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btrfs-progs/extent-tree.c

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/*
* Copyright (C) 2007 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 <stdio.h>
#include <stdlib.h>
#include "kerncompat.h"
#include "radix-tree.h"
#include "ctree.h"
#include "disk-io.h"
#include "print-tree.h"
#include "transaction.h"
#include "crc32c.h"
#define BLOCK_GROUP_DATA EXTENT_WRITEBACK
#define BLOCK_GROUP_METADATA EXTENT_UPTODATE
#define BLOCK_GROUP_DIRTY EXTENT_DIRTY
static int finish_current_insert(struct btrfs_trans_handle *trans, struct
btrfs_root *extent_root);
static int del_pending_extents(struct btrfs_trans_handle *trans, struct
btrfs_root *extent_root);
static int find_previous_extent(struct btrfs_root *root,
struct btrfs_path *path)
{
struct btrfs_key found_key;
struct extent_buffer *leaf;
int ret;
while(1) {
if (path->slots[0] == 0) {
ret = btrfs_prev_leaf(root, path);
if (ret != 0)
return ret;
} else {
path->slots[0]--;
}
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.type == BTRFS_EXTENT_ITEM_KEY)
return 0;
}
return 1;
}
static int cache_block_group(struct btrfs_root *root,
struct btrfs_block_group_cache *block_group)
{
struct btrfs_path *path;
int ret;
struct btrfs_key key;
struct extent_buffer *leaf;
struct extent_map_tree *free_space_cache;
int slot;
u64 last = 0;
u64 hole_size;
u64 first_free;
int found = 0;
if (!block_group)
return 0;
root = root->fs_info->extent_root;
free_space_cache = &root->fs_info->free_space_cache;
if (block_group->cached)
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 2;
first_free = block_group->key.objectid;
key.objectid = block_group->key.objectid;
key.offset = 0;
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
return ret;
ret = find_previous_extent(root, path);
if (ret < 0)
return ret;
if (ret == 0) {
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid + key.offset > first_free)
first_free = key.objectid + key.offset;
}
while(1) {
leaf = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto err;
if (ret == 0) {
continue;
} else {
break;
}
}
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid < block_group->key.objectid) {
goto next;
}
if (key.objectid >= block_group->key.objectid +
block_group->key.offset) {
break;
}
if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
if (!found) {
last = first_free;
found = 1;
}
if (key.objectid > last) {
hole_size = key.objectid - last;
set_extent_dirty(free_space_cache, last,
last + hole_size - 1,
GFP_NOFS);
}
last = key.objectid + key.offset;
}
next:
path->slots[0]++;
}
if (!found)
last = first_free;
if (block_group->key.objectid +
block_group->key.offset > last) {
hole_size = block_group->key.objectid +
block_group->key.offset - last;
set_extent_dirty(free_space_cache, last,
last + hole_size - 1, GFP_NOFS);
}
block_group->cached = 1;
err:
btrfs_free_path(path);
return 0;
}
struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
btrfs_fs_info *info,
u64 bytenr)
{
struct extent_map_tree *block_group_cache;
struct btrfs_block_group_cache *block_group = NULL;
u64 ptr;
u64 start;
u64 end;
int ret;
block_group_cache = &info->block_group_cache;
ret = find_first_extent_bit(block_group_cache,
bytenr, &start, &end,
BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA);
if (ret) {
return NULL;
}
ret = get_state_private(block_group_cache, start, &ptr);
if (ret)
return NULL;
block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
if (block_group->key.objectid <= bytenr && bytenr <
block_group->key.objectid + block_group->key.offset)
return block_group;
return NULL;
}
static u64 noinline find_search_start(struct btrfs_root *root,
struct btrfs_block_group_cache **cache_ret,
u64 search_start, int num, int data)
{
int ret;
struct btrfs_block_group_cache *cache = *cache_ret;
u64 last;
u64 start = 0;
u64 end = 0;
u64 cache_miss = 0;
int wrapped = 0;
if (!cache) {
goto out;
}
again:
ret = cache_block_group(root, cache);
if (ret)
goto out;
last = max(search_start, cache->key.objectid);
while(1) {
ret = find_first_extent_bit(&root->fs_info->free_space_cache,
last, &start, &end, EXTENT_DIRTY);
if (ret) {
if (!cache_miss)
cache_miss = last;
goto new_group;
}
start = max(last, start);
last = end + 1;
if (last - start < num) {
if (last == cache->key.objectid + cache->key.offset)
cache_miss = start;
continue;
}
if (data != BTRFS_BLOCK_GROUP_MIXED &&
start + num > cache->key.objectid + cache->key.offset)
goto new_group;
return start;
}
out:
cache = btrfs_lookup_block_group(root->fs_info, search_start);
if (!cache) {
printk("Unable to find block group for %Lu\n",
search_start);
WARN_ON(1);
return search_start;
}
return search_start;
new_group:
last = cache->key.objectid + cache->key.offset;
wrapped:
cache = btrfs_lookup_block_group(root->fs_info, last);
if (!cache) {
no_cache:
if (!wrapped) {
wrapped = 1;
last = search_start;
data = BTRFS_BLOCK_GROUP_MIXED;
goto wrapped;
}
goto out;
}
if (cache_miss && !cache->cached) {
cache_block_group(root, cache);
last = cache_miss;
cache = btrfs_lookup_block_group(root->fs_info, last);
}
cache = btrfs_find_block_group(root, cache, last, data, 0);
if (!cache)
goto no_cache;
*cache_ret = cache;
cache_miss = 0;
goto again;
}
static u64 div_factor(u64 num, int factor)
{
if (factor == 10)
return num;
num *= factor;
num /= 10;
return num;
}
struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
struct btrfs_block_group_cache
*hint, u64 search_start,
int data, int owner)
{
struct btrfs_block_group_cache *cache;
struct extent_map_tree *block_group_cache;
struct btrfs_block_group_cache *found_group = NULL;
struct btrfs_fs_info *info = root->fs_info;
u64 used;
u64 last = 0;
u64 hint_last;
u64 start;
u64 end;
u64 free_check;
u64 ptr;
int bit;
int ret;
int full_search = 0;
int factor = 8;
int data_swap = 0;
block_group_cache = &info->block_group_cache;
if (!owner)
factor = 8;
if (data == BTRFS_BLOCK_GROUP_MIXED) {
bit = BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA;
factor = 10;
} else if (data)
bit = BLOCK_GROUP_DATA;
else
bit = BLOCK_GROUP_METADATA;
if (search_start) {
struct btrfs_block_group_cache *shint;
shint = btrfs_lookup_block_group(info, search_start);
if (shint && (shint->data == data ||
shint->data == BTRFS_BLOCK_GROUP_MIXED)) {
used = btrfs_block_group_used(&shint->item);
if (used + shint->pinned <
div_factor(shint->key.offset, factor)) {
return shint;
}
}
}
if (hint && (hint->data == data ||
hint->data == BTRFS_BLOCK_GROUP_MIXED)) {
used = btrfs_block_group_used(&hint->item);
if (used + hint->pinned <
div_factor(hint->key.offset, factor)) {
return hint;
}
last = hint->key.objectid + hint->key.offset;
hint_last = last;
} else {
