1 files changed, 116 insertions, 142 deletions

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index f3e4db16fd07..c73376886e7a 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
+// SPDX-License-Identifier: GPL-2.0-only
 /*
    drbd.c
 
@@ -37,7 +37,6 @@
 #include <linux/notifier.h>
 #include <linux/kthread.h>
 #include <linux/workqueue.h>
-#define __KERNEL_SYSCALLS__
 #include <linux/unistd.h>
 #include <linux/vmalloc.h>
 #include <linux/sched/signal.h>
@@ -50,8 +49,8 @@
 #include "drbd_debugfs.h"
 
 static DEFINE_MUTEX(drbd_main_mutex);
-static int drbd_open(struct block_device *bdev, fmode_t mode);
-static void drbd_release(struct gendisk *gd, fmode_t mode);
+static int drbd_open(struct gendisk *disk, blk_mode_t mode);
+static void drbd_release(struct gendisk *gd);
 static void md_sync_timer_fn(struct timer_list *t);
 static int w_bitmap_io(struct drbd_work *w, int unused);
 
@@ -115,20 +114,10 @@ struct kmem_cache *drbd_al_ext_cache;	/* activity log extents */
 mempool_t drbd_request_mempool;
 mempool_t drbd_ee_mempool;
 mempool_t drbd_md_io_page_pool;
+mempool_t drbd_buffer_page_pool;
 struct bio_set drbd_md_io_bio_set;
 struct bio_set drbd_io_bio_set;
 
-/* I do not use a standard mempool, because:
-   1) I want to hand out the pre-allocated objects first.
-   2) I want to be able to interrupt sleeping allocation with a signal.
-   Note: This is a single linked list, the next pointer is the private
-	 member of struct page.
- */
-struct page *drbd_pp_pool;
-DEFINE_SPINLOCK(drbd_pp_lock);
-int          drbd_pp_vacant;
-wait_queue_head_t drbd_pp_wait;
-
 DEFINE_RATELIMIT_STATE(drbd_ratelimit_state, 5 * HZ, 5);
 
 static const struct block_device_operations drbd_ops = {
@@ -231,9 +220,11 @@ void tl_release(struct drbd_connection *connection, unsigned int barrier_nr,
 		}
 	req = list_prepare_entry(tmp, &connection->transfer_log, tl_requests);
 	list_for_each_entry_safe_from(req, r, &connection->transfer_log, tl_requests) {
+		struct drbd_peer_device *peer_device;
 		if (req->epoch != expect_epoch)
 			break;
-		_req_mod(req, BARRIER_ACKED);
+		peer_device = conn_peer_device(connection, req->device->vnr);
+		_req_mod(req, BARRIER_ACKED, peer_device);
 	}
 	spin_unlock_irq(&connection->resource->req_lock);
 
@@ -256,10 +247,13 @@ bail:
 /* must hold resource->req_lock */
 void _tl_restart(struct drbd_connection *connection, enum drbd_req_event what)
 {
+	struct drbd_peer_device *peer_device;
 	struct drbd_request *req, *r;
 
-	list_for_each_entry_safe(req, r, &connection->transfer_log, tl_requests)
-		_req_mod(req, what);
+	list_for_each_entry_safe(req, r, &connection->transfer_log, tl_requests) {
+		peer_device = conn_peer_device(connection, req->device->vnr);
+		_req_mod(req, what, peer_device);
+	}
 }
 
 void tl_restart(struct drbd_connection *connection, enum drbd_req_event what)
@@ -297,7 +291,7 @@ void tl_abort_disk_io(struct drbd_device *device)
 			continue;
 		if (req->device != device)
 			continue;
-		_req_mod(req, ABORT_DISK_IO);
+		_req_mod(req, ABORT_DISK_IO, NULL);
 	}
 	spin_unlock_irq(&connection->resource->req_lock);
 }
@@ -467,20 +461,6 @@ void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait)
 		wait_for_completion(&thi->stop);
 }
 
