| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (C) 2009 Oracle. All rights reserved. |
| */ |
| |
| #include <linux/sched.h> |
| #include <linux/pagemap.h> |
| #include <linux/writeback.h> |
| #include <linux/blkdev.h> |
| #include <linux/rbtree.h> |
| #include <linux/slab.h> |
| #include <linux/error-injection.h> |
| #include "ctree.h" |
| #include "disk-io.h" |
| #include "transaction.h" |
| #include "volumes.h" |
| #include "locking.h" |
| #include "btrfs_inode.h" |
| #include "async-thread.h" |
| #include "free-space-cache.h" |
| #include "inode-map.h" |
| #include "qgroup.h" |
| #include "print-tree.h" |
| #include "delalloc-space.h" |
| #include "block-group.h" |
| #include "backref.h" |
| #include "misc.h" |
| |
| /* |
| * Relocation overview |
| * |
| * [What does relocation do] |
| * |
| * The objective of relocation is to relocate all extents of the target block |
| * group to other block groups. |
| * This is utilized by resize (shrink only), profile converting, compacting |
| * space, or balance routine to spread chunks over devices. |
| * |
| * Before | After |
| * ------------------------------------------------------------------ |
| * BG A: 10 data extents | BG A: deleted |
| * BG B: 2 data extents | BG B: 10 data extents (2 old + 8 relocated) |
| * BG C: 1 extents | BG C: 3 data extents (1 old + 2 relocated) |
| * |
| * [How does relocation work] |
| * |
| * 1. Mark the target block group read-only |
| * New extents won't be allocated from the target block group. |
| * |
| * 2.1 Record each extent in the target block group |
| * To build a proper map of extents to be relocated. |
| * |
| * 2.2 Build data reloc tree and reloc trees |
| * Data reloc tree will contain an inode, recording all newly relocated |
| * data extents. |
| * There will be only one data reloc tree for one data block group. |
| * |
| * Reloc tree will be a special snapshot of its source tree, containing |
| * relocated tree blocks. |
| * Each tree referring to a tree block in target block group will get its |
| * reloc tree built. |
| * |
| * 2.3 Swap source tree with its corresponding reloc tree |
| * Each involved tree only refers to new extents after swap. |
| * |
| * 3. Cleanup reloc trees and data reloc tree. |
| * As old extents in the target block group are still referenced by reloc |
| * trees, we need to clean them up before really freeing the target block |
| * group. |
| * |
| * The main complexity is in steps 2.2 and 2.3. |
| * |
| * The entry point of relocation is relocate_block_group() function. |
| */ |
| |
| #define RELOCATION_RESERVED_NODES 256 |
| /* |
| * map address of tree root to tree |
| */ |
| struct mapping_node { |
| struct { |
| struct rb_node rb_node; |
| u64 bytenr; |
| }; /* Use rb_simle_node for search/insert */ |
| void *data; |
| }; |
| |
| struct mapping_tree { |
| struct rb_root rb_root; |
| spinlock_t lock; |
| }; |
| |
| /* |
| * present a tree block to process |
| */ |
| struct tree_block { |
| struct { |
| struct rb_node rb_node; |
| u64 bytenr; |
| }; /* Use rb_simple_node for search/insert */ |
| struct btrfs_key key; |
| unsigned int level:8; |
| unsigned int key_ready:1; |
| }; |
| |
| #define MAX_EXTENTS 128 |
| |
| struct file_extent_cluster { |
| u64 start; |
| u64 end; |
| u64 boundary[MAX_EXTENTS]; |
| unsigned int nr; |
| }; |
| |
| struct reloc_control { |
| /* block group to relocate */ |
| struct btrfs_block_group *block_group; |
| /* extent tree */ |
| struct btrfs_root *extent_root; |
| /* inode for moving data */ |
| struct inode *data_inode; |
| |
| struct btrfs_block_rsv *block_rsv; |
| |
| struct btrfs_backref_cache backref_cache; |
| |
| struct file_extent_cluster cluster; |
| /* tree blocks have been processed */ |
| struct extent_io_tree processed_blocks; |
| /* map start of tree root to corresponding reloc tree */ |
| struct mapping_tree reloc_root_tree; |
| /* list of reloc trees */ |
| struct list_head reloc_roots; |
| /* list of subvolume trees that get relocated */ |
| struct list_head dirty_subvol_roots; |
| /* size of metadata reservation for merging reloc trees */ |
| u64 merging_rsv_size; |
| /* size of relocated tree nodes */ |
| u64 nodes_relocated; |
| /* reserved size for block group relocation*/ |
| u64 reserved_bytes; |
| |
| u64 search_start; |
| u64 extents_found; |
| |
| unsigned int stage:8; |
| unsigned int create_reloc_tree:1; |
