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Commit e0c476b1 authored by Jeff Mahoney's avatar Jeff Mahoney Committed by David Sterba
Browse files

btrfs: backref, cleanup __ namespace abuse 



We typically use __ to indicate a helper routine that shouldn't be
called directly without understanding the proper context required
to do so.  We use static functions to indicate that a function is
private to a particular C file.  The backref code uses static
function and __ prefixes on nearly everything, which makes the code
difficult to read and establishes a pattern for future code that
shouldn't be followed.  This patch drops all the unnecessary prefixes.

Signed-off-by: default avatarJeff Mahoney <jeffm@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 4dae077a

fs/btrfs/backref.c

+109 −116
Original line number Diff line number Diff line
@@ -387,7 +387,7 @@ static int find_extent_in_eb(const struct extent_buffer *eb, 
/*

 * this structure records all encountered refs on the way up to the root

 */

struct __prelim_ref {

struct prelim_ref {

	struct list_head list;

	u64 root_id;

	struct btrfs_key key_for_search;
@@ -403,7 +403,7 @@ static struct kmem_cache *btrfs_prelim_ref_cache; 
int __init btrfs_prelim_ref_init(void)

{

	btrfs_prelim_ref_cache = kmem_cache_create("btrfs_prelim_ref",

					sizeof(struct __prelim_ref),

					sizeof(struct prelim_ref),

					0,

					SLAB_MEM_SPREAD,

					NULL);
@@ -449,19 +449,17 @@ void btrfs_prelim_ref_exit(void) 
 *

 * - column 1, 3: we've the parent -> done

 * - column 2:    we take the first key from the block to find the parent

 *                (see __add_missing_keys)

 *                (see add_missing_keys)

 * - column 4:    we use the key to find the parent

 *

 * additional information that's available but not required to find the parent

 * block might help in merging entries to gain some speed.

 */



static int __add_prelim_ref(struct list_head *head, u64 root_id,

			    const struct btrfs_key *key, int level,

			    u64 parent, u64 wanted_disk_byte, int count,

			    gfp_t gfp_mask)

static int add_prelim_ref(struct list_head *head, u64 root_id,

			  const struct btrfs_key *key, int level, u64 parent,

			  u64 wanted_disk_byte, int count, gfp_t gfp_mask)

{

	struct __prelim_ref *ref;

	struct prelim_ref *ref;



	if (root_id == BTRFS_DATA_RELOC_TREE_OBJECTID)

		return 0;
@@ -510,7 +508,7 @@ static int __add_prelim_ref(struct list_head *head, u64 root_id, 
}



static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,

			   struct ulist *parents, struct __prelim_ref *ref,

			   struct ulist *parents, struct prelim_ref *ref,

			   int level, u64 time_seq, const u64 *extent_item_pos,

			   u64 total_refs)

{
@@ -600,10 +598,9 @@ static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, 
 * resolve an indirect backref in the form (root_id, key, level)

 * to a logical address

 */

static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,

static int resolve_indirect_ref(struct btrfs_fs_info *fs_info,

				struct btrfs_path *path, u64 time_seq,

				  struct __prelim_ref *ref,

				  struct ulist *parents,

				struct prelim_ref *ref, struct ulist *parents,

				const u64 *extent_item_pos, u64 total_refs)

{

	struct btrfs_root *root;
@@ -693,7 +690,7 @@ unode_aux_to_inode_list(struct ulist_node *node) 
/*

 * resolve all indirect backrefs from the list

 */

static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,

static int resolve_indirect_refs(struct btrfs_fs_info *fs_info,

				 struct btrfs_path *path, u64 time_seq,

				 struct list_head *head,

				 const u64 *extent_item_pos, u64 total_refs,
@@ -701,9 +698,9 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, 
{

	int err;

	int ret = 0;

	struct __prelim_ref *ref;

	struct __prelim_ref *ref_safe;

	struct __prelim_ref *new_ref;

	struct prelim_ref *ref;

	struct prelim_ref *ref_safe;

	struct prelim_ref *new_ref;

	struct ulist *parents;

	struct ulist_node *node;

	struct ulist_iterator uiter;
@@ -726,7 +723,7 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, 
			ret = BACKREF_FOUND_SHARED;

			goto out;

