32 files changed, 344 insertions, 149 deletions

diff --git a/fs/afs/flock.c b/fs/afs/flock.c
index 0568fd986821..e432bd27a2e7 100644
--- a/fs/afs/flock.c
+++ b/fs/afs/flock.c
@@ -208,7 +208,7 @@ again:
 		/* The new front of the queue now owns the state variables. */
 		next = list_entry(vnode->pending_locks.next,
 				  struct file_lock, fl_u.afs.link);
-		vnode->lock_key = afs_file_key(next->fl_file);
+		vnode->lock_key = key_get(afs_file_key(next->fl_file));
 		vnode->lock_type = (next->fl_type == F_RDLCK) ? AFS_LOCK_READ : AFS_LOCK_WRITE;
 		vnode->lock_state = AFS_VNODE_LOCK_WAITING_FOR_CB;
 		goto again;
@@ -413,7 +413,7 @@ static void afs_dequeue_lock(struct afs_vnode *vnode, struct file_lock *fl)
 	/* The new front of the queue now owns the state variables. */
 	next = list_entry(vnode->pending_locks.next,
 			  struct file_lock, fl_u.afs.link);
-	vnode->lock_key = afs_file_key(next->fl_file);
+	vnode->lock_key = key_get(afs_file_key(next->fl_file));
 	vnode->lock_type = (next->fl_type == F_RDLCK) ? AFS_LOCK_READ : AFS_LOCK_WRITE;
 	vnode->lock_state = AFS_VNODE_LOCK_WAITING_FOR_CB;
 	afs_lock_may_be_available(vnode);
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 6b17d3620414..1a4ce07fb406 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -414,7 +414,6 @@ int afs_validate(struct afs_vnode *vnode, struct key *key)
 	} else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
 		valid = true;
 	} else {
-		vnode->cb_s_break = vnode->cb_interest->server->cb_s_break;
 		vnode->cb_v_break = vnode->volume->cb_v_break;
 		valid = false;
 	}
@@ -546,6 +545,8 @@ void afs_evict_inode(struct inode *inode)
 #endif
 
 	afs_put_permits(rcu_access_pointer(vnode->permit_cache));
+	key_put(vnode->lock_key);
+	vnode->lock_key = NULL;
 	_leave("");
 }
 
diff --git a/fs/afs/protocol_yfs.h b/fs/afs/protocol_yfs.h
index 07bc10f076aa..d443e2bfa094 100644
--- a/fs/afs/protocol_yfs.h
+++ b/fs/afs/protocol_yfs.h
@@ -161,3 +161,14 @@ struct yfs_xdr_YFSStoreVolumeStatus {
 	struct yfs_xdr_u64	max_quota;
 	struct yfs_xdr_u64	file_quota;
 } __packed;
+
+enum yfs_lock_type {
+	yfs_LockNone		= -1,
+	yfs_LockRead		= 0,
+	yfs_LockWrite		= 1,
+	yfs_LockExtend		= 2,
+	yfs_LockRelease		= 3,
+	yfs_LockMandatoryRead	= 0x100,
+	yfs_LockMandatoryWrite	= 0x101,
+	yfs_LockMandatoryExtend	= 0x102,
+};
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index a7b44863d502..2c588f9bbbda 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -23,6 +23,7 @@ struct workqueue_struct *afs_async_calls;
 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
 static long afs_wait_for_call_to_complete(struct afs_call *, struct afs_addr_cursor *);
 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
+static void afs_delete_async_call(struct work_struct *);
 static void afs_process_async_call(struct work_struct *);
 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
@@ -203,20 +204,26 @@ void afs_put_call(struct afs_call *call)
 	}
 }
 
+static struct afs_call *afs_get_call(struct afs_call *call,
+				     enum afs_call_trace why)
+{
+	int u = atomic_inc_return(&call->usage);
+
+	trace_afs_call(call, why, u,
+		       atomic_read(&call->net->nr_outstanding_calls),
+		       __builtin_return_address(0));
+	return call;
+}
+
 /*
  * Queue the call for actual work.
  */
 static void afs_queue_call_work(struct afs_call *call)
 {
 	if (call->type->work) {
-		int u = atomic_inc_return(&call->usage);
-
-		trace_afs_call(call, afs_call_trace_work, u,
-			       atomic_read(&call->net->nr_outstanding_calls),
-			       __builtin_return_address(0));
-
 		INIT_WORK(&call->work, call->type->work);
 
+		afs_get_call(call, afs_call_trace_work);
 		if (!queue_work(afs_wq, &call->work))
 			afs_put_call(call);
 	}
@@ -398,6 +405,12 @@ long afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call,
 		}
 	}
 
+	/* If the call is going to be asynchronous, we need an extra ref for
+	 * the call to hold itself so the caller need not hang on to its ref.
+	 */
+	if (call->async)
+		afs_get_call(call, afs_call_trace_get);
+
 	/* create a call */
 	rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
 					 (unsigned long)call,
@@ -438,15 +451,17 @@ long afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call,
 			goto error_do_abort;
 	}
 
-	/* at this point, an async call may no longer exist as it may have
-	 * already completed */
-	if (call->async)
+	/* Note that at this point, we may have received the reply or an abort
+	 * - and an asynchronous call may already have completed.
+	 */
+	if (call->async) {
+		afs_put_call(call);
 		return -EINPROGRESS;
+	}
 
 	return afs_wait_for_call_to_complete(call, ac);
 
 error_do_abort:
-	call->state = AFS_CALL_COMPLETE;
 	if (ret != -ECONNABORTED) {
 		rxrpc_kernel_abort_call(call->net->socket, rxcall,
 					RX_USER_ABORT, ret, "KSD");
@@ -463,8 +478,24 @@ error_do_abort:
 error_kill_call:
 	if (call->type->done)
 		call->type->done(call);
-	afs_put_call(call);
+
+	/* We need to dispose of the extra ref we grabbed for an async call.
+	 * The call, however, might be queued on afs_async_calls and we need to
+	 * make sure we don't get any more notifications that might requeue it.
+	 */
+	if (call->rxcall) {
+		rxrpc_kernel_end_call(call->net->socket, call->rxcall);
+		call->rxcall = NULL;
+	}
+	if (call->async) {
+		if (cancel_work_sync(&call->async_work))
+			afs_put_call(call);
+		afs_put_call(call);
+	}
+
 	ac->error = ret;
+	call->state = AFS_CALL_COMPLETE;
+	afs_put_call(call);
 	_leave(" = %d", ret);
 	return ret;
 }
diff --git a/fs/afs/server_list.c b/fs/afs/server_list.c
index 95d0761cdb34..155dc14caef9 100644
--- a/fs/afs/server_list.c
+++ b/fs/afs/server_list.c
@@ -42,9 +42,7 @@ struct afs_server_list *afs_alloc_server_list(struct afs_cell *cell,
 		if (vldb->fs_mask[i] & type_mask)
 			nr_servers++;
 