| unsigned int merge_reloc_tree:1; |
| unsigned int found_file_extent:1; |
| }; |
| |
| /* stages of data relocation */ |
| #define MOVE_DATA_EXTENTS 0 |
| #define UPDATE_DATA_PTRS 1 |
| |
| static void mark_block_processed(struct reloc_control *rc, |
| struct btrfs_backref_node *node) |
| { |
| u32 blocksize; |
| |
| if (node->level == 0 || |
| in_range(node->bytenr, rc->block_group->start, |
| rc->block_group->length)) { |
| blocksize = rc->extent_root->fs_info->nodesize; |
| set_extent_bits(&rc->processed_blocks, node->bytenr, |
| node->bytenr + blocksize - 1, EXTENT_DIRTY); |
| } |
| node->processed = 1; |
| } |
| |
| |
| static void mapping_tree_init(struct mapping_tree *tree) |
| { |
| tree->rb_root = RB_ROOT; |
| spin_lock_init(&tree->lock); |
| } |
| |
| /* |
| * walk up backref nodes until reach node presents tree root |
| */ |
| static struct btrfs_backref_node *walk_up_backref( |
| struct btrfs_backref_node *node, |
| struct btrfs_backref_edge *edges[], int *index) |
| { |
| struct btrfs_backref_edge *edge; |
| int idx = *index; |
| |
| while (!list_empty(&node->upper)) { |
| edge = list_entry(node->upper.next, |
| struct btrfs_backref_edge, list[LOWER]); |
| edges[idx++] = edge; |
| node = edge->node[UPPER]; |
| } |
| BUG_ON(node->detached); |
| *index = idx; |
| return node; |
| } |
| |
| /* |
| * walk down backref nodes to find start of next reference path |
| */ |
| static struct btrfs_backref_node *walk_down_backref( |
| struct btrfs_backref_edge *edges[], int *index) |
| { |
| struct btrfs_backref_edge *edge; |
| struct btrfs_backref_node *lower; |
| int idx = *index; |
| |
| while (idx > 0) { |
| edge = edges[idx - 1]; |
| lower = edge->node[LOWER]; |
| if (list_is_last(&edge->list[LOWER], &lower->upper)) { |
| idx--; |
| continue; |
| } |
| edge = list_entry(edge->list[LOWER].next, |
| struct btrfs_backref_edge, list[LOWER]); |
| edges[idx - 1] = edge; |
| *index = idx; |
| return edge->node[UPPER]; |
| } |
| *index = 0; |
| return NULL; |
| } |
| |
| static void update_backref_node(struct btrfs_backref_cache *cache, |
| struct btrfs_backref_node *node, u64 bytenr) |
| { |
| struct rb_node *rb_node; |
| rb_erase(&node->rb_node, &cache->rb_root); |
| node->bytenr = bytenr; |
| rb_node = rb_simple_insert(&cache->rb_root, node->bytenr, &node->rb_node); |
| if (rb_node) |
| btrfs_backref_panic(cache->fs_info, bytenr, -EEXIST); |
| } |
| |
| /* |
| * update backref cache after a transaction commit |
| */ |
| static int update_backref_cache(struct btrfs_trans_handle *trans, |
| struct btrfs_backref_cache *cache) |
| { |
| struct btrfs_backref_node *node; |
| int level = 0; |
| |
| if (cache->last_trans == 0) { |
| cache->last_trans = trans->transid; |
| return 0; |
| } |
| |
| if (cache->last_trans == trans->transid) |
| return 0; |
| |
| /* |
| * detached nodes are used to avoid unnecessary backref |
| * lookup. transaction commit changes the extent tree. |
| * so the detached nodes are no longer useful. |
| */ |
| while (!list_empty(&cache->detached)) { |
| node = list_entry(cache->detached.next, |
| struct btrfs_backref_node, list); |
| btrfs_backref_cleanup_node(cache, node); |
| } |
| |
| while (!list_empty(&cache->changed)) { |
| node = list_entry(cache->changed.next, |
| struct btrfs_backref_node, list); |
| list_del_init(&node->list); |
| BUG_ON(node->pending); |
| update_backref_node(cache, node, node->new_bytenr); |
| } |
| |
| /* |
| * some nodes can be left in the pending list if there were |
| * errors during processing the pending nodes. |
| */ |
| for (level = 0; level < BTRFS_MAX_LEVEL; level++) { |
| list_for_each_entry(node, &cache->pending[level], list) { |
| BUG_ON(!node->pending); |
| if (node->bytenr == node->new_bytenr) |
| continue; |
| update_backref_node(cache, node, node->new_bytenr); |
| } |
| } |
| |
| cache->last_trans = 0; |
| return 1; |
| } |
| |
| static bool reloc_root_is_dead(struct btrfs_root *root) |
| { |
| /* |
| * Pair with set_bit/clear_bit in clean_dirty_subvols and |
| * btrfs_update_reloc_root. We need to see the updated bit before |
| * trying to access reloc_root |
| */ |
| smp_rmb(); |
| if (test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state)) |
| return true; |
| return false; |
| } |
| |
| /* |
| * Check if this subvolume tree has valid reloc tree. |
| * |
| * Reloc tree after swap is considered dead, thus not considered as valid. |
