Merge branch 'next' (accumulated 3.16 merge window patches) into master

Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.

* accumulated work in next: (6809 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...

1 files changed, 138 insertions, 58 deletions

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 68e3992e8838..b6c8aaf4931b 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -46,9 +46,10 @@
 #include "drbd_int.h"
 #include "drbd_protocol.h"
 #include "drbd_req.h"
-
 #include "drbd_vli.h"
 
+#define PRO_FEATURES (FF_TRIM)
+
 struct packet_info {
 	enum drbd_packet cmd;
 	unsigned int size;
@@ -65,7 +66,7 @@ enum finish_epoch {
 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);
 
@@ -234,9 +235,17 @@ static void drbd_kick_lo_and_reclaim_net(struct drbd_device *device)
  * @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, unless this allocation would exceed the max_buffers setting.
+ * 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,
@@ -246,10 +255,8 @@ struct page *drbd_alloc_pages(struct drbd_peer_device *peer_device, unsigned int
 	struct page *page = NULL;
 	struct net_conf *nc;
 	DEFINE_WAIT(wait);
-	int mxb;
+	unsigned int mxb;
 
-	/* Yes, we may run up to @number over max_buffers. If we
-	 * follow it strictly, the admin will get it wrong anyways. */
 	rcu_read_lock();
 	nc = rcu_dereference(peer_device->connection->net_conf);
 	mxb = nc ? nc->max_buffers : 1000000;
@@ -277,7 +284,8 @@ struct page *drbd_alloc_pages(struct drbd_peer_device *peer_device, unsigned int
 			break;
 		}
 
-		schedule();
+		if (schedule_timeout(HZ/10) == 0)
+			mxb = UINT_MAX;
 	}
 	finish_wait(&drbd_pp_wait, &wait);
 
@@ -331,7 +339,7 @@ You must not have the req_lock:
 
 struct drbd_peer_request *
 drbd_alloc_peer_req(struct drbd_peer_device *peer_device, u64 id, sector_t sector,
-		    unsigned int data_size, gfp_t gfp_mask) __must_hold(local)
+		    unsigned int data_size, bool has_payload, gfp_t gfp_mask) __must_hold(local)
 {
 	struct drbd_device *device = peer_device->device;
 	struct drbd_peer_request *peer_req;
@@ -348,7 +356,7 @@ drbd_alloc_peer_req(struct drbd_peer_device *peer_device, u64 id, sector_t secto
 		return NULL;
 	}
 
-	if (data_size) {
+	if (has_payload && data_size) {
 		page = drbd_alloc_pages(peer_device, nr_pages, (gfp_mask & __GFP_WAIT));
 		if (!page)
 			goto fail;
@@ -1026,24 +1034,27 @@ randomize:
 	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);
+
 	set_bit(STATE_SENT, &connection->flags);
 
+	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();
 
-		/* 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.
-		 */
-		mutex_lock(device->state_mutex);
-		mutex_unlock(device->state_mutex);
-
 		if (discard_my_data)
 			set_bit(DISCARD_MY_DATA, &device->flags);
 		else
@@ -1315,6 +1326,20 @@ int drbd_submit_peer_request(struct drbd_device *device,
 	unsigned nr_pages = (ds + PAGE_SIZE -1) >> PAGE_SHIFT;
 	int err = -ENOMEM;
 
+	if (peer_req->flags & EE_IS_TRIM_USE_ZEROOUT) {
+		/* wait for all pending IO completions, before we start
+		 * zeroing things out. */
+		conn_wait_active_ee_empty(first_peer_device(device)->connection);
+		if (blkdev_issue_zeroout(device->ldev->backing_bdev,
+			sector, ds >> 9, GFP_NOIO))
+			peer_req->flags |= EE_WAS_ERROR;
+		drbd_endio_write_sec_final(peer_req);
+		return 0;
+	}
+
+	if (peer_req->flags & EE_IS_TRIM)
+		nr_pages = 0; /* discards don't have any payload. */
+
 	/* 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
@@ -1326,7 +1351,7 @@ int drbd_submit_peer_request(struct drbd_device *device,
 next_bio:
 	bio = bio_alloc(GFP_NOIO, nr_pages);
 	if (!bio) {
-		drbd_err(device, "submit_ee: Allocation of a bio failed\n");
+		drbd_err(device, "submit_ee: Allocation of a bio failed (nr_pages=%u)\n", nr_pages);
 		goto fail;
 	}
 	/* > peer_req->i.sector, unless this is the first bio */
@@ -1340,6 +1365,11 @@ next_bio:
 	bios = bio;
 	++n_bios;
 
