Commit 2be12ef7 authored by Nikolay Borisov's avatar Nikolay Borisov Committed by David Sterba
Browse files

btrfs: Separate space_info create/update 



Currently the struct space_info creation code is intermixed in the
udpate_space_info function. There are well-defined points at which the
we actually want to create brand-new space_info structs (e.g. during
mount of the filesystem as well as sometimes when adding/initialising
new chunks). In such cases update_space_info is called with 0 as the
bytes parameter. All of this makes for spaghetti code.

Fix it by factoring out the creation code in a separate
create_space_info structure. This also allows to simplify the internals.
Also remove BUG_ON from do_alloc_chunk since the callers handle errors.
Furthermore it will make the update_space_info function not fail,
allowing us to remove error handling in callers. This will come in a
follow up patch.

Signed-off-by: default avatarNikolay Borisov <nborisov@suse.com>
Reviewed-by: default avatarJeff Mahoney <jeffm@suse.com>
Reviewed-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 555ba411

fs/btrfs/extent-tree.c

+66 −66
Original line number Diff line number Diff line
@@ -3925,15 +3925,60 @@ static const char *alloc_name(u64 flags) 
	};

}



static int create_space_info(struct btrfs_fs_info *info, u64 flags,

			     struct btrfs_space_info **new)

{



	struct btrfs_space_info *space_info;

	int i;

	int ret;



	space_info = kzalloc(sizeof(*space_info), GFP_NOFS);

	if (!space_info)

		return -ENOMEM;



	ret = percpu_counter_init(&space_info->total_bytes_pinned, 0,

				 GFP_KERNEL);

	if (ret) {

		kfree(space_info);

		return ret;

	}



	for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)

		INIT_LIST_HEAD(&space_info->block_groups[i]);

	init_rwsem(&space_info->groups_sem);

	spin_lock_init(&space_info->lock);

	space_info->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;

	space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;

	init_waitqueue_head(&space_info->wait);

	INIT_LIST_HEAD(&space_info->ro_bgs);

	INIT_LIST_HEAD(&space_info->tickets);

	INIT_LIST_HEAD(&space_info->priority_tickets);



	ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,

				    info->space_info_kobj, "%s",

				    alloc_name(space_info->flags));

	if (ret) {

		percpu_counter_destroy(&space_info->total_bytes_pinned);

		kfree(space_info);

		return ret;

	}



	*new = space_info;

	list_add_rcu(&space_info->list, &info->space_info);

	if (flags & BTRFS_BLOCK_GROUP_DATA)

		info->data_sinfo = space_info;



	return ret;

}



static int update_space_info(struct btrfs_fs_info *info, u64 flags,

			     u64 total_bytes, u64 bytes_used,

			     u64 bytes_readonly,

			     struct btrfs_space_info **space_info)

{

	struct btrfs_space_info *found;

	int i;

	int factor;

	int ret;



	if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |

		     BTRFS_BLOCK_GROUP_RAID10))
@@ -3957,54 +4002,6 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags, 
		*space_info = found;

		return 0;

	}

	found = kzalloc(sizeof(*found), GFP_NOFS);

	if (!found)

		return -ENOMEM;



	ret = percpu_counter_init(&found->total_bytes_pinned, 0, GFP_KERNEL);

	if (ret) {

		kfree(found);

		return ret;

	}



	for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)

		INIT_LIST_HEAD(&found->block_groups[i]);

	init_rwsem(&found->groups_sem);

	spin_lock_init(&found->lock);

	found->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;

	found->total_bytes = total_bytes;

	found->disk_total = total_bytes * factor;

	found->bytes_used = bytes_used;

	found->disk_used = bytes_used * factor;

	found->bytes_pinned = 0;

	found->bytes_reserved = 0;

	found->bytes_readonly = bytes_readonly;

	found->bytes_may_use = 0;

	found->full = 0;

	found->max_extent_size = 0;

	found->force_alloc = CHUNK_ALLOC_NO_FORCE;

	found->chunk_alloc = 0;

	found->flush = 0;

	init_waitqueue_head(&found->wait);

	INIT_LIST_HEAD(&found->ro_bgs);

	INIT_LIST_HEAD(&found->tickets);

	INIT_LIST_HEAD(&found->priority_tickets);



	ret = kobject_init_and_add(&found->kobj, &space_info_ktype,

				    info->space_info_kobj, "%s",

				    alloc_name(found->flags));

	if (ret) {

		percpu_counter_destroy(&found->total_bytes_pinned);

		kfree(found);

		return ret;

	}



	*space_info = found;

	list_add_rcu(&found->list, &info->space_info);

	if (flags & BTRFS_BLOCK_GROUP_DATA)

		info->data_sinfo = found;



	return ret;

}



static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
@@ -4521,10 +4518,10 @@ static int do_chunk_alloc(struct btrfs_trans_handle *trans, 


	space_info = __find_space_info(fs_info, flags);

	if (!space_info) {

		ret = update_space_info(fs_info, flags, 0, 0, 0, &space_info);

		BUG_ON(ret); /* -ENOMEM */

		ret = create_space_info(fs_info, flags, &space_info);

		if (ret)

			return ret;

	}

	BUG_ON(!space_info); /* Logic error */



again:

	spin_lock(&space_info->lock);
@@ -10225,17 +10222,20 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, 
	}

#endif

	/*

	 * Call to ensure the corresponding space_info object is created and

	 * assigned to our block group, but don't update its counters just yet.

	 * We want our bg to be added to the rbtree with its ->space_info set.

	 * Ensure the corresponding space_info object is created and

	 * assigned to our block group. We want our bg to be added to the rbtree

	 * with its ->space_info set.

	 */

	ret = update_space_info(fs_info, cache->flags, 0, 0, 0,

	cache->space_info = __find_space_info(fs_info, cache->flags);

	if (!cache->space_info) {

		ret = create_space_info(fs_info, cache->flags,

				       &cache->space_info);

		if (ret) {

			btrfs_remove_free_space_cache(cache);

			btrfs_put_block_group(cache);

			return ret;

		}

	}



	ret = btrfs_add_block_group_cache(fs_info, cache);

	if (ret) {
@@ -10808,21 +10808,21 @@ int btrfs_init_space_info(struct btrfs_fs_info *fs_info) 
		mixed = 1;



	flags = BTRFS_BLOCK_GROUP_SYSTEM;

	ret = update_space_info(fs_info, flags, 0, 0, 0, &space_info);

	ret = create_space_info(fs_info, flags, &space_info);

	if (ret)

		goto out;



	if (mixed) {

		flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;

		ret = update_space_info(fs_info, flags, 0, 0, 0, &space_info);

		ret = create_space_info(fs_info, flags, &space_info);

	} else {

		flags = BTRFS_BLOCK_GROUP_METADATA;

		ret = update_space_info(fs_info, flags, 0, 0, 0, &space_info);

		ret = create_space_info(fs_info, flags, &space_info);

		if (ret)

			goto out;



		flags = BTRFS_BLOCK_GROUP_DATA;

		ret = update_space_info(fs_info, flags, 0, 0, 0, &space_info);

		ret = create_space_info(fs_info, flags, &space_info);

	}

out:

	return ret;

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