-int conn_lowest_minor(struct drbd_connection *connection)
-{
-	struct drbd_peer_device *peer_device;
-	int vnr = 0, minor = -1;
-
-	rcu_read_lock();
-	peer_device = idr_get_next(&connection->peer_devices, &vnr);
-	if (peer_device)
-		minor = device_to_minor(peer_device->device);
-	rcu_read_unlock();
-
-	return minor;
-}
-
 #ifdef CONFIG_SMP
 /*
  * drbd_calc_cpu_mask() - Generate CPU masks, spread over all CPUs
@@ -1198,10 +1178,11 @@ static int fill_bitmap_rle_bits(struct drbd_device *device,
  * code upon failure.
  */
 static int
-send_bitmap_rle_or_plain(struct drbd_device *device, struct bm_xfer_ctx *c)
+send_bitmap_rle_or_plain(struct drbd_peer_device *peer_device, struct bm_xfer_ctx *c)
 {
-	struct drbd_socket *sock = &first_peer_device(device)->connection->data;
-	unsigned int header_size = drbd_header_size(first_peer_device(device)->connection);
+	struct drbd_device *device = peer_device->device;
+	struct drbd_socket *sock = &peer_device->connection->data;
+	unsigned int header_size = drbd_header_size(peer_device->connection);
 	struct p_compressed_bm *p = sock->sbuf + header_size;
 	int len, err;
 
@@ -1212,7 +1193,7 @@ send_bitmap_rle_or_plain(struct drbd_device *device, struct bm_xfer_ctx *c)
 
 	if (len) {
 		dcbp_set_code(p, RLE_VLI_Bits);
-		err = __send_command(first_peer_device(device)->connection, device->vnr, sock,
+		err = __send_command(peer_device->connection, device->vnr, sock,
 				     P_COMPRESSED_BITMAP, sizeof(*p) + len,
 				     NULL, 0);
 		c->packets[0]++;
@@ -1233,7 +1214,8 @@ send_bitmap_rle_or_plain(struct drbd_device *device, struct bm_xfer_ctx *c)
 		len = num_words * sizeof(*p);
 		if (len)
 			drbd_bm_get_lel(device, c->word_offset, num_words, p);
-		err = __send_command(first_peer_device(device)->connection, device->vnr, sock, P_BITMAP, len, NULL, 0);
+		err = __send_command(peer_device->connection, device->vnr, sock, P_BITMAP,
+				     len, NULL, 0);
 		c->word_offset += num_words;
 		c->bit_offset = c->word_offset * BITS_PER_LONG;
 
@@ -1245,7 +1227,7 @@ send_bitmap_rle_or_plain(struct drbd_device *device, struct bm_xfer_ctx *c)
 	}
 	if (!err) {
 		if (len == 0) {
-			INFO_bm_xfer_stats(device, "send", c);
+			INFO_bm_xfer_stats(peer_device, "send", c);
 			return 0;
 		} else
 			return 1;
@@ -1254,19 +1236,20 @@ send_bitmap_rle_or_plain(struct drbd_device *device, struct bm_xfer_ctx *c)
 }
 
 /* See the comment at receive_bitmap() */
-static int _drbd_send_bitmap(struct drbd_device *device)
+static int _drbd_send_bitmap(struct drbd_device *device,
+			    struct drbd_peer_device *peer_device)
 {
 	struct bm_xfer_ctx c;
 	int err;
 
-	if (!expect(device->bitmap))
+	if (!expect(device, device->bitmap))
 		return false;
 
 	if (get_ldev(device)) {
 		if (drbd_md_test_flag(device->ldev, MDF_FULL_SYNC)) {
 			drbd_info(device, "Writing the whole bitmap, MDF_FullSync was set.\n");
 			drbd_bm_set_all(device);
-			if (drbd_bm_write(device)) {
+			if (drbd_bm_write(device, peer_device)) {
 				/* write_bm did fail! Leave full sync flag set in Meta P_DATA
 				 * but otherwise process as per normal - need to tell other
 				 * side that a full resync is required! */
@@ -1285,20 +1268,20 @@ static int _drbd_send_bitmap(struct drbd_device *device)
 	};
 
