Upgrade to 4.4.50-rt62

The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it
to 4.4.50-rt62.
The command to achieve it is:
a) Clone a git repo from
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

b) Get the diff between this two changesets:
git diff 640eca2901f3435e616157b11379d3223a44b391
705619beeea1b0b48219a683fd1a901a86fdaf5e

where the two commits are:
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
640eca2901f3435e616157b11379d3223a44b391
640eca2901f3 v4.4.6-rt14
localversion-rt
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
705619beeea1b0b48219a683fd1a901a86fdaf5e
705619beeea1 Linux 4.4.50-rt62
localversion-rt

c) One patch has been backported thus revert the patch before applying.

 filterdiff -p1 -x scripts/package/Makefile
~/tmp/v4.4.6-rt14-4.4.50-rt62.diff  |patch -p1 --dry-run

Upstream status: backport

Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

19 files changed, 317 insertions, 82 deletions

diff --git a/kernel/fs/btrfs/acl.c b/kernel/fs/btrfs/acl.c
index 9a0124a95..fb3e64d37 100644
--- a/kernel/fs/btrfs/acl.c
+++ b/kernel/fs/btrfs/acl.c
@@ -83,11 +83,9 @@ static int __btrfs_set_acl(struct btrfs_trans_handle *trans,
 	case ACL_TYPE_ACCESS:
 		name = POSIX_ACL_XATTR_ACCESS;
 		if (acl) {
-			ret = posix_acl_equiv_mode(acl, &inode->i_mode);
-			if (ret < 0)
+			ret = posix_acl_update_mode(inode, &inode->i_mode, &acl);
+			if (ret)
 				return ret;
-			if (ret == 0)
-				acl = NULL;
 		}
 		ret = 0;
 		break;
diff --git a/kernel/fs/btrfs/async-thread.c b/kernel/fs/btrfs/async-thread.c
index 9aba42b78..a09264d8b 100644
--- a/kernel/fs/btrfs/async-thread.c
+++ b/kernel/fs/btrfs/async-thread.c
@@ -70,6 +70,20 @@ void btrfs_##name(struct work_struct *arg)				\
 	normal_work_helper(work);					\
 }
 
+bool btrfs_workqueue_normal_congested(struct btrfs_workqueue *wq)
+{
+	/*
+	 * We could compare wq->normal->pending with num_online_cpus()
+	 * to support "thresh == NO_THRESHOLD" case, but it requires
+	 * moving up atomic_inc/dec in thresh_queue/exec_hook. Let's
+	 * postpone it until someone needs the support of that case.
+	 */
+	if (wq->normal->thresh == NO_THRESHOLD)
+		return false;
+
+	return atomic_read(&wq->normal->pending) > wq->normal->thresh * 2;
+}
+
 BTRFS_WORK_HELPER(worker_helper);
 BTRFS_WORK_HELPER(delalloc_helper);
 BTRFS_WORK_HELPER(flush_delalloc_helper);
diff --git a/kernel/fs/btrfs/async-thread.h b/kernel/fs/btrfs/async-thread.h
index ad4d0647d..8e1d6576d 100644
--- a/kernel/fs/btrfs/async-thread.h
+++ b/kernel/fs/btrfs/async-thread.h
@@ -80,4 +80,5 @@ void btrfs_queue_work(struct btrfs_workqueue *wq,
 void btrfs_destroy_workqueue(struct btrfs_workqueue *wq);
 void btrfs_workqueue_set_max(struct btrfs_workqueue *wq, int max);
 void btrfs_set_work_high_priority(struct btrfs_work *work);
+bool btrfs_workqueue_normal_congested(struct btrfs_workqueue *wq);
 #endif
diff --git a/kernel/fs/btrfs/compression.c b/kernel/fs/btrfs/compression.c
index c473c42d7..bae05c5c7 100644
--- a/kernel/fs/btrfs/compression.c
+++ b/kernel/fs/btrfs/compression.c
@@ -694,7 +694,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 			ret = btrfs_map_bio(root, READ, comp_bio,
 					    mirror_num, 0);
 			if (ret) {
-				bio->bi_error = ret;
+				comp_bio->bi_error = ret;
 				bio_endio(comp_bio);
 			}
 
