diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/backref.c | 240 | ||||
| -rw-r--r-- | fs/btrfs/backref.h | 2 |
2 files changed, 158 insertions, 84 deletions
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index 366978c5cdd3..fd13101aafa3 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -24,6 +24,79 @@ #include "delayed-ref.h" #include "locking.h" +struct extent_inode_elem { + u64 inum; + u64 offset; + struct extent_inode_elem *next; +}; + +static int check_extent_in_eb(struct btrfs_key *key, struct extent_buffer *eb, + struct btrfs_file_extent_item *fi, + u64 extent_item_pos, + struct extent_inode_elem **eie) +{ + u64 data_offset; + u64 data_len; + struct extent_inode_elem *e; + + data_offset = btrfs_file_extent_offset(eb, fi); + data_len = btrfs_file_extent_num_bytes(eb, fi); + + if (extent_item_pos < data_offset || + extent_item_pos >= data_offset + data_len) + return 1; + + e = kmalloc(sizeof(*e), GFP_NOFS); + if (!e) + return -ENOMEM; + + e->next = *eie; + e->inum = key->objectid; + e->offset = key->offset + (extent_item_pos - data_offset); + *eie = e; + + return 0; +} + +static int find_extent_in_eb(struct extent_buffer *eb, u64 wanted_disk_byte, + u64 extent_item_pos, + struct extent_inode_elem **eie) +{ + u64 disk_byte; + struct btrfs_key key; + struct btrfs_file_extent_item *fi; + int slot; + int nritems; + int extent_type; + int ret; + + /* + * from the shared data ref, we only have the leaf but we need + * the key. thus, we must look into all items and see that we + * find one (some) with a reference to our extent item. + */ + nritems = btrfs_header_nritems(eb); + for (slot = 0; slot < nritems; ++slot) { + btrfs_item_key_to_cpu(eb, &key, slot); + if (key.type != BTRFS_EXTENT_DATA_KEY) + continue; + fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); + extent_type = btrfs_file_extent_type(eb, fi); + if (extent_type == BTRFS_FILE_EXTENT_INLINE) + continue; + /* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */ + disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); + if (disk_byte != wanted_disk_byte) + continue; + + ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie); + if (ret < 0) + return ret; + } + + return 0; +} + /* * this structure records all encountered refs on the way up to the root */ @@ -103,15 +176,16 @@ 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 extent_buffer *eb, int level, - u64 wanted_objectid, u64 wanted_disk_byte) + struct ulist *parents, int level, + struct btrfs_key *key, u64 wanted_disk_byte, + const u64 *extent_item_pos) { int ret; int slot; + struct extent_buffer *eb = path->nodes[level]; struct btrfs_file_extent_item *fi; - struct btrfs_key key; u64 disk_byte; + u64 wanted_objectid = key->objectid; add_parent: ret = ulist_add(parents, eb->start, 0, GFP_NOFS); @@ -136,9 +210,9 @@ add_parent: eb = path->nodes[0]; for (slot = 0; slot < btrfs_header_nritems(eb); ++slot) { - btrfs_item_key_to_cpu(eb, &key, slot); - if (key.objectid != wanted_objectid || - key.type != BTRFS_EXTENT_DATA_KEY) + btrfs_item_key_to_cpu(eb, key, slot); + if (key->objectid != wanted_objectid || + key->type != BTRFS_EXTENT_DATA_KEY) return 0; fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); @@ -158,7 +232,8 @@ add_parent: static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, int search_commit_root, struct __prelim_ref *ref, - struct ulist *parents) + struct ulist *parents, + const u64 *extent_item_pos) { struct btrfs_path *path; struct btrfs_root *root; @@ -219,9 +294,8 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, btrfs_item_key_to_cpu(eb, &key, path->slots[0]); } - /* the last two parameters will only be used for level == 0 */ - ret = add_all_parents(root, path, parents, eb, level, key.objectid, - ref->wanted_disk_byte); + ret = add_all_parents(root, path, parents, level, &key, + ref->wanted_disk_byte, extent_item_pos); out: btrfs_free_path(path); return ret; @@ -232,7 +306,8 @@ out: */ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, int search_commit_root, - struct list_head *head) + struct list_head *head, + const u64 *extent_item_pos) { int err; int ret = 0; @@ -258,7 +333,7 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, if (ref->count == 0) continue; err = __resolve_indirect_ref(fs_info, search_commit_root, - ref, parents); + ref, parents, extent_item_pos); if (err) { if (ret == 0) ret = err; @@ -675,7 +750,8 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, */ static int find_parent_nodes(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, u64 bytenr, - u64 seq, struct ulist *refs, struct ulist *roots) + u64 seq, struct ulist *refs, struct ulist *roots, + const u64 *extent_item_pos) { struct btrfs_key key; struct btrfs_path *path; @@ -778,7 +854,8 @@ again: if (ret) goto out; - ret = __resolve_indirect_refs(fs_info, search_commit_root, &prefs); + ret = __resolve_indirect_refs(fs_info, search_commit_root, &prefs, + extent_item_pos); if (ret) goto out; @@ -797,7 +874,21 @@ again: BUG_ON(ret < 0); } if (ref->count && ref->parent) { - ret = ulist_add(refs, ref->parent, 0, GFP_NOFS); + struct extent_inode_elem *eie = NULL; + if (extent_item_pos) { + u32 bsz; + struct extent_buffer *eb; + bsz = btrfs_level_size(fs_info->extent_root, + info_level); + eb = read_tree_block(fs_info->extent_root, + ref->parent, bsz, 0); + BUG_ON(!eb); + ret = find_extent_in_eb(eb, bytenr, + *extent_item_pos, &eie); + free_extent_buffer(eb); + } + ret = ulist_add(refs, ref->parent, + (unsigned long)eie, GFP_NOFS); BUG_ON(ret < 0); } kfree(ref); @@ -822,6 +913,28 @@ out: return ret; } +static void free_leaf_list(struct ulist *blocks) +{ + struct ulist_node *node = NULL; + struct extent_inode_elem *eie; + struct extent_inode_elem *eie_next; + struct ulist_iterator uiter; + + ULIST_ITER_INIT(&uiter); + while ((node = ulist_next(blocks, &uiter))) { + if (!node->aux) + continue; + eie = (struct extent_inode_elem *)node->aux; + for (; eie; eie = eie_next) { + eie_next = eie->next; + kfree(eie); + } + node->aux = 0; + } + + ulist_free(blocks); +} + /* * Finds all leafs with a reference to the specified combination of bytenr and * offset. key_list_head will point to a list of corresponding keys (caller must @@ -832,7 +945,8 @@ out: */ static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, u64 bytenr, - u64 num_bytes, u64 seq, struct ulist **leafs) + u64 seq, struct ulist **leafs, + const u64 *extent_item_pos) { struct ulist *tmp; int ret; @@ -846,11 +960,12 @@ static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, return -ENOMEM; } - ret = find_parent_nodes(trans, fs_info, bytenr, seq, *leafs, tmp); + ret = find_parent_nodes(trans, fs_info, bytenr, seq, *leafs, tmp, + extent_item_pos); ulist_free(tmp); if (ret < 0 && ret != -ENOENT) { - ulist_free(*leafs); + free_leaf_list(*leafs); return ret; } @@ -872,7 +987,7 @@ static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, */ int btrfs_find_all_roots(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, u64 bytenr, - u64 num_bytes, u64 seq, struct ulist **roots) + u64 seq, struct ulist **roots) { struct ulist *tmp; struct ulist_node *node = NULL; @@ -891,7 +1006,7 @@ int btrfs_find_all_roots(struct btrfs_trans_handle *trans, ULIST_ITER_INIT(&uiter); while (1) { ret = find_parent_nodes(trans, fs_info, bytenr, seq, - tmp, *roots); + tmp, *roots, NULL); if (ret < 0 && ret != -ENOENT) { ulist_free(tmp); ulist_free(*roots); @@ -1183,67 +1298,25 @@ int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, return 0; } -static int iterate_leaf_refs(struct