btrfs-progs: check: switch to iterating over the backref_tree

We now have two data structures that can be used to iterate the same data
set, and there may be quite a few of them in memory.  Eliminating the
list_head member will reduce memory consumption while iterating over
the extent backrefs.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Jeff Mahoney 2016-06-23 15:26:06 -04:00 committed by David Sterba
parent 31d8235410
commit bbebe814c0

View File

@ -76,7 +76,6 @@ static struct task_ctx ctx = { 0 };
static struct cache_tree *roots_info_cache = NULL;
struct extent_backref {
struct list_head list;
struct rb_node node;
unsigned int is_data:1;
unsigned int found_extent_tree:1;
@ -85,11 +84,6 @@ struct extent_backref {
unsigned int broken:1;
};
static inline struct extent_backref* to_extent_backref(struct list_head *entry)
{
return list_entry(entry, struct extent_backref, list);
}
static inline struct extent_backref* rb_node_to_extent_backref(struct rb_node *node)
{
return rb_entry(node, struct extent_backref, node);
@ -3869,16 +3863,15 @@ out:
static int all_backpointers_checked(struct extent_record *rec, int print_errs)
{
struct list_head *cur = rec->backrefs.next;
struct rb_node *n;
struct extent_backref *back;
struct tree_backref *tback;
struct data_backref *dback;
u64 found = 0;
int err = 0;
while(cur != &rec->backrefs) {
back = to_extent_backref(cur);
cur = cur->next;
for (n = rb_first(&rec->backref_tree); n; n = rb_next(n)) {
back = rb_node_to_extent_backref(n);
if (!back->found_extent_tree) {
err = 1;
if (!print_errs)
@ -3981,17 +3974,16 @@ out:
return err;
}
static int free_all_extent_backrefs(struct extent_record *rec)
static void __free_one_backref(struct rb_node *node)
{
struct extent_backref *back;
struct list_head *cur;
while (!list_empty(&rec->backrefs)) {
cur = rec->backrefs.next;
back = to_extent_backref(cur);
list_del(cur);
free(back);
}
return 0;
struct extent_backref *back = rb_node_to_extent_backref(node);
free(back);
}
static void free_all_extent_backrefs(struct extent_record *rec)
{
rb_free_nodes(&rec->backref_tree, __free_one_backref);
}
static void free_extent_record_cache(struct btrfs_fs_info *fs_info,
@ -4031,7 +4023,7 @@ static int check_owner_ref(struct btrfs_root *root,
struct extent_record *rec,
struct extent_buffer *buf)
{
struct extent_backref *node;
struct extent_backref *node, *tmp;
struct tree_backref *back;
struct btrfs_root *ref_root;
struct btrfs_key key;
@ -4041,7 +4033,8 @@ static int check_owner_ref(struct btrfs_root *root,
int found = 0;
int ret;
list_for_each_entry(node, &rec->backrefs, list) {
rbtree_postorder_for_each_entry_safe(node, tmp,
&rec->backref_tree, node) {
if (node->is_data)
continue;
if (!node->found_ref)
@ -4086,18 +4079,16 @@ static int check_owner_ref(struct btrfs_root *root,
static int is_extent_tree_record(struct extent_record *rec)
{
struct list_head *cur = rec->backrefs.next;
struct extent_backref *node;
struct extent_backref *ref, *tmp;
struct tree_backref *back;
int is_extent = 0;
while(cur != &rec->backrefs) {
node = to_extent_backref(cur);
cur = cur->next;
if (node->is_data)
rbtree_postorder_for_each_entry_safe(ref, tmp,
&rec->backref_tree, node) {
if (ref->is_data)
return 0;
back = to_tree_backref(node);
if (node->full_backref)
back = to_tree_backref(ref);
if (ref->full_backref)
return 0;
if (back->root == BTRFS_EXTENT_TREE_OBJECTID)
is_extent = 1;
@ -4513,7 +4504,6 @@ static struct tree_backref *alloc_tree_backref(struct extent_record *rec,
ref->root = root;
ref->node.full_backref = 0;
}
list_add_tail(&ref->node.list, &rec->backrefs);
rb_insert(&rec->backref_tree, &ref->node.node, compare_extent_backref);
return ref;
@ -4579,7 +4569,6 @@ static struct data_backref *alloc_data_backref(struct extent_record *rec,
ref->bytes = max_size;
ref->found_ref = 0;
ref->num_refs = 0;
list_add_tail(&ref->node.list, &rec->backrefs);
rb_insert(&rec->backref_tree, &ref->node.node, compare_extent_backref);
if (max_size > rec->max_size)
rec->max_size = max_size;