@@ -723,7 +723,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 
 	ret = btrfs_map_bio(root, READ, comp_bio, mirror_num, 0);
 	if (ret) {
-		bio->bi_error = ret;
+		comp_bio->bi_error = ret;
 		bio_endio(comp_bio);
 	}
 
diff --git a/kernel/fs/btrfs/ctree.c b/kernel/fs/btrfs/ctree.c
index 5b8e235c4..0f2b7c622 100644
--- a/kernel/fs/btrfs/ctree.c
+++ b/kernel/fs/btrfs/ctree.c
@@ -1551,6 +1551,7 @@ noinline int btrfs_cow_block(struct btrfs_trans_handle *trans,
 		       trans->transid, root->fs_info->generation);
 
 	if (!should_cow_block(trans, root, buf)) {
+		trans->dirty = true;
 		*cow_ret = buf;
 		return 0;
 	}
@@ -2773,8 +2774,10 @@ again:
 			 * then we don't want to set the path blocking,
 			 * so we test it here
 			 */
-			if (!should_cow_block(trans, root, b))
+			if (!should_cow_block(trans, root, b)) {
+				trans->dirty = true;
 				goto cow_done;
+			}
 
 			/*
 			 * must have write locks on this node and the
diff --git a/kernel/fs/btrfs/ctree.h b/kernel/fs/btrfs/ctree.h
index 385b449fd..e847573c6 100644
--- a/kernel/fs/btrfs/ctree.h
+++ b/kernel/fs/btrfs/ctree.h
@@ -1770,6 +1770,7 @@ struct btrfs_fs_info {
 	struct btrfs_workqueue *qgroup_rescan_workers;
 	struct completion qgroup_rescan_completion;
 	struct btrfs_work qgroup_rescan_work;
+	bool qgroup_rescan_running;	/* protected by qgroup_rescan_lock */
 
 	/* filesystem state */
 	unsigned long fs_state;
@@ -3069,6 +3070,8 @@ btrfs_disk_balance_args_to_cpu(struct btrfs_balance_args *cpu,
 	cpu->target = le64_to_cpu(disk->target);
 	cpu->flags = le64_to_cpu(disk->flags);
 	cpu->limit = le64_to_cpu(disk->limit);
+	cpu->stripes_min = le32_to_cpu(disk->stripes_min);
+	cpu->stripes_max = le32_to_cpu(disk->stripes_max);
 }
 
 static inline void
@@ -3087,6 +3090,8 @@ btrfs_cpu_balance_args_to_disk(struct btrfs_disk_balance_args *disk,
 	disk->target = cpu_to_le64(cpu->target);
 	disk->flags = cpu_to_le64(cpu->flags);
 	disk->limit = cpu_to_le64(cpu->limit);
+	disk->stripes_min = cpu_to_le32(cpu->stripes_min);
+	disk->stripes_max = cpu_to_le32(cpu->stripes_max);
 }
 
 /* struct btrfs_super_block */
diff --git a/kernel/fs/btrfs/delayed-inode.c b/kernel/fs/btrfs/delayed-inode.c
index 02b934d0e..09fa5af97 100644
--- a/kernel/fs/btrfs/delayed-inode.c
+++ b/kernel/fs/btrfs/delayed-inode.c
@@ -1375,7 +1375,8 @@ release_path:
 	total_done++;
 
 	btrfs_release_prepared_delayed_node(delayed_node);
-	if (async_work->nr == 0 || total_done < async_work->nr)
+	if ((async_work->nr == 0 && total_done < BTRFS_DELAYED_WRITEBACK) ||
+	    total_done < async_work->nr)
 		goto again;
 
 free_path:
@@ -1391,7 +1392,8 @@ static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
 {
 	struct btrfs_async_delayed_work *async_work;
 
-	if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
+	if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND ||
+	    btrfs_workqueue_normal_congested(fs_info->delayed_workers))
 		return 0;
 
 	async_work = kmalloc(sizeof(*async_work), GFP_NOFS);
diff --git a/kernel/fs/btrfs/disk-io.c b/kernel/fs/btrfs/disk-io.c
index 41fb43183..85b207d19 100644
--- a/kernel/fs/btrfs/disk-io.c
+++ b/kernel/fs/btrfs/disk-io.c
@@ -2276,6 +2276,7 @@ static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
 	fs_info->quota_enabled = 0;
 	fs_info->pending_quota_state = 0;
 	fs_info->qgroup_ulist = NULL;
+	fs_info->qgroup_rescan_running = false;
 	mutex_init(&fs_info->qgroup_rescan_lock);
 }
 
@@ -3811,7 +3812,7 @@ void close_ctree(struct btrfs_root *root)
 	smp_mb();
 
 	/* wait for the qgroup rescan worker to stop */
-	btrfs_qgroup_wait_for_completion(fs_info);
+	btrfs_qgroup_wait_for_completion(fs_info, false);
 
