Re: [3/4] DST: Network state machine.
On 14:47 Mon 10 Dec , Evgeniy Polyakov wrote:
Network state machine.
Includes network async processing state machine and related tasks.
Hi, I've tried to play a little bit with DST and discover huge memory
leak. Every read request from remote node result in bio + bio's pages leak.
Data flow:
-kst_export_ready ## prepare and submit bio
-generic_make_request(bio) ## submit it
-kst_export_read_end_io## block layer call bio_end_io callback
-kst_thread_process_state ## process ready requests
-kst_data_callback
-kst_data_process_bio ## submit pages to network layer
-kst_complete_req
-kst_bio_endio
-kst_export_read_end_io ## WoW we calling the same bio_end_io
## callback twice
-dst_free_request(req); ## request will be destroyed but it's bio
## and all bio's pages wasn't released.
We may release bio's pages after it was sent to network, it is safe because
sendpage() already called get_page(). I've attached simple patch which
this this.
Signed-off-by: Evgeniy Polyakov [EMAIL PROTECTED]
diff --git a/drivers/block/dst/kst.c b/drivers/block/dst/kst.c
new file mode 100644
index 000..8fa3387
--- /dev/null
+++ b/drivers/block/dst/kst.c
@@ -0,0 +1,1513 @@
+/*
+ * 2007+ Copyright (c) Evgeniy Polyakov [EMAIL PROTECTED] + * All rights
reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include linux/kernel.h
+#include linux/module.h
+#include linux/list.h
+#include linux/slab.h
+#include linux/socket.h
+#include linux/kthread.h
+#include linux/net.h
+#include linux/in.h
+#include linux/poll.h
+#include linux/bio.h
+#include linux/dst.h
+
+#include net/sock.h
+
+struct kst_poll_helper
+{
+ poll_table pt;
+ struct kst_state*st;
+};
+
+static LIST_HEAD(kst_worker_list);
+static DEFINE_MUTEX(kst_worker_mutex);
+
+/*
+ * This function creates bound socket for local export node.
+ */
+static int kst_sock_create(struct kst_state *st, struct saddr *addr,
+ int type, int proto, int backlog)
+{
+ int err;
+
+ err = sock_create(addr-sa_family, type, proto, st-socket);
+ if (err)
+ goto err_out_exit;
+
+ err = st-socket-ops-bind(st-socket, (struct sockaddr *)addr,
+ addr-sa_data_len);
+
+ err = st-socket-ops-listen(st-socket, backlog);
+ if (err)
+ goto err_out_release;
+
+ st-socket-sk-sk_allocation = GFP_NOIO;
+
+ return 0;
+
+err_out_release:
+ sock_release(st-socket);
+err_out_exit:
+ return err;
+}
+
+static void kst_sock_release(struct kst_state *st)
+{
+ if (st-socket) {
+ sock_release(st-socket);
+ st-socket = NULL;
+ }
+}
+
+void kst_wake(struct kst_state *st)
+{
+ if (st) {
+ struct kst_worker *w = st-node-w;
+ unsigned long flags;
+
+ spin_lock_irqsave(w-ready_lock, flags);
+ if (list_empty(st-ready_entry))
+ list_add_tail(st-ready_entry, w-ready_list);
+ spin_unlock_irqrestore(w-ready_lock, flags);
+
+ wake_up(w-wait);
+ }
+}
+EXPORT_SYMBOL_GPL(kst_wake);
+
+/*
+ * Polling machinery.
+ */
+static int kst_state_wake_callback(wait_queue_t *wait, unsigned mode,
+ int sync, void *key)
+{
+ struct kst_state *st = container_of(wait, struct kst_state, wait);
+ kst_wake(st);
+ return 1;
+}
+
+static void kst_queue_func(struct file *file, wait_queue_head_t *whead,
+ poll_table *pt)
+{
+ struct kst_state *st = container_of(pt, struct kst_poll_helper, pt)-st;
+
+ st-whead = whead;
+ init_waitqueue_func_entry(st-wait, kst_state_wake_callback);
+ add_wait_queue(whead, st-wait);
+}
+
+static void kst_poll_exit(struct kst_state *st)
+{
+ if (st-whead) {
+ remove_wait_queue(st-whead, st-wait);
+ st-whead = NULL;
+ }
+}
+
+/*
+ * This function removes request from state tree and ordering list.
+ */
+void kst_del_req(struct dst_request *req)
+{
+ list_del_init(req-request_list_entry);
+}
+EXPORT_SYMBOL_GPL(kst_del_req);
+
+static struct dst_request *kst_req_first(struct kst_state *st)
+{
+ struct dst_request *req = NULL;
+
+ if (!list_empty(st-request_list))
+ req = list_entry(st-request_list.next,
Re: [4/4] DST: Algorithms used in distributed storage.
