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103c19723c
The code used by btrfs_submit_bio only interacts with the rest of volumes.c through __btrfs_map_block (which itself is a more generic version of two exported helpers) and does not really have anything to do with volumes.c. Create a new bio.c file and a bio.h header going along with it for the btrfs_bio-based storage layer, which will grow even more going forward. Also update the file with my copyright notice given that a large part of the moved code was written or rewritten by me. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
4526 lines
114 KiB
C
4526 lines
114 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2009 Oracle. All rights reserved.
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*/
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#include <linux/sched.h>
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#include <linux/pagemap.h>
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#include <linux/writeback.h>
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#include <linux/blkdev.h>
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#include <linux/rbtree.h>
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#include <linux/slab.h>
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#include <linux/error-injection.h>
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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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#include "volumes.h"
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#include "locking.h"
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#include "btrfs_inode.h"
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#include "async-thread.h"
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#include "free-space-cache.h"
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#include "qgroup.h"
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#include "print-tree.h"
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#include "delalloc-space.h"
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#include "block-group.h"
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#include "backref.h"
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#include "misc.h"
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#include "subpage.h"
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#include "zoned.h"
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#include "inode-item.h"
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#include "space-info.h"
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#include "fs.h"
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#include "accessors.h"
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#include "extent-tree.h"
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#include "root-tree.h"
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#include "file-item.h"
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#include "relocation.h"
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#include "super.h"
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#include "tree-checker.h"
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/*
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* Relocation overview
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*
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* [What does relocation do]
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*
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* The objective of relocation is to relocate all extents of the target block
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* group to other block groups.
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* This is utilized by resize (shrink only), profile converting, compacting
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* space, or balance routine to spread chunks over devices.
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*
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* Before | After
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* ------------------------------------------------------------------
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* BG A: 10 data extents | BG A: deleted
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* BG B: 2 data extents | BG B: 10 data extents (2 old + 8 relocated)
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* BG C: 1 extents | BG C: 3 data extents (1 old + 2 relocated)
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*
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* [How does relocation work]
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*
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* 1. Mark the target block group read-only
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* New extents won't be allocated from the target block group.
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*
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* 2.1 Record each extent in the target block group
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* To build a proper map of extents to be relocated.
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*
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* 2.2 Build data reloc tree and reloc trees
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* Data reloc tree will contain an inode, recording all newly relocated
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* data extents.
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* There will be only one data reloc tree for one data block group.
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*
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* Reloc tree will be a special snapshot of its source tree, containing
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* relocated tree blocks.
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* Each tree referring to a tree block in target block group will get its
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* reloc tree built.
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*
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* 2.3 Swap source tree with its corresponding reloc tree
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* Each involved tree only refers to new extents after swap.
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*
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* 3. Cleanup reloc trees and data reloc tree.
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* As old extents in the target block group are still referenced by reloc
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* trees, we need to clean them up before really freeing the target block
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* group.
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*
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* The main complexity is in steps 2.2 and 2.3.
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*
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* The entry point of relocation is relocate_block_group() function.
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*/
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#define RELOCATION_RESERVED_NODES 256
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/*
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* map address of tree root to tree
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*/
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struct mapping_node {
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struct {
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struct rb_node rb_node;
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u64 bytenr;
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}; /* Use rb_simle_node for search/insert */
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void *data;
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};
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struct mapping_tree {
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struct rb_root rb_root;
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spinlock_t lock;
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};
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/*
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* present a tree block to process
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*/
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struct tree_block {
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struct {
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struct rb_node rb_node;
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u64 bytenr;
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}; /* Use rb_simple_node for search/insert */
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u64 owner;
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struct btrfs_key key;
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unsigned int level:8;
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unsigned int key_ready:1;
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};
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#define MAX_EXTENTS 128
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struct file_extent_cluster {
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u64 start;
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u64 end;
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u64 boundary[MAX_EXTENTS];
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unsigned int nr;
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};
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struct reloc_control {
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/* block group to relocate */
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struct btrfs_block_group *block_group;
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/* extent tree */
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struct btrfs_root *extent_root;
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/* inode for moving data */
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struct inode *data_inode;
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struct btrfs_block_rsv *block_rsv;
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struct btrfs_backref_cache backref_cache;
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struct file_extent_cluster cluster;
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/* tree blocks have been processed */
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struct extent_io_tree processed_blocks;
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/* map start of tree root to corresponding reloc tree */
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struct mapping_tree reloc_root_tree;
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/* list of reloc trees */
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struct list_head reloc_roots;
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/* list of subvolume trees that get relocated */
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struct list_head dirty_subvol_roots;
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/* size of metadata reservation for merging reloc trees */
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u64 merging_rsv_size;
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/* size of relocated tree nodes */
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u64 nodes_relocated;
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/* reserved size for block group relocation*/
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u64 reserved_bytes;
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u64 search_start;
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u64 extents_found;
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unsigned int stage:8;
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unsigned int create_reloc_tree:1;
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unsigned int merge_reloc_tree:1;
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unsigned int found_file_extent:1;
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};
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/* stages of data relocation */
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#define MOVE_DATA_EXTENTS 0
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#define UPDATE_DATA_PTRS 1
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static void mark_block_processed(struct reloc_control *rc,
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struct btrfs_backref_node *node)
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{
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u32 blocksize;
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if (node->level == 0 ||
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in_range(node->bytenr, rc->block_group->start,
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rc->block_group->length)) {
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blocksize = rc->extent_root->fs_info->nodesize;
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set_extent_bits(&rc->processed_blocks, node->bytenr,
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node->bytenr + blocksize - 1, EXTENT_DIRTY);
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}
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node->processed = 1;
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}
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static void mapping_tree_init(struct mapping_tree *tree)
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{
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tree->rb_root = RB_ROOT;
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spin_lock_init(&tree->lock);
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}
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/*
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* walk up backref nodes until reach node presents tree root
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*/
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static struct btrfs_backref_node *walk_up_backref(
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struct btrfs_backref_node *node,
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struct btrfs_backref_edge *edges[], int *index)
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{
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struct btrfs_backref_edge *edge;
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int idx = *index;
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while (!list_empty(&node->upper)) {
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edge = list_entry(node->upper.next,
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struct btrfs_backref_edge, list[LOWER]);
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edges[idx++] = edge;
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node = edge->node[UPPER];
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}
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BUG_ON(node->detached);
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*index = idx;
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return node;
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}
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/*
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* walk down backref nodes to find start of next reference path
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*/
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static struct btrfs_backref_node *walk_down_backref(
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struct btrfs_backref_edge *edges[], int *index)
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{
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struct btrfs_backref_edge *edge;
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struct btrfs_backref_node *lower;
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int idx = *index;
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while (idx > 0) {
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edge = edges[idx - 1];
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lower = edge->node[LOWER];
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if (list_is_last(&edge->list[LOWER], &lower->upper)) {
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idx--;
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continue;
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}
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edge = list_entry(edge->list[LOWER].next,
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struct btrfs_backref_edge, list[LOWER]);
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edges[idx - 1] = edge;
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*index = idx;
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return edge->node[UPPER];
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}
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*index = 0;
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return NULL;
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}
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static void update_backref_node(struct btrfs_backref_cache *cache,
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struct btrfs_backref_node *node, u64 bytenr)
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{
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struct rb_node *rb_node;
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rb_erase(&node->rb_node, &cache->rb_root);
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node->bytenr = bytenr;
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rb_node = rb_simple_insert(&cache->rb_root, node->bytenr, &node->rb_node);
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if (rb_node)
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btrfs_backref_panic(cache->fs_info, bytenr, -EEXIST);
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}
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/*
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* update backref cache after a transaction commit
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*/
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static int update_backref_cache(struct btrfs_trans_handle *trans,
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struct btrfs_backref_cache *cache)
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{
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struct btrfs_backref_node *node;
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int level = 0;
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if (cache->last_trans == 0) {
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cache->last_trans = trans->transid;
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return 0;
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}
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if (cache->last_trans == trans->transid)
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return 0;
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/*
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* detached nodes are used to avoid unnecessary backref
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* lookup. transaction commit changes the extent tree.
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* so the detached nodes are no longer useful.
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*/
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while (!list_empty(&cache->detached)) {
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node = list_entry(cache->detached.next,
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struct btrfs_backref_node, list);
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btrfs_backref_cleanup_node(cache, node);
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}
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while (!list_empty(&cache->changed)) {
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node = list_entry(cache->changed.next,
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struct btrfs_backref_node, list);
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list_del_init(&node->list);
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BUG_ON(node->pending);
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update_backref_node(cache, node, node->new_bytenr);
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}
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/*
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* some nodes can be left in the pending list if there were
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* errors during processing the pending nodes.
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*/
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for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
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list_for_each_entry(node, &cache->pending[level], list) {
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BUG_ON(!node->pending);
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if (node->bytenr == node->new_bytenr)
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continue;
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update_backref_node(cache, node, node->new_bytenr);
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}
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}
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cache->last_trans = 0;
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return 1;
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}
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static bool reloc_root_is_dead(struct btrfs_root *root)
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{
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/*
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* Pair with set_bit/clear_bit in clean_dirty_subvols and
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* btrfs_update_reloc_root. We need to see the updated bit before
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* trying to access reloc_root
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*/
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smp_rmb();
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if (test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state))
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return true;
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return false;
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}
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/*
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* Check if this subvolume tree has valid reloc tree.
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*
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* Reloc tree after swap is considered dead, thus not considered as valid.
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* This is enough for most callers, as they don't distinguish dead reloc root
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* from no reloc root. But btrfs_should_ignore_reloc_root() below is a
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* special case.
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*/
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static bool have_reloc_root(struct btrfs_root *root)
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{
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if (reloc_root_is_dead(root))
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return false;
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if (!root->reloc_root)
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return false;
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return true;
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}
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int btrfs_should_ignore_reloc_root(struct btrfs_root *root)
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{
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struct btrfs_root *reloc_root;
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if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
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return 0;
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/* This root has been merged with its reloc tree, we can ignore it */
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if (reloc_root_is_dead(root))
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return 1;
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reloc_root = root->reloc_root;
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if (!reloc_root)
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return 0;
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if (btrfs_header_generation(reloc_root->commit_root) ==
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root->fs_info->running_transaction->transid)
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return 0;
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/*
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* if there is reloc tree and it was created in previous
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* transaction backref lookup can find the reloc tree,
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* so backref node for the fs tree root is useless for
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* relocation.
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*/
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return 1;
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}
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/*
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* find reloc tree by address of tree root
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*/
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struct btrfs_root *find_reloc_root(struct btrfs_fs_info *fs_info, u64 bytenr)
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{
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struct reloc_control *rc = fs_info->reloc_ctl;
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struct rb_node *rb_node;
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struct mapping_node *node;
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struct btrfs_root *root = NULL;
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ASSERT(rc);
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spin_lock(&rc->reloc_root_tree.lock);
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rb_node = rb_simple_search(&rc->reloc_root_tree.rb_root, bytenr);
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if (rb_node) {
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node = rb_entry(rb_node, struct mapping_node, rb_node);
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root = node->data;
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}
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spin_unlock(&rc->reloc_root_tree.lock);
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return btrfs_grab_root(root);
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}
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/*
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* For useless nodes, do two major clean ups:
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*
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* - Cleanup the children edges and nodes
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* If child node is also orphan (no parent) during cleanup, then the child
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* node will also be cleaned up.
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*
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* - Freeing up leaves (level 0), keeps nodes detached
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* For nodes, the node is still cached as "detached"
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*
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* Return false if @node is not in the @useless_nodes list.
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* Return true if @node is in the @useless_nodes list.
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*/
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static bool handle_useless_nodes(struct reloc_control *rc,
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struct btrfs_backref_node *node)
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{
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struct btrfs_backref_cache *cache = &rc->backref_cache;
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struct list_head *useless_node = &cache->useless_node;
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bool ret = false;
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while (!list_empty(useless_node)) {
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struct btrfs_backref_node *cur;
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cur = list_first_entry(useless_node, struct btrfs_backref_node,
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list);
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list_del_init(&cur->list);
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/* Only tree root nodes can be added to @useless_nodes */
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ASSERT(list_empty(&cur->upper));
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if (cur == node)
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ret = true;
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/* The node is the lowest node */
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if (cur->lowest) {
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list_del_init(&cur->lower);
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cur->lowest = 0;
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}
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/* Cleanup the lower edges */
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while (!list_empty(&cur->lower)) {
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struct btrfs_backref_edge *edge;
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struct btrfs_backref_node *lower;
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edge = list_entry(cur->lower.next,
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struct btrfs_backref_edge, list[UPPER]);
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list_del(&edge->list[UPPER]);
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list_del(&edge->list[LOWER]);
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lower = edge->node[LOWER];
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btrfs_backref_free_edge(cache, edge);
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/* Child node is also orphan, queue for cleanup */
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if (list_empty(&lower->upper))
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list_add(&lower->list, useless_node);
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}
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/* Mark this block processed for relocation */
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mark_block_processed(rc, cur);
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|
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/*
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* Backref nodes for tree leaves are deleted from the cache.
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* Backref nodes for upper level tree blocks are left in the
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* cache to avoid unnecessary backref lookup.
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*/
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if (cur->level > 0) {
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list_add(&cur->list, &cache->detached);
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cur->detached = 1;
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} else {
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rb_erase(&cur->rb_node, &cache->rb_root);
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btrfs_backref_free_node(cache, cur);
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}
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}
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return ret;
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}
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/*
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* Build backref tree for a given tree block. Root of the backref tree
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* corresponds the tree block, leaves of the backref tree correspond roots of
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* b-trees that reference the tree block.
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*
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* The basic idea of this function is check backrefs of a given block to find
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* upper level blocks that reference the block, and then check backrefs of
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* these upper level blocks recursively. The recursion stops when tree root is
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* reached or backrefs for the block is cached.
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*
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* NOTE: if we find that backrefs for a block are cached, we know backrefs for
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* all upper level blocks that directly/indirectly reference the block are also
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* cached.
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*/
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static noinline_for_stack struct btrfs_backref_node *build_backref_tree(
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struct reloc_control *rc, struct btrfs_key *node_key,
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int level, u64 bytenr)
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{
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struct btrfs_backref_iter *iter;
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struct btrfs_backref_cache *cache = &rc->backref_cache;
|
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/* For searching parent of TREE_BLOCK_REF */
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struct btrfs_path *path;
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struct btrfs_backref_node *cur;
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struct btrfs_backref_node *node = NULL;
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struct btrfs_backref_edge *edge;
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int ret;
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int err = 0;
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|
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iter = btrfs_backref_iter_alloc(rc->extent_root->fs_info);
|
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if (!iter)
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return ERR_PTR(-ENOMEM);
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path = btrfs_alloc_path();
|
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if (!path) {
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err = -ENOMEM;
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goto out;
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}
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node = btrfs_backref_alloc_node(cache, bytenr, level);
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if (!node) {
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err = -ENOMEM;
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goto out;
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}
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|
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node->lowest = 1;
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cur = node;
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|
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/* Breadth-first search to build backref cache */
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do {
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ret = btrfs_backref_add_tree_node(cache, path, iter, node_key,
|
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cur);
|
|
if (ret < 0) {
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err = ret;
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goto out;
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|
}
|
|
edge = list_first_entry_or_null(&cache->pending_edge,
|
|
struct btrfs_backref_edge, list[UPPER]);
|
|
/*
|
|
* The pending list isn't empty, take the first block to
|
|
* process
|
|
*/
|
|
if (edge) {
|
|
list_del_init(&edge->list[UPPER]);
|
|
cur = edge->node[UPPER];
|
|
}
|
|
} while (edge);
|
|
|
|
/* Finish the upper linkage of newly added edges/nodes */
|
|
ret = btrfs_backref_finish_upper_links(cache, node);
|
|
if (ret < 0) {
|
|
err = ret;
|
|
goto out;
|
|
}
|
|
|
|
if (handle_useless_nodes(rc, node))
|
|
node = NULL;
|
|
out:
|
|
btrfs_backref_iter_free(iter);
|
|
btrfs_free_path(path);
|
|
if (err) {
|
|
btrfs_backref_error_cleanup(cache, node);
|
|
return ERR_PTR(err);
|
|
}
|
|
ASSERT(!node || !node->detached);
|
|
ASSERT(list_empty(&cache->useless_node) &&
|
|
list_empty(&cache->pending_edge));
|
|
return node;
|
|
}
|
|
|
|
/*
|
|
* helper to add backref node for the newly created snapshot.
|
|
* the backref node is created by cloning backref node that
|
|
* corresponds to root of source tree
|
|
*/
|
|
static int clone_backref_node(struct btrfs_trans_handle *trans,
|
|
struct reloc_control *rc,
|
|
struct btrfs_root *src,
|
|
struct btrfs_root *dest)
|
|
{
|
|
struct btrfs_root *reloc_root = src->reloc_root;
|
|
struct btrfs_backref_cache *cache = &rc->backref_cache;
|
|
struct btrfs_backref_node *node = NULL;
|
|
struct btrfs_backref_node *new_node;
|
|
struct btrfs_backref_edge *edge;
|
|
struct btrfs_backref_edge *new_edge;
|
|
struct rb_node *rb_node;
|
|
|
|
if (cache->last_trans > 0)
|
|
update_backref_cache(trans, cache);
|
|
|
|
rb_node = rb_simple_search(&cache->rb_root, src->commit_root->start);
|
|
if (rb_node) {
|
|
node = rb_entry(rb_node, struct btrfs_backref_node, rb_node);
|
|
if (node->detached)
|
|
node = NULL;
|
|
else
|
|
BUG_ON(node->new_bytenr != reloc_root->node->start);
|
|
}
|
|
|
|
if (!node) {
|
|
rb_node = rb_simple_search(&cache->rb_root,
|
|
reloc_root->commit_root->start);
|
|
if (rb_node) {
|
|
node = rb_entry(rb_node, struct btrfs_backref_node,
|
|
rb_node);
|
|
BUG_ON(node->detached);
|
|
}
|
|
}
|
|
|
|
if (!node)
|
|
return 0;
|
|
|
|
new_node = btrfs_backref_alloc_node(cache, dest->node->start,
|
|
node->level);
|
|
if (!new_node)
|
|
return -ENOMEM;
|
|
|
|
new_node->lowest = node->lowest;
|
|
new_node->checked = 1;
|
|
new_node->root = btrfs_grab_root(dest);
|
|
ASSERT(new_node->root);
|
|
|
|
if (!node->lowest) {
|
|
list_for_each_entry(edge, &node->lower, list[UPPER]) {
|
|
new_edge = btrfs_backref_alloc_edge(cache);
|
|
if (!new_edge)
|
|
goto fail;
|
|
|
|
btrfs_backref_link_edge(new_edge, edge->node[LOWER],
|
|
new_node, LINK_UPPER);
|
|
}
|
|
} else {
|
|
list_add_tail(&new_node->lower, &cache->leaves);
|
|
}
|
|
|
|
rb_node = rb_simple_insert(&cache->rb_root, new_node->bytenr,
|
|
&new_node->rb_node);
|
|
if (rb_node)
|
|
btrfs_backref_panic(trans->fs_info, new_node->bytenr, -EEXIST);
|
|
|
|
if (!new_node->lowest) {
|
|
list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
|
|
list_add_tail(&new_edge->list[LOWER],
|
|
&new_edge->node[LOWER]->upper);
|
|
}
|
|
}
|
|
return 0;
|
|
fail:
|
|
while (!list_empty(&new_node->lower)) {
|
|
new_edge = list_entry(new_node->lower.next,
|
|
struct btrfs_backref_edge, list[UPPER]);
|
|
list_del(&new_edge->list[UPPER]);
|
|
btrfs_backref_free_edge(cache, new_edge);
|
|
}
|
|
btrfs_backref_free_node(cache, new_node);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/*
|
|
* helper to add 'address of tree root -> reloc tree' mapping
|
|
*/
|
|
static int __must_check __add_reloc_root(struct btrfs_root *root)
|
|
{
|
|
struct btrfs_fs_info *fs_info = root->fs_info;
|
|
struct rb_node *rb_node;
|
|
struct mapping_node *node;
|
|
struct reloc_control *rc = fs_info->reloc_ctl;
|
|
|
|
node = kmalloc(sizeof(*node), GFP_NOFS);
|
|
if (!node)
|
|
return -ENOMEM;
|
|
|
|
node->bytenr = root->commit_root->start;
|
|
node->data = root;
|
|
|
|
spin_lock(&rc->reloc_root_tree.lock);
|
|
rb_node = rb_simple_insert(&rc->reloc_root_tree.rb_root,
|
|
node->bytenr, &node->rb_node);
|
|
spin_unlock(&rc->reloc_root_tree.lock);
|
|
if (rb_node) {
|
|
btrfs_err(fs_info,
|
|
"Duplicate root found for start=%llu while inserting into relocation tree",
|
|
node->bytenr);
|
|
return -EEXIST;
|
|
}
|
|
|
|
list_add_tail(&root->root_list, &rc->reloc_roots);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* helper to delete the 'address of tree root -> reloc tree'
|
|
* mapping
|
|
*/
|
|
static void __del_reloc_root(struct btrfs_root *root)
|
|
{
|
|
struct btrfs_fs_info *fs_info = root->fs_info;
|
|
struct rb_node *rb_node;
|
|
struct mapping_node *node = NULL;
|
|
struct reloc_control *rc = fs_info->reloc_ctl;
|
|
bool put_ref = false;
|
|
|
|
if (rc && root->node) {
|
|
spin_lock(&rc->reloc_root_tree.lock);
|
|
rb_node = rb_simple_search(&rc->reloc_root_tree.rb_root,
|
|
root->commit_root->start);
|
|
if (rb_node) {
|
|
node = rb_entry(rb_node, struct mapping_node, rb_node);
|
|
rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
|
|
RB_CLEAR_NODE(&node->rb_node);
|
|
}
|
|
spin_unlock(&rc->reloc_root_tree.lock);
|
|
ASSERT(!node || (struct btrfs_root *)node->data == root);
|
|
}
|
|
|
|
/*
|
|
* We only put the reloc root here if it's on the list. There's a lot
|
|
* of places where the pattern is to splice the rc->reloc_roots, process
|
|
* the reloc roots, and then add the reloc root back onto
|
|
* rc->reloc_roots. If we call __del_reloc_root while it's off of the
|
|
* list we don't want the reference being dropped, because the guy
|
|
* messing with the list is in charge of the reference.
