[PATCH 17/19] btrfs: Rename handle_one_tree_block() to backref_cache_add_one_tree_block() and move it to backref.c

Qu Wenruo
2020-03-03T07:15:53Z

This function is the major part of backref cache build process, move it
to backref.c so we can reuse it later.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
fs/btrfs/backref.c | 305 +++++++++++++++++++++++++++++++++++++++++
fs/btrfs/backref.h | 6 +
fs/btrfs/relocation.c | 307 +-----------------------------------------
3 files changed, 313 insertions(+), 305 deletions(-)

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 02455b3bbc35..e1a271c1e9f3 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -13,6 +13,7 @@
#include "transaction.h"
#include "delayed-ref.h"
#include "locking.h"
+#include "misc.h"

/* Just an arbitrary number so we can be sure this happened */
#define BACKREF_FOUND_SHARED 6
@@ -2558,3 +2559,307 @@ void backref_cache_cleanup(struct backref_cache *cache)
ASSERT(!cache->nr_nodes);
ASSERT(!cache->nr_edges);
}
+
+static int handle_one_tree_backref(struct backref_cache *cache,
+ struct btrfs_path *path,
+ struct btrfs_key *ref_key,
+ struct btrfs_key *tree_key,
+ struct backref_node *cur)
+{
+ struct btrfs_fs_info *fs_info = cache->fs_info;
+ struct list_head *useless_node = &cache->useless_node;
+ struct list_head *pending_edge = &cache->pending_edge;
+ struct backref_node *upper;
+ struct backref_node *lower;
+ struct backref_edge *edge;
+ struct extent_buffer *eb;
+ struct btrfs_key root_key;
+ struct btrfs_root *root;
+ struct rb_node *rb_node;
+ bool need_check = true;
+ int level;
+ int ret = 0;
+
+ if (ref_key->type != BTRFS_TREE_BLOCK_REF_KEY &&
+ ref_key->type != BTRFS_SHARED_BLOCK_REF_KEY)
+ return -EUCLEAN;
+
+ /* SHARED_BLOCK_REF means key.offset is the parent bytenr */
+ if (ref_key->type == BTRFS_SHARED_BLOCK_REF_KEY) {
+
+ /* Only reloc root uses backref pointing to itself */
+ if (ref_key->objectid == ref_key->offset) {
+ cur->is_reloc_root = 1;
+ /* Only reloc backref cache cares exact root */
+ if (cache->is_reloc) {
+ root = find_reloc_root(fs_info, cur->bytenr);
+ if (WARN_ON(!root))
+ return -ENOENT;
+ cur->root = root;
+ }
+ return 0;
+ }
+
+ edge = alloc_backref_edge(cache);
+ if (!edge)
+ return -ENOMEM;
+
+ rb_node = simple_search(&cache->rb_root, ref_key->offset);
+ if (!rb_node) {
+ /* Parent node not yet cached */
+ upper = alloc_backref_node(cache, ref_key->offset,
+ cur->level + 1);
+ if (!upper) {
+ free_backref_edge(cache, edge);
+ return -ENOMEM;
+ }
+
+ /*
+ * backrefs for the upper level block isn't
+ * cached, add the block to pending list
+ */
+ list_add_tail(&edge->list[UPPER], pending_edge);
+ } else {
+ /* Parent node already cached */
+ upper = rb_entry(rb_node, struct backref_node,
+ rb_node);
+ ASSERT(upper->checked);
+ INIT_LIST_HEAD(&edge->list[UPPER]);
+ }
+ link_backref_edge(edge, cur, upper, LINK_LOWER);
+ return 0;
+ }
+ /*
+ * ref_key.type == BTRFS_TREE_BLOCK_REF_KEY, ref_key->offset means the
+ * root objectid. We need to search the tree to get its parent bytenr.