 	do {
-		err = send_bitmap_rle_or_plain(device, &c);
+		err = send_bitmap_rle_or_plain(peer_device, &c);
 	} while (err > 0);
 
 	return err == 0;
 }
 
-int drbd_send_bitmap(struct drbd_device *device)
+int drbd_send_bitmap(struct drbd_device *device, struct drbd_peer_device *peer_device)
 {
-	struct drbd_socket *sock = &first_peer_device(device)->connection->data;
+	struct drbd_socket *sock = &peer_device->connection->data;
 	int err = -1;
 
 	mutex_lock(&sock->mutex);
 	if (sock->socket)
-		err = !_drbd_send_bitmap(device);
+		err = !_drbd_send_bitmap(device, peer_device);
 	mutex_unlock(&sock->mutex);
 	return err;
 }
@@ -1532,6 +1515,8 @@ static int _drbd_send_page(struct drbd_peer_device *peer_device, struct page *pa
 		    int offset, size_t size, unsigned msg_flags)
 {
 	struct socket *socket = peer_device->connection->data.socket;
+	struct msghdr msg = { .msg_flags = msg_flags, };
+	struct bio_vec bvec;
 	int len = size;
 	int err = -EIO;
 
@@ -1541,15 +1526,17 @@ static int _drbd_send_page(struct drbd_peer_device *peer_device, struct page *pa
 	 * put_page(); and would cause either a VM_BUG directly, or
 	 * __page_cache_release a page that would actually still be referenced
 	 * by someone, leading to some obscure delayed Oops somewhere else. */
-	if (drbd_disable_sendpage || !sendpage_ok(page))
-		return _drbd_no_send_page(peer_device, page, offset, size, msg_flags);
+	if (!drbd_disable_sendpage && sendpages_ok(page, len, offset))
+		msg.msg_flags |= MSG_NOSIGNAL | MSG_SPLICE_PAGES;
 
-	msg_flags |= MSG_NOSIGNAL;
 	drbd_update_congested(peer_device->connection);
 	do {
 		int sent;
 
-		sent = socket->ops->sendpage(socket, page, offset, len, msg_flags);
+		bvec_set_page(&bvec, page, len, offset);
+		iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, len);
+
+		sent = sock_sendmsg(socket, &msg);
 		if (sent <= 0) {
 			if (sent == -EAGAIN) {
 				if (we_should_drop_the_connection(peer_device->connection, socket))
@@ -1614,6 +1601,7 @@ static int _drbd_send_zc_bio(struct drbd_peer_device *peer_device, struct bio *b
 static int _drbd_send_zc_ee(struct drbd_peer_device *peer_device,
 			    struct drbd_peer_request *peer_req)
 {
+	bool use_sendpage = !(peer_req->flags & EE_RELEASE_TO_MEMPOOL);
 	struct page *page = peer_req->pages;
 	unsigned len = peer_req->i.size;
 	int err;
@@ -1622,8 +1610,13 @@ static int _drbd_send_zc_ee(struct drbd_peer_device *peer_device,
 	page_chain_for_each(page) {
 		unsigned l = min_t(unsigned, len, PAGE_SIZE);
 
-		err = _drbd_send_page(peer_device, page, 0, l,
-				      page_chain_next(page) ? MSG_MORE : 0);
+		if (likely(use_sendpage))
+			err = _drbd_send_page(peer_device, page, 0, l,
+					      page_chain_next(page) ? MSG_MORE : 0);
+		else
+			err = _drbd_no_send_page(peer_device, page, 0, l,
+						 page_chain_next(page) ? MSG_MORE : 0);
+
 		if (err)
 			return err;
 		len -= l;
@@ -1816,7 +1809,7 @@ int drbd_send(struct drbd_connection *connection, struct socket *sock,
 
 	/* THINK  if (signal_pending) return ... ? */
 
-	iov_iter_kvec(&msg.msg_iter, WRITE, &iov, 1, size);
+	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, &iov, 1, size);
 
 	if (sock == connection->data.socket) {
 		rcu_read_lock();
@@ -1875,9 +1868,9 @@ int drbd_send_all(struct drbd_connection *connection, struct socket *sock, void
 	return 0;
 }
 