|
|
*/
|
|
spin_lock(&fs_info->trans_lock);
|
|
if (!list_empty(&root->root_list)) {
|
|
put_ref = true;
|
|
list_del_init(&root->root_list);
|
|
}
|
|
spin_unlock(&fs_info->trans_lock);
|
|
if (put_ref)
|
|
btrfs_put_root(root);
|
|
kfree(node);
|
|
}
|
|
|
|
/*
|
|
* helper to update the 'address of tree root -> reloc tree'
|
|
* mapping
|
|
*/
|
|
static int __update_reloc_root(struct btrfs_root *root)
|
|
{
|
|
struct btrfs_fs_info *fs_info = root->fs_info;
|
|
struct rb_node *rb_node;
|
|
struct mapping_node *node = NULL;
|
|
struct reloc_control *rc = fs_info->reloc_ctl;
|
|
|
|
spin_lock(&rc->reloc_root_tree.lock);
|
|
rb_node = rb_simple_search(&rc->reloc_root_tree.rb_root,
|
|
root->commit_root->start);
|
|
if (rb_node) {
|
|
node = rb_entry(rb_node, struct mapping_node, rb_node);
|
|
rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
|
|
}
|
|
spin_unlock(&rc->reloc_root_tree.lock);
|
|
|
|
if (!node)
|
|
return 0;
|
|
BUG_ON((struct btrfs_root *)node->data != root);
|
|
|
|
spin_lock(&rc->reloc_root_tree.lock);
|
|
node->bytenr = root->node->start;
|
|
rb_node = rb_simple_insert(&rc->reloc_root_tree.rb_root,
|
|
node->bytenr, &node->rb_node);
|
|
spin_unlock(&rc->reloc_root_tree.lock);
|
|
if (rb_node)
|
|
btrfs_backref_panic(fs_info, node->bytenr, -EEXIST);
|
|
return 0;
|
|
}
|
|
|
|
static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
|
|
struct btrfs_root *root, u64 objectid)
|
|
{
|
|
struct btrfs_fs_info *fs_info = root->fs_info;
|
|
struct btrfs_root *reloc_root;
|
|
struct extent_buffer *eb;
|
|
struct btrfs_root_item *root_item;
|
|
struct btrfs_key root_key;
|
|
int ret = 0;
|
|
bool must_abort = false;
|
|
|
|
root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
|
|
if (!root_item)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
|
|
root_key.type = BTRFS_ROOT_ITEM_KEY;
|
|
root_key.offset = objectid;
|
|
|
|
if (root->root_key.objectid == objectid) {
|
|
u64 commit_root_gen;
|
|
|
|
/* called by btrfs_init_reloc_root */
|
|
ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
|
|
BTRFS_TREE_RELOC_OBJECTID);
|
|
if (ret)
|
|
goto fail;
|
|
|
|
/*
|
|
* Set the last_snapshot field to the generation of the commit
|
|
* root - like this ctree.c:btrfs_block_can_be_shared() behaves
|
|
* correctly (returns true) when the relocation root is created
|
|
* either inside the critical section of a transaction commit
|
|
* (through transaction.c:qgroup_account_snapshot()) and when
|
|
* it's created before the transaction commit is started.
|
|
*/
|
|
commit_root_gen = btrfs_header_generation(root->commit_root);
|
|
btrfs_set_root_last_snapshot(&root->root_item, commit_root_gen);
|
|
} else {
|
|
/*
|
|
* called by btrfs_reloc_post_snapshot_hook.
|
|
* the source tree is a reloc tree, all tree blocks
|
|
* modified after it was created have RELOC flag
|
|
* set in their headers. so it's OK to not update
|
|
* the 'last_snapshot'.
|
|
*/
|
|
ret = btrfs_copy_root(trans, root, root->node, &eb,
|
|
BTRFS_TREE_RELOC_OBJECTID);
|
|
if (ret)
|
|
goto fail;
|
|
}
|
|
|
|
/*
|
|
* We have changed references at this point, we must abort the
|
|
* transaction if anything fails.
|
|
*/
|
|
must_abort = true;
|
|
|
|
memcpy(root_item, &root->root_item, sizeof(*root_item));
|
|
btrfs_set_root_bytenr(root_item, eb->start);
|
|
btrfs_set_root_level(root_item, btrfs_header_level(eb));
|
|
btrfs_set_root_generation(root_item, trans->transid);
|
|
|
|
if (root->root_key.objectid == objectid) {
|
|
btrfs_set_root_refs(root_item, 0);
|
|
memset(&root_item->drop_progress, 0,
|
|
sizeof(struct btrfs_disk_key));
|
|
btrfs_set_root_drop_level(root_item, 0);
|
|
}
|
|
|
|
btrfs_tree_unlock(eb);
|
|
free_extent_buffer(eb);
|
|
|
|
ret = btrfs_insert_root(trans, fs_info->tree_root,
|
|
&root_key, root_item);
|
|
if (ret)
|
|
goto fail;
|
|
|
|
kfree(root_item);
|
|
|
|
reloc_root = btrfs_read_tree_root(fs_info->tree_root, &root_key);
|
|
if (IS_ERR(reloc_root)) {
|
|
ret = PTR_ERR(reloc_root);
|
|
goto abort;
|
|
}
|
|
set_bit(BTRFS_ROOT_SHAREABLE, &reloc_root->state);
|
|
reloc_root->last_trans = trans->transid;
|
|
return reloc_root;
|
|
fail:
|
|
kfree(root_item);
|
|
abort:
|
|
if (must_abort)
|
|
btrfs_abort_transaction(trans, ret);
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
/*
|
|
* create reloc tree for a given fs tree. reloc tree is just a
|
|
* snapshot of the fs tree with special root objectid.
|
|
*
|
|
* The reloc_root comes out of here with two references, one for
|
|
* root->reloc_root, and another for being on the rc->reloc_roots list.
|
|
*/
|
|
int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
|
|
struct btrfs_root *root)
|
|
{
|
|
struct btrfs_fs_info *fs_info = root->fs_info;
|
|
struct btrfs_root *reloc_root;
|
|
struct reloc_control *rc = fs_info->reloc_ctl;
|
|
struct btrfs_block_rsv *rsv;
|
|
int clear_rsv = 0;
|
|
int ret;
|
|
|
|
if (!rc)
|
|
return 0;
|
|
|
|
/*
|
|
* The subvolume has reloc tree but the swap is finished, no need to
|
|
* create/update the dead reloc tree
|
|
*/
|
|
if (reloc_root_is_dead(root))
|
|
return 0;
|
|
|
|
/*
|
|
* This is subtle but important. We do not do
|
|
* record_root_in_transaction for reloc roots, instead we record their
|
|
* corresponding fs root, and then here we update the last trans for the
|
|
* reloc root. This means that we have to do this for the entire life
|
|
* of the reloc root, regardless of which stage of the relocation we are
|
|
* in.
|
|
*/
|
|
if (root->reloc_root) {
|
|
reloc_root = root->reloc_root;
|
|
reloc_root->last_trans = trans->transid;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* We are merging reloc roots, we do not need new reloc trees. Also
|
|
* reloc trees never need their own reloc tree.
|
|
*/
|
|
if (!rc->create_reloc_tree ||
|
|
root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
|
|
return 0;
|
|
|
|
if (!trans->reloc_reserved) {
|
|
rsv = trans->block_rsv;
|
|
trans->block_rsv = rc->block_rsv;
|
|
clear_rsv = 1;
|
|
}
|
|
reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
|
|
if (clear_rsv)
|
|
trans->block_rsv = rsv;
|
|
if (IS_ERR(reloc_root))
|
|
return PTR_ERR(reloc_root);
|
|
|
|
ret = __add_reloc_root(reloc_root);
|
|
ASSERT(ret != -EEXIST);
|
|
if (ret) {
|
|
/* Pairs with create_reloc_root */
|
|
btrfs_put_root(reloc_root);
|
|
return ret;
|
|
}
|
|
root->reloc_root = btrfs_grab_root(reloc_root);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* update root item of reloc tree
|
|
*/
|
|
int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
|
|
struct btrfs_root *root)
|
|
{
|
|
struct btrfs_fs_info *fs_info = root->fs_info;
|
|
struct btrfs_root *reloc_root;
|
|
struct btrfs_root_item *root_item;
|
|
int ret;
|
|
|
|
if (!have_reloc_root(root))
|
|
return 0;
|
|
|
|
reloc_root = root->reloc_root;
|
|
root_item = &reloc_root->root_item;
|
|
|
|
/*
|
|
* We are probably ok here, but __del_reloc_root() will drop its ref of
|
|
* the root. We have the ref for root->reloc_root, but just in case
|
|
* hold it while we update the reloc root.
|
|
*/
|
|
btrfs_grab_root(reloc_root);
|
|
|
|
/* root->reloc_root will stay until current relocation finished */
|
|
if (fs_info->reloc_ctl->merge_reloc_tree &&
|
|
btrfs_root_refs(root_item) == 0) {
|
|
set_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state);
|
|
/*
|
|
* Mark the tree as dead before we change reloc_root so
|
|
* have_reloc_root will not touch it from now on.
|
|
*/
|
|
smp_wmb();
|
|
__del_reloc_root(reloc_root);
|
|
}
|
|
|
|
if (reloc_root->commit_root != reloc_root->node) {
|
|
__update_reloc_root(reloc_root);
|
|
btrfs_set_root_node(root_item, reloc_root->node);
|
|
free_extent_buffer(reloc_root->commit_root);
|
|
reloc_root->commit_root = btrfs_root_node(reloc_root);
|
|
}
|
|
|
|
ret = btrfs_update_root(trans, fs_info->tree_root,
|
|
&reloc_root->root_key, root_item);
|
|
btrfs_put_root(reloc_root);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* helper to find first cached inode with inode number >= objectid
|
|
* in a subvolume
|
|
*/
|
|
static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
|
|
{
|
|
struct rb_node *node;
|
|
struct rb_node *prev;
|
|
struct btrfs_inode *entry;
|
|
struct inode *inode;
|
|
|
|
spin_lock(&root->inode_lock);
|
|
again:
|
|
node = root->inode_tree.rb_node;
|
|
prev = NULL;
|
|
while (node) {
|
|
prev = node;
|
|
entry = rb_entry(node, struct btrfs_inode, rb_node);
|
|
|
|
if (objectid < btrfs_ino(entry))
|
|
node = node->rb_left;
|
|
else if (objectid > btrfs_ino(entry))
|
|
node = node->rb_right;
|
|
else
|
|
break;
|
|
}
|
|
if (!node) {
|
|
while (prev) {
|
|
entry = rb_entry(prev, struct btrfs_inode, rb_node);
|
|
if (objectid <= btrfs_ino(entry)) {
|
|
node = prev;
|
|
break;
|
|
}
|
|
prev = rb_next(prev);
|
|
}
|
|
}
|
|
while (node) {
|
|
entry = rb_entry(node, struct btrfs_inode, rb_node);
|
|
inode = igrab(&entry->vfs_inode);
|
|
if (inode) {
|
|
spin_unlock(&root->inode_lock);
|
|
return inode;
|
|
}
|
|
|
|
objectid = btrfs_ino(entry) + 1;
|
|
if (cond_resched_lock(&root->inode_lock))
|
|
goto again;
|
|
|
|
node = rb_next(node);
|
|
}
|
|
spin_unlock(&root->inode_lock);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* get new location of data
|
|
*/
|
|
static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
|
|
u64 bytenr, u64 num_bytes)
|
|
{
|
|
struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
|
|
struct btrfs_path *path;
|
|
struct btrfs_file_extent_item *fi;
|
|
struct extent_buffer *leaf;
|
|
int ret;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
bytenr -= BTRFS_I(reloc_inode)->index_cnt;
|
|
ret = btrfs_lookup_file_extent(NULL, root, path,
|
|
btrfs_ino(BTRFS_I(reloc_inode)), bytenr, 0);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret > 0) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
|
|
leaf = path->nodes[0];
|
|
fi = btrfs_item_ptr(leaf, path->slots[0],
|
|
struct btrfs_file_extent_item);
|
|
|
|
BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
|
|
btrfs_file_extent_compression(leaf, fi) ||
|
|
btrfs_file_extent_encryption(leaf, fi) ||
|
|
btrfs_file_extent_other_encoding(leaf, fi));
|
|
|
|
if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
*new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
|
|
ret = 0;
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* update file extent items in the tree leaf to point to
|
|
* the new locations.
|
|
*/
|
|
static noinline_for_stack
|
|
int replace_file_extents(struct btrfs_trans_handle *trans,
|
|
struct reloc_control *rc,
|
|
struct btrfs_root *root,
|
|
struct extent_buffer *leaf)
|
|
{
|
|
struct btrfs_fs_info *fs_info = root->fs_info;
|
|
struct btrfs_key key;
|
|
struct btrfs_file_extent_item *fi;
|
|
struct inode *inode = NULL;
|
|
u64 parent;
|
|
u64 bytenr;
|
|
u64 new_bytenr = 0;
|
|
u64 num_bytes;
|
|
u64 end;
|
|
u32 nritems;
|
|
u32 i;
|
|
int ret = 0;
|
|
int first = 1;
|
|
int dirty = 0;
|
|
|
|
if (rc->stage != UPDATE_DATA_PTRS)
|
|
return 0;
|
|
|
|
/* reloc trees always use full backref */
|
|
if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
|
|
parent = leaf->start;
|
|
else
|
|
parent = 0;
|
|
|
|
nritems = btrfs_header_nritems(leaf);
|
|
for (i = 0; i < nritems; i++) {
|
|
struct btrfs_ref ref = { 0 };
|
|
|
|
cond_resched();
|
|
btrfs_item_key_to_cpu(leaf, &key, i);
|
|
if (key.type != BTRFS_EXTENT_DATA_KEY)
|
|
continue;
|
|
fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
|
|
if (btrfs_file_extent_type(leaf, fi) ==
|
|
BTRFS_FILE_EXTENT_INLINE)
|
|
continue;
|
|
bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
|
|
num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
|
|
if (bytenr == 0)
|
|
continue;
|
|
if (!in_range(bytenr, rc->block_group->start,
|
|
rc->block_group->length))
|
|
continue;
|
|
|
|
/*
|
|
* if we are modifying block in fs tree, wait for read_folio
|
|
* to complete and drop the extent cache
|
|
*/
|
|
if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
|
|
if (first) {
|
|
inode = find_next_inode(root, key.objectid);
|
|
first = 0;
|
|
} else if (inode && btrfs_ino(BTRFS_I(inode)) < key.objectid) {
|
|
btrfs_add_delayed_iput(BTRFS_I(inode));
|
|
inode = find_next_inode(root, key.objectid);
|
|
}
|
|
if (inode && btrfs_ino(BTRFS_I(inode)) == key.objectid) {
|
|
struct extent_state *cached_state = NULL;
|
|
|
|
end = key.offset +
|
|
btrfs_file_extent_num_bytes(leaf, fi);
|
|
WARN_ON(!IS_ALIGNED(key.offset,
|
|
fs_info->sectorsize));
|
|
WARN_ON(!IS_ALIGNED(end, fs_info->sectorsize));
|
|
end--;
|
|
ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
|
|
key.offset, end,
|
|
&cached_state);
|
|
if (!ret)
|
|
continue;
|
|
|
|
btrfs_drop_extent_map_range(BTRFS_I(inode),
|
|
key.offset, end, true);
|
|
unlock_extent(&BTRFS_I(inode)->io_tree,
|
|
key.offset, end, &cached_state);
|
|
}
|
|
}
|
|
|
|
ret = get_new_location(rc->data_inode, &new_bytenr,
|
|
bytenr, num_bytes);
|
|
if (ret) {
|
|
/*
|
|
* Don't have to abort since we've not changed anything
|
|
* in the file extent yet.
|
|
*/
|
|
break;
|
|
}
|
|
|
|
btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
|
|
dirty = 1;
|
|
|
|
key.offset -= btrfs_file_extent_offset(leaf, fi);
|
|
btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, new_bytenr,
|
|
num_bytes, parent);
|
|
btrfs_init_data_ref(&ref, btrfs_header_owner(leaf),
|
|
key.objectid, key.offset,
|
|
root->root_key.objectid, false);
|
|
ret = btrfs_inc_extent_ref(trans, &ref);
|
|
if (ret) {
|
|
btrfs_abort_transaction(trans, ret);
|
|
break;
|
|
}
|
|
|
|
btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, bytenr,
|
|
num_bytes, parent);
|
|
btrfs_init_data_ref(&ref, btrfs_header_owner(leaf),
|
|
key.objectid, key.offset,
|
|
root->root_key.objectid, false);
|
|
ret = btrfs_free_extent(trans, &ref);
|
|
if (ret) {
|
|
btrfs_abort_transaction(trans, ret);
|
|
break;
|
|
}
|
|
}
|
|
if (dirty)
|
|
btrfs_mark_buffer_dirty(leaf);
|
|
if (inode)
|
|
btrfs_add_delayed_iput(BTRFS_I(inode));
|
|
return ret;
|
|
}
|
|
|
|
static noinline_for_stack
|
|
int memcmp_node_keys(struct extent_buffer *eb, int slot,
|
|
struct btrfs_path *path, int level)
|
|
{
|
|
struct btrfs_disk_key key1;
|
|
struct btrfs_disk_key key2;
|
|
btrfs_node_key(eb, &key1, slot);
|
|
btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
|
|
return memcmp(&key1, &key2, sizeof(key1));
|
|
}
|
|
|
|
/*
|
|
* try to replace tree blocks in fs tree with the new blocks
|
|
* in reloc tree. tree blocks haven't been modified since the
|
|
* reloc tree was create can be replaced.