| * This is enough for most callers, as they don't distinguish dead reloc root |
| * from no reloc root. But btrfs_should_ignore_reloc_root() below is a |
| * special case. |
| */ |
| static bool have_reloc_root(struct btrfs_root *root) |
| { |
| if (reloc_root_is_dead(root)) |
| return false; |
| if (!root->reloc_root) |
| return false; |
| return true; |
| } |
| |
| int btrfs_should_ignore_reloc_root(struct btrfs_root *root) |
| { |
| struct btrfs_root *reloc_root; |
| |
| if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) |
| return 0; |
| |
| /* This root has been merged with its reloc tree, we can ignore it */ |
| if (reloc_root_is_dead(root)) |
| return 1; |
| |
| reloc_root = root->reloc_root; |
| if (!reloc_root) |
| return 0; |
| |
| if (btrfs_header_generation(reloc_root->commit_root) == |
| root->fs_info->running_transaction->transid) |
| return 0; |
| /* |
| * if there is reloc tree and it was created in previous |
| * transaction backref lookup can find the reloc tree, |
| * so backref node for the fs tree root is useless for |
| * relocation. |
| */ |
| return 1; |
| } |
| |
| /* |
| * find reloc tree by address of tree root |
| */ |
| struct btrfs_root *find_reloc_root(struct btrfs_fs_info *fs_info, u64 bytenr) |
| { |
| struct reloc_control *rc = fs_info->reloc_ctl; |
| struct rb_node *rb_node; |
| struct mapping_node *node; |
| struct btrfs_root *root = NULL; |
| |
| ASSERT(rc); |
| spin_lock(&rc->reloc_root_tree.lock); |
| rb_node = rb_simple_search(&rc->reloc_root_tree.rb_root, bytenr); |
| if (rb_node) { |
| node = rb_entry(rb_node, struct mapping_node, rb_node); |
| root = (struct btrfs_root *)node->data; |
| } |
| spin_unlock(&rc->reloc_root_tree.lock); |
| return btrfs_grab_root(root); |
| } |
| |
| /* |
| * For useless nodes, do two major clean ups: |
| * |
| * - Cleanup the children edges and nodes |
| * If child node is also orphan (no parent) during cleanup, then the child |
| * node will also be cleaned up. |
| * |
| * - Freeing up leaves (level 0), keeps nodes detached |
| * For nodes, the node is still cached as "detached" |
| * |
| * Return false if @node is not in the @useless_nodes list. |
| * Return true if @node is in the @useless_nodes list. |
| */ |
| static bool handle_useless_nodes(struct reloc_control *rc, |
| struct btrfs_backref_node *node) |
| { |
| struct btrfs_backref_cache *cache = &rc->backref_cache; |
| struct list_head *useless_node = &cache->useless_node; |
| bool ret = false; |
| |
| while (!list_empty(useless_node)) { |
| struct btrfs_backref_node *cur; |
| |
| cur = list_first_entry(useless_node, struct btrfs_backref_node, |
| list); |
| list_del_init(&cur->list); |
| |
| /* Only tree root nodes can be added to @useless_nodes */ |
| ASSERT(list_empty(&cur->upper)); |
| |
| if (cur == node) |
| ret = true; |
| |
| /* The node is the lowest node */ |
| if (cur->lowest) { |
| list_del_init(&cur->lower); |
| cur->lowest = 0; |
| } |
| |
| /* Cleanup the lower edges */ |
| while (!list_empty(&cur->lower)) { |
| struct btrfs_backref_edge *edge; |
| struct btrfs_backref_node *lower; |
| |
| edge = list_entry(cur->lower.next, |
| struct btrfs_backref_edge, list[UPPER]); |
| list_del(&edge->list[UPPER]); |
| list_del(&edge->list[LOWER]); |
| lower = edge->node[LOWER]; |
| btrfs_backref_free_edge(cache, edge); |
| |
| /* Child node is also orphan, queue for cleanup */ |
| if (list_empty(&lower->upper)) |
| list_add(&lower->list, useless_node); |
| } |
| /* Mark this block processed for relocation */ |
| mark_block_processed(rc, cur); |
| |
| /* |
| * Backref nodes for tree leaves are deleted from the cache. |
| * Backref nodes for upper level tree blocks are left in the |
| * cache to avoid unnecessary backref lookup. |
| */ |
| if (cur->level > 0) { |
| list_add(&cur->list, &cache->detached); |
| cur->detached = 1; |
| } else { |
| rb_erase(&cur->rb_node, &cache->rb_root); |
| btrfs_backref_free_node(cache, cur); |
| } |
| } |
| return ret; |
| } |
| |
| /* |
| * Build backref tree for a given tree block. Root of the backref tree |
| * corresponds the tree block, leaves of the backref tree correspond roots of |
| * b-trees that reference the tree block. |
| * |
| * The basic idea of this function is check backrefs of a given block to find |
| * upper level blocks that reference the block, and then check backrefs of |
| * these upper level blocks recursively. The recursion stops when tree root is |
