diff options
Diffstat (limited to 'backref.c')
| -rw-r--r-- | backref.c | 133 |
1 files changed, 76 insertions, 57 deletions
@@ -130,6 +130,24 @@ struct __prelim_ref { u64 wanted_disk_byte; }; +static struct __prelim_ref *list_first_pref(struct list_head *head) +{ + return list_first_entry(head, struct __prelim_ref, list); +} + +struct pref_state { + struct list_head pending; + struct list_head pending_missing_keys; + struct list_head pending_indirect_refs; +}; + +static void init_pref_state(struct pref_state *prefstate) +{ + INIT_LIST_HEAD(&prefstate->pending); + INIT_LIST_HEAD(&prefstate->pending_missing_keys); + INIT_LIST_HEAD(&prefstate->pending_indirect_refs); +} + /* * the rules for all callers of this function are: * - obtaining the parent is the goal @@ -169,11 +187,12 @@ struct __prelim_ref { * block might help in merging entries to gain some speed. */ -static int __add_prelim_ref(struct list_head *head, u64 root_id, +static int __add_prelim_ref(struct pref_state *prefstate, u64 root_id, struct btrfs_key *key, int level, u64 parent, u64 wanted_disk_byte, int count, gfp_t gfp_mask) { + struct list_head *head; struct __prelim_ref *ref; if (root_id == BTRFS_DATA_RELOC_TREE_OBJECTID) @@ -184,16 +203,20 @@ static int __add_prelim_ref(struct list_head *head, u64 root_id, return -ENOMEM; ref->root_id = root_id; - if (key) + if (key) { ref->key_for_search = *key; - else + head = &prefstate->pending; + } else { memset(&ref->key_for_search, 0, sizeof(ref->key_for_search)); + head = &prefstate->pending_missing_keys; + } ref->inode_list = NULL; ref->level = level; ref->count = count; ref->parent = parent; ref->wanted_disk_byte = wanted_disk_byte; + list_add_tail(&ref->list, head); return 0; @@ -345,14 +368,14 @@ out: * resolve all indirect backrefs from the list */ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, + struct pref_state *prefstate, struct btrfs_path *path, u64 time_seq, - struct list_head *head, const u64 *extent_item_pos, u64 total_refs) { + struct list_head *head = &prefstate->pending_indirect_refs; int err; int ret = 0; struct __prelim_ref *ref; - struct __prelim_ref *ref_safe; struct __prelim_ref *new_ref; struct ulist *parents; struct ulist_node *node; @@ -362,16 +385,11 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, if (!parents) return -ENOMEM; - /* - * _safe allows us to insert directly after the current item without - * iterating over the newly inserted items. - * we're also allowed to re-assign ref during iteration. - */ - list_for_each_entry_safe(ref, ref_safe, head, list) { - if (ref->parent) /* already direct */ - continue; - if (ref->count == 0) - continue; + while (!list_empty(head)) { + ref = list_first_pref(head); + list_move(&ref->list, &prefstate->pending); + ASSERT(!ref->parent); /* already direct */ + ASSERT(ref->count); err = __resolve_indirect_ref(fs_info, path, time_seq, ref, parents, extent_item_pos, total_refs); @@ -404,7 +422,7 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, new_ref->parent = node->val; new_ref->inode_list = (struct extent_inode_elem *) (uintptr_t)node->aux; - list_add(&new_ref->list, &ref->list); + list_add_tail(&new_ref->list, &prefstate->pending); } ulist_reinit(parents); } @@ -436,22 +454,20 @@ 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, - struct list_head *head) + struct pref_state *prefstate) { - struct list_head *pos; struct extent_buffer *eb; - list_for_each(pos, head) { + while (!list_empty(&prefstate->pending_missing_keys)) { struct __prelim_ref *ref; - ref = list_entry(pos, struct __prelim_ref, list); - if (ref->parent) - continue; - if (ref->key_for_search.type) - continue; + ref = list_first_pref(&prefstate->pending_missing_keys); + + ASSERT(ref->root_id); + ASSERT(!ref->parent); + ASSERT(!ref->key_for_search.type); BUG_ON(!ref->wanted_disk_byte); - eb = read_tree_block(fs_info, ref->wanted_disk_byte, - fs_info->nodesize, 0); + eb = read_tree_block(fs_info, ref->wanted_disk_byte, 0); if (!extent_buffer_uptodate(eb)) { free_extent_buffer(eb); return -EIO; @@ -461,6 +477,7 @@ static int __add_missing_keys(struct btrfs_fs_info *fs_info, else btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0); free_extent_buffer(eb); + list_move(&ref->list, &prefstate->pending); } return 0; } @@ -475,8 +492,9 @@ static int __add_missing_keys(struct btrfs_fs_info *fs_info, * having a parent). * mode = 2: merge identical parents */ -static void __merge_refs(struct list_head *head, int mode) +static void __merge_refs(struct pref_state *prefstate, int mode) { + struct list_head *head = &prefstate->pending; struct list_head *pos1; list_for_each(pos1, head) { @@ -527,9 +545,9 @@ static void __merge_refs(struct list_head *head, int mode) * add all inline backrefs for bytenr to the list */ static int __add_inline_refs(struct btrfs_fs_info *fs_info, + struct pref_state *prefstate, struct btrfs_path *path, u64 bytenr, - int *info_level, struct list_head *prefs, - u64 *total_refs) + int *info_level, u64 *total_refs) { int ret = 0; int slot; @@ -541,7 +559,6 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, struct btrfs_extent_item *ei; u64 flags; u64 item_size; - /* * enumerate all inline refs */ @@ -584,7 +601,7 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, switch (type) { case BTRFS_SHARED_BLOCK_REF_KEY: - ret = __add_prelim_ref(prefs, 0, NULL, + ret = __add_prelim_ref(prefstate, 0, NULL, *info_level + 1, offset, bytenr, 1, GFP_NOFS); break; @@ -594,12 +611,12 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, 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(prefstate, 0, NULL, 0, offset, bytenr, count, GFP_NOFS); break; } case BTRFS_TREE_BLOCK_REF_KEY: - ret = __add_prelim_ref(prefs, offset, NULL, + ret = __add_prelim_ref(prefstate, offset, NULL, *info_level + 1, 0, bytenr, 1, GFP_NOFS); break; @@ -615,7 +632,7 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, key.type = BTRFS_EXTENT_DATA_KEY; key.offset = btrfs_extent_data_ref_offset(leaf, dref); root = btrfs_extent_data_ref_root(leaf, dref); - ret = __add_prelim_ref(prefs, root, &key, 0, 0, + ret = __add_prelim_ref(prefstate, root, &key, 0, 0, bytenr, count, GFP_NOFS); break; } @@ -634,8 +651,9 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, * add all non-inline backrefs for bytenr to the list */ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, + struct pref_state *prefstate, struct btrfs_path *path, u64 bytenr, - int info_level, struct list_head *prefs) + int info_level) { struct btrfs_root *extent_root = fs_info->extent_root; int ret; @@ -665,7 +683,7 @@ 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, + ret = __add_prelim_ref(prefstate, 0, NULL, info_level + 1, key.offset, bytenr, 1, GFP_NOFS); break; @@ -676,12 +694,12 @@ 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(prefstate, 0, NULL, 0, key.offset, bytenr, count, GFP_NOFS); break; } case BTRFS_TREE_BLOCK_REF_KEY: - ret = __add_prelim_ref(prefs, key.offset, NULL, + ret = __add_prelim_ref(prefstate, key.offset, NULL, info_level + 1, 0, bytenr, 1, GFP_NOFS); break; @@ -698,7 +716,7 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, key.type = BTRFS_EXTENT_DATA_KEY; key.offset = btrfs_extent_data_ref_offset(leaf, dref); root = btrfs_extent_data_ref_root(leaf, dref); - ret = __add_prelim_ref(prefs, root, &key, 0, 0, + ret = __add_prelim_ref(prefstate, root, &key, 0, 0, bytenr, count, GFP_NOFS); break; } @@ -730,12 +748,12 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, struct btrfs_path *path; int info_level = 0; int ret; - struct list_head prefs; + struct pref_state prefstate; struct __prelim_ref *ref; struct extent_inode_elem *eie = NULL; u64 total_refs = 0; - INIT_LIST_HEAD(&prefs); + init_pref_state(&prefstate); key.objectid = bytenr; key.offset = (u64)-1; @@ -764,34 +782,37 @@ 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(fs_info, path, bytenr, - &info_level, &prefs, + ret = __add_inline_refs(fs_info, &prefstate, path, + bytenr, &info_level, &total_refs); if (ret) goto out; - ret = __add_keyed_refs(fs_info, path, bytenr, - info_level, &prefs); + ret = __add_keyed_refs(fs_info, &prefstate, path, + bytenr, info_level); if (ret) goto out; } } btrfs_release_path(path); - ret = __add_missing_keys(fs_info, &prefs); + ret = __add_missing_keys(fs_info, &prefstate); if (ret) goto out; - __merge_refs(&prefs, 1); + __merge_refs(&prefstate, 1); - ret = __resolve_indirect_refs(fs_info, path, time_seq, &prefs, + ret = __resolve_indirect_refs(fs_info, &prefstate, path, time_seq, extent_item_pos, total_refs); if (ret) goto out; - __merge_refs(&prefs, 2); + __merge_refs(&prefstate, 2); - while (!list_empty(&prefs)) { - ref = list_first_entry(&prefs, struct __prelim_ref, list); + BUG_ON(!list_empty(&prefstate.pending_missing_keys)); + BUG_ON(!list_empty(&prefstate.pending_indirect_refs)); + + while (!list_empty(&prefstate.pending)) { + ref = list_first_pref(&prefstate.pending); WARN_ON(ref->count < 0); if (roots && ref->count && ref->root_id && ref->parent == 0) { /* no parent == root of tree */ @@ -802,11 +823,9 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, if (ref->count && ref->parent) { if (extent_item_pos && !ref->inode_list && ref->level == 0) { - u32 bsz; struct extent_buffer *eb; - bsz = fs_info->nodesize; - eb = read_tree_block(fs_info, - ref->parent, bsz, 0); + + eb = read_tree_block(fs_info, ref->parent, 0); if (!extent_buffer_uptodate(eb)) { free_extent_buffer(eb); ret = -EIO; @@ -842,8 +861,8 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, out: btrfs_free_path(path); - while (!list_empty(&prefs)) { - ref = list_first_entry(&prefs, struct __prelim_ref, list); + while (!list_empty(&prefstate.pending)) { + ref = list_first_pref(&prefstate.pending); list_del(&ref->list); kfree(ref); } |