- 根目录:
- fs
- btrfs
- extent-tree.c
C++程序
|
8952行
|
233.56 KB
/*
* 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 <linux/sort.h>
#include <linux/rcupdate.h>
#include <linux/kthread.h>
#include <linux/slab.h>
#include "compat.h"
#include "hash.h"
#include "ctree.h"
#include "disk-io.h"
#include "print-tree.h"
#include "transaction.h"
#include "volumes.h"
#include "locking.h"
#include "free-space-cache.h"
/* control flags for do_chunk_alloc's force field
* CHUNK_ALLOC_NO_FORCE means to only allocate a chunk
* if we really need one.
*
* CHUNK_ALLOC_FORCE means it must try to allocate one
*
* CHUNK_ALLOC_LIMITED means to only try and allocate one
* if we have very few chunks already allocated. This is
* used as part of the clustering code to help make sure
* we have a good pool of storage to cluster in, without
* filling the FS with empty chunks
*
*/
enum {
CHUNK_ALLOC_NO_FORCE = 0,
CHUNK_ALLOC_FORCE = 1,
CHUNK_ALLOC_LIMITED = 2,
};
static int update_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, int alloc);
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 owner_objectid,
u64 owner_offset, int refs_to_drop,
struct btrfs_delayed_extent_op *extra_op);
static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
struct extent_buffer *leaf,
struct btrfs_extent_item *ei);
static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 parent, u64 root_objectid,
u64 flags, u64 owner, u64 offset,
struct btrfs_key *ins, int ref_mod);
static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 parent, u64 root_objectid,
u64 flags, struct btrfs_disk_key *key,
int level, struct btrfs_key *ins);
static int do_chunk_alloc(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root, u64 alloc_bytes,
u64 flags, int force);
static int find_next_key(struct btrfs_path *path, int level,
struct btrfs_key *key);
static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
int dump_block_groups);
static noinline int
block_group_cache_done(struct btrfs_block_group_cache *cache)
{
smp_mb();
return cache->cached == BTRFS_CACHE_FINISHED;
}
static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
{
return (cache->flags & bits) == bits;
}
void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
{
atomic_inc(&cache->count);
}
void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
{
if (atomic_dec_and_test(&cache->count)) {
WARN_ON(cache->pinned > 0);
WARN_ON(cache->reserved > 0);
WARN_ON(cache->reserved_pinned > 0);
kfree(cache);
}
}
/*
* this adds the block group to the fs_info rb tree for the block group
* cache
*/
static 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;
}
}
if (ret)
btrfs_get_block_group(ret);
spin_unlock(&info->block_group_cache_lock);
return ret;
}
static int add_excluded_extent(struct btrfs_root *root,
u64 start, u64 num_bytes)
{
u64 end = start + num_bytes - 1;
set_extent_bits(&root->fs_info->freed_extents[0],
start, end, EXTENT_UPTODATE, GFP_NOFS);
set_extent_bits(&root->fs_info->freed_extents[1],
start, end, EXTENT_UPTODATE, GFP_NOFS);
return 0;
}
static void free_excluded_extents(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
u64 start, end;
start = cache->key.objectid;
end = start + cache->key.offset - 1;
clear_extent_bits(&root->fs_info->freed_extents[0],
start, end, EXTENT_UPTODATE, GFP_NOFS);
clear_extent_bits(&root->fs_info->freed_extents[1],
start, end, EXTENT_UPTODATE, GFP_NOFS);
}
static int exclude_super_stripes(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
u64 bytenr;
u64 *logical;
int stripe_len;
int i, nr, ret;
if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
cache->bytes_super += stripe_len;
ret = add_excluded_extent(root, cache->key.objectid,
stripe_len);
BUG_ON(ret);
}
for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
cache->key.objectid, bytenr,
0, &logical, &nr, &stripe_len);
BUG_ON(ret);
while (nr--) {
cache->bytes_super += stripe_len;
ret = add_excluded_extent(root, logical[nr],
stripe_len);
BUG_ON(ret);
}
kfree(logical);
}
return 0;
}
static struct btrfs_caching_control *
get_caching_control(struct btrfs_block_group_cache *cache)
{
struct btrfs_caching_control *ctl;
spin_lock(&cache->lock);
if (cache->cached != BTRFS_CACHE_STARTED) {
spin_unlock(&cache->lock);
return NULL;
}
/* We're loading it the fast way, so we don't have a caching_ctl. */
if (!cache->caching_ctl) {
spin_unlock(&cache->lock);
return NULL;
}
ctl = cache->caching_ctl;
atomic_inc(&ctl->count);
spin_unlock(&cache->lock);
return ctl;
}
static void put_caching_control(struct btrfs_caching_control *ctl)
{
if (atomic_dec_and_test(&ctl->count))
kfree(ctl);
}
/*
* 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 u64 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, total_added = 0;
int ret;
while (start < end) {
ret = find_first_extent_bit(info->pinned_extents, start,
&extent_start, &extent_end,
EXTENT_DIRTY | EXTENT_UPTODATE);
if (ret)
break;
if (extent_start <= start) {
start = extent_end + 1;
} else if (extent_start > start && extent_start < end) {
size = extent_start - start;
total_added += size;
ret = btrfs_add_free_space(block_group, start,
size);
BUG_ON(ret);
start = extent_end + 1;
} else {
break;
}
}
if (start < end) {
size = end - start;
total_added += size;
ret = btrfs_add_free_space(block_group, start, size);
BUG_ON(ret);
}
return total_added;
}
static int caching_kthread(void *data)
{
struct btrfs_block_group_cache *block_group = data;
struct btrfs_fs_info *fs_info = block_group->fs_info;
struct btrfs_caching_control *caching_ctl = block_group->caching_ctl;
struct btrfs_root *extent_root = fs_info->extent_root;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key key;
u64 total_found = 0;
u64 last = 0;
u32 nritems;
int ret = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
/*
* We don't want to deadlock with somebody trying to allocate a new
* extent for the extent root while also trying to search the extent
* root to add free space. So we skip locking and search the commit
* root, since its read-only
*/
path->skip_locking = 1;
path->search_commit_root = 1;
path->reada = 2;
key.objectid = last;
key.offset = 0;
key.type = BTRFS_EXTENT_ITEM_KEY;
again:
mutex_lock(&caching_ctl->mutex);
/* need to make sure the commit_root doesn't disappear */
down_read(&fs_info->extent_commit_sem);
ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
if (ret < 0)
goto err;
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
while (1) {
smp_mb();
if (fs_info->closing > 1) {
last = (u64)-1;
break;
}
if (path->slots[0] < nritems) {
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
} else {
ret = find_next_key(path, 0, &key);
if (ret)
break;
caching_ctl->progress = last;
btrfs_release_path(extent_root, path);
up_read(&fs_info->extent_commit_sem);
mutex_unlock(&caching_ctl->mutex);
if (btrfs_transaction_in_commit(fs_info))
schedule_timeout(1);
else
cond_resched();
goto again;
}
if (key.objectid < block_group->key.objectid) {
path->slots[0]++;
continue;
}
if (key.objectid >= block_group->key.objectid +
block_group->key.offset)
break;
if (key.type == BTRFS_EXTENT_ITEM_KEY) {
total_found += add_new_free_space(block_group,
fs_info, last,
key.objectid);
last = key.objectid + key.offset;
if (total_found > (1024 * 1024 * 2)) {
total_found = 0;
wake_up(&caching_ctl->wait);
}
}
path->slots[0]++;
}
ret = 0;
total_found += add_new_free_space(block_group, fs_info, last,
block_group->key.objectid +
block_group->key.offset);
caching_ctl->progress = (u64)-1;
spin_lock(&block_group->lock);
block_group->caching_ctl = NULL;
block_group->cached = BTRFS_CACHE_FINISHED;
spin_unlock(&block_group->lock);
err:
btrfs_free_path(path);
up_read(&fs_info->extent_commit_sem);
free_excluded_extents(extent_root, block_group);
mutex_unlock(&caching_ctl->mutex);
wake_up(&caching_ctl->wait);
put_caching_control(caching_ctl);
atomic_dec(&block_group->space_info->caching_threads);
btrfs_put_block_group(block_group);
return 0;
}
static int cache_block_group(struct btrfs_block_group_cache *cache,
struct btrfs_trans_handle *trans,
struct btrfs_root *root,
int load_cache_only)
{
struct btrfs_fs_info *fs_info = cache->fs_info;
struct btrfs_caching_control *caching_ctl;
struct task_struct *tsk;
int ret = 0;
smp_mb();
if (cache->cached != BTRFS_CACHE_NO)
return 0;
/*
* We can't do the read from on-disk cache during a commit since we need
* to have the normal tree locking. Also if we are currently trying to
* allocate blocks for the tree root we can't do the fast caching since
* we likely hold important locks.
*/
if (trans && (!trans->transaction->in_commit) &&
(root && root != root->fs_info->tree_root)) {
spin_lock(&cache->lock);
if (cache->cached != BTRFS_CACHE_NO) {
spin_unlock(&cache->lock);
return 0;
}
cache->cached = BTRFS_CACHE_STARTED;
spin_unlock(&cache->lock);
ret = load_free_space_cache(fs_info, cache);
spin_lock(&cache->lock);
if (ret == 1) {
cache->cached = BTRFS_CACHE_FINISHED;
cache->last_byte_to_unpin = (u64)-1;
} else {
cache->cached = BTRFS_CACHE_NO;
}
spin_unlock(&cache->lock);
if (ret == 1) {
free_excluded_extents(fs_info->extent_root, cache);
return 0;
}
}
if (load_cache_only)
return 0;
caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
BUG_ON(!caching_ctl);
INIT_LIST_HEAD(&caching_ctl->list);
mutex_init(&caching_ctl->mutex);
init_waitqueue_head(&caching_ctl->wait);
caching_ctl->block_group = cache;
caching_ctl->progress = cache->key.objectid;
/* one for caching kthread, one for caching block group list */
atomic_set(&caching_ctl->count, 2);
spin_lock(&cache->lock);
if (cache->cached != BTRFS_CACHE_NO) {
spin_unlock(&cache->lock);
kfree(caching_ctl);
return 0;
}
cache->caching_ctl = caching_ctl;
cache->cached = BTRFS_CACHE_STARTED;
spin_unlock(&cache->lock);
down_write(&fs_info->extent_commit_sem);
list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
up_write(&fs_info->extent_commit_sem);
atomic_inc(&cache->space_info->caching_threads);
btrfs_get_block_group(cache);
tsk = kthread_run(caching_kthread, cache, "btrfs-cache-%llu\n",
cache->key.objectid);
if (IS_ERR(tsk)) {
ret = PTR_ERR(tsk);
printk(KERN_ERR "error running thread %d\n", ret);
BUG();
}
return ret;
}
/*
* return the block group that starts at or after bytenr
*/
static 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 the 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 struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
u64 flags)
{
struct list_head *head = &info->space_info;
struct btrfs_space_info *found;
flags &= BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_SYSTEM |
BTRFS_BLOCK_GROUP_METADATA;
rcu_read_lock();
list_for_each_entry_rcu(found, head, list) {
if (found->flags & flags) {
rcu_read_unlock();
return found;
}
}
rcu_read_unlock();
return NULL;
}
/*
* after adding space to the filesystem, we need to clear the full flags
* on all the space infos.
*/
void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
{
struct list_head *head = &info->space_info;
struct btrfs_space_info *found;
rcu_read_lock();
list_for_each_entry_rcu(found, head, list)
found->full = 0;
rcu_read_unlock();
}
static u64 div_factor(u64 num, int factor)
{
if (factor == 10)
return num;
num *= factor;
do_div(num, 10);
return num;
}
static u64 div_factor_fine(u64 num, int factor)
{
if (factor == 100)
return num;
num *= factor;
do_div(num, 100);
return num;
}
u64 btrfs_find_block_group(struct btrfs_root *root,
u64 search_start, u64 search_hint, int owner)
{
struct btrfs_block_group_cache *cache;
u64 used;
u64 last = max(search_hint, search_start);
u64 group_start = 0;
int full_search = 0;
int factor = 9;
int wrapped = 0;
again:
while (1) {
cache = btrfs_lookup_first_block_group(root->fs_info, last);
if (!cache)
break;
spin_lock(&cache->lock);
last = cache->key.objectid + cache->key.offset;
used = btrfs_block_group_used(&cache->item);
if ((full_search || !cache->ro) &&
block_group_bits(cache, BTRFS_BLOCK_GROUP_METADATA)) {
if (used + cache->pinned + cache->reserved <
div_factor(cache->key.offset, factor)) {
group_start = cache->key.objectid;
spin_unlock(&cache->lock);
btrfs_put_block_group(cache);
goto found;
}
}
spin_unlock(&cache->lock);
btrfs_put_block_group(cache);
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 group_start;
}
/* 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);
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);
btrfs_free_path(path);
return ret;
}
/*
* helper function to lookup reference count and flags of extent.
*
* the head node for delayed ref is used to store the sum of all the
* reference count modifications queued up in the rbtree. the head
* node may also store the extent flags to set. This way you can check
* to see what the reference count and extent flags would be if all of
* the delayed refs are not processed.
*/
int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr,
u64 num_bytes, u64 *refs, u64 *flags)
{
struct btrfs_delayed_ref_head *head;
struct btrfs_delayed_ref_root *delayed_refs;
struct btrfs_path *path;
struct btrfs_extent_item *ei;
struct extent_buffer *leaf;
struct btrfs_key key;
u32 item_size;
u64 num_refs;
u64 extent_flags;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = num_bytes;
if (!trans) {
path->skip_locking = 1;
path->search_commit_root = 1;
}
again:
ret = btrfs_search_slot(trans, root->fs_info->extent_root,
&key, path, 0, 0);
if (ret < 0)
goto out_free;
if (ret == 0) {
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
if (item_size >= sizeof(*ei)) {
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item);
num_refs = btrfs_extent_refs(leaf, ei);
extent_flags = btrfs_extent_flags(leaf, ei);
} else {
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
struct btrfs_extent_item_v0 *ei0;
BUG_ON(item_size != sizeof(*ei0));
ei0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item_v0);
num_refs = btrfs_extent_refs_v0(leaf, ei0);
/* FIXME: this isn't correct for data */
extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
#else
BUG();
#endif
}
BUG_ON(num_refs == 0);
} else {
num_refs = 0;
extent_flags = 0;
ret = 0;
}
if (!trans)
goto out;
delayed_refs = &trans->transaction->delayed_refs;
spin_lock(&delayed_refs->lock);
head = btrfs_find_delayed_ref_head(trans, bytenr);
if (head) {
if (!mutex_trylock(&head->mutex)) {
atomic_inc(&head->node.refs);
spin_unlock(&delayed_refs->lock);
btrfs_release_path(root->fs_info->extent_root, path);
mutex_lock(&head->mutex);
mutex_unlock(&head->mutex);
btrfs_put_delayed_ref(&head->node);
goto again;
}
if (head->extent_op && head->extent_op->update_flags)
extent_flags |= head->extent_op->flags_to_set;
else
BUG_ON(num_refs == 0);
num_refs += head->node.ref_mod;
mutex_unlock(&head->mutex);
}
spin_unlock(&delayed_refs->lock);
out:
WARN_ON(num_refs == 0);
if (refs)
*refs = num_refs;
if (flags)
*flags = extent_flags;
out_free:
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.
*
* There are two kinds of back refs. The implicit back refs is optimized
* for pointers in non-shared tree blocks. For a given pointer in a block,
* back refs of this kind provide information about the block's owner tree
* and the pointer's key. These information allow us to find the block by
* b-tree searching. The full back refs is for pointers in tree blocks not
* referenced by their owner trees. The location of tree block is recorded
* in the back refs. Actually the full back refs is generic, and can be
* used in all cases the implicit back refs is used. The major shortcoming
* of the full back refs is its overhead. Every time a tree block gets
* COWed, we have to update back refs entry for all pointers in it.
*
* For a newly allocated tree block, we use implicit back refs for
* pointers in it. This means most tree related operations only involve
* implicit back refs. For a tree block created in old transaction, the
* only way to drop a reference to it is COW it. So we can detect the
* event that tree block loses its owner tree's reference and do the
* back refs conversion.
*
* When a tree block is COW'd through a tree, there are four cases:
*
* The reference count of the block is one and the tree is the block's
* owner tree. Nothing to do in this case.
*
* The reference count of the block is one and the tree is not the
* block's owner tree. In this case, full back refs is used for pointers
* in the block. Remove these full back refs, add implicit back refs for
* every pointers in the new block.
*
* The reference count of the block is greater than one and the tree is
* the block's owner tree. In this case, implicit back refs is used for
* pointers in the block. Add full back refs for every pointers in the
* block, increase lower level extents' reference counts. The original
* implicit back refs are entailed to the new block.
*
* The reference count of the block is greater than one and the tree is
* not the block's owner tree. Add implicit back refs for every pointer in
* the new block, increase lower level extents' reference count.
*
* Back Reference Key composing:
*
* The key objectid corresponds to the first byte in the extent,
* The key type is used to differentiate between types of back refs.
* There are different meanings of the key offset for different types
* of back refs.
*
* 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 for the implicit back refs has fields for:
*
* - Objectid of the subvolume root
* - objectid of the file holding the reference
* - original offset in the file
* - how many bookend extents
*
* The key offset for the implicit back refs is hash of the first
* three fields.
*
* The extent ref structure for the full back refs has field for:
*
* - number of pointers in the tree leaf
*
* The key offset for the implicit back refs is the first byte of
* the tree leaf
*
* When a file extent is allocated, The implicit back refs is used.
* the fields are filled in:
*
* (root_key.objectid, inode objectid, offset in file, 1)
*
* When a file extent is removed file truncation, we find the
* corresponding implicit back refs and check the following fields:
*
* (btrfs_header_owner(leaf), inode objectid, offset in file)
*
* Btree extents can be referenced by:
*
* - Different subvolumes
*
* Both the implicit back refs and the full back refs for tree blocks
* only consist of key. The key offset for the implicit back refs is
* objectid of block's owner tree. The key offset for the full back refs
* is the first byte of parent block.
*
* When implicit back refs is used, information about the lowest key and
* level of the tree block are required. These information are stored in
* tree block info structure.
*/
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 owner, u32 extra_size)
{
struct btrfs_extent_item *item;
struct btrfs_extent_item_v0 *ei0;
struct btrfs_extent_ref_v0 *ref0;
struct btrfs_tree_block_info *bi;
struct extent_buffer *leaf;
struct btrfs_key key;
struct btrfs_key found_key;
u32 new_size = sizeof(*item);
u64 refs;
int ret;
leaf = path->nodes[0];
BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
ei0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item_v0);
refs = btrfs_extent_refs_v0(leaf, ei0);
if (owner == (u64)-1) {
while (1) {
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
return ret;
BUG_ON(ret > 0);
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &found_key,
path->slots[0]);
BUG_ON(key.objectid != found_key.objectid);
if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
path->slots[0]++;
continue;
}
ref0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref_v0);
owner = btrfs_ref_objectid_v0(leaf, ref0);
break;
}
}
btrfs_release_path(root, path);
if (owner < BTRFS_FIRST_FREE_OBJECTID)
new_size += sizeof(*bi);
new_size -= sizeof(*ei0);
ret = btrfs_search_slot(trans, root, &key, path,
new_size + extra_size, 1);
if (ret < 0)
return ret;
BUG_ON(ret);
ret = btrfs_extend_item(trans, root, path, new_size);
BUG_ON(ret);
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
btrfs_set_extent_refs(leaf, item, refs);
/* FIXME: get real generation */
btrfs_set_extent_generation(leaf, item, 0);
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
btrfs_set_extent_flags(leaf, item,
BTRFS_EXTENT_FLAG_TREE_BLOCK |
BTRFS_BLOCK_FLAG_FULL_BACKREF);
bi = (struct btrfs_tree_block_info *)(item + 1);
/* FIXME: get first key of the block */
memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
btrfs_set_tree_block_level(leaf, bi, (int)owner);
} else {
btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
}
btrfs_mark_buffer_dirty(leaf);
return 0;
}
#endif
static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
{
u32 high_crc = ~(u32)0;
u32 low_crc = ~(u32)0;
__le64 lenum;
lenum = cpu_to_le64(root_objectid);
high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
lenum = cpu_to_le64(owner);
low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
lenum = cpu_to_le64(offset);
low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
return ((u64)high_crc << 31) ^ (u64)low_crc;
}
static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
struct btrfs_extent_data_ref *ref)
{
return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
btrfs_extent_data_ref_objectid(leaf, ref),
btrfs_extent_data_ref_offset(leaf, ref));
}
static int match_extent_data_ref(struct extent_buffer *leaf,
struct btrfs_extent_data_ref *ref,
u64 root_objectid, u64 owner, u64 offset)
{
if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
btrfs_extent_data_ref_offset(leaf, ref) != offset)
return 0;
return 1;
}
static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent,
u64 root_objectid,
u64 owner, u64 offset)
{
struct btrfs_key key;
struct btrfs_extent_data_ref *ref;
struct extent_buffer *leaf;
u32 nritems;
int ret;
int recow;
int err = -ENOENT;
key.objectid = bytenr;
if (parent) {
key.type = BTRFS_SHARED_DATA_REF_KEY;
key.offset = parent;
} else {
key.type = BTRFS_EXTENT_DATA_REF_KEY;
key.offset = hash_extent_data_ref(root_objectid,
owner, offset);
}
again:
recow = 0;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0) {
err = ret;
goto fail;
}
if (parent) {
if (!ret)
return 0;
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
key.type = BTRFS_EXTENT_REF_V0_KEY;
btrfs_release_path(root, path);
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0) {
err = ret;
goto fail;
}
if (!ret)
return 0;
#endif
goto fail;
}
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
while (1) {
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
err = ret;
if (ret)
goto fail;
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
recow = 1;
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != bytenr ||
key.type != BTRFS_EXTENT_DATA_REF_KEY)
goto fail;
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_data_ref);
if (match_extent_data_ref(leaf, ref, root_objectid,
owner, offset)) {
if (recow) {
btrfs_release_path(root, path);
goto again;
}
err = 0;
break;
}
path->slots[0]++;
}
fail:
return err;
}
static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent,
u64 root_objectid, u64 owner,
u64 offset, int refs_to_add)
{
struct btrfs_key key;
struct extent_buffer *leaf;
u32 size;
u32 num_refs;
int ret;
key.objectid = bytenr;
if (parent) {
key.type = BTRFS_SHARED_DATA_REF_KEY;
key.offset = parent;
size = sizeof(struct btrfs_shared_data_ref);
} else {
key.type = BTRFS_EXTENT_DATA_REF_KEY;
key.offset = hash_extent_data_ref(root_objectid,
owner, offset);
size = sizeof(struct btrfs_extent_data_ref);
}
ret = btrfs_insert_empty_item(trans, root, path, &key, size);
if (ret && ret != -EEXIST)
goto fail;
leaf = path->nodes[0];
if (parent) {
struct btrfs_shared_data_ref *ref;
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_shared_data_ref);
if (ret == 0) {
btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
} else {
num_refs = btrfs_shared_data_ref_count(leaf, ref);
num_refs += refs_to_add;
btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
}
} else {
struct btrfs_extent_data_ref *ref;
while (ret == -EEXIST) {
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_data_ref);
if (match_extent_data_ref(leaf, ref, root_objectid,
owner, offset))
break;
btrfs_release_path(root, path);
key.offset++;
ret = btrfs_insert_empty_item(trans, root, path, &key,
size);
if (ret && ret != -EEXIST)
goto fail;
leaf = path->nodes[0];
}
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_data_ref);
if (ret == 0) {
btrfs_set_extent_data_ref_root(leaf, ref,
root_objectid);
btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
btrfs_set_extent_data_ref_offset(leaf, ref, offset);
btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
} else {
num_refs = btrfs_extent_data_ref_count(leaf, ref);
num_refs += refs_to_add;
btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
}
}
btrfs_mark_buffer_dirty(leaf);
ret = 0;
fail:
btrfs_release_path(root, path);
return ret;
}
static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
int refs_to_drop)
{
struct btrfs_key key;
struct btrfs_extent_data_ref *ref1 = NULL;
struct btrfs_shared_data_ref *ref2 = NULL;
struct extent_buffer *leaf;
u32 num_refs = 0;
int ret = 0;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
ref1 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_data_ref);
num_refs = btrfs_extent_data_ref_count(leaf, ref1);
} else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
ref2 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_shared_data_ref);
num_refs = btrfs_shared_data_ref_count(leaf, ref2);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
} else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
struct btrfs_extent_ref_v0 *ref0;
ref0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref_v0);
num_refs = btrfs_ref_count_v0(leaf, ref0);
#endif
} else {
BUG();
}
BUG_ON(num_refs < refs_to_drop);
num_refs -= refs_to_drop;
if (num_refs == 0) {
ret = btrfs_del_item(trans, root, path);
} else {
if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
else {
struct btrfs_extent_ref_v0 *ref0;
ref0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref_v0);
btrfs_set_ref_count_v0(leaf, ref0, num_refs);
}
#endif
btrfs_mark_buffer_dirty(leaf);
}
return ret;
}
static noinline u32 extent_data_ref_count(struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_extent_inline_ref *iref)
{
struct btrfs_key key;
struct extent_buffer *leaf;
struct btrfs_extent_data_ref *ref1;
struct btrfs_shared_data_ref *ref2;
u32 num_refs = 0;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (iref) {
if (btrfs_extent_inline_ref_type(leaf, iref) ==
BTRFS_EXTENT_DATA_REF_KEY) {
ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
num_refs = btrfs_extent_data_ref_count(leaf, ref1);
} else {
ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
num_refs = btrfs_shared_data_ref_count(leaf, ref2);
}
} else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
ref1 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_data_ref);
num_refs = btrfs_extent_data_ref_count(leaf, ref1);
} else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
ref2 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_shared_data_ref);
num_refs = btrfs_shared_data_ref_count(leaf, ref2);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
} else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
struct btrfs_extent_ref_v0 *ref0;
ref0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref_v0);
num_refs = btrfs_ref_count_v0(leaf, ref0);
#endif
} else {
WARN_ON(1);
}
return num_refs;
}
static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent,
u64 root_objectid)
{
struct btrfs_key key;
int ret;
key.objectid = bytenr;
if (parent) {
key.type = BTRFS_SHARED_BLOCK_REF_KEY;
key.offset = parent;
} else {
key.type = BTRFS_TREE_BLOCK_REF_KEY;
key.offset = root_objectid;
}
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0)
ret = -ENOENT;
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (ret == -ENOENT && parent) {
btrfs_release_path(root, path);
key.type = BTRFS_EXTENT_REF_V0_KEY;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0)
ret = -ENOENT;
}
#endif
return ret;
}
static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent,
u64 root_objectid)
{
struct btrfs_key key;
int ret;
key.objectid = bytenr;
if (parent) {
key.type = BTRFS_SHARED_BLOCK_REF_KEY;
key.offset = parent;
} else {
key.type = BTRFS_TREE_BLOCK_REF_KEY;
key.offset = root_objectid;
}
ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
btrfs_release_path(root, path);
return ret;
}
static inline int extent_ref_type(u64 parent, u64 owner)
{
int type;
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
if (parent > 0)
type = BTRFS_SHARED_BLOCK_REF_KEY;
else
type = BTRFS_TREE_BLOCK_REF_KEY;
} else {
if (parent > 0)
type = BTRFS_SHARED_DATA_REF_KEY;
else
type = BTRFS_EXTENT_DATA_REF_KEY;
}
return type;
}
static int find_next_key(struct btrfs_path *path, int level,
struct btrfs_key *key)
{
for (; level < BTRFS_MAX_LEVEL; level++) {
if (!path->nodes[level])
break;
if (path->slots[level] + 1 >=
btrfs_header_nritems(path->nodes[level]))
continue;
if (level == 0)
btrfs_item_key_to_cpu(path->nodes[level], key,
path->slots[level] + 1);
else
btrfs_node_key_to_cpu(path->nodes[level], key,
path->slots[level] + 1);
return 0;
}
return 1;
}
/*
* look for inline back ref. if back ref is found, *ref_ret is set
* to the address of inline back ref, and 0 is returned.