| * reached or backrefs for the block is cached. |
| * |
| * NOTE: if we find that backrefs for a block are cached, we know backrefs for |
| * all upper level blocks that directly/indirectly reference the block are also |
| * cached. |
| */ |
| static noinline_for_stack struct btrfs_backref_node *build_backref_tree( |
| struct reloc_control *rc, struct btrfs_key *node_key, |
| int level, u64 bytenr) |
| { |
| struct btrfs_backref_iter *iter; |
| struct btrfs_backref_cache *cache = &rc->backref_cache; |
| /* For searching parent of TREE_BLOCK_REF */ |
| struct btrfs_path *path; |
| struct btrfs_backref_node *cur; |
| struct btrfs_backref_node *node = NULL; |
| struct btrfs_backref_edge *edge; |
| int ret; |
| int err = 0; |
| |
| iter = btrfs_backref_iter_alloc(rc->extent_root->fs_info, GFP_NOFS); |
| if (!iter) |
| return ERR_PTR(-ENOMEM); |
| path = btrfs_alloc_path(); |
| if (!path) { |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| node = btrfs_backref_alloc_node(cache, bytenr, level); |
| if (!node) { |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| node->lowest = 1; |
| cur = node; |
| |
| /* Breadth-first search to build backref cache */ |
| do { |
| ret = btrfs_backref_add_tree_node(cache, path, iter, node_key, |
| cur); |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| 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_panic(fs_info, -EEXIST, |
| "Duplicate root found for start=%llu while inserting into relocation tree", |
| node->bytenr); |
| } |
| |
| 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); |
| if (!node) |
| return; |
| BUG_ON((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; |
| |
| root_item = kmalloc(sizeof(*root_item), GFP_NOFS); |
| BUG_ON(!root_item); |
| |
| 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); |
| BUG_ON(ret); |
| /* |
| * 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); |
| BUG_ON(ret); |
| } |
| |
| 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); |
| BUG_ON(ret); |
| kfree(root_item); |
| |
| reloc_root = btrfs_read_tree_root(fs_info->tree_root, &root_key); |
| BUG_ON(IS_ERR(reloc_root)); |
| set_bit(BTRFS_ROOT_SHAREABLE, &reloc_root->state); |
| reloc_root->last_trans = trans->transid; |
| return reloc_root; |
| } |
| |
| /* |
| * 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; |
| |
| ret = __add_reloc_root(reloc_root); |
| BUG_ON(ret < 0); |
| 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)) |
| goto out; |
| |
| 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); |
| BUG_ON(ret); |
| btrfs_put_root(reloc_root); |
| out: |
| return 0; |
| } |
| |
| /* |
| * 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 readpage |
| * 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(inode); |
| inode = find_next_inode(root, key.objectid); |
| } |
| if (inode && btrfs_ino(BTRFS_I(inode)) == key.objectid) { |
| 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); |
| if (!ret) |
| continue; |
| |
| btrfs_drop_extent_cache(BTRFS_I(inode), |
| key.offset, end, 1); |
| unlock_extent(&BTRFS_I(inode)->io_tree, |
| key.offset, end); |
| } |
| } |
| |
| 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); |
| ref.real_root = root->root_key.objectid; |
| btrfs_init_data_ref(&ref, btrfs_header_owner(leaf), |
| key.objectid, key.offset); |
| 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); |
| ref.real_root = root->root_key.objectid; |
| btrfs_init_data_ref(&ref, btrfs_header_owner(leaf), |
| key.objectid, key.offset); |
| 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(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; |
| |
| BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID); |
| BUG_ON(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); |
| BUG_ON(ret); |
| } |
| |
| if (next_key) { |
| next_key->objectid = (u64)-1; |
| next_key->type = (u8)-1; |
| next_key->offset = (u64)-1; |
| } |
| |
| parent = eb; |
| while (1) { |
| struct btrfs_key first_key; |
| |
| level = btrfs_header_level(parent); |
| BUG_ON(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); |
| btrfs_node_key_to_cpu(parent, &first_key, 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 = read_tree_block(fs_info, old_bytenr, old_ptr_gen, |
| level - 1, &first_key); |
| if (IS_ERR(eb)) { |
| ret = PTR_ERR(eb); |
| break; |
| } else if (!extent_buffer_uptodate(eb)) { |
| ret = -EIO; |
| free_extent_buffer(eb); |
