diff options
| -rw-r--r-- | fs/btrfs/backref.c | 361 | ||||
| -rw-r--r-- | fs/btrfs/extent_io.c | 18 |
2 files changed, 369 insertions, 10 deletions
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index 455a6b2fd539..d9688adc763f 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -17,6 +17,7 @@ */ #include <linux/vmalloc.h> +#include <linux/rbtree.h> #include "ctree.h" #include "disk-io.h" #include "backref.h" @@ -34,6 +35,265 @@ struct extent_inode_elem { struct extent_inode_elem *next; }; +/* + * ref_root is used as the root of the ref tree that hold a collection + * of unique references. + */ +struct ref_root { + struct rb_root rb_root; + + /* + * The unique_refs represents the number of ref_nodes with a positive + * count stored in the tree. Even if a ref_node (the count is greater + * than one) is added, the unique_refs will only increase by one. + */ + unsigned int unique_refs; +}; + +/* ref_node is used to store a unique reference to the ref tree. */ +struct ref_node { + struct rb_node rb_node; + + /* For NORMAL_REF, otherwise all these fields should be set to 0 */ + u64 root_id; + u64 object_id; + u64 offset; + + /* For SHARED_REF, otherwise parent field should be set to 0 */ + u64 parent; + + /* Ref to the ref_mod of btrfs_delayed_ref_node */ + int ref_mod; +}; + +/* Dynamically allocate and initialize a ref_root */ +static struct ref_root *ref_root_alloc(void) +{ + struct ref_root *ref_tree; + + ref_tree = kmalloc(sizeof(*ref_tree), GFP_NOFS); + if (!ref_tree) + return NULL; + + ref_tree->rb_root = RB_ROOT; + ref_tree->unique_refs = 0; + + return ref_tree; +} + +/* Free all nodes in the ref tree, and reinit ref_root */ +static void ref_root_fini(struct ref_root *ref_tree) +{ + struct ref_node *node; + struct rb_node *next; + + while ((next = rb_first(&ref_tree->rb_root)) != NULL) { + node = rb_entry(next, struct ref_node, rb_node); + rb_erase(next, &ref_tree->rb_root); + kfree(node); + } + + ref_tree->rb_root = RB_ROOT; + ref_tree->unique_refs = 0; +} + +static void ref_root_free(struct ref_root *ref_tree) +{ + if (!ref_tree) + return; + + ref_root_fini(ref_tree); + kfree(ref_tree); +} + +/* + * Compare ref_node with (root_id, object_id, offset, parent) + * + * The function compares two ref_node a and b. It returns an integer less + * than, equal to, or greater than zero , respectively, to be less than, to + * equal, or be greater than b. + */ +static int ref_node_cmp(struct ref_node *a, struct ref_node *b) +{ + if (a->root_id < b->root_id) + return -1; + else if (a->root_id > b->root_id) + return 1; + + if (a->object_id < b->object_id) + return -1; + else if (a->object_id > b->object_id) + return 1; + + if (a->offset < b->offset) + return -1; + else if (a->offset > b->offset) + return 1; + + if (a->parent < b->parent) + return -1; + else if (a->parent > b->parent) + return 1; + + return 0; +} + +/* + * Search ref_node with (root_id, object_id, offset, parent) in the tree + * + * if found, the pointer of the ref_node will be returned; + * if not found, NULL will be returned and pos will point to the rb_node for + * insert, pos_parent will point to pos'parent for insert; +*/ +static struct ref_node *__ref_tree_search(struct ref_root *ref_tree, + struct rb_node ***pos, + struct rb_node **pos_parent, + u64 root_id, u64 object_id, + u64 offset, u64 parent) +{ + struct ref_node *cur = NULL; + struct ref_node entry; + int ret; + + entry.root_id = root_id; + entry.object_id = object_id; + entry.offset = offset; + entry.parent = parent; + + *pos = &ref_tree->rb_root.rb_node; + + while (**pos) { + *pos_parent = **pos; + cur = rb_entry(*pos_parent, struct ref_node, rb_node); + + ret = ref_node_cmp(cur, &entry); + if (ret > 0) + *pos = &(**pos)->rb_left; + else if (ret < 0) + *pos = &(**pos)->rb_right; + else + return cur; + } + + return NULL; +} + +/* + * Insert a ref_node to the ref tree + * @pos used for specifiy the position to insert + * @pos_parent for specifiy pos's parent + * + * success, return 0; + * ref_node already exists, return -EEXIST; +*/ +static int ref_tree_insert(struct ref_root *ref_tree, struct rb_node **pos, + struct rb_node *pos_parent, struct ref_node *ins) +{ + struct rb_node **p = NULL; + struct rb_node *parent = NULL; + struct ref_node *cur = NULL; + + if (!pos) { + cur = __ref_tree_search(ref_tree, &p, &parent, ins->root_id, + ins->object_id, ins->offset, + ins->parent); + if (cur) + return -EEXIST; + } else { + p = pos; + parent = pos_parent; + } + + rb_link_node(&ins->rb_node, parent, p); + rb_insert_color(&ins->rb_node, &ref_tree->rb_root); + + return 0; +} + +/* Erase and free ref_node, caller should update ref_root->unique_refs */ +static void ref_tree_remove(struct ref_root *ref_tree, struct ref_node *node) +{ + rb_erase(&node->rb_node, &ref_tree->rb_root); + kfree(node); +} + +/* + * Update ref_root->unique_refs + * + * Call __ref_tree_search + * 1. if ref_node doesn't exist, ref_tree_insert this node, and update + * ref_root->unique_refs: + * if ref_node->ref_mod > 0, ref_root->unique_refs++; + * if ref_node->ref_mod < 0, do noting; + * + * 2. if ref_node is found, then get origin ref_node->ref_mod, and update + * ref_node->ref_mod. + * if ref_node->ref_mod is equal to 0,then call ref_tree_remove + * + * according to origin_mod and new_mod, update ref_root->items + * +----------------+--------------+-------------+ + * | |new_count <= 0|new_count > 0| + * +----------------+--------------+-------------+ + * |origin_count < 0| 0 | 1 | + * +----------------+--------------+-------------+ + * |origin_count > 0| -1 | 0 | + * +----------------+--------------+-------------+ + * + * In case of allocation failure, -ENOMEM is returned and the ref_tree stays + * unaltered. + * Success, return 0 + */ +static int ref_tree_add(struct ref_root *ref_tree, u64 root_id, u64 object_id, + u64 offset, u64 parent, int count) +{ + struct ref_node *node = NULL; + struct rb_node **pos = NULL; + struct rb_node *pos_parent = NULL; + int origin_count; + int ret; + + if (!count) + return 0; + + node = __ref_tree_search(ref_tree, &pos, &pos_parent, root_id, + object_id, offset, parent); + if (node == NULL) { + node = kmalloc(sizeof(*node), GFP_NOFS); + if (!node) + return -ENOMEM; + + node->root_id = root_id; + node->object_id = object_id; + node->offset = offset; + node->parent = parent; + node->ref_mod = count; + + ret = ref_tree_insert(ref_tree, pos, pos_parent, node); + ASSERT(!ret); + if (ret) { + kfree(node); + return ret; + } + + ref_tree->unique_refs += node->ref_mod > 0 ? 1 : 0; + + return 0; + } + + origin_count = node->ref_mod; + node->ref_mod += count; + + if (node->ref_mod > 0) + ref_tree->unique_refs += origin_count > 0 ? 