| /* |
| * Copyright (C) 2009 Oracle. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public |
| * License v2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public |
| * License along with this program; if not, write to the |
| * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| * Boston, MA 021110-1307, USA. |
| */ |
| |
| #include <linux/sched.h> |
| #include <linux/pagemap.h> |
| #include <linux/writeback.h> |
| #include <linux/blkdev.h> |
| #include <linux/rbtree.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" |
| |
| /* |
| * 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; |
| /* objectid tree block owner */ |
| u64 owner; |
| /* 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; |
| /* 1 if the block is root of old snapshot */ |
| unsigned int old_root:1; |
| /* 1 if no child blocks 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; |
| }; |
| |
| /* |
| * present a block pointer in the backref cache |
| */ |
| struct backref_edge { |
| struct list_head list[2]; |
| struct backref_node *node[2]; |
| u64 blockptr; |
| }; |
| |
| #define LOWER 0 |
| #define UPPER 1 |
| |
| struct backref_cache { |
| /* red black tree of all backref nodes in the cache */ |
| struct rb_root rb_root; |
| /* list of backref nodes with no child block in the cache */ |
| struct list_head pending[BTRFS_MAX_LEVEL]; |
| spinlock_t lock; |
| }; |
| |
| /* |
| * 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; |
| }; |
| |
| /* inode vector */ |
| #define INODEVEC_SIZE 16 |
| |
| struct inodevec { |
| struct list_head list; |
| struct inode *inode[INODEVEC_SIZE]; |
| int nr; |
| }; |
| |
| #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_cache *block_group; |
| /* extent tree */ |
| struct btrfs_root *extent_root; |
| /* inode for moving data */ |
| struct inode *data_inode; |
| struct btrfs_workers workers; |
| /* 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; |
| u64 search_start; |
| u64 extents_found; |
| u64 extents_skipped; |
| int stage; |
| int create_reloc_root; |
| unsigned int found_file_extent:1; |
| unsigned int found_old_snapshot:1; |
| }; |
| |
| /* stages of data relocation */ |
| #define MOVE_DATA_EXTENTS 0 |
| #define UPDATE_DATA_PTRS 1 |
| |
| /* |
| * merge reloc tree to corresponding fs tree in worker threads |
| */ |
| struct async_merge { |
| struct btrfs_work work; |
| struct reloc_control *rc; |
| struct btrfs_root *root; |
| struct completion *done; |
| atomic_t *num_pending; |
| }; |
| |
| static void mapping_tree_init(struct mapping_tree *tree) |
| { |
| tree->rb_root.rb_node = NULL; |
| spin_lock_init(&tree->lock); |
| } |
| |
| static void backref_cache_init(struct backref_cache *cache) |
| { |
| int i; |
| cache->rb_root.rb_node = NULL; |
| for (i = 0; i < BTRFS_MAX_LEVEL; i++) |
| INIT_LIST_HEAD(&cache->pending[i]); |
| spin_lock_init(&cache->lock); |
| } |
| |
| static void backref_node_init(struct backref_node *node) |
| { |
| memset(node, 0, sizeof(*node)); |
| INIT_LIST_HEAD(&node->upper); |
| INIT_LIST_HEAD(&node->lower); |
| RB_CLEAR_NODE(&node->rb_node); |
| } |
| |
| 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; |
| } |
| |
| /* |
| * 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]; |
| } |
| *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 drop_node_buffer(struct backref_node *node) |
| { |
| if (node->eb) { |
| if (node->locked) { |
| btrfs_tree_unlock(node->eb); |
| node->locked = 0; |
| } |
| free_extent_buffer(node->eb); |
| node->eb = NULL; |
| } |
| } |
| |
| static void drop_backref_node(struct backref_cache *tree, |
| struct backref_node *node) |
| { |
| BUG_ON(!node->lowest); |
| BUG_ON(!list_empty(&node->upper)); |
| |
| drop_node_buffer(node); |
| list_del(&node->lower); |
| |
| rb_erase(&node->rb_node, &tree->rb_root); |
| kfree(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); |
| 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]); |
| kfree(edge); |
| /* |
| * add the node to pending list if no other |
| * child block cached. |
| */ |
| if (list_empty(&upper->lower)) { |
| list_add_tail(&upper->lower, |
| &cache->pending[upper->level]); |
| upper->lowest = 1; |
| } |
| } |
| drop_backref_node(cache, node); |
| } |
| |
| /* |
| * 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) |
| 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_read_fs_root_no_name(fs_info, &key); |
| } |
| |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| static noinline_for_stack |
| struct btrfs_root *find_tree_root(struct reloc_control *rc, |
| struct extent_buffer *leaf, |
| struct btrfs_extent_ref_v0 *ref0) |
| { |
| struct btrfs_root *root; |
| u64 root_objectid = btrfs_ref_root_v0(leaf, ref0); |
| u64 generation = btrfs_ref_generation_v0(leaf, ref0); |
| |
| BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID); |
| |
| root = read_fs_root(rc->extent_root->fs_info, root_objectid); |
| BUG_ON(IS_ERR(root)); |
| |
| if (root->ref_cows && |
| generation != btrfs_root_generation(&root->root_item)) |
| return NULL; |
| |
| return root; |
| } |
| #endif |
| |
| static noinline_for_stack |
| int find_inline_backref(struct extent_buffer *leaf, int slot, |
| unsigned long *ptr, unsigned long *end) |
| { |
| struct btrfs_extent_item *ei; |
| struct btrfs_tree_block_info *bi; |
| u32 item_size; |
| |
| item_size = btrfs_item_size_nr(leaf, slot); |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| if (item_size < sizeof(*ei)) { |
| WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0)); |
| return 1; |
| } |
| #endif |
| ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); |
| WARN_ON(!(btrfs_extent_flags(leaf, ei) & |
| BTRFS_EXTENT_FLAG_TREE_BLOCK)); |
| |
| if (item_size <= sizeof(*ei) + sizeof(*bi)) { |
| WARN_ON(item_size < sizeof(*ei) + sizeof(*bi)); |
| return 1; |
| } |
| |
| bi = (struct btrfs_tree_block_info *)(ei + 1); |
| *ptr = (unsigned long)(bi + 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 refernece the block, and then check |
| * bakcrefs 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 struct backref_node *build_backref_tree(struct reloc_control *rc, |
| struct backref_cache *cache, |
| struct btrfs_key *node_key, |
| int level, u64 bytenr) |
| { |
| struct btrfs_path *path1; |
| struct btrfs_path *path2; |
| 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); |
| int ret; |
| int err = 0; |
| |
| path1 = btrfs_alloc_path(); |
| path2 = btrfs_alloc_path(); |
