diff options
Diffstat (limited to 'fs/btrfs/extent-tree.c')
| -rw-r--r-- | fs/btrfs/extent-tree.c | 5918 |
1 files changed, 5918 insertions, 0 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c new file mode 100644 index 00000000000..ee73efe7542 --- /dev/null +++ b/fs/btrfs/extent-tree.c @@ -0,0 +1,5918 @@ +/* + * 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 <linux/sched.h> +#include <linux/pagemap.h> +#include <linux/writeback.h> +#include <linux/blkdev.h> +#include "hash.h" +#include "crc32c.h" +#include "ctree.h" +#include "disk-io.h" +#include "print-tree.h" +#include "transaction.h" +#include "volumes.h" +#include "locking.h" +#include "ref-cache.h" + +#define PENDING_EXTENT_INSERT 0 +#define PENDING_EXTENT_DELETE 1 +#define PENDING_BACKREF_UPDATE 2 + +struct pending_extent_op { + int type; + u64 bytenr; + u64 num_bytes; + u64 parent; + u64 orig_parent; + u64 generation; + u64 orig_generation; + int level; + struct list_head list; + int del; +}; + +static int finish_current_insert(struct btrfs_trans_handle *trans, struct + btrfs_root *extent_root, int all); +static int del_pending_extents(struct btrfs_trans_handle *trans, struct + btrfs_root *extent_root, int all); +static struct btrfs_block_group_cache * +__btrfs_find_block_group(struct btrfs_root *root, + struct btrfs_block_group_cache *hint, + u64 search_start, int data, int owner); +static int pin_down_bytes(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytenr, u64 num_bytes, int is_data); +static int update_block_group(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytenr, u64 num_bytes, int alloc, + int mark_free); + +static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits) +{ + return (cache->flags & bits) == bits; +} + +/* + * this adds the block group to the fs_info rb tree for the block group + * cache + */ +int btrfs_add_block_group_cache(struct btrfs_fs_info *info, + struct btrfs_block_group_cache *block_group) +{ + struct rb_node **p; + struct rb_node *parent = NULL; + struct btrfs_block_group_cache *cache; + + spin_lock(&info->block_group_cache_lock); + p = &info->block_group_cache_tree.rb_node; + + while (*p) { + parent = *p; + cache = rb_entry(parent, struct btrfs_block_group_cache, + cache_node); + if (block_group->key.objectid < cache->key.objectid) { + p = &(*p)->rb_left; + } else if (block_group->key.objectid > cache->key.objectid) { + p = &(*p)->rb_right; + } else { + spin_unlock(&info->block_group_cache_lock); + return -EEXIST; + } + } + + rb_link_node(&block_group->cache_node, parent, p); + rb_insert_color(&block_group->cache_node, + &info->block_group_cache_tree); + spin_unlock(&info->block_group_cache_lock); + + return 0; +} + +/* + * This will return the block group at or after bytenr if contains is 0, else + * it will return the block group that contains the bytenr + */ +static struct btrfs_block_group_cache * +block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr, + int contains) +{ + struct btrfs_block_group_cache *cache, *ret = NULL; + struct rb_node *n; + u64 end, start; + + spin_lock(&info->block_group_cache_lock); + n = info->block_group_cache_tree.rb_node; + + while (n) { + cache = rb_entry(n, struct btrfs_block_group_cache, + cache_node); + end = cache->key.objectid + cache->key.offset - 1; + start = cache->key.objectid; + + if (bytenr < start) { + if (!contains && (!ret || start < ret->key.objectid)) + ret = cache; + n = n->rb_left; + } else if (bytenr > start) { + if (contains && bytenr <= end) { + ret = cache; + break; + } + n = n->rb_right; + } else { + ret = cache; + break; + } + } + spin_unlock(&info->block_group_cache_lock); + + return ret; +} + +/* + * this is only called by cache_block_group, since we could have freed extents + * we need to check the pinned_extents for any extents that can't be used yet + * since their free space will be released as soon as the transaction commits. + */ +static int add_new_free_space(struct btrfs_block_group_cache *block_group, + struct btrfs_fs_info *info, u64 start, u64 end) +{ + u64 extent_start, extent_end, size; + int ret; + + mutex_lock(&info->pinned_mutex); + while (start < end) { + ret = find_first_extent_bit(&info->pinned_extents, start, + &extent_start, &extent_end, + EXTENT_DIRTY); + if (ret) + break; + + if (extent_start == start) { + start = extent_end + 1; + } else if (extent_start > start && extent_start < end) { + size = extent_start - start; + ret = btrfs_add_free_space_lock(block_group, start, + size); + BUG_ON(ret); + start = extent_end + 1; + } else { + break; + } + } + + if (start < end) { + size = end - start; + ret = btrfs_add_free_space_lock(block_group, start, size); + BUG_ON(ret); + } + mutex_unlock(&info->pinned_mutex); + + return 0; +} + +static int cache_block_group(struct btrfs_root *root, + struct btrfs_block_group_cache *block_group) +{ + struct btrfs_path *path; + int ret = 0; + struct btrfs_key key; + struct extent_buffer *leaf; + int slot; + u64 last = 0; + u64 first_free; + int found = 0; + + if (!block_group) + return 0; + + root = root->fs_info->extent_root; + + if (block_group->cached) + return 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + path->reada = 2; + /* + * we get into deadlocks with paths held by callers of this function. + * since the alloc_mutex is protecting things right now, just + * skip the locking here + */ + path->skip_locking = 1; + first_free = max_t(u64, block_group->key.objectid, + BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE); + key.objectid = block_group->key.objectid; + key.offset = 0; + btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto err; + ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY); + if (ret < 0) + goto err; + if (ret == 0) { + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + if (key.objectid + key.offset > first_free) + first_free = key.objectid + key.offset; + } + while(1) { + leaf = path->nodes[0]; + slot = path->slots[0]; + if (slot >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto err; + if (ret == 0) + continue; + else + break; + } + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid < block_group->key.objectid) + goto next; + + if (key.objectid >= block_group->key.objectid + + block_group->key.offset) + break; + + if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) { + if (!found) { + last = first_free; + found = 1; + } + + add_new_free_space(block_group, root->fs_info, last, + key.objectid); + + last = key.objectid + key.offset; + } +next: + path->slots[0]++; + } + + if (!found) + last = first_free; + + add_new_free_space(block_group, root->fs_info, last, + block_group->key.objectid + + block_group->key.offset); + + block_group->cached = 1; + ret = 0; +err: + btrfs_free_path(path); + return ret; +} + +/* + * return the block group that starts at or after bytenr + */ +struct btrfs_block_group_cache *btrfs_lookup_first_block_group(struct + btrfs_fs_info *info, + u64 bytenr) +{ + struct btrfs_block_group_cache *cache; + + cache = block_group_cache_tree_search(info, bytenr, 0); + + return cache; +} + +/* + * return the block group that contains teh given bytenr + */ +struct btrfs_block_group_cache *btrfs_lookup_block_group(struct + btrfs_fs_info *info, + u64 bytenr) +{ + struct btrfs_block_group_cache *cache; + + cache = block_group_cache_tree_search(info, bytenr, 1); + + return cache; +} + +static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info, + u64 flags) +{ + struct list_head *head = &info->space_info; + struct list_head *cur; + struct btrfs_space_info *found; + list_for_each(cur, head) { + found = list_entry(cur, struct btrfs_space_info, list); + if (found->flags == flags) + return found; + } + return NULL; +} + +static u64 div_factor(u64 num, int factor) +{ + if (factor == 10) + return num; + num *= factor; + do_div(num, 10); + return num; +} + +static struct btrfs_block_group_cache * +__btrfs_find_block_group(struct btrfs_root *root, + struct btrfs_block_group_cache *hint, + u64 search_start, int data, int owner) +{ + struct btrfs_block_group_cache *cache; + struct btrfs_block_group_cache *found_group = NULL; + struct btrfs_fs_info *info = root->fs_info; + u64 used; + u64 last = 0; + u64 free_check; + int full_search = 0; + int factor = 10; + int wrapped = 0; + + if (data & BTRFS_BLOCK_GROUP_METADATA) + factor = 9; + + if (search_start) { + struct btrfs_block_group_cache *shint; + shint = btrfs_lookup_first_block_group(info, search_start); + if (shint && block_group_bits(shint, data)) { + spin_lock(&shint->lock); + used = btrfs_block_group_used(&shint->item); + if (used + shint->pinned + shint->reserved < + div_factor(shint->key.offset, factor)) { + spin_unlock(&shint->lock); + return shint; + } + spin_unlock(&shint->lock); + } + } + if (hint && block_group_bits(hint, data)) { + spin_lock(&hint->lock); + used = btrfs_block_group_used(&hint->item); + if (used + hint->pinned + hint->reserved < + div_factor(hint->key.offset, factor)) { + spin_unlock(&hint->lock); + return hint; + } + spin_unlock(&hint->lock); + last = hint->key.objectid + hint->key.offset; + } else { + if (hint) + last = max(hint->key.objectid, search_start); + else + last = search_start; + } +again: + while (1) { + cache = btrfs_lookup_first_block_group(root->fs_info, last); + if (!cache) + break; + + spin_lock(&cache->lock); + last = cache->key.objectid + cache->key.offset; + used = btrfs_block_group_used(&cache->item); + + if (block_group_bits(cache, data)) { + free_check = div_factor(cache->key.offset, factor); + if (used + cache->pinned + cache->reserved < + free_check) { + found_group = cache; + spin_unlock(&cache->lock); + goto found; + } + } + spin_unlock(&cache->lock); + cond_resched(); + } + if (!wrapped) { + last = search_start; + wrapped = 1; + goto again; + } + if (!full_search && factor < 10) { + last = search_start; + full_search = 1; + factor = 10; + goto again; + } +found: + return found_group; +} + +struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root, + struct btrfs_block_group_cache + *hint, u64 search_start, + int data, int owner) +{ + + struct btrfs_block_group_cache *ret; + ret = __btrfs_find_block_group(root, hint, search_start, data, owner); + return ret; +} + +/* simple helper to search for an existing extent at a given offset */ +int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len) +{ + int ret; + struct btrfs_key key; + struct btrfs_path *path; + + path = btrfs_alloc_path(); + BUG_ON(!path); + key.objectid = start; + key.offset = len; + btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); + ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path, + 0, 0); + btrfs_free_path(path); + return ret; +} + +/* + * Back reference rules. Back refs have three main goals: + * + * 1) differentiate between all holders of references to an extent so that + * when a reference is dropped we can make sure it was a valid reference + * before freeing the extent. + * + * 2) Provide enough information to quickly find the holders of an extent + * if we notice a given block is corrupted or bad. + * + * 3) Make it easy to migrate blocks for FS shrinking or storage pool + * maintenance. This is actually the same as #2, but with a slightly + * different use case. + * + * File extents can be referenced by: + * + * - multiple snapshots, subvolumes, or different generations in one subvol + * - different files inside a single subvolume + * - different offsets inside a file (bookend extents in file.c) + * + * The extent ref structure has fields for: + * + * - Objectid of the subvolume root + * - Generation number of the tree holding the reference + * - objectid of the file holding the reference + * - number of references holding by parent node (alway 1 for tree blocks) + * + * Btree leaf may hold multiple references to a file extent. In most cases, + * these references are from same file and the corresponding offsets inside + * the file are close together. + * + * When a file extent is allocated the fields are filled in: + * (root_key.objectid, trans->transid, inode objectid, 1) + * + * When a leaf is cow'd new references are added for every file extent found + * in the leaf. It looks similar to the create case, but trans->transid will + * be different when the block is cow'd. + * + * (root_key.objectid, trans->transid, inode objectid, + * number of references in the leaf) + * + * When a file extent is removed either during snapshot deletion or + * file truncation, we find the corresponding back reference and check + * the following fields: + * + * (btrfs_header_owner(leaf), btrfs_header_generation(leaf), + * inode objectid) + * + * Btree extents can be referenced by: + * + * - Different subvolumes + * - Different generations of the same subvolume + * + * When a tree block is created, back references are inserted: + * + * (root->root_key.objectid, trans->transid, level, 1) + * + * When a tree block is cow'd, new back references are added for all the + * blocks it points to. If the tree block isn't in reference counted root, + * the old back references are removed. These new back references are of + * the form (trans->transid will have increased since creation): + * + * (root->root_key.objectid, trans->transid, level, 1) + * + * When a backref is in deleting, the following fields are checked: + * + * if backref was for a tree root: + * (btrfs_header_owner(itself), btrfs_header_generation(itself), level) + * else + * (btrfs_header_owner(parent), btrfs_header_generation(parent), level) + * + * Back Reference Key composing: + * + * The key objectid corresponds to the first byte in the extent, the key + * type is set to BTRFS_EXTENT_REF_KEY, and the key offset is the first + * byte of parent extent. If a extent is tree root, the key offset is set + * to the key objectid. + */ + +static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + u64 bytenr, u64 parent, + u64 ref_root, u64 ref_generation, + u64 owner_objectid, int del) +{ + struct btrfs_key key; + struct btrfs_extent_ref *ref; + struct extent_buffer *leaf; + u64 ref_objectid; + int ret; + + key.objectid = bytenr; + key.type = BTRFS_EXTENT_REF_KEY; + key.offset = parent; + + ret = btrfs_search_slot(trans, root, &key, path, del ? -1 : 0, 1); + if (ret < 0) + goto out; + if (ret > 0) { + ret = -ENOENT; + goto out; + } + + leaf = path->nodes[0]; + ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref); + ref_objectid = btrfs_ref_objectid(leaf, ref); + if (btrfs_ref_root(leaf, ref) != ref_root || + btrfs_ref_generation(leaf, ref) != ref_generation || + (ref_objectid != owner_objectid && + ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) { + ret = -EIO; + WARN_ON(1); + goto out; + } + ret = 0; +out: + return ret; +} + +/* + * updates all the backrefs that are pending on update_list for the + * extent_root + */ +static int noinline update_backrefs(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root, + struct btrfs_path *path, + struct list_head *update_list) +{ + struct btrfs_key key; + struct btrfs_extent_ref *ref; + struct btrfs_fs_info *info = extent_root->fs_info; + struct pending_extent_op *op; + struct extent_buffer *leaf; + int ret = 0; + struct list_head *cur = update_list->next; + u64 ref_objectid; + u64 ref_root = extent_root->root_key.objectid; + + op = list_entry(cur, struct pending_extent_op, list); + +search: + key.objectid = op->bytenr; + key.type = BTRFS_EXTENT_REF_KEY; + key.offset = op->orig_parent; + + ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 1); + BUG_ON(ret); + + leaf = path->nodes[0]; + +loop: + ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref); + + ref_objectid = btrfs_ref_objectid(leaf, ref); + + if (btrfs_ref_root(leaf, ref) != ref_root || + btrfs_ref_generation(leaf, ref) != op->orig_generation || + (ref_objectid != op->level && + ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) { + printk(KERN_ERR "couldn't find %Lu, parent %Lu, root %Lu, " + "owner %u\n", op->bytenr, op->orig_parent, + ref_root, op->level); + btrfs_print_leaf(extent_root, leaf); + BUG(); + } + + key.objectid = op->bytenr; + key.offset = op->parent; + key.type = BTRFS_EXTENT_REF_KEY; + ret = btrfs_set_item_key_safe(trans, extent_root, path, &key); + BUG_ON(ret); + ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref); + btrfs_set_ref_generation(leaf, ref, op->generation); + + cur = cur->next; + + list_del_init(&op->list); + unlock_extent(&info->extent_ins, op->bytenr, + op->bytenr + op->num_bytes - 1, GFP_NOFS); + kfree(op); + + if (cur == update_list) { + btrfs_mark_buffer_dirty(path->nodes[0]); + btrfs_release_path(extent_root, path); + goto out; + } + + op = list_entry(cur, struct pending_extent_op, list); + + path->slots[0]++; + while (path->slots[0] < btrfs_header_nritems(leaf)) { + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + if (key.objectid == op->bytenr && + key.type == BTRFS_EXTENT_REF_KEY) + goto loop; + path->slots[0]++; + } + + btrfs_mark_buffer_dirty(path->nodes[0]); + btrfs_release_path(extent_root, path); + goto search; + +out: + return 0; +} + +static int noinline insert_extents(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root, + struct btrfs_path *path, + struct list_head *insert_list, int nr) +{ + struct btrfs_key *keys; + u32 *data_size; + struct pending_extent_op *op; + struct extent_buffer *leaf; + struct list_head *cur = insert_list->next; + struct btrfs_fs_info *info = extent_root->fs_info; + u64 ref_root = extent_root->root_key.objectid; + int i = 0, last = 0, ret; + int total = nr * 2; + + if (!nr) + return 0; + + keys = kzalloc(total * sizeof(struct btrfs_key), GFP_NOFS); + if (!keys) + return -ENOMEM; + + data_size = kzalloc(total * sizeof(u32), GFP_NOFS); + if (!data_size) { + kfree(keys); + return -ENOMEM; + } + + list_for_each_entry(op, insert_list, list) { + keys[i].objectid = op->bytenr; + keys[i].offset = op->num_bytes; + keys[i].type = BTRFS_EXTENT_ITEM_KEY; + data_size[i] = sizeof(struct btrfs_extent_item); + i++; + + keys[i].objectid = op->bytenr; + keys[i].offset = op->parent; + keys[i].type = BTRFS_EXTENT_REF_KEY; + data_size[i] = sizeof(struct btrfs_extent_ref); + i++; + } + + op = list_entry(cur, struct pending_extent_op, list); + i = 0; + while (i < total) { + int c; + ret = btrfs_insert_some_items(trans, extent_root, path, + keys+i, data_size+i, total-i); + BUG_ON(ret < 0); + + if (last && ret > 1) + BUG(); + + leaf = path->nodes[0]; + for (c = 0; c < ret; c++) { + int ref_first = keys[i].type == BTRFS_EXTENT_REF_KEY; + + /* + * if the first item we inserted was a backref, then + * the EXTENT_ITEM will be the odd c's, else it will + * be the even c's + */ + if ((ref_first && (c % 2)) || + (!ref_first && !