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-rw-r--r--fs/btrfs/extent-tree.c5918
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;
+}