| break; |
| } |
| btrfs_tree_lock(eb); |
| if (cow) { |
| ret = btrfs_cow_block(trans, dest, eb, parent, |
| slot, &eb, |
| BTRFS_NESTING_COW); |
| BUG_ON(ret); |
| } |
| |
| 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; |
| ret = btrfs_search_slot(trans, src, &key, path, 0, 1); |
| path->lowest_level = 0; |
| BUG_ON(ret); |
| |
| /* |
| * 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); |
| ref.skip_qgroup = true; |
| btrfs_init_tree_ref(&ref, level - 1, src->root_key.objectid); |
| ret = btrfs_inc_extent_ref(trans, &ref); |
| BUG_ON(ret); |
| btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, new_bytenr, |
| blocksize, 0); |
| ref.skip_qgroup = true; |
| btrfs_init_tree_ref(&ref, level - 1, dest->root_key.objectid); |
| ret = btrfs_inc_extent_ref(trans, &ref); |
| BUG_ON(ret); |
| |
| 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); |
| ref.skip_qgroup = true; |
| ret = btrfs_free_extent(trans, &ref); |
| BUG_ON(ret); |
| |
| btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, old_bytenr, |
| blocksize, 0); |
| btrfs_init_tree_ref(&ref, level - 1, dest->root_key.objectid); |
| ref.skip_qgroup = true; |
| ret = btrfs_free_extent(trans, &ref); |
| BUG_ON(ret); |
| |
| 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 btrfs_fs_info *fs_info = root->fs_info; |
| struct extent_buffer *eb = NULL; |
| int i; |
| u64 bytenr; |
| u64 ptr_gen = 0; |
| u64 last_snapshot; |
| u32 nritems; |
| |
| last_snapshot = btrfs_root_last_snapshot(&root->root_item); |
| |
| for (i = *level; i > 0; i--) { |
| struct btrfs_key first_key; |
| |
| 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; |
| } |
| |
| bytenr = btrfs_node_blockptr(eb, path->slots[i]); |
| btrfs_node_key_to_cpu(eb, &first_key, path->slots[i]); |
| eb = read_tree_block(fs_info, bytenr, ptr_gen, i - 1, |
| &first_key); |
| if (IS_ERR(eb)) { |
| return PTR_ERR(eb); |
| } else if (!extent_buffer_uptodate(eb)) { |
| free_extent_buffer(eb); |
| return -EIO; |
| } |
| 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) { |
| 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 readpage to complete */ |
| lock_extent(&BTRFS_I(inode)->io_tree, start, end); |
| btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 1); |
| unlock_extent(&BTRFS_I(inode)->io_tree, start, end); |
| } |
| 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 void 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; |
| |
| /* @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); |
| btrfs_update_reloc_root(trans, root); |
| |
| if (list_empty(&root->reloc_dirty_list)) { |
| btrfs_grab_root(root); |
| list_add_tail(&root->reloc_dirty_list, &rc->dirty_subvol_roots); |
| } |
| } |
| |
| 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; |
| int err = 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(root, rc->block_rsv, min_reserved, |
| BTRFS_RESERVE_FLUSH_LIMIT); |
| if (ret) { |
| err = ret; |
| goto out; |
| } |
| trans = btrfs_start_transaction(root, 0); |
| if (IS_ERR(trans)) { |
| err = 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) { |
| err = ret; |
| 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) { |
| err = ret; |
| 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); |
| if (ret < 0) |
| err = ret; |
| out: |
| btrfs_free_path(path); |
| |
| if (err == 0) |
| insert_dirty_subvol(trans, rc, root); |
| |
| 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 err; |
| } |
| |
| 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(root, 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); |
| BUG_ON(IS_ERR(root)); |
| BUG_ON(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); |
| btrfs_update_reloc_root(trans, root); |
| |
| list_add(&reloc_root->root_list, &reloc_roots); |
| btrfs_put_root(root); |
| } |
| |
| list_splice(&reloc_roots, &rc->reloc_roots); |
| |
| if (!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) { |
| BUG_ON(IS_ERR(root)); |
| BUG_ON(root->reloc_root != reloc_root); |
| 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); |
| BUG_ON(IS_ERR(root)); |
| BUG_ON(root->reloc_root != reloc_root); |
| 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; |
| |
| next = node; |
| while (1) { |
| cond_resched(); |
| next = walk_up_backref(next, edges, &index); |
| root = next->root; |
| BUG_ON(!root); |
| BUG_ON(!test_bit(BTRFS_ROOT_SHAREABLE, &root->state)); |
| |
