| /* |
| * Copyright (C) 2007 Oracle. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public |
| * License v2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public |
| * License along with this program; if not, write to the |
| * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| * Boston, MA 021110-1307, USA. |
| */ |
| #include "ctree.h" |
| #include "disk-io.h" |
| #include "transaction.h" |
| #include "print-tree.h" |
| #include "repair.h" |
| |
| static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, struct btrfs_path *path, int level); |
| static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, struct btrfs_key *ins_key, |
| struct btrfs_path *path, int data_size, int extend); |
| static int push_node_left(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, struct extent_buffer *dst, |
| struct extent_buffer *src, int empty); |
| static int balance_node_right(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct extent_buffer *dst_buf, |
| struct extent_buffer *src_buf); |
| |
| inline void btrfs_init_path(struct btrfs_path *p) |
| { |
| memset(p, 0, sizeof(*p)); |
| } |
| |
| struct btrfs_path *btrfs_alloc_path(void) |
| { |
| struct btrfs_path *path; |
| path = kzalloc(sizeof(struct btrfs_path), GFP_NOFS); |
| return path; |
| } |
| |
| void btrfs_free_path(struct btrfs_path *p) |
| { |
| if (!p) |
| return; |
| btrfs_release_path(p); |
| kfree(p); |
| } |
| |
| void btrfs_release_path(struct btrfs_path *p) |
| { |
| int i; |
| for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
| if (!p->nodes[i]) |
| continue; |
| free_extent_buffer(p->nodes[i]); |
| } |
| memset(p, 0, sizeof(*p)); |
| } |
| |
| void add_root_to_dirty_list(struct btrfs_root *root) |
| { |
| if (root->track_dirty && list_empty(&root->dirty_list)) { |
| list_add(&root->dirty_list, |
| &root->fs_info->dirty_cowonly_roots); |
| } |
| } |
| |
| int btrfs_copy_root(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct extent_buffer *buf, |
| struct extent_buffer **cow_ret, u64 new_root_objectid) |
| { |
| struct extent_buffer *cow; |
| int ret = 0; |
| int level; |
| struct btrfs_root *new_root; |
| struct btrfs_disk_key disk_key; |
| |
| new_root = kmalloc(sizeof(*new_root), GFP_NOFS); |
| if (!new_root) |
| return -ENOMEM; |
| |
| memcpy(new_root, root, sizeof(*new_root)); |
| new_root->root_key.objectid = new_root_objectid; |
| |
| WARN_ON(root->ref_cows && trans->transid != |
| root->fs_info->running_transaction->transid); |
| WARN_ON(root->ref_cows && trans->transid != root->last_trans); |
| |
| level = btrfs_header_level(buf); |
| if (level == 0) |
| btrfs_item_key(buf, &disk_key, 0); |
| else |
| btrfs_node_key(buf, &disk_key, 0); |
| cow = btrfs_alloc_free_block(trans, new_root, buf->len, |
| new_root_objectid, &disk_key, |
| level, buf->start, 0); |
| if (IS_ERR(cow)) { |
| kfree(new_root); |
| return PTR_ERR(cow); |
| } |
| |
| copy_extent_buffer(cow, buf, 0, 0, cow->len); |
| btrfs_set_header_bytenr(cow, cow->start); |
| btrfs_set_header_generation(cow, trans->transid); |
| btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
| btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | |
| BTRFS_HEADER_FLAG_RELOC); |
| if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) |
| btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); |
| else |
| btrfs_set_header_owner(cow, new_root_objectid); |
| |
| write_extent_buffer(cow, root->fs_info->fsid, |
| btrfs_header_fsid(), BTRFS_FSID_SIZE); |
| |
| WARN_ON(btrfs_header_generation(buf) > trans->transid); |
| ret = btrfs_inc_ref(trans, new_root, cow, 0); |
| kfree(new_root); |
| |
| if (ret) |
| return ret; |
| |
| btrfs_mark_buffer_dirty(cow); |
| *cow_ret = cow; |
| return 0; |
| } |
| |
| /* |
| * check if the tree block can be shared by multiple trees |
| */ |
| static int btrfs_block_can_be_shared(struct btrfs_root *root, |
| struct extent_buffer *buf) |
| { |
| /* |
| * Tree blocks not in refernece counted trees and tree roots |
| * are never shared. If a block was allocated after the last |
| * snapshot and the block was not allocated by tree relocation, |
| * we know the block is not shared. |
| */ |
| if (root->ref_cows && |
| buf != root->node && buf != root->commit_root && |
| (btrfs_header_generation(buf) <= |
| btrfs_root_last_snapshot(&root->root_item) || |
| btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) |
| return 1; |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| if (root->ref_cows && |
| btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) |
| return 1; |
| #endif |
| return 0; |
| } |
| |
| static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct extent_buffer *buf, |
| struct extent_buffer *cow) |
| { |
| u64 refs; |
| u64 owner; |
| u64 flags; |
| u64 new_flags = 0; |
| int ret; |
| |
| /* |
| * Backrefs update rules: |
| * |
| * Always use full backrefs for extent pointers in tree block |
| * allocated by tree relocation. |
| * |
| * If a shared tree block is no longer referenced by its owner |
| * tree (btrfs_header_owner(buf) == root->root_key.objectid), |
| * use full backrefs for extent pointers in tree block. |
| * |
| * If a tree block is been relocating |
| * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), |
| * use full backrefs for extent pointers in tree block. |
| * The reason for this is some operations (such as drop tree) |
| * are only allowed for blocks use full backrefs. |
| */ |
| |
| if (btrfs_block_can_be_shared(root, buf)) { |
| ret = btrfs_lookup_extent_info(trans, root, buf->start, |
| btrfs_header_level(buf), 1, |
| &refs, &flags); |
| BUG_ON(ret); |
| BUG_ON(refs == 0); |
| } else { |
| refs = 1; |
| if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
| btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) |
| flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; |
| else |
| flags = 0; |
| } |
| |
| owner = btrfs_header_owner(buf); |
| BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) && |
| owner == BTRFS_TREE_RELOC_OBJECTID); |
| |
| if (refs > 1) { |
| if ((owner == root->root_key.objectid || |
| root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && |
| !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { |
| ret = btrfs_inc_ref(trans, root, buf, 1); |
| BUG_ON(ret); |
| |
| if (root->root_key.objectid == |
| BTRFS_TREE_RELOC_OBJECTID) { |
| ret = btrfs_dec_ref(trans, root, buf, 0); |
| BUG_ON(ret); |
| ret = btrfs_inc_ref(trans, root, cow, 1); |
| BUG_ON(ret); |
| } |
| new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; |
| } else { |
| |
| if (root->root_key.objectid == |
| BTRFS_TREE_RELOC_OBJECTID) |
| ret = btrfs_inc_ref(trans, root, cow, 1); |
| else |
| ret = btrfs_inc_ref(trans, root, cow, 0); |
| BUG_ON(ret); |
| } |
| if (new_flags != 0) { |
| ret = btrfs_set_block_flags(trans, root, buf->start, |
| btrfs_header_level(buf), |
| new_flags); |
| BUG_ON(ret); |
| } |
| } else { |
| if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { |
| if (root->root_key.objectid == |
| BTRFS_TREE_RELOC_OBJECTID) |
| ret = btrfs_inc_ref(trans, root, cow, 1); |
| else |
| ret = btrfs_inc_ref(trans, root, cow, 0); |
| BUG_ON(ret); |
| ret = btrfs_dec_ref(trans, root, buf, 1); |
| BUG_ON(ret); |
| } |
| clean_tree_block(trans, root, buf); |
| } |
| return 0; |
| } |
| |
| int __btrfs_cow_block(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct extent_buffer *buf, |
| struct extent_buffer *parent, int parent_slot, |
| struct extent_buffer **cow_ret, |
| u64 search_start, u64 empty_size) |
| { |
| struct extent_buffer *cow; |
| struct btrfs_disk_key disk_key; |
| int level; |
| |
| WARN_ON(root->ref_cows && trans->transid != |
| root->fs_info->running_transaction->transid); |
| WARN_ON(root->ref_cows && trans->transid != root->last_trans); |
| |
| level = btrfs_header_level(buf); |
| |
| if (level == 0) |
| btrfs_item_key(buf, &disk_key, 0); |
| else |
| btrfs_node_key(buf, &disk_key, 0); |
| |
| cow = btrfs_alloc_free_block(trans, root, buf->len, |
| root->root_key.objectid, &disk_key, |
| level, search_start, empty_size); |
| if (IS_ERR(cow)) |
| return PTR_ERR(cow); |
| |
| copy_extent_buffer(cow, buf, 0, 0, cow->len); |
| btrfs_set_header_bytenr(cow, cow->start); |
| btrfs_set_header_generation(cow, trans->transid); |
| btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
| btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | |
| BTRFS_HEADER_FLAG_RELOC); |
| if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) |
| btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); |
| else |
| btrfs_set_header_owner(cow, root->root_key.objectid); |
| |
| write_extent_buffer(cow, root->fs_info->fsid, |
| btrfs_header_fsid(), BTRFS_FSID_SIZE); |
| |
| WARN_ON(!(buf->flags & EXTENT_BAD_TRANSID) && |
| btrfs_header_generation(buf) > trans->transid); |
| |
| update_ref_for_cow(trans, root, buf, cow); |
| |
| if (buf == root->node) { |
| root->node = cow; |
| extent_buffer_get(cow); |
| |
| btrfs_free_extent(trans, root, buf->start, buf->len, |
| 0, root->root_key.objectid, level, 0); |
| free_extent_buffer(buf); |
| add_root_to_dirty_list(root); |
| } else { |
| btrfs_set_node_blockptr(parent, parent_slot, |
| cow->start); |
| WARN_ON(trans->transid == 0); |
| btrfs_set_node_ptr_generation(parent, parent_slot, |
| trans->transid); |
| btrfs_mark_buffer_dirty(parent); |
| WARN_ON(btrfs_header_generation(parent) != trans->transid); |
| |
| btrfs_free_extent(trans, root, buf->start, buf->len, |
| 0, root->root_key.objectid, level, 1); |
| } |
| if (!list_empty(&buf->recow)) { |
| list_del_init(&buf->recow); |
| free_extent_buffer(buf); |
| } |
| free_extent_buffer(buf); |
| btrfs_mark_buffer_dirty(cow); |
| *cow_ret = cow; |
| return 0; |
| } |
| |
| static inline int should_cow_block(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct extent_buffer *buf) |
| { |
| if (btrfs_header_generation(buf) == trans->transid && |
| !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && |
| !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && |
| btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) |
| return 0; |