 	/* wait for the uuid_scan task to finish */
 	down(&fs_info->uuid_tree_rescan_sem);
diff --git a/kernel/fs/btrfs/extent-tree.c b/kernel/fs/btrfs/extent-tree.c
index 2368cac11..2a2e37039 100644
--- a/kernel/fs/btrfs/extent-tree.c
+++ b/kernel/fs/btrfs/extent-tree.c
@@ -2520,11 +2520,11 @@ static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
 		if (ref && ref->seq &&
 		    btrfs_check_delayed_seq(fs_info, delayed_refs, ref->seq)) {
 			spin_unlock(&locked_ref->lock);
-			btrfs_delayed_ref_unlock(locked_ref);
 			spin_lock(&delayed_refs->lock);
 			locked_ref->processing = 0;
 			delayed_refs->num_heads_ready++;
 			spin_unlock(&delayed_refs->lock);
+			btrfs_delayed_ref_unlock(locked_ref);
 			locked_ref = NULL;
 			cond_resched();
 			count++;
@@ -2570,7 +2570,10 @@ static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
 					 */
 					if (must_insert_reserved)
 						locked_ref->must_insert_reserved = 1;
+					spin_lock(&delayed_refs->lock);
 					locked_ref->processing = 0;
+					delayed_refs->num_heads_ready++;
+					spin_unlock(&delayed_refs->lock);
 					btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret);
 					btrfs_delayed_ref_unlock(locked_ref);
 					return ret;
@@ -7856,7 +7859,7 @@ btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 		set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
 			 buf->start + buf->len - 1, GFP_NOFS);
 	}
-	trans->blocks_used++;
+	trans->dirty = true;
 	/* this returns a buffer locked for blocking */
 	return buf;
 }
@@ -8486,14 +8489,13 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
 	ret = btrfs_lookup_extent_info(trans, root, bytenr, level - 1, 1,
 				       &wc->refs[level - 1],
 				       &wc->flags[level - 1]);
-	if (ret < 0) {
-		btrfs_tree_unlock(next);
-		return ret;
-	}
+	if (ret < 0)
+		goto out_unlock;
 
 	if (unlikely(wc->refs[level - 1] == 0)) {
 		btrfs_err(root->fs_info, "Missing references.");
-		BUG();
+		ret = -EIO;
+		goto out_unlock;
 	}
 	*lookup_info = 0;
 
@@ -8545,7 +8547,12 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
 	}
 
 	level--;
-	BUG_ON(level != btrfs_header_level(next));
+	ASSERT(level == btrfs_header_level(next));
+	if (level != btrfs_header_level(next)) {
+		btrfs_err(root->fs_info, "mismatched level");
+		ret = -EIO;
+		goto out_unlock;
+	}
 	path->nodes[level] = next;
 	path->slots[level] = 0;
 	path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
@@ -8560,8 +8567,15 @@ skip:
 		if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
 			parent = path->nodes[level]->start;
 		} else {
-			BUG_ON(root->root_key.objectid !=
+			ASSERT(root->root_key.objectid ==
 			       btrfs_header_owner(path->nodes[level]));
+			if (root->root_key.objectid !=
+			    btrfs_header_owner(path->nodes[level])) {
+				btrfs_err(root->fs_info,
+						"mismatched block owner");
+				ret = -EIO;
+				goto out_unlock;
+			}
 			parent = 0;
 		}
 
@@ -8578,12 +8592,18 @@ skip:
 		}
 		ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
 				root->root_key.objectid, level - 1, 0);
-		BUG_ON(ret); /* -ENOMEM */
+		if (ret)
+			goto out_unlock;
 	}
+
+	*lookup_info = 1;
+	ret = 1;
+
+out_unlock:
 	btrfs_tree_unlock(next);
 	free_extent_buffer(next);
-	*lookup_info = 1;
-	return 1;
+
+	return ret;
 }
 
 /*
@@ -9686,6 +9706,11 @@ int btrfs_read_block_groups(struct btrfs_root *root)
 	struct extent_buffer *leaf;
 	int need_clear = 0;
 	u64 cache_gen;
+	u64 feature;
+	int mixed;
+
+	feature = btrfs_super_incompat_flags(info->super_copy);
+	mixed = !!(feature & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS);
 
 	root = info->extent_root;
 	key.objectid = 0;
@@ -9739,6 +9764,15 @@ int btrfs_read_block_groups(struct btrfs_root *root)
 				   btrfs_item_ptr_offset(leaf, path->slots[0]),
 				   sizeof(cache->item));
 		cache->flags = btrfs_block_group_flags(&cache->item);
+		if (!mixed &&
+		    ((cache->flags & BTRFS_BLOCK_GROUP_METADATA) &&
+		    (cache->flags & BTRFS_BLOCK_GROUP_DATA))) {
+			btrfs_err(info,
+"bg %llu is a mixed block group but filesystem hasn't enabled mixed block groups",
+				  cache->key.objectid);
+			ret = -EINVAL;
+			goto error;
+		}
 