if (hint)
hint_last = max(hint->key.objectid, search_start);
else
hint_last = search_start;
last = hint_last;
}
again:
while(1) {
ret = find_first_extent_bit(block_group_cache, last,
&start, &end, bit);
if (ret)
break;
ret = get_state_private(block_group_cache, start, &ptr);
if (ret)
break;
cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
last = cache->key.objectid + cache->key.offset;
used = btrfs_block_group_used(&cache->item);
if (full_search)
free_check = cache->key.offset;
else
free_check = div_factor(cache->key.offset, factor);
if (used + cache->pinned < free_check) {
found_group = cache;
goto found;
}
cond_resched();
}
if (!full_search) {
last = search_start;
full_search = 1;
goto again;
}
if (!data_swap) {
data_swap = 1;
bit = BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA;
last = search_start;
goto again;
}
found:
return found_group;
}
static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation,
u64 owner, u64 owner_offset)
{
u32 high_crc = ~(u32)0;
u32 low_crc = ~(u32)0;
__le64 lenum;
lenum = cpu_to_le64(root_objectid);
high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
lenum = cpu_to_le64(ref_generation);
low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
#if 0
lenum = cpu_to_le64(owner);
low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
lenum = cpu_to_le64(owner_offset);
low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
#endif
return ((u64)high_crc << 32) | (u64)low_crc;
}
static int match_extent_ref(struct extent_buffer *leaf,
struct btrfs_extent_ref *disk_ref,
struct btrfs_extent_ref *cpu_ref)
{
int ret;
int len;
if (cpu_ref->objectid)
len = sizeof(*cpu_ref);
else
len = 2 * sizeof(u64);
ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref,
len);
return ret == 0;
}
static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 bytenr,
u64 root_objectid,
u64 ref_generation, u64 owner,
u64 owner_offset, int del)
{
u64 hash;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_extent_ref ref;
struct extent_buffer *leaf;
struct btrfs_extent_ref *disk_ref;
int ret;
int ret2;
btrfs_set_stack_ref_root(&ref, root_objectid);
btrfs_set_stack_ref_generation(&ref, ref_generation);
btrfs_set_stack_ref_objectid(&ref, owner);
btrfs_set_stack_ref_offset(&ref, owner_offset);
hash = hash_extent_ref(root_objectid, ref_generation, owner,
owner_offset);
key.offset = hash;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_REF_KEY;
while (1) {
ret = btrfs_search_slot(trans, root, &key, path,
del ? -1 : 0, del);
if (ret < 0)
goto out;
leaf = path->nodes[0];
if (ret != 0) {
u32 nritems = btrfs_header_nritems(leaf);
if (path->slots[0] >= nritems) {
ret2 = btrfs_next_leaf(root, path);
if (ret2)
goto out;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != bytenr ||
found_key.type != BTRFS_EXTENT_REF_KEY)
goto out;
key.offset = found_key.offset;
if (del) {
btrfs_release_path(root, path);
continue;
}
}
disk_ref = btrfs_item_ptr(path->nodes[0],
path->slots[0],
struct btrfs_extent_ref);
if (match_extent_ref(path->nodes[0], disk_ref, &ref)) {
ret = 0;
goto out;
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
key.offset = found_key.offset + 1;
btrfs_release_path(root, path);
}
out:
return ret;
}
/*
* Back reference rules. Back refs have three main goals:
*
* 1) differentiate between all holders of references to an extent so that
* when a reference is dropped we can make sure it was a valid reference
* before freeing the extent.
*
* 2) Provide enough information to quickly find the holders of an extent
* if we notice a given block is corrupted or bad.
*
* 3) Make it easy to migrate blocks for FS shrinking or storage pool
* maintenance. This is actually the same as #2, but with a slightly
* different use case.
*
* File extents can be referenced by:
*
* - multiple snapshots, subvolumes, or different generations in one subvol
* - different files inside a single subvolume (in theory, not implemented yet)
* - different offsets inside a file (bookend extents in file.c)
*
* The extent ref structure has fields for:
*
* - Objectid of the subvolume root
* - Generation number of the tree holding the reference
* - objectid of the file holding the reference
* - offset in the file corresponding to the key holding the reference
*
* When a file extent is allocated the fields are filled in:
* (root_key.objectid, trans->transid, inode objectid, offset in file)
*
* When a leaf is cow'd new references are added for every file extent found
* in the leaf. It looks the same as the create case, but trans->transid
* will be different when the block is cow'd.
*
* (root_key.objectid, trans->transid, inode objectid, offset in file)
*
* When a file extent is removed either during snapshot deletion or file
* truncation, the corresponding back reference is found
* by searching for:
*
* (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
* inode objectid, offset in file)
*
* Btree extents can be referenced by:
*
* - Different subvolumes
* - Different generations of the same subvolume
*
* Storing sufficient information for a full reverse mapping of a btree
* block would require storing the lowest key of the block in the backref,
* and it would require updating that lowest key either before write out or
* every time it changed. Instead, the objectid of the lowest key is stored
* along with the level of the tree block. This provides a hint
* about where in the btree the block can be found. Searches through the
* btree only need to look for a pointer to that block, so they stop one
* level higher than the level recorded in the backref.
*
* Some btrees do not do reference counting on their extents. These
* include the extent tree and the tree of tree roots. Backrefs for these
* trees always have a generation of zero.
*
* When a tree block is created, back references are inserted:
*
* (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid)
*
* When a tree block is cow'd in a reference counted root,
* new back references are added for all the blocks it points to.
* These are of the form (trans->transid will have increased since creation):
*
* (root->root_key.objectid, trans->transid, level, lowest_key_objectid)
*
* Because the lowest_key_objectid and the level are just hints
* they are not used when backrefs are deleted. When a backref is deleted:
*
* if backref was for a tree root:
* root_objectid = root->root_key.objectid
* else
* root_objectid = btrfs_header_owner(parent)
*
* (root_objectid, btrfs_header_generation(parent) or zero, 0, 0)
*
* Back Reference Key hashing:
*
* Back references have four fields, each 64 bits long. Unfortunately,
* This is hashed into a single 64 bit number and placed into the key offset.