| return 1; |
| } |
| |
| int btrfs_cow_block(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, struct extent_buffer *buf, |
| struct extent_buffer *parent, int parent_slot, |
| struct extent_buffer **cow_ret) |
| { |
| u64 search_start; |
| int ret; |
| /* |
| if (trans->transaction != root->fs_info->running_transaction) { |
| printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid, |
| root->fs_info->running_transaction->transid); |
| WARN_ON(1); |
| } |
| */ |
| if (trans->transid != root->fs_info->generation) { |
| printk(KERN_CRIT "trans %llu running %llu\n", |
| (unsigned long long)trans->transid, |
| (unsigned long long)root->fs_info->generation); |
| WARN_ON(1); |
| } |
| if (!should_cow_block(trans, root, buf)) { |
| *cow_ret = buf; |
| return 0; |
| } |
| |
| search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1); |
| ret = __btrfs_cow_block(trans, root, buf, parent, |
| parent_slot, cow_ret, search_start, 0); |
| return ret; |
| } |
| |
| int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2) |
| { |
| if (k1->objectid > k2->objectid) |
| return 1; |
| if (k1->objectid < k2->objectid) |
| return -1; |
| if (k1->type > k2->type) |
| return 1; |
| if (k1->type < k2->type) |
| return -1; |
| if (k1->offset > k2->offset) |
| return 1; |
| if (k1->offset < k2->offset) |
| return -1; |
| return 0; |
| } |
| |
| /* |
| * compare two keys in a memcmp fashion |
| */ |
| static int btrfs_comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) |
| { |
| struct btrfs_key k1; |
| |
| btrfs_disk_key_to_cpu(&k1, disk); |
| return btrfs_comp_cpu_keys(&k1, k2); |
| } |
| |
| /* |
| * The leaf data grows from end-to-front in the node. |
| * this returns the address of the start of the last item, |
| * which is the stop of the leaf data stack |
| */ |
| static inline unsigned int leaf_data_end(struct btrfs_root *root, |
| struct extent_buffer *leaf) |
| { |
| u32 nr = btrfs_header_nritems(leaf); |
| if (nr == 0) |
| return BTRFS_LEAF_DATA_SIZE(root); |
| return btrfs_item_offset_nr(leaf, nr - 1); |
| } |
| |
| enum btrfs_tree_block_status |
| btrfs_check_node(struct btrfs_root *root, struct btrfs_disk_key *parent_key, |
| struct extent_buffer *buf) |
| { |
| int i; |
| struct btrfs_key cpukey; |
| struct btrfs_disk_key key; |
| u32 nritems = btrfs_header_nritems(buf); |
| enum btrfs_tree_block_status ret = BTRFS_TREE_BLOCK_INVALID_NRITEMS; |
| |
| if (nritems == 0 || nritems > BTRFS_NODEPTRS_PER_BLOCK(root)) |
| goto fail; |
| |
| ret = BTRFS_TREE_BLOCK_INVALID_PARENT_KEY; |
| if (parent_key && parent_key->type) { |
| btrfs_node_key(buf, &key, 0); |
| if (memcmp(parent_key, &key, sizeof(key))) |
| goto fail; |
| } |
| ret = BTRFS_TREE_BLOCK_BAD_KEY_ORDER; |
| for (i = 0; nritems > 1 && i < nritems - 2; i++) { |
| btrfs_node_key(buf, &key, i); |
| btrfs_node_key_to_cpu(buf, &cpukey, i + 1); |
| if (btrfs_comp_keys(&key, &cpukey) >= 0) |
| goto fail; |
| } |
| return BTRFS_TREE_BLOCK_CLEAN; |
| fail: |
| if (btrfs_header_owner(buf) == BTRFS_EXTENT_TREE_OBJECTID) { |
| if (parent_key) |
| btrfs_disk_key_to_cpu(&cpukey, parent_key); |
| else |
| btrfs_node_key_to_cpu(buf, &cpukey, 0); |
| btrfs_add_corrupt_extent_record(root->fs_info, &cpukey, |
| buf->start, buf->len, |
| btrfs_header_level(buf)); |
| } |
| return ret; |
| } |
| |
| enum btrfs_tree_block_status |
| btrfs_check_leaf(struct btrfs_root *root, struct btrfs_disk_key *parent_key, |
| struct extent_buffer *buf) |
| { |
| int i; |
| struct btrfs_key cpukey; |
| struct btrfs_disk_key key; |
| u32 nritems = btrfs_header_nritems(buf); |
| enum btrfs_tree_block_status ret = BTRFS_TREE_BLOCK_INVALID_NRITEMS; |
| |
| if (nritems * sizeof(struct btrfs_item) > buf->len) { |
| fprintf(stderr, "invalid number of items %llu\n", |
| (unsigned long long)buf->start); |
| goto fail; |
| } |
| |
| if (btrfs_header_level(buf) != 0) { |
| ret = BTRFS_TREE_BLOCK_INVALID_LEVEL; |
| fprintf(stderr, "leaf is not a leaf %llu\n", |
| (unsigned long long)btrfs_header_bytenr(buf)); |
| goto fail; |
| } |
| if (btrfs_leaf_free_space(root, buf) < 0) { |
| ret = BTRFS_TREE_BLOCK_INVALID_FREE_SPACE; |
| fprintf(stderr, "leaf free space incorrect %llu %d\n", |
| (unsigned long long)btrfs_header_bytenr(buf), |
| btrfs_leaf_free_space(root, buf)); |
| goto fail; |
| } |
| |
| if (nritems == 0) |
| return BTRFS_TREE_BLOCK_CLEAN; |
| |
| btrfs_item_key(buf, &key, 0); |
| if (parent_key && parent_key->type && |
| memcmp(parent_key, &key, sizeof(key))) { |
| ret = BTRFS_TREE_BLOCK_INVALID_PARENT_KEY; |
| fprintf(stderr, "leaf parent key incorrect %llu\n", |
| (unsigned long long)btrfs_header_bytenr(buf)); |
| goto fail; |
| } |
| for (i = 0; nritems > 1 && i < nritems - 1; i++) { |
| btrfs_item_key(buf, &key, i); |
| btrfs_item_key_to_cpu(buf, &cpukey, i + 1); |
| if (btrfs_comp_keys(&key, &cpukey) >= 0) { |
| ret = BTRFS_TREE_BLOCK_BAD_KEY_ORDER; |
| fprintf(stderr, "bad key ordering %d %d\n", i, i+1); |
| goto fail; |
| } |
| if (btrfs_item_offset_nr(buf, i) != |
| btrfs_item_end_nr(buf, i + 1)) { |
| ret = BTRFS_TREE_BLOCK_INVALID_OFFSETS; |
| fprintf(stderr, "incorrect offsets %u %u\n", |
| btrfs_item_offset_nr(buf, i), |
| btrfs_item_end_nr(buf, i + 1)); |
| goto fail; |
| } |
| if (i == 0 && btrfs_item_end_nr(buf, i) != |
| BTRFS_LEAF_DATA_SIZE(root)) { |
| ret = BTRFS_TREE_BLOCK_INVALID_OFFSETS; |
| fprintf(stderr, "bad item end %u wanted %u\n", |
| btrfs_item_end_nr(buf, i), |
| (unsigned)BTRFS_LEAF_DATA_SIZE(root)); |
| goto fail; |
| } |
| } |
| return BTRFS_TREE_BLOCK_CLEAN; |
| fail: |
| if (btrfs_header_owner(buf) == BTRFS_EXTENT_TREE_OBJECTID) { |
| if (parent_key) |
| btrfs_disk_key_to_cpu(&cpukey, parent_key); |
| else |
| btrfs_item_key_to_cpu(buf, &cpukey, 0); |
| |
| btrfs_add_corrupt_extent_record(root->fs_info, &cpukey, |
| buf->start, buf->len, 0); |
| } |
| return ret; |
| } |
| |
| static int noinline check_block(struct btrfs_root *root, |
| struct btrfs_path *path, int level) |
| { |
| struct btrfs_disk_key key; |
| struct btrfs_disk_key *key_ptr = NULL; |
| struct extent_buffer *parent; |
| enum btrfs_tree_block_status ret; |
| |
| if (path->skip_check_block) |
| return 0; |
| if (path->nodes[level + 1]) { |
| parent = path->nodes[level + 1]; |
| btrfs_node_key(parent, &key, path->slots[level + 1]); |
| key_ptr = &key; |
| } |
| if (level == 0) |
| ret = btrfs_check_leaf(root, key_ptr, path->nodes[0]); |
| else |
| ret = btrfs_check_node(root, key_ptr, path->nodes[level]); |
| if (ret == BTRFS_TREE_BLOCK_CLEAN) |
| return 0; |
| return -EIO; |
| } |
| |
| /* |
| * search for key in the extent_buffer. The items start at offset p, |
| * and they are item_size apart. There are 'max' items in p. |
| * |
| * the slot in the array is returned via slot, and it points to |
| * the place where you would insert key if it is not found in |
| * the array. |
| * |
| * slot may point to max if the key is bigger than all of the keys |
| */ |
| static int generic_bin_search(struct extent_buffer *eb, unsigned long p, |
| int item_size, struct btrfs_key *key, |
| int max, int *slot) |
| { |
| int low = 0; |
| int high = max; |
| int mid; |
| int ret; |
| unsigned long offset; |
| struct btrfs_disk_key *tmp; |
| |
| while(low < high) { |
| mid = (low + high) / 2; |
| offset = p + mid * item_size; |
| |
| tmp = (struct btrfs_disk_key *)(eb->data + offset); |
| ret = btrfs_comp_keys(tmp, key); |
| |
| if (ret < 0) |
| low = mid + 1; |
| else if (ret > 0) |
| high = mid; |
| else { |
| *slot = mid; |
| return 0; |
| } |
| } |
| *slot = low; |
| return 1; |
| } |
| |
| /* |
| * simple bin_search frontend that does the right thing for |
| * leaves vs nodes |
| */ |
| static int bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
| int level, int *slot) |
| { |
| if (level == 0) |
| return generic_bin_search(eb, |
| offsetof(struct btrfs_leaf, items), |
| sizeof(struct btrfs_item), |
| key, btrfs_header_nritems(eb), |
| slot); |
| else |
| return generic_bin_search(eb, |
| offsetof(struct btrfs_node, ptrs), |
| sizeof(struct btrfs_key_ptr), |
| key, btrfs_header_nritems(eb), |
| slot); |
| } |
| |
| struct extent_buffer *read_node_slot(struct btrfs_root *root, |
| struct extent_buffer *parent, int slot) |
| { |
| int level = btrfs_header_level(parent); |
| if (slot < 0) |
| return NULL; |
| if (slot >= btrfs_header_nritems(parent)) |
| return NULL; |
| |
| if (level == 0) |
| return NULL; |
| |
| return read_tree_block(root, btrfs_node_blockptr(parent, slot), |
| btrfs_level_size(root, level - 1), |
| btrfs_node_ptr_generation(parent, slot)); |
| } |
| |
| static int balance_level(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, int level) |
| { |
| struct extent_buffer *right = NULL; |
| struct extent_buffer *mid; |
| struct extent_buffer *left = NULL; |
| struct extent_buffer *parent = NULL; |
| int ret = 0; |
| int wret; |
| int pslot; |
| int orig_slot = path->slots[level]; |
| u64 orig_ptr; |
| |
| if (level == 0) |
| return 0; |
| |
| mid = path->nodes[level]; |
| WARN_ON(btrfs_header_generation(mid) != trans->transid); |
| |
| orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
| |
| if (level < BTRFS_MAX_LEVEL - 1) { |
| parent = path->nodes[level + 1]; |
| pslot = path->slots[level + 1]; |
| } |
| |
| /* |
| * deal with the case where there is only one pointer in the root |
| * by promoting the node below to a root |
| */ |
| if (!parent) { |
| struct extent_buffer *child; |
| |
| if (btrfs_header_nritems(mid) != 1) |
| return 0; |
| |
| /* promote the child to a root */ |
| child = read_node_slot(root, mid, 0); |
| BUG_ON(!extent_buffer_uptodate(child)); |
| ret = btrfs_cow_block(trans, root, child, mid, 0, &child); |
| BUG_ON(ret); |
| |
| root->node = child; |
| add_root_to_dirty_list(root); |
| path->nodes[level] = NULL; |
| clean_tree_block(trans, root, mid); |
| wait_on_tree_block_writeback(root, mid); |
| /* once for the path */ |
| free_extent_buffer(mid); |
| |
| ret = btrfs_free_extent(trans, root, mid->start, mid->len, |
| 0, root->root_key.objectid, |
| level, 1); |
| /* once for the root ptr */ |
| free_extent_buffer(mid); |
