diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/block/drbd/drbd_receiver.c | 6113 |
1 files changed, 6113 insertions, 0 deletions
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c new file mode 100644 index 000000000..4ba09abbc --- /dev/null +++ b/drivers/block/drbd/drbd_receiver.c @@ -0,0 +1,6113 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + drbd_receiver.c + + This file is part of DRBD by Philipp Reisner and Lars Ellenberg. + + Copyright (C) 2001-2008, LINBIT Information Technologies GmbH. + Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>. + Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>. + + */ + + +#include <linux/module.h> + +#include <linux/uaccess.h> +#include <net/sock.h> + +#include <linux/drbd.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/in.h> +#include <linux/mm.h> +#include <linux/memcontrol.h> +#include <linux/mm_inline.h> +#include <linux/slab.h> +#include <uapi/linux/sched/types.h> +#include <linux/sched/signal.h> +#include <linux/pkt_sched.h> +#define __KERNEL_SYSCALLS__ +#include <linux/unistd.h> +#include <linux/vmalloc.h> +#include <linux/random.h> +#include <linux/string.h> +#include <linux/scatterlist.h> +#include <linux/part_stat.h> +#include "drbd_int.h" +#include "drbd_protocol.h" +#include "drbd_req.h" +#include "drbd_vli.h" + +#define PRO_FEATURES (DRBD_FF_TRIM|DRBD_FF_THIN_RESYNC|DRBD_FF_WSAME|DRBD_FF_WZEROES) + +struct packet_info { + enum drbd_packet cmd; + unsigned int size; + unsigned int vnr; + void *data; +}; + +enum finish_epoch { + FE_STILL_LIVE, + FE_DESTROYED, + FE_RECYCLED, +}; + +static int drbd_do_features(struct drbd_connection *connection); +static int drbd_do_auth(struct drbd_connection *connection); +static int drbd_disconnected(struct drbd_peer_device *); +static void conn_wait_active_ee_empty(struct drbd_connection *connection); +static enum finish_epoch drbd_may_finish_epoch(struct drbd_connection *, struct drbd_epoch *, enum epoch_event); +static int e_end_block(struct drbd_work *, int); + + +#define GFP_TRY (__GFP_HIGHMEM | __GFP_NOWARN) + +/* + * some helper functions to deal with single linked page lists, + * page->private being our "next" pointer. + */ + +/* If at least n pages are linked at head, get n pages off. + * Otherwise, don't modify head, and return NULL. + * Locking is the responsibility of the caller. + */ +static struct page *page_chain_del(struct page **head, int n) +{ + struct page *page; + struct page *tmp; + + BUG_ON(!n); + BUG_ON(!head); + + page = *head; + + if (!page) + return NULL; + + while (page) { + tmp = page_chain_next(page); + if (--n == 0) + break; /* found sufficient pages */ + if (tmp == NULL) + /* insufficient pages, don't use any of them. */ + return NULL; + page = tmp; + } + + /* add end of list marker for the returned list */ + set_page_private(page, 0); + /* actual return value, and adjustment of head */ + page = *head; + *head = tmp; + return page; +} + +/* may be used outside of locks to find the tail of a (usually short) + * "private" page chain, before adding it back to a global chain head + * with page_chain_add() under a spinlock. */ +static struct page *page_chain_tail(struct page *page, int *len) +{ + struct page *tmp; + int i = 1; + while ((tmp = page_chain_next(page))) { + ++i; + page = tmp; + } + if (len) + *len = i; + return page; +} + +static int page_chain_free(struct page *page) +{ + struct page *tmp; + int i = 0; + page_chain_for_each_safe(page, tmp) { + put_page(page); + ++i; + } + return i; +} + +static void page_chain_add(struct page **head, + struct page *chain_first, struct page *chain_last) +{ +#if 1 + struct page *tmp; + tmp = page_chain_tail(chain_first, NULL); + BUG_ON(tmp != chain_last); +#endif + + /* add chain to head */ + set_page_private(chain_last, (unsigned long)*head); + *head = chain_first; +} + +static struct page *__drbd_alloc_pages(struct drbd_device *device, + unsigned int number) +{ + struct page *page = NULL; + struct page *tmp = NULL; + unsigned int i = 0; + + /* Yes, testing drbd_pp_vacant outside the lock is racy. + * So what. It saves a spin_lock. */ + if (drbd_pp_vacant >= number) { + spin_lock(&drbd_pp_lock); + page = page_chain_del(&drbd_pp_pool, number); + if (page) + drbd_pp_vacant -= number; + spin_unlock(&drbd_pp_lock); + if (page) + return page; + } + + /* GFP_TRY, because we must not cause arbitrary write-out: in a DRBD + * "criss-cross" setup, that might cause write-out on some other DRBD, + * which in turn might block on the other node at this very place. */ + for (i = 0; i < number; i++) { + tmp = alloc_page(GFP_TRY); + if (!tmp) + break; + set_page_private(tmp, (unsigned long)page); + page = tmp; + } + + if (i == number) + return page; + + /* Not enough pages immediately available this time. + * No need to jump around here, drbd_alloc_pages will retry this + * function "soon". */ + if (page) { + tmp = page_chain_tail(page, NULL); + spin_lock(&drbd_pp_lock); + page_chain_add(&drbd_pp_pool, page, tmp); + drbd_pp_vacant += i; + spin_unlock(&drbd_pp_lock); + } + return NULL; +} + +static void reclaim_finished_net_peer_reqs(struct drbd_device *device, + struct list_head *to_be_freed) +{ + struct drbd_peer_request *peer_req, *tmp; + + /* The EEs are always appended to the end of the list. Since + they are sent in order over the wire, they have to finish + in order. As soon as we see the first not finished we can + stop to examine the list... */ + + list_for_each_entry_safe(peer_req, tmp, &device->net_ee, w.list) { + if (drbd_peer_req_has_active_page(peer_req)) + break; + list_move(&peer_req->w.list, to_be_freed); + } +} + +static void drbd_reclaim_net_peer_reqs(struct drbd_device *device) +{ + LIST_HEAD(reclaimed); + struct drbd_peer_request *peer_req, *t; + + spin_lock_irq(&device->resource->req_lock); + reclaim_finished_net_peer_reqs(device, &reclaimed); + spin_unlock_irq(&device->resource->req_lock); + list_for_each_entry_safe(peer_req, t, &reclaimed, w.list) + drbd_free_net_peer_req(device, peer_req); +} + +static void conn_reclaim_net_peer_reqs(struct drbd_connection *connection) +{ + struct drbd_peer_device *peer_device; + int vnr; + + rcu_read_lock(); + idr_for_each_entry(&connection->peer_devices, peer_device, vnr) { + struct drbd_device *device = peer_device->device; + if (!atomic_read(&device->pp_in_use_by_net)) + continue; + + kref_get(&device->kref); + rcu_read_unlock(); + drbd_reclaim_net_peer_reqs(device); + kref_put(&device->kref, drbd_destroy_device); + rcu_read_lock(); + } + rcu_read_unlock(); +} + +/** + * drbd_alloc_pages() - Returns @number pages, retries forever (or until signalled) + * @peer_device: DRBD device. + * @number: number of pages requested + * @retry: whether to retry, if not enough pages are available right now + * + * Tries to allocate number pages, first from our own page pool, then from + * the kernel. + * Possibly retry until DRBD frees sufficient pages somewhere else. + * + * If this allocation would exceed the max_buffers setting, we throttle + * allocation (schedule_timeout) to give the system some room to breathe. + * + * We do not use max-buffers as hard limit, because it could lead to + * congestion and further to a distributed deadlock during online-verify or + * (checksum based) resync, if the max-buffers, socket buffer sizes and + * resync-rate settings are mis-configured. + * + * Returns a page chain linked via page->private. + */ +struct page *drbd_alloc_pages(struct drbd_peer_device *peer_device, unsigned int number, + bool retry) +{ + struct drbd_device *device = peer_device->device; + struct page *page = NULL; + struct net_conf *nc; + DEFINE_WAIT(wait); + unsigned int mxb; + + rcu_read_lock(); + nc = rcu_dereference(peer_device->connection->net_conf); + mxb = nc ? nc->max_buffers : 1000000; + rcu_read_unlock(); + + if (atomic_read(&device->pp_in_use) < mxb) + page = __drbd_alloc_pages(device, number); + + /* Try to keep the fast path fast, but occasionally we need + * to reclaim the pages we lended to the network stack. */ + if (page && atomic_read(&device->pp_in_use_by_net) > 512) + drbd_reclaim_net_peer_reqs(device); + + while (page == NULL) { + prepare_to_wait(&drbd_pp_wait, &wait, TASK_INTERRUPTIBLE); + + drbd_reclaim_net_peer_reqs(device); + + if (atomic_read(&device->pp_in_use) < mxb) { + page = __drbd_alloc_pages(device, number); + if (page) + break; + } + + if (!retry) + break; + + if (signal_pending(current)) { + drbd_warn(device, "drbd_alloc_pages interrupted!\n"); + break; + } + + if (schedule_timeout(HZ/10) == 0) + mxb = UINT_MAX; + } + finish_wait(&drbd_pp_wait, &wait); + + if (page) + atomic_add(number, &device->pp_in_use); + return page; +} + +/* Must not be used from irq, as that may deadlock: see drbd_alloc_pages. + * Is also used from inside an other spin_lock_irq(&resource->req_lock); + * Either links the page chain back to the global pool, + * or returns all pages to the system. */ +static void drbd_free_pages(struct drbd_device *device, struct page *page, int is_net) +{ + atomic_t *a = is_net ? &device->pp_in_use_by_net : &device->pp_in_use; + int i; + + if (page == NULL) + return; + + if (drbd_pp_vacant > (DRBD_MAX_BIO_SIZE/PAGE_SIZE) * drbd_minor_count) + i = page_chain_free(page); + else { + struct page *tmp; + tmp = page_chain_tail(page, &i); + spin_lock(&drbd_pp_lock); + page_chain_add(&drbd_pp_pool, page, tmp); + drbd_pp_vacant += i; + spin_unlock(&drbd_pp_lock); + } + i = atomic_sub_return(i, a); + if (i < 0) + drbd_warn(device, "ASSERTION FAILED: %s: %d < 0\n", + is_net ? "pp_in_use_by_net" : "pp_in_use", i); + wake_up(&drbd_pp_wait); +} + +/* +You need to hold the req_lock: + _drbd_wait_ee_list_empty() + +You must not have the req_lock: + drbd_free_peer_req() + drbd_alloc_peer_req() + drbd_free_peer_reqs() + drbd_ee_fix_bhs() + drbd_finish_peer_reqs() + drbd_clear_done_ee() + drbd_wait_ee_list_empty() +*/ + +/* normal: payload_size == request size (bi_size) + * w_same: payload_size == logical_block_size + * trim: payload_size == 0 */ +struct drbd_peer_request * +drbd_alloc_peer_req(struct drbd_peer_device *peer_device, u64 id, sector_t sector, + unsigned int request_size, unsigned int payload_size, gfp_t gfp_mask) __must_hold(local) +{ + struct drbd_device *device = peer_device->device; + struct drbd_peer_request *peer_req; + struct page *page = NULL; + unsigned int nr_pages = PFN_UP(payload_size); + + if (drbd_insert_fault(device, DRBD_FAULT_AL_EE)) + return NULL; + + peer_req = mempool_alloc(&drbd_ee_mempool, gfp_mask & ~__GFP_HIGHMEM); + if (!peer_req) { + if (!(gfp_mask & __GFP_NOWARN)) + drbd_err(device, "%s: allocation failed\n", __func__); + return NULL; + } + + if (nr_pages) { + page = drbd_alloc_pages(peer_device, nr_pages, + gfpflags_allow_blocking(gfp_mask)); + if (!page) + goto fail; + } + + memset(peer_req, 0, sizeof(*peer_req)); + INIT_LIST_HEAD(&peer_req->w.list); + drbd_clear_interval(&peer_req->i); + peer_req->i.size = request_size; + peer_req->i.sector = sector; + peer_req->submit_jif = jiffies; + peer_req->peer_device = peer_device; + peer_req->pages = page; + /* + * The block_id is opaque to the receiver. It is not endianness + * converted, and sent back to the sender unchanged. + */ + peer_req->block_id = id; + + return peer_req; + + fail: + mempool_free(peer_req, &drbd_ee_mempool); + return NULL; +} + +void __drbd_free_peer_req(struct drbd_device *device, struct drbd_peer_request *peer_req, + int is_net) +{ + might_sleep(); + if (peer_req->flags & EE_HAS_DIGEST) + kfree(peer_req->digest); + drbd_free_pages(device, peer_req->pages, is_net); + D_ASSERT(device, atomic_read(&peer_req->pending_bios) == 0); + D_ASSERT(device, drbd_interval_empty(&peer_req->i)); + if (!expect(!(peer_req->flags & EE_CALL_AL_COMPLETE_IO))) { + peer_req->flags &= ~EE_CALL_AL_COMPLETE_IO; + drbd_al_complete_io(device, &peer_req->i); + } + mempool_free(peer_req, &drbd_ee_mempool); +} + +int drbd_free_peer_reqs(struct drbd_device *device, struct list_head *list) +{ + LIST_HEAD(work_list); + struct drbd_peer_request *peer_req, *t; + int count = 0; + int is_net = list == &device->net_ee; + + spin_lock_irq(&device->resource->req_lock); + list_splice_init(list, &work_list); + spin_unlock_irq(&device->resource->req_lock); + + list_for_each_entry_safe(peer_req, t, &work_list, w.list) { + __drbd_free_peer_req(device, peer_req, is_net); + count++; + } + return count; +} + +/* + * See also comments in _req_mod(,BARRIER_ACKED) and receive_Barrier. + */ +static int drbd_finish_peer_reqs(struct drbd_device *device) +{ + LIST_HEAD(work_list); + LIST_HEAD(reclaimed); + struct drbd_peer_request *peer_req, *t; + int err = 0; + + spin_lock_irq(&device->resource->req_lock); + reclaim_finished_net_peer_reqs(device, &reclaimed); + list_splice_init(&device->done_ee, &work_list); + spin_unlock_irq(&device->resource->req_lock); + + list_for_each_entry_safe(peer_req, t, &reclaimed, w.list) + drbd_free_net_peer_req(device, peer_req); + + /* possible callbacks here: + * e_end_block, and e_end_resync_block, e_send_superseded. + * all ignore the last argument. + */ + list_for_each_entry_safe(peer_req, t, &work_list, w.list) { + int err2; + + /* list_del not necessary, next/prev members not touched */ + err2 = peer_req->w.cb(&peer_req->w, !!err); + if (!err) + err = err2; + drbd_free_peer_req(device, peer_req); + } + wake_up(&device->ee_wait); + + return err; +} + +static void _drbd_wait_ee_list_empty(struct drbd_device *device, + struct list_head *head) +{ + DEFINE_WAIT(wait); + + /* avoids spin_lock/unlock + * and calling prepare_to_wait in the fast path */ + while (!list_empty(head)) { + prepare_to_wait(&device->ee_wait, &wait, TASK_UNINTERRUPTIBLE); + spin_unlock_irq(&device->resource->req_lock); + io_schedule(); + finish_wait(&device->ee_wait, &wait); + spin_lock_irq(&device->resource->req_lock); + } +} + +static void drbd_wait_ee_list_empty(struct drbd_device *device, + struct list_head *head) +{ + spin_lock_irq(&device->resource->req_lock); + _drbd_wait_ee_list_empty(device, head); + spin_unlock_irq(&device->resource->req_lock); +} + +static int drbd_recv_short(struct socket *sock, void *buf, size_t size, int flags) +{ + struct kvec iov = { + .iov_base = buf, + .iov_len = size, + }; + struct msghdr msg = { + .msg_flags = (flags ? flags : MSG_WAITALL | MSG_NOSIGNAL) + }; + iov_iter_kvec(&msg.msg_iter, ITER_DEST, &iov, 1, size); + return sock_recvmsg(sock, &msg, msg.msg_flags); +} + +static int drbd_recv(struct drbd_connection *connection, void *buf, size_t size) +{ + int rv; + + rv = drbd_recv_short(connection->data.socket, buf, size, 0); + + if (rv < 0) { + if (rv == -ECONNRESET) + drbd_info(connection, "sock was reset by peer\n"); + else if (rv != -ERESTARTSYS) + drbd_err(connection, "sock_recvmsg returned %d\n", rv); + } else if (rv == 0) { + if (test_bit(DISCONNECT_SENT, &connection->flags)) { + long t; + rcu_read_lock(); + t = rcu_dereference(connection->net_conf)->ping_timeo * HZ/10; + rcu_read_unlock(); + + t = wait_event_timeout(connection->ping_wait, connection->cstate < C_WF_REPORT_PARAMS, t); + + if (t) + goto out; + } + drbd_info(connection, "sock was shut down by peer\n"); + } + + if (rv != size) + conn_request_state(connection, NS(conn, C_BROKEN_PIPE), CS_HARD); + +out: + return rv; +} + +static int drbd_recv_all(struct drbd_connection *connection, void *buf, size_t size) +{ + int err; + + err = drbd_recv(connection, buf, size); + if (err != size) { + if (err >= 0) + err = -EIO; + } else + err = 0; + return err; +} + +static int drbd_recv_all_warn(struct drbd_connection *connection, void *buf, size_t size) +{ + int err; + + err = drbd_recv_all(connection, buf, size); + if (err && !signal_pending(current)) + drbd_warn(connection, "short read (expected size %d)\n", (int)size); + return err; +} + +/* quoting tcp(7): + * On individual connections, the socket buffer size must be set prior to the + * listen(2) or connect(2) calls in order to have it take effect. + * This is our wrapper to do so. + */ +static void drbd_setbufsize(struct socket *sock, unsigned int snd, + unsigned int rcv) +{ + /* open coded SO_SNDBUF, SO_RCVBUF */ + if (snd) { + sock->sk->sk_sndbuf = snd; + sock->sk->sk_userlocks |= SOCK_SNDBUF_LOCK; + } + if (rcv) { + sock->sk->sk_rcvbuf = rcv; + sock->sk->sk_userlocks |= SOCK_RCVBUF_LOCK; + } +} + +static struct socket *drbd_try_connect(struct drbd_connection *connection) +{ + const char *what; + struct socket *sock; + struct sockaddr_in6 src_in6; + struct sockaddr_in6 peer_in6; + struct net_conf *nc; + int err, peer_addr_len, my_addr_len; + int sndbuf_size, rcvbuf_size, connect_int; + int disconnect_on_error = 1; + + rcu_read_lock(); + nc = rcu_dereference(connection->net_conf); + if (!nc) { + rcu_read_unlock(); + return NULL; + } + sndbuf_size = nc->sndbuf_size; + rcvbuf_size = nc->rcvbuf_size; + connect_int = nc->connect_int; + rcu_read_unlock(); + + my_addr_len = min_t(int, connection->my_addr_len, sizeof(src_in6)); + memcpy(&src_in6, &connection->my_addr, my_addr_len); + + if (((struct sockaddr *)&connection->my_addr)->sa_family == AF_INET6) + src_in6.sin6_port = 0; + else + ((struct sockaddr_in *)&src_in6)->sin_port = 0; /* AF_INET & AF_SCI */ + + peer_addr_len = min_t(int, connection->peer_addr_len, sizeof(src_in6)); + memcpy(&peer_in6, &connection->peer_addr, peer_addr_len); + + what = "sock_create_kern"; + err = sock_create_kern(&init_net, ((struct sockaddr *)&src_in6)->sa_family, + SOCK_STREAM, IPPROTO_TCP, &sock); + if (err < 0) { + sock = NULL; + goto out; + } + + sock->sk->sk_rcvtimeo = + sock->sk->sk_sndtimeo = connect_int * HZ; + drbd_setbufsize(sock, sndbuf_size, rcvbuf_size); + + /* explicitly bind to the configured IP as source IP + * for the outgoing connections. + * This is needed for multihomed hosts and to be + * able to use lo: interfaces for drbd. + * Make sure to use 0 as port number, so linux selects + * a free one dynamically. + */ + what = "bind before connect"; + err = sock->ops->bind(sock, (struct sockaddr *) &src_in6, my_addr_len); + if (err < 0) + goto out; + + /* connect may fail, peer not yet available. + * stay C_WF_CONNECTION, don't go Disconnecting! */ + disconnect_on_error = 0; + what = "connect"; + err = sock->ops->connect(sock, (struct sockaddr *) &peer_in6, peer_addr_len, 0); + +out: + if (err < 0) { + if (sock) { + sock_release(sock); + sock = NULL; + } + switch (-err) { + /* timeout, busy, signal pending */ + case ETIMEDOUT: case EAGAIN: case EINPROGRESS: + case EINTR: case ERESTARTSYS: + /* peer not (yet) available, network problem */ + case ECONNREFUSED: case ENETUNREACH: + case EHOSTDOWN: case EHOSTUNREACH: + disconnect_on_error = 0; + break; + default: + drbd_err(connection, "%s failed, err = %d\n", what, err); + } + if (disconnect_on_error) + conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD); + } + + return sock; +} + +struct accept_wait_data { + struct drbd_connection *connection; + struct socket *s_listen; + struct completion door_bell; + void (*original_sk_state_change)(struct sock *sk); + +}; + +static void drbd_incoming_connection(struct sock *sk) +{ + struct accept_wait_data *ad = sk->sk_user_data; + void (*state_change)(struct sock *sk); + + state_change = ad->original_sk_state_change; + if (sk->sk_state == TCP_ESTABLISHED) + complete(&ad->door_bell); + state_change(sk); +} + +static int prepare_listen_socket(struct drbd_connection *connection, struct accept_wait_data *ad) +{ + int err, sndbuf_size, rcvbuf_size, my_addr_len; + struct sockaddr_in6 my_addr; + struct socket *s_listen; + struct net_conf *nc; + const char *what; + + rcu_read_lock(); + nc = rcu_dereference(connection->net_conf); + if (!nc) { + rcu_read_unlock(); + return -EIO; + } + sndbuf_size = nc->sndbuf_size; + rcvbuf_size = nc->rcvbuf_size; + rcu_read_unlock(); + + my_addr_len = min_t(int, connection->my_addr_len, sizeof(struct sockaddr_in6)); + memcpy(&my_addr, &connection->my_addr, my_addr_len); + + what = "sock_create_kern"; + err = sock_create_kern(&init_net, ((struct sockaddr *)&my_addr)->sa_family, + SOCK_STREAM, IPPROTO_TCP, &s_listen); + if (err) { + s_listen = NULL; + goto out; + } + + s_listen->sk->sk_reuse = SK_CAN_REUSE; /* SO_REUSEADDR */ + drbd_setbufsize(s_listen, sndbuf_size, rcvbuf_size); + + what = "bind before listen"; + err = s_listen->ops->bind(s_listen, (struct sockaddr *)&my_addr, my_addr_len); + if (err < 0) + goto out; + + ad->s_listen = s_listen; + write_lock_bh(&s_listen->sk->sk_callback_lock); + ad->original_sk_state_change = s_listen->sk->sk_state_change; + s_listen->sk->sk_state_change = drbd_incoming_connection; + s_listen->sk->sk_user_data = ad; + write_unlock_bh(&s_listen->sk->sk_callback_lock); + + what = "listen"; + err = s_listen->ops->listen(s_listen, 5); + if (err < 0) + goto out; + + return 0; +out: + if (s_listen) + sock_release(s_listen); + if (err < 0) { + if (err != -EAGAIN && err != -EINTR && err != -ERESTARTSYS) { + drbd_err(connection, "%s failed, err = %d\n", what, err); + conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD); + } + } + + return -EIO; +} + +static void unregister_state_change(struct sock *sk, struct accept_wait_data *ad) +{ + write_lock_bh(&sk->sk_callback_lock); + sk->sk_state_change = ad->original_sk_state_change; + sk->sk_user_data = NULL; + write_unlock_bh(&sk->sk_callback_lock); +} + +static struct socket *drbd_wait_for_connect(struct drbd_connection *connection, struct accept_wait_data *ad) +{ + int timeo, connect_int, err = 0; + struct socket *s_estab = NULL; + struct net_conf *nc; + + rcu_read_lock(); + nc = rcu_dereference(connection->net_conf); + if (!nc) { + rcu_read_unlock(); + return NULL; + } + connect_int = nc->connect_int; + rcu_read_unlock(); + + timeo = connect_int * HZ; + /* 28.5% random jitter */ + timeo += prandom_u32_max(2) ? timeo / 7 : -timeo / 7; + + err = wait_for_completion_interruptible_timeout(&ad->door_bell, timeo); + if (err <= 0) + return NULL; + + err = kernel_accept(ad->s_listen, &s_estab, 0); + if (err < 0) { + if (err != -EAGAIN && err != -EINTR && err != -ERESTARTSYS) { + drbd_err(connection, "accept failed, err = %d\n", err); + conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD); + } + } + + if (s_estab) + unregister_state_change(s_estab->sk, ad); + + return s_estab; +} + +static int decode_header(struct drbd_connection *, void *, struct packet_info *); + +static int send_first_packet(struct drbd_connection *connection, struct drbd_socket *sock, + enum drbd_packet cmd) +{ + if (!conn_prepare_command(connection, sock)) + return -EIO; + return conn_send_command(connection, sock, cmd, 0, NULL, 0); +} + +static int receive_first_packet(struct drbd_connection *connection, struct socket *sock) +{ + unsigned int header_size = drbd_header_size(connection); + struct packet_info pi; + struct net_conf *nc; + int err; + + rcu_read_lock(); + nc = rcu_dereference(connection->net_conf); + if (!nc) { + rcu_read_unlock(); + return -EIO; + } + sock->sk->sk_rcvtimeo = nc->ping_timeo * 4 * HZ / 10; + rcu_read_unlock(); + + err = drbd_recv_short(sock, connection->data.rbuf, header_size, 0); + if (err != header_size) { + if (err >= 0) + err = -EIO; + return err; + } + err = decode_header(connection, connection->data.rbuf, &pi); + if (err) + return err; + return pi.cmd; +} + +/** + * drbd_socket_okay() - Free the socket if its connection is not okay + * @sock: pointer to the pointer to the socket. + */ +static bool drbd_socket_okay(struct socket **sock) +{ + int rr; + char tb[4]; + + if (!