|
|
*
|
|
* if a block was replaced, level of the block + 1 is returned.
|
|
* if no block got replaced, 0 is returned. if there are other
|
|
* errors, a negative error number is returned.
|
|
*/
|
|
static noinline_for_stack
|
|
int replace_path(struct btrfs_trans_handle *trans, struct reloc_control *rc,
|
|
struct btrfs_root *dest, struct btrfs_root *src,
|
|
struct btrfs_path *path, struct btrfs_key *next_key,
|
|
int lowest_level, int max_level)
|
|
{
|
|
struct btrfs_fs_info *fs_info = dest->fs_info;
|
|
struct extent_buffer *eb;
|
|
struct extent_buffer *parent;
|
|
struct btrfs_ref ref = { 0 };
|
|
struct btrfs_key key;
|
|
u64 old_bytenr;
|
|
u64 new_bytenr;
|
|
u64 old_ptr_gen;
|
|
u64 new_ptr_gen;
|
|
u64 last_snapshot;
|
|
u32 blocksize;
|
|
int cow = 0;
|
|
int level;
|
|
int ret;
|
|
int slot;
|
|
|
|
ASSERT(src->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
|
|
ASSERT(dest->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
|
|
|
|
last_snapshot = btrfs_root_last_snapshot(&src->root_item);
|
|
again:
|
|
slot = path->slots[lowest_level];
|
|
btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
|
|
|
|
eb = btrfs_lock_root_node(dest);
|
|
level = btrfs_header_level(eb);
|
|
|
|
if (level < lowest_level) {
|
|
btrfs_tree_unlock(eb);
|
|
free_extent_buffer(eb);
|
|
return 0;
|
|
}
|
|
|
|
if (cow) {
|
|
ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb,
|
|
BTRFS_NESTING_COW);
|
|
if (ret) {
|
|
btrfs_tree_unlock(eb);
|
|
free_extent_buffer(eb);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
if (next_key) {
|
|
next_key->objectid = (u64)-1;
|
|
next_key->type = (u8)-1;
|
|
next_key->offset = (u64)-1;
|
|
}
|
|
|
|
parent = eb;
|
|
while (1) {
|
|
level = btrfs_header_level(parent);
|
|
ASSERT(level >= lowest_level);
|
|
|
|
ret = btrfs_bin_search(parent, &key, &slot);
|
|
if (ret < 0)
|
|
break;
|
|
if (ret && slot > 0)
|
|
slot--;
|
|
|
|
if (next_key && slot + 1 < btrfs_header_nritems(parent))
|
|
btrfs_node_key_to_cpu(parent, next_key, slot + 1);
|
|
|
|
old_bytenr = btrfs_node_blockptr(parent, slot);
|
|
blocksize = fs_info->nodesize;
|
|
old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
|
|
|
|
if (level <= max_level) {
|
|
eb = path->nodes[level];
|
|
new_bytenr = btrfs_node_blockptr(eb,
|
|
path->slots[level]);
|
|
new_ptr_gen = btrfs_node_ptr_generation(eb,
|
|
path->slots[level]);
|
|
} else {
|
|
new_bytenr = 0;
|
|
new_ptr_gen = 0;
|
|
}
|
|
|
|
if (WARN_ON(new_bytenr > 0 && new_bytenr == old_bytenr)) {
|
|
ret = level;
|
|
break;
|
|
}
|
|
|
|
if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
|
|
memcmp_node_keys(parent, slot, path, level)) {
|
|
if (level <= lowest_level) {
|
|
ret = 0;
|
|
break;
|
|
}
|
|
|
|
eb = btrfs_read_node_slot(parent, slot);
|
|
if (IS_ERR(eb)) {
|
|
ret = PTR_ERR(eb);
|
|
break;
|
|
}
|
|
btrfs_tree_lock(eb);
|
|
if (cow) {
|
|
ret = btrfs_cow_block(trans, dest, eb, parent,
|
|
slot, &eb,
|
|
BTRFS_NESTING_COW);
|
|
if (ret) {
|
|
btrfs_tree_unlock(eb);
|
|
free_extent_buffer(eb);
|
|
break;
|
|
}
|
|
}
|
|
|
|
btrfs_tree_unlock(parent);
|
|
free_extent_buffer(parent);
|
|
|
|
parent = eb;
|
|
continue;
|
|
}
|
|
|
|
if (!cow) {
|
|
btrfs_tree_unlock(parent);
|
|
free_extent_buffer(parent);
|
|
cow = 1;
|
|
goto again;
|
|
}
|
|
|
|
btrfs_node_key_to_cpu(path->nodes[level], &key,
|
|
path->slots[level]);
|
|
btrfs_release_path(path);
|
|
|
|
path->lowest_level = level;
|
|
set_bit(BTRFS_ROOT_RESET_LOCKDEP_CLASS, &src->state);
|
|
ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
|
|
clear_bit(BTRFS_ROOT_RESET_LOCKDEP_CLASS, &src->state);
|
|
path->lowest_level = 0;
|
|
if (ret) {
|
|
if (ret > 0)
|
|
ret = -ENOENT;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Info qgroup to trace both subtrees.
|
|
*
|
|
* We must trace both trees.
|
|
* 1) Tree reloc subtree
|
|
* If not traced, we will leak data numbers
|
|
* 2) Fs subtree
|
|
* If not traced, we will double count old data
|
|
*
|
|
* We don't scan the subtree right now, but only record
|
|
* the swapped tree blocks.
|
|
* The real subtree rescan is delayed until we have new
|
|
* CoW on the subtree root node before transaction commit.
|
|
*/
|
|
ret = btrfs_qgroup_add_swapped_blocks(trans, dest,
|
|
rc->block_group, parent, slot,
|
|
path->nodes[level], path->slots[level],
|
|
last_snapshot);
|
|
if (ret < 0)
|
|
break;
|
|
/*
|
|
* swap blocks in fs tree and reloc tree.
|
|
*/
|
|
btrfs_set_node_blockptr(parent, slot, new_bytenr);
|
|
btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
|
|
btrfs_mark_buffer_dirty(parent);
|
|
|
|
btrfs_set_node_blockptr(path->nodes[level],
|
|
path->slots[level], old_bytenr);
|
|
btrfs_set_node_ptr_generation(path->nodes[level],
|
|
path->slots[level], old_ptr_gen);
|
|
btrfs_mark_buffer_dirty(path->nodes[level]);
|
|
|
|
btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, old_bytenr,
|
|
blocksize, path->nodes[level]->start);
|
|
btrfs_init_tree_ref(&ref, level - 1, src->root_key.objectid,
|
|
0, true);
|
|
ret = btrfs_inc_extent_ref(trans, &ref);
|
|
if (ret) {
|
|
btrfs_abort_transaction(trans, ret);
|
|
break;
|
|
}
|
|
btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, new_bytenr,
|
|
blocksize, 0);
|
|
btrfs_init_tree_ref(&ref, level - 1, dest->root_key.objectid, 0,
|
|
true);
|
|
ret = btrfs_inc_extent_ref(trans, &ref);
|
|
if (ret) {
|
|
btrfs_abort_transaction(trans, ret);
|
|
break;
|
|
}
|
|
|
|
btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, new_bytenr,
|
|
blocksize, path->nodes[level]->start);
|
|
btrfs_init_tree_ref(&ref, level - 1, src->root_key.objectid,
|
|
0, true);
|
|
ret = btrfs_free_extent(trans, &ref);
|
|
if (ret) {
|
|
btrfs_abort_transaction(trans, ret);
|
|
break;
|
|
}
|
|
|
|
btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, old_bytenr,
|
|
blocksize, 0);
|
|
btrfs_init_tree_ref(&ref, level - 1, dest->root_key.objectid,
|
|
0, true);
|
|
ret = btrfs_free_extent(trans, &ref);
|
|
if (ret) {
|
|
btrfs_abort_transaction(trans, ret);
|
|
break;
|
|
}
|
|
|
|
btrfs_unlock_up_safe(path, 0);
|
|
|
|
ret = level;
|
|
break;
|
|
}
|
|
btrfs_tree_unlock(parent);
|
|
free_extent_buffer(parent);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* helper to find next relocated block in reloc tree
|
|
*/
|
|
static noinline_for_stack
|
|
int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
|
|
int *level)
|
|
{
|
|
struct extent_buffer *eb;
|
|
int i;
|
|
u64 last_snapshot;
|
|
u32 nritems;
|
|
|
|
last_snapshot = btrfs_root_last_snapshot(&root->root_item);
|
|
|
|
for (i = 0; i < *level; i++) {
|
|
free_extent_buffer(path->nodes[i]);
|
|
path->nodes[i] = NULL;
|
|
}
|
|
|
|
for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
|
|
eb = path->nodes[i];
|
|
nritems = btrfs_header_nritems(eb);
|
|
while (path->slots[i] + 1 < nritems) {
|
|
path->slots[i]++;
|
|
if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
|
|
last_snapshot)
|
|
continue;
|
|
|
|
*level = i;
|
|
return 0;
|
|
}
|
|
free_extent_buffer(path->nodes[i]);
|
|
path->nodes[i] = NULL;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* walk down reloc tree to find relocated block of lowest level
|
|
*/
|
|
static noinline_for_stack
|
|
int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
|
|
int *level)
|
|
{
|
|
struct extent_buffer *eb = NULL;
|
|
int i;
|
|
u64 ptr_gen = 0;
|
|
u64 last_snapshot;
|
|
u32 nritems;
|
|
|
|
last_snapshot = btrfs_root_last_snapshot(&root->root_item);
|
|
|
|
for (i = *level; i > 0; i--) {
|
|
eb = path->nodes[i];
|
|
nritems = btrfs_header_nritems(eb);
|
|
while (path->slots[i] < nritems) {
|
|
ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
|
|
if (ptr_gen > last_snapshot)
|
|
break;
|
|
path->slots[i]++;
|
|
}
|
|
if (path->slots[i] >= nritems) {
|
|
if (i == *level)
|
|
break;
|
|
*level = i + 1;
|
|
return 0;
|
|
}
|
|
if (i == 1) {
|
|
*level = i;
|
|
return 0;
|
|
}
|
|
|
|
eb = btrfs_read_node_slot(eb, path->slots[i]);
|
|
if (IS_ERR(eb))
|
|
return PTR_ERR(eb);
|
|
BUG_ON(btrfs_header_level(eb) != i - 1);
|
|
path->nodes[i - 1] = eb;
|
|
path->slots[i - 1] = 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* invalidate extent cache for file extents whose key in range of
|
|
* [min_key, max_key)
|
|
*/
|
|
static int invalidate_extent_cache(struct btrfs_root *root,
|
|
struct btrfs_key *min_key,
|
|
struct btrfs_key *max_key)
|
|
{
|
|
struct btrfs_fs_info *fs_info = root->fs_info;
|
|
struct inode *inode = NULL;
|
|
u64 objectid;
|
|
u64 start, end;
|
|
u64 ino;
|
|
|
|
objectid = min_key->objectid;
|
|
while (1) {
|
|
struct extent_state *cached_state = NULL;
|
|
|
|
cond_resched();
|
|
iput(inode);
|
|
|
|
if (objectid > max_key->objectid)
|
|
break;
|
|
|
|
inode = find_next_inode(root, objectid);
|
|
if (!inode)
|
|
break;
|
|
ino = btrfs_ino(BTRFS_I(inode));
|
|
|
|
if (ino > max_key->objectid) {
|
|
iput(inode);
|
|
break;
|
|
}
|
|
|
|
objectid = ino + 1;
|
|
if (!S_ISREG(inode->i_mode))
|
|
continue;
|
|
|
|
if (unlikely(min_key->objectid == ino)) {
|
|
if (min_key->type > BTRFS_EXTENT_DATA_KEY)
|
|
continue;
|
|
if (min_key->type < BTRFS_EXTENT_DATA_KEY)
|
|
start = 0;
|
|
else {
|
|
start = min_key->offset;
|
|
WARN_ON(!IS_ALIGNED(start, fs_info->sectorsize));
|
|
}
|
|
} else {
|
|
start = 0;
|
|
}
|
|
|
|
if (unlikely(max_key->objectid == ino)) {
|
|
if (max_key->type < BTRFS_EXTENT_DATA_KEY)
|
|
continue;
|
|
if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
|
|
end = (u64)-1;
|
|
} else {
|
|
if (max_key->offset == 0)
|
|
continue;
|
|
end = max_key->offset;
|
|
WARN_ON(!IS_ALIGNED(end, fs_info->sectorsize));
|
|
end--;
|
|
}
|
|
} else {
|
|
end = (u64)-1;
|
|
}
|
|
|
|
/* the lock_extent waits for read_folio to complete */
|
|
lock_extent(&BTRFS_I(inode)->io_tree, start, end, &cached_state);
|
|
btrfs_drop_extent_map_range(BTRFS_I(inode), start, end, true);
|
|
unlock_extent(&BTRFS_I(inode)->io_tree, start, end, &cached_state);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int find_next_key(struct btrfs_path *path, int level,
|
|
struct btrfs_key *key)
|
|
|
|
{
|
|
while (level < BTRFS_MAX_LEVEL) {
|
|
if (!path->nodes[level])
|
|
break;
|
|
if (path->slots[level] + 1 <
|
|
btrfs_header_nritems(path->nodes[level])) {
|
|
btrfs_node_key_to_cpu(path->nodes[level], key,
|
|
path->slots[level] + 1);
|
|
return 0;
|
|
}
|
|
level++;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Insert current subvolume into reloc_control::dirty_subvol_roots
|
|
*/
|
|
static int insert_dirty_subvol(struct btrfs_trans_handle *trans,
|
|
struct reloc_control *rc,
|
|
struct btrfs_root *root)
|
|
{
|
|
struct btrfs_root *reloc_root = root->reloc_root;
|
|
struct btrfs_root_item *reloc_root_item;
|
|
int ret;
|
|
|
|
/* @root must be a subvolume tree root with a valid reloc tree */
|
|
ASSERT(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
|
|
ASSERT(reloc_root);
|
|
|
|
reloc_root_item = &reloc_root->root_item;
|
|
memset(&reloc_root_item->drop_progress, 0,
|
|
sizeof(reloc_root_item->drop_progress));
|
|
btrfs_set_root_drop_level(reloc_root_item, 0);
|
|
btrfs_set_root_refs(reloc_root_item, 0);
|
|
ret = btrfs_update_reloc_root(trans, root);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (list_empty(&root->reloc_dirty_list)) {
|
|
btrfs_grab_root(root);
|
|
list_add_tail(&root->reloc_dirty_list, &rc->dirty_subvol_roots);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int clean_dirty_subvols(struct reloc_control *rc)
|
|
{
|
|
struct btrfs_root *root;
|
|
struct btrfs_root *next;
|
|
int ret = 0;
|
|
int ret2;
|
|
|
|
list_for_each_entry_safe(root, next, &rc->dirty_subvol_roots,
|
|
reloc_dirty_list) {
|
|
if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
|
|
/* Merged subvolume, cleanup its reloc root */
|
|
struct btrfs_root *reloc_root = root->reloc_root;
|
|
|
|
list_del_init(&root->reloc_dirty_list);
|
|
root->reloc_root = NULL;
|
|
/*
|
|
* Need barrier to ensure clear_bit() only happens after
|
|
* root->reloc_root = NULL. Pairs with have_reloc_root.
|
|
*/
|
|
smp_wmb();
|
|
clear_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state);
|
|
if (reloc_root) {
|
|
/*
|
|
* btrfs_drop_snapshot drops our ref we hold for
|
|
* ->reloc_root. If it fails however we must
|
|
* drop the ref ourselves.
|
|
*/
|
|
ret2 = btrfs_drop_snapshot(reloc_root, 0, 1);
|
|
if (ret2 < 0) {
|
|
btrfs_put_root(reloc_root);
|
|
if (!ret)
|
|
ret = ret2;
|
|
}
|
|
}
|
|
btrfs_put_root(root);
|
|
} else {
|
|
/* Orphan reloc tree, just clean it up */
|
|
ret2 = btrfs_drop_snapshot(root, 0, 1);
|
|
if (ret2 < 0) {
|
|
btrfs_put_root(root);
|
|
if (!ret)
|
|
ret = ret2;
|
|
}
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* merge the relocated tree blocks in reloc tree with corresponding
|
|
* fs tree.
|
|
*/
|
|
static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
|
|
struct btrfs_root *root)
|
|
{
|
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
|
|
struct btrfs_key key;
|
|
struct btrfs_key next_key;
|
|
struct btrfs_trans_handle *trans = NULL;
|
|
struct btrfs_root *reloc_root;
|
|
struct btrfs_root_item *root_item;
|
|
struct btrfs_path *path;
|
|
struct extent_buffer *leaf;
|
|
int reserve_level;
|
|
int level;
|
|
int max_level;
|
|
int replaced = 0;
|
|
int ret = 0;
|
|
u32 min_reserved;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
path->reada = READA_FORWARD;
|
|
|
|
reloc_root = root->reloc_root;
|
|
root_item = &reloc_root->root_item;
|
|
|
|
if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
|
|
level = btrfs_root_level(root_item);
|
|
atomic_inc(&reloc_root->node->refs);
|
|
path->nodes[level] = reloc_root->node;
|
|
path->slots[level] = 0;
|
|
} else {
|
|
btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
|
|
|
|
level = btrfs_root_drop_level(root_item);
|
|
BUG_ON(level == 0);
|
|
path->lowest_level = level;
|
|
ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
|
|
path->lowest_level = 0;
|
|
if (ret < 0) {
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
btrfs_node_key_to_cpu(path->nodes[level], &next_key,
|
|
path->slots[level]);
|
|
WARN_ON(memcmp(&key, &next_key, sizeof(key)));
|
|
|
|
btrfs_unlock_up_safe(path, 0);
|
|
}
|
|
|
|
/*
|
|
* In merge_reloc_root(), we modify the upper level pointer to swap the
|
|
* tree blocks between reloc tree and subvolume tree. Thus for tree
|
|
* block COW, we COW at most from level 1 to root level for each tree.
|
|
*
|
|
* Thus the needed metadata size is at most root_level * nodesize,
|
|
* and * 2 since we have two trees to COW.
|
|
*/
|
|
reserve_level = max_t(int, 1, btrfs_root_level(root_item));
|
|
min_reserved = fs_info->nodesize * reserve_level * 2;
|
|
memset(&next_key, 0, sizeof(next_key));
|
|
|
|
while (1) {
|
|
ret = btrfs_block_rsv_refill(fs_info, rc->block_rsv,
|
|
min_reserved,
|
|
BTRFS_RESERVE_FLUSH_LIMIT);
|
|
if (ret)
|
|
goto out;
|
|
trans = btrfs_start_transaction(root, 0);
|
|
if (IS_ERR(trans)) {
|
|
ret = PTR_ERR(trans);
|
|
trans = NULL;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* At this point we no longer have a reloc_control, so we can't
|
|
* depend on btrfs_init_reloc_root to update our last_trans.
