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linux/fs/btrfs/extent-tree.c
Chris Mason 4184ea7f90 Btrfs: Fix locking around adding new space_info 
Storage allocated to different raid levels in btrfs is tracked by
a btrfs_space_info structure, and all of the current space_infos are
collected into a list_head.

Most filesystems have 3 or 4 of these structs total, and the list is
only changed when new raid levels are added or at unmount time.

This commit adds rcu locking on the list head, and properly frees
things at unmount time.  It also clears the space_info->full flag
whenever new space is added to the FS.

The locking for the space info list goes like this:

reads: protected by rcu_read_lock()
writes: protected by the chunk_mutex

At unmount time we don't need special locking because all the readers
are gone.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-10 12:39:20 -04:00

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/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/sched.h>
#include <linux/pagemap.h>
#include <linux/writeback.h>
#include <linux/blkdev.h>
#include <linux/sort.h>
#include <linux/rcupdate.h>
#include "compat.h"
#include "hash.h"
#include "crc32c.h"
#include "ctree.h"
#include "disk-io.h"
#include "print-tree.h"
#include "transaction.h"
#include "volumes.h"
#include "locking.h"
#include "ref-cache.h"
#define PENDING_EXTENT_INSERT 0
#define PENDING_EXTENT_DELETE 1
#define PENDING_BACKREF_UPDATE 2
struct pending_extent_op {
int type;
u64 bytenr;
u64 num_bytes;
u64 parent;
u64 orig_parent;
u64 generation;
u64 orig_generation;
int level;
struct list_head list;
int del;
};
static int finish_current_insert(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root, int all);
static int del_pending_extents(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root, int all);
static int pin_down_bytes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, int is_data);
static int update_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, int alloc,
int mark_free);
static int do_chunk_alloc(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root, u64 alloc_bytes,
u64 flags, int force);
static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
{
return (cache->flags & bits) == bits;
}
/*
* this adds the block group to the fs_info rb tree for the block group
* cache
*/
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)
atomic_inc(&ret->count);
spin_unlock(&info->block_group_cache_lock);
return ret;
}
/*
* this is only called by cache_block_group, since we could have freed extents
* we need to check the pinned_extents for any extents that can't be used yet
* since their free space will be released as soon as the transaction commits.
*/
static int add_new_free_space(struct btrfs_block_group_cache *block_group,
struct btrfs_fs_info *info, u64 start, u64 end)
{
u64 extent_start, extent_end, size;
int ret;
mutex_lock(&info->pinned_mutex);
while (start < end) {
ret = find_first_extent_bit(&info->pinned_extents, start,
&extent_start, &extent_end,
EXTENT_DIRTY);
if (ret)
break;
if (extent_start == start) {
start = extent_end + 1;
} else if (extent_start > start && extent_start < end) {
size = extent_start - start;
ret = btrfs_add_free_space(block_group, start,
size);
BUG_ON(ret);
start = extent_end + 1;
} else {
break;
}
}
if (start < end) {
size = end - start;
ret = btrfs_add_free_space(block_group, start, size);
BUG_ON(ret);
}
mutex_unlock(&info->pinned_mutex);
return 0;
}
static int remove_sb_from_cache(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
u64 bytenr;
u64 *logical;
int stripe_len;
int i, nr, 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--) {
btrfs_remove_free_space(cache, logical[nr],
stripe_len);
}
kfree(logical);
}
return 0;
}
static int cache_block_group(struct btrfs_root *root,
struct btrfs_block_group_cache *block_group)
{
struct btrfs_path *path;
int ret = 0;
struct btrfs_key key;
struct extent_buffer *leaf;
int slot;
u64 last;
if (!block_group)
return 0;
root = root->fs_info->extent_root;
if (block_group->cached)
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 2;
/*
* we get into deadlocks with paths held by callers of this function.
* since the alloc_mutex is protecting things right now, just
* skip the locking here
*/
path->skip_locking = 1;
last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
key.objectid = last;
key.offset = 0;
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto err;
while (1) {
leaf = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto err;
if (ret == 0)
continue;
else
break;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid < block_group->key.objectid)
goto next;
if (key.objectid >= block_group->key.objectid +
block_group->key.offset)
break;
if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
add_new_free_space(block_group, root->fs_info, last,
key.objectid);
last = key.objectid + key.offset;
}
next:
path->slots[0]++;
}
add_new_free_space(block_group, root->fs_info, last,
block_group->key.objectid +
block_group->key.offset);
remove_sb_from_cache(root, block_group);
block_group->cached = 1;
ret = 0;
err:
btrfs_free_path(path);
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 teh given bytenr
*/
struct btrfs_block_group_cache *btrfs_lookup_block_group(
struct btrfs_fs_info *info,
u64 bytenr)
{
struct btrfs_block_group_cache *cache;
cache = block_group_cache_tree_search(info, bytenr, 1);
return cache;
}
static inline void put_block_group(struct btrfs_block_group_cache *cache)
{
if (atomic_dec_and_test(&cache->count))
kfree(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;
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;
}
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);
put_block_group(cache);
goto found;
}
}
spin_unlock(&cache->lock);
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;
}
/*
* Back reference rules. Back refs have three main goals:
*
* 1) differentiate between all holders of references to an extent so that
* when a reference is dropped we can make sure it was a valid reference
* before freeing the extent.
*
* 2) Provide enough information to quickly find the holders of an extent
* if we notice a given block is corrupted or bad.
*
* 3) Make it easy to migrate blocks for FS shrinking or storage pool
* maintenance. This is actually the same as #2, but with a slightly
* different use case.
*
* File extents can be referenced by:
*
* - multiple snapshots, subvolumes, or different generations in one subvol
* - different files inside a single subvolume
* - different offsets inside a file (bookend extents in file.c)
*
* The extent ref structure has fields for:
*
* - Objectid of the subvolume root
* - Generation number of the tree holding the reference
* - objectid of the file holding the reference
* - number of references holding by parent node (alway 1 for tree blocks)
*
* Btree leaf may hold multiple references to a file extent. In most cases,
* these references are from same file and the corresponding offsets inside
* the file are close together.
*
* When a file extent is allocated the fields are filled in:
* (root_key.objectid, trans->transid, inode objectid, 1)
*
* When a leaf is cow'd new references are added for every file extent found
* in the leaf. It looks similar to the create case, but trans->transid will
* be different when the block is cow'd.
*
* (root_key.objectid, trans->transid, inode objectid,
* number of references in the leaf)
*
* When a file extent is removed either during snapshot deletion or
* file truncation, we find the corresponding back reference and check
* the following fields:
*
* (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
* inode objectid)
*
* Btree extents can be referenced by:
*
* - Different subvolumes
* - Different generations of the same subvolume
*
* When a tree block is created, back references are inserted:
*
* (root->root_key.objectid, trans->transid, level, 1)
*
* When a tree block is cow'd, new back references are added for all the
* blocks it points to. If the tree block isn't in reference counted root,
* the old back references are removed. These new back references are of
* the form (trans->transid will have increased since creation):
*
* (root->root_key.objectid, trans->transid, level, 1)
*
* When a backref is in deleting, the following fields are checked:
*
* if backref was for a tree root:
* (btrfs_header_owner(itself), btrfs_header_generation(itself), level)
* else
* (btrfs_header_owner(parent), btrfs_header_generation(parent), level)
*
* Back Reference Key composing:
*
* The key objectid corresponds to the first byte in the extent, the key
* type is set to BTRFS_EXTENT_REF_KEY, and the key offset is the first
* byte of parent extent. If a extent is tree root, the key offset is set
* to the key objectid.
*/
static noinline int lookup_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent,
u64 ref_root, u64 ref_generation,
u64 owner_objectid, int del)
{
struct btrfs_key key;
struct btrfs_extent_ref *ref;
struct extent_buffer *leaf;
u64 ref_objectid;
int ret;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_REF_KEY;
key.offset = parent;
ret = btrfs_search_slot(trans, root, &key, path, del ? -1 : 0, 1);
if (ret < 0)
goto out;
if (ret > 0) {
ret = -ENOENT;
goto out;
}
leaf = path->nodes[0];
ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
ref_objectid = btrfs_ref_objectid(leaf, ref);
if (btrfs_ref_root(leaf, ref) != ref_root ||
btrfs_ref_generation(leaf, ref) != ref_generation ||
(ref_objectid != owner_objectid &&
ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) {
ret = -EIO;
WARN_ON(1);
goto out;
}
ret = 0;
out:
return ret;
}
/*
* updates all the backrefs that are pending on update_list for the
* extent_root
*/
static noinline int update_backrefs(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root,
struct btrfs_path *path,
struct list_head *update_list)
{
struct btrfs_key key;
struct btrfs_extent_ref *ref;
struct btrfs_fs_info *info = extent_root->fs_info;
struct pending_extent_op *op;
struct extent_buffer *leaf;
int ret = 0;
struct list_head *cur = update_list->next;
u64 ref_objectid;
u64 ref_root = extent_root->root_key.objectid;
op = list_entry(cur, struct pending_extent_op, list);
search:
key.objectid = op->bytenr;
key.type = BTRFS_EXTENT_REF_KEY;
key.offset = op->orig_parent;
ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 1);
BUG_ON(ret);
leaf = path->nodes[0];
loop:
ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
ref_objectid = btrfs_ref_objectid(leaf, ref);
if (btrfs_ref_root(leaf, ref) != ref_root ||
btrfs_ref_generation(leaf, ref) != op->orig_generation ||
(ref_objectid != op->level &&
ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) {
printk(KERN_ERR "btrfs couldn't find %llu, parent %llu, "
"root %llu, owner %u\n",
(unsigned long long)op->bytenr,
(unsigned long long)op->orig_parent,
(unsigned long long)ref_root, op->level);
btrfs_print_leaf(extent_root, leaf);
BUG();
}
key.objectid = op->bytenr;
key.offset = op->parent;
key.type = BTRFS_EXTENT_REF_KEY;
ret = btrfs_set_item_key_safe(trans, extent_root, path, &key);
BUG_ON(ret);
ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
btrfs_set_ref_generation(leaf, ref, op->generation);
cur = cur->next;
list_del_init(&op->list);
unlock_extent(&info->extent_ins, op->bytenr,
op->bytenr + op->num_bytes - 1, GFP_NOFS);
kfree(op);
if (cur == update_list) {
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(extent_root, path);
goto out;
}
op = list_entry(cur, struct pending_extent_op, list);
path->slots[0]++;
while (path->slots[0] < btrfs_header_nritems(leaf)) {
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid == op->bytenr &&
key.type == BTRFS_EXTENT_REF_KEY)
goto loop;
path->slots[0]++;
}
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(extent_root, path);
goto search;
out:
return 0;
}
static noinline int insert_extents(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root,
struct btrfs_path *path,
struct list_head *insert_list, int nr)
{
struct btrfs_key *keys;
u32 *data_size;
struct pending_extent_op *op;
struct extent_buffer *leaf;
struct list_head *cur = insert_list->next;
struct btrfs_fs_info *info = extent_root->fs_info;
u64 ref_root = extent_root->root_key.objectid;
int i = 0, last = 0, ret;
int total = nr * 2;
if (!nr)
return 0;
keys = kzalloc(total * sizeof(struct btrfs_key), GFP_NOFS);
if (!keys)
return -ENOMEM;
data_size = kzalloc(total * sizeof(u32), GFP_NOFS);
if (!data_size) {
kfree(keys);
return -ENOMEM;
}
list_for_each_entry(op, insert_list, list) {
keys[i].objectid = op->bytenr;
keys[i].offset = op->num_bytes;
keys[i].type = BTRFS_EXTENT_ITEM_KEY;
data_size[i] = sizeof(struct btrfs_extent_item);
i++;
keys[i].objectid = op->bytenr;
keys[i].offset = op->parent;
keys[i].type = BTRFS_EXTENT_REF_KEY;
data_size[i] = sizeof(struct btrfs_extent_ref);
i++;
}
op = list_entry(cur, struct pending_extent_op, list);
i = 0;
while (i < total) {
int c;
ret = btrfs_insert_some_items(trans, extent_root, path,
keys+i, data_size+i, total-i);
BUG_ON(ret < 0);
if (last && ret > 1)
BUG();
leaf = path->nodes[0];
for (c = 0; c < ret; c++) {
int ref_first = keys[i].type == BTRFS_EXTENT_REF_KEY;
/*
* if the first item we inserted was a backref, then
* the EXTENT_ITEM will be the odd c's, else it will
* be the even c's
*/
if ((ref_first && (c % 2)) ||
(!ref_first && !(c % 2))) {
struct btrfs_extent_item *itm;
itm = btrfs_item_ptr(leaf, path->slots[0] + c,
struct btrfs_extent_item);
btrfs_set_extent_refs(path->nodes[0], itm, 1);
op->del++;
} else {
struct btrfs_extent_ref *ref;
ref = btrfs_item_ptr(leaf, path->slots[0] + c,
struct btrfs_extent_ref);
btrfs_set_ref_root(leaf, ref, ref_root);
btrfs_set_ref_generation(leaf, ref,
op->generation);
btrfs_set_ref_objectid(leaf, ref, op->level);
btrfs_set_ref_num_refs(leaf, ref, 1);
op->del++;
}
/*
* using del to see when its ok to free up the
* pending_extent_op. In the case where we insert the
* last item on the list in order to help do batching
* we need to not free the extent op until we actually
* insert the extent_item
*/
if (op->del == 2) {
unlock_extent(&info->extent_ins, op->bytenr,
op->bytenr + op->num_bytes - 1,
GFP_NOFS);
cur = cur->next;
list_del_init(&op->list);
kfree(op);
if (cur != insert_list)
op = list_entry(cur,
struct pending_extent_op,
list);
}
}
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(extent_root, path);
/*
* Ok backref's and items usually go right next to eachother,
* but if we could only insert 1 item that means that we
* inserted on the end of a leaf, and we have no idea what may
* be on the next leaf so we just play it safe. In order to
* try and help this case we insert the last thing on our
* insert list so hopefully it will end up being the last
* thing on the leaf and everything else will be before it,
* which will let us insert a whole bunch of items at the same
* time.