| if (!path1 || !path2) { |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| node = kmalloc(sizeof(*node), GFP_NOFS); |
| if (!node) { |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| backref_node_init(node); |
| node->bytenr = bytenr; |
| node->owner = 0; |
| node->level = level; |
| node->lowest = 1; |
| cur = node; |
| again: |
| end = 0; |
| ptr = 0; |
| key.objectid = cur->bytenr; |
| key.type = BTRFS_EXTENT_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; |
| } |
| BUG_ON(!ret || !path1->slots[0]); |
| |
| path1->slots[0]--; |
| |
| WARN_ON(cur->checked); |
| if (!list_empty(&cur->upper)) { |
| /* |
| * the backref was added previously when processsing |
| * backref of type BTRFS_TREE_BLOCK_REF_KEY |
| */ |
| BUG_ON(!list_is_singular(&cur->upper)); |
| edge = list_entry(cur->upper.next, struct backref_edge, |
| list[LOWER]); |
| BUG_ON(!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) { |
| 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; |
| iref = (struct btrfs_extent_inline_ref *)ptr; |
| key.type = btrfs_extent_inline_ref_type(eb, iref); |
| 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); |
| } |
| |
| 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; |
| } |
| |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| if (key.type == BTRFS_SHARED_BLOCK_REF_KEY || |
| key.type == BTRFS_EXTENT_REF_V0_KEY) { |
| if (key.objectid == key.offset && |
| key.type == BTRFS_EXTENT_REF_V0_KEY) { |
| struct btrfs_extent_ref_v0 *ref0; |
| ref0 = btrfs_item_ptr(eb, path1->slots[0], |
| struct btrfs_extent_ref_v0); |
| root = find_tree_root(rc, eb, ref0); |
| if (root) |
| cur->root = root; |
| else |
| cur->old_root = 1; |
| break; |
| } |
| #else |
| BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY); |
| if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) { |
| #endif |
| if (key.objectid == key.offset) { |
| /* |
| * only root blocks of reloc trees use |
| * backref of this type. |
| */ |
| root = find_reloc_root(rc, cur->bytenr); |
| BUG_ON(!root); |
| cur->root = root; |
| break; |
| } |
| |
| edge = kzalloc(sizeof(*edge), GFP_NOFS); |
| if (!edge) { |
| err = -ENOMEM; |
| goto out; |
| } |
| rb_node = tree_search(&cache->rb_root, key.offset); |
| if (!rb_node) { |
| upper = kmalloc(sizeof(*upper), GFP_NOFS); |
| if (!upper) { |
| kfree(edge); |
| err = -ENOMEM; |
| goto out; |
| } |
| backref_node_init(upper); |
| upper->bytenr = key.offset; |
| upper->owner = 0; |
| 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); |
| INIT_LIST_HEAD(&edge->list[UPPER]); |
| } |
| list_add(&edge->list[LOWER], &cur->upper); |
| edge->node[UPPER] = upper; |
| edge->node[LOWER] = cur; |
| |
| goto next; |
| } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) { |
| goto next; |
| } |
| |
| /* key.type == BTRFS_TREE_BLOCK_REF_KEY */ |
| root = read_fs_root(rc->extent_root->fs_info, key.offset); |
| if (IS_ERR(root)) { |
| err = PTR_ERR(root); |
| goto out; |
| } |
| |
| if (btrfs_root_level(&root->root_item) == cur->level) { |
| /* tree root */ |
| BUG_ON(btrfs_root_bytenr(&root->root_item) != |
| cur->bytenr); |
| cur->root = root; |
| break; |
| } |
| |
| level = cur->level + 1; |
| |
| /* |
| * searching the tree to find upper level blocks |
| * reference 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]; |
| WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) != |
| cur->bytenr); |
| |
| lower = cur; |
| for (; level < BTRFS_MAX_LEVEL; level++) { |
| if (!path2->nodes[level]) { |
| BUG_ON(btrfs_root_bytenr(&root->root_item) != |
| lower->bytenr); |
| lower->root = root; |
| break; |
| } |
| |
| edge = kzalloc(sizeof(*edge), GFP_NOFS); |
| if (!edge) { |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| eb = path2->nodes[level]; |
| rb_node = tree_search(&cache->rb_root, eb->start); |
| if (!rb_node) { |
| upper = kmalloc(sizeof(*upper), GFP_NOFS); |
| if (!upper) { |
| kfree(edge); |
| err = -ENOMEM; |
| goto out; |
| } |
| backref_node_init(upper); |
| upper->bytenr = eb->start; |
| upper->owner = btrfs_header_owner(eb); |
| upper->level = lower->level + 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. only block |
| * at 'cur->level + 1' is added to the |
| * tail of pending list. this guarantees |
| * we check backrefs from lower level |
| * blocks to upper level blocks. |
| */ |
| if (!upper->checked && |
| level == cur->level + 1) { |
| list_add_tail(&edge->list[UPPER], |
| &list); |
| } else |
| INIT_LIST_HEAD(&edge->list[UPPER]); |
| } else { |
| upper = rb_entry(rb_node, struct backref_node, |
| rb_node); |
| BUG_ON(!upper->checked); |
| INIT_LIST_HEAD(&edge->list[UPPER]); |
| } |
| list_add_tail(&edge->list[LOWER], &lower->upper); |
| edge->node[UPPER] = upper; |
| edge->node[LOWER] = lower; |
| |
| if (rb_node) |
| break; |
| lower = upper; |
| upper = NULL; |
| } |
| btrfs_release_path(root, 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(rc->extent_root, 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. |
| */ |
| BUG_ON(!node->checked); |
| rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node); |
| BUG_ON(rb_node); |
| |
| 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 (!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; |
| } |
| |
| BUG_ON(!upper->checked); |
| rb_node = tree_insert(&cache->rb_root, upper->bytenr, |
| &upper->rb_node); |
| BUG_ON(rb_node); |
| |
| list_add_tail(&edge->list[UPPER], &upper->lower); |
| |
| list_for_each_entry(edge, &upper->upper, list[LOWER]) |
| list_add_tail(&edge->list[UPPER], &list); |
| } |
| out: |
| btrfs_free_path(path1); |
| btrfs_free_path(path2); |
| if (err) { |
| INIT_LIST_HEAD(&list); |
| upper = node; |
| while (upper) { |
| if (RB_EMPTY_NODE(&upper->rb_node)) { |
| list_splice_tail(&upper->upper, &list); |
| kfree(upper); |
| } |
| |
| if (list_empty(&list)) |
| break; |
| |
| edge = list_entry(list.next, struct backref_edge, |
| list[LOWER]); |
| upper = edge->node[UPPER]; |
| kfree(edge); |
| } |
| return ERR_PTR(err); |
| } |
| return node; |
| } |
| |
| /* |
| * helper to add 'address of tree root -> reloc tree' mapping |
| */ |
| static int __add_reloc_root(struct btrfs_root *root) |
| { |
| struct rb_node *rb_node; |
| struct mapping_node *node; |
| struct reloc_control *rc = root->fs_info->reloc_ctl; |
| |
| node = kmalloc(sizeof(*node), GFP_NOFS); |
| BUG_ON(!node); |
| |
| 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); |
| BUG_ON(rb_node); |
| |
| list_add_tail(&root->root_list, &rc->reloc_roots); |