|
|
*
|
|
* But that's ok, we started the trans handle on our
|
|
* corresponding fs_root, which means it's been added to the
|
|
* dirty list. At commit time we'll still call
|
|
* btrfs_update_reloc_root() and update our root item
|
|
* appropriately.
|
|
*/
|
|
reloc_root->last_trans = trans->transid;
|
|
trans->block_rsv = rc->block_rsv;
|
|
|
|
replaced = 0;
|
|
max_level = level;
|
|
|
|
ret = walk_down_reloc_tree(reloc_root, path, &level);
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret > 0)
|
|
break;
|
|
|
|
if (!find_next_key(path, level, &key) &&
|
|
btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
|
|
ret = 0;
|
|
} else {
|
|
ret = replace_path(trans, rc, root, reloc_root, path,
|
|
&next_key, level, max_level);
|
|
}
|
|
if (ret < 0)
|
|
goto out;
|
|
if (ret > 0) {
|
|
level = ret;
|
|
btrfs_node_key_to_cpu(path->nodes[level], &key,
|
|
path->slots[level]);
|
|
replaced = 1;
|
|
}
|
|
|
|
ret = walk_up_reloc_tree(reloc_root, path, &level);
|
|
if (ret > 0)
|
|
break;
|
|
|
|
BUG_ON(level == 0);
|
|
/*
|
|
* save the merging progress in the drop_progress.
|
|
* this is OK since root refs == 1 in this case.
|
|
*/
|
|
btrfs_node_key(path->nodes[level], &root_item->drop_progress,
|
|
path->slots[level]);
|
|
btrfs_set_root_drop_level(root_item, level);
|
|
|
|
btrfs_end_transaction_throttle(trans);
|
|
trans = NULL;
|
|
|
|
btrfs_btree_balance_dirty(fs_info);
|
|
|
|
if (replaced && rc->stage == UPDATE_DATA_PTRS)
|
|
invalidate_extent_cache(root, &key, &next_key);
|
|
}
|
|
|
|
/*
|
|
* handle the case only one block in the fs tree need to be
|
|
* relocated and the block is tree root.
|
|
*/
|
|
leaf = btrfs_lock_root_node(root);
|
|
ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf,
|
|
BTRFS_NESTING_COW);
|
|
btrfs_tree_unlock(leaf);
|
|
free_extent_buffer(leaf);
|
|
out:
|
|
btrfs_free_path(path);
|
|
|
|
if (ret == 0) {
|
|
ret = insert_dirty_subvol(trans, rc, root);
|
|
if (ret)
|
|
btrfs_abort_transaction(trans, ret);
|
|
}
|
|
|
|
if (trans)
|
|
btrfs_end_transaction_throttle(trans);
|
|
|
|
btrfs_btree_balance_dirty(fs_info);
|
|
|
|
if (replaced && rc->stage == UPDATE_DATA_PTRS)
|
|
invalidate_extent_cache(root, &key, &next_key);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static noinline_for_stack
|
|
int prepare_to_merge(struct reloc_control *rc, int err)
|
|
{
|
|
struct btrfs_root *root = rc->extent_root;
|
|
struct btrfs_fs_info *fs_info = root->fs_info;
|
|
struct btrfs_root *reloc_root;
|
|
struct btrfs_trans_handle *trans;
|
|
LIST_HEAD(reloc_roots);
|
|
u64 num_bytes = 0;
|
|
int ret;
|
|
|
|
mutex_lock(&fs_info->reloc_mutex);
|
|
rc->merging_rsv_size += fs_info->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
|
|
rc->merging_rsv_size += rc->nodes_relocated * 2;
|
|
mutex_unlock(&fs_info->reloc_mutex);
|
|
|
|
again:
|
|
if (!err) {
|
|
num_bytes = rc->merging_rsv_size;
|
|
ret = btrfs_block_rsv_add(fs_info, rc->block_rsv, num_bytes,
|
|
BTRFS_RESERVE_FLUSH_ALL);
|
|
if (ret)
|
|
err = ret;
|
|
}
|
|
|
|
trans = btrfs_join_transaction(rc->extent_root);
|
|
if (IS_ERR(trans)) {
|
|
if (!err)
|
|
btrfs_block_rsv_release(fs_info, rc->block_rsv,
|
|
num_bytes, NULL);
|
|
return PTR_ERR(trans);
|
|
}
|
|
|
|
if (!err) {
|
|
if (num_bytes != rc->merging_rsv_size) {
|
|
btrfs_end_transaction(trans);
|
|
btrfs_block_rsv_release(fs_info, rc->block_rsv,
|
|
num_bytes, NULL);
|
|
goto again;
|
|
}
|
|
}
|
|
|
|
rc->merge_reloc_tree = 1;
|
|
|
|
while (!list_empty(&rc->reloc_roots)) {
|
|
reloc_root = list_entry(rc->reloc_roots.next,
|
|
struct btrfs_root, root_list);
|
|
list_del_init(&reloc_root->root_list);
|
|
|
|
root = btrfs_get_fs_root(fs_info, reloc_root->root_key.offset,
|
|
false);
|
|
if (IS_ERR(root)) {
|
|
/*
|
|
* Even if we have an error we need this reloc root
|
|
* back on our list so we can clean up properly.
|
|
*/
|
|
list_add(&reloc_root->root_list, &reloc_roots);
|
|
btrfs_abort_transaction(trans, (int)PTR_ERR(root));
|
|
if (!err)
|
|
err = PTR_ERR(root);
|
|
break;
|
|
}
|
|
ASSERT(root->reloc_root == reloc_root);
|
|
|
|
/*
|
|
* set reference count to 1, so btrfs_recover_relocation
|
|
* knows it should resumes merging
|
|
*/
|
|
if (!err)
|
|
btrfs_set_root_refs(&reloc_root->root_item, 1);
|
|
ret = btrfs_update_reloc_root(trans, root);
|
|
|
|
/*
|
|
* Even if we have an error we need this reloc root back on our
|
|
* list so we can clean up properly.
|
|
*/
|
|
list_add(&reloc_root->root_list, &reloc_roots);
|
|
btrfs_put_root(root);
|
|
|
|
if (ret) {
|
|
btrfs_abort_transaction(trans, ret);
|
|
if (!err)
|
|
err = ret;
|
|
break;
|
|
}
|
|
}
|
|
|
|
list_splice(&reloc_roots, &rc->reloc_roots);
|
|
|
|
if (!err)
|
|
err = btrfs_commit_transaction(trans);
|
|
else
|
|
btrfs_end_transaction(trans);
|
|
return err;
|
|
}
|
|
|
|
static noinline_for_stack
|
|
void free_reloc_roots(struct list_head *list)
|
|
{
|
|
struct btrfs_root *reloc_root, *tmp;
|
|
|
|
list_for_each_entry_safe(reloc_root, tmp, list, root_list)
|
|
__del_reloc_root(reloc_root);
|
|
}
|
|
|
|
static noinline_for_stack
|
|
void merge_reloc_roots(struct reloc_control *rc)
|
|
{
|
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
|
|
struct btrfs_root *root;
|
|
struct btrfs_root *reloc_root;
|
|
LIST_HEAD(reloc_roots);
|
|
int found = 0;
|
|
int ret = 0;
|
|
again:
|
|
root = rc->extent_root;
|
|
|
|
/*
|
|
* this serializes us with btrfs_record_root_in_transaction,
|
|
* we have to make sure nobody is in the middle of
|
|
* adding their roots to the list while we are
|
|
* doing this splice
|
|
*/
|
|
mutex_lock(&fs_info->reloc_mutex);
|
|
list_splice_init(&rc->reloc_roots, &reloc_roots);
|
|
mutex_unlock(&fs_info->reloc_mutex);
|
|
|
|
while (!list_empty(&reloc_roots)) {
|
|
found = 1;
|
|
reloc_root = list_entry(reloc_roots.next,
|
|
struct btrfs_root, root_list);
|
|
|
|
root = btrfs_get_fs_root(fs_info, reloc_root->root_key.offset,
|
|
false);
|
|
if (btrfs_root_refs(&reloc_root->root_item) > 0) {
|
|
if (IS_ERR(root)) {
|
|
/*
|
|
* For recovery we read the fs roots on mount,
|
|
* and if we didn't find the root then we marked
|
|
* the reloc root as a garbage root. For normal
|
|
* relocation obviously the root should exist in
|
|
* memory. However there's no reason we can't
|
|
* handle the error properly here just in case.
|
|
*/
|
|
ASSERT(0);
|
|
ret = PTR_ERR(root);
|
|
goto out;
|
|
}
|
|
if (root->reloc_root != reloc_root) {
|
|
/*
|
|
* This is actually impossible without something
|
|
* going really wrong (like weird race condition
|
|
* or cosmic rays).
|
|
*/
|
|
ASSERT(0);
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
ret = merge_reloc_root(rc, root);
|
|
btrfs_put_root(root);
|
|
if (ret) {
|
|
if (list_empty(&reloc_root->root_list))
|
|
list_add_tail(&reloc_root->root_list,
|
|
&reloc_roots);
|
|
goto out;
|
|
}
|
|
} else {
|
|
if (!IS_ERR(root)) {
|
|
if (root->reloc_root == reloc_root) {
|
|
root->reloc_root = NULL;
|
|
btrfs_put_root(reloc_root);
|
|
}
|
|
clear_bit(BTRFS_ROOT_DEAD_RELOC_TREE,
|
|
&root->state);
|
|
btrfs_put_root(root);
|
|
}
|
|
|
|
list_del_init(&reloc_root->root_list);
|
|
/* Don't forget to queue this reloc root for cleanup */
|
|
list_add_tail(&reloc_root->reloc_dirty_list,
|
|
&rc->dirty_subvol_roots);
|
|
}
|
|
}
|
|
|
|
if (found) {
|
|
found = 0;
|
|
goto again;
|
|
}
|
|
out:
|
|
if (ret) {
|
|
btrfs_handle_fs_error(fs_info, ret, NULL);
|
|
free_reloc_roots(&reloc_roots);
|
|
|
|
/* new reloc root may be added */
|
|
mutex_lock(&fs_info->reloc_mutex);
|
|
list_splice_init(&rc->reloc_roots, &reloc_roots);
|
|
mutex_unlock(&fs_info->reloc_mutex);
|
|
free_reloc_roots(&reloc_roots);
|
|
}
|
|
|
|
/*
|
|
* We used to have
|
|
*
|
|
* BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
|
|
*
|
|
* here, but it's wrong. If we fail to start the transaction in
|
|
* prepare_to_merge() we will have only 0 ref reloc roots, none of which
|
|
* have actually been removed from the reloc_root_tree rb tree. This is
|
|
* fine because we're bailing here, and we hold a reference on the root
|
|
* for the list that holds it, so these roots will be cleaned up when we
|
|
* do the reloc_dirty_list afterwards. Meanwhile the root->reloc_root
|
|
* will be cleaned up on unmount.
|
|
*
|
|
* The remaining nodes will be cleaned up by free_reloc_control.
|
|
*/
|
|
}
|
|
|
|
static void free_block_list(struct rb_root *blocks)
|
|
{
|
|
struct tree_block *block;
|
|
struct rb_node *rb_node;
|
|
while ((rb_node = rb_first(blocks))) {
|
|
block = rb_entry(rb_node, struct tree_block, rb_node);
|
|
rb_erase(rb_node, blocks);
|
|
kfree(block);
|
|
}
|
|
}
|
|
|
|
static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
|
|
struct btrfs_root *reloc_root)
|
|
{
|
|
struct btrfs_fs_info *fs_info = reloc_root->fs_info;
|
|
struct btrfs_root *root;
|
|
int ret;
|
|
|
|
if (reloc_root->last_trans == trans->transid)
|
|
return 0;
|
|
|
|
root = btrfs_get_fs_root(fs_info, reloc_root->root_key.offset, false);
|
|
|
|
/*
|
|
* This should succeed, since we can't have a reloc root without having
|
|
* already looked up the actual root and created the reloc root for this
|
|
* root.
|
|
*
|
|
* However if there's some sort of corruption where we have a ref to a
|
|
* reloc root without a corresponding root this could return ENOENT.
|
|
*/
|
|
if (IS_ERR(root)) {
|
|
ASSERT(0);
|
|
return PTR_ERR(root);
|
|
}
|
|
if (root->reloc_root != reloc_root) {
|
|
ASSERT(0);
|
|
btrfs_err(fs_info,
|
|
"root %llu has two reloc roots associated with it",
|
|
reloc_root->root_key.offset);
|
|
btrfs_put_root(root);
|
|
return -EUCLEAN;
|
|
}
|
|
ret = btrfs_record_root_in_trans(trans, root);
|
|
btrfs_put_root(root);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static noinline_for_stack
|
|
struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
|
|
struct reloc_control *rc,
|
|
struct btrfs_backref_node *node,
|
|
struct btrfs_backref_edge *edges[])
|
|
{
|
|
struct btrfs_backref_node *next;
|
|
struct btrfs_root *root;
|
|
int index = 0;
|
|
int ret;
|
|
|
|
next = node;
|
|
while (1) {
|
|
cond_resched();
|
|
next = walk_up_backref(next, edges, &index);
|
|
root = next->root;
|
|
|
|
/*
|
|
* If there is no root, then our references for this block are
|
|
* incomplete, as we should be able to walk all the way up to a
|
|
* block that is owned by a root.
|
|
*
|
|
* This path is only for SHAREABLE roots, so if we come upon a
|
|
* non-SHAREABLE root then we have backrefs that resolve
|
|
* improperly.
|
|
*
|
|
* Both of these cases indicate file system corruption, or a bug
|
|
* in the backref walking code.
|
|
*/
|
|
if (!root) {
|
|
ASSERT(0);
|
|
btrfs_err(trans->fs_info,
|
|
"bytenr %llu doesn't have a backref path ending in a root",
|
|
node->bytenr);
|
|
return ERR_PTR(-EUCLEAN);
|
|
}
|
|
if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) {
|
|
ASSERT(0);
|
|
btrfs_err(trans->fs_info,
|
|
"bytenr %llu has multiple refs with one ending in a non-shareable root",
|
|
node->bytenr);
|
|
return ERR_PTR(-EUCLEAN);
|
|
}
|
|
|
|
if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
|
|
ret = record_reloc_root_in_trans(trans, root);
|
|
if (ret)
|
|
return ERR_PTR(ret);
|
|
break;
|
|
}
|
|
|
|
ret = btrfs_record_root_in_trans(trans, root);
|
|
if (ret)
|
|
return ERR_PTR(ret);
|
|
root = root->reloc_root;
|
|
|
|
/*
|
|
* We could have raced with another thread which failed, so
|
|
* root->reloc_root may not be set, return ENOENT in this case.
|
|
*/
|
|
if (!root)
|
|
return ERR_PTR(-ENOENT);
|
|
|
|
if (next->new_bytenr != root->node->start) {
|
|
/*
|
|
* We just created the reloc root, so we shouldn't have
|
|
* ->new_bytenr set and this shouldn't be in the changed
|
|
* list. If it is then we have multiple roots pointing
|
|
* at the same bytenr which indicates corruption, or
|
|
* we've made a mistake in the backref walking code.
|
|
*/
|
|
ASSERT(next->new_bytenr == 0);
|
|
ASSERT(list_empty(&next->list));
|
|
if (next->new_bytenr || !list_empty(&next->list)) {
|
|
btrfs_err(trans->fs_info,
|
|
"bytenr %llu possibly has multiple roots pointing at the same bytenr %llu",
|
|
node->bytenr, next->bytenr);
|
|
return ERR_PTR(-EUCLEAN);
|
|
}
|
|
|
|
next->new_bytenr = root->node->start;
|
|
btrfs_put_root(next->root);
|
|
next->root = btrfs_grab_root(root);
|
|
ASSERT(next->root);
|
|
list_add_tail(&next->list,
|
|
&rc->backref_cache.changed);
|
|
mark_block_processed(rc, next);
|
|
break;
|
|
}
|
|
|
|
WARN_ON(1);
|
|
root = NULL;
|
|
next = walk_down_backref(edges, &index);
|
|
if (!next || next->level <= node->level)
|
|
break;
|
|
}
|
|
if (!root) {
|
|
/*
|
|
* This can happen if there's fs corruption or if there's a bug
|
|
* in the backref lookup code.
|
|
*/
|
|
ASSERT(0);
|
|
return ERR_PTR(-ENOENT);
|
|
}
|
|
|
|
next = node;
|
|
/* setup backref node path for btrfs_reloc_cow_block */
|
|
while (1) {
|
|
rc->backref_cache.path[next->level] = next;
|
|
if (--index < 0)
|
|
break;
|
|
next = edges[index]->node[UPPER];
|
|
}
|
|
return root;
|
|
}
|
|
|
|
/*
|
|
* Select a tree root for relocation.
|
|
*
|
|
* Return NULL if the block is not shareable. We should use do_relocation() in
|
|
* this case.
|
|
*
|
|
* Return a tree root pointer if the block is shareable.
|
|
* Return -ENOENT if the block is root of reloc tree.
|
|
*/
|
|
static noinline_for_stack
|
|
struct btrfs_root *select_one_root(struct btrfs_backref_node *node)
|
|
{
|
|
struct btrfs_backref_node *next;
|
|
struct btrfs_root *root;
|
|
struct btrfs_root *fs_root = NULL;
|
|
struct btrfs_backref_edge *edges[BTRFS_MAX_LEVEL - 1];
|
|
int index = 0;
|
|
|
|
next = node;
|
|
while (1) {
|
|
cond_resched();
|
|
next = walk_up_backref(next, edges, &index);
|
|
root = next->root;
|
|
|
|
/*
|
|
* This can occur if we have incomplete extent refs leading all
|
|
* the way up a particular path, in this case return -EUCLEAN.
|
|
*/
|
|
if (!root)
|
|
return ERR_PTR(-EUCLEAN);
|
|
|
|
/* No other choice for non-shareable tree */
|
|
if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
|
|
return root;
|
|
|
|
if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
|
|
fs_root = root;
|
|
|
|
if (next != node)
|
|
return NULL;
|
|
|
|
next = walk_down_backref(edges, &index);
|
|
if (!next || next->level <= node->level)
|
|
break;
|
|
}
|
|
|
|
if (!fs_root)
|
|
return ERR_PTR(-ENOENT);
|
|
return fs_root;
|
|
}
|
|
|
|
static noinline_for_stack
|
|
u64 calcu_metadata_size(struct reloc_control *rc,
|
|
struct btrfs_backref_node *node, int reserve)
|
|
{
|
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
|
|
struct btrfs_backref_node *next = node;
|
|
struct btrfs_backref_edge *edge;
|
|
struct btrfs_backref_edge *edges[BTRFS_MAX_LEVEL - 1];
|
|
u64 num_bytes = 0;
|
|
int index = 0;
|
|
|
|
BUG_ON(reserve && node->processed);
|
|
|
|
while (next) {
|
|
cond_resched();
|
|
while (1) {
|
|
if (next->processed && (reserve || next != node))
|
|
break;
|
|
|
|
num_bytes += fs_info->nodesize;
|
|
|
|
if (list_empty(&next->upper))
|
|
break;
|
|
|
|
edge = list_entry(next->upper.next,
|
|
struct btrfs_backref_edge, list[LOWER]);
|
|
edges[index++] = edge;
|
|
next = edge->node[UPPER];
|
|
}
|
|
next = walk_down_backref(edges, &index);
|
|
}
|
|
return num_bytes;
|
|
}
|
|
|
|
static int reserve_metadata_space(struct btrfs_trans_handle *trans,
|
|
struct reloc_control *rc,
|
|
struct btrfs_backref_node *node)
|
|
{
|
|
struct btrfs_root *root = rc->extent_root;
|
|
struct btrfs_fs_info *fs_info = root->fs_info;
|
|
u64 num_bytes;
|
|
int ret;
|
|
u64 tmp;
|
|
|
|
num_bytes = calcu_metadata_size(rc, node, 1) * 2;
|
|
|
|
trans->block_rsv = rc->block_rsv;
|
|
rc->reserved_bytes += num_bytes;
|
|
|
|
/*
|
|
* We are under a transaction here so we can only do limited flushing.
