| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Zheng Yan | 18220 | 79.42% | 11 | 5.85% |
| Josef Bacik | 1103 | 4.81% | 25 | 13.30% |
| Qu Wenruo | 1012 | 4.41% | 26 | 13.83% |
| Jeff Mahoney | 614 | 2.68% | 9 | 4.79% |
| Liu Bo | 414 | 1.80% | 15 | 7.98% |
| Shilong Wang | 375 | 1.63% | 8 | 4.26% |
| Nikolay Borisov | 297 | 1.29% | 8 | 4.26% |
| Tsutomu Itoh | 132 | 0.58% | 4 | 2.13% |
| Miao Xie | 121 | 0.53% | 13 | 6.91% |
| David Sterba | 94 | 0.41% | 16 | 8.51% |
| Filipe David Borba Manana | 94 | 0.41% | 8 | 4.26% |
| Chris Mason | 92 | 0.40% | 5 | 2.66% |
| Josef Whiter | 67 | 0.29% | 6 | 3.19% |
| Xiaoguang Wang | 60 | 0.26% | 2 | 1.06% |
| Omar Sandoval | 52 | 0.23% | 2 | 1.06% |
| Adam Borowski | 48 | 0.21% | 1 | 0.53% |
| Li Zefan | 38 | 0.17% | 2 | 1.06% |
| Yan Zheng | 30 | 0.13% | 2 | 1.06% |
| Daniel J Blueman | 12 | 0.05% | 1 | 0.53% |
| Dulshani Gunawardhana | 9 | 0.04% | 1 | 0.53% |
| Anand Jain | 8 | 0.03% | 3 | 1.60% |
| Kirill A. Shutemov | 8 | 0.03% | 1 | 0.53% |
| Naohiro Aota | 5 | 0.02% | 1 | 0.53% |
| Pan Bian | 4 | 0.02% | 1 | 0.53% |
| Joe Perches | 4 | 0.02% | 1 | 0.53% |
| Nicholas D Steeves | 3 | 0.01% | 1 | 0.53% |
| Tejun Heo | 3 | 0.01% | 1 | 0.53% |
| Su Yue | 2 | 0.01% | 1 | 0.53% |
| Zhao Lei | 2 | 0.01% | 1 | 0.53% |
| Misono, Tomohiro | 2 | 0.01% | 1 | 0.53% |
| Arne Jansen | 2 | 0.01% | 1 | 0.53% |
| Frank Holton | 2 | 0.01% | 1 | 0.53% |
| Al Viro | 2 | 0.01% | 1 | 0.53% |
| Eric Paris | 2 | 0.01% | 1 | 0.53% |
| Lu Fengqi | 1 | 0.00% | 1 | 0.53% |
| Andrea Gelmini | 1 | 0.00% | 1 | 0.53% |
| Justin P. Mattock | 1 | 0.00% | 1 | 0.53% |
| Andi Kleen | 1 | 0.00% | 1 | 0.53% |
| Stefan Behrens | 1 | 0.00% | 1 | 0.53% |
| Lucas De Marchi | 1 | 0.00% | 1 | 0.53% |
| Eric Sandeen | 1 | 0.00% | 1 | 0.53% |
| Total | 22940 | 188 |
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// 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 "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" /* * backref_node, mapping_node and tree_block start with this */ struct tree_entry { struct rb_node rb_node; u64 bytenr; }; /* * present a tree block in the backref cache */ struct backref_node { struct rb_node rb_node; u64 bytenr; u64 new_bytenr; /* objectid of tree block owner, can be not uptodate */ u64 owner; /* link to pending, changed or detached list */ struct list_head list; /* list of upper level blocks reference this block */ struct list_head upper; /* list of child blocks in the cache */ struct list_head lower; /* NULL if this node is not tree root */ struct btrfs_root *root; /* extent buffer got by COW the block */ struct extent_buffer *eb; /* level of tree block */ unsigned int level:8; /* is the block in non-reference counted tree */ unsigned int cowonly:1; /* 1 if no child node in the cache */ unsigned int lowest:1; /* is the extent buffer locked */ unsigned int locked:1; /* has the block been processed */ unsigned int processed:1; /* have backrefs of this block been checked */ unsigned int checked:1; /* * 1 if corresponding block has been cowed but some upper * level block pointers may not point to the new location */ unsigned int pending:1; /* * 1 if the backref node isn't connected to any other * backref node. */ unsigned int detached:1; }; /* * present a block pointer in the backref cache */ struct backref_edge { struct list_head list[2]; struct backref_node *node[2]; }; #define LOWER 0 #define UPPER 1 #define RELOCATION_RESERVED_NODES 256 struct backref_cache { /* red black tree of all backref nodes in the cache */ struct rb_root rb_root; /* for passing backref nodes to btrfs_reloc_cow_block */ struct backref_node *path[BTRFS_MAX_LEVEL]; /* * list of blocks that have been cowed but some block * pointers in upper level blocks may not reflect the * new location */ struct list_head pending[BTRFS_MAX_LEVEL]; /* list of backref nodes with no child node */ struct list_head leaves; /* list of blocks that have been cowed in current transaction */ struct list_head changed; /* list of detached backref node. */ struct list_head detached; u64 last_trans; int nr_nodes; int nr_edges; }; /* * map address of tree root to tree */ struct mapping_node { struct rb_node rb_node; u64 bytenr; void *data; }; struct mapping_tree { struct rb_root rb_root; spinlock_t lock; }; /* * present a tree block to process */ struct tree_block { struct rb_node rb_node; u64 bytenr; 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 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 remove_backref_node(struct backref_cache *cache, struct backref_node *node); static void __mark_block_processed(struct reloc_control *rc, struct backref_node *node); static void mapping_tree_init(struct mapping_tree *tree) { tree->rb_root = RB_ROOT; spin_lock_init(&tree->lock); } static void backref_cache_init(struct backref_cache *cache) { int i; cache->rb_root = RB_ROOT; for (i = 0; i < BTRFS_MAX_LEVEL; i++) INIT_LIST_HEAD(&cache->pending[i]); INIT_LIST_HEAD(&cache->changed); INIT_LIST_HEAD(&cache->detached); INIT_LIST_HEAD(&cache->leaves); } static void backref_cache_cleanup(struct backref_cache *cache) { struct backref_node *node; int i; while (!list_empty(&cache->detached)) { node = list_entry(cache->detached.next, struct backref_node, list); remove_backref_node(cache, node); } while (!list_empty(&cache->leaves)) { node = list_entry(cache->leaves.next, struct backref_node, lower); remove_backref_node(cache, node); } cache->last_trans = 0; for (i = 0; i < BTRFS_MAX_LEVEL; i++) ASSERT(list_empty(&cache->pending[i])); ASSERT(list_empty(&cache->changed)); ASSERT(list_empty(&cache->detached)); ASSERT(RB_EMPTY_ROOT(&cache->rb_root)); ASSERT(!cache->nr_nodes); ASSERT(!cache->nr_edges); } static struct backref_node *alloc_backref_node(struct backref_cache *cache) { struct backref_node *node; node = kzalloc(sizeof(*node), GFP_NOFS); if (node) { INIT_LIST_HEAD(&node->list); INIT_LIST_HEAD(&node->upper); INIT_LIST_HEAD(&node->lower); RB_CLEAR_NODE(&node->rb_node); cache->nr_nodes++; } return node; } static void free_backref_node(struct backref_cache *cache, struct backref_node *node) { if (node) { cache->nr_nodes--; kfree(node); } } static struct backref_edge *alloc_backref_edge(struct backref_cache *cache) { struct backref_edge *edge; edge = kzalloc(sizeof(*edge), GFP_NOFS); if (edge) cache->nr_edges++; return edge; } static void free_backref_edge(struct backref_cache *cache, struct backref_edge *edge) { if (edge) { cache->nr_edges--; kfree(edge); } } static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr, struct rb_node *node) { struct rb_node **p = &root->rb_node; struct rb_node *parent = NULL; struct tree_entry *entry; while (*p) { parent = *p; entry = rb_entry(parent, struct tree_entry, rb_node); if (bytenr < entry->bytenr) p = &(*p)->rb_left; else if (bytenr > entry->bytenr) p = &(*p)->rb_right; else return parent; } rb_link_node(node, parent, p); rb_insert_color(node, root); return NULL; } static struct rb_node *tree_search(struct rb_root *root, u64 bytenr) { struct rb_node *n = root->rb_node; struct tree_entry *entry; while (n) { entry = rb_entry(n, struct tree_entry, rb_node); if (bytenr < entry->bytenr) n = n->rb_left; else if (bytenr > entry->bytenr) n = n->rb_right; else return n; } return NULL; } static void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr) { struct btrfs_fs_info *fs_info = NULL; struct backref_node *bnode = rb_entry(rb_node, struct backref_node, rb_node); if (bnode->root) fs_info = bnode->root->fs_info; btrfs_panic(fs_info, errno, "Inconsistency in backref cache found at offset %llu", bytenr); } /* * walk up backref nodes until reach node presents tree root */ static struct backref_node *walk_up_backref(struct backref_node *node, struct backref_edge *edges[], int *index) { struct backref_edge *edge; int idx = *index; while (!list_empty(&node->upper)) { edge = list_entry(node->upper.next, struct 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 backref_node *walk_down_backref(struct backref_edge *edges[], int *index) { struct backref_edge *edge; struct 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 backref_edge, list[LOWER]); edges[idx - 1] = edge; *index = idx; return edge->node[UPPER]; } *index = 0; return NULL; } static void unlock_node_buffer(struct backref_node *node) { if (node->locked) { btrfs_tree_unlock(node->eb); node->locked = 0; } } static void drop_node_buffer(struct backref_node *node) { if (node->eb) { unlock_node_buffer(node); free_extent_buffer(node->eb); node->eb = NULL; } } static void drop_backref_node(struct backref_cache *tree, struct backref_node *node) { BUG_ON(!list_empty(&node->upper)); drop_node_buffer(node); list_del(&node->list); list_del(&node->lower); if (!RB_EMPTY_NODE(&node->rb_node)) rb_erase(&node->rb_node, &tree->rb_root); free_backref_node(tree, node); } /* * remove a backref node from the backref cache */ static void remove_backref_node(struct backref_cache *cache, struct backref_node *node) { struct backref_node *upper; struct backref_edge *edge; if (!node) return; BUG_ON(!node->lowest && !node->detached); while (!list_empty(&node->upper)) { edge = list_entry(node->upper.next, struct backref_edge, list[LOWER]); upper = edge->node[UPPER]; list_del(&edge->list[LOWER]); list_del(&edge->list[UPPER]); free_backref_edge(cache, edge); if (RB_EMPTY_NODE(&upper->rb_node)) { BUG_ON(!list_empty(&node->upper)); drop_backref_node(cache, node); node = upper; node->lowest = 1; continue; } /* * add the node to leaf node list if no other * child block cached. */ if (list_empty(&upper->lower)) { list_add_tail(&upper->lower, &cache->leaves); upper->lowest = 1; } } drop_backref_node(cache, node); } static void update_backref_node(struct backref_cache *cache, struct backref_node *node, u64 bytenr) { struct rb_node *rb_node; rb_erase(&node->rb_node, &cache->rb_root); node->bytenr = bytenr; rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node); if (rb_node) backref_tree_panic(rb_node, -EEXIST, bytenr); } /* * update backref cache after a transaction commit */ static int update_backref_cache(struct btrfs_trans_handle *trans, struct backref_cache *cache) { struct 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 backref_node, list); remove_backref_node(cache, node); } while (!list_empty(&cache->changed)) { node = list_entry(cache->changed.next, struct 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 should_ignore_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; } static int should_ignore_root(struct btrfs_root *root) { struct btrfs_root *reloc_root; if (!test_bit(BTRFS_ROOT_REF_COWS, &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_root_last_snapshot(&reloc_root->root_item) == root->fs_info->running_transaction->transid - 1) 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 */ static struct btrfs_root *find_reloc_root(struct reloc_control *rc, u64 bytenr) { struct rb_node *rb_node; struct mapping_node *node; struct btrfs_root *root = NULL; spin_lock(&rc->reloc_root_tree.lock); rb_node = tree_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 root; } static int is_cowonly_root(u64 root_objectid) { if (root_objectid == BTRFS_ROOT_TREE_OBJECTID || root_objectid == BTRFS_EXTENT_TREE_OBJECTID || root_objectid == BTRFS_CHUNK_TREE_OBJECTID || root_objectid == BTRFS_DEV_TREE_OBJECTID || root_objectid == BTRFS_TREE_LOG_OBJECTID || root_objectid == BTRFS_CSUM_TREE_OBJECTID || root_objectid == BTRFS_UUID_TREE_OBJECTID || root_objectid == BTRFS_QUOTA_TREE_OBJECTID || root_objectid == BTRFS_FREE_SPACE_TREE_OBJECTID) return 1; return 0; } static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info, u64 root_objectid) { struct btrfs_key key; key.objectid = root_objectid; key.type = BTRFS_ROOT_ITEM_KEY; if (is_cowonly_root(root_objectid)) key.offset = 0; else key.offset = (u64)-1; return btrfs_get_fs_root(fs_info, &key, false); } static noinline_for_stack int find_inline_backref(struct extent_buffer *leaf, int slot, unsigned long *ptr, unsigned long *end) { struct btrfs_key key; struct btrfs_extent_item *ei; struct btrfs_tree_block_info *bi; u32 item_size; btrfs_item_key_to_cpu(leaf, &key, slot); item_size = btrfs_item_size_nr(leaf, slot); if (item_size < sizeof(*ei)) { btrfs_print_v0_err(leaf->fs_info); btrfs_handle_fs_error(leaf->fs_info, -EINVAL, NULL); return 1; } ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); WARN_ON(!