+ */
+ root_key.objectid = ref_key->offset;
+ root_key.type = BTRFS_ROOT_ITEM_KEY;
+ root_key.offset = (u64)-1;
+ root = btrfs_get_fs_root(fs_info, &root_key, false);
+ if (IS_ERR(root))
+ return PTR_ERR(root);
+ if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
+ cur->cowonly = 1;
+
+ if (btrfs_root_level(&root->root_item) == cur->level) {
+ /* tree root */
+ ASSERT(btrfs_root_bytenr(&root->root_item) ==
+ cur->bytenr);
+ if (should_ignore_reloc_root(root)) {
+ btrfs_put_root(root);
+ list_add(&cur->list, useless_node);
+ } else {
+ cur->root = root;
+ }
+ return 0;
+ }
+
+ level = cur->level + 1;
+
+ /* Search the tree to find parent blocks referring the block. */
+ path->search_commit_root = 1;
+ path->skip_locking = 1;
+ path->lowest_level = level;
+ ret = btrfs_search_slot(NULL, root, tree_key, path, 0, 0);
+ path->lowest_level = 0;
+ if (ret < 0) {
+ btrfs_put_root(root);
+ return ret;
+ }
+ if (ret > 0 && path->slots[level] > 0)
+ path->slots[level]--;
+
+ eb = path->nodes[level];
+ if (btrfs_node_blockptr(eb, path->slots[level]) != cur->bytenr) {
+ btrfs_err(fs_info,
+"couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)",
+ cur->bytenr, level - 1, root->root_key.objectid,
+ tree_key->objectid, tree_key->type, tree_key->offset);
+ btrfs_put_root(root);
+ ret = -ENOENT;
+ goto out;
+ }
+ lower = cur;
+
+ /* Add all nodes and edges in the path */
+ for (; level < BTRFS_MAX_LEVEL; level++) {
+ if (!path->nodes[level]) {
+ ASSERT(btrfs_root_bytenr(&root->root_item) ==
+ lower->bytenr);
+ if (should_ignore_reloc_root(root)) {
+ btrfs_put_root(root);
+ list_add(&lower->list, useless_node);
+ } else {
+ lower->root = root;
+ }
+ break;
+ }
+
+ edge = alloc_backref_edge(cache);
+ if (!edge) {
+ btrfs_put_root(root);
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ eb = path->nodes[level];
+ rb_node = simple_search(&cache->rb_root, eb->start);
+ if (!rb_node) {
+ upper = alloc_backref_node(cache, eb->start,
+ lower->level + 1);
+ if (!upper) {
+ btrfs_put_root(root);
+ free_backref_edge(cache, edge);
+ ret = -ENOMEM;
+ goto out;
+ }
+ upper->owner = btrfs_header_owner(eb);
+ if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
+ upper->cowonly = 1;
+
+ /*
+ * if we know the block isn't shared we can void
+ * checking its backrefs.
+ */
+ if (btrfs_block_can_be_shared(root, eb))
+ upper->checked = 0;
+ else
+ upper->checked = 1;
+
+ /*
+ * add the block to pending list if we need check its
+ * backrefs, we only do this once while walking up a
+ * tree as we will catch anything else later on.
+ */
+ if (!upper->checked && need_check) {
+ need_check = false;
+ list_add_tail(&edge->list[UPPER], pending_edge);
+ } else {
+ if (upper->checked)
+ need_check = true;
+ INIT_LIST_HEAD(&edge->list[UPPER]);
+ }
+ } else {
+ upper = rb_entry(rb_node, struct backref_node, rb_node);
+ ASSERT(upper->checked);
+ INIT_LIST_HEAD(&edge->list[UPPER]);
+ if (!upper->owner)
+ upper->owner = btrfs_header_owner(eb);
+ }
+ link_backref_edge(edge, lower, upper, LINK_LOWER);
+
+ if (rb_node) {
+ btrfs_put_root(root);
+ break;
+ }
+ lower = upper;
+ upper = NULL;
+ }
+out:
+ btrfs_release_path(path);
+ return ret;
+}
+
+int backref_cache_add_one_tree_block(struct backref_cache *cache,
+ struct btrfs_path *path,
+ struct btrfs_backref_iter *iter,
+ struct btrfs_key *node_key,
+ struct backref_node *cur)
+{
+ struct backref_edge *edge;
+ struct backref_node *exist;
+ int ret;
+
+ ret = btrfs_backref_iter_start(iter, cur->bytenr);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * We skip the first btrfs_tree_block_info, as we don't use the key
+ * stored in it, but fetch it from the tree block.