*
* if back ref isn't found, *ref_ret is set to the address where it
* should be inserted, and -ENOENT is returned.
*
* if insert is true and there are too many inline back refs, the path
* points to the extent item, and -EAGAIN is returned.
*
* NOTE: inline back refs are ordered in the same way that back ref
* items in the tree are ordered.
*/
static noinline_for_stack
int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_extent_inline_ref **ref_ret,
u64 bytenr, u64 num_bytes,
u64 parent, u64 root_objectid,
u64 owner, u64 offset, int insert)
{
struct btrfs_key key;
struct extent_buffer *leaf;
struct btrfs_extent_item *ei;
struct btrfs_extent_inline_ref *iref;
u64 flags;
u64 item_size;
unsigned long ptr;
unsigned long end;
int extra_size;
int type;
int want;
int ret;
int err = 0;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = num_bytes;
want = extent_ref_type(parent, owner);
if (insert) {
extra_size = btrfs_extent_inline_ref_size(want);
path->keep_locks = 1;
} else
extra_size = -1;
ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
if (ret < 0) {
err = ret;
goto out;
}
BUG_ON(ret);
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
if (!insert) {
err = -ENOENT;
goto out;
}
ret = convert_extent_item_v0(trans, root, path, owner,
extra_size);
if (ret < 0) {
err = ret;
goto out;
}
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
}
#endif
BUG_ON(item_size < sizeof(*ei));
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
flags = btrfs_extent_flags(leaf, ei);
ptr = (unsigned long)(ei + 1);
end = (unsigned long)ei + item_size;
if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
ptr += sizeof(struct btrfs_tree_block_info);
BUG_ON(ptr > end);
} else {
BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA));
}
err = -ENOENT;
while (1) {
if (ptr >= end) {
WARN_ON(ptr > end);
break;
}
iref = (struct btrfs_extent_inline_ref *)ptr;
type = btrfs_extent_inline_ref_type(leaf, iref);
if (want < type)
break;
if (want > type) {
ptr += btrfs_extent_inline_ref_size(type);
continue;
}
if (type == BTRFS_EXTENT_DATA_REF_KEY) {
struct btrfs_extent_data_ref *dref;
dref = (struct btrfs_extent_data_ref *)(&iref->offset);
if (match_extent_data_ref(leaf, dref, root_objectid,
owner, offset)) {
err = 0;
break;
}
if (hash_extent_data_ref_item(leaf, dref) <
hash_extent_data_ref(root_objectid, owner, offset))
break;
} else {
u64 ref_offset;
ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
if (parent > 0) {
if (parent == ref_offset) {
err = 0;
break;
}
if (ref_offset < parent)
break;
} else {
if (root_objectid == ref_offset) {
err = 0;
break;
}
if (ref_offset < root_objectid)
break;
}
}
ptr += btrfs_extent_inline_ref_size(type);
}
if (err == -ENOENT && insert) {
if (item_size + extra_size >=
BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
err = -EAGAIN;
goto out;
}
/*
* To add new inline back ref, we have to make sure
* there is no corresponding back ref item.
* For simplicity, we just do not add new inline back
* ref if there is any kind of item for this block
*/
if (find_next_key(path, 0, &key) == 0 &&
key.objectid == bytenr &&
key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
err = -EAGAIN;
goto out;
}
}
*ref_ret = (struct btrfs_extent_inline_ref *)ptr;
out:
if (insert) {
path->keep_locks = 0;
btrfs_unlock_up_safe(path, 1);
}
return err;
}
/*
* helper to add new inline back ref
*/
static noinline_for_stack
int setup_inline_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_extent_inline_ref *iref,
u64 parent, u64 root_objectid,
u64 owner, u64 offset, int refs_to_add,
struct btrfs_delayed_extent_op *extent_op)
{
struct extent_buffer *leaf;
struct btrfs_extent_item *ei;
unsigned long ptr;
unsigned long end;
unsigned long item_offset;
u64 refs;
int size;
int type;
int ret;
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
item_offset = (unsigned long)iref - (unsigned long)ei;
type = extent_ref_type(parent, owner);
size = btrfs_extent_inline_ref_size(type);
ret = btrfs_extend_item(trans, root, path, size);
BUG_ON(ret);
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
refs = btrfs_extent_refs(leaf, ei);
refs += refs_to_add;
btrfs_set_extent_refs(leaf, ei, refs);
if (extent_op)
__run_delayed_extent_op(extent_op, leaf, ei);
ptr = (unsigned long)ei + item_offset;
end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
if (ptr < end - size)
memmove_extent_buffer(leaf, ptr + size, ptr,
end - size - ptr);
iref = (struct btrfs_extent_inline_ref *)ptr;
btrfs_set_extent_inline_ref_type(leaf, iref, type);
if (type == BTRFS_EXTENT_DATA_REF_KEY) {
struct btrfs_extent_data_ref *dref;
dref = (struct btrfs_extent_data_ref *)(&iref->offset);
btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
btrfs_set_extent_data_ref_offset(leaf, dref, offset);
btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
} else if (type == BTRFS_SHARED_DATA_REF_KEY) {
struct btrfs_shared_data_ref *sref;
sref = (struct btrfs_shared_data_ref *)(iref + 1);
btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
} else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
} else {
btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
}
btrfs_mark_buffer_dirty(leaf);
return 0;
}
static int lookup_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_extent_inline_ref **ref_ret,
u64 bytenr, u64 num_bytes, u64 parent,
u64 root_objectid, u64 owner, u64 offset)
{
int ret;
ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
bytenr, num_bytes, parent,
root_objectid, owner, offset, 0);
if (ret != -ENOENT)
return ret;
btrfs_release_path(root, path);
*ref_ret = NULL;
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
root_objectid);
} else {
ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
root_objectid, owner, offset);
}
return ret;
}
/*
* helper to update/remove inline back ref
*/
static noinline_for_stack
int update_inline_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_extent_inline_ref *iref,
int refs_to_mod,
struct btrfs_delayed_extent_op *extent_op)
{
struct extent_buffer *leaf;
struct btrfs_extent_item *ei;
struct btrfs_extent_data_ref *dref = NULL;
struct btrfs_shared_data_ref *sref = NULL;
unsigned long ptr;
unsigned long end;
u32 item_size;
int size;
int type;
int ret;
u64 refs;
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
refs = btrfs_extent_refs(leaf, ei);
WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
refs += refs_to_mod;
btrfs_set_extent_refs(leaf, ei, refs);
if (extent_op)
__run_delayed_extent_op(extent_op, leaf, ei);
type = btrfs_extent_inline_ref_type(leaf, iref);
if (type == BTRFS_EXTENT_DATA_REF_KEY) {
dref = (struct btrfs_extent_data_ref *)(&iref->offset);
refs = btrfs_extent_data_ref_count(leaf, dref);
} else if (type == BTRFS_SHARED_DATA_REF_KEY) {
sref = (struct btrfs_shared_data_ref *)(iref + 1);
refs = btrfs_shared_data_ref_count(leaf, sref);
} else {
refs = 1;
BUG_ON(refs_to_mod != -1);
}
BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
refs += refs_to_mod;
if (refs > 0) {
if (type == BTRFS_EXTENT_DATA_REF_KEY)
btrfs_set_extent_data_ref_count(leaf, dref, refs);
else
btrfs_set_shared_data_ref_count(leaf, sref, refs);
} else {
size = btrfs_extent_inline_ref_size(type);
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
ptr = (unsigned long)iref;
end = (unsigned long)ei + item_size;
if (ptr + size < end)
memmove_extent_buffer(leaf, ptr, ptr + size,
end - ptr - size);
item_size -= size;
ret = btrfs_truncate_item(trans, root, path, item_size, 1);
BUG_ON(ret);
}
btrfs_mark_buffer_dirty(leaf);
return 0;
}
static noinline_for_stack
int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 num_bytes, u64 parent,
u64 root_objectid, u64 owner,
u64 offset, int refs_to_add,
struct btrfs_delayed_extent_op *extent_op)
{
struct btrfs_extent_inline_ref *iref;
int ret;
ret = lookup_inline_extent_backref(trans, root, path, &iref,
bytenr, num_bytes, parent,
root_objectid, owner, offset, 1);
if (ret == 0) {
BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
ret = update_inline_extent_backref(trans, root, path, iref,
refs_to_add, extent_op);
} else if (ret == -ENOENT) {
ret = setup_inline_extent_backref(trans, root, path, iref,
parent, root_objectid,
owner, offset, refs_to_add,
extent_op);
}
return ret;
}
static int insert_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent, u64 root_objectid,
u64 owner, u64 offset, int refs_to_add)
{
int ret;
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
BUG_ON(refs_to_add != 1);
ret = insert_tree_block_ref(trans, root, path, bytenr,
parent, root_objectid);
} else {
ret = insert_extent_data_ref(trans, root, path, bytenr,
parent, root_objectid,
owner, offset, refs_to_add);
}
return ret;
}
static int remove_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_extent_inline_ref *iref,
int refs_to_drop, int is_data)
{
int ret;
BUG_ON(!is_data && refs_to_drop != 1);
if (iref) {
ret = update_inline_extent_backref(trans, root, path, iref,
-refs_to_drop, NULL);
} else if (is_data) {
ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
} else {
ret = btrfs_del_item(trans, root, path);
}
return ret;
}
static int btrfs_issue_discard(struct block_device *bdev,
u64 start, u64 len)
{
return blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_NOFS, 0);
}
static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
u64 num_bytes, u64 *actual_bytes)
{
int ret;
u64 discarded_bytes = 0;
struct btrfs_multi_bio *multi = NULL;
/* Tell the block device(s) that the sectors can be discarded */
ret = btrfs_map_block(&root->fs_info->mapping_tree, REQ_DISCARD,
bytenr, &num_bytes, &multi, 0);
if (!ret) {
struct btrfs_bio_stripe *stripe = multi->stripes;
int i;
for (i = 0; i < multi->num_stripes; i++, stripe++) {
ret = btrfs_issue_discard(stripe->dev->bdev,
stripe->physical,
stripe->length);
if (!ret)
discarded_bytes += stripe->length;
else if (ret != -EOPNOTSUPP)
break;
}
kfree(multi);
}
if (discarded_bytes && ret == -EOPNOTSUPP)
ret = 0;
if (actual_bytes)
*actual_bytes = discarded_bytes;
return ret;
}
int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent,
u64 root_objectid, u64 owner, u64 offset)
{
int ret;
BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
root_objectid == BTRFS_TREE_LOG_OBJECTID);
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
parent, root_objectid, (int)owner,
BTRFS_ADD_DELAYED_REF, NULL);
} else {
ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
parent, root_objectid, owner, offset,
BTRFS_ADD_DELAYED_REF, NULL);
}
return ret;
}
static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes,
u64 parent, u64 root_objectid,
u64 owner, u64 offset, int refs_to_add,
struct btrfs_delayed_extent_op *extent_op)
{
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_extent_item *item;
u64 refs;
int ret;
int err = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 1;
path->leave_spinning = 1;
/* this will setup the path even if it fails to insert the back ref */
ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
path, bytenr, num_bytes, parent,
root_objectid, owner, offset,
refs_to_add, extent_op);
if (ret == 0)
goto out;
if (ret != -EAGAIN) {
err = ret;
goto out;
}
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
refs = btrfs_extent_refs(leaf, item);
btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
if (extent_op)
__run_delayed_extent_op(extent_op, leaf, item);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(root->fs_info->extent_root, path);
path->reada = 1;
path->leave_spinning = 1;
/* now insert the actual backref */
ret = insert_extent_backref(trans, root->fs_info->extent_root,
path, bytenr, parent, root_objectid,
owner, offset, refs_to_add);
BUG_ON(ret);
out:
btrfs_free_path(path);
return err;
}
static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_delayed_ref_node *node,
struct btrfs_delayed_extent_op *extent_op,
int insert_reserved)
{
int ret = 0;
struct btrfs_delayed_data_ref *ref;
struct btrfs_key ins;
u64 parent = 0;
u64 ref_root = 0;
u64 flags = 0;
ins.objectid = node->bytenr;
ins.offset = node->num_bytes;
ins.type = BTRFS_EXTENT_ITEM_KEY;
ref = btrfs_delayed_node_to_data_ref(node);
if (node->type == BTRFS_SHARED_DATA_REF_KEY)
parent = ref->parent;
else
ref_root = ref->root;
if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
if (extent_op) {
BUG_ON(extent_op->update_key);
flags |= extent_op->flags_to_set;
}
ret = alloc_reserved_file_extent(trans, root,
parent, ref_root, flags,
ref->objectid, ref->offset,
&ins, node->ref_mod);
} else if (node->action == BTRFS_ADD_DELAYED_REF) {
ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
node->num_bytes, parent,
ref_root, ref->objectid,
ref->offset, node->ref_mod,
extent_op);
} else if (node->action == BTRFS_DROP_DELAYED_REF) {
ret = __btrfs_free_extent(trans, root, node->bytenr,
node->num_bytes, parent,
ref_root, ref->objectid,
ref->offset, node->ref_mod,
extent_op);
} else {
BUG();
}
return ret;
}
static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
struct extent_buffer *leaf,
struct btrfs_extent_item *ei)
{
u64 flags = btrfs_extent_flags(leaf, ei);
if (extent_op->update_flags) {
flags |= extent_op->flags_to_set;
btrfs_set_extent_flags(leaf, ei, flags);
}
if (extent_op->update_key) {
struct btrfs_tree_block_info *bi;
BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
bi = (struct btrfs_tree_block_info *)(ei + 1);
btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
}
}
static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_delayed_ref_node *node,
struct btrfs_delayed_extent_op *extent_op)
{
struct btrfs_key key;
struct btrfs_path *path;
struct btrfs_extent_item *ei;
struct extent_buffer *leaf;
u32 item_size;
int ret;
int err = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = node->bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = node->num_bytes;
path->reada = 1;
path->leave_spinning = 1;
ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key,
path, 0, 1);
if (ret < 0) {
err = ret;
goto out;
}
if (ret > 0) {
err = -EIO;
goto out;
}
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
path, (u64)-1, 0);
if (ret < 0) {
err = ret;
goto out;
}
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
}
#endif
BUG_ON(item_size < sizeof(*ei));
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
__run_delayed_extent_op(extent_op, leaf, ei);
btrfs_mark_buffer_dirty(leaf);
out:
btrfs_free_path(path);
return err;
}
static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_delayed_ref_node *node,
struct btrfs_delayed_extent_op *extent_op,
int insert_reserved)
{
int ret = 0;
struct btrfs_delayed_tree_ref *ref;
struct btrfs_key ins;
u64 parent = 0;
u64 ref_root = 0;
ins.objectid = node->bytenr;
ins.offset = node->num_bytes;
ins.type = BTRFS_EXTENT_ITEM_KEY;
ref = btrfs_delayed_node_to_tree_ref(node);
if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
parent = ref->parent;
else
ref_root = ref->root;
BUG_ON(node->ref_mod != 1);
if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
BUG_ON(!extent_op || !extent_op->update_flags ||
!extent_op->update_key);
ret = alloc_reserved_tree_block(trans, root,
parent, ref_root,
extent_op->flags_to_set,
&extent_op->key,
ref->level, &ins);
} else if (node->action == BTRFS_ADD_DELAYED_REF) {
ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
node->num_bytes, parent, ref_root,
ref->level, 0, 1, extent_op);
} else if (node->action == BTRFS_DROP_DELAYED_REF) {
ret = __btrfs_free_extent(trans, root, node->bytenr,
node->num_bytes, parent, ref_root,
ref->level, 0, 1, extent_op);
} else {
BUG();
}
return ret;
}
/* helper function to actually process a single delayed ref entry */
static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_delayed_ref_node *node,
struct btrfs_delayed_extent_op *extent_op,
int insert_reserved)
{
int ret;
if (btrfs_delayed_ref_is_head(node)) {
struct btrfs_delayed_ref_head *head;
/*
* we've hit the end of the chain and we were supposed
* to insert this extent into the tree. But, it got
* deleted before we ever needed to insert it, so all
* we have to do is clean up the accounting
*/
BUG_ON(extent_op);
head = btrfs_delayed_node_to_head(node);
if (insert_reserved) {
btrfs_pin_extent(root, node->bytenr,
node->num_bytes, 1);
if (head->is_data) {
ret = btrfs_del_csums(trans, root,
node->bytenr,
node->num_bytes);
BUG_ON(ret);
}
}
mutex_unlock(&head->mutex);
return 0;
}
if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
node->type == BTRFS_SHARED_BLOCK_REF_KEY)
ret = run_delayed_tree_ref(trans, root, node, extent_op,
insert_reserved);
else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
node->type == BTRFS_SHARED_DATA_REF_KEY)
ret = run_delayed_data_ref(trans, root, node, extent_op,
insert_reserved);
else
BUG();
return ret;
}
static noinline struct btrfs_delayed_ref_node *
select_delayed_ref(struct btrfs_delayed_ref_head *head)
{
struct rb_node *node;
struct btrfs_delayed_ref_node *ref;
int action = BTRFS_ADD_DELAYED_REF;
again:
/*
* select delayed ref of type BTRFS_ADD_DELAYED_REF first.
* this prevents ref count from going down to zero when
* there still are pending delayed ref.
*/
node = rb_prev(&head->node.rb_node);
while (1) {
if (!node)
break;
ref = rb_entry(node, struct btrfs_delayed_ref_node,
rb_node);
if (ref->bytenr != head->node.bytenr)
break;
if (ref->action == action)
return ref;
node = rb_prev(node);
}
if (action == BTRFS_ADD_DELAYED_REF) {
action = BTRFS_DROP_DELAYED_REF;
goto again;
}
return NULL;
}
static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct list_head *cluster)
{
struct btrfs_delayed_ref_root *delayed_refs;
struct btrfs_delayed_ref_node *ref;
struct btrfs_delayed_ref_head *locked_ref = NULL;
struct btrfs_delayed_extent_op *extent_op;
int ret;
int count = 0;
int must_insert_reserved = 0;
delayed_refs = &trans->transaction->delayed_refs;
while (1) {
if (!locked_ref) {
/* pick a new head ref from the cluster list */
if (list_empty(cluster))
break;
locked_ref = list_entry(cluster->next,
struct btrfs_delayed_ref_head, cluster);
/* grab the lock that says we are going to process
* all the refs for this head */
ret = btrfs_delayed_ref_lock(trans, locked_ref);
/*
* we may have dropped the spin lock to get the head
* mutex lock, and that might have given someone else
* time to free the head. If that's true, it has been
* removed from our list and we can move on.
*/
if (ret == -EAGAIN) {
locked_ref = NULL;
count++;
continue;
}
}
/*
* record the must insert reserved flag before we
* drop the spin lock.
*/
must_insert_reserved = locked_ref->must_insert_reserved;
locked_ref->must_insert_reserved = 0;
extent_op = locked_ref->extent_op;
locked_ref->extent_op = NULL;
/*
* locked_ref is the head node, so we have to go one
* node back for any delayed ref updates
*/
ref = select_delayed_ref(locked_ref);
if (!ref) {
/* All delayed refs have been processed, Go ahead
* and send the head node to run_one_delayed_ref,
* so that any accounting fixes can happen
*/
ref = &locked_ref->node;
if (extent_op && must_insert_reserved) {
kfree(extent_op);
extent_op = NULL;
}
if (extent_op) {
spin_unlock(&delayed_refs->lock);
ret = run_delayed_extent_op(trans, root,
ref, extent_op);
BUG_ON(ret);
kfree(extent_op);
cond_resched();
spin_lock(&delayed_refs->lock);
continue;
}
list_del_init(&locked_ref->cluster);
locked_ref = NULL;
}
ref->in_tree = 0;
rb_erase(&ref->rb_node, &delayed_refs->root);
delayed_refs->num_entries--;
spin_unlock(&delayed_refs->lock);
ret = run_one_delayed_ref(trans, root, ref, extent_op,
must_insert_reserved);
BUG_ON(ret);
btrfs_put_delayed_ref(ref);
kfree(extent_op);
count++;
cond_resched();
spin_lock(&delayed_refs->lock);
}
return count;
}
/*
* this starts processing the delayed reference count updates and
* extent insertions we have queued up so far. count can be
* 0, which means to process everything in the tree at the start
* of the run (but not newly added entries), or it can be some target
* number you'd like to process.
*/
int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
struct btrfs_root *root, unsigned long count)
{
struct rb_node *node;
struct btrfs_delayed_ref_root *delayed_refs;
struct btrfs_delayed_ref_node *ref;
struct list_head cluster;
int ret;
int run_all = count == (unsigned long)-1;
int run_most = 0;
if (root == root->fs_info->extent_root)
root = root->fs_info->tree_root;
delayed_refs = &trans->transaction->delayed_refs;
INIT_LIST_HEAD(&cluster);
again:
spin_lock(&delayed_refs->lock);
if (count == 0) {
count = delayed_refs->num_entries * 2;
run_most = 1;
}
while (1) {
if (!(run_all || run_most) &&
delayed_refs->num_heads_ready < 64)
break;
/*
* go find something we can process in the rbtree. We start at
* the beginning of the tree, and then build a cluster
* of refs to process starting at the first one we are able to
* lock
*/
ret = btrfs_find_ref_cluster(trans, &cluster,
delayed_refs->run_delayed_start);
if (ret)
break;
ret = run_clustered_refs(trans, root, &cluster);
BUG_ON(ret < 0);
count -= min_t(unsigned long, ret, count);
if (count == 0)
break;
}
if (run_all) {
node = rb_first(&delayed_refs->root);
if (!node)
goto out;
count = (unsigned long)-1;
while (node) {
ref = rb_entry(node, struct btrfs_delayed_ref_node,
rb_node);
if (btrfs_delayed_ref_is_head(ref)) {
struct btrfs_delayed_ref_head *head;
head = btrfs_delayed_node_to_head(ref);
atomic_inc(&ref->refs);
spin_unlock(&delayed_refs->lock);
mutex_lock(&head->mutex);
mutex_unlock(&head->mutex);
btrfs_put_delayed_ref(ref);
cond_resched();
goto again;
}
node = rb_next(node);
}
spin_unlock(&delayed_refs->lock);
schedule_timeout(1);
goto again;
}
out:
spin_unlock(&delayed_refs->lock);
return 0;
}
int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 flags,
int is_data)
{
struct btrfs_delayed_extent_op *extent_op;
int ret;
extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
if (!extent_op)
return -ENOMEM;
extent_op->flags_to_set = flags;
extent_op->update_flags = 1;
extent_op->update_key = 0;
extent_op->is_data = is_data ? 1 : 0;
ret = btrfs_add_delayed_extent_op(trans, bytenr, num_bytes, extent_op);
if (ret)
kfree(extent_op);
return ret;
}
static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 objectid, u64 offset, u64 bytenr)
{
struct btrfs_delayed_ref_head *head;
struct btrfs_delayed_ref_node *ref;
struct btrfs_delayed_data_ref *data_ref;
struct btrfs_delayed_ref_root *delayed_refs;
struct rb_node *node;
int ret = 0;
ret = -ENOENT;
delayed_refs = &trans->transaction->delayed_refs;
spin_lock(&delayed_refs->lock);
head = btrfs_find_delayed_ref_head(trans, bytenr);
if (!head)
goto out;
if (!mutex_trylock(&head->mutex)) {
atomic_inc(&head->node.refs);
spin_unlock(&delayed_refs->lock);
btrfs_release_path(root->fs_info->extent_root, path);
mutex_lock(&head->mutex);
mutex_unlock(&head->mutex);
btrfs_put_delayed_ref(&head->node);
return -EAGAIN;
}
node = rb_prev(&head->node.rb_node);
if (!node)
goto out_unlock;
ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
if (ref->bytenr != bytenr)
goto out_unlock;
ret = 1;
if (ref->type != BTRFS_EXTENT_DATA_REF_KEY)
goto out_unlock;
data_ref = btrfs_delayed_node_to_data_ref(ref);
node = rb_prev(node);
if (node) {
ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
if (ref->bytenr == bytenr)
goto out_unlock;
}
if (data_ref->root != root->root_key.objectid ||
data_ref->objectid != objectid || data_ref->offset != offset)
goto out_unlock;
ret = 0;
out_unlock:
mutex_unlock(&head->mutex);
out:
spin_unlock(&delayed_refs->lock);
return ret;
}
static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 objectid, u64 offset, u64 bytenr)
{
struct btrfs_root *extent_root = root->fs_info->extent_root;
struct extent_buffer *leaf;
struct btrfs_extent_data_ref *ref;
struct btrfs_extent_inline_ref *iref;
struct btrfs_extent_item *ei;
struct btrfs_key key;
u32 item_size;
int ret;
key.objectid = bytenr;
key.offset = (u64)-1;
key.type = BTRFS_EXTENT_ITEM_KEY;
ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
if (ret < 0)
goto out;
BUG_ON(ret == 0);
ret = -ENOENT;
if (path->slots[0] == 0)
goto out;
path->slots[0]--;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
goto out;
ret = 1;
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
goto out;
}
#endif
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
if (item_size != sizeof(*ei) +
btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
goto out;
if (btrfs_extent_generation(leaf, ei) <=
btrfs_root_last_snapshot(&root->root_item))
goto out;
iref = (struct btrfs_extent_inline_ref *)(ei + 1);
if (btrfs_extent_inline_ref_type(leaf, iref) !=
BTRFS_EXTENT_DATA_REF_KEY)
goto out;
ref = (struct btrfs_extent_data_ref *)(&iref->offset);
if (btrfs_extent_refs(leaf, ei) !=
btrfs_extent_data_ref_count(leaf, ref) ||
btrfs_extent_data_ref_root(leaf, ref) !=
root->root_key.objectid ||
btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
btrfs_extent_data_ref_offset(leaf, ref) != offset)
goto out;
ret = 0;
out:
return ret;
}
int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 offset, u64 bytenr)
{
struct btrfs_path *path;
int ret;
int ret2;
path = btrfs_alloc_path();
if (!path)
return -ENOENT;
do {
ret = check_committed_ref(trans, root, path, objectid,
offset, bytenr);
if (ret && ret != -ENOENT)
goto out;
ret2 = check_delayed_ref(trans, root, path, objectid,
offset, bytenr);
} while (ret2 == -EAGAIN);
if (ret2 && ret2 != -ENOENT) {
ret = ret2;
goto out;
}
if (ret != -ENOENT || ret2 != -ENOENT)
ret = 0;
out:
btrfs_free_path(path);
if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
WARN_ON(ret > 0);
return ret;
}
#if 0
int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct extent_buffer *buf, u32 nr_extents)
{
struct btrfs_key key;
struct btrfs_file_extent_item *fi;
u64 root_gen;
u32 nritems;
int i;
int level;
int ret = 0;
int shared = 0;
if (!root->ref_cows)
return 0;
if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
shared = 0;
root_gen = root->root_key.offset;
} else {
shared = 1;
root_gen = trans->transid - 1;
}
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_gen;
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++;
}
ret = btrfs_add_leaf_ref(root, ref, shared);
if (ret == -EEXIST && shared) {
struct btrfs_leaf_ref *old;
old = btrfs_lookup_leaf_ref(root, ref->bytenr);
BUG_ON(!old);
btrfs_remove_leaf_ref(root, old);
btrfs_free_leaf_ref(root, old);
ret = btrfs_add_leaf_ref(root, ref, shared);
}
WARN_ON(ret);
btrfs_free_leaf_ref(root, ref);
}
out:
return ret;
}
/* when a block goes through cow, we update the reference counts of
* everything that block points to. The internal pointers of the block
* can be in just about any order, and it is likely to have clusters of
* things that are close together and clusters of things that are not.