 		key.objectid = found_key.objectid + found_key.offset;
 		btrfs_release_path(path);
diff --git a/kernel/fs/btrfs/extent_io.c b/kernel/fs/btrfs/extent_io.c
index 9abe18763..e767f347f 100644
--- a/kernel/fs/btrfs/extent_io.c
+++ b/kernel/fs/btrfs/extent_io.c
@@ -2786,12 +2786,6 @@ struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask)
 		btrfs_bio->csum = NULL;
 		btrfs_bio->csum_allocated = NULL;
 		btrfs_bio->end_io = NULL;
-
-#ifdef CONFIG_BLK_CGROUP
-		/* FIXME, put this into bio_clone_bioset */
-		if (bio->bi_css)
-			bio_associate_blkcg(new, bio->bi_css);
-#endif
 	}
 	return new;
 }
@@ -5300,11 +5294,20 @@ int read_extent_buffer_pages(struct extent_io_tree *tree,
 			lock_page(page);
 		}
 		locked_pages++;
+	}
+	/*
+	 * We need to firstly lock all pages to make sure that
+	 * the uptodate bit of our pages won't be affected by
+	 * clear_extent_buffer_uptodate().
+	 */
+	for (i = start_i; i < num_pages; i++) {
+		page = eb->pages[i];
 		if (!PageUptodate(page)) {
 			num_reads++;
 			all_uptodate = 0;
 		}
 	}
+
 	if (all_uptodate) {
 		if (start_i == 0)
 			set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
diff --git a/kernel/fs/btrfs/file.c b/kernel/fs/btrfs/file.c
index 0f09526aa..353f4bae6 100644
--- a/kernel/fs/btrfs/file.c
+++ b/kernel/fs/btrfs/file.c
@@ -1526,27 +1526,24 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
 
 		reserve_bytes = num_pages << PAGE_CACHE_SHIFT;
 
-		if (BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
-					     BTRFS_INODE_PREALLOC)) {
-			ret = check_can_nocow(inode, pos, &write_bytes);
-			if (ret < 0)
-				break;
-			if (ret > 0) {
-				/*
-				 * For nodata cow case, no need to reserve
-				 * data space.
-				 */
-				only_release_metadata = true;
-				/*
-				 * our prealloc extent may be smaller than
-				 * write_bytes, so scale down.
-				 */
-				num_pages = DIV_ROUND_UP(write_bytes + offset,
-							 PAGE_CACHE_SIZE);
-				reserve_bytes = num_pages << PAGE_CACHE_SHIFT;
-				goto reserve_metadata;
-			}
+		if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
+					      BTRFS_INODE_PREALLOC)) &&
+		    check_can_nocow(inode, pos, &write_bytes) > 0) {
+			/*
+			 * For nodata cow case, no need to reserve
+			 * data space.
+			 */
+			only_release_metadata = true;
+			/*
+			 * our prealloc extent may be smaller than
+			 * write_bytes, so scale down.
+			 */
+			num_pages = DIV_ROUND_UP(write_bytes + offset,
+						 PAGE_CACHE_SIZE);
+			reserve_bytes = num_pages << PAGE_CACHE_SHIFT;
+			goto reserve_metadata;
 		}
+
 		ret = btrfs_check_data_free_space(inode, pos, write_bytes);
 		if (ret < 0)
 			break;
@@ -1885,7 +1882,7 @@ static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end)
  */
 int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 {
-	struct dentry *dentry = file->f_path.dentry;
+	struct dentry *dentry = file_dentry(file);
 	struct inode *inode = d_inode(dentry);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_trans_handle *trans;
diff --git a/kernel/fs/btrfs/inode.c b/kernel/fs/btrfs/inode.c
index 4bc9dbf29..3cff6523f 100644
--- a/kernel/fs/btrfs/inode.c
+++ b/kernel/fs/btrfs/inode.c
@@ -8691,9 +8691,14 @@ static void btrfs_invalidatepage(struct page *page, unsigned int offset,
 	 *    So even we call qgroup_free_data(), it won't decrease reserved
 	 *    space.
 	 * 2) Not written to disk
-	 *    This means the reserved space should be freed here.
+	 *    This means the reserved space should be freed here. However,
+	 *    if a truncate invalidates the page (by clearing PageDirty)
+	 *    and the page is accounted for while allocating extent
+	 *    in btrfs_check_data_free_space() we let delayed_ref to
+	 *    free the entire extent.
 	 */
-	btrfs_qgroup_free_data(inode, page_start, PAGE_CACHE_SIZE);
+	if (PageDirty(page))
+		btrfs_qgroup_free_data(inode, page_start, PAGE_SIZE);
 	if (!inode_evicting) {
 		clear_extent_bit(tree, page_start, page_end,
 				 EXTENT_LOCKED | EXTENT_DIRTY |
diff --git a/kernel/fs/btrfs/ioctl.c b/kernel/fs/btrfs/ioctl.c
index f07d01bc4..317b99acd 100644
--- a/kernel/fs/btrfs/ioctl.c
+++ b/kernel/fs/btrfs/ioctl.c
@@ -1619,6 +1619,9 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
 	int namelen;
 	int ret = 0;
 
