Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable

* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
Btrfs: fix panic when trying to destroy a newly allocated
Btrfs: allow more metadata chunk preallocation
Btrfs: fallback on uncompressed io if compressed io fails
Btrfs: find ideal block group for caching
Btrfs: avoid null deref in unpin_extent_cache()
Btrfs: skip btrfs_release_path in btrfs_update_root and btrfs_del_root
Btrfs: fix some metadata enospc issues
Btrfs: fix how we set max_size for free space clusters
Btrfs: cleanup transaction starting and fix journal_info usage
Btrfs: fix data allocation hint start

fs/btrfs/extent-tree.c

···
 
 	free_space = btrfs_super_total_bytes(disk_super);
 	/*
-	 * we allow the metadata to grow to a max of either 5gb or 5% of the
+	 * we allow the metadata to grow to a max of either 10gb or 5% of the
 	 * space in the volume.
 	 */
-	min_metadata = min((u64)5 * 1024 * 1024 * 1024,
+	min_metadata = min((u64)10 * 1024 * 1024 * 1024,
 			     div64_u64(free_space * 5, 100));
 	if (info->total_bytes >= min_metadata) {
 		spin_unlock(&info->lock);
···
 }
 
 enum btrfs_loop_type {
-	LOOP_CACHED_ONLY = 0,
+	LOOP_FIND_IDEAL = 0,
 	LOOP_CACHING_NOWAIT = 1,
 	LOOP_CACHING_WAIT = 2,
 	LOOP_ALLOC_CHUNK = 3,
···
 	struct btrfs_block_group_cache *block_group = NULL;
 	int empty_cluster = 2 * 1024 * 1024;
 	int allowed_chunk_alloc = 0;
+	int done_chunk_alloc = 0;
 	struct btrfs_space_info *space_info;
 	int last_ptr_loop = 0;
 	int loop = 0;
 	bool found_uncached_bg = false;
 	bool failed_cluster_refill = false;
 	bool failed_alloc = false;
+	u64 ideal_cache_percent = 0;
+	u64 ideal_cache_offset = 0;
 
 	WARN_ON(num_bytes < root->sectorsize);
 	btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
···
 		empty_cluster = 0;
 
 	if (search_start == hint_byte) {
+ideal_cache:
 		block_group = btrfs_lookup_block_group(root->fs_info,
 						       search_start);
 		/*
 		 * we don't want to use the block group if it doesn't match our
 		 * allocation bits, or if its not cached.
+		 *
+		 * However if we are re-searching with an ideal block group
+		 * picked out then we don't care that the block group is cached.
 		 */
 		if (block_group && block_group_bits(block_group, data) &&
-		    block_group_cache_done(block_group)) {
+		    (block_group->cached != BTRFS_CACHE_NO ||
+		     search_start == ideal_cache_offset)) {
 			down_read(&space_info->groups_sem);
 			if (list_empty(&block_group->list) ||
 			    block_group->ro) {
···
 				 */
 				btrfs_put_block_group(block_group);
 				up_read(&space_info->groups_sem);
-			} else
+			} else {
 				goto have_block_group;
+			}
 		} else if (block_group) {
 			btrfs_put_block_group(block_group);
 		}
 	}
-
 search:
 	down_read(&space_info->groups_sem);
 	list_for_each_entry(block_group, &space_info->block_groups, list) {
···
 
 have_block_group:
 		if (unlikely(block_group->cached == BTRFS_CACHE_NO)) {
+			u64 free_percent;
+
+			free_percent = btrfs_block_group_used(&block_group->item);
+			free_percent *= 100;
+			free_percent = div64_u64(free_percent,
+						 block_group->key.offset);
+			free_percent = 100 - free_percent;
+			if (free_percent > ideal_cache_percent &&
+			    likely(!block_group->ro)) {
+				ideal_cache_offset = block_group->key.objectid;
+				ideal_cache_percent = free_percent;
+			}
+
 			/*
-			 * we want to start caching kthreads, but not too many
-			 * right off the bat so we don't overwhelm the system,
-			 * so only start them if there are less than 2 and we're
-			 * in the initial allocation phase.
+			 * We only want to start kthread caching if we are at
+			 * the point where we will wait for caching to make
+			 * progress, or if our ideal search is over and we've
+			 * found somebody to start caching.
 			 */
 			if (loop > LOOP_CACHING_NOWAIT ||
-			    atomic_read(&space_info->caching_threads) < 2) {
+			    (loop > LOOP_FIND_IDEAL &&
+			     atomic_read(&space_info->caching_threads) < 2)) {
 				ret = cache_block_group(block_group);
 				BUG_ON(ret);
 			}
+			found_uncached_bg = true;
+
+			/*
+			 * If loop is set for cached only, try the next block
+			 * group.
+			 */
+			if (loop == LOOP_FIND_IDEAL)
+				goto loop;
 		}
 