*sock) + return false; + + rr = drbd_recv_short(*sock, tb, 4, MSG_DONTWAIT | MSG_PEEK); + + if (rr > 0 || rr == -EAGAIN) { + return true; + } else { + sock_release(*sock); + *sock = NULL; + return false; + } +} + +static bool connection_established(struct drbd_connection *connection, + struct socket **sock1, + struct socket **sock2) +{ + struct net_conf *nc; + int timeout; + bool ok; + + if (!*sock1 || !*sock2) + return false; + + rcu_read_lock(); + nc = rcu_dereference(connection->net_conf); + timeout = (nc->sock_check_timeo ?: nc->ping_timeo) * HZ / 10; + rcu_read_unlock(); + schedule_timeout_interruptible(timeout); + + ok = drbd_socket_okay(sock1); + ok = drbd_socket_okay(sock2) && ok; + + return ok; +} + +/* Gets called if a connection is established, or if a new minor gets created + in a connection */ +int drbd_connected(struct drbd_peer_device *peer_device) +{ + struct drbd_device *device = peer_device->device; + int err; + + atomic_set(&device->packet_seq, 0); + device->peer_seq = 0; + + device->state_mutex = peer_device->connection->agreed_pro_version < 100 ? + &peer_device->connection->cstate_mutex : + &device->own_state_mutex; + + err = drbd_send_sync_param(peer_device); + if (!err) + err = drbd_send_sizes(peer_device, 0, 0); + if (!err) + err = drbd_send_uuids(peer_device); + if (!err) + err = drbd_send_current_state(peer_device); + clear_bit(USE_DEGR_WFC_T, &device->flags); + clear_bit(RESIZE_PENDING, &device->flags); + atomic_set(&device->ap_in_flight, 0); + mod_timer(&device->request_timer, jiffies + HZ); /* just start it here. */ + return err; +} + +/* + * return values: + * 1 yes, we have a valid connection + * 0 oops, did not work out, please try again + * -1 peer talks different language, + * no point in trying again, please go standalone. + * -2 We do not have a network config... + */ +static int conn_connect(struct drbd_connection *connection) +{ + struct drbd_socket sock, msock; + struct drbd_peer_device *peer_device; + struct net_conf *nc; + int vnr, timeout, h; + bool discard_my_data, ok; + enum drbd_state_rv rv; + struct accept_wait_data ad = { + .connection = connection, + .door_bell = COMPLETION_INITIALIZER_ONSTACK(ad.door_bell), + }; + + clear_bit(DISCONNECT_SENT, &connection->flags); + if (conn_request_state(connection, NS(conn, C_WF_CONNECTION), CS_VERBOSE) < SS_SUCCESS) + return -2; + + mutex_init(&sock.mutex); + sock.sbuf = connection->data.sbuf; + sock.rbuf = connection->data.rbuf; + sock.socket = NULL; + mutex_init(&msock.mutex); + msock.sbuf = connection->meta.sbuf; + msock.rbuf = connection->meta.rbuf; + msock.socket = NULL; + + /* Assume that the peer only understands protocol 80 until we know better. */ + connection->agreed_pro_version = 80; + + if (prepare_listen_socket(connection, &ad)) + return 0; + + do { + struct socket *s; + + s = drbd_try_connect(connection); + if (s) { + if (!sock.socket) { + sock.socket = s; + send_first_packet(connection, &sock, P_INITIAL_DATA); + } else if (!msock.socket) { + clear_bit(RESOLVE_CONFLICTS, &connection->flags); + msock.socket = s; + send_first_packet(connection, &msock, P_INITIAL_META); + } else { + drbd_err(connection, "Logic error in conn_connect()\n"); + goto out_release_sockets; + } + } + + if (connection_established(connection, &sock.socket, &msock.socket)) + break; + +retry: + s = drbd_wait_for_connect(connection, &ad); + if (s) { + int fp = receive_first_packet(connection, s); + drbd_socket_okay(&sock.socket); + drbd_socket_okay(&msock.socket); + switch (fp) { + case P_INITIAL_DATA: + if (sock.socket) { + drbd_warn(connection, "initial packet S crossed\n"); + sock_release(sock.socket); + sock.socket = s; + goto randomize; + } + sock.socket = s; + break; + case P_INITIAL_META: + set_bit(RESOLVE_CONFLICTS, &connection->flags); + if (msock.socket) { + drbd_warn(connection, "initial packet M crossed\n"); + sock_release(msock.socket); + msock.socket = s; + goto randomize; + } + msock.socket = s; + break; + default: + drbd_warn(connection, "Error receiving initial packet\n"); + sock_release(s); +randomize: + if (prandom_u32_max(2)) + goto retry; + } + } + + if (connection->cstate <= C_DISCONNECTING) + goto out_release_sockets; + if (signal_pending(current)) { + flush_signals(current); + smp_rmb(); + if (get_t_state(&connection->receiver) == EXITING) + goto out_release_sockets; + } + + ok = connection_established(connection, &sock.socket, &msock.socket); + } while (!ok); + + if (ad.s_listen) + sock_release(ad.s_listen); + + sock.socket->sk->sk_reuse = SK_CAN_REUSE; /* SO_REUSEADDR */ + msock.socket->sk->sk_reuse = SK_CAN_REUSE; /* SO_REUSEADDR */ + + sock.socket->sk->sk_allocation = GFP_NOIO; + msock.socket->sk->sk_allocation = GFP_NOIO; + + sock.socket->sk->sk_priority = TC_PRIO_INTERACTIVE_BULK; + msock.socket->sk->sk_priority = TC_PRIO_INTERACTIVE; + + /* NOT YET ... + * sock.socket->sk->sk_sndtimeo = connection->net_conf->timeout*HZ/10; + * sock.socket->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT; + * first set it to the P_CONNECTION_FEATURES timeout, + * which we set to 4x the configured ping_timeout. */ + rcu_read_lock(); + nc = rcu_dereference(connection->net_conf); + + sock.socket->sk->sk_sndtimeo = + sock.socket->sk->sk_rcvtimeo = nc->ping_timeo*4*HZ/10; + + msock.socket->sk->sk_rcvtimeo = nc->ping_int*HZ; + timeout = nc->timeout * HZ / 10; + discard_my_data = nc->discard_my_data; + rcu_read_unlock(); + + msock.socket->sk->sk_sndtimeo = timeout; + + /* we don't want delays. + * we use TCP_CORK where appropriate, though */ + tcp_sock_set_nodelay(sock.socket->sk); + tcp_sock_set_nodelay(msock.socket->sk); + + connection->data.socket = sock.socket; + connection->meta.socket = msock.socket; + connection->last_received = jiffies; + + h = drbd_do_features(connection); + if (h <= 0) + return h; + + if (connection->cram_hmac_tfm) { + /* drbd_request_state(device, NS(conn, WFAuth)); */ + switch (drbd_do_auth(connection)) { + case -1: + drbd_err(connection, "Authentication of peer failed\n"); + return -1; + case 0: + drbd_err(connection, "Authentication of peer failed, trying again.\n"); + return 0; + } + } + + connection->data.socket->sk->sk_sndtimeo = timeout; + connection->data.socket->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT; + + if (drbd_send_protocol(connection) == -EOPNOTSUPP) + return -1; + + /* Prevent a race between resync-handshake and + * being promoted to Primary. + * + * Grab and release the state mutex, so we know that any current + * drbd_set_role() is finished, and any incoming drbd_set_role + * will see the STATE_SENT flag, and wait for it to be cleared. + */ + idr_for_each_entry(&connection->peer_devices, peer_device, vnr) + mutex_lock(peer_device->device->state_mutex); + + /* avoid a race with conn_request_state( C_DISCONNECTING ) */ + spin_lock_irq(&connection->resource->req_lock); + set_bit(STATE_SENT, &connection->flags); + spin_unlock_irq(&connection->resource->req_lock); + + idr_for_each_entry(&connection->peer_devices, peer_device, vnr) + mutex_unlock(peer_device->device->state_mutex); + + rcu_read_lock(); + idr_for_each_entry(&connection->peer_devices, peer_device, vnr) { + struct drbd_device *device = peer_device->device; + kref_get(&device->kref); + rcu_read_unlock(); + + if (discard_my_data) + set_bit(DISCARD_MY_DATA, &device->flags); + else + clear_bit(DISCARD_MY_DATA, &device->flags); + + drbd_connected(peer_device); + kref_put(&device->kref, drbd_destroy_device); + rcu_read_lock(); + } + rcu_read_unlock(); + + rv = conn_request_state(connection, NS(conn, C_WF_REPORT_PARAMS), CS_VERBOSE); + if (rv < SS_SUCCESS || connection->cstate != C_WF_REPORT_PARAMS) { + clear_bit(STATE_SENT, &connection->flags); + return 0; + } + + drbd_thread_start(&connection->ack_receiver); + /* opencoded create_singlethread_workqueue(), + * to be able to use format string arguments */ + connection->ack_sender = + alloc_ordered_workqueue("drbd_as_%s", WQ_MEM_RECLAIM, connection->resource->name); + if (!connection->ack_sender) { + drbd_err(connection, "Failed to create workqueue ack_sender\n"); + return 0; + } + + mutex_lock(&connection->resource->conf_update); + /* The discard_my_data flag is a single-shot modifier to the next + * connection attempt, the handshake of which is now well underway. + * No need for rcu style copying of the whole struct + * just to clear a single value. */ + connection->net_conf->discard_my_data = 0; + mutex_unlock(&connection->resource->conf_update); + + return h; + +out_release_sockets: + if (ad.s_listen) + sock_release(ad.s_listen); + if (sock.socket) + sock_release(sock.socket); + if (msock.socket) + sock_release(msock.socket); + return -1; +} + +static int decode_header(struct drbd_connection *connection, void *header, struct packet_info *pi) +{ + unsigned int header_size = drbd_header_size(connection); + + if (header_size == sizeof(struct p_header100) && + *(__be32 *)header == cpu_to_be32(DRBD_MAGIC_100)) { + struct p_header100 *h = header; + if (h->pad != 0) { + drbd_err(connection, "Header padding is not zero\n"); + return -EINVAL; + } + pi->vnr = be16_to_cpu(h->volume); + pi->cmd = be16_to_cpu(h->command); + pi->size = be32_to_cpu(h->length); + } else if (header_size == sizeof(struct p_header95) && + *(__be16 *)header == cpu_to_be16(DRBD_MAGIC_BIG)) { + struct p_header95 *h = header; + pi->cmd = be16_to_cpu(h->command); + pi->size = be32_to_cpu(h->length); + pi->vnr = 0; + } else if (header_size == sizeof(struct p_header80) && + *(__be32 *)header == cpu_to_be32(DRBD_MAGIC)) { + struct p_header80 *h = header; + pi->cmd = be16_to_cpu(h->command); + pi->size = be16_to_cpu(h->length); + pi->vnr = 0; + } else { + drbd_err(connection, "Wrong magic value 0x%08x in protocol version %d\n", + be32_to_cpu(*(__be32 *)header), + connection->agreed_pro_version); + return -EINVAL; + } + pi->data = header + header_size; + return 0; +} + +static void drbd_unplug_all_devices(struct drbd_connection *connection) +{ + if (current->plug == &connection->receiver_plug) { + blk_finish_plug(&connection->receiver_plug); + blk_start_plug(&connection->receiver_plug); + } /* else: maybe just schedule() ?? */ +} + +static int drbd_recv_header(struct drbd_connection *connection, struct packet_info *pi) +{ + void *buffer = connection->data.rbuf; + int err; + + err = drbd_recv_all_warn(connection, buffer, drbd_header_size(connection)); + if (err) + return err; + + err = decode_header(connection, buffer, pi); + connection->last_received = jiffies; + + return err; +} + +static int drbd_recv_header_maybe_unplug(struct drbd_connection *connection, struct packet_info *pi) +{ + void *buffer = connection->data.rbuf; + unsigned int size = drbd_header_size(connection); + int err; + + err = drbd_recv_short(connection->data.socket, buffer, size, MSG_NOSIGNAL|MSG_DONTWAIT); + if (err != size) { + /* If we have nothing in the receive buffer now, to reduce + * application latency, try to drain the backend queues as + * quickly as possible, and let remote TCP know what we have + * received so far. */ + if (err == -EAGAIN) { + tcp_sock_set_quickack(connection->data.socket->sk, 2); + drbd_unplug_all_devices(connection); + } + if (err > 0) { + buffer += err; + size -= err; + } + err = drbd_recv_all_warn(connection, buffer, size); + if (err) + return err; + } + + err = decode_header(connection, connection->data.rbuf, pi); + connection->last_received = jiffies; + + return err; +} +/* This is blkdev_issue_flush, but asynchronous. + * We want to submit to all component volumes in parallel, + * then wait for all completions. + */ +struct issue_flush_context { + atomic_t pending; + int error; + struct completion done; +}; +struct one_flush_context { + struct drbd_device *device; + struct issue_flush_context *ctx; +}; + +static void one_flush_endio(struct bio *bio) +{ + struct one_flush_context *octx = bio->bi_private; + struct drbd_device *device = octx->device; + struct issue_flush_context *ctx = octx->ctx; + + if (bio->bi_status) { + ctx->error = blk_status_to_errno(bio->bi_status); + drbd_info(device, "local disk FLUSH FAILED with status %d\n", bio->bi_status); + } + kfree(octx); + bio_put(bio); + + clear_bit(FLUSH_PENDING, &device->flags); + put_ldev(device); + kref_put(&device->kref, drbd_destroy_device); + + if (atomic_dec_and_test(&ctx->pending)) + complete(&ctx->done); +} + +static void submit_one_flush(struct drbd_device *device, struct issue_flush_context *ctx) +{ + struct bio *bio = bio_alloc(device->ldev->backing_bdev, 0, + REQ_OP_WRITE | REQ_PREFLUSH, GFP_NOIO); + struct one_flush_context *octx = kmalloc(sizeof(*octx), GFP_NOIO); + + if (!octx) { + drbd_warn(device, "Could not allocate a octx, CANNOT ISSUE FLUSH\n"); + /* FIXME: what else can I do now? disconnecting or detaching + * really does not help to improve the state of the world, either. + */ + bio_put(bio); + + ctx->error = -ENOMEM; + put_ldev(device); + kref_put(&device->kref, drbd_destroy_device); + return; + } + + octx->device = device; + octx->ctx = ctx; + bio->bi_private = octx; + bio->bi_end_io = one_flush_endio; + + device->flush_jif = jiffies; + set_bit(FLUSH_PENDING, &device->flags); + atomic_inc(&ctx->pending); + submit_bio(bio); +} + +static void drbd_flush(struct drbd_connection *connection) +{ + if (connection->resource->write_ordering >= WO_BDEV_FLUSH) { + struct drbd_peer_device *peer_device; + struct issue_flush_context ctx; + int vnr; + + atomic_set(&ctx.pending, 1); + ctx.error = 0; + init_completion(&ctx.done); + + rcu_read_lock(); + idr_for_each_entry(&connection->peer_devices, peer_device, vnr) { + struct drbd_device *device = peer_device->device; + + if (!get_ldev(device)) + continue; + kref_get(&device->kref); + rcu_read_unlock(); + + submit_one_flush(device, &ctx); + + rcu_read_lock(); + } + rcu_read_unlock(); + + /* Do we want to add a timeout, + * if disk-timeout is set? */ + if (!atomic_dec_and_test(&ctx.pending)) + wait_for_completion(&ctx.done); + + if (ctx.error) { + /* would rather check on EOPNOTSUPP, but that is not reliable. + * don't try again for ANY return value != 0 + * if (rv == -EOPNOTSUPP) */ + /* Any error is already reported by bio_endio callback. */ + drbd_bump_write_ordering(connection->resource, NULL, WO_DRAIN_IO); + } + } +} + +/** + * drbd_may_finish_epoch() - Applies an epoch_event to the epoch's state, eventually finishes it. + * @connection: DRBD connection. + * @epoch: Epoch object. + * @ev: Epoch event. + */ +static enum finish_epoch drbd_may_finish_epoch(struct drbd_connection *connection, + struct drbd_epoch *epoch, + enum epoch_event ev) +{ + int epoch_size; + struct drbd_epoch *next_epoch; + enum finish_epoch rv = FE_STILL_LIVE; + + spin_lock(&connection->epoch_lock); + do { + next_epoch = NULL; + + epoch_size = atomic_read(&epoch->epoch_size); + + switch (ev & ~EV_CLEANUP) { + case EV_PUT: + atomic_dec(&epoch->active); + break; + case EV_GOT_BARRIER_NR: + set_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags); + break; + case EV_BECAME_LAST: + /* nothing to do*/ + break; + } + + if (epoch_size != 0 && + atomic_read(&epoch->active) == 0 && + (test_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags) || ev & EV_CLEANUP)) { + if (!(ev & EV_CLEANUP)) { + spin_unlock(&connection->epoch_lock); + drbd_send_b_ack(epoch->connection, epoch->barrier_nr, epoch_size); + spin_lock(&connection->epoch_lock); + } +#if 0 + /* FIXME: dec unacked on connection, once we have + * something to count pending connection packets in. */ + if (test_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags)) + dec_unacked(epoch->connection); +#endif + + if (connection->current_epoch != epoch) { + next_epoch = list_entry(epoch->list.next, struct drbd_epoch, list); + list_del(&epoch->list); + ev = EV_BECAME_LAST | (ev & EV_CLEANUP); + connection->epochs--; + kfree(epoch); + + if (rv == FE_STILL_LIVE) + rv = FE_DESTROYED; + } else { + epoch->flags = 0; + atomic_set(&epoch->epoch_size, 0); + /* atomic_set(&epoch->active, 0); is already zero */ + if (rv == FE_STILL_LIVE) + rv = FE_RECYCLED; + } + } + + if (!next_epoch) + break; + + epoch = next_epoch; + } while (1); + + spin_unlock(&connection->epoch_lock); + + return rv; +} + +static enum write_ordering_e +max_allowed_wo(struct drbd_backing_dev *bdev, enum write_ordering_e wo) +{ + struct disk_conf *dc; + + dc = rcu_dereference(bdev->disk_conf); + + if (wo == WO_BDEV_FLUSH && !dc->disk_flushes) + wo = WO_DRAIN_IO; + if (wo == WO_DRAIN_IO && !dc->disk_drain) + wo = WO_NONE; + + return wo; +} + +/* + * drbd_bump_write_ordering() - Fall back to an other write ordering method + * @wo: Write ordering method to try. + */ +void drbd_bump_write_ordering(struct drbd_resource *resource, struct drbd_backing_dev *bdev, + enum write_ordering_e wo) +{ + struct drbd_device *device; + enum write_ordering_e pwo; + int vnr; + static char *write_ordering_str[] = { + [WO_NONE] = "none", + [WO_DRAIN_IO] = "drain", + [WO_BDEV_FLUSH] = "flush", + }; + + pwo = resource->write_ordering; + if (wo != WO_BDEV_FLUSH) + wo = min(pwo, wo); + rcu_read_lock(); + idr_for_each_entry(&resource->devices, device, vnr) { + if (get_ldev(device)) { + wo = max_allowed_wo(device->ldev, wo); + if (device->ldev == bdev) + bdev = NULL; + put_ldev(device); + } + } + + if (bdev) + wo = max_allowed_wo(bdev, wo); + + rcu_read_unlock(); + + resource->write_ordering = wo; + if (pwo != resource->write_ordering || wo == WO_BDEV_FLUSH) + drbd_info(resource, "Method to ensure write ordering: %s\n", write_ordering_str[resource->write_ordering]); +} + +/* + * Mapping "discard" to ZEROOUT with UNMAP does not work for us: + * Drivers have to "announce" q->limits.max_write_zeroes_sectors, or it + * will directly go to fallback mode, submitting normal writes, and + * never even try to UNMAP. + * + * And dm-thin does not do this (yet), mostly because in general it has + * to assume that "skip_block_zeroing" is set. See also: + * https://www.mail-archive.com/dm-devel%40redhat.com/msg07965.html + * https://www.redhat.com/archives/dm-devel/2018-January/msg00271.html + * + * We *may* ignore the discard-zeroes-data setting, if so configured. + * + * Assumption is that this "discard_zeroes_data=0" is only because the backend + * may ignore partial unaligned discards. + * + * LVM/DM thin as of at least + * LVM version: 2.02.115(2)-RHEL7 (2015-01-28) + * Library version: 1.02.93-RHEL7 (2015-01-28) + * Driver version: 4.29.0 + * still behaves this way. + * + * For unaligned (wrt. alignment and granularity) or too small discards, + * we zero-out the initial (and/or) trailing unaligned partial chunks, + * but discard all the aligned full chunks. + * + * At least for LVM/DM thin, with skip_block_zeroing=false, + * the result is effectively "discard_zeroes_data=1". + */ +/* flags: EE_TRIM|EE_ZEROOUT */ +int drbd_issue_discard_or_zero_out(struct drbd_device *device, sector_t start, unsigned int nr_sectors, int flags) +{ + struct block_device *bdev = device->ldev->backing_bdev; + sector_t tmp, nr; + unsigned int max_discard_sectors, granularity; + int alignment; + int err = 0; + + if ((flags & EE_ZEROOUT) || !(flags & EE_TRIM)) + goto zero_out; + + /* Zero-sector (unknown) and one-sector granularities are the same. */ + granularity = max(bdev_discard_granularity(bdev) >> 9, 1U); + alignment = (bdev_discard_alignment(bdev) >> 9) % granularity; + + max_discard_sectors = min(bdev_max_discard_sectors(bdev), (1U << 22)); + max_discard_sectors -= max_discard_sectors % granularity; + if (unlikely(!max_discard_sectors)) + goto zero_out; + + if (nr_sectors < granularity) + goto zero_out; + + tmp = start; + if (sector_div(tmp, granularity) != alignment) { + if (nr_sectors < 2*granularity) + goto zero_out; + /* start + gran - (start + gran - align) % gran */ + tmp = start + granularity - alignment; + tmp = start + granularity - sector_div(tmp, granularity); + + nr = tmp - start; + /* don't flag BLKDEV_ZERO_NOUNMAP, we don't know how many + * layers are below us, some may have smaller granularity */ + err |= blkdev_issue_zeroout(bdev, start, nr, GFP_NOIO, 0); + nr_sectors -= nr; + start = tmp; + } + while (nr_sectors >= max_discard_sectors) { + err |= blkdev_issue_discard(bdev, start, max_discard_sectors, + GFP_NOIO); + nr_sectors -= max_discard_sectors; + start += max_discard_sectors; + } + if (nr_sectors) { + /* max_discard_sectors is unsigned int (and a multiple of + * granularity, we made sure of that above already); + * nr is < max_discard_sectors; + * I don't need sector_div here, even though nr is sector_t */ + nr = nr_sectors; + nr -= (unsigned int)nr % granularity; + if (nr) { + err |= blkdev_issue_discard(bdev, start, nr, GFP_NOIO); + nr_sectors -= nr; + start += nr; + } + } + zero_out: + if (nr_sectors) { + err |= blkdev_issue_zeroout(bdev, start, nr_sectors, GFP_NOIO, + (flags & EE_TRIM) ? 