-	slist = kzalloc(sizeof(struct afs_server_list) +
-			sizeof(struct afs_server_entry) * nr_servers,
-			GFP_KERNEL);
+	slist = kzalloc(struct_size(slist, servers, nr_servers), GFP_KERNEL);
 	if (!slist)
 		goto error;
 
diff --git a/fs/afs/yfsclient.c b/fs/afs/yfsclient.c
index 12658c1363ae..5aa57929e8c2 100644
--- a/fs/afs/yfsclient.c
+++ b/fs/afs/yfsclient.c
@@ -803,7 +803,7 @@ int yfs_fs_create_file(struct afs_fs_cursor *fc,
 	bp = xdr_encode_YFSFid(bp, &vnode->fid);
 	bp = xdr_encode_string(bp, name, namesz);
 	bp = xdr_encode_YFSStoreStatus_mode(bp, mode);
-	bp = xdr_encode_u32(bp, 0); /* ViceLockType */
+	bp = xdr_encode_u32(bp, yfs_LockNone); /* ViceLockType */
 	yfs_check_req(call, bp);
 
 	afs_use_fs_server(call, fc->cbi);
diff --git a/fs/block_dev.c b/fs/block_dev.c
index c546cdce77e6..58a4c1217fa8 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -104,6 +104,20 @@ void invalidate_bdev(struct block_device *bdev)
 }
 EXPORT_SYMBOL(invalidate_bdev);
 
+static void set_init_blocksize(struct block_device *bdev)
+{
+	unsigned bsize = bdev_logical_block_size(bdev);
+	loff_t size = i_size_read(bdev->bd_inode);
+
+	while (bsize < PAGE_SIZE) {
+		if (size & bsize)
+			break;
+		bsize <<= 1;
+	}
+	bdev->bd_block_size = bsize;
+	bdev->bd_inode->i_blkbits = blksize_bits(bsize);
+}
+
 int set_blocksize(struct block_device *bdev, int size)
 {
 	/* Size must be a power of two, and between 512 and PAGE_SIZE */
@@ -1431,18 +1445,9 @@ EXPORT_SYMBOL(check_disk_change);
 
 void bd_set_size(struct block_device *bdev, loff_t size)
 {
-	unsigned bsize = bdev_logical_block_size(bdev);
-
 	inode_lock(bdev->bd_inode);
 	i_size_write(bdev->bd_inode, size);
 	inode_unlock(bdev->bd_inode);
-	while (bsize < PAGE_SIZE) {
-		if (size & bsize)
-			break;
-		bsize <<= 1;
-	}
-	bdev->bd_block_size = bsize;
-	bdev->bd_inode->i_blkbits = blksize_bits(bsize);
 }
 EXPORT_SYMBOL(bd_set_size);
 
@@ -1519,8 +1524,10 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 				}
 			}
 
-			if (!ret)
+			if (!ret) {
 				bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
+				set_init_blocksize(bdev);
+			}
 
 			/*
 			 * If the device is invalidated, rescan partition
@@ -1555,6 +1562,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 				goto out_clear;
 			}
 			bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
+			set_init_blocksize(bdev);
 		}
 
 		if (bdev->bd_bdi == &noop_backing_dev_info)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0a68cf7032f5..7a2a2621f0d9 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -35,6 +35,7 @@
 struct btrfs_trans_handle;
 struct btrfs_transaction;
 struct btrfs_pending_snapshot;
+struct btrfs_delayed_ref_root;
 extern struct kmem_cache *btrfs_trans_handle_cachep;
 extern struct kmem_cache *btrfs_bit_radix_cachep;
 extern struct kmem_cache *btrfs_path_cachep;
@@ -786,6 +787,9 @@ enum {
 	 * main phase. The fs_info::balance_ctl is initialized.
 	 */
 	BTRFS_FS_BALANCE_RUNNING,
+
+	/* Indicate that the cleaner thread is awake and doing something. */
+	BTRFS_FS_CLEANER_RUNNING,
 };
 
 struct btrfs_fs_info {
@@ -2661,6 +2665,9 @@ int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
 			   unsigned long count);
 int btrfs_async_run_delayed_refs(struct btrfs_fs_info *fs_info,
 				 unsigned long count, u64 transid, int wait);
+void btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info *fs_info,
+				  struct btrfs_delayed_ref_root *delayed_refs,
+				  struct btrfs_delayed_ref_head *head);
 int btrfs_lookup_data_extent(struct btrfs_fs_info *fs_info, u64 start, u64 len);
 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
 			     struct btrfs_fs_info *fs_info, u64 bytenr,
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 8da2f380d3c0..6a2a2a951705 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1682,6 +1682,8 @@ static int cleaner_kthread(void *arg)
 	while (1) {
 		again = 0;
 
+		set_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
+
 		/* Make the cleaner go to sleep early. */
 		if (btrfs_need_cleaner_sleep(fs_info))
 			goto sleep;
@@ -1728,6 +1730,7 @@ static int cleaner_kthread(void *arg)
 		 */
 		btrfs_delete_unused_bgs(fs_info);
 sleep:
+		clear_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
 		if (kthread_should_park())
 			kthread_parkme();
 		if (kthread_should_stop())
@@ -4201,6 +4204,14 @@ static void btrfs_destroy_all_ordered_extents(struct btrfs_fs_info *fs_info)
 		spin_lock(&fs_info->ordered_root_lock);
 	}
 	spin_unlock(&fs_info->ordered_root_lock);
+
+	/*
+	 * We need this here because if we've been flipped read-only we won't
+	 * get sync() from the umount, so we need to make sure any ordered
+	 * extents that haven't had their dirty pages IO start writeout yet
+	 * actually get run and error out properly.
+	 */
+	btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
 }
 
