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LeafOS / LeafOS-Devices / android_kernel_samsung_gta4xl / 31840ae1a6b433ca0e6a8d341756ff478bbf959e / . / fs / btrfs / extent-tree.c
blob: 5258923d621f0b3030deba2cf9a5451d38711d3c [file] [log] [blame]
/*
* 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 <linux/sched.h>
#include <linux/pagemap.h>
#include <linux/writeback.h>
#include <linux/blkdev.h>
#include "hash.h"
#include "crc32c.h"
#include "ctree.h"
#include "disk-io.h"
#include "print-tree.h"
#include "transaction.h"
#include "volumes.h"
#include "locking.h"
#include "ref-cache.h"
#define PENDING_EXTENT_INSERT 0
#define PENDING_EXTENT_DELETE 1
#define PENDING_BACKREF_UPDATE 2
struct pending_extent_op {
int type;
u64 bytenr;
u64 num_bytes;
u64 parent;
u64 orig_parent;
u64 generation;
u64 orig_generation;
int level;
};
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 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);
void maybe_lock_mutex(struct btrfs_root *root)
{
if (root != root->fs_info->extent_root &&
root != root->fs_info->chunk_root &&
root != root->fs_info->dev_root) {
mutex_lock(&root->fs_info->alloc_mutex);
}
}
void maybe_unlock_mutex(struct btrfs_root *root)
{
if (root != root->fs_info->extent_root &&
root != root->fs_info->chunk_root &&
root != root->fs_info->dev_root) {
mutex_unlock(&root->fs_info->alloc_mutex);
}
}
static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
{
return (cache->flags & bits) == bits;
}
/*
* this adds the block group to the fs_info rb tree for the block group
* cache
*/
int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
struct btrfs_block_group_cache *block_group)
{
struct rb_node **p;
struct rb_node *parent = NULL;
struct btrfs_block_group_cache *cache;
spin_lock(&info->block_group_cache_lock);
p = &info->block_group_cache_tree.rb_node;
while (*p) {
parent = *p;
cache = rb_entry(parent, struct btrfs_block_group_cache,
cache_node);
if (block_group->key.objectid < cache->key.objectid) {
p = &(*p)->rb_left;
} else if (block_group->key.objectid > cache->key.objectid) {
p = &(*p)->rb_right;
} else {
spin_unlock(&info->block_group_cache_lock);
return -EEXIST;
}
}
rb_link_node(&block_group->cache_node, parent, p);
rb_insert_color(&block_group->cache_node,
&info->block_group_cache_tree);
spin_unlock(&info->block_group_cache_lock);
return 0;
}
/*
* This will return the block group at or after bytenr if contains is 0, else
* it will return the block group that contains the bytenr
*/
static struct btrfs_block_group_cache *
block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
int contains)
{
struct btrfs_block_group_cache *cache, *ret = NULL;
struct rb_node *n;
u64 end, start;
spin_lock(&info->block_group_cache_lock);
n = info->block_group_cache_tree.rb_node;
while (n) {
cache = rb_entry(n, struct btrfs_block_group_cache,
cache_node);
end = cache->key.objectid + cache->key.offset - 1;
start = cache->key.objectid;
if (bytenr < start) {
if (!contains && (!ret || start < ret->key.objectid))
ret = cache;
n = n->rb_left;
} else if (bytenr > start) {
if (contains && bytenr <= end) {
ret = cache;
break;
}
n = n->rb_right;
} else {
ret = cache;
break;
}
}
spin_unlock(&info->block_group_cache_lock);
return ret;
}
/*
* this is only called by cache_block_group, since we could have freed extents
* we need to check the pinned_extents for any extents that can't be used yet
* since their free space will be released as soon as the transaction commits.
*/
static int add_new_free_space(struct btrfs_block_group_cache *block_group,
struct btrfs_fs_info *info, u64 start, u64 end)
{
u64 extent_start, extent_end, size;
int ret;
while (start < end) {
ret = find_first_extent_bit(&info->pinned_extents, start,
&extent_start, &extent_end,
EXTENT_DIRTY);
if (ret)
break;
if (extent_start == start) {
start = extent_end + 1;
} else if (extent_start > start && extent_start < end) {
size = extent_start - start;
ret = btrfs_add_free_space(block_group, start, size);
BUG_ON(ret);
start = extent_end + 1;
} else {
break;
}
}
if (start < end) {
size = end - start;
ret = btrfs_add_free_space(block_group, start, size);
BUG_ON(ret);
}
return 0;
}
static int cache_block_group(struct btrfs_root *root,
struct btrfs_block_group_cache *block_group)
{
struct btrfs_path *path;
int ret = 0;
struct btrfs_key key;
struct extent_buffer *leaf;
int slot;
u64 last = 0;
u64 first_free;
int found = 0;
if (!block_group)
return 0;
root = root->fs_info->extent_root;
if (block_group->cached)
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 2;
/*
* we get into deadlocks with paths held by callers of this function.
* since the alloc_mutex is protecting things right now, just
* skip the locking here
*/
path->skip_locking = 1;
first_free = max_t(u64, block_group->key.objectid,
BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE);
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)
goto err;
ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
if (ret < 0)
goto err;
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;
}
add_new_free_space(block_group, root->fs_info, last,
key.objectid);
last = key.objectid + key.offset;
}
next:
path->slots[0]++;
}
if (!found)
last = first_free;
add_new_free_space(block_group, root->fs_info, last,
block_group->key.objectid +
block_group->key.offset);
block_group->cached = 1;
ret = 0;
err:
btrfs_free_path(path);
return ret;
}
/*
* return the block group that starts at or after bytenr
*/
struct btrfs_block_group_cache *btrfs_lookup_first_block_group(struct
btrfs_fs_info *info,
u64 bytenr)
{
struct btrfs_block_group_cache *cache;
cache = block_group_cache_tree_search(info, bytenr, 0);
return cache;
}
/*
* return the block group that contains teh given bytenr
*/
struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
btrfs_fs_info *info,
u64 bytenr)
{
struct btrfs_block_group_cache *cache;
cache = block_group_cache_tree_search(info, bytenr, 1);
return cache;
}
static int noinline find_free_space(struct btrfs_root *root,
struct btrfs_block_group_cache **cache_ret,
u64 *start_ret, u64 num, int data)
{
int ret;
struct btrfs_block_group_cache *cache = *cache_ret;
struct btrfs_free_space *info = NULL;
u64 last;
u64 total_fs_bytes;
u64 search_start = *start_ret;
WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
if (!cache)
goto out;
last = max(search_start, cache->key.objectid);
again:
ret = cache_block_group(root, cache);
if (ret)
goto out;
if (cache->ro || !block_group_bits(cache, data))
goto new_group;
info = btrfs_find_free_space(cache, last, num);
if (info) {
*start_ret = info->offset;
return 0;
}
new_group:
last = cache->key.objectid + cache->key.offset;
cache = btrfs_lookup_first_block_group(root->fs_info, last);
if (!cache || cache->key.objectid >= total_fs_bytes)
goto out;
*cache_ret = cache;
goto again;
out:
return -ENOSPC;
}
static u64 div_factor(u64 num, int factor)
{
if (factor == 10)
return num;
num *= factor;
do_div(num, 10);
return num;
}
static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
u64 flags)
{
struct list_head *head = &info->space_info;
struct list_head *cur;
struct btrfs_space_info *found;
list_for_each(cur, head) {
found = list_entry(cur, struct btrfs_space_info, list);
if (found->flags == flags)
return found;
}
return NULL;
}
static 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 btrfs_block_group_cache *found_group = NULL;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_space_info *sinfo;
u64 used;
u64 last = 0;
u64 free_check;
int full_search = 0;
int factor = 10;
int wrapped = 0;
if (data & BTRFS_BLOCK_GROUP_METADATA)
factor = 9;
if (search_start) {
struct btrfs_block_group_cache *shint;
shint = btrfs_lookup_first_block_group(info, search_start);
if (shint && block_group_bits(shint, data) && !shint->ro) {
spin_lock(&shint->lock);
used = btrfs_block_group_used(&shint->item);
if (used + shint->pinned <
div_factor(shint->key.offset, factor)) {
spin_unlock(&shint->lock);
return shint;
}
spin_unlock(&shint->lock);
}
}
if (hint && !hint->ro && block_group_bits(hint, data)) {
spin_lock(&hint->lock);
used = btrfs_block_group_used(&hint->item);
if (used + hint->pinned <
div_factor(hint->key.offset, factor)) {
spin_unlock(&hint->lock);
return hint;
}
spin_unlock(&hint->lock);
last = hint->key.objectid + hint->key.offset;
} else {
if (hint)
last = max(hint->key.objectid, search_start);
else
last = search_start;
}
sinfo = __find_space_info(root->fs_info, data);
if (!sinfo)
goto found;
again:
while(1) {
struct list_head *l;
cache = NULL;
spin_lock(&sinfo->lock);
list_for_each(l, &sinfo->block_groups) {
struct btrfs_block_group_cache *entry;
entry = list_entry(l, struct btrfs_block_group_cache,
list);
if ((entry->key.objectid >= last) &&
(!cache || (entry->key.objectid <
cache->key.objectid)))
cache = entry;
}
spin_unlock(&sinfo->lock);
if (!cache)
break;
spin_lock(&cache->lock);
last = cache->key.objectid + cache->key.offset;
used = btrfs_block_group_used(&cache->item);
if (!cache->ro && block_group_bits(cache, data)) {
free_check = div_factor(cache->key.offset, factor);
if (used + cache->pinned < free_check) {
found_group = cache;
spin_unlock(&cache->lock);
goto found;
}
}
spin_unlock(&cache->lock);
cond_resched();
}
if (!wrapped) {
last = search_start;
wrapped = 1;
goto again;
}
if (!full_search && factor < 10) {
last = search_start;
full_search = 1;
factor = 10;
goto again;
}
found:
return found_group;
}
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 *ret;
ret = __btrfs_find_block_group(root, hint, search_start, data, owner);
return ret;
}
/* simple helper to search for an existing extent at a given offset */
int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
{
int ret;
struct btrfs_key key;
struct btrfs_path *path;
path = btrfs_alloc_path();
BUG_ON(!path);
maybe_lock_mutex(root);
key.objectid = start;
key.offset = len;
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
0, 0);
maybe_unlock_mutex(root);
btrfs_free_path(path);
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
* - 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
* - number of references holding by parent node (alway 1 for tree blocks)
*
* Btree leaf may hold multiple references to a file extent. In most cases,
* these references are from same file and the corresponding offsets inside
* the file are close together. So inode objectid and offset in file are
* just hints, they provide hints about where in the btree the references
* can be found and when we can stop searching.
*
* When a file extent is allocated the fields are filled in:
* (root_key.objectid, trans->transid, inode objectid, offset in file, 1)
*
* When a leaf is cow'd new references are added for every file extent found
* in the leaf. It looks similar to 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,
* number of references in the leaf)
*
* Because inode objectid and offset in file are just hints, they are not
* used when backrefs are deleted. When a file extent is removed either
* during snapshot deletion or file truncation, we find the corresponding
* back back reference and check the following fields.