0 : BLKDEV_ZERO_NOUNMAP); + } + return err != 0; +} + +static bool can_do_reliable_discards(struct drbd_device *device) +{ + struct disk_conf *dc; + bool can_do; + + if (!bdev_max_discard_sectors(device->ldev->backing_bdev)) + return false; + + rcu_read_lock(); + dc = rcu_dereference(device->ldev->disk_conf); + can_do = dc->discard_zeroes_if_aligned; + rcu_read_unlock(); + return can_do; +} + +static void drbd_issue_peer_discard_or_zero_out(struct drbd_device *device, struct drbd_peer_request *peer_req) +{ + /* If the backend cannot discard, or does not guarantee + * read-back zeroes in discarded ranges, we fall back to + * zero-out. Unless configuration specifically requested + * otherwise. */ + if (!can_do_reliable_discards(device)) + peer_req->flags |= EE_ZEROOUT; + + if (drbd_issue_discard_or_zero_out(device, peer_req->i.sector, + peer_req->i.size >> 9, peer_req->flags & (EE_ZEROOUT|EE_TRIM))) + peer_req->flags |= EE_WAS_ERROR; + drbd_endio_write_sec_final(peer_req); +} + +/** + * drbd_submit_peer_request() + * @device: DRBD device. + * @peer_req: peer request + * + * May spread the pages to multiple bios, + * depending on bio_add_page restrictions. + * + * Returns 0 if all bios have been submitted, + * -ENOMEM if we could not allocate enough bios, + * -ENOSPC (any better suggestion?) if we have not been able to bio_add_page a + * single page to an empty bio (which should never happen and likely indicates + * that the lower level IO stack is in some way broken). This has been observed + * on certain Xen deployments. + */ +/* TODO allocate from our own bio_set. */ +int drbd_submit_peer_request(struct drbd_device *device, + struct drbd_peer_request *peer_req, + const blk_opf_t opf, const int fault_type) +{ + struct bio *bios = NULL; + struct bio *bio; + struct page *page = peer_req->pages; + sector_t sector = peer_req->i.sector; + unsigned int data_size = peer_req->i.size; + unsigned int n_bios = 0; + unsigned int nr_pages = PFN_UP(data_size); + + /* TRIM/DISCARD: for now, always use the helper function + * blkdev_issue_zeroout(..., discard=true). + * It's synchronous, but it does the right thing wrt. bio splitting. + * Correctness first, performance later. Next step is to code an + * asynchronous variant of the same. + */ + if (peer_req->flags & (EE_TRIM | EE_ZEROOUT)) { + /* wait for all pending IO completions, before we start + * zeroing things out. */ + conn_wait_active_ee_empty(peer_req->peer_device->connection); + /* add it to the active list now, + * so we can find it to present it in debugfs */ + peer_req->submit_jif = jiffies; + peer_req->flags |= EE_SUBMITTED; + + /* If this was a resync request from receive_rs_deallocated(), + * it is already on the sync_ee list */ + if (list_empty(&peer_req->w.list)) { + spin_lock_irq(&device->resource->req_lock); + list_add_tail(&peer_req->w.list, &device->active_ee); + spin_unlock_irq(&device->resource->req_lock); + } + + drbd_issue_peer_discard_or_zero_out(device, peer_req); + return 0; + } + + /* In most cases, we will only need one bio. But in case the lower + * level restrictions happen to be different at this offset on this + * side than those of the sending peer, we may need to submit the + * request in more than one bio. + * + * Plain bio_alloc is good enough here, this is no DRBD internally + * generated bio, but a bio allocated on behalf of the peer. + */ +next_bio: + bio = bio_alloc(device->ldev->backing_bdev, nr_pages, opf, GFP_NOIO); + /* > peer_req->i.sector, unless this is the first bio */ + bio->bi_iter.bi_sector = sector; + bio->bi_private = peer_req; + bio->bi_end_io = drbd_peer_request_endio; + + bio->bi_next = bios; + bios = bio; + ++n_bios; + + page_chain_for_each(page) { + unsigned len = min_t(unsigned, data_size, PAGE_SIZE); + if (!bio_add_page(bio, page, len, 0)) + goto next_bio; + data_size -= len; + sector += len >> 9; + --nr_pages; + } + D_ASSERT(device, data_size == 0); + D_ASSERT(device, page == NULL); + + atomic_set(&peer_req->pending_bios, n_bios); + /* for debugfs: update timestamp, mark as submitted */ + peer_req->submit_jif = jiffies; + peer_req->flags |= EE_SUBMITTED; + do { + bio = bios; + bios = bios->bi_next; + bio->bi_next = NULL; + + drbd_submit_bio_noacct(device, fault_type, bio); + } while (bios); + return 0; +} + +static void drbd_remove_epoch_entry_interval(struct drbd_device *device, + struct drbd_peer_request *peer_req) +{ + struct drbd_interval *i = &peer_req->i; + + drbd_remove_interval(&device->write_requests, i); + drbd_clear_interval(i); + + /* Wake up any processes waiting for this peer request to complete. */ + if (i->waiting) + wake_up(&device->misc_wait); +} + +static void conn_wait_active_ee_empty(struct drbd_connection *connection) +{ + struct drbd_peer_device *peer_device; + int vnr; + + rcu_read_lock(); + idr_for_each_entry(&connection->peer_devices, peer_device, vnr) { + struct drbd_device *device = peer_device->device; + + kref_get(&device->kref); + rcu_read_unlock(); + drbd_wait_ee_list_empty(device, &device->active_ee); + kref_put(&device->kref, drbd_destroy_device); + rcu_read_lock(); + } + rcu_read_unlock(); +} + +static int receive_Barrier(struct drbd_connection *connection, struct packet_info *pi) +{ + int rv; + struct p_barrier *p = pi->data; + struct drbd_epoch *epoch; + + /* FIXME these are unacked on connection, + * not a specific (peer)device. + */ + connection->current_epoch->barrier_nr = p->barrier; + connection->current_epoch->connection = connection; + rv = drbd_may_finish_epoch(connection, connection->current_epoch, EV_GOT_BARRIER_NR); + + /* P_BARRIER_ACK may imply that the corresponding extent is dropped from + * the activity log, which means it would not be resynced in case the + * R_PRIMARY crashes now. + * Therefore we must send the barrier_ack after the barrier request was + * completed. */ + switch (connection->resource->write_ordering) { + case WO_NONE: + if (rv == FE_RECYCLED) + return 0; + + /* receiver context, in the writeout path of the other node. + * avoid potential distributed deadlock */ + epoch = kmalloc(sizeof(struct drbd_epoch), GFP_NOIO); + if (epoch) + break; + else + drbd_warn(connection, "Allocation of an epoch failed, slowing down\n"); + fallthrough; + + case WO_BDEV_FLUSH: + case WO_DRAIN_IO: + conn_wait_active_ee_empty(connection); + drbd_flush(connection); + + if (atomic_read(&connection->current_epoch->epoch_size)) { + epoch = kmalloc(sizeof(struct drbd_epoch), GFP_NOIO); + if (epoch) + break; + } + + return 0; + default: + drbd_err(connection, "Strangeness in connection->write_ordering %d\n", + connection->resource->write_ordering); + return -EIO; + } + + epoch->flags = 0; + atomic_set(&epoch->epoch_size, 0); + atomic_set(&epoch->active, 0); + + spin_lock(&connection->epoch_lock); + if (atomic_read(&connection->current_epoch->epoch_size)) { + list_add(&epoch->list, &connection->current_epoch->list); + connection->current_epoch = epoch; + connection->epochs++; + } else { + /* The current_epoch got recycled while we allocated this one... */ + kfree(epoch); + } + spin_unlock(&connection->epoch_lock); + + return 0; +} + +/* quick wrapper in case payload size != request_size (write same) */ +static void drbd_csum_ee_size(struct crypto_shash *h, + struct drbd_peer_request *r, void *d, + unsigned int payload_size) +{ + unsigned int tmp = r->i.size; + r->i.size = payload_size; + drbd_csum_ee(h, r, d); + r->i.size = tmp; +} + +/* used from receive_RSDataReply (recv_resync_read) + * and from receive_Data. + * data_size: actual payload ("data in") + * for normal writes that is bi_size. + * for discards, that is zero. + * for write same, it is logical_block_size. + * both trim and write same have the bi_size ("data len to be affected") + * as extra argument in the packet header. + */ +static struct drbd_peer_request * +read_in_block(struct drbd_peer_device *peer_device, u64 id, sector_t sector, + struct packet_info *pi) __must_hold(local) +{ + struct drbd_device *device = peer_device->device; + const sector_t capacity = get_capacity(device->vdisk); + struct drbd_peer_request *peer_req; + struct page *page; + int digest_size, err; + unsigned int data_size = pi->size, ds; + void *dig_in = peer_device->connection->int_dig_in; + void *dig_vv = peer_device->connection->int_dig_vv; + unsigned long *data; + struct p_trim *trim = (pi->cmd == P_TRIM) ? pi->data : NULL; + struct p_trim *zeroes = (pi->cmd == P_ZEROES) ? pi->data : NULL; + + digest_size = 0; + if (!trim && peer_device->connection->peer_integrity_tfm) { + digest_size = crypto_shash_digestsize(peer_device->connection->peer_integrity_tfm); + /* + * FIXME: Receive the incoming digest into the receive buffer + * here, together with its struct p_data? + */ + err = drbd_recv_all_warn(peer_device->connection, dig_in, digest_size); + if (err) + return NULL; + data_size -= digest_size; + } + + /* assume request_size == data_size, but special case trim. */ + ds = data_size; + if (trim) { + if (!expect(data_size == 0)) + return NULL; + ds = be32_to_cpu(trim->size); + } else if (zeroes) { + if (!expect(data_size == 0)) + return NULL; + ds = be32_to_cpu(zeroes->size); + } + + if (!expect(IS_ALIGNED(ds, 512))) + return NULL; + if (trim || zeroes) { + if (!expect(ds <= (DRBD_MAX_BBIO_SECTORS << 9))) + return NULL; + } else if (!expect(ds <= DRBD_MAX_BIO_SIZE)) + return NULL; + + /* even though we trust out peer, + * we sometimes have to double check. */ + if (sector + (ds>>9) > capacity) { + drbd_err(device, "request from peer beyond end of local disk: " + "capacity: %llus < sector: %llus + size: %u\n", + (unsigned long long)capacity, + (unsigned long long)sector, ds); + return NULL; + } + + /* GFP_NOIO, because we must not cause arbitrary write-out: in a DRBD + * "criss-cross" setup, that might cause write-out on some other DRBD, + * which in turn might block on the other node at this very place. */ + peer_req = drbd_alloc_peer_req(peer_device, id, sector, ds, data_size, GFP_NOIO); + if (!peer_req) + return NULL; + + peer_req->flags |= EE_WRITE; + if (trim) { + peer_req->flags |= EE_TRIM; + return peer_req; + } + if (zeroes) { + peer_req->flags |= EE_ZEROOUT; + return peer_req; + } + + /* receive payload size bytes into page chain */ + ds = data_size; + page = peer_req->pages; + page_chain_for_each(page) { + unsigned len = min_t(int, ds, PAGE_SIZE); + data = kmap(page); + err = drbd_recv_all_warn(peer_device->connection, data, len); + if (drbd_insert_fault(device, DRBD_FAULT_RECEIVE)) { + drbd_err(device, "Fault injection: Corrupting data on receive\n"); + data[0] = data[0] ^ (unsigned long)-1; + } + kunmap(page); + if (err) { + drbd_free_peer_req(device, peer_req); + return NULL; + } + ds -= len; + } + + if (digest_size) { + drbd_csum_ee_size(peer_device->connection->peer_integrity_tfm, peer_req, dig_vv, data_size); + if (memcmp(dig_in, dig_vv, digest_size)) { + drbd_err(device, "Digest integrity check FAILED: %llus +%u\n", + (unsigned long long)sector, data_size); + drbd_free_peer_req(device, peer_req); + return NULL; + } + } + device->recv_cnt += data_size >> 9; + return peer_req; +} + +/* drbd_drain_block() just takes a data block + * out of the socket input buffer, and discards it. + */ +static int drbd_drain_block(struct drbd_peer_device *peer_device, int data_size) +{ + struct page *page; + int err = 0; + void *data; + + if (!data_size) + return 0; + + page = drbd_alloc_pages(peer_device, 1, 1); + + data = kmap(page); + while (data_size) { + unsigned int len = min_t(int, data_size, PAGE_SIZE); + + err = drbd_recv_all_warn(peer_device->connection, data, len); + if (err) + break; + data_size -= len; + } + kunmap(page); + drbd_free_pages(peer_device->device, page, 0); + return err; +} + +static int recv_dless_read(struct drbd_peer_device *peer_device, struct drbd_request *req, + sector_t sector, int data_size) +{ + struct bio_vec bvec; + struct bvec_iter iter; + struct bio *bio; + int digest_size, err, expect; + void *dig_in = peer_device->connection->int_dig_in; + void *dig_vv = peer_device->connection->int_dig_vv; + + digest_size = 0; + if (peer_device->connection->peer_integrity_tfm) { + digest_size = crypto_shash_digestsize(peer_device->connection->peer_integrity_tfm); + err = drbd_recv_all_warn(peer_device->connection, dig_in, digest_size); + if (err) + return err; + data_size -= digest_size; + } + + /* optimistically update recv_cnt. if receiving fails below, + * we disconnect anyways, and counters will be reset. */ + peer_device->device->recv_cnt += data_size>>9; + + bio = req->master_bio; + D_ASSERT(peer_device->device, sector == bio->bi_iter.bi_sector); + + bio_for_each_segment(bvec, bio, iter) { + void *mapped = bvec_kmap_local(&bvec); + expect = min_t(int, data_size, bvec.bv_len); + err = drbd_recv_all_warn(peer_device->connection, mapped, expect); + kunmap_local(mapped); + if (err) + return err; + data_size -= expect; + } + + if (digest_size) { + drbd_csum_bio(peer_device->connection->peer_integrity_tfm, bio, dig_vv); + if (memcmp(dig_in, dig_vv, digest_size)) { + drbd_err(peer_device, "Digest integrity check FAILED. Broken NICs?\n"); + return -EINVAL; + } + } + + D_ASSERT(peer_device->device, data_size == 0); + return 0; +} + +/* + * e_end_resync_block() is called in ack_sender context via + * drbd_finish_peer_reqs(). + */ +static int e_end_resync_block(struct drbd_work *w, int unused) +{ + struct drbd_peer_request *peer_req = + container_of(w, struct drbd_peer_request, w); + struct drbd_peer_device *peer_device = peer_req->peer_device; + struct drbd_device *device = peer_device->device; + sector_t sector = peer_req->i.sector; + int err; + + D_ASSERT(device, drbd_interval_empty(&peer_req->i)); + + if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) { + drbd_set_in_sync(device, sector, peer_req->i.size); + err = drbd_send_ack(peer_device, P_RS_WRITE_ACK, peer_req); + } else { + /* Record failure to sync */ + drbd_rs_failed_io(device, sector, peer_req->i.size); + + err = drbd_send_ack(peer_device, P_NEG_ACK, peer_req); + } + dec_unacked(device); + + return err; +} + +static int recv_resync_read(struct drbd_peer_device *peer_device, sector_t sector, + struct packet_info *pi) __releases(local) +{ + struct drbd_device *device = peer_device->device; + struct drbd_peer_request *peer_req; + + peer_req = read_in_block(peer_device, ID_SYNCER, sector, pi); + if (!peer_req) + goto fail; + + dec_rs_pending(device); + + inc_unacked(device); + /* corresponding dec_unacked() in e_end_resync_block() + * respective _drbd_clear_done_ee */ + + peer_req->w.cb = e_end_resync_block; + peer_req->submit_jif = jiffies; + + spin_lock_irq(&device->resource->req_lock); + list_add_tail(&peer_req->w.list, &device->sync_ee); + spin_unlock_irq(&device->resource->req_lock); + + atomic_add(pi->size >> 9, &device->rs_sect_ev); + if (drbd_submit_peer_request(device, peer_req, REQ_OP_WRITE, + DRBD_FAULT_RS_WR) == 0) + return 0; + + /* don't care for the reason here */ + drbd_err(device, "submit failed, triggering re-connect\n"); + spin_lock_irq(&device->resource->req_lock); + list_del(&peer_req->w.list); + spin_unlock_irq(&device->resource->req_lock); + + drbd_free_peer_req(device, peer_req); +fail: + put_ldev(device); + return -EIO; +} + +static struct drbd_request * +find_request(struct drbd_device *device, struct rb_root *root, u64 id, + sector_t sector, bool missing_ok, const char *func) +{ + struct drbd_request *req; + + /* Request object according to our peer */ + req = (struct drbd_request *)(unsigned long)id; + if (drbd_contains_interval(root, sector, &req->i) && req->i.local) + return req; + if (!missing_ok) { + drbd_err(device, "%s: failed to find request 0x%lx, sector %llus\n", func, + (unsigned long)id, (unsigned long long)sector); + } + return NULL; +} + +static int receive_DataReply(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + struct drbd_request *req; + sector_t sector; + int err; + struct p_data *p = pi->data; + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return -EIO; + device = peer_device->device; + + sector = be64_to_cpu(p->sector); + + spin_lock_irq(&device->resource->req_lock); + req = find_request(device, &device->read_requests, p->block_id, sector, false, __func__); + spin_unlock_irq(&device->resource->req_lock); + if (unlikely(!req)) + return -EIO; + + err = recv_dless_read(peer_device, req, sector, pi->size); + if (!err) + req_mod(req, DATA_RECEIVED); + /* else: nothing. handled from drbd_disconnect... + * I don't think we may complete this just yet + * in case we are "on-disconnect: freeze" */ + + return err; +} + +static int receive_RSDataReply(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + sector_t sector; + int err; + struct p_data *p = pi->data; + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return -EIO; + device = peer_device->device; + + sector = be64_to_cpu(p->sector); + D_ASSERT(device, p->block_id == ID_SYNCER); + + if (get_ldev(device)) { + /* data is submitted to disk within recv_resync_read. + * corresponding put_ldev done below on error, + * or in drbd_peer_request_endio. */ + err = recv_resync_read(peer_device, sector, pi); + } else { + if (__ratelimit(&drbd_ratelimit_state)) + drbd_err(device, "Can not write resync data to local disk.\n"); + + err = drbd_drain_block(peer_device, pi->size); + + drbd_send_ack_dp(peer_device, P_NEG_ACK, p, pi->size); + } + + atomic_add(pi->size >> 9, &device->rs_sect_in); + + return err; +} + +static void restart_conflicting_writes(struct drbd_device *device, + sector_t sector, int size) +{ + struct drbd_interval *i; + struct drbd_request *req; + + drbd_for_each_overlap(i, &device->write_requests, sector, size) { + if (!i->local) + continue; + req = container_of(i, struct drbd_request, i); + if (req->rq_state & RQ_LOCAL_PENDING || + !(req->rq_state & RQ_POSTPONED)) + continue; + /* as it is RQ_POSTPONED, this will cause it to + * be queued on the retry workqueue. */ + __req_mod(req, CONFLICT_RESOLVED, NULL); + } +} + +/* + * e_end_block() is called in ack_sender context via drbd_finish_peer_reqs(). + */ +static int e_end_block(struct drbd_work *w, int cancel) +{ + struct drbd_peer_request *peer_req = + container_of(w, struct drbd_peer_request, w); + struct drbd_peer_device *peer_device = peer_req->peer_device; + struct drbd_device *device = peer_device->device; + sector_t sector = peer_req->i.sector; + int err = 0, pcmd; + + if (peer_req->flags & EE_SEND_WRITE_ACK) { + if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) { + pcmd = (device->state.conn >= C_SYNC_SOURCE && + device->state.conn <= C_PAUSED_SYNC_T && + peer_req->flags & EE_MAY_SET_IN_SYNC) ? + P_RS_WRITE_ACK : P_WRITE_ACK; + err = drbd_send_ack(peer_device, pcmd, peer_req); + if (pcmd == P_RS_WRITE_ACK) + drbd_set_in_sync(device, sector, peer_req->i.size); + } else { + err = drbd_send_ack(peer_device, P_NEG_ACK, peer_req); + /* we expect it to be marked out of sync anyways... + * maybe assert this? */ + } + dec_unacked(device); + } + + /* we delete from the conflict detection hash _after_ we sent out the + * P_WRITE_ACK / P_NEG_ACK, to get the sequence number right. */ + if (peer_req->flags & EE_IN_INTERVAL_TREE) { + spin_lock_irq(&device->resource->req_lock); + D_ASSERT(device, !drbd_interval_empty(&peer_req->i)); + drbd_remove_epoch_entry_interval(device, peer_req); + if (peer_req->flags & EE_RESTART_REQUESTS) + restart_conflicting_writes(device, sector, peer_req->i.size); + spin_unlock_irq(&device->resource->req_lock); + } else + D_ASSERT(device, drbd_interval_empty(&peer_req->i)); + + drbd_may_finish_epoch(peer_device->connection, peer_req->epoch, EV_PUT + (cancel ? EV_CLEANUP : 0)); + + return err; +} + +static int e_send_ack(struct drbd_work *w, enum drbd_packet ack) +{ + struct drbd_peer_request *peer_req = + container_of(w, struct drbd_peer_request, w); + struct drbd_peer_device *peer_device = peer_req->peer_device; + int err; + + err = drbd_send_ack(peer_device, ack, peer_req); + dec_unacked(peer_device->device); + + return err; +} + +static int e_send_superseded(struct drbd_work *w, int unused) +{ + return e_send_ack(w, P_SUPERSEDED); +} + +static int e_send_retry_write(struct drbd_work *w, int unused) +{ + struct drbd_peer_request *peer_req = + container_of(w, struct drbd_peer_request, w); + struct drbd_connection *connection = peer_req->peer_device->connection; + + return e_send_ack(w, connection->agreed_pro_version >= 100 ? + P_RETRY_WRITE : P_SUPERSEDED); +} + +static bool seq_greater(u32 a, u32 b) +{ + /* + * We assume 32-bit wrap-around here. + * For 24-bit wrap-around, we would have to shift: + * a <<= 8; b <<= 8; + */ + return (s32)a - (s32)b > 0; +} + +static u32 seq_max(u32 a, u32 b) +{ + return seq_greater(a, b) ? a : b; +} + +static void update_peer_seq(struct drbd_peer_device *peer_device, unsigned int peer_seq) +{ + struct drbd_device *device = peer_device->device; + unsigned int newest_peer_seq; + + if (test_bit(RESOLVE_CONFLICTS, &peer_device->connection->flags)) { + spin_lock(&device->peer_seq_lock); + newest_peer_seq = seq_max(device->peer_seq, peer_seq); + device->peer_seq = newest_peer_seq; + spin_unlock(&device->peer_seq_lock); + /* wake up only if we actually changed device->peer_seq */ + if (peer_seq == newest_peer_seq) + wake_up(&device->seq_wait); + } +} + +static inline int overlaps(sector_t s1, int l1, sector_t s2, int l2) +{ + return !