+	if (!S_ISDIR(file_inode(file)->i_mode))
+		return -ENOTDIR;
+
 	ret = mnt_want_write_file(file);
 	if (ret)
 		goto out;
@@ -1648,7 +1651,7 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
 
 		src_inode = file_inode(src.file);
 		if (src_inode->i_sb != file_inode(file)->i_sb) {
-			btrfs_info(BTRFS_I(src_inode)->root->fs_info,
+			btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
 				   "Snapshot src from another FS");
 			ret = -EXDEV;
 		} else if (!inode_owner_or_capable(src_inode)) {
@@ -1676,6 +1679,9 @@ static noinline int btrfs_ioctl_snap_create(struct file *file,
 	struct btrfs_ioctl_vol_args *vol_args;
 	int ret;
 
+	if (!S_ISDIR(file_inode(file)->i_mode))
+		return -ENOTDIR;
+
 	vol_args = memdup_user(arg, sizeof(*vol_args));
 	if (IS_ERR(vol_args))
 		return PTR_ERR(vol_args);
@@ -1699,6 +1705,9 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
 	bool readonly = false;
 	struct btrfs_qgroup_inherit *inherit = NULL;
 
+	if (!S_ISDIR(file_inode(file)->i_mode))
+		return -ENOTDIR;
+
 	vol_args = memdup_user(arg, sizeof(*vol_args));
 	if (IS_ERR(vol_args))
 		return PTR_ERR(vol_args);
@@ -2345,6 +2354,9 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 	int ret;
 	int err = 0;
 
+	if (!S_ISDIR(dir->i_mode))
+		return -ENOTDIR;
+
 	vol_args = memdup_user(arg, sizeof(*vol_args));
 	if (IS_ERR(vol_args))
 		return PTR_ERR(vol_args);
@@ -3813,6 +3825,11 @@ process_slot:
 		}
 		btrfs_release_path(path);
 		key.offset = next_key_min_offset;
+
+		if (fatal_signal_pending(current)) {
+			ret = -EINTR;
+			goto out;
+		}
 	}
 	ret = 0;
 
@@ -5121,7 +5138,7 @@ static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	return btrfs_qgroup_wait_for_completion(root->fs_info);
+	return btrfs_qgroup_wait_for_completion(root->fs_info, true);
 }
 
 static long _btrfs_ioctl_set_received_subvol(struct file *file,
diff --git a/kernel/fs/btrfs/qgroup.c b/kernel/fs/btrfs/qgroup.c
index 5279fdae7..88d9b66e2 100644
--- a/kernel/fs/btrfs/qgroup.c
+++ b/kernel/fs/btrfs/qgroup.c
@@ -995,7 +995,7 @@ int btrfs_quota_disable(struct btrfs_trans_handle *trans,
 		goto out;
 	fs_info->quota_enabled = 0;
 	fs_info->pending_quota_state = 0;
-	btrfs_qgroup_wait_for_completion(fs_info);
+	btrfs_qgroup_wait_for_completion(fs_info, false);
 	spin_lock(&fs_info->qgroup_lock);
 	quota_root = fs_info->quota_root;
 	fs_info->quota_root = NULL;
@@ -2349,6 +2349,9 @@ out:
 	}
 
 done:
+	mutex_lock(&fs_info->qgroup_rescan_lock);
+	fs_info->qgroup_rescan_running = false;
+	mutex_unlock(&fs_info->qgroup_rescan_lock);
 	complete_all(&fs_info->qgroup_rescan_completion);
 }
 