* The key objectid corresponds to the first byte in the extent, and the
* key type is set to BTRFS_EXTENT_REF_KEY
*/
int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 bytenr,
u64 root_objectid, u64 ref_generation,
u64 owner, u64 owner_offset)
{
u64 hash;
struct btrfs_key key;
struct btrfs_extent_ref ref;
struct btrfs_extent_ref *disk_ref;
int ret;
btrfs_set_stack_ref_root(&ref, root_objectid);
btrfs_set_stack_ref_generation(&ref, ref_generation);
btrfs_set_stack_ref_objectid(&ref, owner);
btrfs_set_stack_ref_offset(&ref, owner_offset);
hash = hash_extent_ref(root_objectid, ref_generation, owner,
owner_offset);
key.offset = hash;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_REF_KEY;
ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));
while (ret == -EEXIST) {
disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_extent_ref);
if (match_extent_ref(path->nodes[0], disk_ref, &ref))
goto out;
key.offset++;
btrfs_release_path(root, path);
ret = btrfs_insert_empty_item(trans, root, path, &key,
sizeof(ref));
}
if (ret)
goto out;
disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_extent_ref);
write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref,
sizeof(ref));
btrfs_mark_buffer_dirty(path->nodes[0]);
out:
btrfs_release_path(root, path);
return ret;
}
int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes,
u64 root_objectid, u64 ref_generation,
u64 owner, u64 owner_offset)
{
struct btrfs_path *path;
int ret;
struct btrfs_key key;
struct extent_buffer *l;
struct btrfs_extent_item *item;
u32 refs;
WARN_ON(num_bytes < root->sectorsize);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = bytenr;
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
key.offset = num_bytes;
ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
0, 1);
if (ret < 0)
return ret;
if (ret != 0) {
BUG();
}
BUG_ON(ret != 0);
l = path->nodes[0];
item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
refs = btrfs_extent_refs(l, item);
btrfs_set_extent_refs(l, item, refs + 1);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(root->fs_info->extent_root, path);
ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root,
path, bytenr, root_objectid,
ref_generation, owner, owner_offset);
BUG_ON(ret);
finish_current_insert(trans, root->fs_info->extent_root);
del_pending_extents(trans, root->fs_info->extent_root);
btrfs_free_path(path);
return 0;
}
int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
finish_current_insert(trans, root->fs_info->extent_root);
del_pending_extents(trans, root->fs_info->extent_root);
return 0;
}
static int lookup_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr,
u64 num_bytes, u32 *refs)
{
struct btrfs_path *path;
int ret;
struct btrfs_key key;
struct extent_buffer *l;
struct btrfs_extent_item *item;
WARN_ON(num_bytes < root->sectorsize);
path = btrfs_alloc_path();
key.objectid = bytenr;
key.offset = num_bytes;
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
0, 0);
if (ret < 0)
goto out;
if (ret != 0) {
btrfs_print_leaf(root, path->nodes[0]);
printk("failed to find block number %Lu\n", bytenr);
BUG();
}
l = path->nodes[0];
item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
*refs = btrfs_extent_refs(l, item);
out:
btrfs_free_path(path);
return 0;
}
u32 btrfs_count_snapshots_in_path(struct btrfs_root *root,
struct btrfs_path *count_path,
u64 first_extent)
{
struct btrfs_root *extent_root = root->fs_info->extent_root;
struct btrfs_path *path;
u64 bytenr;
u64 found_objectid;
u64 root_objectid = root->root_key.objectid;
u32 total_count = 0;
u32 cur_count;
u32 refs;
u32 nritems;
int ret;
struct btrfs_key key;
struct btrfs_key found_key;
struct extent_buffer *l;
struct btrfs_extent_item *item;
struct btrfs_extent_ref *ref_item;
int level = -1;
path = btrfs_alloc_path();
again:
if (level == -1)
bytenr = first_extent;
else
bytenr = count_path->nodes[level]->start;
cur_count = 0;
key.objectid = bytenr;
key.offset = 0;
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
if (ret < 0)
goto out;
BUG_ON(ret == 0);
l = path->nodes[0];
btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
if (found_key.objectid != bytenr ||
found_key.type != BTRFS_EXTENT_ITEM_KEY) {
goto out;
}
item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
refs = btrfs_extent_refs(l, item);
while (1) {
nritems = btrfs_header_nritems(l);
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(extent_root, path);
if (ret == 0)
continue;
break;
}
btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
if (found_key.objectid != bytenr)
break;
if (found_key.type != BTRFS_EXTENT_REF_KEY) {
path->slots[0]++;
continue;
}
cur_count++;
ref_item = btrfs_item_ptr(l, path->slots[0],
struct btrfs_extent_ref);
found_objectid = btrfs_ref_root(l, ref_item);
if (found_objectid != root_objectid) {
total_count = 2;
goto out;
}
total_count = 1;
path->slots[0]++;
}
if (cur_count == 0) {
total_count = 0;
goto out;
}
if (level >= 0 && root->node == count_path->nodes[level])
goto out;
level++;
btrfs_release_path(root, path);
goto again;
out:
btrfs_free_path(path);
return total_count;
}
int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 owner_objectid)
{
u64 generation;
u64 key_objectid;
u64 level;
u32 nritems;
struct btrfs_disk_key disk_key;
level = btrfs_header_level(root->node);
generation = trans->transid;
nritems = btrfs_header_nritems(root->node);
if (nritems > 0) {
if (level == 0)
btrfs_item_key(root->node, &disk_key, 0);
else
btrfs_node_key(root->node, &disk_key, 0);
key_objectid = btrfs_disk_key_objectid(&disk_key);
} else {
key_objectid = 0;
}
return btrfs_inc_extent_ref(trans, root, root->node->start,
root->node->len, owner_objectid,
generation, level, key_objectid);
}
int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct extent_buffer *buf)
{
u64 bytenr;
u32 nritems;
struct btrfs_key key;
struct btrfs_file_extent_item *fi;
int i;
int level;
int ret;
int faili;
if (!root->ref_cows)
return 0;
level = btrfs_header_level(buf);
nritems = btrfs_header_nritems(buf);
for (i = 0; i < nritems; i++) {
if (level == 0) {
u64 disk_bytenr;
btrfs_item_key_to_cpu(buf, &key, i);
if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
continue;
fi = btrfs_item_ptr(buf, i,
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(buf, fi) ==
BTRFS_FILE_EXTENT_INLINE)
continue;
disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
if (disk_bytenr == 0)
continue;
ret = btrfs_inc_extent_ref(trans, root, disk_bytenr,
btrfs_file_extent_disk_num_bytes(buf, fi),
root->root_key.objectid, trans->transid,
key.objectid, key.offset);
if (ret) {
faili = i;
goto fail;
}
} else {
bytenr = btrfs_node_blockptr(buf, i);
btrfs_node_key_to_cpu(buf, &key, i);
ret = btrfs_inc_extent_ref(trans, root, bytenr,
btrfs_level_size(root, level - 1),
root->root_key.objectid,
trans->transid,
level - 1, key.objectid);
if (ret) {
faili = i;
goto fail;
}
}
}
return 0;
fail:
WARN_ON(1);
#if 0
for (i =0; i < faili; i++) {
if (level == 0) {
u64 disk_bytenr;