 		cached = block_group_cache_done(block_group);
-		if (unlikely(!cached)) {
+		if (unlikely(!cached))
 			found_uncached_bg = true;
-
-			/* if we only want cached bgs, loop */
-			if (loop == LOOP_CACHED_ONLY)
-				goto loop;
-		}
 
 		if (unlikely(block_group->ro))
 			goto loop;
···
 	}
 	up_read(&space_info->groups_sem);
 
-	/* LOOP_CACHED_ONLY, only search fully cached block groups
-	 * LOOP_CACHING_NOWAIT, search partially cached block groups, but
-	 *			dont wait foR them to finish caching
+	/* LOOP_FIND_IDEAL, only search caching/cached bg's, and don't wait for
+	 *			for them to make caching progress.  Also
+	 *			determine the best possible bg to cache
+	 * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
+	 *			caching kthreads as we move along
 	 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
 	 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
 	 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
···
 	if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE &&
 	    (found_uncached_bg || empty_size || empty_cluster ||
 	     allowed_chunk_alloc)) {
-		if (found_uncached_bg) {
+		if (loop == LOOP_FIND_IDEAL && found_uncached_bg) {
 			found_uncached_bg = false;
-			if (loop < LOOP_CACHING_WAIT) {
-				loop++;
+			loop++;
+			if (!ideal_cache_percent &&
+			    atomic_read(&space_info->caching_threads))
 				goto search;
-			}
+
+			/*
+			 * 1 of the following 2 things have happened so far
+			 *
+			 * 1) We found an ideal block group for caching that
+			 * is mostly full and will cache quickly, so we might
+			 * as well wait for it.
+			 *
+			 * 2) We searched for cached only and we didn't find
+			 * anything, and we didn't start any caching kthreads
+			 * either, so chances are we will loop through and
+			 * start a couple caching kthreads, and then come back
+			 * around and just wait for them.  This will be slower
+			 * because we will have 2 caching kthreads reading at
+			 * the same time when we could have just started one
+			 * and waited for it to get far enough to give us an
+			 * allocation, so go ahead and go to the wait caching
+			 * loop.
+			 */
+			loop = LOOP_CACHING_WAIT;
+			search_start = ideal_cache_offset;
+			ideal_cache_percent = 0;
+			goto ideal_cache;
+		} else if (loop == LOOP_FIND_IDEAL) {
+			/*
+			 * Didn't find a uncached bg, wait on anything we find
+			 * next.
+			 */
+			loop = LOOP_CACHING_WAIT;
+			goto search;
+		}
+
+		if (loop < LOOP_CACHING_WAIT) {
+			loop++;
+			goto search;
 		}
 
 		if (loop == LOOP_ALLOC_CHUNK) {
···
 			ret = do_chunk_alloc(trans, root, num_bytes +
 					     2 * 1024 * 1024, data, 1);
 			allowed_chunk_alloc = 0;
-		} else {
+			done_chunk_alloc = 1;
+		} else if (!done_chunk_alloc) {
 			space_info->force_alloc = 1;
 		}
 

fs/btrfs/extent_map.c

···
 	write_lock(&tree->lock);
 	em = lookup_extent_mapping(tree, start, len);
 
-	WARN_ON(em->start != start || !em);
+	WARN_ON(!em || em->start != start);
 
 	if (!em)
 		goto out;

fs/btrfs/free-space-cache.c

···
 			window_start = entry->offset;
 			window_free = entry->bytes;
 			last = entry;
-			max_extent = 0;
+			max_extent = entry->bytes;
 		} else {
 			last = next;
 			window_free += next->bytes;

fs/btrfs/inode.c

···
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 	struct extent_io_tree *io_tree;
-	int ret;
+	int ret = 0;
 
 	if (list_empty(&async_cow->extents))
 		return 0;
···
 
 		io_tree = &BTRFS_I(inode)->io_tree;
 