| return 0; |
| } |
| |
| /* |
| * helper to update/delete the 'address of tree root -> reloc tree' |
| * mapping |
| */ |
| static int __update_reloc_root(struct btrfs_root *root, int del) |
| { |
| struct rb_node *rb_node; |
| struct mapping_node *node = NULL; |
| struct reloc_control *rc = root->fs_info->reloc_ctl; |
| |
| spin_lock(&rc->reloc_root_tree.lock); |
| rb_node = tree_search(&rc->reloc_root_tree.rb_root, |
| root->commit_root->start); |
| if (rb_node) { |
| node = rb_entry(rb_node, struct mapping_node, rb_node); |
| rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root); |
| } |
| spin_unlock(&rc->reloc_root_tree.lock); |
| |
| BUG_ON((struct btrfs_root *)node->data != root); |
| |
| if (!del) { |
| spin_lock(&rc->reloc_root_tree.lock); |
| node->bytenr = root->node->start; |
| rb_node = tree_insert(&rc->reloc_root_tree.rb_root, |
| node->bytenr, &node->rb_node); |
| spin_unlock(&rc->reloc_root_tree.lock); |
| BUG_ON(rb_node); |
| } else { |
| list_del_init(&root->root_list); |
| kfree(node); |
| } |
| return 0; |
| } |
| |
| /* |
| * 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_root *reloc_root; |
| struct extent_buffer *eb; |
| struct btrfs_root_item *root_item; |
| struct btrfs_key root_key; |
| int ret; |
| |
| if (root->reloc_root) { |
| reloc_root = root->reloc_root; |
| reloc_root->last_trans = trans->transid; |
| return 0; |
| } |
| |
| if (!root->fs_info->reloc_ctl || |
| !root->fs_info->reloc_ctl->create_reloc_root || |
| root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) |
| return 0; |
| |
| 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 = root->root_key.objectid; |
| |
| ret = btrfs_copy_root(trans, root, root->commit_root, &eb, |
| BTRFS_TREE_RELOC_OBJECTID); |
| BUG_ON(ret); |
| |
| btrfs_set_root_last_snapshot(&root->root_item, trans->transid - 1); |
| memcpy(root_item, &root->root_item, sizeof(*root_item)); |
| btrfs_set_root_refs(root_item, 1); |
| 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); |
| 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, root->fs_info->tree_root, |
| &root_key, root_item); |
| BUG_ON(ret); |
| kfree(root_item); |
| |
| reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root, |
| &root_key); |
| BUG_ON(IS_ERR(reloc_root)); |
| reloc_root->last_trans = trans->transid; |
| |
| __add_reloc_root(reloc_root); |
| 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_root *reloc_root; |
| struct btrfs_root_item *root_item; |
| int del = 0; |
| int ret; |
| |
| if (!root->reloc_root) |
| return 0; |
| |
| reloc_root = root->reloc_root; |
| root_item = &reloc_root->root_item; |
| |
| if (btrfs_root_refs(root_item) == 0) { |
| root->reloc_root = NULL; |
| del = 1; |
| } |
| |
| __update_reloc_root(reloc_root, del); |
| |
| 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, root->fs_info->tree_root, |
| &reloc_root->root_key, root_item); |
| BUG_ON(ret); |
| 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 < entry->vfs_inode.i_ino) |
| node = node->rb_left; |
| else if (objectid > entry->vfs_inode.i_ino) |
| node = node->rb_right; |
| else |
| break; |
| } |
| if (!node) { |
| while (prev) { |
| entry = rb_entry(prev, struct btrfs_inode, rb_node); |
| if (objectid <= entry->vfs_inode.i_ino) { |
| 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 = entry->vfs_inode.i_ino + 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_cache *block_group) |
| { |
| if (bytenr >= block_group->key.objectid && |
| bytenr < block_group->key.objectid + block_group->key.offset) |
| 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, reloc_inode->i_ino, |
| 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 = 1; |
| goto out; |
| } |
| |
| if (new_bytenr) |
| *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 int replace_file_extents(struct btrfs_trans_handle *trans, |
| struct reloc_control *rc, |
| struct btrfs_root *root, |
| struct extent_buffer *leaf, |
| struct list_head *inode_list) |
| { |
| struct btrfs_key key; |
| struct btrfs_file_extent_item *fi; |
| struct inode *inode = NULL; |
| struct inodevec *ivec = NULL; |
| u64 parent; |
| u64 bytenr; |
| u64 new_bytenr; |
| u64 num_bytes; |
| u64 end; |
| u32 nritems; |
| u32 i; |
| int ret; |
| 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++) { |
| 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 (!ivec || ivec->nr == INODEVEC_SIZE) { |
| ivec = kmalloc(sizeof(*ivec), GFP_NOFS); |
| BUG_ON(!ivec); |
| ivec->nr = 0; |
| list_add_tail(&ivec->list, inode_list); |
| } |
| if (first) { |
| inode = find_next_inode(root, key.objectid); |
| if (inode) |
| ivec->inode[ivec->nr++] = inode; |
| first = 0; |
| } else if (inode && inode->i_ino < key.objectid) { |
| inode = find_next_inode(root, key.objectid); |
| if (inode) |
| ivec->inode[ivec->nr++] = inode; |
| } |
| if (inode && inode->i_ino == key.objectid) { |
| end = key.offset + |
| btrfs_file_extent_num_bytes(leaf, fi); |
| WARN_ON(!IS_ALIGNED(key.offset, |
| root->sectorsize)); |
| WARN_ON(!IS_ALIGNED(end, root->sectorsize)); |
| end--; |
| ret = try_lock_extent(&BTRFS_I(inode)->io_tree, |
| key.offset, end, |
| GFP_NOFS); |
| if (!ret) |
| continue; |
| |
| btrfs_drop_extent_cache(inode, key.offset, end, |
| 1); |
| unlock_extent(&BTRFS_I(inode)->io_tree, |
| key.offset, end, GFP_NOFS); |
| } |
| } |
| |
| ret = get_new_location(rc->data_inode, &new_bytenr, |
| bytenr, num_bytes); |
| if (ret > 0) |
| continue; |
| BUG_ON(ret < 0); |
| |
| btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr); |
| dirty = 1; |
| |
| key.offset -= btrfs_file_extent_offset(leaf, fi); |
| ret = btrfs_inc_extent_ref(trans, root, new_bytenr, |
| num_bytes, parent, |
| btrfs_header_owner(leaf), |
| key.objectid, key.offset); |
| BUG_ON(ret); |
| |
| ret = btrfs_free_extent(trans, root, bytenr, num_bytes, |
| parent, btrfs_header_owner(leaf), |
| key.objectid, key.offset); |
| BUG_ON(ret); |
| } |
| if (dirty) |
| btrfs_mark_buffer_dirty(leaf); |
| return 0; |
| } |
| |
| 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 int replace_path(struct btrfs_trans_handle *trans, |
| struct btrfs_root *dest, struct btrfs_root *src, |
| struct btrfs_path *path, struct btrfs_key *next_key, |
| struct extent_buffer **leaf, |
| int lowest_level, int max_level) |
| { |
| struct extent_buffer *eb; |
| struct extent_buffer *parent; |
| struct btrfs_key key; |
| u64 old_bytenr; |
| u64 new_bytenr; |
| u64 old_ptr_gen; |
| u64 new_ptr_gen; |
| u64 last_snapshot; |