		}

		err = __resolve_indirect_ref(fs_info, path, time_seq, ref,

		err = resolve_indirect_ref(fs_info, path, time_seq, ref,

					   parents, extent_item_pos,

					   total_refs);

		/*
@@ -766,8 +763,8 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, 
	return ret;

}



static inline int ref_for_same_block(struct __prelim_ref *ref1,

				     struct __prelim_ref *ref2)

static inline int ref_for_same_block(struct prelim_ref *ref1,

				     struct prelim_ref *ref2)

{

	if (ref1->level != ref2->level)

		return 0;
@@ -788,10 +785,10 @@ static inline int ref_for_same_block(struct __prelim_ref *ref1, 
/*

 * read tree blocks and add keys where required.

 */

static int __add_missing_keys(struct btrfs_fs_info *fs_info,

static int add_missing_keys(struct btrfs_fs_info *fs_info,

			    struct list_head *head)

{

	struct __prelim_ref *ref;

	struct prelim_ref *ref;

	struct extent_buffer *eb;



	list_for_each_entry(ref, head, list) {
@@ -821,20 +818,20 @@ static int __add_missing_keys(struct btrfs_fs_info *fs_info, 
/*

 * merge backrefs and adjust counts accordingly

 *

 *    FIXME: For MERGE_IDENTICAL_KEYS, if we add more keys in __add_prelim_ref

 *    FIXME: For MERGE_IDENTICAL_KEYS, if we add more keys in add_prelim_ref

 *           then we can merge more here. Additionally, we could even add a key

 *           range for the blocks we looked into to merge even more (-> replace

 *           unresolved refs by those having a parent).

 */

static void __merge_refs(struct list_head *head, enum merge_mode mode)

static void merge_refs(struct list_head *head, enum merge_mode mode)

{

	struct __prelim_ref *pos1;

	struct prelim_ref *pos1;



	list_for_each_entry(pos1, head, list) {

		struct __prelim_ref *pos2 = pos1, *tmp;

		struct prelim_ref *pos2 = pos1, *tmp;



		list_for_each_entry_safe_continue(pos2, tmp, head, list) {

			struct __prelim_ref *ref1 = pos1, *ref2 = pos2;

			struct prelim_ref *ref1 = pos1, *ref2 = pos2;

			struct extent_inode_elem *eie;



			if (!ref_for_same_block(ref1, ref2))
@@ -868,7 +865,7 @@ static void __merge_refs(struct list_head *head, enum merge_mode mode) 
 * add all currently queued delayed refs from this head whose seq nr is

 * smaller or equal that seq to the list

 */

static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq,

static int add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq,

			    struct list_head *prefs, u64 *total_refs,

			    u64 inum)

{
@@ -907,7 +904,7 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, 
			struct btrfs_delayed_tree_ref *ref;



			ref = btrfs_delayed_node_to_tree_ref(node);

			ret = __add_prelim_ref(prefs, ref->root, &op_key,

			ret = add_prelim_ref(prefs, ref->root, &op_key,

					     ref->level + 1, 0, node->bytenr,

					     node->ref_mod * sgn, GFP_ATOMIC);

			break;
@@ -916,9 +913,8 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, 
			struct btrfs_delayed_tree_ref *ref;



			ref = btrfs_delayed_node_to_tree_ref(node);

			ret = __add_prelim_ref(prefs, 0, NULL,

					       ref->level + 1, ref->parent,

					       node->bytenr,

			ret = add_prelim_ref(prefs, 0, NULL, ref->level + 1,

					     ref->parent, node->bytenr,

					     node->ref_mod * sgn, GFP_ATOMIC);

			break;

		}
@@ -939,18 +935,18 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, 
				break;