+retry:
 		/* did the compression code fall back to uncompressed IO? */
 		if (!async_extent->pages) {
 			int page_started = 0;
···
 				    async_extent->ram_size - 1, GFP_NOFS);
 
 			/* allocate blocks */
-			cow_file_range(inode, async_cow->locked_page,
-				       async_extent->start,
-				       async_extent->start +
-				       async_extent->ram_size - 1,
-				       &page_started, &nr_written, 0);
+			ret = cow_file_range(inode, async_cow->locked_page,
+					     async_extent->start,
+					     async_extent->start +
+					     async_extent->ram_size - 1,
+					     &page_started, &nr_written, 0);
 
 			/*
 			 * if page_started, cow_file_range inserted an
···
 			 * and IO for us.  Otherwise, we need to submit
 			 * all those pages down to the drive.
 			 */
-			if (!page_started)
+			if (!page_started && !ret)
 				extent_write_locked_range(io_tree,
 						  inode, async_extent->start,
 						  async_extent->start +
···
 					   async_extent->compressed_size,
 					   0, alloc_hint,
 					   (u64)-1, &ins, 1);
-		BUG_ON(ret);
+		if (ret) {
+			int i;
+			for (i = 0; i < async_extent->nr_pages; i++) {
+				WARN_ON(async_extent->pages[i]->mapping);
+				page_cache_release(async_extent->pages[i]);
+			}
+			kfree(async_extent->pages);
+			async_extent->nr_pages = 0;
+			async_extent->pages = NULL;
+			unlock_extent(io_tree, async_extent->start,
+				      async_extent->start +
+				      async_extent->ram_size - 1, GFP_NOFS);
+			goto retry;
+		}
+
 		em = alloc_extent_map(GFP_NOFS);
 		em->start = async_extent->start;
 		em->len = async_extent->ram_size;
···
 	em = search_extent_mapping(&BTRFS_I(inode)->extent_tree,
 				   start, num_bytes);
 	if (em) {
-		alloc_hint = em->block_start;
-		free_extent_map(em);
+		/*
+		 * if block start isn't an actual block number then find the
+		 * first block in this inode and use that as a hint.  If that
+		 * block is also bogus then just don't worry about it.
+		 */
+		if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
+			free_extent_map(em);
+			em = search_extent_mapping(em_tree, 0, 0);
+			if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
+				alloc_hint = em->block_start;
+			if (em)
+				free_extent_map(em);
+		} else {
+			alloc_hint = em->block_start;
+			free_extent_map(em);
+		}
 	}
 	read_unlock(&BTRFS_I(inode)->extent_tree.lock);
 	btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
···
 
 	root = BTRFS_I(dir)->root;
 
+	/*
+	 * 5 items for unlink inode
+	 * 1 for orphan
+	 */
+	ret = btrfs_reserve_metadata_space(root, 6);
+	if (ret)
+		return ret;
+
 	trans = btrfs_start_transaction(root, 1);
+	if (IS_ERR(trans)) {
+		btrfs_unreserve_metadata_space(root, 6);
+		return PTR_ERR(trans);
+	}
 
 	btrfs_set_trans_block_group(trans, dir);
 
···
 	nr = trans->blocks_used;
 
 	btrfs_end_transaction_throttle(trans, root);
+	btrfs_unreserve_metadata_space(root, 6);
 	btrfs_btree_balance_dirty(root, nr);
 	return ret;
 }
···
 	    inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
 		return -ENOTEMPTY;
 