+	if (rw & REQ_DISCARD) {
+		bio->bi_iter.bi_size = ds;
+		goto submit;
+	}
+
 	page_chain_for_each(page) {
 		unsigned len = min_t(unsigned, ds, PAGE_SIZE);
 		if (!bio_add_page(bio, page, len, 0)) {
@@ -1360,8 +1390,9 @@ next_bio:
 		sector += len >> 9;
 		--nr_pages;
 	}
-	D_ASSERT(device, page == NULL);
 	D_ASSERT(device, ds == 0);
+submit:
+	D_ASSERT(device, page == NULL);
 
 	atomic_set(&peer_req->pending_bios, n_bios);
 	do {
@@ -1490,19 +1521,21 @@ static int receive_Barrier(struct drbd_connection *connection, struct packet_inf
  * and from receive_Data */
 static struct drbd_peer_request *
 read_in_block(struct drbd_peer_device *peer_device, u64 id, sector_t sector,
-	      int data_size) __must_hold(local)
+	      struct packet_info *pi) __must_hold(local)
 {
 	struct drbd_device *device = peer_device->device;
 	const sector_t capacity = drbd_get_capacity(device->this_bdev);
 	struct drbd_peer_request *peer_req;
 	struct page *page;
 	int dgs, ds, err;
+	int data_size = pi->size;
 	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;
 
 	dgs = 0;
-	if (peer_device->connection->peer_integrity_tfm) {
+	if (!trim && peer_device->connection->peer_integrity_tfm) {
 		dgs = crypto_hash_digestsize(peer_device->connection->peer_integrity_tfm);
 		/*
 		 * FIXME: Receive the incoming digest into the receive buffer
@@ -1514,9 +1547,15 @@ read_in_block(struct drbd_peer_device *peer_device, u64 id, sector_t sector,
 		data_size -= dgs;
 	}
 
+	if (trim) {
+		D_ASSERT(peer_device, data_size == 0);
+		data_size = be32_to_cpu(trim->size);
+	}
+
 	if (!expect(IS_ALIGNED(data_size, 512)))
 		return NULL;
-	if (!expect(data_size <= DRBD_MAX_BIO_SIZE))
+	/* prepare for larger trim requests. */
+	if (!trim && !expect(data_size <= DRBD_MAX_BIO_SIZE))
 		return NULL;
 
 	/* even though we trust out peer,
@@ -1532,11 +1571,11 @@ read_in_block(struct drbd_peer_device *peer_device, u64 id, sector_t sector,
 	/* 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, data_size, GFP_NOIO);
+	peer_req = drbd_alloc_peer_req(peer_device, id, sector, data_size, trim == NULL, GFP_NOIO);
 	if (!peer_req)
 		return NULL;
 
-	if (!data_size)
+	if (trim)
 		return peer_req;
 
 	ds = data_size;
@@ -1676,12 +1715,12 @@ static int e_end_resync_block(struct drbd_work *w, int unused)
 }
 
 static int recv_resync_read(struct drbd_peer_device *peer_device, sector_t sector,
-			    int data_size) __releases(local)
+			    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, data_size);
+	peer_req = read_in_block(peer_device, ID_SYNCER, sector, pi);
 	if (!peer_req)
 		goto fail;
 
@@ -1697,7 +1736,7 @@ static int recv_resync_read(struct drbd_peer_device *peer_device, sector_t secto
 	list_add(&peer_req->w.list, &device->sync_ee);
 	spin_unlock_irq(&device->resource->req_lock);
 
-	atomic_add(data_size >> 9, &device->rs_sect_ev);
+	atomic_add(pi->size >> 9, &device->rs_sect_ev);
 	if (drbd_submit_peer_request(device, peer_req, WRITE, DRBD_FAULT_RS_WR) == 0)
 		return 0;
 
@@ -1785,7 +1824,7 @@ static int receive_RSDataReply(struct drbd_connection *connection, struct packet
 		/* 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->size);
+		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");
@@ -2196,7 +2235,7 @@ static int receive_Data(struct drbd_connection *connection, struct packet_info *
 	 */
 
 	sector = be64_to_cpu(p->sector);
-	peer_req = read_in_block(peer_device, p->block_id, sector, pi->size);
+	peer_req = read_in_block(peer_device, p->block_id, sector, pi);
 	if (!peer_req) {
 		put_ldev(device);
 		return -EIO;
@@ -2206,7 +2245,15 @@ static int receive_Data(struct drbd_connection *connection, struct packet_info *
 
 	dp_flags = be32_to_cpu(p->dp_flags);
 	rw |= wire_flags_to_bio(dp_flags);
-	if (peer_req->pages == NULL) {
+	if (pi->cmd == P_TRIM) {
+		struct request_queue *q = bdev_get_queue(device->ldev->backing_bdev);
+		peer_req->flags |= EE_IS_TRIM;
+		if (!blk_queue_discard(q))
+			peer_req->flags |= EE_IS_TRIM_USE_ZEROOUT;
+		D_ASSERT(peer_device, peer_req->i.size > 0);
+		D_ASSERT(peer_device, rw & REQ_DISCARD);
+		D_ASSERT(peer_device, peer_req->pages == NULL);
+	} else if (peer_req->pages == NULL) {
 		D_ASSERT(device, peer_req->i.size == 0);
 		D_ASSERT(device, dp_flags & DP_FLUSH);
 	}
@@ -2242,7 +2289,12 @@ static int receive_Data(struct drbd_connection *connection, struct packet_info *
 		update_peer_seq(peer_device, peer_seq);
 		spin_lock_irq(&device->resource->req_lock);
 	}
-	list_add(&peer_req->w.list, &device->active_ee);
+	/* if we use the zeroout fallback code, we process synchronously
+	 * and 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_IS_TRIM_USE_ZEROOUT) == 0)
+		list_add(&peer_req->w.list, &device->active_ee);
 	spin_unlock_irq(&device->resource->req_lock);
 