0 : 1; + else if (node->ref_mod <= 0) + ref_tree->unique_refs += origin_count > 0 ? -1 : 0; + + if (!node->ref_mod) + ref_tree_remove(ref_tree, node); + + return 0; +} + static int check_extent_in_eb(struct btrfs_key *key, struct extent_buffer *eb, struct btrfs_file_extent_item *fi, u64 extent_item_pos, @@ -700,6 +960,7 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, static int __add_inline_refs(struct btrfs_fs_info *fs_info, struct btrfs_path *path, u64 bytenr, int *info_level, struct list_head *prefs, + struct ref_root *ref_tree, u64 *total_refs, u64 inum) { int ret = 0; @@ -767,6 +1028,13 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, count = btrfs_shared_data_ref_count(leaf, sdref); ret = __add_prelim_ref(prefs, 0, NULL, 0, offset, bytenr, count, GFP_NOFS); + if (ref_tree) { + if (!ret) + ret = ref_tree_add(ref_tree, 0, 0, 0, + bytenr, count); + if (!ret && ref_tree->unique_refs > 1) + ret = BACKREF_FOUND_SHARED; + } break; } case BTRFS_TREE_BLOCK_REF_KEY: @@ -794,6 +1062,15 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, root = btrfs_extent_data_ref_root(leaf, dref); ret = __add_prelim_ref(prefs, root, &key, 0, 0, bytenr, count, GFP_NOFS); + if (ref_tree) { + if (!ret) + ret = ref_tree_add(ref_tree, root, + key.objectid, + key.offset, 0, + count); + if (!ret && ref_tree->unique_refs > 1) + ret = BACKREF_FOUND_SHARED; + } break; } default: @@ -812,7 +1089,8 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, */ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, struct btrfs_path *path, u64 bytenr, - int info_level, struct list_head *prefs, u64 inum) + int info_level, struct list_head *prefs, + struct ref_root *ref_tree, u64 inum) { struct btrfs_root *extent_root = fs_info->extent_root; int ret; @@ -855,6 +1133,13 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, count = btrfs_shared_data_ref_count(leaf, sdref); ret = __add_prelim_ref(prefs, 0, NULL, 0, key.offset, bytenr, count, GFP_NOFS); + if (ref_tree) { + if (!ret) + ret = ref_tree_add(ref_tree, 0, 0, 0, + bytenr, count); + if (!ret && ref_tree->unique_refs > 1) + ret = BACKREF_FOUND_SHARED; + } break; } case BTRFS_TREE_BLOCK_REF_KEY: @@ -883,6 +1168,15 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, root = btrfs_extent_data_ref_root(leaf, dref); ret = __add_prelim_ref(prefs, root, &key, 0, 0, bytenr, count, GFP_NOFS); + if (ref_tree) { + if (!ret) + ret = ref_tree_add(ref_tree, root, + key.objectid, + key.offset, 0, + count); + if (!ret && ref_tree->unique_refs > 1) + ret = BACKREF_FOUND_SHARED; + } break; } default: @@ -909,13 +1203,16 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, * commit root. * The special case is for qgroup to search roots in commit_transaction(). * + * If check_shared is set to 1, any extent has more than one ref item, will + * be returned BACKREF_FOUND_SHARED immediately. + * * FIXME some caching might speed things up */ static int find_parent_nodes(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, u64 bytenr, u64 time_seq, struct ulist *refs, struct ulist *roots, const u64 *extent_item_pos, - u64 root_objectid, u64 inum) + u64 root_objectid, u64 inum, int check_shared) { struct btrfs_key key; struct btrfs_path *path; @@ -927,6 +1224,7 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, struct list_head prefs; struct __prelim_ref *ref; struct extent_inode_elem *eie = NULL; + struct ref_root *ref_tree = NULL; u64 total_refs = 0; INIT_LIST_HEAD(&prefs); @@ -958,6 +1256,18 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, again: head = NULL; + if (check_shared) { + if (!ref_tree) { + ref_tree = ref_root_alloc(); + if (!ref_tree) { + ret = -ENOMEM; + goto out; + } + } else { + ref_root_fini(ref_tree); + } + } + ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0); if (ret < 0) goto out; @@ -1002,6 +1312,36 @@ again: } else { spin_unlock(&delayed_refs->lock); } + + if (check_shared && !list_empty(&prefs_delayed)) { + /* + * Add