(c % 2))) { + struct btrfs_extent_item *itm; + + itm = btrfs_item_ptr(leaf, path->slots[0] + c, + struct btrfs_extent_item); + btrfs_set_extent_refs(path->nodes[0], itm, 1); + op->del++; + } else { + struct btrfs_extent_ref *ref; + + ref = btrfs_item_ptr(leaf, path->slots[0] + c, + struct btrfs_extent_ref); + btrfs_set_ref_root(leaf, ref, ref_root); + btrfs_set_ref_generation(leaf, ref, + op->generation); + btrfs_set_ref_objectid(leaf, ref, op->level); + btrfs_set_ref_num_refs(leaf, ref, 1); + op->del++; + } + + /* + * using del to see when its ok to free up the + * pending_extent_op. In the case where we insert the + * last item on the list in order to help do batching + * we need to not free the extent op until we actually + * insert the extent_item + */ + if (op->del == 2) { + unlock_extent(&info->extent_ins, op->bytenr, + op->bytenr + op->num_bytes - 1, + GFP_NOFS); + cur = cur->next; + list_del_init(&op->list); + kfree(op); + if (cur != insert_list) + op = list_entry(cur, + struct pending_extent_op, + list); + } + } + btrfs_mark_buffer_dirty(leaf); + btrfs_release_path(extent_root, path); + + /* + * Ok backref's and items usually go right next to eachother, + * but if we could only insert 1 item that means that we + * inserted on the end of a leaf, and we have no idea what may + * be on the next leaf so we just play it safe. In order to + * try and help this case we insert the last thing on our + * insert list so hopefully it will end up being the last + * thing on the leaf and everything else will be before it, + * which will let us insert a whole bunch of items at the same + * time. + */ + if (ret == 1 && !last && (i + ret < total)) { + /* + * last: where we will pick up the next time around + * i: our current key to insert, will be total - 1 + * cur: the current op we are screwing with + * op: duh + */ + last = i + ret; + i = total - 1; + cur = insert_list->prev; + op = list_entry(cur, struct pending_extent_op, list); + } else if (last) { + /* + * ok we successfully inserted the last item on the + * list, lets reset everything + * + * i: our current key to insert, so where we left off + * last time + * last: done with this + * cur: the op we are messing with + * op: duh + * total: since we inserted the last key, we need to + * decrement total so we dont overflow + */ + i = last; + last = 0; + total--; + if (i < total) { + cur = insert_list->next; + op = list_entry(cur, struct pending_extent_op, + list); + } + } else { + i += ret; + } + + cond_resched(); + } + ret = 0; + kfree(keys); + kfree(data_size); + return ret; +} + +static int noinline insert_extent_backref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + u64 bytenr, u64 parent, + u64 ref_root, u64 ref_generation, + u64 owner_objectid) +{ + struct btrfs_key key; + struct extent_buffer *leaf; + struct btrfs_extent_ref *ref; + u32 num_refs; + int ret; + + key.objectid = bytenr; + key.type = BTRFS_EXTENT_REF_KEY; + key.offset = parent; + + ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*ref)); + if (ret == 0) { + leaf = path->nodes[0]; + ref = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_extent_ref); + btrfs_set_ref_root(leaf, ref, ref_root); + btrfs_set_ref_generation(leaf, ref, ref_generation); + btrfs_set_ref_objectid(leaf, ref, owner_objectid); + btrfs_set_ref_num_refs(leaf, ref, 1); + } else if (ret == -EEXIST) { + u64 existing_owner; + BUG_ON(owner_objectid < BTRFS_FIRST_FREE_OBJECTID); + leaf = path->nodes[0]; + ref = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_extent_ref); + if (btrfs_ref_root(leaf, ref) != ref_root || + btrfs_ref_generation(leaf, ref) != ref_generation) { + ret = -EIO; + WARN_ON(1); + goto out; + } + + num_refs = btrfs_ref_num_refs(leaf, ref); + BUG_ON(num_refs == 0); + btrfs_set_ref_num_refs(leaf, ref, num_refs + 1); + + existing_owner = btrfs_ref_objectid(leaf, ref); + if (existing_owner != owner_objectid && + existing_owner != BTRFS_MULTIPLE_OBJECTIDS) { + btrfs_set_ref_objectid(leaf, ref, + BTRFS_MULTIPLE_OBJECTIDS); + } + ret = 0; + } else { + goto out; + } + btrfs_mark_buffer_dirty(path->nodes[0]); +out: + btrfs_release_path(root, path); + return ret; +} + +static int noinline remove_extent_backref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path) +{ + struct extent_buffer *leaf; + struct btrfs_extent_ref *ref; + u32 num_refs; + int ret = 0; + + leaf = path->nodes[0]; + ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref); + num_refs = btrfs_ref_num_refs(leaf, ref); + BUG_ON(num_refs == 0); + num_refs -= 1; + if (num_refs == 0) { + ret = btrfs_del_item(trans, root, path); + } else { + btrfs_set_ref_num_refs(leaf, ref, num_refs); + btrfs_mark_buffer_dirty(leaf); + } + btrfs_release_path(root, path); + return ret; +} + +static int noinline free_extents(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root, + struct list_head *del_list) +{ + struct btrfs_fs_info *info = extent_root->fs_info; + struct btrfs_path *path; + struct btrfs_key key, found_key; + struct extent_buffer *leaf; + struct list_head *cur; + struct pending_extent_op *op; + struct btrfs_extent_item *ei; + int ret, num_to_del, extent_slot = 0, found_extent = 0; + u32 refs; + u64 bytes_freed = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + path->reada = 1; + +search: + /* search for the backref for the current ref we want to delete */ + cur = del_list->next; + op = list_entry(cur, struct pending_extent_op, list); + ret = lookup_extent_backref(trans, extent_root, path, op->bytenr, + op->orig_parent, + extent_root->root_key.objectid, + op->orig_generation, op->level, 1); + if (ret) { + printk("Unable to find backref byte nr %Lu root %Lu gen %Lu " + "owner %u\n", op->bytenr, + extent_root->root_key.objectid, op->orig_generation, + op->level); + btrfs_print_leaf(extent_root, path->nodes[0]); + WARN_ON(1); + goto out; + } + + extent_slot = path->slots[0]; + num_to_del = 1; + found_extent = 0; + + /* + * if we aren't the first item on the leaf we can move back one and see + * if our ref is right next to our extent item + */ + if (likely(extent_slot)) { + extent_slot--; + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + extent_slot); + if (found_key.objectid == op->bytenr && + found_key.type == BTRFS_EXTENT_ITEM_KEY && + found_key.offset == op->num_bytes) { + num_to_del++; + found_extent = 1; + } + } + + /* + * if we didn't find the extent we need to delete the backref and then + * search for the extent item key so we can update its ref count + */ + if (!found_extent) { + key.objectid = op->bytenr; + key.type = BTRFS_EXTENT_ITEM_KEY; + key.offset = op->num_bytes; + + ret = remove_extent_backref(trans, extent_root, path); + BUG_ON(ret); + btrfs_release_path(extent_root, path); + ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1); + BUG_ON(ret); + extent_slot = path->slots[0]; + } + + /* this is where we update the ref count for the extent */ + leaf = path->nodes[0]; + ei = btrfs_item_ptr(leaf, extent_slot, struct btrfs_extent_item); + refs = btrfs_extent_refs(leaf, ei); + BUG_ON(refs == 0); + refs--; + btrfs_set_extent_refs(leaf, ei, refs); + + btrfs_mark_buffer_dirty(leaf); + + /* + * This extent needs deleting. The reason cur_slot is extent_slot + + * num_to_del is because extent_slot points to the slot where the extent + * is, and if the backref was not right next to the extent we will be + * deleting at least 1 item, and will want to start searching at the + * slot directly next to extent_slot. However if we did find the + * backref next to the extent item them we will be deleting at least 2 + * items and will want to start searching directly after the ref slot + */ + if (!refs) { + struct list_head *pos, *n, *end; + int cur_slot = extent_slot+num_to_del; + u64 super_used; + u64 root_used; + + path->slots[0] = extent_slot; + bytes_freed = op->num_bytes; + + mutex_lock(&info->pinned_mutex); + ret = pin_down_bytes(trans, extent_root, op->bytenr, + op->num_bytes, op->level >= + BTRFS_FIRST_FREE_OBJECTID); + mutex_unlock(&info->pinned_mutex); + BUG_ON(ret < 0); + op->del = ret; + + /* + * we need to see if we can delete multiple things at once, so + * start looping through the list of extents we are wanting to + * delete and see if their extent/backref's are right next to + * eachother and the extents only have 1 ref + */ + for (pos = cur->next; pos != del_list; pos = pos->next) { + struct pending_extent_op *tmp; + + tmp = list_entry(pos, struct pending_extent_op, list); + + /* we only want to delete extent+ref at this stage */ + if (cur_slot >= btrfs_header_nritems(leaf) - 1) + break; + + btrfs_item_key_to_cpu(leaf, &found_key, cur_slot); + if (found_key.objectid != tmp->bytenr || + found_key.type != BTRFS_EXTENT_ITEM_KEY || + found_key.offset != tmp->num_bytes) + break; + + /* check to make sure this extent only has one ref */ + ei = btrfs_item_ptr(leaf, cur_slot, + struct btrfs_extent_item); + if (btrfs_extent_refs(leaf, ei) != 1) + break; + + btrfs_item_key_to_cpu(leaf, &found_key, cur_slot+1); + if (found_key.objectid != tmp->bytenr || + found_key.type != BTRFS_EXTENT_REF_KEY || + found_key.offset != tmp->orig_parent) + break; + + /* + * the ref is right next to the extent, we can set the + * ref count to 0 since we will delete them both now + */ + btrfs_set_extent_refs(leaf, ei, 0); + + /* pin down the bytes for this extent */ + mutex_lock(&info->pinned_mutex); + ret = pin_down_bytes(trans, extent_root, tmp->bytenr, + tmp->num_bytes, tmp->level >= + BTRFS_FIRST_FREE_OBJECTID); + mutex_unlock(&info->pinned_mutex); + BUG_ON(ret < 0); + + /* + * use the del field to tell if we need to go ahead and + * free up the extent when we delete the item or not. + */ + tmp->del = ret; + bytes_freed += tmp->num_bytes; + + num_to_del += 2; + cur_slot += 2; + } + end = pos; + + /* update the free space counters */ + spin_lock_irq(&info->delalloc_lock); + super_used = btrfs_super_bytes_used(&info->super_copy); + btrfs_set_super_bytes_used(&info->super_copy, + super_used - bytes_freed); + spin_unlock_irq(&info->delalloc_lock); + + root_used = btrfs_root_used(&extent_root->root_item); + btrfs_set_root_used(&extent_root->root_item, + root_used - bytes_freed); + + /* delete the items */ + ret = btrfs_del_items(trans, extent_root, path, + path->slots[0], num_to_del); + BUG_ON(ret); + + /* + * loop through the extents we deleted and do the cleanup work + * on them + */ + for (pos = cur, n = pos->next; pos != end; + pos = n, n = pos->next) { + struct pending_extent_op *tmp; +#ifdef BIO_RW_DISCARD + u64 map_length; + struct btrfs_multi_bio *multi = NULL; +#endif + tmp = list_entry(pos, struct pending_extent_op, list); + + /* + * remember tmp->del tells us wether or not we pinned + * down the extent + */ + ret = update_block_group(trans, extent_root, + tmp->bytenr, tmp->num_bytes, 0, + tmp->del); + BUG_ON(ret); + +#ifdef BIO_RW_DISCARD + ret = btrfs_map_block(&info->mapping_tree, READ, + tmp->bytenr, &map_length, &multi, + 0); + if (!ret) { + struct btrfs_bio_stripe *stripe; + int i; + + stripe = multi->stripe; + + if (map_length > tmp->num_bytes) + map_length = tmp->num_bytes; + + for (i = 0; i < multi->num_stripes; + i++, stripe++) + blkdev_issue_discard(stripe->dev->bdev, + stripe->physical >> 9, + map_length >> 9); + kfree(multi); + } +#endif + list_del_init(&tmp->list); + unlock_extent(&info->extent_ins, tmp->bytenr, + tmp->bytenr + tmp->num_bytes - 1, + GFP_NOFS); + kfree(tmp); + } + } else if (refs && found_extent) { + /* + * the ref and extent were right next to eachother, but the + * extent still has a ref, so just free the backref and keep + * going + */ + ret = remove_extent_backref(trans, extent_root, path); + BUG_ON(ret); + + list_del_init(&op->list); + unlock_extent(&info->extent_ins, op->bytenr, + op->bytenr + op->num_bytes - 1, GFP_NOFS); + kfree(op); + } else { + /* + * the extent has multiple refs and the backref we were looking + * for was not right next to it, so just unlock and go next, + * we're good to go + */ + list_del_init(&op->list); + unlock_extent(&info->extent_ins, op->bytenr, + op->bytenr + op->num_bytes - 1, GFP_NOFS); + kfree(op); + } + + btrfs_release_path(extent_root, path); + if (!list_empty(del_list)) + goto search; + +out: + btrfs_free_path(path); + return ret; +} + +static int __btrfs_update_extent_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 bytenr, + u64 orig_parent, u64 parent, + u64 orig_root, u64 ref_root, + u64 orig_generation, u64 ref_generation, + u64 owner_objectid) +{ + int ret; + struct btrfs_root *extent_root = root->fs_info->extent_root; + struct btrfs_path *path; + + if (root == root->fs_info->extent_root) { + struct pending_extent_op *extent_op; + u64 num_bytes; + + BUG_ON(owner_objectid >= BTRFS_MAX_LEVEL); + num_bytes = btrfs_level_size(root, (int)owner_objectid); + mutex_lock(&root->fs_info->extent_ins_mutex); + if (test_range_bit(&root->fs_info->extent_ins, bytenr, + bytenr + num_bytes - 1, EXTENT_WRITEBACK, 0)) { + u64 priv; + ret = get_state_private(&root->fs_info->extent_ins, + bytenr, &priv); + BUG_ON(ret); + extent_op = (struct pending_extent_op *) + (unsigned long)priv; + BUG_ON(extent_op->parent != orig_parent); + BUG_ON(extent_op->generation != orig_generation); + + extent_op->parent = parent; + extent_op->generation = ref_generation; + } else { + extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS); + BUG_ON(!extent_op); + + extent_op->type = PENDING_BACKREF_UPDATE; + extent_op->bytenr = bytenr; + extent_op->num_bytes = num_bytes; + extent_op->parent = parent; + extent_op->orig_parent = orig_parent; + extent_op->generation = ref_generation; + extent_op->orig_generation = orig_generation; + extent_op->level = (int)owner_objectid; + INIT_LIST_HEAD(&extent_op->list); + extent_op->del = 0; + + set_extent_bits(&root->fs_info->extent_ins, + bytenr, bytenr + num_bytes - 1, + EXTENT_WRITEBACK, GFP_NOFS); + set_state_private(&root->fs_info->extent_ins, + bytenr, (unsigned long)extent_op); + } + mutex_unlock(&root->fs_info->extent_ins_mutex); + return 0; + } + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + ret = lookup_extent_backref(trans, extent_root, path, + bytenr, orig_parent, orig_root, + orig_generation, owner_objectid, 1); + if (ret) + goto out; + ret = remove_extent_backref(trans, extent_root, path); + if (ret) + goto out; + ret = insert_extent_backref(trans, extent_root, path, bytenr, + parent, ref_root, ref_generation, + owner_objectid); + BUG_ON(ret); + finish_current_insert(trans, extent_root, 0); + del_pending_extents(trans, extent_root, 0); +out: + btrfs_free_path(path); + return ret; +} + +int btrfs_update_extent_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 bytenr, + u64 orig_parent, u64 parent, + u64 ref_root, u64 ref_generation, + u64 owner_objectid) +{ + int ret; + if (ref_root == BTRFS_TREE_LOG_OBJECTID && + owner_objectid < BTRFS_FIRST_FREE_OBJECTID) + return 0; + ret = __btrfs_update_extent_ref(trans, root, bytenr, orig_parent, + parent, ref_root, ref_root, + ref_generation, ref_generation, + owner_objectid); + return ret; +} + +static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 bytenr, + u64 orig_parent, u64 parent, + u64 orig_root, u64 ref_root, + u64 orig_generation, u64 ref_generation, + u64 owner_objectid) +{ + struct btrfs_path *path; + int ret; + struct btrfs_key key; + struct extent_buffer *l; + struct btrfs_extent_item *item; + u32 refs; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + path->reada = 1; + key.objectid = bytenr; + key.type = BTRFS_EXTENT_ITEM_KEY; + key.offset = (u64)-1; + + ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path, + 0, 1); + if (ret < 0) + return ret; + BUG_ON(ret == 0 || path->slots[0] == 0); + + path->slots[0]--; + l = path->nodes[0]; + + btrfs_item_key_to_cpu(l, &key, path->slots[0]); + if (key.objectid != bytenr) { + btrfs_print_leaf(root->fs_info->extent_root, path->nodes[0]); + printk("wanted %Lu found %Lu\n", bytenr, key.objectid); + BUG(); + } + BUG_ON(key.type != BTRFS_EXTENT_ITEM_KEY); + + item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); + refs = btrfs_extent_refs(l, item); + btrfs_set_extent_refs(l, item, refs + 1); + btrfs_mark_buffer_dirty(path->nodes[0]); + + btrfs_release_path(root->fs_info->extent_root, path); + + path->reada = 1; + ret = insert_extent_backref(trans, root->fs_info->extent_root, + path, bytenr, parent, + ref_root, ref_generation, + owner_objectid); + BUG_ON(ret); + finish_current_insert(trans, root->fs_info->extent_root, 0); + del_pending_extents(trans, root->fs_info->extent_root, 0); + + btrfs_free_path(path); + return 0; +} + +int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytenr, u64 num_bytes, u64 parent, + u64 ref_root, u64 ref_generation, + u64 owner_objectid) +{ + int ret; + if (ref_root == BTRFS_TREE_LOG_OBJECTID && + owner_objectid < BTRFS_FIRST_FREE_OBJECTID) + return 0; + ret = __btrfs_inc_extent_ref(trans, root, bytenr, 0, parent, + 0, ref_root, 0, ref_generation, + owner_objectid); + return ret; +} + +int btrfs_extent_post_op(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + finish_current_insert(trans, root->fs_info->extent_root, 1); + del_pending_extents(trans, root->fs_info->extent_root, 1); + return 0; +} + +int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 bytenr, + u64 num_bytes, u32 *refs) +{ + struct btrfs_path *path; + int ret; + struct btrfs_key key; + struct extent_buffer *l; + struct btrfs_extent_item *item; + + WARN_ON(num_bytes < root->sectorsize); + path = btrfs_alloc_path(); + path->reada = 1; + key.objectid = bytenr; + key.offset = num_bytes; + btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); + ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path, + 0, 0); + if (ret < 0) + goto out; + if (ret != 0) { + btrfs_print_leaf(root, path->nodes[0]); + printk("failed to find block number %Lu\n", bytenr); + BUG(); + } + l = path->nodes[0]; + item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); + *refs = btrfs_extent_refs(l, item); +out: + btrfs_free_path(path); + return 0; +} + +int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 bytenr) +{ + struct btrfs_root *extent_root = root->fs_info->extent_root; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_extent_ref *ref_item; + struct btrfs_key key; + struct btrfs_key found_key; + u64 ref_root; + u64 last_snapshot; + u32 nritems; + int ret; + + key.objectid = bytenr; + key.offset = (u64)-1; + key.type = BTRFS_EXTENT_ITEM_KEY; + + path = btrfs_alloc_path(); + ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); + if (ret < 0) + goto out; + BUG_ON(ret == 0); + + ret = -ENOENT; + if (path->slots[0] == 0) + goto out; + + path->slots[0]--; + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + if (found_key.objectid != bytenr || + found_key.type != BTRFS_EXTENT_ITEM_KEY) + goto out; + + last_snapshot = btrfs_root_last_snapshot(&root->root_item); + while (1) { + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + if (path->slots[0] >= nritems) { + ret = btrfs_next_leaf(extent_root, path); + if (ret < 0) + goto out; + if (ret == 0) + continue; + break; + } + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + if (found_key.objectid != bytenr) + break; + + if (found_key.type != BTRFS_EXTENT_REF_KEY) { + path->slots[0]++; + continue; + } + + ref_item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_extent_ref); + ref_root = btrfs_ref_root(leaf, ref_item); + if (ref_root != root->root_key.objectid && + ref_root != BTRFS_TREE_LOG_OBJECTID) { + ret = 1; + goto out; + } + if (btrfs_ref_generation(leaf, ref_item) <= last_snapshot) { + ret = 1; + goto out; + } + + path->slots[0]++; + } + ret = 0; +out: + btrfs_free_path(path); + return ret; +} + +int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, + struct extent_buffer *buf, u32 nr_extents) +{ + struct btrfs_key key; + struct btrfs_file_extent_item *fi; + u64 root_gen; + u32 nritems; + int i; + int level; + int ret = 0; + int shared = 0; + + if (!root->ref_cows) + return 0; + + if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) { + shared = 0; + root_gen = root->root_key.offset; + } else { + shared = 1; + root_gen = trans->transid - 1; + } + + level = btrfs_header_level(buf); + nritems = btrfs_header_nritems(buf); + + if (level == 0) { + struct btrfs_leaf_ref *ref; + struct btrfs_extent_info *info; + + ref = btrfs_alloc_leaf_ref(root, nr_extents); + if (!ref) { + ret = -ENOMEM; + goto out; + } + + ref->root_gen = root_gen; + ref->bytenr = buf->start; + ref->owner = btrfs_header_owner(buf); + ref->generation = btrfs_header_generation(buf); + ref->nritems = nr_extents; + info = ref->extents; + + for (i = 0; nr_extents > 0 && i < nritems; i++) { + u64 disk_bytenr; + btrfs_item_key_to_cpu(buf, &key, i); + if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) + continue; + fi = btrfs_item_ptr(buf, i, + struct btrfs_file_extent_item); + if (btrfs_file_extent_type(buf, fi) == + BTRFS_FILE_EXTENT_INLINE) + continue; + disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi); + if (disk_bytenr == 0) + continue; + + info->bytenr = disk_bytenr; + info->num_bytes = + btrfs_file_extent_disk_num_bytes(buf, fi); + info->objectid = key.objectid; + info->offset = key.offset; + info++; + } + + ret = btrfs_add_leaf_ref(root, ref, shared); + if (ret == -EEXIST && shared) { + struct btrfs_leaf_ref *old; + old = btrfs_lookup_leaf_ref(root, ref->bytenr); + BUG_ON(!old); + btrfs_remove_leaf_ref(root, old); + btrfs_free_leaf_ref(root, old); + ret = btrfs_add_leaf_ref(root, ref, shared); + } + WARN_ON(ret); + btrfs_free_leaf_ref(root, ref); + } +out: + return ret; +} + +int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, + struct extent_buffer *orig_buf, struct extent_buffer *buf, + u32 *nr_extents) +{ + u64 bytenr; + u64 ref_root; + u64 orig_root; + u64 ref_generation; + u64 orig_generation; + u32 nritems; + u32 nr_file_extents = 0; + struct btrfs_key key; + struct btrfs_file_extent_item *fi; + int i; + int level; + int ret = 0; + int faili = 0; + int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *, + u64, u64, u64, u64, u64, u64, u64, u64); + + ref_root = btrfs_header_owner(buf); + ref_generation = btrfs_header_generation(buf); + orig_root = btrfs_header_owner(orig_buf); + orig_generation = btrfs_header_generation(orig_buf); + + nritems = btrfs_header_nritems(buf); + level = btrfs_header_level(buf); + + if (root->ref_cows) { + process_func = __btrfs_inc_extent_ref; + } else { + if (level == 0 && + root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) + goto out; + if (level != 0 && + root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) + goto out; + process_func = __btrfs_update_extent_ref; + } + + for (i = 0; i < nritems; i++) { + cond_resched(); + if (level == 0) { + btrfs_item_key_to_cpu(buf, &key, i); + if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) + continue; + fi = btrfs_item_ptr(buf, i, + struct btrfs_file_extent_item); + if (btrfs_file_extent_type(buf, fi) == + BTRFS_FILE_EXTENT_INLINE) + continue; + bytenr = btrfs_file_extent_disk_bytenr(buf, fi); + if (bytenr == 0) + continue; + + nr_file_extents++; + + ret = process_func(trans, root, bytenr, + orig_buf->start, buf->start, + orig_root, ref_root, + orig_generation, ref_generation, + key.objectid); + + if (ret) { + faili = i; + WARN_ON(1); + goto fail; + } + } else { + bytenr = btrfs_node_blockptr(buf, i); + ret = process_func(trans, root, bytenr, + orig_buf->start, buf->start, + orig_root, ref_root, + orig_generation, ref_generation, + level - 1); + if (ret) { + faili = i; + WARN_ON(1); + goto fail; + } + } + } +out: + if (nr_extents) { + if (level == 0) + *nr_extents = nr_file_extents; + else + *nr_extents = nritems; + } + return 0; +fail: + WARN_ON(1); + return ret; +} + +int btrfs_update_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct extent_buffer *orig_buf, + struct extent_buffer *buf, int start_slot, int nr) + +{ + u64 bytenr; + u64 ref_root; + u64 orig_root; + u64 ref_generation; + u64 orig_generation; + struct btrfs_key key; + struct btrfs_file_extent_item *fi; + int i; + int ret; + int slot; + int level; + + BUG_ON(start_slot < 0); + BUG_ON(start_slot + nr > btrfs_header_nritems(buf)); + + ref_root = btrfs_header_owner(buf); + ref_generation = btrfs_header_generation(buf); + orig_root = btrfs_header_owner(orig_buf); + orig_generation = btrfs_header_generation(orig_buf); + level = btrfs_header_level(buf); + + if (!root->ref_cows) { + if (level == 0 && + root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) + return 0; + if (level != 0 && + root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) + return 0; + } + + for (i = 0, slot = start_slot; i < nr; i++, slot++) { + cond_resched(); + if (level == 0) { + btrfs_item_key_to_cpu(buf, &key, slot); + if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) + continue; + fi = btrfs_item_ptr(buf, slot, + struct btrfs_file_extent_item); + if (btrfs_file_extent_type(buf, fi) == + BTRFS_FILE_EXTENT_INLINE) + continue; + bytenr = btrfs_file_extent_disk_bytenr(buf, fi); + if (bytenr == 0) + continue; + ret = __btrfs_update_extent_ref(trans, root, bytenr, + orig_buf->start, buf->start, + orig_root, ref_root, + orig_generation, ref_generation, + key.objectid); + if (ret) + goto fail; + } else { + bytenr = btrfs_node_blockptr(buf, slot); + ret = __btrfs_update_extent_ref(trans, root, bytenr, + orig_buf->start, buf->start, + orig_root, ref_root, + orig_generation, ref_generation, + level - 1); + if (ret) + goto fail; + } + } + return 0; +fail: + WARN_ON(1); + return -1; +} + +static int write_one_cache_group(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_block_group_cache *cache) +{ + int ret; + int pending_ret; + struct btrfs_root *extent_root = root->fs_info->extent_root; + unsigned long bi; + struct extent_buffer *leaf; + + ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1); + if (ret < 0) + goto fail; + BUG_ON(ret); + + leaf = path->nodes[0]; + bi = btrfs_item_ptr_offset(leaf, path->slots[0]); + write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item)); + btrfs_mark_buffer_dirty(leaf); + btrfs_release_path(extent_root, path); +fail: + finish_current_insert(trans, extent_root, 0); + pending_ret = del_pending_extents(trans, extent_root, 0); + if (ret) + return ret; + if (pending_ret) + return pending_ret; + return 0; + +} + +int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_block_group_cache *cache, *entry; + struct rb_node *n; + int err = 0; + int werr = 0; + struct btrfs_path *path; + u64 last = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + while(1) { + cache = NULL; + spin_lock(&root->fs_info->block_group_cache_lock); + for (n = rb_first(&root->fs_info->block_group_cache_tree); + n; n = rb_next(n)) { + entry = rb_entry(n, struct btrfs_block_group_cache, + cache_node); + if (entry->dirty) { + cache = entry; + break; + } + } + spin_unlock(&root->fs_info->block_group_cache_lock); + + if (!cache) + break; + + cache->dirty = 0; + last += cache->key.offset; + + err = write_one_cache_group(trans, root, + path, cache); + /* + * if we fail to write the cache group, we want + * to keep it marked dirty in hopes that a later + * write will work + */ + if (err) { + werr = err; + continue; + } + } + btrfs_free_path(path); + return werr; +} + +static int update_space_info(struct btrfs_fs_info *info, u64 flags, + u64 total_bytes, u64 bytes_used, + struct btrfs_space_info **space_info) +{ + struct btrfs_space_info *found; + + found = __find_space_info(info, flags); + if (found) { + spin_lock(&found->lock); + found->total_bytes += total_bytes; + found->bytes_used += bytes_used; + found->full = 0; + spin_unlock(&found->lock); + *space_info = found; + return 0; + } + found = kzalloc(sizeof(*found), GFP_NOFS); + if (!found) + return -ENOMEM; + + list_add(&found->list, &info->space_info); + INIT_LIST_HEAD(&found->block_groups); + init_rwsem(&found->groups_sem); + spin_lock_init(&found->lock); + found->flags = flags; + found->total_bytes = total_bytes; + found->bytes_used = bytes_used; + found->bytes_pinned = 0; + found->bytes_reserved = 0; + found->bytes_readonly = 0; + found->full = 0; + found->force_alloc = 0; + *space_info = found; + return 0; +} + +static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) +{ + u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10 | + BTRFS_BLOCK_GROUP_DUP); + if (extra_flags) { + if (flags & BTRFS_BLOCK_GROUP_DATA) + fs_info->avail_data_alloc_bits |= extra_flags; + if (flags & BTRFS_BLOCK_GROUP_METADATA) + fs_info->avail_metadata_alloc_bits |= extra_flags; + if (flags & BTRFS_BLOCK_GROUP_SYSTEM) + fs_info->avail_system_alloc_bits |= extra_flags; + } +} + +static void set_block_group_readonly(struct btrfs_block_group_cache *cache) +{ + spin_lock(&cache->space_info->lock); + spin_lock(&cache->lock); + if (!cache->ro) { + cache->space_info->bytes_readonly += cache->key.offset - + btrfs_block_group_used(&cache->item); + cache->ro = 1; + } + spin_unlock(&cache->lock); + spin_unlock(&cache->space_info->lock); +} + +u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags) +{ + u64 num_devices = root->fs_info->fs_devices->rw_devices; + + if (num_devices == 1) + flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0); + if (num_devices < 4) + flags &= ~BTRFS_BLOCK_GROUP_RAID10; + + if ((flags & BTRFS_BLOCK_GROUP_DUP) && + (flags & (BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10))) { + flags &= ~BTRFS_BLOCK_GROUP_DUP; + } + + if ((flags & BTRFS_BLOCK_GROUP_RAID1) && + (flags & BTRFS_BLOCK_GROUP_RAID10)) { + flags &= ~BTRFS_BLOCK_GROUP_RAID1; + } + + if ((flags & BTRFS_BLOCK_GROUP_RAID0) && + ((flags & BTRFS_BLOCK_GROUP_RAID1) | + (flags & BTRFS_BLOCK_GROUP_RAID10) | + (flags & BTRFS_BLOCK_GROUP_DUP))) + flags &= ~BTRFS_BLOCK_GROUP_RAID0; + return flags; +} + +static int do_chunk_alloc(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root, u64 alloc_bytes, + u64 flags, int force) +{ + struct btrfs_space_info *space_info; + u64 thresh; + int ret = 0; + + mutex_lock(&extent_root->fs_info->chunk_mutex); + + flags = btrfs_reduce_alloc_profile(extent_root, flags); + + space_info = __find_space_info(extent_root->fs_info, flags); + if (!space_info) { + ret = update_space_info(extent_root->fs_info, flags, + 0, 0, &space_info); + BUG_ON(ret); + } + BUG_ON(!space_info); + + spin_lock(&space_info->lock); + if (space_info->force_alloc) { + force = 1; + space_info->force_alloc = 0; + } + if (space_info->full) { + spin_unlock(&space_info->lock); + goto out; + } + + thresh = space_info->total_bytes - space_info->bytes_readonly; + thresh = div_factor(thresh, 6); + if (!force && + (space_info->bytes_used + space_info->bytes_pinned + + space_info->bytes_reserved + alloc_bytes) < thresh) { + spin_unlock(&space_info->lock); + goto out; + } + spin_unlock(&space_info->lock); + + ret = btrfs_alloc_chunk(trans, extent_root, flags); + if (ret) { +printk("space info full %Lu\n", flags); + space_info->full = 1; + } +out: + mutex_unlock(&extent_root->fs_info->chunk_mutex); + return ret; +} + +static int update_block_group(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytenr, u64 num_bytes, int alloc, + int mark_free) +{ + struct btrfs_block_group_cache *cache; + struct btrfs_fs_info *info = root->fs_info; + u64 total = num_bytes; + u64 old_val; + u64 byte_in_group; + + while(total) { + cache = btrfs_lookup_block_group(info, bytenr); + if (!cache) + return -1; + byte_in_group = bytenr - cache->key.objectid; + WARN_ON(byte_in_group > cache->key.offset); + + spin_lock(&cache->space_info->lock); + spin_lock(&cache->lock); + cache->dirty = 1; + old_val = btrfs_block_group_used(&cache->item); + num_bytes = min(total, cache->key.offset - byte_in_group); + if (alloc) { + old_val += num_bytes; + cache->space_info->bytes_used += num_bytes; + if (cache->ro) { + cache->space_info->bytes_readonly -= num_bytes; + WARN_ON(1); + } + btrfs_set_block_group_used(&cache->item, old_val); + spin_unlock(&cache->lock); + spin_unlock(&cache->space_info->lock); + } else { + old_val -= num_bytes; + cache->space_info->bytes_used -= num_bytes; + if (cache->ro) + cache->space_info->bytes_readonly += num_bytes; + btrfs_set_block_group_used(&cache->item, old_val); + spin_unlock(&cache->lock); + spin_unlock(&cache->space_info->lock); + if (mark_free) { + int ret; + ret = btrfs_add_free_space(cache, bytenr, + num_bytes); + if (ret) + return -1; + } + } + total -= num_bytes; + bytenr += num_bytes; + } + return 0; +} + +static u64 first_logical_byte(struct btrfs_root *root, u64 search_start) +{ + struct btrfs_block_group_cache *cache; + + cache = btrfs_lookup_first_block_group(root->fs_info, search_start); + if (!cache) + return 0; + + return cache->key.objectid; +} + +int btrfs_update_pinned_extents(struct btrfs_root *root, + u64 bytenr, u64 num, int pin) +{ + u64 len; + struct btrfs_block_group_cache *cache; + struct btrfs_fs_info *fs_info = root->fs_info; + + WARN_ON(!mutex_is_locked(&root->fs_info->pinned_mutex)); + if (pin) { + set_extent_dirty(&fs_info->pinned_extents, + bytenr, bytenr + num - 1, GFP_NOFS); + } else { + clear_extent_dirty(&fs_info->pinned_extents, + bytenr, bytenr + num - 1, GFP_NOFS); + } + while (num > 0) { + cache = btrfs_lookup_block_group(fs_info, bytenr); + BUG_ON(!cache); + len = min(num, cache->key.offset - + (bytenr - cache->key.objectid)); + if (pin) { + spin_lock(&cache->space_info->lock); + spin_lock(&cache->lock); + cache->pinned += len; + cache->space_info->bytes_pinned += len; + spin_unlock(&cache->lock); + spin_unlock(&cache->space_info->lock); + fs_info->total_pinned += len; + } else { + spin_lock(&cache->space_info->lock); + spin_lock(&cache->lock); + cache->pinned -= len; + cache->space_info->bytes_pinned -= len; + spin_unlock(&cache->lock); + spin_unlock(&cache->space_info->lock); + fs_info->total_pinned -= len; + if (cache->cached) + btrfs_add_free_space(cache, bytenr, len); + } + bytenr += len; + num -= len; + } + return 0; +} + +static int update_reserved_extents(struct btrfs_root *root, + u64 bytenr, u64 num, int reserve) +{ + u64 len; + struct btrfs_block_group_cache *cache; + struct btrfs_fs_info *fs_info = root->fs_info; + + while (num > 0) { + cache = btrfs_lookup_block_group(fs_info, bytenr); + BUG_ON(!cache); + len = min(num, cache->key.offset - + (bytenr - cache->key.objectid)); + + spin_lock(&cache->space_info->lock); + spin_lock(&cache->lock); + if (reserve) { + cache->reserved += len; + cache->space_info->bytes_reserved += len; + } else { + cache->reserved -= len; + cache->space_info->bytes_reserved -= len; + } + spin_unlock(&cache->lock); + spin_unlock(&cache->space_info->lock); + bytenr += len; + num -= len; + } + return 0; +} + +int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy) +{ + u64 last = 0; + u64 start; + u64 end; + struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents; + int ret; + + mutex_lock(&root->fs_info->pinned_mutex); + while(1) { + ret = find_first_extent_bit(pinned_extents, last, + &start, &end, EXTENT_DIRTY); + if (ret) + break; + set_extent_dirty(copy, start, end, GFP_NOFS); + last = end + 1; + } + mutex_unlock(&root->fs_info->pinned_mutex); + return 0; +} + +int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct extent_io_tree *unpin) +{ + u64 start; + u64 end; + int ret; + + mutex_lock(&root->fs_info->pinned_mutex); + while(1) { + ret = find_first_extent_bit(unpin, 0, &start, &end, + EXTENT_DIRTY); + if (ret) + break; + btrfs_update_pinned_extents(root, start, end + 1 - start, 0); + clear_extent_dirty(unpin, start, end, GFP_NOFS); + if (need_resched()) { + mutex_unlock(&root->fs_info->pinned_mutex); + cond_resched(); + mutex_lock(&root->fs_info->pinned_mutex); + } + } + mutex_unlock(&root->fs_info->pinned_mutex); + return 0; +} + +static int finish_current_insert(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root, int all) +{ + u64 start; + u64 end; + u64 priv; + u64 search = 0; + u64 skipped = 0; + struct btrfs_fs_info *info = extent_root->fs_info; + struct btrfs_path *path; + struct pending_extent_op *extent_op, *tmp; + struct list_head insert_list, update_list; + int ret; + int num_inserts = 0, max_inserts; + + path = btrfs_alloc_path(); + INIT_LIST_HEAD(&insert_list); + INIT_LIST_HEAD(&update_list); + + max_inserts = extent_root->leafsize / + (2 * sizeof(struct btrfs_key) + 2 * sizeof(struct btrfs_item) + + sizeof(struct btrfs_extent_ref) + + sizeof(struct btrfs_extent_item)); +again: + mutex_lock(&info->extent_ins_mutex); + while (1) { + ret = find_first_extent_bit(&info->extent_ins, search, &start, + &end, EXTENT_WRITEBACK); + if (ret) { + if (skipped && all && !num_inserts) { + skipped = 0; + search = 0; + continue; + } + mutex_unlock(&info->extent_ins_mutex); + break; + } + + ret = try_lock_extent(&info->extent_ins, start, end, GFP_NOFS); + if (!ret) { + skipped = 1; + search = end + 1; + if (need_resched()) { + mutex_unlock(&info->extent_ins_mutex); + cond_resched(); + mutex_lock(&info->extent_ins_mutex); + } + continue; + } + + ret = get_state_private(&info->extent_ins, start, &priv); + BUG_ON(ret); + extent_op = (struct pending_extent_op *)(unsigned long) priv; + + if (extent_op->type == PENDING_EXTENT_INSERT) { + num_inserts++; + list_add_tail(&extent_op->list, &insert_list); + search = end + 1; + if (num_inserts == max_inserts) { + mutex_unlock(&info->extent_ins_mutex); + break; + } + } else if (extent_op->type == PENDING_BACKREF_UPDATE) { + list_add_tail(&extent_op->list, &update_list); + search = end + 1; + } else { + BUG(); + } + } + + /* + * process the update list, clear the writeback bit for it, and if + * somebody marked this thing for deletion then just unlock it and be + * done, the free_extents will handle it + */ + mutex_lock(&info->extent_ins_mutex); + list_for_each_entry_safe(extent_op, tmp, &update_list, list) { + clear_extent_bits(&info->extent_ins, extent_op->bytenr, + extent_op->bytenr + extent_op->num_bytes - 1, + EXTENT_WRITEBACK, GFP_NOFS); + if (extent_op->del) { + list_del_init(&extent_op->list); + unlock_extent(&info->extent_ins, extent_op->bytenr, + extent_op->bytenr + extent_op->num_bytes + - 1, GFP_NOFS); + kfree(extent_op); + } + } + mutex_unlock(&info->extent_ins_mutex); + + /* + * still have things left on the update list, go ahead an update + * everything + */ + if (!list_empty(&update_list)) { + ret = update_backrefs(trans, extent_root, path, &update_list); + BUG_ON(ret); + } + + /* + * if no inserts need to be done, but we skipped