 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
@@ -4265,6 +4276,7 @@ static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
 		if (pin_bytes)
 			btrfs_pin_extent(fs_info, head->bytenr,
 					 head->num_bytes, 1);
+		btrfs_cleanup_ref_head_accounting(fs_info, delayed_refs, head);
 		btrfs_put_delayed_ref_head(head);
 		cond_resched();
 		spin_lock(&delayed_refs->lock);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index b15afeae16df..d81035b7ea7d 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2456,12 +2456,10 @@ static int run_and_cleanup_extent_op(struct btrfs_trans_handle *trans,
 	return ret ? ret : 1;
 }
 
-static void cleanup_ref_head_accounting(struct btrfs_trans_handle *trans,
-					struct btrfs_delayed_ref_head *head)
+void btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info *fs_info,
+				  struct btrfs_delayed_ref_root *delayed_refs,
+				  struct btrfs_delayed_ref_head *head)
 {
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_delayed_ref_root *delayed_refs =
-		&trans->transaction->delayed_refs;
 	int nr_items = 1;	/* Dropping this ref head update. */
 
 	if (head->total_ref_mod < 0) {
@@ -2544,7 +2542,7 @@ static int cleanup_ref_head(struct btrfs_trans_handle *trans,
 		}
 	}
 
-	cleanup_ref_head_accounting(trans, head);
+	btrfs_cleanup_ref_head_accounting(fs_info, delayed_refs, head);
 
 	trace_run_delayed_ref_head(fs_info, head, 0);
 	btrfs_delayed_ref_unlock(head);
@@ -4954,6 +4952,15 @@ static void flush_space(struct btrfs_fs_info *fs_info,
 			ret = 0;
 		break;
 	case COMMIT_TRANS:
+		/*
+		 * If we have pending delayed iputs then we could free up a
+		 * bunch of pinned space, so make sure we run the iputs before
+		 * we do our pinned bytes check below.
+		 */
+		mutex_lock(&fs_info->cleaner_delayed_iput_mutex);
+		btrfs_run_delayed_iputs(fs_info);
+		mutex_unlock(&fs_info->cleaner_delayed_iput_mutex);
+
 		ret = may_commit_transaction(fs_info, space_info);
 		break;
 	default:
@@ -7188,7 +7195,7 @@ static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
 	if (head->must_insert_reserved)
 		ret = 1;
 
-	cleanup_ref_head_accounting(trans, head);
+	btrfs_cleanup_ref_head_accounting(trans->fs_info, delayed_refs, head);
 	mutex_unlock(&head->mutex);
 	btrfs_put_delayed_ref_head(head);
 	return ret;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 43eb4535319d..5c349667c761 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3129,9 +3129,6 @@ out:
 	/* once for the tree */
 	btrfs_put_ordered_extent(ordered_extent);
 
-	/* Try to release some metadata so we don't get an OOM but don't wait */
-	btrfs_btree_balance_dirty_nodelay(fs_info);
-
 	return ret;
 }
 
@@ -3254,6 +3251,8 @@ void btrfs_add_delayed_iput(struct inode *inode)
 	ASSERT(list_empty(&binode->delayed_iput));
 	list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
 	spin_unlock(&fs_info->delayed_iput_lock);
+	if (!test_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags))
+		wake_up_process(fs_info->cleaner_kthread);
 }
 
 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 94c026bba2c2..bba28a5034ba 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1035,6 +1035,8 @@ static void drop_inode_snap_realm(struct ceph_inode_info *ci)
 	list_del_init(&ci->i_snap_realm_item);
 	ci->i_snap_realm_counter++;
 	ci->i_snap_realm = NULL;
+	if (realm->ino == ci->i_vino.ino)
+		realm->inode = NULL;
 	spin_unlock(&realm->inodes_with_caps_lock);
 	ceph_put_snap_realm(ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc,
 			    realm);
diff --git a/fs/ceph/quota.c b/fs/ceph/quota.c
index 03f4d24db8fe..9455d3aef0c3 100644
--- a/fs/ceph/quota.c
+++ b/fs/ceph/quota.c
@@ -3,19 +3,6 @@
  * quota.c - CephFS quota
  *
  * Copyright (C) 2017-2018 SUSE
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
 #include <linux/statfs.h>
diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
index 593fb422d0f3..e92a2fee3c57 100644
--- a/fs/cifs/cifs_debug.c
+++ b/fs/cifs/cifs_debug.c
@@ -252,6 +252,7 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v)
 	seq_printf(m, ",ACL");
 #endif
 	seq_putc(m, '\n');
+	seq_printf(m, "CIFSMaxBufSize: %d\n", CIFSMaxBufSize);
 	seq_printf(m, "Active VFS Requests: %d\n", GlobalTotalActiveXid);
 	seq_printf(m, "Servers:");
 
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index e18915415e13..bb54ccf8481c 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -1549,18 +1549,26 @@ cifs_discard_remaining_data(struct TCP_Server_Info *server)
 }
 
 static int
-cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
+__cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid,
+		     bool malformed)
 {
 	int length;
-	struct cifs_readdata *rdata = mid->callback_data;
 
 	length = cifs_discard_remaining_data(server);
-	dequeue_mid(mid, rdata->result);
+	dequeue_mid(mid, malformed);
 	mid->resp_buf = server->smallbuf;
 	server->smallbuf = NULL;
 	return length;
 }
 
+static int
+cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
+{
+	struct cifs_readdata *rdata = mid->callback_data;
+
+	return  __cifs_readv_discard(server, mid, rdata->result);
+}
+
 int
 cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 {
@@ -1602,12 +1610,23 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 		return -1;
 	}
 