*
* To help reduce the seeks that come with updating all of these reference
* counts, sort them by byte number before actual updates are done.
*
* struct refsort is used to match byte number to slot in the btree block.
* we sort based on the byte number and then use the slot to actually
* find the item.
*
* struct refsort is smaller than strcut btrfs_item and smaller than
* struct btrfs_key_ptr. Since we're currently limited to the page size
* for a btree block, there's no way for a kmalloc of refsorts for a
* single node to be bigger than a page.
*/
struct refsort {
u64 bytenr;
u32 slot;
};
/*
* for passing into sort()
*/
static int refsort_cmp(const void *a_void, const void *b_void)
{
const struct refsort *a = a_void;
const struct refsort *b = b_void;
if (a->bytenr < b->bytenr)
return -1;
if (a->bytenr > b->bytenr)
return 1;
return 0;
}
#endif
static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf,
int full_backref, int inc)
{
u64 bytenr;
u64 num_bytes;
u64 parent;
u64 ref_root;
u32 nritems;
struct btrfs_key key;
struct btrfs_file_extent_item *fi;
int i;
int level;
int ret = 0;
int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
u64, u64, u64, u64, u64, u64);
ref_root = btrfs_header_owner(buf);
nritems = btrfs_header_nritems(buf);
level = btrfs_header_level(buf);
if (!root->ref_cows && level == 0)
return 0;
if (inc)
process_func = btrfs_inc_extent_ref;
else
process_func = btrfs_free_extent;
if (full_backref)
parent = buf->start;
else
parent = 0;
for (i = 0; i < nritems; i++) {
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;
num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
key.offset -= btrfs_file_extent_offset(buf, fi);
ret = process_func(trans, root, bytenr, num_bytes,
parent, ref_root, key.objectid,
key.offset);
if (ret)
goto fail;
} else {
bytenr = btrfs_node_blockptr(buf, i);
num_bytes = btrfs_level_size(root, level - 1);
ret = process_func(trans, root, bytenr, num_bytes,
parent, ref_root, level - 1, 0);
if (ret)
goto fail;
}
}
return 0;
fail:
BUG();
return ret;
}
int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct extent_buffer *buf, int full_backref)
{
return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
}
int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct extent_buffer *buf, int full_backref)
{
return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
}
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;
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:
if (ret)
return ret;
return 0;
}
static struct btrfs_block_group_cache *
next_block_group(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
struct rb_node *node;
spin_lock(&root->fs_info->block_group_cache_lock);
node = rb_next(&cache->cache_node);
btrfs_put_block_group(cache);
if (node) {
cache = rb_entry(node, struct btrfs_block_group_cache,
cache_node);
btrfs_get_block_group(cache);
} else
cache = NULL;
spin_unlock(&root->fs_info->block_group_cache_lock);
return cache;
}
static int cache_save_setup(struct btrfs_block_group_cache *block_group,
struct btrfs_trans_handle *trans,
struct btrfs_path *path)
{
struct btrfs_root *root = block_group->fs_info->tree_root;
struct inode *inode = NULL;
u64 alloc_hint = 0;
int dcs = BTRFS_DC_ERROR;
int num_pages = 0;
int retries = 0;
int ret = 0;
/*
* If this block group is smaller than 100 megs don't bother caching the
* block group.
*/
if (block_group->key.offset < (100 * 1024 * 1024)) {
spin_lock(&block_group->lock);
block_group->disk_cache_state = BTRFS_DC_WRITTEN;
spin_unlock(&block_group->lock);
return 0;
}
again:
inode = lookup_free_space_inode(root, block_group, path);
if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
ret = PTR_ERR(inode);
btrfs_release_path(root, path);
goto out;
}
if (IS_ERR(inode)) {
BUG_ON(retries);
retries++;
if (block_group->ro)
goto out_free;
ret = create_free_space_inode(root, trans, block_group, path);
if (ret)
goto out_free;
goto again;
}
/*
* We want to set the generation to 0, that way if anything goes wrong
* from here on out we know not to trust this cache when we load up next
* time.
*/
BTRFS_I(inode)->generation = 0;
ret = btrfs_update_inode(trans, root, inode);
WARN_ON(ret);
if (i_size_read(inode) > 0) {
ret = btrfs_truncate_free_space_cache(root, trans, path,
inode);
if (ret)
goto out_put;
}
spin_lock(&block_group->lock);
if (block_group->cached != BTRFS_CACHE_FINISHED) {
/* We're not cached, don't bother trying to write stuff out */
dcs = BTRFS_DC_WRITTEN;
spin_unlock(&block_group->lock);
goto out_put;
}
spin_unlock(&block_group->lock);
num_pages = (int)div64_u64(block_group->key.offset, 1024 * 1024 * 1024);
if (!num_pages)
num_pages = 1;
/*
* Just to make absolutely sure we have enough space, we're going to
* preallocate 12 pages worth of space for each block group. In
* practice we ought to use at most 8, but we need extra space so we can
* add our header and have a terminator between the extents and the
* bitmaps.
*/
num_pages *= 16;
num_pages *= PAGE_CACHE_SIZE;
ret = btrfs_check_data_free_space(inode, num_pages);
if (ret)
goto out_put;
ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
num_pages, num_pages,
&alloc_hint);
if (!ret)
dcs = BTRFS_DC_SETUP;
btrfs_free_reserved_data_space(inode, num_pages);
out_put:
iput(inode);
out_free:
btrfs_release_path(root, path);
out:
spin_lock(&block_group->lock);
block_group->disk_cache_state = dcs;
spin_unlock(&block_group->lock);
return ret;
}
int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_block_group_cache *cache;
int err = 0;
struct btrfs_path *path;
u64 last = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
again:
while (1) {
cache = btrfs_lookup_first_block_group(root->fs_info, last);
while (cache) {
if (cache->disk_cache_state == BTRFS_DC_CLEAR)
break;
cache = next_block_group(root, cache);
}
if (!cache) {
if (last == 0)
break;
last = 0;
continue;
}
err = cache_save_setup(cache, trans, path);
last = cache->key.objectid + cache->key.offset;
btrfs_put_block_group(cache);
}
while (1) {
if (last == 0) {
err = btrfs_run_delayed_refs(trans, root,
(unsigned long)-1);
BUG_ON(err);
}
cache = btrfs_lookup_first_block_group(root->fs_info, last);
while (cache) {
if (cache->disk_cache_state == BTRFS_DC_CLEAR) {
btrfs_put_block_group(cache);
goto again;
}
if (cache->dirty)
break;
cache = next_block_group(root, cache);
}
if (!cache) {
if (last == 0)
break;
last = 0;
continue;
}
if (cache->disk_cache_state == BTRFS_DC_SETUP)
cache->disk_cache_state = BTRFS_DC_NEED_WRITE;
cache->dirty = 0;
last = cache->key.objectid + cache->key.offset;
err = write_one_cache_group(trans, root, path, cache);
BUG_ON(err);
btrfs_put_block_group(cache);
}
while (1) {
/*
* I don't think this is needed since we're just marking our
* preallocated extent as written, but just in case it can't
* hurt.
*/
if (last == 0) {
err = btrfs_run_delayed_refs(trans, root,
(unsigned long)-1);
BUG_ON(err);
}
cache = btrfs_lookup_first_block_group(root->fs_info, last);
while (cache) {
/*
* Really this shouldn't happen, but it could if we
* couldn't write the entire preallocated extent and
* splitting the extent resulted in a new block.
*/
if (cache->dirty) {
btrfs_put_block_group(cache);
goto again;
}
if (cache->disk_cache_state == BTRFS_DC_NEED_WRITE)
break;
cache = next_block_group(root, cache);
}
if (!cache) {
if (last == 0)
break;
last = 0;
continue;
}
btrfs_write_out_cache(root, trans, cache, path);
/*
* If we didn't have an error then the cache state is still
* NEED_WRITE, so we can set it to WRITTEN.
*/
if (cache->disk_cache_state == BTRFS_DC_NEED_WRITE)
cache->disk_cache_state = BTRFS_DC_WRITTEN;
last = cache->key.objectid + cache->key.offset;
btrfs_put_block_group(cache);
}
btrfs_free_path(path);
return 0;
}
int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
{
struct btrfs_block_group_cache *block_group;
int readonly = 0;
block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
if (!block_group || block_group->ro)
readonly = 1;
if (block_group)
btrfs_put_block_group(block_group);
return readonly;
}
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;
int i;
int factor;
if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10))
factor = 2;
else
factor = 1;
found = __find_space_info(info, flags);
if (found) {
spin_lock(&found->lock);
found->total_bytes += total_bytes;
found->disk_total += total_bytes * factor;
found->bytes_used += bytes_used;
found->disk_used += bytes_used * factor;
found->full = 0;
spin_unlock(&found->lock);
*space_info = found;
return 0;
}
found = kzalloc(sizeof(*found), GFP_NOFS);
if (!found)
return -ENOMEM;
for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
INIT_LIST_HEAD(&found->block_groups[i]);
init_rwsem(&found->groups_sem);
spin_lock_init(&found->lock);
found->flags = flags & (BTRFS_BLOCK_GROUP_DATA |
BTRFS_BLOCK_GROUP_SYSTEM |
BTRFS_BLOCK_GROUP_METADATA);
found->total_bytes = total_bytes;
found->disk_total = total_bytes * factor;
found->bytes_used = bytes_used;
found->disk_used = bytes_used * factor;
found->bytes_pinned = 0;
found->bytes_reserved = 0;
found->bytes_readonly = 0;
found->bytes_may_use = 0;
found->full = 0;
found->force_alloc = CHUNK_ALLOC_NO_FORCE;
found->chunk_alloc = 0;
*space_info = found;
list_add_rcu(&found->list, &info->space_info);
atomic_set(&found->caching_threads, 0);
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;
}
}
u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
{
/*
* we add in the count of missing devices because we want
* to make sure that any RAID levels on a degraded FS
* continue to be honored.
*/
u64 num_devices = root->fs_info->fs_devices->rw_devices +
root->fs_info->fs_devices->missing_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 u64 get_alloc_profile(struct btrfs_root *root, u64 flags)
{
if (flags & BTRFS_BLOCK_GROUP_DATA)
flags |= root->fs_info->avail_data_alloc_bits &
root->fs_info->data_alloc_profile;
else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
flags |= root->fs_info->avail_system_alloc_bits &
root->fs_info->system_alloc_profile;
else if (flags & BTRFS_BLOCK_GROUP_METADATA)
flags |= root->fs_info->avail_metadata_alloc_bits &
root->fs_info->metadata_alloc_profile;
return btrfs_reduce_alloc_profile(root, flags);
}
u64 btrfs_get_alloc_profile(struct btrfs_root *root, int data)
{
u64 flags;
if (data)
flags = BTRFS_BLOCK_GROUP_DATA;
else if (root == root->fs_info->chunk_root)
flags = BTRFS_BLOCK_GROUP_SYSTEM;
else
flags = BTRFS_BLOCK_GROUP_METADATA;
return get_alloc_profile(root, flags);
}
void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)
{
BTRFS_I(inode)->space_info = __find_space_info(root->fs_info,
BTRFS_BLOCK_GROUP_DATA);
}
/*
* This will check the space that the inode allocates from to make sure we have
* enough space for bytes.
*/
int btrfs_check_data_free_space(struct inode *inode, u64 bytes)
{
struct btrfs_space_info *data_sinfo;
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 used;
int ret = 0, committed = 0, alloc_chunk = 1;
/* make sure bytes are sectorsize aligned */
bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
if (root == root->fs_info->tree_root) {
alloc_chunk = 0;
committed = 1;
}
data_sinfo = BTRFS_I(inode)->space_info;
if (!data_sinfo)
goto alloc;
again:
/* make sure we have enough space to handle the data first */
spin_lock(&data_sinfo->lock);
used = data_sinfo->bytes_used + data_sinfo->bytes_reserved +
data_sinfo->bytes_pinned + data_sinfo->bytes_readonly +
data_sinfo->bytes_may_use;
if (used + bytes > data_sinfo->total_bytes) {
struct btrfs_trans_handle *trans;
/*
* if we don't have enough free bytes in this space then we need
* to alloc a new chunk.
*/
if (!data_sinfo->full && alloc_chunk) {
u64 alloc_target;
data_sinfo->force_alloc = CHUNK_ALLOC_FORCE;
spin_unlock(&data_sinfo->lock);
alloc:
alloc_target = btrfs_get_alloc_profile(root, 1);
trans = btrfs_join_transaction(root, 1);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = do_chunk_alloc(trans, root->fs_info->extent_root,
bytes + 2 * 1024 * 1024,
alloc_target,
CHUNK_ALLOC_NO_FORCE);
btrfs_end_transaction(trans, root);
if (ret < 0) {
if (ret != -ENOSPC)
return ret;
else
goto commit_trans;
}
if (!data_sinfo) {
btrfs_set_inode_space_info(root, inode);
data_sinfo = BTRFS_I(inode)->space_info;
}
goto again;
}
spin_unlock(&data_sinfo->lock);
/* commit the current transaction and try again */
commit_trans:
if (!committed && !root->fs_info->open_ioctl_trans) {
committed = 1;
trans = btrfs_join_transaction(root, 1);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_commit_transaction(trans, root);
if (ret)
return ret;
goto again;
}
#if 0 /* I hope we never need this code again, just in case */
printk(KERN_ERR "no space left, need %llu, %llu bytes_used, "
"%llu bytes_reserved, " "%llu bytes_pinned, "
"%llu bytes_readonly, %llu may use %llu total\n",
(unsigned long long)bytes,
(unsigned long long)data_sinfo->bytes_used,
(unsigned long long)data_sinfo->bytes_reserved,
(unsigned long long)data_sinfo->bytes_pinned,
(unsigned long long)data_sinfo->bytes_readonly,
(unsigned long long)data_sinfo->bytes_may_use,
(unsigned long long)data_sinfo->total_bytes);
#endif
return -ENOSPC;
}
data_sinfo->bytes_may_use += bytes;
BTRFS_I(inode)->reserved_bytes += bytes;
spin_unlock(&data_sinfo->lock);
return 0;
}
/*
* called when we are clearing an delalloc extent from the
* inode's io_tree or there was an error for whatever reason
* after calling btrfs_check_data_free_space
*/
void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_space_info *data_sinfo;
/* make sure bytes are sectorsize aligned */
bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
data_sinfo = BTRFS_I(inode)->space_info;
spin_lock(&data_sinfo->lock);
data_sinfo->bytes_may_use -= bytes;
BTRFS_I(inode)->reserved_bytes -= bytes;
spin_unlock(&data_sinfo->lock);
}
static void force_metadata_allocation(struct btrfs_fs_info *info)
{
struct list_head *head = &info->space_info;
struct btrfs_space_info *found;
rcu_read_lock();
list_for_each_entry_rcu(found, head, list) {
if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
found->force_alloc = CHUNK_ALLOC_FORCE;
}
rcu_read_unlock();
}
static int should_alloc_chunk(struct btrfs_root *root,
struct btrfs_space_info *sinfo, u64 alloc_bytes,
int force)
{
u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly;
u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved;
u64 thresh;
if (force == CHUNK_ALLOC_FORCE)
return 1;
/*
* in limited mode, we want to have some free space up to
* about 1% of the FS size.
*/
if (force == CHUNK_ALLOC_LIMITED) {
thresh = btrfs_super_total_bytes(&root->fs_info->super_copy);
thresh = max_t(u64, 64 * 1024 * 1024,
div_factor_fine(thresh, 1));
if (num_bytes - num_allocated < thresh)
return 1;
}
/*
* we have two similar checks here, one based on percentage
* and once based on a hard number of 256MB. The idea
* is that if we have a good amount of free
* room, don't allocate a chunk. A good mount is
* less than 80% utilized of the chunks we have allocated,
* or more than 256MB free
*/
if (num_allocated + alloc_bytes + 256 * 1024 * 1024 < num_bytes)
return 0;
if (num_allocated + alloc_bytes < div_factor(num_bytes, 8))
return 0;
thresh = btrfs_super_total_bytes(&root->fs_info->super_copy);
/* 256MB or 5% of the FS */
thresh = max_t(u64, 256 * 1024 * 1024, div_factor_fine(thresh, 5));
if (num_bytes > thresh && sinfo->bytes_used < div_factor(num_bytes, 3))
return 0;
return 1;
}
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;
struct btrfs_fs_info *fs_info = extent_root->fs_info;
int wait_for_alloc = 0;
int ret = 0;
flags = btrfs_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);
again:
spin_lock(&space_info->lock);
if (space_info->force_alloc)
force = space_info->force_alloc;
if (space_info->full) {
spin_unlock(&space_info->lock);
return 0;
}
if (!should_alloc_chunk(extent_root, space_info, alloc_bytes, force)) {
spin_unlock(&space_info->lock);
return 0;
} else if (space_info->chunk_alloc) {
wait_for_alloc = 1;
} else {
space_info->chunk_alloc = 1;
}
spin_unlock(&space_info->lock);
mutex_lock(&fs_info->chunk_mutex);
/*
* The chunk_mutex is held throughout the entirety of a chunk
* allocation, so once we've acquired the chunk_mutex we know that the
* other guy is done and we need to recheck and see if we should
* allocate.
*/
if (wait_for_alloc) {
mutex_unlock(&fs_info->chunk_mutex);
wait_for_alloc = 0;
goto again;
}
/*
* If we have mixed data/metadata chunks we want to make sure we keep
* allocating mixed chunks instead of individual chunks.
*/
if (btrfs_mixed_space_info(space_info))
flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
/*
* if we're doing a data chunk, go ahead and make sure that
* we keep a reasonable number of metadata chunks allocated in the
* FS as well.
*/
if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
fs_info->data_chunk_allocations++;
if (!(fs_info->data_chunk_allocations %
fs_info->metadata_ratio))
force_metadata_allocation(fs_info);
}
ret = btrfs_alloc_chunk(trans, extent_root, flags);
spin_lock(&space_info->lock);
if (ret)
space_info->full = 1;
else
ret = 1;
space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
space_info->chunk_alloc = 0;
spin_unlock(&space_info->lock);
mutex_unlock(&extent_root->fs_info->chunk_mutex);
return ret;
}
/*
* shrink metadata reservation for delalloc
*/
static int shrink_delalloc(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 to_reclaim, int sync)
{
struct btrfs_block_rsv *block_rsv;
struct btrfs_space_info *space_info;
u64 reserved;
u64 max_reclaim;
u64 reclaimed = 0;
long time_left;
int nr_pages = (2 * 1024 * 1024) >> PAGE_CACHE_SHIFT;
int loops = 0;
unsigned long progress;
block_rsv = &root->fs_info->delalloc_block_rsv;
space_info = block_rsv->space_info;
smp_mb();
reserved = space_info->bytes_reserved;
progress = space_info->reservation_progress;
if (reserved == 0)
return 0;
max_reclaim = min(reserved, to_reclaim);
while (loops < 1024) {
/* have the flusher threads jump in and do some IO */
smp_mb();
nr_pages = min_t(unsigned long, nr_pages,
root->fs_info->delalloc_bytes >> PAGE_CACHE_SHIFT);
writeback_inodes_sb_nr_if_idle(root->fs_info->sb, nr_pages);
spin_lock(&space_info->lock);
if (reserved > space_info->bytes_reserved)
reclaimed += reserved - space_info->bytes_reserved;
reserved = space_info->bytes_reserved;
spin_unlock(&space_info->lock);
loops++;
if (reserved == 0 || reclaimed >= max_reclaim)
break;
if (trans && trans->transaction->blocked)
return -EAGAIN;
time_left = schedule_timeout_interruptible(1);
/* We were interrupted, exit */
if (time_left)
break;
/* we've kicked the IO a few times, if anything has been freed,
* exit. There is no sense in looping here for a long time
* when we really need to commit the transaction, or there are
* just too many writers without enough free space
*/
if (loops > 3) {
smp_mb();
if (progress != space_info->reservation_progress)
break;
}
}
return reclaimed >= to_reclaim;
}
/*
* Retries tells us how many times we've called reserve_metadata_bytes. The
* idea is if this is the first call (retries == 0) then we will add to our
* reserved count if we can't make the allocation in order to hold our place
* while we go and try and free up space. That way for retries > 1 we don't try
* and add space, we just check to see if the amount of unused space is >= the
* total space, meaning that our reservation is valid.
*
* However if we don't intend to retry this reservation, pass -1 as retries so
* that it short circuits this logic.
*/
static int reserve_metadata_bytes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv,
u64 orig_bytes, int flush)
{
struct btrfs_space_info *space_info = block_rsv->space_info;
u64 unused;
u64 num_bytes = orig_bytes;
int retries = 0;
int ret = 0;
bool reserved = false;
bool committed = false;
again:
ret = -ENOSPC;
if (reserved)
num_bytes = 0;
spin_lock(&space_info->lock);
unused = space_info->bytes_used + space_info->bytes_reserved +
space_info->bytes_pinned + space_info->bytes_readonly +
space_info->bytes_may_use;
/*
* The idea here is that we've not already over-reserved the block group
* then we can go ahead and save our reservation first and then start
* flushing if we need to. Otherwise if we've already overcommitted
* lets start flushing stuff first and then come back and try to make
* our reservation.
*/
if (unused <= space_info->total_bytes) {
unused = space_info->total_bytes - unused;
if (unused >= num_bytes) {
if (!reserved)
space_info->bytes_reserved += orig_bytes;
ret = 0;
} else {
/*
* Ok set num_bytes to orig_bytes since we aren't
* overocmmitted, this way we only try and reclaim what
* we need.
*/
num_bytes = orig_bytes;
}
} else {
/*
* Ok we're over committed, set num_bytes to the overcommitted
* amount plus the amount of bytes that we need for this
* reservation.
*/
num_bytes = unused - space_info->total_bytes +
(orig_bytes * (retries + 1));
}
/*
* Couldn't make our reservation, save our place so while we're trying
* to reclaim space we can actually use it instead of somebody else
* stealing it from us.
*/
if (ret && !reserved) {
space_info->bytes_reserved += orig_bytes;
reserved = true;
}
spin_unlock(&space_info->lock);
if (!ret)
return 0;
if (!flush)
goto out;
/*
* We do synchronous shrinking since we don't actually unreserve
* metadata until after the IO is completed.
*/
ret = shrink_delalloc(trans, root, num_bytes, 1);
if (ret > 0)
return 0;
else if (ret < 0)
goto out;
/*
* So if we were overcommitted it's possible that somebody else flushed
* out enough space and we simply didn't have enough space to reclaim,
* so go back around and try again.