| return ret; |
| } |
| if (btrfs_header_nritems(mid) > |
| BTRFS_NODEPTRS_PER_BLOCK(root) / 4) |
| return 0; |
| |
| left = read_node_slot(root, parent, pslot - 1); |
| if (extent_buffer_uptodate(left)) { |
| wret = btrfs_cow_block(trans, root, left, |
| parent, pslot - 1, &left); |
| if (wret) { |
| ret = wret; |
| goto enospc; |
| } |
| } |
| right = read_node_slot(root, parent, pslot + 1); |
| if (extent_buffer_uptodate(right)) { |
| wret = btrfs_cow_block(trans, root, right, |
| parent, pslot + 1, &right); |
| if (wret) { |
| ret = wret; |
| goto enospc; |
| } |
| } |
| |
| /* first, try to make some room in the middle buffer */ |
| if (left) { |
| orig_slot += btrfs_header_nritems(left); |
| wret = push_node_left(trans, root, left, mid, 1); |
| if (wret < 0) |
| ret = wret; |
| } |
| |
| /* |
| * then try to empty the right most buffer into the middle |
| */ |
| if (right) { |
| wret = push_node_left(trans, root, mid, right, 1); |
| if (wret < 0 && wret != -ENOSPC) |
| ret = wret; |
| if (btrfs_header_nritems(right) == 0) { |
| u64 bytenr = right->start; |
| u32 blocksize = right->len; |
| |
| clean_tree_block(trans, root, right); |
| wait_on_tree_block_writeback(root, right); |
| free_extent_buffer(right); |
| right = NULL; |
| wret = btrfs_del_ptr(trans, root, path, |
| level + 1, pslot + 1); |
| if (wret) |
| ret = wret; |
| wret = btrfs_free_extent(trans, root, bytenr, |
| blocksize, 0, |
| root->root_key.objectid, |
| level, 0); |
| if (wret) |
| ret = wret; |
| } else { |
| struct btrfs_disk_key right_key; |
| btrfs_node_key(right, &right_key, 0); |
| btrfs_set_node_key(parent, &right_key, pslot + 1); |
| btrfs_mark_buffer_dirty(parent); |
| } |
| } |
| if (btrfs_header_nritems(mid) == 1) { |
| /* |
| * we're not allowed to leave a node with one item in the |
| * tree during a delete. A deletion from lower in the tree |
| * could try to delete the only pointer in this node. |
| * So, pull some keys from the left. |
| * There has to be a left pointer at this point because |
| * otherwise we would have pulled some pointers from the |
| * right |
| */ |
| BUG_ON(!left); |
| wret = balance_node_right(trans, root, mid, left); |
| if (wret < 0) { |
| ret = wret; |
| goto enospc; |
| } |
| if (wret == 1) { |
| wret = push_node_left(trans, root, left, mid, 1); |
| if (wret < 0) |
| ret = wret; |
| } |
| BUG_ON(wret == 1); |
| } |
| if (btrfs_header_nritems(mid) == 0) { |
| /* we've managed to empty the middle node, drop it */ |
| u64 bytenr = mid->start; |
| u32 blocksize = mid->len; |
| clean_tree_block(trans, root, mid); |
| wait_on_tree_block_writeback(root, mid); |
| free_extent_buffer(mid); |
| mid = NULL; |
| wret = btrfs_del_ptr(trans, root, path, level + 1, pslot); |
| if (wret) |
| ret = wret; |
| wret = btrfs_free_extent(trans, root, bytenr, blocksize, |
| 0, root->root_key.objectid, |
| level, 0); |
| if (wret) |
| ret = wret; |
| } else { |
| /* update the parent key to reflect our changes */ |
| struct btrfs_disk_key mid_key; |
| btrfs_node_key(mid, &mid_key, 0); |
| btrfs_set_node_key(parent, &mid_key, pslot); |
| btrfs_mark_buffer_dirty(parent); |
| } |
| |
| /* update the path */ |
| if (left) { |
| if (btrfs_header_nritems(left) > orig_slot) { |
| extent_buffer_get(left); |
| path->nodes[level] = left; |
| path->slots[level + 1] -= 1; |
| path->slots[level] = orig_slot; |
| if (mid) |
| free_extent_buffer(mid); |
| } else { |
| orig_slot -= btrfs_header_nritems(left); |
| path->slots[level] = orig_slot; |
| } |
| } |
| /* double check we haven't messed things up */ |
| check_block(root, path, level); |
| if (orig_ptr != |
| btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
| BUG(); |
| enospc: |
| if (right) |
| free_extent_buffer(right); |
| if (left) |
| free_extent_buffer(left); |
| return ret; |
| } |
| |
| /* returns zero if the push worked, non-zero otherwise */ |
| static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, int level) |
| { |
| struct extent_buffer *right = NULL; |
| struct extent_buffer *mid; |
| struct extent_buffer *left = NULL; |
| struct extent_buffer *parent = NULL; |
| int ret = 0; |
| int wret; |
| int pslot; |
| int orig_slot = path->slots[level]; |
| |
| if (level == 0) |
| return 1; |
| |
| mid = path->nodes[level]; |
| WARN_ON(btrfs_header_generation(mid) != trans->transid); |
| |
| if (level < BTRFS_MAX_LEVEL - 1) { |
| parent = path->nodes[level + 1]; |
| pslot = path->slots[level + 1]; |
| } |
| |
| if (!parent) |
| return 1; |
| |
| left = read_node_slot(root, parent, pslot - 1); |
| |
| /* first, try to make some room in the middle buffer */ |
| if (extent_buffer_uptodate(left)) { |
| u32 left_nr; |
| left_nr = btrfs_header_nritems(left); |
| if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
| wret = 1; |
| } else { |
| ret = btrfs_cow_block(trans, root, left, parent, |
| pslot - 1, &left); |
| if (ret) |
| wret = 1; |
| else { |
| wret = push_node_left(trans, root, |
| left, mid, 0); |
| } |
| } |
| if (wret < 0) |
| ret = wret; |
| if (wret == 0) { |
| struct btrfs_disk_key disk_key; |
| orig_slot += left_nr; |
| btrfs_node_key(mid, &disk_key, 0); |
| btrfs_set_node_key(parent, &disk_key, pslot); |
| btrfs_mark_buffer_dirty(parent); |
| if (btrfs_header_nritems(left) > orig_slot) { |
| path->nodes[level] = left; |
| path->slots[level + 1] -= 1; |
| path->slots[level] = orig_slot; |
| free_extent_buffer(mid); |
| } else { |
| orig_slot -= |
| btrfs_header_nritems(left); |
| path->slots[level] = orig_slot; |
| free_extent_buffer(left); |
| } |
| return 0; |
| } |
| free_extent_buffer(left); |
| } |
| right= read_node_slot(root, parent, pslot + 1); |
| |
| /* |
| * then try to empty the right most buffer into the middle |
| */ |
| if (extent_buffer_uptodate(right)) { |
| u32 right_nr; |
| right_nr = btrfs_header_nritems(right); |
| if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
| wret = 1; |
| } else { |
| ret = btrfs_cow_block(trans, root, right, |
| parent, pslot + 1, |
| &right); |
| if (ret) |
| wret = 1; |
| else { |
| wret = balance_node_right(trans, root, |
| right, mid); |
| } |
| } |
| if (wret < 0) |
| ret = wret; |
| if (wret == 0) { |
| struct btrfs_disk_key disk_key; |
| |
| btrfs_node_key(right, &disk_key, 0); |
| btrfs_set_node_key(parent, &disk_key, pslot + 1); |
| btrfs_mark_buffer_dirty(parent); |
| |
| if (btrfs_header_nritems(mid) <= orig_slot) { |
| path->nodes[level] = right; |
| path->slots[level + 1] += 1; |
| path->slots[level] = orig_slot - |
| btrfs_header_nritems(mid); |
| free_extent_buffer(mid); |
| } else { |
| free_extent_buffer(right); |
| } |
| return 0; |
| } |
| free_extent_buffer(right); |
| } |
| return 1; |
| } |
| |
| /* |
| * readahead one full node of leaves |
| */ |
| void reada_for_search(struct btrfs_root *root, struct btrfs_path *path, |
| int level, int slot, u64 objectid) |
| { |
| struct extent_buffer *node; |
| struct btrfs_disk_key disk_key; |
| u32 nritems; |
| u64 search; |
| u64 lowest_read; |
| u64 highest_read; |
| u64 nread = 0; |
| int direction = path->reada; |
| struct extent_buffer *eb; |
| u32 nr; |
| u32 blocksize; |
| u32 nscan = 0; |
| |
| if (level != 1) |
| return; |
| |
| if (!path->nodes[level]) |
| return; |
| |
| node = path->nodes[level]; |
| search = btrfs_node_blockptr(node, slot); |
| blocksize = btrfs_level_size(root, level - 1); |
| eb = btrfs_find_tree_block(root, search, blocksize); |
| if (eb) { |
| free_extent_buffer(eb); |
| return; |
| } |
| |
| highest_read = search; |
| lowest_read = search; |
| |
| nritems = btrfs_header_nritems(node); |
| nr = slot; |
| while(1) { |
| if (direction < 0) { |
| if (nr == 0) |
| break; |
| nr--; |
| } else if (direction > 0) { |
| nr++; |
| if (nr >= nritems) |
| break; |
| } |
| if (path->reada < 0 && objectid) { |
| btrfs_node_key(node, &disk_key, nr); |
| if (btrfs_disk_key_objectid(&disk_key) != objectid) |
| break; |
| } |
| search = btrfs_node_blockptr(node, nr); |
| if ((search >= lowest_read && search <= highest_read) || |
| (search < lowest_read && lowest_read - search <= 32768) || |
| (search > highest_read && search - highest_read <= 32768)) { |
| readahead_tree_block(root, search, blocksize, |
| btrfs_node_ptr_generation(node, nr)); |
| nread += blocksize; |
| } |
| nscan++; |
| if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32)) |
| break; |
| if(nread > (1024 * 1024) || nscan > 128) |
| break; |
| |
| if (search < lowest_read) |
| lowest_read = search; |
| if (search > highest_read) |
| highest_read = search; |
| } |
| } |
| |
| int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *found_path, |
| u64 iobjectid, u64 ioff, u8 key_type, |
| struct btrfs_key *found_key) |
| { |
| int ret; |
| struct btrfs_key key; |
| struct extent_buffer *eb; |
| struct btrfs_path *path; |
| |
| key.type = key_type; |
| key.objectid = iobjectid; |
| key.offset = ioff; |
| |
| if (found_path == NULL) { |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| } else |
| path = found_path; |
| |
| ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); |
| if ((ret < 0) || (found_key == NULL)) { |
| if (path != found_path) |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| eb = path->nodes[0]; |
| if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { |
| ret = btrfs_next_leaf(fs_root, path); |
| if (ret) |
| return ret; |
| eb = path->nodes[0]; |
| } |
| |
| btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); |
| if (found_key->type != key.type || |
| found_key->objectid != key.objectid) |
| return 1; |
| |
| return 0; |
| } |
| |
| /* |
| * look for key in the tree. path is filled in with nodes along the way |
| * if key is found, we return zero and you can find the item in the leaf |
| * level of the path (level 0) |
| * |
| * If the key isn't found, the path points to the slot where it should |
| * be inserted, and 1 is returned. If there are other errors during the |
| * search a negative error number is returned. |
| * |
| * if ins_len > 0, nodes and leaves will be split as we walk down the |
| * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if |
| * possible) |
| */ |