btrfs_item_key_to_cpu(buf, &key, i);
if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
continue;
fi = btrfs_item_ptr(buf, i,
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(buf, fi) ==
BTRFS_FILE_EXTENT_INLINE)
continue;
disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
if (disk_bytenr == 0)
continue;
err = btrfs_free_extent(trans, root, disk_bytenr,
btrfs_file_extent_disk_num_bytes(buf,
fi), 0);
BUG_ON(err);
} else {
bytenr = btrfs_node_blockptr(buf, i);
err = btrfs_free_extent(trans, root, bytenr,
btrfs_level_size(root, level - 1), 0);
BUG_ON(err);
}
}
#endif
return ret;
}
static int write_one_cache_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_block_group_cache *cache)
{
int ret;
int pending_ret;
struct btrfs_root *extent_root = root->fs_info->extent_root;
unsigned long bi;
struct extent_buffer *leaf;
ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
if (ret < 0)
goto fail;
BUG_ON(ret);
leaf = path->nodes[0];
bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(extent_root, path);
fail:
finish_current_insert(trans, extent_root);
pending_ret = del_pending_extents(trans, extent_root);
if (ret)
return ret;
if (pending_ret)
return pending_ret;
return 0;
}
int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct extent_map_tree *block_group_cache;
struct btrfs_block_group_cache *cache;
int ret;
int err = 0;
int werr = 0;
struct btrfs_path *path;
u64 last = 0;
u64 start;
u64 end;
u64 ptr;
block_group_cache = &root->fs_info->block_group_cache;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
while(1) {
ret = find_first_extent_bit(block_group_cache, last,
&start, &end, BLOCK_GROUP_DIRTY);
if (ret)
break;
last = end + 1;
ret = get_state_private(block_group_cache, start, &ptr);
if (ret)
break;
cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
err = write_one_cache_group(trans, root,
path, cache);
/*
* if we fail to write the cache group, we want
* to keep it marked dirty in hopes that a later
* write will work
*/
if (err) {
werr = err;
continue;
}
clear_extent_bits(block_group_cache, start, end,
BLOCK_GROUP_DIRTY, GFP_NOFS);
}
btrfs_free_path(path);
return werr;
}
static int update_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, int alloc,
int mark_free, int data)
{
struct btrfs_block_group_cache *cache;
struct btrfs_fs_info *info = root->fs_info;
u64 total = num_bytes;
u64 old_val;
u64 byte_in_group;
u64 start;
u64 end;
while(total) {
cache = btrfs_lookup_block_group(info, bytenr);
if (!cache) {
return -1;
}
byte_in_group = bytenr - cache->key.objectid;
WARN_ON(byte_in_group > cache->key.offset);
start = cache->key.objectid;
end = start + cache->key.offset - 1;
set_extent_bits(&info->block_group_cache, start, end,
BLOCK_GROUP_DIRTY, GFP_NOFS);
old_val = btrfs_block_group_used(&cache->item);
num_bytes = min(total, cache->key.offset - byte_in_group);
if (alloc) {
if (cache->data != data &&
old_val < (cache->key.offset >> 1)) {
int bit_to_clear;
int bit_to_set;
cache->data = data;
if (data) {
bit_to_clear = BLOCK_GROUP_METADATA;
bit_to_set = BLOCK_GROUP_DATA;
cache->item.flags &=
~BTRFS_BLOCK_GROUP_MIXED;
cache->item.flags |=
BTRFS_BLOCK_GROUP_DATA;
} else {
bit_to_clear = BLOCK_GROUP_DATA;
bit_to_set = BLOCK_GROUP_METADATA;
cache->item.flags &=
~BTRFS_BLOCK_GROUP_MIXED;
cache->item.flags &=
~BTRFS_BLOCK_GROUP_DATA;
}
clear_extent_bits(&info->block_group_cache,
start, end, bit_to_clear,
GFP_NOFS);
set_extent_bits(&info->block_group_cache,
start, end, bit_to_set,
GFP_NOFS);
} else if (cache->data != data &&
cache->data != BTRFS_BLOCK_GROUP_MIXED) {
cache->data = BTRFS_BLOCK_GROUP_MIXED;
set_extent_bits(&info->block_group_cache,
start, end,
BLOCK_GROUP_DATA |
BLOCK_GROUP_METADATA,
GFP_NOFS);
}
old_val += num_bytes;
} else {
old_val -= num_bytes;
if (mark_free) {
set_extent_dirty(&info->free_space_cache,
bytenr, bytenr + num_bytes - 1,
GFP_NOFS);
}
}
btrfs_set_block_group_used(&cache->item, old_val);
total -= num_bytes;
bytenr += num_bytes;
}
return 0;
}
static int update_pinned_extents(struct btrfs_root *root,
u64 bytenr, u64 num, int pin)
{
u64 len;
struct btrfs_block_group_cache *cache;
struct btrfs_fs_info *fs_info = root->fs_info;
if (pin) {
set_extent_dirty(&fs_info->pinned_extents,
bytenr, bytenr + num - 1, GFP_NOFS);
} else {
clear_extent_dirty(&fs_info->pinned_extents,
bytenr, bytenr + num - 1, GFP_NOFS);
}
while (num > 0) {
cache = btrfs_lookup_block_group(fs_info, bytenr);
WARN_ON(!cache);
len = min(num, cache->key.offset -
(bytenr - cache->key.objectid));
if (pin) {
cache->pinned += len;
fs_info->total_pinned += len;
} else {
cache->pinned -= len;
fs_info->total_pinned -= len;
}
bytenr += len;
num -= len;
}
return 0;
}
int btrfs_copy_pinned(struct btrfs_root *root, struct extent_map_tree *copy)
{
u64 last = 0;
u64 start;
u64 end;
struct extent_map_tree *pinned_extents = &root->fs_info->pinned_extents;
int ret;
while(1) {
ret = find_first_extent_bit(pinned_extents, last,
&start, &end, EXTENT_DIRTY);
if (ret)
break;
set_extent_dirty(copy, start, end, GFP_NOFS);
last = end + 1;
}
return 0;
}
int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_map_tree *unpin)
{
u64 start;
u64 end;
int ret;
struct extent_map_tree *free_space_cache;
free_space_cache = &root->fs_info->free_space_cache;
while(1) {
ret = find_first_extent_bit(unpin, 0, &start, &end,
EXTENT_DIRTY);
if (ret)
break;
update_pinned_extents(root, start, end + 1 - start, 0);
clear_extent_dirty(unpin, start, end, GFP_NOFS);
set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
}
return 0;
}
static int finish_current_insert(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root)
{
u64 start;
u64 end;
struct btrfs_fs_info *info = extent_root->fs_info;
struct extent_buffer *eb;
struct btrfs_path *path;
struct btrfs_key ins;
struct btrfs_disk_key first;
struct btrfs_extent_item extent_item;
int ret;
int level;
int err = 0;
btrfs_set_stack_extent_refs(&extent_item, 1);
btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
path = btrfs_alloc_path();
while(1) {
ret = find_first_extent_bit(&info->extent_ins, 0, &start,
&end, EXTENT_LOCKED);
if (ret)
break;
ins.objectid = start;
ins.offset = end + 1 - start;
err = btrfs_insert_item(trans, extent_root, &ins,
&extent_item, sizeof(extent_item));
clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
GFP_NOFS);
eb = read_tree_block(extent_root, ins.objectid, ins.offset);
level = btrfs_header_level(eb);
if (level == 0) {
btrfs_item_key(eb, &first, 0);
} else {
btrfs_node_key(eb, &first, 0);
}
err = btrfs_insert_extent_backref(trans, extent_root, path,
start, extent_root->root_key.objectid,
0, level,
btrfs_disk_key_objectid(&first));
BUG_ON(err);
free_extent_buffer(eb);
}
btrfs_free_path(path);
return 0;
}
static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
int pending)
{
int err = 0;
struct extent_buffer *buf;
if (!pending) {
buf = btrfs_find_tree_block(root, bytenr, num_bytes);
if (buf) {
if (btrfs_buffer_uptodate(buf)) {
u64 transid =