-static int drbd_open(struct block_device *bdev, fmode_t mode)
+static int drbd_open(struct gendisk *disk, blk_mode_t mode)
 {
-	struct drbd_device *device = bdev->bd_disk->private_data;
+	struct drbd_device *device = disk->private_data;
 	unsigned long flags;
 	int rv = 0;
 
@@ -1887,7 +1880,7 @@ static int drbd_open(struct block_device *bdev, fmode_t mode)
 	 * and no race with updating open_cnt */
 
 	if (device->state.role != R_PRIMARY) {
-		if (mode & FMODE_WRITE)
+		if (mode & BLK_OPEN_WRITE)
 			rv = -EROFS;
 		else if (!drbd_allow_oos)
 			rv = -EMEDIUMTYPE;
@@ -1901,9 +1894,10 @@ static int drbd_open(struct block_device *bdev, fmode_t mode)
 	return rv;
 }
 
-static void drbd_release(struct gendisk *gd, fmode_t mode)
+static void drbd_release(struct gendisk *gd)
 {
 	struct drbd_device *device = gd->private_data;
+
 	mutex_lock(&drbd_main_mutex);
 	device->open_cnt--;
 	mutex_unlock(&drbd_main_mutex);
@@ -1964,7 +1958,6 @@ void drbd_init_set_defaults(struct drbd_device *device)
 	INIT_LIST_HEAD(&device->sync_ee);
 	INIT_LIST_HEAD(&device->done_ee);
 	INIT_LIST_HEAD(&device->read_ee);
-	INIT_LIST_HEAD(&device->net_ee);
 	INIT_LIST_HEAD(&device->resync_reads);
 	INIT_LIST_HEAD(&device->resync_work.list);
 	INIT_LIST_HEAD(&device->unplug_work.list);
@@ -2045,7 +2038,6 @@ void drbd_device_cleanup(struct drbd_device *device)
 	D_ASSERT(device, list_empty(&device->sync_ee));
 	D_ASSERT(device, list_empty(&device->done_ee));
 	D_ASSERT(device, list_empty(&device->read_ee));
-	D_ASSERT(device, list_empty(&device->net_ee));
 	D_ASSERT(device, list_empty(&device->resync_reads));
 	D_ASSERT(device, list_empty(&first_peer_device(device)->connection->sender_work.q));
 	D_ASSERT(device, list_empty(&device->resync_work.list));
@@ -2057,19 +2049,11 @@ void drbd_device_cleanup(struct drbd_device *device)
 
 static void drbd_destroy_mempools(void)
 {
-	struct page *page;
-
-	while (drbd_pp_pool) {
-		page = drbd_pp_pool;
-		drbd_pp_pool = (struct page *)page_private(page);
-		__free_page(page);
-		drbd_pp_vacant--;
-	}
-
 	/* D_ASSERT(device, atomic_read(&drbd_pp_vacant)==0); */
 
 	bioset_exit(&drbd_io_bio_set);
 	bioset_exit(&drbd_md_io_bio_set);
+	mempool_exit(&drbd_buffer_page_pool);
 	mempool_exit(&drbd_md_io_page_pool);
 	mempool_exit(&drbd_ee_mempool);
 	mempool_exit(&drbd_request_mempool);
@@ -2088,9 +2072,8 @@ static void drbd_destroy_mempools(void)
 
 static int drbd_create_mempools(void)
 {
-	struct page *page;
 	const int number = (DRBD_MAX_BIO_SIZE/PAGE_SIZE) * drbd_minor_count;
-	int i, ret;
+	int ret;
 
 	/* caches */
 	drbd_request_cache = kmem_cache_create(
@@ -2127,6 +2110,10 @@ static int drbd_create_mempools(void)
 	if (ret)
 		goto Enomem;
 
+	ret = mempool_init_page_pool(&drbd_buffer_page_pool, number, 0);
+	if (ret)
+		goto Enomem;
+
 	ret = mempool_init_slab_pool(&drbd_request_mempool, number,
 				     drbd_request_cache);
 	if (ret)
@@ -2136,15 +2123,6 @@ static int drbd_create_mempools(void)
 	if (ret)
 		goto Enomem;
 