((s1 + (l1>>9) <= s2) || (s1 >= s2 + (l2>>9))); +} + +/* maybe change sync_ee into interval trees as well? */ +static bool overlapping_resync_write(struct drbd_device *device, struct drbd_peer_request *peer_req) +{ + struct drbd_peer_request *rs_req; + bool rv = false; + + spin_lock_irq(&device->resource->req_lock); + list_for_each_entry(rs_req, &device->sync_ee, w.list) { + if (overlaps(peer_req->i.sector, peer_req->i.size, + rs_req->i.sector, rs_req->i.size)) { + rv = true; + break; + } + } + spin_unlock_irq(&device->resource->req_lock); + + return rv; +} + +/* Called from receive_Data. + * Synchronize packets on sock with packets on msock. + * + * This is here so even when a P_DATA packet traveling via sock overtook an Ack + * packet traveling on msock, they are still processed in the order they have + * been sent. + * + * Note: we don't care for Ack packets overtaking P_DATA packets. + * + * In case packet_seq is larger than device->peer_seq number, there are + * outstanding packets on the msock. We wait for them to arrive. + * In case we are the logically next packet, we update device->peer_seq + * ourselves. Correctly handles 32bit wrap around. + * + * Assume we have a 10 GBit connection, that is about 1<<30 byte per second, + * about 1<<21 sectors per second. So "worst" case, we have 1<<3 == 8 seconds + * for the 24bit wrap (historical atomic_t guarantee on some archs), and we have + * 1<<9 == 512 seconds aka ages for the 32bit wrap around... + * + * returns 0 if we may process the packet, + * -ERESTARTSYS if we were interrupted (by disconnect signal). */ +static int wait_for_and_update_peer_seq(struct drbd_peer_device *peer_device, const u32 peer_seq) +{ + struct drbd_device *device = peer_device->device; + DEFINE_WAIT(wait); + long timeout; + int ret = 0, tp; + + if (!test_bit(RESOLVE_CONFLICTS, &peer_device->connection->flags)) + return 0; + + spin_lock(&device->peer_seq_lock); + for (;;) { + if (!seq_greater(peer_seq - 1, device->peer_seq)) { + device->peer_seq = seq_max(device->peer_seq, peer_seq); + break; + } + + if (signal_pending(current)) { + ret = -ERESTARTSYS; + break; + } + + rcu_read_lock(); + tp = rcu_dereference(peer_device->connection->net_conf)->two_primaries; + rcu_read_unlock(); + + if (!tp) + break; + + /* Only need to wait if two_primaries is enabled */ + prepare_to_wait(&device->seq_wait, &wait, TASK_INTERRUPTIBLE); + spin_unlock(&device->peer_seq_lock); + rcu_read_lock(); + timeout = rcu_dereference(peer_device->connection->net_conf)->ping_timeo*HZ/10; + rcu_read_unlock(); + timeout = schedule_timeout(timeout); + spin_lock(&device->peer_seq_lock); + if (!timeout) { + ret = -ETIMEDOUT; + drbd_err(device, "Timed out waiting for missing ack packets; disconnecting\n"); + break; + } + } + spin_unlock(&device->peer_seq_lock); + finish_wait(&device->seq_wait, &wait); + return ret; +} + +/* see also bio_flags_to_wire() + * DRBD_REQ_*, because we need to semantically map the flags to data packet + * flags and back. We may replicate to other kernel versions. */ +static blk_opf_t wire_flags_to_bio_flags(u32 dpf) +{ + return (dpf & DP_RW_SYNC ? REQ_SYNC : 0) | + (dpf & DP_FUA ? REQ_FUA : 0) | + (dpf & DP_FLUSH ? REQ_PREFLUSH : 0); +} + +static enum req_op wire_flags_to_bio_op(u32 dpf) +{ + if (dpf & DP_ZEROES) + return REQ_OP_WRITE_ZEROES; + if (dpf & DP_DISCARD) + return REQ_OP_DISCARD; + else + return REQ_OP_WRITE; +} + +static void fail_postponed_requests(struct drbd_device *device, sector_t sector, + unsigned int size) +{ + struct drbd_interval *i; + + repeat: + drbd_for_each_overlap(i, &device->write_requests, sector, size) { + struct drbd_request *req; + struct bio_and_error m; + + if (!i->local) + continue; + req = container_of(i, struct drbd_request, i); + if (!(req->rq_state & RQ_POSTPONED)) + continue; + req->rq_state &= ~RQ_POSTPONED; + __req_mod(req, NEG_ACKED, &m); + spin_unlock_irq(&device->resource->req_lock); + if (m.bio) + complete_master_bio(device, &m); + spin_lock_irq(&device->resource->req_lock); + goto repeat; + } +} + +static int handle_write_conflicts(struct drbd_device *device, + struct drbd_peer_request *peer_req) +{ + struct drbd_connection *connection = peer_req->peer_device->connection; + bool resolve_conflicts = test_bit(RESOLVE_CONFLICTS, &connection->flags); + sector_t sector = peer_req->i.sector; + const unsigned int size = peer_req->i.size; + struct drbd_interval *i; + bool equal; + int err; + + /* + * Inserting the peer request into the write_requests tree will prevent + * new conflicting local requests from being added. + */ + drbd_insert_interval(&device->write_requests, &peer_req->i); + + repeat: + drbd_for_each_overlap(i, &device->write_requests, sector, size) { + if (i == &peer_req->i) + continue; + if (i->completed) + continue; + + if (!i->local) { + /* + * Our peer has sent a conflicting remote request; this + * should not happen in a two-node setup. Wait for the + * earlier peer request to complete. + */ + err = drbd_wait_misc(device, i); + if (err) + goto out; + goto repeat; + } + + equal = i->sector == sector && i->size == size; + if (resolve_conflicts) { + /* + * If the peer request is fully contained within the + * overlapping request, it can be considered overwritten + * and thus superseded; otherwise, it will be retried + * once all overlapping requests have completed. + */ + bool superseded = i->sector <= sector && i->sector + + (i->size >> 9) >= sector + (size >> 9); + + if (!equal) + drbd_alert(device, "Concurrent writes detected: " + "local=%llus +%u, remote=%llus +%u, " + "assuming %s came first\n", + (unsigned long long)i->sector, i->size, + (unsigned long long)sector, size, + superseded ? "local" : "remote"); + + peer_req->w.cb = superseded ? e_send_superseded : + e_send_retry_write; + list_add_tail(&peer_req->w.list, &device->done_ee); + queue_work(connection->ack_sender, &peer_req->peer_device->send_acks_work); + + err = -ENOENT; + goto out; + } else { + struct drbd_request *req = + container_of(i, struct drbd_request, i); + + if (!equal) + drbd_alert(device, "Concurrent writes detected: " + "local=%llus +%u, remote=%llus +%u\n", + (unsigned long long)i->sector, i->size, + (unsigned long long)sector, size); + + if (req->rq_state & RQ_LOCAL_PENDING || + !(req->rq_state & RQ_POSTPONED)) { + /* + * Wait for the node with the discard flag to + * decide if this request has been superseded + * or needs to be retried. + * Requests that have been superseded will + * disappear from the write_requests tree. + * + * In addition, wait for the conflicting + * request to finish locally before submitting + * the conflicting peer request. + */ + err = drbd_wait_misc(device, &req->i); + if (err) { + _conn_request_state(connection, NS(conn, C_TIMEOUT), CS_HARD); + fail_postponed_requests(device, sector, size); + goto out; + } + goto repeat; + } + /* + * Remember to restart the conflicting requests after + * the new peer request has completed. + */ + peer_req->flags |= EE_RESTART_REQUESTS; + } + } + err = 0; + + out: + if (err) + drbd_remove_epoch_entry_interval(device, peer_req); + return err; +} + +/* mirrored write */ +static int receive_Data(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + struct net_conf *nc; + sector_t sector; + struct drbd_peer_request *peer_req; + struct p_data *p = pi->data; + u32 peer_seq = be32_to_cpu(p->seq_num); + enum req_op op; + blk_opf_t op_flags; + u32 dp_flags; + int err, tp; + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return -EIO; + device = peer_device->device; + + if (!get_ldev(device)) { + int err2; + + err = wait_for_and_update_peer_seq(peer_device, peer_seq); + drbd_send_ack_dp(peer_device, P_NEG_ACK, p, pi->size); + atomic_inc(&connection->current_epoch->epoch_size); + err2 = drbd_drain_block(peer_device, pi->size); + if (!err) + err = err2; + return err; + } + + /* + * Corresponding put_ldev done either below (on various errors), or in + * drbd_peer_request_endio, if we successfully submit the data at the + * end of this function. + */ + + sector = be64_to_cpu(p->sector); + peer_req = read_in_block(peer_device, p->block_id, sector, pi); + if (!peer_req) { + put_ldev(device); + return -EIO; + } + + peer_req->w.cb = e_end_block; + peer_req->submit_jif = jiffies; + peer_req->flags |= EE_APPLICATION; + + dp_flags = be32_to_cpu(p->dp_flags); + op = wire_flags_to_bio_op(dp_flags); + op_flags = wire_flags_to_bio_flags(dp_flags); + if (pi->cmd == P_TRIM) { + D_ASSERT(peer_device, peer_req->i.size > 0); + D_ASSERT(peer_device, op == REQ_OP_DISCARD); + D_ASSERT(peer_device, peer_req->pages == NULL); + /* need to play safe: an older DRBD sender + * may mean zero-out while sending P_TRIM. */ + if (0 == (connection->agreed_features & DRBD_FF_WZEROES)) + peer_req->flags |= EE_ZEROOUT; + } else if (pi->cmd == P_ZEROES) { + D_ASSERT(peer_device, peer_req->i.size > 0); + D_ASSERT(peer_device, op == REQ_OP_WRITE_ZEROES); + D_ASSERT(peer_device, peer_req->pages == NULL); + /* Do (not) pass down BLKDEV_ZERO_NOUNMAP? */ + if (dp_flags & DP_DISCARD) + peer_req->flags |= EE_TRIM; + } else if (peer_req->pages == NULL) { + D_ASSERT(device, peer_req->i.size == 0); + D_ASSERT(device, dp_flags & DP_FLUSH); + } + + if (dp_flags & DP_MAY_SET_IN_SYNC) + peer_req->flags |= EE_MAY_SET_IN_SYNC; + + spin_lock(&connection->epoch_lock); + peer_req->epoch = connection->current_epoch; + atomic_inc(&peer_req->epoch->epoch_size); + atomic_inc(&peer_req->epoch->active); + spin_unlock(&connection->epoch_lock); + + rcu_read_lock(); + nc = rcu_dereference(peer_device->connection->net_conf); + tp = nc->two_primaries; + if (peer_device->connection->agreed_pro_version < 100) { + switch (nc->wire_protocol) { + case DRBD_PROT_C: + dp_flags |= DP_SEND_WRITE_ACK; + break; + case DRBD_PROT_B: + dp_flags |= DP_SEND_RECEIVE_ACK; + break; + } + } + rcu_read_unlock(); + + if (dp_flags & DP_SEND_WRITE_ACK) { + peer_req->flags |= EE_SEND_WRITE_ACK; + inc_unacked(device); + /* corresponding dec_unacked() in e_end_block() + * respective _drbd_clear_done_ee */ + } + + if (dp_flags & DP_SEND_RECEIVE_ACK) { + /* I really don't like it that the receiver thread + * sends on the msock, but anyways */ + drbd_send_ack(peer_device, P_RECV_ACK, peer_req); + } + + if (tp) { + /* two primaries implies protocol C */ + D_ASSERT(device, dp_flags & DP_SEND_WRITE_ACK); + peer_req->flags |= EE_IN_INTERVAL_TREE; + err = wait_for_and_update_peer_seq(peer_device, peer_seq); + if (err) + goto out_interrupted; + spin_lock_irq(&device->resource->req_lock); + err = handle_write_conflicts(device, peer_req); + if (err) { + spin_unlock_irq(&device->resource->req_lock); + if (err == -ENOENT) { + put_ldev(device); + return 0; + } + goto out_interrupted; + } + } else { + update_peer_seq(peer_device, peer_seq); + spin_lock_irq(&device->resource->req_lock); + } + /* TRIM and is processed synchronously, + * we wait for all pending requests, respectively wait for + * active_ee to become empty in drbd_submit_peer_request(); + * better not add ourselves here. */ + if ((peer_req->flags & (EE_TRIM | EE_ZEROOUT)) == 0) + list_add_tail(&peer_req->w.list, &device->active_ee); + spin_unlock_irq(&device->resource->req_lock); + + if (device->state.conn == C_SYNC_TARGET) + wait_event(device->ee_wait, !overlapping_resync_write(device, peer_req)); + + if (device->state.pdsk < D_INCONSISTENT) { + /* In case we have the only disk of the cluster, */ + drbd_set_out_of_sync(device, peer_req->i.sector, peer_req->i.size); + peer_req->flags &= ~EE_MAY_SET_IN_SYNC; + drbd_al_begin_io(device, &peer_req->i); + peer_req->flags |= EE_CALL_AL_COMPLETE_IO; + } + + err = drbd_submit_peer_request(device, peer_req, op | op_flags, + DRBD_FAULT_DT_WR); + if (!err) + return 0; + + /* don't care for the reason here */ + drbd_err(device, "submit failed, triggering re-connect\n"); + spin_lock_irq(&device->resource->req_lock); + list_del(&peer_req->w.list); + drbd_remove_epoch_entry_interval(device, peer_req); + spin_unlock_irq(&device->resource->req_lock); + if (peer_req->flags & EE_CALL_AL_COMPLETE_IO) { + peer_req->flags &= ~EE_CALL_AL_COMPLETE_IO; + drbd_al_complete_io(device, &peer_req->i); + } + +out_interrupted: + drbd_may_finish_epoch(connection, peer_req->epoch, EV_PUT | EV_CLEANUP); + put_ldev(device); + drbd_free_peer_req(device, peer_req); + return err; +} + +/* We may throttle resync, if the lower device seems to be busy, + * and current sync rate is above c_min_rate. + * + * To decide whether or not the lower device is busy, we use a scheme similar + * to MD RAID is_mddev_idle(): if the partition stats reveal "significant" + * (more than 64 sectors) of activity we cannot account for with our own resync + * activity, it obviously is "busy". + * + * The current sync rate used here uses only the most recent two step marks, + * to have a short time average so we can react faster. + */ +bool drbd_rs_should_slow_down(struct drbd_device *device, sector_t sector, + bool throttle_if_app_is_waiting) +{ + struct lc_element *tmp; + bool throttle = drbd_rs_c_min_rate_throttle(device); + + if (!throttle || throttle_if_app_is_waiting) + return throttle; + + spin_lock_irq(&device->al_lock); + tmp = lc_find(device->resync, BM_SECT_TO_EXT(sector)); + if (tmp) { + struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce); + if (test_bit(BME_PRIORITY, &bm_ext->flags)) + throttle = false; + /* Do not slow down if app IO is already waiting for this extent, + * and our progress is necessary for application IO to complete. */ + } + spin_unlock_irq(&device->al_lock); + + return throttle; +} + +bool drbd_rs_c_min_rate_throttle(struct drbd_device *device) +{ + struct gendisk *disk = device->ldev->backing_bdev->bd_disk; + unsigned long db, dt, dbdt; + unsigned int c_min_rate; + int curr_events; + + rcu_read_lock(); + c_min_rate = rcu_dereference(device->ldev->disk_conf)->c_min_rate; + rcu_read_unlock(); + + /* feature disabled? */ + if (c_min_rate == 0) + return false; + + curr_events = (int)part_stat_read_accum(disk->part0, sectors) - + atomic_read(&device->rs_sect_ev); + + if (atomic_read(&device->ap_actlog_cnt) + || curr_events - device->rs_last_events > 64) { + unsigned long rs_left; + int i; + + device->rs_last_events = curr_events; + + /* sync speed average over the last 2*DRBD_SYNC_MARK_STEP, + * approx. */ + i = (device->rs_last_mark + DRBD_SYNC_MARKS-1) % DRBD_SYNC_MARKS; + + if (device->state.conn == C_VERIFY_S || device->state.conn == C_VERIFY_T) + rs_left = device->ov_left; + else + rs_left = drbd_bm_total_weight(device) - device->rs_failed; + + dt = ((long)jiffies - (long)device->rs_mark_time[i]) / HZ; + if (!dt) + dt++; + db = device->rs_mark_left[i] - rs_left; + dbdt = Bit2KB(db/dt); + + if (dbdt > c_min_rate) + return true; + } + return false; +} + +static int receive_DataRequest(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + sector_t sector; + sector_t capacity; + struct drbd_peer_request *peer_req; + struct digest_info *di = NULL; + int size, verb; + unsigned int fault_type; + struct p_block_req *p = pi->data; + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return -EIO; + device = peer_device->device; + capacity = get_capacity(device->vdisk); + + sector = be64_to_cpu(p->sector); + size = be32_to_cpu(p->blksize); + + if (size <= 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) { + drbd_err(device, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__, + (unsigned long long)sector, size); + return -EINVAL; + } + if (sector + (size>>9) > capacity) { + drbd_err(device, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__, + (unsigned long long)sector, size); + return -EINVAL; + } + + if (!get_ldev_if_state(device, D_UP_TO_DATE)) { + verb = 1; + switch (pi->cmd) { + case P_DATA_REQUEST: + drbd_send_ack_rp(peer_device, P_NEG_DREPLY, p); + break; + case P_RS_THIN_REQ: + case P_RS_DATA_REQUEST: + case P_CSUM_RS_REQUEST: + case P_OV_REQUEST: + drbd_send_ack_rp(peer_device, P_NEG_RS_DREPLY , p); + break; + case P_OV_REPLY: + verb = 0; + dec_rs_pending(device); + drbd_send_ack_ex(peer_device, P_OV_RESULT, sector, size, ID_IN_SYNC); + break; + default: + BUG(); + } + if (verb && __ratelimit(&drbd_ratelimit_state)) + drbd_err(device, "Can not satisfy peer's read request, " + "no local data.\n"); + + /* drain possibly payload */ + return drbd_drain_block(peer_device, pi->size); + } + + /* GFP_NOIO, because we must not cause arbitrary write-out: in a DRBD + * "criss-cross" setup, that might cause write-out on some other DRBD, + * which in turn might block on the other node at this very place. */ + peer_req = drbd_alloc_peer_req(peer_device, p->block_id, sector, size, + size, GFP_NOIO); + if (!peer_req) { + put_ldev(device); + return -ENOMEM; + } + + switch (pi->cmd) { + case P_DATA_REQUEST: + peer_req->w.cb = w_e_end_data_req; + fault_type = DRBD_FAULT_DT_RD; + /* application IO, don't drbd_rs_begin_io */ + peer_req->flags |= EE_APPLICATION; + goto submit; + + case P_RS_THIN_REQ: + /* If at some point in the future we have a smart way to + find out if this data block is completely deallocated, + then we would do something smarter here than reading + the block... */ + peer_req->flags |= EE_RS_THIN_REQ; + fallthrough; + case P_RS_DATA_REQUEST: + peer_req->w.cb = w_e_end_rsdata_req; + fault_type = DRBD_FAULT_RS_RD; + /* used in the sector offset progress display */ + device->bm_resync_fo = BM_SECT_TO_BIT(sector); + break; + + case P_OV_REPLY: + case P_CSUM_RS_REQUEST: + fault_type = DRBD_FAULT_RS_RD; + di = kmalloc(sizeof(*di) + pi->size, GFP_NOIO); + if (!di) + goto out_free_e; + + di->digest_size = pi->size; + di->digest = (((char *)di)+sizeof(struct digest_info)); + + peer_req->digest = di; + peer_req->flags |= EE_HAS_DIGEST; + + if (drbd_recv_all(peer_device->connection, di->digest, pi->size)) + goto out_free_e; + + if (pi->cmd == P_CSUM_RS_REQUEST) { + D_ASSERT(device, peer_device->connection->agreed_pro_version >= 89); + peer_req->w.cb = w_e_end_csum_rs_req; + /* used in the sector offset progress display */ + device->bm_resync_fo = BM_SECT_TO_BIT(sector); + /* remember to report stats in drbd_resync_finished */ + device->use_csums = true; + } else if (pi->cmd == P_OV_REPLY) { + /* track progress, we may need to throttle */ + atomic_add(size >> 9, &device->rs_sect_in); + peer_req->w.cb = w_e_end_ov_reply; + dec_rs_pending(device); + /* drbd_rs_begin_io done when we sent this request, + * but accounting still needs to be done. */ + goto submit_for_resync; + } + break; + + case P_OV_REQUEST: + if (device->ov_start_sector == ~(sector_t)0 && + peer_device->connection->agreed_pro_version >= 90) { + unsigned long now = jiffies; + int i; + device->ov_start_sector = sector; + device->ov_position = sector; + device->ov_left = drbd_bm_bits(device) - BM_SECT_TO_BIT(sector); + device->rs_total = device->ov_left; + for (i = 0; i < DRBD_SYNC_MARKS; i++) { + device->rs_mark_left[i] = device->ov_left; + device->rs_mark_time[i] = now; + } + drbd_info(device, "Online Verify start sector: %llu\n", + (unsigned long long)sector); + } + peer_req->w.cb = w_e_end_ov_req; + fault_type = DRBD_FAULT_RS_RD; + break; + + default: + BUG(); + } + + /* Throttle, drbd_rs_begin_io and submit should become asynchronous + * wrt the receiver, but it is not as straightforward as it may seem. + * Various places in the resync start and stop logic assume resync + * requests are processed in order, requeuing this on the worker thread + * introduces a bunch of new code for synchronization between threads. + * + * Unlimited throttling before drbd_rs_begin_io may stall the resync + * "forever", throttling after drbd_rs_begin_io will lock that extent + * for application writes for the same time. For now, just throttle + * here, where the rest of the code expects the receiver to sleep for + * a while, anyways. + */ + + /* Throttle before drbd_rs_begin_io, as that locks out application IO; + * this defers syncer requests for some time, before letting at least + * on request through. The resync controller on the receiving side + * will adapt to the incoming rate accordingly. + * + * We cannot throttle here if remote is Primary/SyncTarget: + * we would also throttle its application reads. + * In that case, throttling is done on the SyncTarget only. + */ + + /* Even though this may be a resync request, we do add to "read_ee"; + * "sync_ee" is only used for resync WRITEs. + * Add to list early, so debugfs can find this request + * even if we have to sleep below. */ + spin_lock_irq(&device->resource->req_lock); + list_add_tail(&peer_req->w.list, &device->read_ee); + spin_unlock_irq(&device->resource->req_lock); + + update_receiver_timing_details(connection, drbd_rs_should_slow_down); + if (device->state.peer != R_PRIMARY + && drbd_rs_should_slow_down(device, sector, false)) + schedule_timeout_uninterruptible(HZ/10); + update_receiver_timing_details(connection, drbd_rs_begin_io); + if (drbd_rs_begin_io(device, sector)) + goto out_free_e; + +submit_for_resync: + atomic_add(size >> 9, &device->rs_sect_ev); + +submit: + update_receiver_timing_details(connection, drbd_submit_peer_request); + inc_unacked(device); + if (drbd_submit_peer_request(device, peer_req, REQ_OP_READ, + fault_type) == 0) + return 0; + + /* don't care for the reason here */ + drbd_err(device, "submit failed, triggering re-connect\n"); + +out_free_e: + spin_lock_irq(&device->resource->req_lock); + list_del(&peer_req->w.list); + spin_unlock_irq(&device->resource->req_lock); + /* no drbd_rs_complete_io(), we are dropping the connection anyways */ + + put_ldev(device); + drbd_free_peer_req(device, peer_req); + return -EIO; +} + +/* + * drbd_asb_recover_0p - Recover after split-brain with no remaining primaries + */ +static int drbd_asb_recover_0p(struct drbd_peer_device *peer_device) __must_hold(local) +{ + struct drbd_device *device = peer_device->device; + int self, peer, rv = -100; + unsigned long ch_self, ch_peer; + enum drbd_after_sb_p after_sb_0p; + + self = device->ldev->md.uuid[UI_BITMAP] & 1; + peer = device->p_uuid[UI_BITMAP] & 1; + + ch_peer = device->p_uuid[UI_SIZE]; + ch_self = device->comm_bm_set; + + rcu_read_lock(); + after_sb_0p = rcu_dereference(peer_device->connection->net_conf)->after_sb_0p; + rcu_read_unlock(); + switch (after_sb_0p) { + case ASB_CONSENSUS: + case ASB_DISCARD_SECONDARY: + case ASB_CALL_HELPER: + case ASB_VIOLENTLY: + drbd_err(device, "Configuration error.\n"); + break; + case ASB_DISCONNECT: + break; + case ASB_DISCARD_YOUNGER_PRI: + if (self == 0 && peer == 1) { + rv = -1; + break; + } + if (self == 1 && peer == 0) { + rv = 1; + break; + } + fallthrough; /* to one of the other strategies */ + case ASB_DISCARD_OLDER_PRI: + if (self == 0 && peer == 1) { + rv = 1; + break; + } + if (self == 1 && peer == 0) { + rv = -1; + break; + } + /* Else fall through to one of the other strategies... */ + drbd_warn(device, "Discard younger/older primary did not find a decision\n" + "Using discard-least-changes instead\n"); + fallthrough; + case ASB_DISCARD_ZERO_CHG: + if (ch_peer == 0 && ch_self == 0) { + rv = test_bit(RESOLVE_CONFLICTS, &peer_device->connection->flags) + ? -1 : 1; + break; + } else { + if (ch_peer == 0) { rv = 1; break; } + if (ch_self == 0) { rv = -1; break; } + } + if (after_sb_0p == ASB_DISCARD_ZERO_CHG) + break; + fallthrough; + case ASB_DISCARD_LEAST_CHG: + if (ch_self < ch_peer) + rv = -1; + else if (ch_self > ch_peer) + rv = 1; + else /* ( ch_self == ch_peer ) */ + /* Well, then use something else. */ + rv = test_bit(RESOLVE_CONFLICTS, &peer_device->connection->flags) + ? -1 : 1; + break; + case ASB_DISCARD_LOCAL: + rv = -1; + break; + case ASB_DISCARD_REMOTE: + rv = 1; + } + + return rv; +} + +/* + * drbd_asb_recover_1p - Recover after split-brain with one remaining primary + */ +static int drbd_asb_recover_1p(struct drbd_peer_device *peer_device) __must_hold(local) +{ + struct drbd_device *device = peer_device->device; + int hg, rv = -100; + enum drbd_after_sb_p after_sb_1p; + + rcu_read_lock(); + after_sb_1p = rcu_dereference(peer_device->connection->net_conf)->after_sb_1p; + rcu_read_unlock(); + switch (after_sb_1p) { + case ASB_DISCARD_YOUNGER_PRI: + case ASB_DISCARD_OLDER_PRI: + case ASB_DISCARD_LEAST_CHG: + case ASB_DISCARD_LOCAL: + case ASB_DISCARD_REMOTE: + case ASB_DISCARD_ZERO_CHG: + drbd_err(device, "Configuration error.