@@ -2390,6 +2393,7 @@ qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
 		sizeof(fs_info->qgroup_rescan_progress));
 	fs_info->qgroup_rescan_progress.objectid = progress_objectid;
 	init_completion(&fs_info->qgroup_rescan_completion);
+	fs_info->qgroup_rescan_running = true;
 
 	spin_unlock(&fs_info->qgroup_lock);
 	mutex_unlock(&fs_info->qgroup_rescan_lock);
@@ -2467,20 +2471,26 @@ btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
 	return 0;
 }
 
-int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info)
+int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
+				     bool interruptible)
 {
 	int running;
 	int ret = 0;
 
 	mutex_lock(&fs_info->qgroup_rescan_lock);
 	spin_lock(&fs_info->qgroup_lock);
-	running = fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN;
+	running = fs_info->qgroup_rescan_running;
 	spin_unlock(&fs_info->qgroup_lock);
 	mutex_unlock(&fs_info->qgroup_rescan_lock);
 
-	if (running)
+	if (!running)
+		return 0;
+
+	if (interruptible)
 		ret = wait_for_completion_interruptible(
 					&fs_info->qgroup_rescan_completion);
+	else
+		wait_for_completion(&fs_info->qgroup_rescan_completion);
 
 	return ret;
 }
diff --git a/kernel/fs/btrfs/qgroup.h b/kernel/fs/btrfs/qgroup.h
index ecb2c143e..3d73e4c9c 100644
--- a/kernel/fs/btrfs/qgroup.h
+++ b/kernel/fs/btrfs/qgroup.h
@@ -46,7 +46,8 @@ int btrfs_quota_disable(struct btrfs_trans_handle *trans,
 			struct btrfs_fs_info *fs_info);
 int btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info);
 void btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info);
-int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info);
+int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
+				     bool interruptible);
 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
 			      struct btrfs_fs_info *fs_info, u64 src, u64 dst);
 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
diff --git a/kernel/fs/btrfs/relocation.c b/kernel/fs/btrfs/relocation.c
index b4ca5454e..8ca9aa929 100644
--- a/kernel/fs/btrfs/relocation.c
+++ b/kernel/fs/btrfs/relocation.c
@@ -921,9 +921,16 @@ again:
 			path2->slots[level]--;
 
 		eb = path2->nodes[level];
-		WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) !=
-			cur->bytenr);
-
+		if (btrfs_node_blockptr(eb, path2->slots[level]) !=
+		    cur->bytenr) {
+			btrfs_err(root->fs_info,
+	"couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)",
+				  cur->bytenr, level - 1, root->objectid,
+				  node_key->objectid, node_key->type,
+				  node_key->offset);
+			err = -ENOENT;
+			goto out;
+		}
 		lower = cur;
 		need_check = true;
 		for (; level < BTRFS_MAX_LEVEL; level++) {
@@ -2343,6 +2350,10 @@ void free_reloc_roots(struct list_head *list)
 	while (!list_empty(list)) {
 		reloc_root = list_entry(list->next, struct btrfs_root,
 					root_list);
+		free_extent_buffer(reloc_root->node);
+		free_extent_buffer(reloc_root->commit_root);
+		reloc_root->node = NULL;
+		reloc_root->commit_root = NULL;
 		__del_reloc_root(reloc_root);
 	}
 }
@@ -2676,11 +2687,15 @@ static int do_relocation(struct btrfs_trans_handle *trans,
 
 		if (!upper->eb) {
 			ret = btrfs_search_slot(trans, root, key, path, 0, 1);
-			if (ret < 0) {
-				err = ret;
+			if (ret) {
+				if (ret < 0)
+					err = ret;
+				else
+					err = -ENOENT;
+
+				btrfs_release_path(path);
 				break;
 			}
-			BUG_ON(ret > 0);
 
 			if (!upper->eb) {
 				upper->eb = path->nodes[upper->level];
diff --git a/kernel/fs/btrfs/super.c b/kernel/fs/btrfs/super.c
index fe609b81d..5d34a062c 100644
--- a/kernel/fs/btrfs/super.c
+++ b/kernel/fs/btrfs/super.c
@@ -239,7 +239,7 @@ void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
 	trans->aborted = errno;
 	/* Nothing used. The other threads that have joined this
 	 * transaction may be able to continue. */
-	if (!trans->blocks_used && list_empty(&trans->new_bgs)) {
+	if (!trans->dirty && list_empty(&trans->new_bgs)) {
 		const char *errstr;
 