-	for (i = 0; i < number; i++) {
-		page = alloc_page(GFP_HIGHUSER);
-		if (!page)
-			goto Enomem;
-		set_page_private(page, (unsigned long)drbd_pp_pool);
-		drbd_pp_pool = page;
-	}
-	drbd_pp_vacant = number;
-
 	return 0;
 
 Enomem:
@@ -2171,10 +2149,6 @@ static void drbd_release_all_peer_reqs(struct drbd_device *device)
 	rr = drbd_free_peer_reqs(device, &device->done_ee);
 	if (rr)
 		drbd_err(device, "%d EEs in done list found!\n", rr);
-
-	rr = drbd_free_peer_reqs(device, &device->net_ee);
-	if (rr)
-		drbd_err(device, "%d EEs in net list found!\n", rr);
 }
 
 /* caution. no locking. */
@@ -2184,7 +2158,7 @@ void drbd_destroy_device(struct kref *kref)
 	struct drbd_resource *resource = device->resource;
 	struct drbd_peer_device *peer_device, *tmp_peer_device;
 
-	del_timer_sync(&device->request_timer);
+	timer_shutdown_sync(&device->request_timer);
 
 	/* paranoia asserts */
 	D_ASSERT(device, device->open_cnt == 0);
@@ -2217,7 +2191,8 @@ void drbd_destroy_device(struct kref *kref)
 		kref_put(&peer_device->connection->kref, drbd_destroy_connection);
 		kfree(peer_device);
 	}
-	memset(device, 0xfd, sizeof(*device));
+	if (device->submit.wq)
+		destroy_workqueue(device->submit.wq);
 	kfree(device);
 	kref_put(&resource->kref, drbd_destroy_resource);
 }
@@ -2249,9 +2224,9 @@ static void do_retry(struct work_struct *ws)
 		bool expected;
 
 		expected =
-			expect(atomic_read(&req->completion_ref) == 0) &&
-			expect(req->rq_state & RQ_POSTPONED) &&
-			expect((req->rq_state & RQ_LOCAL_PENDING) == 0 ||
+			expect(device, atomic_read(&req->completion_ref) == 0) &&
+			expect(device, req->rq_state & RQ_POSTPONED) &&
+			expect(device, (req->rq_state & RQ_LOCAL_PENDING) == 0 ||
 				(req->rq_state & RQ_LOCAL_ABORTED) != 0);
 
 		if (!expected)
@@ -2309,7 +2284,6 @@ void drbd_destroy_resource(struct kref *kref)
 	idr_destroy(&resource->devices);
 	free_cpumask_var(resource->cpu_mask);
 	kfree(resource->name);
-	memset(resource, 0xf2, sizeof(*resource));
 	kfree(resource);
 }
 
@@ -2650,7 +2624,6 @@ void drbd_destroy_connection(struct kref *kref)
 	drbd_free_socket(&connection->data);
 	kfree(connection->int_dig_in);
 	kfree(connection->int_dig_vv);
-	memset(connection, 0xfc, sizeof(*connection));
 	kfree(connection);
 	kref_put(&resource->kref, drbd_destroy_resource);
 }
@@ -2672,13 +2645,24 @@ static int init_submitter(struct drbd_device *device)
 enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsigned int minor)
 {
 	struct drbd_resource *resource = adm_ctx->resource;
-	struct drbd_connection *connection;
+	struct drbd_connection *connection, *n;
 	struct drbd_device *device;
 	struct drbd_peer_device *peer_device, *tmp_peer_device;
 	struct gendisk *disk;
 	int id;
 	int vnr = adm_ctx->volume;
 	enum drbd_ret_code err = ERR_NOMEM;
+	struct queue_limits lim = {
+		/*
+		 * Setting the max_hw_sectors to an odd value of 8kibyte here.
+		 * This triggers a max_bio_size message upon first attach or
+		 * connect.
+		 */
+		.max_hw_sectors		= DRBD_MAX_BIO_SIZE_SAFE >> 8,
+		.features		= BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA |
+					  BLK_FEAT_ROTATIONAL |
+					  BLK_FEAT_STABLE_WRITES,
+	};
 
 	device = minor_to_device(minor);
 	if (device)
@@ -2697,9 +2681,11 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig
 
 	drbd_init_set_defaults(device);
 