+	/* set up first two iov for signature check and to get credits */
+	rdata->iov[0].iov_base = buf;
+	rdata->iov[0].iov_len = 4;
+	rdata->iov[1].iov_base = buf + 4;
+	rdata->iov[1].iov_len = server->total_read - 4;
+	cifs_dbg(FYI, "0: iov_base=%p iov_len=%zu\n",
+		 rdata->iov[0].iov_base, rdata->iov[0].iov_len);
+	cifs_dbg(FYI, "1: iov_base=%p iov_len=%zu\n",
+		 rdata->iov[1].iov_base, rdata->iov[1].iov_len);
+
 	/* Was the SMB read successful? */
 	rdata->result = server->ops->map_error(buf, false);
 	if (rdata->result != 0) {
 		cifs_dbg(FYI, "%s: server returned error %d\n",
 			 __func__, rdata->result);
-		return cifs_readv_discard(server, mid);
+		/* normal error on read response */
+		return __cifs_readv_discard(server, mid, false);
 	}
 
 	/* Is there enough to get to the rest of the READ_RSP header? */
@@ -1651,14 +1670,6 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 		server->total_read += length;
 	}
 
-	/* set up first iov for signature check */
-	rdata->iov[0].iov_base = buf;
-	rdata->iov[0].iov_len = 4;
-	rdata->iov[1].iov_base = buf + 4;
-	rdata->iov[1].iov_len = server->total_read - 4;
-	cifs_dbg(FYI, "0: iov_base=%p iov_len=%u\n",
-		 rdata->iov[0].iov_base, server->total_read);
-
 	/* how much data is in the response? */
 #ifdef CONFIG_CIFS_SMB_DIRECT
 	use_rdma_mr = rdata->mr;
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 683310f26171..8463c940e0e5 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -720,6 +720,21 @@ server_unresponsive(struct TCP_Server_Info *server)
 	return false;
 }
 
+static inline bool
+zero_credits(struct TCP_Server_Info *server)
+{
+	int val;
+
+	spin_lock(&server->req_lock);
+	val = server->credits + server->echo_credits + server->oplock_credits;
+	if (server->in_flight == 0 && val == 0) {
+		spin_unlock(&server->req_lock);
+		return true;
+	}
+	spin_unlock(&server->req_lock);
+	return false;
+}
+
 static int
 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 {
@@ -732,6 +747,12 @@ cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 	for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 		try_to_freeze();
 
+		/* reconnect if no credits and no requests in flight */
+		if (zero_credits(server)) {
+			cifs_reconnect(server);
+			return -ECONNABORTED;
+		}
+
 		if (server_unresponsive(server))
 			return -ECONNABORTED;
 		if (cifs_rdma_enabled(server) && server->smbd_conn)
diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c
index f14533da3a93..01a76bccdb8d 100644
--- a/fs/cifs/smb2inode.c
+++ b/fs/cifs/smb2inode.c
@@ -293,6 +293,8 @@ smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,
 	int rc;
 	struct smb2_file_all_info *smb2_data;
 	__u32 create_options = 0;
+	struct cifs_fid fid;
+	bool no_cached_open = tcon->nohandlecache;
 
 	*adjust_tz = false;
 	*symlink = false;
@@ -301,6 +303,21 @@ smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,
 			    GFP_KERNEL);
 	if (smb2_data == NULL)
 		return -ENOMEM;
+
+	/* If it is a root and its handle is cached then use it */
+	if (!strlen(full_path) && !no_cached_open) {
+		rc = open_shroot(xid, tcon, &fid);
+		if (rc)
+			goto out;
+		rc = SMB2_query_info(xid, tcon, fid.persistent_fid,
+				     fid.volatile_fid, smb2_data);
+		close_shroot(&tcon->crfid);
+		if (rc)
+			goto out;
+		move_smb2_info_to_cifs(data, smb2_data);
+		goto out;
+	}
+
 	if (backup_cred(cifs_sb))
 		create_options |= CREATE_OPEN_BACKUP_INTENT;
 
diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index 6a9c47541c53..7b8b58fb4d3f 100644
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -648,6 +648,13 @@ smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
 	if (rsp->sync_hdr.Command != SMB2_OPLOCK_BREAK)
 		return false;
 
+	if (rsp->sync_hdr.CreditRequest) {
+		spin_lock(&server->req_lock);
+		server->credits += le16_to_cpu(rsp->sync_hdr.CreditRequest);
+		spin_unlock(&server->req_lock);
+		wake_up(&server->request_q);
+	}
+
 	if (rsp->StructureSize !=
 				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
 		if (le16_to_cpu(rsp->StructureSize) == 44)
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index cf7eb891804f..153238fc4fa9 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -34,6 +34,7 @@
 #include "cifs_ioctl.h"
 #include "smbdirect.h"
 
+/* Change credits for different ops and return the total number of credits */
 static int
 change_conf(struct TCP_Server_Info *server)
 {
@@ -41,17 +42,15 @@ change_conf(struct TCP_Server_Info *server)
 	server->oplock_credits = server->echo_credits = 0;
 	switch (server->credits) {
 	case 0:
-		return -1;
+		return 0;
 	case 1:
 		server->echoes = false;
 		server->oplocks = false;
-		cifs_dbg(VFS, "disabling echoes and oplocks\n");
 		break;
 	case 2:
 		server->echoes = true;
 		server->oplocks = false;
 		server->echo_credits = 1;
-		cifs_dbg(FYI, "disabling oplocks\n");
 		break;
 	default:
 		server->echoes = true;
@@ -64,14 +63,15 @@ change_conf(struct TCP_Server_Info *server)
 		server->echo_credits = 1;
 	}
 	server->credits -= server->echo_credits + server->oplock_credits;
-	return 0;
+	return server->credits + server->echo_credits + server->oplock_credits;
 }
 
 static void
 smb2_add_credits(struct TCP_Server_Info *server, const unsigned int add,
 		 const int optype)
 {
-	int *val, rc = 0;
+	int *val, rc = -1;
+
 	spin_lock(&server->req_lock);
 	val = server->ops->get_credits_field(server, optype);
 
