All metadata and data extents are allocated here. A single btree holds
records for all of the extents allocated on the FS. It also records
backreferences from those extents to the objects that have references on
them.
Btree blocks for the extent allocation tree are allocated from the
extent allocation tree. This leads to some ugly recursion, which is
avoided by building up a list of pending allocations/deletions for the
extent allocation tree and processing them at safe times.
--- /dev/null 2008-06-10 15:56:50.000000000 -0400
+++ a/fs/btrfs/extent-tree.c 2009-01-08 09:56:31.803215082 -0500
@@ -0,0 +1,3336 @@
+/*
+ * 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 <linux/version.h>
+#include "compat.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"
+#include "compat.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 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
+ */
+static 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;
+ }
+ }
+ if (ret)
+ atomic_inc(&ret->count);
+ 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(block_group, start,
+ size);
+ BUG_ON(ret);
+ start = extent_end + 1;
+ } else {
+ break;
+ }
+ }
+
+ if (start < end) {
+ size = end - start;
+ ret = btrfs_add_free_space(block_group, start, size);
+ BUG_ON(ret);
+ }
+ mutex_unlock(&info->pinned_mutex);
+
+ return 0;
+}
+
+static int remove_sb_from_cache(struct btrfs_root *root,
+ struct btrfs_block_group_cache *cache)
+{
+ u64 bytenr;
+ u64 *logical;
+ int stripe_len;
+ int i, nr, ret;
+
+ for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
+ bytenr = btrfs_sb_offset(i);
+ ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
+ cache->key.objectid, bytenr, 0,
+ &logical, &nr, &stripe_len);
+ BUG_ON(ret);
+ while (nr--) {
+ btrfs_remove_free_space(cache, logical[nr],
+ stripe_len);
+ }
+ kfree(logical);
+ }
+ 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;
+
+ 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;
+ last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
+ key.objectid = last;
+ 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;
+
+ 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) {
+ add_new_free_space(block_group, root->fs_info, last,
+ key.objectid);
+
+ last = key.objectid + key.offset;
+ }
+next:
+ path->slots[0]++;
+ }
+
+ add_new_free_space(block_group, root->fs_info, last,
+ block_group->key.objectid +
+ block_group->key.offset);
+
+ remove_sb_from_cache(root, block_group);
+ block_group->cached = 1;
+ ret = 0;
+err:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * return the block group that starts at or after bytenr
+ */
+static 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 inline void put_block_group(struct btrfs_block_group_cache *cache)
+{
+ if (atomic_dec_and_test(&cache->count))
+ kfree(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;
+}
+
+u64 btrfs_find_block_group(struct btrfs_root *root,
+ u64 search_start, u64 search_hint, int owner)
+{
+ struct btrfs_block_group_cache *cache;
+ u64 used;
+ u64 last = max(search_hint, search_start);
+ u64 group_start = 0;
+ int full_search = 0;
+ int factor = 9;
+ int wrapped = 0;
+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 ((full_search || !cache->ro) &&
+ block_group_bits(cache, BTRFS_BLOCK_GROUP_METADATA)) {
+ if (used + cache->pinned + cache->reserved <
+ div_factor(cache->key.offset, factor)) {
+ group_start = cache->key.objectid;
+ spin_unlock(&cache->lock);
+ put_block_group(cache);
+ goto found;
+ }
+ }
+ spin_unlock(&cache->lock);
+ put_block_group(cache);
+ 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 group_start;
+}
+
+/* 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 noinline int 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 noinline int 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 "btrfs couldn't find %llu, parent %llu, "
+ "root %llu, owner %u\n",
+ (unsigned long long)op->bytenr,
+ (unsigned long long)op->orig_parent,
+ (unsigned long long)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 noinline int 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 noinline int 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 noinline int 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;
+}
+
+#ifdef BIO_RW_DISCARD
+static void btrfs_issue_discard(struct block_device *bdev,
+ u64 start, u64 len)
+{
+ blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL);
+}
+#endif
+
+static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
+ u64 num_bytes)
+{
+#ifdef BIO_RW_DISCARD
+ int ret;
+ u64 map_length = num_bytes;
+ struct btrfs_multi_bio *multi = NULL;
+
+ /* 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++) {
+ btrfs_issue_discard(stripe->dev->bdev,
+ stripe->physical,
+ map_length);
+ }
+ kfree(multi);
+ }
+
+ return ret;
+#else
+ return 0;
+#endif
+}
+
+static noinline int 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(KERN_ERR "btrfs unable to find backref byte nr %llu "
+ "root %llu gen %llu owner %u\n",
+ (unsigned long long)op->bytenr,
+ (unsigned long long)extent_root->root_key.objectid,
+ (unsigned long long)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(&info->delalloc_lock);
+ super_used = btrfs_super_bytes_used(&info->super_copy);
+ btrfs_set_super_bytes_used(&info->super_copy,
+ super_used - bytes_freed);
+
+ root_used = btrfs_root_used(&extent_root->root_item);
+ btrfs_set_root_used(&extent_root->root_item,
+ root_used - bytes_freed);
+ spin_unlock(&info->delalloc_lock);
+
+ /* 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;
+ 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);
+
+ 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(KERN_ERR "btrfs wanted %llu found %llu\n",
+ (unsigned long long)bytenr,
+ (unsigned long long)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(KERN_INFO "btrfs failed to find block number %llu\n",
+ (unsigned long long)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 objectid, 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) ||
+ objectid != btrfs_ref_objectid(leaf, ref_item)) {
+ 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;