+ */
+ if (btrfs_backref_has_tree_block_info(iter)) {
+ ret = btrfs_backref_iter_next(iter);
+ if (ret < 0)
+ goto out;
+ /* No extra backref? This means the tree block is corrupted */
+ if (ret > 0) {
+ ret = -EUCLEAN;
+ goto out;
+ }
+ }
+ WARN_ON(cur->checked);
+ if (!list_empty(&cur->upper)) {
+ /*
+ * the backref was added previously when processing
+ * backref of type BTRFS_TREE_BLOCK_REF_KEY
+ */
+ ASSERT(list_is_singular(&cur->upper));
+ edge = list_entry(cur->upper.next, struct backref_edge,
+ list[LOWER]);
+ ASSERT(list_empty(&edge->list[UPPER]));
+ exist = edge->node[UPPER];
+ /*
+ * add the upper level block to pending list if we need
+ * check its backrefs
+ */
+ if (!exist->checked)
+ list_add_tail(&edge->list[UPPER], &cache->pending_edge);
+ } else {
+ exist = NULL;
+ }
+
+ for (; ret == 0; ret = btrfs_backref_iter_next(iter)) {
+ struct extent_buffer *eb;
+ struct btrfs_key key;
+ int type;
+
+ cond_resched();
+ eb = btrfs_backref_get_eb(iter);
+
+ key.objectid = iter->bytenr;
+ if (btrfs_backref_iter_is_inline_ref(iter)) {
+ struct btrfs_extent_inline_ref *iref;
+
+ /* update key for inline back ref */
+ iref = (struct btrfs_extent_inline_ref *)iter->cur_ptr;
+ type = btrfs_get_extent_inline_ref_type(eb, iref,
+ BTRFS_REF_TYPE_BLOCK);
+ if (type == BTRFS_REF_TYPE_INVALID) {
+ ret = -EUCLEAN;
+ goto out;
+ }
+ key.type = type;
+ key.offset = btrfs_extent_inline_ref_offset(eb, iref);
+ } else {
+ key.type = iter->cur_key.type;
+ key.offset = iter->cur_key.offset;
+ }
+
+ /*
+ * Parent node found and matches current inline ref, no need to
+ * rebuild this node for this inline ref.
+ */
+ if (exist &&
+ ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
+ exist->owner == key.offset) ||
+ (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
+ exist->bytenr == key.offset))) {
+ exist = NULL;
+ continue;
+ }
+
+ ret = handle_one_tree_backref(cache, path, &key, node_key, cur);
+ if (ret < 0)
+ goto out;
+ }
+ if (ret < 0)
+ goto out;
+ ret = 0;
+ cur->checked = 1;
+ WARN_ON(exist);
+out:
+ btrfs_backref_iter_release(iter);
+ return ret;
+}
diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h
index 4a4c9070a38b..6b8b48bf6958 100644
--- a/fs/btrfs/backref.h
+++ b/fs/btrfs/backref.h
@@ -386,4 +386,10 @@ static inline void backref_cache_panic(struct btrfs_fs_info *fs_info,
"Inconsistency in backref cache found at offset %llu",
bytenr);
}
+
+int backref_cache_add_one_tree_block(struct backref_cache *cache,
+ struct btrfs_path *path,
+ struct btrfs_backref_iter *iter,
+ struct btrfs_key *node_key,
+ struct backref_node *cur);
#endif
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 441d2b28d8e7..4cb61165d852 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -384,310 +384,6 @@ static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
return btrfs_get_fs_root(fs_info, &key, false);
}

-static int handle_one_tree_backref(struct backref_cache *cache,
- struct btrfs_path *path,
- struct btrfs_key *ref_key,
- struct btrfs_key *tree_key,
- struct backref_node *cur)
-{
- struct btrfs_fs_info *fs_info = cache->fs_info;
- struct list_head *useless_node = &cache->useless_node;
- struct list_head *pending_edge = &cache->pending_edge;
- struct backref_node *upper;
- struct backref_node *lower;
- struct backref_edge *edge;
- struct extent_buffer *eb;
- struct btrfs_key root_key;
- struct btrfs_root *root;
- struct rb_node *rb_node;
- bool need_check = true;
- int level;
- int ret = 0;
-
- if (ref_key->type != BTRFS_TREE_BLOCK_REF_KEY &&
- ref_key->type != BTRFS_SHARED_BLOCK_REF_KEY)
- return -EUCLEAN;
-
- /* SHARED_BLOCK_REF means key.offset is the parent bytenr */
- if (ref_key->type == BTRFS_SHARED_BLOCK_REF_KEY) {
-
- /* Only reloc root uses backref pointing to itself */
- if (ref_key->objectid == ref_key->offset) {
- cur->is_reloc_root = 1;
- /* Only reloc backref cache cares exact root */
- if (cache->is_reloc) {
- root = find_reloc_root(fs_info, cur->bytenr);
- if (WARN_ON(!root))
- return -ENOENT;
- cur->root = root;
- }
- return 0;
- }
-
- edge = alloc_backref_edge(cache);
- if (!edge)
- return -ENOMEM;
-
- rb_node = simple_search(&cache->rb_root, ref_key->offset);
- if (!rb_node) {
- /* Parent node not yet cached */
- upper = alloc_backref_node(cache, ref_key->offset,
- cur->level + 1);
- if (!upper) {
- free_backref_edge(cache, edge);
- return -ENOMEM;
- }
-
- /*
- * backrefs for the upper level block isn't
- * cached, add the block to pending list
- */
- list_add_tail(&edge->list[UPPER], pending_edge);
- } else {
- /* Parent node already cached */
- upper = rb_entry(rb_node, struct backref_node,
- rb_node);
- ASSERT(upper->checked);
- INIT_LIST_HEAD(&edge->list[UPPER]);
- }
- link_backref_edge(edge, cur, upper, LINK_LOWER);
- return 0;
- }
- /*
- * ref_key.type == BTRFS_TREE_BLOCK_REF_KEY, ref_key->offset means the
- * root objectid. We need to search the tree to get its parent bytenr.