@@ -101,8 +101,26 @@ smb2_add_credits(struct TCP_Server_Info *server, const unsigned int add,
 	}
 	spin_unlock(&server->req_lock);
 	wake_up(&server->request_q);
-	if (rc)
-		cifs_reconnect(server);
+
+	if (server->tcpStatus == CifsNeedReconnect)
+		return;
+
+	switch (rc) {
+	case -1:
+		/* change_conf hasn't been executed */
+		break;
+	case 0:
+		cifs_dbg(VFS, "Possible client or server bug - zero credits\n");
+		break;
+	case 1:
+		cifs_dbg(VFS, "disabling echoes and oplocks\n");
+		break;
+	case 2:
+		cifs_dbg(FYI, "disabling oplocks\n");
+		break;
+	default:
+		cifs_dbg(FYI, "add %u credits total=%d\n", add, rc);
+	}
 }
 
 static void
@@ -136,7 +154,11 @@ smb2_get_credits(struct mid_q_entry *mid)
 {
 	struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)mid->resp_buf;
 
-	return le16_to_cpu(shdr->CreditRequest);
+	if (mid->mid_state == MID_RESPONSE_RECEIVED
+	    || mid->mid_state == MID_RESPONSE_MALFORMED)
+		return le16_to_cpu(shdr->CreditRequest);
+
+	return 0;
 }
 
 static int
@@ -165,14 +187,14 @@ smb2_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
 
 			scredits = server->credits;
 			/* can deadlock with reopen */
-			if (scredits == 1) {
+			if (scredits <= 8) {
 				*num = SMB2_MAX_BUFFER_SIZE;
 				*credits = 0;
 				break;
 			}
 
-			/* leave one credit for a possible reopen */
-			scredits--;
+			/* leave some credits for reopen and other ops */
+			scredits -= 8;
 			*num = min_t(unsigned int, size,
 				     scredits * SMB2_MAX_BUFFER_SIZE);
 
@@ -3189,11 +3211,23 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
 			server->ops->is_status_pending(buf, server, 0))
 		return -1;
 
-	rdata->result = server->ops->map_error(buf, false);
+	/* set up first two iov to get credits */
+	rdata->iov[0].iov_base = buf;
+	rdata->iov[0].iov_len = 4;
+	rdata->iov[1].iov_base = buf + 4;
+	rdata->iov[1].iov_len =
+		min_t(unsigned int, buf_len, server->vals->read_rsp_size) - 4;
+	cifs_dbg(FYI, "0: iov_base=%p iov_len=%zu\n",
+		 rdata->iov[0].iov_base, rdata->iov[0].iov_len);
+	cifs_dbg(FYI, "1: iov_base=%p iov_len=%zu\n",
+		 rdata->iov[1].iov_base, rdata->iov[1].iov_len);
+
+	rdata->result = server->ops->map_error(buf, true);
 	if (rdata->result != 0) {
 		cifs_dbg(FYI, "%s: server returned error %d\n",
 			 __func__, rdata->result);
-		dequeue_mid(mid, rdata->result);
+		/* normal error on read response */
+		dequeue_mid(mid, false);
 		return 0;
 	}
 
@@ -3266,14 +3300,6 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
 		return 0;
 	}
 
-	/* set up first iov for signature check */
-	rdata->iov[0].iov_base = buf;
-	rdata->iov[0].iov_len = 4;
-	rdata->iov[1].iov_base = buf + 4;
-	rdata->iov[1].iov_len = server->vals->read_rsp_size - 4;
-	cifs_dbg(FYI, "0: iov_base=%p iov_len=%zu\n",
-		 rdata->iov[0].iov_base, server->vals->read_rsp_size);
-
 	length = rdata->copy_into_pages(server, rdata, &iter);
 
 	kfree(bvec);
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 50811a7dc0e0..2ff209ec4fab 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2816,6 +2816,7 @@ query_info(const unsigned int xid, struct cifs_tcon *tcon,
 	int resp_buftype = CIFS_NO_BUFFER;
 	struct cifs_ses *ses = tcon->ses;
 	int flags = 0;
+	bool allocated = false;
 
 	cifs_dbg(FYI, "Query Info\n");
 
@@ -2855,14 +2856,21 @@ query_info(const unsigned int xid, struct cifs_tcon *tcon,
 					"Error %d allocating memory for acl\n",
 					rc);
 				*dlen = 0;
+				rc = -ENOMEM;
 				goto qinf_exit;
 			}
+			allocated = true;
 		}
 	}
 
 	rc = smb2_validate_and_copy_iov(le16_to_cpu(rsp->OutputBufferOffset),
 					le32_to_cpu(rsp->OutputBufferLength),
 					&rsp_iov, min_len, *data);
+	if (rc && allocated) {
+		kfree(*data);
+		*data = NULL;
+		*dlen = 0;
+	}
 
 qinf_exit:
 	SMB2_query_info_free(&rqst);
@@ -2916,9 +2924,10 @@ smb2_echo_callback(struct mid_q_entry *mid)
 {
 	struct TCP_Server_Info *server = mid->callback_data;
 	struct smb2_echo_rsp *rsp = (struct smb2_echo_rsp *)mid->resp_buf;
-	unsigned int credits_received = 1;
+	unsigned int credits_received = 0;
 
-	if (mid->mid_state == MID_RESPONSE_RECEIVED)
+	if (mid->mid_state == MID_RESPONSE_RECEIVED
+	    || mid->mid_state == MID_RESPONSE_MALFORMED)
 		credits_received = le16_to_cpu(rsp->sync_hdr.CreditRequest);
 
 	DeleteMidQEntry(mid);
@@ -3175,7 +3184,7 @@ smb2_readv_callback(struct mid_q_entry *mid)
 	struct TCP_Server_Info *server = tcon->ses->server;
 	struct smb2_sync_hdr *shdr =
 				(struct smb2_sync_hdr *)rdata->iov[0].iov_base;
-	unsigned int credits_received = 1;
+	unsigned int credits_received = 0;
 	struct smb_rqst rqst = { .rq_iov = rdata->iov,
 				 .rq_nvec = 2,
 				 .rq_pages = rdata->pages,
@@ -3214,6 +3223,9 @@ smb2_readv_callback(struct mid_q_entry *mid)
 		task_io_account_read(rdata->got_bytes);
 		cifs_stats_bytes_read(tcon, rdata->got_bytes);
 		break;
+	case MID_RESPONSE_MALFORMED:
+		credits_received = le16_to_cpu(shdr->CreditRequest);
+		/* fall through */
 	default:
 		if (rdata->result != -ENODATA)
 			rdata->result = -EIO;
@@ -3399,7 +3411,7 @@ smb2_writev_callback(struct mid_q_entry *mid)
 	struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink);
 	unsigned int written;
 	struct smb2_write_rsp *rsp = (struct smb2_write_rsp *)mid->resp_buf;
-	unsigned int credits_received = 1;
+	unsigned int credits_received = 0;
 