On 14:47 Mon 10 Dec , Evgeniy Polyakov wrote:
Algorithms used in distributed storage.
Mirror and linear mapping code.
Hi, i've finally take a look on your DST solution.
It seems what your current implementation will not work on nonstandard
devices for example software raid0.
other comments are follows:
Signed-off-by: Evgeniy Polyakov [EMAIL PROTECTED]
diff --git a/drivers/block/dst/alg_linear.c b/drivers/block/dst/alg_linear.c
new file mode 100644
index 000..9dc0976
--- /dev/null
+++ b/drivers/block/dst/alg_linear.c
@@ -0,0 +1,105 @@
+/*
+ * 2007+ Copyright (c) Evgeniy Polyakov [EMAIL PROTECTED]
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include linux/module.h
+#include linux/kernel.h
+#include linux/init.h
+#include linux/dst.h
+
+static struct dst_alg *alg_linear;
+
+/*
+ * This callback is invoked when node is removed from storage.
+ */
+static void dst_linear_del_node(struct dst_node *n)
+{
+}
+
+/*
+ * This callback is invoked when node is added to storage.
+ */
+static int dst_linear_add_node(struct dst_node *n)
+{
+ struct dst_storage *st = n-st;
+
+ dprintk(%s: disk_size: %llu, node_size: %llu.\n,
+ __func__, st-disk_size, n-size);
+
+ mutex_lock(st-tree_lock);
+ n-start = st-disk_size;
+ st-disk_size += n-size;
+ set_capacity(st-disk, st-disk_size);
+ mutex_unlock(st-tree_lock);
+
+ return 0;
+}
+
+static int dst_linear_remap(struct dst_request *req)
+{
+ int err;
+
+ if (req-node-bdev) {
+ generic_make_request(req-bio);
+ return 0;
+ }
+
+ err = kst_check_permissions(req-state, req-bio);
+ if (err)
+ return err;
+
+ return req-state-ops-push(req);
+}
+
+/*
+ * Failover callback - it is invoked each time error happens during
+ * request processing.
+ */
+static int dst_linear_error(struct kst_state *st, int err)
+{
+ if (err)
+ set_bit(DST_NODE_FROZEN, st-node-flags);
+ else
+ clear_bit(DST_NODE_FROZEN, st-node-flags);
+ return 0;
+}
+
+static struct dst_alg_ops alg_linear_ops = {
+ .remap = dst_linear_remap,
+ .add_node = dst_linear_add_node,
+ .del_node = dst_linear_del_node,
+ .error = dst_linear_error,
+ .owner = THIS_MODULE,
+};
+
+static int __devinit alg_linear_init(void)
+{
+ alg_linear = dst_alloc_alg(alg_linear, alg_linear_ops);
+ if (!alg_linear)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void __devexit alg_linear_exit(void)
+{
+ dst_remove_alg(alg_linear);
+}
+
+module_init(alg_linear_init);
+module_exit(alg_linear_exit);
+
+MODULE_LICENSE(GPL);
+MODULE_AUTHOR(Evgeniy Polyakov [EMAIL PROTECTED]);
+MODULE_DESCRIPTION(Linear distributed algorithm.);
diff --git a/drivers/block/dst/alg_mirror.c b/drivers/block/dst/alg_mirror.c
new file mode 100644
index 000..3c457ff
--- /dev/null
+++ b/drivers/block/dst/alg_mirror.c
@@ -0,0 +1,1128 @@
+/*
+ * 2007+ Copyright (c) Evgeniy Polyakov [EMAIL PROTECTED]
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include linux/module.h
+#include linux/kernel.h
+#include linux/init.h
+#include linux/poll.h
+#include linux/dst.h
+
+struct dst_mirror_node_data
+{
+ u64 age;
+};
+
+struct dst_mirror_priv
+{
+ unsigned intchunk_num;
+
+ u64 last_start;
+
+ spinlock_t backlog_lock;
+ struct list_headbacklog_list;
+
+ struct dst_mirror_node_data old_data, new_data;
+
+ unsigned long *chunk;
+};
+
+static struct dst_alg *alg_mirror;
+static struct bio_set *dst_mirror_bio_set;
+
+static int dst_mirror_resync(struct dst_node *n, int ndp);
+
+static void dst_mirror_mark_sync(struct dst_node *n)
+{
+ if (test_bit(DST_NODE_NOTSYNC, n-flags)) {
+