| int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, struct btrfs_key *key, struct btrfs_path *p, int |
| ins_len, int cow) |
| { |
| struct extent_buffer *b; |
| int slot; |
| int ret; |
| int level; |
| int should_reada = p->reada; |
| u8 lowest_level = 0; |
| |
| lowest_level = p->lowest_level; |
| WARN_ON(lowest_level && ins_len > 0); |
| WARN_ON(p->nodes[0] != NULL); |
| /* |
| WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex)); |
| */ |
| again: |
| b = root->node; |
| extent_buffer_get(b); |
| while (b) { |
| level = btrfs_header_level(b); |
| if (cow) { |
| int wret; |
| wret = btrfs_cow_block(trans, root, b, |
| p->nodes[level + 1], |
| p->slots[level + 1], |
| &b); |
| if (wret) { |
| free_extent_buffer(b); |
| return wret; |
| } |
| } |
| BUG_ON(!cow && ins_len); |
| if (level != btrfs_header_level(b)) |
| WARN_ON(1); |
| level = btrfs_header_level(b); |
| p->nodes[level] = b; |
| ret = check_block(root, p, level); |
| if (ret) |
| return -1; |
| ret = bin_search(b, key, level, &slot); |
| if (level != 0) { |
| if (ret && slot > 0) |
| slot -= 1; |
| p->slots[level] = slot; |
| if ((p->search_for_split || ins_len > 0) && |
| btrfs_header_nritems(b) >= |
| BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { |
| int sret = split_node(trans, root, p, level); |
| BUG_ON(sret > 0); |
| if (sret) |
| return sret; |
| b = p->nodes[level]; |
| slot = p->slots[level]; |
| } else if (ins_len < 0) { |
| int sret = balance_level(trans, root, p, |
| level); |
| if (sret) |
| return sret; |
| b = p->nodes[level]; |
| if (!b) { |
| btrfs_release_path(p); |
| goto again; |
| } |
| slot = p->slots[level]; |
| BUG_ON(btrfs_header_nritems(b) == 1); |
| } |
| /* this is only true while dropping a snapshot */ |
| if (level == lowest_level) |
| break; |
| |
| if (should_reada) |
| reada_for_search(root, p, level, slot, |
| key->objectid); |
| |
| b = read_node_slot(root, b, slot); |
| if (!extent_buffer_uptodate(b)) |
| return -EIO; |
| } else { |
| p->slots[level] = slot; |
| if (ins_len > 0 && |
| ins_len > btrfs_leaf_free_space(root, b)) { |
| int sret = split_leaf(trans, root, key, |
| p, ins_len, ret == 0); |
| BUG_ON(sret > 0); |
| if (sret) |
| return sret; |
| } |
| return ret; |
| } |
| } |
| return 1; |
| } |
| |
| /* |
| * adjust the pointers going up the tree, starting at level |
| * making sure the right key of each node is points to 'key'. |
| * This is used after shifting pointers to the left, so it stops |
| * fixing up pointers when a given leaf/node is not in slot 0 of the |
| * higher levels |
| */ |
| void btrfs_fixup_low_keys(struct btrfs_root *root, struct btrfs_path *path, |
| struct btrfs_disk_key *key, int level) |
| { |
| int i; |
| struct extent_buffer *t; |
| |
| for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
| int tslot = path->slots[i]; |
| if (!path->nodes[i]) |
| break; |
| t = path->nodes[i]; |
| btrfs_set_node_key(t, key, tslot); |
| btrfs_mark_buffer_dirty(path->nodes[i]); |
| if (tslot != 0) |
| break; |
| } |
| } |
| |
| /* |
| * update item key. |
| * |
| * This function isn't completely safe. It's the caller's responsibility |
| * that the new key won't break the order |
| */ |
| int btrfs_set_item_key_safe(struct btrfs_root *root, struct btrfs_path *path, |
| struct btrfs_key *new_key) |
| { |
| struct btrfs_disk_key disk_key; |
| struct extent_buffer *eb; |
| int slot; |
| |
| eb = path->nodes[0]; |
| slot = path->slots[0]; |
| if (slot > 0) { |
| btrfs_item_key(eb, &disk_key, slot - 1); |
| if (btrfs_comp_keys(&disk_key, new_key) >= 0) |
| return -1; |
| } |
| if (slot < btrfs_header_nritems(eb) - 1) { |
| btrfs_item_key(eb, &disk_key, slot + 1); |
| if (btrfs_comp_keys(&disk_key, new_key) <= 0) |
| return -1; |
| } |
| |
| btrfs_cpu_key_to_disk(&disk_key, new_key); |
| btrfs_set_item_key(eb, &disk_key, slot); |
| btrfs_mark_buffer_dirty(eb); |
| if (slot == 0) |
| btrfs_fixup_low_keys(root, path, &disk_key, 1); |
| return 0; |
| } |
| |
| /* |
| * update an item key without the safety checks. This is meant to be called by |
| * fsck only. |
| */ |
| void btrfs_set_item_key_unsafe(struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct btrfs_key *new_key) |
| { |
| struct btrfs_disk_key disk_key; |
| struct extent_buffer *eb; |
| int slot; |
| |
| eb = path->nodes[0]; |
| slot = path->slots[0]; |
| |
| btrfs_cpu_key_to_disk(&disk_key, new_key); |
| btrfs_set_item_key(eb, &disk_key, slot); |
| btrfs_mark_buffer_dirty(eb); |
| if (slot == 0) |
| btrfs_fixup_low_keys(root, path, &disk_key, 1); |
| } |
| |
| /* |
| * try to push data from one node into the next node left in the |
| * tree. |
| * |
| * returns 0 if some ptrs were pushed left, < 0 if there was some horrible |
| * error, and > 0 if there was no room in the left hand block. |
| */ |
| static int push_node_left(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, struct extent_buffer *dst, |
| struct extent_buffer *src, int empty) |
| { |
| int push_items = 0; |
| int src_nritems; |
| int dst_nritems; |
| int ret = 0; |
| |
| src_nritems = btrfs_header_nritems(src); |
| dst_nritems = btrfs_header_nritems(dst); |
| push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
| WARN_ON(btrfs_header_generation(src) != trans->transid); |
| WARN_ON(btrfs_header_generation(dst) != trans->transid); |
| |
| if (!empty && src_nritems <= 8) |
| return 1; |
| |
| if (push_items <= 0) { |
| return 1; |
| } |
| |
| if (empty) { |
| push_items = min(src_nritems, push_items); |
| if (push_items < src_nritems) { |
| /* leave at least 8 pointers in the node if |
| * we aren't going to empty it |
| */ |
| if (src_nritems - push_items < 8) { |
| if (push_items <= 8) |
| return 1; |
| push_items -= 8; |
| } |
| } |
| } else |
| push_items = min(src_nritems - 8, push_items); |
| |
| copy_extent_buffer(dst, src, |
| btrfs_node_key_ptr_offset(dst_nritems), |
| btrfs_node_key_ptr_offset(0), |
| push_items * sizeof(struct btrfs_key_ptr)); |
| |
| if (push_items < src_nritems) { |
| memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), |
| btrfs_node_key_ptr_offset(push_items), |
| (src_nritems - push_items) * |
| sizeof(struct btrfs_key_ptr)); |
| } |
| btrfs_set_header_nritems(src, src_nritems - push_items); |
| btrfs_set_header_nritems(dst, dst_nritems + push_items); |
| btrfs_mark_buffer_dirty(src); |
| btrfs_mark_buffer_dirty(dst); |
| |
| return ret; |
| } |
| |
| /* |
| * try to push data from one node into the next node right in the |
| * tree. |
| * |
| * returns 0 if some ptrs were pushed, < 0 if there was some horrible |
| * error, and > 0 if there was no room in the right hand block. |
| * |
| * this will only push up to 1/2 the contents of the left node over |
| */ |
| static int balance_node_right(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct extent_buffer *dst, |
| struct extent_buffer *src) |
| { |
| int push_items = 0; |
| int max_push; |
| int src_nritems; |
| int dst_nritems; |
| int ret = 0; |
| |
| WARN_ON(btrfs_header_generation(src) != trans->transid); |
| WARN_ON(btrfs_header_generation(dst) != trans->transid); |
| |
| src_nritems = btrfs_header_nritems(src); |
| dst_nritems = btrfs_header_nritems(dst); |
| push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
| if (push_items <= 0) { |
| return 1; |
| } |
| |
| if (src_nritems < 4) { |
| return 1; |
| } |
| |
| max_push = src_nritems / 2 + 1; |
| /* don't try to empty the node */ |
| if (max_push >= src_nritems) { |
| return 1; |
| } |
| |
| if (max_push < push_items) |
| push_items = max_push; |
| |
| memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), |
| btrfs_node_key_ptr_offset(0), |
| (dst_nritems) * |
| sizeof(struct btrfs_key_ptr)); |
| |
| copy_extent_buffer(dst, src, |
| btrfs_node_key_ptr_offset(0), |
| btrfs_node_key_ptr_offset(src_nritems - push_items), |
| push_items * sizeof(struct btrfs_key_ptr)); |
| |
| btrfs_set_header_nritems(src, src_nritems - push_items); |
| btrfs_set_header_nritems(dst, dst_nritems + push_items); |
| |
| btrfs_mark_buffer_dirty(src); |
| btrfs_mark_buffer_dirty(dst); |
| |
| return ret; |
| } |
| |
| /* |
| * helper function to insert a new root level in the tree. |
| * A new node is allocated, and a single item is inserted to |
| * point to the existing root |
| * |
| * returns zero on success or < 0 on failure. |
| */ |
| static int noinline insert_new_root(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, int level) |
| { |
| u64 lower_gen; |
| struct extent_buffer *lower; |
| struct extent_buffer *c; |
| struct extent_buffer *old; |
| struct btrfs_disk_key lower_key; |
| |
| BUG_ON(path->nodes[level]); |
| BUG_ON(path->nodes[level-1] != root->node); |
| |
| lower = path->nodes[level-1]; |
| if (level == 1) |
| btrfs_item_key(lower, &lower_key, 0); |
| else |
| btrfs_node_key(lower, &lower_key, 0); |
| |
| c = btrfs_alloc_free_block(trans, root, root->nodesize, |
| root->root_key.objectid, &lower_key, |
| level, root->node->start, 0); |
| |
| if (IS_ERR(c)) |
| return PTR_ERR(c); |
| |
| memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header)); |
| btrfs_set_header_nritems(c, 1); |
| btrfs_set_header_level(c, level); |
| btrfs_set_header_bytenr(c, c->start); |
| btrfs_set_header_generation(c, trans->transid); |
| btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV); |
| btrfs_set_header_owner(c, root->root_key.objectid); |
| |
| write_extent_buffer(c, root->fs_info->fsid, |
| btrfs_header_fsid(), BTRFS_FSID_SIZE); |
| |
| write_extent_buffer(c, root->fs_info->chunk_tree_uuid, |
| btrfs_header_chunk_tree_uuid(c), |
| BTRFS_UUID_SIZE); |
| |
| btrfs_set_node_key(c, &lower_key, 0); |
| btrfs_set_node_blockptr(c, 0, lower->start); |
| lower_gen = btrfs_header_generation(lower); |
| WARN_ON(lower_gen != trans->transid); |
| |
| btrfs_set_node_ptr_generation(c, 0, lower_gen); |
| |
| btrfs_mark_buffer_dirty(c); |
| |
| old = root->node; |
| root->node = c; |
| |
| /* the super has an extra ref to root->node */ |
| free_extent_buffer(old); |
| |
| add_root_to_dirty_list(root); |
| extent_buffer_get(c); |
| path->nodes[level] = c; |
| path->slots[level] = 0; |