+}
+
+int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
+{
+ struct btrfs_block_group_cache *block_group;
+ int readonly = 0;
+
+ block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
+ if (!block_group || block_group->ro)
+ readonly = 1;
+ if (block_group)
+ put_block_group(block_group);
+ return readonly;
+}
+
+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 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;
+ 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_discard_extent(root, bytenr,
+ num_bytes);
+ WARN_ON(ret);
+
+ ret = btrfs_add_free_space(cache, bytenr,
+ num_bytes);
+ WARN_ON(ret);
+ }
+ }
+ put_block_group(cache);
+ 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;
+ u64 bytenr;
+
+ cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
+ if (!cache)
+ return 0;
+
+ bytenr = cache->key.objectid;
+ put_block_group(cache);
+
+ return bytenr;
+}
+
+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);
+ }
+ put_block_group(cache);
+ 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);
+ put_block_group(cache);
+ 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;
+
+ ret = btrfs_discard_extent(root, start, end + 1 - start);
+
+ 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 ret;
+}
+
+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) {
+ u64 used;
+ 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);
+
+ spin_lock(&info->delalloc_lock);
+ used = btrfs_super_bytes_used(&info->super_copy);
+ btrfs_set_super_bytes_used(&info->super_copy,
+ used - extent_op->num_bytes);
+ used = btrfs_root_used(&extent_root->root_item);
+ btrfs_set_root_used(&extent_root->root_item,
+ used - extent_op->num_bytes);
+ spin_unlock(&info->delalloc_lock);
+
+ 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 %llu\n", ret,
+ (unsigned long long)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(KERN_ERR "btrfs unable to find ref byte nr %llu "
+ "root %llu gen %llu owner %llu\n",
+ (unsigned long long)bytenr,
+ (unsigned long long)root_objectid,
+ (unsigned long long)ref_generation,
+ (unsigned long long)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;
+
+ 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(&info->delalloc_lock);
+ super_used = btrfs_super_bytes_used(&info->super_copy);
+ btrfs_set_super_bytes_used(&info->super_copy,
+ super_used - num_bytes);
+
+ /* block accounting for root item */
+ root_used = btrfs_root_used(&root->root_item);
+ btrfs_set_root_used(&root->root_item,
+ root_used - num_bytes);
+ spin_unlock(&info->delalloc_lock);
+ ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
+ num_to_del);
+ BUG_ON(ret);
+ btrfs_release_path(extent_root, path);
+
+ if (owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
+ ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
+ BUG_ON(ret);
+ }
+
+ ret = update_block_group(trans, root, bytenr, num_bytes, 0,
+ mark_free);
+ BUG_ON(ret);
+ }
+ 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);
+ put_block_group(cache);
+ 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 noinline int 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;
+
+ if (unlikely(!block_group->cached)) {
+ mutex_lock(&block_group->cache_mutex);
+ ret = cache_block_group(root, block_group);
+ mutex_unlock(&block_group->cache_mutex);
+ if (ret)
+ break;
+ }
+
+ mutex_lock(&block_group->alloc_mutex);
+ if (unlikely(!block_group_bits(block_group, data)))
+ goto new_group;
+
+ if (unlikely(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);
+ put_block_group(block_group);
+ block_group = NULL;
+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);
+ atomic_inc(&block_group->count);
+
+ 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->key.objectid;
+
+ if (last_ptr)
+ *last_ptr = ins->objectid + ins->offset;
+ ret = 0;
+ } else if (!ret) {
+ printk(KERN_ERR "btrfs searching for %llu bytes, "
+ "num_bytes %llu, loop %d, allowed_alloc %d\n",
+ (unsigned long long)total_needed,
+ (unsigned long long)num_bytes,
+ loop, allowed_chunk_alloc);
+ ret = -ENOSPC;
+ }
+ if (block_group)
+ put_block_group(block_group);
+
+ 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 %llu free, is %sfull\n",
+ (unsigned long long)(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 %llu has %llu bytes, %llu used "
+ "%llu pinned %llu reserved\n",
+ (unsigned long long)cache->key.objectid,
+ (unsigned long long)cache->key.offset,
+ (unsigned long long)btrfs_block_group_used(&cache->item),
+ (unsigned long long)cache->pinned,
+ (unsigned long long)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(KERN_ERR "btrfs allocation failed flags %llu, "
+ "wanted %llu\n", (unsigned long long)data,
+ (unsigned long long)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;
+ int ret = 0;
+
+ cache = btrfs_lookup_block_group(root->fs_info, start);
+ if (!cache) {
+ printk(KERN_ERR "Unable to find block group for %llu\n",
+ (unsigned long long)start);
+ return -ENOSPC;
+ }
+
+ ret = btrfs_discard_extent(root, start, len);
+
+ btrfs_add_free_space(cache, start, len);
+ put_block_group(cache);
+ update_reserved_extents(root, start, len, 0);
+
+ return ret;
+}
+
+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(&info->delalloc_lock);
+ super_used = btrfs_super_bytes_used(&info->super_copy);
+ btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
+
+ /* block accounting for root item */
+ root_used = btrfs_root_used(&root->root_item);
+ btrfs_set_root_used(&root->root_item, root_used + num_bytes);
+ spin_unlock(&info->delalloc_lock);
+
+ 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(KERN_ERR "btrfs update block group failed for %llu "
+ "%llu\n", (unsigned long long)ins->objectid,
+ (unsigned long long)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->cache_mutex);
+ cache_block_group(root, block_group);
+ mutex_unlock(&block_group->cache_mutex);
+
+ ret = btrfs_remove_free_space(block_group, ins->objectid,
+ ins->offset);
+ BUG_ON(ret);
+ put_block_group(block_group);
+ 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;
+}
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