*/
if (ret == 1 && !last && (i + ret < total)) {
/*
* last: where we will pick up the next time around
* i: our current key to insert, will be total - 1
* cur: the current op we are screwing with
* op: duh
*/
last = i + ret;
i = total - 1;
cur = insert_list->prev;
op = list_entry(cur, struct pending_extent_op, list);
} else if (last) {
/*
* ok we successfully inserted the last item on the
* list, lets reset everything
*
* i: our current key to insert, so where we left off
* last time
* last: done with this
* cur: the op we are messing with
* op: duh
* total: since we inserted the last key, we need to
* decrement total so we dont overflow
*/
i = last;
last = 0;
total--;
if (i < total) {
cur = insert_list->next;
op = list_entry(cur, struct pending_extent_op,
list);
}
} else {
i += ret;
}
cond_resched();
}
ret = 0;
kfree(keys);
kfree(data_size);
return ret;
}
static noinline int insert_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent,
u64 ref_root, u64 ref_generation,
u64 owner_objectid)
{
struct btrfs_key key;
struct extent_buffer *leaf;
struct btrfs_extent_ref *ref;
u32 num_refs;
int ret;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_REF_KEY;
key.offset = parent;
ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*ref));
if (ret == 0) {
leaf = path->nodes[0];
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref);
btrfs_set_ref_root(leaf, ref, ref_root);
btrfs_set_ref_generation(leaf, ref, ref_generation);
btrfs_set_ref_objectid(leaf, ref, owner_objectid);
btrfs_set_ref_num_refs(leaf, ref, 1);
} else if (ret == -EEXIST) {
u64 existing_owner;
BUG_ON(owner_objectid < BTRFS_FIRST_FREE_OBJECTID);
leaf = path->nodes[0];
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref);
if (btrfs_ref_root(leaf, ref) != ref_root ||
btrfs_ref_generation(leaf, ref) != ref_generation) {
ret = -EIO;
WARN_ON(1);
goto out;
}
num_refs = btrfs_ref_num_refs(leaf, ref);
BUG_ON(num_refs == 0);
btrfs_set_ref_num_refs(leaf, ref, num_refs + 1);
existing_owner = btrfs_ref_objectid(leaf, ref);
if (existing_owner != owner_objectid &&
existing_owner != BTRFS_MULTIPLE_OBJECTIDS) {
btrfs_set_ref_objectid(leaf, ref,
BTRFS_MULTIPLE_OBJECTIDS);
}
ret = 0;
} else {
goto out;
}
btrfs_mark_buffer_dirty(path->nodes[0]);
out:
btrfs_release_path(root, path);
return ret;
}
static noinline int remove_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path)
{
struct extent_buffer *leaf;
struct btrfs_extent_ref *ref;
u32 num_refs;
int ret = 0;
leaf = path->nodes[0];
ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
num_refs = btrfs_ref_num_refs(leaf, ref);
BUG_ON(num_refs == 0);
num_refs -= 1;
if (num_refs == 0) {
ret = btrfs_del_item(trans, root, path);
} else {
btrfs_set_ref_num_refs(leaf, ref, num_refs);
btrfs_mark_buffer_dirty(leaf);
}
btrfs_release_path(root, path);
return ret;
}
#ifdef BIO_RW_DISCARD
static void btrfs_issue_discard(struct block_device *bdev,
u64 start, u64 len)
{
blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL);
}
#endif
static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
u64 num_bytes)
{
#ifdef BIO_RW_DISCARD
int ret;
u64 map_length = num_bytes;
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, READ,
bytenr, &map_length, &multi, 0);
if (!ret) {
struct btrfs_bio_stripe *stripe = multi->stripes;
int i;
if (map_length > num_bytes)
map_length = num_bytes;
for (i = 0; i < multi->num_stripes; i++, stripe++) {
btrfs_issue_discard(stripe->dev->bdev,
stripe->physical,
map_length);
}
kfree(multi);
}
return ret;
#else
return 0;
#endif
}
static noinline int free_extents(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root,
struct list_head *del_list)
{
struct btrfs_fs_info *info = extent_root->fs_info;
struct btrfs_path *path;
struct btrfs_key key, found_key;
struct extent_buffer *leaf;
struct list_head *cur;
struct pending_extent_op *op;
struct btrfs_extent_item *ei;
int ret, num_to_del, extent_slot = 0, found_extent = 0;
u32 refs;
u64 bytes_freed = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 1;
search:
/* search for the backref for the current ref we want to delete */
cur = del_list->next;
op = list_entry(cur, struct pending_extent_op, list);
ret = lookup_extent_backref(trans, extent_root, path, op->bytenr,
op->orig_parent,
extent_root->root_key.objectid,
op->orig_generation, op->level, 1);
if (ret) {
printk(KERN_ERR "btrfs unable to find backref byte nr %llu "
"root %llu gen %llu owner %u\n",
(unsigned long long)op->bytenr,
(unsigned long long)extent_root->root_key.objectid,
(unsigned long long)op->orig_generation, op->level);
btrfs_print_leaf(extent_root, path->nodes[0]);
WARN_ON(1);
goto out;
}
extent_slot = path->slots[0];
num_to_del = 1;
found_extent = 0;
/*
* if we aren't the first item on the leaf we can move back one and see
* if our ref is right next to our extent item
*/
if (likely(extent_slot)) {
extent_slot--;
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
extent_slot);
if (found_key.objectid == op->bytenr &&
found_key.type == BTRFS_EXTENT_ITEM_KEY &&
found_key.offset == op->num_bytes) {
num_to_del++;
found_extent = 1;
}
}
/*
* if we didn't find the extent we need to delete the backref and then
* search for the extent item key so we can update its ref count
*/
if (!found_extent) {
key.objectid = op->bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = op->num_bytes;
ret = remove_extent_backref(trans, extent_root, path);
BUG_ON(ret);
btrfs_release_path(extent_root, path);
ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
BUG_ON(ret);
extent_slot = path->slots[0];
}
/* this is where we update the ref count for the extent */
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, extent_slot, struct btrfs_extent_item);
refs = btrfs_extent_refs(leaf, ei);
BUG_ON(refs == 0);
refs--;
btrfs_set_extent_refs(leaf, ei, refs);
btrfs_mark_buffer_dirty(leaf);
/*
* This extent needs deleting. The reason cur_slot is extent_slot +
* num_to_del is because extent_slot points to the slot where the extent
* is, and if the backref was not right next to the extent we will be
* deleting at least 1 item, and will want to start searching at the
* slot directly next to extent_slot. However if we did find the
* backref next to the extent item them we will be deleting at least 2
* items and will want to start searching directly after the ref slot
*/
if (!refs) {
struct list_head *pos, *n, *end;
int cur_slot = extent_slot+num_to_del;
u64 super_used;
u64 root_used;
path->slots[0] = extent_slot;
bytes_freed = op->num_bytes;
mutex_lock(&info->pinned_mutex);
ret = pin_down_bytes(trans, extent_root, op->bytenr,
op->num_bytes, op->level >=
BTRFS_FIRST_FREE_OBJECTID);
mutex_unlock(&info->pinned_mutex);
BUG_ON(ret < 0);
op->del = ret;
/*
* we need to see if we can delete multiple things at once, so
* start looping through the list of extents we are wanting to
* delete and see if their extent/backref's are right next to
* eachother and the extents only have 1 ref
*/
for (pos = cur->next; pos != del_list; pos = pos->next) {
struct pending_extent_op *tmp;
tmp = list_entry(pos, struct pending_extent_op, list);
/* we only want to delete extent+ref at this stage */
if (cur_slot >= btrfs_header_nritems(leaf) - 1)
break;
btrfs_item_key_to_cpu(leaf, &found_key, cur_slot);
if (found_key.objectid != tmp->bytenr ||
found_key.type != BTRFS_EXTENT_ITEM_KEY ||
found_key.offset != tmp->num_bytes)
break;
/* check to make sure this extent only has one ref */
ei = btrfs_item_ptr(leaf, cur_slot,
struct btrfs_extent_item);
if (btrfs_extent_refs(leaf, ei) != 1)
break;
btrfs_item_key_to_cpu(leaf, &found_key, cur_slot+1);
if (found_key.objectid != tmp->bytenr ||
found_key.type != BTRFS_EXTENT_REF_KEY ||
found_key.offset != tmp->orig_parent)
break;
/*
* the ref is right next to the extent, we can set the
* ref count to 0 since we will delete them both now
*/
btrfs_set_extent_refs(leaf, ei, 0);
/* pin down the bytes for this extent */
mutex_lock(&info->pinned_mutex);
ret = pin_down_bytes(trans, extent_root, tmp->bytenr,
tmp->num_bytes, tmp->level >=
BTRFS_FIRST_FREE_OBJECTID);
mutex_unlock(&info->pinned_mutex);
BUG_ON(ret < 0);
/*
* use the del field to tell if we need to go ahead and
* free up the extent when we delete the item or not.