| u32 blocksize; |
| 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); |
| BUG_ON(lowest_level > 1 && leaf); |
| |
| last_snapshot = btrfs_root_last_snapshot(&src->root_item); |
| |
| 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(eb); |
| level = btrfs_header_level(eb); |
| |
| if (level < lowest_level) { |
| btrfs_tree_unlock(eb); |
| free_extent_buffer(eb); |
| return 0; |
| } |
| |
| ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb); |
| BUG_ON(ret); |
| btrfs_set_lock_blocking(eb); |
| |
| if (next_key) { |
| next_key->objectid = (u64)-1; |
| next_key->type = (u8)-1; |
| next_key->offset = (u64)-1; |
| } |
| |
| parent = eb; |
| while (1) { |
| level = btrfs_header_level(parent); |
| BUG_ON(level < lowest_level); |
| |
| ret = btrfs_bin_search(parent, &key, level, &slot); |
| 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 = btrfs_level_size(dest, level - 1); |
| old_ptr_gen = btrfs_node_ptr_generation(parent, slot); |
| |
| if (level <= max_level) { |
| eb = path->nodes[level]; |
| new_bytenr = btrfs_node_blockptr(eb, |
| path->slots[level]); |
| new_ptr_gen = btrfs_node_ptr_generation(eb, |
| path->slots[level]); |
| } else { |
| new_bytenr = 0; |
| new_ptr_gen = 0; |
| } |
| |
| if (new_bytenr > 0 && new_bytenr == old_bytenr) { |
| WARN_ON(1); |
| ret = level; |
| break; |
| } |
| |
| if (new_bytenr == 0 || old_ptr_gen > last_snapshot || |
| memcmp_node_keys(parent, slot, path, level)) { |
| if (level <= lowest_level && !leaf) { |
| ret = 0; |
| break; |
| } |
| |
| eb = read_tree_block(dest, old_bytenr, blocksize, |
| old_ptr_gen); |
| btrfs_tree_lock(eb); |
| ret = btrfs_cow_block(trans, dest, eb, parent, |
| slot, &eb); |
| BUG_ON(ret); |
| btrfs_set_lock_blocking(eb); |
| |
| if (level <= lowest_level) { |
| *leaf = eb; |
| ret = 0; |
| break; |
| } |
| |
| btrfs_tree_unlock(parent); |
| free_extent_buffer(parent); |
| |
| parent = eb; |
| continue; |
| } |
| |
| btrfs_node_key_to_cpu(path->nodes[level], &key, |
| path->slots[level]); |
| btrfs_release_path(src, path); |
| |
| path->lowest_level = level; |
| ret = btrfs_search_slot(trans, src, &key, path, 0, 1); |
| path->lowest_level = 0; |
| BUG_ON(ret); |
| |
| /* |
| * 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]); |
| |
| ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize, |
| path->nodes[level]->start, |
| src->root_key.objectid, level - 1, 0); |
| BUG_ON(ret); |
| ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize, |
| 0, dest->root_key.objectid, level - 1, |
| 0); |
| BUG_ON(ret); |
| |
| ret = btrfs_free_extent(trans, src, new_bytenr, blocksize, |
| path->nodes[level]->start, |
| src->root_key.objectid, level - 1, 0); |
| BUG_ON(ret); |
| |
| ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize, |
| 0, dest->root_key.objectid, level - 1, |
| 0); |
| 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 extent_buffer *eb = NULL; |
| int i; |
| u64 bytenr; |
| u64 ptr_gen = 0; |
| u64 last_snapshot; |
| u32 blocksize; |
| u32 nritems; |
| |
| last_snapshot = btrfs_root_last_snapshot(&root->root_item); |
| |
| for (i = *level; i > 0; i--) { |
| eb = path->nodes[i]; |
| nritems = btrfs_header_nritems(eb); |
| while (path->slots[i] < nritems) { |
| ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]); |
| if (ptr_gen > last_snapshot) |
| break; |
| path->slots[i]++; |
| } |
| if (path->slots[i] >= nritems) { |
| if (i == *level) |
| break; |
| *level = i + 1; |
| return 0; |
| } |
| if (i == 1) { |
| *level = i; |
| return 0; |
| } |
| |
| bytenr = btrfs_node_blockptr(eb, path->slots[i]); |
| blocksize = btrfs_level_size(root, i - 1); |
| eb = read_tree_block(root, bytenr, blocksize, ptr_gen); |
| 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 inode *inode = NULL; |
| u64 objectid; |
| u64 start, end; |
| |
| 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; |
| |
| if (inode->i_ino > max_key->objectid) { |
| iput(inode); |
| break; |
| } |
| |
| objectid = inode->i_ino + 1; |
| if (!S_ISREG(inode->i_mode)) |
| continue; |
| |
| if (unlikely(min_key->objectid == inode->i_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, root->sectorsize)); |
| } |
| } else { |
| start = 0; |
| } |
| |
| if (unlikely(max_key->objectid == inode->i_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, root->sectorsize)); |
| end--; |
| } |
| } else { |
| end = (u64)-1; |
| } |
| |
| /* the lock_extent waits for readpage to complete */ |
| lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS); |
| btrfs_drop_extent_cache(inode, start, end, 1); |
| unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS); |
| } |
| 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; |
| } |
| |
| /* |
| * 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) |
| { |
| LIST_HEAD(inode_list); |
| struct btrfs_key key; |
| struct btrfs_key next_key; |
| struct btrfs_trans_handle *trans; |
| struct btrfs_root *reloc_root; |
| struct btrfs_root_item *root_item; |
| struct btrfs_path *path; |
| struct extent_buffer *leaf = NULL; |
| unsigned long nr; |
| int level; |
| int max_level; |
| int replaced = 0; |
| int ret; |
| int err = 0; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| 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); |
| extent_buffer_get(reloc_root->node); |
| 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); |
| } |
| |
| if (level == 0 && rc->stage == UPDATE_DATA_PTRS) { |
| trans = btrfs_start_transaction(root, 1); |
| |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &key, 0); |
| btrfs_release_path(reloc_root, path); |
| |
| ret = btrfs_search_slot(trans, root, &key, path, 0, 1); |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| |
| leaf = path->nodes[0]; |
| btrfs_unlock_up_safe(path, 1); |
| ret = replace_file_extents(trans, rc, root, leaf, |
| &inode_list); |
| if (ret < 0) |
| err = ret; |
| goto out; |
| } |
| |
| memset(&next_key, 0, sizeof(next_key)); |
| |
| while (1) { |
| leaf = NULL; |
| replaced = 0; |
| trans = btrfs_start_transaction(root, 1); |
| 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 if (level == 1 && rc->stage == UPDATE_DATA_PTRS) { |
| ret = replace_path(trans, root, reloc_root, |
| path, &next_key, &leaf, |
| level, max_level); |
| } else { |
| ret = replace_path(trans, root, reloc_root, |
| path, &next_key, NULL, |
| 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; |
| } else if (leaf) { |
| /* |
| * no block got replaced, try replacing file extents |