root->fs_info->running_transaction->transid;
if (btrfs_header_generation(buf) == transid) {
free_extent_buffer(buf);
return 1;
}
}
free_extent_buffer(buf);
}
update_pinned_extents(root, bytenr, num_bytes, 1);
} else {
set_extent_bits(&root->fs_info->pending_del,
bytenr, bytenr + num_bytes - 1,
EXTENT_LOCKED, GFP_NOFS);
}
BUG_ON(err < 0);
return 0;
}
/*
* remove an extent from the root, returns 0 on success
*/
static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
*root, u64 bytenr, u64 num_bytes,
u64 root_objectid, u64 ref_generation,
u64 owner_objectid, u64 owner_offset, int pin,
int mark_free)
{
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_extent_ops *ops = info->extent_ops;
struct btrfs_root *extent_root = info->extent_root;
struct extent_buffer *leaf;
int ret;
struct btrfs_extent_item *ei;
u32 refs;
key.objectid = bytenr;
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
key.offset = num_bytes;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = lookup_extent_backref(trans, extent_root, path,
bytenr, root_objectid,
ref_generation,
owner_objectid, owner_offset, 1);
if (ret == 0) {
ret = btrfs_del_item(trans, extent_root, path);
} else {
btrfs_print_leaf(extent_root, path->nodes[0]);
WARN_ON(1);
printk("Unable to find ref byte nr %Lu root %Lu "
" gen %Lu owner %Lu offset %Lu\n", bytenr,
root_objectid, ref_generation, owner_objectid,
owner_offset);
}
btrfs_release_path(extent_root, path);
ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
if (ret < 0)
return ret;
BUG_ON(ret);
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item);
refs = btrfs_extent_refs(leaf, ei);
BUG_ON(refs == 0);
refs -= 1;
btrfs_set_extent_refs(leaf, ei, refs);
btrfs_mark_buffer_dirty(leaf);
if (refs == 0) {
u64 super_used;
u64 root_used;
if (pin) {
ret = pin_down_bytes(root, bytenr, num_bytes, 0);
if (ret > 0)
mark_free = 1;
BUG_ON(ret < 0);
}
/* block accounting for super block */
super_used = btrfs_super_bytes_used(&info->super_copy);
btrfs_set_super_bytes_used(&info->super_copy,
super_used - num_bytes);
/* block accounting for root item */
root_used = btrfs_root_used(&root->root_item);
btrfs_set_root_used(&root->root_item,
root_used - num_bytes);
ret = btrfs_del_item(trans, extent_root, path);
if (ret)
return ret;
if (ops && ops->free_extent)
ops->free_extent(root, bytenr, num_bytes);
ret = update_block_group(trans, root, bytenr, num_bytes, 0,
mark_free, 0);
BUG_ON(ret);
}
btrfs_free_path(path);
finish_current_insert(trans, extent_root);
return ret;
}
/*
* find all the blocks marked as pending in the radix tree and remove
* them from the extent map
*/
static int del_pending_extents(struct btrfs_trans_handle *trans, struct
btrfs_root *extent_root)
{
int ret;
int err = 0;
u64 start;
u64 end;
struct extent_map_tree *pending_del;
struct extent_map_tree *pinned_extents;
pending_del = &extent_root->fs_info->pending_del;
pinned_extents = &extent_root->fs_info->pinned_extents;
while(1) {
ret = find_first_extent_bit(pending_del, 0, &start, &end,
EXTENT_LOCKED);
if (ret)
break;
update_pinned_extents(extent_root, start, end + 1 - start, 1);
clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
GFP_NOFS);
ret = __free_extent(trans, extent_root,
start, end + 1 - start,
extent_root->root_key.objectid,
0, 0, 0, 0, 0);
if (ret)
err = ret;
}
return err;
}
/*
* remove an extent from the root, returns 0 on success
*/
int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
*root, u64 bytenr, u64 num_bytes,
u64 root_objectid, u64 ref_generation,
u64 owner_objectid, u64 owner_offset, int pin)
{
struct btrfs_root *extent_root = root->fs_info->extent_root;
int pending_ret;
int ret;
WARN_ON(num_bytes < root->sectorsize);
if (!root->ref_cows)
ref_generation = 0;
if (root == extent_root) {
pin_down_bytes(root, bytenr, num_bytes, 1);
return 0;
}
ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
ref_generation, owner_objectid, owner_offset,
pin, pin == 0);
pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
return ret ? ret : pending_ret;
}
static u64 stripe_align(struct btrfs_root *root, u64 val)
{
u64 mask = ((u64)root->stripesize - 1);
u64 ret = (val + mask) & ~mask;
return ret;
}
/*
* walks the btree of allocated extents and find a hole of a given size.
* The key ins is changed to record the hole:
* ins->objectid == block start
* ins->flags = BTRFS_EXTENT_ITEM_KEY
* ins->offset == number of blocks
* Any available blocks before search_start are skipped.
*/
static int noinline find_free_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *orig_root,
u64 num_bytes, u64 empty_size,
u64 search_start, u64 search_end,
u64 hint_byte, struct btrfs_key *ins,
u64 exclude_start, u64 exclude_nr,
int data)
{
struct btrfs_path *path;
struct btrfs_key key;
u64 hole_size = 0;
u64 aligned;
int ret;
int slot = 0;
u64 last_byte = 0;
u64 orig_search_start = search_start;
int start_found;
struct extent_buffer *l;
struct btrfs_root * root = orig_root->fs_info->extent_root;
struct btrfs_fs_info *info = root->fs_info;
u64 total_needed = num_bytes;
int level;
struct btrfs_block_group_cache *block_group;
int full_scan = 0;
int wrapped = 0;
u64 cached_start;
WARN_ON(num_bytes < root->sectorsize);
btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
level = btrfs_header_level(root->node);
if (num_bytes >= 32 * 1024 * 1024 && hint_byte) {
data = BTRFS_BLOCK_GROUP_MIXED;
}
if (search_end == (u64)-1)
search_end = btrfs_super_total_bytes(&info->super_copy);
if (hint_byte) {
block_group = btrfs_lookup_block_group(info, hint_byte);
if (!block_group)
hint_byte = search_start;
block_group = btrfs_find_block_group(root, block_group,
hint_byte, data, 1);
} else {
block_group = btrfs_find_block_group(root,
trans->block_group,
search_start, data, 1);
}
total_needed += empty_size;
path = btrfs_alloc_path();
check_failed:
if (!block_group) {
block_group = btrfs_lookup_block_group(info, search_start);
if (!block_group)
block_group = btrfs_lookup_block_group(info,
orig_search_start);
}
search_start = find_search_start(root, &block_group, search_start,
total_needed, data);
search_start = stripe_align(root, search_start);
cached_start = search_start;
btrfs_init_path(path);
ins->objectid = search_start;
ins->offset = 0;
start_found = 0;
path->reada = 2;
ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
if (ret < 0)
goto error;
ret = find_previous_extent(root, path);
if (ret < 0)
goto error;
l = path->nodes[0];
btrfs_item_key_to_cpu(l, &key, path->slots[0]);
while (1) {
l = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(l)) {
ret = btrfs_next_leaf(root, path);
if (ret == 0)
continue;
if (ret < 0)
goto error;
search_start = max(search_start,
block_group->key.objectid);
if (!start_found) {
aligned = stripe_align(root, search_start);
ins->objectid = aligned;
if (aligned >= search_end) {
ret = -ENOSPC;
goto error;
}
ins->offset = search_end - aligned;
start_found = 1;
goto check_pending;
}
ins->objectid = stripe_align(root,
last_byte > search_start ?