*/
if (retries < 2) {
retries++;
goto again;
}
spin_lock(&space_info->lock);
/*
* Not enough space to be reclaimed, don't bother committing the
* transaction.
*/
if (space_info->bytes_pinned < orig_bytes)
ret = -ENOSPC;
spin_unlock(&space_info->lock);
if (ret)
goto out;
ret = -EAGAIN;
if (trans || committed)
goto out;
ret = -ENOSPC;
trans = btrfs_join_transaction(root, 1);
if (IS_ERR(trans))
goto out;
ret = btrfs_commit_transaction(trans, root);
if (!ret) {
trans = NULL;
committed = true;
goto again;
}
out:
if (reserved) {
spin_lock(&space_info->lock);
space_info->bytes_reserved -= orig_bytes;
spin_unlock(&space_info->lock);
}
return ret;
}
static struct btrfs_block_rsv *get_block_rsv(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_block_rsv *block_rsv;
if (root->ref_cows)
block_rsv = trans->block_rsv;
else
block_rsv = root->block_rsv;
if (!block_rsv)
block_rsv = &root->fs_info->empty_block_rsv;
return block_rsv;
}
static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
u64 num_bytes)
{
int ret = -ENOSPC;
spin_lock(&block_rsv->lock);
if (block_rsv->reserved >= num_bytes) {
block_rsv->reserved -= num_bytes;
if (block_rsv->reserved < block_rsv->size)
block_rsv->full = 0;
ret = 0;
}
spin_unlock(&block_rsv->lock);
return ret;
}
static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
u64 num_bytes, int update_size)
{
spin_lock(&block_rsv->lock);
block_rsv->reserved += num_bytes;
if (update_size)
block_rsv->size += num_bytes;
else if (block_rsv->reserved >= block_rsv->size)
block_rsv->full = 1;
spin_unlock(&block_rsv->lock);
}
void block_rsv_release_bytes(struct btrfs_block_rsv *block_rsv,
struct btrfs_block_rsv *dest, u64 num_bytes)
{
struct btrfs_space_info *space_info = block_rsv->space_info;
spin_lock(&block_rsv->lock);
if (num_bytes == (u64)-1)
num_bytes = block_rsv->size;
block_rsv->size -= num_bytes;
if (block_rsv->reserved >= block_rsv->size) {
num_bytes = block_rsv->reserved - block_rsv->size;
block_rsv->reserved = block_rsv->size;
block_rsv->full = 1;
} else {
num_bytes = 0;
}
spin_unlock(&block_rsv->lock);
if (num_bytes > 0) {
if (dest) {
spin_lock(&dest->lock);
if (!dest->full) {
u64 bytes_to_add;
bytes_to_add = dest->size - dest->reserved;
bytes_to_add = min(num_bytes, bytes_to_add);
dest->reserved += bytes_to_add;
if (dest->reserved >= dest->size)
dest->full = 1;
num_bytes -= bytes_to_add;
}
spin_unlock(&dest->lock);
}
if (num_bytes) {
spin_lock(&space_info->lock);
space_info->bytes_reserved -= num_bytes;
space_info->reservation_progress++;
spin_unlock(&space_info->lock);
}
}
}
static int block_rsv_migrate_bytes(struct btrfs_block_rsv *src,
struct btrfs_block_rsv *dst, u64 num_bytes)
{
int ret;
ret = block_rsv_use_bytes(src, num_bytes);
if (ret)
return ret;
block_rsv_add_bytes(dst, num_bytes, 1);
return 0;
}
void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv)
{
memset(rsv, 0, sizeof(*rsv));
spin_lock_init(&rsv->lock);
atomic_set(&rsv->usage, 1);
rsv->priority = 6;
INIT_LIST_HEAD(&rsv->list);
}
struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root)
{
struct btrfs_block_rsv *block_rsv;
struct btrfs_fs_info *fs_info = root->fs_info;
block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
if (!block_rsv)
return NULL;
btrfs_init_block_rsv(block_rsv);
block_rsv->space_info = __find_space_info(fs_info,
BTRFS_BLOCK_GROUP_METADATA);
return block_rsv;
}
void btrfs_free_block_rsv(struct btrfs_root *root,
struct btrfs_block_rsv *rsv)
{
if (rsv && atomic_dec_and_test(&rsv->usage)) {
btrfs_block_rsv_release(root, rsv, (u64)-1);
if (!rsv->durable)
kfree(rsv);
}
}
/*
* make the block_rsv struct be able to capture freed space.
* the captured space will re-add to the the block_rsv struct
* after transaction commit
*/
void btrfs_add_durable_block_rsv(struct btrfs_fs_info *fs_info,
struct btrfs_block_rsv *block_rsv)
{
block_rsv->durable = 1;
mutex_lock(&fs_info->durable_block_rsv_mutex);
list_add_tail(&block_rsv->list, &fs_info->durable_block_rsv_list);
mutex_unlock(&fs_info->durable_block_rsv_mutex);
}
int btrfs_block_rsv_add(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv,
u64 num_bytes)
{
int ret;
if (num_bytes == 0)
return 0;
ret = reserve_metadata_bytes(trans, root, block_rsv, num_bytes, 1);
if (!ret) {
block_rsv_add_bytes(block_rsv, num_bytes, 1);
return 0;
}
return ret;
}
int btrfs_block_rsv_check(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv,
u64 min_reserved, int min_factor)
{
u64 num_bytes = 0;
int commit_trans = 0;
int ret = -ENOSPC;
if (!block_rsv)
return 0;
spin_lock(&block_rsv->lock);
if (min_factor > 0)
num_bytes = div_factor(block_rsv->size, min_factor);
if (min_reserved > num_bytes)
num_bytes = min_reserved;
if (block_rsv->reserved >= num_bytes) {
ret = 0;
} else {
num_bytes -= block_rsv->reserved;
if (block_rsv->durable &&
block_rsv->freed[0] + block_rsv->freed[1] >= num_bytes)
commit_trans = 1;
}
spin_unlock(&block_rsv->lock);
if (!ret)
return 0;
if (block_rsv->refill_used) {
ret = reserve_metadata_bytes(trans, root, block_rsv,
num_bytes, 0);
if (!ret) {
block_rsv_add_bytes(block_rsv, num_bytes, 0);
return 0;
}
}
if (commit_trans) {
if (trans)
return -EAGAIN;
trans = btrfs_join_transaction(root, 1);
BUG_ON(IS_ERR(trans));
ret = btrfs_commit_transaction(trans, root);
return 0;
}
return -ENOSPC;
}
int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
struct btrfs_block_rsv *dst_rsv,
u64 num_bytes)
{
return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
}
void btrfs_block_rsv_release(struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv,
u64 num_bytes)
{
struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
if (global_rsv->full || global_rsv == block_rsv ||
block_rsv->space_info != global_rsv->space_info)
global_rsv = NULL;
block_rsv_release_bytes(block_rsv, global_rsv, num_bytes);
}
/*
* helper to calculate size of global block reservation.
* the desired value is sum of space used by extent tree,
* checksum tree and root tree
*/
static u64 calc_global_metadata_size(struct btrfs_fs_info *fs_info)
{
struct btrfs_space_info *sinfo;
u64 num_bytes;
u64 meta_used;
u64 data_used;
int csum_size = btrfs_super_csum_size(&fs_info->super_copy);
#if 0
/*
* per tree used space accounting can be inaccuracy, so we
* can't rely on it.
*/
spin_lock(&fs_info->extent_root->accounting_lock);
num_bytes = btrfs_root_used(&fs_info->extent_root->root_item);
spin_unlock(&fs_info->extent_root->accounting_lock);
spin_lock(&fs_info->csum_root->accounting_lock);
num_bytes += btrfs_root_used(&fs_info->csum_root->root_item);
spin_unlock(&fs_info->csum_root->accounting_lock);
spin_lock(&fs_info->tree_root->accounting_lock);
num_bytes += btrfs_root_used(&fs_info->tree_root->root_item);
spin_unlock(&fs_info->tree_root->accounting_lock);
#endif
sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA);
spin_lock(&sinfo->lock);
data_used = sinfo->bytes_used;
spin_unlock(&sinfo->lock);
sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
spin_lock(&sinfo->lock);
if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA)
data_used = 0;
meta_used = sinfo->bytes_used;
spin_unlock(&sinfo->lock);
num_bytes = (data_used >> fs_info->sb->s_blocksize_bits) *
csum_size * 2;
num_bytes += div64_u64(data_used + meta_used, 50);
if (num_bytes * 3 > meta_used)
num_bytes = div64_u64(meta_used, 3);
return ALIGN(num_bytes, fs_info->extent_root->leafsize << 10);
}
static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
{
struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
struct btrfs_space_info *sinfo = block_rsv->space_info;
u64 num_bytes;
num_bytes = calc_global_metadata_size(fs_info);
spin_lock(&block_rsv->lock);
spin_lock(&sinfo->lock);
block_rsv->size = num_bytes;
num_bytes = sinfo->bytes_used + sinfo->bytes_pinned +
sinfo->bytes_reserved + sinfo->bytes_readonly +
sinfo->bytes_may_use;
if (sinfo->total_bytes > num_bytes) {
num_bytes = sinfo->total_bytes - num_bytes;
block_rsv->reserved += num_bytes;
sinfo->bytes_reserved += num_bytes;
}
if (block_rsv->reserved >= block_rsv->size) {
num_bytes = block_rsv->reserved - block_rsv->size;
sinfo->bytes_reserved -= num_bytes;
sinfo->reservation_progress++;
block_rsv->reserved = block_rsv->size;
block_rsv->full = 1;
}
#if 0
printk(KERN_INFO"global block rsv size %llu reserved %llu\n",
block_rsv->size, block_rsv->reserved);
#endif
spin_unlock(&sinfo->lock);
spin_unlock(&block_rsv->lock);
}
static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
{
struct btrfs_space_info *space_info;
space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
fs_info->chunk_block_rsv.space_info = space_info;
fs_info->chunk_block_rsv.priority = 10;
space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
fs_info->global_block_rsv.space_info = space_info;
fs_info->global_block_rsv.priority = 10;
fs_info->global_block_rsv.refill_used = 1;
fs_info->delalloc_block_rsv.space_info = space_info;
fs_info->trans_block_rsv.space_info = space_info;
fs_info->empty_block_rsv.space_info = space_info;
fs_info->empty_block_rsv.priority = 10;
fs_info->extent_root->block_rsv = &fs_info->global_block_rsv;
fs_info->csum_root->block_rsv = &fs_info->global_block_rsv;
fs_info->dev_root->block_rsv = &fs_info->global_block_rsv;
fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
btrfs_add_durable_block_rsv(fs_info, &fs_info->global_block_rsv);
btrfs_add_durable_block_rsv(fs_info, &fs_info->delalloc_block_rsv);
update_global_block_rsv(fs_info);
}
static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
{
block_rsv_release_bytes(&fs_info->global_block_rsv, NULL, (u64)-1);
WARN_ON(fs_info->delalloc_block_rsv.size > 0);
WARN_ON(fs_info->delalloc_block_rsv.reserved > 0);
WARN_ON(fs_info->trans_block_rsv.size > 0);
WARN_ON(fs_info->trans_block_rsv.reserved > 0);
WARN_ON(fs_info->chunk_block_rsv.size > 0);
WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
}
static u64 calc_trans_metadata_size(struct btrfs_root *root, int num_items)
{
return (root->leafsize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) *
3 * num_items;
}
int btrfs_trans_reserve_metadata(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
int num_items)
{
u64 num_bytes;
int ret;
if (num_items == 0 || root->fs_info->chunk_root == root)
return 0;
num_bytes = calc_trans_metadata_size(root, num_items);
ret = btrfs_block_rsv_add(trans, root, &root->fs_info->trans_block_rsv,
num_bytes);
if (!ret) {
trans->bytes_reserved += num_bytes;
trans->block_rsv = &root->fs_info->trans_block_rsv;
}
return ret;
}
void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
if (!trans->bytes_reserved)
return;
BUG_ON(trans->block_rsv != &root->fs_info->trans_block_rsv);
btrfs_block_rsv_release(root, trans->block_rsv,
trans->bytes_reserved);
trans->bytes_reserved = 0;
}
int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
struct btrfs_block_rsv *dst_rsv = root->orphan_block_rsv;
/*
* one for deleting orphan item, one for updating inode and
* two for calling btrfs_truncate_inode_items.
*
* btrfs_truncate_inode_items is a delete operation, it frees
* more space than it uses in most cases. So two units of
* metadata space should be enough for calling it many times.
* If all of the metadata space is used, we can commit
* transaction and use space it freed.
*/
u64 num_bytes = calc_trans_metadata_size(root, 4);
return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
}
void btrfs_orphan_release_metadata(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 num_bytes = calc_trans_metadata_size(root, 4);
btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);
}
int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,
struct btrfs_pending_snapshot *pending)
{
struct btrfs_root *root = pending->root;
struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
struct btrfs_block_rsv *dst_rsv = &pending->block_rsv;
/*
* two for root back/forward refs, two for directory entries
* and one for root of the snapshot.
*/
u64 num_bytes = calc_trans_metadata_size(root, 5);
dst_rsv->space_info = src_rsv->space_info;
return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
}
static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes)
{
return num_bytes >>= 3;
}
int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *block_rsv = &root->fs_info->delalloc_block_rsv;
u64 to_reserve;
int nr_extents;
int reserved_extents;
int ret;
if (btrfs_transaction_in_commit(root->fs_info))
schedule_timeout(1);
num_bytes = ALIGN(num_bytes, root->sectorsize);
nr_extents = atomic_read(&BTRFS_I(inode)->outstanding_extents) + 1;
reserved_extents = atomic_read(&BTRFS_I(inode)->reserved_extents);
if (nr_extents > reserved_extents) {
nr_extents -= reserved_extents;
to_reserve = calc_trans_metadata_size(root, nr_extents);
} else {
nr_extents = 0;
to_reserve = 0;
}
to_reserve += calc_csum_metadata_size(inode, num_bytes);
ret = reserve_metadata_bytes(NULL, root, block_rsv, to_reserve, 1);
if (ret)
return ret;
atomic_add(nr_extents, &BTRFS_I(inode)->reserved_extents);
atomic_inc(&BTRFS_I(inode)->outstanding_extents);
block_rsv_add_bytes(block_rsv, to_reserve, 1);
if (block_rsv->size > 512 * 1024 * 1024)
shrink_delalloc(NULL, root, to_reserve, 0);
return 0;
}
void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 to_free;
int nr_extents;
int reserved_extents;
num_bytes = ALIGN(num_bytes, root->sectorsize);
atomic_dec(&BTRFS_I(inode)->outstanding_extents);
WARN_ON(atomic_read(&BTRFS_I(inode)->outstanding_extents) < 0);
reserved_extents = atomic_read(&BTRFS_I(inode)->reserved_extents);
do {
int old, new;
nr_extents = atomic_read(&BTRFS_I(inode)->outstanding_extents);
if (nr_extents >= reserved_extents) {
nr_extents = 0;
break;
}
old = reserved_extents;
nr_extents = reserved_extents - nr_extents;
new = reserved_extents - nr_extents;
old = atomic_cmpxchg(&BTRFS_I(inode)->reserved_extents,
reserved_extents, new);
if (likely(old == reserved_extents))
break;
reserved_extents = old;
} while (1);
to_free = calc_csum_metadata_size(inode, num_bytes);
if (nr_extents > 0)
to_free += calc_trans_metadata_size(root, nr_extents);
btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv,
to_free);
}
int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes)
{
int ret;
ret = btrfs_check_data_free_space(inode, num_bytes);
if (ret)
return ret;
ret = btrfs_delalloc_reserve_metadata(inode, num_bytes);
if (ret) {
btrfs_free_reserved_data_space(inode, num_bytes);
return ret;
}
return 0;
}
void btrfs_delalloc_release_space(struct inode *inode, u64 num_bytes)
{
btrfs_delalloc_release_metadata(inode, num_bytes);
btrfs_free_reserved_data_space(inode, num_bytes);
}
static int update_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, int alloc)
{
struct btrfs_block_group_cache *cache = NULL;
struct btrfs_fs_info *info = root->fs_info;
u64 total = num_bytes;
u64 old_val;
u64 byte_in_group;
int factor;
/* block accounting for super block */
spin_lock(&info->delalloc_lock);
old_val = btrfs_super_bytes_used(&info->super_copy);
if (alloc)
old_val += num_bytes;
else
old_val -= num_bytes;
btrfs_set_super_bytes_used(&info->super_copy, old_val);
spin_unlock(&info->delalloc_lock);
while (total) {
cache = btrfs_lookup_block_group(info, bytenr);
if (!cache)
return -1;
if (cache->flags & (BTRFS_BLOCK_GROUP_DUP |
BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10))
factor = 2;
else
factor = 1;
/*
* If this block group has free space cache written out, we
* need to make sure to load it if we are removing space. This
* is because we need the unpinning stage to actually add the
* space back to the block group, otherwise we will leak space.
*/
if (!alloc && cache->cached == BTRFS_CACHE_NO)
cache_block_group(cache, trans, NULL, 1);
byte_in_group = bytenr - cache->key.objectid;
WARN_ON(byte_in_group > cache->key.offset);
spin_lock(&cache->space_info->lock);
spin_lock(&cache->lock);
if (btrfs_super_cache_generation(&info->super_copy) != 0 &&
cache->disk_cache_state < BTRFS_DC_CLEAR)
cache->disk_cache_state = BTRFS_DC_CLEAR;
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;
btrfs_set_block_group_used(&cache->item, old_val);
cache->reserved -= num_bytes;
cache->space_info->bytes_reserved -= num_bytes;
cache->space_info->reservation_progress++;
cache->space_info->bytes_used += num_bytes;
cache->space_info->disk_used += num_bytes * factor;
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
} else {
old_val -= num_bytes;
btrfs_set_block_group_used(&cache->item, old_val);
cache->pinned += num_bytes;
cache->space_info->bytes_pinned += num_bytes;
cache->space_info->bytes_used -= num_bytes;
cache->space_info->disk_used -= num_bytes * factor;
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
set_extent_dirty(info->pinned_extents,
bytenr, bytenr + num_bytes - 1,
GFP_NOFS | __GFP_NOFAIL);
}
btrfs_put_block_group(cache);
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;
u64 bytenr;
cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
if (!cache)
return 0;
bytenr = cache->key.objectid;
btrfs_put_block_group(cache);
return bytenr;
}
static int pin_down_extent(struct btrfs_root *root,
struct btrfs_block_group_cache *cache,
u64 bytenr, u64 num_bytes, int reserved)
{
spin_lock(&cache->space_info->lock);
spin_lock(&cache->lock);
cache->pinned += num_bytes;
cache->space_info->bytes_pinned += num_bytes;
if (reserved) {
cache->reserved -= num_bytes;
cache->space_info->bytes_reserved -= num_bytes;
cache->space_info->reservation_progress++;
}
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
set_extent_dirty(root->fs_info->pinned_extents, bytenr,
bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
return 0;
}
/*
* this function must be called within transaction
*/
int btrfs_pin_extent(struct btrfs_root *root,
u64 bytenr, u64 num_bytes, int reserved)
{
struct btrfs_block_group_cache *cache;
cache = btrfs_lookup_block_group(root->fs_info, bytenr);
BUG_ON(!cache);
pin_down_extent(root, cache, bytenr, num_bytes, reserved);
btrfs_put_block_group(cache);
return 0;
}
/*
* update size of reserved extents. this function may return -EAGAIN
* if 'reserve' is true or 'sinfo' is false.
*/
int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
u64 num_bytes, int reserve, int sinfo)
{
int ret = 0;
if (sinfo) {
struct btrfs_space_info *space_info = cache->space_info;
spin_lock(&space_info->lock);
spin_lock(&cache->lock);
if (reserve) {
if (cache->ro) {
ret = -EAGAIN;
} else {
cache->reserved += num_bytes;
space_info->bytes_reserved += num_bytes;
}
} else {
if (cache->ro)
space_info->bytes_readonly += num_bytes;
cache->reserved -= num_bytes;
space_info->bytes_reserved -= num_bytes;
space_info->reservation_progress++;
}
spin_unlock(&cache->lock);
spin_unlock(&space_info->lock);
} else {
spin_lock(&cache->lock);
if (cache->ro) {
ret = -EAGAIN;
} else {
if (reserve)
cache->reserved += num_bytes;
else
cache->reserved -= num_bytes;
}
spin_unlock(&cache->lock);
}
return ret;
}
int btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_caching_control *next;
struct btrfs_caching_control *caching_ctl;
struct btrfs_block_group_cache *cache;
down_write(&fs_info->extent_commit_sem);
list_for_each_entry_safe(caching_ctl, next,
&fs_info->caching_block_groups, list) {
cache = caching_ctl->block_group;
if (block_group_cache_done(cache)) {
cache->last_byte_to_unpin = (u64)-1;
list_del_init(&caching_ctl->list);
put_caching_control(caching_ctl);
} else {
cache->last_byte_to_unpin = caching_ctl->progress;
}
}
if (fs_info->pinned_extents == &fs_info->freed_extents[0])
fs_info->pinned_extents = &fs_info->freed_extents[1];
else
fs_info->pinned_extents = &fs_info->freed_extents[0];
up_write(&fs_info->extent_commit_sem);
update_global_block_rsv(fs_info);
return 0;
}
static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_block_group_cache *cache = NULL;
u64 len;
while (start <= end) {
if (!cache ||
start >= cache->key.objectid + cache->key.offset) {
if (cache)
btrfs_put_block_group(cache);
cache = btrfs_lookup_block_group(fs_info, start);
BUG_ON(!cache);
}
len = cache->key.objectid + cache->key.offset - start;
len = min(len, end + 1 - start);
if (start < cache->last_byte_to_unpin) {
len = min(len, cache->last_byte_to_unpin - start);
btrfs_add_free_space(cache, start, len);
}
start += len;
spin_lock(&cache->space_info->lock);
spin_lock(&cache->lock);
cache->pinned -= len;
cache->space_info->bytes_pinned -= len;
if (cache->ro) {
cache->space_info->bytes_readonly += len;
} else if (cache->reserved_pinned > 0) {
len = min(len, cache->reserved_pinned);
cache->reserved_pinned -= len;
cache->space_info->bytes_reserved += len;
}
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
}
if (cache)
btrfs_put_block_group(cache);
return 0;
}
int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_io_tree *unpin;
struct btrfs_block_rsv *block_rsv;
struct btrfs_block_rsv *next_rsv;
u64 start;
u64 end;
int idx;
int ret;
if (fs_info->pinned_extents == &fs_info->freed_extents[0])
unpin = &fs_info->freed_extents[1];
else
unpin = &fs_info->freed_extents[0];
while (1) {
ret = find_first_extent_bit(unpin, 0, &start, &end,
EXTENT_DIRTY);
if (ret)
break;
if (btrfs_test_opt(root, DISCARD))
ret = btrfs_discard_extent(root, start,
end + 1 - start, NULL);
clear_extent_dirty(unpin, start, end, GFP_NOFS);
unpin_extent_range(root, start, end);
cond_resched();
}
mutex_lock(&fs_info->durable_block_rsv_mutex);
list_for_each_entry_safe(block_rsv, next_rsv,
&fs_info->durable_block_rsv_list, list) {
idx = trans->transid & 0x1;
if (block_rsv->freed[idx] > 0) {
block_rsv_add_bytes(block_rsv,
block_rsv->freed[idx], 0);
block_rsv->freed[idx] = 0;
}
if (atomic_read(&block_rsv->usage) == 0) {
btrfs_block_rsv_release(root, block_rsv, (u64)-1);
if (block_rsv->freed[0] == 0 &&
block_rsv->freed[1] == 0) {
list_del_init(&block_rsv->list);
kfree(block_rsv);
}
} else {
btrfs_block_rsv_release(root, block_rsv, 0);
}
}
mutex_unlock(&fs_info->durable_block_rsv_mutex);
return 0;
}
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 owner_objectid,
u64 owner_offset, int refs_to_drop,
struct btrfs_delayed_extent_op *extent_op)
{
struct btrfs_key key;
struct btrfs_path *path;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_root *extent_root = info->extent_root;
struct extent_buffer *leaf;
struct btrfs_extent_item *ei;
struct btrfs_extent_inline_ref *iref;
int ret;
int is_data;
int extent_slot = 0;
int found_extent = 0;
int num_to_del = 1;
u32 item_size;
u64 refs;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 1;
path->leave_spinning = 1;
is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
BUG_ON(!is_data && refs_to_drop != 1);
ret = lookup_extent_backref(trans, extent_root, path, &iref,
bytenr, num_bytes, parent,
root_objectid, owner_objectid,
owner_offset);
if (ret == 0) {
extent_slot = path->slots[0];
while (extent_slot >= 0) {
btrfs_item_key_to_cpu(path->nodes[0], &key,
extent_slot);
if (key.objectid != bytenr)
break;
if (key.type == BTRFS_EXTENT_ITEM_KEY &&
key.offset == num_bytes) {
found_extent = 1;
break;
}
if (path->slots[0] - extent_slot > 5)
break;
extent_slot--;
}
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
if (found_extent && item_size < sizeof(*ei))
found_extent = 0;
#endif
if (!found_extent) {
BUG_ON(iref);
ret = remove_extent_backref(trans, extent_root, path,
NULL, refs_to_drop,
is_data);
BUG_ON(ret);
btrfs_release_path(extent_root, path);
path->leave_spinning = 1;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = num_bytes;
ret = btrfs_search_slot(trans, extent_root,
&key, path, -1, 1);
if (ret) {
printk(KERN_ERR "umm, got %d back from search"
", was looking for %llu\n", ret,
(unsigned long long)bytenr);
btrfs_print_leaf(extent_root, path->nodes[0]);
}
BUG_ON(ret);
extent_slot = path->slots[0];
}
} else {
btrfs_print_leaf(extent_root, path->nodes[0]);
WARN_ON(1);
printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
"parent %llu root %llu owner %llu offset %llu\n",
(unsigned long long)bytenr,
(unsigned long long)parent,
(unsigned long long)root_objectid,
(unsigned long long)owner_objectid,
(unsigned long long)owner_offset);
}
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, extent_slot);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
BUG_ON(found_extent || extent_slot != path->slots[0]);
ret = convert_extent_item_v0(trans, extent_root, path,
owner_objectid, 0);
BUG_ON(ret < 0);
btrfs_release_path(extent_root, path);
path->leave_spinning = 1;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = num_bytes;
ret = btrfs_search_slot(trans, extent_root, &key, path,
-1, 1);
if (ret) {
printk(KERN_ERR "umm, got %d back from search"
", was looking for %llu\n", ret,
(unsigned long long)bytenr);
btrfs_print_leaf(extent_root, path->nodes[0]);
}
BUG_ON(ret);
extent_slot = path->slots[0];
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, extent_slot);
}
#endif
BUG_ON(item_size < sizeof(*ei));
ei = btrfs_item_ptr(leaf, extent_slot,
struct btrfs_extent_item);
if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
struct btrfs_tree_block_info *bi;
BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
bi = (struct btrfs_tree_block_info *)(ei + 1);
WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
}
refs = btrfs_extent_refs(leaf, ei);
BUG_ON(refs < refs_to_drop);
refs -= refs_to_drop;
if (refs > 0) {
if (extent_op)
__run_delayed_extent_op(extent_op, leaf, ei);
/*
* In the case of inline back ref, reference count will
* be updated by remove_extent_backref
*/
if (iref) {
BUG_ON(!found_extent);
} else {
btrfs_set_extent_refs(leaf, ei, refs);
btrfs_mark_buffer_dirty(leaf);
}
if (found_extent) {
ret = remove_extent_backref(trans, extent_root, path,
iref, refs_to_drop,
is_data);
BUG_ON(ret);
}
} else {
if (found_extent) {
BUG_ON(is_data && refs_to_drop !=
extent_data_ref_count(root, path, iref));
if (iref) {
BUG_ON(path->slots[0] != extent_slot);
} else {
BUG_ON(path->slots[0] != extent_slot + 1);
path->slots[0] = extent_slot;
num_to_del = 2;
}
}
ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
num_to_del);
BUG_ON(ret);
btrfs_release_path(extent_root, path);
if (is_data) {
ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
BUG_ON(ret);
} else {
invalidate_mapping_pages(info->btree_inode->i_mapping,
bytenr >> PAGE_CACHE_SHIFT,
(bytenr + num_bytes - 1) >> PAGE_CACHE_SHIFT);
}
ret = update_block_group(trans, root, bytenr, num_bytes, 0);
BUG_ON(ret);
}
btrfs_free_path(path);
return ret;
}
/*
* when we free an block, it is possible (and likely) that we free the last
* delayed ref for that extent as well. This searches the delayed ref tree for
* a given extent, and if there are no other delayed refs to be processed, it
* removes it from the tree.
