_mon_client *monc,
- struct ceph_mon_generic_request *req)
-{
- int err;
-
- mutex_lock(&monc->mutex);
- err = __do_generic_request(monc, 0, req);
- mutex_unlock(&monc->mutex);
-
- return err;
-}
-
/*
* statfs
*/
@@ -584,22 +652,24 @@
struct ceph_mon_statfs_reply *reply = msg->front.iov_base;
u64 tid = le64_to_cpu(msg->hdr.tid);
+ dout("%s msg %p tid %llu\n", __func__, msg, tid);
+
if (msg->front.iov_len != sizeof(*reply))
goto bad;
- dout("handle_statfs_reply %p tid %llu\n", msg, tid);
mutex_lock(&monc->mutex);
req = lookup_generic_request(&monc->generic_request_tree, tid);
- if (req) {
- *(struct ceph_statfs *)req->buf = reply->st;
- req->result = 0;
- get_generic_request(req);
+ if (!req) {
+ mutex_unlock(&monc->mutex);
+ return;
}
+
+ req->result = 0;
+ *req->u.st = reply->st; /* struct */
+ __finish_generic_request(req);
mutex_unlock(&monc->mutex);
- if (req) {
- complete_all(&req->completion);
- put_generic_request(req);
- }
+
+ complete_generic_request(req);
return;
bad:
@@ -614,39 +684,38 @@
{
struct ceph_mon_generic_request *req;
struct ceph_mon_statfs *h;
- int err;
+ int ret = -ENOMEM;
- req = kzalloc(sizeof(*req), GFP_NOFS);
+ req = alloc_generic_request(monc, GFP_NOFS);
if (!req)
- return -ENOMEM;
+ goto out;
- kref_init(&req->kref);
- RB_CLEAR_NODE(&req->node);
- req->buf = buf;
- init_completion(&req->completion);
-
- err = -ENOMEM;
req->request = ceph_msg_new(CEPH_MSG_STATFS, sizeof(*h), GFP_NOFS,
true);
if (!req->request)
goto out;
- req->reply = ceph_msg_new(CEPH_MSG_STATFS_REPLY, 1024, GFP_NOFS,
- true);
+
+ req->reply = ceph_msg_new(CEPH_MSG_STATFS_REPLY, 64, GFP_NOFS, true);
if (!req->reply)
goto out;
+ req->u.st = buf;
+
+ mutex_lock(&monc->mutex);
+ register_generic_request(req);
/* fill out request */
h = req->request->front.iov_base;
h->monhdr.have_version = 0;
h->monhdr.session_mon = cpu_to_le16(-1);
h->monhdr.session_mon_tid = 0;
h->fsid = monc->monmap->fsid;
+ send_generic_request(monc, req);
+ mutex_unlock(&monc->mutex);
- err = do_generic_request(monc, req);
-
+ ret = wait_generic_request(req);
out:
put_generic_request(req);
- return err;
+ return ret;
}
EXPORT_SYMBOL(ceph_monc_do_statfs);
@@ -659,7 +728,7 @@
void *end = p + msg->front_alloc_len;
u64 handle;
- dout("%s %p tid %llu\n", __func__, msg, tid);
+ dout("%s msg %p tid %llu\n", __func__, msg, tid);
ceph_decode_need(&p, end, 2*sizeof(u64), bad);
handle = ceph_decode_64(&p);
@@ -668,77 +737,110 @@
mutex_lock(&monc->mutex);
req = lookup_generic_request(&monc->generic_request_tree, handle);
- if (req) {
- *(u64 *)req->buf = ceph_decode_64(&p);
- req->result = 0;
- get_generic_request(req);
- }
- mutex_unlock(&monc->mutex);
- if (req) {
- complete_all(&req->completion);
- put_generic_request(req);
+ if (!req) {
+ mutex_unlock(&monc->mutex);
+ return;
}
+ req->result = 0;
+ req->u.newest = ceph_decode_64(&p);
+ __finish_generic_request(req);
+ mutex_unlock(&monc->mutex);
+
+ complete_generic_request(req);
return;
+
bad:
pr_err("corrupt mon_get_version reply, tid %llu\n", tid);
ceph_msg_dump(msg);
}
+static struct ceph_mon_generic_request *
+__ceph_monc_get_version(struct ceph_mon_client *monc, const char *what,
+ ceph_monc_callback_t cb, u64 private_data)