*
* (btrfs_header_owner(leaf), btrfs_header_generation(leaf))
*
* Btree extents can be referenced by:
*
* - Different subvolumes
* - Different generations of the same subvolume
*
* When a tree block is created, back references are inserted:
*
* (root->root_key.objectid, trans->transid, level, 0, 1)
*
* When a tree block is cow'd, new back references are added for all the
* blocks it points to. If the tree block isn't in reference counted root,
* the old back references are removed. These new back references are of
* the form (trans->transid will have increased since creation):
*
* (root->root_key.objectid, trans->transid, level, 0, 1)
*
* When a backref is in deleting, the following fields are checked:
*
* if backref was for a tree root:
* (btrfs_header_owner(itself), btrfs_header_generation(itself))
* else
* (btrfs_header_owner(parent), btrfs_header_generation(parent))
*
* Back Reference Key composing:
*
* The key objectid corresponds to the first byte in the extent, the key
* type is set to BTRFS_EXTENT_REF_KEY, and the key offset is the first
* byte of parent extent. If a extent is tree root, the key offset is set
* to the key objectid.
*/
static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 bytenr,
u64 parent, u64 ref_root,
u64 ref_generation, int del)
{
struct btrfs_key key;
struct btrfs_extent_ref *ref;
struct extent_buffer *leaf;
int ret;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_REF_KEY;
key.offset = parent;
ret = btrfs_search_slot(trans, root, &key, path, del ? -1 : 0, 1);
if (ret < 0)
goto out;
if (ret > 0) {
ret = -ENOENT;
goto out;
}
leaf = path->nodes[0];
ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
if (btrfs_ref_root(leaf, ref) != ref_root ||
btrfs_ref_generation(leaf, ref) != ref_generation) {
ret = -EIO;
WARN_ON(1);
goto out;
}
ret = 0;
out:
return ret;
}
static int noinline insert_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent,
u64 ref_root, u64 ref_generation,
u64 owner_objectid, u64 owner_offset)
{
struct btrfs_key key;
struct extent_buffer *leaf;
struct btrfs_extent_ref *ref;
u32 num_refs;
int ret;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_REF_KEY;
key.offset = parent;
ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*ref));
if (ret == 0) {
leaf = path->nodes[0];
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref);
btrfs_set_ref_root(leaf, ref, ref_root);
btrfs_set_ref_generation(leaf, ref, ref_generation);
btrfs_set_ref_objectid(leaf, ref, owner_objectid);
btrfs_set_ref_offset(leaf, ref, owner_offset);
btrfs_set_ref_num_refs(leaf, ref, 1);
} else if (ret == -EEXIST) {
u64 existing_owner;
BUG_ON(owner_objectid < BTRFS_FIRST_FREE_OBJECTID);
leaf = path->nodes[0];
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref);
if (btrfs_ref_root(leaf, ref) != ref_root ||
btrfs_ref_generation(leaf, ref) != ref_generation) {
ret = -EIO;
WARN_ON(1);
goto out;
}
num_refs = btrfs_ref_num_refs(leaf, ref);
BUG_ON(num_refs == 0);
btrfs_set_ref_num_refs(leaf, ref, num_refs + 1);
existing_owner = btrfs_ref_objectid(leaf, ref);
if (existing_owner == owner_objectid &&
btrfs_ref_offset(leaf, ref) > owner_offset) {
btrfs_set_ref_offset(leaf, ref, owner_offset);
} else if (existing_owner != owner_objectid &&
existing_owner != BTRFS_MULTIPLE_OBJECTIDS) {
btrfs_set_ref_objectid(leaf, ref,
BTRFS_MULTIPLE_OBJECTIDS);
btrfs_set_ref_offset(leaf, ref, 0);
}
ret = 0;
} else {
goto out;
}
btrfs_mark_buffer_dirty(path->nodes[0]);
out:
btrfs_release_path(root, path);
return ret;
}
static int noinline remove_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path)
{
struct extent_buffer *leaf;
struct btrfs_extent_ref *ref;
u32 num_refs;
int ret = 0;
leaf = path->nodes[0];
ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
num_refs = btrfs_ref_num_refs(leaf, ref);
BUG_ON(num_refs == 0);
num_refs -= 1;
if (num_refs == 0) {
ret = btrfs_del_item(trans, root, path);
} else {
btrfs_set_ref_num_refs(leaf, ref, num_refs);
btrfs_mark_buffer_dirty(leaf);
}
btrfs_release_path(root, path);
return ret;
}
static int __btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr,
u64 orig_parent, u64 parent,
u64 orig_root, u64 ref_root,
u64 orig_generation, u64 ref_generation,
u64 owner_objectid, u64 owner_offset)
{
int ret;
struct btrfs_root *extent_root = root->fs_info->extent_root;
struct btrfs_path *path;
if (root == root->fs_info->extent_root) {
struct pending_extent_op *extent_op;
u64 num_bytes;
BUG_ON(owner_objectid >= BTRFS_MAX_LEVEL);
num_bytes = btrfs_level_size(root, (int)owner_objectid);
if (test_range_bit(&root->fs_info->extent_ins, bytenr,
bytenr + num_bytes - 1, EXTENT_LOCKED, 0)) {
u64 priv;
ret = get_state_private(&root->fs_info->extent_ins,
bytenr, &priv);
BUG_ON(ret);
extent_op = (struct pending_extent_op *)
(unsigned long)priv;
BUG_ON(extent_op->parent != orig_parent);
BUG_ON(extent_op->generation != orig_generation);
extent_op->parent = parent;
extent_op->generation = ref_generation;
} else {
extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
BUG_ON(!extent_op);
extent_op->type = PENDING_BACKREF_UPDATE;
extent_op->bytenr = bytenr;
extent_op->num_bytes = num_bytes;
extent_op->parent = parent;
extent_op->orig_parent = orig_parent;
extent_op->generation = ref_generation;
extent_op->orig_generation = orig_generation;
extent_op->level = (int)owner_objectid;
set_extent_bits(&root->fs_info->extent_ins,
bytenr, bytenr + num_bytes - 1,
EXTENT_LOCKED, GFP_NOFS);
set_state_private(&root->fs_info->extent_ins,
bytenr, (unsigned long)extent_op);
}
return 0;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = lookup_extent_backref(trans, extent_root, path,
bytenr, orig_parent, orig_root,
orig_generation, 1);
if (ret)
goto out;
ret = remove_extent_backref(trans, extent_root, path);
if (ret)
goto out;
ret = insert_extent_backref(trans, extent_root, path, bytenr,
parent, ref_root, ref_generation,
owner_objectid, owner_offset);
BUG_ON(ret);
finish_current_insert(trans, extent_root);
del_pending_extents(trans, extent_root);
out:
btrfs_free_path(path);
return ret;
}
int btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr,
u64 orig_parent, u64 parent,
u64 ref_root, u64 ref_generation,
u64 owner_objectid, u64 owner_offset)
{
int ret;
if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
return 0;
maybe_lock_mutex(root);
ret = __btrfs_update_extent_ref(trans, root, bytenr, orig_parent,
parent, ref_root, ref_root,
ref_generation, ref_generation,
owner_objectid, owner_offset);
maybe_unlock_mutex(root);
return ret;
}
static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr,
u64 orig_parent, u64 parent,
u64 orig_root, u64 ref_root,
u64 orig_generation, u64 ref_generation,
u64 owner_objectid, u64 owner_offset)
{
struct btrfs_path *path;
int ret;
struct btrfs_key key;
struct extent_buffer *l;
struct btrfs_extent_item *item;
u32 refs;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 1;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = (u64)-1;
ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
0, 1);
if (ret < 0)
return ret;
BUG_ON(ret == 0 || path->slots[0] == 0);
path->slots[0]--;
l = path->nodes[0];
btrfs_item_key_to_cpu(l, &key, path->slots[0]);
BUG_ON(key.objectid != bytenr);
BUG_ON(key.type != BTRFS_EXTENT_ITEM_KEY);
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);
path->reada = 1;
ret = insert_extent_backref(trans, root->fs_info->extent_root,
path, bytenr, parent,
ref_root, ref_generation,
owner_objectid, 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_inc_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent,
u64 ref_root, u64 ref_generation,
u64 owner_objectid, u64 owner_offset)
{
int ret;
if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
return 0;
maybe_lock_mutex(root);
ret = __btrfs_inc_extent_ref(trans, root, bytenr, 0, parent,
0, ref_root, 0, ref_generation,
owner_objectid, owner_offset);
maybe_unlock_mutex(root);
return ret;
}
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;
}
int btrfs_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();
path->reada = 1;
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;
}
static int get_reference_status(struct btrfs_root *root, u64 bytenr,
u64 parent_gen, u64 ref_objectid,
u64 *min_generation, u32 *ref_count)
{
struct btrfs_root *extent_root = root->fs_info->extent_root;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_extent_ref *ref_item;
struct btrfs_key key;
struct btrfs_key found_key;
u64 root_objectid = root->root_key.objectid;
u64 ref_generation;
u32 nritems;
int ret;
key.objectid = bytenr;
key.offset = (u64)-1;
key.type = BTRFS_EXTENT_ITEM_KEY;
path = btrfs_alloc_path();
mutex_lock(&root->fs_info->alloc_mutex);
ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
if (ret < 0)
goto out;
BUG_ON(ret == 0);
if (ret < 0 || path->slots[0] == 0)
goto out;
path->slots[0]--;
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_ITEM_KEY) {
ret = 1;
goto out;
}
*ref_count = 0;
*min_generation = (u64)-1;
while (1) {
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(extent_root, path);
if (ret < 0)
goto out;
if (ret == 0)
continue;
break;
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != bytenr)
break;
if (found_key.type != BTRFS_EXTENT_REF_KEY) {
path->slots[0]++;
continue;
}
ref_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref);
ref_generation = btrfs_ref_generation(leaf, ref_item);
/*
* For (parent_gen > 0 && parent_gen > ref_generation):
*
* we reach here through the oldest root, therefore
* all other reference from same snapshot should have
* a larger generation.