 	switch (mid->mid_state) {
 	case MID_RESPONSE_RECEIVED:
@@ -3427,6 +3439,9 @@ smb2_writev_callback(struct mid_q_entry *mid)
 	case MID_RETRY_NEEDED:
 		wdata->result = -EAGAIN;
 		break;
+	case MID_RESPONSE_MALFORMED:
+		credits_received = le16_to_cpu(rsp->sync_hdr.CreditRequest);
+		/* fall through */
 	default:
 		wdata->result = -EIO;
 		break;
diff --git a/fs/cifs/trace.c b/fs/cifs/trace.c
index bd4a546feec1..465483787193 100644
--- a/fs/cifs/trace.c
+++ b/fs/cifs/trace.c
@@ -3,16 +3,6 @@
  *   Copyright (C) 2018, Microsoft Corporation.
  *
  *   Author(s): Steve French <stfrench@microsoft.com>
- *
- *   This program is free software;  you can redistribute it and/or modify
- *   it under the terms of the GNU General Public License as published by
- *   the Free Software Foundation; either version 2 of the License, or
- *   (at your option) any later version.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
- *   the GNU General Public License for more details.
  */
 #define CREATE_TRACE_POINTS
 #include "trace.h"
diff --git a/fs/cifs/trace.h b/fs/cifs/trace.h
index fb049809555f..59be48206932 100644
--- a/fs/cifs/trace.h
+++ b/fs/cifs/trace.h
@@ -3,16 +3,6 @@
  *   Copyright (C) 2018, Microsoft Corporation.
  *
  *   Author(s): Steve French <stfrench@microsoft.com>
- *
- *   This program is free software;  you can redistribute it and/or modify
- *   it under the terms of the GNU General Public License as published by
- *   the Free Software Foundation; either version 2 of the License, or
- *   (at your option) any later version.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
- *   the GNU General Public License for more details.
  */
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM cifs
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 202e0e84efdd..53532bd3f50d 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -786,17 +786,8 @@ static void
 cifs_compound_callback(struct mid_q_entry *mid)
 {
 	struct TCP_Server_Info *server = mid->server;
-	unsigned int optype = mid->optype;
-	unsigned int credits_received = 0;
 
-	if (mid->mid_state == MID_RESPONSE_RECEIVED) {
-		if (mid->resp_buf)
-			credits_received = server->ops->get_credits(mid);
-		else
-			cifs_dbg(FYI, "Bad state for cancelled MID\n");
-	}
-
-	add_credits(server, credits_received, optype);
+	add_credits(server, server->ops->get_credits(mid), mid->optype);
 }
 
 static void
diff --git a/fs/dcache.c b/fs/dcache.c
index 2593153471cf..aac41adf4743 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -119,6 +119,7 @@ struct dentry_stat_t dentry_stat = {
 
 static DEFINE_PER_CPU(long, nr_dentry);
 static DEFINE_PER_CPU(long, nr_dentry_unused);
+static DEFINE_PER_CPU(long, nr_dentry_negative);
 
 #if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS)
 
@@ -152,11 +153,22 @@ static long get_nr_dentry_unused(void)
 	return sum < 0 ? 0 : sum;
 }
 
+static long get_nr_dentry_negative(void)
+{
+	int i;
+	long sum = 0;
+
+	for_each_possible_cpu(i)
+		sum += per_cpu(nr_dentry_negative, i);
+	return sum < 0 ? 0 : sum;
+}
+
 int proc_nr_dentry(struct ctl_table *table, int write, void __user *buffer,
 		   size_t *lenp, loff_t *ppos)
 {
 	dentry_stat.nr_dentry = get_nr_dentry();
 	dentry_stat.nr_unused = get_nr_dentry_unused();
+	dentry_stat.nr_negative = get_nr_dentry_negative();
 	return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
 }
 #endif
@@ -317,6 +329,8 @@ static inline void __d_clear_type_and_inode(struct dentry *dentry)
 	flags &= ~(DCACHE_ENTRY_TYPE | DCACHE_FALLTHRU);
 	WRITE_ONCE(dentry->d_flags, flags);
 	dentry->d_inode = NULL;
+	if (dentry->d_flags & DCACHE_LRU_LIST)
+		this_cpu_inc(nr_dentry_negative);
 }
 
 static void dentry_free(struct dentry *dentry)
@@ -371,6 +385,11 @@ static void dentry_unlink_inode(struct dentry * dentry)
  * The per-cpu "nr_dentry_unused" counters are updated with
  * the DCACHE_LRU_LIST bit.
  *
+ * The per-cpu "nr_dentry_negative" counters are only updated
+ * when deleted from or added to the per-superblock LRU list, not
+ * from/to the shrink list. That is to avoid an unneeded dec/inc
+ * pair when moving from LRU to shrink list in select_collect().
+ *
  * These helper functions make sure we always follow the
  * rules. d_lock must be held by the caller.
  */
@@ -380,6 +399,8 @@ static void d_lru_add(struct dentry *dentry)
 	D_FLAG_VERIFY(dentry, 0);
 	dentry->d_flags |= DCACHE_LRU_LIST;
 	this_cpu_inc(nr_dentry_unused);
+	if (d_is_negative(dentry))
+		this_cpu_inc(nr_dentry_negative);
 	WARN_ON_ONCE(!list_lru_add(&dentry->d_sb->s_dentry_lru, &dentry->d_lru));
 }
 
@@ -388,6 +409,8 @@ static void d_lru_del(struct dentry *dentry)
 	D_FLAG_VERIFY(dentry, DCACHE_LRU_LIST);
 	dentry->d_flags &= ~DCACHE_LRU_LIST;
 	this_cpu_dec(nr_dentry_unused);
+	if (d_is_negative(dentry))
+		this_cpu_dec(nr_dentry_negative);
 	WARN_ON_ONCE(!list_lru_del(&dentry->d_sb->s_dentry_lru, &dentry->d_lru));
 }
 