- */
- root_key.objectid = ref_key->offset;
- root_key.type = BTRFS_ROOT_ITEM_KEY;
- root_key.offset = (u64)-1;
- root = btrfs_get_fs_root(fs_info, &root_key, false);
- if (IS_ERR(root))
- return PTR_ERR(root);
- if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
- cur->cowonly = 1;
-
- if (btrfs_root_level(&root->root_item) == cur->level) {
- /* tree root */
- ASSERT(btrfs_root_bytenr(&root->root_item) ==
- cur->bytenr);
- if (should_ignore_reloc_root(root)) {
- btrfs_put_root(root);
- list_add(&cur->list, useless_node);
- } else {
- cur->root = root;
- }
- return 0;
- }
-
- level = cur->level + 1;
-
- /* Search the tree to find parent blocks referring the block. */
- path->search_commit_root = 1;
- path->skip_locking = 1;
- path->lowest_level = level;
- ret = btrfs_search_slot(NULL, root, tree_key, path, 0, 0);
- path->lowest_level = 0;
- if (ret < 0) {
- btrfs_put_root(root);
- return ret;
- }
- if (ret > 0 && path->slots[level] > 0)
- path->slots[level]--;
-
- eb = path->nodes[level];
- if (btrfs_node_blockptr(eb, path->slots[level]) != cur->bytenr) {
- btrfs_err(fs_info,
-"couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)",
- cur->bytenr, level - 1, root->root_key.objectid,
- tree_key->objectid, tree_key->type, tree_key->offset);
- btrfs_put_root(root);
- ret = -ENOENT;
- goto out;
- }
- lower = cur;
-
- /* Add all nodes and edges in the path */
- for (; level < BTRFS_MAX_LEVEL; level++) {
- if (!path->nodes[level]) {
- ASSERT(btrfs_root_bytenr(&root->root_item) ==
- lower->bytenr);
- if (should_ignore_reloc_root(root)) {
- btrfs_put_root(root);
- list_add(&lower->list, useless_node);
- } else {
- lower->root = root;
- }
- break;
- }
-
- edge = alloc_backref_edge(cache);
- if (!edge) {
- btrfs_put_root(root);
- ret = -ENOMEM;
- goto out;
- }
-
- eb = path->nodes[level];
- rb_node = simple_search(&cache->rb_root, eb->start);
- if (!rb_node) {
- upper = alloc_backref_node(cache, eb->start,
- lower->level + 1);
- if (!upper) {
- btrfs_put_root(root);
- free_backref_edge(cache, edge);
- ret = -ENOMEM;
- goto out;
- }
- upper->owner = btrfs_header_owner(eb);
- if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
- upper->cowonly = 1;
-
- /*
- * if we know the block isn't shared we can void
- * checking its backrefs.
- */
- if (btrfs_block_can_be_shared(root, eb))
- upper->checked = 0;
- else
- upper->checked = 1;
-
- /*
- * add the block to pending list if we need check its
- * backrefs, we only do this once while walking up a
- * tree as we will catch anything else later on.