*/
if ((root_objectid != btrfs_ref_root(leaf, ref_item)) ||
(parent_gen > 0 && parent_gen > ref_generation) ||
(ref_objectid >= BTRFS_FIRST_FREE_OBJECTID &&
ref_objectid != btrfs_ref_objectid(leaf, ref_item))) {
*ref_count = 2;
break;
}
*ref_count = 1;
if (*min_generation > ref_generation)
*min_generation = ref_generation;
path->slots[0]++;
}
ret = 0;
out:
mutex_unlock(&root->fs_info->alloc_mutex);
btrfs_free_path(path);
return ret;
}
int btrfs_cross_ref_exists(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_key *key, u64 bytenr)
{
struct btrfs_root *old_root;
struct btrfs_path *path = NULL;
struct extent_buffer *eb;
struct btrfs_file_extent_item *item;
u64 ref_generation;
u64 min_generation;
u64 extent_start;
u32 ref_count;
int level;
int ret;
BUG_ON(trans == NULL);
BUG_ON(key->type != BTRFS_EXTENT_DATA_KEY);
ret = get_reference_status(root, bytenr, 0, key->objectid,
&min_generation, &ref_count);
if (ret)
return ret;
if (ref_count != 1)
return 1;
old_root = root->dirty_root->root;
ref_generation = old_root->root_key.offset;
/* all references are created in running transaction */
if (min_generation > ref_generation) {
ret = 0;
goto out;
}
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
path->skip_locking = 1;
/* if no item found, the extent is referenced by other snapshot */
ret = btrfs_search_slot(NULL, old_root, key, path, 0, 0);
if (ret)
goto out;
eb = path->nodes[0];
item = btrfs_item_ptr(eb, path->slots[0],
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(eb, item) != BTRFS_FILE_EXTENT_REG ||
btrfs_file_extent_disk_bytenr(eb, item) != bytenr) {
ret = 1;
goto out;
}
for (level = BTRFS_MAX_LEVEL - 1; level >= -1; level--) {
if (level >= 0) {
eb = path->nodes[level];
if (!eb)
continue;
extent_start = eb->start;
} else
extent_start = bytenr;
ret = get_reference_status(root, extent_start, ref_generation,
0, &min_generation, &ref_count);
if (ret)
goto out;
if (ref_count != 1) {
ret = 1;
goto out;
}
if (level >= 0)
ref_generation = btrfs_header_generation(eb);
}
ret = 0;
out:
if (path)
btrfs_free_path(path);
return ret;
}
int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct extent_buffer *buf, u32 nr_extents)
{
u32 nritems;
struct btrfs_key key;
struct btrfs_file_extent_item *fi;
int i;
int level;
int ret = 0;
if (!root->ref_cows)
return 0;
level = btrfs_header_level(buf);
nritems = btrfs_header_nritems(buf);
if (level == 0) {
struct btrfs_leaf_ref *ref;
struct btrfs_extent_info *info;
ref = btrfs_alloc_leaf_ref(root, nr_extents);
if (!ref) {
ret = -ENOMEM;
goto out;
}
ref->root_gen = root->root_key.offset;
ref->bytenr = buf->start;
ref->owner = btrfs_header_owner(buf);
ref->generation = btrfs_header_generation(buf);
ref->nritems = nr_extents;
info = ref->extents;
for (i = 0; nr_extents > 0 && i < nritems; i++) {
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;
info->bytenr = disk_bytenr;
info->num_bytes =
btrfs_file_extent_disk_num_bytes(buf, fi);
info->objectid = key.objectid;
info->offset = key.offset;
info++;
}
BUG_ON(!root->ref_tree);
ret = btrfs_add_leaf_ref(root, ref);
WARN_ON(ret);
btrfs_free_leaf_ref(root, ref);
}
out:
return ret;
}
int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct extent_buffer *orig_buf, struct extent_buffer *buf,
u32 *nr_extents)
{
u64 bytenr;
u64 ref_root;
u64 orig_root;
u64 ref_generation;
u64 orig_generation;
u32 nritems;
u32 nr_file_extents = 0;
struct btrfs_key key;
struct btrfs_file_extent_item *fi;
int i;
int level;
int ret = 0;
int faili = 0;
int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
u64, u64, u64, u64, u64, u64, u64, u64, u64);
ref_root = btrfs_header_owner(buf);
ref_generation = btrfs_header_generation(buf);
orig_root = btrfs_header_owner(orig_buf);
orig_generation = btrfs_header_generation(orig_buf);
nritems = btrfs_header_nritems(buf);
level = btrfs_header_level(buf);
if (root->ref_cows) {
process_func = __btrfs_inc_extent_ref;
} else {
if (level == 0 &&
root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
goto out;
if (level != 0 &&
root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
goto out;
process_func = __btrfs_update_extent_ref;
}
for (i = 0; i < nritems; i++) {
cond_resched();
if (level == 0) {
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;
bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
if (bytenr == 0)
continue;
nr_file_extents++;
maybe_lock_mutex(root);
ret = process_func(trans, root, bytenr,
orig_buf->start, buf->start,
orig_root, ref_root,
orig_generation, ref_generation,
key.objectid, key.offset);
maybe_unlock_mutex(root);
if (ret) {
faili = i;
WARN_ON(1);
goto fail;
}
} else {
bytenr = btrfs_node_blockptr(buf, i);
maybe_lock_mutex(root);
ret = process_func(trans, root, bytenr,
orig_buf->start, buf->start,
orig_root, ref_root,
orig_generation, ref_generation,
level - 1, 0);
maybe_unlock_mutex(root);
if (ret) {
faili = i;
WARN_ON(1);
goto fail;
}
}
}
out:
if (nr_extents) {
if (level == 0)
*nr_extents = nr_file_extents;
else
*nr_extents = nritems;
}
return 0;
fail:
WARN_ON(1);
return ret;
}
int btrfs_update_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct extent_buffer *orig_buf,
struct extent_buffer *buf, int start_slot, int nr)
{
u64 bytenr;
u64 ref_root;
u64 orig_root;
u64 ref_generation;
u64 orig_generation;
struct btrfs_key key;
struct btrfs_file_extent_item *fi;
int i;
int ret;
int slot;
int level;
BUG_ON(start_slot < 0);
BUG_ON(start_slot + nr > btrfs_header_nritems(buf));
ref_root = btrfs_header_owner(buf);
ref_generation = btrfs_header_generation(buf);
orig_root = btrfs_header_owner(orig_buf);
orig_generation = btrfs_header_generation(orig_buf);
level = btrfs_header_level(buf);
if (!root->ref_cows) {
if (level == 0 &&
root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
return 0;
if (level != 0 &&
root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
return 0;
}
for (i = 0, slot = start_slot; i < nr; i++, slot++) {
cond_resched();
if (level == 0) {
btrfs_item_key_to_cpu(buf, &key, slot);
if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
continue;
fi = btrfs_item_ptr(buf, slot,
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(buf, fi) ==
BTRFS_FILE_EXTENT_INLINE)
continue;
bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
if (bytenr == 0)
continue;
maybe_lock_mutex(root);
ret = __btrfs_update_extent_ref(trans, root, bytenr,
orig_buf->start, buf->start,
orig_root, ref_root,
orig_generation, ref_generation,
key.objectid, key.offset);
maybe_unlock_mutex(root);
if (ret)
goto fail;
} else {
bytenr = btrfs_node_blockptr(buf, slot);
maybe_lock_mutex(root);
ret = __btrfs_update_extent_ref(trans, root, bytenr,
orig_buf->start, buf->start,
orig_root, ref_root,
orig_generation, ref_generation,
level - 1, 0);
maybe_unlock_mutex(root);
if (ret)
goto fail;
}
}
return 0;
fail:
WARN_ON(1);
return -1;
}
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 btrfs_block_group_cache *cache, *entry;
struct rb_node *n;
int err = 0;
int werr = 0;
struct btrfs_path *path;
u64 last = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
mutex_lock(&root->fs_info->alloc_mutex);
while(1) {
cache = NULL;
spin_lock(&root->fs_info->block_group_cache_lock);
for (n = rb_first(&root->fs_info->block_group_cache_tree);
n; n = rb_next(n)) {
entry = rb_entry(n, struct btrfs_block_group_cache,
cache_node);
if (entry->dirty) {
cache = entry;
break;
}
}
spin_unlock(&root->fs_info->block_group_cache_lock);
if (!cache)
break;
last += cache->key.offset;
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;
}
cache->dirty = 0;
}
btrfs_free_path(path);
mutex_unlock(&root->fs_info->alloc_mutex);
return werr;
}
static int update_space_info(struct btrfs_fs_info *info, u64 flags,
u64 total_bytes, u64 bytes_used,
struct btrfs_space_info **space_info)
{
struct btrfs_space_info *found;
found = __find_space_info(info, flags);
if (found) {
found->total_bytes += total_bytes;
found->bytes_used += bytes_used;
found->full = 0;
*space_info = found;
return 0;
}
found = kmalloc(sizeof(*found), GFP_NOFS);
if (!found)
return -ENOMEM;
list_add(&found->list, &info->space_info);
INIT_LIST_HEAD(&found->block_groups);
spin_lock_init(&found->lock);
found->flags = flags;
found->total_bytes = total_bytes;
found->bytes_used = bytes_used;
found->bytes_pinned = 0;
found->full = 0;
found->force_alloc = 0;
*space_info = found;
return 0;
}
static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
{
u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10 |
BTRFS_BLOCK_GROUP_DUP);
if (extra_flags) {
if (flags & BTRFS_BLOCK_GROUP_DATA)
fs_info->avail_data_alloc_bits |= extra_flags;
if (flags & BTRFS_BLOCK_GROUP_METADATA)
fs_info->avail_metadata_alloc_bits |= extra_flags;
if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
fs_info->avail_system_alloc_bits |= extra_flags;
}
}
static u64 reduce_alloc_profile(struct btrfs_root *root, u64 flags)
{
u64 num_devices = root->fs_info->fs_devices->num_devices;
if (num_devices == 1)
flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
if (num_devices < 4)
flags &= ~BTRFS_BLOCK_GROUP_RAID10;
if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
(flags & (BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10))) {
flags &= ~BTRFS_BLOCK_GROUP_DUP;
}
if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
(flags & BTRFS_BLOCK_GROUP_RAID10)) {
flags &= ~BTRFS_BLOCK_GROUP_RAID1;
}
if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
((flags & BTRFS_BLOCK_GROUP_RAID1) |
(flags & BTRFS_BLOCK_GROUP_RAID10) |
(flags & BTRFS_BLOCK_GROUP_DUP)))
flags &= ~BTRFS_BLOCK_GROUP_RAID0;
return flags;
}
static int do_chunk_alloc(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root, u64 alloc_bytes,
u64 flags, int force)
{
struct btrfs_space_info *space_info;
u64 thresh;
u64 start;
u64 num_bytes;
int ret = 0;
flags = reduce_alloc_profile(extent_root, flags);
space_info = __find_space_info(extent_root->fs_info, flags);
if (!space_info) {
ret = update_space_info(extent_root->fs_info, flags,
0, 0, &space_info);
BUG_ON(ret);
}
BUG_ON(!space_info);