*/
static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr)
{
struct btrfs_delayed_ref_head *head;
struct btrfs_delayed_ref_root *delayed_refs;
struct btrfs_delayed_ref_node *ref;
struct rb_node *node;
int ret = 0;
delayed_refs = &trans->transaction->delayed_refs;
spin_lock(&delayed_refs->lock);
head = btrfs_find_delayed_ref_head(trans, bytenr);
if (!head)
goto out;
node = rb_prev(&head->node.rb_node);
if (!node)
goto out;
ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
/* there are still entries for this ref, we can't drop it */
if (ref->bytenr == bytenr)
goto out;
if (head->extent_op) {
if (!head->must_insert_reserved)
goto out;
kfree(head->extent_op);
head->extent_op = NULL;
}
/*
* waiting for the lock here would deadlock. If someone else has it
* locked they are already in the process of dropping it anyway
*/
if (!mutex_trylock(&head->mutex))
goto out;
/*
* at this point we have a head with no other entries. Go
* ahead and process it.
*/
head->node.in_tree = 0;
rb_erase(&head->node.rb_node, &delayed_refs->root);
delayed_refs->num_entries--;
/*
* we don't take a ref on the node because we're removing it from the
* tree, so we just steal the ref the tree was holding.
*/
delayed_refs->num_heads--;
if (list_empty(&head->cluster))
delayed_refs->num_heads_ready--;
list_del_init(&head->cluster);
spin_unlock(&delayed_refs->lock);
BUG_ON(head->extent_op);
if (head->must_insert_reserved)
ret = 1;
mutex_unlock(&head->mutex);
btrfs_put_delayed_ref(&head->node);
return ret;
out:
spin_unlock(&delayed_refs->lock);
return 0;
}
void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf,
u64 parent, int last_ref)
{
struct btrfs_block_rsv *block_rsv;
struct btrfs_block_group_cache *cache = NULL;
int ret;
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
ret = btrfs_add_delayed_tree_ref(trans, buf->start, buf->len,
parent, root->root_key.objectid,
btrfs_header_level(buf),
BTRFS_DROP_DELAYED_REF, NULL);
BUG_ON(ret);
}
if (!last_ref)
return;
block_rsv = get_block_rsv(trans, root);
cache = btrfs_lookup_block_group(root->fs_info, buf->start);
if (block_rsv->space_info != cache->space_info)
goto out;
if (btrfs_header_generation(buf) == trans->transid) {
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
ret = check_ref_cleanup(trans, root, buf->start);
if (!ret)
goto pin;
}
if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
pin_down_extent(root, cache, buf->start, buf->len, 1);
goto pin;
}
WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
btrfs_add_free_space(cache, buf->start, buf->len);
ret = btrfs_update_reserved_bytes(cache, buf->len, 0, 0);
if (ret == -EAGAIN) {
/* block group became read-only */
btrfs_update_reserved_bytes(cache, buf->len, 0, 1);
goto out;
}
ret = 1;
spin_lock(&block_rsv->lock);
if (block_rsv->reserved < block_rsv->size) {
block_rsv->reserved += buf->len;
ret = 0;
}
spin_unlock(&block_rsv->lock);
if (ret) {
spin_lock(&cache->space_info->lock);
cache->space_info->bytes_reserved -= buf->len;
cache->space_info->reservation_progress++;
spin_unlock(&cache->space_info->lock);
}
goto out;
}
pin:
if (block_rsv->durable && !cache->ro) {
ret = 0;
spin_lock(&cache->lock);
if (!cache->ro) {
cache->reserved_pinned += buf->len;
ret = 1;
}
spin_unlock(&cache->lock);
if (ret) {
spin_lock(&block_rsv->lock);
block_rsv->freed[trans->transid & 0x1] += buf->len;
spin_unlock(&block_rsv->lock);
}
}
out:
/*
* Deleting the buffer, clear the corrupt flag since it doesn't matter
* anymore.
*/
clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags);
btrfs_put_block_group(cache);
}
int btrfs_free_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent,
u64 root_objectid, u64 owner, u64 offset)
{
int ret;
/*
* tree log blocks never actually go into the extent allocation
* tree, just update pinning info and exit early.
*/
if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
/* unlocks the pinned mutex */
btrfs_pin_extent(root, bytenr, num_bytes, 1);
ret = 0;
} else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
parent, root_objectid, (int)owner,
BTRFS_DROP_DELAYED_REF, NULL);
BUG_ON(ret);
} else {
ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
parent, root_objectid, owner,
offset, BTRFS_DROP_DELAYED_REF, NULL);
BUG_ON(ret);
}
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;
}
/*
* when we wait for progress in the block group caching, its because
* our allocation attempt failed at least once. So, we must sleep
* and let some progress happen before we try again.
*
* This function will sleep at least once waiting for new free space to
* show up, and then it will check the block group free space numbers
* for our min num_bytes. Another option is to have it go ahead
* and look in the rbtree for a free extent of a given size, but this
* is a good start.
*/
static noinline int
wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
u64 num_bytes)
{
struct btrfs_caching_control *caching_ctl;
DEFINE_WAIT(wait);
caching_ctl = get_caching_control(cache);
if (!caching_ctl)
return 0;
wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
(cache->free_space >= num_bytes));
put_caching_control(caching_ctl);
return 0;
}
static noinline int
wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
{
struct btrfs_caching_control *caching_ctl;
DEFINE_WAIT(wait);
caching_ctl = get_caching_control(cache);
if (!caching_ctl)
return 0;
wait_event(caching_ctl->wait, block_group_cache_done(cache));
put_caching_control(caching_ctl);
return 0;
}
static int get_block_group_index(struct btrfs_block_group_cache *cache)
{
int index;
if (cache->flags & BTRFS_BLOCK_GROUP_RAID10)
index = 0;
else if (cache->flags & BTRFS_BLOCK_GROUP_RAID1)
index = 1;
else if (cache->flags & BTRFS_BLOCK_GROUP_DUP)
index = 2;
else if (cache->flags & BTRFS_BLOCK_GROUP_RAID0)
index = 3;
else
index = 4;
return index;
}
enum btrfs_loop_type {
LOOP_FIND_IDEAL = 0,
LOOP_CACHING_NOWAIT = 1,
LOOP_CACHING_WAIT = 2,
LOOP_ALLOC_CHUNK = 3,
LOOP_NO_EMPTY_SIZE = 4,
};
/*
* 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 noinline int 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,
int data)
{
int ret = 0;
struct btrfs_root *root = orig_root->fs_info->extent_root;
struct btrfs_free_cluster *last_ptr = NULL;
struct btrfs_block_group_cache *block_group = NULL;
int empty_cluster = 2 * 1024 * 1024;
int allowed_chunk_alloc = 0;
int done_chunk_alloc = 0;
struct btrfs_space_info *space_info;
int last_ptr_loop = 0;
int loop = 0;
int index = 0;
bool found_uncached_bg = false;
bool failed_cluster_refill = false;
bool failed_alloc = false;
bool use_cluster = true;
u64 ideal_cache_percent = 0;
u64 ideal_cache_offset = 0;
WARN_ON(num_bytes < root->sectorsize);
btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
ins->objectid = 0;
ins->offset = 0;
space_info = __find_space_info(root->fs_info, data);
if (!space_info) {
printk(KERN_ERR "No space info for %d\n", data);
return -ENOSPC;
}
/*
* If the space info is for both data and metadata it means we have a
* small filesystem and we can't use the clustering stuff.
*/
if (btrfs_mixed_space_info(space_info))
use_cluster = false;
if (orig_root->ref_cows || empty_size)
allowed_chunk_alloc = 1;
if (data & BTRFS_BLOCK_GROUP_METADATA && use_cluster) {
last_ptr = &root->fs_info->meta_alloc_cluster;
if (!btrfs_test_opt(root, SSD))
empty_cluster = 64 * 1024;
}
if ((data & BTRFS_BLOCK_GROUP_DATA) && use_cluster &&
btrfs_test_opt(root, SSD)) {
last_ptr = &root->fs_info->data_alloc_cluster;
}
if (last_ptr) {
spin_lock(&last_ptr->lock);
if (last_ptr->block_group)
hint_byte = last_ptr->window_start;
spin_unlock(&last_ptr->lock);
}
search_start = max(search_start, first_logical_byte(root, 0));
search_start = max(search_start, hint_byte);
if (!last_ptr)
empty_cluster = 0;
if (search_start == hint_byte) {
ideal_cache:
block_group = btrfs_lookup_block_group(root->fs_info,
search_start);
/*
* we don't want to use the block group if it doesn't match our
* allocation bits, or if its not cached.
*
* However if we are re-searching with an ideal block group
* picked out then we don't care that the block group is cached.
*/
if (block_group && block_group_bits(block_group, data) &&
(block_group->cached != BTRFS_CACHE_NO ||
search_start == ideal_cache_offset)) {
down_read(&space_info->groups_sem);
if (list_empty(&block_group->list) ||
block_group->ro) {
/*
* someone is removing this block group,
* we can't jump into the have_block_group
* target because our list pointers are not
* valid
*/
btrfs_put_block_group(block_group);
up_read(&space_info->groups_sem);
} else {
index = get_block_group_index(block_group);
goto have_block_group;
}
} else if (block_group) {
btrfs_put_block_group(block_group);
}
}
search:
down_read(&space_info->groups_sem);
list_for_each_entry(block_group, &space_info->block_groups[index],
list) {
u64 offset;
int cached;
btrfs_get_block_group(block_group);
search_start = block_group->key.objectid;
/*
* this can happen if we end up cycling through all the
* raid types, but we want to make sure we only allocate
* for the proper type.
*/
if (!block_group_bits(block_group, data)) {
u64 extra = BTRFS_BLOCK_GROUP_DUP |
BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10;
/*
* if they asked for extra copies and this block group
* doesn't provide them, bail. This does allow us to
* fill raid0 from raid1.
*/
if ((data & extra) && !(block_group->flags & extra))
goto loop;
}
have_block_group:
if (unlikely(block_group->cached == BTRFS_CACHE_NO)) {
u64 free_percent;
ret = cache_block_group(block_group, trans,
orig_root, 1);
if (block_group->cached == BTRFS_CACHE_FINISHED)
goto have_block_group;
free_percent = btrfs_block_group_used(&block_group->item);
free_percent *= 100;
free_percent = div64_u64(free_percent,
block_group->key.offset);
free_percent = 100 - free_percent;
if (free_percent > ideal_cache_percent &&
likely(!block_group->ro)) {
ideal_cache_offset = block_group->key.objectid;
ideal_cache_percent = free_percent;
}
/*
* We only want to start kthread caching if we are at
* the point where we will wait for caching to make
* progress, or if our ideal search is over and we've
* found somebody to start caching.
*/
if (loop > LOOP_CACHING_NOWAIT ||
(loop > LOOP_FIND_IDEAL &&
atomic_read(&space_info->caching_threads) < 2)) {
ret = cache_block_group(block_group, trans,
orig_root, 0);
BUG_ON(ret);
}
found_uncached_bg = true;
/*
* If loop is set for cached only, try the next block
* group.
*/
if (loop == LOOP_FIND_IDEAL)
goto loop;
}
cached = block_group_cache_done(block_group);
if (unlikely(!cached))
found_uncached_bg = true;
if (unlikely(block_group->ro))
goto loop;
/*
* Ok we want to try and use the cluster allocator, so lets look
* there, unless we are on LOOP_NO_EMPTY_SIZE, since we will
* have tried the cluster allocator plenty of times at this
* point and not have found anything, so we are likely way too
* fragmented for the clustering stuff to find anything, so lets
* just skip it and let the allocator find whatever block it can
* find
*/
if (last_ptr && loop < LOOP_NO_EMPTY_SIZE) {
/*
* the refill lock keeps out other
* people trying to start a new cluster
*/
spin_lock(&last_ptr->refill_lock);
if (last_ptr->block_group &&
(last_ptr->block_group->ro ||
!block_group_bits(last_ptr->block_group, data))) {
offset = 0;
goto refill_cluster;
}
offset = btrfs_alloc_from_cluster(block_group, last_ptr,
num_bytes, search_start);
if (offset) {
/* we have a block, we're done */
spin_unlock(&last_ptr->refill_lock);
goto checks;
}
spin_lock(&last_ptr->lock);
/*
* whoops, this cluster doesn't actually point to
* this block group. Get a ref on the block
* group is does point to and try again
*/
if (!last_ptr_loop && last_ptr->block_group &&
last_ptr->block_group != block_group) {
btrfs_put_block_group(block_group);
block_group = last_ptr->block_group;
btrfs_get_block_group(block_group);
spin_unlock(&last_ptr->lock);
spin_unlock(&last_ptr->refill_lock);
last_ptr_loop = 1;
search_start = block_group->key.objectid;
/*
* we know this block group is properly
* in the list because
* btrfs_remove_block_group, drops the
* cluster before it removes the block
* group from the list
*/
goto have_block_group;
}
spin_unlock(&last_ptr->lock);
refill_cluster:
/*
* this cluster didn't work out, free it and
* start over
*/
btrfs_return_cluster_to_free_space(NULL, last_ptr);
last_ptr_loop = 0;
/* allocate a cluster in this block group */
ret = btrfs_find_space_cluster(trans, root,
block_group, last_ptr,
offset, num_bytes,
empty_cluster + empty_size);
if (ret == 0) {
/*
* now pull our allocation out of this
* cluster
*/
offset = btrfs_alloc_from_cluster(block_group,
last_ptr, num_bytes,
search_start);
if (offset) {
/* we found one, proceed */
spin_unlock(&last_ptr->refill_lock);
goto checks;
}
} else if (!cached && loop > LOOP_CACHING_NOWAIT
&& !failed_cluster_refill) {
spin_unlock(&last_ptr->refill_lock);
failed_cluster_refill = true;
wait_block_group_cache_progress(block_group,
num_bytes + empty_cluster + empty_size);
goto have_block_group;
}
/*
* at this point we either didn't find a cluster
* or we weren't able to allocate a block from our
* cluster. Free the cluster we've been trying
* to use, and go to the next block group
*/
btrfs_return_cluster_to_free_space(NULL, last_ptr);
spin_unlock(&last_ptr->refill_lock);
goto loop;
}
offset = btrfs_find_space_for_alloc(block_group, search_start,
num_bytes, empty_size);
/*
* If we didn't find a chunk, and we haven't failed on this
* block group before, and this block group is in the middle of
* caching and we are ok with waiting, then go ahead and wait
* for progress to be made, and set failed_alloc to true.
*
* If failed_alloc is true then we've already waited on this
* block group once and should move on to the next block group.
*/
if (!offset && !failed_alloc && !cached &&
loop > LOOP_CACHING_NOWAIT) {
wait_block_group_cache_progress(block_group,
num_bytes + empty_size);
failed_alloc = true;
goto have_block_group;
} else if (!offset) {
goto loop;
}
checks:
search_start = stripe_align(root, offset);
/* move on to the next group */
if (search_start + num_bytes >= search_end) {
btrfs_add_free_space(block_group, offset, num_bytes);
goto loop;
}
/* move on to the next group */
if (search_start + num_bytes >
block_group->key.objectid + block_group->key.offset) {
btrfs_add_free_space(block_group, offset, num_bytes);
goto loop;
}
ins->objectid = search_start;
ins->offset = num_bytes;
if (offset < search_start)
btrfs_add_free_space(block_group, offset,
search_start - offset);
BUG_ON(offset > search_start);
ret = btrfs_update_reserved_bytes(block_group, num_bytes, 1,
(data & BTRFS_BLOCK_GROUP_DATA));
if (ret == -EAGAIN) {
btrfs_add_free_space(block_group, offset, num_bytes);
goto loop;
}
/* we are all good, lets return */
ins->objectid = search_start;
ins->offset = num_bytes;
if (offset < search_start)
btrfs_add_free_space(block_group, offset,
search_start - offset);
BUG_ON(offset > search_start);
break;
loop:
failed_cluster_refill = false;
failed_alloc = false;
BUG_ON(index != get_block_group_index(block_group));
btrfs_put_block_group(block_group);
}
up_read(&space_info->groups_sem);
if (!ins->objectid && ++index < BTRFS_NR_RAID_TYPES)
goto search;
/* LOOP_FIND_IDEAL, only search caching/cached bg's, and don't wait for
* for them to make caching progress. Also
* determine the best possible bg to cache
* LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
* caching kthreads as we move along
* LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
* LOOP_ALLOC_CHUNK, force a chunk allocation and try again
* LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
* again
*/
if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE &&
(found_uncached_bg || empty_size || empty_cluster ||
allowed_chunk_alloc)) {
index = 0;
if (loop == LOOP_FIND_IDEAL && found_uncached_bg) {
found_uncached_bg = false;
loop++;
if (!ideal_cache_percent &&
atomic_read(&space_info->caching_threads))
goto search;
/*
* 1 of the following 2 things have happened so far
*
* 1) We found an ideal block group for caching that
* is mostly full and will cache quickly, so we might
* as well wait for it.
*
* 2) We searched for cached only and we didn't find
* anything, and we didn't start any caching kthreads
* either, so chances are we will loop through and
* start a couple caching kthreads, and then come back
* around and just wait for them. This will be slower
* because we will have 2 caching kthreads reading at
* the same time when we could have just started one
* and waited for it to get far enough to give us an
* allocation, so go ahead and go to the wait caching
* loop.
*/
loop = LOOP_CACHING_WAIT;
search_start = ideal_cache_offset;
ideal_cache_percent = 0;
goto ideal_cache;
} else if (loop == LOOP_FIND_IDEAL) {
/*
* Didn't find a uncached bg, wait on anything we find
* next.
*/
loop = LOOP_CACHING_WAIT;
goto search;
}
if (loop < LOOP_CACHING_WAIT) {
loop++;
goto search;
}
if (loop == LOOP_ALLOC_CHUNK) {
empty_size = 0;
empty_cluster = 0;
}
if (allowed_chunk_alloc) {
ret = do_chunk_alloc(trans, root, num_bytes +
2 * 1024 * 1024, data,
CHUNK_ALLOC_LIMITED);
allowed_chunk_alloc = 0;
done_chunk_alloc = 1;
} else if (!done_chunk_alloc &&
space_info->force_alloc == CHUNK_ALLOC_NO_FORCE) {
space_info->force_alloc = CHUNK_ALLOC_LIMITED;
}
if (loop < LOOP_NO_EMPTY_SIZE) {
loop++;
goto search;
}
ret = -ENOSPC;
} else if (!ins->objectid) {
ret = -ENOSPC;
}
/* we found what we needed */
if (ins->objectid) {
if (!(data & BTRFS_BLOCK_GROUP_DATA))
trans->block_group = block_group->key.objectid;
btrfs_put_block_group(block_group);
ret = 0;
}
return ret;
}
static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
int dump_block_groups)
{
struct btrfs_block_group_cache *cache;
int index = 0;
spin_lock(&info->lock);
printk(KERN_INFO "space_info has %llu free, is %sfull\n",
(unsigned long long)(info->total_bytes - info->bytes_used -
info->bytes_pinned - info->bytes_reserved -
info->bytes_readonly),
(info->full) ? "" : "not ");
printk(KERN_INFO "space_info total=%llu, used=%llu, pinned=%llu, "
"reserved=%llu, may_use=%llu, readonly=%llu\n",
(unsigned long long)info->total_bytes,
(unsigned long long)info->bytes_used,
(unsigned long long)info->bytes_pinned,
(unsigned long long)info->bytes_reserved,
(unsigned long long)info->bytes_may_use,
(unsigned long long)info->bytes_readonly);
spin_unlock(&info->lock);
if (!dump_block_groups)
return;
down_read(&info->groups_sem);
again:
list_for_each_entry(cache, &info->block_groups[index], list) {
spin_lock(&cache->lock);
printk(KERN_INFO "block group %llu has %llu bytes, %llu used "
"%llu pinned %llu reserved\n",
(unsigned long long)cache->key.objectid,
(unsigned long long)cache->key.offset,
(unsigned long long)btrfs_block_group_used(&cache->item),
(unsigned long long)cache->pinned,
(unsigned long long)cache->reserved);
btrfs_dump_free_space(cache, bytes);
spin_unlock(&cache->lock);
}
if (++index < BTRFS_NR_RAID_TYPES)
goto again;
up_read(&info->groups_sem);
}
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;
data = btrfs_get_alloc_profile(root, data);
again:
/*
* the only place that sets empty_size is btrfs_realloc_node, which
* is not called recursively on allocations
*/
if (empty_size || root->ref_cows)
ret = do_chunk_alloc(trans, root->fs_info->extent_root,
num_bytes + 2 * 1024 * 1024, data,
CHUNK_ALLOC_NO_FORCE);
WARN_ON(num_bytes < root->sectorsize);
ret = find_free_extent(trans, root, num_bytes, empty_size,
search_start, search_end, hint_byte,
ins, 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, CHUNK_ALLOC_FORCE);
goto again;
}
if (ret == -ENOSPC && btrfs_test_opt(root, ENOSPC_DEBUG)) {
struct btrfs_space_info *sinfo;
sinfo = __find_space_info(root->fs_info, data);
printk(KERN_ERR "btrfs allocation failed flags %llu, "
"wanted %llu\n", (unsigned long long)data,
(unsigned long long)num_bytes);
dump_space_info(sinfo, num_bytes, 1);
}
trace_btrfs_reserved_extent_alloc(root, 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;
int ret = 0;
cache = btrfs_lookup_block_group(root->fs_info, start);
if (!cache) {
printk(KERN_ERR "Unable to find block group for %llu\n",
(unsigned long long)start);
return -ENOSPC;
}
if (btrfs_test_opt(root, DISCARD))
ret = btrfs_discard_extent(root, start, len, NULL);
btrfs_add_free_space(cache, start, len);
btrfs_update_reserved_bytes(cache, len, 0, 1);
btrfs_put_block_group(cache);
trace_btrfs_reserved_extent_free(root, start, len);
return ret;
}
static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 parent, u64 root_objectid,
u64 flags, u64 owner, u64 offset,
struct btrfs_key *ins, int ref_mod)
{
int ret;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_extent_item *extent_item;
struct btrfs_extent_inline_ref *iref;
struct btrfs_path *path;
struct extent_buffer *leaf;
int type;
u32 size;
if (parent > 0)
type = BTRFS_SHARED_DATA_REF_KEY;
else
type = BTRFS_EXTENT_DATA_REF_KEY;
size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->leave_spinning = 1;
ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
ins, size);
BUG_ON(ret);
leaf = path->nodes[0];
extent_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item);
btrfs_set_extent_refs(leaf, extent_item, ref_mod);
btrfs_set_extent_generation(leaf, extent_item, trans->transid);
btrfs_set_extent_flags(leaf, extent_item,
flags | BTRFS_EXTENT_FLAG_DATA);
iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
btrfs_set_extent_inline_ref_type(leaf, iref, type);
if (parent > 0) {
struct btrfs_shared_data_ref *ref;
ref = (struct btrfs_shared_data_ref *)(iref + 1);
btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
} else {
struct btrfs_extent_data_ref *ref;
ref = (struct btrfs_extent_data_ref *)(&iref->offset);
btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
btrfs_set_extent_data_ref_offset(leaf, ref, offset);
btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
}
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_free_path(path);
ret = update_block_group(trans, root, ins->objectid, ins->offset, 1);
if (ret) {
printk(KERN_ERR "btrfs update block group failed for %llu "
"%llu\n", (unsigned long long)ins->objectid,
(unsigned long long)ins->offset);
BUG();
}
return ret;
}
static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 parent, u64 root_objectid,
u64 flags, struct btrfs_disk_key *key,
int level, struct btrfs_key *ins)
{
int ret;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_extent_item *extent_item;
struct btrfs_tree_block_info *block_info;
struct btrfs_extent_inline_ref *iref;
struct btrfs_path *path;
struct extent_buffer *leaf;
u32 size = sizeof(*extent_item) + sizeof(*block_info) + sizeof(*iref);
path = btrfs_alloc_path();
BUG_ON(!path);
path->leave_spinning = 1;
ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
ins, size);
BUG_ON(ret);
leaf = path->nodes[0];
extent_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item);
btrfs_set_extent_refs(leaf, extent_item, 1);
btrfs_set_extent_generation(leaf, extent_item, trans->transid);
btrfs_set_extent_flags(leaf, extent_item,
flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
btrfs_set_tree_block_key(leaf, block_info, key);
btrfs_set_tree_block_level(leaf, block_info, level);
iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
if (parent > 0) {
BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
btrfs_set_extent_inline_ref_type(leaf, iref,
BTRFS_SHARED_BLOCK_REF_KEY);
btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
} else {
btrfs_set_extent_inline_ref_type(leaf, iref,
BTRFS_TREE_BLOCK_REF_KEY);
btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
}
btrfs_mark_buffer_dirty(leaf);
btrfs_free_path(path);
ret = update_block_group(trans, root, ins->objectid, ins->offset, 1);
if (ret) {
printk(KERN_ERR "btrfs update block group failed for %llu "
"%llu\n", (unsigned long long)ins->objectid,
(unsigned long long)ins->offset);
BUG();
}
return ret;
}
int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 root_objectid, u64 owner,
u64 offset, struct btrfs_key *ins)
{
int ret;
BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
ret = btrfs_add_delayed_data_ref(trans, ins->objectid, ins->offset,
0, root_objectid, owner, offset,
BTRFS_ADD_DELAYED_EXTENT, NULL);
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_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 root_objectid, u64 owner, u64 offset,
struct btrfs_key *ins)
{
int ret;
struct btrfs_block_group_cache *block_group;
struct btrfs_caching_control *caching_ctl;
u64 start = ins->objectid;
u64 num_bytes = ins->offset;
block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
cache_block_group(block_group, trans, NULL, 0);
caching_ctl = get_caching_control(block_group);
if (!caching_ctl) {
BUG_ON(!block_group_cache_done(block_group));
ret = btrfs_remove_free_space(block_group, start, num_bytes);
BUG_ON(ret);
} else {
mutex_lock(&caching_ctl->mutex);
if (start >= caching_ctl->progress) {
ret = add_excluded_extent(root, start, num_bytes);
BUG_ON(ret);
} else if (start + num_bytes <= caching_ctl->progress) {
ret = btrfs_remove_free_space(block_group,
start, num_bytes);
BUG_ON(ret);
} else {
num_bytes = caching_ctl->progress - start;
ret = btrfs_remove_free_space(block_group,
start, num_bytes);
BUG_ON(ret);
start = caching_ctl->progress;
num_bytes = ins->objectid + ins->offset -
caching_ctl->progress;
ret = add_excluded_extent(root, start, num_bytes);
BUG_ON(ret);
}
mutex_unlock(&caching_ctl->mutex);
put_caching_control(caching_ctl);
}
ret = btrfs_update_reserved_bytes(block_group, ins->offset, 1, 1);
BUG_ON(ret);
btrfs_put_block_group(block_group);
ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
0, owner, offset, ins, 1);
return ret;
}
struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u32 blocksize,
int level)
{
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_set_buffer_lockdep_class(buf, level);
btrfs_tree_lock(buf);
clean_tree_block(trans, root, buf);
btrfs_set_lock_blocking(buf);
btrfs_set_buffer_uptodate(buf);
if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
/*
* we allow two log transactions at a time, use different
* EXENT bit to differentiate dirty pages.