 		errstr = btrfs_decode_error(errno);
diff --git a/kernel/fs/btrfs/transaction.h b/kernel/fs/btrfs/transaction.h
index 64c8221b6..1e872923e 100644
--- a/kernel/fs/btrfs/transaction.h
+++ b/kernel/fs/btrfs/transaction.h
@@ -110,7 +110,6 @@ struct btrfs_trans_handle {
 	u64 chunk_bytes_reserved;
 	unsigned long use_count;
 	unsigned long blocks_reserved;
-	unsigned long blocks_used;
 	unsigned long delayed_ref_updates;
 	struct btrfs_transaction *transaction;
 	struct btrfs_block_rsv *block_rsv;
@@ -121,6 +120,7 @@ struct btrfs_trans_handle {
 	bool can_flush_pending_bgs;
 	bool reloc_reserved;
 	bool sync;
+	bool dirty;
 	unsigned int type;
 	/*
 	 * this root is only needed to validate that the root passed to
diff --git a/kernel/fs/btrfs/tree-log.c b/kernel/fs/btrfs/tree-log.c
index 323e12cc9..ee7832e2d 100644
--- a/kernel/fs/btrfs/tree-log.c
+++ b/kernel/fs/btrfs/tree-log.c
@@ -1923,12 +1923,11 @@ static noinline int find_dir_range(struct btrfs_root *root,
 next:
 	/* check the next slot in the tree to see if it is a valid item */
 	nritems = btrfs_header_nritems(path->nodes[0]);
+	path->slots[0]++;
 	if (path->slots[0] >= nritems) {
 		ret = btrfs_next_leaf(root, path);
 		if (ret)
 			goto out;
-	} else {
-		path->slots[0]++;
 	}
 
 	btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
@@ -2696,14 +2695,12 @@ static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root,
 					     int index, int error)
 {
 	struct btrfs_log_ctx *ctx;
+	struct btrfs_log_ctx *safe;
 
-	if (!error) {
-		INIT_LIST_HEAD(&root->log_ctxs[index]);
-		return;
-	}
-
-	list_for_each_entry(ctx, &root->log_ctxs[index], list)
+	list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) {
+		list_del_init(&ctx->list);
 		ctx->log_ret = error;
+	}
 
 	INIT_LIST_HEAD(&root->log_ctxs[index]);
 }
@@ -2850,6 +2847,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 
 	if (log_root_tree->log_transid_committed >= root_log_ctx.log_transid) {
 		blk_finish_plug(&plug);
+		list_del_init(&root_log_ctx.list);
 		mutex_unlock(&log_root_tree->log_mutex);
 		ret = root_log_ctx.log_ret;
 		goto out;
@@ -2943,13 +2941,9 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 	mutex_unlock(&root->log_mutex);
 
 out_wake_log_root:
-	/*
-	 * We needn't get log_mutex here because we are sure all
-	 * the other tasks are blocked.
-	 */
+	mutex_lock(&log_root_tree->log_mutex);
 	btrfs_remove_all_log_ctxs(log_root_tree, index2, ret);
 