| */ |
| btrfs_item_key_to_cpu(leaf, &key, 0); |
| ret = replace_file_extents(trans, rc, root, leaf, |
| &inode_list); |
| btrfs_tree_unlock(leaf); |
| free_extent_buffer(leaf); |
| BUG_ON(ret < 0); |
| } |
| |
| 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; |
| |
| nr = trans->blocks_used; |
| btrfs_end_transaction(trans, root); |
| |
| btrfs_btree_balance_dirty(root, nr); |
| |
| 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) { |
| memset(&root_item->drop_progress, 0, |
| sizeof(root_item->drop_progress)); |
| root_item->drop_level = 0; |
| btrfs_set_root_refs(root_item, 0); |
| } |
| |
| nr = trans->blocks_used; |
| btrfs_end_transaction(trans, root); |
| |
| btrfs_btree_balance_dirty(root, nr); |
| |
| /* |
| * put inodes while we aren't holding the tree locks |
| */ |
| while (!list_empty(&inode_list)) { |
| struct inodevec *ivec; |
| ivec = list_entry(inode_list.next, struct inodevec, list); |
| list_del(&ivec->list); |
| while (ivec->nr > 0) { |
| ivec->nr--; |
| iput(ivec->inode[ivec->nr]); |
| } |
| kfree(ivec); |
| } |
| |
| if (replaced && rc->stage == UPDATE_DATA_PTRS) |
| invalidate_extent_cache(root, &key, &next_key); |
| |
| return err; |
| } |
| |
| /* |
| * callback for the work threads. |
| * this function merges reloc tree with corresponding fs tree, |
| * and then drops the reloc tree. |
| */ |
| static void merge_func(struct btrfs_work *work) |
| { |
| struct btrfs_trans_handle *trans; |
| struct btrfs_root *root; |
| struct btrfs_root *reloc_root; |
| struct async_merge *async; |
| |
| async = container_of(work, struct async_merge, work); |
| reloc_root = async->root; |
| |
| if (btrfs_root_refs(&reloc_root->root_item) > 0) { |
| root = read_fs_root(reloc_root->fs_info, |
| reloc_root->root_key.offset); |
| BUG_ON(IS_ERR(root)); |
| BUG_ON(root->reloc_root != reloc_root); |
| |
| merge_reloc_root(async->rc, root); |
| |
| trans = btrfs_start_transaction(root, 1); |
| btrfs_update_reloc_root(trans, root); |
| btrfs_end_transaction(trans, root); |
| } |
| |
| btrfs_drop_snapshot(reloc_root, 0); |
| |
| if (atomic_dec_and_test(async->num_pending)) |
| complete(async->done); |
| |
| kfree(async); |
| } |
| |
| static int merge_reloc_roots(struct reloc_control *rc) |
| { |
| struct async_merge *async; |
| struct btrfs_root *root; |
| struct completion done; |
| atomic_t num_pending; |
| |
| init_completion(&done); |
| atomic_set(&num_pending, 1); |
| |
| while (!list_empty(&rc->reloc_roots)) { |
| root = list_entry(rc->reloc_roots.next, |
| struct btrfs_root, root_list); |
| list_del_init(&root->root_list); |
| |
| async = kmalloc(sizeof(*async), GFP_NOFS); |
| BUG_ON(!async); |
| async->work.func = merge_func; |
| async->work.flags = 0; |
| async->rc = rc; |
| async->root = root; |
| async->done = &done; |
| async->num_pending = &num_pending; |
| atomic_inc(&num_pending); |
| btrfs_queue_worker(&rc->workers, &async->work); |
| } |
| |
| if (!atomic_dec_and_test(&num_pending)) |
| wait_for_completion(&done); |
| |
| BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root)); |
| return 0; |
| } |
| |
| 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_root *root; |
| |
| if (reloc_root->last_trans == trans->transid) |
| return 0; |
| |
| root = read_fs_root(reloc_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); |
| } |
| |
| /* |
| * select one tree from trees that references the block. |
| * for blocks in refernce counted trees, we preper reloc tree. |
| * if no reloc tree found and reloc_only is true, NULL is returned. |
| */ |
| static struct btrfs_root *__select_one_root(struct btrfs_trans_handle *trans, |
| struct backref_node *node, |
| struct backref_edge *edges[], |
| int *nr, int reloc_only) |
| { |
| struct backref_node *next; |
| struct btrfs_root *root; |
| int index; |
| int loop = 0; |
| again: |
| index = 0; |
| next = node; |
| while (1) { |
| cond_resched(); |
| next = walk_up_backref(next, edges, &index); |
| root = next->root; |
| if (!root) { |
| BUG_ON(!node->old_root); |
| goto skip; |
| } |
| |
| /* no other choice for non-refernce counted tree */ |
| if (!root->ref_cows) { |
| BUG_ON(reloc_only); |
| break; |
| } |
| |
| if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { |
| record_reloc_root_in_trans(trans, root); |
| break; |
| } |
| |
| if (loop) { |
| btrfs_record_root_in_trans(trans, root); |
| break; |
| } |
| |
| if (reloc_only || next != node) { |
| if (!root->reloc_root) |
| btrfs_record_root_in_trans(trans, root); |
| root = root->reloc_root; |
| /* |
| * if the reloc tree was created in current |
| * transation, there is no node in backref tree |
| * corresponds to the root of the reloc tree. |
| */ |
| if (btrfs_root_last_snapshot(&root->root_item) == |
| trans->transid - 1) |
| break; |
| } |
| skip: |
| root = NULL; |
| next = walk_down_backref(edges, &index); |
| if (!next || next->level <= node->level) |
| break; |
| } |
| |
| if (!root && !loop && !reloc_only) { |
| loop = 1; |
| goto again; |
| } |
| |
| if (root) |
| *nr = index; |
| else |
| *nr = 0; |
| |
| return root; |
| } |
| |
| static noinline_for_stack |
| struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans, |
| struct backref_node *node) |
| { |
| struct backref_edge *edges[BTRFS_MAX_LEVEL - 1]; |
| int nr; |
| return __select_one_root(trans, node, edges, &nr, 0); |
| } |
| |
| static noinline_for_stack |
| struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans, |
| struct backref_node *node, |
| struct backref_edge *edges[], int *nr) |
| { |
| return __select_one_root(trans, node, edges, nr, 1); |
| } |
| |
| static void grab_path_buffers(struct btrfs_path *path, |
| struct backref_node *node, |
| struct backref_edge *edges[], int nr) |
| { |
| int i = 0; |
| while (1) { |
| drop_node_buffer(node); |
| node->eb = path->nodes[node->level]; |
| BUG_ON(!node->eb); |
| if (path->locks[node->level]) |
| node->locked = 1; |
| path->nodes[node->level] = NULL; |
| path->locks[node->level] = 0; |
| |
| if (i >= nr) |
| break; |
| |
| edges[i]->blockptr = node->eb->start; |
| node = edges[i]->node[UPPER]; |
| i++; |
| } |
| } |
| |
| /* |
| * 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 backref_node *node, |
| struct btrfs_key *key, |
| struct btrfs_path *path, int lowest) |
| { |
| 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 nr; |
| int slot; |
| int ret; |
| int err = 0; |
| |
| BUG_ON(lowest && node->eb); |
| |
| path->lowest_level = node->level + 1; |