\n"); + break; + case ASB_DISCONNECT: + break; + case ASB_CONSENSUS: + hg = drbd_asb_recover_0p(peer_device); + if (hg == -1 && device->state.role == R_SECONDARY) + rv = hg; + if (hg == 1 && device->state.role == R_PRIMARY) + rv = hg; + break; + case ASB_VIOLENTLY: + rv = drbd_asb_recover_0p(peer_device); + break; + case ASB_DISCARD_SECONDARY: + return device->state.role == R_PRIMARY ? 1 : -1; + case ASB_CALL_HELPER: + hg = drbd_asb_recover_0p(peer_device); + if (hg == -1 && device->state.role == R_PRIMARY) { + enum drbd_state_rv rv2; + + /* drbd_change_state() does not sleep while in SS_IN_TRANSIENT_STATE, + * we might be here in C_WF_REPORT_PARAMS which is transient. + * we do not need to wait for the after state change work either. */ + rv2 = drbd_change_state(device, CS_VERBOSE, NS(role, R_SECONDARY)); + if (rv2 != SS_SUCCESS) { + drbd_khelper(device, "pri-lost-after-sb"); + } else { + drbd_warn(device, "Successfully gave up primary role.\n"); + rv = hg; + } + } else + rv = hg; + } + + return rv; +} + +/* + * drbd_asb_recover_2p - Recover after split-brain with two remaining primaries + */ +static int drbd_asb_recover_2p(struct drbd_peer_device *peer_device) __must_hold(local) +{ + struct drbd_device *device = peer_device->device; + int hg, rv = -100; + enum drbd_after_sb_p after_sb_2p; + + rcu_read_lock(); + after_sb_2p = rcu_dereference(peer_device->connection->net_conf)->after_sb_2p; + rcu_read_unlock(); + switch (after_sb_2p) { + case ASB_DISCARD_YOUNGER_PRI: + case ASB_DISCARD_OLDER_PRI: + case ASB_DISCARD_LEAST_CHG: + case ASB_DISCARD_LOCAL: + case ASB_DISCARD_REMOTE: + case ASB_CONSENSUS: + case ASB_DISCARD_SECONDARY: + case ASB_DISCARD_ZERO_CHG: + drbd_err(device, "Configuration error.\n"); + break; + case ASB_VIOLENTLY: + rv = drbd_asb_recover_0p(peer_device); + break; + case ASB_DISCONNECT: + break; + case ASB_CALL_HELPER: + hg = drbd_asb_recover_0p(peer_device); + if (hg == -1) { + enum drbd_state_rv rv2; + + /* drbd_change_state() does not sleep while in SS_IN_TRANSIENT_STATE, + * we might be here in C_WF_REPORT_PARAMS which is transient. + * we do not need to wait for the after state change work either. */ + rv2 = drbd_change_state(device, CS_VERBOSE, NS(role, R_SECONDARY)); + if (rv2 != SS_SUCCESS) { + drbd_khelper(device, "pri-lost-after-sb"); + } else { + drbd_warn(device, "Successfully gave up primary role.\n"); + rv = hg; + } + } else + rv = hg; + } + + return rv; +} + +static void drbd_uuid_dump(struct drbd_device *device, char *text, u64 *uuid, + u64 bits, u64 flags) +{ + if (!uuid) { + drbd_info(device, "%s uuid info vanished while I was looking!\n", text); + return; + } + drbd_info(device, "%s %016llX:%016llX:%016llX:%016llX bits:%llu flags:%llX\n", + text, + (unsigned long long)uuid[UI_CURRENT], + (unsigned long long)uuid[UI_BITMAP], + (unsigned long long)uuid[UI_HISTORY_START], + (unsigned long long)uuid[UI_HISTORY_END], + (unsigned long long)bits, + (unsigned long long)flags); +} + +/* + 100 after split brain try auto recover + 2 C_SYNC_SOURCE set BitMap + 1 C_SYNC_SOURCE use BitMap + 0 no Sync + -1 C_SYNC_TARGET use BitMap + -2 C_SYNC_TARGET set BitMap + -100 after split brain, disconnect +-1000 unrelated data +-1091 requires proto 91 +-1096 requires proto 96 + */ + +static int drbd_uuid_compare(struct drbd_device *const device, enum drbd_role const peer_role, int *rule_nr) __must_hold(local) +{ + struct drbd_peer_device *const peer_device = first_peer_device(device); + struct drbd_connection *const connection = peer_device ? peer_device->connection : NULL; + u64 self, peer; + int i, j; + + self = device->ldev->md.uuid[UI_CURRENT] & ~((u64)1); + peer = device->p_uuid[UI_CURRENT] & ~((u64)1); + + *rule_nr = 10; + if (self == UUID_JUST_CREATED && peer == UUID_JUST_CREATED) + return 0; + + *rule_nr = 20; + if ((self == UUID_JUST_CREATED || self == (u64)0) && + peer != UUID_JUST_CREATED) + return -2; + + *rule_nr = 30; + if (self != UUID_JUST_CREATED && + (peer == UUID_JUST_CREATED || peer == (u64)0)) + return 2; + + if (self == peer) { + int rct, dc; /* roles at crash time */ + + if (device->p_uuid[UI_BITMAP] == (u64)0 && device->ldev->md.uuid[UI_BITMAP] != (u64)0) { + + if (connection->agreed_pro_version < 91) + return -1091; + + if ((device->ldev->md.uuid[UI_BITMAP] & ~((u64)1)) == (device->p_uuid[UI_HISTORY_START] & ~((u64)1)) && + (device->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) == (device->p_uuid[UI_HISTORY_START + 1] & ~((u64)1))) { + drbd_info(device, "was SyncSource, missed the resync finished event, corrected myself:\n"); + drbd_uuid_move_history(device); + device->ldev->md.uuid[UI_HISTORY_START] = device->ldev->md.uuid[UI_BITMAP]; + device->ldev->md.uuid[UI_BITMAP] = 0; + + drbd_uuid_dump(device, "self", device->ldev->md.uuid, + device->state.disk >= D_NEGOTIATING ? drbd_bm_total_weight(device) : 0, 0); + *rule_nr = 34; + } else { + drbd_info(device, "was SyncSource (peer failed to write sync_uuid)\n"); + *rule_nr = 36; + } + + return 1; + } + + if (device->ldev->md.uuid[UI_BITMAP] == (u64)0 && device->p_uuid[UI_BITMAP] != (u64)0) { + + if (connection->agreed_pro_version < 91) + return -1091; + + if ((device->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) == (device->p_uuid[UI_BITMAP] & ~((u64)1)) && + (device->ldev->md.uuid[UI_HISTORY_START + 1] & ~((u64)1)) == (device->p_uuid[UI_HISTORY_START] & ~((u64)1))) { + drbd_info(device, "was SyncTarget, peer missed the resync finished event, corrected peer:\n"); + + device->p_uuid[UI_HISTORY_START + 1] = device->p_uuid[UI_HISTORY_START]; + device->p_uuid[UI_HISTORY_START] = device->p_uuid[UI_BITMAP]; + device->p_uuid[UI_BITMAP] = 0UL; + + drbd_uuid_dump(device, "peer", device->p_uuid, device->p_uuid[UI_SIZE], device->p_uuid[UI_FLAGS]); + *rule_nr = 35; + } else { + drbd_info(device, "was SyncTarget (failed to write sync_uuid)\n"); + *rule_nr = 37; + } + + return -1; + } + + /* Common power [off|failure] */ + rct = (test_bit(CRASHED_PRIMARY, &device->flags) ? 1 : 0) + + (device->p_uuid[UI_FLAGS] & 2); + /* lowest bit is set when we were primary, + * next bit (weight 2) is set when peer was primary */ + *rule_nr = 40; + + /* Neither has the "crashed primary" flag set, + * only a replication link hickup. */ + if (rct == 0) + return 0; + + /* Current UUID equal and no bitmap uuid; does not necessarily + * mean this was a "simultaneous hard crash", maybe IO was + * frozen, so no UUID-bump happened. + * This is a protocol change, overload DRBD_FF_WSAME as flag + * for "new-enough" peer DRBD version. */ + if (device->state.role == R_PRIMARY || peer_role == R_PRIMARY) { + *rule_nr = 41; + if (!(connection->agreed_features & DRBD_FF_WSAME)) { + drbd_warn(peer_device, "Equivalent unrotated UUIDs, but current primary present.\n"); + return -(0x10000 | PRO_VERSION_MAX | (DRBD_FF_WSAME << 8)); + } + if (device->state.role == R_PRIMARY && peer_role == R_PRIMARY) { + /* At least one has the "crashed primary" bit set, + * both are primary now, but neither has rotated its UUIDs? + * "Can not happen." */ + drbd_err(peer_device, "Equivalent unrotated UUIDs, but both are primary. Can not resolve this.\n"); + return -100; + } + if (device->state.role == R_PRIMARY) + return 1; + return -1; + } + + /* Both are secondary. + * Really looks like recovery from simultaneous hard crash. + * Check which had been primary before, and arbitrate. */ + switch (rct) { + case 0: /* !self_pri && !peer_pri */ return 0; /* already handled */ + case 1: /* self_pri && !peer_pri */ return 1; + case 2: /* !self_pri && peer_pri */ return -1; + case 3: /* self_pri && peer_pri */ + dc = test_bit(RESOLVE_CONFLICTS, &connection->flags); + return dc ? -1 : 1; + } + } + + *rule_nr = 50; + peer = device->p_uuid[UI_BITMAP] & ~((u64)1); + if (self == peer) + return -1; + + *rule_nr = 51; + peer = device->p_uuid[UI_HISTORY_START] & ~((u64)1); + if (self == peer) { + if (connection->agreed_pro_version < 96 ? + (device->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) == + (device->p_uuid[UI_HISTORY_START + 1] & ~((u64)1)) : + peer + UUID_NEW_BM_OFFSET == (device->p_uuid[UI_BITMAP] & ~((u64)1))) { + /* The last P_SYNC_UUID did not get though. Undo the last start of + resync as sync source modifications of the peer's UUIDs. */ + + if (connection->agreed_pro_version < 91) + return -1091; + + device->p_uuid[UI_BITMAP] = device->p_uuid[UI_HISTORY_START]; + device->p_uuid[UI_HISTORY_START] = device->p_uuid[UI_HISTORY_START + 1]; + + drbd_info(device, "Lost last syncUUID packet, corrected:\n"); + drbd_uuid_dump(device, "peer", device->p_uuid, device->p_uuid[UI_SIZE], device->p_uuid[UI_FLAGS]); + + return -1; + } + } + + *rule_nr = 60; + self = device->ldev->md.uuid[UI_CURRENT] & ~((u64)1); + for (i = UI_HISTORY_START; i <= UI_HISTORY_END; i++) { + peer = device->p_uuid[i] & ~((u64)1); + if (self == peer) + return -2; + } + + *rule_nr = 70; + self = device->ldev->md.uuid[UI_BITMAP] & ~((u64)1); + peer = device->p_uuid[UI_CURRENT] & ~((u64)1); + if (self == peer) + return 1; + + *rule_nr = 71; + self = device->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1); + if (self == peer) { + if (connection->agreed_pro_version < 96 ? + (device->ldev->md.uuid[UI_HISTORY_START + 1] & ~((u64)1)) == + (device->p_uuid[UI_HISTORY_START] & ~((u64)1)) : + self + UUID_NEW_BM_OFFSET == (device->ldev->md.uuid[UI_BITMAP] & ~((u64)1))) { + /* The last P_SYNC_UUID did not get though. Undo the last start of + resync as sync source modifications of our UUIDs. */ + + if (connection->agreed_pro_version < 91) + return -1091; + + __drbd_uuid_set(device, UI_BITMAP, device->ldev->md.uuid[UI_HISTORY_START]); + __drbd_uuid_set(device, UI_HISTORY_START, device->ldev->md.uuid[UI_HISTORY_START + 1]); + + drbd_info(device, "Last syncUUID did not get through, corrected:\n"); + drbd_uuid_dump(device, "self", device->ldev->md.uuid, + device->state.disk >= D_NEGOTIATING ? drbd_bm_total_weight(device) : 0, 0); + + return 1; + } + } + + + *rule_nr = 80; + peer = device->p_uuid[UI_CURRENT] & ~((u64)1); + for (i = UI_HISTORY_START; i <= UI_HISTORY_END; i++) { + self = device->ldev->md.uuid[i] & ~((u64)1); + if (self == peer) + return 2; + } + + *rule_nr = 90; + self = device->ldev->md.uuid[UI_BITMAP] & ~((u64)1); + peer = device->p_uuid[UI_BITMAP] & ~((u64)1); + if (self == peer && self != ((u64)0)) + return 100; + + *rule_nr = 100; + for (i = UI_HISTORY_START; i <= UI_HISTORY_END; i++) { + self = device->ldev->md.uuid[i] & ~((u64)1); + for (j = UI_HISTORY_START; j <= UI_HISTORY_END; j++) { + peer = device->p_uuid[j] & ~((u64)1); + if (self == peer) + return -100; + } + } + + return -1000; +} + +/* drbd_sync_handshake() returns the new conn state on success, or + CONN_MASK (-1) on failure. + */ +static enum drbd_conns drbd_sync_handshake(struct drbd_peer_device *peer_device, + enum drbd_role peer_role, + enum drbd_disk_state peer_disk) __must_hold(local) +{ + struct drbd_device *device = peer_device->device; + enum drbd_conns rv = C_MASK; + enum drbd_disk_state mydisk; + struct net_conf *nc; + int hg, rule_nr, rr_conflict, tentative, always_asbp; + + mydisk = device->state.disk; + if (mydisk == D_NEGOTIATING) + mydisk = device->new_state_tmp.disk; + + drbd_info(device, "drbd_sync_handshake:\n"); + + spin_lock_irq(&device->ldev->md.uuid_lock); + drbd_uuid_dump(device, "self", device->ldev->md.uuid, device->comm_bm_set, 0); + drbd_uuid_dump(device, "peer", device->p_uuid, + device->p_uuid[UI_SIZE], device->p_uuid[UI_FLAGS]); + + hg = drbd_uuid_compare(device, peer_role, &rule_nr); + spin_unlock_irq(&device->ldev->md.uuid_lock); + + drbd_info(device, "uuid_compare()=%d by rule %d\n", hg, rule_nr); + + if (hg == -1000) { + drbd_alert(device, "Unrelated data, aborting!\n"); + return C_MASK; + } + if (hg < -0x10000) { + int proto, fflags; + hg = -hg; + proto = hg & 0xff; + fflags = (hg >> 8) & 0xff; + drbd_alert(device, "To resolve this both sides have to support at least protocol %d and feature flags 0x%x\n", + proto, fflags); + return C_MASK; + } + if (hg < -1000) { + drbd_alert(device, "To resolve this both sides have to support at least protocol %d\n", -hg - 1000); + return C_MASK; + } + + if ((mydisk == D_INCONSISTENT && peer_disk > D_INCONSISTENT) || + (peer_disk == D_INCONSISTENT && mydisk > D_INCONSISTENT)) { + int f = (hg == -100) || abs(hg) == 2; + hg = mydisk > D_INCONSISTENT ? 1 : -1; + if (f) + hg = hg*2; + drbd_info(device, "Becoming sync %s due to disk states.\n", + hg > 0 ? "source" : "target"); + } + + if (abs(hg) == 100) + drbd_khelper(device, "initial-split-brain"); + + rcu_read_lock(); + nc = rcu_dereference(peer_device->connection->net_conf); + always_asbp = nc->always_asbp; + rr_conflict = nc->rr_conflict; + tentative = nc->tentative; + rcu_read_unlock(); + + if (hg == 100 || (hg == -100 && always_asbp)) { + int pcount = (device->state.role == R_PRIMARY) + + (peer_role == R_PRIMARY); + int forced = (hg == -100); + + switch (pcount) { + case 0: + hg = drbd_asb_recover_0p(peer_device); + break; + case 1: + hg = drbd_asb_recover_1p(peer_device); + break; + case 2: + hg = drbd_asb_recover_2p(peer_device); + break; + } + if (abs(hg) < 100) { + drbd_warn(device, "Split-Brain detected, %d primaries, " + "automatically solved. Sync from %s node\n", + pcount, (hg < 0) ? "peer" : "this"); + if (forced) { + drbd_warn(device, "Doing a full sync, since" + " UUIDs where ambiguous.\n"); + hg = hg*2; + } + } + } + + if (hg == -100) { + if (test_bit(DISCARD_MY_DATA, &device->flags) && !(device->p_uuid[UI_FLAGS]&1)) + hg = -1; + if (!test_bit(DISCARD_MY_DATA, &device->flags) && (device->p_uuid[UI_FLAGS]&1)) + hg = 1; + + if (abs(hg) < 100) + drbd_warn(device, "Split-Brain detected, manually solved. " + "Sync from %s node\n", + (hg < 0) ? "peer" : "this"); + } + + if (hg == -100) { + /* FIXME this log message is not correct if we end up here + * after an attempted attach on a diskless node. + * We just refuse to attach -- well, we drop the "connection" + * to that disk, in a way... */ + drbd_alert(device, "Split-Brain detected but unresolved, dropping connection!\n"); + drbd_khelper(device, "split-brain"); + return C_MASK; + } + + if (hg > 0 && mydisk <= D_INCONSISTENT) { + drbd_err(device, "I shall become SyncSource, but I am inconsistent!\n"); + return C_MASK; + } + + if (hg < 0 && /* by intention we do not use mydisk here. */ + device->state.role == R_PRIMARY && device->state.disk >= D_CONSISTENT) { + switch (rr_conflict) { + case ASB_CALL_HELPER: + drbd_khelper(device, "pri-lost"); + fallthrough; + case ASB_DISCONNECT: + drbd_err(device, "I shall become SyncTarget, but I am primary!\n"); + return C_MASK; + case ASB_VIOLENTLY: + drbd_warn(device, "Becoming SyncTarget, violating the stable-data" + "assumption\n"); + } + } + + if (tentative || test_bit(CONN_DRY_RUN, &peer_device->connection->flags)) { + if (hg == 0) + drbd_info(device, "dry-run connect: No resync, would become Connected immediately.\n"); + else + drbd_info(device, "dry-run connect: Would become %s, doing a %s resync.", + drbd_conn_str(hg > 0 ? C_SYNC_SOURCE : C_SYNC_TARGET), + abs(hg) >= 2 ? "full" : "bit-map based"); + return C_MASK; + } + + if (abs(hg) >= 2) { + drbd_info(device, "Writing the whole bitmap, full sync required after drbd_sync_handshake.\n"); + if (drbd_bitmap_io(device, &drbd_bmio_set_n_write, "set_n_write from sync_handshake", + BM_LOCKED_SET_ALLOWED)) + return C_MASK; + } + + if (hg > 0) { /* become sync source. */ + rv = C_WF_BITMAP_S; + } else if (hg < 0) { /* become sync target */ + rv = C_WF_BITMAP_T; + } else { + rv = C_CONNECTED; + if (drbd_bm_total_weight(device)) { + drbd_info(device, "No resync, but %lu bits in bitmap!\n", + drbd_bm_total_weight(device)); + } + } + + return rv; +} + +static enum drbd_after_sb_p convert_after_sb(enum drbd_after_sb_p peer) +{ + /* ASB_DISCARD_REMOTE - ASB_DISCARD_LOCAL is valid */ + if (peer == ASB_DISCARD_REMOTE) + return ASB_DISCARD_LOCAL; + + /* any other things with ASB_DISCARD_REMOTE or ASB_DISCARD_LOCAL are invalid */ + if (peer == ASB_DISCARD_LOCAL) + return ASB_DISCARD_REMOTE; + + /* everything else is valid if they are equal on both sides. */ + return peer; +} + +static int receive_protocol(struct drbd_connection *connection, struct packet_info *pi) +{ + struct p_protocol *p = pi->data; + enum drbd_after_sb_p p_after_sb_0p, p_after_sb_1p, p_after_sb_2p; + int p_proto, p_discard_my_data, p_two_primaries, cf; + struct net_conf *nc, *old_net_conf, *new_net_conf = NULL; + char integrity_alg[SHARED_SECRET_MAX] = ""; + struct crypto_shash *peer_integrity_tfm = NULL; + void *int_dig_in = NULL, *int_dig_vv = NULL; + + p_proto = be32_to_cpu(p->protocol); + p_after_sb_0p = be32_to_cpu(p->after_sb_0p); + p_after_sb_1p = be32_to_cpu(p->after_sb_1p); + p_after_sb_2p = be32_to_cpu(p->after_sb_2p); + p_two_primaries = be32_to_cpu(p->two_primaries); + cf = be32_to_cpu(p->conn_flags); + p_discard_my_data = cf & CF_DISCARD_MY_DATA; + + if (connection->agreed_pro_version >= 87) { + int err; + + if (pi->size > sizeof(integrity_alg)) + return -EIO; + err = drbd_recv_all(connection, integrity_alg, pi->size); + if (err) + return err; + integrity_alg[SHARED_SECRET_MAX - 1] = 0; + } + + if (pi->cmd != P_PROTOCOL_UPDATE) { + clear_bit(CONN_DRY_RUN, &connection->flags); + + if (cf & CF_DRY_RUN) + set_bit(CONN_DRY_RUN, &connection->flags); + + rcu_read_lock(); + nc = rcu_dereference(connection->net_conf); + + if (p_proto != nc->wire_protocol) { + drbd_err(connection, "incompatible %s settings\n", "protocol"); + goto disconnect_rcu_unlock; + } + + if (convert_after_sb(p_after_sb_0p) != nc->after_sb_0p) { + drbd_err(connection, "incompatible %s settings\n", "after-sb-0pri"); + goto disconnect_rcu_unlock; + } + + if (convert_after_sb(p_after_sb_1p) != nc->after_sb_1p) { + drbd_err(connection, "incompatible %s settings\n", "after-sb-1pri"); + goto disconnect_rcu_unlock; + } + + if (convert_after_sb(p_after_sb_2p) != nc->after_sb_2p) { + drbd_err(connection, "incompatible %s settings\n", "after-sb-2pri"); + goto disconnect_rcu_unlock; + } + + if (p_discard_my_data && nc->discard_my_data) { + drbd_err(connection, "incompatible %s settings\n", "discard-my-data"); + goto disconnect_rcu_unlock; + } + + if (p_two_primaries != nc->two_primaries) { + drbd_err(connection, "incompatible %s settings\n", "allow-two-primaries"); + goto disconnect_rcu_unlock; + } + + if (strcmp(integrity_alg, nc->integrity_alg)) { + drbd_err(connection, "incompatible %s settings\n", "data-integrity-alg"); + goto disconnect_rcu_unlock; + } + + rcu_read_unlock(); + } + + if (integrity_alg[0]) { + int hash_size; + + /* + * We can only change the peer data integrity algorithm + * here. Changing our own data integrity algorithm + * requires that we send a P_PROTOCOL_UPDATE packet at + * the same time; otherwise, the peer has no way to + * tell between which packets the algorithm should + * change. + */ + + peer_integrity_tfm = crypto_alloc_shash(integrity_alg, 0, 0); + if (IS_ERR(peer_integrity_tfm)) { + peer_integrity_tfm = NULL; + drbd_err(connection, "peer data-integrity-alg %s not supported\n", + integrity_alg); + goto disconnect; + } + + hash_size = crypto_shash_digestsize(peer_integrity_tfm); + int_dig_in = kmalloc(hash_size, GFP_KERNEL); + int_dig_vv = kmalloc(hash_size, GFP_KERNEL); + if (!