*/
tmp->del = ret;
bytes_freed += tmp->num_bytes;
num_to_del += 2;
cur_slot += 2;
}
end = pos;
/* update the free space counters */
spin_lock(&info->delalloc_lock);
super_used = btrfs_super_bytes_used(&info->super_copy);
btrfs_set_super_bytes_used(&info->super_copy,
super_used - bytes_freed);
root_used = btrfs_root_used(&extent_root->root_item);
btrfs_set_root_used(&extent_root->root_item,
root_used - bytes_freed);
spin_unlock(&info->delalloc_lock);
/* delete the items */
ret = btrfs_del_items(trans, extent_root, path,
path->slots[0], num_to_del);
BUG_ON(ret);
/*
* loop through the extents we deleted and do the cleanup work
* on them
*/
for (pos = cur, n = pos->next; pos != end;
pos = n, n = pos->next) {
struct pending_extent_op *tmp;
tmp = list_entry(pos, struct pending_extent_op, list);
/*
* remember tmp->del tells us wether or not we pinned
* down the extent
*/
ret = update_block_group(trans, extent_root,
tmp->bytenr, tmp->num_bytes, 0,
tmp->del);
BUG_ON(ret);
list_del_init(&tmp->list);
unlock_extent(&info->extent_ins, tmp->bytenr,
tmp->bytenr + tmp->num_bytes - 1,
GFP_NOFS);
kfree(tmp);
}
} else if (refs && found_extent) {
/*
* the ref and extent were right next to eachother, but the
* extent still has a ref, so just free the backref and keep
* going
*/
ret = remove_extent_backref(trans, extent_root, path);
BUG_ON(ret);
list_del_init(&op->list);
unlock_extent(&info->extent_ins, op->bytenr,
op->bytenr + op->num_bytes - 1, GFP_NOFS);
kfree(op);
} else {
/*
* the extent has multiple refs and the backref we were looking
* for was not right next to it, so just unlock and go next,
* we're good to go
*/
list_del_init(&op->list);
unlock_extent(&info->extent_ins, op->bytenr,
op->bytenr + op->num_bytes - 1, GFP_NOFS);
kfree(op);
}
btrfs_release_path(extent_root, path);
if (!list_empty(del_list))
goto search;
out:
btrfs_free_path(path);
return ret;
}
static int __btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr,
u64 orig_parent, u64 parent,
u64 orig_root, u64 ref_root,
u64 orig_generation, u64 ref_generation,
u64 owner_objectid)
{
int ret;
struct btrfs_root *extent_root = root->fs_info->extent_root;
struct btrfs_path *path;
if (root == root->fs_info->extent_root) {
struct pending_extent_op *extent_op;
u64 num_bytes;
BUG_ON(owner_objectid >= BTRFS_MAX_LEVEL);
num_bytes = btrfs_level_size(root, (int)owner_objectid);
mutex_lock(&root->fs_info->extent_ins_mutex);
if (test_range_bit(&root->fs_info->extent_ins, bytenr,
bytenr + num_bytes - 1, EXTENT_WRITEBACK, 0)) {
u64 priv;
ret = get_state_private(&root->fs_info->extent_ins,
bytenr, &priv);
BUG_ON(ret);
extent_op = (struct pending_extent_op *)
(unsigned long)priv;
BUG_ON(extent_op->parent != orig_parent);
BUG_ON(extent_op->generation != orig_generation);
extent_op->parent = parent;
extent_op->generation = ref_generation;
} else {
extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
BUG_ON(!extent_op);
extent_op->type = PENDING_BACKREF_UPDATE;
extent_op->bytenr = bytenr;
extent_op->num_bytes = num_bytes;
extent_op->parent = parent;
extent_op->orig_parent = orig_parent;
extent_op->generation = ref_generation;
extent_op->orig_generation = orig_generation;
extent_op->level = (int)owner_objectid;
INIT_LIST_HEAD(&extent_op->list);
extent_op->del = 0;
set_extent_bits(&root->fs_info->extent_ins,
bytenr, bytenr + num_bytes - 1,
EXTENT_WRITEBACK, GFP_NOFS);
set_state_private(&root->fs_info->extent_ins,
bytenr, (unsigned long)extent_op);
}
mutex_unlock(&root->fs_info->extent_ins_mutex);
return 0;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = lookup_extent_backref(trans, extent_root, path,
bytenr, orig_parent, orig_root,
orig_generation, owner_objectid, 1);
if (ret)
goto out;
ret = remove_extent_backref(trans, extent_root, path);
if (ret)
goto out;
ret = insert_extent_backref(trans, extent_root, path, bytenr,
parent, ref_root, ref_generation,
owner_objectid);
BUG_ON(ret);
finish_current_insert(trans, extent_root, 0);
del_pending_extents(trans, extent_root, 0);
out:
btrfs_free_path(path);
return ret;
}
int btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr,
u64 orig_parent, u64 parent,
u64 ref_root, u64 ref_generation,
u64 owner_objectid)
{
int ret;
if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
return 0;
ret = __btrfs_update_extent_ref(trans, root, bytenr, orig_parent,
parent, ref_root, ref_root,
ref_generation, ref_generation,
owner_objectid);
return ret;
}
static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr,
u64 orig_parent, u64 parent,
u64 orig_root, u64 ref_root,
u64 orig_generation, u64 ref_generation,
u64 owner_objectid)
{
struct btrfs_path *path;
int ret;
struct btrfs_key key;
struct extent_buffer *l;
struct btrfs_extent_item *item;
u32 refs;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 1;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = (u64)-1;
ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
0, 1);
if (ret < 0)
return ret;
BUG_ON(ret == 0 || path->slots[0] == 0);
path->slots[0]--;
l = path->nodes[0];
btrfs_item_key_to_cpu(l, &key, path->slots[0]);
if (key.objectid != bytenr) {
btrfs_print_leaf(root->fs_info->extent_root, path->nodes[0]);
printk(KERN_ERR "btrfs wanted %llu found %llu\n",
(unsigned long long)bytenr,
(unsigned long long)key.objectid);
BUG();
}
BUG_ON(key.type != BTRFS_EXTENT_ITEM_KEY);
item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
refs = btrfs_extent_refs(l, item);
btrfs_set_extent_refs(l, item, refs + 1);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(root->fs_info->extent_root, path);
path->reada = 1;
ret = insert_extent_backref(trans, root->fs_info->extent_root,
path, bytenr, parent,
ref_root, ref_generation,
owner_objectid);
BUG_ON(ret);
finish_current_insert(trans, root->fs_info->extent_root, 0);
del_pending_extents(trans, root->fs_info->extent_root, 0);
btrfs_free_path(path);
return 0;
}
int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent,
u64 ref_root, u64 ref_generation,
u64 owner_objectid)
{
int ret;
if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
return 0;
ret = __btrfs_inc_extent_ref(trans, root, bytenr, 0, parent,
0, ref_root, 0, ref_generation,
owner_objectid);
return ret;
}
int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
u64 start;
u64 end;
int ret;
while(1) {
finish_current_insert(trans, root->fs_info->extent_root, 1);
del_pending_extents(trans, root->fs_info->extent_root, 1);
/* is there more work to do? */
ret = find_first_extent_bit(&root->fs_info->pending_del,
0, &start, &end, EXTENT_WRITEBACK);
if (!ret)
continue;
ret = find_first_extent_bit(&root->fs_info->extent_ins,
0, &start, &end, EXTENT_WRITEBACK);
if (!ret)
continue;
break;
}
return 0;
}
int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr,
u64 num_bytes, u32 *refs)
{
struct btrfs_path *path;
int ret;
struct btrfs_key key;
struct extent_buffer *l;
struct btrfs_extent_item *item;
WARN_ON(num_bytes < root->sectorsize);
path = btrfs_alloc_path();
path->reada = 1;
key.objectid = bytenr;
key.offset = num_bytes;
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
0, 0);
if (ret < 0)
goto out;
if (ret != 0) {
btrfs_print_leaf(root, path->nodes[0]);
printk(KERN_INFO "btrfs failed to find block number %llu\n",
(unsigned long long)bytenr);
BUG();
}
l = path->nodes[0];
item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
*refs = btrfs_extent_refs(l, item);
out:
btrfs_free_path(path);
return 0;
}
int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 objectid, u64 bytenr)
{
struct btrfs_root *extent_root = root->fs_info->extent_root;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_extent_ref *ref_item;
struct btrfs_key key;
struct btrfs_key found_key;
u64 ref_root;
u64 last_snapshot;
u32 nritems;
int ret;
key.objectid = bytenr;
key.offset = (u64)-1;
key.type = BTRFS_EXTENT_ITEM_KEY;
path = btrfs_alloc_path();
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, &found_key, path->slots[0]);
if (found_key.objectid != bytenr ||
found_key.type != BTRFS_EXTENT_ITEM_KEY)
goto out;
last_snapshot = btrfs_root_last_snapshot(&root->root_item);
while (1) {
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(extent_root, path);
if (ret < 0)
goto out;
if (ret == 0)
continue;
break;
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != bytenr)
break;
if (found_key.type != BTRFS_EXTENT_REF_KEY) {
path->slots[0]++;
continue;
}
ref_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref);
ref_root = btrfs_ref_root(leaf, ref_item);
if ((ref_root != root->root_key.objectid &&
ref_root != BTRFS_TREE_LOG_OBJECTID) ||
objectid != btrfs_ref_objectid(leaf, ref_item)) {
ret = 1;
goto out;
}
if (btrfs_ref_generation(leaf, ref_item) <= last_snapshot) {
ret = 1;
goto out;
}
path->slots[0]++;
}
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct extent_buffer *buf, u32 nr_extents)
{
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;
}
noinline int btrfs_inc_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *orig_buf,
struct extent_buffer *buf, u32 *nr_extents)
{
u64 bytenr;
u64 ref_root;
u64 orig_root;
u64 ref_generation;
u64 orig_generation;
struct refsort *sorted;
u32 nritems;
u32 nr_file_extents = 0;
struct btrfs_key key;
struct btrfs_file_extent_item *fi;
int i;
int level;
int ret = 0;
int faili = 0;
int refi = 0;
int slot;
int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
u64, u64, u64, u64, u64, u64, u64, u64);
ref_root = btrfs_header_owner(buf);
ref_generation = btrfs_header_generation(buf);
orig_root = btrfs_header_owner(orig_buf);
orig_generation = btrfs_header_generation(orig_buf);
nritems = btrfs_header_nritems(buf);
level = btrfs_header_level(buf);
sorted = kmalloc(sizeof(struct refsort) * nritems, GFP_NOFS);
BUG_ON(!sorted);
if (root->ref_cows) {
process_func = __btrfs_inc_extent_ref;
} else {
if (level == 0 &&
root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
goto out;
if (level != 0 &&
root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
goto out;
process_func = __btrfs_update_extent_ref;
}
/*
* we make two passes through the items. In the first pass we
* only record the byte number and slot. Then we sort based on
* byte number and do the actual work based on the sorted results
*/
for (i = 0; i < nritems; i++) {
cond_resched();
if (level == 0) {
btrfs_item_key_to_cpu(buf, &key, i);
if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