last_byte : search_start);
if (search_end <= ins->objectid) {
ret = -ENOSPC;
goto error;
}
ins->offset = search_end - ins->objectid;
BUG_ON(ins->objectid >= search_end);
goto check_pending;
}
btrfs_item_key_to_cpu(l, &key, slot);
if (key.objectid >= search_start && key.objectid > last_byte &&
start_found) {
if (last_byte < search_start)
last_byte = search_start;
aligned = stripe_align(root, last_byte);
hole_size = key.objectid - aligned;
if (key.objectid > aligned && hole_size >= num_bytes) {
ins->objectid = aligned;
ins->offset = hole_size;
goto check_pending;
}
}
if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY) {
if (!start_found && btrfs_key_type(&key) ==
BTRFS_BLOCK_GROUP_ITEM_KEY) {
last_byte = key.objectid;
start_found = 1;
}
goto next;
}
start_found = 1;
last_byte = key.objectid + key.offset;
if (!full_scan && data != BTRFS_BLOCK_GROUP_MIXED &&
last_byte >= block_group->key.objectid +
block_group->key.offset) {
btrfs_release_path(root, path);
search_start = block_group->key.objectid +
block_group->key.offset;
goto new_group;
}
next:
path->slots[0]++;
cond_resched();
}
check_pending:
/* we have to make sure we didn't find an extent that has already
* been allocated by the map tree or the original allocation
*/
btrfs_release_path(root, path);
BUG_ON(ins->objectid < search_start);
if (ins->objectid + num_bytes >= search_end)
goto enospc;
if (!full_scan && data != BTRFS_BLOCK_GROUP_MIXED &&
ins->objectid + num_bytes > block_group->
key.objectid + block_group->key.offset) {
search_start = block_group->key.objectid +
block_group->key.offset;
goto new_group;
}
if (test_range_bit(&info->extent_ins, ins->objectid,
ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
search_start = ins->objectid + num_bytes;
goto new_group;
}
if (test_range_bit(&info->pinned_extents, ins->objectid,
ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
search_start = ins->objectid + num_bytes;
goto new_group;
}
if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
ins->objectid < exclude_start + exclude_nr)) {
search_start = exclude_start + exclude_nr;
goto new_group;
}
if (!data) {
block_group = btrfs_lookup_block_group(info, ins->objectid);
if (block_group)
trans->block_group = block_group;
}
ins->offset = num_bytes;
btrfs_free_path(path);
return 0;
new_group:
if (search_start + num_bytes >= search_end) {
enospc:
search_start = orig_search_start;
if (full_scan) {
ret = -ENOSPC;
goto error;
}
if (wrapped) {
if (!full_scan)
total_needed -= empty_size;
full_scan = 1;
data = BTRFS_BLOCK_GROUP_MIXED;
} else
wrapped = 1;
}
block_group = btrfs_lookup_block_group(info, search_start);
cond_resched();
block_group = btrfs_find_block_group(root, block_group,
search_start, data, 0);
goto check_failed;
error:
btrfs_release_path(root, path);
btrfs_free_path(path);
return ret;
}
/*
* finds a free extent and does all the dirty work required for allocation
* returns the key for the extent through ins, and a tree buffer for
* the first block of the extent through buf.
*
* returns 0 if everything worked, non-zero otherwise.
*/
int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 num_bytes, u64 root_objectid, u64 ref_generation,
u64 owner, u64 owner_offset,
u64 empty_size, u64 hint_byte,
u64 search_end, struct btrfs_key *ins, int data)
{
int ret;
int pending_ret;
u64 super_used, root_used;
u64 search_start = 0;
/*
u64 new_hint;
*/
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_extent_ops *ops = info->extent_ops;
struct btrfs_root *extent_root = info->extent_root;
struct btrfs_extent_item extent_item;
struct btrfs_path *path;
btrfs_set_stack_extent_refs(&extent_item, 1);
/*
new_hint = max(hint_byte, root->fs_info->alloc_start);
if (new_hint < btrfs_super_total_bytes(&info->super_copy))
hint_byte = new_hint;
*/
WARN_ON(num_bytes < root->sectorsize);
if (ops && ops->alloc_extent) {
ret = ops->alloc_extent(root, num_bytes, hint_byte, ins);
} else {
ret = find_free_extent(trans, root, num_bytes, empty_size,
search_start, search_end, hint_byte,
ins, trans->alloc_exclude_start,
trans->alloc_exclude_nr, data);
}
BUG_ON(ret);
if (ret)
return ret;
/* block accounting for super block */
super_used = btrfs_super_bytes_used(&info->super_copy);
btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
/* block accounting for root item */
root_used = btrfs_root_used(&root->root_item);
btrfs_set_root_used(&root->root_item, root_used + num_bytes);
clear_extent_dirty(&root->fs_info->free_space_cache,
ins->objectid, ins->objectid + ins->offset - 1,
GFP_NOFS);
if (root == extent_root) {
set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
ins->objectid + ins->offset - 1,
EXTENT_LOCKED, GFP_NOFS);
WARN_ON(data == 1);
goto update_block;
}
WARN_ON(trans->alloc_exclude_nr);
trans->alloc_exclude_start = ins->objectid;
trans->alloc_exclude_nr = ins->offset;
ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
sizeof(extent_item));
trans->alloc_exclude_start = 0;
trans->alloc_exclude_nr = 0;
BUG_ON(ret);
path = btrfs_alloc_path();
BUG_ON(!path);
ret = btrfs_insert_extent_backref(trans, extent_root, path,
ins->objectid, root_objectid,
ref_generation, owner, owner_offset);
BUG_ON(ret);
btrfs_free_path(path);
finish_current_insert(trans, extent_root);
pending_ret = del_pending_extents(trans, extent_root);
if (ret) {
return ret;
}
if (pending_ret) {
return pending_ret;
}
update_block:
ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0,
data);
BUG_ON(ret);
return 0;
}
/*
* helper function to allocate a block for a given tree
* returns the tree buffer or NULL.
*/
struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u32 blocksize,
u64 root_objectid, u64 hint,
u64 empty_size)
{
u64 ref_generation;
if (root->ref_cows)
ref_generation = trans->transid;
else
ref_generation = 0;
return __btrfs_alloc_free_block(trans, root, blocksize, root_objectid,
ref_generation, 0, 0, hint, empty_size);
}
/*
* helper function to allocate a block for a given tree
* returns the tree buffer or NULL.