@@ -418,6 +441,8 @@ static void d_lru_isolate(struct list_lru_one *lru, struct dentry *dentry)
 	D_FLAG_VERIFY(dentry, DCACHE_LRU_LIST);
 	dentry->d_flags &= ~DCACHE_LRU_LIST;
 	this_cpu_dec(nr_dentry_unused);
+	if (d_is_negative(dentry))
+		this_cpu_dec(nr_dentry_negative);
 	list_lru_isolate(lru, &dentry->d_lru);
 }
 
@@ -426,6 +451,8 @@ static void d_lru_shrink_move(struct list_lru_one *lru, struct dentry *dentry,
 {
 	D_FLAG_VERIFY(dentry, DCACHE_LRU_LIST);
 	dentry->d_flags |= DCACHE_SHRINK_LIST;
+	if (d_is_negative(dentry))
+		this_cpu_dec(nr_dentry_negative);
 	list_lru_isolate_move(lru, &dentry->d_lru, list);
 }
 
@@ -1188,15 +1215,11 @@ static enum lru_status dentry_lru_isolate_shrink(struct list_head *item,
  */
 void shrink_dcache_sb(struct super_block *sb)
 {
-	long freed;
-
 	do {
 		LIST_HEAD(dispose);
 
-		freed = list_lru_walk(&sb->s_dentry_lru,
+		list_lru_walk(&sb->s_dentry_lru,
 			dentry_lru_isolate_shrink, &dispose, 1024);
-
-		this_cpu_sub(nr_dentry_unused, freed);
 		shrink_dentry_list(&dispose);
 	} while (list_lru_count(&sb->s_dentry_lru) > 0);
 }
@@ -1820,6 +1843,11 @@ static void __d_instantiate(struct dentry *dentry, struct inode *inode)
 	WARN_ON(d_in_lookup(dentry));
 
 	spin_lock(&dentry->d_lock);
+	/*
+	 * Decrement negative dentry count if it was in the LRU list.
+	 */
+	if (dentry->d_flags & DCACHE_LRU_LIST)
+		this_cpu_dec(nr_dentry_negative);
 	hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry);
 	raw_write_seqcount_begin(&dentry->d_seq);
 	__d_set_inode_and_type(dentry, inode, add_flags);
diff --git a/fs/direct-io.c b/fs/direct-io.c
index dbc1a1f080ce..ec2fb6fe6d37 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -679,6 +679,7 @@ static int get_more_blocks(struct dio *dio, struct dio_submit *sdio,
 	unsigned long fs_count;	/* Number of filesystem-sized blocks */
 	int create;
 	unsigned int i_blkbits = sdio->blkbits + sdio->blkfactor;
+	loff_t i_size;
 
 	/*
 	 * If there was a memory error and we've overwritten all the
@@ -708,8 +709,8 @@ static int get_more_blocks(struct dio *dio, struct dio_submit *sdio,
 		 */
 		create = dio->op == REQ_OP_WRITE;
 		if (dio->flags & DIO_SKIP_HOLES) {
-			if (fs_startblk <= ((i_size_read(dio->inode) - 1) >>
-							i_blkbits))
+			i_size = i_size_read(dio->inode);
+			if (i_size && fs_startblk <= (i_size - 1) >> i_blkbits)
 				create = 0;
 		}
 
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index b40168fcc94a..36855c1f8daf 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -331,11 +331,22 @@ struct inode_switch_wbs_context {
 	struct work_struct	work;
 };
 
+static void bdi_down_write_wb_switch_rwsem(struct backing_dev_info *bdi)
+{
+	down_write(&bdi->wb_switch_rwsem);
+}
+
+static void bdi_up_write_wb_switch_rwsem(struct backing_dev_info *bdi)
+{
+	up_write(&bdi->wb_switch_rwsem);
+}
+
 static void inode_switch_wbs_work_fn(struct work_struct *work)
 {
 	struct inode_switch_wbs_context *isw =
 		container_of(work, struct inode_switch_wbs_context, work);
 	struct inode *inode = isw->inode;
+	struct backing_dev_info *bdi = inode_to_bdi(inode);
 	struct address_space *mapping = inode->i_mapping;
 	struct bdi_writeback *old_wb = inode->i_wb;
 	struct bdi_writeback *new_wb = isw->new_wb;
@@ -344,6 +355,12 @@ static void inode_switch_wbs_work_fn(struct work_struct *work)
 	bool switched = false;
 
 	/*
+	 * If @inode switches cgwb membership while sync_inodes_sb() is
+	 * being issued, sync_inodes_sb() might miss it.  Synchronize.
+	 */
+	down_read(&bdi->wb_switch_rwsem);
+
+	/*
 	 * By the time control reaches here, RCU grace period has passed
 	 * since I_WB_SWITCH assertion and all wb stat update transactions
 	 * between unlocked_inode_to_wb_begin/end() are guaranteed to be
@@ -428,6 +445,8 @@ skip_switch:
 	spin_unlock(&new_wb->list_lock);
 	spin_unlock(&old_wb->list_lock);
 
+	up_read(&bdi->wb_switch_rwsem);
+
 	if (switched) {
 		wb_wakeup(new_wb);
 		wb_put(old_wb);
@@ -468,9 +487,18 @@ static void inode_switch_wbs(struct inode *inode, int new_wb_id)
 	if (inode->i_state & I_WB_SWITCH)
 		return;
 
+	/*
+	 * Avoid starting new switches while sync_inodes_sb() is in
+	 * progress.  Otherwise, if the down_write protected issue path
+	 * blocks heavily, we might end up starting a large number of
+	 * switches which will block on the rwsem.
+	 */
+	if (!down_read_trylock(&bdi->wb_switch_rwsem))
+		return;
+
 	isw = kzalloc(sizeof(*isw), GFP_ATOMIC);
 	if (!isw)
-		return;
+		goto out_unlock;
 