-	disk = blk_alloc_disk(NUMA_NO_NODE);
-	if (!disk)
+	disk = blk_alloc_disk(&lim, NUMA_NO_NODE);
+	if (IS_ERR(disk)) {
+		err = PTR_ERR(disk);
 		goto out_no_disk;
+	}
 
 	device->vdisk = disk;
 	device->rq_queue = disk->queue;
@@ -2714,12 +2700,6 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig
 	sprintf(disk->disk_name, "drbd%d", minor);
 	disk->private_data = device;
 
-	blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, disk->queue);
-	blk_queue_write_cache(disk->queue, true, true);
-	/* Setting the max_hw_sectors to an odd value of 8kibyte here
-	   This triggers a max_bio_size message upon first attach or connect */
-	blk_queue_max_hw_sectors(disk->queue, DRBD_MAX_BIO_SIZE_SAFE >> 8);
-
 	device->md_io.page = alloc_page(GFP_KERNEL);
 	if (!device->md_io.page)
 		goto out_no_io_page;
@@ -2774,7 +2754,7 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig
 
 	err = add_disk(disk);
 	if (err)
-		goto out_idr_remove_from_resource;
+		goto out_destroy_workqueue;
 
 	/* inherit the connection state */
 	device->state.conn = first_connection(resource)->cstate;
@@ -2788,8 +2768,10 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig
 	drbd_debugfs_device_add(device);
 	return NO_ERROR;
 
+out_destroy_workqueue:
+	destroy_workqueue(device->submit.wq);
 out_idr_remove_from_resource:
-	for_each_connection(connection, resource) {
+	for_each_connection_safe(connection, n, resource) {
 		peer_device = idr_remove(&connection->peer_devices, vnr);
 		if (peer_device)
 			kref_put(&connection->kref, drbd_destroy_connection);
@@ -2857,11 +2839,6 @@ static int __init drbd_init(void)
 		return err;
 	}
 
-	/*
-	 * allocate all necessary structs
-	 */
-	init_waitqueue_head(&drbd_pp_wait);
-
 	drbd_proc = NULL; /* play safe for drbd_cleanup */
 	idr_init(&drbd_devices);
 
@@ -2898,7 +2875,7 @@ static int __init drbd_init(void)
 
 	pr_info("initialized. "
 	       "Version: " REL_VERSION " (api:%d/proto:%d-%d)\n",
-	       API_VERSION, PRO_VERSION_MIN, PRO_VERSION_MAX);
+	       GENL_MAGIC_VERSION, PRO_VERSION_MIN, PRO_VERSION_MAX);
 	pr_info("%s\n", drbd_buildtag());
 	pr_info("registered as block device major %d\n", DRBD_MAJOR);
 	return 0; /* Success! */
@@ -3028,7 +3005,7 @@ void drbd_md_sync(struct drbd_device *device)
 	BUILD_BUG_ON(UI_SIZE != 4);
 	BUILD_BUG_ON(sizeof(struct meta_data_on_disk) != 4096);
 
-	del_timer(&device->md_sync_timer);
+	timer_delete(&device->md_sync_timer);
 	/* timer may be rearmed by drbd_md_mark_dirty() now. */
 	if (!test_and_clear_bit(MD_DIRTY, &device->flags))
 		return;
@@ -3379,10 +3356,12 @@ void drbd_uuid_new_current(struct drbd_device *device) __must_hold(local)
 void drbd_uuid_set_bm(struct drbd_device *device, u64 val) __must_hold(local)
 {
 	unsigned long flags;
-	if (device->ldev->md.uuid[UI_BITMAP] == 0 && val == 0)
+	spin_lock_irqsave(&device->ldev->md.uuid_lock, flags);
+	if (device->ldev->md.uuid[UI_BITMAP] == 0 && val == 0) {
+		spin_unlock_irqrestore(&device->ldev->md.uuid_lock, flags);
 		return;
+	}
 