*/
struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u32 blocksize,
u64 root_objectid,
u64 ref_generation,
u64 first_objectid,
int level,
u64 hint,
u64 empty_size)
{
struct btrfs_key ins;
int ret;
struct extent_buffer *buf;
ret = btrfs_alloc_extent(trans, root, blocksize,
root_objectid, ref_generation,
level, first_objectid, empty_size, hint,
(u64)-1, &ins, 0);
if (ret) {
BUG_ON(ret > 0);
return ERR_PTR(ret);
}
buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
if (!buf) {
btrfs_free_extent(trans, root, ins.objectid, blocksize,
root->root_key.objectid, ref_generation,
0, 0, 0);
return ERR_PTR(-ENOMEM);
}
btrfs_set_buffer_uptodate(buf);
/*
set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
buf->start + buf->len - 1, GFP_NOFS);
set_extent_bits(&BTRFS_I(root->fs_info->btree_inode)->extent_tree,
buf->start, buf->start + buf->len - 1,
EXTENT_CSUM, GFP_NOFS);
buf->flags |= EXTENT_CSUM;
btrfs_set_buffer_defrag(buf);
*/
trans->blocks_used++;
return buf;
}
static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *leaf)
{
u64 leaf_owner;
u64 leaf_generation;
struct btrfs_key key;
struct btrfs_file_extent_item *fi;
int i;
int nritems;
int ret;
BUG_ON(!btrfs_is_leaf(leaf));
nritems = btrfs_header_nritems(leaf);
leaf_owner = btrfs_header_owner(leaf);
leaf_generation = btrfs_header_generation(leaf);
for (i = 0; i < nritems; i++) {
u64 disk_bytenr;
btrfs_item_key_to_cpu(leaf, &key, i);
if (btrfs_key_type(&key) != 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;
/*
* FIXME make sure to insert a trans record that
* repeats the snapshot del on crash
*/
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
if (disk_bytenr == 0)
continue;
ret = btrfs_free_extent(trans, root, disk_bytenr,
btrfs_file_extent_disk_num_bytes(leaf, fi),
leaf_owner, leaf_generation,
key.objectid, key.offset, 0);
BUG_ON(ret);
}
return 0;
}
static void noinline reada_walk_down(struct btrfs_root *root,
struct extent_buffer *node)
{
int i;
u32 nritems;
u64 bytenr;
int ret;
u32 refs;
int level;
u32 blocksize;
nritems = btrfs_header_nritems(node);
level = btrfs_header_level(node);
for (i = 0; i < nritems; i++) {
bytenr = btrfs_node_blockptr(node, i);
blocksize = btrfs_level_size(root, level - 1);
ret = lookup_extent_ref(NULL, root, bytenr, blocksize, &refs);
BUG_ON(ret);
if (refs != 1)
continue;
mutex_unlock(&root->fs_info->fs_mutex);
ret = readahead_tree_block(root, bytenr, blocksize);
cond_resched();
mutex_lock(&root->fs_info->fs_mutex);
if (ret)
break;
}
}
/*
* helper function for drop_snapshot, this walks down the tree dropping ref
* counts as it goes.
*/
static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int *level)
{
u64 root_owner;
u64 root_gen;
u64 bytenr;
struct extent_buffer *next;
struct extent_buffer *cur;
struct extent_buffer *parent;
u32 blocksize;
int ret;
u32 refs;
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
ret = lookup_extent_ref(trans, root,
path->nodes[*level]->start,
path->nodes[*level]->len, &refs);
BUG_ON(ret);
if (refs > 1)
goto out;
/*
* walk down to the last node level and free all the leaves
*/
while(*level >= 0) {
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
cur = path->nodes[*level];
if (*level > 0 && path->slots[*level] == 0)
reada_walk_down(root, cur);
if (btrfs_header_level(cur) != *level)
WARN_ON(1);
if (path->slots[*level] >=
btrfs_header_nritems(cur))
break;
if (*level == 0) {
ret = drop_leaf_ref(trans, root, cur);
BUG_ON(ret);
break;
}
bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
blocksize = btrfs_level_size(root, *level - 1);
ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs);
BUG_ON(ret);
if (refs != 1) {
parent = path->nodes[*level];
root_owner = btrfs_header_owner(parent);
root_gen = btrfs_header_generation(parent);
path->slots[*level]++;
ret = btrfs_free_extent(trans, root, bytenr,
blocksize, root_owner,
root_gen, 0, 0, 1);
BUG_ON(ret);
continue;
}
next = btrfs_find_tree_block(root, bytenr, blocksize);
if (!next || !btrfs_buffer_uptodate(next)) {
free_extent_buffer(next);
mutex_unlock(&root->fs_info->fs_mutex);
next = read_tree_block(root, bytenr, blocksize);
mutex_lock(&root->fs_info->fs_mutex);
/* we dropped the lock, check one more time */
ret = lookup_extent_ref(trans, root, bytenr,
blocksize, &refs);
BUG_ON(ret);
if (refs != 1) {
parent = path->nodes[*level];
root_owner = btrfs_header_owner(parent);
root_gen = btrfs_header_generation(parent);
path->slots[*level]++;
free_extent_buffer(next);
ret = btrfs_free_extent(trans, root, bytenr,
blocksize,
root_owner,
root_gen, 0, 0, 1);
BUG_ON(ret);
continue;
}
}
WARN_ON(*level <= 0);
if (path->nodes[*level-1])
free_extent_buffer(path->nodes[*level-1]);
path->nodes[*level-1] = next;
*level = btrfs_header_level(next);
path->slots[*level] = 0;
}
out:
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
if (path->nodes[*level] == root->node) {
root_owner = root->root_key.objectid;
parent = path->nodes[*level];
} else {
parent = path->nodes[*level + 1];
root_owner = btrfs_header_owner(parent);
}
root_gen = btrfs_header_generation(parent);
ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
path->nodes[*level]->len,
root_owner, root_gen, 0, 0, 1);
free_extent_buffer(path->nodes[*level]);
path->nodes[*level] = NULL;
*level += 1;
BUG_ON(ret);
return 0;
}
/*
* helper for dropping snapshots. This walks back up the tree in the path
* to find the first node higher up where we haven't yet gone through
* all the slots
*/
static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int *level)
{
u64 root_owner;
u64 root_gen;
struct btrfs_root_item *root_item = &root->root_item;
int i;
int slot;
int ret;
for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
slot = path->slots[i];
if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
struct extent_buffer *node;
struct btrfs_disk_key disk_key;
node = path->nodes[i];
path->slots[i]++;
*level = i;
WARN_ON(*level == 0);
btrfs_node_key(node, &disk_key, path->slots[i]);
memcpy(&root_item->drop_progress,
&disk_key, sizeof(disk_key));
root_item->drop_level = i;
return 0;
} else {
if (path->nodes[*level] == root->node) {
root_owner = root->root_key.objectid;
root_gen =
btrfs_header_generation(path->nodes[*level]);
} else {
struct extent_buffer *node;
node = path->nodes[*level + 1];
root_owner = btrfs_header_owner(node);
root_gen = btrfs_header_generation(node);
}
ret = btrfs_free_extent(trans, root,
path->nodes[*level]->start,
path->nodes[*level]->len,
root_owner, root_gen, 0, 0, 1);
BUG_ON(ret);
free_extent_buffer(path->nodes[*level]);
path->nodes[*level] = NULL;
*level = i + 1;
}
}
return 1;
}
/*
* drop the reference count on the tree rooted at 'snap'. This traverses
* the tree freeing any blocks that have a ref count of zero after being
* decremented.