| return 0; |
| } |
| |
| /* |
| * worker function to insert a single pointer in a node. |
| * the node should have enough room for the pointer already |
| * |
| * slot and level indicate where you want the key to go, and |
| * blocknr is the block the key points to. |
| * |
| * returns zero on success and < 0 on any error |
| */ |
| static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, struct btrfs_path *path, struct btrfs_disk_key |
| *key, u64 bytenr, int slot, int level) |
| { |
| struct extent_buffer *lower; |
| int nritems; |
| |
| BUG_ON(!path->nodes[level]); |
| lower = path->nodes[level]; |
| nritems = btrfs_header_nritems(lower); |
| if (slot > nritems) |
| BUG(); |
| if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root)) |
| BUG(); |
| if (slot != nritems) { |
| memmove_extent_buffer(lower, |
| btrfs_node_key_ptr_offset(slot + 1), |
| btrfs_node_key_ptr_offset(slot), |
| (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
| } |
| btrfs_set_node_key(lower, key, slot); |
| btrfs_set_node_blockptr(lower, slot, bytenr); |
| WARN_ON(trans->transid == 0); |
| btrfs_set_node_ptr_generation(lower, slot, trans->transid); |
| btrfs_set_header_nritems(lower, nritems + 1); |
| btrfs_mark_buffer_dirty(lower); |
| return 0; |
| } |
| |
| /* |
| * split the node at the specified level in path in two. |
| * The path is corrected to point to the appropriate node after the split |
| * |
| * Before splitting this tries to make some room in the node by pushing |
| * left and right, if either one works, it returns right away. |
| * |
| * returns 0 on success and < 0 on failure |
| */ |
| static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, struct btrfs_path *path, int level) |
| { |
| struct extent_buffer *c; |
| struct extent_buffer *split; |
| struct btrfs_disk_key disk_key; |
| int mid; |
| int ret; |
| int wret; |
| u32 c_nritems; |
| |
| c = path->nodes[level]; |
| WARN_ON(btrfs_header_generation(c) != trans->transid); |
| if (c == root->node) { |
| /* trying to split the root, lets make a new one */ |
| ret = insert_new_root(trans, root, path, level + 1); |
| if (ret) |
| return ret; |
| } else { |
| ret = push_nodes_for_insert(trans, root, path, level); |
| c = path->nodes[level]; |
| if (!ret && btrfs_header_nritems(c) < |
| BTRFS_NODEPTRS_PER_BLOCK(root) - 3) |
| return 0; |
| if (ret < 0) |
| return ret; |
| } |
| |
| c_nritems = btrfs_header_nritems(c); |
| mid = (c_nritems + 1) / 2; |
| btrfs_node_key(c, &disk_key, mid); |
| |
| split = btrfs_alloc_free_block(trans, root, root->nodesize, |
| root->root_key.objectid, |
| &disk_key, level, c->start, 0); |
| if (IS_ERR(split)) |
| return PTR_ERR(split); |
| |
| memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header)); |
| btrfs_set_header_level(split, btrfs_header_level(c)); |
| btrfs_set_header_bytenr(split, split->start); |
| btrfs_set_header_generation(split, trans->transid); |
| btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV); |
| btrfs_set_header_owner(split, root->root_key.objectid); |
| write_extent_buffer(split, root->fs_info->fsid, |
| btrfs_header_fsid(), BTRFS_FSID_SIZE); |
| write_extent_buffer(split, root->fs_info->chunk_tree_uuid, |
| btrfs_header_chunk_tree_uuid(split), |
| BTRFS_UUID_SIZE); |
| |
| |
| copy_extent_buffer(split, c, |
| btrfs_node_key_ptr_offset(0), |
| btrfs_node_key_ptr_offset(mid), |
| (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); |
| btrfs_set_header_nritems(split, c_nritems - mid); |
| btrfs_set_header_nritems(c, mid); |
| ret = 0; |
| |
| btrfs_mark_buffer_dirty(c); |
| btrfs_mark_buffer_dirty(split); |
| |
| wret = insert_ptr(trans, root, path, &disk_key, split->start, |
| path->slots[level + 1] + 1, |
| level + 1); |
| if (wret) |
| ret = wret; |
| |
| if (path->slots[level] >= mid) { |
| path->slots[level] -= mid; |
| free_extent_buffer(c); |
| path->nodes[level] = split; |
| path->slots[level + 1] += 1; |
| } else { |
| free_extent_buffer(split); |
| } |
| return ret; |
| } |
| |
| /* |
| * how many bytes are required to store the items in a leaf. start |
| * and nr indicate which items in the leaf to check. This totals up the |
| * space used both by the item structs and the item data |
| */ |
| static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
| { |
| int data_len; |
| int nritems = btrfs_header_nritems(l); |
| int end = min(nritems, start + nr) - 1; |
| |
| if (!nr) |
| return 0; |
| data_len = btrfs_item_end_nr(l, start); |
| data_len = data_len - btrfs_item_offset_nr(l, end); |
| data_len += sizeof(struct btrfs_item) * nr; |
| WARN_ON(data_len < 0); |
| return data_len; |
| } |
| |
| /* |
| * The space between the end of the leaf items and |
| * the start of the leaf data. IOW, how much room |
| * the leaf has left for both items and data |
| */ |
| int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf) |
| { |
| int nritems = btrfs_header_nritems(leaf); |
| int ret; |
| ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); |
| if (ret < 0) { |
| printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n", |
| ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root), |
| leaf_space_used(leaf, 0, nritems), nritems); |
| } |
| return ret; |
| } |
| |
| /* |
| * push some data in the path leaf to the right, trying to free up at |
| * least data_size bytes. returns zero if the push worked, nonzero otherwise |
| * |
| * returns 1 if the push failed because the other node didn't have enough |
| * room, 0 if everything worked out and < 0 if there were major errors. |
| */ |
| static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, struct btrfs_path *path, int data_size, |
| int empty) |
| { |
| struct extent_buffer *left = path->nodes[0]; |
| struct extent_buffer *right; |
| struct extent_buffer *upper; |
| struct btrfs_disk_key disk_key; |
| int slot; |
| u32 i; |
| int free_space; |
| int push_space = 0; |
| int push_items = 0; |
| struct btrfs_item *item; |
| u32 left_nritems; |
| u32 nr; |
| u32 right_nritems; |
| u32 data_end; |
| u32 this_item_size; |
| int ret; |
| |
| slot = path->slots[1]; |
| if (!path->nodes[1]) { |
| return 1; |
| } |
| upper = path->nodes[1]; |
| if (slot >= btrfs_header_nritems(upper) - 1) |
| return 1; |
| |
| right = read_node_slot(root, upper, slot + 1); |
| if (!extent_buffer_uptodate(right)) { |
| if (IS_ERR(right)) |
| return PTR_ERR(right); |
| return -EIO; |
| } |
| free_space = btrfs_leaf_free_space(root, right); |
| if (free_space < data_size) { |
| free_extent_buffer(right); |
| return 1; |
| } |
| |
| /* cow and double check */ |
| ret = btrfs_cow_block(trans, root, right, upper, |
| slot + 1, &right); |
| if (ret) { |
| free_extent_buffer(right); |
| return 1; |
| } |
| free_space = btrfs_leaf_free_space(root, right); |
| if (free_space < data_size) { |
| free_extent_buffer(right); |
| return 1; |
| } |
| |
| left_nritems = btrfs_header_nritems(left); |
| if (left_nritems == 0) { |
| free_extent_buffer(right); |
| return 1; |
| } |
| |
| if (empty) |
| nr = 0; |
| else |
| nr = 1; |
| |
| i = left_nritems - 1; |
| while (i >= nr) { |
| item = btrfs_item_nr(i); |
| |
| if (path->slots[0] == i) |
| push_space += data_size + sizeof(*item); |
| |
| this_item_size = btrfs_item_size(left, item); |
| if (this_item_size + sizeof(*item) + push_space > free_space) |
| break; |
| push_items++; |
| push_space += this_item_size + sizeof(*item); |
| if (i == 0) |
| break; |
| i--; |
| } |
| |
| if (push_items == 0) { |
| free_extent_buffer(right); |
| return 1; |
| } |
| |
| if (!empty && push_items == left_nritems) |
| WARN_ON(1); |
| |
| /* push left to right */ |
| right_nritems = btrfs_header_nritems(right); |
| |
| push_space = btrfs_item_end_nr(left, left_nritems - push_items); |
| push_space -= leaf_data_end(root, left); |
| |
| /* make room in the right data area */ |
| data_end = leaf_data_end(root, right); |
| memmove_extent_buffer(right, |
| btrfs_leaf_data(right) + data_end - push_space, |
| btrfs_leaf_data(right) + data_end, |
| BTRFS_LEAF_DATA_SIZE(root) - data_end); |
| |
| /* copy from the left data area */ |
| copy_extent_buffer(right, left, btrfs_leaf_data(right) + |
| BTRFS_LEAF_DATA_SIZE(root) - push_space, |
| btrfs_leaf_data(left) + leaf_data_end(root, left), |
| push_space); |
| |
| memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), |
| btrfs_item_nr_offset(0), |
| right_nritems * sizeof(struct btrfs_item)); |
| |
| /* copy the items from left to right */ |
| copy_extent_buffer(right, left, btrfs_item_nr_offset(0), |
| btrfs_item_nr_offset(left_nritems - push_items), |
| push_items * sizeof(struct btrfs_item)); |
| |
| /* update the item pointers */ |
| right_nritems += push_items; |
| btrfs_set_header_nritems(right, right_nritems); |
| push_space = BTRFS_LEAF_DATA_SIZE(root); |
| for (i = 0; i < right_nritems; i++) { |
| item = btrfs_item_nr(i); |
| push_space -= btrfs_item_size(right, item); |
| btrfs_set_item_offset(right, item, push_space); |
| } |
| |
| left_nritems -= push_items; |
| btrfs_set_header_nritems(left, left_nritems); |
| |
| if (left_nritems) |
| btrfs_mark_buffer_dirty(left); |
| btrfs_mark_buffer_dirty(right); |
| |
| btrfs_item_key(right, &disk_key, 0); |
| btrfs_set_node_key(upper, &disk_key, slot + 1); |
| btrfs_mark_buffer_dirty(upper); |
| |
| /* then fixup the leaf pointer in the path */ |
| if (path->slots[0] >= left_nritems) { |
| path->slots[0] -= left_nritems; |
| free_extent_buffer(path->nodes[0]); |
| path->nodes[0] = right; |
| path->slots[1] += 1; |
| } else { |
| free_extent_buffer(right); |
| } |
| return 0; |
| } |
| /* |
| * push some data in the path leaf to the left, trying to free up at |
| * least data_size bytes. returns zero if the push worked, nonzero otherwise |
| */ |
| static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, struct btrfs_path *path, int data_size, |
| int empty) |
| { |
| struct btrfs_disk_key disk_key; |
| struct extent_buffer *right = path->nodes[0]; |
| struct extent_buffer *left; |
| int slot; |
| int i; |
| int free_space; |
| int push_space = 0; |
| int push_items = 0; |
| struct btrfs_item *item; |