(btrfs_extent_flags(leaf, ei) & BTRFS_EXTENT_FLAG_TREE_BLOCK)); if (key.type == BTRFS_EXTENT_ITEM_KEY && item_size <= sizeof(*ei) + sizeof(*bi)) { WARN_ON(item_size < sizeof(*ei) + sizeof(*bi)); return 1; } if (key.type == BTRFS_METADATA_ITEM_KEY && item_size <= sizeof(*ei)) { WARN_ON(item_size < sizeof(*ei)); return 1; } if (key.type == BTRFS_EXTENT_ITEM_KEY) { bi = (struct btrfs_tree_block_info *)(ei + 1); *ptr = (unsigned long)(bi + 1); } else { *ptr = (unsigned long)(ei + 1); } *end = (unsigned long)ei + item_size; return 0; } /* * 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 stop * when tree root is reached or backrefs for the block is cached. * * NOTE: if we find 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 backref_node *build_backref_tree(struct reloc_control *rc, struct btrfs_key *node_key, int level, u64 bytenr) { struct backref_cache *cache = &rc->backref_cache; struct btrfs_path *path1; /* For searching extent root */ struct btrfs_path *path2; /* For searching parent of TREE_BLOCK_REF */ struct extent_buffer *eb; struct btrfs_root *root; struct backref_node *cur; struct backref_node *upper; struct backref_node *lower; struct backref_node *node = NULL; struct backref_node *exist = NULL; struct backref_edge *edge; struct rb_node *rb_node; struct btrfs_key key; unsigned long end; unsigned long ptr; LIST_HEAD(list); /* Pending edge list, upper node needs to be checked */ LIST_HEAD(useless); int cowonly; int ret; int err = 0; bool need_check = true; path1 = btrfs_alloc_path(); path2 = btrfs_alloc_path(); if (!path1 || !path2) { err = -ENOMEM; goto out; } path1->reada = READA_FORWARD; path2->reada = READA_FORWARD; node = alloc_backref_node(cache); if (!node) { err = -ENOMEM; goto out; } node->bytenr = bytenr; node->level = level; node->lowest = 1; cur = node; again: end = 0; ptr = 0; key.objectid = cur->bytenr; key.type = BTRFS_METADATA_ITEM_KEY; key.offset = (u64)-1; path1->search_commit_root = 1; path1->skip_locking = 1; ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1, 0, 0); if (ret < 0) { err = ret; goto out; } ASSERT(ret); ASSERT(path1->slots[0]); path1->slots[0]--; WARN_ON(cur->checked); if (!list_empty(&cur->upper)) { /* * the backref was added previously when processing * backref of type BTRFS_TREE_BLOCK_REF_KEY */ ASSERT(list_is_singular(&cur->upper)); edge = list_entry(cur->upper.next, struct backref_edge, list[LOWER]); ASSERT(list_empty(&edge->list[UPPER])); exist = edge->node[UPPER]; /* * add the upper level block to pending list if we need * check its backrefs */ if (!exist->checked) list_add_tail(&edge->list[UPPER], &list); } else { exist = NULL; } while (1) { cond_resched(); eb = path1->nodes[0]; if (ptr >= end) { if (path1->slots[0] >= btrfs_header_nritems(eb)) { ret = btrfs_next_leaf(rc->extent_root, path1); if (ret < 0) { err = ret; goto out; } if (ret > 0) break; eb = path1->nodes[0]; } btrfs_item_key_to_cpu(eb, &key, path1->slots[0]); if (key.objectid != cur->bytenr) { WARN_ON(exist); break; } if (key.type == BTRFS_EXTENT_ITEM_KEY || key.type == BTRFS_METADATA_ITEM_KEY) { ret = find_inline_backref(eb, path1->slots[0], &ptr, &end); if (ret) goto next; } } if (ptr < end) { /* update key for inline back ref */ struct btrfs_extent_inline_ref *iref; int type; iref = (struct btrfs_extent_inline_ref *)ptr; type = btrfs_get_extent_inline_ref_type(eb, iref, BTRFS_REF_TYPE_BLOCK); if (type == BTRFS_REF_TYPE_INVALID) { err = -EUCLEAN; goto out; } key.type = type; key.offset = btrfs_extent_inline_ref_offset(eb, iref); WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY && key.type != BTRFS_SHARED_BLOCK_REF_KEY); } /* * Parent node found and matches current inline ref, no need to * rebuild this node for this inline ref. */ if (exist && ((key.type == BTRFS_TREE_BLOCK_REF_KEY && exist->owner == key.offset) || (key.type == BTRFS_SHARED_BLOCK_REF_KEY && exist->bytenr == key.offset))) { exist = NULL; goto next; } /* SHARED_BLOCK_REF means key.offset is the parent bytenr */ if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) { if (key.objectid == key.offset) { /* * Only root blocks of reloc trees use backref * pointing to itself. */ root = find_reloc_root(rc, cur->bytenr); ASSERT(root); cur->root = root; break; } edge = alloc_backref_edge(cache); if (!edge) { err = -ENOMEM; goto out; } rb_node = tree_search(&cache->rb_root, key.offset); if (!rb_node) { upper = alloc_backref_node(cache); if (!upper) { free_backref_edge(cache, edge); err = -ENOMEM; goto out; } upper->bytenr = key.offset; upper->level = cur->level + 1; /* * backrefs for the upper level block isn't * cached, add the block to pending list */ list_add_tail(&edge->list[UPPER], &list); } else { upper = rb_entry(rb_node, struct backref_node, rb_node); ASSERT(upper->checked); INIT_LIST_HEAD(&edge->list[UPPER]); } list_add_tail(&edge->list[LOWER], &cur->upper); edge->node[LOWER] = cur; edge->node[UPPER] = upper; goto next; } else if (unlikely(key.type == BTRFS_EXTENT_REF_V0_KEY)) { err = -EINVAL; btrfs_print_v0_err(rc->extent_root->fs_info); btrfs_handle_fs_error(rc->extent_root->fs_info, err, NULL); goto out; } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) { goto next; } /* * key.type == BTRFS_TREE_BLOCK_REF_KEY, inline ref offset * means the root objectid. We need to search the tree to get * its parent bytenr. */ root = read_fs_root(rc->extent_root->fs_info, key.offset); if (IS_ERR(root)) { err = PTR_ERR(root); goto out; } if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state)) cur->cowonly = 1; if (btrfs_root_level(&root->root_item) == cur->level) { /* tree root */ ASSERT(btrfs_root_bytenr(&root->root_item) == cur->bytenr); if (should_ignore_root(root)) list_add(&cur->list, &useless); else cur->root = root; break; } level = cur->level + 1; /* Search the tree to find parent blocks referring the block. */ path2->search_commit_root = 1; path2->skip_locking = 1; path2->lowest_level = level; ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0); path2->lowest_level = 0; if (ret < 0) { err = ret; goto out; } if (ret > 0 && path2->slots[level] > 0) path2->slots[level]--; eb = path2->nodes[level]; if (btrfs_node_blockptr(eb, path2->slots[level]) != cur->bytenr) { btrfs_err(root->fs_info, "couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)", cur->bytenr, level - 1, root->root_key.objectid, node_key->objectid, node_key->type, node_key->offset); err = -ENOENT; goto out; } lower = cur; need_check = true; /* Add all nodes and edges in the path */ for (; level < BTRFS_MAX_LEVEL; level++) { if (!path2->nodes[level]) { ASSERT(btrfs_root_bytenr(&root->root_item) == lower->bytenr); if (should_ignore_root(root)) list_add(&lower->list, &useless); else lower->root = root; break; } edge = alloc_backref_edge(cache); if (!edge) { err = -ENOMEM; goto out; } eb = path2->nodes[level]; rb_node = tree_search(&cache->rb_root, eb->start); if (!rb_node) { upper = alloc_backref_node(cache); if (!upper) { free_backref_edge(cache, edge); err = -ENOMEM; goto out; } upper->bytenr = eb->start; upper->owner = btrfs_header_owner(eb); upper->level = lower->level + 1; if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state)) upper->cowonly = 1; /* * if we know the block isn't shared * we can void checking its backrefs. */ if (btrfs_block_can_be_shared(root, eb)) upper->checked = 0; else upper->checked = 1; /* * add the block to pending list if we * need check its backrefs, we only do this once * while walking up a tree as we will catch * anything else later on. */ if (!upper->checked && need_check) { need_check = false; list_add_tail(&edge->list[UPPER], &list); } else { if (upper->checked) need_check = true; INIT_LIST_HEAD(&edge->list[UPPER]); } } else { upper = rb_entry(rb_node, struct backref_node, rb_node); ASSERT(upper->checked); INIT_LIST_HEAD(&edge->list[UPPER]); if (!upper->owner) upper->owner = btrfs_header_owner(eb); } list_add_tail(&edge->list[LOWER], &lower->upper); edge->node[LOWER] = lower; edge->node[UPPER] = upper; if (rb_node) break; lower = upper; upper = NULL; } btrfs_release_path(path2); next: if (ptr < end) { ptr += btrfs_extent_inline_ref_size(key.type); if (ptr >= end) { WARN_ON(ptr > end); ptr = 0; end = 0; } } if (ptr >= end) path1->slots[0]++; } btrfs_release_path(path1); cur->checked = 1; WARN_ON(exist); /* the pending list isn't empty, take the first block to process */ if (!list_empty(&list)) { edge = list_entry(list.next, struct backref_edge, list[UPPER]); list_del_init(&edge->list[UPPER]); cur = edge->node[UPPER]; goto again; } /* * everything goes well, connect backref nodes and insert backref nodes * into the cache. */ ASSERT(node->checked); cowonly = node->cowonly; if (!cowonly) { rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node); if (rb_node) backref_tree_panic(rb_node, -EEXIST, node->bytenr); list_add_tail(&node->lower, &cache->leaves); } list_for_each_entry(edge, &node->upper, list[LOWER]) list_add_tail(&edge->list[UPPER], &list); while (!list_empty(&list)) { edge = list_entry(list.next, struct backref_edge, list[UPPER]); list_del_init(&edge->list[UPPER]); upper = edge->node[UPPER]; if (upper->detached) { list_del(&edge->list[LOWER]); lower = edge->node[LOWER]; free_backref_edge(cache, edge); if (list_empty(&lower->upper)) list_add(&lower->list, &useless); continue; } if (!RB_EMPTY_NODE(&upper->rb_node)) { if (upper->lowest) { list_del_init(&upper->lower); upper->lowest = 0; } list_add_tail(&edge->list[UPPER], &upper->lower); continue; } if (!upper->checked) { /* * Still want to blow up for developers since this is a * logic bug. */ ASSERT(0); err = -EINVAL; goto out; } if (cowonly != upper->cowonly) { ASSERT(0); err = -EINVAL; goto out; } if (!cowonly) { rb_node = tree_insert(&cache->rb_root, upper->bytenr, &upper->rb_node); if (rb_node) backref_tree_panic(rb_node, -EEXIST, upper->bytenr); } list_add_tail(&edge->list[UPPER], &upper->lower); list_for_each_entry(edge, &upper->upper, list[LOWER]) list_add_tail(&edge->list[UPPER], &list); } /* * process useless backref nodes. 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. */ while (!list_empty(&useless)) { upper = list_entry(useless.next, struct backref_node, list); list_del_init(&upper->list); ASSERT(list_empty(&upper->upper)); if (upper == node) node = NULL; if (upper->lowest) { list_del_init(&upper->lower); upper->lowest = 0; } while (!list_empty(&upper->lower)) { edge = list_entry(upper->lower.next, struct backref_edge, list[UPPER]); list_del(&edge->list[UPPER]); list_del(&edge->list[LOWER]); lower = edge->node[LOWER]; free_backref_edge(cache, edge); if (list_empty(&lower->upper)) list_add(&lower->list, &useless); } __mark_block_processed(rc, upper); if (upper->level > 0) { list_add(&upper->list, &cache->detached); upper->detached = 1; } else { rb_erase(&upper->rb_node, &cache->rb_root); free_backref_node(cache, upper); } } out: btrfs_free_path(path1); btrfs_free_path(path2); if (err) { while (!list_empty(&useless)) { lower = list_entry(useless.next, struct backref_node, list); list_del_init(&lower->list); } while (!list_empty(&list)) { edge = list_first_entry(&list, struct backref_edge, list[UPPER]); list_del(&edge->list[UPPER]); list_del(&edge->list[LOWER]); lower = edge->node[LOWER]; upper = edge->node[UPPER]; free_backref_edge(cache, edge); /* * Lower is no longer linked to any upper backref nodes * and isn't in the cache, we can free it ourselves. */ if (list_empty(&lower->upper) && RB_EMPTY_NODE(&lower->rb_node)) list_add(&lower->list, &useless); if (!RB_EMPTY_NODE(&upper->rb_node)) continue; /* Add this guy's upper edges to the list to process */ list_for_each_entry(edge, &upper->upper, list[LOWER]) list_add_tail(&edge->list[UPPER], &list); if (list_empty(&upper->upper)) list_add(&upper->list, &useless); } while (!list_empty(&useless)) { lower = list_entry(useless.next, struct backref_node, list); list_del_init(&lower->list); if (lower == node) node = NULL; free_backref_node(cache, lower); } free_backref_node(cache, node); return ERR_PTR(err); } ASSERT(!node || !node->detached); 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 backref_cache *cache = &rc->backref_cache; struct backref_node *node = NULL; struct backref_node *new_node; struct backref_edge *edge; struct backref_edge *new_edge; struct rb_node *rb_node; if (cache->last_trans > 0) update_backref_cache(trans, cache); rb_node = tree_search(&cache->rb_root, src->commit_root->start); if (rb_node) { node = rb_entry(rb_node, struct backref_node, rb_node); if (node->detached) node = NULL; else BUG_ON(node->new_bytenr != reloc_root->node->start); } if (!node) { rb_node = tree_search(&cache->rb_root, reloc_root->commit_root->start); if (rb_node) { node = rb_entry(rb_node, struct backref_node, rb_node); BUG_ON(node->detached); } } if (!node) return 0; new_node = alloc_backref_node(cache); if (!new_node) return -ENOMEM; new_node->bytenr = dest->node->start; new_node->level = node->level; new_node->lowest = node->lowest; new_node->checked = 1; new_node->root = dest; if (!node->lowest) { list_for_each_entry(edge, &node->lower, list[UPPER]) { new_edge = alloc_backref_edge(cache); if (!new_edge) goto fail; new_edge->node[UPPER] = new_node; new_edge->node[LOWER] = edge->node[LOWER]; list_add_tail(&new_edge->list[UPPER], &new_node->lower); } } else { list_add_tail(&new_node->lower, &cache->leaves); } rb_node = tree_insert(&cache->rb_root, new_node->bytenr, &new_node->rb_node); if (rb_node) backref_tree_panic(rb_node, -EEXIST, new_node->bytenr); 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 backref_edge, list[UPPER]); list_del(&new_edge->list[UPPER]); free_backref_edge(cache, new_edge); } free_backref_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->node->start; node->data = root; spin_lock(&rc->reloc_root_tree.lock); rb_node = tree_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; if (rc && root->node) { spin_lock(&rc->reloc_root_tree.lock); rb_node = tree_search(&rc->reloc_root_tree.rb_root, root->node->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; BUG_ON((struct btrfs_root *)node->data != root); } spin_lock(&fs_info->trans_lock); list_del_init(&root->root_list); spin_unlock(&fs_info->trans_lock); kfree(node); } /* * helper to update the 'address of tree root -> reloc tree' * mapping */ static int __update_reloc_root(struct btrfs_root *root, u64 new_bytenr) { 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 = tree_search(&rc->reloc_root_tree.rb_root, root->node->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 = new_bytenr; rb_node = tree_insert(&rc->reloc_root_tree.rb_root, node->bytenr, &node->rb_node); spin_unlock(&rc->reloc_root_tree.lock); if (rb_node) backref_tree_panic(rb_node, -EEXIST, node->bytenr); 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)); root_item->drop_level = 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_fs_root(fs_info->tree_root, &root_key); BUG_ON(IS_ERR(reloc_root)); 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. */ 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; /* * 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; if (root->reloc_root) { reloc_root = root->reloc_root; reloc_root->last_trans = trans->transid; return 0; } if (!rc || !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 = 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; /* 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) { 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); 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; } static int in_block_group(u64 bytenr, struct btrfs_block_group *block_group) { if (bytenr >= block_group->start && bytenr < block_group->start + block_group->length) return 1; return 0; } /* * 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_block_group(bytenr, rc->block_group)) 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); btrfs_set_lock_blocking_write(eb); 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); BUG_ON(ret); } btrfs_set_lock_blocking_write(eb); 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, level, &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); BUG_ON(ret); } btrfs_set_lock_blocking_write(eb); 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)); reloc_root_item->drop_level = 0; btrfs_set_root_refs(reloc_root_item, 0); btrfs_update_reloc_root(trans, root); if (list_empty(&root->reloc_dirty_list)) { btrfs_grab_fs_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; if (reloc_root) { ret2 = btrfs_drop_snapshot(reloc_root, NULL, 0, 1); if (ret2 < 0 && !ret) ret = ret2; } /* * 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); btrfs_put_fs_root(root); } else { /* Orphan reloc tree, just clean it up */ ret2 = btrfs_drop_snapshot(root, NULL, 0, 1); if (ret2 < 0 && !