| list_for_each_entry(edge, &node->upper, list[LOWER]) { |
| cond_resched(); |
| if (node->eb && node->eb->start == edge->blockptr) |
| continue; |
| |
| upper = edge->node[UPPER]; |
| root = select_reloc_root(trans, upper, edges, &nr); |
| if (!root) |
| continue; |
| |
| if (upper->eb && !upper->locked) |
| drop_node_buffer(upper); |
| |
| if (!upper->eb) { |
| ret = btrfs_search_slot(trans, root, key, path, 0, 1); |
| if (ret < 0) { |
| err = ret; |
| break; |
| } |
| BUG_ON(ret > 0); |
| |
| slot = path->slots[upper->level]; |
| |
| btrfs_unlock_up_safe(path, upper->level + 1); |
| grab_path_buffers(path, upper, edges, nr); |
| |
| btrfs_release_path(NULL, path); |
| } else { |
| ret = btrfs_bin_search(upper->eb, key, upper->level, |
| &slot); |
| BUG_ON(ret); |
| } |
| |
| bytenr = btrfs_node_blockptr(upper->eb, slot); |
| if (!lowest) { |
| if (node->eb->start == bytenr) { |
| btrfs_tree_unlock(upper->eb); |
| upper->locked = 0; |
| continue; |
| } |
| } else { |
| BUG_ON(node->bytenr != bytenr); |
| } |
| |
| blocksize = btrfs_level_size(root, node->level); |
| generation = btrfs_node_ptr_generation(upper->eb, slot); |
| eb = read_tree_block(root, bytenr, blocksize, generation); |
| btrfs_tree_lock(eb); |
| btrfs_set_lock_blocking(eb); |
| |
| if (!node->eb) { |
| ret = btrfs_cow_block(trans, root, eb, upper->eb, |
| slot, &eb); |
| if (ret < 0) { |
| err = ret; |
| break; |
| } |
| btrfs_set_lock_blocking(eb); |
| node->eb = eb; |
| node->locked = 1; |
| } 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); |
| |
| ret = btrfs_inc_extent_ref(trans, root, |
| node->eb->start, blocksize, |
| upper->eb->start, |
| btrfs_header_owner(upper->eb), |
| node->level, 0); |
| BUG_ON(ret); |
| |
| ret = btrfs_drop_subtree(trans, root, eb, upper->eb); |
| BUG_ON(ret); |
| } |
| if (!lowest) { |
| btrfs_tree_unlock(upper->eb); |
| upper->locked = 0; |
| } |
| } |
| path->lowest_level = 0; |
| return err; |
| } |
| |
| static int link_to_upper(struct btrfs_trans_handle *trans, |
| struct backref_node *node, |
| struct btrfs_path *path) |
| { |
| struct btrfs_key key; |
| if (!node->eb || list_empty(&node->upper)) |
| return 0; |
| |
| btrfs_node_key_to_cpu(node->eb, &key, 0); |
| return do_relocation(trans, node, &key, path, 0); |
| } |
| |
| static int finish_pending_nodes(struct btrfs_trans_handle *trans, |
| struct backref_cache *cache, |
| struct btrfs_path *path) |
| { |
| struct backref_node *node; |
| int level; |
| int ret; |
| int err = 0; |
| |
| for (level = 0; level < BTRFS_MAX_LEVEL; level++) { |
| while (!list_empty(&cache->pending[level])) { |
| node = list_entry(cache->pending[level].next, |
| struct backref_node, lower); |
| BUG_ON(node->level != level); |
| |
| ret = link_to_upper(trans, node, path); |
| if (ret < 0) |
| err = ret; |
| /* |
| * this remove the node from the pending list and |
| * may add some other nodes to the level + 1 |
| * pending list |
| */ |
| remove_backref_node(cache, node); |
| } |
| } |
| BUG_ON(!RB_EMPTY_ROOT(&cache->rb_root)); |
| return err; |
| } |
| |
| 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 = btrfs_level_size(rc->extent_root, node->level); |
| set_extent_bits(&rc->processed_blocks, node->bytenr, |
| node->bytenr + blocksize - 1, EXTENT_DIRTY, |
| GFP_NOFS); |
| } |
| 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, u32 blocksize, |
| struct reloc_control *rc) |
| { |
| if (test_range_bit(&rc->processed_blocks, bytenr, |
| bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL)) |
| return 1; |
| return 0; |
| } |
| |
| /* |
| * check if there are any file extent pointers in the leaf point to |
| * data require processing |
| */ |
| static int check_file_extents(struct reloc_control *rc, |
| u64 bytenr, u32 blocksize, u64 ptr_gen) |
| { |
| struct btrfs_key found_key; |
| struct btrfs_file_extent_item *fi; |
| struct extent_buffer *leaf; |
| u32 nritems; |
| int i; |
| int ret = 0; |
| |
| leaf = read_tree_block(rc->extent_root, bytenr, blocksize, ptr_gen); |
| |
| nritems = btrfs_header_nritems(leaf); |
| for (i = 0; i < nritems; i++) { |
| cond_resched(); |
| btrfs_item_key_to_cpu(leaf, &found_key, i); |
| if (found_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); |
| if (bytenr == 0) |
| continue; |
| if (in_block_group(bytenr, rc->block_group)) { |
| ret = 1; |
| break; |
| } |
| } |
| free_extent_buffer(leaf); |
| return ret; |
| } |
| |
| /* |
| * scan child blocks of a given block to find blocks require processing |
| */ |
| static int add_child_blocks(struct btrfs_trans_handle *trans, |
| struct reloc_control *rc, |
| struct backref_node *node, |
| struct rb_root *blocks) |
| { |
| struct tree_block *block; |
| struct rb_node *rb_node; |
| u64 bytenr; |
| u64 ptr_gen; |
| u32 blocksize; |
| u32 nritems; |
| int i; |
| int err = 0; |
| |
| nritems = btrfs_header_nritems(node->eb); |
| blocksize = btrfs_level_size(rc->extent_root, node->level - 1); |
| for (i = 0; i < nritems; i++) { |
| cond_resched(); |
| bytenr = btrfs_node_blockptr(node->eb, i); |
| ptr_gen = btrfs_node_ptr_generation(node->eb, i); |
| if (ptr_gen == trans->transid) |
| continue; |
| if (!in_block_group(bytenr, rc->block_group) && |
| (node->level > 1 || rc->stage == MOVE_DATA_EXTENTS)) |
| continue; |
| if (tree_block_processed(bytenr, blocksize, rc)) |
| continue; |
| |
| readahead_tree_block(rc->extent_root, |
| bytenr, blocksize, ptr_gen); |
| } |
| |
| for (i = 0; i < nritems; i++) { |
| cond_resched(); |
| bytenr = btrfs_node_blockptr(node->eb, i); |
| ptr_gen = btrfs_node_ptr_generation(node->eb, i); |
| if (ptr_gen == trans->transid) |
| continue; |
| if (!in_block_group(bytenr, rc->block_group) && |
| (node->level > 1 || rc->stage == MOVE_DATA_EXTENTS)) |
| continue; |
| if (tree_block_processed(bytenr, blocksize, rc)) |
| continue; |
| if (!in_block_group(bytenr, rc->block_group) && |
| !check_file_extents(rc, bytenr, blocksize, ptr_gen)) |
| continue; |
| |
| block = kmalloc(sizeof(*block), GFP_NOFS); |
| if (!block) { |
| err = -ENOMEM; |
| break; |
| } |
| block->bytenr = bytenr; |
| btrfs_node_key_to_cpu(node->eb, &block->key, i); |
| block->level = node->level - 1; |
| block->key_ready = 1; |
| rb_node = tree_insert(blocks, block->bytenr, &block->rb_node); |
| BUG_ON(rb_node); |
| } |
| if (err) |
| free_block_list(blocks); |
| return err; |
| } |
| |
| /* |
| * find adjacent blocks require processing |
| */ |
| static noinline_for_stack |