(int_dig_in && int_dig_vv)) { + drbd_err(connection, "Allocation of buffers for data integrity checking failed\n"); + goto disconnect; + } + } + + new_net_conf = kmalloc(sizeof(struct net_conf), GFP_KERNEL); + if (!new_net_conf) + goto disconnect; + + mutex_lock(&connection->data.mutex); + mutex_lock(&connection->resource->conf_update); + old_net_conf = connection->net_conf; + *new_net_conf = *old_net_conf; + + new_net_conf->wire_protocol = p_proto; + new_net_conf->after_sb_0p = convert_after_sb(p_after_sb_0p); + new_net_conf->after_sb_1p = convert_after_sb(p_after_sb_1p); + new_net_conf->after_sb_2p = convert_after_sb(p_after_sb_2p); + new_net_conf->two_primaries = p_two_primaries; + + rcu_assign_pointer(connection->net_conf, new_net_conf); + mutex_unlock(&connection->resource->conf_update); + mutex_unlock(&connection->data.mutex); + + crypto_free_shash(connection->peer_integrity_tfm); + kfree(connection->int_dig_in); + kfree(connection->int_dig_vv); + connection->peer_integrity_tfm = peer_integrity_tfm; + connection->int_dig_in = int_dig_in; + connection->int_dig_vv = int_dig_vv; + + if (strcmp(old_net_conf->integrity_alg, integrity_alg)) + drbd_info(connection, "peer data-integrity-alg: %s\n", + integrity_alg[0] ? integrity_alg : "(none)"); + + kvfree_rcu(old_net_conf); + return 0; + +disconnect_rcu_unlock: + rcu_read_unlock(); +disconnect: + crypto_free_shash(peer_integrity_tfm); + kfree(int_dig_in); + kfree(int_dig_vv); + conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD); + return -EIO; +} + +/* helper function + * input: alg name, feature name + * return: NULL (alg name was "") + * ERR_PTR(error) if something goes wrong + * or the crypto hash ptr, if it worked out ok. */ +static struct crypto_shash *drbd_crypto_alloc_digest_safe( + const struct drbd_device *device, + const char *alg, const char *name) +{ + struct crypto_shash *tfm; + + if (!alg[0]) + return NULL; + + tfm = crypto_alloc_shash(alg, 0, 0); + if (IS_ERR(tfm)) { + drbd_err(device, "Can not allocate \"%s\" as %s (reason: %ld)\n", + alg, name, PTR_ERR(tfm)); + return tfm; + } + return tfm; +} + +static int ignore_remaining_packet(struct drbd_connection *connection, struct packet_info *pi) +{ + void *buffer = connection->data.rbuf; + int size = pi->size; + + while (size) { + int s = min_t(int, size, DRBD_SOCKET_BUFFER_SIZE); + s = drbd_recv(connection, buffer, s); + if (s <= 0) { + if (s < 0) + return s; + break; + } + size -= s; + } + if (size) + return -EIO; + return 0; +} + +/* + * config_unknown_volume - device configuration command for unknown volume + * + * When a device is added to an existing connection, the node on which the + * device is added first will send configuration commands to its peer but the + * peer will not know about the device yet. It will warn and ignore these + * commands. Once the device is added on the second node, the second node will + * send the same device configuration commands, but in the other direction. + * + * (We can also end up here if drbd is misconfigured.) + */ +static int config_unknown_volume(struct drbd_connection *connection, struct packet_info *pi) +{ + drbd_warn(connection, "%s packet received for volume %u, which is not configured locally\n", + cmdname(pi->cmd), pi->vnr); + return ignore_remaining_packet(connection, pi); +} + +static int receive_SyncParam(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + struct p_rs_param_95 *p; + unsigned int header_size, data_size, exp_max_sz; + struct crypto_shash *verify_tfm = NULL; + struct crypto_shash *csums_tfm = NULL; + struct net_conf *old_net_conf, *new_net_conf = NULL; + struct disk_conf *old_disk_conf = NULL, *new_disk_conf = NULL; + const int apv = connection->agreed_pro_version; + struct fifo_buffer *old_plan = NULL, *new_plan = NULL; + unsigned int fifo_size = 0; + int err; + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return config_unknown_volume(connection, pi); + device = peer_device->device; + + exp_max_sz = apv <= 87 ? sizeof(struct p_rs_param) + : apv == 88 ? sizeof(struct p_rs_param) + + SHARED_SECRET_MAX + : apv <= 94 ? sizeof(struct p_rs_param_89) + : /* apv >= 95 */ sizeof(struct p_rs_param_95); + + if (pi->size > exp_max_sz) { + drbd_err(device, "SyncParam packet too long: received %u, expected <= %u bytes\n", + pi->size, exp_max_sz); + return -EIO; + } + + if (apv <= 88) { + header_size = sizeof(struct p_rs_param); + data_size = pi->size - header_size; + } else if (apv <= 94) { + header_size = sizeof(struct p_rs_param_89); + data_size = pi->size - header_size; + D_ASSERT(device, data_size == 0); + } else { + header_size = sizeof(struct p_rs_param_95); + data_size = pi->size - header_size; + D_ASSERT(device, data_size == 0); + } + + /* initialize verify_alg and csums_alg */ + p = pi->data; + BUILD_BUG_ON(sizeof(p->algs) != 2 * SHARED_SECRET_MAX); + memset(&p->algs, 0, sizeof(p->algs)); + + err = drbd_recv_all(peer_device->connection, p, header_size); + if (err) + return err; + + mutex_lock(&connection->resource->conf_update); + old_net_conf = peer_device->connection->net_conf; + if (get_ldev(device)) { + new_disk_conf = kzalloc(sizeof(struct disk_conf), GFP_KERNEL); + if (!new_disk_conf) { + put_ldev(device); + mutex_unlock(&connection->resource->conf_update); + drbd_err(device, "Allocation of new disk_conf failed\n"); + return -ENOMEM; + } + + old_disk_conf = device->ldev->disk_conf; + *new_disk_conf = *old_disk_conf; + + new_disk_conf->resync_rate = be32_to_cpu(p->resync_rate); + } + + if (apv >= 88) { + if (apv == 88) { + if (data_size > SHARED_SECRET_MAX || data_size == 0) { + drbd_err(device, "verify-alg of wrong size, " + "peer wants %u, accepting only up to %u byte\n", + data_size, SHARED_SECRET_MAX); + goto reconnect; + } + + err = drbd_recv_all(peer_device->connection, p->verify_alg, data_size); + if (err) + goto reconnect; + /* we expect NUL terminated string */ + /* but just in case someone tries to be evil */ + D_ASSERT(device, p->verify_alg[data_size-1] == 0); + p->verify_alg[data_size-1] = 0; + + } else /* apv >= 89 */ { + /* we still expect NUL terminated strings */ + /* but just in case someone tries to be evil */ + D_ASSERT(device, p->verify_alg[SHARED_SECRET_MAX-1] == 0); + D_ASSERT(device, p->csums_alg[SHARED_SECRET_MAX-1] == 0); + p->verify_alg[SHARED_SECRET_MAX-1] = 0; + p->csums_alg[SHARED_SECRET_MAX-1] = 0; + } + + if (strcmp(old_net_conf->verify_alg, p->verify_alg)) { + if (device->state.conn == C_WF_REPORT_PARAMS) { + drbd_err(device, "Different verify-alg settings. me=\"%s\" peer=\"%s\"\n", + old_net_conf->verify_alg, p->verify_alg); + goto disconnect; + } + verify_tfm = drbd_crypto_alloc_digest_safe(device, + p->verify_alg, "verify-alg"); + if (IS_ERR(verify_tfm)) { + verify_tfm = NULL; + goto disconnect; + } + } + + if (apv >= 89 && strcmp(old_net_conf->csums_alg, p->csums_alg)) { + if (device->state.conn == C_WF_REPORT_PARAMS) { + drbd_err(device, "Different csums-alg settings. me=\"%s\" peer=\"%s\"\n", + old_net_conf->csums_alg, p->csums_alg); + goto disconnect; + } + csums_tfm = drbd_crypto_alloc_digest_safe(device, + p->csums_alg, "csums-alg"); + if (IS_ERR(csums_tfm)) { + csums_tfm = NULL; + goto disconnect; + } + } + + if (apv > 94 && new_disk_conf) { + new_disk_conf->c_plan_ahead = be32_to_cpu(p->c_plan_ahead); + new_disk_conf->c_delay_target = be32_to_cpu(p->c_delay_target); + new_disk_conf->c_fill_target = be32_to_cpu(p->c_fill_target); + new_disk_conf->c_max_rate = be32_to_cpu(p->c_max_rate); + + fifo_size = (new_disk_conf->c_plan_ahead * 10 * SLEEP_TIME) / HZ; + if (fifo_size != device->rs_plan_s->size) { + new_plan = fifo_alloc(fifo_size); + if (!new_plan) { + drbd_err(device, "kmalloc of fifo_buffer failed"); + put_ldev(device); + goto disconnect; + } + } + } + + if (verify_tfm || csums_tfm) { + new_net_conf = kzalloc(sizeof(struct net_conf), GFP_KERNEL); + if (!new_net_conf) + goto disconnect; + + *new_net_conf = *old_net_conf; + + if (verify_tfm) { + strcpy(new_net_conf->verify_alg, p->verify_alg); + new_net_conf->verify_alg_len = strlen(p->verify_alg) + 1; + crypto_free_shash(peer_device->connection->verify_tfm); + peer_device->connection->verify_tfm = verify_tfm; + drbd_info(device, "using verify-alg: \"%s\"\n", p->verify_alg); + } + if (csums_tfm) { + strcpy(new_net_conf->csums_alg, p->csums_alg); + new_net_conf->csums_alg_len = strlen(p->csums_alg) + 1; + crypto_free_shash(peer_device->connection->csums_tfm); + peer_device->connection->csums_tfm = csums_tfm; + drbd_info(device, "using csums-alg: \"%s\"\n", p->csums_alg); + } + rcu_assign_pointer(connection->net_conf, new_net_conf); + } + } + + if (new_disk_conf) { + rcu_assign_pointer(device->ldev->disk_conf, new_disk_conf); + put_ldev(device); + } + + if (new_plan) { + old_plan = device->rs_plan_s; + rcu_assign_pointer(device->rs_plan_s, new_plan); + } + + mutex_unlock(&connection->resource->conf_update); + synchronize_rcu(); + if (new_net_conf) + kfree(old_net_conf); + kfree(old_disk_conf); + kfree(old_plan); + + return 0; + +reconnect: + if (new_disk_conf) { + put_ldev(device); + kfree(new_disk_conf); + } + mutex_unlock(&connection->resource->conf_update); + return -EIO; + +disconnect: + kfree(new_plan); + if (new_disk_conf) { + put_ldev(device); + kfree(new_disk_conf); + } + mutex_unlock(&connection->resource->conf_update); + /* just for completeness: actually not needed, + * as this is not reached if csums_tfm was ok. */ + crypto_free_shash(csums_tfm); + /* but free the verify_tfm again, if csums_tfm did not work out */ + crypto_free_shash(verify_tfm); + conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD); + return -EIO; +} + +/* warn if the arguments differ by more than 12.5% */ +static void warn_if_differ_considerably(struct drbd_device *device, + const char *s, sector_t a, sector_t b) +{ + sector_t d; + if (a == 0 || b == 0) + return; + d = (a > b) ? (a - b) : (b - a); + if (d > (a>>3) || d > (b>>3)) + drbd_warn(device, "Considerable difference in %s: %llus vs. %llus\n", s, + (unsigned long long)a, (unsigned long long)b); +} + +static int receive_sizes(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + struct p_sizes *p = pi->data; + struct o_qlim *o = (connection->agreed_features & DRBD_FF_WSAME) ? p->qlim : NULL; + enum determine_dev_size dd = DS_UNCHANGED; + sector_t p_size, p_usize, p_csize, my_usize; + sector_t new_size, cur_size; + int ldsc = 0; /* local disk size changed */ + enum dds_flags ddsf; + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return config_unknown_volume(connection, pi); + device = peer_device->device; + cur_size = get_capacity(device->vdisk); + + p_size = be64_to_cpu(p->d_size); + p_usize = be64_to_cpu(p->u_size); + p_csize = be64_to_cpu(p->c_size); + + /* just store the peer's disk size for now. + * we still need to figure out whether we accept that. */ + device->p_size = p_size; + + if (get_ldev(device)) { + rcu_read_lock(); + my_usize = rcu_dereference(device->ldev->disk_conf)->disk_size; + rcu_read_unlock(); + + warn_if_differ_considerably(device, "lower level device sizes", + p_size, drbd_get_max_capacity(device->ldev)); + warn_if_differ_considerably(device, "user requested size", + p_usize, my_usize); + + /* if this is the first connect, or an otherwise expected + * param exchange, choose the minimum */ + if (device->state.conn == C_WF_REPORT_PARAMS) + p_usize = min_not_zero(my_usize, p_usize); + + /* Never shrink a device with usable data during connect, + * or "attach" on the peer. + * But allow online shrinking if we are connected. */ + new_size = drbd_new_dev_size(device, device->ldev, p_usize, 0); + if (new_size < cur_size && + device->state.disk >= D_OUTDATED && + (device->state.conn < C_CONNECTED || device->state.pdsk == D_DISKLESS)) { + drbd_err(device, "The peer's disk size is too small! (%llu < %llu sectors)\n", + (unsigned long long)new_size, (unsigned long long)cur_size); + conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD); + put_ldev(device); + return -EIO; + } + + if (my_usize != p_usize) { + struct disk_conf *old_disk_conf, *new_disk_conf = NULL; + + new_disk_conf = kzalloc(sizeof(struct disk_conf), GFP_KERNEL); + if (!new_disk_conf) { + put_ldev(device); + return -ENOMEM; + } + + mutex_lock(&connection->resource->conf_update); + old_disk_conf = device->ldev->disk_conf; + *new_disk_conf = *old_disk_conf; + new_disk_conf->disk_size = p_usize; + + rcu_assign_pointer(device->ldev->disk_conf, new_disk_conf); + mutex_unlock(&connection->resource->conf_update); + kvfree_rcu(old_disk_conf); + + drbd_info(device, "Peer sets u_size to %lu sectors (old: %lu)\n", + (unsigned long)p_usize, (unsigned long)my_usize); + } + + put_ldev(device); + } + + device->peer_max_bio_size = be32_to_cpu(p->max_bio_size); + /* Leave drbd_reconsider_queue_parameters() before drbd_determine_dev_size(). + In case we cleared the QUEUE_FLAG_DISCARD from our queue in + drbd_reconsider_queue_parameters(), we can be sure that after + drbd_determine_dev_size() no REQ_DISCARDs are in the queue. */ + + ddsf = be16_to_cpu(p->dds_flags); + if (get_ldev(device)) { + drbd_reconsider_queue_parameters(device, device->ldev, o); + dd = drbd_determine_dev_size(device, ddsf, NULL); + put_ldev(device); + if (dd == DS_ERROR) + return -EIO; + drbd_md_sync(device); + } else { + /* + * I am diskless, need to accept the peer's *current* size. + * I must NOT accept the peers backing disk size, + * it may have been larger than mine all along... + * + * At this point, the peer knows more about my disk, or at + * least about what we last agreed upon, than myself. + * So if his c_size is less than his d_size, the most likely + * reason is that *my* d_size was smaller last time we checked. + * + * However, if he sends a zero current size, + * take his (user-capped or) backing disk size anyways. + * + * Unless of course he does not have a disk himself. + * In which case we ignore this completely. + */ + sector_t new_size = p_csize ?: p_usize ?: p_size; + drbd_reconsider_queue_parameters(device, NULL, o); + if (new_size == 0) { + /* Ignore, peer does not know nothing. */ + } else if (new_size == cur_size) { + /* nothing to do */ + } else if (cur_size != 0 && p_size == 0) { + drbd_warn(device, "Ignored diskless peer device size (peer:%llu != me:%llu sectors)!\n", + (unsigned long long)new_size, (unsigned long long)cur_size); + } else if (new_size < cur_size && device->state.role == R_PRIMARY) { + drbd_err(device, "The peer's device size is too small! (%llu < %llu sectors); demote me first!\n", + (unsigned long long)new_size, (unsigned long long)cur_size); + conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD); + return -EIO; + } else { + /* I believe the peer, if + * - I don't have a current size myself + * - we agree on the size anyways + * - I do have a current size, am Secondary, + * and he has the only disk + * - I do have a current size, am Primary, + * and he has the only disk, + * which is larger than my current size + */ + drbd_set_my_capacity(device, new_size); + } + } + + if (get_ldev(device)) { + if (device->ldev->known_size != drbd_get_capacity(device->ldev->backing_bdev)) { + device->ldev->known_size = drbd_get_capacity(device->ldev->backing_bdev); + ldsc = 1; + } + + put_ldev(device); + } + + if (device->state.conn > C_WF_REPORT_PARAMS) { + if (be64_to_cpu(p->c_size) != get_capacity(device->vdisk) || + ldsc) { + /* we have different sizes, probably peer + * needs to know my new size... */ + drbd_send_sizes(peer_device, 0, ddsf); + } + if (test_and_clear_bit(RESIZE_PENDING, &device->flags) || + (dd == DS_GREW && device->state.conn == C_CONNECTED)) { + if (device->state.pdsk >= D_INCONSISTENT && + device->state.disk >= D_INCONSISTENT) { + if (ddsf & DDSF_NO_RESYNC) + drbd_info(device, "Resync of new storage suppressed with --assume-clean\n"); + else + resync_after_online_grow(device); + } else + set_bit(RESYNC_AFTER_NEG, &device->flags); + } + } + + return 0; +} + +static int receive_uuids(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + struct p_uuids *p = pi->data; + u64 *p_uuid; + int i, updated_uuids = 0; + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return config_unknown_volume(connection, pi); + device = peer_device->device; + + p_uuid = kmalloc_array(UI_EXTENDED_SIZE, sizeof(*p_uuid), GFP_NOIO); + if (!p_uuid) + return false; + + for (i = UI_CURRENT; i < UI_EXTENDED_SIZE; i++) + p_uuid[i] = be64_to_cpu(p->uuid[i]); + + kfree(device->p_uuid); + device->p_uuid = p_uuid; + + if ((device->state.conn < C_CONNECTED || device->state.pdsk == D_DISKLESS) && + device->state.disk < D_INCONSISTENT && + device->state.role == R_PRIMARY && + (device->ed_uuid & ~((u64)1)) != (p_uuid[UI_CURRENT] & ~((u64)1))) { + drbd_err(device, "Can only connect to data with current UUID=%016llX\n", + (unsigned long long)device->ed_uuid); + conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD); + return -EIO; + } + + if (get_ldev(device)) { + int skip_initial_sync = + device->state.conn == C_CONNECTED && + peer_device->connection->agreed_pro_version >= 90 && + device->ldev->md.uuid[UI_CURRENT] == UUID_JUST_CREATED && + (p_uuid[UI_FLAGS] & 8); + if (skip_initial_sync) { + drbd_info(device, "Accepted new current UUID, preparing to skip initial sync\n"); + drbd_bitmap_io(device, &drbd_bmio_clear_n_write, + "clear_n_write from receive_uuids", + BM_LOCKED_TEST_ALLOWED); + _drbd_uuid_set(device, UI_CURRENT, p_uuid[UI_CURRENT]); + _drbd_uuid_set(device, UI_BITMAP, 0); + _drbd_set_state(_NS2(device, disk, D_UP_TO_DATE, pdsk, D_UP_TO_DATE), + CS_VERBOSE, NULL); + drbd_md_sync(device); + updated_uuids = 1; + } + put_ldev(device); + } else if (device->state.disk < D_INCONSISTENT && + device->state.role == R_PRIMARY) { + /* I am a diskless primary, the peer just created a new current UUID + for me. */ + updated_uuids = drbd_set_ed_uuid(device, p_uuid[UI_CURRENT]); + } + + /* Before we test for the disk state, we should wait until an eventually + ongoing cluster wide state change is finished. That is important if + we are primary and are detaching from our disk. We need to see the + new disk state... */ + mutex_lock(device->state_mutex); + mutex_unlock(device->state_mutex); + if (device->state.conn >= C_CONNECTED && device->state.disk < D_INCONSISTENT) + updated_uuids |= drbd_set_ed_uuid(device, p_uuid[UI_CURRENT]); + + if (updated_uuids) + drbd_print_uuids(device, "receiver updated UUIDs to"); + + return 0; +} + +/** + * convert_state() - Converts the peer's view of the cluster state to our point of view + * @ps: The state as seen by the peer. + */ +static union drbd_state convert_state(union drbd_state ps) +{ + union drbd_state ms; + + static enum drbd_conns c_tab[] = { + [C_WF_REPORT_PARAMS] = C_WF_REPORT_PARAMS, + [C_CONNECTED] = C_CONNECTED, + + [C_STARTING_SYNC_S] = C_STARTING_SYNC_T, + [C_STARTING_SYNC_T] = C_STARTING_SYNC_S, + [C_DISCONNECTING] = C_TEAR_DOWN, /* C_NETWORK_FAILURE, */ + [C_VERIFY_S] = C_VERIFY_T, + [C_MASK] = C_MASK, + }; + + ms.i = ps.i; + + ms.conn = c_tab[ps.conn]; + ms.peer = ps.role; + ms.role = ps.peer; + ms.pdsk = ps.disk; + ms.disk = ps.pdsk; + ms.peer_isp = (ps.aftr_isp | ps.user_isp); + + return ms; +} + +static int receive_req_state(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + struct p_req_state *p = pi->data; + union drbd_state mask, val; + enum drbd_state_rv rv; + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return -EIO; + device = peer_device->device; + + mask.i = be32_to_cpu(p->mask); + val.i = be32_to_cpu(p->val); + + if (test_bit(RESOLVE_CONFLICTS, &peer_device->connection->flags) && + mutex_is_locked(device->state_mutex)) { + drbd_send_sr_reply(peer_device, SS_CONCURRENT_ST_CHG); + return 0; + } + + mask = convert_state(mask); + val = convert_state(val); + + rv = drbd_change_state(device, CS_VERBOSE, mask, val); + drbd_send_sr_reply(peer_device, rv); + + drbd_md_sync(device); + + return 0; +} + +static int receive_req_conn_state(struct drbd_connection *connection, struct packet_info *pi) +{ + struct p_req_state *p = pi->data; + union drbd_state mask, val; + enum drbd_state_rv rv; + + mask.i = be32_to_cpu(p->mask); + val.i = be32_to_cpu(p->val); + + if (test_bit(RESOLVE_CONFLICTS, &connection->flags) && + mutex_is_locked(&connection->cstate_mutex)) { + conn_send_sr_reply(connection, SS_CONCURRENT_ST_CHG); + return 0; + } + + mask = convert_state(mask); + val = convert_state(val); + + rv = conn_request_state(connection, mask, val, CS_VERBOSE | CS_LOCAL_ONLY | CS_IGN_OUTD_FAIL); + conn_send_sr_reply(connection, rv); + + return 0; +} + +static int receive_state(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + struct p_state *p = pi->data; + union drbd_state os, ns, peer_state; + enum drbd_disk_state real_peer_disk; + enum chg_state_flags cs_flags; + int rv; + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return config_unknown_volume(connection, pi); + device = peer_device->device; + + peer_state.i = be32_to_cpu(p->state); + + real_peer_disk = peer_state.disk; + if (peer_state.disk == D_NEGOTIATING) { + real_peer_disk = device->p_uuid[UI_FLAGS] & 4 ? D_INCONSISTENT : D_CONSISTENT; + drbd_info(device, "real peer disk state = %s\n", drbd_disk_str(real_peer_disk)); + } + + spin_lock_irq(&device->resource->req_lock); + retry: + os = ns = drbd_read_state(device); + spin_unlock_irq(&device->resource->req_lock); + + /* If some other part of the code (ack_receiver thread, timeout) + * already decided to close the connection again, + * we must not "re-establish" it here. */ + if (os.conn <= C_TEAR_DOWN) + return -ECONNRESET; + + /* If this is the "end of sync" confirmation, usually the peer disk + * transitions from D_INCONSISTENT to D_UP_TO_DATE. For empty (0 bits + * set) resync started in PausedSyncT, or if the timing of pause-/ + * unpause-sync events has been "just right", the peer disk may + * transition from D_CONSISTENT to D_UP_TO_DATE as well. + */ + if ((os.pdsk == D_INCONSISTENT || os.pdsk == D_CONSISTENT) && + real_peer_disk == D_UP_TO_DATE && + os.conn > C_CONNECTED && os.disk == D_UP_TO_DATE) { + /* If we are (becoming) SyncSource, but peer is still in sync + * preparation, ignore its uptodate-ness to avoid flapping, it + * will change to inconsistent once the peer reaches active + * syncing states. + * It may have changed syncer-paused flags, however, so we + * cannot ignore this completely. */ + if (peer_state.conn > C_CONNECTED && + peer_state.conn < C_SYNC_SOURCE) + real_peer_disk = D_INCONSISTENT; + + /* if peer_state changes to connected at the same time, + * it explicitly notifies us that it finished resync. + * Maybe we should finish it up, too? */ + else if (os.conn >= C_SYNC_SOURCE && + peer_state.conn == C_CONNECTED) { + if (drbd_bm_total_weight(device) <= device->rs_failed) + drbd_resync_finished(device); + return 0; + } + } + + /* explicit verify finished notification, stop sector reached. */ + if (os.conn == C_VERIFY_T && os.disk == D_UP_TO_DATE && + peer_state.conn == C_CONNECTED && real_peer_disk == D_UP_TO_DATE) { + ov_out_of_sync_print(device); + drbd_resync_finished(device); + return 0; + } + + /* peer says his disk is inconsistent, while we think it is uptodate, + * and this happens while the peer still thinks we have a sync going on, + * but we think we are already done with the sync. + * We ignore this to avoid flapping pdsk. + * This should not happen, if the peer is a recent version of drbd. */ + if (os.pdsk == D_UP_TO_DATE && real_peer_disk == D_INCONSISTENT && + os.conn == C_CONNECTED && peer_state.conn > C_SYNC_SOURCE) + real_peer_disk = D_UP_TO_DATE; + + if (ns.conn == C_WF_REPORT_PARAMS) + ns.conn = C_CONNECTED; + + if (peer_state.conn == C_AHEAD) + ns.conn = C_BEHIND; + + /* TODO: + * if (primary and diskless and peer uuid != effective uuid) + * abort attach on peer; + * + * If this node does not have good data, was already connected, but + * the peer did a late attach only now, trying to "negotiate" with me, + * AND I am currently Primary, possibly frozen, with some specific + * "effective" uuid, this should never be reached, really, because + * we first send the uuids, then the current state. + * + * In this scenario, we already dropped the connection hard + * when we received the unsuitable uuids (receive_uuids(). + * + * Should we want to change this, that is: not drop the connection in + * receive_uuids() already, then we would need to add a branch here + * that aborts the attach of "unsuitable uuids" on the peer in case + * this node is currently Diskless Primary. + */ + + if (device->p_uuid && peer_state.disk >= D_NEGOTIATING && + get_ldev_if_state(device, D_NEGOTIATING)) { + int cr; /* consider resync */ + + /* if we established a new connection */ + cr = (os.conn < C_CONNECTED); + /* if we had an established connection + * and one of the nodes newly attaches a disk */ + cr |= (os.conn == C_CONNECTED && + (peer_state.disk == D_NEGOTIATING || + os.disk == D_NEGOTIATING)); + /* if we have both been inconsistent, and the peer has been + * forced to be UpToDate with --force */ + cr |= test_bit(CONSIDER_RESYNC, &device->flags); + /* if we had been plain connected, and the admin requested to + * start a sync by "invalidate" or "invalidate-remote" */ + cr |= (os.conn == C_CONNECTED && + (peer_state.conn >= C_STARTING_SYNC_S && + peer_state.conn <= C_WF_BITMAP_T)); + + if (cr) + ns.conn = drbd_sync_handshake(peer_device, peer_state.role, real_peer_disk); + + put_ldev(device); + if (ns.conn == C_MASK) { + ns.conn = C_CONNECTED; + if (device->state.disk == D_NEGOTIATING) { + drbd_force_state(device, NS(disk, D_FAILED)); + } else if (peer_state.disk == D_NEGOTIATING) { + drbd_err(device, "Disk attach process on the peer node was aborted.