*/
if (root->log_transid % 2 == 0)
set_extent_dirty(&root->dirty_log_pages, buf->start,
buf->start + buf->len - 1, GFP_NOFS);
else
set_extent_new(&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++;
/* this returns a buffer locked for blocking */
return buf;
}
static struct btrfs_block_rsv *
use_block_rsv(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u32 blocksize)
{
struct btrfs_block_rsv *block_rsv;
struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
int ret;
block_rsv = get_block_rsv(trans, root);
if (block_rsv->size == 0) {
ret = reserve_metadata_bytes(trans, root, block_rsv,
blocksize, 0);
/*
* If we couldn't reserve metadata bytes try and use some from
* the global reserve.
*/
if (ret && block_rsv != global_rsv) {
ret = block_rsv_use_bytes(global_rsv, blocksize);
if (!ret)
return global_rsv;
return ERR_PTR(ret);
} else if (ret) {
return ERR_PTR(ret);
}
return block_rsv;
}
ret = block_rsv_use_bytes(block_rsv, blocksize);
if (!ret)
return block_rsv;
if (ret) {
WARN_ON(1);
ret = reserve_metadata_bytes(trans, root, block_rsv, blocksize,
0);
if (!ret) {
spin_lock(&block_rsv->lock);
block_rsv->size += blocksize;
spin_unlock(&block_rsv->lock);
return block_rsv;
} else if (ret && block_rsv != global_rsv) {
ret = block_rsv_use_bytes(global_rsv, blocksize);
if (!ret)
return global_rsv;
}
}
return ERR_PTR(-ENOSPC);
}
static void unuse_block_rsv(struct btrfs_block_rsv *block_rsv, u32 blocksize)
{
block_rsv_add_bytes(block_rsv, blocksize, 0);
block_rsv_release_bytes(block_rsv, NULL, 0);
}
/*
* 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 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,
struct btrfs_disk_key *key, int level,
u64 hint, u64 empty_size)
{
struct btrfs_key ins;
struct btrfs_block_rsv *block_rsv;
struct extent_buffer *buf;
u64 flags = 0;
int ret;
block_rsv = use_block_rsv(trans, root, blocksize);
if (IS_ERR(block_rsv))
return ERR_CAST(block_rsv);
ret = btrfs_reserve_extent(trans, root, blocksize, blocksize,
empty_size, hint, (u64)-1, &ins, 0);
if (ret) {
unuse_block_rsv(block_rsv, blocksize);
return ERR_PTR(ret);
}
buf = btrfs_init_new_buffer(trans, root, ins.objectid,
blocksize, level);
BUG_ON(IS_ERR(buf));
if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
if (parent == 0)
parent = ins.objectid;
flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
} else
BUG_ON(parent > 0);
if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
struct btrfs_delayed_extent_op *extent_op;
extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
BUG_ON(!extent_op);
if (key)
memcpy(&extent_op->key, key, sizeof(extent_op->key));
else
memset(&extent_op->key, 0, sizeof(extent_op->key));
extent_op->flags_to_set = flags;
extent_op->update_key = 1;
extent_op->update_flags = 1;
extent_op->is_data = 0;
ret = btrfs_add_delayed_tree_ref(trans, ins.objectid,
ins.offset, parent, root_objectid,
level, BTRFS_ADD_DELAYED_EXTENT,
extent_op);
BUG_ON(ret);
}
return buf;
}
struct walk_control {
u64 refs[BTRFS_MAX_LEVEL];
u64 flags[BTRFS_MAX_LEVEL];
struct btrfs_key update_progress;
int stage;
int level;
int shared_level;
int update_ref;
int keep_locks;
int reada_slot;
int reada_count;
};
#define DROP_REFERENCE 1
#define UPDATE_BACKREF 2
static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct walk_control *wc,
struct btrfs_path *path)
{
u64 bytenr;
u64 generation;
u64 refs;
u64 flags;
u32 nritems;
u32 blocksize;
struct btrfs_key key;
struct extent_buffer *eb;
int ret;
int slot;
int nread = 0;
if (path->slots[wc->level] < wc->reada_slot) {
wc->reada_count = wc->reada_count * 2 / 3;
wc->reada_count = max(wc->reada_count, 2);
} else {
wc->reada_count = wc->reada_count * 3 / 2;
wc->reada_count = min_t(int, wc->reada_count,
BTRFS_NODEPTRS_PER_BLOCK(root));
}
eb = path->nodes[wc->level];
nritems = btrfs_header_nritems(eb);
blocksize = btrfs_level_size(root, wc->level - 1);
for (slot = path->slots[wc->level]; slot < nritems; slot++) {
if (nread >= wc->reada_count)
break;
cond_resched();
bytenr = btrfs_node_blockptr(eb, slot);
generation = btrfs_node_ptr_generation(eb, slot);
if (slot == path->slots[wc->level])
goto reada;
if (wc->stage == UPDATE_BACKREF &&
generation <= root->root_key.offset)
continue;
/* We don't lock the tree block, it's OK to be racy here */
ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
&refs, &flags);
BUG_ON(ret);
BUG_ON(refs == 0);
if (wc->stage == DROP_REFERENCE) {
if (refs == 1)
goto reada;
if (wc->level == 1 &&
(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
continue;
if (!wc->update_ref ||
generation <= root->root_key.offset)
continue;
btrfs_node_key_to_cpu(eb, &key, slot);
ret = btrfs_comp_cpu_keys(&key,
&wc->update_progress);
if (ret < 0)
continue;
} else {
if (wc->level == 1 &&
(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
continue;
}
reada:
ret = readahead_tree_block(root, bytenr, blocksize,
generation);
if (ret)
break;
nread++;
}
wc->reada_slot = slot;
}
/*
* hepler to process tree block while walking down the tree.
*
* when wc->stage == UPDATE_BACKREF, this function updates
* back refs for pointers in the block.
*
* NOTE: return value 1 means we should stop walking down.
*/
static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct walk_control *wc, int lookup_info)
{
int level = wc->level;
struct extent_buffer *eb = path->nodes[level];
u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
int ret;
if (wc->stage == UPDATE_BACKREF &&
btrfs_header_owner(eb) != root->root_key.objectid)
return 1;
/*
* when reference count of tree block is 1, it won't increase
* again. once full backref flag is set, we never clear it.
*/
if (lookup_info &&
((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
(wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
BUG_ON(!path->locks[level]);
ret = btrfs_lookup_extent_info(trans, root,
eb->start, eb->len,
&wc->refs[level],
&wc->flags[level]);
BUG_ON(ret);
BUG_ON(wc->refs[level] == 0);
}
if (wc->stage == DROP_REFERENCE) {
if (wc->refs[level] > 1)
return 1;
if (path->locks[level] && !wc->keep_locks) {
btrfs_tree_unlock(eb);
path->locks[level] = 0;
}
return 0;
}
/* wc->stage == UPDATE_BACKREF */
if (!(wc->flags[level] & flag)) {
BUG_ON(!path->locks[level]);
ret = btrfs_inc_ref(trans, root, eb, 1);
BUG_ON(ret);
ret = btrfs_dec_ref(trans, root, eb, 0);
BUG_ON(ret);
ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
eb->len, flag, 0);
BUG_ON(ret);
wc->flags[level] |= flag;
}
/*
* the block is shared by multiple trees, so it's not good to
* keep the tree lock
*/
if (path->locks[level] && level > 0) {
btrfs_tree_unlock(eb);
path->locks[level] = 0;
}
return 0;
}
/*
* hepler to process tree block pointer.
*
* when wc->stage == DROP_REFERENCE, this function checks
* reference count of the block pointed to. if the block
* is shared and we need update back refs for the subtree
* rooted at the block, this function changes wc->stage to
* UPDATE_BACKREF. if the block is shared and there is no
* need to update back, this function drops the reference
* to the block.
*
* NOTE: return value 1 means we should stop walking down.
*/
static noinline int do_walk_down(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct walk_control *wc, int *lookup_info)
{
u64 bytenr;
u64 generation;
u64 parent;
u32 blocksize;
struct btrfs_key key;
struct extent_buffer *next;
int level = wc->level;
int reada = 0;
int ret = 0;
generation = btrfs_node_ptr_generation(path->nodes[level],
path->slots[level]);
/*
* if the lower level block was created before the snapshot
* was created, we know there is no need to update back refs
* for the subtree
*/
if (wc->stage == UPDATE_BACKREF &&
generation <= root->root_key.offset) {
*lookup_info = 1;
return 1;
}
bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
blocksize = btrfs_level_size(root, level - 1);
next = btrfs_find_tree_block(root, bytenr, blocksize);
if (!next) {
next = btrfs_find_create_tree_block(root, bytenr, blocksize);
if (!next)
return -ENOMEM;
reada = 1;
}
btrfs_tree_lock(next);
btrfs_set_lock_blocking(next);
ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
&wc->refs[level - 1],
&wc->flags[level - 1]);
BUG_ON(ret);
BUG_ON(wc->refs[level - 1] == 0);
*lookup_info = 0;
if (wc->stage == DROP_REFERENCE) {
if (wc->refs[level - 1] > 1) {
if (level == 1 &&
(wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
goto skip;
if (!wc->update_ref ||
generation <= root->root_key.offset)
goto skip;
btrfs_node_key_to_cpu(path->nodes[level], &key,
path->slots[level]);
ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
if (ret < 0)
goto skip;
wc->stage = UPDATE_BACKREF;
wc->shared_level = level - 1;
}
} else {
if (level == 1 &&
(wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
goto skip;
}
if (!btrfs_buffer_uptodate(next, generation)) {
btrfs_tree_unlock(next);
free_extent_buffer(next);
next = NULL;
*lookup_info = 1;
}
if (!next) {
if (reada && level == 1)
reada_walk_down(trans, root, wc, path);
next = read_tree_block(root, bytenr, blocksize, generation);
if (!next)
return -EIO;
btrfs_tree_lock(next);
btrfs_set_lock_blocking(next);
}
level--;
BUG_ON(level != btrfs_header_level(next));
path->nodes[level] = next;
path->slots[level] = 0;
path->locks[level] = 1;
wc->level = level;
if (wc->level == 1)
wc->reada_slot = 0;
return 0;
skip:
wc->refs[level - 1] = 0;
wc->flags[level - 1] = 0;
if (wc->stage == DROP_REFERENCE) {
if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
parent = path->nodes[level]->start;
} else {
BUG_ON(root->root_key.objectid !=
btrfs_header_owner(path->nodes[level]));
parent = 0;
}
ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
root->root_key.objectid, level - 1, 0);
BUG_ON(ret);
}
btrfs_tree_unlock(next);
free_extent_buffer(next);
*lookup_info = 1;
return 1;
}
/*
* hepler to process tree block while walking up the tree.
*
* when wc->stage == DROP_REFERENCE, this function drops
* reference count on the block.
*
* when wc->stage == UPDATE_BACKREF, this function changes
* wc->stage back to DROP_REFERENCE if we changed wc->stage
* to UPDATE_BACKREF previously while processing the block.
*
* NOTE: return value 1 means we should stop walking up.
*/
static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct walk_control *wc)
{
int ret;
int level = wc->level;
struct extent_buffer *eb = path->nodes[level];
u64 parent = 0;
if (wc->stage == UPDATE_BACKREF) {
BUG_ON(wc->shared_level < level);
if (level < wc->shared_level)
goto out;
ret = find_next_key(path, level + 1, &wc->update_progress);
if (ret > 0)
wc->update_ref = 0;
wc->stage = DROP_REFERENCE;
wc->shared_level = -1;
path->slots[level] = 0;
/*
* check reference count again if the block isn't locked.
* we should start walking down the tree again if reference
* count is one.
*/
if (!path->locks[level]) {
BUG_ON(level == 0);
btrfs_tree_lock(eb);
btrfs_set_lock_blocking(eb);
path->locks[level] = 1;
ret = btrfs_lookup_extent_info(trans, root,
eb->start, eb->len,
&wc->refs[level],
&wc->flags[level]);
BUG_ON(ret);
BUG_ON(wc->refs[level] == 0);
if (wc->refs[level] == 1) {
btrfs_tree_unlock(eb);
path->locks[level] = 0;
return 1;
}
}
}
/* wc->stage == DROP_REFERENCE */
BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
if (wc->refs[level] == 1) {
if (level == 0) {
if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
ret = btrfs_dec_ref(trans, root, eb, 1);
else
ret = btrfs_dec_ref(trans, root, eb, 0);
BUG_ON(ret);
}
/* make block locked assertion in clean_tree_block happy */
if (!path->locks[level] &&
btrfs_header_generation(eb) == trans->transid) {
btrfs_tree_lock(eb);
btrfs_set_lock_blocking(eb);
path->locks[level] = 1;
}
clean_tree_block(trans, root, eb);
}
if (eb == root->node) {
if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
parent = eb->start;
else
BUG_ON(root->root_key.objectid !=
btrfs_header_owner(eb));
} else {
if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
parent = path->nodes[level + 1]->start;
else
BUG_ON(root->root_key.objectid !=
btrfs_header_owner(path->nodes[level + 1]));
}
btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1);
out:
wc->refs[level] = 0;
wc->flags[level] = 0;
return 0;
}
static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct walk_control *wc)
{
int level = wc->level;
int lookup_info = 1;
int ret;
while (level >= 0) {
ret = walk_down_proc(trans, root, path, wc, lookup_info);
if (ret > 0)
break;
if (level == 0)
break;
if (path->slots[level] >=
btrfs_header_nritems(path->nodes[level]))
break;
ret = do_walk_down(trans, root, path, wc, &lookup_info);
if (ret > 0) {
path->slots[level]++;
continue;
} else if (ret < 0)
return ret;
level = wc->level;
}
return 0;
}
static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct walk_control *wc, int max_level)
{
int level = wc->level;
int ret;
path->slots[level] = btrfs_header_nritems(path->nodes[level]);
while (level < max_level && path->nodes[level]) {
wc->level = level;
if (path->slots[level] + 1 <
btrfs_header_nritems(path->nodes[level])) {
path->slots[level]++;
return 0;
} else {
ret = walk_up_proc(trans, root, path, wc);
if (ret > 0)
return 0;
if (path->locks[level]) {
btrfs_tree_unlock(path->nodes[level]);
path->locks[level] = 0;
}
free_extent_buffer(path->nodes[level]);
path->nodes[level] = NULL;
level++;
}
}
return 1;
}
/*
* drop a subvolume tree.
*
* this function traverses the tree freeing any blocks that only
* referenced by the tree.
*
* when a shared tree block is found. this function decreases its
* reference count by one. if update_ref is true, this function
* also make sure backrefs for the shared block and all lower level
* blocks are properly updated.
*/
int btrfs_drop_snapshot(struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv, int update_ref)
{
struct btrfs_path *path;
struct btrfs_trans_handle *trans;
struct btrfs_root *tree_root = root->fs_info->tree_root;
struct btrfs_root_item *root_item = &root->root_item;
struct walk_control *wc;
struct btrfs_key key;
int err = 0;
int ret;
int level;
path = btrfs_alloc_path();
BUG_ON(!path);
wc = kzalloc(sizeof(*wc), GFP_NOFS);
BUG_ON(!wc);
trans = btrfs_start_transaction(tree_root, 0);
BUG_ON(IS_ERR(trans));
if (block_rsv)
trans->block_rsv = block_rsv;
if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
level = btrfs_header_level(root->node);
path->nodes[level] = btrfs_lock_root_node(root);
btrfs_set_lock_blocking(path->nodes[level]);
path->slots[level] = 0;
path->locks[level] = 1;
memset(&wc->update_progress, 0,
sizeof(wc->update_progress));
} else {
btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
memcpy(&wc->update_progress, &key,
sizeof(wc->update_progress));
level = root_item->drop_level;
BUG_ON(level == 0);
path->lowest_level = level;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
path->lowest_level = 0;
if (ret < 0) {
err = ret;
goto out;
}
WARN_ON(ret > 0);
/*
* unlock our path, this is safe because only this
* function is allowed to delete this snapshot
*/
btrfs_unlock_up_safe(path, 0);
level = btrfs_header_level(root->node);
while (1) {
btrfs_tree_lock(path->nodes[level]);
btrfs_set_lock_blocking(path->nodes[level]);
ret = btrfs_lookup_extent_info(trans, root,
path->nodes[level]->start,
path->nodes[level]->len,
&wc->refs[level],
&wc->flags[level]);
BUG_ON(ret);
BUG_ON(wc->refs[level] == 0);
if (level == root_item->drop_level)
break;
btrfs_tree_unlock(path->nodes[level]);
WARN_ON(wc->refs[level] != 1);
level--;
}
}
wc->level = level;
wc->shared_level = -1;
wc->stage = DROP_REFERENCE;
wc->update_ref = update_ref;
wc->keep_locks = 0;
wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
while (1) {
ret = walk_down_tree(trans, root, path, wc);
if (ret < 0) {
err = ret;
break;
}
ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
if (ret < 0) {
err = ret;
break;
}
if (ret > 0) {
BUG_ON(wc->stage != DROP_REFERENCE);
break;
}
if (wc->stage == DROP_REFERENCE) {
level = wc->level;
btrfs_node_key(path->nodes[level],
&root_item->drop_progress,
path->slots[level]);
root_item->drop_level = level;
}
BUG_ON(wc->level == 0);
if (btrfs_should_end_transaction(trans, tree_root)) {
ret = btrfs_update_root(trans, tree_root,
&root->root_key,
root_item);
BUG_ON(ret);
btrfs_end_transaction_throttle(trans, tree_root);
trans = btrfs_start_transaction(tree_root, 0);
BUG_ON(IS_ERR(trans));
if (block_rsv)
trans->block_rsv = block_rsv;
}
}
btrfs_release_path(root, path);
BUG_ON(err);
ret = btrfs_del_root(trans, tree_root, &root->root_key);
BUG_ON(ret);
if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
ret = btrfs_find_last_root(tree_root, root->root_key.objectid,
NULL, NULL);
BUG_ON(ret < 0);
if (ret > 0) {
/* if we fail to delete the orphan item this time
* around, it'll get picked up the next time.
*
* The most common failure here is just -ENOENT.
*/
btrfs_del_orphan_item(trans, tree_root,
root->root_key.objectid);
}
}
if (root->in_radix) {
btrfs_free_fs_root(tree_root->fs_info, root);
} else {
free_extent_buffer(root->node);
free_extent_buffer(root->commit_root);
kfree(root);
}
out:
btrfs_end_transaction_throttle(trans, tree_root);
kfree(wc);
btrfs_free_path(path);
return err;
}
/*
* drop subtree rooted at tree block 'node'.