if (space_info->force_alloc) {
force = 1;
space_info->force_alloc = 0;
}
if (space_info->full)
goto out;
thresh = div_factor(space_info->total_bytes, 6);
if (!force &&
(space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) <
thresh)
goto out;
mutex_lock(&extent_root->fs_info->chunk_mutex);
ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
if (ret == -ENOSPC) {
printk("space info full %Lu\n", flags);
space_info->full = 1;
goto out_unlock;
}
BUG_ON(ret);
ret = btrfs_make_block_group(trans, extent_root, 0, flags,
BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
BUG_ON(ret);
out_unlock:
mutex_unlock(&extent_root->fs_info->chunk_mutex);
out:
return ret;
}
static int update_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, int alloc,
int mark_free)
{
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;
WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
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);
spin_lock(&cache->lock);
cache->dirty = 1;
old_val = btrfs_block_group_used(&cache->item);
num_bytes = min(total, cache->key.offset - byte_in_group);
if (alloc) {
old_val += num_bytes;
cache->space_info->bytes_used += num_bytes;
btrfs_set_block_group_used(&cache->item, old_val);
spin_unlock(&cache->lock);
} else {
old_val -= num_bytes;
cache->space_info->bytes_used -= num_bytes;
btrfs_set_block_group_used(&cache->item, old_val);
spin_unlock(&cache->lock);
if (mark_free) {
int ret;
ret = btrfs_add_free_space(cache, bytenr,
num_bytes);
if (ret)
return -1;
}
}
total -= num_bytes;
bytenr += num_bytes;
}
return 0;
}
static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
{
struct btrfs_block_group_cache *cache;
cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
if (!cache)
return 0;
return cache->key.objectid;
}
int btrfs_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;
WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
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);
if (!cache) {
u64 first = first_logical_byte(root, bytenr);
WARN_ON(first < bytenr);
len = min(first - bytenr, num);
} else {
len = min(num, cache->key.offset -
(bytenr - cache->key.objectid));
}
if (pin) {
if (cache) {
spin_lock(&cache->lock);
cache->pinned += len;
cache->space_info->bytes_pinned += len;
spin_unlock(&cache->lock);
}
fs_info->total_pinned += len;
} else {
if (cache) {
spin_lock(&cache->lock);
cache->pinned -= len;
cache->space_info->bytes_pinned -= len;
spin_unlock(&cache->lock);
}
fs_info->total_pinned -= len;
}
bytenr += len;
num -= len;
}
return 0;
}
int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
{
u64 last = 0;
u64 start;
u64 end;
struct extent_io_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_io_tree *unpin)
{
u64 start;
u64 end;
int ret;
struct btrfs_block_group_cache *cache;
mutex_lock(&root->fs_info->alloc_mutex);
while(1) {
ret = find_first_extent_bit(unpin, 0, &start, &end,
EXTENT_DIRTY);
if (ret)
break;
btrfs_update_pinned_extents(root, start, end + 1 - start, 0);
clear_extent_dirty(unpin, start, end, GFP_NOFS);
cache = btrfs_lookup_block_group(root->fs_info, start);
if (cache->cached)
btrfs_add_free_space(cache, start, end - start + 1);
if (need_resched()) {
mutex_unlock(&root->fs_info->alloc_mutex);
cond_resched();
mutex_lock(&root->fs_info->alloc_mutex);
}
}
mutex_unlock(&root->fs_info->alloc_mutex);
return 0;
}
static int finish_current_insert(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root)
{
u64 start;
u64 end;
u64 priv;
struct btrfs_fs_info *info = extent_root->fs_info;
struct btrfs_path *path;
struct btrfs_extent_ref *ref;
struct pending_extent_op *extent_op;
struct btrfs_key key;
struct btrfs_extent_item extent_item;
int ret;
int err = 0;
WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
btrfs_set_stack_extent_refs(&extent_item, 1);
path = btrfs_alloc_path();
while(1) {
ret = find_first_extent_bit(&info->extent_ins, 0, &start,
&end, EXTENT_LOCKED);
if (ret)
break;
ret = get_state_private(&info->extent_ins, start, &priv);
BUG_ON(ret);
extent_op = (struct pending_extent_op *)(unsigned long)priv;
if (extent_op->type == PENDING_EXTENT_INSERT) {
key.objectid = start;
key.offset = end + 1 - start;
key.type = BTRFS_EXTENT_ITEM_KEY;
err = btrfs_insert_item(trans, extent_root, &key,
&extent_item, sizeof(extent_item));
BUG_ON(err);
clear_extent_bits(&info->extent_ins, start, end,
EXTENT_LOCKED, GFP_NOFS);
err = insert_extent_backref(trans, extent_root, path,
start, extent_op->parent,
extent_root->root_key.objectid,
extent_op->generation,
extent_op->level, 0);
BUG_ON(err);
} else if (extent_op->type == PENDING_BACKREF_UPDATE) {
err = lookup_extent_backref(trans, extent_root, path,
start, extent_op->orig_parent,
extent_root->root_key.objectid,
extent_op->orig_generation, 0);
BUG_ON(err);
clear_extent_bits(&info->extent_ins, start, end,
EXTENT_LOCKED, GFP_NOFS);
key.objectid = start;
key.offset = extent_op->parent;
key.type = BTRFS_EXTENT_REF_KEY;
err = btrfs_set_item_key_safe(trans, extent_root, path,
&key);
BUG_ON(err);
ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_extent_ref);
btrfs_set_ref_generation(path->nodes[0], ref,
extent_op->generation);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(extent_root, path);
} else {
BUG_ON(1);
}
kfree(extent_op);
if (need_resched()) {
mutex_unlock(&extent_root->fs_info->alloc_mutex);
cond_resched();
mutex_lock(&extent_root->fs_info->alloc_mutex);
}
}
btrfs_free_path(path);
return 0;
}
static int pin_down_bytes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, int is_data)
{
int err = 0;
struct extent_buffer *buf;
WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
if (is_data)
goto pinit;
buf = btrfs_find_tree_block(root, bytenr, num_bytes);
if (!buf)
goto pinit;
/* we can reuse a block if it hasn't been written
* and it is from this transaction. We can't
* reuse anything from the tree log root because
* it has tiny sub-transactions.
*/
if (btrfs_buffer_uptodate(buf, 0) &&
btrfs_try_tree_lock(buf)) {
u64 header_owner = btrfs_header_owner(buf);
u64 header_transid = btrfs_header_generation(buf);
if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
header_transid == trans->transid &&
!btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
clean_tree_block(NULL, root, buf);
btrfs_tree_unlock(buf);
free_extent_buffer(buf);
return 1;
}
btrfs_tree_unlock(buf);
}
free_extent_buffer(buf);
pinit:
btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
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 parent,
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_root *extent_root = info->extent_root;
struct extent_buffer *leaf;
int ret;
int extent_slot = 0;
int found_extent = 0;
int num_to_del = 1;
struct btrfs_extent_item *ei;
u32 refs;
WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
key.objectid = bytenr;
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
key.offset = num_bytes;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 1;
ret = lookup_extent_backref(trans, extent_root, path, bytenr, parent,
root_objectid, ref_generation, 1);
if (ret == 0) {
struct btrfs_key found_key;
extent_slot = path->slots[0];
while(extent_slot > 0) {
extent_slot--;
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
extent_slot);
if (found_key.objectid != bytenr)
break;
if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
found_key.offset == num_bytes) {
found_extent = 1;
break;
}
if (path->slots[0] - extent_slot > 5)
break;
}
if (!found_extent) {
ret = remove_extent_backref(trans, extent_root, path);
BUG_ON(ret);
btrfs_release_path(extent_root, path);
ret = btrfs_search_slot(trans, extent_root,
&key, path, -1, 1);
BUG_ON(ret);
extent_slot = path->slots[0];
}
} 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);
}
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, extent_slot,
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 && found_extent && path->slots[0] == extent_slot + 1) {
struct btrfs_extent_ref *ref;
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref);
BUG_ON(btrfs_ref_num_refs(leaf, ref) != 1);
/* if the back ref and the extent are next to each other
* they get deleted below in one shot
*/
path->slots[0] = extent_slot;
num_to_del = 2;
} else if (found_extent) {
/* otherwise delete the extent back ref */
ret = remove_extent_backref(trans, extent_root, path);
BUG_ON(ret);
/* if refs are 0, we need to setup the path for deletion */
if (refs == 0) {
btrfs_release_path(extent_root, path);
ret = btrfs_search_slot(trans, extent_root, &key, path,
-1, 1);
BUG_ON(ret);
}
}
if (refs == 0) {
u64 super_used;
u64 root_used;
#ifdef BIO_RW_DISCARD
u64 map_length = num_bytes;
struct btrfs_multi_bio *multi = NULL;
#endif
if (pin) {
ret = pin_down_bytes(trans, root, bytenr, num_bytes,
owner_objectid >= BTRFS_FIRST_FREE_OBJECTID);
if (ret > 0)
mark_free = 1;
BUG_ON(ret < 0);
}
/* block accounting for super block */
spin_lock_irq(&info->delalloc_lock);
super_used = btrfs_super_bytes_used(&info->super_copy);
btrfs_set_super_bytes_used(&info->super_copy,
super_used - num_bytes);
spin_unlock_irq(&info->delalloc_lock);
/* 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_items(trans, extent_root, path, path->slots[0],
num_to_del);
BUG_ON(ret);
ret = update_block_group(trans, root, bytenr, num_bytes, 0,
mark_free);
BUG_ON(ret);
#ifdef BIO_RW_DISCARD
/* Tell the block device(s) that the sectors can be discarded */
ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
bytenr, &map_length, &multi, 0);
if (!ret) {
struct btrfs_bio_stripe *stripe = multi->stripes;
int i;
if (map_length > num_bytes)
map_length = num_bytes;
for (i = 0; i < multi->num_stripes; i++, stripe++) {
blkdev_issue_discard(stripe->dev->bdev,
stripe->physical >> 9,
map_length >> 9);
}
kfree(multi);
}
#endif
}
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;
int mark_free = 0;
u64 start;
u64 end;
u64 priv;
struct extent_io_tree *pending_del;
struct extent_io_tree *extent_ins;
struct pending_extent_op *extent_op;
WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