+{
+ struct ceph_mon_generic_request *req;
+
+ req = alloc_generic_request(monc, GFP_NOIO);
+ if (!req)
+ goto err_put_req;
+
+ req->request = ceph_msg_new(CEPH_MSG_MON_GET_VERSION,
+ sizeof(u64) + sizeof(u32) + strlen(what),
+ GFP_NOIO, true);
+ if (!req->request)
+ goto err_put_req;
+
+ req->reply = ceph_msg_new(CEPH_MSG_MON_GET_VERSION_REPLY, 32, GFP_NOIO,
+ true);
+ if (!req->reply)
+ goto err_put_req;
+
+ req->complete_cb = cb;
+ req->private_data = private_data;
+
+ mutex_lock(&monc->mutex);
+ register_generic_request(req);
+ {
+ void *p = req->request->front.iov_base;
+ void *const end = p + req->request->front_alloc_len;
+
+ ceph_encode_64(&p, req->tid); /* handle */
+ ceph_encode_string(&p, end, what, strlen(what));
+ WARN_ON(p != end);
+ }
+ send_generic_request(monc, req);
+ mutex_unlock(&monc->mutex);
+
+ return req;
+
+err_put_req:
+ put_generic_request(req);
+ return ERR_PTR(-ENOMEM);
+}
+
/*
* Send MMonGetVersion and wait for the reply.
*
* @what: one of "mdsmap", "osdmap" or "monmap"
*/
-int ceph_monc_do_get_version(struct ceph_mon_client *monc, const char *what,
- u64 *newest)
+int ceph_monc_get_version(struct ceph_mon_client *monc, const char *what,
+ u64 *newest)
{
struct ceph_mon_generic_request *req;
- void *p, *end;
- u64 tid;
- int err;
+ int ret;
- req = kzalloc(sizeof(*req), GFP_NOFS);
- if (!req)
- return -ENOMEM;
+ req = __ceph_monc_get_version(monc, what, NULL, 0);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
- kref_init(&req->kref);
- RB_CLEAR_NODE(&req->node);
- req->buf = newest;
- init_completion(&req->completion);
+ ret = wait_generic_request(req);
+ if (!ret)
+ *newest = req->u.newest;
- req->request = ceph_msg_new(CEPH_MSG_MON_GET_VERSION,
- sizeof(u64) + sizeof(u32) + strlen(what),
- GFP_NOFS, true);
- if (!req->request) {
- err = -ENOMEM;
- goto out;
- }
-
- req->reply = ceph_msg_new(CEPH_MSG_MON_GET_VERSION_REPLY, 1024,
- GFP_NOFS, true);
- if (!req->reply) {
- err = -ENOMEM;
- goto out;
- }
-
- p = req->request->front.iov_base;
- end = p + req->request->front_alloc_len;
-
- /* fill out request */
- mutex_lock(&monc->mutex);
- tid = ++monc->last_tid;
- ceph_encode_64(&p, tid); /* handle */
- ceph_encode_string(&p, end, what, strlen(what));
-
- err = __do_generic_request(monc, tid, req);
-
- mutex_unlock(&monc->mutex);
-out:
put_generic_request(req);
- return err;
+ return ret;
}
-EXPORT_SYMBOL(ceph_monc_do_get_version);
+EXPORT_SYMBOL(ceph_monc_get_version);
+
+/*
+ * Send MMonGetVersion,
+ *
+ * @what: one of "mdsmap", "osdmap" or "monmap"
+ */
+int ceph_monc_get_version_async(struct ceph_mon_client *monc, const char *what,
+ ceph_monc_callback_t cb, u64 private_data)
+{
+ struct ceph_mon_generic_request *req;
+
+ req = __ceph_monc_get_version(monc, what, cb, private_data);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+
+ put_generic_request(req);
+ return 0;
+}
+EXPORT_SYMBOL(ceph_monc_get_version_async);
/*
* Resend pending generic requests.
@@ -923,6 +1025,8 @@
ceph_auth_destroy(monc->auth);
+ WARN_ON(!RB_EMPTY_ROOT(&monc->generic_request_tree));
+
ceph_msg_put(monc->m_auth);
ceph_msg_put(monc->m_auth_reply);
ceph_msg_put(monc->m_subscribe);