*
* NOTE: this function will unlock and release tree block 'node'
*/
int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *node,
struct extent_buffer *parent)
{
struct btrfs_path *path;
struct walk_control *wc;
int level;
int parent_level;
int ret = 0;
int wret;
BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
wc = kzalloc(sizeof(*wc), GFP_NOFS);
if (!wc) {
btrfs_free_path(path);
return -ENOMEM;
}
btrfs_assert_tree_locked(parent);
parent_level = btrfs_header_level(parent);
extent_buffer_get(parent);
path->nodes[parent_level] = parent;
path->slots[parent_level] = btrfs_header_nritems(parent);
btrfs_assert_tree_locked(node);
level = btrfs_header_level(node);
path->nodes[level] = node;
path->slots[level] = 0;
path->locks[level] = 1;
wc->refs[parent_level] = 1;
wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
wc->level = level;
wc->shared_level = -1;
wc->stage = DROP_REFERENCE;
wc->update_ref = 0;
wc->keep_locks = 1;
wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
while (1) {
wret = walk_down_tree(trans, root, path, wc);
if (wret < 0) {
ret = wret;
break;
}
wret = walk_up_tree(trans, root, path, wc, parent_level);
if (wret < 0)
ret = wret;
if (wret != 0)
break;
}
kfree(wc);
btrfs_free_path(path);
return ret;
}
#if 0
static unsigned long calc_ra(unsigned long start, unsigned long last,
unsigned long nr)
{
return min(last, start + nr - 1);
}
static noinline int relocate_inode_pages(struct inode *inode, u64 start,
u64 len)
{
u64 page_start;
u64 page_end;
unsigned long first_index;
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;
struct btrfs_ordered_extent *ordered;
unsigned int total_read = 0;
unsigned int total_dirty = 0;
int ret = 0;
ra = kzalloc(sizeof(*ra), GFP_NOFS);
if (!ra)
return -ENOMEM;
mutex_lock(&inode->i_mutex);
first_index = start >> PAGE_CACHE_SHIFT;
last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
/* make sure the dirty trick played by the caller work */
ret = invalidate_inode_pages2_range(inode->i_mapping,
first_index, last_index);
if (ret)
goto out_unlock;
file_ra_state_init(ra, inode->i_mapping);
for (i = first_index ; i <= last_index; i++) {
if (total_read % ra->ra_pages == 0) {
btrfs_force_ra(inode->i_mapping, ra, NULL, i,
calc_ra(i, last_index, ra->ra_pages));
}
total_read++;
again:
if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
BUG_ON(1);
page = grab_cache_page(inode->i_mapping, i);
if (!page) {
ret = -ENOMEM;
goto out_unlock;
}
if (!PageUptodate(page)) {
btrfs_readpage(NULL, page);
lock_page(page);
if (!PageUptodate(page)) {
unlock_page(page);
page_cache_release(page);
ret = -EIO;
goto out_unlock;
}
}
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);
if (i == first_index)
set_extent_bits(io_tree, page_start, page_end,
EXTENT_BOUNDARY, GFP_NOFS);
btrfs_set_extent_delalloc(inode, page_start, page_end);
set_page_dirty(page);
total_dirty++;
unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
unlock_page(page);
page_cache_release(page);
}
out_unlock:
kfree(ra);
mutex_unlock(&inode->i_mutex);
balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
return ret;
}
static noinline int relocate_data_extent(struct inode *reloc_inode,
struct btrfs_key *extent_key,
u64 offset)
{
struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
struct extent_map *em;
u64 start = extent_key->objectid - offset;
u64 end = start + extent_key->offset - 1;
em = alloc_extent_map(GFP_NOFS);
BUG_ON(!em);
em->start = start;
em->len = extent_key->offset;
em->block_len = extent_key->offset;
em->block_start = extent_key->objectid;
em->bdev = root->fs_info->fs_devices->latest_bdev;
set_bit(EXTENT_FLAG_PINNED, &em->flags);
/* setup extent map to cheat btrfs_readpage */
lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
while (1) {
int ret;
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
write_unlock(&em_tree->lock);
if (ret != -EEXIST) {
free_extent_map(em);
break;
}
btrfs_drop_extent_cache(reloc_inode, start, end, 0);
}
unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
return relocate_inode_pages(reloc_inode, start, extent_key->offset);
}
struct btrfs_ref_path {
u64 extent_start;
u64 nodes[BTRFS_MAX_LEVEL];
u64 root_objectid;
u64 root_generation;
u64 owner_objectid;
u32 num_refs;
int lowest_level;
int current_level;
int shared_level;
struct btrfs_key node_keys[BTRFS_MAX_LEVEL];
u64 new_nodes[BTRFS_MAX_LEVEL];
};
struct disk_extent {
u64 ram_bytes;
u64 disk_bytenr;
u64 disk_num_bytes;
u64 offset;
u64 num_bytes;
u8 compression;
u8 encryption;
u16 other_encoding;
};
static int is_cowonly_root(u64 root_objectid)
{
if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
root_objectid == BTRFS_DEV_TREE_OBJECTID ||
root_objectid == BTRFS_TREE_LOG_OBJECTID ||
root_objectid == BTRFS_CSUM_TREE_OBJECTID)
return 1;
return 0;
}
static noinline int __next_ref_path(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root,
struct btrfs_ref_path *ref_path,
int first_time)
{
struct extent_buffer *leaf;
struct btrfs_path *path;
struct btrfs_extent_ref *ref;
struct btrfs_key key;
struct btrfs_key found_key;
u64 bytenr;
u32 nritems;
int level;
int ret = 1;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
if (first_time) {
ref_path->lowest_level = -1;
ref_path->current_level = -1;
ref_path->shared_level = -1;
goto walk_up;
}
walk_down:
level = ref_path->current_level - 1;
while (level >= -1) {
u64 parent;
if (level < ref_path->lowest_level)
break;
if (level >= 0)
bytenr = ref_path->nodes[level];
else
bytenr = ref_path->extent_start;
BUG_ON(bytenr == 0);
parent = ref_path->nodes[level + 1];
ref_path->nodes[level + 1] = 0;
ref_path->current_level = level;
BUG_ON(parent == 0);
key.objectid = bytenr;
key.offset = parent + 1;
key.type = BTRFS_EXTENT_REF_KEY;
ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
if (ret < 0)
goto out;
BUG_ON(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)
goto out;
if (ret > 0)
goto next;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid == bytenr &&
found_key.type == BTRFS_EXTENT_REF_KEY) {
if (level < ref_path->shared_level)
ref_path->shared_level = level;
goto found;
}
next:
level--;
btrfs_release_path(extent_root, path);
cond_resched();
}
/* reached lowest level */
ret = 1;
goto out;
walk_up:
level = ref_path->current_level;
while (level < BTRFS_MAX_LEVEL - 1) {
u64 ref_objectid;
if (level >= 0)
bytenr = ref_path->nodes[level];
else
bytenr = ref_path->extent_start;
BUG_ON(bytenr == 0);
key.objectid = bytenr;
key.offset = 0;
key.type = BTRFS_EXTENT_REF_KEY;
ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
if (ret < 0)
goto out;
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) {
/* the extent was freed by someone */
if (ref_path->lowest_level == level)
goto out;
btrfs_release_path(extent_root, path);
goto walk_down;
}
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != bytenr ||
found_key.type != BTRFS_EXTENT_REF_KEY) {
/* the extent was freed by someone */
if (ref_path->lowest_level == level) {
ret = 1;
goto out;
}
btrfs_release_path(extent_root, path);
goto walk_down;
}
found:
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref);
ref_objectid = btrfs_ref_objectid(leaf, ref);
if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
if (first_time) {
level = (int)ref_objectid;
BUG_ON(level >= BTRFS_MAX_LEVEL);
ref_path->lowest_level = level;
ref_path->current_level = level;
ref_path->nodes[level] = bytenr;
} else {
WARN_ON(ref_objectid != level);
}
} else {
WARN_ON(level != -1);
}
first_time = 0;
if (ref_path->lowest_level == level) {
ref_path->owner_objectid = ref_objectid;
ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
}
/*
* the block is tree root or the block isn't in reference
* counted tree.
*/
if (found_key.objectid == found_key.offset ||
is_cowonly_root(btrfs_ref_root(leaf, ref))) {
ref_path->root_objectid = btrfs_ref_root(leaf, ref);
ref_path->root_generation =
btrfs_ref_generation(leaf, ref);
if (level < 0) {
/* special reference from the tree log */
ref_path->nodes[0] = found_key.offset;
ref_path->current_level = 0;
}
ret = 0;
goto out;
}
level++;
BUG_ON(ref_path->nodes[level] != 0);
ref_path->nodes[level] = found_key.offset;
ref_path->current_level = level;
/*
* the reference was created in the running transaction,
* no need to continue walking up.
*/
if (btrfs_ref_generation(leaf, ref) == trans->transid) {
ref_path->root_objectid = btrfs_ref_root(leaf, ref);
ref_path->root_generation =
btrfs_ref_generation(leaf, ref);
ret = 0;
goto out;
}
btrfs_release_path(extent_root, path);
cond_resched();
}
/* reached max tree level, but no tree root found. */
BUG();
out:
btrfs_free_path(path);
return ret;
}
static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root,
struct btrfs_ref_path *ref_path,
u64 extent_start)
{
memset(ref_path, 0, sizeof(*ref_path));
ref_path->extent_start = extent_start;
return __next_ref_path(trans, extent_root, ref_path, 1);
}
static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root,
struct btrfs_ref_path *ref_path)
{
return __next_ref_path(trans, extent_root, ref_path, 0);
}
static noinline int get_new_locations(struct inode *reloc_inode,
struct btrfs_key *extent_key,
u64 offset, int no_fragment,
struct disk_extent **extents,
int *nr_extents)
{
struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
struct btrfs_path *path;
struct btrfs_file_extent_item *fi;
struct extent_buffer *leaf;
struct disk_extent *exts = *extents;
struct btrfs_key found_key;
u64 cur_pos;
u64 last_byte;
u32 nritems;
int nr = 0;
int max = *nr_extents;
int ret;
WARN_ON(!no_fragment && *extents);
if (!exts) {
max = 1;
exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
if (!exts)
return -ENOMEM;
}
path = btrfs_alloc_path();
if (!path) {
if (exts != *extents)
kfree(exts);
return -ENOMEM;
}
cur_pos = extent_key->objectid - offset;
last_byte = extent_key->objectid + extent_key->offset;
ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
cur_pos, 0);
if (ret < 0)
goto out;
if (ret > 0) {
ret = -ENOENT;
goto out;
}
while (1) {
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 > 0)
break;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.offset != cur_pos ||
found_key.type != BTRFS_EXTENT_DATA_KEY ||
found_key.objectid != reloc_inode->i_ino)
break;
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(leaf, fi) !=
BTRFS_FILE_EXTENT_REG ||
btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
break;
if (nr == max) {
struct disk_extent *old = exts;
max *= 2;
exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
if (!exts) {
ret = -ENOMEM;
goto out;
}
memcpy(exts, old, sizeof(*exts) * nr);
if (old != *extents)
kfree(old);
}
exts[nr].disk_bytenr =
btrfs_file_extent_disk_bytenr(leaf, fi);
exts[nr].disk_num_bytes =
btrfs_file_extent_disk_num_bytes(leaf, fi);
exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
exts[nr].compression = btrfs_file_extent_compression(leaf, fi);
exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi);
exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf,
fi);
BUG_ON(exts[nr].offset > 0);
BUG_ON(exts[nr].compression || exts[nr].encryption);
BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
cur_pos += exts[nr].num_bytes;
nr++;
if (cur_pos + offset >= last_byte)
break;
if (no_fragment) {
ret = 1;
goto out;
}
path->slots[0]++;
}
BUG_ON(cur_pos + offset > last_byte);
if (cur_pos + offset < last_byte) {
ret = -ENOENT;
goto out;
}
ret = 0;
out:
btrfs_free_path(path);
if (ret) {
if (exts != *extents)
kfree(exts);
} else {
*extents = exts;
*nr_extents = nr;
}
return ret;
}
static noinline int replace_one_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_key *extent_key,
struct btrfs_key *leaf_key,
struct btrfs_ref_path *ref_path,
struct disk_extent *new_extents,
int nr_extents)
{
struct extent_buffer *leaf;
struct btrfs_file_extent_item *fi;
struct inode *inode = NULL;
struct btrfs_key key;
u64 lock_start = 0;
u64 lock_end = 0;
u64 num_bytes;
u64 ext_offset;
u64 search_end = (u64)-1;
u32 nritems;
int nr_scaned = 0;
int extent_locked = 0;
int extent_type;
int ret;
memcpy(&key, leaf_key, sizeof(key));
if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
if (key.objectid < ref_path->owner_objectid ||
(key.objectid == ref_path->owner_objectid &&
key.type < BTRFS_EXTENT_DATA_KEY)) {
key.objectid = ref_path->owner_objectid;
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = 0;
}
}
while (1) {
ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
if (ret < 0)
goto out;
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
next:
if (extent_locked && ret > 0) {
/*
* the file extent item was modified by someone
* before the extent got locked.
*/
unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
lock_end, GFP_NOFS);
extent_locked = 0;
}
if (path->slots[0] >= nritems) {
if (++nr_scaned > 2)
break;
BUG_ON(extent_locked);
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
if (ret > 0)
break;
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
if ((key.objectid > ref_path->owner_objectid) ||
(key.objectid == ref_path->owner_objectid &&
key.type > BTRFS_EXTENT_DATA_KEY) ||
key.offset >= search_end)
break;
}
if (inode && key.objectid != inode->i_ino) {
BUG_ON(extent_locked);
btrfs_release_path(root, path);
mutex_unlock(&inode->i_mutex);
iput(inode);
inode = NULL;
continue;
}
if (key.type != BTRFS_EXTENT_DATA_KEY) {
path->slots[0]++;
ret = 1;
goto next;
}
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
if ((extent_type != BTRFS_FILE_EXTENT_REG &&
extent_type != BTRFS_FILE_EXTENT_PREALLOC) ||
(btrfs_file_extent_disk_bytenr(leaf, fi) !=
extent_key->objectid)) {
path->slots[0]++;
ret = 1;
goto next;
}
num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
ext_offset = btrfs_file_extent_offset(leaf, fi);
if (search_end == (u64)-1) {
search_end = key.offset - ext_offset +
btrfs_file_extent_ram_bytes(leaf, fi);
}
if (!extent_locked) {
lock_start = key.offset;
lock_end = lock_start + num_bytes - 1;
} else {
if (lock_start > key.offset ||
lock_end + 1 < key.offset + num_bytes) {
unlock_extent(&BTRFS_I(inode)->io_tree,
lock_start, lock_end, GFP_NOFS);
extent_locked = 0;
}
}
if (!inode) {
btrfs_release_path(root, path);
inode = btrfs_iget_locked(root->fs_info->sb,
key.objectid, root);
if (inode->i_state & I_NEW) {
BTRFS_I(inode)->root = root;
BTRFS_I(inode)->location.objectid =
key.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);
}
/*
* some code call btrfs_commit_transaction while
* holding the i_mutex, so we can't use mutex_lock
* here.
*/
if (is_bad_inode(inode) ||
!mutex_trylock(&inode->i_mutex)) {
iput(inode);
inode = NULL;
key.offset = (u64)-1;
goto skip;
}
}
if (!extent_locked) {
struct btrfs_ordered_extent *ordered;
btrfs_release_path(root, path);
lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
lock_end, GFP_NOFS);
ordered = btrfs_lookup_first_ordered_extent(inode,
lock_end);
if (ordered &&
ordered->file_offset <= lock_end &&
ordered->file_offset + ordered->len > lock_start) {
unlock_extent(&BTRFS_I(inode)->io_tree,
lock_start, lock_end, GFP_NOFS);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
key.offset += num_bytes;
goto skip;
}
if (ordered)
btrfs_put_ordered_extent(ordered);
extent_locked = 1;
continue;
}
if (nr_extents == 1) {
/* update extent pointer in place */
btrfs_set_file_extent_disk_bytenr(leaf, fi,
new_extents[0].disk_bytenr);
btrfs_set_file_extent_disk_num_bytes(leaf, fi,
new_extents[0].disk_num_bytes);
btrfs_mark_buffer_dirty(leaf);
btrfs_drop_extent_cache(inode, key.offset,
key.offset + num_bytes - 1, 0);
ret = btrfs_inc_extent_ref(trans, root,
new_extents[0].disk_bytenr,
new_extents[0].disk_num_bytes,
leaf->start,
root->root_key.objectid,
trans->transid,
key.objectid);
BUG_ON(ret);
ret = btrfs_free_extent(trans, root,
extent_key->objectid,
extent_key->offset,
leaf->start,
btrfs_header_owner(leaf),
btrfs_header_generation(leaf),
key.objectid, 0);
BUG_ON(ret);
btrfs_release_path(root, path);
key.offset += num_bytes;
} else {
BUG_ON(1);
#if 0
u64 alloc_hint;
u64 extent_len;
int i;
/*
* drop old extent pointer at first, then insert the
* new pointers one bye one
*/
btrfs_release_path(root, path);
ret = btrfs_drop_extents(trans, root, inode, key.offset,
key.offset + num_bytes,
key.offset, &alloc_hint);
BUG_ON(ret);
for (i = 0; i < nr_extents; i++) {
if (ext_offset >= new_extents[i].num_bytes) {
ext_offset -= new_extents[i].num_bytes;
continue;
}
extent_len = min(new_extents[i].num_bytes -
ext_offset, num_bytes);
ret = btrfs_insert_empty_item(trans, root,
path, &key,
sizeof(*fi));
BUG_ON(ret);
leaf = path->nodes[0];
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, fi,
trans->transid);
btrfs_set_file_extent_type(leaf, fi,
BTRFS_FILE_EXTENT_REG);
btrfs_set_file_extent_disk_bytenr(leaf, fi,
new_extents[i].disk_bytenr);
btrfs_set_file_extent_disk_num_bytes(leaf, fi,
new_extents[i].disk_num_bytes);
btrfs_set_file_extent_ram_bytes(leaf, fi,
new_extents[i].ram_bytes);
btrfs_set_file_extent_compression(leaf, fi,
new_extents[i].compression);
btrfs_set_file_extent_encryption(leaf, fi,
new_extents[i].encryption);
btrfs_set_file_extent_other_encoding(leaf, fi,
new_extents[i].other_encoding);
btrfs_set_file_extent_num_bytes(leaf, fi,
extent_len);
ext_offset += new_extents[i].offset;
btrfs_set_file_extent_offset(leaf, fi,
ext_offset);
btrfs_mark_buffer_dirty(leaf);
btrfs_drop_extent_cache(inode, key.offset,
key.offset + extent_len - 1, 0);
ret = btrfs_inc_extent_ref(trans, root,
new_extents[i].disk_bytenr,
new_extents[i].disk_num_bytes,
leaf->start,
root->root_key.objectid,
trans->transid, key.objectid);
BUG_ON(ret);
btrfs_release_path(root, path);
inode_add_bytes(inode, extent_len);
ext_offset = 0;
num_bytes -= extent_len;
key.offset += extent_len;
if (num_bytes == 0)
break;
}
BUG_ON(i >= nr_extents);
#endif
}
if (extent_locked) {
unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
lock_end, GFP_NOFS);
extent_locked = 0;
}
skip:
if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
key.offset >= search_end)
break;
cond_resched();
}
ret = 0;
out:
btrfs_release_path(root, path);
if (inode) {
mutex_unlock(&inode->i_mutex);
if (extent_locked) {
unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
lock_end, GFP_NOFS);
}
iput(inode);
}
return ret;
}
int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf, u64 orig_start)
{
int level;
int ret;
BUG_ON(btrfs_header_generation(buf) != trans->transid);
BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
level = btrfs_header_level(buf);
if (level == 0) {
struct btrfs_leaf_ref *ref;
struct btrfs_leaf_ref *orig_ref;
orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
if (!orig_ref)
return -ENOENT;
ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
if (!ref) {
btrfs_free_leaf_ref(root, orig_ref);
return -ENOMEM;
}
ref->nritems = orig_ref->nritems;
memcpy(ref->extents, orig_ref->extents,
sizeof(ref->extents[0]) * ref->nritems);
btrfs_free_leaf_ref(root, orig_ref);
ref->root_gen = trans->transid;
ref->bytenr = buf->start;
ref->owner = btrfs_header_owner(buf);
ref->generation = btrfs_header_generation(buf);
ret = btrfs_add_leaf_ref(root, ref, 0);
WARN_ON(ret);
btrfs_free_leaf_ref(root, ref);
}
return 0;
}
static noinline int invalidate_extent_cache(struct btrfs_root *root,
struct extent_buffer *leaf,
struct btrfs_block_group_cache *group,
struct btrfs_root *target_root)
{
struct btrfs_key key;
struct inode *inode = NULL;
struct btrfs_file_extent_item *fi;
struct extent_state *cached_state = NULL;
u64 num_bytes;
u64 skip_objectid = 0;
u32 nritems;
u32 i;
nritems = btrfs_header_nritems(leaf);
for (i = 0; i < nritems; i++) {
btrfs_item_key_to_cpu(leaf, &key, i);
if (key.objectid == skip_objectid ||
key.type != BTRFS_EXTENT_DATA_KEY)
continue;
fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
if (btrfs_file_extent_type(leaf, fi) ==
BTRFS_FILE_EXTENT_INLINE)
continue;
if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
continue;
if (!inode || inode->i_ino != key.objectid) {
iput(inode);
inode = btrfs_ilookup(target_root->fs_info->sb,
key.objectid, target_root, 1);
}
if (!inode) {
skip_objectid = key.objectid;
continue;
}
num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
lock_extent_bits(&BTRFS_I(inode)->io_tree, key.offset,
key.offset + num_bytes - 1, 0, &cached_state,
GFP_NOFS);
btrfs_drop_extent_cache(inode, key.offset,
key.offset + num_bytes - 1, 1);
unlock_extent_cached(&BTRFS_I(inode)->io_tree, key.offset,
key.offset + num_bytes - 1, &cached_state,
GFP_NOFS);
cond_resched();
}
iput(inode);
return 0;
}
static noinline int replace_extents_in_leaf(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *leaf,
struct btrfs_block_group_cache *group,
struct inode *reloc_inode)
{
struct btrfs_key key;
struct btrfs_key extent_key;
struct btrfs_file_extent_item *fi;
struct btrfs_leaf_ref *ref;
struct disk_extent *new_extent;
u64 bytenr;
u64 num_bytes;
u32 nritems;
u32 i;
int ext_index;
int nr_extent;
int ret;
new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
if (!new_extent)
return -ENOMEM;
ref = btrfs_lookup_leaf_ref(root, leaf->start);
BUG_ON(!ref);
ext_index = -1;
nritems = btrfs_header_nritems(leaf);
for (i = 0; i < nritems; i++) {
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;
bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
if (bytenr == 0)
continue;
ext_index++;
if (bytenr >= group->key.objectid + group->key.offset ||
bytenr + num_bytes <= group->key.objectid)
continue;
extent_key.objectid = bytenr;
extent_key.offset = num_bytes;
extent_key.type = BTRFS_EXTENT_ITEM_KEY;
nr_extent = 1;
ret = get_new_locations(reloc_inode, &extent_key,
group->key.objectid, 1,
&new_extent, &nr_extent);
if (ret > 0)
continue;
BUG_ON(ret < 0);
BUG_ON(ref->extents[ext_index].bytenr != bytenr);
BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
btrfs_set_file_extent_disk_bytenr(leaf, fi,
new_extent->disk_bytenr);
btrfs_set_file_extent_disk_num_bytes(leaf, fi,
new_extent->disk_num_bytes);
btrfs_mark_buffer_dirty(leaf);
ret = btrfs_inc_extent_ref(trans, root,
new_extent->disk_bytenr,
new_extent->disk_num_bytes,
leaf->start,
root->root_key.objectid,
trans->transid, key.objectid);
BUG_ON(ret);
ret = btrfs_free_extent(trans, root,
bytenr, num_bytes, leaf->start,
btrfs_header_owner(leaf),
btrfs_header_generation(leaf),
key.objectid, 0);
BUG_ON(ret);
cond_resched();
}
kfree(new_extent);
BUG_ON(ext_index + 1 != ref->nritems);
btrfs_free_leaf_ref(root, ref);
return 0;
}
int btrfs_free_reloc_root(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_root *reloc_root;
int ret;
if (root->reloc_root) {
reloc_root = root->reloc_root;
root->reloc_root = NULL;
list_add(&reloc_root->dead_list,
&root->fs_info->dead_reloc_roots);
btrfs_set_root_bytenr(&reloc_root->root_item,
reloc_root->node->start);
btrfs_set_root_level(&root->root_item,
btrfs_header_level(reloc_root->node));
memset(&reloc_root->root_item.drop_progress, 0,
sizeof(struct btrfs_disk_key));
reloc_root->root_item.drop_level = 0;
ret = btrfs_update_root(trans, root->fs_info->tree_root,
&reloc_root->root_key,
&reloc_root->root_item);
BUG_ON(ret);
}
return 0;
}
int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *reloc_root;
struct btrfs_root *prev_root = NULL;
struct list_head dead_roots;
int ret;
unsigned long nr;
INIT_LIST_HEAD(&dead_roots);
list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
while (!list_empty(&dead_roots)) {
reloc_root = list_entry(dead_roots.prev,
struct btrfs_root, dead_list);
list_del_init(&reloc_root->dead_list);
BUG_ON(reloc_root->commit_root != NULL);
while (1) {
trans = btrfs_join_transaction(root, 1);
BUG_ON(IS_ERR(trans));
mutex_lock(&root->fs_info->drop_mutex);
ret = btrfs_drop_snapshot(trans, reloc_root);
if (ret != -EAGAIN)
break;
mutex_unlock(&root->fs_info->drop_mutex);
nr = trans->blocks_used;
ret = btrfs_end_transaction(trans, root);
BUG_ON(ret);
btrfs_btree_balance_dirty(root, nr);
}
free_extent_buffer(reloc_root->node);
ret = btrfs_del_root(trans, root->fs_info->tree_root,
&reloc_root->root_key);
BUG_ON(ret);
mutex_unlock(&root->fs_info->drop_mutex);
nr = trans->blocks_used;
ret = btrfs_end_transaction(trans, root);
BUG_ON(ret);
btrfs_btree_balance_dirty(root, nr);
kfree(prev_root);
prev_root = reloc_root;
}
if (prev_root) {
btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
kfree(prev_root);
}
return 0;
}
int btrfs_add_dead_reloc_root(struct btrfs_root *root)
{
list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
return 0;
}
int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
{
struct btrfs_root *reloc_root;
struct btrfs_trans_handle *trans;
struct btrfs_key location;
int found;
int ret;
mutex_lock(&root->fs_info->tree_reloc_mutex);
ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
BUG_ON(ret);
found = !list_empty(&root->fs_info->dead_reloc_roots);
mutex_unlock(&root->fs_info->tree_reloc_mutex);
if (found) {
trans = btrfs_start_transaction(root, 1);
BUG_ON(IS_ERR(trans));
ret = btrfs_commit_transaction(trans, root);
BUG_ON(ret);
}
location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
location.offset = (u64)-1;
location.type = BTRFS_ROOT_ITEM_KEY;
reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
BUG_ON(!reloc_root);
ret = btrfs_orphan_cleanup(reloc_root);
BUG_ON(ret);
return 0;
}
static noinline int init_reloc_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_root *reloc_root;
struct extent_buffer *eb;
struct btrfs_root_item *root_item;
struct btrfs_key root_key;
int ret;
BUG_ON(!root->ref_cows);
if (root->reloc_root)
return 0;
root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
if (!root_item)
return -ENOMEM;
ret = btrfs_copy_root(trans, root, root->commit_root,
&eb, BTRFS_TREE_RELOC_OBJECTID);
BUG_ON(ret);
root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
root_key.offset = root->root_key.objectid;
root_key.type = BTRFS_ROOT_ITEM_KEY;
memcpy(root_item, &root->root_item, sizeof(root_item));
btrfs_set_root_refs(root_item, 0);
btrfs_set_root_bytenr(root_item, eb->start);
btrfs_set_root_level(root_item, btrfs_header_level(eb));
btrfs_set_root_generation(root_item, trans->transid);
btrfs_tree_unlock(eb);
free_extent_buffer(eb);
ret = btrfs_insert_root(trans, root->fs_info->tree_root,
&root_key, root_item);
BUG_ON(ret);
kfree(root_item);
reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
&root_key);
BUG_ON(IS_ERR(reloc_root));
reloc_root->last_trans = trans->transid;
reloc_root->commit_root = NULL;
reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
root->reloc_root = reloc_root;
return 0;
}
/*
* Core function of space balance.
*
* The idea is using reloc trees to relocate tree blocks in reference
* counted roots. There is one reloc tree for each subvol, and all
* reloc trees share same root key objectid. Reloc trees are snapshots
* of the latest committed roots of subvols (root->commit_root).
*
* To relocate a tree block referenced by a subvol, there are two steps.
* COW the block through subvol's reloc tree, then update block pointer
* in the subvol to point to the new block. Since all reloc trees share
* same root key objectid, doing special handing for tree blocks owned
* by them is easy. Once a tree block has been COWed in one reloc tree,
* we can use the resulting new block directly when the same block is
* required to COW again through other reloc trees. By this way, relocated
* tree blocks are shared between reloc trees, so they are also shared
* between subvols.