| u32 old_left_nritems; |
| u32 right_nritems; |
| u32 nr; |
| int ret = 0; |
| u32 this_item_size; |
| u32 old_left_item_size; |
| |
| slot = path->slots[1]; |
| if (slot == 0) |
| return 1; |
| if (!path->nodes[1]) |
| return 1; |
| |
| right_nritems = btrfs_header_nritems(right); |
| if (right_nritems == 0) { |
| return 1; |
| } |
| |
| left = read_node_slot(root, path->nodes[1], slot - 1); |
| free_space = btrfs_leaf_free_space(root, left); |
| if (free_space < data_size) { |
| free_extent_buffer(left); |
| return 1; |
| } |
| |
| /* cow and double check */ |
| ret = btrfs_cow_block(trans, root, left, |
| path->nodes[1], slot - 1, &left); |
| if (ret) { |
| /* we hit -ENOSPC, but it isn't fatal here */ |
| free_extent_buffer(left); |
| return 1; |
| } |
| |
| free_space = btrfs_leaf_free_space(root, left); |
| if (free_space < data_size) { |
| free_extent_buffer(left); |
| return 1; |
| } |
| |
| if (empty) |
| nr = right_nritems; |
| else |
| nr = right_nritems - 1; |
| |
| for (i = 0; i < nr; i++) { |
| item = btrfs_item_nr(i); |
| |
| if (path->slots[0] == i) |
| push_space += data_size + sizeof(*item); |
| |
| this_item_size = btrfs_item_size(right, item); |
| if (this_item_size + sizeof(*item) + push_space > free_space) |
| break; |
| |
| push_items++; |
| push_space += this_item_size + sizeof(*item); |
| } |
| |
| if (push_items == 0) { |
| free_extent_buffer(left); |
| return 1; |
| } |
| if (!empty && push_items == btrfs_header_nritems(right)) |
| WARN_ON(1); |
| |
| /* push data from right to left */ |
| copy_extent_buffer(left, right, |
| btrfs_item_nr_offset(btrfs_header_nritems(left)), |
| btrfs_item_nr_offset(0), |
| push_items * sizeof(struct btrfs_item)); |
| |
| push_space = BTRFS_LEAF_DATA_SIZE(root) - |
| btrfs_item_offset_nr(right, push_items -1); |
| |
| copy_extent_buffer(left, right, btrfs_leaf_data(left) + |
| leaf_data_end(root, left) - push_space, |
| btrfs_leaf_data(right) + |
| btrfs_item_offset_nr(right, push_items - 1), |
| push_space); |
| old_left_nritems = btrfs_header_nritems(left); |
| BUG_ON(old_left_nritems == 0); |
| |
| old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); |
| for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
| u32 ioff; |
| |
| item = btrfs_item_nr(i); |
| ioff = btrfs_item_offset(left, item); |
| btrfs_set_item_offset(left, item, |
| ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size)); |
| } |
| btrfs_set_header_nritems(left, old_left_nritems + push_items); |
| |
| /* fixup right node */ |
| if (push_items > right_nritems) { |
| printk("push items %d nr %u\n", push_items, right_nritems); |
| WARN_ON(1); |
| } |
| |
| if (push_items < right_nritems) { |
| push_space = btrfs_item_offset_nr(right, push_items - 1) - |
| leaf_data_end(root, right); |
| memmove_extent_buffer(right, btrfs_leaf_data(right) + |
| BTRFS_LEAF_DATA_SIZE(root) - push_space, |
| btrfs_leaf_data(right) + |
| leaf_data_end(root, right), push_space); |
| |
| memmove_extent_buffer(right, btrfs_item_nr_offset(0), |
| btrfs_item_nr_offset(push_items), |
| (btrfs_header_nritems(right) - push_items) * |
| sizeof(struct btrfs_item)); |
| } |
| right_nritems -= push_items; |
| btrfs_set_header_nritems(right, right_nritems); |
| push_space = BTRFS_LEAF_DATA_SIZE(root); |
| for (i = 0; i < right_nritems; i++) { |
| item = btrfs_item_nr(i); |
| push_space = push_space - btrfs_item_size(right, item); |
| btrfs_set_item_offset(right, item, push_space); |
| } |
| |
| btrfs_mark_buffer_dirty(left); |
| if (right_nritems) |
| btrfs_mark_buffer_dirty(right); |
| |
| btrfs_item_key(right, &disk_key, 0); |
| btrfs_fixup_low_keys(root, path, &disk_key, 1); |
| |
| /* then fixup the leaf pointer in the path */ |
| if (path->slots[0] < push_items) { |
| path->slots[0] += old_left_nritems; |
| free_extent_buffer(path->nodes[0]); |
| path->nodes[0] = left; |
| path->slots[1] -= 1; |
| } else { |
| free_extent_buffer(left); |
| path->slots[0] -= push_items; |
| } |
| BUG_ON(path->slots[0] < 0); |
| return ret; |
| } |
| |
| /* |
| * split the path's leaf in two, making sure there is at least data_size |
| * available for the resulting leaf level of the path. |
| * |
| * returns 0 if all went well and < 0 on failure. |
| */ |
| static noinline int copy_for_split(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct extent_buffer *l, |
| struct extent_buffer *right, |
| int slot, int mid, int nritems) |
| { |
| int data_copy_size; |
| int rt_data_off; |
| int i; |
| int ret = 0; |
| int wret; |
| struct btrfs_disk_key disk_key; |
| |
| nritems = nritems - mid; |
| btrfs_set_header_nritems(right, nritems); |
| data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l); |
| |
| copy_extent_buffer(right, l, btrfs_item_nr_offset(0), |
| btrfs_item_nr_offset(mid), |
| nritems * sizeof(struct btrfs_item)); |
| |
| copy_extent_buffer(right, l, |
| btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - |
| data_copy_size, btrfs_leaf_data(l) + |
| leaf_data_end(root, l), data_copy_size); |
| |
| rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - |
| btrfs_item_end_nr(l, mid); |
| |
| for (i = 0; i < nritems; i++) { |
| struct btrfs_item *item = btrfs_item_nr(i); |
| u32 ioff = btrfs_item_offset(right, item); |
| btrfs_set_item_offset(right, item, ioff + rt_data_off); |
| } |
| |
| btrfs_set_header_nritems(l, mid); |
| ret = 0; |
| btrfs_item_key(right, &disk_key, 0); |
| wret = insert_ptr(trans, root, path, &disk_key, right->start, |
| path->slots[1] + 1, 1); |
| if (wret) |
| ret = wret; |
| |
| btrfs_mark_buffer_dirty(right); |
| btrfs_mark_buffer_dirty(l); |
| BUG_ON(path->slots[0] != slot); |
| |
| if (mid <= slot) { |
| free_extent_buffer(path->nodes[0]); |
| path->nodes[0] = right; |
| path->slots[0] -= mid; |
| path->slots[1] += 1; |
| } else { |
| free_extent_buffer(right); |
| } |
| |
| BUG_ON(path->slots[0] < 0); |
| |
| return ret; |
| } |
| |
| /* |
| * split the path's leaf in two, making sure there is at least data_size |
| * available for the resulting leaf level of the path. |
| * |
| * returns 0 if all went well and < 0 on failure. |
| */ |
| static noinline int split_leaf(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_key *ins_key, |
| struct btrfs_path *path, int data_size, |
| int extend) |
| { |
| struct btrfs_disk_key disk_key; |
| struct extent_buffer *l; |
| u32 nritems; |
| int mid; |
| int slot; |
| struct extent_buffer *right; |
| int ret = 0; |
| int wret; |
| int split; |
| int num_doubles = 0; |
| |
| l = path->nodes[0]; |
| slot = path->slots[0]; |
| if (extend && data_size + btrfs_item_size_nr(l, slot) + |
| sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) |
| return -EOVERFLOW; |
| |
| /* first try to make some room by pushing left and right */ |
| if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) { |
| wret = push_leaf_right(trans, root, path, data_size, 0); |
| if (wret < 0) |
| return wret; |
| if (wret) { |
| wret = push_leaf_left(trans, root, path, data_size, 0); |
| if (wret < 0) |
| return wret; |
| } |
| l = path->nodes[0]; |
| |
| /* did the pushes work? */ |
| if (btrfs_leaf_free_space(root, l) >= data_size) |
| return 0; |
| } |
| |
| if (!path->nodes[1]) { |
| ret = insert_new_root(trans, root, path, 1); |
| if (ret) |
| return ret; |
| } |
| again: |
| split = 1; |
| l = path->nodes[0]; |
| slot = path->slots[0]; |
| nritems = btrfs_header_nritems(l); |
| mid = (nritems + 1) / 2; |
| |
| if (mid <= slot) { |
| if (nritems == 1 || |
| leaf_space_used(l, mid, nritems - mid) + data_size > |
| BTRFS_LEAF_DATA_SIZE(root)) { |
| if (slot >= nritems) { |
| split = 0; |
| } else { |
| mid = slot; |
| if (mid != nritems && |
| leaf_space_used(l, mid, nritems - mid) + |
| data_size > BTRFS_LEAF_DATA_SIZE(root)) { |
| split = 2; |
| } |
| } |
| } |
| } else { |
| if (leaf_space_used(l, 0, mid) + data_size > |
| BTRFS_LEAF_DATA_SIZE(root)) { |
| if (!extend && data_size && slot == 0) { |
| split = 0; |
| } else if ((extend || !data_size) && slot == 0) { |
| mid = 1; |
| } else { |
| mid = slot; |
| if (mid != nritems && |
| leaf_space_used(l, mid, nritems - mid) + |
| data_size > BTRFS_LEAF_DATA_SIZE(root)) { |
| split = 2 ; |
| } |
| } |
| } |
| } |
| |
| if (split == 0) |
| btrfs_cpu_key_to_disk(&disk_key, ins_key); |
| else |
| btrfs_item_key(l, &disk_key, mid); |
| |
| right = btrfs_alloc_free_block(trans, root, root->leafsize, |
| root->root_key.objectid, |
| &disk_key, 0, l->start, 0); |
| if (IS_ERR(right)) { |
| BUG_ON(1); |
| return PTR_ERR(right); |
| } |
| |
| memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); |
| btrfs_set_header_bytenr(right, right->start); |
| btrfs_set_header_generation(right, trans->transid); |
| btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV); |
| btrfs_set_header_owner(right, root->root_key.objectid); |
| btrfs_set_header_level(right, 0); |
| write_extent_buffer(right, root->fs_info->fsid, |
| btrfs_header_fsid(), BTRFS_FSID_SIZE); |
| |
| write_extent_buffer(right, root->fs_info->chunk_tree_uuid, |
| btrfs_header_chunk_tree_uuid(right), |
| BTRFS_UUID_SIZE); |
| |
| if (split == 0) { |
| if (mid <= slot) { |
| btrfs_set_header_nritems(right, 0); |
| wret = insert_ptr(trans, root, path, |
| &disk_key, right->start, |
| path->slots[1] + 1, 1); |
| if (wret) |
| ret = wret; |
| |
| free_extent_buffer(path->nodes[0]); |
| path->nodes[0] = right; |
| path->slots[0] = 0; |
| path->slots[1] += 1; |
| } else { |
| btrfs_set_header_nritems(right, 0); |
| wret = insert_ptr(trans, root, path, |
| &disk_key, |
| right->start, |
| path->slots[1], 1); |
| if (wret) |
| ret = wret; |
| free_extent_buffer(path->nodes[0]); |
| path->nodes[0] = right; |
| path->slots[0] = 0; |
| if (path->slots[1] == 0) { |
| btrfs_fixup_low_keys(root, path, |
| &disk_key, 1); |
| } |
| } |
| btrfs_mark_buffer_dirty(right); |
| return ret; |
| } |
| |
| ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems); |
| BUG_ON(ret); |
| |
| if (split == 2) { |
| BUG_ON(num_doubles != 0); |
| num_doubles++; |
| goto again; |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * This function splits a single item into two items, |