some extents and we + * need to make sure everything is cleaned then reset everything and + * go back to the beginning + */ + if (!num_inserts && all && skipped) { + search = 0; + skipped = 0; + INIT_LIST_HEAD(&update_list); + INIT_LIST_HEAD(&insert_list); + goto again; + } else if (!num_inserts) { + goto out; + } + + /* + * process the insert extents list. Again if we are deleting this + * extent, then just unlock it, pin down the bytes if need be, and be + * done with it. Saves us from having to actually insert the extent + * into the tree and then subsequently come along and delete it + */ + mutex_lock(&info->extent_ins_mutex); + list_for_each_entry_safe(extent_op, tmp, &insert_list, list) { + clear_extent_bits(&info->extent_ins, extent_op->bytenr, + extent_op->bytenr + extent_op->num_bytes - 1, + EXTENT_WRITEBACK, GFP_NOFS); + if (extent_op->del) { + list_del_init(&extent_op->list); + unlock_extent(&info->extent_ins, extent_op->bytenr, + extent_op->bytenr + extent_op->num_bytes + - 1, GFP_NOFS); + + mutex_lock(&extent_root->fs_info->pinned_mutex); + ret = pin_down_bytes(trans, extent_root, + extent_op->bytenr, + extent_op->num_bytes, 0); + mutex_unlock(&extent_root->fs_info->pinned_mutex); + + ret = update_block_group(trans, extent_root, + extent_op->bytenr, + extent_op->num_bytes, + 0, ret > 0); + BUG_ON(ret); + kfree(extent_op); + num_inserts--; + } + } + mutex_unlock(&info->extent_ins_mutex); + + ret = insert_extents(trans, extent_root, path, &insert_list, + num_inserts); + BUG_ON(ret); + + /* + * if we broke out of the loop in order to insert stuff because we hit + * the maximum number of inserts at a time we can handle, then loop + * back and pick up where we left off + */ + if (num_inserts == max_inserts) { + INIT_LIST_HEAD(&insert_list); + INIT_LIST_HEAD(&update_list); + num_inserts = 0; + goto again; + } + + /* + * again, if we need to make absolutely sure there are no more pending + * extent operations left and we know that we skipped some, go back to + * the beginning and do it all again + */ + if (all && skipped) { + INIT_LIST_HEAD(&insert_list); + INIT_LIST_HEAD(&update_list); + search = 0; + skipped = 0; + num_inserts = 0; + goto again; + } +out: + btrfs_free_path(path); + return 0; +} + +static int pin_down_bytes(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytenr, u64 num_bytes, int is_data) +{ + int err = 0; + struct extent_buffer *buf; + + if (is_data) + goto pinit; + + buf = btrfs_find_tree_block(root, bytenr, num_bytes); + if (!buf) + goto pinit; + + /* we can reuse a block if it hasn't been written + * and it is from this transaction. We can't + * reuse anything from the tree log root because + * it has tiny sub-transactions. + */ + if (btrfs_buffer_uptodate(buf, 0) && + btrfs_try_tree_lock(buf)) { + u64 header_owner = btrfs_header_owner(buf); + u64 header_transid = btrfs_header_generation(buf); + if (header_owner != BTRFS_TREE_LOG_OBJECTID && + header_owner != BTRFS_TREE_RELOC_OBJECTID && + header_transid == trans->transid && + !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) { + clean_tree_block(NULL, root, buf); + btrfs_tree_unlock(buf); + free_extent_buffer(buf); + return 1; + } + btrfs_tree_unlock(buf); + } + free_extent_buffer(buf); +pinit: + btrfs_update_pinned_extents(root, bytenr, num_bytes, 1); + + BUG_ON(err < 0); + return 0; +} + +/* + * remove an extent from the root, returns 0 on success + */ +static int __free_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytenr, u64 num_bytes, u64 parent, + u64 root_objectid, u64 ref_generation, + u64 owner_objectid, int pin, int mark_free) +{ + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_fs_info *info = root->fs_info; + struct btrfs_root *extent_root = info->extent_root; + struct extent_buffer *leaf; + int ret; + int extent_slot = 0; + int found_extent = 0; + int num_to_del = 1; + struct btrfs_extent_item *ei; + u32 refs; + + key.objectid = bytenr; + btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); + key.offset = num_bytes; + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + path->reada = 1; + ret = lookup_extent_backref(trans, extent_root, path, + bytenr, parent, root_objectid, + ref_generation, owner_objectid, 1); + if (ret == 0) { + struct btrfs_key found_key; + extent_slot = path->slots[0]; + while(extent_slot > 0) { + extent_slot--; + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + extent_slot); + if (found_key.objectid != bytenr) + break; + if (found_key.type == BTRFS_EXTENT_ITEM_KEY && + found_key.offset == num_bytes) { + found_extent = 1; + break; + } + if (path->slots[0] - extent_slot > 5) + break; + } + if (!found_extent) { + ret = remove_extent_backref(trans, extent_root, path); + BUG_ON(ret); + btrfs_release_path(extent_root, path); + ret = btrfs_search_slot(trans, extent_root, + &key, path, -1, 1); + if (ret) { + printk(KERN_ERR "umm, got %d back from search" + ", was looking for %Lu\n", ret, + bytenr); + btrfs_print_leaf(extent_root, path->nodes[0]); + } + BUG_ON(ret); + extent_slot = path->slots[0]; + } + } else { + btrfs_print_leaf(extent_root, path->nodes[0]); + WARN_ON(1); + printk("Unable to find ref byte nr %Lu root %Lu " + "gen %Lu owner %Lu\n", bytenr, + root_objectid, ref_generation, owner_objectid); + } + + leaf = path->nodes[0]; + ei = btrfs_item_ptr(leaf, extent_slot, + struct btrfs_extent_item); + refs = btrfs_extent_refs(leaf, ei); + BUG_ON(refs == 0); + refs -= 1; + btrfs_set_extent_refs(leaf, ei, refs); + + btrfs_mark_buffer_dirty(leaf); + + if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) { + struct btrfs_extent_ref *ref; + ref = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_extent_ref); + BUG_ON(btrfs_ref_num_refs(leaf, ref) != 1); + /* if the back ref and the extent are next to each other + * they get deleted below in one shot + */ + path->slots[0] = extent_slot; + num_to_del = 2; + } else if (found_extent) { + /* otherwise delete the extent back ref */ + ret = remove_extent_backref(trans, extent_root, path); + BUG_ON(ret); + /* if refs are 0, we need to setup the path for deletion */ + if (refs == 0) { + btrfs_release_path(extent_root, path); + ret = btrfs_search_slot(trans, extent_root, &key, path, + -1, 1); + BUG_ON(ret); + } + } + + if (refs == 0) { + u64 super_used; + u64 root_used; +#ifdef BIO_RW_DISCARD + u64 map_length = num_bytes; + struct btrfs_multi_bio *multi = NULL; +#endif + + if (pin) { + mutex_lock(&root->fs_info->pinned_mutex); + ret = pin_down_bytes(trans, root, bytenr, num_bytes, + owner_objectid >= BTRFS_FIRST_FREE_OBJECTID); + mutex_unlock(&root->fs_info->pinned_mutex); + if (ret > 0) + mark_free = 1; + BUG_ON(ret < 0); + } + + /* block accounting for super block */ + spin_lock_irq(&info->delalloc_lock); + super_used = btrfs_super_bytes_used(&info->super_copy); + btrfs_set_super_bytes_used(&info->super_copy, + super_used - num_bytes); + spin_unlock_irq(&info->delalloc_lock); + + /* block accounting for root item */ + root_used = btrfs_root_used(&root->root_item); + btrfs_set_root_used(&root->root_item, + root_used - num_bytes); + ret = btrfs_del_items(trans, extent_root, path, path->slots[0], + num_to_del); + BUG_ON(ret); + btrfs_release_path(extent_root, path); + ret = update_block_group(trans, root, bytenr, num_bytes, 0, + mark_free); + BUG_ON(ret); + +#ifdef BIO_RW_DISCARD + /* Tell the block device(s) that the sectors can be discarded */ + ret = btrfs_map_block(&root->fs_info->mapping_tree, READ, + bytenr, &map_length, &multi, 0); + if (!ret) { + struct btrfs_bio_stripe *stripe = multi->stripes; + int i; + + if (map_length > num_bytes) + map_length = num_bytes; + + for (i = 0; i < multi->num_stripes; i++, stripe++) { + blkdev_issue_discard(stripe->dev->bdev, + stripe->physical >> 9, + map_length >> 9); + } + kfree(multi); + } +#endif + } + btrfs_free_path(path); + finish_current_insert(trans, extent_root, 0); + return ret; +} + +/* + * find all the blocks marked as pending in the radix tree and remove + * them from the extent map + */ +static int del_pending_extents(struct btrfs_trans_handle *trans, struct + btrfs_root *extent_root, int all) +{ + int ret; + int err = 0; + u64 start; + u64 end; + u64 priv; + u64 search = 0; + int nr = 0, skipped = 0; + struct extent_io_tree *pending_del; + struct extent_io_tree *extent_ins; + struct pending_extent_op *extent_op; + struct btrfs_fs_info *info = extent_root->fs_info; + struct list_head delete_list; + + INIT_LIST_HEAD(&delete_list); + extent_ins = &extent_root->fs_info->extent_ins; + pending_del = &extent_root->fs_info->pending_del; + +again: + mutex_lock(&info->extent_ins_mutex); + while(1) { + ret = find_first_extent_bit(pending_del, search, &start, &end, + EXTENT_WRITEBACK); + if (ret) { + if (all && skipped && !nr) { + search = 0; + continue; + } + mutex_unlock(&info->extent_ins_mutex); + break; + } + + ret = try_lock_extent(extent_ins, start, end, GFP_NOFS); + if (!ret) { + search = end+1; + skipped = 1; + + if (need_resched()) { + mutex_unlock(&info->extent_ins_mutex); + cond_resched(); + mutex_lock(&info->extent_ins_mutex); + } + + continue; + } + BUG_ON(ret < 0); + + ret = get_state_private(pending_del, start, &priv); + BUG_ON(ret); + extent_op = (struct pending_extent_op *)(unsigned long)priv; + + clear_extent_bits(pending_del, start, end, EXTENT_WRITEBACK, + GFP_NOFS); + if (!test_range_bit(extent_ins, start, end, + EXTENT_WRITEBACK, 0)) { + list_add_tail(&extent_op->list, &delete_list); + nr++; + } else { + kfree(extent_op); + + ret = get_state_private(&info->extent_ins, start, + &priv); + BUG_ON(ret); + extent_op = (struct pending_extent_op *) + (unsigned long)priv; + + clear_extent_bits(&info->extent_ins, start, end, + EXTENT_WRITEBACK, GFP_NOFS); + + if (extent_op->type == PENDING_BACKREF_UPDATE) { + list_add_tail(&extent_op->list, &delete_list); + search = end + 1; + nr++; + continue; + } + + mutex_lock(&extent_root->fs_info->pinned_mutex); + ret = pin_down_bytes(trans, extent_root, start, + end + 1 - start, 0); + mutex_unlock(&extent_root->fs_info->pinned_mutex); + + ret = update_block_group(trans, extent_root, start, + end + 1 - start, 0, ret > 0); + + unlock_extent(extent_ins, start, end, GFP_NOFS); + BUG_ON(ret); + kfree(extent_op); + } + if (ret) + err = ret; + + search = end + 1; + + if (need_resched()) { + mutex_unlock(&info->extent_ins_mutex); + cond_resched(); + mutex_lock(&info->extent_ins_mutex); + } + } + + if (nr) { + ret = free_extents(trans, extent_root, &delete_list); + BUG_ON(ret); + } + + if (all && skipped) { + INIT_LIST_HEAD(&delete_list); + search = 0; + nr = 0; + goto again; + } + + return err; +} + +/* + * remove an extent from the root, returns 0 on success + */ +static int __btrfs_free_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytenr, u64 num_bytes, u64 parent, + u64 root_objectid, u64 ref_generation, + u64 owner_objectid, int pin) +{ + struct btrfs_root *extent_root = root->fs_info->extent_root; + int pending_ret; + int ret; + + WARN_ON(num_bytes < root->sectorsize); + if (root == extent_root) { + struct pending_extent_op *extent_op = NULL; + + mutex_lock(&root->fs_info->extent_ins_mutex); + if (test_range_bit(&root->fs_info->extent_ins, bytenr, + bytenr + num_bytes - 1, EXTENT_WRITEBACK, 0)) { + u64 priv; + ret = get_state_private(&root->fs_info->extent_ins, + bytenr, &priv); + BUG_ON(ret); + extent_op = (struct pending_extent_op *) + (unsigned long)priv; + + extent_op->del = 1; + if (extent_op->type == PENDING_EXTENT_INSERT) { + mutex_unlock(&root->fs_info->extent_ins_mutex); + return 0; + } + } + + if (extent_op) { + ref_generation = extent_op->orig_generation; + parent = extent_op->orig_parent; + } + + extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS); + BUG_ON(!extent_op); + + extent_op->type = PENDING_EXTENT_DELETE; + extent_op->bytenr = bytenr; + extent_op->num_bytes = num_bytes; + extent_op->parent = parent; + extent_op->orig_parent = parent; + extent_op->generation = ref_generation; + extent_op->orig_generation = ref_generation; + extent_op->level = (int)owner_objectid; + INIT_LIST_HEAD(&extent_op->list); + extent_op->del = 0; + + set_extent_bits(&root->fs_info->pending_del, + bytenr, bytenr + num_bytes - 1, + EXTENT_WRITEBACK, GFP_NOFS); + set_state_private(&root->fs_info->pending_del, + bytenr, (unsigned long)extent_op); + mutex_unlock(&root->fs_info->extent_ins_mutex); + return 0; + } + /* if metadata always pin */ + if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) { + if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) { + struct btrfs_block_group_cache *cache; + + /* btrfs_free_reserved_extent */ + cache = btrfs_lookup_block_group(root->fs_info, bytenr); + BUG_ON(!cache); + btrfs_add_free_space(cache, bytenr, num_bytes); + update_reserved_extents(root, bytenr, num_bytes, 0); + return 0; + } + pin = 1; + } + + /* if data pin when any transaction has committed this */ + if (ref_generation != trans->transid) + pin = 1; + + ret = __free_extent(trans, root, bytenr, num_bytes, parent, + root_objectid, ref_generation, + owner_objectid, pin, pin == 0); + + finish_current_insert(trans, root->fs_info->extent_root, 0); + pending_ret = del_pending_extents(trans, root->fs_info->extent_root, 0); + return ret ? ret : pending_ret; +} + +int btrfs_free_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytenr, u64 num_bytes, u64 parent, + u64 root_objectid, u64 ref_generation, + u64 owner_objectid, int pin) +{ + int ret; + + ret = __btrfs_free_extent(trans, root, bytenr, num_bytes, parent, + root_objectid, ref_generation, + owner_objectid, pin); + return ret; +} + +static u64 stripe_align(struct btrfs_root *root, u64 val) +{ + u64 mask = ((u64)root->stripesize - 1); + u64 ret = (val + mask) & ~mask; + return ret; +} + +/* + * walks the btree of allocated extents and find a hole of a given size. + * The key ins is changed to record the hole: + * ins->objectid == block start + * ins->flags = BTRFS_EXTENT_ITEM_KEY + * ins->offset == number of blocks + * Any available blocks before search_start are skipped. + */ +static int noinline find_free_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *orig_root, + u64 num_bytes, u64 empty_size, + u64 search_start, u64 search_end, + u64 hint_byte, struct btrfs_key *ins, + u64 exclude_start, u64 exclude_nr, + int data) +{ + int ret = 0; + struct btrfs_root * root = orig_root->fs_info->extent_root; + u64 total_needed = num_bytes; + u64 *last_ptr = NULL; + u64 last_wanted = 0; + struct btrfs_block_group_cache *block_group = NULL; + int chunk_alloc_done = 0; + int empty_cluster = 2 * 1024 * 1024; + int allowed_chunk_alloc = 0; + struct list_head *head = NULL, *cur = NULL; + int loop = 0; + int extra_loop = 0; + struct btrfs_space_info *space_info; + + WARN_ON(num_bytes < root->sectorsize); + btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY); + ins->objectid = 0; + ins->offset = 0; + + if (orig_root->ref_cows || empty_size) + allowed_chunk_alloc = 1; + + if (data & BTRFS_BLOCK_GROUP_METADATA) { + last_ptr = &root->fs_info->last_alloc; + empty_cluster = 64 * 1024; + } + + if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) + last_ptr = &root->fs_info->last_data_alloc; + + if (last_ptr) { + if (*last_ptr) { + hint_byte = *last_ptr; + last_wanted = *last_ptr; + } else + empty_size += empty_cluster; + } else { + empty_cluster = 0; + } + search_start = max(search_start, first_logical_byte(root, 0)); + search_start = max(search_start, hint_byte); + + if (last_wanted && search_start != last_wanted) { + last_wanted = 0; + empty_size += empty_cluster; + } + + total_needed += empty_size; + block_group = btrfs_lookup_block_group(root->fs_info, search_start); + if (!block_group) + block_group = btrfs_lookup_first_block_group(root->fs_info, + search_start); + space_info = __find_space_info(root->fs_info, data); + + down_read(&space_info->groups_sem); + while (1) { + struct btrfs_free_space *free_space; + /* + * the only way this happens if our hint points to a block + * group thats not of the proper type, while looping this + * should never happen + */ + if (empty_size) + extra_loop = 1; + + if (!block_group) + goto new_group_no_lock; + + mutex_lock(&block_group->alloc_mutex); + if (unlikely(!block_group_bits(block_group, data))) + goto new_group; + + ret = cache_block_group(root, block_group); + if (ret) { + mutex_unlock(&block_group->alloc_mutex); + break; + } + + if (block_group->ro) + goto new_group; + + free_space = btrfs_find_free_space(block_group, search_start, + total_needed); + if (free_space) { + u64 start = block_group->key.objectid; + u64 end = block_group->key.objectid + + block_group->key.offset; + + search_start = stripe_align(root, free_space->offset); + + /* move on to the next group */ + if (search_start + num_bytes >= search_end) + goto new_group; + + /* move on to the next group */ + if (search_start + num_bytes > end) + goto new_group; + + if (last_wanted && search_start != last_wanted) { + total_needed += empty_cluster; + empty_size += empty_cluster; + last_wanted = 0; + /* + * if search_start is still in this block group + * then we just re-search this block group + */ + if (search_start >= start && + search_start < end) { + mutex_unlock(&block_group->alloc_mutex); + continue; + } + + /* else we go to the next block group */ + goto new_group; + } + + if (exclude_nr > 0 && + (search_start + num_bytes > exclude_start && + search_start < exclude_start + exclude_nr)) { + search_start = exclude_start + exclude_nr; + /* + * if search_start is still in this block group + * then we just re-search this block group + */ + if (search_start >= start && + search_start < end) { + mutex_unlock(&block_group->alloc_mutex); + last_wanted = 0; + continue; + } + + /* else we go to the next block group */ + goto new_group; + } + + ins->objectid = search_start; + ins->offset = num_bytes; + + btrfs_remove_free_space_lock(block_group, search_start, + num_bytes); + /* we are all good, lets return */ + mutex_unlock(&block_group->alloc_mutex); + break; + } +new_group: + mutex_unlock(&block_group->alloc_mutex); +new_group_no_lock: + /* don't try to compare new allocations against the + * last allocation any more + */ + last_wanted = 0; + + /* + * Here's how this works. + * loop == 0: we were searching a block group via a hint + * and didn't find anything, so we start at + * the head of the block groups and keep searching + * loop == 1: we're searching through all of the block groups + * if we hit the head again we have searched + * all of the block groups for this space and we + * need to try and allocate, if we cant error out. + * loop == 2: we allocated more space and are looping through + * all of the block groups again. + */ + if (loop == 0) { + head = &space_info->block_groups; + cur = head->next; + loop++; + } else if (loop == 1 && cur == head) { + int keep_going; + + /* at this point we give up on the empty_size + * allocations and just try to allocate the min + * space. + * + * The extra_loop field was set if an empty_size + * allocation was attempted above, and if this + * is try we need to try the loop again without + * the additional empty_size. + */ + total_needed -= empty_size; + empty_size = 0; + keep_going = extra_loop; + loop++; + + if (allowed_chunk_alloc && !chunk_alloc_done) { + up_read(&space_info->groups_sem); + ret = do_chunk_alloc(trans, root, num_bytes + + 2 * 1024 * 1024, data, 1); + down_read(&space_info->groups_sem); + if (ret < 0) + goto loop_check; + head = &space_info->block_groups; + /* + * we've allocated a new chunk, keep + * trying + */ + keep_going = 1; + chunk_alloc_done = 1; + } else if (!allowed_chunk_alloc) { + space_info->force_alloc = 1; + } +loop_check: + if (keep_going) { + cur = head->next; + extra_loop = 0; + } else { + break; + } + } else if (cur == head) { + break; + } + + block_group = list_entry(cur, struct btrfs_block_group_cache, + list); + search_start = block_group->key.objectid; + cur = cur->next; + } + + /* we found what we needed */ + if (ins->objectid) { + if (!