continue;
fi = btrfs_item_ptr(buf, i,
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(buf, fi) ==
BTRFS_FILE_EXTENT_INLINE)
continue;
bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
if (bytenr == 0)
continue;
nr_file_extents++;
sorted[refi].bytenr = bytenr;
sorted[refi].slot = i;
refi++;
} else {
bytenr = btrfs_node_blockptr(buf, i);
sorted[refi].bytenr = bytenr;
sorted[refi].slot = i;
refi++;
}
}
/*
* if refi == 0, we didn't actually put anything into the sorted
* array and we're done
*/
if (refi == 0)
goto out;
sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL);
for (i = 0; i < refi; i++) {
cond_resched();
slot = sorted[i].slot;
bytenr = sorted[i].bytenr;
if (level == 0) {
btrfs_item_key_to_cpu(buf, &key, slot);
ret = process_func(trans, root, bytenr,
orig_buf->start, buf->start,
orig_root, ref_root,
orig_generation, ref_generation,
key.objectid);
if (ret) {
faili = slot;
WARN_ON(1);
goto fail;
}
} else {
ret = process_func(trans, root, bytenr,
orig_buf->start, buf->start,
orig_root, ref_root,
orig_generation, ref_generation,
level - 1);
if (ret) {
faili = slot;
WARN_ON(1);
goto fail;
}
}
}
out:
kfree(sorted);
if (nr_extents) {
if (level == 0)
*nr_extents = nr_file_extents;
else
*nr_extents = nritems;
}
return 0;
fail:
kfree(sorted);
WARN_ON(1);
return ret;
}
int btrfs_update_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct extent_buffer *orig_buf,
struct extent_buffer *buf, int start_slot, int nr)
{
u64 bytenr;
u64 ref_root;
u64 orig_root;
u64 ref_generation;
u64 orig_generation;
struct btrfs_key key;
struct btrfs_file_extent_item *fi;
int i;
int ret;
int slot;
int level;
BUG_ON(start_slot < 0);
BUG_ON(start_slot + nr > btrfs_header_nritems(buf));
ref_root = btrfs_header_owner(buf);
ref_generation = btrfs_header_generation(buf);
orig_root = btrfs_header_owner(orig_buf);
orig_generation = btrfs_header_generation(orig_buf);
level = btrfs_header_level(buf);
if (!root->ref_cows) {
if (level == 0 &&
root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
return 0;
if (level != 0 &&
root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
return 0;
}
for (i = 0, slot = start_slot; i < nr; i++, slot++) {
cond_resched();
if (level == 0) {
btrfs_item_key_to_cpu(buf, &key, slot);
if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
continue;
fi = btrfs_item_ptr(buf, slot,
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(buf, fi) ==
BTRFS_FILE_EXTENT_INLINE)
continue;
bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
if (bytenr == 0)
continue;
ret = __btrfs_update_extent_ref(trans, root, bytenr,
orig_buf->start, buf->start,
orig_root, ref_root,
orig_generation, ref_generation,
key.objectid);
if (ret)
goto fail;
} else {
bytenr = btrfs_node_blockptr(buf, slot);
ret = __btrfs_update_extent_ref(trans, root, bytenr,
orig_buf->start, buf->start,
orig_root, ref_root,
orig_generation, ref_generation,
level - 1);
if (ret)
goto fail;
}
}
return 0;
fail:
WARN_ON(1);
return -1;
}
static int write_one_cache_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_block_group_cache *cache)
{
int ret;
int pending_ret;
struct btrfs_root *extent_root = root->fs_info->extent_root;
unsigned long bi;
struct extent_buffer *leaf;
ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
if (ret < 0)
goto fail;
BUG_ON(ret);
leaf = path->nodes[0];
bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(extent_root, path);
fail:
finish_current_insert(trans, extent_root, 0);
pending_ret = del_pending_extents(trans, extent_root, 0);
if (ret)
return ret;
if (pending_ret)
return pending_ret;
return 0;
}
int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_block_group_cache *cache, *entry;
struct rb_node *n;
int err = 0;
int werr = 0;
struct btrfs_path *path;
u64 last = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
while (1) {
cache = NULL;
spin_lock(&root->fs_info->block_group_cache_lock);
for (n = rb_first(&root->fs_info->block_group_cache_tree);
n; n = rb_next(n)) {
entry = rb_entry(n, struct btrfs_block_group_cache,
cache_node);
if (entry->dirty) {
cache = entry;
break;
}
}
spin_unlock(&root->fs_info->block_group_cache_lock);
if (!cache)
break;
cache->dirty = 0;
last += cache->key.offset;
err = write_one_cache_group(trans, root,
path, cache);
/*
* if we fail to write the cache group, we want
* to keep it marked dirty in hopes that a later
* write will work
*/
if (err) {
werr = err;
continue;
}
}
btrfs_free_path(path);
return werr;
}
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)
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;
found = __find_space_info(info, flags);
if (found) {
spin_lock(&found->lock);
found->total_bytes += total_bytes;
found->bytes_used += bytes_used;
found->full = 0;
spin_unlock(&found->lock);
*space_info = found;
return 0;
}
found = kzalloc(sizeof(*found), GFP_NOFS);
if (!found)
return -ENOMEM;
INIT_LIST_HEAD(&found->block_groups);
init_rwsem(&found->groups_sem);
spin_lock_init(&found->lock);
found->flags = flags;
found->total_bytes = total_bytes;
found->bytes_used = bytes_used;
found->bytes_pinned = 0;
found->bytes_reserved = 0;
found->bytes_readonly = 0;
found->bytes_delalloc = 0;
found->full = 0;
found->force_alloc = 0;
*space_info = found;
list_add_rcu(&found->list, &info->space_info);
return 0;
}
static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
{
u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10 |
BTRFS_BLOCK_GROUP_DUP);
if (extra_flags) {
if (flags & BTRFS_BLOCK_GROUP_DATA)
fs_info->avail_data_alloc_bits |= extra_flags;
if (flags & BTRFS_BLOCK_GROUP_METADATA)
fs_info->avail_metadata_alloc_bits |= extra_flags;
if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
fs_info->avail_system_alloc_bits |= extra_flags;
}
}
static void set_block_group_readonly(struct btrfs_block_group_cache *cache)
{
spin_lock(&cache->space_info->lock);
spin_lock(&cache->lock);
if (!cache->ro) {
cache->space_info->bytes_readonly += cache->key.offset -
btrfs_block_group_used(&cache->item);
cache->ro = 1;
}
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
}
u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
{
u64 num_devices = root->fs_info->fs_devices->rw_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 btrfs_get_alloc_profile(struct btrfs_root *root, u64 data)
{
struct btrfs_fs_info *info = root->fs_info;
u64 alloc_profile;
if (data) {
alloc_profile = info->avail_data_alloc_bits &
info->data_alloc_profile;
data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
} else if (root == root->fs_info->chunk_root) {
alloc_profile = info->avail_system_alloc_bits &
info->system_alloc_profile;
data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
} else {
alloc_profile = info->avail_metadata_alloc_bits &
info->metadata_alloc_profile;
data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
}
return btrfs_reduce_alloc_profile(root, data);
}
void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)
{
u64 alloc_target;
alloc_target = btrfs_get_alloc_profile(root, 1);
BTRFS_I(inode)->space_info = __find_space_info(root->fs_info,
alloc_target);
}
/*
* for now this just makes sure we have at least 5% of our metadata space free
* for use.
*/
int btrfs_check_metadata_free_space(struct btrfs_root *root)
{
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_space_info *meta_sinfo;
u64 alloc_target, thresh;
int committed = 0, ret;
/* get the space info for where the metadata will live */
alloc_target = btrfs_get_alloc_profile(root, 0);
meta_sinfo = __find_space_info(info, alloc_target);
again:
spin_lock(&meta_sinfo->lock);
if (!meta_sinfo->full)
thresh = meta_sinfo->total_bytes * 80;
else
thresh = meta_sinfo->total_bytes * 95;
do_div(thresh, 100);
if (meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly > thresh) {
struct btrfs_trans_handle *trans;
if (!meta_sinfo->full) {
meta_sinfo->force_alloc = 1;
spin_unlock(&meta_sinfo->lock);
trans = btrfs_start_transaction(root, 1);
if (!trans)
return -ENOMEM;
ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2 * 1024 * 1024, alloc_target, 0);
btrfs_end_transaction(trans, root);
goto again;
}
spin_unlock(&meta_sinfo->lock);
if (!committed) {
committed = 1;
trans = btrfs_join_transaction(root, 1);
if (!trans)
return -ENOMEM;
ret = btrfs_commit_transaction(trans, root);
if (ret)
return ret;
goto again;
}
return -ENOSPC;
}
spin_unlock(&meta_sinfo->lock);
return 0;
}
/*
* 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 btrfs_root *root, struct inode *inode,
u64 bytes)
{
struct btrfs_space_info *data_sinfo;
int ret = 0, committed = 0;
/* make sure bytes are sectorsize aligned */
bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
data_sinfo = BTRFS_I(inode)->space_info;
again:
/* make sure we have enough space to handle the data first */
spin_lock(&data_sinfo->lock);
if (data_sinfo->total_bytes - data_sinfo->bytes_used -
data_sinfo->bytes_delalloc - data_sinfo->bytes_reserved -
data_sinfo->bytes_pinned - data_sinfo->bytes_readonly -
data_sinfo->bytes_may_use < 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) {
u64 alloc_target;
data_sinfo->force_alloc = 1;
spin_unlock(&data_sinfo->lock);
alloc_target = btrfs_get_alloc_profile(root, 1);
trans = btrfs_start_transaction(root, 1);
if (!trans)
return -ENOMEM;
ret = do_chunk_alloc(trans, root->fs_info->extent_root,
bytes + 2 * 1024 * 1024,
alloc_target, 0);
btrfs_end_transaction(trans, root);
if (ret)
return ret;
goto again;
}
spin_unlock(&data_sinfo->lock);
/* commit the current transaction and try again */
if (!committed) {
committed = 1;
trans = btrfs_join_transaction(root, 1);
if (!trans)
return -ENOMEM;
ret = btrfs_commit_transaction(trans, root);
if (ret)
return ret;
goto again;
}
printk(KERN_ERR "no space left, need %llu, %llu delalloc bytes"
", %llu bytes_used, %llu bytes_reserved, "
"%llu bytes_pinned, %llu bytes_readonly, %llu may use"
"%llu total\n", bytes, data_sinfo->bytes_delalloc,
data_sinfo->bytes_used, data_sinfo->bytes_reserved,
data_sinfo->bytes_pinned, data_sinfo->bytes_readonly,
data_sinfo->bytes_may_use, data_sinfo->total_bytes);
return -ENOSPC;
}
data_sinfo->bytes_may_use += bytes;
BTRFS_I(inode)->reserved_bytes += bytes;
spin_unlock(&data_sinfo->lock);
return btrfs_check_metadata_free_space(root);
}
/*
* if there was an error for whatever reason after calling
* btrfs_check_data_free_space, call this so we can cleanup the counters.