extent_ins = &extent_root->fs_info->extent_ins;
pending_del = &extent_root->fs_info->pending_del;
while(1) {
ret = find_first_extent_bit(pending_del, 0, &start, &end,
EXTENT_LOCKED);
if (ret)
break;
ret = get_state_private(pending_del, start, &priv);
BUG_ON(ret);
extent_op = (struct pending_extent_op *)(unsigned long)priv;
clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
GFP_NOFS);
ret = pin_down_bytes(trans, extent_root, start,
end + 1 - start, 0);
mark_free = ret > 0;
if (!test_range_bit(extent_ins, start, end,
EXTENT_LOCKED, 0)) {
free_extent:
ret = __free_extent(trans, extent_root,
start, end + 1 - start,
extent_op->orig_parent,
extent_root->root_key.objectid,
extent_op->orig_generation,
extent_op->level, 0, 0, mark_free);
kfree(extent_op);
} else {
kfree(extent_op);
ret = get_state_private(extent_ins, start, &priv);
BUG_ON(ret);
extent_op = (struct pending_extent_op *)
(unsigned long)priv;
clear_extent_bits(extent_ins, start, end,
EXTENT_LOCKED, GFP_NOFS);
if (extent_op->type == PENDING_BACKREF_UPDATE)
goto free_extent;
ret = update_block_group(trans, extent_root, start,
end + 1 - start, 0, mark_free);
BUG_ON(ret);
kfree(extent_op);
}
if (ret)
err = ret;
if (need_resched()) {
mutex_unlock(&extent_root->fs_info->alloc_mutex);
cond_resched();
mutex_lock(&extent_root->fs_info->alloc_mutex);
}
}
return err;
}
/*
* remove an extent from the root, returns 0 on success
*/
static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent,
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 == extent_root) {
struct pending_extent_op *extent_op;
extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
BUG_ON(!extent_op);
extent_op->type = PENDING_EXTENT_DELETE;
extent_op->bytenr = bytenr;
extent_op->num_bytes = num_bytes;
extent_op->parent = parent;
extent_op->orig_parent = parent;
extent_op->generation = ref_generation;
extent_op->orig_generation = ref_generation;
extent_op->level = (int)owner_objectid;
set_extent_bits(&root->fs_info->pending_del,
bytenr, bytenr + num_bytes - 1,
EXTENT_LOCKED, GFP_NOFS);
set_state_private(&root->fs_info->pending_del,
bytenr, (unsigned long)extent_op);
return 0;
}
/* if metadata always pin */
if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
struct btrfs_block_group_cache *cache;
/* btrfs_free_reserved_extent */
cache = btrfs_lookup_block_group(root->fs_info, bytenr);
BUG_ON(!cache);
btrfs_add_free_space(cache, bytenr, num_bytes);
return 0;
}
pin = 1;
}
/* if data pin when any transaction has committed this */
if (ref_generation != trans->transid)
pin = 1;
ret = __free_extent(trans, root, bytenr, num_bytes, parent,
root_objectid, ref_generation, owner_objectid,
owner_offset, pin, pin == 0);
finish_current_insert(trans, root->fs_info->extent_root);
pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
return ret ? ret : pending_ret;
}
int btrfs_free_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent,
u64 root_objectid, u64 ref_generation,
u64 owner_objectid, u64 owner_offset, int pin)
{
int ret;
maybe_lock_mutex(root);
ret = __btrfs_free_extent(trans, root, bytenr, num_bytes, parent,
root_objectid, ref_generation,
owner_objectid, owner_offset, pin);
maybe_unlock_mutex(root);
return 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)
{
int ret;
u64 orig_search_start;
struct btrfs_root * root = orig_root->fs_info->extent_root;
struct btrfs_fs_info *info = root->fs_info;
u64 total_needed = num_bytes;
u64 *last_ptr = NULL;
struct btrfs_block_group_cache *block_group;
int chunk_alloc_done = 0;
int empty_cluster = 2 * 1024 * 1024;
int allowed_chunk_alloc = 0;
WARN_ON(num_bytes < root->sectorsize);
btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
if (orig_root->ref_cows || empty_size)
allowed_chunk_alloc = 1;
if (data & BTRFS_BLOCK_GROUP_METADATA) {
last_ptr = &root->fs_info->last_alloc;
empty_cluster = 256 * 1024;
}
if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD))
last_ptr = &root->fs_info->last_data_alloc;
if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
last_ptr = &root->fs_info->last_log_alloc;
if (!last_ptr == 0 && root->fs_info->last_alloc) {
*last_ptr = root->fs_info->last_alloc + empty_cluster;
}
}
if (last_ptr) {
if (*last_ptr)
hint_byte = *last_ptr;
else
empty_size += empty_cluster;
}
search_start = max(search_start, first_logical_byte(root, 0));
orig_search_start = search_start;
if (search_end == (u64)-1)
search_end = btrfs_super_total_bytes(&info->super_copy);
search_start = max(search_start, hint_byte);
total_needed += empty_size;
new_group:
block_group = btrfs_lookup_block_group(info, search_start);
/*
* Ok this looks a little tricky, buts its really simple. First if we
* didn't find a block group obviously we want to start over.
* Secondly, if the block group we found does not match the type we
* need, and we have a last_ptr and its not 0, chances are the last
* allocation we made was at the end of the block group, so lets go
* ahead and skip the looking through the rest of the block groups and
* start at the beginning. This helps with metadata allocations,
* since you are likely to have a bunch of data block groups to search
* through first before you realize that you need to start over, so go
* ahead and start over and save the time.
*/
if (!block_group || (!block_group_bits(block_group, data) &&
last_ptr && *last_ptr)) {
if (search_start != orig_search_start) {
if (last_ptr && *last_ptr)
*last_ptr = 0;
search_start = orig_search_start;
goto new_group;
} else if (!chunk_alloc_done && allowed_chunk_alloc) {
ret = do_chunk_alloc(trans, root,
num_bytes + 2 * 1024 * 1024,
data, 1);
if (ret < 0) {
struct btrfs_space_info *info;
info = __find_space_info(root->fs_info, data);
goto error;
}
BUG_ON(ret);
chunk_alloc_done = 1;
search_start = orig_search_start;
goto new_group;
} else {
ret = -ENOSPC;
goto error;
}
}
/*
* this is going to seach through all of the existing block groups it
* can find, so if we don't find something we need to see if we can
* allocate what we need.
*/
ret = find_free_space(root, &block_group, &search_start,
total_needed, data);
if (ret == -ENOSPC) {
/*
* instead of allocating, start at the original search start
* and see if there is something to be found, if not then we
* allocate
*/
if (search_start != orig_search_start) {
if (last_ptr && *last_ptr) {
*last_ptr = 0;
total_needed += empty_cluster;
}
search_start = orig_search_start;
goto new_group;
}
/*
* we've already allocated, we're pretty screwed
*/
if (chunk_alloc_done) {
goto error;
} else if (!allowed_chunk_alloc && block_group &&
block_group_bits(block_group, data)) {
block_group->space_info->force_alloc = 1;
goto error;
} else if (!allowed_chunk_alloc) {
goto error;
}
ret = do_chunk_alloc(trans, root, num_bytes + 2 * 1024 * 1024,
data, 1);
if (ret < 0)
goto error;
BUG_ON(ret);
chunk_alloc_done = 1;
if (block_group)
search_start = block_group->key.objectid +
block_group->key.offset;
else
search_start = orig_search_start;
goto new_group;
}
if (ret)
goto error;
search_start = stripe_align(root, search_start);
ins->objectid = search_start;
ins->offset = num_bytes;
if (ins->objectid + num_bytes >= search_end) {
search_start = orig_search_start;
if (chunk_alloc_done) {
ret = -ENOSPC;
goto error;
}
goto new_group;
}
if (ins->objectid + num_bytes >
block_group->key.objectid + block_group->key.offset) {
if (search_start == orig_search_start && chunk_alloc_done) {
ret = -ENOSPC;
goto error;
}
search_start = block_group->key.objectid +
block_group->key.offset;
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 & BTRFS_BLOCK_GROUP_DATA))
trans->block_group = block_group;
ins->offset = num_bytes;
if (last_ptr) {
*last_ptr = ins->objectid + ins->offset;
if (*last_ptr ==
btrfs_super_total_bytes(&root->fs_info->super_copy))
*last_ptr = 0;
}
ret = 0;
error:
return ret;
}
static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
{
struct btrfs_block_group_cache *cache;
struct list_head *l;
printk(KERN_INFO "space_info has %Lu free, is %sfull\n",
info->total_bytes - info->bytes_used - info->bytes_pinned,
(info->full) ? "" : "not ");
spin_lock(&info->lock);
list_for_each(l, &info->block_groups) {
cache = list_entry(l, struct btrfs_block_group_cache, list);
spin_lock(&cache->lock);
printk(KERN_INFO "block group %Lu has %Lu bytes, %Lu used "
"%Lu pinned\n",
cache->key.objectid, cache->key.offset,
btrfs_block_group_used(&cache->item), cache->pinned);
btrfs_dump_free_space(cache, bytes);
spin_unlock(&cache->lock);
}
spin_unlock(&info->lock);
}
static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 num_bytes, u64 min_alloc_size,
u64 empty_size, u64 hint_byte,
u64 search_end, struct btrfs_key *ins,
u64 data)
{
int ret;
u64 search_start = 0;
u64 alloc_profile;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_block_group_cache *cache;
if (data) {
alloc_profile = info->avail_data_alloc_bits &
info->data_alloc_profile;
data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
} else if (root == root->fs_info->chunk_root) {
alloc_profile = info->avail_system_alloc_bits &
info->system_alloc_profile;
data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
} else {
alloc_profile = info->avail_metadata_alloc_bits &
info->metadata_alloc_profile;
data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
}
again:
data = reduce_alloc_profile(root, data);
/*
* the only place that sets empty_size is btrfs_realloc_node, which
* is not called recursively on allocations
*/
if (empty_size || root->ref_cows) {
if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2 * 1024 * 1024,
BTRFS_BLOCK_GROUP_METADATA |
(info->metadata_alloc_profile &
info->avail_metadata_alloc_bits), 0);
}
ret = do_chunk_alloc(trans, root->fs_info->extent_root,
num_bytes + 2 * 1024 * 1024, data, 0);
}
WARN_ON(num_bytes < root->sectorsize);
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);
if (ret == -ENOSPC && num_bytes > min_alloc_size) {
num_bytes = num_bytes >> 1;
num_bytes = num_bytes & ~(root->sectorsize - 1);
num_bytes = max(num_bytes, min_alloc_size);