| int add_adjacent_blocks(struct btrfs_trans_handle *trans, |
| struct reloc_control *rc, |
| struct backref_cache *cache, |
| struct rb_root *blocks, int level, |
| struct backref_node **upper) |
| { |
| struct backref_node *node; |
| int ret = 0; |
| |
| WARN_ON(!list_empty(&cache->pending[level])); |
| |
| if (list_empty(&cache->pending[level + 1])) |
| return 1; |
| |
| node = list_entry(cache->pending[level + 1].next, |
| struct backref_node, lower); |
| if (node->eb) |
| ret = add_child_blocks(trans, rc, node, blocks); |
| |
| *upper = node; |
| return ret; |
| } |
| |
| static int get_tree_block_key(struct reloc_control *rc, |
| struct tree_block *block) |
| { |
| struct extent_buffer *eb; |
| |
| BUG_ON(block->key_ready); |
| eb = read_tree_block(rc->extent_root, block->bytenr, |
| block->key.objectid, block->key.offset); |
| WARN_ON(btrfs_header_level(eb) != block->level); |
| 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; |
| } |
| |
| static int reada_tree_block(struct reloc_control *rc, |
| struct tree_block *block) |
| { |
| BUG_ON(block->key_ready); |
| readahead_tree_block(rc->extent_root, block->bytenr, |
| block->key.objectid, block->key.offset); |
| 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; |
| |
| root = select_one_root(trans, node); |
| if (unlikely(!root)) { |
| rc->found_old_snapshot = 1; |
| update_processed_blocks(rc, node); |
| return 0; |
| } |
| |
| if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { |
| ret = do_relocation(trans, node, key, path, 1); |
| if (ret < 0) |
| goto out; |
| if (node->level == 0 && rc->stage == UPDATE_DATA_PTRS) { |
| ret = replace_file_extents(trans, rc, root, |
| node->eb, NULL); |
| if (ret < 0) |
| goto out; |
| } |
| drop_node_buffer(node); |
| } else if (!root->ref_cows) { |
| path->lowest_level = node->level; |
| ret = btrfs_search_slot(trans, root, key, path, 0, 1); |
| btrfs_release_path(root, path); |
| if (ret < 0) |
| goto out; |
| } else if (root != node->root) { |
| WARN_ON(node->level > 0 || rc->stage != UPDATE_DATA_PTRS); |
| } |
| |
| update_processed_blocks(rc, node); |
| ret = 0; |
| out: |
| drop_node_buffer(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 backref_cache *cache; |
| struct backref_node *node; |
| struct btrfs_path *path; |
| struct tree_block *block; |
| struct rb_node *rb_node; |
| int level = -1; |
| int ret; |
| int err = 0; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| cache = kmalloc(sizeof(*cache), GFP_NOFS); |
| if (!cache) { |
| btrfs_free_path(path); |
| return -ENOMEM; |
| } |
| |
| backref_cache_init(cache); |
| |
| rb_node = rb_first(blocks); |
| while (rb_node) { |
| block = rb_entry(rb_node, struct tree_block, rb_node); |
| if (level == -1) |
| level = block->level; |
| else |
| BUG_ON(level != block->level); |
| if (!block->key_ready) |
| reada_tree_block(rc, block); |
| rb_node = rb_next(rb_node); |
| } |
| |
| rb_node = rb_first(blocks); |
| while (rb_node) { |
| block = rb_entry(rb_node, struct tree_block, rb_node); |
| if (!block->key_ready) |
| get_tree_block_key(rc, block); |
| rb_node = rb_next(rb_node); |
| } |
| |
| rb_node = rb_first(blocks); |
| while (rb_node) { |
| block = rb_entry(rb_node, struct tree_block, rb_node); |
| |
| node = build_backref_tree(rc, cache, &block->key, |
| block->level, block->bytenr); |
| if (IS_ERR(node)) { |
| err = PTR_ERR(node); |
| goto out; |
| } |
| |
| ret = relocate_tree_block(trans, rc, node, &block->key, |
| path); |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| remove_backref_node(cache, node); |
| rb_node = rb_next(rb_node); |
| } |
| |
| if (level > 0) |
| goto out; |
| |
| free_block_list(blocks); |
| |
| /* |
| * now backrefs of some upper level tree blocks have been cached, |
| * try relocating blocks referenced by these upper level blocks. |
| */ |
| while (1) { |
| struct backref_node *upper = NULL; |
| if (trans->transaction->in_commit || |
| trans->transaction->delayed_refs.flushing) |
| break; |
| |
| ret = add_adjacent_blocks(trans, rc, cache, blocks, level, |
| &upper); |
| if (ret < 0) |
| err = ret; |
| if (ret != 0) |
| break; |
| |
| rb_node = rb_first(blocks); |
| while (rb_node) { |
| block = rb_entry(rb_node, struct tree_block, rb_node); |
| if (trans->transaction->in_commit || |
| trans->transaction->delayed_refs.flushing) |
| goto out; |
| BUG_ON(!block->key_ready); |
| node = build_backref_tree(rc, cache, &block->key, |
| level, block->bytenr); |
| if (IS_ERR(node)) { |
| err = PTR_ERR(node); |
| goto out; |
| } |
| |
| ret = relocate_tree_block(trans, rc, node, |
| &block->key, path); |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| remove_backref_node(cache, node); |
| rb_node = rb_next(rb_node); |
| } |
| free_block_list(blocks); |
| |
| if (upper) { |
| ret = link_to_upper(trans, upper, path); |
| if (ret < 0) { |
| err = ret; |
| break; |
| } |
| remove_backref_node(cache, upper); |
| } |
| } |
| out: |
| free_block_list(blocks); |
| |
| ret = finish_pending_nodes(trans, cache, path); |
| if (ret < 0) |
| err = ret; |
| |
| kfree(cache); |
| btrfs_free_path(path); |
| return err; |
| } |
| |
| static noinline_for_stack |
| int setup_extent_mapping(struct inode *inode, u64 start, u64 end, |
| u64 block_start) |
| { |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; |
| struct extent_map *em; |
| int ret = 0; |
| |
| em = alloc_extent_map(GFP_NOFS); |
| if (!em) |
| return -ENOMEM; |
| |
| em->start = start; |
| em->len = end + 1 - start; |
| em->block_len = em->len; |
| em->block_start = block_start; |
| em->bdev = root->fs_info->fs_devices->latest_bdev; |
| set_bit(EXTENT_FLAG_PINNED, &em->flags); |
| |
| lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS); |
| while (1) { |
| write_lock(&em_tree->lock); |
| ret = add_extent_mapping(em_tree, em); |
| write_unlock(&em_tree->lock); |
| if (ret != -EEXIST) { |
| free_extent_map(em); |
| break; |
| } |
| btrfs_drop_extent_cache(inode, start, end, 0); |
| } |
| unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS); |
| return ret; |
| } |
| |
| static int relocate_file_extent_cluster(struct inode *inode, |
| struct file_extent_cluster *cluster) |
| { |
| u64 page_start; |
| u64 page_end; |
| u64 offset = BTRFS_I(inode)->index_cnt; |
| unsigned long index; |
| unsigned long last_index; |
| unsigned int dirty_page = 0; |
| struct page *page; |
| struct file_ra_state *ra; |
| int nr = 0; |
| int ret = 0; |
| |
| if (!cluster->nr) |
| return 0; |
| |
| ra = kzalloc(sizeof(*ra), GFP_NOFS); |