*/
void btrfs_free_reserved_data_space(struct btrfs_root *root,
struct inode *inode, u64 bytes)
{
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);
}
/* called when we are adding a delalloc extent to the inode's io_tree */
void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode,
u64 bytes)
{
struct btrfs_space_info *data_sinfo;
/* get the space info for where this inode will be storing its data */
data_sinfo = BTRFS_I(inode)->space_info;
/* make sure we have enough space to handle the data first */
spin_lock(&data_sinfo->lock);
data_sinfo->bytes_delalloc += bytes;
/*
* we are adding a delalloc extent without calling
* btrfs_check_data_free_space first. This happens on a weird
* writepage condition, but shouldn't hurt our accounting
*/
if (unlikely(bytes > BTRFS_I(inode)->reserved_bytes)) {
data_sinfo->bytes_may_use -= BTRFS_I(inode)->reserved_bytes;
BTRFS_I(inode)->reserved_bytes = 0;
} else {
data_sinfo->bytes_may_use -= bytes;
BTRFS_I(inode)->reserved_bytes -= bytes;
}
spin_unlock(&data_sinfo->lock);
}
/* called when we are clearing an delalloc extent from the inode's io_tree */
void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode,
u64 bytes)
{
struct btrfs_space_info *info;
info = BTRFS_I(inode)->space_info;
spin_lock(&info->lock);
info->bytes_delalloc -= bytes;
spin_unlock(&info->lock);
}
static int do_chunk_alloc(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root, u64 alloc_bytes,
u64 flags, int force)
{
struct btrfs_space_info *space_info;
u64 thresh;
int ret = 0;
mutex_lock(&extent_root->fs_info->chunk_mutex);
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);
spin_lock(&space_info->lock);
if (space_info->force_alloc) {
force = 1;
space_info->force_alloc = 0;
}
if (space_info->full) {
spin_unlock(&space_info->lock);
goto out;
}
thresh = space_info->total_bytes - space_info->bytes_readonly;
thresh = div_factor(thresh, 6);
if (!force &&
(space_info->bytes_used + space_info->bytes_pinned +
space_info->bytes_reserved + alloc_bytes) < thresh) {
spin_unlock(&space_info->lock);
goto out;
}
spin_unlock(&space_info->lock);
ret = btrfs_alloc_chunk(trans, extent_root, flags);
if (ret)
space_info->full = 1;
out:
mutex_unlock(&extent_root->fs_info->chunk_mutex);
return ret;
}
static int update_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, int alloc,
int mark_free)
{
struct btrfs_block_group_cache *cache;
struct btrfs_fs_info *info = root->fs_info;
u64 total = num_bytes;
u64 old_val;
u64 byte_in_group;
while (total) {
cache = btrfs_lookup_block_group(info, bytenr);
if (!cache)
return -1;
byte_in_group = bytenr - cache->key.objectid;
WARN_ON(byte_in_group > cache->key.offset);
spin_lock(&cache->space_info->lock);
spin_lock(&cache->lock);
cache->dirty = 1;
old_val = btrfs_block_group_used(&cache->item);
num_bytes = min(total, cache->key.offset - byte_in_group);
if (alloc) {
old_val += num_bytes;
cache->space_info->bytes_used += num_bytes;
if (cache->ro)
cache->space_info->bytes_readonly -= num_bytes;
btrfs_set_block_group_used(&cache->item, old_val);
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
} else {
old_val -= num_bytes;
cache->space_info->bytes_used -= num_bytes;
if (cache->ro)
cache->space_info->bytes_readonly += num_bytes;
btrfs_set_block_group_used(&cache->item, old_val);
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
if (mark_free) {
int ret;
ret = btrfs_discard_extent(root, bytenr,
num_bytes);
WARN_ON(ret);
ret = btrfs_add_free_space(cache, bytenr,
num_bytes);
WARN_ON(ret);
}
}
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;
put_block_group(cache);
return bytenr;
}
int btrfs_update_pinned_extents(struct btrfs_root *root,
u64 bytenr, u64 num, int pin)
{
u64 len;
struct btrfs_block_group_cache *cache;
struct btrfs_fs_info *fs_info = root->fs_info;
WARN_ON(!mutex_is_locked(&root->fs_info->pinned_mutex));
if (pin) {
set_extent_dirty(&fs_info->pinned_extents,
bytenr, bytenr + num - 1, GFP_NOFS);
} else {
clear_extent_dirty(&fs_info->pinned_extents,
bytenr, bytenr + num - 1, GFP_NOFS);
}
while (num > 0) {
cache = btrfs_lookup_block_group(fs_info, bytenr);
BUG_ON(!cache);
len = min(num, cache->key.offset -
(bytenr - cache->key.objectid));
if (pin) {
spin_lock(&cache->space_info->lock);
spin_lock(&cache->lock);
cache->pinned += len;
cache->space_info->bytes_pinned += len;
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
fs_info->total_pinned += len;
} else {
spin_lock(&cache->space_info->lock);
spin_lock(&cache->lock);
cache->pinned -= len;
cache->space_info->bytes_pinned -= len;
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
fs_info->total_pinned -= len;
if (cache->cached)
btrfs_add_free_space(cache, bytenr, len);
}
put_block_group(cache);
bytenr += len;
num -= len;
}
return 0;
}
static int update_reserved_extents(struct btrfs_root *root,
u64 bytenr, u64 num, int reserve)
{
u64 len;
struct btrfs_block_group_cache *cache;
struct btrfs_fs_info *fs_info = root->fs_info;
while (num > 0) {
cache = btrfs_lookup_block_group(fs_info, bytenr);
BUG_ON(!cache);
len = min(num, cache->key.offset -
(bytenr - cache->key.objectid));
spin_lock(&cache->space_info->lock);
spin_lock(&cache->lock);
if (reserve) {
cache->reserved += len;
cache->space_info->bytes_reserved += len;
} else {
cache->reserved -= len;
cache->space_info->bytes_reserved -= len;
}
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
put_block_group(cache);
bytenr += len;
num -= len;
}
return 0;
}
int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
{
u64 last = 0;
u64 start;
u64 end;
struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
int ret;
mutex_lock(&root->fs_info->pinned_mutex);
while (1) {
ret = find_first_extent_bit(pinned_extents, last,
&start, &end, EXTENT_DIRTY);
if (ret)
break;
set_extent_dirty(copy, start, end, GFP_NOFS);
last = end + 1;
}
mutex_unlock(&root->fs_info->pinned_mutex);
return 0;
}
int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_io_tree *unpin)
{
u64 start;
u64 end;
int ret;
mutex_lock(&root->fs_info->pinned_mutex);
while (1) {
ret = find_first_extent_bit(unpin, 0, &start, &end,
EXTENT_DIRTY);
if (ret)
break;
ret = btrfs_discard_extent(root, start, end + 1 - start);
btrfs_update_pinned_extents(root, start, end + 1 - start, 0);
clear_extent_dirty(unpin, start, end, GFP_NOFS);
if (need_resched()) {
mutex_unlock(&root->fs_info->pinned_mutex);
cond_resched();
mutex_lock(&root->fs_info->pinned_mutex);
}
}
mutex_unlock(&root->fs_info->pinned_mutex);
return ret;
}
static int finish_current_insert(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root, int all)
{
u64 start;
u64 end;
u64 priv;
u64 search = 0;
struct btrfs_fs_info *info = extent_root->fs_info;
struct btrfs_path *path;
struct pending_extent_op *extent_op, *tmp;
struct list_head insert_list, update_list;
int ret;
int num_inserts = 0, max_inserts, restart = 0;
path = btrfs_alloc_path();
INIT_LIST_HEAD(&insert_list);
INIT_LIST_HEAD(&update_list);
max_inserts = extent_root->leafsize /
(2 * sizeof(struct btrfs_key) + 2 * sizeof(struct btrfs_item) +
sizeof(struct btrfs_extent_ref) +
sizeof(struct btrfs_extent_item));
again:
mutex_lock(&info->extent_ins_mutex);
while (1) {
ret = find_first_extent_bit(&info->extent_ins, search, &start,
&end, EXTENT_WRITEBACK);
if (ret) {
if (restart && !num_inserts &&
list_empty(&update_list)) {
restart = 0;
search = 0;
continue;
}
break;
}
ret = try_lock_extent(&info->extent_ins, start, end, GFP_NOFS);
if (!ret) {
if (all)
restart = 1;
search = end + 1;
if (need_resched()) {
mutex_unlock(&info->extent_ins_mutex);
cond_resched();
mutex_lock(&info->extent_ins_mutex);
}
continue;
}
ret = get_state_private(&info->extent_ins, start, &priv);
BUG_ON(ret);
extent_op = (struct pending_extent_op *)(unsigned long) priv;
if (extent_op->type == PENDING_EXTENT_INSERT) {
num_inserts++;
list_add_tail(&extent_op->list, &insert_list);
search = end + 1;
if (num_inserts == max_inserts) {
restart = 1;
break;
}
} else if (extent_op->type == PENDING_BACKREF_UPDATE) {
list_add_tail(&extent_op->list, &update_list);
search = end + 1;
} else {
BUG();
}
}
/*
* process the update list, clear the writeback bit for it, and if
* somebody marked this thing for deletion then just unlock it and be
* done, the free_extents will handle it
*/
list_for_each_entry_safe(extent_op, tmp, &update_list, list) {
clear_extent_bits(&info->extent_ins, extent_op->bytenr,
extent_op->bytenr + extent_op->num_bytes - 1,
EXTENT_WRITEBACK, GFP_NOFS);
if (extent_op->del) {
list_del_init(&extent_op->list);
unlock_extent(&info->extent_ins, extent_op->bytenr,
extent_op->bytenr + extent_op->num_bytes
- 1, GFP_NOFS);
kfree(extent_op);
}
}
mutex_unlock(&info->extent_ins_mutex);
/*
* still have things left on the update list, go ahead an update
* everything
*/
if (!list_empty(&update_list)) {
ret = update_backrefs(trans, extent_root, path, &update_list);
BUG_ON(ret);
/* we may have COW'ed new blocks, so lets start over */
if (all)
restart = 1;
}
/*
* if no inserts need to be done, but we skipped some extents and we
* need to make sure everything is cleaned then reset everything and
* go back to the beginning
*/
if (!num_inserts && restart) {
search = 0;
restart = 0;
INIT_LIST_HEAD(&update_list);
INIT_LIST_HEAD(&insert_list);
goto again;
} else if (!num_inserts) {
goto out;
}
/*
* process the insert extents list. Again if we are deleting this
* extent, then just unlock it, pin down the bytes if need be, and be
* done with it. Saves us from having to actually insert the extent
* into the tree and then subsequently come along and delete it
*/
mutex_lock(&info->extent_ins_mutex);
list_for_each_entry_safe(extent_op, tmp, &insert_list, list) {
clear_extent_bits(&info->extent_ins, extent_op->bytenr,
extent_op->bytenr + extent_op->num_bytes - 1,
EXTENT_WRITEBACK, GFP_NOFS);
if (extent_op->del) {
u64 used;
list_del_init(&extent_op->list);
unlock_extent(&info->extent_ins, extent_op->bytenr,
extent_op->bytenr + extent_op->num_bytes
- 1, GFP_NOFS);
mutex_lock(&extent_root->fs_info->pinned_mutex);
ret = pin_down_bytes(trans, extent_root,
extent_op->bytenr,
extent_op->num_bytes, 0);
mutex_unlock(&extent_root->fs_info->pinned_mutex);
spin_lock(&info->delalloc_lock);
used = btrfs_super_bytes_used(&info->super_copy);
btrfs_set_super_bytes_used(&info->super_copy,
used - extent_op->num_bytes);
used = btrfs_root_used(&extent_root->root_item);
btrfs_set_root_used(&extent_root->root_item,
used - extent_op->num_bytes);
spin_unlock(&info->delalloc_lock);
ret = update_block_group(trans, extent_root,
extent_op->bytenr,
extent_op->num_bytes,
0, ret > 0);
BUG_ON(ret);
kfree(extent_op);
num_inserts--;
}
}
mutex_unlock(&info->extent_ins_mutex);
ret = insert_extents(trans, extent_root, path, &insert_list,
num_inserts);
BUG_ON(ret);
/*
* if restart is set for whatever reason we need to go back and start
* searching through the pending list again.