|
|
* If we get an enospc just kick back -EAGAIN so we know to drop the
|
|
* transaction and try to refill when we can flush all the things.
|
|
*/
|
|
ret = btrfs_block_rsv_refill(fs_info, rc->block_rsv, num_bytes,
|
|
BTRFS_RESERVE_FLUSH_LIMIT);
|
|
if (ret) {
|
|
tmp = fs_info->nodesize * RELOCATION_RESERVED_NODES;
|
|
while (tmp <= rc->reserved_bytes)
|
|
tmp <<= 1;
|
|
/*
|
|
* only one thread can access block_rsv at this point,
|
|
* so we don't need hold lock to protect block_rsv.
|
|
* we expand more reservation size here to allow enough
|
|
* space for relocation and we will return earlier in
|
|
* enospc case.
|
|
*/
|
|
rc->block_rsv->size = tmp + fs_info->nodesize *
|
|
RELOCATION_RESERVED_NODES;
|
|
return -EAGAIN;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* relocate a block tree, and then update pointers in upper level
|
|
* blocks that reference the block to point to the new location.
|
|
*
|
|
* if called by link_to_upper, the block has already been relocated.
|
|
* in that case this function just updates pointers.
|
|
*/
|
|
static int do_relocation(struct btrfs_trans_handle *trans,
|
|
struct reloc_control *rc,
|
|
struct btrfs_backref_node *node,
|
|
struct btrfs_key *key,
|
|
struct btrfs_path *path, int lowest)
|
|
{
|
|
struct btrfs_backref_node *upper;
|
|
struct btrfs_backref_edge *edge;
|
|
struct btrfs_backref_edge *edges[BTRFS_MAX_LEVEL - 1];
|
|
struct btrfs_root *root;
|
|
struct extent_buffer *eb;
|
|
u32 blocksize;
|
|
u64 bytenr;
|
|
int slot;
|
|
int ret = 0;
|
|
|
|
/*
|
|
* If we are lowest then this is the first time we're processing this
|
|
* block, and thus shouldn't have an eb associated with it yet.
|
|
*/
|
|
ASSERT(!lowest || !node->eb);
|
|
|
|
path->lowest_level = node->level + 1;
|
|
rc->backref_cache.path[node->level] = node;
|
|
list_for_each_entry(edge, &node->upper, list[LOWER]) {
|
|
struct btrfs_ref ref = { 0 };
|
|
|
|
cond_resched();
|
|
|
|
upper = edge->node[UPPER];
|
|
root = select_reloc_root(trans, rc, upper, edges);
|
|
if (IS_ERR(root)) {
|
|
ret = PTR_ERR(root);
|
|
goto next;
|
|
}
|
|
|
|
if (upper->eb && !upper->locked) {
|
|
if (!lowest) {
|
|
ret = btrfs_bin_search(upper->eb, key, &slot);
|
|
if (ret < 0)
|
|
goto next;
|
|
BUG_ON(ret);
|
|
bytenr = btrfs_node_blockptr(upper->eb, slot);
|
|
if (node->eb->start == bytenr)
|
|
goto next;
|
|
}
|
|
btrfs_backref_drop_node_buffer(upper);
|
|
}
|
|
|
|
if (!upper->eb) {
|
|
ret = btrfs_search_slot(trans, root, key, path, 0, 1);
|
|
if (ret) {
|
|
if (ret > 0)
|
|
ret = -ENOENT;
|
|
|
|
btrfs_release_path(path);
|
|
break;
|
|
}
|
|
|
|
if (!upper->eb) {
|
|
upper->eb = path->nodes[upper->level];
|
|
path->nodes[upper->level] = NULL;
|
|
} else {
|
|
BUG_ON(upper->eb != path->nodes[upper->level]);
|
|
}
|
|
|
|
upper->locked = 1;
|
|
path->locks[upper->level] = 0;
|
|
|
|
slot = path->slots[upper->level];
|
|
btrfs_release_path(path);
|
|
} else {
|
|
ret = btrfs_bin_search(upper->eb, key, &slot);
|
|
if (ret < 0)
|
|
goto next;
|
|
BUG_ON(ret);
|
|
}
|
|
|
|
bytenr = btrfs_node_blockptr(upper->eb, slot);
|
|
if (lowest) {
|
|
if (bytenr != node->bytenr) {
|
|
btrfs_err(root->fs_info,
|
|
"lowest leaf/node mismatch: bytenr %llu node->bytenr %llu slot %d upper %llu",
|
|
bytenr, node->bytenr, slot,
|
|
upper->eb->start);
|
|
ret = -EIO;
|
|
goto next;
|
|
}
|
|
} else {
|
|
if (node->eb->start == bytenr)
|
|
goto next;
|
|
}
|
|
|
|
blocksize = root->fs_info->nodesize;
|
|
eb = btrfs_read_node_slot(upper->eb, slot);
|
|
if (IS_ERR(eb)) {
|
|
ret = PTR_ERR(eb);
|
|
goto next;
|
|
}
|
|
btrfs_tree_lock(eb);
|
|
|
|
if (!node->eb) {
|
|
ret = btrfs_cow_block(trans, root, eb, upper->eb,
|
|
slot, &eb, BTRFS_NESTING_COW);
|
|
btrfs_tree_unlock(eb);
|
|
free_extent_buffer(eb);
|
|
if (ret < 0)
|
|
goto next;
|
|
/*
|
|
* We've just COWed this block, it should have updated
|
|
* the correct backref node entry.
|
|
*/
|
|
ASSERT(node->eb == eb);
|
|
} else {
|
|
btrfs_set_node_blockptr(upper->eb, slot,
|
|
node->eb->start);
|
|
btrfs_set_node_ptr_generation(upper->eb, slot,
|
|
trans->transid);
|
|
btrfs_mark_buffer_dirty(upper->eb);
|
|
|
|
btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF,
|
|
node->eb->start, blocksize,
|
|
upper->eb->start);
|
|
btrfs_init_tree_ref(&ref, node->level,
|
|
btrfs_header_owner(upper->eb),
|
|
root->root_key.objectid, false);
|
|
ret = btrfs_inc_extent_ref(trans, &ref);
|
|
if (!ret)
|
|
ret = btrfs_drop_subtree(trans, root, eb,
|
|
upper->eb);
|
|
if (ret)
|
|
btrfs_abort_transaction(trans, ret);
|
|
}
|
|
next:
|
|
if (!upper->pending)
|
|
btrfs_backref_drop_node_buffer(upper);
|
|
else
|
|
btrfs_backref_unlock_node_buffer(upper);
|
|
if (ret)
|
|
break;
|
|
}
|
|
|
|
if (!ret && node->pending) {
|
|
btrfs_backref_drop_node_buffer(node);
|
|
list_move_tail(&node->list, &rc->backref_cache.changed);
|
|
node->pending = 0;
|
|
}
|
|
|
|
path->lowest_level = 0;
|
|
|
|
/*
|
|
* We should have allocated all of our space in the block rsv and thus
|
|
* shouldn't ENOSPC.
|
|
*/
|
|
ASSERT(ret != -ENOSPC);
|
|
return ret;
|
|
}
|
|
|
|
static int link_to_upper(struct btrfs_trans_handle *trans,
|
|
struct reloc_control *rc,
|
|
struct btrfs_backref_node *node,
|
|
struct btrfs_path *path)
|
|
{
|
|
struct btrfs_key key;
|
|
|
|
btrfs_node_key_to_cpu(node->eb, &key, 0);
|
|
return do_relocation(trans, rc, node, &key, path, 0);
|
|
}
|
|
|
|
static int finish_pending_nodes(struct btrfs_trans_handle *trans,
|
|
struct reloc_control *rc,
|
|
struct btrfs_path *path, int err)
|
|
{
|
|
LIST_HEAD(list);
|
|
struct btrfs_backref_cache *cache = &rc->backref_cache;
|
|
struct btrfs_backref_node *node;
|
|
int level;
|
|
int ret;
|
|
|
|
for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
|
|
while (!list_empty(&cache->pending[level])) {
|
|
node = list_entry(cache->pending[level].next,
|
|
struct btrfs_backref_node, list);
|
|
list_move_tail(&node->list, &list);
|
|
BUG_ON(!node->pending);
|
|
|
|
if (!err) {
|
|
ret = link_to_upper(trans, rc, node, path);
|
|
if (ret < 0)
|
|
err = ret;
|
|
}
|
|
}
|
|
list_splice_init(&list, &cache->pending[level]);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* mark a block and all blocks directly/indirectly reference the block
|
|
* as processed.
|
|
*/
|
|
static void update_processed_blocks(struct reloc_control *rc,
|
|
struct btrfs_backref_node *node)
|
|
{
|
|
struct btrfs_backref_node *next = node;
|
|
struct btrfs_backref_edge *edge;
|
|
struct btrfs_backref_edge *edges[BTRFS_MAX_LEVEL - 1];
|
|
int index = 0;
|
|
|
|
while (next) {
|
|
cond_resched();
|
|
while (1) {
|
|
if (next->processed)
|
|
break;
|
|
|
|
mark_block_processed(rc, next);
|
|
|
|
if (list_empty(&next->upper))
|
|
break;
|
|
|
|
edge = list_entry(next->upper.next,
|
|
struct btrfs_backref_edge, list[LOWER]);
|
|
edges[index++] = edge;
|
|
next = edge->node[UPPER];
|
|
}
|
|
next = walk_down_backref(edges, &index);
|
|
}
|
|
}
|
|
|
|
static int tree_block_processed(u64 bytenr, struct reloc_control *rc)
|
|
{
|
|
u32 blocksize = rc->extent_root->fs_info->nodesize;
|
|
|
|
if (test_range_bit(&rc->processed_blocks, bytenr,
|
|
bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static int get_tree_block_key(struct btrfs_fs_info *fs_info,
|
|
struct tree_block *block)
|
|
{
|
|
struct btrfs_tree_parent_check check = {
|
|
.level = block->level,
|
|
.owner_root = block->owner,
|
|
.transid = block->key.offset
|
|
};
|
|
struct extent_buffer *eb;
|
|
|
|
eb = read_tree_block(fs_info, block->bytenr, &check);
|
|
if (IS_ERR(eb))
|
|
return PTR_ERR(eb);
|
|
if (!extent_buffer_uptodate(eb)) {
|
|
free_extent_buffer(eb);
|
|
return -EIO;
|
|
}
|
|
if (block->level == 0)
|
|
btrfs_item_key_to_cpu(eb, &block->key, 0);
|
|
else
|
|
btrfs_node_key_to_cpu(eb, &block->key, 0);
|
|
free_extent_buffer(eb);
|
|
block->key_ready = 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* helper function to relocate a tree block
|
|
*/
|
|
static int relocate_tree_block(struct btrfs_trans_handle *trans,
|
|
struct reloc_control *rc,
|
|
struct btrfs_backref_node *node,
|
|
struct btrfs_key *key,
|
|
struct btrfs_path *path)
|
|
{
|
|
struct btrfs_root *root;
|
|
int ret = 0;
|
|
|
|
if (!node)
|
|
return 0;
|
|
|
|
/*
|
|
* If we fail here we want to drop our backref_node because we are going
|
|
* to start over and regenerate the tree for it.
|
|
*/
|
|
ret = reserve_metadata_space(trans, rc, node);
|
|
if (ret)
|
|
goto out;
|
|
|
|
BUG_ON(node->processed);
|
|
root = select_one_root(node);
|
|
if (IS_ERR(root)) {
|
|
ret = PTR_ERR(root);
|
|
|
|
/* See explanation in select_one_root for the -EUCLEAN case. */
|
|
ASSERT(ret == -ENOENT);
|
|
if (ret == -ENOENT) {
|
|
ret = 0;
|
|
update_processed_blocks(rc, node);
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
if (root) {
|
|
if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) {
|
|
/*
|
|
* This block was the root block of a root, and this is
|
|
* the first time we're processing the block and thus it
|
|
* should not have had the ->new_bytenr modified and
|
|
* should have not been included on the changed list.
|
|
*
|
|
* However in the case of corruption we could have
|
|
* multiple refs pointing to the same block improperly,
|
|
* and thus we would trip over these checks. ASSERT()
|
|
* for the developer case, because it could indicate a
|
|
* bug in the backref code, however error out for a
|
|
* normal user in the case of corruption.
|
|
*/
|
|
ASSERT(node->new_bytenr == 0);
|
|
ASSERT(list_empty(&node->list));
|
|
if (node->new_bytenr || !list_empty(&node->list)) {
|
|
btrfs_err(root->fs_info,
|
|
"bytenr %llu has improper references to it",
|
|
node->bytenr);
|
|
ret = -EUCLEAN;
|
|
goto out;
|
|
}
|
|
ret = btrfs_record_root_in_trans(trans, root);
|
|
if (ret)
|
|
goto out;
|
|
/*
|
|
* Another thread could have failed, need to check if we
|
|
* have reloc_root actually set.
|
|
*/
|
|
if (!root->reloc_root) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
root = root->reloc_root;
|
|
node->new_bytenr = root->node->start;
|
|
btrfs_put_root(node->root);
|
|
node->root = btrfs_grab_root(root);
|
|
ASSERT(node->root);
|
|
list_add_tail(&node->list, &rc->backref_cache.changed);
|
|
} else {
|
|
path->lowest_level = node->level;
|
|
if (root == root->fs_info->chunk_root)
|
|
btrfs_reserve_chunk_metadata(trans, false);
|
|
ret = btrfs_search_slot(trans, root, key, path, 0, 1);
|
|
btrfs_release_path(path);
|
|
if (root == root->fs_info->chunk_root)
|
|
btrfs_trans_release_chunk_metadata(trans);
|
|
if (ret > 0)
|
|
ret = 0;
|
|
}
|
|
if (!ret)
|
|
update_processed_blocks(rc, node);
|
|
} else {
|
|
ret = do_relocation(trans, rc, node, key, path, 1);
|
|
}
|
|
out:
|
|
if (ret || node->level == 0 || node->cowonly)
|
|
btrfs_backref_cleanup_node(&rc->backref_cache, node);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* relocate a list of blocks
|
|
*/
|
|
static noinline_for_stack
|
|
int relocate_tree_blocks(struct btrfs_trans_handle *trans,
|
|
struct reloc_control *rc, struct rb_root *blocks)
|
|
{
|
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
|
|
struct btrfs_backref_node *node;
|
|
struct btrfs_path *path;
|
|
struct tree_block *block;
|
|
struct tree_block *next;
|
|
int ret;
|
|
int err = 0;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path) {
|
|
err = -ENOMEM;
|
|
goto out_free_blocks;
|
|
}
|
|
|
|
/* Kick in readahead for tree blocks with missing keys */
|
|
rbtree_postorder_for_each_entry_safe(block, next, blocks, rb_node) {
|
|
if (!block->key_ready)
|
|
btrfs_readahead_tree_block(fs_info, block->bytenr,
|
|
block->owner, 0,
|
|
block->level);
|
|
}
|
|
|
|
/* Get first keys */
|
|
rbtree_postorder_for_each_entry_safe(block, next, blocks, rb_node) {
|
|
if (!block->key_ready) {
|
|
err = get_tree_block_key(fs_info, block);
|
|
if (err)
|
|
goto out_free_path;
|
|
}
|
|
}
|
|
|
|
/* Do tree relocation */
|
|
rbtree_postorder_for_each_entry_safe(block, next, blocks, rb_node) {
|
|
node = build_backref_tree(rc, &block->key,
|
|
block->level, block->bytenr);
|
|
if (IS_ERR(node)) {
|
|
err = PTR_ERR(node);
|
|
goto out;
|
|
}
|
|
|
|
ret = relocate_tree_block(trans, rc, node, &block->key,
|
|
path);
|
|
if (ret < 0) {
|
|
err = ret;
|
|
break;
|
|
}
|
|
}
|
|
out:
|
|
err = finish_pending_nodes(trans, rc, path, err);
|
|
|
|
out_free_path:
|
|
btrfs_free_path(path);
|
|
out_free_blocks:
|
|
free_block_list(blocks);
|
|
return err;
|
|
}
|
|
|
|
static noinline_for_stack int prealloc_file_extent_cluster(
|
|
struct btrfs_inode *inode,
|
|
struct file_extent_cluster *cluster)
|
|
{
|
|
u64 alloc_hint = 0;
|
|
u64 start;
|
|
u64 end;
|
|
u64 offset = inode->index_cnt;
|
|
u64 num_bytes;
|
|
int nr;
|
|
int ret = 0;
|
|
u64 i_size = i_size_read(&inode->vfs_inode);
|
|
u64 prealloc_start = cluster->start - offset;
|
|
u64 prealloc_end = cluster->end - offset;
|
|
u64 cur_offset = prealloc_start;
|
|
|
|
/*
|
|
* For subpage case, previous i_size may not be aligned to PAGE_SIZE.
|
|
* This means the range [i_size, PAGE_END + 1) is filled with zeros by
|
|
* btrfs_do_readpage() call of previously relocated file cluster.
|
|
*
|
|
* If the current cluster starts in the above range, btrfs_do_readpage()
|
|
* will skip the read, and relocate_one_page() will later writeback
|
|
* the padding zeros as new data, causing data corruption.
|
|
*
|
|
* Here we have to manually invalidate the range (i_size, PAGE_END + 1).
|
|
*/
|
|
if (!IS_ALIGNED(i_size, PAGE_SIZE)) {
|
|
struct address_space *mapping = inode->vfs_inode.i_mapping;
|
|
struct btrfs_fs_info *fs_info = inode->root->fs_info;
|
|
const u32 sectorsize = fs_info->sectorsize;
|
|
struct page *page;
|
|
|
|
ASSERT(sectorsize < PAGE_SIZE);
|
|
ASSERT(IS_ALIGNED(i_size, sectorsize));
|
|
|
|
/*
|
|
* Subpage can't handle page with DIRTY but without UPTODATE
|
|
* bit as it can lead to the following deadlock:
|
|
*
|
|
* btrfs_read_folio()
|
|
* | Page already *locked*
|
|
* |- btrfs_lock_and_flush_ordered_range()
|
|
* |- btrfs_start_ordered_extent()
|
|
* |- extent_write_cache_pages()
|
|
* |- lock_page()
|
|
* We try to lock the page we already hold.
|
|
*
|
|
* Here we just writeback the whole data reloc inode, so that
|
|
* we will be ensured to have no dirty range in the page, and
|
|
* are safe to clear the uptodate bits.
|
|
*
|
|
* This shouldn't cause too much overhead, as we need to write
|
|
* the data back anyway.
|
|
*/
|
|
ret = filemap_write_and_wait(mapping);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
clear_extent_bits(&inode->io_tree, i_size,
|
|
round_up(i_size, PAGE_SIZE) - 1,
|
|
EXTENT_UPTODATE);
|
|
page = find_lock_page(mapping, i_size >> PAGE_SHIFT);
|
|
/*
|
|
* If page is freed we don't need to do anything then, as we
|
|
* will re-read the whole page anyway.