do_chunk_alloc(trans, root->fs_info->extent_root,
num_bytes, data, 1);
goto again;
}
if (ret) {
struct btrfs_space_info *sinfo;
sinfo = __find_space_info(root->fs_info, data);
printk("allocation failed flags %Lu, wanted %Lu\n",
data, num_bytes);
dump_space_info(sinfo, num_bytes);
BUG();
}
cache = btrfs_lookup_block_group(root->fs_info, ins->objectid);
if (!cache) {
printk(KERN_ERR "Unable to find block group for %Lu\n", ins->objectid);
return -ENOSPC;
}
ret = btrfs_remove_free_space(cache, ins->objectid, ins->offset);
return ret;
}
int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
{
struct btrfs_block_group_cache *cache;
maybe_lock_mutex(root);
cache = btrfs_lookup_block_group(root->fs_info, start);
if (!cache) {
printk(KERN_ERR "Unable to find block group for %Lu\n", start);
maybe_unlock_mutex(root);
return -ENOSPC;
}
btrfs_add_free_space(cache, start, len);
maybe_unlock_mutex(root);
return 0;
}
int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 num_bytes, u64 min_alloc_size,
u64 empty_size, u64 hint_byte,
u64 search_end, struct btrfs_key *ins,
u64 data)
{
int ret;
maybe_lock_mutex(root);
ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
empty_size, hint_byte, search_end, ins,
data);
maybe_unlock_mutex(root);
return ret;
}
static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 parent,
u64 root_objectid, u64 ref_generation,
u64 owner, u64 owner_offset,
struct btrfs_key *ins)
{
int ret;
int pending_ret;
u64 super_used;
u64 root_used;
u64 num_bytes = ins->offset;
u32 sizes[2];
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_root *extent_root = info->extent_root;
struct btrfs_extent_item *extent_item;
struct btrfs_extent_ref *ref;
struct btrfs_path *path;
struct btrfs_key keys[2];
if (parent == 0)
parent = ins->objectid;
/* block accounting for super block */
spin_lock_irq(&info->delalloc_lock);
super_used = btrfs_super_bytes_used(&info->super_copy);
btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
spin_unlock_irq(&info->delalloc_lock);
/* block accounting for root item */
root_used = btrfs_root_used(&root->root_item);
btrfs_set_root_used(&root->root_item, root_used + num_bytes);
if (root == extent_root) {
struct pending_extent_op *extent_op;
extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
BUG_ON(!extent_op);
extent_op->type = PENDING_EXTENT_INSERT;
extent_op->bytenr = ins->objectid;
extent_op->num_bytes = ins->offset;
extent_op->parent = parent;
extent_op->orig_parent = 0;
extent_op->generation = ref_generation;
extent_op->orig_generation = 0;
extent_op->level = (int)owner;
set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
ins->objectid + ins->offset - 1,
EXTENT_LOCKED, GFP_NOFS);
set_state_private(&root->fs_info->extent_ins,
ins->objectid, (unsigned long)extent_op);
goto update_block;
}
memcpy(&keys[0], ins, sizeof(*ins));
keys[1].objectid = ins->objectid;
keys[1].type = BTRFS_EXTENT_REF_KEY;
keys[1].offset = parent;
sizes[0] = sizeof(*extent_item);
sizes[1] = sizeof(*ref);
path = btrfs_alloc_path();
BUG_ON(!path);
ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
sizes, 2);
BUG_ON(ret);
extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_extent_item);
btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
struct btrfs_extent_ref);
btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
btrfs_set_ref_objectid(path->nodes[0], ref, owner);
btrfs_set_ref_offset(path->nodes[0], ref, owner_offset);
btrfs_set_ref_num_refs(path->nodes[0], ref, 1);
btrfs_mark_buffer_dirty(path->nodes[0]);
trans->alloc_exclude_start = 0;
trans->alloc_exclude_nr = 0;
btrfs_free_path(path);
finish_current_insert(trans, extent_root);
pending_ret = del_pending_extents(trans, extent_root);
if (ret)
goto out;
if (pending_ret) {
ret = pending_ret;
goto out;
}
update_block:
ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
if (ret) {
printk("update block group failed for %Lu %Lu\n",
ins->objectid, ins->offset);
BUG();
}
out:
return ret;
}
int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 parent,
u64 root_objectid, u64 ref_generation,
u64 owner, u64 owner_offset,
struct btrfs_key *ins)
{
int ret;
if (root_objectid == BTRFS_TREE_LOG_OBJECTID)
return 0;
maybe_lock_mutex(root);
ret = __btrfs_alloc_reserved_extent(trans, root, parent,
root_objectid, ref_generation,
owner, owner_offset, ins);
maybe_unlock_mutex(root);
return ret;
}
/*
* this is used by the tree logging recovery code. It records that
* an extent has been allocated and makes sure to clear the free
* space cache bits as well
*/
int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 parent,
u64 root_objectid, u64 ref_generation,
u64 owner, u64 owner_offset,
struct btrfs_key *ins)
{
int ret;
struct btrfs_block_group_cache *block_group;
maybe_lock_mutex(root);
block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
cache_block_group(root, block_group);
ret = btrfs_remove_free_space(block_group, ins->objectid, ins->offset);
BUG_ON(ret);
ret = __btrfs_alloc_reserved_extent(trans, root, parent,
root_objectid, ref_generation,
owner, owner_offset, ins);
maybe_unlock_mutex(root);
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 parent, u64 min_alloc_size,
u64 root_objectid, u64 ref_generation,
u64 owner_objectid, u64 owner_offset,
u64 empty_size, u64 hint_byte,
u64 search_end, struct btrfs_key *ins, u64 data)
{
int ret;
maybe_lock_mutex(root);
ret = __btrfs_reserve_extent(trans, root, num_bytes,
min_alloc_size, empty_size, hint_byte,
search_end, ins, data);
BUG_ON(ret);
if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
ret = __btrfs_alloc_reserved_extent(trans, root, parent,
root_objectid, ref_generation,
owner_objectid, owner_offset, ins);
BUG_ON(ret);
}
maybe_unlock_mutex(root);
return ret;
}
struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u32 blocksize)
{
struct extent_buffer *buf;
buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
if (!buf)
return ERR_PTR(-ENOMEM);
btrfs_set_header_generation(buf, trans->transid);
btrfs_tree_lock(buf);
clean_tree_block(trans, root, buf);
btrfs_set_buffer_uptodate(buf);
if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
set_extent_dirty(&root->dirty_log_pages, buf->start,
buf->start + buf->len - 1, GFP_NOFS);
} else {
set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
buf->start + buf->len - 1, GFP_NOFS);
}
trans->blocks_used++;
return buf;
}
/*
* 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 parent,
u64 root_objectid,
u64 ref_generation,
int level,
u64 hint,
u64 empty_size)
{
struct btrfs_key ins;
int ret;
struct extent_buffer *buf;
ret = btrfs_alloc_extent(trans, root, blocksize, parent, blocksize,
root_objectid, ref_generation, level, 0,
empty_size, hint, (u64)-1, &ins, 0);
if (ret) {
BUG_ON(ret > 0);
return ERR_PTR(ret);
}
buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize);
return buf;
}
int btrfs_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;
cond_resched();
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;
mutex_lock(&root->fs_info->alloc_mutex);
ret = __btrfs_free_extent(trans, root, disk_bytenr,
btrfs_file_extent_disk_num_bytes(leaf, fi),
leaf->start, leaf_owner, leaf_generation,
key.objectid, key.offset, 0);
mutex_unlock(&root->fs_info->alloc_mutex);
BUG_ON(ret);
atomic_inc(&root->fs_info->throttle_gen);
wake_up(&root->fs_info->transaction_throttle);
cond_resched();
}
return 0;
}
static int noinline cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_leaf_ref *ref)
{
int i;
int ret;
struct btrfs_extent_info *info = ref->extents;
for (i = 0; i < ref->nritems; i++) {
mutex_lock(&root->fs_info->alloc_mutex);
ret = __btrfs_free_extent(trans, root, info->bytenr,
info->num_bytes, ref->bytenr,
ref->owner, ref->generation,
info->objectid, info->offset, 0);
mutex_unlock(&root->fs_info->alloc_mutex);
atomic_inc(&root->fs_info->throttle_gen);
wake_up(&root->fs_info->transaction_throttle);
cond_resched();
BUG_ON(ret);
info++;
}
return 0;
}
int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start, u64 len,
u32 *refs)
{
int ret;
ret = btrfs_lookup_extent_ref(NULL, root, start, len, refs);
BUG_ON(ret);
#if 0 // some debugging code in case we see problems here
/* if the refs count is one, it won't get increased again. But
* if the ref count is > 1, someone may be decreasing it at
* the same time we are.
*/
if (*refs != 1) {
struct extent_buffer *eb = NULL;
eb = btrfs_find_create_tree_block(root, start, len);
if (eb)
btrfs_tree_lock(eb);
mutex_lock(&root->fs_info->alloc_mutex);
ret = lookup_extent_ref(NULL, root, start, len, refs);
BUG_ON(ret);
mutex_unlock(&root->fs_info->alloc_mutex);
if (eb) {
btrfs_tree_unlock(eb);
free_extent_buffer(eb);
}
if (*refs == 1) {
printk("block %llu went down to one during drop_snap\n",
(unsigned long long)start);
}
}
#endif
cond_resched();
return ret;
}
/*
* 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;
u64 ptr_gen;
struct extent_buffer *next;
struct extent_buffer *cur;
struct extent_buffer *parent;
struct btrfs_leaf_ref *ref;
u32 blocksize;
int ret;
u32 refs;
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
ret = drop_snap_lookup_refcount(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 (btrfs_header_level(cur) != *level)
WARN_ON(1);
if (path->slots[*level] >=
btrfs_header_nritems(cur))
break;
if (*level == 0) {
ret = btrfs_drop_leaf_ref(trans, root, cur);
BUG_ON(ret);
break;
}
bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
blocksize = btrfs_level_size(root, *level - 1);
ret = drop_snap_lookup_refcount(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]++;
mutex_lock(&root->fs_info->alloc_mutex);
ret = __btrfs_free_extent(trans, root, bytenr,
blocksize, parent->start,
root_owner, root_gen, 0, 0, 1);
BUG_ON(ret);
mutex_unlock(&root->fs_info->alloc_mutex);
atomic_inc(&root->fs_info->throttle_gen);
wake_up(&root->fs_info->transaction_throttle);
cond_resched();
continue;
}
/*
* at this point, we have a single ref, and since the
* only place referencing this extent is a dead root
* the reference count should never go higher.
