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 2017-07-25 16:51:33 -04:00 committed by David Sterba
parent 756105181e
commit ad39e6252b
1 changed files with 36 additions and 47 deletions

View File

@ -85,7 +85,6 @@ enum btrfs_check_mode {
static enum btrfs_check_mode check_mode = CHECK_MODE_DEFAULT;
struct extent_backref {
struct list_head list;
struct rb_node node;
unsigned int is_data:1;
unsigned int found_extent_tree:1;
@ -94,11 +93,6 @@ 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);
@ -5483,16 +5477,14 @@ static int do_check_fs_roots(struct btrfs_fs_info *fs_info,
static int all_backpointers_checked(struct extent_record *rec, int print_errs)
{
struct list_head *cur = rec->backrefs.next;
struct extent_backref *back;
struct extent_backref *back, *tmp;
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;
rbtree_postorder_for_each_entry_safe(back, tmp,
&rec->backref_tree, node) {
if (!back->found_extent_tree) {
err = 1;
if (!print_errs)
@ -5595,17 +5587,16 @@ 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);
struct extent_backref *back = rb_node_to_extent_backref(node);
free(back);
}
return 0;
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 cache_tree *extent_cache)
@ -5644,7 +5635,7 @@ 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;
@ -5654,7 +5645,8 @@ 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)
@ -5699,14 +5691,12 @@ 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 *node, *tmp;
struct tree_backref *back;
int is_extent = 0;
while(cur != &rec->backrefs) {
node = to_extent_backref(cur);
cur = cur->next;
rbtree_postorder_for_each_entry_safe(node, tmp,
&rec->backref_tree, node) {
if (node->is_data)
return 0;
back = to_tree_backref(node);
@ -6116,7 +6106,6 @@ 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);
return ref;
}
@ -6186,7 +6175,6 @@ 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);
if (max_size > rec->max_size)
rec->max_size = max_size;
return ref;
@ -6219,12 +6207,12 @@ 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;
@ -8217,7 +8205,7 @@ 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 {
@ -8236,7 +8224,7 @@ 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);
}
}
@ -8677,7 +8665,7 @@ 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);
@ -8693,7 +8681,8 @@ 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;
@ -8819,7 +8808,8 @@ 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;
@ -9043,7 +9033,7 @@ 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;
@ -9051,7 +9041,8 @@ 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;
@ -9139,7 +9130,7 @@ 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;
@ -9149,7 +9140,8 @@ static int record_orphan_data_extents(struct btrfs_fs_info *fs_info,
if (rec->metadata)
return 1;
btrfs_init_path(&path);
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;
@ -9217,9 +9209,8 @@ 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;
@ -9267,10 +9258,8 @@ 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