btrfs_fs_info *fs_info, u64 logical, - u64 orig_extent_item_objectid, - u64 extent_item_pos, u64 root, +static int iterate_leaf_refs(struct extent_inode_elem *inode_list, + u64 root, u64 extent_item_objectid, iterate_extent_inodes_t *iterate, void *ctx) { - u64 disk_byte; - struct btrfs_key key; - struct btrfs_file_extent_item *fi; - struct extent_buffer *eb; - int slot; - int nritems; + struct extent_inode_elem *eie; int ret = 0; - int extent_type; - u64 data_offset; - u64 data_len; - - eb = read_tree_block(fs_info->tree_root, logical, - fs_info->tree_root->leafsize, 0); - if (!eb) - return -EIO; - - /* - * from the shared data ref, we only have the leaf but we need - * the key. thus, we must look into all items and see that we - * find one (some) with a reference to our extent item. - */ - nritems = btrfs_header_nritems(eb); - for (slot = 0; slot < nritems; ++slot) { - btrfs_item_key_to_cpu(eb, &key, slot); - if (key.type != BTRFS_EXTENT_DATA_KEY) - continue; - fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); - extent_type = btrfs_file_extent_type(eb, fi); - if (extent_type == BTRFS_FILE_EXTENT_INLINE) - continue; - /* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */ - disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); - if (disk_byte != orig_extent_item_objectid) - continue; - - data_offset = btrfs_file_extent_offset(eb, fi); - data_len = btrfs_file_extent_num_bytes(eb, fi); - - if (extent_item_pos < data_offset || - extent_item_pos >= data_offset + data_len) - continue; + for (eie = inode_list; eie; eie = eie->next) { pr_debug("ref for %llu resolved, key (%llu EXTEND_DATA %llu), " - "root %llu\n", orig_extent_item_objectid, - key.objectid, key.offset, root); - ret = iterate(key.objectid, - key.offset + (extent_item_pos - data_offset), - root, ctx); + "root %llu\n", extent_item_objectid, + eie->inum, eie->offset, root); + ret = iterate(eie->inum, eie->offset, root, ctx); if (ret) { - pr_debug("stopping iteration because ret=%d\n", ret); + pr_debug("stopping iteration for %llu due to ret=%d\n", + extent_item_objectid, ret); break; } } - free_extent_buffer(eb); - return ret; } @@ -1287,30 +1360,31 @@ int iterate_extent_inodes(struct btrfs_fs_info *fs_info, } ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid, - extent_item_pos, seq_elem.seq, - &refs); - + seq_elem.seq, &refs, &extent_item_pos); if (ret) goto out; 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, -1, + ret = btrfs_find_all_roots(trans, fs_info, ref_node->val, seq_elem.seq, &roots); if (ret) break; ULIST_ITER_INIT(&root_uiter); while (!ret && (root_node = ulist_next(roots, &root_uiter))) { - pr_debug("root %llu references leaf %llu\n", - root_node->val, ref_node->val); - ret = iterate_leaf_refs(fs_info, ref_node->val, - extent_item_objectid, - extent_item_pos, root_node->val, - iterate, ctx); + pr_debug("root %llu references leaf %llu, data list " + "%#lx\n", root_node->val, ref_node->val, + ref_node->aux); + ret = iterate_leaf_refs( + (struct extent_inode_elem *)ref_node->aux, + root_node->val, extent_item_objectid, + iterate, ctx); } + ulist_free(roots); + roots = NULL; } - ulist_free(refs); + free_leaf_list(refs); ulist_free(roots); out: if (!search_commit_root) { diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h index 57ea2e959e4d..94ba1b2e733b 100644 --- a/fs/btrfs/backref.h +++ b/fs/btrfs/backref.h @@ -58,7 +58,7 @@ int paths_from_inode(u64 inum, struct inode_fs_paths *ipath); int btrfs_find_all_roots(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, u64 bytenr, - u64 num_bytes, u64 seq, struct ulist **roots); + u64 seq, struct ulist **roots); struct btrfs_data_container *init_data_container(u32 total_bytes); struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, |