 	/* find and pin the new wb */
 	rcu_read_lock();
@@ -504,12 +532,14 @@ static void inode_switch_wbs(struct inode *inode, int new_wb_id)
 	 * Let's continue after I_WB_SWITCH is guaranteed to be visible.
 	 */
 	call_rcu(&isw->rcu_head, inode_switch_wbs_rcu_fn);
-	return;
+	goto out_unlock;
 
 out_free:
 	if (isw->new_wb)
 		wb_put(isw->new_wb);
 	kfree(isw);
+out_unlock:
+	up_read(&bdi->wb_switch_rwsem);
 }
 
 /**
@@ -887,6 +917,9 @@ fs_initcall(cgroup_writeback_init);
 
 #else	/* CONFIG_CGROUP_WRITEBACK */
 
+static void bdi_down_write_wb_switch_rwsem(struct backing_dev_info *bdi) { }
+static void bdi_up_write_wb_switch_rwsem(struct backing_dev_info *bdi) { }
+
 static struct bdi_writeback *
 locked_inode_to_wb_and_lock_list(struct inode *inode)
 	__releases(&inode->i_lock)
@@ -2413,8 +2446,11 @@ void sync_inodes_sb(struct super_block *sb)
 		return;
 	WARN_ON(!rwsem_is_locked(&sb->s_umount));
 
+	/* protect against inode wb switch, see inode_switch_wbs_work_fn() */
+	bdi_down_write_wb_switch_rwsem(bdi);
 	bdi_split_work_to_wbs(bdi, &work, false);
 	wb_wait_for_completion(bdi, &done);
+	bdi_up_write_wb_switch_rwsem(bdi);
 
 	wait_sb_inodes(sb);
 }
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 831d7cb5a49c..17a8d3b43990 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -1780,9 +1780,9 @@ static int gfs2_rbm_find(struct gfs2_rbm *rbm, u8 state, u32 *minext,
 			goto next_iter;
 		}
 		if (ret == -E2BIG) {
-			n += rbm->bii - initial_bii;
 			rbm->bii = 0;
 			rbm->offset = 0;
+			n += (rbm->bii - initial_bii);
 			goto res_covered_end_of_rgrp;
 		}
 		return ret;
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index 46d691ba04bc..45b2322e092d 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -133,15 +133,9 @@ static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
 				    struct file *file_out, loff_t pos_out,
 				    size_t count, unsigned int flags)
 {
-	ssize_t ret;
-
 	if (file_inode(file_in) == file_inode(file_out))
 		return -EINVAL;
-retry:
-	ret = nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
-	if (ret == -EAGAIN)
-		goto retry;
-	return ret;
+	return nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
 }
 
 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 22ce3c8a2f46..0570391eaa16 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1895,6 +1895,11 @@ static int nfs_parse_devname(const char *dev_name,
 	size_t len;
 	char *end;
 
+	if (unlikely(!dev_name || !*dev_name)) {
+		dfprintk(MOUNT, "NFS: device name not specified\n");
+		return -EINVAL;
+	}
+
 	/* Is the host name protected with square brakcets? */
 	if (*dev_name == '[') {
 		end = strchr(++dev_name, ']');
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 5a0bbf917a32..f12cb31a41e5 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -621,11 +621,12 @@ static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
 	nfs_set_page_writeback(page);
 	WARN_ON_ONCE(test_bit(PG_CLEAN, &req->wb_flags));
 
-	ret = 0;
+	ret = req->wb_context->error;
 	/* If there is a fatal error that covers this write, just exit */
-	if (nfs_error_is_fatal_on_server(req->wb_context->error))
+	if (nfs_error_is_fatal_on_server(ret))
 		goto out_launder;
 
+	ret = 0;
 	if (!nfs_pageio_add_request(pgio, req)) {
 		ret = pgio->pg_error;
 		/*
@@ -635,9 +636,9 @@ static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
 			nfs_context_set_write_error(req->wb_context, ret);
 			if (nfs_error_is_fatal_on_server(ret))
 				goto out_launder;
-		}
+		} else
+			ret = -EAGAIN;
 		nfs_redirty_request(req);
-		ret = -EAGAIN;
 	} else
 		nfs_add_stats(page_file_mapping(page)->host,
 				NFSIOS_WRITEPAGES, 1);
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 105576daca4a..798f1253141a 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -724,8 +724,10 @@ SYSCALL_DEFINE3(inotify_add_watch, int, fd, const char __user *, pathname,
 		return -EBADF;
 
 	/* IN_MASK_ADD and IN_MASK_CREATE don't make sense together */
-	if (unlikely((mask & IN_MASK_ADD) && (mask & IN_MASK_CREATE)))
-		return -EINVAL;
+	if (unlikely((mask & IN_MASK_ADD) && (mask & IN_MASK_CREATE))) {
+		ret = -EINVAL;
+		goto fput_and_out;
+	}
 
 	/* verify that this is indeed an inotify instance */
 	if (unlikely(f.file->f_op != &inotify_fops)) {
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 96f7d32cd184..898c8321b343 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -128,7 +128,6 @@ ramoops_get_next_prz(struct persistent_ram_zone *przs[], int id,
 		     struct pstore_record *record)
 {
 	struct persistent_ram_zone *prz;
-	bool update = (record->type == PSTORE_TYPE_DMESG);
 
 	/* Give up if we never existed or have hit the end. */
 	if (!przs)
@@ -139,7 +138,7 @@ ramoops_get_next_prz(struct persistent_ram_zone *przs[], int id,
 		return NULL;
 
 	/* Update old/shadowed buffer. */
-	if (update)
+	if (prz->type == PSTORE_TYPE_DMESG)
 		persistent_ram_save_old(prz);
 
 	if (!persistent_ram_old_size(prz))
@@ -711,18 +710,15 @@ static int ramoops_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct ramoops_platform_data *pdata = dev->platform_data;
+	struct ramoops_platform_data pdata_local;
 	struct ramoops_context *cxt = &oops_cxt;
 	size_t dump_mem_sz;
 	phys_addr_t paddr;
 	int err = -EINVAL;
 
 	if (dev_of_node(dev) && !pdata) {
-		pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
-		if (!pdata) {
-			pr_err("cannot allocate platform data buffer\n");
-			err = -ENOMEM;
-			goto fail_out;
-		}
+		pdata = &pdata_local;
+		memset(pdata, 0, sizeof(*pdata));
 
 		err = ramoops_parse_dt(pdev, pdata);
 		if (err < 0)