-	spin_lock_irqsave(&device->ldev->md.uuid_lock, flags);
 	if (val == 0) {
 		drbd_uuid_move_history(device);
 		device->ldev->md.uuid[UI_HISTORY_START] = device->ldev->md.uuid[UI_BITMAP];
@@ -3402,10 +3381,13 @@ void drbd_uuid_set_bm(struct drbd_device *device, u64 val) __must_hold(local)
 /**
  * drbd_bmio_set_n_write() - io_fn for drbd_queue_bitmap_io() or drbd_bitmap_io()
  * @device:	DRBD device.
+ * @peer_device: Peer DRBD device.
  *
  * Sets all bits in the bitmap and writes the whole bitmap to stable storage.
  */
-int drbd_bmio_set_n_write(struct drbd_device *device) __must_hold(local)
+int drbd_bmio_set_n_write(struct drbd_device *device,
+			  struct drbd_peer_device *peer_device) __must_hold(local)
+
 {
 	int rv = -EIO;
 
@@ -3413,7 +3395,7 @@ int drbd_bmio_set_n_write(struct drbd_device *device) __must_hold(local)
 	drbd_md_sync(device);
 	drbd_bm_set_all(device);
 
-	rv = drbd_bm_write(device);
+	rv = drbd_bm_write(device, peer_device);
 
 	if (!rv) {
 		drbd_md_clear_flag(device, MDF_FULL_SYNC);
@@ -3426,14 +3408,17 @@ int drbd_bmio_set_n_write(struct drbd_device *device) __must_hold(local)
 /**
  * drbd_bmio_clear_n_write() - io_fn for drbd_queue_bitmap_io() or drbd_bitmap_io()
  * @device:	DRBD device.
+ * @peer_device: Peer DRBD device.
  *
  * Clears all bits in the bitmap and writes the whole bitmap to stable storage.
  */
-int drbd_bmio_clear_n_write(struct drbd_device *device) __must_hold(local)
+int drbd_bmio_clear_n_write(struct drbd_device *device,
+			  struct drbd_peer_device *peer_device) __must_hold(local)
+
 {
 	drbd_resume_al(device);
 	drbd_bm_clear_all(device);
-	return drbd_bm_write(device);
+	return drbd_bm_write(device, peer_device);
 }
 
 static int w_bitmap_io(struct drbd_work *w, int unused)
@@ -3452,7 +3437,7 @@ static int w_bitmap_io(struct drbd_work *w, int unused)
 
 	if (get_ldev(device)) {
 		drbd_bm_lock(device, work->why, work->flags);
-		rv = work->io_fn(device);
+		rv = work->io_fn(device, work->peer_device);
 		drbd_bm_unlock(device);
 		put_ldev(device);
 	}
@@ -3477,6 +3462,7 @@ static int w_bitmap_io(struct drbd_work *w, int unused)
  * @done:	callback to be called after the bitmap IO was performed
  * @why:	Descriptive text of the reason for doing the IO
  * @flags:	Bitmap flags
+ * @peer_device: Peer DRBD device.
  *
  * While IO on the bitmap happens we freeze application IO thus we ensure
  * that drbd_set_out_of_sync() can not be called. This function MAY ONLY be
@@ -3487,11 +3473,12 @@ static int w_bitmap_io(struct drbd_work *w, int unused)
  * put_ldev().
  */
 void drbd_queue_bitmap_io(struct drbd_device *device,
-			  int (*io_fn)(struct drbd_device *),
+			  int (*io_fn)(struct drbd_device *, struct drbd_peer_device *),
 			  void (*done)(struct drbd_device *, int),
-			  char *why, enum bm_flag flags)
+			  char *why, enum bm_flag flags,
+			  struct drbd_peer_device *peer_device)
 {
-	D_ASSERT(device, current == first_peer_device(device)->connection->worker.task);
+	D_ASSERT(device, current == peer_device->connection->worker.task);
 
