forked from luck/tmp_suning_uos_patched
a213501153
Extent alloctions are still protected by a large alloc_mutex. Objectid allocations are covered by a objectid mutex Other btree operations are protected by a lock on individual btree nodes Signed-off-by: Chris Mason <chris.mason@oracle.com>
141 lines
3.4 KiB
C
141 lines
3.4 KiB
C
/*
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* Copyright (C) 2007 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#include "ctree.h"
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#include "disk-io.h"
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#include "transaction.h"
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int btrfs_find_highest_inode(struct btrfs_root *root, u64 *objectid)
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{
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struct btrfs_path *path;
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int ret;
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struct extent_buffer *l;
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struct btrfs_key search_key;
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struct btrfs_key found_key;
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int slot;
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path = btrfs_alloc_path();
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BUG_ON(!path);
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search_key.objectid = (u64)-1;
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search_key.offset = (u64)-1;
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ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
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if (ret < 0)
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goto error;
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BUG_ON(ret == 0);
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if (path->slots[0] > 0) {
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slot = path->slots[0] - 1;
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l = path->nodes[0];
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btrfs_item_key_to_cpu(l, &found_key, slot);
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*objectid = found_key.objectid;
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} else {
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*objectid = BTRFS_FIRST_FREE_OBJECTID;
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}
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ret = 0;
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error:
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btrfs_free_path(path);
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return ret;
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}
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/*
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* walks the btree of allocated inodes and find a hole.
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*/
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int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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u64 dirid, u64 *objectid)
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{
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struct btrfs_path *path;
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struct btrfs_key key;
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int ret;
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int slot = 0;
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u64 last_ino = 0;
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int start_found;
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struct extent_buffer *l;
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struct btrfs_key search_key;
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u64 search_start = dirid;
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mutex_lock(&root->objectid_mutex);
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if (root->last_inode_alloc) {
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*objectid = ++root->last_inode_alloc;
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mutex_unlock(&root->objectid_mutex);
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return 0;
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}
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path = btrfs_alloc_path();
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BUG_ON(!path);
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search_start = root->last_inode_alloc;
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search_start = max(search_start, BTRFS_FIRST_FREE_OBJECTID);
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search_key.objectid = search_start;
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search_key.offset = 0;
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btrfs_init_path(path);
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start_found = 0;
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ret = btrfs_search_slot(trans, root, &search_key, path, 0, 0);
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if (ret < 0)
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goto error;
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if (path->slots[0] > 0)
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path->slots[0]--;
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while (1) {
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l = path->nodes[0];
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slot = path->slots[0];
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if (slot >= btrfs_header_nritems(l)) {
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ret = btrfs_next_leaf(root, path);
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if (ret == 0)
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continue;
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if (ret < 0)
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goto error;
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if (!start_found) {
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*objectid = search_start;
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start_found = 1;
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goto found;
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}
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*objectid = last_ino > search_start ?
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last_ino : search_start;
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goto found;
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}
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btrfs_item_key_to_cpu(l, &key, slot);
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if (key.objectid >= search_start) {
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if (start_found) {
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if (last_ino < search_start)
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last_ino = search_start;
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if (key.objectid > last_ino) {
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*objectid = last_ino;
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goto found;
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}
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}
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}
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start_found = 1;
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last_ino = key.objectid + 1;
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path->slots[0]++;
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}
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// FIXME -ENOSPC
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found:
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root->last_inode_alloc = *objectid;
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btrfs_release_path(root, path);
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btrfs_free_path(path);
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BUG_ON(*objectid < search_start);
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mutex_unlock(&root->objectid_mutex);
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return 0;
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error:
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btrfs_release_path(root, path);
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btrfs_free_path(path);
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mutex_unlock(&root->objectid_mutex);
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return ret;
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}
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