+	ret = btrfs_reserve_metadata_space(root, 5);
+	if (ret)
+		return ret;
+
 	trans = btrfs_start_transaction(root, 1);
+	if (IS_ERR(trans)) {
+		btrfs_unreserve_metadata_space(root, 5);
+		return PTR_ERR(trans);
+	}
+
 	btrfs_set_trans_block_group(trans, dir);
 
 	if (unlikely(inode->i_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
···
 out:
 	nr = trans->blocks_used;
 	ret = btrfs_end_transaction_throttle(trans, root);
+	btrfs_unreserve_metadata_space(root, 5);
 	btrfs_btree_balance_dirty(root, nr);
 
 	if (ret && !err)
···
 	ei->logged_trans = 0;
 	ei->outstanding_extents = 0;
 	ei->reserved_extents = 0;
+	ei->root = NULL;
 	spin_lock_init(&ei->accounting_lock);
 	btrfs_ordered_inode_tree_init(&ei->ordered_tree);
 	INIT_LIST_HEAD(&ei->i_orphan);
···
 
 	WARN_ON(!list_empty(&inode->i_dentry));
 	WARN_ON(inode->i_data.nrpages);
+
+	/*
+	 * This can happen where we create an inode, but somebody else also
+	 * created the same inode and we need to destroy the one we already
+	 * created.
+	 */
+	if (!root)
+		goto free;
 
 	/*
 	 * Make sure we're properly removed from the ordered operation
···
 	}
 	inode_tree_del(inode);
 	btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
+free:
 	kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
 }
 
···
 		return -ENOTEMPTY;
 
 	/*
-	 * 2 items for dir items
-	 * 1 item for orphan entry
-	 * 1 item for ref
+	 * We want to reserve the absolute worst case amount of items.  So if
+	 * both inodes are subvols and we need to unlink them then that would
+	 * require 4 item modifications, but if they are both normal inodes it
+	 * would require 5 item modifications, so we'll assume their normal
+	 * inodes.  So 5 * 2 is 10, plus 1 for the new link, so 11 total items
+	 * should cover the worst case number of items we'll modify.
 	 */
-	ret = btrfs_reserve_metadata_space(root, 4);
+	ret = btrfs_reserve_metadata_space(root, 11);
 	if (ret)
 		return ret;
 
···
 	if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
 		up_read(&root->fs_info->subvol_sem);
 
-	btrfs_unreserve_metadata_space(root, 4);
+	btrfs_unreserve_metadata_space(root, 11);
 	return ret;
 }
 

fs/btrfs/root-tree.c

···
 	write_extent_buffer(l, item, ptr, sizeof(*item));
 	btrfs_mark_buffer_dirty(path->nodes[0]);
 out:
-	btrfs_release_path(root, path);
 	btrfs_free_path(path);
 	return ret;
 }
···
 	BUG_ON(refs != 0);
 	ret = btrfs_del_item(trans, root, path);
 out:
-	btrfs_release_path(root, path);
 	btrfs_free_path(path);
 	return ret;
 }

fs/btrfs/transaction.c

···
 	}
 }
 
+enum btrfs_trans_type {
+	TRANS_START,
+	TRANS_JOIN,
+	TRANS_USERSPACE,
+};
+
 static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
-					     int num_blocks, int wait)
+					     int num_blocks, int type)
 {
 	struct btrfs_trans_handle *h =
 		kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
···
 
 	mutex_lock(&root->fs_info->trans_mutex);
 	if (!root->fs_info->log_root_recovering &&
-	    ((wait == 1 && !root->fs_info->open_ioctl_trans) || wait == 2))
+	    ((type == TRANS_START && !root->fs_info->open_ioctl_trans) ||
+	     type == TRANS_USERSPACE))
 		wait_current_trans(root);
 	ret = join_transaction(root);
 	BUG_ON(ret);
···
 	h->alloc_exclude_start = 0;
 	h->delayed_ref_updates = 0;
 
-	if (!current->journal_info)
+	if (!current->journal_info && type != TRANS_USERSPACE)
 		current->journal_info = h;
 
 	root->fs_info->running_transaction->use_count++;
···
 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
 						   int num_blocks)
 {
-	return start_transaction(root, num_blocks, 1);
+	return start_transaction(root, num_blocks, TRANS_START);
 }
 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root,
 						   int num_blocks)
 {
-	return start_transaction(root, num_blocks, 0);
+	return start_transaction(root, num_blocks, TRANS_JOIN);
 }
 
 struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *r,
 							 int num_blocks)
 {
-	return start_transaction(r, num_blocks, 2);
+	return start_transaction(r, num_blocks, TRANS_USERSPACE);
 }
 
 /* wait for a transaction commit to be fully complete */