			}



			ret = __add_prelim_ref(prefs, ref->root, &key, 0, 0,

					       node->bytenr,

					       node->ref_mod * sgn, GFP_ATOMIC);

			ret = add_prelim_ref(prefs, ref->root, &key, 0, 0,

					     node->bytenr, node->ref_mod * sgn,

					     GFP_ATOMIC);

			break;

		}

		case BTRFS_SHARED_DATA_REF_KEY: {

			struct btrfs_delayed_data_ref *ref;



			ref = btrfs_delayed_node_to_data_ref(node);

			ret = __add_prelim_ref(prefs, 0, NULL, 0,

					       ref->parent, node->bytenr,

					       node->ref_mod * sgn, GFP_ATOMIC);

			ret = add_prelim_ref(prefs, 0, NULL, 0, ref->parent,

					     node->bytenr, node->ref_mod * sgn,

					     GFP_ATOMIC);

			break;

		}

		default:
@@ -966,7 +962,7 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, 
/*

 * add all inline backrefs for bytenr to the list

 */

static int __add_inline_refs(struct btrfs_path *path, u64 bytenr,

static int add_inline_refs(struct btrfs_path *path, u64 bytenr,

			   int *info_level, struct list_head *prefs,

			   struct ref_root *ref_tree,

			   u64 *total_refs, u64 inum)
@@ -1024,9 +1020,8 @@ static int __add_inline_refs(struct btrfs_path *path, u64 bytenr, 


		switch (type) {

		case BTRFS_SHARED_BLOCK_REF_KEY:

			ret = __add_prelim_ref(prefs, 0, NULL,

						*info_level + 1, offset,

						bytenr, 1, GFP_NOFS);

			ret = add_prelim_ref(prefs, 0, NULL, *info_level + 1,

					     offset, bytenr, 1, GFP_NOFS);

			break;

		case BTRFS_SHARED_DATA_REF_KEY: {

			struct btrfs_shared_data_ref *sdref;
@@ -1034,7 +1029,7 @@ static int __add_inline_refs(struct btrfs_path *path, u64 bytenr, 


			sdref = (struct btrfs_shared_data_ref *)(iref + 1);

			count = btrfs_shared_data_ref_count(leaf, sdref);

			ret = __add_prelim_ref(prefs, 0, NULL, 0, offset,

			ret = add_prelim_ref(prefs, 0, NULL, 0, offset,

					     bytenr, count, GFP_NOFS);

			if (ref_tree) {

				if (!ret)
@@ -1046,7 +1041,7 @@ static int __add_inline_refs(struct btrfs_path *path, u64 bytenr, 
			break;

		}

		case BTRFS_TREE_BLOCK_REF_KEY:

			ret = __add_prelim_ref(prefs, offset, NULL,

			ret = add_prelim_ref(prefs, offset, NULL,

					     *info_level + 1, 0,

					     bytenr, 1, GFP_NOFS);

			break;
@@ -1068,7 +1063,7 @@ static int __add_inline_refs(struct btrfs_path *path, u64 bytenr, 
			}



			root = btrfs_extent_data_ref_root(leaf, dref);

			ret = __add_prelim_ref(prefs, root, &key, 0, 0,

			ret = add_prelim_ref(prefs, root, &key, 0, 0,

					     bytenr, count, GFP_NOFS);

			if (ref_tree) {

				if (!ret)
@@ -1095,7 +1090,7 @@ static int __add_inline_refs(struct btrfs_path *path, u64 bytenr, 
/*