 	D_ASSERT(device, !test_bit(BITMAP_IO_QUEUED, &device->flags));
 	D_ASSERT(device, !test_bit(BITMAP_IO, &device->flags));
@@ -3500,6 +3487,7 @@ void drbd_queue_bitmap_io(struct drbd_device *device,
 		drbd_err(device, "FIXME going to queue '%s' but '%s' still pending?\n",
 			why, device->bm_io_work.why);
 
+	device->bm_io_work.peer_device = peer_device;
 	device->bm_io_work.io_fn = io_fn;
 	device->bm_io_work.done = done;
 	device->bm_io_work.why = why;
@@ -3511,7 +3499,7 @@ void drbd_queue_bitmap_io(struct drbd_device *device,
 	 * application IO does not conflict anyways. */
 	if (flags == BM_LOCKED_CHANGE_ALLOWED || atomic_read(&device->ap_bio_cnt) == 0) {
 		if (!test_and_set_bit(BITMAP_IO_QUEUED, &device->flags))
-			drbd_queue_work(&first_peer_device(device)->connection->sender_work,
+			drbd_queue_work(&peer_device->connection->sender_work,
 					&device->bm_io_work.w);
 	}
 	spin_unlock_irq(&device->resource->req_lock);
@@ -3523,12 +3511,15 @@ void drbd_queue_bitmap_io(struct drbd_device *device,
  * @io_fn:	IO callback to be called when bitmap IO is possible
  * @why:	Descriptive text of the reason for doing the IO
  * @flags:	Bitmap flags
+ * @peer_device: Peer DRBD device.
  *
  * freezes application IO while that the actual IO operations runs. This
  * functions MAY NOT be called from worker context.
  */
-int drbd_bitmap_io(struct drbd_device *device, int (*io_fn)(struct drbd_device *),
-		char *why, enum bm_flag flags)
+int drbd_bitmap_io(struct drbd_device *device,
+		int (*io_fn)(struct drbd_device *, struct drbd_peer_device *),
+		char *why, enum bm_flag flags,
+		struct drbd_peer_device *peer_device)
 {
 	/* Only suspend io, if some operation is supposed to be locked out */
 	const bool do_suspend_io = flags & (BM_DONT_CLEAR|BM_DONT_SET|BM_DONT_TEST);
@@ -3540,7 +3531,7 @@ int drbd_bitmap_io(struct drbd_device *device, int (*io_fn)(struct drbd_device *
 		drbd_suspend_io(device);
 
 	drbd_bm_lock(device, why, flags);
-	rv = io_fn(device);
+	rv = io_fn(device, peer_device);
 	drbd_bm_unlock(device);
 
 	if (do_suspend_io)
@@ -3571,7 +3562,8 @@ int drbd_md_test_flag(struct drbd_backing_dev *bdev, int flag)
 
 static void md_sync_timer_fn(struct timer_list *t)
 {
-	struct drbd_device *device = from_timer(device, t, md_sync_timer);
+	struct drbd_device *device = timer_container_of(device, t,
+							md_sync_timer);
 	drbd_device_post_work(device, MD_SYNC);
 }
 
@@ -3766,7 +3758,7 @@ _drbd_insert_fault(struct drbd_device *device, unsigned int type)
 	if (ret) {
 		drbd_fault_count++;
 
-		if (__ratelimit(&drbd_ratelimit_state))
+		if (drbd_ratelimit())
 			drbd_warn(device, "***Simulating %s failure\n",
 				_drbd_fault_str(type));
 	}
@@ -3775,24 +3767,6 @@ _drbd_insert_fault(struct drbd_device *device, unsigned int type)
 }
 #endif
 
-const char *drbd_buildtag(void)
-{
-	/* DRBD built from external sources has here a reference to the
-	   git hash of the source code. */
-
-	static char buildtag[38] = "\0uilt-in";
-
-	if (buildtag[0] == 0) {
-#ifdef MODULE
-		sprintf(buildtag, "srcversion: %-24s", THIS_MODULE->srcversion);
-#else
-		buildtag[0] = 'b';
-#endif
-	}
-
-	return buildtag;
-}
-
 module_init(drbd_init)
 module_exit(drbd_cleanup)