\n"); + peer_state.disk = D_DISKLESS; + real_peer_disk = D_DISKLESS; + } else { + if (test_and_clear_bit(CONN_DRY_RUN, &peer_device->connection->flags)) + return -EIO; + D_ASSERT(device, os.conn == C_WF_REPORT_PARAMS); + conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD); + return -EIO; + } + } + } + + spin_lock_irq(&device->resource->req_lock); + if (os.i != drbd_read_state(device).i) + goto retry; + clear_bit(CONSIDER_RESYNC, &device->flags); + ns.peer = peer_state.role; + ns.pdsk = real_peer_disk; + ns.peer_isp = (peer_state.aftr_isp | peer_state.user_isp); + if ((ns.conn == C_CONNECTED || ns.conn == C_WF_BITMAP_S) && ns.disk == D_NEGOTIATING) + ns.disk = device->new_state_tmp.disk; + cs_flags = CS_VERBOSE + (os.conn < C_CONNECTED && ns.conn >= C_CONNECTED ? 0 : CS_HARD); + if (ns.pdsk == D_CONSISTENT && drbd_suspended(device) && ns.conn == C_CONNECTED && os.conn < C_CONNECTED && + test_bit(NEW_CUR_UUID, &device->flags)) { + /* Do not allow tl_restart(RESEND) for a rebooted peer. We can only allow this + for temporal network outages! */ + spin_unlock_irq(&device->resource->req_lock); + drbd_err(device, "Aborting Connect, can not thaw IO with an only Consistent peer\n"); + tl_clear(peer_device->connection); + drbd_uuid_new_current(device); + clear_bit(NEW_CUR_UUID, &device->flags); + conn_request_state(peer_device->connection, NS2(conn, C_PROTOCOL_ERROR, susp, 0), CS_HARD); + return -EIO; + } + rv = _drbd_set_state(device, ns, cs_flags, NULL); + ns = drbd_read_state(device); + spin_unlock_irq(&device->resource->req_lock); + + if (rv < SS_SUCCESS) { + conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD); + return -EIO; + } + + if (os.conn > C_WF_REPORT_PARAMS) { + if (ns.conn > C_CONNECTED && peer_state.conn <= C_CONNECTED && + peer_state.disk != D_NEGOTIATING ) { + /* we want resync, peer has not yet decided to sync... */ + /* Nowadays only used when forcing a node into primary role and + setting its disk to UpToDate with that */ + drbd_send_uuids(peer_device); + drbd_send_current_state(peer_device); + } + } + + clear_bit(DISCARD_MY_DATA, &device->flags); + + drbd_md_sync(device); /* update connected indicator, la_size_sect, ... */ + + return 0; +} + +static int receive_sync_uuid(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + struct p_rs_uuid *p = pi->data; + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return -EIO; + device = peer_device->device; + + wait_event(device->misc_wait, + device->state.conn == C_WF_SYNC_UUID || + device->state.conn == C_BEHIND || + device->state.conn < C_CONNECTED || + device->state.disk < D_NEGOTIATING); + + /* D_ASSERT(device, device->state.conn == C_WF_SYNC_UUID ); */ + + /* Here the _drbd_uuid_ functions are right, current should + _not_ be rotated into the history */ + if (get_ldev_if_state(device, D_NEGOTIATING)) { + _drbd_uuid_set(device, UI_CURRENT, be64_to_cpu(p->uuid)); + _drbd_uuid_set(device, UI_BITMAP, 0UL); + + drbd_print_uuids(device, "updated sync uuid"); + drbd_start_resync(device, C_SYNC_TARGET); + + put_ldev(device); + } else + drbd_err(device, "Ignoring SyncUUID packet!\n"); + + return 0; +} + +/* + * receive_bitmap_plain + * + * Return 0 when done, 1 when another iteration is needed, and a negative error + * code upon failure. + */ +static int +receive_bitmap_plain(struct drbd_peer_device *peer_device, unsigned int size, + unsigned long *p, struct bm_xfer_ctx *c) +{ + unsigned int data_size = DRBD_SOCKET_BUFFER_SIZE - + drbd_header_size(peer_device->connection); + unsigned int num_words = min_t(size_t, data_size / sizeof(*p), + c->bm_words - c->word_offset); + unsigned int want = num_words * sizeof(*p); + int err; + + if (want != size) { + drbd_err(peer_device, "%s:want (%u) != size (%u)\n", __func__, want, size); + return -EIO; + } + if (want == 0) + return 0; + err = drbd_recv_all(peer_device->connection, p, want); + if (err) + return err; + + drbd_bm_merge_lel(peer_device->device, c->word_offset, num_words, p); + + c->word_offset += num_words; + c->bit_offset = c->word_offset * BITS_PER_LONG; + if (c->bit_offset > c->bm_bits) + c->bit_offset = c->bm_bits; + + return 1; +} + +static enum drbd_bitmap_code dcbp_get_code(struct p_compressed_bm *p) +{ + return (enum drbd_bitmap_code)(p->encoding & 0x0f); +} + +static int dcbp_get_start(struct p_compressed_bm *p) +{ + return (p->encoding & 0x80) != 0; +} + +static int dcbp_get_pad_bits(struct p_compressed_bm *p) +{ + return (p->encoding >> 4) & 0x7; +} + +/* + * recv_bm_rle_bits + * + * Return 0 when done, 1 when another iteration is needed, and a negative error + * code upon failure. + */ +static int +recv_bm_rle_bits(struct drbd_peer_device *peer_device, + struct p_compressed_bm *p, + struct bm_xfer_ctx *c, + unsigned int len) +{ + struct bitstream bs; + u64 look_ahead; + u64 rl; + u64 tmp; + unsigned long s = c->bit_offset; + unsigned long e; + int toggle = dcbp_get_start(p); + int have; + int bits; + + bitstream_init(&bs, p->code, len, dcbp_get_pad_bits(p)); + + bits = bitstream_get_bits(&bs, &look_ahead, 64); + if (bits < 0) + return -EIO; + + for (have = bits; have > 0; s += rl, toggle = !toggle) { + bits = vli_decode_bits(&rl, look_ahead); + if (bits <= 0) + return -EIO; + + if (toggle) { + e = s + rl -1; + if (e >= c->bm_bits) { + drbd_err(peer_device, "bitmap overflow (e:%lu) while decoding bm RLE packet\n", e); + return -EIO; + } + _drbd_bm_set_bits(peer_device->device, s, e); + } + + if (have < bits) { + drbd_err(peer_device, "bitmap decoding error: h:%d b:%d la:0x%08llx l:%u/%u\n", + have, bits, look_ahead, + (unsigned int)(bs.cur.b - p->code), + (unsigned int)bs.buf_len); + return -EIO; + } + /* if we consumed all 64 bits, assign 0; >> 64 is "undefined"; */ + if (likely(bits < 64)) + look_ahead >>= bits; + else + look_ahead = 0; + have -= bits; + + bits = bitstream_get_bits(&bs, &tmp, 64 - have); + if (bits < 0) + return -EIO; + look_ahead |= tmp << have; + have += bits; + } + + c->bit_offset = s; + bm_xfer_ctx_bit_to_word_offset(c); + + return (s != c->bm_bits); +} + +/* + * decode_bitmap_c + * + * Return 0 when done, 1 when another iteration is needed, and a negative error + * code upon failure. + */ +static int +decode_bitmap_c(struct drbd_peer_device *peer_device, + struct p_compressed_bm *p, + struct bm_xfer_ctx *c, + unsigned int len) +{ + if (dcbp_get_code(p) == RLE_VLI_Bits) + return recv_bm_rle_bits(peer_device, p, c, len - sizeof(*p)); + + /* other variants had been implemented for evaluation, + * but have been dropped as this one turned out to be "best" + * during all our tests. */ + + drbd_err(peer_device, "receive_bitmap_c: unknown encoding %u\n", p->encoding); + conn_request_state(peer_device->connection, NS(conn, C_PROTOCOL_ERROR), CS_HARD); + return -EIO; +} + +void INFO_bm_xfer_stats(struct drbd_device *device, + const char *direction, struct bm_xfer_ctx *c) +{ + /* what would it take to transfer it "plaintext" */ + unsigned int header_size = drbd_header_size(first_peer_device(device)->connection); + unsigned int data_size = DRBD_SOCKET_BUFFER_SIZE - header_size; + unsigned int plain = + header_size * (DIV_ROUND_UP(c->bm_words, data_size) + 1) + + c->bm_words * sizeof(unsigned long); + unsigned int total = c->bytes[0] + c->bytes[1]; + unsigned int r; + + /* total can not be zero. but just in case: */ + if (total == 0) + return; + + /* don't report if not compressed */ + if (total >= plain) + return; + + /* total < plain. check for overflow, still */ + r = (total > UINT_MAX/1000) ? (total / (plain/1000)) + : (1000 * total / plain); + + if (r > 1000) + r = 1000; + + r = 1000 - r; + drbd_info(device, "%s bitmap stats [Bytes(packets)]: plain %u(%u), RLE %u(%u), " + "total %u; compression: %u.%u%%\n", + direction, + c->bytes[1], c->packets[1], + c->bytes[0], c->packets[0], + total, r/10, r % 10); +} + +/* Since we are processing the bitfield from lower addresses to higher, + it does not matter if the process it in 32 bit chunks or 64 bit + chunks as long as it is little endian. (Understand it as byte stream, + beginning with the lowest byte...) If we would use big endian + we would need to process it from the highest address to the lowest, + in order to be agnostic to the 32 vs 64 bits issue. + + returns 0 on failure, 1 if we successfully received it. */ +static int receive_bitmap(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + struct bm_xfer_ctx c; + int err; + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return -EIO; + device = peer_device->device; + + drbd_bm_lock(device, "receive bitmap", BM_LOCKED_SET_ALLOWED); + /* you are supposed to send additional out-of-sync information + * if you actually set bits during this phase */ + + c = (struct bm_xfer_ctx) { + .bm_bits = drbd_bm_bits(device), + .bm_words = drbd_bm_words(device), + }; + + for(;;) { + if (pi->cmd == P_BITMAP) + err = receive_bitmap_plain(peer_device, pi->size, pi->data, &c); + else if (pi->cmd == P_COMPRESSED_BITMAP) { + /* MAYBE: sanity check that we speak proto >= 90, + * and the feature is enabled! */ + struct p_compressed_bm *p = pi->data; + + if (pi->size > DRBD_SOCKET_BUFFER_SIZE - drbd_header_size(connection)) { + drbd_err(device, "ReportCBitmap packet too large\n"); + err = -EIO; + goto out; + } + if (pi->size <= sizeof(*p)) { + drbd_err(device, "ReportCBitmap packet too small (l:%u)\n", pi->size); + err = -EIO; + goto out; + } + err = drbd_recv_all(peer_device->connection, p, pi->size); + if (err) + goto out; + err = decode_bitmap_c(peer_device, p, &c, pi->size); + } else { + drbd_warn(device, "receive_bitmap: cmd neither ReportBitMap nor ReportCBitMap (is 0x%x)", pi->cmd); + err = -EIO; + goto out; + } + + c.packets[pi->cmd == P_BITMAP]++; + c.bytes[pi->cmd == P_BITMAP] += drbd_header_size(connection) + pi->size; + + if (err <= 0) { + if (err < 0) + goto out; + break; + } + err = drbd_recv_header(peer_device->connection, pi); + if (err) + goto out; + } + + INFO_bm_xfer_stats(device, "receive", &c); + + if (device->state.conn == C_WF_BITMAP_T) { + enum drbd_state_rv rv; + + err = drbd_send_bitmap(device); + if (err) + goto out; + /* Omit CS_ORDERED with this state transition to avoid deadlocks. */ + rv = _drbd_request_state(device, NS(conn, C_WF_SYNC_UUID), CS_VERBOSE); + D_ASSERT(device, rv == SS_SUCCESS); + } else if (device->state.conn != C_WF_BITMAP_S) { + /* admin may have requested C_DISCONNECTING, + * other threads may have noticed network errors */ + drbd_info(device, "unexpected cstate (%s) in receive_bitmap\n", + drbd_conn_str(device->state.conn)); + } + err = 0; + + out: + drbd_bm_unlock(device); + if (!err && device->state.conn == C_WF_BITMAP_S) + drbd_start_resync(device, C_SYNC_SOURCE); + return err; +} + +static int receive_skip(struct drbd_connection *connection, struct packet_info *pi) +{ + drbd_warn(connection, "skipping unknown optional packet type %d, l: %d!\n", + pi->cmd, pi->size); + + return ignore_remaining_packet(connection, pi); +} + +static int receive_UnplugRemote(struct drbd_connection *connection, struct packet_info *pi) +{ + /* Make sure we've acked all the TCP data associated + * with the data requests being unplugged */ + tcp_sock_set_quickack(connection->data.socket->sk, 2); + return 0; +} + +static int receive_out_of_sync(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + struct p_block_desc *p = pi->data; + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return -EIO; + device = peer_device->device; + + switch (device->state.conn) { + case C_WF_SYNC_UUID: + case C_WF_BITMAP_T: + case C_BEHIND: + break; + default: + drbd_err(device, "ASSERT FAILED cstate = %s, expected: WFSyncUUID|WFBitMapT|Behind\n", + drbd_conn_str(device->state.conn)); + } + + drbd_set_out_of_sync(device, be64_to_cpu(p->sector), be32_to_cpu(p->blksize)); + + return 0; +} + +static int receive_rs_deallocated(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct p_block_desc *p = pi->data; + struct drbd_device *device; + sector_t sector; + int size, err = 0; + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return -EIO; + device = peer_device->device; + + sector = be64_to_cpu(p->sector); + size = be32_to_cpu(p->blksize); + + dec_rs_pending(device); + + if (get_ldev(device)) { + struct drbd_peer_request *peer_req; + const enum req_op op = REQ_OP_WRITE_ZEROES; + + peer_req = drbd_alloc_peer_req(peer_device, ID_SYNCER, sector, + size, 0, GFP_NOIO); + if (!peer_req) { + put_ldev(device); + return -ENOMEM; + } + + peer_req->w.cb = e_end_resync_block; + peer_req->submit_jif = jiffies; + peer_req->flags |= EE_TRIM; + + spin_lock_irq(&device->resource->req_lock); + list_add_tail(&peer_req->w.list, &device->sync_ee); + spin_unlock_irq(&device->resource->req_lock); + + atomic_add(pi->size >> 9, &device->rs_sect_ev); + err = drbd_submit_peer_request(device, peer_req, op, + DRBD_FAULT_RS_WR); + + if (err) { + spin_lock_irq(&device->resource->req_lock); + list_del(&peer_req->w.list); + spin_unlock_irq(&device->resource->req_lock); + + drbd_free_peer_req(device, peer_req); + put_ldev(device); + err = 0; + goto fail; + } + + inc_unacked(device); + + /* No put_ldev() here. Gets called in drbd_endio_write_sec_final(), + as well as drbd_rs_complete_io() */ + } else { + fail: + drbd_rs_complete_io(device, sector); + drbd_send_ack_ex(peer_device, P_NEG_ACK, sector, size, ID_SYNCER); + } + + atomic_add(size >> 9, &device->rs_sect_in); + + return err; +} + +struct data_cmd { + int expect_payload; + unsigned int pkt_size; + int (*fn)(struct drbd_connection *, struct packet_info *); +}; + +static struct data_cmd drbd_cmd_handler[] = { + [P_DATA] = { 1, sizeof(struct p_data), receive_Data }, + [P_DATA_REPLY] = { 1, sizeof(struct p_data), receive_DataReply }, + [P_RS_DATA_REPLY] = { 1, sizeof(struct p_data), receive_RSDataReply } , + [P_BARRIER] = { 0, sizeof(struct p_barrier), receive_Barrier } , + [P_BITMAP] = { 1, 0, receive_bitmap } , + [P_COMPRESSED_BITMAP] = { 1, 0, receive_bitmap } , + [P_UNPLUG_REMOTE] = { 0, 0, receive_UnplugRemote }, + [P_DATA_REQUEST] = { 0, sizeof(struct p_block_req), receive_DataRequest }, + [P_RS_DATA_REQUEST] = { 0, sizeof(struct p_block_req), receive_DataRequest }, + [P_SYNC_PARAM] = { 1, 0, receive_SyncParam }, + [P_SYNC_PARAM89] = { 1, 0, receive_SyncParam }, + [P_PROTOCOL] = { 1, sizeof(struct p_protocol), receive_protocol }, + [P_UUIDS] = { 0, sizeof(struct p_uuids), receive_uuids }, + [P_SIZES] = { 0, sizeof(struct p_sizes), receive_sizes }, + [P_STATE] = { 0, sizeof(struct p_state), receive_state }, + [P_STATE_CHG_REQ] = { 0, sizeof(struct p_req_state), receive_req_state }, + [P_SYNC_UUID] = { 0, sizeof(struct p_rs_uuid), receive_sync_uuid }, + [P_OV_REQUEST] = { 0, sizeof(struct p_block_req), receive_DataRequest }, + [P_OV_REPLY] = { 1, sizeof(struct p_block_req), receive_DataRequest }, + [P_CSUM_RS_REQUEST] = { 1, sizeof(struct p_block_req), receive_DataRequest }, + [P_RS_THIN_REQ] = { 0, sizeof(struct p_block_req), receive_DataRequest }, + [P_DELAY_PROBE] = { 0, sizeof(struct p_delay_probe93), receive_skip }, + [P_OUT_OF_SYNC] = { 0, sizeof(struct p_block_desc), receive_out_of_sync }, + [P_CONN_ST_CHG_REQ] = { 0, sizeof(struct p_req_state), receive_req_conn_state }, + [P_PROTOCOL_UPDATE] = { 1, sizeof(struct p_protocol), receive_protocol }, + [P_TRIM] = { 0, sizeof(struct p_trim), receive_Data }, + [P_ZEROES] = { 0, sizeof(struct p_trim), receive_Data }, + [P_RS_DEALLOCATED] = { 0, sizeof(struct p_block_desc), receive_rs_deallocated }, +}; + +static void drbdd(struct drbd_connection *connection) +{ + struct packet_info pi; + size_t shs; /* sub header size */ + int err; + + while (get_t_state(&connection->receiver) == RUNNING) { + struct data_cmd const *cmd; + + drbd_thread_current_set_cpu(&connection->receiver); + update_receiver_timing_details(connection, drbd_recv_header_maybe_unplug); + if (drbd_recv_header_maybe_unplug(connection, &pi)) + goto err_out; + + cmd = &drbd_cmd_handler[pi.cmd]; + if (unlikely(pi.cmd >= ARRAY_SIZE(drbd_cmd_handler) || !cmd->fn)) { + drbd_err(connection, "Unexpected data packet %s (0x%04x)", + cmdname(pi.cmd), pi.cmd); + goto err_out; + } + + shs = cmd->pkt_size; + if (pi.cmd == P_SIZES && connection->agreed_features & DRBD_FF_WSAME) + shs += sizeof(struct o_qlim); + if (pi.size > shs && !cmd->expect_payload) { + drbd_err(connection, "No payload expected %s l:%d\n", + cmdname(pi.cmd), pi.size); + goto err_out; + } + if (pi.size < shs) { + drbd_err(connection, "%s: unexpected packet size, expected:%d received:%d\n", + cmdname(pi.cmd), (int)shs, pi.size); + goto err_out; + } + + if (shs) { + update_receiver_timing_details(connection, drbd_recv_all_warn); + err = drbd_recv_all_warn(connection, pi.data, shs); + if (err) + goto err_out; + pi.size -= shs; + } + + update_receiver_timing_details(connection, cmd->fn); + err = cmd->fn(connection, &pi); + if (err) { + drbd_err(connection, "error receiving %s, e: %d l: %d!\n", + cmdname(pi.cmd), err, pi.size); + goto err_out; + } + } + return; + + err_out: + conn_request_state(connection, NS(conn, C_PROTOCOL_ERROR), CS_HARD); +} + +static void conn_disconnect(struct drbd_connection *connection) +{ + struct drbd_peer_device *peer_device; + enum drbd_conns oc; + int vnr; + + if (connection->cstate == C_STANDALONE) + return; + + /* We are about to start the cleanup after connection loss. + * Make sure drbd_make_request knows about that. + * Usually we should be in some network failure state already, + * but just in case we are not, we fix it up here. + */ + conn_request_state(connection, NS(conn, C_NETWORK_FAILURE), CS_HARD); + + /* ack_receiver does not clean up anything. it must not interfere, either */ + drbd_thread_stop(&connection->ack_receiver); + if (connection->ack_sender) { + destroy_workqueue(connection->ack_sender); + connection->ack_sender = NULL; + } + drbd_free_sock(connection); + + rcu_read_lock(); + idr_for_each_entry(&connection->peer_devices, peer_device, vnr) { + struct drbd_device *device = peer_device->device; + kref_get(&device->kref); + rcu_read_unlock(); + drbd_disconnected(peer_device); + kref_put(&device->kref, drbd_destroy_device); + rcu_read_lock(); + } + rcu_read_unlock(); + + if (!list_empty(&connection->current_epoch->list)) + drbd_err(connection, "ASSERTION FAILED: connection->current_epoch->list not empty\n"); + /* ok, no more ee's on the fly, it is safe to reset the epoch_size */ + atomic_set(&connection->current_epoch->epoch_size, 0); + connection->send.seen_any_write_yet = false; + + drbd_info(connection, "Connection closed\n"); + + if (conn_highest_role(connection) == R_PRIMARY && conn_highest_pdsk(connection) >= D_UNKNOWN) + conn_try_outdate_peer_async(connection); + + spin_lock_irq(&connection->resource->req_lock); + oc = connection->cstate; + if (oc >= C_UNCONNECTED) + _conn_request_state(connection, NS(conn, C_UNCONNECTED), CS_VERBOSE); + + spin_unlock_irq(&connection->resource->req_lock); + + if (oc == C_DISCONNECTING) + conn_request_state(connection, NS(conn, C_STANDALONE), CS_VERBOSE | CS_HARD); +} + +static int drbd_disconnected(struct drbd_peer_device *peer_device) +{ + struct drbd_device *device = peer_device->device; + unsigned int i; + + /* wait for current activity to cease. */ + spin_lock_irq(&device->resource->req_lock); + _drbd_wait_ee_list_empty(device, &device->active_ee); + _drbd_wait_ee_list_empty(device, &device->sync_ee); + _drbd_wait_ee_list_empty(device, &device->read_ee); + spin_unlock_irq(&device->resource->req_lock); + + /* We do not have data structures that would allow us to + * get the rs_pending_cnt down to 0 again. + * * On C_SYNC_TARGET we do not have any data structures describing + * the pending RSDataRequest's we have sent. + * * On C_SYNC_SOURCE there is no data structure that tracks + * the P_RS_DATA_REPLY blocks that we sent to the SyncTarget. + * And no, it is not the sum of the reference counts in the + * resync_LRU. The resync_LRU tracks the whole operation including + * the disk-IO, while the rs_pending_cnt only tracks the blocks + * on the fly. */ + drbd_rs_cancel_all(device); + device->rs_total = 0; + device->rs_failed = 0; + atomic_set(&device->rs_pending_cnt, 0); + wake_up(&device->misc_wait); + + del_timer_sync(&device->resync_timer); + resync_timer_fn(&device->resync_timer); + + /* wait for all w_e_end_data_req, w_e_end_rsdata_req, w_send_barrier, + * w_make_resync_request etc. which may still be on the worker queue + * to be "canceled" */ + drbd_flush_workqueue(&peer_device->connection->sender_work); + + drbd_finish_peer_reqs(device); + + /* This second workqueue flush is necessary, since drbd_finish_peer_reqs() + might have issued a work again. The one before drbd_finish_peer_reqs() is + necessary to reclain net_ee in drbd_finish_peer_reqs(). */ + drbd_flush_workqueue(&peer_device->connection->sender_work); + + /* need to do it again, drbd_finish_peer_reqs() may have populated it + * again via drbd_try_clear_on_disk_bm(). */ + drbd_rs_cancel_all(device); + + kfree(device->p_uuid); + device->p_uuid = NULL; + + if (!drbd_suspended(device)) + tl_clear(peer_device->connection); + + drbd_md_sync(device); + + if (get_ldev(device)) { + drbd_bitmap_io(device, &drbd_bm_write_copy_pages, + "write from disconnected", BM_LOCKED_CHANGE_ALLOWED); + put_ldev(device); + } + + /* tcp_close and release of sendpage pages can be deferred. I don't + * want to use SO_LINGER, because apparently it can be deferred for + * more than 20 seconds (longest time I checked). + * + * Actually we don't care for exactly when the network stack does its + * put_page(), but release our reference on these pages right here. + */ + i = drbd_free_peer_reqs(device, &device->net_ee); + if (i) + drbd_info(device, "net_ee not empty, killed %u entries\n", i); + i = atomic_read(&device->pp_in_use_by_net); + if (i) + drbd_info(device, "pp_in_use_by_net = %d, expected 0\n", i); + i = atomic_read(&device->pp_in_use); + if (i) + drbd_info(device, "pp_in_use = %d, expected 0\n", i); + + D_ASSERT(device, list_empty(&device->read_ee)); + D_ASSERT(device, list_empty(&device->active_ee)); + D_ASSERT(device, list_empty(&device->sync_ee)); + D_ASSERT(device, list_empty(&device->done_ee)); + + return 0; +} + +/* + * We support PRO_VERSION_MIN to PRO_VERSION_MAX. The protocol version + * we can agree on is stored in agreed_pro_version. + * + * feature flags and the reserved array should be enough room for future + * enhancements of the handshake protocol, and possible plugins... + * + * for now, they are expected to be zero, but ignored. + */ +static int drbd_send_features(struct drbd_connection *connection) +{ + struct drbd_socket *sock; + struct p_connection_features *p; + + sock = &connection->data; + p = conn_prepare_command(connection, sock); + if (!p) + return -EIO; + memset(p, 0, sizeof(*p)); + p->protocol_min = cpu_to_be32(PRO_VERSION_MIN); + p->protocol_max = cpu_to_be32(PRO_VERSION_MAX); + p->feature_flags = cpu_to_be32(PRO_FEATURES); + return conn_send_command(connection, sock, P_CONNECTION_FEATURES, sizeof(*p), NULL, 0); +} + +/* + * return values: + * 1 yes, we have a valid connection + * 0 oops, did not work out, please try again + * -1 peer talks different language, + * no point in trying again, please go standalone. + */ +static int drbd_do_features(struct drbd_connection *connection) +{ + /* ASSERT current == connection->receiver ... */ + struct p_connection_features *p; + const int expect = sizeof(struct p_connection_features); + struct packet_info pi; + int err; + + err = drbd_send_features(connection); + if (err) + return 0; + + err = drbd_recv_header(connection, &pi); + if (err) + return 0; + + if (pi.cmd != P_CONNECTION_FEATURES) { + drbd_err(connection, "expected ConnectionFeatures packet, received: %s (0x%04x)\n", + cmdname(pi.cmd), pi.cmd); + return -1; + } + + if (pi.size != expect) { + drbd_err(connection, "expected ConnectionFeatures length: %u, received: %u\n", + expect, pi.size); + return -1; + } + + p = pi.data; + err = drbd_recv_all_warn(connection, p, expect); + if (err) + return 0; + + p->protocol_min = be32_to_cpu(p->protocol_min); + p->protocol_max = be32_to_cpu(p->protocol_max); + if (p->protocol_max == 0) + p->protocol_max = p->protocol_min; + + if (PRO_VERSION_MAX < p->protocol_min || + PRO_VERSION_MIN > p->protocol_max) + goto incompat; + + connection->agreed_pro_version = min_t(int, PRO_VERSION_MAX, p->protocol_max); + connection->agreed_features = PRO_FEATURES & be32_to_cpu(p->feature_flags); + + drbd_info(connection, "Handshake successful: " + "Agreed network protocol version %d\n", connection->agreed_pro_version); + + drbd_info(connection, "Feature flags enabled on protocol level: 0x%x%s%s%s%s.