@ -4613,12 +4602,12 @@ static void check_extent_type(struct extent_record *rec)
* Check SYSTEM extent, as it's also marked as metadata, we can only
* make sure it's a SYSTEM extent by its backref
*/
if (!list_empty(&rec->backrefs)) {
if (!RB_EMPTY_ROOT(&rec->backref_tree)) {
struct extent_backref *node;
struct tree_backref *tback;
u64 bg_type;
node = to_extent_backref(rec->backrefs.next);
node = rb_node_to_extent_backref(rb_first(&rec->backref_tree));
if (node->is_data) {
/* tree block shouldn't have data backref */
rec->wrong_chunk_type = 1;
@ -6471,7 +6460,7 @@ static int free_extent_hook(struct btrfs_trans_handle *trans,
back->node.found_extent_tree = 0;
if (!back->node.found_extent_tree && back->node.found_ref) {
list_del(&back->node.list);
rb_erase(&back->node.node, &rec->backref_tree);
free(back);
}
} else {
@ -6490,7 +6479,7 @@ static int free_extent_hook(struct btrfs_trans_handle *trans,
back->node.found_extent_tree = 0;
}
if (!back->node.found_extent_tree && back->node.found_ref) {
list_del(&back->node.list);
rb_erase(&back->node.node, &rec->backref_tree);
free(back);
}
}
@ -6927,7 +6916,7 @@ out:
static int verify_backrefs(struct btrfs_fs_info *info, struct btrfs_path *path,
struct extent_record *rec)
{
struct extent_backref *back;
struct extent_backref *back, *tmp;
struct data_backref *dback;
struct extent_entry *entry, *best = NULL;
LIST_HEAD(entries);
@ -6943,7 +6932,8 @@ static int verify_backrefs(struct btrfs_fs_info *info, struct btrfs_path *path,
if (rec->metadata)
return 0;
list_for_each_entry(back, &rec->backrefs, list) {
rbtree_postorder_for_each_entry_safe(back, tmp,
&rec->backref_tree, node) {
if (back->full_backref || !back->is_data)
continue;
@ -7069,7 +7059,8 @@ static int verify_backrefs(struct btrfs_fs_info *info, struct btrfs_path *path,
* Ok great we all agreed on an extent record, let's go find the real
* references and fix up the ones that don't match.
*/
list_for_each_entry(back, &rec->backrefs, list) {
rbtree_postorder_for_each_entry_safe(back, tmp,
&rec->backref_tree, node) {
if (back->full_backref || !back->is_data)
continue;
@ -7298,7 +7289,7 @@ static int find_possible_backrefs(struct btrfs_fs_info *info,
struct extent_record *rec)
{
struct btrfs_root *root;
struct extent_backref *back;
struct extent_backref *back, *tmp;
struct data_backref *dback;
struct cache_extent *cache;
struct btrfs_file_extent_item *fi;
@ -7306,7 +7297,8 @@ static int find_possible_backrefs(struct btrfs_fs_info *info,
u64 bytenr, bytes;
int ret;
list_for_each_entry(back, &rec->backrefs, list) {
rbtree_postorder_for_each_entry_safe(back, tmp,
&rec->backref_tree, node) {
/* Don't care about full backrefs (poor unloved backrefs) */
if (back->full_backref || !back->is_data)
continue;
@ -7394,7 +7386,7 @@ static int record_orphan_data_extents(struct btrfs_fs_info *fs_info,
{
struct btrfs_key key;
struct btrfs_root *dest_root;
struct extent_backref *back;
struct extent_backref *back, *tmp;
struct data_backref *dback;
struct orphan_data_extent *orphan;
struct btrfs_path *path;
@ -7406,7 +7398,8 @@ static int record_orphan_data_extents(struct btrfs_fs_info *fs_info,
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
list_for_each_entry(back, &rec->backrefs, list) {
rbtree_postorder_for_each_entry_safe(back, tmp,
&rec->backref_tree, node) {
if (back->full_backref || !back->is_data ||
!back->found_extent_tree)
continue;
@ -7473,9 +7466,8 @@ static int fixup_extent_refs(struct btrfs_fs_info *info,
struct btrfs_trans_handle *trans = NULL;
int ret;
struct btrfs_path *path;
struct list_head *cur = rec->backrefs.next;
struct cache_extent *cache;
struct extent_backref *back;
struct extent_backref *back, *tmp;
int allocated = 0;
u64 flags = 0;
@ -7526,10 +7518,8 @@ static int fixup_extent_refs(struct btrfs_fs_info *info,
}
/* step three, recreate all the refs we did find */
while(cur != &rec->backrefs) {
back = to_extent_backref(cur);
cur = cur->next;
rbtree_postorder_for_each_entry_safe(back, tmp,
&rec->backref_tree, node) {
/*
* if we didn't find any references, don't create a
* new extent record