|
|
*/
|
|
if (page) {
|
|
btrfs_subpage_clear_uptodate(fs_info, page, i_size,
|
|
round_up(i_size, PAGE_SIZE) - i_size);
|
|
unlock_page(page);
|
|
put_page(page);
|
|
}
|
|
}
|
|
|
|
BUG_ON(cluster->start != cluster->boundary[0]);
|
|
ret = btrfs_alloc_data_chunk_ondemand(inode,
|
|
prealloc_end + 1 - prealloc_start);
|
|
if (ret)
|
|
return ret;
|
|
|
|
btrfs_inode_lock(inode, 0);
|
|
for (nr = 0; nr < cluster->nr; nr++) {
|
|
struct extent_state *cached_state = NULL;
|
|
|
|
start = cluster->boundary[nr] - offset;
|
|
if (nr + 1 < cluster->nr)
|
|
end = cluster->boundary[nr + 1] - 1 - offset;
|
|
else
|
|
end = cluster->end - offset;
|
|
|
|
lock_extent(&inode->io_tree, start, end, &cached_state);
|
|
num_bytes = end + 1 - start;
|
|
ret = btrfs_prealloc_file_range(&inode->vfs_inode, 0, start,
|
|
num_bytes, num_bytes,
|
|
end + 1, &alloc_hint);
|
|
cur_offset = end + 1;
|
|
unlock_extent(&inode->io_tree, start, end, &cached_state);
|
|
if (ret)
|
|
break;
|
|
}
|
|
btrfs_inode_unlock(inode, 0);
|
|
|
|
if (cur_offset < prealloc_end)
|
|
btrfs_free_reserved_data_space_noquota(inode->root->fs_info,
|
|
prealloc_end + 1 - cur_offset);
|
|
return ret;
|
|
}
|
|
|
|
static noinline_for_stack int setup_relocation_extent_mapping(struct inode *inode,
|
|
u64 start, u64 end, u64 block_start)
|
|
{
|
|
struct extent_map *em;
|
|
struct extent_state *cached_state = NULL;
|
|
int ret = 0;
|
|
|
|
em = alloc_extent_map();
|
|
if (!em)
|
|
return -ENOMEM;
|
|
|
|
em->start = start;
|
|
em->len = end + 1 - start;
|
|
em->block_len = em->len;
|
|
em->block_start = block_start;
|
|
set_bit(EXTENT_FLAG_PINNED, &em->flags);
|
|
|
|
lock_extent(&BTRFS_I(inode)->io_tree, start, end, &cached_state);
|
|
ret = btrfs_replace_extent_map_range(BTRFS_I(inode), em, false);
|
|
unlock_extent(&BTRFS_I(inode)->io_tree, start, end, &cached_state);
|
|
free_extent_map(em);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Allow error injection to test balance/relocation cancellation
|
|
*/
|
|
noinline int btrfs_should_cancel_balance(struct btrfs_fs_info *fs_info)
|
|
{
|
|
return atomic_read(&fs_info->balance_cancel_req) ||
|
|
atomic_read(&fs_info->reloc_cancel_req) ||
|
|
fatal_signal_pending(current);
|
|
}
|
|
ALLOW_ERROR_INJECTION(btrfs_should_cancel_balance, TRUE);
|
|
|
|
static u64 get_cluster_boundary_end(struct file_extent_cluster *cluster,
|
|
int cluster_nr)
|
|
{
|
|
/* Last extent, use cluster end directly */
|
|
if (cluster_nr >= cluster->nr - 1)
|
|
return cluster->end;
|
|
|
|
/* Use next boundary start*/
|
|
return cluster->boundary[cluster_nr + 1] - 1;
|
|
}
|
|
|
|
static int relocate_one_page(struct inode *inode, struct file_ra_state *ra,
|
|
struct file_extent_cluster *cluster,
|
|
int *cluster_nr, unsigned long page_index)
|
|
{
|
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
|
|
u64 offset = BTRFS_I(inode)->index_cnt;
|
|
const unsigned long last_index = (cluster->end - offset) >> PAGE_SHIFT;
|
|
gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
|
|
struct page *page;
|
|
u64 page_start;
|
|
u64 page_end;
|
|
u64 cur;
|
|
int ret;
|
|
|
|
ASSERT(page_index <= last_index);
|
|
page = find_lock_page(inode->i_mapping, page_index);
|
|
if (!page) {
|
|
page_cache_sync_readahead(inode->i_mapping, ra, NULL,
|
|
page_index, last_index + 1 - page_index);
|
|
page = find_or_create_page(inode->i_mapping, page_index, mask);
|
|
if (!page)
|
|
return -ENOMEM;
|
|
}
|
|
ret = set_page_extent_mapped(page);
|
|
if (ret < 0)
|
|
goto release_page;
|
|
|
|
if (PageReadahead(page))
|
|
page_cache_async_readahead(inode->i_mapping, ra, NULL,
|
|
page_folio(page), page_index,
|
|
last_index + 1 - page_index);
|
|
|
|
if (!PageUptodate(page)) {
|
|
btrfs_read_folio(NULL, page_folio(page));
|
|
lock_page(page);
|
|
if (!PageUptodate(page)) {
|
|
ret = -EIO;
|
|
goto release_page;
|
|
}
|
|
}
|
|
|
|
page_start = page_offset(page);
|
|
page_end = page_start + PAGE_SIZE - 1;
|
|
|
|
/*
|
|
* Start from the cluster, as for subpage case, the cluster can start
|
|
* inside the page.
|
|
*/
|
|
cur = max(page_start, cluster->boundary[*cluster_nr] - offset);
|
|
while (cur <= page_end) {
|
|
struct extent_state *cached_state = NULL;
|
|
u64 extent_start = cluster->boundary[*cluster_nr] - offset;
|
|
u64 extent_end = get_cluster_boundary_end(cluster,
|
|
*cluster_nr) - offset;
|
|
u64 clamped_start = max(page_start, extent_start);
|
|
u64 clamped_end = min(page_end, extent_end);
|
|
u32 clamped_len = clamped_end + 1 - clamped_start;
|
|
|
|
/* Reserve metadata for this range */
|
|
ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
|
|
clamped_len, clamped_len,
|
|
false);
|
|
if (ret)
|
|
goto release_page;
|
|
|
|
/* Mark the range delalloc and dirty for later writeback */
|
|
lock_extent(&BTRFS_I(inode)->io_tree, clamped_start, clamped_end,
|
|
&cached_state);
|
|
ret = btrfs_set_extent_delalloc(BTRFS_I(inode), clamped_start,
|
|
clamped_end, 0, &cached_state);
|
|
if (ret) {
|
|
clear_extent_bit(&BTRFS_I(inode)->io_tree,
|
|
clamped_start, clamped_end,
|
|
EXTENT_LOCKED | EXTENT_BOUNDARY,
|
|
&cached_state);
|
|
btrfs_delalloc_release_metadata(BTRFS_I(inode),
|
|
clamped_len, true);
|
|
btrfs_delalloc_release_extents(BTRFS_I(inode),
|
|
clamped_len);
|
|
goto release_page;
|
|
}
|
|
btrfs_page_set_dirty(fs_info, page, clamped_start, clamped_len);
|
|
|
|
/*
|
|
* Set the boundary if it's inside the page.
|
|
* Data relocation requires the destination extents to have the
|
|
* same size as the source.
|
|
* EXTENT_BOUNDARY bit prevents current extent from being merged
|
|
* with previous extent.
|
|
*/
|
|
if (in_range(cluster->boundary[*cluster_nr] - offset,
|
|
page_start, PAGE_SIZE)) {
|
|
u64 boundary_start = cluster->boundary[*cluster_nr] -
|
|
offset;
|
|
u64 boundary_end = boundary_start +
|
|
fs_info->sectorsize - 1;
|
|
|
|
set_extent_bits(&BTRFS_I(inode)->io_tree,
|
|
boundary_start, boundary_end,
|
|
EXTENT_BOUNDARY);
|
|
}
|
|
unlock_extent(&BTRFS_I(inode)->io_tree, clamped_start, clamped_end,
|
|
&cached_state);
|
|
btrfs_delalloc_release_extents(BTRFS_I(inode), clamped_len);
|
|
cur += clamped_len;
|
|
|
|
/* Crossed extent end, go to next extent */
|
|
if (cur >= extent_end) {
|
|
(*cluster_nr)++;
|
|
/* Just finished the last extent of the cluster, exit. */
|
|
if (*cluster_nr >= cluster->nr)
|
|
break;
|
|
}
|
|
}
|
|
unlock_page(page);
|
|
put_page(page);
|
|
|
|
balance_dirty_pages_ratelimited(inode->i_mapping);
|
|
btrfs_throttle(fs_info);
|
|
if (btrfs_should_cancel_balance(fs_info))
|
|
ret = -ECANCELED;
|
|
return ret;
|
|
|
|
release_page:
|
|
unlock_page(page);
|
|
put_page(page);
|
|
return ret;
|
|
}
|
|
|
|
static int relocate_file_extent_cluster(struct inode *inode,
|
|
struct file_extent_cluster *cluster)
|
|
{
|
|
u64 offset = BTRFS_I(inode)->index_cnt;
|
|
unsigned long index;
|
|
unsigned long last_index;
|
|
struct file_ra_state *ra;
|
|
int cluster_nr = 0;
|
|
int ret = 0;
|
|
|
|
if (!cluster->nr)
|
|
return 0;
|
|
|
|
ra = kzalloc(sizeof(*ra), GFP_NOFS);
|
|
if (!ra)
|
|
return -ENOMEM;
|
|
|
|
ret = prealloc_file_extent_cluster(BTRFS_I(inode), cluster);
|
|
if (ret)
|
|
goto out;
|
|
|
|
file_ra_state_init(ra, inode->i_mapping);
|
|
|
|
ret = setup_relocation_extent_mapping(inode, cluster->start - offset,
|
|
cluster->end - offset, cluster->start);
|
|
if (ret)
|
|
goto out;
|
|
|
|
last_index = (cluster->end - offset) >> PAGE_SHIFT;
|
|
for (index = (cluster->start - offset) >> PAGE_SHIFT;
|
|
index <= last_index && !ret; index++)
|
|
ret = relocate_one_page(inode, ra, cluster, &cluster_nr, index);
|
|
if (ret == 0)
|
|
WARN_ON(cluster_nr != cluster->nr);
|
|
out:
|
|
kfree(ra);
|
|
return ret;
|
|
}
|
|
|
|
static noinline_for_stack
|
|
int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
|
|
struct file_extent_cluster *cluster)
|
|
{
|
|
int ret;
|
|
|
|
if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
|
|
ret = relocate_file_extent_cluster(inode, cluster);
|
|
if (ret)
|
|
return ret;
|
|
cluster->nr = 0;
|
|
}
|
|
|
|
if (!cluster->nr)
|
|
cluster->start = extent_key->objectid;
|
|
else
|
|
BUG_ON(cluster->nr >= MAX_EXTENTS);
|
|
cluster->end = extent_key->objectid + extent_key->offset - 1;
|
|
cluster->boundary[cluster->nr] = extent_key->objectid;
|
|
cluster->nr++;
|
|
|
|
if (cluster->nr >= MAX_EXTENTS) {
|
|
ret = relocate_file_extent_cluster(inode, cluster);
|
|
if (ret)
|
|
return ret;
|
|
cluster->nr = 0;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* helper to add a tree block to the list.
|
|
* the major work is getting the generation and level of the block
|
|
*/
|
|
static int add_tree_block(struct reloc_control *rc,
|
|
struct btrfs_key *extent_key,
|
|
struct btrfs_path *path,
|
|
struct rb_root *blocks)
|
|
{
|
|
struct extent_buffer *eb;
|
|
struct btrfs_extent_item *ei;
|
|
struct btrfs_tree_block_info *bi;
|
|
struct tree_block *block;
|
|
struct rb_node *rb_node;
|
|
u32 item_size;
|
|
int level = -1;
|
|
u64 generation;
|
|
u64 owner = 0;
|
|
|
|
eb = path->nodes[0];
|
|
item_size = btrfs_item_size(eb, path->slots[0]);
|
|
|
|
if (extent_key->type == BTRFS_METADATA_ITEM_KEY ||
|
|
item_size >= sizeof(*ei) + sizeof(*bi)) {
|
|
unsigned long ptr = 0, end;
|
|
|
|
ei = btrfs_item_ptr(eb, path->slots[0],
|
|
struct btrfs_extent_item);
|
|
end = (unsigned long)ei + item_size;
|
|
if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) {
|
|
bi = (struct btrfs_tree_block_info *)(ei + 1);
|
|
level = btrfs_tree_block_level(eb, bi);
|
|
ptr = (unsigned long)(bi + 1);
|
|
} else {
|
|
level = (int)extent_key->offset;
|
|
ptr = (unsigned long)(ei + 1);
|
|
}
|
|
generation = btrfs_extent_generation(eb, ei);
|
|
|
|
/*
|
|
* We're reading random blocks without knowing their owner ahead
|
|
* of time. This is ok most of the time, as all reloc roots and
|
|
* fs roots have the same lock type. However normal trees do
|
|
* not, and the only way to know ahead of time is to read the
|
|
* inline ref offset. We know it's an fs root if
|
|
*
|
|
* 1. There's more than one ref.
|
|
* 2. There's a SHARED_DATA_REF_KEY set.
|
|
* 3. FULL_BACKREF is set on the flags.
|
|
*
|
|
* Otherwise it's safe to assume that the ref offset == the
|
|
* owner of this block, so we can use that when calling
|
|
* read_tree_block.
|
|
*/
|
|
if (btrfs_extent_refs(eb, ei) == 1 &&
|
|
!(btrfs_extent_flags(eb, ei) &
|
|
BTRFS_BLOCK_FLAG_FULL_BACKREF) &&
|
|
ptr < end) {
|
|
struct btrfs_extent_inline_ref *iref;
|
|
int type;
|
|
|
|
iref = (struct btrfs_extent_inline_ref *)ptr;
|
|
type = btrfs_get_extent_inline_ref_type(eb, iref,
|
|
BTRFS_REF_TYPE_BLOCK);
|
|
if (type == BTRFS_REF_TYPE_INVALID)
|
|
return -EINVAL;
|
|
if (type == BTRFS_TREE_BLOCK_REF_KEY)
|
|
owner = btrfs_extent_inline_ref_offset(eb, iref);
|
|
}
|
|
} else if (unlikely(item_size == sizeof(struct btrfs_extent_item_v0))) {
|
|
btrfs_print_v0_err(eb->fs_info);
|
|
btrfs_handle_fs_error(eb->fs_info, -EINVAL, NULL);
|
|
return -EINVAL;
|
|
} else {
|
|
BUG();
|
|
}
|
|
|
|
btrfs_release_path(path);
|
|
|
|
BUG_ON(level == -1);
|
|
|
|
block = kmalloc(sizeof(*block), GFP_NOFS);
|
|
if (!block)
|
|
return -ENOMEM;
|
|
|
|
block->bytenr = extent_key->objectid;
|
|
block->key.objectid = rc->extent_root->fs_info->nodesize;
|
|
block->key.offset = generation;
|
|
block->level = level;
|
|
block->key_ready = 0;
|
|
block->owner = owner;
|
|
|
|
rb_node = rb_simple_insert(blocks, block->bytenr, &block->rb_node);
|
|
if (rb_node)
|
|
btrfs_backref_panic(rc->extent_root->fs_info, block->bytenr,
|
|
-EEXIST);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
|
|
*/
|
|
static int __add_tree_block(struct reloc_control *rc,
|
|
u64 bytenr, u32 blocksize,
|
|
struct rb_root *blocks)
|
|
{
|
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
|
|
struct btrfs_path *path;
|
|
struct btrfs_key key;
|
|
int ret;
|
|
bool skinny = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
|
|
|
|
if (tree_block_processed(bytenr, rc))
|
|
return 0;
|
|
|
|
if (rb_simple_search(blocks, bytenr))
|
|
return 0;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
again:
|
|
key.objectid = bytenr;
|
|
if (skinny) {
|
|
key.type = BTRFS_METADATA_ITEM_KEY;
|
|
key.offset = (u64)-1;
|
|
} else {
|
|
key.type = BTRFS_EXTENT_ITEM_KEY;
|
|
key.offset = blocksize;
|
|
}
|
|
|
|
path->search_commit_root = 1;
|
|
path->skip_locking = 1;
|
|
ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
if (ret > 0 && skinny) {
|
|
if (path->slots[0]) {
|
|
path->slots[0]--;
|
|
btrfs_item_key_to_cpu(path->nodes[0], &key,
|
|
path->slots[0]);
|
|
if (key.objectid == bytenr &&
|
|
(key.type == BTRFS_METADATA_ITEM_KEY ||
|
|
(key.type == BTRFS_EXTENT_ITEM_KEY &&
|
|
key.offset == blocksize)))
|
|
ret = 0;
|
|
}
|
|
|
|
if (ret) {
|
|
skinny = false;
|
|
btrfs_release_path(path);
|
|
goto again;
|
|
}
|
|
}
|
|
if (ret) {
|
|
ASSERT(ret == 1);
|
|
btrfs_print_leaf(path->nodes[0]);
|
|
btrfs_err(fs_info,
|
|
"tree block extent item (%llu) is not found in extent tree",
|
|
bytenr);
|
|
WARN_ON(1);
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
ret = add_tree_block(rc, &key, path, blocks);
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_block_group *block_group,
|
|
struct inode *inode,
|
|
u64 ino)
|
|
{
|
|
struct btrfs_root *root = fs_info->tree_root;
|
|
struct btrfs_trans_handle *trans;
|
|
int ret = 0;
|
|
|
|
if (inode)
|
|
goto truncate;
|
|
|
|
inode = btrfs_iget(fs_info->sb, ino, root);
|
|
if (IS_ERR(inode))
|
|
return -ENOENT;
|
|
|
|
truncate:
|
|
ret = btrfs_check_trunc_cache_free_space(fs_info,
|
|
&fs_info->global_block_rsv);
|
|
if (ret)
|
|
goto out;
|
|
|
|
trans = btrfs_join_transaction(root);
|
|
if (IS_ERR(trans)) {
|
|
ret = PTR_ERR(trans);
|
|
goto out;
|
|
}
|
|
|
|
ret = btrfs_truncate_free_space_cache(trans, block_group, inode);
|
|
|
|
btrfs_end_transaction(trans);
|
|
btrfs_btree_balance_dirty(fs_info);
|
|
out:
|
|
iput(inode);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Locate the free space cache EXTENT_DATA in root tree leaf and delete the
|
|
* cache inode, to avoid free space cache data extent blocking data relocation.