* So, we don't need to check it again
*/
if (*level == 1) {
ref = btrfs_lookup_leaf_ref(root, bytenr);
if (ref) {
ret = cache_drop_leaf_ref(trans, root, ref);
BUG_ON(ret);
btrfs_remove_leaf_ref(root, ref);
btrfs_free_leaf_ref(root, ref);
*level = 0;
break;
}
if (printk_ratelimit())
printk("leaf ref miss for bytenr %llu\n",
(unsigned long long)bytenr);
}
next = btrfs_find_tree_block(root, bytenr, blocksize);
if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
free_extent_buffer(next);
next = read_tree_block(root, bytenr, blocksize,
ptr_gen);
cond_resched();
#if 0
/*
* this is a debugging check and can go away
* the ref should never go all the way down to 1
* at this point
*/
ret = lookup_extent_ref(NULL, root, bytenr, blocksize,
&refs);
BUG_ON(ret);
WARN_ON(refs != 1);
#endif
}
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;
cond_resched();
}
out:
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
if (path->nodes[*level] == root->node) {
parent = path->nodes[*level];
bytenr = path->nodes[*level]->start;
} else {
parent = path->nodes[*level + 1];
bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
}
blocksize = btrfs_level_size(root, *level);
root_owner = btrfs_header_owner(parent);
root_gen = btrfs_header_generation(parent);
mutex_lock(&root->fs_info->alloc_mutex);
ret = __btrfs_free_extent(trans, root, bytenr, blocksize,
parent->start, root_owner, root_gen,
0, 0, 1);
mutex_unlock(&root->fs_info->alloc_mutex);
free_extent_buffer(path->nodes[*level]);
path->nodes[*level] = NULL;
*level += 1;
BUG_ON(ret);
cond_resched();
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 {
struct extent_buffer *parent;
if (path->nodes[*level] == root->node)
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,
parent->start,
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;
WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex));
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)));
/*
* unlock our path, this is safe because only this
* function is allowed to delete this snapshot
*/
for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
if (path->nodes[i] && path->locks[i]) {
path->locks[i] = 0;
btrfs_tree_unlock(path->nodes[i]);
}
}
}
while(1) {
wret = walk_down_tree(trans, root, path, &level);
if (wret > 0)
break;
if (wret < 0)
ret = wret;
wret = walk_up_tree(trans, root, path, &level);
if (wret > 0)
break;
if (wret < 0)
ret = wret;
if (trans->transaction->in_commit) {
ret = -EAGAIN;
break;
}
atomic_inc(&root->fs_info->throttle_gen);
wake_up(&root->fs_info->transaction_throttle);
}
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)
{
struct btrfs_block_group_cache *block_group;
struct rb_node *n;
mutex_lock(&info->alloc_mutex);
spin_lock(&info->block_group_cache_lock);
while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
block_group = rb_entry(n, struct btrfs_block_group_cache,
cache_node);
btrfs_remove_free_space_cache(block_group);
rb_erase(&block_group->cache_node,
&info->block_group_cache_tree);
spin_lock(&block_group->space_info->lock);
list_del(&block_group->list);
spin_unlock(&block_group->space_info->lock);
kfree(block_group);
}
spin_unlock(&info->block_group_cache_lock);
mutex_unlock(&info->alloc_mutex);
return 0;
}
static unsigned long calc_ra(unsigned long start, unsigned long last,
unsigned long nr)
{
return min(last, start + nr - 1);
}
static int noinline relocate_inode_pages(struct inode *inode, u64 start,
u64 len)
{
u64 page_start;
u64 page_end;
unsigned long last_index;
unsigned long i;
struct page *page;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct file_ra_state *ra;
unsigned long total_read = 0;
unsigned long ra_pages;
struct btrfs_ordered_extent *ordered;
struct btrfs_trans_handle *trans;
ra = kzalloc(sizeof(*ra), GFP_NOFS);
mutex_lock(&inode->i_mutex);
i = start >> PAGE_CACHE_SHIFT;
last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
ra_pages = BTRFS_I(inode)->root->fs_info->bdi.ra_pages;
file_ra_state_init(ra, inode->i_mapping);
for (; i <= last_index; i++) {
if (total_read % ra_pages == 0) {
btrfs_force_ra(inode->i_mapping, ra, NULL, i,
calc_ra(i, last_index, ra_pages));
}
total_read++;
again:
if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
goto truncate_racing;
page = grab_cache_page(inode->i_mapping, i);
if (!page) {
goto out_unlock;
}
if (!PageUptodate(page)) {
btrfs_readpage(NULL, page);
lock_page(page);
if (!PageUptodate(page)) {
unlock_page(page);
page_cache_release(page);
goto out_unlock;
}
}
wait_on_page_writeback(page);
page_start = (u64)page->index << PAGE_CACHE_SHIFT;
page_end = page_start + PAGE_CACHE_SIZE - 1;
lock_extent(io_tree, page_start, page_end, GFP_NOFS);
ordered = btrfs_lookup_ordered_extent(inode, page_start);
if (ordered) {
unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
unlock_page(page);
page_cache_release(page);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
set_page_extent_mapped(page);
/*
* make sure page_mkwrite is called for this page if userland
* wants to change it from mmap
*/
clear_page_dirty_for_io(page);
btrfs_set_extent_delalloc(inode, page_start, page_end);
set_page_dirty(page);
unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
unlock_page(page);
page_cache_release(page);
}
out_unlock:
/* we have to start the IO in order to get the ordered extents
* instantiated. This allows the relocation to code to wait
* for all the ordered extents to hit the disk.
*
* Otherwise, it would constantly loop over the same extents
* because the old ones don't get deleted until the IO is
* started
*/
btrfs_fdatawrite_range(inode->i_mapping, start, start + len - 1,
WB_SYNC_NONE);
kfree(ra);
trans = btrfs_start_transaction(BTRFS_I(inode)->root, 1);
if (trans) {
btrfs_end_transaction(trans, BTRFS_I(inode)->root);
mark_inode_dirty(inode);
}
mutex_unlock(&inode->i_mutex);
return 0;
truncate_racing:
vmtruncate(inode, inode->i_size);
balance_dirty_pages_ratelimited_nr(inode->i_mapping,
total_read);
goto out_unlock;
}
/*
* The back references tell us which tree holds a ref on a block,
* but it is possible for the tree root field in the reference to
* reflect the original root before a snapshot was made. In this
* case we should search through all the children of a given root
* to find potential holders of references on a block.
*
* Instead, we do something a little less fancy and just search
* all the roots for a given key/block combination.
*/
static int find_root_for_ref(struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_key *key0,
int level,
int file_key,
struct btrfs_root **found_root,
u64 bytenr)
{
struct btrfs_key root_location;
struct btrfs_root *cur_root = *found_root;
struct btrfs_file_extent_item *file_extent;
u64 root_search_start = BTRFS_FS_TREE_OBJECTID;
u64 found_bytenr;
int ret;
root_location.offset = (u64)-1;
root_location.type = BTRFS_ROOT_ITEM_KEY;
path->lowest_level = level;
path->reada = 0;
while(1) {
ret = btrfs_search_slot(NULL, cur_root, key0, path, 0, 0);
found_bytenr = 0;
if (ret == 0 && file_key) {
struct extent_buffer *leaf = path->nodes[0];
file_extent = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(leaf, file_extent) ==
BTRFS_FILE_EXTENT_REG) {
found_bytenr =
btrfs_file_extent_disk_bytenr(leaf,
file_extent);
}
} else if (!file_key) {
if (path->nodes[level])
found_bytenr = path->nodes[level]->start;
}
btrfs_release_path(cur_root, path);
if (found_bytenr == bytenr) {
*found_root = cur_root;
ret = 0;
goto out;
}
ret = btrfs_search_root(root->fs_info->tree_root,
root_search_start, &root_search_start);
if (ret)
break;
root_location.objectid = root_search_start;
cur_root = btrfs_read_fs_root_no_name(root->fs_info,
&root_location);
if (!cur_root) {
ret = 1;
break;
}
}
out:
path->lowest_level = 0;
return ret;
}
/*
* note, this releases the path
*/
static int noinline relocate_one_reference(struct btrfs_root *extent_root,
struct btrfs_path *path,
struct btrfs_key *extent_key,
u64 *last_file_objectid,
u64 *last_file_offset,
u64 *last_file_root,
u64 last_extent)
{
struct inode *inode;
struct btrfs_root *found_root;
struct btrfs_key root_location;
struct btrfs_key found_key;
struct btrfs_extent_ref *ref;
u64 ref_root;
u64 ref_gen;
u64 ref_objectid;
u64 ref_offset;
int ret;
int level;
WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_extent_ref);
ref_root = btrfs_ref_root(path->nodes[0], ref);
ref_gen = btrfs_ref_generation(path->nodes[0], ref);
ref_objectid = btrfs_ref_objectid(path->nodes[0], ref);
ref_offset = btrfs_ref_offset(path->nodes[0], ref);
btrfs_release_path(extent_root, path);
root_location.objectid = ref_root;
if (ref_gen == 0)
root_location.offset = 0;
else
root_location.offset = (u64)-1;
root_location.type = BTRFS_ROOT_ITEM_KEY;
found_root = btrfs_read_fs_root_no_name(extent_root->fs_info,
&root_location);
BUG_ON(!found_root);
mutex_unlock(&extent_root->fs_info->alloc_mutex);
if (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
found_key.objectid = ref_objectid;
found_key.type = BTRFS_EXTENT_DATA_KEY;
found_key.offset = ref_offset;
level = 0;
if (last_extent == extent_key->objectid &&
*last_file_objectid == ref_objectid &&
*last_file_offset == ref_offset &&
*last_file_root == ref_root)
goto out;
ret = find_root_for_ref(extent_root, path, &found_key,
level, 1, &found_root,
extent_key->objectid);
if (ret)
goto out;
if (last_extent == extent_key->objectid &&
*last_file_objectid == ref_objectid &&
*last_file_offset == ref_offset &&
*last_file_root == ref_root)
goto out;
inode = btrfs_iget_locked(extent_root->fs_info->sb,
ref_objectid, found_root);
if (inode->i_state & I_NEW) {
/* the inode and parent dir are two different roots */
BTRFS_I(inode)->root = found_root;
BTRFS_I(inode)->location.objectid = ref_objectid;
BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
BTRFS_I(inode)->location.offset = 0;
btrfs_read_locked_inode(inode);
unlock_new_inode(inode);
}
/* this can happen if the reference is not against
* the latest version of the tree root
*/
if (is_bad_inode(inode))
goto out;
*last_file_objectid = inode->i_ino;
*last_file_root = found_root->root_key.objectid;
*last_file_offset = ref_offset;
relocate_inode_pages(inode, ref_offset, extent_key->offset);
iput(inode);
} else {
struct btrfs_trans_handle *trans;
struct extent_buffer *eb;
int needs_lock = 0;
eb = read_tree_block(found_root, extent_key->objectid,
extent_key->offset, 0);
btrfs_tree_lock(eb);
level = btrfs_header_level(eb);
if (level == 0)
btrfs_item_key_to_cpu(eb, &found_key, 0);
else
btrfs_node_key_to_cpu(eb, &found_key, 0);
btrfs_tree_unlock(eb);
free_extent_buffer(eb);
ret = find_root_for_ref(extent_root, path, &found_key,
level, 0, &found_root,
extent_key->objectid);
if (ret)
goto out;
/*
* right here almost anything could happen to our key,
* but that's ok. The cow below will either relocate it
* or someone else will have relocated it. Either way,
* it is in a different spot than it was before and
* we're happy.