 * add all non-inline backrefs for bytenr to the list

 */

static int __add_keyed_refs(struct btrfs_fs_info *fs_info,

static int add_keyed_refs(struct btrfs_fs_info *fs_info,

			  struct btrfs_path *path, u64 bytenr,

			  int info_level, struct list_head *prefs,

			  struct ref_root *ref_tree, u64 inum)
@@ -1128,9 +1123,8 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, 


		switch (key.type) {

		case BTRFS_SHARED_BLOCK_REF_KEY:

			ret = __add_prelim_ref(prefs, 0, NULL,

						info_level + 1, key.offset,

						bytenr, 1, GFP_NOFS);

			ret = add_prelim_ref(prefs, 0, NULL, info_level + 1,

					     key.offset, bytenr, 1, GFP_NOFS);

			break;

		case BTRFS_SHARED_DATA_REF_KEY: {

			struct btrfs_shared_data_ref *sdref;
@@ -1139,7 +1133,7 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, 
			sdref = btrfs_item_ptr(leaf, slot,

					      struct btrfs_shared_data_ref);

			count = btrfs_shared_data_ref_count(leaf, sdref);

			ret = __add_prelim_ref(prefs, 0, NULL, 0, key.offset,

			ret = add_prelim_ref(prefs, 0, NULL, 0, key.offset,

					     bytenr, count, GFP_NOFS);

			if (ref_tree) {

				if (!ret)
@@ -1151,7 +1145,7 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, 
			break;

		}

		case BTRFS_TREE_BLOCK_REF_KEY:

			ret = __add_prelim_ref(prefs, key.offset, NULL,

			ret = add_prelim_ref(prefs, key.offset, NULL,

					     info_level + 1, 0,

					     bytenr, 1, GFP_NOFS);

			break;
@@ -1174,7 +1168,7 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, 
			}



			root = btrfs_extent_data_ref_root(leaf, dref);

			ret = __add_prelim_ref(prefs, root, &key, 0, 0,

			ret = add_prelim_ref(prefs, root, &key, 0, 0,

					     bytenr, count, GFP_NOFS);

			if (ref_tree) {

				if (!ret)
@@ -1230,7 +1224,7 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, 
	int ret;

	struct list_head prefs_delayed;

	struct list_head prefs;

	struct __prelim_ref *ref;

	struct prelim_ref *ref;

	struct extent_inode_elem *eie = NULL;

	struct ref_root *ref_tree = NULL;

	u64 total_refs = 0;
@@ -1311,7 +1305,7 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, 
				goto again;

			}

			spin_unlock(&delayed_refs->lock);

			ret = __add_delayed_refs(head, time_seq,

			ret = add_delayed_refs(head, time_seq,

					       &prefs_delayed, &total_refs,

					       inum);

			mutex_unlock(&head->mutex);
@@ -1363,15 +1357,13 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, 
		if (key.objectid == bytenr &&

		    (key.type == BTRFS_EXTENT_ITEM_KEY ||

		     key.type == BTRFS_METADATA_ITEM_KEY)) {

			ret = __add_inline_refs(path, bytenr,

						&info_level, &prefs,

						ref_tree, &total_refs,

			ret = add_inline_refs(path, bytenr, &info_level,

					      &prefs, ref_tree, &total_refs,

					      inum);

			if (ret)

				goto out;

			ret = __add_keyed_refs(fs_info, path, bytenr,

					       info_level, &prefs,

					       ref_tree, inum);

			ret = add_keyed_refs(fs_info, path, bytenr, info_level,

					     &prefs, ref_tree, inum);

			if (ret)

				goto out;

		}
@@ -1380,22 +1372,22 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, 


	list_splice_init(&prefs_delayed, &prefs);



	ret = __add_missing_keys(fs_info, &prefs);

	ret = add_missing_keys(fs_info, &prefs);

	if (ret)

		goto out;



	__merge_refs(&prefs, MERGE_IDENTICAL_KEYS);

	merge_refs(&prefs, MERGE_IDENTICAL_KEYS);



	ret = __resolve_indirect_refs(fs_info, path, time_seq, &prefs,

	ret = resolve_indirect_refs(fs_info, path, time_seq, &prefs,

				    extent_item_pos, total_refs,

				    root_objectid);

	if (ret)

		goto out;