|
|
*/
|
|
static int delete_v1_space_cache(struct extent_buffer *leaf,
|
|
struct btrfs_block_group *block_group,
|
|
u64 data_bytenr)
|
|
{
|
|
u64 space_cache_ino;
|
|
struct btrfs_file_extent_item *ei;
|
|
struct btrfs_key key;
|
|
bool found = false;
|
|
int i;
|
|
int ret;
|
|
|
|
if (btrfs_header_owner(leaf) != BTRFS_ROOT_TREE_OBJECTID)
|
|
return 0;
|
|
|
|
for (i = 0; i < btrfs_header_nritems(leaf); i++) {
|
|
u8 type;
|
|
|
|
btrfs_item_key_to_cpu(leaf, &key, i);
|
|
if (key.type != BTRFS_EXTENT_DATA_KEY)
|
|
continue;
|
|
ei = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
|
|
type = btrfs_file_extent_type(leaf, ei);
|
|
|
|
if ((type == BTRFS_FILE_EXTENT_REG ||
|
|
type == BTRFS_FILE_EXTENT_PREALLOC) &&
|
|
btrfs_file_extent_disk_bytenr(leaf, ei) == data_bytenr) {
|
|
found = true;
|
|
space_cache_ino = key.objectid;
|
|
break;
|
|
}
|
|
}
|
|
if (!found)
|
|
return -ENOENT;
|
|
ret = delete_block_group_cache(leaf->fs_info, block_group, NULL,
|
|
space_cache_ino);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* helper to find all tree blocks that reference a given data extent
|
|
*/
|
|
static noinline_for_stack
|
|
int add_data_references(struct reloc_control *rc,
|
|
struct btrfs_key *extent_key,
|
|
struct btrfs_path *path,
|
|
struct rb_root *blocks)
|
|
{
|
|
struct btrfs_backref_walk_ctx ctx = { 0 };
|
|
struct ulist_iterator leaf_uiter;
|
|
struct ulist_node *ref_node = NULL;
|
|
const u32 blocksize = rc->extent_root->fs_info->nodesize;
|
|
int ret = 0;
|
|
|
|
btrfs_release_path(path);
|
|
|
|
ctx.bytenr = extent_key->objectid;
|
|
ctx.ignore_extent_item_pos = true;
|
|
ctx.fs_info = rc->extent_root->fs_info;
|
|
|
|
ret = btrfs_find_all_leafs(&ctx);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ULIST_ITER_INIT(&leaf_uiter);
|
|
while ((ref_node = ulist_next(ctx.refs, &leaf_uiter))) {
|
|
struct btrfs_tree_parent_check check = { 0 };
|
|
struct extent_buffer *eb;
|
|
|
|
eb = read_tree_block(ctx.fs_info, ref_node->val, &check);
|
|
if (IS_ERR(eb)) {
|
|
ret = PTR_ERR(eb);
|
|
break;
|
|
}
|
|
ret = delete_v1_space_cache(eb, rc->block_group,
|
|
extent_key->objectid);
|
|
free_extent_buffer(eb);
|
|
if (ret < 0)
|
|
break;
|
|
ret = __add_tree_block(rc, ref_node->val, blocksize, blocks);
|
|
if (ret < 0)
|
|
break;
|
|
}
|
|
if (ret < 0)
|
|
free_block_list(blocks);
|
|
ulist_free(ctx.refs);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* helper to find next unprocessed extent
|
|
*/
|
|
static noinline_for_stack
|
|
int find_next_extent(struct reloc_control *rc, struct btrfs_path *path,
|
|
struct btrfs_key *extent_key)
|
|
{
|
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
|
|
struct btrfs_key key;
|
|
struct extent_buffer *leaf;
|
|
u64 start, end, last;
|
|
int ret;
|
|
|
|
last = rc->block_group->start + rc->block_group->length;
|
|
while (1) {
|
|
cond_resched();
|
|
if (rc->search_start >= last) {
|
|
ret = 1;
|
|
break;
|
|
}
|
|
|
|
key.objectid = rc->search_start;
|
|
key.type = BTRFS_EXTENT_ITEM_KEY;
|
|
key.offset = 0;
|
|
|
|
path->search_commit_root = 1;
|
|
path->skip_locking = 1;
|
|
ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
|
|
0, 0);
|
|
if (ret < 0)
|
|
break;
|
|
next:
|
|
leaf = path->nodes[0];
|
|
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
|
|
ret = btrfs_next_leaf(rc->extent_root, path);
|
|
if (ret != 0)
|
|
break;
|
|
leaf = path->nodes[0];
|
|
}
|
|
|
|
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
|
|
if (key.objectid >= last) {
|
|
ret = 1;
|
|
break;
|
|
}
|
|
|
|
if (key.type != BTRFS_EXTENT_ITEM_KEY &&
|
|
key.type != BTRFS_METADATA_ITEM_KEY) {
|
|
path->slots[0]++;
|
|
goto next;
|
|
}
|
|
|
|
if (key.type == BTRFS_EXTENT_ITEM_KEY &&
|
|
key.objectid + key.offset <= rc->search_start) {
|
|
path->slots[0]++;
|
|
goto next;
|
|
}
|
|
|
|
if (key.type == BTRFS_METADATA_ITEM_KEY &&
|
|
key.objectid + fs_info->nodesize <=
|
|
rc->search_start) {
|
|
path->slots[0]++;
|
|
goto next;
|
|
}
|
|
|
|
ret = find_first_extent_bit(&rc->processed_blocks,
|
|
key.objectid, &start, &end,
|
|
EXTENT_DIRTY, NULL);
|
|
|
|
if (ret == 0 && start <= key.objectid) {
|
|
btrfs_release_path(path);
|
|
rc->search_start = end + 1;
|
|
} else {
|
|
if (key.type == BTRFS_EXTENT_ITEM_KEY)
|
|
rc->search_start = key.objectid + key.offset;
|
|
else
|
|
rc->search_start = key.objectid +
|
|
fs_info->nodesize;
|
|
memcpy(extent_key, &key, sizeof(key));
|
|
return 0;
|
|
}
|
|
}
|
|
btrfs_release_path(path);
|
|
return ret;
|
|
}
|
|
|
|
static void set_reloc_control(struct reloc_control *rc)
|
|
{
|
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
|
|
|
|
mutex_lock(&fs_info->reloc_mutex);
|
|
fs_info->reloc_ctl = rc;
|
|
mutex_unlock(&fs_info->reloc_mutex);
|
|
}
|
|
|
|
static void unset_reloc_control(struct reloc_control *rc)
|
|
{
|
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
|
|
|
|
mutex_lock(&fs_info->reloc_mutex);
|
|
fs_info->reloc_ctl = NULL;
|
|
mutex_unlock(&fs_info->reloc_mutex);
|
|
}
|
|
|
|
static noinline_for_stack
|
|
int prepare_to_relocate(struct reloc_control *rc)
|
|
{
|
|
struct btrfs_trans_handle *trans;
|
|
int ret;
|
|
|
|
rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root->fs_info,
|
|
BTRFS_BLOCK_RSV_TEMP);
|
|
if (!rc->block_rsv)
|
|
return -ENOMEM;
|
|
|
|
memset(&rc->cluster, 0, sizeof(rc->cluster));
|
|
rc->search_start = rc->block_group->start;
|
|
rc->extents_found = 0;
|
|
rc->nodes_relocated = 0;
|
|
rc->merging_rsv_size = 0;
|
|
rc->reserved_bytes = 0;
|
|
rc->block_rsv->size = rc->extent_root->fs_info->nodesize *
|
|
RELOCATION_RESERVED_NODES;
|
|
ret = btrfs_block_rsv_refill(rc->extent_root->fs_info,
|
|
rc->block_rsv, rc->block_rsv->size,
|
|
BTRFS_RESERVE_FLUSH_ALL);
|
|
if (ret)
|
|
return ret;
|
|
|
|
rc->create_reloc_tree = 1;
|
|
set_reloc_control(rc);
|
|
|
|
trans = btrfs_join_transaction(rc->extent_root);
|
|
if (IS_ERR(trans)) {
|
|
unset_reloc_control(rc);
|
|
/*
|
|
* extent tree is not a ref_cow tree and has no reloc_root to
|
|
* cleanup. And callers are responsible to free the above
|
|
* block rsv.
|
|
*/
|
|
return PTR_ERR(trans);
|
|
}
|
|
|
|
ret = btrfs_commit_transaction(trans);
|
|
if (ret)
|
|
unset_reloc_control(rc);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
|
|
{
|
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
|
|
struct rb_root blocks = RB_ROOT;
|
|
struct btrfs_key key;
|
|
struct btrfs_trans_handle *trans = NULL;
|
|
struct btrfs_path *path;
|
|
struct btrfs_extent_item *ei;
|
|
u64 flags;
|
|
int ret;
|
|
int err = 0;
|
|
int progress = 0;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
path->reada = READA_FORWARD;
|
|
|
|
ret = prepare_to_relocate(rc);
|
|
if (ret) {
|
|
err = ret;
|
|
goto out_free;
|
|
}
|
|
|
|
while (1) {
|
|
rc->reserved_bytes = 0;
|
|
ret = btrfs_block_rsv_refill(fs_info, rc->block_rsv,
|
|
rc->block_rsv->size,
|
|
BTRFS_RESERVE_FLUSH_ALL);
|
|
if (ret) {
|
|
err = ret;
|
|
break;
|
|
}
|
|
progress++;
|
|
trans = btrfs_start_transaction(rc->extent_root, 0);
|
|
if (IS_ERR(trans)) {
|
|
err = PTR_ERR(trans);
|
|
trans = NULL;
|
|
break;
|
|
}
|
|
restart:
|
|
if (update_backref_cache(trans, &rc->backref_cache)) {
|
|
btrfs_end_transaction(trans);
|
|
trans = NULL;
|
|
continue;
|
|
}
|
|
|
|
ret = find_next_extent(rc, path, &key);
|
|
if (ret < 0)
|
|
err = ret;
|
|
if (ret != 0)
|
|
break;
|
|
|
|
rc->extents_found++;
|
|
|
|
ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
|
|
struct btrfs_extent_item);
|
|
flags = btrfs_extent_flags(path->nodes[0], ei);
|
|
|
|
if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
|
|
ret = add_tree_block(rc, &key, path, &blocks);
|
|
} else if (rc->stage == UPDATE_DATA_PTRS &&
|
|
(flags & BTRFS_EXTENT_FLAG_DATA)) {
|
|
ret = add_data_references(rc, &key, path, &blocks);
|
|
} else {
|
|
btrfs_release_path(path);
|
|
ret = 0;
|
|
}
|
|
if (ret < 0) {
|
|
err = ret;
|
|
break;
|
|
}
|
|
|
|
if (!RB_EMPTY_ROOT(&blocks)) {
|
|
ret = relocate_tree_blocks(trans, rc, &blocks);
|
|
if (ret < 0) {
|
|
if (ret != -EAGAIN) {
|
|
err = ret;
|
|
break;
|
|
}
|
|
rc->extents_found--;
|
|
rc->search_start = key.objectid;
|
|
}
|
|
}
|
|
|
|
btrfs_end_transaction_throttle(trans);
|
|
btrfs_btree_balance_dirty(fs_info);
|
|
trans = NULL;
|
|
|
|
if (rc->stage == MOVE_DATA_EXTENTS &&
|
|
(flags & BTRFS_EXTENT_FLAG_DATA)) {
|
|
rc->found_file_extent = 1;
|
|
ret = relocate_data_extent(rc->data_inode,
|
|
&key, &rc->cluster);
|
|
if (ret < 0) {
|
|
err = ret;
|
|
break;
|
|
}
|
|
}
|
|
if (btrfs_should_cancel_balance(fs_info)) {
|
|
err = -ECANCELED;
|
|
break;
|
|
}
|
|
}
|
|
if (trans && progress && err == -ENOSPC) {
|
|
ret = btrfs_force_chunk_alloc(trans, rc->block_group->flags);
|
|
if (ret == 1) {
|
|
err = 0;
|
|
progress = 0;
|
|
goto restart;
|
|
}
|
|
}
|
|
|
|
btrfs_release_path(path);
|
|
clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY);
|
|
|
|
if (trans) {
|
|
btrfs_end_transaction_throttle(trans);
|
|
btrfs_btree_balance_dirty(fs_info);
|
|
}
|
|
|
|
if (!err) {
|
|
ret = relocate_file_extent_cluster(rc->data_inode,
|
|
&rc->cluster);
|
|
if (ret < 0)
|
|
err = ret;
|
|
}
|
|
|
|
rc->create_reloc_tree = 0;
|
|
set_reloc_control(rc);
|
|
|
|
btrfs_backref_release_cache(&rc->backref_cache);
|
|
btrfs_block_rsv_release(fs_info, rc->block_rsv, (u64)-1, NULL);
|
|
|
|
/*
|
|
* Even in the case when the relocation is cancelled, we should all go
|
|
* through prepare_to_merge() and merge_reloc_roots().
|
|
*
|
|
* For error (including cancelled balance), prepare_to_merge() will
|
|
* mark all reloc trees orphan, then queue them for cleanup in
|
|
* merge_reloc_roots()
|
|
*/
|
|
err = prepare_to_merge(rc, err);
|
|
|
|
merge_reloc_roots(rc);
|
|
|
|
rc->merge_reloc_tree = 0;
|
|
unset_reloc_control(rc);
|
|
btrfs_block_rsv_release(fs_info, rc->block_rsv, (u64)-1, NULL);
|
|
|
|
/* get rid of pinned extents */
|
|
trans = btrfs_join_transaction(rc->extent_root);
|
|
if (IS_ERR(trans)) {
|
|
err = PTR_ERR(trans);
|
|
goto out_free;
|
|
}
|
|
ret = btrfs_commit_transaction(trans);
|
|
if (ret && !err)
|
|
err = ret;
|
|
out_free:
|
|
ret = clean_dirty_subvols(rc);
|
|
if (ret < 0 && !err)
|
|
err = ret;
|
|
btrfs_free_block_rsv(fs_info, rc->block_rsv);
|
|
btrfs_free_path(path);
|
|
return err;
|
|
}
|
|
|
|
static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
|
|
struct btrfs_root *root, u64 objectid)
|
|
{
|
|
struct btrfs_path *path;
|
|
struct btrfs_inode_item *item;
|
|
struct extent_buffer *leaf;
|
|
int ret;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
ret = btrfs_insert_empty_inode(trans, root, path, objectid);
|
|
if (ret)
|
|
goto out;
|
|
|
|
leaf = path->nodes[0];
|
|
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
|
|
memzero_extent_buffer(leaf, (unsigned long)item, sizeof(*item));
|
|
btrfs_set_inode_generation(leaf, item, 1);
|
|
btrfs_set_inode_size(leaf, item, 0);
|
|
btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
|
|
btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
|
|
BTRFS_INODE_PREALLOC);
|
|
btrfs_mark_buffer_dirty(leaf);
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
static void delete_orphan_inode(struct btrfs_trans_handle *trans,
|
|
struct btrfs_root *root, u64 objectid)
|
|
{
|
|
struct btrfs_path *path;
|
|
struct btrfs_key key;
|
|
int ret = 0;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
key.objectid = objectid;
|
|
key.type = BTRFS_INODE_ITEM_KEY;
|
|
key.offset = 0;
|
|
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
|
|
if (ret) {
|
|
if (ret > 0)
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
ret = btrfs_del_item(trans, root, path);
|
|
out:
|
|
if (ret)
|
|
btrfs_abort_transaction(trans, ret);
|
|
btrfs_free_path(path);
|
|
}
|
|
|
|
/*
|
|
* helper to create inode for data relocation.
|
|
* the inode is in data relocation tree and its link count is 0
|
|
*/
|
|
static noinline_for_stack
|
|
struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_block_group *group)
|
|
{
|
|
struct inode *inode = NULL;
|
|
struct btrfs_trans_handle *trans;
|
|
struct btrfs_root *root;
|
|
u64 objectid;
|
|
int err = 0;
|
|
|
|
root = btrfs_grab_root(fs_info->data_reloc_root);
|
|
trans = btrfs_start_transaction(root, 6);
|
|
if (IS_ERR(trans)) {
|
|
btrfs_put_root(root);
|
|
return ERR_CAST(trans);
|
|
}
|
|
|
|
err = btrfs_get_free_objectid(root, &objectid);
|
|
if (err)
|
|
goto out;
|
|
|
|
err = __insert_orphan_inode(trans, root, objectid);
|
|
if (err)
|
|
goto out;
|
|
|
|
inode = btrfs_iget(fs_info->sb, objectid, root);
|
|
if (IS_ERR(inode)) {
|
|
delete_orphan_inode(trans, root, objectid);
|
|
err = PTR_ERR(inode);
|
|
inode = NULL;
|
|
goto out;
|
|
}
|
|
BTRFS_I(inode)->index_cnt = group->start;
|
|
|
|
err = btrfs_orphan_add(trans, BTRFS_I(inode));
|
|
out:
|
|
btrfs_put_root(root);
|
|
btrfs_end_transaction(trans);
|
|
btrfs_btree_balance_dirty(fs_info);
|
|
if (err) {
|
|
iput(inode);
|
|
inode = ERR_PTR(err);
|
|
}
|
|
return inode;
|
|
}
|
|
|
|
/*
|
|
* Mark start of chunk relocation that is cancellable. Check if the cancellation
|
|
* has been requested meanwhile and don't start in that case.
|
|
*
|
|
* Return:
|
|
* 0 success
|
|
* -EINPROGRESS operation is already in progress, that's probably a bug
|
|
* -ECANCELED cancellation request was set before the operation started
|
|
*/
|
|
static int reloc_chunk_start(struct btrfs_fs_info *fs_info)
|
|
{
|
|
if (test_and_set_bit(BTRFS_FS_RELOC_RUNNING, &fs_info->flags)) {
|
|
/* This should not happen */
|
|
btrfs_err(fs_info, "reloc already running, cannot start");
|
|
return -EINPROGRESS;
|
|
}
|
|
|
|
if (atomic_read(&fs_info->reloc_cancel_req) > 0) {
|
|
btrfs_info(fs_info, "chunk relocation canceled on start");
|
|
/*
|
|
* On cancel, clear all requests but let the caller mark
|
|
* the end after cleanup operations.
|
|
*/
|
|
atomic_set(&fs_info->reloc_cancel_req, 0);
|
|
return -ECANCELED;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Mark end of chunk relocation that is cancellable and wake any waiters.
|
|
*/
|
|
static void reloc_chunk_end(struct btrfs_fs_info *fs_info)
|
|
{
|
|
/* Requested after start, clear bit first so any waiters can continue */
|
|
if (atomic_read(&fs_info->reloc_cancel_req) > 0)
|
|
btrfs_info(fs_info, "chunk relocation canceled during operation");
|
|
clear_and_wake_up_bit(BTRFS_FS_RELOC_RUNNING, &fs_info->flags);
|
|
atomic_set(&fs_info->reloc_cancel_req, 0);
|
|
}
|
|
|
|
static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info)
|
|
{
|
|
struct reloc_control *rc;
|
|
|
|
rc = kzalloc(sizeof(*rc), GFP_NOFS);
|
|
if (!rc)
|
|
return NULL;
|
|
|
|
INIT_LIST_HEAD(&rc->reloc_roots);
|
|
INIT_LIST_HEAD(&rc->dirty_subvol_roots);
|
|
btrfs_backref_init_cache(fs_info, &rc->backref_cache, 1);
|
|
mapping_tree_init(&rc->reloc_root_tree);
|
|
extent_io_tree_init(fs_info, &rc->processed_blocks, IO_TREE_RELOC_BLOCKS);
|
|
return rc;
|
|
}
|
|
|
|
static void free_reloc_control(struct reloc_control *rc)
|
|
{
|
|
struct mapping_node *node, *tmp;
|
|
|
|
free_reloc_roots(&rc->reloc_roots);
|
|
rbtree_postorder_for_each_entry_safe(node, tmp,
|
|
&rc->reloc_root_tree.rb_root, rb_node)
|
|
kfree(node);
|
|
|
|
kfree(rc);
|
|
}
|
|
|
|
/*
|
|
* Print the block group being relocated
|
|
*/
|
|
static void describe_relocation(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_block_group *block_group)
|
|
{
|
|
char buf[128] = {'\0'};
|
|
|
|
btrfs_describe_block_groups(block_group->flags, buf, sizeof(buf));
|
|
|
|
btrfs_info(fs_info,
|
|
"relocating block group %llu flags %s",
|
|
block_group->start, buf);
|
|
}
|
|
|
|
static const char *stage_to_string(int stage)
|
|
{
|
|
if (stage == MOVE_DATA_EXTENTS)
|
|
return "move data extents";
|
|
if (stage == UPDATE_DATA_PTRS)
|
|
return "update data pointers";
|
|
return "unknown";
|
|
}
|
|
|
|
/*
|
|
* function to relocate all extents in a block group.