| if (!ra) |
| return -ENOMEM; |
| |
| index = (cluster->start - offset) >> PAGE_CACHE_SHIFT; |
| last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT; |
| |
| mutex_lock(&inode->i_mutex); |
| |
| i_size_write(inode, cluster->end + 1 - offset); |
| ret = setup_extent_mapping(inode, cluster->start - offset, |
| cluster->end - offset, cluster->start); |
| if (ret) |
| goto out_unlock; |
| |
| file_ra_state_init(ra, inode->i_mapping); |
| |
| WARN_ON(cluster->start != cluster->boundary[0]); |
| while (index <= last_index) { |
| 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 = grab_cache_page(inode->i_mapping, index); |
| if (!page) { |
| ret = -ENOMEM; |
| goto out_unlock; |
| } |
| } |
| |
| 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); |
| page_cache_release(page); |
| ret = -EIO; |
| goto out_unlock; |
| } |
| } |
| |
| page_start = (u64)page->index << PAGE_CACHE_SHIFT; |
| page_end = page_start + PAGE_CACHE_SIZE - 1; |
| |
| lock_extent(&BTRFS_I(inode)->io_tree, |
| page_start, page_end, GFP_NOFS); |
| |
| 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, GFP_NOFS); |
| nr++; |
| } |
| btrfs_set_extent_delalloc(inode, page_start, page_end); |
| |
| set_page_dirty(page); |
| dirty_page++; |
| |
| unlock_extent(&BTRFS_I(inode)->io_tree, |
| page_start, page_end, GFP_NOFS); |
| unlock_page(page); |
| page_cache_release(page); |
| |
| index++; |
| if (nr < cluster->nr && |
| page_end + 1 + offset == cluster->boundary[nr]) { |
| balance_dirty_pages_ratelimited_nr(inode->i_mapping, |
| dirty_page); |
| dirty_page = 0; |
| } |
| } |
| if (dirty_page) { |
| balance_dirty_pages_ratelimited_nr(inode->i_mapping, |
| dirty_page); |
| } |
| WARN_ON(nr != cluster->nr); |
| out_unlock: |
| mutex_unlock(&inode->i_mutex); |
| 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; |
| } |
| |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| static int get_ref_objectid_v0(struct reloc_control *rc, |
| struct btrfs_path *path, |
| struct btrfs_key *extent_key, |
| u64 *ref_objectid, int *path_change) |
| { |
| struct btrfs_key key; |
| struct extent_buffer *leaf; |
| struct btrfs_extent_ref_v0 *ref0; |
| int ret; |
| int slot; |
| |
| leaf = path->nodes[0]; |
| slot = path->slots[0]; |
| while (1) { |
| if (slot >= btrfs_header_nritems(leaf)) { |
| ret = btrfs_next_leaf(rc->extent_root, path); |
| if (ret < 0) |
| return ret; |
| BUG_ON(ret > 0); |
| leaf = path->nodes[0]; |
| slot = path->slots[0]; |
| if (path_change) |
| *path_change = 1; |
| } |
| btrfs_item_key_to_cpu(leaf, &key, slot); |
| if (key.objectid != extent_key->objectid) |
| return -ENOENT; |
| |
| if (key.type != BTRFS_EXTENT_REF_V0_KEY) { |
| slot++; |
| continue; |
| } |
| ref0 = btrfs_item_ptr(leaf, slot, |
| struct btrfs_extent_ref_v0); |
| *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0); |
| break; |
| } |
| return 0; |
| } |
| #endif |
| |
| /* |
| * 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; |
| int generation; |
| |
| eb = path->nodes[0]; |
| item_size = btrfs_item_size_nr(eb, path->slots[0]); |
| |
| if (item_size >= sizeof(*ei) + sizeof(*bi)) { |
| ei = btrfs_item_ptr(eb, path->slots[0], |
| struct btrfs_extent_item); |
| bi = (struct btrfs_tree_block_info *)(ei + 1); |
| generation = btrfs_extent_generation(eb, ei); |
| level = btrfs_tree_block_level(eb, bi); |
| } else { |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| u64 ref_owner; |
| int ret; |
| |
| BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0)); |
| ret = get_ref_objectid_v0(rc, path, extent_key, |
| &ref_owner, NULL); |
| BUG_ON(ref_owner >= BTRFS_MAX_LEVEL); |
| level = (int)ref_owner; |
| /* FIXME: get real generation */ |
| generation = 0; |
| #else |
| BUG(); |
| #endif |
| } |
| |
| btrfs_release_path(rc->extent_root, path); |
| |
| BUG_ON(level == -1); |
| |
| block = kmalloc(sizeof(*block), GFP_NOFS); |
| if (!block) |
| return -ENOMEM; |
| |
| block->bytenr = extent_key->objectid; |
| block->key.objectid = extent_key->offset; |
| block->key.offset = generation; |
| block->level = level; |
| block->key_ready = 0; |
| |
| rb_node = tree_insert(blocks, block->bytenr, &block->rb_node); |
| BUG_ON(rb_node); |
| |
| 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_path *path; |
| struct btrfs_key key; |
| int ret; |
| |
| if (tree_block_processed(bytenr, blocksize, rc)) |
| return 0; |
| |
| if (tree_search(blocks, bytenr)) |
| return 0; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| key.objectid = bytenr; |
| 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; |
| BUG_ON(ret); |
| |
| btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); |
| 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) |
| { |
| struct btrfs_path *path; |
| struct btrfs_extent_item *ei; |
| struct btrfs_key key; |
| u64 flags; |
| int ret; |
| |
| if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) || |
| btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV) |
| return 1; |
| |
| path = btrfs_alloc_path(); |
| BUG_ON(!path); |
| |
| key.objectid = eb->start; |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| key.offset = eb->len; |
| |
| path->search_commit_root = 1; |
| path->skip_locking = 1; |
| ret = btrfs_search_slot(NULL, rc->extent_root, |
| &key, path, 0, 0); |
| BUG_ON(ret); |
| |
| ei = btrfs_item_ptr(path->nodes[0], path->slots[0], |
| struct btrfs_extent_item); |
| flags = btrfs_extent_flags(path->nodes[0], ei); |
| BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)); |
| if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) |
| ret = 1; |
| else |
| ret = 0; |
| btrfs_free_path(path); |
| 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_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; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| 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); |
| |
| root = read_fs_root(rc->extent_root->fs_info, ref_root); |
| if (IS_ERR(root)) { |
| err = PTR_ERR(root); |
| goto out; |
| } |
| |
| key.objectid = ref_objectid; |
| key.offset = ref_offset; |
| key.type = BTRFS_EXTENT_DATA_KEY; |
| |
| 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 (ret > 0) { |
| WARN_ON(1); |
| 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 (key.objectid != ref_objectid || |
| key.type != BTRFS_EXTENT_DATA_KEY) { |
| WARN_ON(1); |
| 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, leaf->len, 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); |
| BUG_ON |