*/
trans = btrfs_start_transaction(found_root, 1);
if (found_root == extent_root->fs_info->extent_root ||
found_root == extent_root->fs_info->chunk_root ||
found_root == extent_root->fs_info->dev_root) {
needs_lock = 1;
mutex_lock(&extent_root->fs_info->alloc_mutex);
}
path->lowest_level = level;
path->reada = 2;
ret = btrfs_search_slot(trans, found_root, &found_key, path,
0, 1);
path->lowest_level = 0;
btrfs_release_path(found_root, path);
if (found_root == found_root->fs_info->extent_root)
btrfs_extent_post_op(trans, found_root);
if (needs_lock)
mutex_unlock(&extent_root->fs_info->alloc_mutex);
btrfs_end_transaction(trans, found_root);
}
out:
mutex_lock(&extent_root->fs_info->alloc_mutex);
return 0;
}
static int noinline del_extent_zero(struct btrfs_root *extent_root,
struct btrfs_path *path,
struct btrfs_key *extent_key)
{
int ret;
struct btrfs_trans_handle *trans;
trans = btrfs_start_transaction(extent_root, 1);
ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
if (ret > 0) {
ret = -EIO;
goto out;
}
if (ret < 0)
goto out;
ret = btrfs_del_item(trans, extent_root, path);
out:
btrfs_end_transaction(trans, extent_root);
return ret;
}
static int noinline relocate_one_extent(struct btrfs_root *extent_root,
struct btrfs_path *path,
struct btrfs_key *extent_key)
{
struct btrfs_key key;
struct btrfs_key found_key;
struct extent_buffer *leaf;
u64 last_file_objectid = 0;
u64 last_file_root = 0;
u64 last_file_offset = (u64)-1;
u64 last_extent = 0;
u32 nritems;
u32 item_size;
int ret = 0;
if (extent_key->objectid == 0) {
ret = del_extent_zero(extent_root, path, extent_key);
goto out;
}
key.objectid = extent_key->objectid;
key.type = BTRFS_EXTENT_REF_KEY;
key.offset = 0;
while(1) {
ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
if (ret < 0)
goto out;
ret = 0;
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
if (path->slots[0] == nritems) {
ret = btrfs_next_leaf(extent_root, path);
if (ret > 0) {
ret = 0;
goto out;
}
if (ret < 0)
goto out;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != extent_key->objectid) {
break;
}
if (found_key.type != BTRFS_EXTENT_REF_KEY) {
break;
}
key.offset = found_key.offset + 1;
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
ret = relocate_one_reference(extent_root, path, extent_key,
&last_file_objectid,
&last_file_offset,
&last_file_root, last_extent);
if (ret)
goto out;
last_extent = extent_key->objectid;
}
ret = 0;
out:
btrfs_release_path(extent_root, path);
return ret;
}
static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
{
u64 num_devices;
u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
num_devices = root->fs_info->fs_devices->num_devices;
if (num_devices == 1) {
stripped |= BTRFS_BLOCK_GROUP_DUP;
stripped = flags & ~stripped;
/* turn raid0 into single device chunks */
if (flags & BTRFS_BLOCK_GROUP_RAID0)
return stripped;
/* turn mirroring into duplication */
if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10))
return stripped | BTRFS_BLOCK_GROUP_DUP;
return flags;
} else {
/* they already had raid on here, just return */
if (flags & stripped)
return flags;
stripped |= BTRFS_BLOCK_GROUP_DUP;
stripped = flags & ~stripped;
/* switch duplicated blocks with raid1 */
if (flags & BTRFS_BLOCK_GROUP_DUP)
return stripped | BTRFS_BLOCK_GROUP_RAID1;
/* turn single device chunks into raid0 */
return stripped | BTRFS_BLOCK_GROUP_RAID0;
}
return flags;
}
int __alloc_chunk_for_shrink(struct btrfs_root *root,
struct btrfs_block_group_cache *shrink_block_group,
int force)
{
struct btrfs_trans_handle *trans;
u64 new_alloc_flags;
u64 calc;
spin_lock(&shrink_block_group->lock);
if (btrfs_block_group_used(&shrink_block_group->item) > 0) {
spin_unlock(&shrink_block_group->lock);
mutex_unlock(&root->fs_info->alloc_mutex);
trans = btrfs_start_transaction(root, 1);
mutex_lock(&root->fs_info->alloc_mutex);
spin_lock(&shrink_block_group->lock);
new_alloc_flags = update_block_group_flags(root,
shrink_block_group->flags);
if (new_alloc_flags != shrink_block_group->flags) {
calc =
btrfs_block_group_used(&shrink_block_group->item);
} else {
calc = shrink_block_group->key.offset;
}
spin_unlock(&shrink_block_group->lock);
do_chunk_alloc(trans, root->fs_info->extent_root,
calc + 2 * 1024 * 1024, new_alloc_flags, force);
mutex_unlock(&root->fs_info->alloc_mutex);
btrfs_end_transaction(trans, root);
mutex_lock(&root->fs_info->alloc_mutex);
} else
spin_unlock(&shrink_block_group->lock);
return 0;
}
int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 shrink_start)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *tree_root = root->fs_info->tree_root;
struct btrfs_path *path;
u64 cur_byte;
u64 total_found;
u64 shrink_last_byte;
struct btrfs_block_group_cache *shrink_block_group;
struct btrfs_key key;
struct btrfs_key found_key;
struct extent_buffer *leaf;
u32 nritems;
int ret;
int progress;
mutex_lock(&root->fs_info->alloc_mutex);
shrink_block_group = btrfs_lookup_block_group(root->fs_info,
shrink_start);
BUG_ON(!shrink_block_group);
shrink_last_byte = shrink_block_group->key.objectid +
shrink_block_group->key.offset;
shrink_block_group->space_info->total_bytes -=
shrink_block_group->key.offset;
path = btrfs_alloc_path();
root = root->fs_info->extent_root;
path->reada = 2;
printk("btrfs relocating block group %llu flags %llu\n",
(unsigned long long)shrink_start,
(unsigned long long)shrink_block_group->flags);
__alloc_chunk_for_shrink(root, shrink_block_group, 1);
again:
shrink_block_group->ro = 1;
total_found = 0;
progress = 0;
key.objectid = shrink_start;
key.offset = 0;
key.type = 0;
cur_byte = key.objectid;
mutex_unlock(&root->fs_info->alloc_mutex);
btrfs_start_delalloc_inodes(root);
btrfs_wait_ordered_extents(tree_root, 0);
mutex_lock(&root->fs_info->alloc_mutex);
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
if (ret < 0)
goto out;
if (ret == 0) {
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid + found_key.offset > shrink_start &&
found_key.objectid < shrink_last_byte) {
cur_byte = found_key.objectid;
key.objectid = cur_byte;
}
}
btrfs_release_path(root, path);
while(1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
next:
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
if (ret == 1) {
ret = 0;
break;
}
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid >= shrink_last_byte)
break;
if (progress && need_resched()) {
memcpy(&key, &found_key, sizeof(key));
cond_resched();
btrfs_release_path(root, path);
btrfs_search_slot(NULL, root, &key, path, 0, 0);
progress = 0;
goto next;
}
progress = 1;
if (btrfs_key_type(&found_key) != BTRFS_EXTENT_ITEM_KEY ||
found_key.objectid + found_key.offset <= cur_byte) {
memcpy(&key, &found_key, sizeof(key));
key.offset++;
path->slots[0]++;
goto next;
}
total_found++;
cur_byte = found_key.objectid + found_key.offset;
key.objectid = cur_byte;
btrfs_release_path(root, path);
ret = relocate_one_extent(root, path, &found_key);
__alloc_chunk_for_shrink(root, shrink_block_group, 0);
}
btrfs_release_path(root, path);
if (total_found > 0) {
printk("btrfs relocate found %llu last extent was %llu\n",
(unsigned long long)total_found,
(unsigned long long)found_key.objectid);
mutex_unlock(&root->fs_info->alloc_mutex);
trans = btrfs_start_transaction(tree_root, 1);
btrfs_commit_transaction(trans, tree_root);
btrfs_clean_old_snapshots(tree_root);
btrfs_start_delalloc_inodes(root);
btrfs_wait_ordered_extents(tree_root, 0);
trans = btrfs_start_transaction(tree_root, 1);
btrfs_commit_transaction(trans, tree_root);
mutex_lock(&root->fs_info->alloc_mutex);
goto again;
}
/*
* we've freed all the extents, now remove the block
* group item from the tree
*/
mutex_unlock(&root->fs_info->alloc_mutex);
trans = btrfs_start_transaction(root, 1);
mutex_lock(&root->fs_info->alloc_mutex);
memcpy(&key, &shrink_block_group->key, sizeof(key));
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0)
ret = -EIO;
if (ret < 0) {
btrfs_end_transaction(trans, root);
goto out;
}
spin_lock(&root->fs_info->block_group_cache_lock);
rb_erase(&shrink_block_group->cache_node,
&root->fs_info->block_group_cache_tree);
spin_unlock(&root->fs_info->block_group_cache_lock);
ret = btrfs_remove_free_space(shrink_block_group, key.objectid,
key.offset);
if (ret) {
btrfs_end_transaction(trans, root);
goto out;
}
/*
memset(shrink_block_group, 0, sizeof(*shrink_block_group));
kfree(shrink_block_group);
*/
btrfs_del_item(trans, root, path);
btrfs_release_path(root, path);
mutex_unlock(&root->fs_info->alloc_mutex);
btrfs_commit_transaction(trans, root);
mutex_lock(&root->fs_info->alloc_mutex);
/* the code to unpin extents might set a few bits in the free
* space cache for this range again
*/
/* XXX? */
ret = btrfs_remove_free_space(shrink_block_group, key.objectid,
key.offset);
out:
btrfs_free_path(path);
mutex_unlock(&root->fs_info->alloc_mutex);
return ret;
}
int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
struct btrfs_key *key)
{
int ret = 0;
struct btrfs_key found_key;
struct extent_buffer *leaf;
int slot;
ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
if (ret < 0)
goto out;
while(1) {
slot = path->slots[0];
leaf = path->nodes[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret == 0)
continue;
if (ret < 0)
goto out;
break;
}
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid >= key->objectid &&
found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
ret = 0;
goto out;
}
path->slots[0]++;
}
ret = -ENOENT;
out:
return ret;
}
int btrfs_read_block_groups(struct btrfs_root *root)
{
struct btrfs_path *path;
int ret;
struct btrfs_block_group_cache *cache;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_space_info *space_info;
struct btrfs_key key;
struct btrfs_key found_key;
struct extent_buffer *leaf;
root = info->extent_root;
key.objectid = 0;
key.offset = 0;
btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
mutex_lock(&root->fs_info->alloc_mutex);
while(1) {
ret = find_first_block_group(root, path, &key);
if (ret > 0) {
ret = 0;
goto error;
}
if (ret != 0)
goto error;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
cache = kzalloc(sizeof(*cache), GFP_NOFS);
if (!cache) {
ret = -ENOMEM;
break;
}
spin_lock_init(&cache->lock);
INIT_LIST_HEAD(&cache->list);
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));
key.objectid = found_key.objectid + found_key.offset;
btrfs_release_path(root, path);
cache->flags = btrfs_block_group_flags(&cache->item);
ret = update_space_info(info, cache->flags, found_key.offset,
btrfs_block_group_used(&cache->item),
&space_info);
BUG_ON(ret);
cache->space_info = space_info;
spin_lock(&space_info->lock);
list_add(&cache->list, &space_info->block_groups);
spin_unlock(&space_info->lock);
ret = btrfs_add_block_group_cache(root->fs_info, cache);
BUG_ON(ret);
if (key.objectid >=
btrfs_super_total_bytes(&info->super_copy))
break;
}
ret = 0;
error:
btrfs_free_path(path);
mutex_unlock(&root->fs_info->alloc_mutex);
return ret;
}
int btrfs_make_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytes_used,
u64 type, u64 chunk_objectid, u64 chunk_offset,
u64 size)
{
int ret;
struct btrfs_root *extent_root;
struct btrfs_block_group_cache *cache;
WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
extent_root = root->fs_info->extent_root;
root->fs_info->last_trans_new_blockgroup = trans->transid;
cache = kzalloc(sizeof(*cache), GFP_NOFS);
if (!cache)
return -ENOMEM;
cache->key.objectid = chunk_offset;
cache->key.offset = size;
spin_lock_init(&cache->lock);
INIT_LIST_HEAD(&cache->list);
btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
btrfs_set_block_group_used(&cache->item, bytes_used);
btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
cache->flags = type;
btrfs_set_block_group_flags(&cache->item, type);
ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
&cache->space_info);
BUG_ON(ret);
spin_lock(&cache->space_info->lock);
list_add(&cache->list, &cache->space_info->block_groups);
spin_unlock(&cache->space_info->lock);
ret = btrfs_add_block_group_cache(root->fs_info, cache);
BUG_ON(ret);
ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
sizeof(cache->item));
BUG_ON(ret);
finish_current_insert(trans, extent_root);
ret = del_pending_extents(trans, extent_root);
BUG_ON(ret);
set_avail_alloc_bits(extent_root->fs_info, type);
return 0;
}