|
|
*/
|
|
int btrfs_relocate_block_group(struct btrfs_fs_info *fs_info, u64 group_start)
|
|
{
|
|
struct btrfs_block_group *bg;
|
|
struct btrfs_root *extent_root = btrfs_extent_root(fs_info, group_start);
|
|
struct reloc_control *rc;
|
|
struct inode *inode;
|
|
struct btrfs_path *path;
|
|
int ret;
|
|
int rw = 0;
|
|
int err = 0;
|
|
|
|
/*
|
|
* This only gets set if we had a half-deleted snapshot on mount. We
|
|
* cannot allow relocation to start while we're still trying to clean up
|
|
* these pending deletions.
|
|
*/
|
|
ret = wait_on_bit(&fs_info->flags, BTRFS_FS_UNFINISHED_DROPS, TASK_INTERRUPTIBLE);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* We may have been woken up by close_ctree, so bail if we're closing. */
|
|
if (btrfs_fs_closing(fs_info))
|
|
return -EINTR;
|
|
|
|
bg = btrfs_lookup_block_group(fs_info, group_start);
|
|
if (!bg)
|
|
return -ENOENT;
|
|
|
|
/*
|
|
* Relocation of a data block group creates ordered extents. Without
|
|
* sb_start_write(), we can freeze the filesystem while unfinished
|
|
* ordered extents are left. Such ordered extents can cause a deadlock
|
|
* e.g. when syncfs() is waiting for their completion but they can't
|
|
* finish because they block when joining a transaction, due to the
|
|
* fact that the freeze locks are being held in write mode.
|
|
*/
|
|
if (bg->flags & BTRFS_BLOCK_GROUP_DATA)
|
|
ASSERT(sb_write_started(fs_info->sb));
|
|
|
|
if (btrfs_pinned_by_swapfile(fs_info, bg)) {
|
|
btrfs_put_block_group(bg);
|
|
return -ETXTBSY;
|
|
}
|
|
|
|
rc = alloc_reloc_control(fs_info);
|
|
if (!rc) {
|
|
btrfs_put_block_group(bg);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
ret = reloc_chunk_start(fs_info);
|
|
if (ret < 0) {
|
|
err = ret;
|
|
goto out_put_bg;
|
|
}
|
|
|
|
rc->extent_root = extent_root;
|
|
rc->block_group = bg;
|
|
|
|
ret = btrfs_inc_block_group_ro(rc->block_group, true);
|
|
if (ret) {
|
|
err = ret;
|
|
goto out;
|
|
}
|
|
rw = 1;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
inode = lookup_free_space_inode(rc->block_group, path);
|
|
btrfs_free_path(path);
|
|
|
|
if (!IS_ERR(inode))
|
|
ret = delete_block_group_cache(fs_info, rc->block_group, inode, 0);
|
|
else
|
|
ret = PTR_ERR(inode);
|
|
|
|
if (ret && ret != -ENOENT) {
|
|
err = ret;
|
|
goto out;
|
|
}
|
|
|
|
rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
|
|
if (IS_ERR(rc->data_inode)) {
|
|
err = PTR_ERR(rc->data_inode);
|
|
rc->data_inode = NULL;
|
|
goto out;
|
|
}
|
|
|
|
describe_relocation(fs_info, rc->block_group);
|
|
|
|
btrfs_wait_block_group_reservations(rc->block_group);
|
|
btrfs_wait_nocow_writers(rc->block_group);
|
|
btrfs_wait_ordered_roots(fs_info, U64_MAX,
|
|
rc->block_group->start,
|
|
rc->block_group->length);
|
|
|
|
ret = btrfs_zone_finish(rc->block_group);
|
|
WARN_ON(ret && ret != -EAGAIN);
|
|
|
|
while (1) {
|
|
int finishes_stage;
|
|
|
|
mutex_lock(&fs_info->cleaner_mutex);
|
|
ret = relocate_block_group(rc);
|
|
mutex_unlock(&fs_info->cleaner_mutex);
|
|
if (ret < 0)
|
|
err = ret;
|
|
|
|
finishes_stage = rc->stage;
|
|
/*
|
|
* We may have gotten ENOSPC after we already dirtied some
|
|
* extents. If writeout happens while we're relocating a
|
|
* different block group we could end up hitting the
|
|
* BUG_ON(rc->stage == UPDATE_DATA_PTRS) in
|
|
* btrfs_reloc_cow_block. Make sure we write everything out
|
|
* properly so we don't trip over this problem, and then break
|
|
* out of the loop if we hit an error.
|
|
*/
|
|
if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
|
|
ret = btrfs_wait_ordered_range(rc->data_inode, 0,
|
|
(u64)-1);
|
|
if (ret)
|
|
err = ret;
|
|
invalidate_mapping_pages(rc->data_inode->i_mapping,
|
|
0, -1);
|
|
rc->stage = UPDATE_DATA_PTRS;
|
|
}
|
|
|
|
if (err < 0)
|
|
goto out;
|
|
|
|
if (rc->extents_found == 0)
|
|
break;
|
|
|
|
btrfs_info(fs_info, "found %llu extents, stage: %s",
|
|
rc->extents_found, stage_to_string(finishes_stage));
|
|
}
|
|
|
|
WARN_ON(rc->block_group->pinned > 0);
|
|
WARN_ON(rc->block_group->reserved > 0);
|
|
WARN_ON(rc->block_group->used > 0);
|
|
out:
|
|
if (err && rw)
|
|
btrfs_dec_block_group_ro(rc->block_group);
|
|
iput(rc->data_inode);
|
|
out_put_bg:
|
|
btrfs_put_block_group(bg);
|
|
reloc_chunk_end(fs_info);
|
|
free_reloc_control(rc);
|
|
return err;
|
|
}
|
|
|
|
static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
|
|
{
|
|
struct btrfs_fs_info *fs_info = root->fs_info;
|
|
struct btrfs_trans_handle *trans;
|
|
int ret, err;
|
|
|
|
trans = btrfs_start_transaction(fs_info->tree_root, 0);
|
|
if (IS_ERR(trans))
|
|
return PTR_ERR(trans);
|
|
|
|
memset(&root->root_item.drop_progress, 0,
|
|
sizeof(root->root_item.drop_progress));
|
|
btrfs_set_root_drop_level(&root->root_item, 0);
|
|
btrfs_set_root_refs(&root->root_item, 0);
|
|
ret = btrfs_update_root(trans, fs_info->tree_root,
|
|
&root->root_key, &root->root_item);
|
|
|
|
err = btrfs_end_transaction(trans);
|
|
if (err)
|
|
return err;
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* recover relocation interrupted by system crash.
|
|
*
|
|
* this function resumes merging reloc trees with corresponding fs trees.
|
|
* this is important for keeping the sharing of tree blocks
|
|
*/
|
|
int btrfs_recover_relocation(struct btrfs_fs_info *fs_info)
|
|
{
|
|
LIST_HEAD(reloc_roots);
|
|
struct btrfs_key key;
|
|
struct btrfs_root *fs_root;
|
|
struct btrfs_root *reloc_root;
|
|
struct btrfs_path *path;
|
|
struct extent_buffer *leaf;
|
|
struct reloc_control *rc = NULL;
|
|
struct btrfs_trans_handle *trans;
|
|
int ret;
|
|
int err = 0;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
path->reada = READA_BACK;
|
|
|
|
key.objectid = BTRFS_TREE_RELOC_OBJECTID;
|
|
key.type = BTRFS_ROOT_ITEM_KEY;
|
|
key.offset = (u64)-1;
|
|
|
|
while (1) {
|
|
ret = btrfs_search_slot(NULL, fs_info->tree_root, &key,
|
|
path, 0, 0);
|
|
if (ret < 0) {
|
|
err = ret;
|
|
goto out;
|
|
}
|
|
if (ret > 0) {
|
|
if (path->slots[0] == 0)
|
|
break;
|
|
path->slots[0]--;
|
|
}
|
|
leaf = path->nodes[0];
|
|
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
|
|
btrfs_release_path(path);
|
|
|
|
if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
|
|
key.type != BTRFS_ROOT_ITEM_KEY)
|
|
break;
|
|
|
|
reloc_root = btrfs_read_tree_root(fs_info->tree_root, &key);
|
|
if (IS_ERR(reloc_root)) {
|
|
err = PTR_ERR(reloc_root);
|
|
goto out;
|
|
}
|
|
|
|
set_bit(BTRFS_ROOT_SHAREABLE, &reloc_root->state);
|
|
list_add(&reloc_root->root_list, &reloc_roots);
|
|
|
|
if (btrfs_root_refs(&reloc_root->root_item) > 0) {
|
|
fs_root = btrfs_get_fs_root(fs_info,
|
|
reloc_root->root_key.offset, false);
|
|
if (IS_ERR(fs_root)) {
|
|
ret = PTR_ERR(fs_root);
|
|
if (ret != -ENOENT) {
|
|
err = ret;
|
|
goto out;
|
|
}
|
|
ret = mark_garbage_root(reloc_root);
|
|
if (ret < 0) {
|
|
err = ret;
|
|
goto out;
|
|
}
|
|
} else {
|
|
btrfs_put_root(fs_root);
|
|
}
|
|
}
|
|
|
|
if (key.offset == 0)
|
|
break;
|
|
|
|
key.offset--;
|
|
}
|
|
btrfs_release_path(path);
|
|
|
|
if (list_empty(&reloc_roots))
|
|
goto out;
|
|
|
|
rc = alloc_reloc_control(fs_info);
|
|
if (!rc) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
ret = reloc_chunk_start(fs_info);
|
|
if (ret < 0) {
|
|
err = ret;
|
|
goto out_end;
|
|
}
|
|
|
|
rc->extent_root = btrfs_extent_root(fs_info, 0);
|
|
|
|
set_reloc_control(rc);
|
|
|
|
trans = btrfs_join_transaction(rc->extent_root);
|
|
if (IS_ERR(trans)) {
|
|
err = PTR_ERR(trans);
|
|
goto out_unset;
|
|
}
|
|
|
|
rc->merge_reloc_tree = 1;
|
|
|
|
while (!list_empty(&reloc_roots)) {
|
|
reloc_root = list_entry(reloc_roots.next,
|
|
struct btrfs_root, root_list);
|
|
list_del(&reloc_root->root_list);
|
|
|
|
if (btrfs_root_refs(&reloc_root->root_item) == 0) {
|
|
list_add_tail(&reloc_root->root_list,
|
|
&rc->reloc_roots);
|
|
continue;
|
|
}
|
|
|
|
fs_root = btrfs_get_fs_root(fs_info, reloc_root->root_key.offset,
|
|
false);
|
|
if (IS_ERR(fs_root)) {
|
|
err = PTR_ERR(fs_root);
|
|
list_add_tail(&reloc_root->root_list, &reloc_roots);
|
|
btrfs_end_transaction(trans);
|
|
goto out_unset;
|
|
}
|
|
|
|
err = __add_reloc_root(reloc_root);
|
|
ASSERT(err != -EEXIST);
|
|
if (err) {
|
|
list_add_tail(&reloc_root->root_list, &reloc_roots);
|
|
btrfs_put_root(fs_root);
|
|
btrfs_end_transaction(trans);
|
|
goto out_unset;
|
|
}
|
|
fs_root->reloc_root = btrfs_grab_root(reloc_root);
|
|
btrfs_put_root(fs_root);
|
|
}
|
|
|
|
err = btrfs_commit_transaction(trans);
|
|
if (err)
|
|
goto out_unset;
|
|
|
|
merge_reloc_roots(rc);
|
|
|
|
unset_reloc_control(rc);
|
|
|
|
trans = btrfs_join_transaction(rc->extent_root);
|
|
if (IS_ERR(trans)) {
|
|
err = PTR_ERR(trans);
|
|
goto out_clean;
|
|
}
|
|
err = btrfs_commit_transaction(trans);
|
|
out_clean:
|
|
ret = clean_dirty_subvols(rc);
|
|
if (ret < 0 && !err)
|
|
err = ret;
|
|
out_unset:
|
|
unset_reloc_control(rc);
|
|
out_end:
|
|
reloc_chunk_end(fs_info);
|
|
free_reloc_control(rc);
|
|
out:
|
|
free_reloc_roots(&reloc_roots);
|
|
|
|
btrfs_free_path(path);
|
|
|
|
if (err == 0) {
|
|
/* cleanup orphan inode in data relocation tree */
|
|
fs_root = btrfs_grab_root(fs_info->data_reloc_root);
|
|
ASSERT(fs_root);
|
|
err = btrfs_orphan_cleanup(fs_root);
|
|
btrfs_put_root(fs_root);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* helper to add ordered checksum for data relocation.
|
|
*
|
|
* cloning checksum properly handles the nodatasum extents.
|
|
* it also saves CPU time to re-calculate the checksum.
|
|
*/
|
|
int btrfs_reloc_clone_csums(struct btrfs_inode *inode, u64 file_pos, u64 len)
|
|
{
|
|
struct btrfs_fs_info *fs_info = inode->root->fs_info;
|
|
struct btrfs_root *csum_root;
|
|
struct btrfs_ordered_sum *sums;
|
|
struct btrfs_ordered_extent *ordered;
|
|
int ret;
|
|
u64 disk_bytenr;
|
|
u64 new_bytenr;
|
|
LIST_HEAD(list);
|
|
|
|
ordered = btrfs_lookup_ordered_extent(inode, file_pos);
|
|
BUG_ON(ordered->file_offset != file_pos || ordered->num_bytes != len);
|
|
|
|
disk_bytenr = file_pos + inode->index_cnt;
|
|
csum_root = btrfs_csum_root(fs_info, disk_bytenr);
|
|
ret = btrfs_lookup_csums_list(csum_root, disk_bytenr,
|
|
disk_bytenr + len - 1, &list, 0, false);
|
|
if (ret)
|
|
goto out;
|
|
|
|
while (!list_empty(&list)) {
|
|
sums = list_entry(list.next, struct btrfs_ordered_sum, list);
|
|
list_del_init(&sums->list);
|
|
|
|
/*
|
|
* We need to offset the new_bytenr based on where the csum is.
|
|
* We need to do this because we will read in entire prealloc
|
|
* extents but we may have written to say the middle of the
|
|
* prealloc extent, so we need to make sure the csum goes with
|
|
* the right disk offset.
|
|
*
|
|
* We can do this because the data reloc inode refers strictly
|
|
* to the on disk bytes, so we don't have to worry about
|
|
* disk_len vs real len like with real inodes since it's all
|
|
* disk length.
|
|
*/
|
|
new_bytenr = ordered->disk_bytenr + sums->bytenr - disk_bytenr;
|
|
sums->bytenr = new_bytenr;
|
|
|
|
btrfs_add_ordered_sum(ordered, sums);
|
|
}
|
|
out:
|
|
btrfs_put_ordered_extent(ordered);
|
|
return ret;
|
|
}
|
|
|
|
int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
|
|
struct btrfs_root *root, struct extent_buffer *buf,
|
|
struct extent_buffer *cow)
|
|
{
|
|
struct btrfs_fs_info *fs_info = root->fs_info;
|
|
struct reloc_control *rc;
|
|
struct btrfs_backref_node *node;
|
|
int first_cow = 0;
|
|
int level;
|
|
int ret = 0;
|
|
|
|
rc = fs_info->reloc_ctl;
|
|
if (!rc)
|
|
return 0;
|
|
|
|
BUG_ON(rc->stage == UPDATE_DATA_PTRS && btrfs_is_data_reloc_root(root));
|
|
|
|
level = btrfs_header_level(buf);
|
|
if (btrfs_header_generation(buf) <=
|
|
btrfs_root_last_snapshot(&root->root_item))
|
|
first_cow = 1;
|
|
|
|
if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
|
|
rc->create_reloc_tree) {
|
|
WARN_ON(!first_cow && level == 0);
|
|
|
|
node = rc->backref_cache.path[level];
|
|
BUG_ON(node->bytenr != buf->start &&
|
|
node->new_bytenr != buf->start);
|
|
|
|
btrfs_backref_drop_node_buffer(node);
|
|
atomic_inc(&cow->refs);
|
|
node->eb = cow;
|
|
node->new_bytenr = cow->start;
|
|
|
|
if (!node->pending) {
|
|
list_move_tail(&node->list,
|
|
&rc->backref_cache.pending[level]);
|
|
node->pending = 1;
|
|
}
|
|
|
|
if (first_cow)
|
|
mark_block_processed(rc, node);
|
|
|
|
if (first_cow && level > 0)
|
|
rc->nodes_relocated += buf->len;
|
|
}
|
|
|
|
if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS)
|
|
ret = replace_file_extents(trans, rc, root, cow);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* called before creating snapshot. it calculates metadata reservation
|
|
* required for relocating tree blocks in the snapshot
|
|
*/
|
|
void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot *pending,
|
|
u64 *bytes_to_reserve)
|
|
{
|
|
struct btrfs_root *root = pending->root;
|
|
struct reloc_control *rc = root->fs_info->reloc_ctl;
|
|
|
|
if (!rc || !have_reloc_root(root))
|
|
return;
|
|
|
|
if (!rc->merge_reloc_tree)
|
|
return;
|
|
|
|
root = root->reloc_root;
|
|
BUG_ON(btrfs_root_refs(&root->root_item) == 0);
|
|
/*
|
|
* relocation is in the stage of merging trees. the space
|
|
* used by merging a reloc tree is twice the size of
|
|
* relocated tree nodes in the worst case. half for cowing
|
|
* the reloc tree, half for cowing the fs tree. the space
|
|
* used by cowing the reloc tree will be freed after the
|
|
* tree is dropped. if we create snapshot, cowing the fs
|
|
* tree may use more space than it frees. so we need
|
|
* reserve extra space.
|
|
*/
|
|
*bytes_to_reserve += rc->nodes_relocated;
|
|
}
|
|
|
|
/*
|
|
* called after snapshot is created. migrate block reservation
|
|
* and create reloc root for the newly created snapshot
|
|
*
|
|
* This is similar to btrfs_init_reloc_root(), we come out of here with two
|
|
* references held on the reloc_root, one for root->reloc_root and one for
|
|
* rc->reloc_roots.
|
|
*/
|
|
int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
|
|
struct btrfs_pending_snapshot *pending)
|
|
{
|
|
struct btrfs_root *root = pending->root;
|
|
struct btrfs_root *reloc_root;
|
|
struct btrfs_root *new_root;
|
|
struct reloc_control *rc = root->fs_info->reloc_ctl;
|
|
int ret;
|
|
|
|
if (!rc || !have_reloc_root(root))
|
|
return 0;
|
|
|
|
rc = root->fs_info->reloc_ctl;
|
|
rc->merging_rsv_size += rc->nodes_relocated;
|
|
|
|
if (rc->merge_reloc_tree) {
|
|
ret = btrfs_block_rsv_migrate(&pending->block_rsv,
|
|
rc->block_rsv,
|
|
rc->nodes_relocated, true);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
new_root = pending->snap;
|
|
reloc_root = create_reloc_root(trans, root->reloc_root,
|
|
new_root->root_key.objectid);
|
|
if (IS_ERR(reloc_root))
|
|
return PTR_ERR(reloc_root);
|
|
|
|
ret = __add_reloc_root(reloc_root);
|
|
ASSERT(ret != -EEXIST);
|
|
if (ret) {
|
|
/* Pairs with create_reloc_root */
|
|
btrfs_put_root(reloc_root);
|
|
return ret;
|
|
}
|
|
new_root->reloc_root = btrfs_grab_root(reloc_root);
|
|
|
|
if (rc->create_reloc_tree)
|
|
ret = clone_backref_node(trans, rc, root, reloc_root);
|
|
return ret;
|
|
}
|