	__merge_refs(&prefs, MERGE_IDENTICAL_PARENTS);

	merge_refs(&prefs, MERGE_IDENTICAL_PARENTS);



	while (!list_empty(&prefs)) {

		ref = list_first_entry(&prefs, struct __prelim_ref, list);

		ref = list_first_entry(&prefs, struct prelim_ref, list);

		WARN_ON(ref->count < 0);

		if (roots && ref->count && ref->root_id && ref->parent == 0) {

			if (root_objectid && ref->root_id != root_objectid) {
@@ -1457,12 +1449,12 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, 
	btrfs_free_path(path);

	ref_root_free(ref_tree);

	while (!list_empty(&prefs)) {

		ref = list_first_entry(&prefs, struct __prelim_ref, list);

		ref = list_first_entry(&prefs, struct prelim_ref, list);

		list_del(&ref->list);

		kmem_cache_free(btrfs_prelim_ref_cache, ref);

	}

	while (!list_empty(&prefs_delayed)) {

		ref = list_first_entry(&prefs_delayed, struct __prelim_ref,

		ref = list_first_entry(&prefs_delayed, struct prelim_ref,

				       list);

		list_del(&ref->list);

		kmem_cache_free(btrfs_prelim_ref_cache, ref);
@@ -1532,7 +1524,7 @@ static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, 
 *

 * returns 0 on success, < 0 on error.

 */

static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans,

static int btrfs_find_all_roots_safe(struct btrfs_trans_handle *trans,

				     struct btrfs_fs_info *fs_info, u64 bytenr,

				     u64 time_seq, struct ulist **roots)

{
@@ -1578,7 +1570,8 @@ int btrfs_find_all_roots(struct btrfs_trans_handle *trans, 


	if (!trans)

		down_read(&fs_info->commit_root_sem);

	ret = __btrfs_find_all_roots(trans, fs_info, bytenr, time_seq, roots);

	ret = btrfs_find_all_roots_safe(trans, fs_info, bytenr,

					time_seq, roots);

	if (!trans)

		up_read(&fs_info->commit_root_sem);

	return ret;
@@ -1877,11 +1870,11 @@ int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, 
 * helper function to iterate extent inline refs. ptr must point to a 0 value

 * for the first call and may be modified. it is used to track state.

 * if more refs exist, 0 is returned and the next call to

 * __get_extent_inline_ref must pass the modified ptr parameter to get the

 * get_extent_inline_ref must pass the modified ptr parameter to get the

 * next ref. after the last ref was processed, 1 is returned.

 * returns <0 on error

 */

static int __get_extent_inline_ref(unsigned long *ptr,

static int get_extent_inline_ref(unsigned long *ptr,

				 const struct extent_buffer *eb,

				 const struct btrfs_key *key,

				 const struct btrfs_extent_item *ei,
@@ -1930,7 +1923,7 @@ static int __get_extent_inline_ref(unsigned long *ptr, 
/*

 * reads the tree block backref for an extent. tree level and root are returned

 * through out_level and out_root. ptr must point to a 0 value for the first

 * call and may be modified (see __get_extent_inline_ref comment).

 * call and may be modified (see get_extent_inline_ref comment).

 * returns 0 if data was provided, 1 if there was no more data to provide or

 * <0 on error.

 */
@@ -1946,7 +1939,7 @@ int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, 
		return 1;



	while (1) {

		ret = __get_extent_inline_ref(ptr, eb, key, ei, item_size,

		ret = get_extent_inline_ref(ptr, eb, key, ei, item_size,

					      &eiref, &type);

		if (ret < 0)

			return ret;
@@ -2043,7 +2036,7 @@ int iterate_extent_inodes(struct btrfs_fs_info *fs_info, 


	ULIST_ITER_INIT(&ref_uiter);

	while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) {

		ret = __btrfs_find_all_roots(trans, fs_info, ref_node->val,

		ret = btrfs_find_all_roots_safe(trans, fs_info, ref_node->val,

						tree_mod_seq_elem.seq, &roots);

		if (ret)

			break;