 	if (device->state.conn == C_SYNC_TARGET)
@@ -2313,39 +2365,45 @@ out_interrupted:
  * 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.
  */
-int drbd_rs_should_slow_down(struct drbd_device *device, sector_t sector)
+bool drbd_rs_should_slow_down(struct drbd_device *device, sector_t sector)
 {
-	struct gendisk *disk = device->ldev->backing_bdev->bd_contains->bd_disk;
-	unsigned long db, dt, dbdt;
 	struct lc_element *tmp;
-	int curr_events;
-	int throttle = 0;
-	unsigned int c_min_rate;
-
-	rcu_read_lock();
-	c_min_rate = rcu_dereference(device->ldev->disk_conf)->c_min_rate;
-	rcu_read_unlock();
+	bool throttle = true;
 
-	/* feature disabled? */
-	if (c_min_rate == 0)
-		return 0;
+	if (!drbd_rs_c_min_rate_throttle(device))
+		return false;
 
 	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)) {
-			spin_unlock_irq(&device->al_lock);
-			return 0;
-		}
+		if (test_bit(BME_PRIORITY, &bm_ext->flags))
+			throttle = false;
 		/* Do not slow down if app IO is already waiting for this extent */
 	}
 	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_contains->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(&disk->part0, sectors[0]) +
 		      (int)part_stat_read(&disk->part0, sectors[1]) -
 			atomic_read(&device->rs_sect_ev);
-
 	if (!device->rs_last_events || curr_events - device->rs_last_events > 64) {
 		unsigned long rs_left;
 		int i;
@@ -2368,12 +2426,11 @@ int drbd_rs_should_slow_down(struct drbd_device *device, sector_t sector)
 		dbdt = Bit2KB(db/dt);
 
 		if (dbdt > c_min_rate)
-			throttle = 1;
+			return true;
 	}
-	return throttle;
+	return false;
 }
 
-
 static int receive_DataRequest(struct drbd_connection *connection, struct packet_info *pi)
 {
 	struct drbd_peer_device *peer_device;
@@ -2436,7 +2493,8 @@ static int receive_DataRequest(struct drbd_connection *connection, struct packet
 	/* 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, GFP_NOIO);
+	peer_req = drbd_alloc_peer_req(peer_device, p->block_id, sector, size,
+			true /* has real payload */, GFP_NOIO);
 	if (!peer_req) {
 		put_ldev(device);
 		return -ENOMEM;
@@ -3648,6 +3706,13 @@ static int receive_sizes(struct drbd_connection *connection, struct packet_info
 		put_ldev(device);
 	}
 
+	device->peer_max_bio_size = be32_to_cpu(p->max_bio_size);
+	drbd_reconsider_max_bio_size(device);
+	/* Leave drbd_reconsider_max_bio_size() before drbd_determine_dev_size().
+	   In case we cleared the QUEUE_FLAG_DISCARD from our queue in
+	   drbd_reconsider_max_bio_size(), 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)) {
 		dd = drbd_determine_dev_size(device, ddsf, NULL);
@@ -3660,9 +3725,6 @@ static int receive_sizes(struct drbd_connection *connection, struct packet_info
 		drbd_set_my_capacity(device, p_size);
 	}
 
-	device->peer_max_bio_size = be32_to_cpu(p->max_bio_size);
-	drbd_reconsider_max_bio_size(device);
-
 	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);
@@ -4423,6 +4485,7 @@ static struct data_cmd drbd_cmd_handler[] = {
 	[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 },
 };
 
 static void drbdd(struct drbd_connection *connection)
@@ -4630,6 +4693,7 @@ static int drbd_send_features(struct drbd_connection *connection)
 	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);
 }
 
@@ -4683,10 +4747,14 @@ static int drbd_do_features(struct drbd_connection *connection)
 		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, "Agreed to%ssupport TRIM on protocol level\n",
+		  connection->agreed_features & FF_TRIM ? " " : " not ");
+
 	return 1;
 
  incompat:
@@ -4778,6 +4846,12 @@ static int drbd_do_auth(struct drbd_connection *connection)
 		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 == NULL) {
 		drbd_err(connection, "kmalloc of peers_ch failed\n");
@@ -4791,6 +4865,12 @@ static int drbd_do_auth(struct drbd_connection *connection)
 		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_hash_digestsize(connection->cram_hmac_tfm);
 	response = kmalloc(resp_size, GFP_NOIO);
 	if (response == NULL) {