- */
- if (!upper->checked && need_check) {
- need_check = false;
- list_add_tail(&edge->list[UPPER], pending_edge);
- } else {
- if (upper->checked)
- need_check = true;
- INIT_LIST_HEAD(&edge->list[UPPER]);
- }
- } else {
- upper = rb_entry(rb_node, struct backref_node, rb_node);
- ASSERT(upper->checked);
- INIT_LIST_HEAD(&edge->list[UPPER]);
- if (!upper->owner)
- upper->owner = btrfs_header_owner(eb);
- }
- link_backref_edge(edge, lower, upper, LINK_LOWER);
-
- if (rb_node) {
- btrfs_put_root(root);
- break;
- }
- lower = upper;
- upper = NULL;
- }
-out:
- btrfs_release_path(path);
- return ret;
-}
-
-static int handle_one_tree_block(struct backref_cache *cache,
- struct btrfs_path *path,
- struct btrfs_backref_iter *iter,
- struct btrfs_key *node_key,
- struct backref_node *cur)
-{
- struct backref_edge *edge;
- struct backref_node *exist;
- int ret;
-
- ret = btrfs_backref_iter_start(iter, cur->bytenr);
- if (ret < 0)
- return ret;
-
- /*
- * We skip the first btrfs_tree_block_info, as we don't use the key
- * stored in it, but fetch it from the tree block.
- */
- if (btrfs_backref_has_tree_block_info(iter)) {
- ret = btrfs_backref_iter_next(iter);
- if (ret < 0)
- goto out;
- /* No extra backref? This means the tree block is corrupted */
- if (ret > 0) {
- ret = -EUCLEAN;
- goto out;
- }
- }
- WARN_ON(cur->checked);
- if (!list_empty(&cur->upper)) {
- /*
- * the backref was added previously when processing
- * backref of type BTRFS_TREE_BLOCK_REF_KEY
- */
- ASSERT(list_is_singular(&cur->upper));
- edge = list_entry(cur->upper.next, struct backref_edge,
- list[LOWER]);
- ASSERT(list_empty(&edge->list[UPPER]));
- exist = edge->node[UPPER];
- /*
- * add the upper level block to pending list if we need
- * check its backrefs
- */
- if (!exist->checked)
- list_add_tail(&edge->list[UPPER], &cache->pending_edge);
- } else {
- exist = NULL;
- }
-
- for (; ret == 0; ret = btrfs_backref_iter_next(iter)) {
- struct extent_buffer *eb;
- struct btrfs_key key;
- int type;
-
- cond_resched();
- eb = btrfs_backref_get_eb(iter);
-
- key.objectid = iter->bytenr;
- if (btrfs_backref_iter_is_inline_ref(iter)) {
- struct btrfs_extent_inline_ref *iref;
-
- /* update key for inline back ref */
- iref = (struct btrfs_extent_inline_ref *)iter->cur_ptr;
- type = btrfs_get_extent_inline_ref_type(eb, iref,
- BTRFS_REF_TYPE_BLOCK);
- if (type == BTRFS_REF_TYPE_INVALID) {
- ret = -EUCLEAN;
- goto out;
- }
- key.type = type;
- key.offset = btrfs_extent_inline_ref_offset(eb, iref);
- } else {
- key.type = iter->cur_key.type;
- key.offset = iter->cur_key.offset;
- }
-
- /*
- * Parent node found and matches current inline ref, no need to
- * rebuild this node for this inline ref.
- */
- if (exist &&
- ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
- exist->owner == key.offset) ||
- (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
- exist->bytenr == key.offset))) {
- exist = NULL;
- continue;
- }
-
- ret = handle_one_tree_backref(cache, path, &key, node_key, cur);
- if (ret < 0)
- goto out;
- }
- if (ret < 0)
- goto out;
- ret = 0;
- cur->checked = 1;
- WARN_ON(exist);
-out:
- btrfs_backref_iter_release(iter);
- return ret;
-}
-
/*
* In handle_one_tree_backref(), we have only linked the lower node to the edge,
* but the upper node hasn't been linked to the edge.
@@ -916,7 +612,8 @@ struct backref_node *build_backref_tree(struct reloc_control *rc,

/* Breadth-first search to build backref cache */
while (1) {
- ret = handle_one_tree_block(cache, path, iter, node_key, cur);
+ ret = backref_cache_add_one_tree_block(cache, path, iter,
+ node_key, cur);
if (ret < 0) {
err = ret;
goto out;
--
2.25.1