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 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 = root_item->drop_level; 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); } min_reserved = fs_info->nodesize * (BTRFS_MAX_LEVEL - 1) * 2; memset(&next_key, 0, sizeof(next_key)); while (1) { ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved, BTRFS_RESERVE_FLUSH_ALL); if (ret) { err = ret; goto out; } trans = btrfs_start_transaction(root, 0); if (IS_ERR(trans)) { err = PTR_ERR(trans); trans = NULL; goto out; } 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]); root_item->drop_level = 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_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); 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); 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 = read_fs_root(fs_info, reloc_root->root_key.offset); 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); } 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; while (!list_empty(list)) { reloc_root = list_entry(list->next, struct btrfs_root, root_list); __del_reloc_root(reloc_root); free_extent_buffer(reloc_root->node); free_extent_buffer(reloc_root->commit_root); reloc_root->node = NULL; reloc_root->commit_root = NULL; } } 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); if (btrfs_root_refs(&reloc_root->root_item) > 0) { root = read_fs_root(fs_info, reloc_root->root_key.offset); BUG_ON(IS_ERR(root)); BUG_ON(root->reloc_root != reloc_root); ret = merge_reloc_root(rc, root); if (ret) { if (list_empty(&reloc_root->root_list)) list_add_tail(&reloc_root->root_list, &reloc_roots); goto out; } } else { 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); if (!list_empty(&reloc_roots)) 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); if (!list_empty(&reloc_roots)) free_reloc_roots(&reloc_roots); } BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root)); } 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; if (reloc_root->last_trans == trans->transid) return 0; root = read_fs_root(fs_info, reloc_root->root_key.offset); BUG_ON(IS_ERR(root)); BUG_ON(root->reloc_root != reloc_root); return btrfs_record_root_in_trans(trans, root); } static noinline_for_stack struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans, struct reloc_control *rc, struct backref_node *node, struct backref_edge *edges[]) { struct 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_REF_COWS, &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; next->root = 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 reference counted. we should use do_relocation() in this * case. return a tree root pointer if the block isn't reference * counted. return -ENOENT if the block is root of reloc tree. */ static noinline_for_stack struct btrfs_root *select_one_root(struct backref_node *node) { struct backref_node *next; struct btrfs_root *root; struct btrfs_root *fs_root = NULL; struct 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-references counted tree */ if (!test_bit(BTRFS_ROOT_REF_COWS, &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 backref_node *node, int reserve) { struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; struct backref_node *next = node; struct backref_edge *edge; struct 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 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 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 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 backref_node *upper; struct backref_edge *edge; struct 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, upper->level, &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; } 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, upper->level, &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); btrfs_set_lock_blocking_write(eb); if (!node->eb) { ret = btrfs_cow_block(trans, root, eb, upper->eb, slot, &eb); 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) drop_node_buffer(upper); else unlock_node_buffer(upper); if (err) break; } if (!err && node->pending) { 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 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 backref_cache *cache = &rc->backref_cache; struct 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 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; } static void mark_block_processed(struct reloc_control *rc, u64 bytenr, u32 blocksize) { set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1, EXTENT_DIRTY); } static void __mark_block_processed(struct reloc_control *rc, struct backref_node *node) { u32 blocksize; if (node->level == 0 || in_block_group(node->bytenr, rc->block_group)) { blocksize = rc->extent_root->fs_info->nodesize; mark_block_processed(rc, node->bytenr, blocksize); } node->processed = 1; } /* * mark a block and all blocks directly/indirectly reference the block * as processed. */ static void update_processed_blocks(struct reloc_control *rc, struct backref_node *node) { struct backref_node *next = node; struct backref_edge *edge; struct 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 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; BUG_ON(block->key_ready); 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 backref_node *node, struct btrfs_key *key, struct btrfs_path *path) { struct btrfs_root *root; int ret = 0; if (!node) return 0; BUG_ON(node->processed); root = select_one_root(node); if (root == ERR_PTR(-ENOENT)) { update_processed_blocks(rc, node); goto out; } if (!root || test_bit(BTRFS_ROOT_REF_COWS, &root->state)) { ret = reserve_metadata_space(trans, rc, node); if (ret) goto out; } if (root) { if (test_bit(BTRFS_ROOT_REF_COWS, &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; node->root = 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) remove_backref_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 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) { if (ret != -EAGAIN || &block->rb_node == rb_first(blocks)) err = ret; goto