| if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { |
| record_reloc_root_in_trans(trans, root); |
| break; |
| } |
| |
| btrfs_record_root_in_trans(trans, root); |
| root = root->reloc_root; |
| |
| if (next->new_bytenr != root->node->start) { |
| BUG_ON(next->new_bytenr); |
| BUG_ON(!list_empty(&next->list)); |
| 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) |
| return NULL; |
| |
| 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; |
| BUG_ON(!root); |
| |
| /* 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(root, 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_fs_info *fs_info = rc->extent_root->fs_info; |
| 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; |
| u64 generation; |
| int slot; |
| int ret; |
| int err = 0; |
| |
| BUG_ON(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_key first_key; |
| struct btrfs_ref ref = { 0 }; |
| |
| cond_resched(); |
| |
| upper = edge->node[UPPER]; |
| root = select_reloc_root(trans, rc, upper, edges); |
| BUG_ON(!root); |
| |
| if (upper->eb && !upper->locked) { |
| if (!lowest) { |
| ret = btrfs_bin_search(upper->eb, key, &slot); |
| if (ret < 0) { |
| err = ret; |
| 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) |
| err = ret; |
| else |
| err = -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) { |
| err = ret; |
| 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); |
| err = -EIO; |
| goto next; |
| } |
| } else { |
| if (node->eb->start == bytenr) |
| goto next; |
| } |
| |
| blocksize = root->fs_info->nodesize; |
| generation = btrfs_node_ptr_generation(upper->eb, slot); |
| btrfs_node_key_to_cpu(upper->eb, &first_key, slot); |
| eb = read_tree_block(fs_info, bytenr, generation, |
| upper->level - 1, &first_key); |
| if (IS_ERR(eb)) { |
| err = PTR_ERR(eb); |
| goto next; |
| } else if (!extent_buffer_uptodate(eb)) { |
| free_extent_buffer(eb); |
| err = -EIO; |
| 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) { |
| err = ret; |
| goto next; |
| } |
| BUG_ON(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); |
| ref.real_root = root->root_key.objectid; |
| btrfs_init_tree_ref(&ref, node->level, |
| btrfs_header_owner(upper->eb)); |
| ret = btrfs_inc_extent_ref(trans, &ref); |
| BUG_ON(ret); |
| |
| ret = btrfs_drop_subtree(trans, root, eb, upper->eb); |
| BUG_ON(ret); |
| } |
| next: |
| if (!upper->pending) |
| btrfs_backref_drop_node_buffer(upper); |
| else |
| btrfs_backref_unlock_node_buffer(upper); |
| if (err) |
| break; |
| } |
| |
| if (!err && node->pending) { |
| btrfs_backref_drop_node_buffer(node); |
| list_move_tail(&node->list, &rc->backref_cache.changed); |
| node->pending = 0; |
| } |
| |
| path->lowest_level = 0; |
| BUG_ON(err == -ENOSPC); |
| return err; |
| } |
| |
| 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 extent_buffer *eb; |
| |
| eb = read_tree_block(fs_info, block->bytenr, block->key.offset, |
| block->level, NULL); |
| if (IS_ERR(eb)) { |
| return PTR_ERR(eb); |
| } else 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 (root == ERR_PTR(-ENOENT)) { |
| update_processed_blocks(rc, node); |
| goto out; |
| } |
| |
| if (root) { |
| if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) { |
| BUG_ON(node->new_bytenr); |
| BUG_ON(!list_empty(&node->list)); |
| btrfs_record_root_in_trans(trans, root); |
| 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; |
| ret = btrfs_search_slot(trans, root, key, path, 0, 1); |
| btrfs_release_path(path); |
| 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) |
| readahead_tree_block(fs_info, block->bytenr); |
| } |
| |
| /* 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 prealloc_start = cluster->start - offset; |
| u64 prealloc_end = cluster->end - offset; |
| u64 cur_offset = prealloc_start; |
| |
| BUG_ON(cluster->start != cluster->boundary[0]); |
| ret = btrfs_alloc_data_chunk_ondemand(inode, |
| prealloc_end + 1 - prealloc_start); |
| if (ret) |
| return ret; |
| |
| inode_lock(&inode->vfs_inode); |
| for (nr = 0; nr < cluster->nr; nr++) { |
| 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); |
| 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); |
| if (ret) |
| break; |
| } |
| inode_unlock(&inode->vfs_inode); |
| |
| 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_extent_mapping(struct inode *inode, u64 start, u64 end, |
| u64 block_start) |
| { |
| struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; |