\n", + connection->agreed_features, + connection->agreed_features & DRBD_FF_TRIM ? " TRIM" : "", + connection->agreed_features & DRBD_FF_THIN_RESYNC ? " THIN_RESYNC" : "", + connection->agreed_features & DRBD_FF_WSAME ? " WRITE_SAME" : "", + connection->agreed_features & DRBD_FF_WZEROES ? " WRITE_ZEROES" : + connection->agreed_features ? "" : " none"); + + return 1; + + incompat: + drbd_err(connection, "incompatible DRBD dialects: " + "I support %d-%d, peer supports %d-%d\n", + PRO_VERSION_MIN, PRO_VERSION_MAX, + p->protocol_min, p->protocol_max); + return -1; +} + +#if !defined(CONFIG_CRYPTO_HMAC) && !defined(CONFIG_CRYPTO_HMAC_MODULE) +static int drbd_do_auth(struct drbd_connection *connection) +{ + drbd_err(connection, "This kernel was build without CONFIG_CRYPTO_HMAC.\n"); + drbd_err(connection, "You need to disable 'cram-hmac-alg' in drbd.conf.\n"); + return -1; +} +#else +#define CHALLENGE_LEN 64 + +/* Return value: + 1 - auth succeeded, + 0 - failed, try again (network error), + -1 - auth failed, don't try again. +*/ + +static int drbd_do_auth(struct drbd_connection *connection) +{ + struct drbd_socket *sock; + char my_challenge[CHALLENGE_LEN]; /* 64 Bytes... */ + char *response = NULL; + char *right_response = NULL; + char *peers_ch = NULL; + unsigned int key_len; + char secret[SHARED_SECRET_MAX]; /* 64 byte */ + unsigned int resp_size; + struct shash_desc *desc; + struct packet_info pi; + struct net_conf *nc; + int err, rv; + + /* FIXME: Put the challenge/response into the preallocated socket buffer. */ + + rcu_read_lock(); + nc = rcu_dereference(connection->net_conf); + key_len = strlen(nc->shared_secret); + memcpy(secret, nc->shared_secret, key_len); + rcu_read_unlock(); + + desc = kmalloc(sizeof(struct shash_desc) + + crypto_shash_descsize(connection->cram_hmac_tfm), + GFP_KERNEL); + if (!desc) { + rv = -1; + goto fail; + } + desc->tfm = connection->cram_hmac_tfm; + + rv = crypto_shash_setkey(connection->cram_hmac_tfm, (u8 *)secret, key_len); + if (rv) { + drbd_err(connection, "crypto_shash_setkey() failed with %d\n", rv); + rv = -1; + goto fail; + } + + get_random_bytes(my_challenge, CHALLENGE_LEN); + + sock = &connection->data; + if (!conn_prepare_command(connection, sock)) { + rv = 0; + goto fail; + } + rv = !conn_send_command(connection, sock, P_AUTH_CHALLENGE, 0, + my_challenge, CHALLENGE_LEN); + if (!rv) + goto fail; + + err = drbd_recv_header(connection, &pi); + if (err) { + rv = 0; + goto fail; + } + + if (pi.cmd != P_AUTH_CHALLENGE) { + drbd_err(connection, "expected AuthChallenge packet, received: %s (0x%04x)\n", + cmdname(pi.cmd), pi.cmd); + rv = -1; + goto fail; + } + + if (pi.size > CHALLENGE_LEN * 2) { + drbd_err(connection, "expected AuthChallenge payload too big.\n"); + rv = -1; + goto fail; + } + + if (pi.size < CHALLENGE_LEN) { + drbd_err(connection, "AuthChallenge payload too small.\n"); + rv = -1; + goto fail; + } + + peers_ch = kmalloc(pi.size, GFP_NOIO); + if (!peers_ch) { + rv = -1; + goto fail; + } + + err = drbd_recv_all_warn(connection, peers_ch, pi.size); + if (err) { + rv = 0; + goto fail; + } + + if (!memcmp(my_challenge, peers_ch, CHALLENGE_LEN)) { + drbd_err(connection, "Peer presented the same challenge!\n"); + rv = -1; + goto fail; + } + + resp_size = crypto_shash_digestsize(connection->cram_hmac_tfm); + response = kmalloc(resp_size, GFP_NOIO); + if (!response) { + rv = -1; + goto fail; + } + + rv = crypto_shash_digest(desc, peers_ch, pi.size, response); + if (rv) { + drbd_err(connection, "crypto_hash_digest() failed with %d\n", rv); + rv = -1; + goto fail; + } + + if (!conn_prepare_command(connection, sock)) { + rv = 0; + goto fail; + } + rv = !conn_send_command(connection, sock, P_AUTH_RESPONSE, 0, + response, resp_size); + if (!rv) + goto fail; + + err = drbd_recv_header(connection, &pi); + if (err) { + rv = 0; + goto fail; + } + + if (pi.cmd != P_AUTH_RESPONSE) { + drbd_err(connection, "expected AuthResponse packet, received: %s (0x%04x)\n", + cmdname(pi.cmd), pi.cmd); + rv = 0; + goto fail; + } + + if (pi.size != resp_size) { + drbd_err(connection, "expected AuthResponse payload of wrong size\n"); + rv = 0; + goto fail; + } + + err = drbd_recv_all_warn(connection, response , resp_size); + if (err) { + rv = 0; + goto fail; + } + + right_response = kmalloc(resp_size, GFP_NOIO); + if (!right_response) { + rv = -1; + goto fail; + } + + rv = crypto_shash_digest(desc, my_challenge, CHALLENGE_LEN, + right_response); + if (rv) { + drbd_err(connection, "crypto_hash_digest() failed with %d\n", rv); + rv = -1; + goto fail; + } + + rv = !memcmp(response, right_response, resp_size); + + if (rv) + drbd_info(connection, "Peer authenticated using %d bytes HMAC\n", + resp_size); + else + rv = -1; + + fail: + kfree(peers_ch); + kfree(response); + kfree(right_response); + if (desc) { + shash_desc_zero(desc); + kfree(desc); + } + + return rv; +} +#endif + +int drbd_receiver(struct drbd_thread *thi) +{ + struct drbd_connection *connection = thi->connection; + int h; + + drbd_info(connection, "receiver (re)started\n"); + + do { + h = conn_connect(connection); + if (h == 0) { + conn_disconnect(connection); + schedule_timeout_interruptible(HZ); + } + if (h == -1) { + drbd_warn(connection, "Discarding network configuration.\n"); + conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD); + } + } while (h == 0); + + if (h > 0) { + blk_start_plug(&connection->receiver_plug); + drbdd(connection); + blk_finish_plug(&connection->receiver_plug); + } + + conn_disconnect(connection); + + drbd_info(connection, "receiver terminated\n"); + return 0; +} + +/* ********* acknowledge sender ******** */ + +static int got_conn_RqSReply(struct drbd_connection *connection, struct packet_info *pi) +{ + struct p_req_state_reply *p = pi->data; + int retcode = be32_to_cpu(p->retcode); + + if (retcode >= SS_SUCCESS) { + set_bit(CONN_WD_ST_CHG_OKAY, &connection->flags); + } else { + set_bit(CONN_WD_ST_CHG_FAIL, &connection->flags); + drbd_err(connection, "Requested state change failed by peer: %s (%d)\n", + drbd_set_st_err_str(retcode), retcode); + } + wake_up(&connection->ping_wait); + + return 0; +} + +static int got_RqSReply(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + struct p_req_state_reply *p = pi->data; + int retcode = be32_to_cpu(p->retcode); + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return -EIO; + device = peer_device->device; + + if (test_bit(CONN_WD_ST_CHG_REQ, &connection->flags)) { + D_ASSERT(device, connection->agreed_pro_version < 100); + return got_conn_RqSReply(connection, pi); + } + + if (retcode >= SS_SUCCESS) { + set_bit(CL_ST_CHG_SUCCESS, &device->flags); + } else { + set_bit(CL_ST_CHG_FAIL, &device->flags); + drbd_err(device, "Requested state change failed by peer: %s (%d)\n", + drbd_set_st_err_str(retcode), retcode); + } + wake_up(&device->state_wait); + + return 0; +} + +static int got_Ping(struct drbd_connection *connection, struct packet_info *pi) +{ + return drbd_send_ping_ack(connection); + +} + +static int got_PingAck(struct drbd_connection *connection, struct packet_info *pi) +{ + /* restore idle timeout */ + connection->meta.socket->sk->sk_rcvtimeo = connection->net_conf->ping_int*HZ; + if (!test_and_set_bit(GOT_PING_ACK, &connection->flags)) + wake_up(&connection->ping_wait); + + return 0; +} + +static int got_IsInSync(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + struct p_block_ack *p = pi->data; + sector_t sector = be64_to_cpu(p->sector); + int blksize = be32_to_cpu(p->blksize); + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return -EIO; + device = peer_device->device; + + D_ASSERT(device, peer_device->connection->agreed_pro_version >= 89); + + update_peer_seq(peer_device, be32_to_cpu(p->seq_num)); + + if (get_ldev(device)) { + drbd_rs_complete_io(device, sector); + drbd_set_in_sync(device, sector, blksize); + /* rs_same_csums is supposed to count in units of BM_BLOCK_SIZE */ + device->rs_same_csum += (blksize >> BM_BLOCK_SHIFT); + put_ldev(device); + } + dec_rs_pending(device); + atomic_add(blksize >> 9, &device->rs_sect_in); + + return 0; +} + +static int +validate_req_change_req_state(struct drbd_device *device, u64 id, sector_t sector, + struct rb_root *root, const char *func, + enum drbd_req_event what, bool missing_ok) +{ + struct drbd_request *req; + struct bio_and_error m; + + spin_lock_irq(&device->resource->req_lock); + req = find_request(device, root, id, sector, missing_ok, func); + if (unlikely(!req)) { + spin_unlock_irq(&device->resource->req_lock); + return -EIO; + } + __req_mod(req, what, &m); + spin_unlock_irq(&device->resource->req_lock); + + if (m.bio) + complete_master_bio(device, &m); + return 0; +} + +static int got_BlockAck(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + struct p_block_ack *p = pi->data; + sector_t sector = be64_to_cpu(p->sector); + int blksize = be32_to_cpu(p->blksize); + enum drbd_req_event what; + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return -EIO; + device = peer_device->device; + + update_peer_seq(peer_device, be32_to_cpu(p->seq_num)); + + if (p->block_id == ID_SYNCER) { + drbd_set_in_sync(device, sector, blksize); + dec_rs_pending(device); + return 0; + } + switch (pi->cmd) { + case P_RS_WRITE_ACK: + what = WRITE_ACKED_BY_PEER_AND_SIS; + break; + case P_WRITE_ACK: + what = WRITE_ACKED_BY_PEER; + break; + case P_RECV_ACK: + what = RECV_ACKED_BY_PEER; + break; + case P_SUPERSEDED: + what = CONFLICT_RESOLVED; + break; + case P_RETRY_WRITE: + what = POSTPONE_WRITE; + break; + default: + BUG(); + } + + return validate_req_change_req_state(device, p->block_id, sector, + &device->write_requests, __func__, + what, false); +} + +static int got_NegAck(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + struct p_block_ack *p = pi->data; + sector_t sector = be64_to_cpu(p->sector); + int size = be32_to_cpu(p->blksize); + int err; + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return -EIO; + device = peer_device->device; + + update_peer_seq(peer_device, be32_to_cpu(p->seq_num)); + + if (p->block_id == ID_SYNCER) { + dec_rs_pending(device); + drbd_rs_failed_io(device, sector, size); + return 0; + } + + err = validate_req_change_req_state(device, p->block_id, sector, + &device->write_requests, __func__, + NEG_ACKED, true); + if (err) { + /* Protocol A has no P_WRITE_ACKs, but has P_NEG_ACKs. + The master bio might already be completed, therefore the + request is no longer in the collision hash. */ + /* In Protocol B we might already have got a P_RECV_ACK + but then get a P_NEG_ACK afterwards. */ + drbd_set_out_of_sync(device, sector, size); + } + return 0; +} + +static int got_NegDReply(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + struct p_block_ack *p = pi->data; + sector_t sector = be64_to_cpu(p->sector); + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return -EIO; + device = peer_device->device; + + update_peer_seq(peer_device, be32_to_cpu(p->seq_num)); + + drbd_err(device, "Got NegDReply; Sector %llus, len %u.\n", + (unsigned long long)sector, be32_to_cpu(p->blksize)); + + return validate_req_change_req_state(device, p->block_id, sector, + &device->read_requests, __func__, + NEG_ACKED, false); +} + +static int got_NegRSDReply(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + sector_t sector; + int size; + struct p_block_ack *p = pi->data; + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return -EIO; + device = peer_device->device; + + sector = be64_to_cpu(p->sector); + size = be32_to_cpu(p->blksize); + + update_peer_seq(peer_device, be32_to_cpu(p->seq_num)); + + dec_rs_pending(device); + + if (get_ldev_if_state(device, D_FAILED)) { + drbd_rs_complete_io(device, sector); + switch (pi->cmd) { + case P_NEG_RS_DREPLY: + drbd_rs_failed_io(device, sector, size); + break; + case P_RS_CANCEL: + break; + default: + BUG(); + } + put_ldev(device); + } + + return 0; +} + +static int got_BarrierAck(struct drbd_connection *connection, struct packet_info *pi) +{ + struct p_barrier_ack *p = pi->data; + struct drbd_peer_device *peer_device; + int vnr; + + tl_release(connection, p->barrier, be32_to_cpu(p->set_size)); + + rcu_read_lock(); + idr_for_each_entry(&connection->peer_devices, peer_device, vnr) { + struct drbd_device *device = peer_device->device; + + if (device->state.conn == C_AHEAD && + atomic_read(&device->ap_in_flight) == 0 && + !test_and_set_bit(AHEAD_TO_SYNC_SOURCE, &device->flags)) { + device->start_resync_timer.expires = jiffies + HZ; + add_timer(&device->start_resync_timer); + } + } + rcu_read_unlock(); + + return 0; +} + +static int got_OVResult(struct drbd_connection *connection, struct packet_info *pi) +{ + struct drbd_peer_device *peer_device; + struct drbd_device *device; + struct p_block_ack *p = pi->data; + struct drbd_device_work *dw; + sector_t sector; + int size; + + peer_device = conn_peer_device(connection, pi->vnr); + if (!peer_device) + return -EIO; + device = peer_device->device; + + sector = be64_to_cpu(p->sector); + size = be32_to_cpu(p->blksize); + + update_peer_seq(peer_device, be32_to_cpu(p->seq_num)); + + if (be64_to_cpu(p->block_id) == ID_OUT_OF_SYNC) + drbd_ov_out_of_sync_found(device, sector, size); + else + ov_out_of_sync_print(device); + + if (!get_ldev(device)) + return 0; + + drbd_rs_complete_io(device, sector); + dec_rs_pending(device); + + --device->ov_left; + + /* let's advance progress step marks only for every other megabyte */ + if ((device->ov_left & 0x200) == 0x200) + drbd_advance_rs_marks(device, device->ov_left); + + if (device->ov_left == 0) { + dw = kmalloc(sizeof(*dw), GFP_NOIO); + if (dw) { + dw->w.cb = w_ov_finished; + dw->device = device; + drbd_queue_work(&peer_device->connection->sender_work, &dw->w); + } else { + drbd_err(device, "kmalloc(dw) failed."); + ov_out_of_sync_print(device); + drbd_resync_finished(device); + } + } + put_ldev(device); + return 0; +} + +static int got_skip(struct drbd_connection *connection, struct packet_info *pi) +{ + return 0; +} + +struct meta_sock_cmd { + size_t pkt_size; + int (*fn)(struct drbd_connection *connection, struct packet_info *); +}; + +static void set_rcvtimeo(struct drbd_connection *connection, bool ping_timeout) +{ + long t; + struct net_conf *nc; + + rcu_read_lock(); + nc = rcu_dereference(connection->net_conf); + t = ping_timeout ? nc->ping_timeo : nc->ping_int; + rcu_read_unlock(); + + t *= HZ; + if (ping_timeout) + t /= 10; + + connection->meta.socket->sk->sk_rcvtimeo = t; +} + +static void set_ping_timeout(struct drbd_connection *connection) +{ + set_rcvtimeo(connection, 1); +} + +static void set_idle_timeout(struct drbd_connection *connection) +{ + set_rcvtimeo(connection, 0); +} + +static struct meta_sock_cmd ack_receiver_tbl[] = { + [P_PING] = { 0, got_Ping }, + [P_PING_ACK] = { 0, got_PingAck }, + [P_RECV_ACK] = { sizeof(struct p_block_ack), got_BlockAck }, + [P_WRITE_ACK] = { sizeof(struct p_block_ack), got_BlockAck }, + [P_RS_WRITE_ACK] = { sizeof(struct p_block_ack), got_BlockAck }, + [P_SUPERSEDED] = { sizeof(struct p_block_ack), got_BlockAck }, + [P_NEG_ACK] = { sizeof(struct p_block_ack), got_NegAck }, + [P_NEG_DREPLY] = { sizeof(struct p_block_ack), got_NegDReply }, + [P_NEG_RS_DREPLY] = { sizeof(struct p_block_ack), got_NegRSDReply }, + [P_OV_RESULT] = { sizeof(struct p_block_ack), got_OVResult }, + [P_BARRIER_ACK] = { sizeof(struct p_barrier_ack), got_BarrierAck }, + [P_STATE_CHG_REPLY] = { sizeof(struct p_req_state_reply), got_RqSReply }, + [P_RS_IS_IN_SYNC] = { sizeof(struct p_block_ack), got_IsInSync }, + [P_DELAY_PROBE] = { sizeof(struct p_delay_probe93), got_skip }, + [P_RS_CANCEL] = { sizeof(struct p_block_ack), got_NegRSDReply }, + [P_CONN_ST_CHG_REPLY]={ sizeof(struct p_req_state_reply), got_conn_RqSReply }, + [P_RETRY_WRITE] = { sizeof(struct p_block_ack), got_BlockAck }, +}; + +int drbd_ack_receiver(struct drbd_thread *thi) +{ + struct drbd_connection *connection = thi->connection; + struct meta_sock_cmd *cmd = NULL; + struct packet_info pi; + unsigned long pre_recv_jif; + int rv; + void *buf = connection->meta.rbuf; + int received = 0; + unsigned int header_size = drbd_header_size(connection); + int expect = header_size; + bool ping_timeout_active = false; + + sched_set_fifo_low(current); + + while (get_t_state(thi) == RUNNING) { + drbd_thread_current_set_cpu(thi); + + conn_reclaim_net_peer_reqs(connection); + + if (test_and_clear_bit(SEND_PING, &connection->flags)) { + if (drbd_send_ping(connection)) { + drbd_err(connection, "drbd_send_ping has failed\n"); + goto reconnect; + } + set_ping_timeout(connection); + ping_timeout_active = true; + } + + pre_recv_jif = jiffies; + rv = drbd_recv_short(connection->meta.socket, buf, expect-received, 0); + + /* Note: + * -EINTR (on meta) we got a signal + * -EAGAIN (on meta) rcvtimeo expired + * -ECONNRESET other side closed the connection + * -ERESTARTSYS (on data) we got a signal + * rv < 0 other than above: unexpected error! + * rv == expected: full header or command + * rv < expected: "woken" by signal during receive + * rv == 0 : "connection shut down by peer" + */ + if (likely(rv > 0)) { + received += rv; + buf += rv; + } else if (rv == 0) { + if (test_bit(DISCONNECT_SENT, &connection->flags)) { + long t; + rcu_read_lock(); + t = rcu_dereference(connection->net_conf)->ping_timeo * HZ/10; + rcu_read_unlock(); + + t = wait_event_timeout(connection->ping_wait, + connection->cstate < C_WF_REPORT_PARAMS, + t); + if (t) + break; + } + drbd_err(connection, "meta connection shut down by peer.\n"); + goto reconnect; + } else if (rv == -EAGAIN) { + /* If the data socket received something meanwhile, + * that is good enough: peer is still alive. */ + if (time_after(connection->last_received, pre_recv_jif)) + continue; + if (ping_timeout_active) { + drbd_err(connection, "PingAck did not arrive in time.\n"); + goto reconnect; + } + set_bit(SEND_PING, &connection->flags); + continue; + } else if (rv == -EINTR) { + /* maybe drbd_thread_stop(): the while condition will notice. + * maybe woken for send_ping: we'll send a ping above, + * and change the rcvtimeo */ + flush_signals(current); + continue; + } else { + drbd_err(connection, "sock_recvmsg returned %d\n", rv); + goto reconnect; + } + + if (received == expect && cmd == NULL) { + if (decode_header(connection, connection->meta.rbuf, &pi)) + goto reconnect; + cmd = &ack_receiver_tbl[pi.cmd]; + if (pi.cmd >= ARRAY_SIZE(ack_receiver_tbl) || !cmd->fn) { + drbd_err(connection, "Unexpected meta packet %s (0x%04x)\n", + cmdname(pi.cmd), pi.cmd); + goto disconnect; + } + expect = header_size + cmd->pkt_size; + if (pi.size != expect - header_size) { + drbd_err(connection, "Wrong packet size on meta (c: %d, l: %d)\n", + pi.cmd, pi.size); + goto reconnect; + } + } + if (received == expect) { + bool err; + + err = cmd->fn(connection, &pi); + if (err) { + drbd_err(connection, "%ps failed\n", cmd->fn); + goto reconnect; + } + + connection->last_received = jiffies; + + if (cmd == &ack_receiver_tbl[P_PING_ACK]) { + set_idle_timeout(connection); + ping_timeout_active = false; + } + + buf = connection->meta.rbuf; + received = 0; + expect = header_size; + cmd = NULL; + } + } + + if (0) { +reconnect: + conn_request_state(connection, NS(conn, C_NETWORK_FAILURE), CS_HARD); + conn_md_sync(connection); + } + if (0) { +disconnect: + conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD); + } + + drbd_info(connection, "ack_receiver terminated\n"); + + return 0; +} + +void drbd_send_acks_wf(struct work_struct *ws) +{ + struct drbd_peer_device *peer_device = + container_of(ws, struct drbd_peer_device, send_acks_work); + struct drbd_connection *connection = peer_device->connection; + struct drbd_device *device = peer_device->device; + struct net_conf *nc; + int tcp_cork, err; + + rcu_read_lock(); + nc = rcu_dereference(connection->net_conf); + tcp_cork = nc->tcp_cork; + rcu_read_unlock(); + + if (tcp_cork) + tcp_sock_set_cork(connection->meta.socket->sk, true); + + err = drbd_finish_peer_reqs(device); + kref_put(&device->kref, drbd_destroy_device); + /* get is in drbd_endio_write_sec_final(). That is necessary to keep the + struct work_struct send_acks_work alive, which is in the peer_device object */ + + if (err) { + conn_request_state(connection, NS(conn, C_NETWORK_FAILURE), CS_HARD); + return; + } + + if (tcp_cork) + tcp_sock_set_cork(connection->meta.socket->sk, false); + + return; +} |