out; } } 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 inode *inode, struct file_extent_cluster *cluster) { u64 alloc_hint = 0; u64 start; u64 end; u64 offset = BTRFS_I(inode)->index_cnt; u64 num_bytes; int nr = 0; int ret = 0; u64 prealloc_start = cluster->start - offset; u64 prealloc_end = cluster->end - offset; u64 cur_offset; struct extent_changeset *data_reserved = NULL; BUG_ON(cluster->start != cluster->boundary[0]); inode_lock(inode); ret = btrfs_check_data_free_space(inode, &data_reserved, prealloc_start, prealloc_end + 1 - prealloc_start); if (ret) goto out; cur_offset = prealloc_start; while (nr < cluster->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(&BTRFS_I(inode)->io_tree, start, end); num_bytes = end + 1 - start; if (cur_offset < start) btrfs_free_reserved_data_space(inode, data_reserved, cur_offset, start - cur_offset); ret = btrfs_prealloc_file_range(inode, 0, start, num_bytes, num_bytes, end + 1, &alloc_hint); cur_offset = end + 1; unlock_extent(&BTRFS_I(inode)->io_tree, start, end); if (ret) break; nr++; } if (cur_offset < prealloc_end) btrfs_free_reserved_data_space(inode, data_reserved, cur_offset, prealloc_end + 1 - cur_offset); out: inode_unlock(inode); extent_changeset_free(data_reserved); 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; } 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(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(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); } 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 = tree_insert(blocks, block->bytenr, &block->rb_node); if (rb_node) backref_tree_panic(rb_node, -EEXIST, block->bytenr); 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 (tree_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; } /* * helper to check if the block use full backrefs for pointers in it */ static int block_use_full_backref(struct reloc_control *rc, struct extent_buffer *eb) { u64 flags; int ret; if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) || btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV) return 1; ret = btrfs_lookup_extent_info(NULL, rc->extent_root->fs_info, eb->start, btrfs_header_level(eb), 1, NULL, &flags); BUG_ON(ret); if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) ret = 1; else ret = 0; 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_key key; struct btrfs_root *root = fs_info->tree_root; struct btrfs_trans_handle *trans; int ret = 0; if (inode) goto truncate; key.objectid = ino; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; inode = btrfs_iget(fs_info->sb, &key, 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; } /* * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY * this function scans fs tree to find blocks reference the data extent */ static int find_data_references(struct reloc_control *rc, struct btrfs_key *extent_key, struct extent_buffer *leaf, struct btrfs_extent_data_ref *ref, struct rb_root *blocks) { struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; struct btrfs_path *path; struct tree_block *block; struct btrfs_root *root; struct btrfs_file_extent_item *fi; struct rb_node *rb_node; struct btrfs_key key; u64 ref_root; u64 ref_objectid; u64 ref_offset; u32 ref_count; u32 nritems; int err = 0; int added = 0; int counted; int ret; ref_root = btrfs_extent_data_ref_root(leaf, ref); ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref); ref_offset = btrfs_extent_data_ref_offset(leaf, ref); ref_count = btrfs_extent_data_ref_count(leaf, ref); /* * This is an extent belonging to the free space cache, lets just delete * it and redo the search. */ if (ref_root == BTRFS_ROOT_TREE_OBJECTID) { ret = delete_block_group_cache(fs_info, rc->block_group, NULL, ref_objectid); if (ret != -ENOENT) return ret; ret = 0; } path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->reada = READA_FORWARD; root = read_fs_root(fs_info, ref_root); if (IS_ERR(root)) { err = PTR_ERR(root); goto out; } key.objectid = ref_objectid; key.type = BTRFS_EXTENT_DATA_KEY; if (ref_offset > ((u64)-1 << 32)) key.offset = 0; else key.offset = ref_offset; path->search_commit_root = 1; path->skip_locking = 1; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) { err = ret; goto out; } leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); /* * the references in tree blocks that use full backrefs * are not counted in */ if (block_use_full_backref(rc, leaf)) counted = 0; else counted = 1; rb_node = tree_search(blocks, leaf->start); if (rb_node) { if (counted) added = 1; else path->slots[0] = nritems; } while (ref_count > 0) { while (path->slots[0] >= nritems) { ret = btrfs_next_leaf(root, path); if (ret < 0) { err = ret; goto out; } if (WARN_ON(ret > 0)) goto out; leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); added = 0; if (block_use_full_backref(rc, leaf)) counted = 0; else counted = 1; rb_node = tree_search(blocks, leaf->start); if (rb_node) { if (counted) added = 1; else path->slots[0] = nritems; } } btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (WARN_ON(key.objectid != ref_objectid || key.type != BTRFS_EXTENT_DATA_KEY)) break; fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) goto next; if (btrfs_file_extent_disk_bytenr(leaf, fi) != extent_key->objectid) goto next; key.offset -= btrfs_file_extent_offset(leaf, fi); if (key.offset != ref_offset) goto next; if (counted) ref_count--; if (added) goto next; if (!tree_block_processed(leaf->start, rc)) { block = kmalloc(sizeof(*block), GFP_NOFS); if (!block) { err = -ENOMEM; break; } block->bytenr = leaf->start; btrfs_item_key_to_cpu(leaf, &block->key, 0); block->level = 0; block->key_ready = 1; rb_node = tree_insert(blocks, block->bytenr, &block->rb_node); if (rb_node) backref_tree_panic(rb_node, -EEXIST, block->bytenr); } if (counted) added = 1; else path->slots[0] = nritems; next: path->slots[0]++; } out: btrfs_free_path(path); return err; } /* * 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_key key; struct extent_buffer *eb; struct btrfs_extent_data_ref *dref; struct btrfs_extent_inline_ref *iref; unsigned long ptr; unsigned long end; u32 blocksize = rc->extent_root->fs_info->nodesize; int ret = 0; int err = 0; eb = path->nodes[0]; ptr = btrfs_item_ptr_offset(eb, path->slots[0]); end = ptr + btrfs_item_size_nr(eb, path->slots[0]); ptr += sizeof(struct btrfs_extent_item); while (ptr < end) { iref = (struct btrfs_extent_inline_ref *)ptr; key.type = btrfs_get_extent_inline_ref_type(eb, iref, BTRFS_REF_TYPE_DATA); if (key.type == BTRFS_SHARED_DATA_REF_KEY) { key.offset = btrfs_extent_inline_ref_offset(eb, iref); ret = __add_tree_block(rc, key.offset, blocksize, blocks); } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { dref = (struct btrfs_extent_data_ref *)(&iref->offset); ret = find_data_references(rc, extent_key, eb, dref, blocks); } else { ret = -EUCLEAN; btrfs_err(rc->extent_root->fs_info, "extent %llu slot %d has an invalid inline ref type", eb->start, path->slots[0]); } if (ret) { err = ret; goto out; } ptr += btrfs_extent_inline_ref_size(key.type); } WARN_ON(ptr > end); while (1) { cond_resched(); eb = path->nodes[0]; if (path->slots[0] >= btrfs_header_nritems(eb)) { ret = btrfs_next_leaf(rc->extent_root, path); if (ret < 0) { err = ret; break; } if (ret > 0) break; eb = path->nodes[0]; } btrfs_item_key_to_cpu(eb, &key, path->slots[0]); if (key.objectid != extent_key->objectid) break; if (key.type == BTRFS_SHARED_DATA_REF_KEY) { ret = __add_tree_block(rc, key.offset, blocksize, blocks); } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { dref = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_data_ref); ret = find_data_references(rc, extent_key, eb, dref, blocks); } else if (unlikely(key.type == BTRFS_EXTENT_REF_V0_KEY)) { btrfs_print_v0_err(eb->fs_info); btrfs_handle_fs_error(eb->fs_info, -EINVAL, NULL); ret = -EINVAL; } else { ret = 0; } if (ret) { err = ret; break; } path->slots[0]++; } out: btrfs_release_path(path); if (err) free_block_list(blocks); return err; } /* * 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 we fail to relocate tree blocks, force to update * backref cache when committing transaction. */ rc->backref_cache.last_trans = trans->transid - 1; 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 (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); backref_cache_cleanup(&rc->backref_cache); btrfs_block_rsv_release(fs_info, rc->block_rsv, (u64)-1); 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); /* 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); ret = clean_dirty_subvols(rc); if (ret < 0 && !err) err = ret; out_free: 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; struct btrfs_key key; u64 objectid; int err = 0; root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID); if (IS_ERR(root)) return ERR_CAST(root); trans = btrfs_start_transaction(root, 6); if (IS_ERR(trans)) 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); key.objectid = objectid; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; inode = btrfs_iget(fs_info->sb, &key, root); BUG_ON(IS_ERR(inode)); BTRFS_I(inode)->index_cnt = group->start; err = btrfs_orphan_add(trans, BTRFS_I(inode)); out: 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); backref_cache_init(&rc->backref_cache); mapping_tree_init(&rc->reloc_root_tree); extent_io_tree_init(fs_info, &rc->processed_blocks, IO_TREE_RELOC_BLOCKS, NULL); return 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); kfree(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)); root->root_item.drop_level = 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_fs_root(root, &key); if (IS_ERR(reloc_root)) { err = PTR_ERR(reloc_root); goto out; } list_add(&reloc_root->root_list, &reloc_roots); if (btrfs_root_refs(&reloc_root->root_item) > 0) { fs_root = read_fs_root(fs_info, reloc_root->root_key.offset); 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; } } } 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)) { unset_reloc_control(rc); err = PTR_ERR(trans); goto out_free; } 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 = read_fs_root(fs_info, reloc_root->root_key.offset); if (IS_ERR(fs_root)) { err = PTR_ERR(fs_root); list_add_tail(&reloc_root->root_list, &reloc_roots); goto out_free; } err = __add_reloc_root(reloc_root); BUG_ON(err < 0); /* -ENOMEM or logic error */ fs_root->reloc_root = reloc_root; } err = btrfs_commit_transaction(trans); if (err) goto out_free; 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_free; } err = btrfs_commit_transaction(trans); ret = clean_dirty_subvols(rc); if (ret < 0 && !err) err = ret; out_free: kfree(rc); out: if (!list_empty(&reloc_roots)) free_reloc_roots(&reloc_roots); btrfs_free_path(path); if (err == 0) { /* cleanup orphan inode in data relocation tree */ fs_root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID); if (IS_ERR(fs_root)) err = PTR_ERR(fs_root); else err = btrfs_orphan_cleanup(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 inode *inode, u64 file_pos, u64 len) { struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 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 + BTRFS_I(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 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); if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { if (buf == root->node) __update_reloc_root(root, cow->start); } 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); 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 */ 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 = reloc_root; if (rc->create_reloc_tree) ret = clone_backref_node(trans, rc, root, reloc_root); return ret; }
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