*
* We just inserted some extents, which could have resulted in new
* blocks being allocated, which would result in new blocks needing
* updates, so if all is set we _must_ restart to get the updated
* blocks.
*/
if (restart || all) {
INIT_LIST_HEAD(&insert_list);
INIT_LIST_HEAD(&update_list);
search = 0;
restart = 0;
num_inserts = 0;
goto again;
}
out:
btrfs_free_path(path);
return 0;
}
static int pin_down_bytes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, int is_data)
{
int err = 0;
struct extent_buffer *buf;
if (is_data)
goto pinit;
buf = btrfs_find_tree_block(root, bytenr, num_bytes);
if (!buf)
goto pinit;
/* we can reuse a block if it hasn't been written
* and it is from this transaction. We can't
* reuse anything from the tree log root because
* it has tiny sub-transactions.
*/
if (btrfs_buffer_uptodate(buf, 0) &&
btrfs_try_tree_lock(buf)) {
u64 header_owner = btrfs_header_owner(buf);
u64 header_transid = btrfs_header_generation(buf);
if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
header_owner != BTRFS_TREE_RELOC_OBJECTID &&
header_transid == trans->transid &&
!btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
clean_tree_block(NULL, root, buf);
btrfs_tree_unlock(buf);
free_extent_buffer(buf);
return 1;
}
btrfs_tree_unlock(buf);
}
free_extent_buffer(buf);
pinit:
btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
BUG_ON(err < 0);
return 0;
}
/*
* remove an extent from the root, returns 0 on success
*/
static int __free_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent,
u64 root_objectid, u64 ref_generation,
u64 owner_objectid, int pin, int mark_free)
{
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_root *extent_root = info->extent_root;
struct extent_buffer *leaf;
int ret;
int extent_slot = 0;
int found_extent = 0;
int num_to_del = 1;
struct btrfs_extent_item *ei;
u32 refs;
key.objectid = bytenr;
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
key.offset = num_bytes;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 1;
ret = lookup_extent_backref(trans, extent_root, path,
bytenr, parent, root_objectid,
ref_generation, owner_objectid, 1);
if (ret == 0) {
struct btrfs_key found_key;
extent_slot = path->slots[0];
while (extent_slot > 0) {
extent_slot--;
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
extent_slot);
if (found_key.objectid != bytenr)
break;
if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
found_key.offset == num_bytes) {
found_extent = 1;
break;
}
if (path->slots[0] - extent_slot > 5)
break;
}
if (!found_extent) {
ret = remove_extent_backref(trans, extent_root, path);
BUG_ON(ret);
btrfs_release_path(extent_root, path);
ret = btrfs_search_slot(trans, extent_root,
&key, path, -1, 1);
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 "
"root %llu gen %llu owner %llu\n",
(unsigned long long)bytenr,
(unsigned long long)root_objectid,
(unsigned long long)ref_generation,
(unsigned long long)owner_objectid);
}
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, extent_slot,
struct btrfs_extent_item);
refs = btrfs_extent_refs(leaf, ei);
BUG_ON(refs == 0);
refs -= 1;
btrfs_set_extent_refs(leaf, ei, refs);
btrfs_mark_buffer_dirty(leaf);
if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
struct btrfs_extent_ref *ref;
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref);
BUG_ON(btrfs_ref_num_refs(leaf, ref) != 1);
/* if the back ref and the extent are next to each other
* they get deleted below in one shot
*/
path->slots[0] = extent_slot;
num_to_del = 2;
} else if (found_extent) {
/* otherwise delete the extent back ref */
ret = remove_extent_backref(trans, extent_root, path);
BUG_ON(ret);
/* if refs are 0, we need to setup the path for deletion */
if (refs == 0) {
btrfs_release_path(extent_root, path);
ret = btrfs_search_slot(trans, extent_root, &key, path,
-1, 1);
BUG_ON(ret);
}
}
if (refs == 0) {
u64 super_used;
u64 root_used;
if (pin) {
mutex_lock(&root->fs_info->pinned_mutex);
ret = pin_down_bytes(trans, root, bytenr, num_bytes,
owner_objectid >= BTRFS_FIRST_FREE_OBJECTID);
mutex_unlock(&root->fs_info->pinned_mutex);
if (ret > 0)
mark_free = 1;
BUG_ON(ret < 0);
}
/* block accounting for super block */
spin_lock(&info->delalloc_lock);
super_used = btrfs_super_bytes_used(&info->super_copy);
btrfs_set_super_bytes_used(&info->super_copy,
super_used - num_bytes);
/* block accounting for root item */
root_used = btrfs_root_used(&root->root_item);
btrfs_set_root_used(&root->root_item,
root_used - num_bytes);
spin_unlock(&info->delalloc_lock);
ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
num_to_del);
BUG_ON(ret);
btrfs_release_path(extent_root, path);
if (owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
BUG_ON(ret);
}
ret = update_block_group(trans, root, bytenr, num_bytes, 0,
mark_free);
BUG_ON(ret);
}
btrfs_free_path(path);
finish_current_insert(trans, extent_root, 0);
return ret;
}
/*
* find all the blocks marked as pending in the radix tree and remove
* them from the extent map
*/
static int del_pending_extents(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root, int all)
{
int ret;
int err = 0;
u64 start;
u64 end;
u64 priv;
u64 search = 0;
int nr = 0, skipped = 0;
struct extent_io_tree *pending_del;
struct extent_io_tree *extent_ins;
struct pending_extent_op *extent_op;
struct btrfs_fs_info *info = extent_root->fs_info;
struct list_head delete_list;
INIT_LIST_HEAD(&delete_list);
extent_ins = &extent_root->fs_info->extent_ins;
pending_del = &extent_root->fs_info->pending_del;
again:
mutex_lock(&info->extent_ins_mutex);
while (1) {
ret = find_first_extent_bit(pending_del, search, &start, &end,
EXTENT_WRITEBACK);
if (ret) {
if (all && skipped && !nr) {
search = 0;
skipped = 0;
continue;
}
mutex_unlock(&info->extent_ins_mutex);
break;
}
ret = try_lock_extent(extent_ins, start, end, GFP_NOFS);
if (!ret) {
search = end+1;
skipped = 1;
if (need_resched()) {
mutex_unlock(&info->extent_ins_mutex);
cond_resched();
mutex_lock(&info->extent_ins_mutex);
}
continue;
}
BUG_ON(ret < 0);
ret = get_state_private(pending_del, start, &priv);
BUG_ON(ret);
extent_op = (struct pending_extent_op *)(unsigned long)priv;
clear_extent_bits(pending_del, start, end, EXTENT_WRITEBACK,
GFP_NOFS);
if (!test_range_bit(extent_ins, start, end,
EXTENT_WRITEBACK, 0)) {
list_add_tail(&extent_op->list, &delete_list);
nr++;
} else {
kfree(extent_op);
ret = get_state_private(&info->extent_ins, start,
&priv);
BUG_ON(ret);
extent_op = (struct pending_extent_op *)
(unsigned long)priv;
clear_extent_bits(&info->extent_ins, start, end,
EXTENT_WRITEBACK, GFP_NOFS);
if (extent_op->type == PENDING_BACKREF_UPDATE) {
list_add_tail(&extent_op->list, &delete_list);
search = end + 1;
nr++;
continue;
}
mutex_lock(&extent_root->fs_info->pinned_mutex);
ret = pin_down_bytes(trans, extent_root, start,
end + 1 - start, 0);
mutex_unlock(&extent_root->fs_info->pinned_mutex);
ret = update_block_group(trans, extent_root, start,
end + 1 - start, 0, ret > 0);
unlock_extent(extent_ins, start, end, GFP_NOFS);
BUG_ON(ret);
kfree(extent_op);
}
if (ret)
err = ret;
search = end + 1;
if (need_resched()) {
mutex_unlock(&info->extent_ins_mutex);
cond_resched();
mutex_lock(&info->extent_ins_mutex);
}
}
if (nr) {
ret = free_extents(trans, extent_root, &delete_list);
BUG_ON(ret);
}
if (all && skipped) {
INIT_LIST_HEAD(&delete_list);
search = 0;
nr = 0;
goto again;
}
if (!err)
finish_current_insert(trans, extent_root, 0);
return err;
}
/*
* remove an extent from the root, returns 0 on success
*/
static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent,
u64 root_objectid, u64 ref_generation,
u64 owner_objectid, int pin)
{
struct btrfs_root *extent_root = root->fs_info->extent_root;
int pending_ret;
int ret;
WARN_ON(num_bytes < root->sectorsize);
if (root == extent_root) {
struct pending_extent_op *extent_op = NULL;
mutex_lock(&root->fs_info->extent_ins_mutex);
if (test_range_bit(&root->fs_info->extent_ins, bytenr,
bytenr + num_bytes - 1, EXTENT_WRITEBACK, 0)) {
u64 priv;
ret = get_state_private(&root->fs_info->extent_ins,
bytenr, &priv);
BUG_ON(ret);
extent_op = (struct pending_extent_op *)
(unsigned long)priv;
extent_op->del = 1;
if (extent_op->type == PENDING_EXTENT_INSERT) {
mutex_unlock(&root->fs_info->extent_ins_mutex);
return 0;
}
}
if (extent_op) {
ref_generation = extent_op->orig_generation;
parent = extent_op->orig_parent;
}
extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
BUG_ON(!extent_op);
extent_op->type = PENDING_EXTENT_DELETE;
extent_op->bytenr = bytenr;
extent_op->num_bytes = num_bytes;
extent_op->parent = parent;
extent_op->orig_parent = parent;
extent_op->generation = ref_generation;
extent_op->orig_generation = ref_generation;
extent_op->level = (int)owner_objectid;
INIT_LIST_HEAD(&extent_op->list);
extent_op->del = 0;
set_extent_bits(&root->fs_info->pending_del,
bytenr, bytenr + num_bytes - 1,
EXTENT_WRITEBACK, GFP_NOFS);
set_state_private(&root->fs_info->pending_del,
bytenr, (unsigned long)extent_op);
mutex_unlock(&root->fs_info->extent_ins_mutex);
return 0;
}
/* if metadata always pin */
if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
mutex_lock(&root->fs_info->pinned_mutex);
btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
mutex_unlock(&root->fs_info->pinned_mutex);
update_reserved_extents(root, bytenr, num_bytes, 0);
return 0;
}
pin = 1;
}
/* if data pin when any transaction has committed this */
if (ref_generation != trans->transid)
pin = 1;
ret = __free_extent(trans, root, bytenr, num_bytes, parent,
root_objectid, ref_generation,
owner_objectid, pin, pin == 0);
finish_current_insert(trans, root->fs_info->extent_root, 0);
pending_ret = del_pending_extents(trans, root->fs_info->extent_root, 0);
return ret ? ret : pending_ret;
}
int btrfs_free_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent,
u64 root_objectid, u64 ref_generation,
u64 owner_objectid, int pin)
{
int ret;
ret = __btrfs_free_extent(trans, root, bytenr, num_bytes, parent,
root_objectid, ref_generation,
owner_objectid, pin);
return ret;
}
static u64 stripe_align(struct btrfs_root *root, u64 val)
{
u64 mask = ((u64)root->stripesize - 1);
u64 ret = (val + mask) & ~mask;
return ret;
}
/*
* walks the btree of allocated extents and find a hole of a given size.