| struct extent_map *em; |
| 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); |
| while (1) { |
| write_lock(&em_tree->lock); |
| ret = add_extent_mapping(em_tree, em, 0); |
| write_unlock(&em_tree->lock); |
| if (ret != -EEXIST) { |
| free_extent_map(em); |
| break; |
| } |
| btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 0); |
| } |
| unlock_extent(&BTRFS_I(inode)->io_tree, start, end); |
| return ret; |
| } |
| |
| /* |
| * Allow error injection to test balance cancellation |
| */ |
| int btrfs_should_cancel_balance(struct btrfs_fs_info *fs_info) |
| { |
| return atomic_read(&fs_info->balance_cancel_req) || |
| fatal_signal_pending(current); |
| } |
| ALLOW_ERROR_INJECTION(btrfs_should_cancel_balance, TRUE); |
| |
| static int relocate_file_extent_cluster(struct inode *inode, |
| struct file_extent_cluster *cluster) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
| u64 page_start; |
| u64 page_end; |
| u64 offset = BTRFS_I(inode)->index_cnt; |
| unsigned long index; |
| unsigned long last_index; |
| struct page *page; |
| struct file_ra_state *ra; |
| gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping); |
| int 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_extent_mapping(inode, cluster->start - offset, |
| cluster->end - offset, cluster->start); |
| if (ret) |
| goto out; |
| |
| index = (cluster->start - offset) >> PAGE_SHIFT; |
| last_index = (cluster->end - offset) >> PAGE_SHIFT; |
| while (index <= last_index) { |
| ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), |
| PAGE_SIZE); |
| if (ret) |
| goto out; |
| |
| page = find_lock_page(inode->i_mapping, index); |
| if (!page) { |
| page_cache_sync_readahead(inode->i_mapping, |
| ra, NULL, index, |
| last_index + 1 - index); |
| page = find_or_create_page(inode->i_mapping, index, |
| mask); |
| if (!page) { |
| btrfs_delalloc_release_metadata(BTRFS_I(inode), |
| PAGE_SIZE, true); |
| btrfs_delalloc_release_extents(BTRFS_I(inode), |
| PAGE_SIZE); |
| ret = -ENOMEM; |
| goto out; |
| } |
| } |
| |
| if (PageReadahead(page)) { |
| page_cache_async_readahead(inode->i_mapping, |
| ra, NULL, page, index, |
| last_index + 1 - index); |
| } |
| |
| if (!PageUptodate(page)) { |
| btrfs_readpage(NULL, page); |
| lock_page(page); |
| if (!PageUptodate(page)) { |
| unlock_page(page); |
| put_page(page); |
| btrfs_delalloc_release_metadata(BTRFS_I(inode), |
| PAGE_SIZE, true); |
| btrfs_delalloc_release_extents(BTRFS_I(inode), |
| PAGE_SIZE); |
| ret = -EIO; |
| goto out; |
| } |
| } |
| |
| page_start = page_offset(page); |
| page_end = page_start + PAGE_SIZE - 1; |
| |
| lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end); |
| |
| set_page_extent_mapped(page); |
| |
| if (nr < cluster->nr && |
| page_start + offset == cluster->boundary[nr]) { |
| set_extent_bits(&BTRFS_I(inode)->io_tree, |
| page_start, page_end, |
| EXTENT_BOUNDARY); |
| nr++; |
| } |
| |
| ret = btrfs_set_extent_delalloc(BTRFS_I(inode), page_start, |
| page_end, 0, NULL); |
| if (ret) { |
| unlock_page(page); |
| put_page(page); |
| btrfs_delalloc_release_metadata(BTRFS_I(inode), |
| PAGE_SIZE, true); |
| btrfs_delalloc_release_extents(BTRFS_I(inode), |
| PAGE_SIZE); |
| |
| clear_extent_bits(&BTRFS_I(inode)->io_tree, |
| page_start, page_end, |
| EXTENT_LOCKED | EXTENT_BOUNDARY); |
| goto out; |
| |
| } |
| set_page_dirty(page); |
| |
| unlock_extent(&BTRFS_I(inode)->io_tree, |
| page_start, page_end); |
| unlock_page(page); |
| put_page(page); |
| |
| index++; |
| btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE); |
| balance_dirty_pages_ratelimited(inode->i_mapping); |
| btrfs_throttle(fs_info); |
| if (btrfs_should_cancel_balance(fs_info)) { |
| ret = -ECANCELED; |
| goto out; |
| } |
| } |
| WARN_ON(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; |
| |
| eb = path->nodes[0]; |
| item_size = btrfs_item_size_nr(eb, path->slots[0]); |
| |
| if (extent_key->type == BTRFS_METADATA_ITEM_KEY || |
| item_size >= sizeof(*ei) + sizeof(*bi)) { |
| ei = btrfs_item_ptr(eb, path->slots[0], |
| struct btrfs_extent_item); |
| if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) { |
| bi = (struct btrfs_tree_block_info *)(ei + 1); |
| level = btrfs_tree_block_level(eb, bi); |
| } else { |
| level = (int)extent_key->offset; |
| } |
| generation = btrfs_extent_generation(eb, ei); |
| } 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; |