*/
static noinline int relocate_one_path(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_key *first_key,
struct btrfs_ref_path *ref_path,
struct btrfs_block_group_cache *group,
struct inode *reloc_inode)
{
struct btrfs_root *reloc_root;
struct extent_buffer *eb = NULL;
struct btrfs_key *keys;
u64 *nodes;
int level;
int shared_level;
int lowest_level = 0;
int ret;
if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
lowest_level = ref_path->owner_objectid;
if (!root->ref_cows) {
path->lowest_level = lowest_level;
ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
BUG_ON(ret < 0);
path->lowest_level = 0;
btrfs_release_path(root, path);
return 0;
}
mutex_lock(&root->fs_info->tree_reloc_mutex);
ret = init_reloc_tree(trans, root);
BUG_ON(ret);
reloc_root = root->reloc_root;
shared_level = ref_path->shared_level;
ref_path->shared_level = BTRFS_MAX_LEVEL - 1;
keys = ref_path->node_keys;
nodes = ref_path->new_nodes;
memset(&keys[shared_level + 1], 0,
sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1));
memset(&nodes[shared_level + 1], 0,
sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1));
if (nodes[lowest_level] == 0) {
path->lowest_level = lowest_level;
ret = btrfs_search_slot(trans, reloc_root, first_key, path,
0, 1);
BUG_ON(ret);
for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) {
eb = path->nodes[level];
if (!eb || eb == reloc_root->node)
break;
nodes[level] = eb->start;
if (level == 0)
btrfs_item_key_to_cpu(eb, &keys[level], 0);
else
btrfs_node_key_to_cpu(eb, &keys[level], 0);
}
if (nodes[0] &&
ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
eb = path->nodes[0];
ret = replace_extents_in_leaf(trans, reloc_root, eb,
group, reloc_inode);
BUG_ON(ret);
}
btrfs_release_path(reloc_root, path);
} else {
ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
lowest_level);
BUG_ON(ret);
}
/*
* replace tree blocks in the fs tree with tree blocks in
* the reloc tree.
*/
ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
BUG_ON(ret < 0);
if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
ret = btrfs_search_slot(trans, reloc_root, first_key, path,
0, 0);
BUG_ON(ret);
extent_buffer_get(path->nodes[0]);
eb = path->nodes[0];
btrfs_release_path(reloc_root, path);
ret = invalidate_extent_cache(reloc_root, eb, group, root);
BUG_ON(ret);
free_extent_buffer(eb);
}
mutex_unlock(&root->fs_info->tree_reloc_mutex);
path->lowest_level = 0;
return 0;
}
static noinline int relocate_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_key *first_key,
struct btrfs_ref_path *ref_path)
{
int ret;
ret = relocate_one_path(trans, root, path, first_key,
ref_path, NULL, NULL);
BUG_ON(ret);
return 0;
}
static noinline int del_extent_zero(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root,
struct btrfs_path *path,
struct btrfs_key *extent_key)
{
int ret;
ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
if (ret)
goto out;
ret = btrfs_del_item(trans, extent_root, path);
out:
btrfs_release_path(extent_root, path);
return ret;
}
static noinline struct btrfs_root *read_ref_root(struct btrfs_fs_info *fs_info,
struct btrfs_ref_path *ref_path)
{
struct btrfs_key root_key;
root_key.objectid = ref_path->root_objectid;
root_key.type = BTRFS_ROOT_ITEM_KEY;
if (is_cowonly_root(ref_path->root_objectid))
root_key.offset = 0;
else
root_key.offset = (u64)-1;
return btrfs_read_fs_root_no_name(fs_info, &root_key);
}
static noinline int relocate_one_extent(struct btrfs_root *extent_root,
struct btrfs_path *path,
struct btrfs_key *extent_key,
struct btrfs_block_group_cache *group,
struct inode *reloc_inode, int pass)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *found_root;
struct btrfs_ref_path *ref_path = NULL;
struct disk_extent *new_extents = NULL;
int nr_extents = 0;
int loops;
int ret;
int level;
struct btrfs_key first_key;
u64 prev_block = 0;
trans = btrfs_start_transaction(extent_root, 1);
BUG_ON(IS_ERR(trans));
if (extent_key->objectid == 0) {
ret = del_extent_zero(trans, extent_root, path, extent_key);
goto out;
}
ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
if (!ref_path) {
ret = -ENOMEM;
goto out;
}
for (loops = 0; ; loops++) {
if (loops == 0) {
ret = btrfs_first_ref_path(trans, extent_root, ref_path,
extent_key->objectid);
} else {
ret = btrfs_next_ref_path(trans, extent_root, ref_path);
}
if (ret < 0)
goto out;
if (ret > 0)
break;
if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
continue;
found_root = read_ref_root(extent_root->fs_info, ref_path);
BUG_ON(!found_root);
/*
* for reference counted tree, only process reference paths
* rooted at the latest committed root.
*/
if (found_root->ref_cows &&
ref_path->root_generation != found_root->root_key.offset)
continue;
if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
if (pass == 0) {
/*
* copy data extents to new locations
*/
u64 group_start = group->key.objectid;
ret = relocate_data_extent(reloc_inode,
extent_key,
group_start);
if (ret < 0)
goto out;
break;
}
level = 0;
} else {
level = ref_path->owner_objectid;
}
if (prev_block != ref_path->nodes[level]) {
struct extent_buffer *eb;
u64 block_start = ref_path->nodes[level];
u64 block_size = btrfs_level_size(found_root, level);
eb = read_tree_block(found_root, block_start,
block_size, 0);
if (!eb) {
ret = -EIO;
goto out;
}
btrfs_tree_lock(eb);
BUG_ON(level != btrfs_header_level(eb));
if (level == 0)
btrfs_item_key_to_cpu(eb, &first_key, 0);
else
btrfs_node_key_to_cpu(eb, &first_key, 0);
btrfs_tree_unlock(eb);
free_extent_buffer(eb);
prev_block = block_start;
}
mutex_lock(&extent_root->fs_info->trans_mutex);
btrfs_record_root_in_trans(found_root);
mutex_unlock(&extent_root->fs_info->trans_mutex);
if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
/*
* try to update data extent references while
* keeping metadata shared between snapshots.
*/
if (pass == 1) {
ret = relocate_one_path(trans, found_root,
path, &first_key, ref_path,
group, reloc_inode);
if (ret < 0)
goto out;
continue;
}
/*
* use fallback method to process the remaining
* references.
*/
if (!new_extents) {
u64 group_start = group->key.objectid;
new_extents = kmalloc(sizeof(*new_extents),
GFP_NOFS);
if (!new_extents) {
ret = -ENOMEM;
goto out;
}
nr_extents = 1;
ret = get_new_locations(reloc_inode,
extent_key,
group_start, 1,
&new_extents,
&nr_extents);
if (ret)
goto out;
}
ret = replace_one_extent(trans, found_root,
path, extent_key,
&first_key, ref_path,
new_extents, nr_extents);
} else {
ret = relocate_tree_block(trans, found_root, path,
&first_key, ref_path);
}
if (ret < 0)
goto out;
}
ret = 0;
out:
btrfs_end_transaction(trans, extent_root);
kfree(new_extents);
kfree(ref_path);
return ret;
}
#endif
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;
/*
* we add in the count of missing devices because we want
* to make sure that any RAID levels on a degraded FS
* continue to be honored.
*/
num_devices = root->fs_info->fs_devices->rw_devices +
root->fs_info->fs_devices->missing_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;
}
static int set_block_group_ro(struct btrfs_block_group_cache *cache)
{
struct btrfs_space_info *sinfo = cache->space_info;
u64 num_bytes;
int ret = -ENOSPC;
if (cache->ro)
return 0;
spin_lock(&sinfo->lock);
spin_lock(&cache->lock);
num_bytes = cache->key.offset - cache->reserved - cache->pinned -
cache->bytes_super - btrfs_block_group_used(&cache->item);
if (sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned +
sinfo->bytes_may_use + sinfo->bytes_readonly +
cache->reserved_pinned + num_bytes <= sinfo->total_bytes) {
sinfo->bytes_readonly += num_bytes;
sinfo->bytes_reserved += cache->reserved_pinned;
cache->reserved_pinned = 0;
cache->ro = 1;
ret = 0;
}
spin_unlock(&cache->lock);
spin_unlock(&sinfo->lock);
return ret;
}
int btrfs_set_block_group_ro(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
struct btrfs_trans_handle *trans;
u64 alloc_flags;
int ret;
BUG_ON(cache->ro);
trans = btrfs_join_transaction(root, 1);
BUG_ON(IS_ERR(trans));
alloc_flags = update_block_group_flags(root, cache->flags);
if (alloc_flags != cache->flags)
do_chunk_alloc(trans, root, 2 * 1024 * 1024, alloc_flags,
CHUNK_ALLOC_FORCE);
ret = set_block_group_ro(cache);
if (!ret)
goto out;
alloc_flags = get_alloc_profile(root, cache->space_info->flags);
ret = do_chunk_alloc(trans, root, 2 * 1024 * 1024, alloc_flags,
CHUNK_ALLOC_FORCE);
if (ret < 0)
goto out;
ret = set_block_group_ro(cache);
out:
btrfs_end_transaction(trans, root);
return ret;
}
int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 type)
{
u64 alloc_flags = get_alloc_profile(root, type);
return do_chunk_alloc(trans, root, 2 * 1024 * 1024, alloc_flags,
CHUNK_ALLOC_FORCE);
}
/*
* helper to account the unused space of all the readonly block group in the
* list. takes mirrors into account.
*/
static u64 __btrfs_get_ro_block_group_free_space(struct list_head *groups_list)
{
struct btrfs_block_group_cache *block_group;
u64 free_bytes = 0;
int factor;
list_for_each_entry(block_group, groups_list, list) {
spin_lock(&block_group->lock);
if (!block_group->ro) {
spin_unlock(&block_group->lock);
continue;
}
if (block_group->flags & (BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10 |
BTRFS_BLOCK_GROUP_DUP))
factor = 2;
else
factor = 1;
free_bytes += (block_group->key.offset -
btrfs_block_group_used(&block_group->item)) *
factor;
spin_unlock(&block_group->lock);
}
return free_bytes;
}
/*
* helper to account the unused space of all the readonly block group in the
* space_info. takes mirrors into account.
*/
u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
{
int i;
u64 free_bytes = 0;
spin_lock(&sinfo->lock);
for(i = 0; i < BTRFS_NR_RAID_TYPES; i++)
if (!list_empty(&sinfo->block_groups[i]))
free_bytes += __btrfs_get_ro_block_group_free_space(
&sinfo->block_groups[i]);
spin_unlock(&sinfo->lock);
return free_bytes;
}
int btrfs_set_block_group_rw(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
struct btrfs_space_info *sinfo = cache->space_info;
u64 num_bytes;
BUG_ON(!cache->ro);
spin_lock(&sinfo->lock);
spin_lock(&cache->lock);
num_bytes = cache->key.offset - cache->reserved - cache->pinned -
cache->bytes_super - btrfs_block_group_used(&cache->item);
sinfo->bytes_readonly -= num_bytes;
cache->ro = 0;
spin_unlock(&cache->lock);
spin_unlock(&sinfo->lock);
return 0;
}
/*
* checks to see if its even possible to relocate this block group.
*
* @return - -1 if it's not a good idea to relocate this block group, 0 if its
* ok to go ahead and try.
*/
int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
{
struct btrfs_block_group_cache *block_group;
struct btrfs_space_info *space_info;
struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
struct btrfs_device *device;
int full = 0;
int ret = 0;
block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
/* odd, couldn't find the block group, leave it alone */
if (!block_group)
return -1;
/* no bytes used, we're good */
if (!btrfs_block_group_used(&block_group->item))
goto out;
space_info = block_group->space_info;
spin_lock(&space_info->lock);
full = space_info->full;
/*
* if this is the last block group we have in this space, we can't
* relocate it unless we're able to allocate a new chunk below.
*
* Otherwise, we need to make sure we have room in the space to handle
* all of the extents from this block group. If we can, we're good
*/
if ((space_info->total_bytes != block_group->key.offset) &&
(space_info->bytes_used + space_info->bytes_reserved +
space_info->bytes_pinned + space_info->bytes_readonly +
btrfs_block_group_used(&block_group->item) <
space_info->total_bytes)) {
spin_unlock(&space_info->lock);
goto out;
}
spin_unlock(&space_info->lock);
/*
* ok we don't have enough space, but maybe we have free space on our
* devices to allocate new chunks for relocation, so loop through our
* alloc devices and guess if we have enough space. However, if we
* were marked as full, then we know there aren't enough chunks, and we
* can just return.
*/
ret = -1;
if (full)
goto out;
mutex_lock(&root->fs_info->chunk_mutex);
list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
u64 min_free = btrfs_block_group_used(&block_group->item);
u64 dev_offset;
/*
* check to make sure we can actually find a chunk with enough
* space to fit our block group in.
*/
if (device->total_bytes > device->bytes_used + min_free) {
ret = find_free_dev_extent(NULL, device, min_free,
&dev_offset, NULL);
if (!ret)
break;
ret = -1;
}
}
mutex_unlock(&root->fs_info->chunk_mutex);
out:
btrfs_put_block_group(block_group);
return ret;
}
static 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]++;
}
out:
return ret;
}
void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
{
struct btrfs_block_group_cache *block_group;
u64 last = 0;
while (1) {
struct inode *inode;
block_group = btrfs_lookup_first_block_group(info, last);
while (block_group) {
spin_lock(&block_group->lock);
if (block_group->iref)
break;
spin_unlock(&block_group->lock);
block_group = next_block_group(info->tree_root,
block_group);
}
if (!block_group) {
if (last == 0)
break;
last = 0;
continue;
}
inode = block_group->inode;
block_group->iref = 0;
block_group->inode = NULL;
spin_unlock(&block_group->lock);
iput(inode);
last = block_group->key.objectid + block_group->key.offset;
btrfs_put_block_group(block_group);
}
}
int btrfs_free_block_groups(struct btrfs_fs_info *info)
{
struct btrfs_block_group_cache *block_group;
struct btrfs_space_info *space_info;
struct btrfs_caching_control *caching_ctl;
struct rb_node *n;
down_write(&info->extent_commit_sem);
while (!list_empty(&info->caching_block_groups)) {
caching_ctl = list_entry(info->caching_block_groups.next,
struct btrfs_caching_control, list);
list_del(&caching_ctl->list);
put_caching_control(caching_ctl);
}
up_write(&info->extent_commit_sem);
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);
rb_erase(&block_group->cache_node,
&info->block_group_cache_tree);
spin_unlock(&info->block_group_cache_lock);
down_write(&block_group->space_info->groups_sem);
list_del(&block_group->list);
up_write(&block_group->space_info->groups_sem);
if (block_group->cached == BTRFS_CACHE_STARTED)
wait_block_group_cache_done(block_group);
/*
* We haven't cached this block group, which means we could
* possibly have excluded extents on this block group.
*/
if (block_group->cached == BTRFS_CACHE_NO)
free_excluded_extents(info->extent_root, block_group);
btrfs_remove_free_space_cache(block_group);
btrfs_put_block_group(block_group);
spin_lock(&info->block_group_cache_lock);
}
spin_unlock(&info->block_group_cache_lock);
/* now that all the block groups are freed, go through and
* free all the space_info structs. This is only called during
* the final stages of unmount, and so we know nobody is
* using them. We call synchronize_rcu() once before we start,
* just to be on the safe side.
*/
synchronize_rcu();
release_global_block_rsv(info);
while(!list_empty(&info->space_info)) {
space_info = list_entry(info->space_info.next,
struct btrfs_space_info,
list);
if (space_info->bytes_pinned > 0 ||
space_info->bytes_reserved > 0) {
WARN_ON(1);
dump_space_info(space_info, 0, 0);
}
list_del(&space_info->list);
kfree(space_info);
}
return 0;
}
static void __link_block_group(struct btrfs_space_info *space_info,
struct btrfs_block_group_cache *cache)
{
int index = get_block_group_index(cache);
down_write(&space_info->groups_sem);
list_add_tail(&cache->list, &space_info->block_groups[index]);
up_write(&space_info->groups_sem);
}
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;
int need_clear = 0;
u64 cache_gen;
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;
cache_gen = btrfs_super_cache_generation(&root->fs_info->super_copy);
if (cache_gen != 0 &&
btrfs_super_generation(&root->fs_info->super_copy) != cache_gen)
need_clear = 1;
if (btrfs_test_opt(root, CLEAR_CACHE))
need_clear = 1;
if (!btrfs_test_opt(root, SPACE_CACHE) && cache_gen)
printk(KERN_INFO "btrfs: disk space caching is enabled\n");
while (1) {
ret = find_first_block_group(root, path, &key);
if (ret > 0)
break;
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;
goto error;
}
atomic_set(&cache->count, 1);
spin_lock_init(&cache->lock);
spin_lock_init(&cache->tree_lock);
cache->fs_info = info;
INIT_LIST_HEAD(&cache->list);
INIT_LIST_HEAD(&cache->cluster_list);
if (need_clear)
cache->disk_cache_state = BTRFS_DC_CLEAR;
/*
* we only want to have 32k of ram per block group for keeping
* track of free space, and if we pass 1/2 of that we want to
* start converting things over to using bitmaps
*/
cache->extents_thresh = ((1024 * 32) / 2) /
sizeof(struct btrfs_free_space);
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);
cache->sectorsize = root->sectorsize;
/*
* We need to exclude the super stripes now so that the space
* info has super bytes accounted for, otherwise we'll think
* we have more space than we actually do.
*/
exclude_super_stripes(root, cache);
/*
* check for two cases, either we are full, and therefore
* don't need to bother with the caching work since we won't
* find any space, or we are empty, and we can just add all
* the space in and be done with it. This saves us _alot_ of
* time, particularly in the full case.
*/
if (found_key.offset == btrfs_block_group_used(&cache->item)) {
cache->last_byte_to_unpin = (u64)-1;
cache->cached = BTRFS_CACHE_FINISHED;
free_excluded_extents(root, cache);
} else if (btrfs_block_group_used(&cache->item) == 0) {
cache->last_byte_to_unpin = (u64)-1;
cache->cached = BTRFS_CACHE_FINISHED;
add_new_free_space(cache, root->fs_info,
found_key.objectid,
found_key.objectid +
found_key.offset);
free_excluded_extents(root, cache);
}
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(&cache->space_info->lock);
cache->space_info->bytes_readonly += cache->bytes_super;
spin_unlock(&cache->space_info->lock);
__link_block_group(space_info, cache);
ret = btrfs_add_block_group_cache(root->fs_info, cache);
BUG_ON(ret);
set_avail_alloc_bits(root->fs_info, cache->flags);
if (btrfs_chunk_readonly(root, cache->key.objectid))
set_block_group_ro(cache);
}
list_for_each_entry_rcu(space_info, &root->fs_info->space_info, list) {
if (!(get_alloc_profile(root, space_info->flags) &
(BTRFS_BLOCK_GROUP_RAID10 |
BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_DUP)))
continue;
/*
* avoid allocating from un-mirrored block group if there are
* mirrored block groups.
*/
list_for_each_entry(cache, &space_info->block_groups[3], list)
set_block_group_ro(cache);
list_for_each_entry(cache, &space_info->block_groups[4], list)
set_block_group_ro(cache);
}
init_global_block_rsv(info);
ret = 0;
error:
btrfs_free_path(path);
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;
extent_root = root->fs_info->extent_root;
root->fs_info->last_trans_log_full_commit = trans->transid;
cache = kzalloc(sizeof(*cache), GFP_NOFS);
if (!cache)
return -ENOMEM;
cache->key.objectid = chunk_offset;
cache->key.offset = size;
cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
cache->sectorsize = root->sectorsize;
cache->fs_info = root->fs_info;
/*
* we only want to have 32k of ram per block group for keeping track
* of free space, and if we pass 1/2 of that we want to start
* converting things over to using bitmaps
*/
cache->extents_thresh = ((1024 * 32) / 2) /
sizeof(struct btrfs_free_space);
atomic_set(&cache->count, 1);
spin_lock_init(&cache->lock);
spin_lock_init(&cache->tree_lock);
INIT_LIST_HEAD(&cache->list);
INIT_LIST_HEAD(&cache->cluster_list);
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);
cache->last_byte_to_unpin = (u64)-1;
cache->cached = BTRFS_CACHE_FINISHED;
exclude_super_stripes(root, cache);
add_new_free_space(cache, root->fs_info, chunk_offset,
chunk_offset + size);
free_excluded_extents(root, cache);
ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
&cache->space_info);
BUG_ON(ret);
spin_lock(&cache->space_info->lock);
cache->space_info->bytes_readonly += cache->bytes_super;
spin_unlock(&cache->space_info->lock);
__link_block_group(cache->space_info, cache);
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);
set_avail_alloc_bits(extent_root->fs_info, type);
return 0;
}
int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 group_start)
{
struct btrfs_path *path;
struct btrfs_block_group_cache *block_group;
struct btrfs_free_cluster *cluster;
struct btrfs_root *tree_root = root->fs_info->tree_root;
struct btrfs_key key;
struct inode *inode;
int ret;
int factor;
root = root->fs_info->extent_root;
block_group = btrfs_lookup_block_group(root->fs_info, group_start);
BUG_ON(!block_group);
BUG_ON(!block_group->ro);
/*
* Free the reserved super bytes from this block group before
* remove it.
*/
free_excluded_extents(root, block_group);
memcpy(&key, &block_group->key, sizeof(key));
if (block_group->flags & (BTRFS_BLOCK_GROUP_DUP |
BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10))
factor = 2;
else
factor = 1;
/* make sure this block group isn't part of an allocation cluster */
cluster = &root->fs_info->data_alloc_cluster;
spin_lock(&cluster->refill_lock);
btrfs_return_cluster_to_free_space(block_group, cluster);
spin_unlock(&cluster->refill_lock);
/*
* make sure this block group isn't part of a metadata
* allocation cluster
*/
cluster = &root->fs_info->meta_alloc_cluster;
spin_lock(&cluster->refill_lock);
btrfs_return_cluster_to_free_space(block_group, cluster);
spin_unlock(&cluster->refill_lock);
path = btrfs_alloc_path();
BUG_ON(!path);
inode = lookup_free_space_inode(root, block_group, path);
if (!IS_ERR(inode)) {
btrfs_orphan_add(trans, inode);
clear_nlink(inode);
/* One for the block groups ref */
spin_lock(&block_group->lock);
if (block_group->iref) {
block_group->iref = 0;
block_group->inode = NULL;
spin_unlock(&block_group->lock);
iput(inode);
} else {
spin_unlock(&block_group->lock);
}
/* One for our lookup ref */
iput(inode);
}
key.objectid = BTRFS_FREE_SPACE_OBJECTID;
key.offset = block_group->key.objectid;
key.type = 0;
ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
if (ret < 0)
goto out;
if (ret > 0)
btrfs_release_path(tree_root, path);
if (ret == 0) {
ret = btrfs_del_item(trans, tree_root, path);
if (ret)
goto out;
btrfs_release_path(tree_root, path);
}
spin_lock(&root->fs_info->block_group_cache_lock);
rb_erase(&block_group->cache_node,
&root->fs_info->block_group_cache_tree);
spin_unlock(&root->fs_info->block_group_cache_lock);
down_write(&block_group->space_info->groups_sem);
/*
* we must use list_del_init so people can check to see if they
* are still on the list after taking the semaphore
*/
list_del_init(&block_group->list);
up_write(&block_group->space_info->groups_sem);
if (block_group->cached == BTRFS_CACHE_STARTED)
wait_block_group_cache_done(block_group);
btrfs_remove_free_space_cache(block_group);
spin_lock(&block_group->space_info->lock);
block_group->space_info->total_bytes -= block_group->key.offset;
block_group->space_info->bytes_readonly -= block_group->key.offset;
block_group->space_info->disk_total -= block_group->key.offset * factor;
spin_unlock(&block_group->space_info->lock);
memcpy(&key, &block_group->key, sizeof(key));
btrfs_clear_space_info_full(root->fs_info);
btrfs_put_block_group(block_group);
btrfs_put_block_group(block_group);
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0)
ret = -EIO;
if (ret < 0)
goto out;
ret = btrfs_del_item(trans, root, path);
out:
btrfs_free_path(path);
return ret;
}
int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
{
struct btrfs_space_info *space_info;
struct btrfs_super_block *disk_super;
u64 features;
u64 flags;
int mixed = 0;
int ret;
disk_super = &fs_info->super_copy;
if (!btrfs_super_root(disk_super))
return 1;
features = btrfs_super_incompat_flags(disk_super);
if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
mixed = 1;
flags = BTRFS_BLOCK_GROUP_SYSTEM;
ret = update_space_info(fs_info, flags, 0, 0, &space_info);
if (ret)
goto out;
if (mixed) {
flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
ret = update_space_info(fs_info, flags, 0, 0, &space_info);
} else {
flags = BTRFS_BLOCK_GROUP_METADATA;
ret = update_space_info(fs_info, flags, 0, 0, &space_info);
if (ret)
goto out;
flags = BTRFS_BLOCK_GROUP_DATA;
ret = update_space_info(fs_info, flags, 0, 0, &space_info);
}
out:
return ret;
}
int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
{
return unpin_extent_range(root, start, end);
}
int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,
u64 num_bytes, u64 *actual_bytes)
{
return btrfs_discard_extent(root, bytenr, num_bytes, actual_bytes);
}
int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_block_group_cache *cache = NULL;
u64 group_trimmed;
u64 start;
u64 end;
u64 trimmed = 0;
int ret = 0;
cache = btrfs_lookup_block_group(fs_info, range->start);
while (cache) {
if (cache->key.objectid >= (range->start + range->len)) {
btrfs_put_block_group(cache);
break;
}
start = max(range->start, cache->key.objectid);
end = min(range->start + range->len,
cache->key.objectid + cache->key.offset);
if (end - start >= range->minlen) {
if (!block_group_cache_done(cache)) {
ret = cache_block_group(cache, NULL, root, 0);
if (!ret)
wait_block_group_cache_done(cache);
}
ret = btrfs_trim_block_group(cache,
&group_trimmed,
start,
end,
range->minlen);
trimmed += group_trimmed;
if (ret) {
btrfs_put_block_group(cache);
break;
}
}
cache = next_block_group(fs_info->tree_root, cache);
}
range->len = trimmed;
return ret;
}