* The key ins is changed to record the hole:
* ins->objectid == block start
* ins->flags = BTRFS_EXTENT_ITEM_KEY
* ins->offset == number of blocks
* Any available blocks before search_start are skipped.
*/
static 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,
u64 exclude_start, u64 exclude_nr,
int data)
{
int ret = 0;
struct btrfs_root *root = orig_root->fs_info->extent_root;
u64 total_needed = num_bytes;
u64 *last_ptr = NULL;
u64 last_wanted = 0;
struct btrfs_block_group_cache *block_group = NULL;
int chunk_alloc_done = 0;
int empty_cluster = 2 * 1024 * 1024;
int allowed_chunk_alloc = 0;
struct list_head *head = NULL, *cur = NULL;
int loop = 0;
int extra_loop = 0;
struct btrfs_space_info *space_info;
WARN_ON(num_bytes < root->sectorsize);
btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
ins->objectid = 0;
ins->offset = 0;
if (orig_root->ref_cows || empty_size)
allowed_chunk_alloc = 1;
if (data & BTRFS_BLOCK_GROUP_METADATA) {
last_ptr = &root->fs_info->last_alloc;
if (!btrfs_test_opt(root, SSD))
empty_cluster = 64 * 1024;
}
if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD))
last_ptr = &root->fs_info->last_data_alloc;
if (last_ptr) {
if (*last_ptr) {
hint_byte = *last_ptr;
last_wanted = *last_ptr;
} else
empty_size += empty_cluster;
} else {
empty_cluster = 0;
}
search_start = max(search_start, first_logical_byte(root, 0));
search_start = max(search_start, hint_byte);
if (last_wanted && search_start != last_wanted) {
last_wanted = 0;
empty_size += empty_cluster;
}
total_needed += empty_size;
block_group = btrfs_lookup_block_group(root->fs_info, search_start);
if (!block_group)
block_group = btrfs_lookup_first_block_group(root->fs_info,
search_start);
space_info = __find_space_info(root->fs_info, data);
down_read(&space_info->groups_sem);
while (1) {
struct btrfs_free_space *free_space;
/*
* the only way this happens if our hint points to a block
* group thats not of the proper type, while looping this
* should never happen
*/
if (empty_size)
extra_loop = 1;
if (!block_group)
goto new_group_no_lock;
if (unlikely(!block_group->cached)) {
mutex_lock(&block_group->cache_mutex);
ret = cache_block_group(root, block_group);
mutex_unlock(&block_group->cache_mutex);
if (ret)
break;
}
mutex_lock(&block_group->alloc_mutex);
if (unlikely(!block_group_bits(block_group, data)))
goto new_group;
if (unlikely(block_group->ro))
goto new_group;
free_space = btrfs_find_free_space(block_group, search_start,
total_needed);
if (free_space) {
u64 start = block_group->key.objectid;
u64 end = block_group->key.objectid +
block_group->key.offset;
search_start = stripe_align(root, free_space->offset);
/* move on to the next group */
if (search_start + num_bytes >= search_end)
goto new_group;
/* move on to the next group */
if (search_start + num_bytes > end)
goto new_group;
if (last_wanted && search_start != last_wanted) {
total_needed += empty_cluster;
empty_size += empty_cluster;
last_wanted = 0;
/*
* if search_start is still in this block group
* then we just re-search this block group
*/
if (search_start >= start &&
search_start < end) {
mutex_unlock(&block_group->alloc_mutex);
continue;
}
/* else we go to the next block group */
goto new_group;
}
if (exclude_nr > 0 &&
(search_start + num_bytes > exclude_start &&
search_start < exclude_start + exclude_nr)) {
search_start = exclude_start + exclude_nr;
/*
* if search_start is still in this block group
* then we just re-search this block group
*/
if (search_start >= start &&
search_start < end) {
mutex_unlock(&block_group->alloc_mutex);
last_wanted = 0;
continue;
}
/* else we go to the next block group */
goto new_group;
}
ins->objectid = search_start;
ins->offset = num_bytes;
btrfs_remove_free_space_lock(block_group, search_start,
num_bytes);
/* we are all good, lets return */
mutex_unlock(&block_group->alloc_mutex);
break;
}
new_group:
mutex_unlock(&block_group->alloc_mutex);
put_block_group(block_group);
block_group = NULL;
new_group_no_lock:
/* don't try to compare new allocations against the
* last allocation any more
*/
last_wanted = 0;
/*
* Here's how this works.
* loop == 0: we were searching a block group via a hint
* and didn't find anything, so we start at
* the head of the block groups and keep searching
* loop == 1: we're searching through all of the block groups
* if we hit the head again we have searched
* all of the block groups for this space and we
* need to try and allocate, if we cant error out.
* loop == 2: we allocated more space and are looping through
* all of the block groups again.
*/
if (loop == 0) {
head = &space_info->block_groups;
cur = head->next;
loop++;
} else if (loop == 1 && cur == head) {
int keep_going;
/* at this point we give up on the empty_size
* allocations and just try to allocate the min
* space.
*
* The extra_loop field was set if an empty_size
* allocation was attempted above, and if this
* is try we need to try the loop again without
* the additional empty_size.
*/
total_needed -= empty_size;
empty_size = 0;
keep_going = extra_loop;
loop++;
if (allowed_chunk_alloc && !chunk_alloc_done) {
up_read(&space_info->groups_sem);
ret = do_chunk_alloc(trans, root, num_bytes +
2 * 1024 * 1024, data, 1);
down_read(&space_info->groups_sem);
if (ret < 0)
goto loop_check;
head = &space_info->block_groups;
/*
* we've allocated a new chunk, keep
* trying
*/
keep_going = 1;
chunk_alloc_done = 1;
} else if (!allowed_chunk_alloc) {
space_info->force_alloc = 1;
}
loop_check:
if (keep_going) {
cur = head->next;
extra_loop = 0;
} else {
break;
}
} else if (cur == head) {
break;
}
block_group = list_entry(cur, struct btrfs_block_group_cache,
list);
atomic_inc(&block_group->count);
search_start = block_group->key.objectid;
cur = cur->next;
}
/* we found what we needed */
if (ins->objectid) {
if (!(data & BTRFS_BLOCK_GROUP_DATA))
trans->block_group = block_group->key.objectid;
if (last_ptr)
*last_ptr = ins->objectid + ins->offset;
ret = 0;
} else if (!ret) {
printk(KERN_ERR "btrfs searching for %llu bytes, "
"num_bytes %llu, loop %d, allowed_alloc %d\n",
(unsigned long long)total_needed,
(unsigned long long)num_bytes,
loop, allowed_chunk_alloc);
ret = -ENOSPC;
}
if (block_group)
put_block_group(block_group);
up_read(&space_info->groups_sem);
return ret;
}
static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
{
struct btrfs_block_group_cache *cache;
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->full) ? "" : "not ");
printk(KERN_INFO "space_info total=%llu, pinned=%llu, delalloc=%llu,"
" may_use=%llu, used=%llu\n", info->total_bytes,
info->bytes_pinned, info->bytes_delalloc, info->bytes_may_use,
info->bytes_used);
down_read(&info->groups_sem);
list_for_each_entry(cache, &info->block_groups, 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);
}
up_read(&info->groups_sem);
}
static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 num_bytes, u64 min_alloc_size,
u64 empty_size, u64 hint_byte,
u64 search_end, struct btrfs_key *ins,
u64 data)
{
int ret;
u64 search_start = 0;
struct btrfs_fs_info *info = root->fs_info;
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) {
if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2 * 1024 * 1024,
BTRFS_BLOCK_GROUP_METADATA |
(info->metadata_alloc_profile &
info->avail_metadata_alloc_bits), 0);
}
ret = do_chunk_alloc(trans, root->fs_info->extent_root,
num_bytes + 2 * 1024 * 1024, data, 0);
}
WARN_ON(num_bytes < root->sectorsize);
ret = find_free_extent(trans, root, num_bytes, empty_size,
search_start, search_end, hint_byte, ins,
trans->alloc_exclude_start,
trans->alloc_exclude_nr, data);
if (ret == -ENOSPC && num_bytes > min_alloc_size) {
num_bytes = num_bytes >> 1;
num_bytes = num_bytes & ~(root->sectorsize - 1);
num_bytes = max(num_bytes, min_alloc_size);
do_chunk_alloc(trans, root->fs_info->extent_root,
num_bytes, data, 1);
goto again;
}
if (ret) {
struct btrfs_space_info *sinfo;
sinfo = __find_space_info(root->fs_info, data);
printk(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);
BUG();
}
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;
}
ret = btrfs_discard_extent(root, start, len);
btrfs_add_free_space(cache, start, len);
put_block_group(cache);
update_reserved_extents(root, start, len, 0);
return ret;
}
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;
ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
empty_size, hint_byte, search_end, ins,
data);
update_reserved_extents(root, ins->objectid, ins->offset, 1);
return ret;
}
static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 parent,
u64 root_objectid, u64 ref_generation,
u64 owner, struct btrfs_key *ins)
{
int ret;
int pending_ret;
u64 super_used;
u64 root_used;
u64 num_bytes = ins->offset;
u32 sizes[2];
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_root *extent_root = info->extent_root;
struct btrfs_extent_item *extent_item;
struct btrfs_extent_ref *ref;
struct btrfs_path *path;
struct btrfs_key keys[2];
if (parent == 0)
parent = ins->objectid;
/* block accounting for super block */
spin_lock(&info->delalloc_lock);
super_used = btrfs_super_bytes_used(&info->super_copy);
btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
/* block accounting for root item */
root_used = btrfs_root_used(&root->root_item);
btrfs_set_root_used(&root->root_item, root_used + num_bytes);
spin_unlock(&info->delalloc_lock);
if (root == extent_root) {
struct pending_extent_op *extent_op;
extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
BUG_ON(!extent_op);
extent_op->type = PENDING_EXTENT_INSERT;
extent_op->bytenr = ins->objectid;
extent_op->num_bytes = ins->offset;
extent_op->parent = parent;
extent_op->orig_parent = 0;
extent_op->generation = ref_generation;
extent_op->orig_generation = 0;
extent_op->level = (int)owner;
INIT_LIST_HEAD(&extent_op->list);
extent_op->del = 0;
mutex_lock(&root->fs_info->extent_ins_mutex);
set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
ins->objectid + ins->offset - 1,
EXTENT_WRITEBACK, GFP_NOFS);
set_state_private(&root->fs_info->extent_ins,
ins->objectid, (unsigned long)extent_op);
mutex_unlock(&root->fs_info->extent_ins_mutex);
goto update_block;
}
memcpy(&keys[0], ins, sizeof(*ins));
keys[1].objectid = ins->objectid;
keys[1].type = BTRFS_EXTENT_REF_KEY;
keys[1].offset = parent;
sizes[0] = sizeof(*extent_item);
sizes[1] = sizeof(*ref);
path = btrfs_alloc_path();
BUG_ON(!path);
ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
sizes, 2);
BUG_ON(ret);
extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_extent_item);
btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
struct btrfs_extent_ref);
btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
btrfs_set_ref_objectid(path->nodes[0], ref, owner);
btrfs_set_ref_num_refs(path->nodes[0], ref, 1);
btrfs_mark_buffer_dirty(path->nodes[0]);
trans->alloc_exclude_start = 0;
trans->alloc_exclude_nr = 0;
btrfs_free_path(path);
finish_current_insert(trans, extent_root, 0);
pending_ret = del_pending_extents(trans, extent_root, 0);
if (ret)
goto out;
if (pending_ret) {
ret = pending_ret;
goto out;
}
update_block:
ret = update_block_group(trans, root, ins->objectid,
ins->offset, 1, 0);
if (ret) {
printk(KERN_ERR "btrfs update block group failed for %llu "
"%llu\n", (unsigned long long)ins->objectid,
(unsigned long long)ins->offset);
BUG();
}
out:
return ret;
}
int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 parent,
u64 root_objectid, u64 ref_generation,
u64 owner, struct btrfs_key *ins)
{
int ret;
if (root_objectid == BTRFS_TREE_LOG_OBJECTID)
return 0;
ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
ref_generation, owner, ins);
update_reserved_extents(root, ins->objectid, ins->offset, 0);
return ret;
}
/*
* this is used by the tree logging recovery code. It records that
* an extent has been allocated and makes sure to clear the free
* space cache bits as well
*/
int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 parent,
u64 root_objectid, u64 ref_generation,
u64 owner, struct btrfs_key *ins)
{
int ret;
struct btrfs_block_group_cache *block_group;
block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
mutex_lock(&block_group->cache_mutex);
cache_block_group(root, block_group);
mutex_unlock(&block_group->cache_mutex);
ret = btrfs_remove_free_space(block_group, ins->objectid,
ins->offset);
BUG_ON(ret);
put_block_group(block_group);
ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
ref_generation, owner, ins);
return ret;
}
/*
* finds a free extent and does all the dirty work required for allocation
* returns the key for the extent through ins, and a tree buffer for
* the first block of the extent through buf.