| |
| 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++) { |
| 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); |
| if (btrfs_file_extent_type(leaf, ei) == BTRFS_FILE_EXTENT_REG && |
| 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_fs_info *fs_info = rc->extent_root->fs_info; |
| struct ulist *leaves = NULL; |
| struct ulist_iterator leaf_uiter; |
| struct ulist_node *ref_node = NULL; |
| const u32 blocksize = fs_info->nodesize; |
| int ret = 0; |
| |
| btrfs_release_path(path); |
| ret = btrfs_find_all_leafs(NULL, fs_info, extent_key->objectid, |
| 0, &leaves, NULL, true); |
| if (ret < 0) |
| return ret; |
| |
| ULIST_ITER_INIT(&leaf_uiter); |
| while ((ref_node = ulist_next(leaves, &leaf_uiter))) { |
| struct extent_buffer *eb; |
| |
| eb = read_tree_block(fs_info, ref_node->val, 0, 0, NULL); |
| 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(leaves); |
| 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 int check_extent_flags(u64 flags) |
| { |
| if ((flags & BTRFS_EXTENT_FLAG_DATA) && |
| (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) |
| return 1; |
| if (!(flags & BTRFS_EXTENT_FLAG_DATA) && |
| !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) |
| return 1; |
| if ((flags & BTRFS_EXTENT_FLAG_DATA) && |
| (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) |
| return 1; |
| return 0; |
| } |
| |
| 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, |
| 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); |
| } |
| btrfs_commit_transaction(trans); |
| return 0; |
| } |
| |
| 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; |
| u32 item_size; |
| 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(rc->extent_root, |
| 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); |
| item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]); |
| if (item_size >= sizeof(*ei)) { |
| flags = btrfs_extent_flags(path->nodes[0], ei); |
| ret = check_extent_flags(flags); |
| BUG_ON(ret); |
| } else if (unlikely(item_size == sizeof(struct btrfs_extent_item_v0))) { |
| err = -EINVAL; |
| btrfs_print_v0_err(trans->fs_info); |
| btrfs_abort_transaction(trans, err); |
| break; |
| } else { |
| BUG(); |
| } |
| |
| 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; |
| } |
| btrfs_commit_transaction(trans); |
| 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; |
| } |
| |
| /* |
| * 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_find_free_objectid(root, &objectid); |
| if (err) |
| goto out; |
| |
| err = __insert_orphan_inode(trans, root, objectid); |
| BUG_ON(err); |
| |
| inode = btrfs_iget(fs_info->sb, objectid, root); |
| BUG_ON(IS_ERR(inode)); |
| 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) { |
| if (inode) |
| iput(inode); |
| inode = ERR_PTR(err); |
| } |
| return inode; |
| } |
| |
| 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, NULL); |
| 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 = fs_info->extent_root; |
| struct reloc_control *rc; |
| struct inode *inode; |
| struct btrfs_path *path; |
| int ret; |
| int rw = 0; |
| int err = 0; |
| |
| bg = btrfs_lookup_block_group(fs_info, group_start); |
| if (!bg) |
| return -ENOENT; |
| |
| 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; |
| } |
| |
| 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); |
| |
| 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); |
| btrfs_put_block_group(rc->block_group); |
| 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_root *root) |
| { |
| struct btrfs_fs_info *fs_info = root->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(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; |
| } |
| |
| rc->extent_root = fs_info->extent_root; |
| |
| 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); |
| BUG_ON(err < 0); /* -ENOMEM or logic error */ |
| 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); |
| 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_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; |
| ret = btrfs_lookup_csums_range(fs_info->csum_root, disk_bytenr, |
| disk_bytenr + len - 1, &list, 0); |
| 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 && |
| root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID); |
| |
| 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); |
| BUG_ON(ret < 0); |
| 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; |
| } |