| * giving 'new_key' to the new item and splitting the |
| * old one at split_offset (from the start of the item). |
| * |
| * The path may be released by this operation. After |
| * the split, the path is pointing to the old item. The |
| * new item is going to be in the same node as the old one. |
| * |
| * Note, the item being split must be smaller enough to live alone on |
| * a tree block with room for one extra struct btrfs_item |
| * |
| * This allows us to split the item in place, keeping a lock on the |
| * leaf the entire time. |
| */ |
| int btrfs_split_item(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct btrfs_key *new_key, |
| unsigned long split_offset) |
| { |
| u32 item_size; |
| struct extent_buffer *leaf; |
| struct btrfs_key orig_key; |
| struct btrfs_item *item; |
| struct btrfs_item *new_item; |
| int ret = 0; |
| int slot; |
| u32 nritems; |
| u32 orig_offset; |
| struct btrfs_disk_key disk_key; |
| char *buf; |
| |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &orig_key, path->slots[0]); |
| if (btrfs_leaf_free_space(root, leaf) >= sizeof(struct btrfs_item)) |
| goto split; |
| |
| item_size = btrfs_item_size_nr(leaf, path->slots[0]); |
| btrfs_release_path(path); |
| |
| path->search_for_split = 1; |
| |
| ret = btrfs_search_slot(trans, root, &orig_key, path, 0, 1); |
| path->search_for_split = 0; |
| |
| /* if our item isn't there or got smaller, return now */ |
| if (ret != 0 || item_size != btrfs_item_size_nr(path->nodes[0], |
| path->slots[0])) { |
| return -EAGAIN; |
| } |
| |
| ret = split_leaf(trans, root, &orig_key, path, 0, 0); |
| BUG_ON(ret); |
| |
| BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item)); |
| leaf = path->nodes[0]; |
| |
| split: |
| item = btrfs_item_nr(path->slots[0]); |
| orig_offset = btrfs_item_offset(leaf, item); |
| item_size = btrfs_item_size(leaf, item); |
| |
| |
| buf = kmalloc(item_size, GFP_NOFS); |
| read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, |
| path->slots[0]), item_size); |
| slot = path->slots[0] + 1; |
| leaf = path->nodes[0]; |
| |
| nritems = btrfs_header_nritems(leaf); |
| |
| if (slot != nritems) { |
| /* shift the items */ |
| memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), |
| btrfs_item_nr_offset(slot), |
| (nritems - slot) * sizeof(struct btrfs_item)); |
| |
| } |
| |
| btrfs_cpu_key_to_disk(&disk_key, new_key); |
| btrfs_set_item_key(leaf, &disk_key, slot); |
| |
| new_item = btrfs_item_nr(slot); |
| |
| btrfs_set_item_offset(leaf, new_item, orig_offset); |
| btrfs_set_item_size(leaf, new_item, item_size - split_offset); |
| |
| btrfs_set_item_offset(leaf, item, |
| orig_offset + item_size - split_offset); |
| btrfs_set_item_size(leaf, item, split_offset); |
| |
| btrfs_set_header_nritems(leaf, nritems + 1); |
| |
| /* write the data for the start of the original item */ |
| write_extent_buffer(leaf, buf, |
| btrfs_item_ptr_offset(leaf, path->slots[0]), |
| split_offset); |
| |
| /* write the data for the new item */ |
| write_extent_buffer(leaf, buf + split_offset, |
| btrfs_item_ptr_offset(leaf, slot), |
| item_size - split_offset); |
| btrfs_mark_buffer_dirty(leaf); |
| |
| ret = 0; |
| if (btrfs_leaf_free_space(root, leaf) < 0) { |
| btrfs_print_leaf(root, leaf); |
| BUG(); |
| } |
| kfree(buf); |
| return ret; |
| } |
| |
| int btrfs_truncate_item(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| u32 new_size, int from_end) |
| { |
| int ret = 0; |
| int slot; |
| struct extent_buffer *leaf; |
| struct btrfs_item *item; |
| u32 nritems; |
| unsigned int data_end; |
| unsigned int old_data_start; |
| unsigned int old_size; |
| unsigned int size_diff; |
| int i; |
| |
| leaf = path->nodes[0]; |
| slot = path->slots[0]; |
| |
| old_size = btrfs_item_size_nr(leaf, slot); |
| if (old_size == new_size) |
| return 0; |
| |
| nritems = btrfs_header_nritems(leaf); |
| data_end = leaf_data_end(root, leaf); |
| |
| old_data_start = btrfs_item_offset_nr(leaf, slot); |
| |
| size_diff = old_size - new_size; |
| |
| BUG_ON(slot < 0); |
| BUG_ON(slot >= nritems); |
| |
| /* |
| * item0..itemN ... dataN.offset..dataN.size .. data0.size |
| */ |
| /* first correct the data pointers */ |
| for (i = slot; i < nritems; i++) { |
| u32 ioff; |
| item = btrfs_item_nr(i); |
| ioff = btrfs_item_offset(leaf, item); |
| btrfs_set_item_offset(leaf, item, ioff + size_diff); |
| } |
| |
| /* shift the data */ |
| if (from_end) { |
| memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
| data_end + size_diff, btrfs_leaf_data(leaf) + |
| data_end, old_data_start + new_size - data_end); |
| } else { |
| struct btrfs_disk_key disk_key; |
| u64 offset; |
| |
| btrfs_item_key(leaf, &disk_key, slot); |
| |
| if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { |
| unsigned long ptr; |
| struct btrfs_file_extent_item *fi; |
| |
| fi = btrfs_item_ptr(leaf, slot, |
| struct btrfs_file_extent_item); |
| fi = (struct btrfs_file_extent_item *)( |
| (unsigned long)fi - size_diff); |
| |
| if (btrfs_file_extent_type(leaf, fi) == |
| BTRFS_FILE_EXTENT_INLINE) { |
| ptr = btrfs_item_ptr_offset(leaf, slot); |
| memmove_extent_buffer(leaf, ptr, |
| (unsigned long)fi, |
| offsetof(struct btrfs_file_extent_item, |
| disk_bytenr)); |
| } |
| } |
| |
| memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
| data_end + size_diff, btrfs_leaf_data(leaf) + |
| data_end, old_data_start - data_end); |
| |
| offset = btrfs_disk_key_offset(&disk_key); |
| btrfs_set_disk_key_offset(&disk_key, offset + size_diff); |
| btrfs_set_item_key(leaf, &disk_key, slot); |
| if (slot == 0) |
| btrfs_fixup_low_keys(root, path, &disk_key, 1); |
| } |
| |
| item = btrfs_item_nr(slot); |
| btrfs_set_item_size(leaf, item, new_size); |
| btrfs_mark_buffer_dirty(leaf); |
| |
| ret = 0; |
| if (btrfs_leaf_free_space(root, leaf) < 0) { |
| btrfs_print_leaf(root, leaf); |
| BUG(); |
| } |
| return ret; |
| } |
| |
| int btrfs_extend_item(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, struct btrfs_path *path, |
| u32 data_size) |
| { |
| int ret = 0; |
| int slot; |
| struct extent_buffer *leaf; |
| struct btrfs_item *item; |
| u32 nritems; |
| unsigned int data_end; |
| unsigned int old_data; |
| unsigned int old_size; |
| int i; |
| |
| leaf = path->nodes[0]; |
| |
| nritems = btrfs_header_nritems(leaf); |
| data_end = leaf_data_end(root, leaf); |
| |
| if (btrfs_leaf_free_space(root, leaf) < data_size) { |
| btrfs_print_leaf(root, leaf); |
| BUG(); |
| } |
| slot = path->slots[0]; |
| old_data = btrfs_item_end_nr(leaf, slot); |
| |
| BUG_ON(slot < 0); |
| if (slot >= nritems) { |
| btrfs_print_leaf(root, leaf); |
| printk("slot %d too large, nritems %d\n", slot, nritems); |
| BUG_ON(1); |
| } |
| |
| /* |
| * item0..itemN ... dataN.offset..dataN.size .. data0.size |
| */ |
| /* first correct the data pointers */ |
| for (i = slot; i < nritems; i++) { |
| u32 ioff; |
| item = btrfs_item_nr(i); |
| ioff = btrfs_item_offset(leaf, item); |
| btrfs_set_item_offset(leaf, item, ioff - data_size); |
| } |
| |
| /* shift the data */ |
| memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
| data_end - data_size, btrfs_leaf_data(leaf) + |
| data_end, old_data - data_end); |
| |
| data_end = old_data; |
| old_size = btrfs_item_size_nr(leaf, slot); |
| item = btrfs_item_nr(slot); |
| btrfs_set_item_size(leaf, item, old_size + data_size); |
| btrfs_mark_buffer_dirty(leaf); |
| |
| ret = 0; |
| if (btrfs_leaf_free_space(root, leaf) < 0) { |
| btrfs_print_leaf(root, leaf); |
| BUG(); |
| } |
| return ret; |
| } |
| |
| /* |
| * Given a key and some data, insert an item into the tree. |
| * This does all the path init required, making room in the tree if needed. |
| */ |
| int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct btrfs_key *cpu_key, u32 *data_size, |
| int nr) |
| { |
| struct extent_buffer *leaf; |
| struct btrfs_item *item; |
| int ret = 0; |
| int slot; |
| int i; |
| u32 nritems; |
| u32 total_size = 0; |
| u32 total_data = 0; |
| unsigned int data_end; |
| struct btrfs_disk_key disk_key; |
| |
| for (i = 0; i < nr; i++) { |
| total_data += data_size[i]; |
| } |
| |
| /* create a root if there isn't one */ |
| if (!root->node) |
| BUG(); |
| |
| total_size = total_data + nr * sizeof(struct btrfs_item); |
| ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); |
| if (ret == 0) { |
| return -EEXIST; |
| } |
| if (ret < 0) |
| goto out; |
| |
| leaf = path->nodes[0]; |
| |
| nritems = btrfs_header_nritems(leaf); |
| data_end = leaf_data_end(root, leaf); |
| |
| if (btrfs_leaf_free_space(root, leaf) < total_size) { |
| btrfs_print_leaf(root, leaf); |
| printk("not enough freespace need %u have %d\n", |
| total_size, btrfs_leaf_free_space(root, leaf)); |
| BUG(); |
| } |
| |
| slot = path->slots[0]; |
| BUG_ON(slot < 0); |
| |
| if (slot != nritems) { |
| unsigned int old_data = btrfs_item_end_nr(leaf, slot); |
| |
| if (old_data < data_end) { |
| btrfs_print_leaf(root, leaf); |
| printk("slot %d old_data %d data_end %d\n", |
| slot, old_data, data_end); |
| BUG_ON(1); |
| } |
| /* |
| * item0..itemN ... dataN.offset..dataN.size .. data0.size |
| */ |
| /* first correct the data pointers */ |
| for (i = slot; i < nritems; i++) { |
| u32 ioff; |
| |
| item = btrfs_item_nr(i); |
| ioff = btrfs_item_offset(leaf, item); |
| btrfs_set_item_offset(leaf, item, ioff - total_data); |
| } |
| |
| /* shift the items */ |
| memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), |
| btrfs_item_nr_offset(slot), |
| (nritems - slot) * sizeof(struct btrfs_item)); |
| |
| /* shift the data */ |
| memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
| data_end - total_data, btrfs_leaf_data(leaf) + |
| data_end, old_data - data_end); |
| data_end = old_data; |
| } |
| |
| /* setup the item for the new data */ |
| for (i = 0; i < nr; i++) { |
| btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); |
| btrfs_set_item_key(leaf, &disk_key, slot + i); |
| item = btrfs_item_nr(slot + i); |
| btrfs_set_item_offset(leaf, item, data_end - data_size[i]); |
| data_end -= data_size[i]; |