(data & BTRFS_BLOCK_GROUP_DATA)) + trans->block_group = block_group; + + if (last_ptr) + *last_ptr = ins->objectid + ins->offset; + ret = 0; + } else if (!ret) { + printk(KERN_ERR "we were searching for %Lu bytes, num_bytes %Lu," + " loop %d, allowed_alloc %d\n", total_needed, num_bytes, + loop, allowed_chunk_alloc); + ret = -ENOSPC; + } + + up_read(&space_info->groups_sem); + return ret; +} + +static void dump_space_info(struct btrfs_space_info *info, u64 bytes) +{ + struct btrfs_block_group_cache *cache; + struct list_head *l; + + printk(KERN_INFO "space_info has %Lu free, is %sfull\n", + info->total_bytes - info->bytes_used - info->bytes_pinned - + info->bytes_reserved, (info->full) ? "" : "not "); + + down_read(&info->groups_sem); + list_for_each(l, &info->block_groups) { + cache = list_entry(l, struct btrfs_block_group_cache, list); + spin_lock(&cache->lock); + printk(KERN_INFO "block group %Lu has %Lu bytes, %Lu used " + "%Lu pinned %Lu reserved\n", + cache->key.objectid, cache->key.offset, + btrfs_block_group_used(&cache->item), + cache->pinned, cache->reserved); + btrfs_dump_free_space(cache, bytes); + spin_unlock(&cache->lock); + } + up_read(&info->groups_sem); +} + +static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 num_bytes, u64 min_alloc_size, + u64 empty_size, u64 hint_byte, + u64 search_end, struct btrfs_key *ins, + u64 data) +{ + int ret; + u64 search_start = 0; + u64 alloc_profile; + struct btrfs_fs_info *info = root->fs_info; + + if (data) { + alloc_profile = info->avail_data_alloc_bits & + info->data_alloc_profile; + data = BTRFS_BLOCK_GROUP_DATA | alloc_profile; + } else if (root == root->fs_info->chunk_root) { + alloc_profile = info->avail_system_alloc_bits & + info->system_alloc_profile; + data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile; + } else { + alloc_profile = info->avail_metadata_alloc_bits & + info->metadata_alloc_profile; + data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile; + } +again: + data = btrfs_reduce_alloc_profile(root, data); + /* + * the only place that sets empty_size is btrfs_realloc_node, which + * is not called recursively on allocations + */ + if (empty_size || root->ref_cows) { + if (!(data & BTRFS_BLOCK_GROUP_METADATA)) { + ret = do_chunk_alloc(trans, root->fs_info->extent_root, + 2 * 1024 * 1024, + BTRFS_BLOCK_GROUP_METADATA | + (info->metadata_alloc_profile & + info->avail_metadata_alloc_bits), 0); + } + ret = do_chunk_alloc(trans, root->fs_info->extent_root, + num_bytes + 2 * 1024 * 1024, data, 0); + } + + WARN_ON(num_bytes < root->sectorsize); + ret = find_free_extent(trans, root, num_bytes, empty_size, + search_start, search_end, hint_byte, ins, + trans->alloc_exclude_start, + trans->alloc_exclude_nr, data); + + if (ret == -ENOSPC && num_bytes > min_alloc_size) { + num_bytes = num_bytes >> 1; + num_bytes = num_bytes & ~(root->sectorsize - 1); + num_bytes = max(num_bytes, min_alloc_size); + do_chunk_alloc(trans, root->fs_info->extent_root, + num_bytes, data, 1); + goto again; + } + if (ret) { + struct btrfs_space_info *sinfo; + + sinfo = __find_space_info(root->fs_info, data); + printk("allocation failed flags %Lu, wanted %Lu\n", + data, num_bytes); + dump_space_info(sinfo, num_bytes); + BUG(); + } + + return ret; +} + +int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len) +{ + struct btrfs_block_group_cache *cache; + + cache = btrfs_lookup_block_group(root->fs_info, start); + if (!cache) { + printk(KERN_ERR "Unable to find block group for %Lu\n", start); + return -ENOSPC; + } + btrfs_add_free_space(cache, start, len); + update_reserved_extents(root, start, len, 0); + return 0; +} + +int btrfs_reserve_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 num_bytes, u64 min_alloc_size, + u64 empty_size, u64 hint_byte, + u64 search_end, struct btrfs_key *ins, + u64 data) +{ + int ret; + ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size, + empty_size, hint_byte, search_end, ins, + data); + update_reserved_extents(root, ins->objectid, ins->offset, 1); + return ret; +} + +static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 parent, + u64 root_objectid, u64 ref_generation, + u64 owner, struct btrfs_key *ins) +{ + int ret; + int pending_ret; + u64 super_used; + u64 root_used; + u64 num_bytes = ins->offset; + u32 sizes[2]; + struct btrfs_fs_info *info = root->fs_info; + struct btrfs_root *extent_root = info->extent_root; + struct btrfs_extent_item *extent_item; + struct btrfs_extent_ref *ref; + struct btrfs_path *path; + struct btrfs_key keys[2]; + + if (parent == 0) + parent = ins->objectid; + + /* block accounting for super block */ + spin_lock_irq(&info->delalloc_lock); + super_used = btrfs_super_bytes_used(&info->super_copy); + btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes); + spin_unlock_irq(&info->delalloc_lock); + + /* block accounting for root item */ + root_used = btrfs_root_used(&root->root_item); + btrfs_set_root_used(&root->root_item, root_used + num_bytes); + + if (root == extent_root) { + struct pending_extent_op *extent_op; + + extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS); + BUG_ON(!extent_op); + + extent_op->type = PENDING_EXTENT_INSERT; + extent_op->bytenr = ins->objectid; + extent_op->num_bytes = ins->offset; + extent_op->parent = parent; + extent_op->orig_parent = 0; + extent_op->generation = ref_generation; + extent_op->orig_generation = 0; + extent_op->level = (int)owner; + INIT_LIST_HEAD(&extent_op->list); + extent_op->del = 0; + + mutex_lock(&root->fs_info->extent_ins_mutex); + set_extent_bits(&root->fs_info->extent_ins, ins->objectid, + ins->objectid + ins->offset - 1, + EXTENT_WRITEBACK, GFP_NOFS); + set_state_private(&root->fs_info->extent_ins, + ins->objectid, (unsigned long)extent_op); + mutex_unlock(&root->fs_info->extent_ins_mutex); + goto update_block; + } + + memcpy(&keys[0], ins, sizeof(*ins)); + keys[1].objectid = ins->objectid; + keys[1].type = BTRFS_EXTENT_REF_KEY; + keys[1].offset = parent; + sizes[0] = sizeof(*extent_item); + sizes[1] = sizeof(*ref); + + path = btrfs_alloc_path(); + BUG_ON(!path); + + ret = btrfs_insert_empty_items(trans, extent_root, path, keys, + sizes, 2); + BUG_ON(ret); + + extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_extent_item); + btrfs_set_extent_refs(path->nodes[0], extent_item, 1); + ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, + struct btrfs_extent_ref); + + btrfs_set_ref_root(path->nodes[0], ref, root_objectid); + btrfs_set_ref_generation(path->nodes[0], ref, ref_generation); + btrfs_set_ref_objectid(path->nodes[0], ref, owner); + btrfs_set_ref_num_refs(path->nodes[0], ref, 1); + + btrfs_mark_buffer_dirty(path->nodes[0]); + + trans->alloc_exclude_start = 0; + trans->alloc_exclude_nr = 0; + btrfs_free_path(path); + finish_current_insert(trans, extent_root, 0); + pending_ret = del_pending_extents(trans, extent_root, 0); + + if (ret) + goto out; + if (pending_ret) { + ret = pending_ret; + goto out; + } + +update_block: + ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0); + if (ret) { + printk("update block group failed for %Lu %Lu\n", + ins->objectid, ins->offset); + BUG(); + } +out: + return ret; +} + +int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 parent, + u64 root_objectid, u64 ref_generation, + u64 owner, struct btrfs_key *ins) +{ + int ret; + + if (root_objectid == BTRFS_TREE_LOG_OBJECTID) + return 0; + ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid, + ref_generation, owner, ins); + update_reserved_extents(root, ins->objectid, ins->offset, 0); + return ret; +} + +/* + * this is used by the tree logging recovery code. It records that + * an extent has been allocated and makes sure to clear the free + * space cache bits as well + */ +int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 parent, + u64 root_objectid, u64 ref_generation, + u64 owner, struct btrfs_key *ins) +{ + int ret; + struct btrfs_block_group_cache *block_group; + + block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid); + mutex_lock(&block_group->alloc_mutex); + cache_block_group(root, block_group); + + ret = btrfs_remove_free_space_lock(block_group, ins->objectid, + ins->offset); + mutex_unlock(&block_group->alloc_mutex); + BUG_ON(ret); + ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid, + ref_generation, owner, ins); + return ret; +} + +/* + * finds a free extent and does all the dirty work required for allocation + * returns the key for the extent through ins, and a tree buffer for + * the first block of the extent through buf. + * + * returns 0 if everything worked, non-zero otherwise. + */ +int btrfs_alloc_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 num_bytes, u64 parent, u64 min_alloc_size, + u64 root_objectid, u64 ref_generation, + u64 owner_objectid, u64 empty_size, u64 hint_byte, + u64 search_end, struct btrfs_key *ins, u64 data) +{ + int ret; + + ret = __btrfs_reserve_extent(trans, root, num_bytes, + min_alloc_size, empty_size, hint_byte, + search_end, ins, data); + BUG_ON(ret); + if (root_objectid != BTRFS_TREE_LOG_OBJECTID) { + ret = __btrfs_alloc_reserved_extent(trans, root, parent, + root_objectid, ref_generation, + owner_objectid, ins); + BUG_ON(ret); + + } else { + update_reserved_extents(root, ins->objectid, ins->offset, 1); + } + return ret; +} + +struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytenr, u32 blocksize) +{ + struct extent_buffer *buf; + + buf = btrfs_find_create_tree_block(root, bytenr, blocksize); + if (!buf) + return ERR_PTR(-ENOMEM); + btrfs_set_header_generation(buf, trans->transid); + btrfs_tree_lock(buf); + clean_tree_block(trans, root, buf); + btrfs_set_buffer_uptodate(buf); + if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) { + set_extent_dirty(&root->dirty_log_pages, buf->start, + buf->start + buf->len - 1, GFP_NOFS); + } else { + set_extent_dirty(&trans->transaction->dirty_pages, buf->start, + buf->start + buf->len - 1, GFP_NOFS); + } + trans->blocks_used++; + return buf; +} + +/* + * helper function to allocate a block for a given tree + * returns the tree buffer or NULL. + */ +struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u32 blocksize, u64 parent, + u64 root_objectid, + u64 ref_generation, + int level, + u64 hint, + u64 empty_size) +{ + struct btrfs_key ins; + int ret; + struct extent_buffer *buf; + + ret = btrfs_alloc_extent(trans, root, blocksize, parent, blocksize, + root_objectid, ref_generation, level, + empty_size, hint, (u64)-1, &ins, 0); + if (ret) { + BUG_ON(ret > 0); + return ERR_PTR(ret); + } + + buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize); + return buf; +} + +int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct extent_buffer *leaf) +{ + u64 leaf_owner; + u64 leaf_generation; + struct btrfs_key key; + struct btrfs_file_extent_item *fi; + int i; + int nritems; + int ret; + + BUG_ON(!btrfs_is_leaf(leaf)); + nritems = btrfs_header_nritems(leaf); + leaf_owner = btrfs_header_owner(leaf); + leaf_generation = btrfs_header_generation(leaf); + + for (i = 0; i < nritems; i++) { + u64 disk_bytenr; + cond_resched(); + + btrfs_item_key_to_cpu(leaf, &key, i); + if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) + continue; + fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); + if (btrfs_file_extent_type(leaf, fi) == + BTRFS_FILE_EXTENT_INLINE) + continue; + /* + * FIXME make sure to insert a trans record that + * repeats the snapshot del on crash + */ + disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); + if (disk_bytenr == 0) + continue; + + ret = __btrfs_free_extent(trans, root, disk_bytenr, + btrfs_file_extent_disk_num_bytes(leaf, fi), + leaf->start, leaf_owner, leaf_generation, + key.objectid, 0); + BUG_ON(ret); + + atomic_inc(&root->fs_info->throttle_gen); + wake_up(&root->fs_info->transaction_throttle); + cond_resched(); + } + return 0; +} + +static int noinline cache_drop_leaf_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_leaf_ref *ref) +{ + int i; + int ret; + struct btrfs_extent_info *info = ref->extents; + + for (i = 0; i < ref->nritems; i++) { + ret = __btrfs_free_extent(trans, root, info->bytenr, + info->num_bytes, ref->bytenr, + ref->owner, ref->generation, + info->objectid, 0); + + atomic_inc(&root->fs_info->throttle_gen); + wake_up(&root->fs_info->transaction_throttle); + cond_resched(); + + BUG_ON(ret); + info++; + } + + return 0; +} + +int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start, u64 len, + u32 *refs) +{ + int ret; + + ret = btrfs_lookup_extent_ref(NULL, root, start, len, refs); + BUG_ON(ret); + +#if 0 // some debugging code in case we see problems here + /* if the refs count is one, it won't get increased again. But + * if the ref count is > 1, someone may be decreasing it at + * the same time we are. + */ + if (*refs != 1) { + struct extent_buffer *eb = NULL; + eb = btrfs_find_create_tree_block(root, start, len); + if (eb) + btrfs_tree_lock(eb); + + mutex_lock(&root->fs_info->alloc_mutex); + ret = lookup_extent_ref(NULL, root, start, len, refs); + BUG_ON(ret); + mutex_unlock(&root->fs_info->alloc_mutex); + + if (eb) { + btrfs_tree_unlock(eb); + free_extent_buffer(eb); + } + if (*refs == 1) { + printk("block %llu went down to one during drop_snap\n", + (unsigned long long)start); + } + + } +#endif + + cond_resched(); + return ret; +} + +/* + * helper function for drop_snapshot, this walks down the tree dropping ref + * counts as it goes. + */ +static int noinline walk_down_tree(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, int *level) +{ + u64 root_owner; + u64 root_gen; + u64 bytenr; + u64 ptr_gen; + struct extent_buffer *next; + struct extent_buffer *cur; + struct extent_buffer *parent; + struct btrfs_leaf_ref *ref; + u32 blocksize; + int ret; + u32 refs; + + WARN_ON(*level < 0); + WARN_ON(*level >= BTRFS_MAX_LEVEL); + ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start, + path->nodes[*level]->len, &refs); + BUG_ON(ret); + if (refs > 1) + goto out; + + /* + * walk down to the last node level and free all the leaves + */ + while(*level >= 0) { + WARN_ON(*level < 0); + WARN_ON(*level >= BTRFS_MAX_LEVEL); + cur = path->nodes[*level]; + + if (btrfs_header_level(cur) != *level) + WARN_ON(1); + + if (path->slots[*level] >= + btrfs_header_nritems(cur)) + break; + if (*level == 0) { + ret = btrfs_drop_leaf_ref(trans, root, cur); + BUG_ON(ret); + break; + } + bytenr = btrfs_node_blockptr(cur, path->slots[*level]); + ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]); + blocksize = btrfs_level_size(root, *level - 1); + + ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs); + BUG_ON(ret); + if (refs != 1) { + parent = path->nodes[*level]; + root_owner = btrfs_header_owner(parent); + root_gen = btrfs_header_generation(parent); + path->slots[*level]++; + + ret = __btrfs_free_extent(trans, root, bytenr, + blocksize, parent->start, + root_owner, root_gen, + *level - 1, 1); + BUG_ON(ret); + + atomic_inc(&root->fs_info->throttle_gen); + wake_up(&root->fs_info->transaction_throttle); + cond_resched(); + + continue; + } + /* + * at this point, we have a single ref, and since the + * only place referencing this extent is a dead root + * the reference count should never go higher. + * So, we don't need to check it again + */ + if (*level == 1) { + ref = btrfs_lookup_leaf_ref(root, bytenr); + if (ref && ref->generation != ptr_gen) { + btrfs_free_leaf_ref(root, ref); + ref = NULL; + } + if (ref) { + ret = cache_drop_leaf_ref(trans, root, ref); + BUG_ON(ret); + btrfs_remove_leaf_ref(root, ref); + btrfs_free_leaf_ref(root, ref); + *level = 0; + break; + } + if (printk_ratelimit()) { + printk("leaf ref miss for bytenr %llu\n", + (unsigned long long)bytenr); + } + } + next = btrfs_find_tree_block(root, bytenr, blocksize); + if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) { + free_extent_buffer(next); + + next = read_tree_block(root, bytenr, blocksize, + ptr_gen); + cond_resched(); +#if 0 + /* + * this is a debugging check and can go away + * the ref should never go all the way down to 1 + * at this point + */ + ret = lookup_extent_ref(NULL, root, bytenr, blocksize, + &refs); + BUG_ON(ret); + WARN_ON(refs != 1); +#endif + } + WARN_ON(*level <= 0); + if (path->nodes[*level-1]) + free_extent_buffer(path->nodes[*level-1]); + path->nodes[*level-1] = next; + *level = btrfs_header_level(next); + path->slots[*level] = 0; + cond_resched(); + } +out: + WARN_ON(*level < 0); + WARN_ON(*level >= BTRFS_MAX_LEVEL); + + if (path->nodes[*level] == root->node) { + parent = path->nodes[*level]; + bytenr = path->nodes[*level]->start; + } else { + parent = path->nodes[*level + 1]; + bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]); + } + + blocksize = btrfs_level_size(root, *level); + root_owner = btrfs_header_owner(parent); + root_gen = btrfs_header_generation(parent); + + ret = __btrfs_free_extent(trans, root, bytenr, blocksize, + parent->start, root_owner, root_gen, + *level, 1); + free_extent_buffer(path->nodes[*level]); + path->nodes[*level] = NULL; + *level += 1; + BUG_ON(ret); + + cond_resched(); + return 0; +} + +/* + * helper function for drop_subtree, this function is similar to + * walk_down_tree. The main difference is that it checks reference + * counts while tree blocks are locked. + */ +static int noinline walk_down_subtree(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, int *level) +{ + struct extent_buffer *next; + struct extent_buffer *cur; + struct extent_buffer *parent; + u64 bytenr; + u64 ptr_gen; + u32 blocksize; + u32 refs; + int ret; + + cur = path->nodes[*level]; + ret = btrfs_lookup_extent_ref(trans, root, cur->start, cur->len, + &refs); + BUG_ON(ret); + if (refs > 1) + goto out; + + while (*level >= 0) { + cur = path->nodes[*level]; + if (*level == 0) { + ret = btrfs_drop_leaf_ref(trans, root, cur); + BUG_ON(ret); + clean_tree_block(trans, root, cur); + break; + } + if (path->slots[*level] >= btrfs_header_nritems(cur)) { + clean_tree_block(trans, root, cur); + break; + } + + bytenr = btrfs_node_blockptr(cur, path->slots[*level]); + blocksize = btrfs_level_size(root, *level - 1); + ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]); + + next = read_tree_block(root, bytenr, blocksize, ptr_gen); + btrfs_tree_lock(next); + + ret = btrfs_lookup_extent_ref(trans, root, bytenr, blocksize, + &refs); + BUG_ON(ret); + if (refs > 1) { + parent = path->nodes[*level]; + ret = btrfs_free_extent(trans, root, bytenr, + blocksize, parent->start, + btrfs_header_owner(parent), + btrfs_header_generation(parent), + *level - 1, 1); + BUG_ON(ret); + path->slots[*level]++; + btrfs_tree_unlock(next); + free_extent_buffer(next); + continue; + } + + *level = btrfs_header_level(next); + path->nodes[*level] = next; + path->slots[*level] = 0; + path->locks[*level] = 1; + cond_resched(); + } +out: + parent = path->nodes[*level + 1]; + bytenr = path->nodes[*level]->start; + blocksize = path->nodes[*level]->len; + + ret = btrfs_free_extent(trans, root, bytenr, blocksize, + parent->start, btrfs_header_owner(parent), + btrfs_header_generation(parent), *level, 1); + BUG_ON(ret); + + if (path->locks[*level]) { + btrfs_tree_unlock(path->nodes[*level]); + path->locks[*level] = 0; + } + free_extent_buffer(path->nodes[*level]); + path->nodes[*level] = NULL; + *level += 1; + cond_resched(); + return 0; +} + +/* + * helper for dropping snapshots. This walks back up the tree in the path + * to find the first node higher up where we haven't yet gone through + * all the slots + */ +static int noinline walk_up_tree(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + int *level, int max_level) +{ + u64 root_owner; + u64 root_gen; + struct btrfs_root_item *root_item = &root->root_item; + int i; + int slot; + int ret; + + for (i = *level; i < max_level && path->nodes[i]; i++) { + slot = path->slots[i]; + if (slot < btrfs_header_nritems(path->nodes[i]) - 1) { + struct extent_buffer *node; + struct btrfs_disk_key disk_key; + node = path->nodes[i]; + path->slots[i]++; + *level = i; + WARN_ON(*level == 0); + btrfs_node_key(node, &disk_key, path->slots[i]); + memcpy(&root_item->drop_progress, + &disk_key, sizeof(disk_key)); + root_item->drop_level = i; + return 0; + } else { + struct extent_buffer *parent; + if (path->nodes[*level] == root->node) + parent = path->nodes[*level]; + else + parent = path->nodes[*level + 1]; + + root_owner = btrfs_header_owner(parent); + root_gen = btrfs_header_generation(parent); + + clean_tree_block(trans, root, path->nodes[*level]); + ret = btrfs_free_extent(trans, root, + path->nodes[*level]->start, + path->nodes[*level]->len, + parent->start, root_owner, + root_gen, *level, 1); + BUG_ON(ret); + if (path->locks[*level]) { + btrfs_tree_unlock(path->nodes[*level]); + path->locks[*level] = 0; + } + free_extent_buffer(path->nodes[*level]); + path->nodes[*level] = NULL; + *level = i + 1; + } + } + return 1; +} + +/* + * drop the reference count on the tree rooted at 'snap'. This traverses + * the tree freeing any blocks that have a ref count of zero after being + * decremented. + */ +int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root + *root) +{ + int ret = 0; + int wret; + int level; + struct btrfs_path *path; + int i; + int orig_level; + struct btrfs_root_item *root_item = &root->root_item; + + WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex)); + path = btrfs_alloc_path(); + BUG_ON(!path); + + level = btrfs_header_level(root->node); + orig_level = level; + if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) { + path->nodes[level] = root->node; + extent_buffer_get(root->node); + path->slots[level] = 0; + } else { + struct btrfs_key key; + struct btrfs_disk_key found_key; + struct extent_buffer *node; + + btrfs_disk_key_to_cpu(&key, &root_item->drop_progress); + level = root_item->drop_level; + path->lowest_level = level; + wret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (wret < 0) { + ret = wret; + goto out; + } + node = path->nodes[level]; + btrfs_node_key(node, &found_key, path->slots[level]); + WARN_ON(memcmp(&found_key, &root_item->drop_progress, + sizeof(found_key))); + /* + * unlock our path, this is safe because only this + * function is allowed to delete this snapshot + */ + for (i = 0; i < BTRFS_MAX_LEVEL; i++) { + if (path->nodes[i] && path->locks[i]) { + path->locks[i] = 0; + btrfs_tree_unlock(path->nodes[i]); + } + } + } + while(1) { + wret = walk_down_tree(trans, root, path, &level); + if (wret > 0) + break; + if (wret < 0) + ret = wret; + + wret = walk_up_tree(trans, root, path, &level, + BTRFS_MAX_LEVEL); + if (wret > 0) + break; + if (wret < 0) + ret = wret; + if (trans->transaction->in_commit) { + ret = -EAGAIN; + break; + } + atomic_inc(&root->fs_info->throttle_gen); + wake_up(&root->fs_info->transaction_throttle); + } + for (i = 0; i <= orig_level; i++) { + if (path->nodes[i]) { + free_extent_buffer(path->nodes[i]); + path->nodes[i] = NULL; + } + } +out: + btrfs_free_path(path); + return ret; +} + +int btrfs_drop_subtree(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct extent_buffer *node, + struct extent_buffer *parent) +{ + struct btrfs_path *path; + int level; + int parent_level; + int ret = 0; + int wret; + + path = btrfs_alloc_path(); + BUG_ON(!path); + + BUG_ON(!btrfs_tree_locked(parent)); + parent_level = btrfs_header_level(parent); + extent_buffer_get(parent); + path->nodes[parent_level] = parent; + path->slots[parent_level] = btrfs_header_nritems(parent); + + BUG_ON(!btrfs_tree_locked(node)); + level = btrfs_header_level(node); + extent_buffer_get(node); + path->nodes[level] = node; + path->slots[level] = 0; + + while (1) { + wret = walk_down_subtree(trans, root, path, &level); + if (wret < 0) + ret = wret; + if (wret != 0) + break; + + wret = walk_up_tree(trans, root, path, &level, parent_level); + if (wret < 0) + ret = wret; + if (wret != 0) + break; + } + + btrfs_free_path(path); + return ret; +} + +static unsigned long calc_ra(unsigned long start, unsigned long last, + unsigned long nr) +{ + return min(last, start + nr - 1); +} + +static int noinline relocate_inode_pages(struct inode *inode, u64 start, + u64 len) +{ + u64 page_start; + u64 page_end; + unsigned long first_index; + unsigned long last_index; + unsigned long i; + struct page *page; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct file_ra_state *ra; + struct btrfs_ordered_extent *ordered; + unsigned int total_read = 0; + unsigned int total_dirty = 0; + int ret = 0; + + ra = kzalloc(sizeof(*ra), GFP_NOFS); + + mutex_lock(&inode->i_mutex); + first_index = start >> PAGE_CACHE_SHIFT; + last_index = (start + len - 1) >> PAGE_CACHE_SHIFT; + + /* make sure the dirty trick played by the caller work */ + ret = invalidate_inode_pages2_range(inode->i_mapping, + first_index, last_index); + if (ret) + goto out_unlock; + + file_ra_state_init(ra, inode->i_mapping); + + for (i = first_index ; i <= last_index; i++) { + if (total_read % ra->ra_pages == 0) { + btrfs_force_ra(inode->i_mapping, ra, NULL, i, + calc_ra(i, last_index, ra->ra_pages)); + } + total_read++; +again: + if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode)) + BUG_ON(1); + page = grab_cache_page(inode->i_mapping, i); + if (!page) { + ret = -ENOMEM; + goto out_unlock; + } + if (!PageUptodate(page)) { + btrfs_readpage(NULL, page); + lock_page(page); + if (!PageUptodate(page)) { + unlock_page(page); + page_cache_release(page); + ret = -EIO; + goto out_unlock; + } + } + wait_on_page_writeback(page); + + page_start = (u64)page->index << PAGE_CACHE_SHIFT; + page_end = page_start + PAGE_CACHE_SIZE - 1; + lock_extent(io_tree, page_start, page_end, GFP_NOFS); + + ordered = btrfs_lookup_ordered_extent(inode, page_start); + if (ordered) { + unlock_extent(io_tree, page_start, page_end, GFP_NOFS); + unlock_page(page); + page_cache_release(page); + btrfs_start_ordered_extent(inode, ordered, 1); + btrfs_put_ordered_extent(ordered); + goto again; + } + set_page_extent_mapped(page); + + btrfs_set_extent_delalloc(inode, page_start, page_end); + if (i == first_index) + set_extent_bits(io_tree, page_start, page_end, + EXTENT_BOUNDARY, GFP_NOFS); + + set_page_dirty(page); + total_dirty++; + + unlock_extent(io_tree, page_start, page_end, GFP_NOFS); + unlock_page(page); + page_cache_release(page); + } + +out_unlock: + kfree(ra); + mutex_unlock(&inode->i_mutex); + balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty); + return ret; +} + +static int noinline relocate_data_extent(struct inode *reloc_inode, + struct btrfs_key *extent_key, + u64 offset) +{ + struct btrfs_root *root = BTRFS_I(reloc_inode)->root; + struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree; + struct extent_map *em; + u64 start = extent_key->objectid - offset; + u64 end = start + extent_key->offset - 1; + + em = alloc_extent_map(GFP_NOFS); + BUG_ON(!em || IS_ERR(em)); + + em->start = start; + em->len = extent_key->offset; + em->block_len = extent_key->offset; + em->block_start = extent_key->objectid; + em->bdev = root->fs_info->fs_devices->latest_bdev; + set_bit(EXTENT_FLAG_PINNED, &em->flags); + + /* setup extent map to cheat btrfs_readpage */ + lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS); + while (1) { + int ret; + spin_lock(&em_tree->lock); + ret = add_extent_mapping(em_tree, em); + spin_unlock(&em_tree->lock); + if (ret != -EEXIST) { + free_extent_map(em); + break; + } + btrfs_drop_extent_cache(reloc_inode, start, end, 0); + } + unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS); + + return relocate_inode_pages(reloc_inode, start, extent_key->offset); +} + +struct btrfs_ref_path { + u64 extent_start; + u64 nodes[BTRFS_MAX_LEVEL]; + u64 root_objectid; + u64 root_generation; + u64 owner_objectid; + u32 num_refs; + int lowest_level; + int current_level; + int shared_level; + + struct btrfs_key node_keys[BTRFS_MAX_LEVEL]; + u64 new_nodes[BTRFS_MAX_LEVEL]; +}; + +struct disk_extent { + u64 ram_bytes; + u64 disk_bytenr; + u64 disk_num_bytes; + u64 offset; + u64 num_bytes; + u8 compression; + u8 encryption; + u16 other_encoding; +}; + +static int is_cowonly_root(u64 root_objectid) +{ + if (root_objectid == BTRFS_ROOT_TREE_OBJECTID || + root_objectid == BTRFS_EXTENT_TREE_OBJECTID || + root_objectid == BTRFS_CHUNK_TREE_OBJECTID || + root_objectid == BTRFS_DEV_TREE_OBJECTID || + root_objectid == BTRFS_TREE_LOG_OBJECTID) + return 1; + return 0; +} + +static int noinline __next_ref_path(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root, + struct btrfs_ref_path *ref_path, + int first_time) +{ + struct extent_buffer *leaf; + struct btrfs_path *path; + struct btrfs_extent_ref *ref; + struct btrfs_key key; + struct btrfs_key found_key; + u64 bytenr; + u32 nritems; + int level; + int ret = 1; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + if (first_time) { + ref_path->lowest_level = -1; + ref_path->current_level = -1; + ref_path->shared_level = -1; + goto walk_up; + } +walk_down: + level = ref_path->current_level - 1; + while (level >= -1) { + u64 parent; + if (level < ref_path->lowest_level) + break; + + if (level >= 0) { + bytenr = ref_path->nodes[level]; + } else { + bytenr = ref_path->extent_start; + } + BUG_ON(bytenr == 0); + + parent = ref_path->nodes[level + 1]; + ref_path->nodes[level + 1] = 0; + ref_path->current_level = level; + BUG_ON(parent == 0); + + key.objectid = bytenr; + key.offset = parent + 1; + key.type = BTRFS_EXTENT_REF_KEY; + + ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0); + if (ret < 0) + goto out; + BUG_ON(ret == 0); + + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + if (path->slots[0] >= nritems) { + ret = btrfs_next_leaf(extent_root, path); + if (ret < 0) + goto out; + if (ret > 0) + goto next; + leaf = path->nodes[0]; + } + + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + if (found_key.objectid == bytenr && + found_key.type == BTRFS_EXTENT_REF_KEY) { + if (level < ref_path->shared_level) + ref_path->shared_level = level; + goto found; + } +next: + level--; + btrfs_release_path(extent_root, path); + cond_resched(); + } + /* reached lowest level */ + ret = 1; + goto out; +walk_up: + level = ref_path->current_level; + while (level < BTRFS_MAX_LEVEL - 1) { + u64 ref_objectid; + if (level >= 0) { + bytenr = ref_path->nodes[level]; + } else { + bytenr = ref_path->extent_start; + } + BUG_ON(bytenr == 0); + + key.objectid = bytenr; + key.offset = 0; + key.type = BTRFS_EXTENT_REF_KEY; + + ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0); + if (ret < 0) + goto out; + + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + if (path->slots[0] >= nritems) { + ret = btrfs_next_leaf(extent_root, path); + if (ret < 0) + goto out; + if (ret > 0) { + /* the extent was freed by someone */ + if (ref_path->lowest_level == level) + goto out; + btrfs_release_path(extent_root, path); + goto walk_down; + } + leaf = path->nodes[0]; + } + + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + if (found_key.objectid != bytenr || + found_key.type != BTRFS_EXTENT_REF_KEY) { + /* the extent was freed by someone */ + if (ref_path->lowest_level == level) { + ret = 1; + goto out; + } + btrfs_release_path(extent_root, path); + goto walk_down; + } +found: + ref = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_extent_ref); + ref_objectid = btrfs_ref_objectid(leaf, ref); + if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) { + if (first_time) { + level = (int)ref_objectid; + BUG_ON(level >= BTRFS_MAX_LEVEL); + ref_path->lowest_level = level; + ref_path->current_level = level; + ref_path->nodes[level] = bytenr; + } else { + WARN_ON(ref_objectid != level); + } + } else { + WARN_ON(level != -1); + } + first_time = 0; + + if (ref_path->lowest_level == level) { + ref_path->owner_objectid = ref_objectid; + ref_path->num_refs = btrfs_ref_num_refs(leaf, ref); + } + + /* + * the block is tree root or the block isn't in reference + * counted tree. + */ + if (found_key.objectid == found_key.offset || + is_cowonly_root(btrfs_ref_root(leaf, ref))) { + ref_path->root_objectid = btrfs_ref_root(leaf, ref); + ref_path->root_generation = + btrfs_ref_generation(leaf, ref); + if (level < 0) { + /* special reference from the tree log */ + ref_path->nodes[0] = found_key.offset; + ref_path->current_level = 0; + } + ret = 0; + goto out; + } + + level++; + BUG_ON(ref_path->nodes[level] != 0); + ref_path->nodes[level] = found_key.offset; + ref_path->current_level = level; + + /* + * the reference was created in the running transaction, + * no need to continue walking up. + */ + if (btrfs_ref_generation(leaf, ref) == trans->transid) { + ref_path->root_objectid = btrfs_ref_root(leaf, ref); + ref_path->root_generation = + btrfs_ref_generation(leaf, ref); + ret = 0; + goto out; + } + + btrfs_release_path(extent_root, path); + cond_resched(); + } + /* reached max tree level, but no tree root found. */ + BUG(); +out: + btrfs_free_path(path); + return ret; +} + +static int btrfs_first_ref_path(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root, + struct btrfs_ref_path *ref_path, + u64 extent_start) +{ + memset(ref_path, 0, sizeof(*ref_path)); + ref_path->extent_start = extent_start; + + return __next_ref_path(trans, extent_root, ref_path, 1); +} + +static int btrfs_next_ref_path(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root, + struct btrfs_ref_path *ref_path) +{ + return __next_ref_path(trans, extent_root, ref_path, 0); +} + +static int noinline get_new_locations(struct inode *reloc_inode, + struct btrfs_key *extent_key, + u64 offset, int no_fragment, + struct disk_extent **extents, + int *nr_extents) +{ + struct btrfs_root *root = BTRFS_I(reloc_inode)->root; + struct btrfs_path *path; + struct btrfs_file_extent_item *fi; + struct extent_buffer *leaf; + struct disk_extent *exts = *extents; + struct btrfs_key found_key; + u64 cur_pos; + u64 last_byte; + u32 nritems; + int nr = 0; + int max = *nr_extents; + int ret; + + WARN_ON(!no_fragment && *extents); + if (!exts) { + max = 1; + exts = kmalloc(sizeof(*exts) * max, GFP_NOFS); + if (!exts) + return -ENOMEM; + } + + path = btrfs_alloc_path(); + BUG_ON(!path); + + cur_pos = extent_key->objectid - offset; + last_byte = extent_key->objectid + extent_key->offset; + ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino, + cur_pos, 0); + if (ret < 0) + goto out; + if (ret > 0) { + ret = -ENOENT; + goto out; + } + + while (1) { + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + if (path->slots[0] >= nritems) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + if (ret > 0) + break; + leaf = path->nodes[0]; + } + + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + if (found_key.offset != cur_pos || + found_key.type != BTRFS_EXTENT_DATA_KEY || + found_key.objectid != reloc_inode->i_ino) + break; + + fi = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + if (btrfs_file_extent_type(leaf, fi) != + BTRFS_FILE_EXTENT_REG || + btrfs_file_extent_disk_bytenr(leaf, fi) == 0) + break; + + if (nr == max) { + struct disk_extent *old = exts; + max *= 2; + exts = kzalloc(sizeof(*exts) * max, GFP_NOFS); + memcpy(exts, old, sizeof(*exts) * nr); + if (old != *extents) + kfree(old); + } + + exts[nr].disk_bytenr = + btrfs_file_extent_disk_bytenr(leaf, fi); + exts[nr].disk_num_bytes = + btrfs_file_extent_disk_num_bytes(leaf, fi); + exts[nr].offset = btrfs_file_extent_offset(leaf, fi); + exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi); + exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); + exts[nr].compression = btrfs_file_extent_compression(leaf, fi); + exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi); + exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf, + fi); + BUG_ON(exts[nr].offset > 0); + BUG_ON(exts[nr].compression || exts[nr].encryption); + BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes); + + cur_pos += exts[nr].num_bytes; + nr++; + + if (cur_pos + offset >= last_byte) + break; + + if (no_fragment) { + ret = 1; + goto out; + } + path->slots[0]++; + } + + WARN_ON(cur_pos + offset > last_byte); + if (cur_pos + offset < last_byte) { + ret = -ENOENT; + goto out; + } + ret = 0; +out: + btrfs_free_path(path); + if (ret) { + if (exts != *extents) + kfree(exts); + } else { + *extents = exts; + *nr_extents = nr; + } + return ret; +} + +static int noinline replace_one_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_key *extent_key, + struct btrfs_key *leaf_key, + struct btrfs_ref_path *ref_path, + struct disk_extent *new_extents, + int nr_extents) +{ + struct extent_buffer *leaf; + struct btrfs_file_extent_item *fi; + struct inode *inode = NULL; + struct btrfs_key key; + u64 lock_start = 0; + u64 lock_end = 0; + u64 num_bytes; + u64 ext_offset; + u64 first_pos; + u32 nritems; + int nr_scaned = 0; + int extent_locked = 0; + int extent_type; + int ret; + + memcpy(&key, leaf_key, sizeof(key)); + first_pos = INT_LIMIT(loff_t) - extent_key->offset; + if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) { + if (key.objectid < ref_path->owner_objectid || + (key.objectid == ref_path->owner_objectid && + key.type < BTRFS_EXTENT_DATA_KEY)) { + key.objectid = ref_path->owner_objectid; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = 0; + } + } + + while (1) { + ret = btrfs_search_slot(trans, root, &key, path, 0, 1); + if (ret < 0) + goto out; + + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); +next: + if (extent_locked && ret > 0) { + /* + * the file extent item was modified by someone + * before the extent got locked. + */ + unlock_extent(&BTRFS_I(inode)->io_tree, lock_start, + lock_end, GFP_NOFS); + extent_locked = 0; + } + + if (path->slots[0] >= nritems) { + if (++nr_scaned > 2) + break; + + BUG_ON(extent_locked); + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + if (ret > 0) + break; + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + } + + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + + if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) { + if ((key.objectid > ref_path->owner_objectid) || + (key.objectid == ref_path->owner_objectid && + key.type > BTRFS_EXTENT_DATA_KEY) || + (key.offset >= first_pos + extent_key->offset)) + break; + } + + if (inode && key.objectid != inode->i_ino) { + BUG_ON(extent_locked); + btrfs_release_path(root, path); + mutex_unlock(&inode->i_mutex); + iput(inode); + inode = NULL; + continue; + } + + if (key.type != BTRFS_EXTENT_DATA_KEY) { + path->slots[0]++; + ret = 1; + goto next; + } + fi = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + extent_type = btrfs_file_extent_type(leaf, fi); + if ((extent_type != BTRFS_FILE_EXTENT_REG && + extent_type != BTRFS_FILE_EXTENT_PREALLOC) || + (btrfs_file_extent_disk_bytenr(leaf, fi) != + extent_key->objectid)) { + path->slots[0]++; + ret = 1; + goto next; + } + + num_bytes = btrfs_file_extent_num_bytes(leaf, fi); + ext_offset = btrfs_file_extent_offset(leaf, fi); + + if (first_pos > key.offset - ext_offset) + first_pos = key.offset - ext_offset; + + if (!extent_locked) { + lock_start = key.offset; + lock_end = lock_start + num_bytes - 1; + } else { + if (lock_start > key.offset || + lock_end + 1 < key.offset + num_bytes) { + unlock_extent(&BTRFS_I(inode)->io_tree, + lock_start, lock_end, GFP_NOFS); + extent_locked = 0; + } + } + + if (!inode) { + btrfs_release_path(root, path); + + inode = btrfs_iget_locked(root->fs_info->sb, + key.objectid, root); + if (inode->i_state & I_NEW) { + BTRFS_I(inode)->root = root; + BTRFS_I(inode)->location.objectid = + key.objectid; + BTRFS_I(inode)->location.type = + BTRFS_INODE_ITEM_KEY; + BTRFS_I(inode)->location.offset = 0; + btrfs_read_locked_inode(inode); + unlock_new_inode(inode); + } + /* + * some code call btrfs_commit_transaction while + * holding the i_mutex, so we can't use mutex_lock + * here. + */ + if (is_bad_inode(inode) || + !mutex_trylock(&inode->i_mutex)) { + iput(inode); + inode = NULL; + key.offset = (u64)-1; + goto skip; + } + } + + if (!extent_locked) { + struct btrfs_ordered_extent *ordered; + + btrfs_release_path(root, path); + + lock_extent(&BTRFS_I(inode)->io_tree, lock_start, + lock_end, GFP_NOFS); + ordered = btrfs_lookup_first_ordered_extent(inode, + lock_end); + if (ordered && + ordered->file_offset <= lock_end && + ordered->file_offset + ordered->len > lock_start) { + unlock_extent(&BTRFS_I(inode)->io_tree, + lock_start, lock_end, GFP_NOFS); + btrfs_start_ordered_extent(inode, ordered, 1); + btrfs_put_ordered_extent(ordered); + key.offset += num_bytes; + goto skip; + } + if (ordered) + btrfs_put_ordered_extent(ordered); + + extent_locked = 1; + continue; + } + + if (nr_extents == 1) { + /* update extent pointer in place */ + btrfs_set_file_extent_disk_bytenr(leaf, fi, + new_extents[0].disk_bytenr); + btrfs_set_file_extent_disk_num_bytes(leaf, fi, + new_extents[0].disk_num_bytes); + btrfs_mark_buffer_dirty(leaf); + + btrfs_drop_extent_cache(inode, key.offset, + key.offset + num_bytes - 1, 0); + + ret = btrfs_inc_extent_ref(trans, root, + new_extents[0].disk_bytenr, + new_extents[0].disk_num_bytes, + leaf->start, + root->root_key.objectid, + trans->transid, + key.objectid); + BUG_ON(ret); + + ret = btrfs_free_extent(trans, root, + extent_key->objectid, + extent_key->offset, + leaf->start, + btrfs_header_owner(leaf), + btrfs_header_generation(leaf), + key.objectid, 0); + BUG_ON(ret); + + btrfs_release_path(root, path); + key.offset += num_bytes; + } else { + BUG_ON(1); +#if 0 + u64 alloc_hint; + u64 extent_len; + int i; + /* + * drop old extent pointer at first, then insert the + * new pointers one bye one + */ + btrfs_release_path(root, path); + ret = btrfs_drop_extents(trans, root, inode, key.offset, + key.offset + num_bytes, + key.offset, &alloc_hint); + BUG_ON(ret); + + for (i = 0; i < nr_extents; i++) { + if (ext_offset >= new_extents[i].num_bytes) { + ext_offset -= new_extents[i].num_bytes; + continue; + } + extent_len = min(new_extents[i].num_bytes - + ext_offset, num_bytes); + + ret = btrfs_insert_empty_item(trans, root, + path, &key, + sizeof(*fi)); + BUG_ON(ret); + + leaf = path->nodes[0]; + fi = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + btrfs_set_file_extent_generation(leaf, fi, + trans->transid); + btrfs_set_file_extent_type(leaf, fi, + BTRFS_FILE_EXTENT_REG); + btrfs_set_file_extent_disk_bytenr(leaf, fi, + new_extents[i].disk_bytenr); + btrfs_set_file_extent_disk_num_bytes(leaf, fi, + new_extents[i].disk_num_bytes); + btrfs_set_file_extent_ram_bytes(leaf, fi, + new_extents[i].ram_bytes); + + btrfs_set_file_extent_compression(leaf, fi, + new_extents[i].compression); + btrfs_set_file_extent_encryption(leaf, fi, + new_extents[i].encryption); + btrfs_set_file_extent_other_encoding(leaf, fi, + new_extents[i].other_encoding); + + btrfs_set_file_extent_num_bytes(leaf, fi, + extent_len); + ext_offset += new_extents[i].offset; + btrfs_set_file_extent_offset(leaf, fi, + ext_offset); + btrfs_mark_buffer_dirty(leaf); + + btrfs_drop_extent_cache(inode, key.offset, + key.offset + extent_len - 1, 0); + + ret = btrfs_inc_extent_ref(trans, root, + new_extents[i].disk_bytenr, + new_extents[i].disk_num_bytes, + leaf->start, + root->root_key.objectid, + trans->transid, key.objectid); + BUG_ON(ret); + btrfs_release_path(root, path); + + inode_add_bytes(inode, extent_len); + + ext_offset = 0; + num_bytes -= extent_len; + key.offset += extent_len; + + if (num_bytes == 0) + break; + } + BUG_ON(i >= nr_extents); +#endif + } + + if (extent_locked) { + unlock_extent(&BTRFS_I(inode)->io_tree, lock_start, + lock_end, GFP_NOFS); + extent_locked = 0; + } +skip: + if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS && + key.offset >= first_pos + extent_key->offset) + break; + + cond_resched(); + } + ret = 0; +out: + btrfs_release_path(root, path); + if (inode) { + mutex_unlock(&inode->i_mutex); + if (extent_locked) { + unlock_extent(&BTRFS_I(inode)->io_tree, lock_start, + lock_end, GFP_NOFS); + } + iput(inode); + } + return ret; +} + +int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct extent_buffer *buf, u64 orig_start) +{ + int level; + int ret; + + BUG_ON(btrfs_header_generation(buf) != trans->transid); + BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID); + + level = btrfs_header_level(buf); + if (level == 0) { + struct btrfs_leaf_ref *ref; + struct btrfs_leaf_ref *orig_ref; + + orig_ref = btrfs_lookup_leaf_ref(root, orig_start); + if (!orig_ref) + return -ENOENT; + + ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems); + if (!ref) { + btrfs_free_leaf_ref(root, orig_ref); + return -ENOMEM; + } + + ref->nritems = orig_ref->nritems; + memcpy(ref->extents, orig_ref->extents, + sizeof(ref->extents[0]) * ref->nritems); + + btrfs_free_leaf_ref(root, orig_ref); + + ref->root_gen = trans->transid; + ref->bytenr = buf->start; + ref->owner = btrfs_header_owner(buf); + ref->generation = btrfs_header_generation(buf); + ret = btrfs_add_leaf_ref(root, ref, 0); + WARN_ON(ret); + btrfs_free_leaf_ref(root, ref); + } + return 0; +} + +static int noinline invalidate_extent_cache(struct btrfs_root *root, + struct extent_buffer *leaf, + struct btrfs_block_group_cache *group, + struct btrfs_root *target_root) +{ + struct btrfs_key key; + struct inode *inode = NULL; + struct btrfs_file_extent_item *fi; + u64 num_bytes; + u64 skip_objectid = 0; + u32 nritems; + u32 i; + + nritems = btrfs_header_nritems(leaf); + for (i = 0; i < nritems; i++) { + btrfs_item_key_to_cpu(leaf, &key, i); + if (key.objectid == skip_objectid || + key.type != BTRFS_EXTENT_DATA_KEY) + continue; + fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); + if (btrfs_file_extent_type(leaf, fi) == + BTRFS_FILE_EXTENT_INLINE) + continue; + if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0) + continue; + if (!inode || inode->i_ino != key.objectid) { + iput(inode); + inode = btrfs_ilookup(target_root->fs_info->sb, + key.objectid, target_root, 1); + } + if (!inode) { + skip_objectid = key.objectid; + continue; + } + num_bytes = btrfs_file_extent_num_bytes(leaf, fi); + + lock_extent(&BTRFS_I(inode)->io_tree, key.offset, + key.offset + num_bytes - 1, GFP_NOFS); + btrfs_drop_extent_cache(inode, key.offset, + key.offset + num_bytes - 1, 1); + unlock_extent(&BTRFS_I(inode)->io_tree, key.offset, + key.offset + num_bytes - 1, GFP_NOFS); + cond_resched(); + } + iput(inode); + return 0; +} + +static int noinline replace_extents_in_leaf(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct extent_buffer *leaf, + struct btrfs_block_group_cache *group, + struct inode *reloc_inode) +{ + struct btrfs_key key; + struct btrfs_key extent_key; + struct btrfs_file_extent_item *fi; + struct btrfs_leaf_ref *ref; + struct disk_extent *new_extent; + u64 bytenr; + u64 num_bytes; + u32 nritems; + u32 i; + int ext_index; + int nr_extent; + int ret; + + new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS); + BUG_ON(!new_extent); + + ref = btrfs_lookup_leaf_ref(root, leaf->start); + BUG_ON(!ref); + + ext_index = -1; + nritems = btrfs_header_nritems(leaf); + for (i = 0; i < nritems; i++) { + btrfs_item_key_to_cpu(leaf, &key, i); + if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) + continue; + fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); + if (btrfs_file_extent_type(leaf, fi) == + BTRFS_FILE_EXTENT_INLINE) + continue; + bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); + num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); + if (bytenr == 0) + continue; + + ext_index++; + if (bytenr >= group->key.objectid + group->key.offset || + bytenr + num_bytes <= group->key.objectid) + continue; + + extent_key.objectid = bytenr; + extent_key.offset = num_bytes; + extent_key.type = BTRFS_EXTENT_ITEM_KEY; + nr_extent = 1; + ret = get_new_locations(reloc_inode, &extent_key, + group->key.objectid, 1, + &new_extent, &nr_extent); + if (ret > 0) + continue; + BUG_ON(ret < 0); + + BUG_ON(ref->extents[ext_index].bytenr != bytenr); + BUG_ON(ref->extents[ext_index].num_bytes != num_bytes); + ref->extents[ext_index].bytenr = new_extent->disk_bytenr; + ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes; + + btrfs_set_file_extent_disk_bytenr(leaf, fi, + new_extent->disk_bytenr); + btrfs_set_file_extent_disk_num_bytes(leaf, fi, + new_extent->disk_num_bytes); + btrfs_mark_buffer_dirty(leaf); + + ret = btrfs_inc_extent_ref(trans, root, + new_extent->disk_bytenr, + new_extent->disk_num_bytes, + leaf->start, + root->root_key.objectid, + trans->transid, key.objectid); + BUG_ON(ret); + ret = btrfs_free_extent(trans, root, + bytenr, num_bytes, leaf->start, + btrfs_header_owner(leaf), + btrfs_header_generation(leaf), + key.objectid, 0); + BUG_ON(ret); + cond_resched(); + } + kfree(new_extent); + BUG_ON(ext_index + 1 != ref->nritems); + btrfs_free_leaf_ref(root, ref); + return 0; +} + +int btrfs_free_reloc_root(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_root *reloc_root; + int ret; + + if (root->reloc_root) { + reloc_root = root->reloc_root; + root->reloc_root = NULL; + list_add(&reloc_root->dead_list, + &root->fs_info->dead_reloc_roots); + + btrfs_set_root_bytenr(&reloc_root->root_item, + reloc_root->node->start); + btrfs_set_root_level(&root->root_item, + btrfs_header_level(reloc_root->node)); + memset(&reloc_root->root_item.drop_progress, 0, + sizeof(struct btrfs_disk_key)); + reloc_root->root_item.drop_level = 0; + + ret = btrfs_update_root(trans, root->fs_info->tree_root, + &reloc_root->root_key, + &reloc_root->root_item); + BUG_ON(ret); + } + return 0; +} + +int btrfs_drop_dead_reloc_roots(struct btrfs_root *root) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *reloc_root; + struct btrfs_root *prev_root = NULL; + struct list_head dead_roots; + int ret; + unsigned long nr; + + INIT_LIST_HEAD(&dead_roots); + list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots); + + while (!list_empty(&dead_roots)) { + reloc_root = list_entry(dead_roots.prev, + struct btrfs_root, dead_list); + list_del_init(&reloc_root->dead_list); + + BUG_ON(reloc_root->commit_root != NULL); + while (1) { + trans = btrfs_join_transaction(root, 1); + BUG_ON(!trans); + + mutex_lock(&root->fs_info->drop_mutex); + ret = btrfs_drop_snapshot(trans, reloc_root); + if (ret != -EAGAIN) + break; + mutex_unlock(&root->fs_info->drop_mutex); + + nr = trans->blocks_used; + ret = btrfs_end_transaction(trans, root); + BUG_ON(ret); + btrfs_btree_balance_dirty(root, nr); + } + + free_extent_buffer(reloc_root->node); + + ret = btrfs_del_root(trans, root->fs_info->tree_root, + &reloc_root->root_key); + BUG_ON(ret); + mutex_unlock(&root->fs_info->drop_mutex); + + nr = trans->blocks_used; + ret = btrfs_end_transaction(trans, root); + BUG_ON(ret); + btrfs_btree_balance_dirty(root, nr); + + kfree(prev_root); + prev_root = reloc_root; + } + if (prev_root) { + btrfs_remove_leaf_refs(prev_root, (u64)-1, 0); + kfree(prev_root); + } + return 0; +} + +int btrfs_add_dead_reloc_root(struct btrfs_root *root) +{ + list_add(&root->dead_list, &root->fs_info->dead_reloc_roots); + return 0; +} + +int btrfs_cleanup_reloc_trees(struct btrfs_root *root) +{ + struct btrfs_root *reloc_root; + struct btrfs_trans_handle *trans; + struct btrfs_key location; + int found; + int ret; + + mutex_lock(&root->fs_info->tree_reloc_mutex); + ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL); + BUG_ON(ret); + found = !list_empty(&root->fs_info->dead_reloc_roots); + mutex_unlock(&root->fs_info->tree_reloc_mutex); + + if (found) { + trans = btrfs_start_transaction(root, 1); + BUG_ON(!trans); + ret = btrfs_commit_transaction(trans, root); + BUG_ON(ret); + } + + location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID; + location.offset = (u64)-1; + location.type = BTRFS_ROOT_ITEM_KEY; + + reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location); + BUG_ON(!reloc_root); + btrfs_orphan_cleanup(reloc_root); + return 0; +} + +static int noinline init_reloc_tree(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_root *reloc_root; + struct extent_buffer *eb; + struct btrfs_root_item *root_item; + struct btrfs_key root_key; + int ret; + + BUG_ON(!root->ref_cows); + if (root->reloc_root) + return 0; + + root_item = kmalloc(sizeof(*root_item), GFP_NOFS); + BUG_ON(!root_item); + + ret = btrfs_copy_root(trans, root, root->commit_root, + &eb, BTRFS_TREE_RELOC_OBJECTID); + BUG_ON(ret); + + root_key.objectid = BTRFS_TREE_RELOC_OBJECTID; + root_key.offset = root->root_key.objectid; + root_key.type = BTRFS_ROOT_ITEM_KEY; + + memcpy(root_item, &root->root_item, sizeof(root_item)); + btrfs_set_root_refs(root_item, 0); + btrfs_set_root_bytenr(root_item, eb->start); + btrfs_set_root_level(root_item, btrfs_header_level(eb)); + btrfs_set_root_generation(root_item, trans->transid); + + btrfs_tree_unlock(eb); + free_extent_buffer(eb); + + ret = btrfs_insert_root(trans, root->fs_info->tree_root, + &root_key, root_item); + BUG_ON(ret); + kfree(root_item); + + reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root, + &root_key); + BUG_ON(!reloc_root); + reloc_root->last_trans = trans->transid; + reloc_root->commit_root = NULL; + reloc_root->ref_tree = &root->fs_info->reloc_ref_tree; + + root->reloc_root = reloc_root; + return 0; +} + +/* + * Core function of space balance. + * + * The idea is using reloc trees to relocate tree blocks in reference + * counted roots. There is one reloc tree for each subvol, and all + * reloc trees share same root key objectid. Reloc trees are snapshots + * of the latest committed roots of subvols (root->commit_root). + * + * To relocate a tree block referenced by a subvol, there are two steps. + * COW the block through subvol's reloc tree, then update block pointer + * in the subvol to point to the new block. Since all reloc trees share + * same root key objectid, doing special handing for tree blocks owned + * by them is easy. Once a tree block has been COWed in one reloc tree, + * we can use the resulting new block directly when the same block is + * required to COW again through other reloc trees. By this way, relocated + * tree blocks are shared between reloc trees, so they are also shared + * between subvols. + */ +static int noinline relocate_one_path(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_key *first_key, + struct btrfs_ref_path *ref_path, + struct btrfs_block_group_cache *group, + struct inode *reloc_inode) +{ + struct btrfs_root *reloc_root; + struct extent_buffer *eb = NULL; + struct btrfs_key *keys; + u64 *nodes; + int level; + int shared_level; + int lowest_level = 0; + int ret; + + if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID) + lowest_level = ref_path->owner_objectid; + + if (!root->ref_cows) { + path->lowest_level = lowest_level; + ret = btrfs_search_slot(trans, root, first_key, path, 0, 1); + BUG_ON(ret < 0); + path->lowest_level = 0; + btrfs_release_path(root, path); + return 0; + } + + mutex_lock(&root->fs_info->tree_reloc_mutex); + ret = init_reloc_tree(trans, root); + BUG_ON(ret); + reloc_root = root->reloc_root; + + shared_level = ref_path->shared_level; + ref_path->shared_level = BTRFS_MAX_LEVEL - 1; + + keys = ref_path->node_keys; + nodes = ref_path->new_nodes; + memset(&keys[shared_level + 1], 0, + sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1)); + memset(&nodes[shared_level + 1], 0, + sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1)); + + if (nodes[lowest_level] == 0) { + path->lowest_level = lowest_level; + ret = btrfs_search_slot(trans, reloc_root, first_key, path, + 0, 1); + BUG_ON(ret); + for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) { + eb = path->nodes[level]; + if (!eb || eb == reloc_root->node) + break; + nodes[level] = eb->start; + if (level == 0) + btrfs_item_key_to_cpu(eb, &keys[level], 0); + else + btrfs_node_key_to_cpu(eb, &keys[level], 0); + } + if (nodes[0] && + ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) { + eb = path->nodes[0]; + ret = replace_extents_in_leaf(trans, reloc_root, eb, + group, reloc_inode); + BUG_ON(ret); + } + btrfs_release_path(reloc_root, path); + } else { + ret = btrfs_merge_path(trans, reloc_root, keys, nodes, + lowest_level); + BUG_ON(ret); + } + + /* + * replace tree blocks in the fs tree with tree blocks in + * the reloc tree. + */ + ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level); + BUG_ON(ret < 0); + + if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) { + ret = btrfs_search_slot(trans, reloc_root, first_key, path, + 0, 0); + BUG_ON(ret); + extent_buffer_get(path->nodes[0]); + eb = path->nodes[0]; + btrfs_release_path(reloc_root, path); + ret = invalidate_extent_cache(reloc_root, eb, group, root); + BUG_ON(ret); + free_extent_buffer(eb); + } + + mutex_unlock(&root->fs_info->tree_reloc_mutex); + path->lowest_level = 0; + return 0; +} + +static int noinline relocate_tree_block(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_key *first_key, + struct btrfs_ref_path *ref_path) +{ + int ret; + + ret = relocate_one_path(trans, root, path, first_key, + ref_path, NULL, NULL); + BUG_ON(ret); + + if (root == root->fs_info->extent_root) + btrfs_extent_post_op(trans, root); + + return 0; +} + +static int noinline del_extent_zero(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root, + struct btrfs_path *path, + struct btrfs_key *extent_key) +{ + int ret; + + ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1); + if (ret) + goto out; + ret = btrfs_del_item(trans, extent_root, path); +out: + btrfs_release_path(extent_root, path); + return ret; +} + +static struct btrfs_root noinline *read_ref_root(struct btrfs_fs_info *fs_info, + struct btrfs_ref_path *ref_path) +{ + struct btrfs_key root_key; + + root_key.objectid = ref_path->root_objectid; + root_key.type = BTRFS_ROOT_ITEM_KEY; + if (is_cowonly_root(ref_path->root_objectid)) + root_key.offset = 0; + else + root_key.offset = (u64)-1; + + return btrfs_read_fs_root_no_name(fs_info, &root_key); +} + +static int noinline relocate_one_extent(struct btrfs_root *extent_root, + struct btrfs_path *path, + struct btrfs_key *extent_key, + struct btrfs_block_group_cache *group, + struct inode *reloc_inode, int pass) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *found_root; + struct btrfs_ref_path *ref_path = NULL; + struct disk_extent *new_extents = NULL; + int nr_extents = 0; + int loops; + int ret; + int level; + struct btrfs_key first_key; + u64 prev_block = 0; + + + trans = btrfs_start_transaction(extent_root, 1); + BUG_ON(!trans); + + if (extent_key->objectid == 0) { + ret = del_extent_zero(trans, extent_root, path, extent_key); + goto out; + } + + ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS); + if (!ref_path) { + ret = -ENOMEM; + goto out; + } + + for (loops = 0; ; loops++) { + if (loops == 0) { + ret = btrfs_first_ref_path(trans, extent_root, ref_path, + extent_key->objectid); + } else { + ret = btrfs_next_ref_path(trans, extent_root, ref_path); + } + if (ret < 0) + goto out; + if (ret > 0) + break; + + if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID || + ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID) + continue; + + found_root = read_ref_root(extent_root->fs_info, ref_path); + BUG_ON(!found_root); + /* + * for reference counted tree, only process reference paths + * rooted at the latest committed root. + */ + if (found_root->ref_cows && + ref_path->root_generation != found_root->root_key.offset) + continue; + + if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) { + if (pass == 0) { + /* + * copy data extents to new locations + */ + u64 group_start = group->key.objectid; + ret = relocate_data_extent(reloc_inode, + extent_key, + group_start); + if (ret < 0) + goto out; + break; + } + level = 0; + } else { + level = ref_path->owner_objectid; + } + + if (prev_block != ref_path->nodes[level]) { + struct extent_buffer *eb; + u64 block_start = ref_path->nodes[level]; + u64 block_size = btrfs_level_size(found_root, level); + + eb = read_tree_block(found_root, block_start, + block_size, 0); + btrfs_tree_lock(eb); + BUG_ON(level != btrfs_header_level(eb)); + + if (level == 0) + btrfs_item_key_to_cpu(eb, &first_key, 0); + else + btrfs_node_key_to_cpu(eb, &first_key, 0); + + btrfs_tree_unlock(eb); + free_extent_buffer(eb); + prev_block = block_start; + } + + if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID && + pass >= 2) { + /* + * use fallback method to process the remaining + * references. + */ + if (!new_extents) { + u64 group_start = group->key.objectid; + new_extents = kmalloc(sizeof(*new_extents), + GFP_NOFS); + nr_extents = 1; + ret = get_new_locations(reloc_inode, + extent_key, + group_start, 1, + &new_extents, + &nr_extents); + if (ret) + goto out; + } + btrfs_record_root_in_trans(found_root); + ret = replace_one_extent(trans, found_root, + path, extent_key, + &first_key, ref_path, + new_extents, nr_extents); + if (ret < 0) + goto out; + continue; + } + + btrfs_record_root_in_trans(found_root); + if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID) { + ret = relocate_tree_block(trans, found_root, path, + &first_key, ref_path); + } else { + /* + * try to update data extent references while + * keeping metadata shared between snapshots. + */ + ret = relocate_one_path(trans, found_root, path, + &first_key, ref_path, + group, reloc_inode); + } + if (ret < 0) + goto out; + } + ret = 0; +out: + btrfs_end_transaction(trans, extent_root); + kfree(new_extents); + kfree(ref_path); + return ret; +} + +static u64 update_block_group_flags(struct btrfs_root *root, u64 flags) +{ + u64 num_devices; + u64 stripped = BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10; + + num_devices = root->fs_info->fs_devices->rw_devices; + if (num_devices == 1) { + stripped |= BTRFS_BLOCK_GROUP_DUP; + stripped = flags & ~stripped; + + /* turn raid0 into single device chunks */ + if (flags & BTRFS_BLOCK_GROUP_RAID0) + return stripped; + + /* turn mirroring into duplication */ + if (flags & (BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10)) + return stripped | BTRFS_BLOCK_GROUP_DUP; + return flags; + } else { + /* they already had raid on here, just return */ + if (flags & stripped) + return flags; + + stripped |= BTRFS_BLOCK_GROUP_DUP; + stripped = flags & ~stripped; + + /* switch duplicated blocks with raid1 */ + if (flags & BTRFS_BLOCK_GROUP_DUP) + return stripped | BTRFS_BLOCK_GROUP_RAID1; + + /* turn single device chunks into raid0 */ + return stripped | BTRFS_BLOCK_GROUP_RAID0; + } + return flags; +} + +int __alloc_chunk_for_shrink(struct btrfs_root *root, + struct btrfs_block_group_cache *shrink_block_group, + int force) +{ + struct btrfs_trans_handle *trans; + u64 new_alloc_flags; + u64 calc; + + spin_lock(&shrink_block_group->lock); + if (btrfs_block_group_used(&shrink_block_group->item) > 0) { + spin_unlock(&shrink_block_group->lock); + + trans = btrfs_start_transaction(root, 1); + spin_lock(&shrink_block_group->lock); + + new_alloc_flags = update_block_group_flags(root, + shrink_block_group->flags); + if (new_alloc_flags != shrink_block_group->flags) { + calc = + btrfs_block_group_used(&shrink_block_group->item); + } else { + calc = shrink_block_group->key.offset; + } + spin_unlock(&shrink_block_group->lock); + + do_chunk_alloc(trans, root->fs_info->extent_root, + calc + 2 * 1024 * 1024, new_alloc_flags, force); + + btrfs_end_transaction(trans, root); + } else + spin_unlock(&shrink_block_group->lock); + return 0; +} + +static int __insert_orphan_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 objectid, u64 size) +{ + struct btrfs_path *path; + struct btrfs_inode_item *item; + struct extent_buffer *leaf; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = btrfs_insert_empty_inode(trans, root, path, objectid); + if (ret) + goto out; + + leaf = path->nodes[0]; + item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item); + memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item)); + btrfs_set_inode_generation(leaf, item, 1); + btrfs_set_inode_size(leaf, item, size); + btrfs_set_inode_mode(leaf, item, S_IFREG | 0600); + btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NODATASUM | + BTRFS_INODE_NOCOMPRESS); + btrfs_mark_buffer_dirty(leaf); + btrfs_release_path(root, path); +out: + btrfs_free_path(path); + return ret; +} + +static struct inode noinline *create_reloc_inode(struct btrfs_fs_info *fs_info, + struct btrfs_block_group_cache *group) +{ + struct inode *inode = NULL; + struct btrfs_trans_handle *trans; + struct btrfs_root *root; + struct btrfs_key root_key; + u64 objectid = BTRFS_FIRST_FREE_OBJECTID; + int err = 0; + + root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID; + root_key.type = BTRFS_ROOT_ITEM_KEY; + root_key.offset = (u64)-1; + root = btrfs_read_fs_root_no_name(fs_info, &root_key); + if (IS_ERR(root)) + return ERR_CAST(root); + + trans = btrfs_start_transaction(root, 1); + BUG_ON(!trans); + + err = btrfs_find_free_objectid(trans, root, objectid, &objectid); + if (err) + goto out; + + err = __insert_orphan_inode(trans, root, objectid, group->key.offset); + BUG_ON(err); + + err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0, + group->key.offset, 0, group->key.offset, + 0, 0, 0); + BUG_ON(err); + + inode = btrfs_iget_locked(root->fs_info->sb, objectid, root); + if (inode->i_state & I_NEW) { + BTRFS_I(inode)->root = root; + BTRFS_I(inode)->location.objectid = objectid; + BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY; + BTRFS_I(inode)->location.offset = 0; + btrfs_read_locked_inode(inode); + unlock_new_inode(inode); + BUG_ON(is_bad_inode(inode)); + } else { + BUG_ON(1); + } + + err = btrfs_orphan_add(trans, inode); +out: + btrfs_end_transaction(trans, root); + if (err) { + if (inode) + iput(inode); + inode = ERR_PTR(err); + } + return inode; +} + +int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start) +{ + struct btrfs_trans_handle *trans; + struct btrfs_path *path; + struct btrfs_fs_info *info = root->fs_info; + struct extent_buffer *leaf; + struct inode *reloc_inode; + struct btrfs_block_group_cache *block_group; + struct btrfs_key key; + u64 skipped; + u64 cur_byte; + u64 total_found; + u32 nritems; + int ret; + int progress; + int pass = 0; + + root = root->fs_info->extent_root; + + block_group = btrfs_lookup_block_group(info, group_start); + BUG_ON(!block_group); + + printk("btrfs relocating block group %llu flags %llu\n", + (unsigned long long)block_group->key.objectid, + (unsigned long long)block_group->flags); + + path = btrfs_alloc_path(); + BUG_ON(!path); + + reloc_inode = create_reloc_inode(info, block_group); + BUG_ON(IS_ERR(reloc_inode)); + + __alloc_chunk_for_shrink(root, block_group, 1); + set_block_group_readonly(block_group); + + btrfs_start_delalloc_inodes(info->tree_root); + btrfs_wait_ordered_extents(info->tree_root, 0); +again: + skipped = 0; + total_found = 0; + progress = 0; + key.objectid = block_group->key.objectid; + key.offset = 0; + key.type = 0; + cur_byte = key.objectid; + + trans = btrfs_start_transaction(info->tree_root, 1); + btrfs_commit_transaction(trans, info->tree_root); + + mutex_lock(&root->fs_info->cleaner_mutex); + btrfs_clean_old_snapshots(info->tree_root); + btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1); + mutex_unlock(&root->fs_info->cleaner_mutex); + + while(1) { + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; +next: + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + if (path->slots[0] >= nritems) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + if (ret == 1) { + ret = 0; + break; + } + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + } + + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + + if (key.objectid >= block_group->key.objectid + + block_group->key.offset) + break; + + if (progress && need_resched()) { + btrfs_release_path(root, path); + cond_resched(); + progress = 0; + continue; + } + progress = 1; + + if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY || + key.objectid + key.offset <= cur_byte) { + path->slots[0]++; + goto next; + } + + total_found++; + cur_byte = key.objectid + key.offset; + btrfs_release_path(root, path); + + __alloc_chunk_for_shrink(root, block_group, 0); + ret = relocate_one_extent(root, path, &key, block_group, + reloc_inode, pass); + BUG_ON(ret < 0); + if (ret > 0) + skipped++; + + key.objectid = cur_byte; + key.type = 0; + key.offset = 0; + } + + btrfs_release_path(root, path); + + if (pass == 0) { + btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1); + invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1); + WARN_ON(reloc_inode->i_mapping->nrpages); + } + + if (total_found > 0) { + printk("btrfs found %llu extents in pass %d\n", + (unsigned long long)total_found, pass); + pass++; + if (total_found == skipped && pass > 2) { + iput(reloc_inode); + reloc_inode = create_reloc_inode(info, block_group); + pass = 0; + } + goto again; + } + + /* delete reloc_inode */ + iput(reloc_inode); + + /* unpin extents in this range */ + trans = btrfs_start_transaction(info->tree_root, 1); + btrfs_commit_transaction(trans, info->tree_root); + + spin_lock(&block_group->lock); + WARN_ON(block_group->pinned > 0); + WARN_ON(block_group->reserved > 0); + WARN_ON(btrfs_block_group_used(&block_group->item) > 0); + spin_unlock(&block_group->lock); + ret = 0; +out: + btrfs_free_path(path); + return ret; +} + +int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path, + struct btrfs_key *key) +{ + int ret = 0; + struct btrfs_key found_key; + struct extent_buffer *leaf; + int slot; + + ret = btrfs_search_slot(NULL, root, key, path, 0, 0); + if (ret < 0) + goto out; + + while(1) { + slot = path->slots[0]; + leaf = path->nodes[0]; + if (slot >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret == 0) + continue; + if (ret < 0) + goto out; + break; + } + btrfs_item_key_to_cpu(leaf, &found_key, slot); + + if (found_key.objectid >= key->objectid && + found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) { + ret = 0; + goto out; + } + path->slots[0]++; + } + ret = -ENOENT; +out: + return ret; +} + +int btrfs_free_block_groups(struct btrfs_fs_info *info) +{ + struct btrfs_block_group_cache *block_group; + struct rb_node *n; + + spin_lock(&info->block_group_cache_lock); + while ((n = rb_last(&info->block_group_cache_tree)) != NULL) { + block_group = rb_entry(n, struct btrfs_block_group_cache, + cache_node); + rb_erase(&block_group->cache_node, + &info->block_group_cache_tree); + spin_unlock(&info->block_group_cache_lock); + + btrfs_remove_free_space_cache(block_group); + down_write(&block_group->space_info->groups_sem); + list_del(&block_group->list); + up_write(&block_group->space_info->groups_sem); + kfree(block_group); + + spin_lock(&info->block_group_cache_lock); + } + spin_unlock(&info->block_group_cache_lock); + return 0; +} + +int btrfs_read_block_groups(struct btrfs_root *root) +{ + struct btrfs_path *path; + int ret; + struct btrfs_block_group_cache *cache; + struct btrfs_fs_info *info = root->fs_info; + struct btrfs_space_info *space_info; + struct btrfs_key key; + struct btrfs_key found_key; + struct extent_buffer *leaf; + + root = info->extent_root; + key.objectid = 0; + key.offset = 0; + btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY); + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + while(1) { + ret = find_first_block_group(root, path, &key); + if (ret > 0) { + ret = 0; + goto error; + } + if (ret != 0) + goto error; + + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + cache = kzalloc(sizeof(*cache), GFP_NOFS); + if (!cache) { + ret = -ENOMEM; + break; + } + + spin_lock_init(&cache->lock); + mutex_init(&cache->alloc_mutex); + INIT_LIST_HEAD(&cache->list); + read_extent_buffer(leaf, &cache->item, + btrfs_item_ptr_offset(leaf, path->slots[0]), + sizeof(cache->item)); + memcpy(&cache->key, &found_key, sizeof(found_key)); + + key.objectid = found_key.objectid + found_key.offset; + btrfs_release_path(root, path); + cache->flags = btrfs_block_group_flags(&cache->item); + + ret = update_space_info(info, cache->flags, found_key.offset, + btrfs_block_group_used(&cache->item), + &space_info); + BUG_ON(ret); + cache->space_info = space_info; + down_write(&space_info->groups_sem); + list_add_tail(&cache->list, &space_info->block_groups); + up_write(&space_info->groups_sem); + + ret = btrfs_add_block_group_cache(root->fs_info, cache); + BUG_ON(ret); + + set_avail_alloc_bits(root->fs_info, cache->flags); + if (btrfs_chunk_readonly(root, cache->key.objectid)) + set_block_group_readonly(cache); + } + ret = 0; +error: + btrfs_free_path(path); + return ret; +} + +int btrfs_make_block_group(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 bytes_used, + u64 type, u64 chunk_objectid, u64 chunk_offset, + u64 size) +{ + int ret; + struct btrfs_root *extent_root; + struct btrfs_block_group_cache *cache; + + extent_root = root->fs_info->extent_root; + + root->fs_info->last_trans_new_blockgroup = trans->transid; + + cache = kzalloc(sizeof(*cache), GFP_NOFS); + if (!cache) + return -ENOMEM; + + cache->key.objectid = chunk_offset; + cache->key.offset = size; + spin_lock_init(&cache->lock); + mutex_init(&cache->alloc_mutex); + INIT_LIST_HEAD(&cache->list); + btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY); + + btrfs_set_block_group_used(&cache->item, bytes_used); + btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid); + cache->flags = type; + btrfs_set_block_group_flags(&cache->item, type); + + ret = update_space_info(root->fs_info, cache->flags, size, bytes_used, + &cache->space_info); + BUG_ON(ret); + down_write(&cache->space_info->groups_sem); + list_add_tail(&cache->list, &cache->space_info->block_groups); + up_write(&cache->space_info->groups_sem); + + ret = btrfs_add_block_group_cache(root->fs_info, cache); + BUG_ON(ret); + + ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item, + sizeof(cache->item)); + BUG_ON(ret); + + finish_current_insert(trans, extent_root, 0); + ret = del_pending_extents(trans, extent_root, 0); + BUG_ON(ret); + set_avail_alloc_bits(extent_root->fs_info, type); + + return 0; +} + +int btrfs_remove_block_group(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 group_start) +{ + struct btrfs_path *path; + struct btrfs_block_group_cache *block_group; + struct btrfs_key key; + int ret; + + root = root->fs_info->extent_root; + + block_group = btrfs_lookup_block_group(root->fs_info, group_start); + BUG_ON(!block_group); + BUG_ON(!block_group->ro); + + memcpy(&key, &block_group->key, sizeof(key)); + + path = btrfs_alloc_path(); + BUG_ON(!path); + + btrfs_remove_free_space_cache(block_group); + rb_erase(&block_group->cache_node, + &root->fs_info->block_group_cache_tree); + down_write(&block_group->space_info->groups_sem); + list_del(&block_group->list); + up_write(&block_group->space_info->groups_sem); + + spin_lock(&block_group->space_info->lock); + block_group->space_info->total_bytes -= block_group->key.offset; + block_group->space_info->bytes_readonly -= block_group->key.offset; + spin_unlock(&block_group->space_info->lock); + block_group->space_info->full = 0; + + /* + memset(shrink_block_group, 0, sizeof(*shrink_block_group)); + kfree(shrink_block_group); + */ + + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret > 0) + ret = -EIO; + if (ret < 0) + goto out; + + ret = btrfs_del_item(trans, root, path); +out: + btrfs_free_path(path); + return ret; +} |