*/
int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
*root)
{
int ret = 0;
int wret;
int level;
struct btrfs_path *path;
int i;
int orig_level;
struct btrfs_root_item *root_item = &root->root_item;
path = btrfs_alloc_path();
BUG_ON(!path);
level = btrfs_header_level(root->node);
orig_level = level;
if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
path->nodes[level] = root->node;
extent_buffer_get(root->node);
path->slots[level] = 0;
} else {
struct btrfs_key key;
struct btrfs_disk_key found_key;
struct extent_buffer *node;
btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
level = root_item->drop_level;
path->lowest_level = level;
wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (wret < 0) {
ret = wret;
goto out;
}
node = path->nodes[level];
btrfs_node_key(node, &found_key, path->slots[level]);
WARN_ON(memcmp(&found_key, &root_item->drop_progress,
sizeof(found_key)));
}
while(1) {
wret = walk_down_tree(trans, root, path, &level);
if (wret < 0)
ret = wret;
if (wret != 0)
break;
wret = walk_up_tree(trans, root, path, &level);
if (wret < 0)
ret = wret;
if (wret != 0)
break;
/*
ret = -EAGAIN;
break;
*/
}
for (i = 0; i <= orig_level; i++) {
if (path->nodes[i]) {
free_extent_buffer(path->nodes[i]);
path->nodes[i] = NULL;
}
}
out:
btrfs_free_path(path);
return ret;
}
int btrfs_free_block_groups(struct btrfs_fs_info *info)
{
u64 start;
u64 end;
u64 ptr;
int ret;
while(1) {
ret = find_first_extent_bit(&info->block_group_cache, 0,
&start, &end, (unsigned int)-1);
if (ret)
break;
ret = get_state_private(&info->block_group_cache, start, &ptr);
if (!ret)
kfree((void *)(unsigned long)ptr);
clear_extent_bits(&info->block_group_cache, start,
end, (unsigned int)-1, GFP_NOFS);
}
while(1) {
ret = find_first_extent_bit(&info->free_space_cache, 0,
&start, &end, EXTENT_DIRTY);
if (ret)
break;
clear_extent_dirty(&info->free_space_cache, start,
end, GFP_NOFS);
}
return 0;
}
int btrfs_read_block_groups(struct btrfs_root *root)
{
struct btrfs_path *path;
int ret;
int err = 0;
int bit;
struct btrfs_block_group_cache *cache;
struct btrfs_fs_info *info = root->fs_info;
struct extent_map_tree *block_group_cache;
struct btrfs_key key;
struct btrfs_key found_key;
struct extent_buffer *leaf;
block_group_cache = &info->block_group_cache;
root = info->extent_root;
key.objectid = 0;
key.offset = BTRFS_BLOCK_GROUP_SIZE;
btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
while(1) {
ret = btrfs_search_slot(NULL, info->extent_root,
&key, path, 0, 0);
if (ret != 0) {
err = ret;
break;
}
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
cache = kmalloc(sizeof(*cache), GFP_NOFS);
if (!cache) {
err = -1;
break;
}
read_extent_buffer(leaf, &cache->item,
btrfs_item_ptr_offset(leaf, path->slots[0]),
sizeof(cache->item));
memcpy(&cache->key, &found_key, sizeof(found_key));
cache->cached = 0;
cache->pinned = 0;
key.objectid = found_key.objectid + found_key.offset;
btrfs_release_path(root, path);
if (cache->item.flags & BTRFS_BLOCK_GROUP_MIXED) {
bit = BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA;
cache->data = BTRFS_BLOCK_GROUP_MIXED;
} else if (cache->item.flags & BTRFS_BLOCK_GROUP_DATA) {
bit = BLOCK_GROUP_DATA;
cache->data = BTRFS_BLOCK_GROUP_DATA;
} else {
bit = BLOCK_GROUP_METADATA;
cache->data = 0;
}
/* use EXTENT_LOCKED to prevent merging */
set_extent_bits(block_group_cache, found_key.objectid,
found_key.objectid + found_key.offset - 1,
bit | EXTENT_LOCKED, GFP_NOFS);
set_state_private(block_group_cache, found_key.objectid,
(unsigned long)cache);
if (key.objectid >=
btrfs_super_total_bytes(&info->super_copy))
break;
}
btrfs_free_path(path);
return 0;
}
static int btrfs_insert_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_key *key,
struct btrfs_block_group_item *bi)
{
int ret;
int pending_ret;
struct btrfs_root *extent_root;
extent_root = root->fs_info->extent_root;
ret = btrfs_insert_item(trans, extent_root, key, bi, sizeof(*bi));
finish_current_insert(trans, extent_root);
pending_ret = del_pending_extents(trans, extent_root);
if (ret)
return ret;
if (pending_ret)
return pending_ret;
return 0;
}
int btrfs_make_block_groups(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
u64 group_size;
u64 bytes_used;
u64 total_bytes;
u64 cur_start;
u64 nr = 0;
int ret;
int bit;
struct btrfs_root *extent_root;
struct btrfs_block_group_cache *cache;
struct extent_map_tree *block_group_cache;
extent_root = root->fs_info->extent_root;
block_group_cache = &root->fs_info->block_group_cache;
group_size = BTRFS_BLOCK_GROUP_SIZE;
bytes_used = btrfs_super_bytes_used(&root->fs_info->super_copy);
total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
cur_start = 0;
while (cur_start < total_bytes) {
cache = malloc(sizeof(*cache));
BUG_ON(!cache);
cache->key.objectid = cur_start;
cache->key.offset = group_size;
btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
memset(&cache->item, 0, sizeof(cache->item));
if (nr == 0)
btrfs_set_block_group_used(&cache->item, bytes_used);
if (nr++ % 3) {
bit = BLOCK_GROUP_DATA;
cache->data = 1;
cache->item.flags |= BTRFS_BLOCK_GROUP_DATA;
} else {
bit = BLOCK_GROUP_METADATA;
cache->data = 0;
}
set_extent_bits(block_group_cache, cur_start,
cur_start + group_size - 1,
bit | EXTENT_LOCKED, GFP_NOFS);
set_state_private(block_group_cache, cur_start,
(unsigned long)cache);
cur_start += group_size;
}
/* then insert all the items */
cur_start = 0;
while(cur_start < total_bytes) {
cache = btrfs_lookup_block_group(root->fs_info, cur_start);
BUG_ON(!cache);
ret = btrfs_insert_block_group(trans, root, &cache->key,
&cache->item);
BUG_ON(ret);
cur_start += group_size;
}
return 0;
}
u64 btrfs_hash_extent_ref(u64 root_objectid, u64 ref_generation,
u64 owner, u64 owner_offset)
{
return hash_extent_ref(root_objectid, ref_generation,
owner, owner_offset);
}
int btrfs_update_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, int alloc,
int mark_free, int data)
{
return update_block_group(trans, root, bytenr, num_bytes,
alloc, mark_free, data);
}
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