-	mutex_lock(&log_root_tree->log_mutex);
 	log_root_tree->log_transid_committed++;
 	atomic_set(&log_root_tree->log_commit[index2], 0);
 	mutex_unlock(&log_root_tree->log_mutex);
@@ -2960,10 +2954,8 @@ out_wake_log_root:
 	if (waitqueue_active(&log_root_tree->log_commit_wait[index2]))
 		wake_up(&log_root_tree->log_commit_wait[index2]);
 out:
-	/* See above. */
-	btrfs_remove_all_log_ctxs(root, index1, ret);
-
 	mutex_lock(&root->log_mutex);
+	btrfs_remove_all_log_ctxs(root, index1, ret);
 	root->log_transid_committed++;
 	atomic_set(&root->log_commit[index1], 0);
 	mutex_unlock(&root->log_mutex);
@@ -4406,6 +4398,127 @@ static int btrfs_log_trailing_hole(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
+/*
+ * When we are logging a new inode X, check if it doesn't have a reference that
+ * matches the reference from some other inode Y created in a past transaction
+ * and that was renamed in the current transaction. If we don't do this, then at
+ * log replay time we can lose inode Y (and all its files if it's a directory):
+ *
+ * mkdir /mnt/x
+ * echo "hello world" > /mnt/x/foobar
+ * sync
+ * mv /mnt/x /mnt/y
+ * mkdir /mnt/x                 # or touch /mnt/x
+ * xfs_io -c fsync /mnt/x
+ * <power fail>
+ * mount fs, trigger log replay
+ *
+ * After the log replay procedure, we would lose the first directory and all its
+ * files (file foobar).
+ * For the case where inode Y is not a directory we simply end up losing it:
+ *
+ * echo "123" > /mnt/foo
+ * sync
+ * mv /mnt/foo /mnt/bar
+ * echo "abc" > /mnt/foo
+ * xfs_io -c fsync /mnt/foo
+ * <power fail>
+ *
+ * We also need this for cases where a snapshot entry is replaced by some other
+ * entry (file or directory) otherwise we end up with an unreplayable log due to
+ * attempts to delete the snapshot entry (entry of type BTRFS_ROOT_ITEM_KEY) as
+ * if it were a regular entry:
+ *
+ * mkdir /mnt/x
+ * btrfs subvolume snapshot /mnt /mnt/x/snap
+ * btrfs subvolume delete /mnt/x/snap
+ * rmdir /mnt/x
+ * mkdir /mnt/x
+ * fsync /mnt/x or fsync some new file inside it
+ * <power fail>
+ *
+ * The snapshot delete, rmdir of x, mkdir of a new x and the fsync all happen in
+ * the same transaction.
+ */
+static int btrfs_check_ref_name_override(struct extent_buffer *eb,
+					 const int slot,
+					 const struct btrfs_key *key,
+					 struct inode *inode)
+{
+	int ret;
+	struct btrfs_path *search_path;
+	char *name = NULL;
+	u32 name_len = 0;
+	u32 item_size = btrfs_item_size_nr(eb, slot);
+	u32 cur_offset = 0;
+	unsigned long ptr = btrfs_item_ptr_offset(eb, slot);
+
+	search_path = btrfs_alloc_path();
+	if (!search_path)
+		return -ENOMEM;
+	search_path->search_commit_root = 1;
+	search_path->skip_locking = 1;
+
+	while (cur_offset < item_size) {
+		u64 parent;
+		u32 this_name_len;
+		u32 this_len;
+		unsigned long name_ptr;
+		struct btrfs_dir_item *di;
+
+		if (key->type == BTRFS_INODE_REF_KEY) {
+			struct btrfs_inode_ref *iref;
+
+			iref = (struct btrfs_inode_ref *)(ptr + cur_offset);
+			parent = key->offset;
+			this_name_len = btrfs_inode_ref_name_len(eb, iref);
+			name_ptr = (unsigned long)(iref + 1);
+			this_len = sizeof(*iref) + this_name_len;
+		} else {
+			struct btrfs_inode_extref *extref;
+
+			extref = (struct btrfs_inode_extref *)(ptr +
+							       cur_offset);
+			parent = btrfs_inode_extref_parent(eb, extref);
+			this_name_len = btrfs_inode_extref_name_len(eb, extref);
+			name_ptr = (unsigned long)&extref->name;
+			this_len = sizeof(*extref) + this_name_len;
+		}
+
+		if (this_name_len > name_len) {
+			char *new_name;
+
+			new_name = krealloc(name, this_name_len, GFP_NOFS);
+			if (!new_name) {
+				ret = -ENOMEM;
+				goto out;
+			}
+			name_len = this_name_len;
+			name = new_name;
+		}
+
+		read_extent_buffer(eb, name, name_ptr, this_name_len);
+		di = btrfs_lookup_dir_item(NULL, BTRFS_I(inode)->root,
+					   search_path, parent,
+					   name, this_name_len, 0);
+		if (di && !IS_ERR(di)) {
+			ret = 1;
+			goto out;
+		} else if (IS_ERR(di)) {
+			ret = PTR_ERR(di);
+			goto out;
+		}
+		btrfs_release_path(search_path);
+
+		cur_offset += this_len;
+	}
+	ret = 0;
+out:
+	btrfs_free_path(search_path);
+	kfree(name);
+	return ret;
+}
+
 /* log a single inode in the tree log.
  * At least one parent directory for this inode must exist in the tree
  * or be logged already.
@@ -4578,6 +4691,22 @@ again:
 		if (min_key.type == BTRFS_INODE_ITEM_KEY)
 			need_log_inode_item = false;
 
+		if ((min_key.type == BTRFS_INODE_REF_KEY ||
+		     min_key.type == BTRFS_INODE_EXTREF_KEY) &&
+		    BTRFS_I(inode)->generation == trans->transid) {
+			ret = btrfs_check_ref_name_override(path->nodes[0],
+							    path->slots[0],
+							    &min_key, inode);
+			if (ret < 0) {
+				err = ret;
+				goto out_unlock;
+			} else if (ret > 0) {
+				err = 1;
+				btrfs_set_log_full_commit(root->fs_info, trans);
+				goto out_unlock;
+			}
+		}
+
 		/* Skip xattrs, we log them later with btrfs_log_all_xattrs() */
 		if (min_key.type == BTRFS_XATTR_ITEM_KEY) {
 			if (ins_nr == 0)