all delay_ref to the ref_tree and check if there + * are multiple ref items added. + */ + list_for_each_entry(ref, &prefs_delayed, list) { + if (ref->key_for_search.type) { + ret = ref_tree_add(ref_tree, + ref->root_id, + ref->key_for_search.objectid, + ref->key_for_search.offset, + 0, ref->count); + if (ret) + goto out; + } else { + ret = ref_tree_add(ref_tree, 0, 0, 0, + ref->parent, ref->count); + if (ret) + goto out; + } + + } + + if (ref_tree->unique_refs > 1) { + ret = BACKREF_FOUND_SHARED; + goto out; + } + + } } if (path->slots[0]) { @@ -1017,11 +1357,13 @@ again: key.type == BTRFS_METADATA_ITEM_KEY)) { ret = __add_inline_refs(fs_info, path, bytenr, &info_level, &prefs, - &total_refs, inum); + ref_tree, &total_refs, + inum); if (ret) goto out; ret = __add_keyed_refs(fs_info, path, bytenr, - info_level, &prefs, inum); + info_level, &prefs, + ref_tree, inum); if (ret) goto out; } @@ -1106,6 +1448,7 @@ again: out: btrfs_free_path(path); + ref_root_free(ref_tree); while (!list_empty(&prefs)) { ref = list_first_entry(&prefs, struct __prelim_ref, list); list_del(&ref->list); @@ -1159,8 +1502,8 @@ static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, if (!*leafs) return -ENOMEM; - ret = find_parent_nodes(trans, fs_info, bytenr, - time_seq, *leafs, NULL, extent_item_pos, 0, 0); + ret = find_parent_nodes(trans, fs_info, bytenr, time_seq, + *leafs, NULL, extent_item_pos, 0, 0, 0); if (ret < 0 && ret != -ENOENT) { free_leaf_list(*leafs); return ret; @@ -1202,8 +1545,8 @@ static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans, ULIST_ITER_INIT(&uiter); while (1) { - ret = find_parent_nodes(trans, fs_info, bytenr, - time_seq, tmp, *roots, NULL, 0, 0); + ret = find_parent_nodes(trans, fs_info, bytenr, time_seq, + tmp, *roots, NULL, 0, 0, 0); if (ret < 0 && ret != -ENOENT) { ulist_free(tmp); ulist_free(*roots); @@ -1273,7 +1616,7 @@ int btrfs_check_shared(struct btrfs_trans_handle *trans, ULIST_ITER_INIT(&uiter); while (1) { ret = find_parent_nodes(trans, fs_info, bytenr, elem.seq, tmp, - roots, NULL, root_objectid, inum); + roots, NULL, root_objectid, inum, 1); if (ret == BACKREF_FOUND_SHARED) { /* this is the only condition under which we return 1 */ ret = 1; diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 44fe66b53c8b..8644df8ba527 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -20,6 +20,7 @@ #include "locking.h" #include "rcu-string.h" #include "backref.h" +#include "transaction.h" static struct kmem_cache *extent_state_cache; static struct kmem_cache *extent_buffer_cache; @@ -4487,21 +4488,36 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, flags |= (FIEMAP_EXTENT_DELALLOC | FIEMAP_EXTENT_UNKNOWN); } else if (fieinfo->fi_extents_max) { + struct btrfs_trans_handle *trans; + u64 bytenr = em->block_start - (em->start - em->orig_start); disko = em->block_start + offset_in_extent; /* + * We need a trans handle to get delayed refs + */ + trans = btrfs_join_transaction(root); + /* + * It's OK if we can't start a trans we can still check + * from commit_root + */ + if (IS_ERR(trans)) + trans = NULL; + + /* * As btrfs supports shared space, this information * can be exported to userspace tools via * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0 * then we're just getting a count and we can skip the * lookup stuff. */ - ret = btrfs_check_shared(NULL, root->fs_info, + ret = btrfs_check_shared(trans, root->fs_info, root->objectid, btrfs_ino(inode), bytenr); + if (trans) + btrfs_end_transaction(trans, root); if (ret < 0) goto out_free; if (ret) |