| btrfs_set_item_size(leaf, item, data_size[i]); |
| } |
| btrfs_set_header_nritems(leaf, nritems + nr); |
| btrfs_mark_buffer_dirty(leaf); |
| |
| ret = 0; |
| if (slot == 0) { |
| btrfs_cpu_key_to_disk(&disk_key, cpu_key); |
| btrfs_fixup_low_keys(root, path, &disk_key, 1); |
| } |
| |
| if (btrfs_leaf_free_space(root, leaf) < 0) { |
| btrfs_print_leaf(root, leaf); |
| BUG(); |
| } |
| |
| out: |
| return ret; |
| } |
| |
| /* |
| * Given a key and some data, insert an item into the tree. |
| * This does all the path init required, making room in the tree if needed. |
| */ |
| int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, struct btrfs_key *cpu_key, void *data, u32 |
| data_size) |
| { |
| int ret = 0; |
| struct btrfs_path *path; |
| struct extent_buffer *leaf; |
| unsigned long ptr; |
| |
| path = btrfs_alloc_path(); |
| BUG_ON(!path); |
| ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
| if (!ret) { |
| leaf = path->nodes[0]; |
| ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); |
| write_extent_buffer(leaf, data, ptr, data_size); |
| btrfs_mark_buffer_dirty(leaf); |
| } |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| /* |
| * delete the pointer from a given node. |
| * |
| * If the delete empties a node, the node is removed from the tree, |
| * continuing all the way the root if required. The root is converted into |
| * a leaf if all the nodes are emptied. |
| */ |
| int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
| struct btrfs_path *path, int level, int slot) |
| { |
| struct extent_buffer *parent = path->nodes[level]; |
| u32 nritems; |
| int ret = 0; |
| |
| nritems = btrfs_header_nritems(parent); |
| if (slot != nritems -1) { |
| memmove_extent_buffer(parent, |
| btrfs_node_key_ptr_offset(slot), |
| btrfs_node_key_ptr_offset(slot + 1), |
| sizeof(struct btrfs_key_ptr) * |
| (nritems - slot - 1)); |
| } |
| nritems--; |
| btrfs_set_header_nritems(parent, nritems); |
| if (nritems == 0 && parent == root->node) { |
| BUG_ON(btrfs_header_level(root->node) != 1); |
| /* just turn the root into a leaf and break */ |
| btrfs_set_header_level(root->node, 0); |
| } else if (slot == 0) { |
| struct btrfs_disk_key disk_key; |
| |
| btrfs_node_key(parent, &disk_key, 0); |
| btrfs_fixup_low_keys(root, path, &disk_key, level + 1); |
| } |
| btrfs_mark_buffer_dirty(parent); |
| return ret; |
| } |
| |
| /* |
| * a helper function to delete the leaf pointed to by path->slots[1] and |
| * path->nodes[1]. |
| * |
| * This deletes the pointer in path->nodes[1] and frees the leaf |
| * block extent. zero is returned if it all worked out, < 0 otherwise. |
| * |
| * The path must have already been setup for deleting the leaf, including |
| * all the proper balancing. path->nodes[1] must be locked. |
| */ |
| static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct extent_buffer *leaf) |
| { |
| int ret; |
| |
| WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
| ret = btrfs_del_ptr(trans, root, path, 1, path->slots[1]); |
| if (ret) |
| return ret; |
| |
| ret = btrfs_free_extent(trans, root, leaf->start, leaf->len, |
| 0, root->root_key.objectid, 0, 0); |
| return ret; |
| } |
| |
| /* |
| * delete the item at the leaf level in path. If that empties |
| * the leaf, remove it from the tree |
| */ |
| int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
| struct btrfs_path *path, int slot, int nr) |
| { |
| struct extent_buffer *leaf; |
| struct btrfs_item *item; |
| int last_off; |
| int dsize = 0; |
| int ret = 0; |
| int wret; |
| int i; |
| u32 nritems; |
| |
| leaf = path->nodes[0]; |
| last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); |
| |
| for (i = 0; i < nr; i++) |
| dsize += btrfs_item_size_nr(leaf, slot + i); |
| |
| nritems = btrfs_header_nritems(leaf); |
| |
| if (slot + nr != nritems) { |
| int data_end = leaf_data_end(root, leaf); |
| |
| memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
| data_end + dsize, |
| btrfs_leaf_data(leaf) + data_end, |
| last_off - data_end); |
| |
| for (i = slot + nr; i < nritems; i++) { |
| u32 ioff; |
| |
| item = btrfs_item_nr(i); |
| ioff = btrfs_item_offset(leaf, item); |
| btrfs_set_item_offset(leaf, item, ioff + dsize); |
| } |
| |
| memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), |
| btrfs_item_nr_offset(slot + nr), |
| sizeof(struct btrfs_item) * |
| (nritems - slot - nr)); |
| } |
| btrfs_set_header_nritems(leaf, nritems - nr); |
| nritems -= nr; |
| |
| /* delete the leaf if we've emptied it */ |
| if (nritems == 0) { |
| if (leaf == root->node) { |
| btrfs_set_header_level(leaf, 0); |
| } else { |
| clean_tree_block(trans, root, leaf); |
| wait_on_tree_block_writeback(root, leaf); |
| |
| wret = btrfs_del_leaf(trans, root, path, leaf); |
| BUG_ON(ret); |
| if (wret) |
| ret = wret; |
| } |
| } else { |
| int used = leaf_space_used(leaf, 0, nritems); |
| if (slot == 0) { |
| struct btrfs_disk_key disk_key; |
| |
| btrfs_item_key(leaf, &disk_key, 0); |
| btrfs_fixup_low_keys(root, path, &disk_key, 1); |
| } |
| |
| /* delete the leaf if it is mostly empty */ |
| if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) { |
| /* push_leaf_left fixes the path. |
| * make sure the path still points to our leaf |
| * for possible call to del_ptr below |
| */ |
| slot = path->slots[1]; |
| extent_buffer_get(leaf); |
| |
| wret = push_leaf_left(trans, root, path, 1, 1); |
| if (wret < 0 && wret != -ENOSPC) |
| ret = wret; |
| |
| if (path->nodes[0] == leaf && |
| btrfs_header_nritems(leaf)) { |
| wret = push_leaf_right(trans, root, path, 1, 1); |
| if (wret < 0 && wret != -ENOSPC) |
| ret = wret; |
| } |
| |
| if (btrfs_header_nritems(leaf) == 0) { |
| clean_tree_block(trans, root, leaf); |
| wait_on_tree_block_writeback(root, leaf); |
| |
| path->slots[1] = slot; |
| ret = btrfs_del_leaf(trans, root, path, leaf); |
| BUG_ON(ret); |
| free_extent_buffer(leaf); |
| |
| } else { |
| btrfs_mark_buffer_dirty(leaf); |
| free_extent_buffer(leaf); |
| } |
| } else { |
| btrfs_mark_buffer_dirty(leaf); |
| } |
| } |
| return ret; |
| } |
| |
| /* |
| * walk up the tree as far as required to find the previous leaf. |
| * returns 0 if it found something or 1 if there are no lesser leaves. |
| * returns < 0 on io errors. |
| */ |
| int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) |
| { |
| int slot; |
| int level = 1; |
| struct extent_buffer *c; |
| struct extent_buffer *next = NULL; |
| |
| while(level < BTRFS_MAX_LEVEL) { |
| if (!path->nodes[level]) |
| return 1; |
| |
| slot = path->slots[level]; |
| c = path->nodes[level]; |
| if (slot == 0) { |
| level++; |
| if (level == BTRFS_MAX_LEVEL) |
| return 1; |
| continue; |
| } |
| slot--; |
| |
| next = read_node_slot(root, c, slot); |
| if (!extent_buffer_uptodate(next)) { |
| if (IS_ERR(next)) |
| return PTR_ERR(next); |
| return -EIO; |
| } |
| break; |
| } |
| path->slots[level] = slot; |
| while(1) { |
| level--; |
| c = path->nodes[level]; |
| free_extent_buffer(c); |
| slot = btrfs_header_nritems(next); |
| if (slot != 0) |
| slot--; |
| path->nodes[level] = next; |
| path->slots[level] = slot; |
| if (!level) |
| break; |
| next = read_node_slot(root, next, slot); |
| if (!extent_buffer_uptodate(next)) { |
| if (IS_ERR(next)) |
| return PTR_ERR(next); |
| return -EIO; |
| } |
| } |
| return 0; |
| } |
| |
| /* |
| * walk up the tree as far as required to find the next leaf. |
| * returns 0 if it found something or 1 if there are no greater leaves. |
| * returns < 0 on io errors. |
| */ |
| int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
| { |
| int slot; |
| int level = 1; |
| struct extent_buffer *c; |
| struct extent_buffer *next = NULL; |
| |
| while(level < BTRFS_MAX_LEVEL) { |
| if (!path->nodes[level]) |
| return 1; |
| |
| slot = path->slots[level] + 1; |
| c = path->nodes[level]; |
| if (slot >= btrfs_header_nritems(c)) { |
| level++; |
| if (level == BTRFS_MAX_LEVEL) |
| return 1; |
| continue; |
| } |
| |
| if (path->reada) |
| reada_for_search(root, path, level, slot, 0); |
| |
| next = read_node_slot(root, c, slot); |
| if (!extent_buffer_uptodate(next)) |
| return -EIO; |
| break; |
| } |
| path->slots[level] = slot; |
| while(1) { |
| level--; |
| c = path->nodes[level]; |
| free_extent_buffer(c); |
| path->nodes[level] = next; |
| path->slots[level] = 0; |
| if (!level) |
| break; |
| if (path->reada) |
| reada_for_search(root, path, level, 0, 0); |
| next = read_node_slot(root, next, 0); |
| if (!extent_buffer_uptodate(next)) |
| return -EIO; |
| } |
| return 0; |
| } |
| |
| int btrfs_previous_item(struct btrfs_root *root, |
| struct btrfs_path *path, u64 min_objectid, |
| int type) |
| { |
| struct btrfs_key found_key; |
| struct extent_buffer *leaf; |
| int ret; |
| |
| while(1) { |
| if (path->slots[0] == 0) { |
| ret = btrfs_prev_leaf(root, path); |
| if (ret != 0) |
| return ret; |
| } else { |
| path->slots[0]--; |
| } |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| if (found_key.type == type) |
| return 0; |
| } |
| return 1; |
| } |
| |
| /* |
| * search in extent tree to find a previous Metadata/Data extent item with |
| * min objecitd. |
| * |
| * returns 0 if something is found, 1 if nothing was found and < 0 on error |
| */ |
| int btrfs_previous_extent_item(struct btrfs_root *root, |
| struct btrfs_path *path, u64 min_objectid) |
| { |
| struct btrfs_key found_key; |
| struct extent_buffer *leaf; |
| u32 nritems; |
| int ret; |
| |
| while (1) { |
| if (path->slots[0] == 0) { |
| ret = btrfs_prev_leaf(root, path); |
| if (ret != 0) |
| return ret; |
| } else { |
| path->slots[0]--; |
| } |
| leaf = path->nodes[0]; |
| nritems = btrfs_header_nritems(leaf); |
| if (nritems == 0) |
| return 1; |
| if (path->slots[0] == nritems) |
| path->slots[0]--; |
| |
| btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| if (found_key.objectid < min_objectid) |
| break; |
| if (found_key.type == BTRFS_EXTENT_ITEM_KEY || |
| found_key.type == BTRFS_METADATA_ITEM_KEY) |
| return 0; |
| if (found_key.objectid == min_objectid && |
| found_key.type < BTRFS_EXTENT_ITEM_KEY) |
| break; |
| } |
| return 1; |
| } |