Commit 73fa48b6 authored by Omar Sandoval's avatar Omar Sandoval Committed by Chris Mason
Browse files

Btrfs: refactor caching_thread() 



We're also going to load the free space tree from caching_thread(), so
we should refactor some of the common code.

Signed-off-by: default avatarOmar Sandoval <osandov@fb.com>
Signed-off-by: default avatarChris Mason <clm@fb.com>
parent 1abfbcdf

fs/btrfs/ctree.h

+3 −0
Original line number Diff line number Diff line
@@ -1262,6 +1262,9 @@ struct btrfs_caching_control { 
	atomic_t count;

};



/* Once caching_thread() finds this much free space, it will wake up waiters. */

#define CACHING_CTL_WAKE_UP (1024 * 1024 * 2)



struct btrfs_io_ctl {

	void *cur, *orig;

	struct page *page;

fs/btrfs/extent-tree.c

+33 −26
Original line number Diff line number Diff line
@@ -375,11 +375,10 @@ static u64 add_new_free_space(struct btrfs_block_group_cache *block_group, 
	return total_added;

}



static noinline void caching_thread(struct btrfs_work *work)

static int load_extent_tree_free(struct btrfs_caching_control *caching_ctl)

{

	struct btrfs_block_group_cache *block_group;

	struct btrfs_fs_info *fs_info;

	struct btrfs_caching_control *caching_ctl;

	struct btrfs_root *extent_root;

	struct btrfs_path *path;

	struct extent_buffer *leaf;
@@ -387,16 +386,15 @@ static noinline void caching_thread(struct btrfs_work *work) 
	u64 total_found = 0;

	u64 last = 0;

	u32 nritems;

	int ret = -ENOMEM;

	int ret;



	caching_ctl = container_of(work, struct btrfs_caching_control, work);

	block_group = caching_ctl->block_group;

	fs_info = block_group->fs_info;

	extent_root = fs_info->extent_root;



	path = btrfs_alloc_path();

	if (!path)

		goto out;

		return -ENOMEM;



	last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
@@ -413,15 +411,11 @@ static noinline void caching_thread(struct btrfs_work *work) 
	key.objectid = last;

	key.offset = 0;

	key.type = BTRFS_EXTENT_ITEM_KEY;

again:

	mutex_lock(&caching_ctl->mutex);

	/* need to make sure the commit_root doesn't disappear */

	down_read(&fs_info->commit_root_sem);



next:

	ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);

	if (ret < 0)

		goto err;

		goto out;



	leaf = path->nodes[0];

	nritems = btrfs_header_nritems(leaf);
@@ -446,12 +440,14 @@ static noinline void caching_thread(struct btrfs_work *work) 
				up_read(&fs_info->commit_root_sem);

				mutex_unlock(&caching_ctl->mutex);

				cond_resched();

				goto again;

				mutex_lock(&caching_ctl->mutex);

				down_read(&fs_info->commit_root_sem);

				goto next;

			}



			ret = btrfs_next_leaf(extent_root, path);

			if (ret < 0)

				goto err;

				goto out;

			if (ret)

				break;

			leaf = path->nodes[0];
@@ -489,7 +485,7 @@ static noinline void caching_thread(struct btrfs_work *work) 
			else

				last = key.objectid + key.offset;



			if (total_found > (1024 * 1024 * 2)) {

			if (total_found > CACHING_CTL_WAKE_UP) {

				total_found = 0;

				wake_up(&caching_ctl->wait);

			}
@@ -503,25 +499,36 @@ static noinline void caching_thread(struct btrfs_work *work) 
					  block_group->key.offset);

	caching_ctl->progress = (u64)-1;



	spin_lock(&block_group->lock);

	block_group->caching_ctl = NULL;

	block_group->cached = BTRFS_CACHE_FINISHED;

	spin_unlock(&block_group->lock);



err:

out:

	btrfs_free_path(path);

	up_read(&fs_info->commit_root_sem);

	return ret;

}



	free_excluded_extents(extent_root, block_group);

static noinline void caching_thread(struct btrfs_work *work)

{

	struct btrfs_block_group_cache *block_group;

	struct btrfs_fs_info *fs_info;

	struct btrfs_caching_control *caching_ctl;

	int ret;



	caching_ctl = container_of(work, struct btrfs_caching_control, work);

	block_group = caching_ctl->block_group;

	fs_info = block_group->fs_info;



	mutex_lock(&caching_ctl->mutex);

	down_read(&fs_info->commit_root_sem);



	ret = load_extent_tree_free(caching_ctl);



	mutex_unlock(&caching_ctl->mutex);

out:

	if (ret) {

	spin_lock(&block_group->lock);

	block_group->caching_ctl = NULL;

		block_group->cached = BTRFS_CACHE_ERROR;

	block_group->cached = ret ? BTRFS_CACHE_ERROR : BTRFS_CACHE_FINISHED;

	spin_unlock(&block_group->lock);

	}



	up_read(&fs_info->commit_root_sem);

	free_excluded_extents(fs_info->extent_root, block_group);

	mutex_unlock(&caching_ctl->mutex);



	wake_up(&caching_ctl->wait);



	put_caching_control(caching_ctl);