*
* returns 0 if everything worked, non-zero otherwise.
*/
int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 num_bytes, u64 parent, u64 min_alloc_size,
u64 root_objectid, u64 ref_generation,
u64 owner_objectid, u64 empty_size, u64 hint_byte,
u64 search_end, struct btrfs_key *ins, u64 data)
{
int ret;
ret = __btrfs_reserve_extent(trans, root, num_bytes,
min_alloc_size, empty_size, hint_byte,
search_end, ins, data);
BUG_ON(ret);
if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
ret = __btrfs_alloc_reserved_extent(trans, root, parent,
root_objectid, ref_generation,
owner_objectid, ins);
BUG_ON(ret);
} else {
update_reserved_extents(root, ins->objectid, ins->offset, 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) {
set_extent_dirty(&root->dirty_log_pages, buf->start,
buf->start + buf->len - 1, GFP_NOFS);
} else {
set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
buf->start + buf->len - 1, GFP_NOFS);
}
trans->blocks_used++;
/* this returns a buffer locked for blocking */
return buf;
}
/*
* helper function to allocate a block for a given tree
* returns the tree buffer or NULL.
*/
struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u32 blocksize, u64 parent,
u64 root_objectid,
u64 ref_generation,
int level,
u64 hint,
u64 empty_size)
{
struct btrfs_key ins;
int ret;
struct extent_buffer *buf;
ret = btrfs_alloc_extent(trans, root, blocksize, parent, blocksize,
root_objectid, ref_generation, level,
empty_size, hint, (u64)-1, &ins, 0);
if (ret) {
BUG_ON(ret > 0);
return ERR_PTR(ret);
}
buf = btrfs_init_new_buffer(trans, root, ins.objectid,
blocksize, level);
return buf;
}
int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct extent_buffer *leaf)
{
u64 leaf_owner;
u64 leaf_generation;
struct refsort *sorted;
struct btrfs_key key;
struct btrfs_file_extent_item *fi;
int i;
int nritems;
int ret;
int refi = 0;
int slot;
BUG_ON(!btrfs_is_leaf(leaf));
nritems = btrfs_header_nritems(leaf);
leaf_owner = btrfs_header_owner(leaf);
leaf_generation = btrfs_header_generation(leaf);
sorted = kmalloc(sizeof(*sorted) * nritems, GFP_NOFS);
/* we do this loop twice. The first time we build a list
* of the extents we have a reference on, then we sort the list
* by bytenr. The second time around we actually do the
* extent freeing.
*/
for (i = 0; i < nritems; i++) {
u64 disk_bytenr;
cond_resched();
btrfs_item_key_to_cpu(leaf, &key, i);
/* only extents have references, skip everything else */
if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
continue;
fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
/* inline extents live in the btree, they don't have refs */
if (btrfs_file_extent_type(leaf, fi) ==
BTRFS_FILE_EXTENT_INLINE)
continue;
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
/* holes don't have refs */
if (disk_bytenr == 0)
continue;
sorted[refi].bytenr = disk_bytenr;
sorted[refi].slot = i;
refi++;
}
if (refi == 0)
goto out;
sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL);
for (i = 0; i < refi; i++) {
u64 disk_bytenr;
disk_bytenr = sorted[i].bytenr;
slot = sorted[i].slot;
cond_resched();
btrfs_item_key_to_cpu(leaf, &key, slot);
if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
continue;
fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
ret = __btrfs_free_extent(trans, root, disk_bytenr,
btrfs_file_extent_disk_num_bytes(leaf, fi),
leaf->start, leaf_owner, leaf_generation,
key.objectid, 0);
BUG_ON(ret);
atomic_inc(&root->fs_info->throttle_gen);
wake_up(&root->fs_info->transaction_throttle);
cond_resched();
}
out:
kfree(sorted);
return 0;
}
static noinline int cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_leaf_ref *ref)
{
int i;
int ret;
struct btrfs_extent_info *info;
struct refsort *sorted;
if (ref->nritems == 0)
return 0;
sorted = kmalloc(sizeof(*sorted) * ref->nritems, GFP_NOFS);
for (i = 0; i < ref->nritems; i++) {
sorted[i].bytenr = ref->extents[i].bytenr;
sorted[i].slot = i;
}
sort(sorted, ref->nritems, sizeof(struct refsort), refsort_cmp, NULL);
/*
* the items in the ref were sorted when the ref was inserted
* into the ref cache, so this is already in order
*/
for (i = 0; i < ref->nritems; i++) {
info = ref->extents + sorted[i].slot;
ret = __btrfs_free_extent(trans, root, info->bytenr,
info->num_bytes, ref->bytenr,
ref->owner, ref->generation,
info->objectid, 0);
atomic_inc(&root->fs_info->throttle_gen);
wake_up(&root->fs_info->transaction_throttle);
cond_resched();
BUG_ON(ret);
info++;
}
kfree(sorted);
return 0;
}
static int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start,
u64 len, u32 *refs)
{
int ret;
ret = btrfs_lookup_extent_ref(NULL, root, start, len, refs);
BUG_ON(ret);
#if 0 /* some debugging code in case we see problems here */
/* if the refs count is one, it won't get increased again. But
* if the ref count is > 1, someone may be decreasing it at
* the same time we are.
*/
if (*refs != 1) {
struct extent_buffer *eb = NULL;
eb = btrfs_find_create_tree_block(root, start, len);
if (eb)
btrfs_tree_lock(eb);
mutex_lock(&root->fs_info->alloc_mutex);
ret = lookup_extent_ref(NULL, root, start, len, refs);
BUG_ON(ret);
mutex_unlock(&root->fs_info->alloc_mutex);
if (eb) {
btrfs_tree_unlock(eb);
free_extent_buffer(eb);
}
if (*refs == 1) {
printk(KERN_ERR "btrfs block %llu went down to one "
"during drop_snap\n", (unsigned long long)start);
}
}
#endif
cond_resched();
return ret;
}
/*
* this is used while deleting old snapshots, and it drops the refs
* on a whole subtree starting from a level 1 node.
*
* The idea is to sort all the leaf pointers, and then drop the
* ref on all the leaves in order. Most of the time the leaves
* will have ref cache entries, so no leaf IOs will be required to
* find the extents they have references on.
*
* For each leaf, any references it has are also dropped in order
*
* This ends up dropping the references in something close to optimal
* order for reading and modifying the extent allocation tree.
*/
static noinline int drop_level_one_refs(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path)
{
u64 bytenr;
u64 root_owner;
u64 root_gen;
struct extent_buffer *eb = path->nodes[1];
struct extent_buffer *leaf;
struct btrfs_leaf_ref *ref;
struct refsort *sorted = NULL;
int nritems = btrfs_header_nritems(eb);
int ret;
int i;
int refi = 0;
int slot = path->slots[1];
u32 blocksize = btrfs_level_size(root, 0);
u32 refs;
if (nritems == 0)
goto out;
root_owner = btrfs_header_owner(eb);
root_gen = btrfs_header_generation(eb);
sorted = kmalloc(sizeof(*sorted) * nritems, GFP_NOFS);
/*
* step one, sort all the leaf pointers so we don't scribble
* randomly into the extent allocation tree
*/
for (i = slot; i < nritems; i++) {
sorted[refi].bytenr = btrfs_node_blockptr(eb, i);
sorted[refi].slot = i;
refi++;
}
/*
* nritems won't be zero, but if we're picking up drop_snapshot
* after a crash, slot might be > 0, so double check things
* just in case.
*/
if (refi == 0)
goto out;
sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL);
/*
* the first loop frees everything the leaves point to
*/
for (i = 0; i < refi; i++) {
u64 ptr_gen;
bytenr = sorted[i].bytenr;
/*
* check the reference count on this leaf. If it is > 1
* we just decrement it below and don't update any
* of the refs the leaf points to.
*/
ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
BUG_ON(ret);
if (refs != 1)
continue;
ptr_gen = btrfs_node_ptr_generation(eb, sorted[i].slot);
/*
* the leaf only had one reference, which means the
* only thing pointing to this leaf is the snapshot
* we're deleting. It isn't possible for the reference
* count to increase again later
*
* The reference cache is checked for the leaf,
* and if found we'll be able to drop any refs held by
* the leaf without needing to read it in.
*/
ref = btrfs_lookup_leaf_ref(root, bytenr);
if (ref && ref->generation != ptr_gen) {
btrfs_free_leaf_ref(root, ref);
ref = NULL;
}
if (ref) {
ret = cache_drop_leaf_ref(trans, root, ref);
BUG_ON(ret);
btrfs_remove_leaf_ref(root, ref);
btrfs_free_leaf_ref(root, ref);
} else {
/*
* the leaf wasn't in the reference cache, so
* we have to read it.
*/
leaf = read_tree_block(root, bytenr, blocksize,
ptr_gen);
ret = btrfs_drop_leaf_ref(trans, root, leaf);
BUG_ON(ret);
free_extent_buffer(leaf);
}
atomic_inc(&root->fs_info->throttle_gen);
wake_up(&root->fs_info->transaction_throttle);
cond_resched();
}
/*
* run through the loop again to free the refs on the leaves.
* This is faster than doing it in the loop above because
* the leaves are likely to be clustered together. We end up
* working in nice chunks on the extent allocation tree.
*/
for (i = 0; i < refi; i++) {
bytenr = sorted[i].bytenr;
ret = __btrfs_free_extent(trans, root, bytenr,
blocksize, eb->start,
root_owner, root_gen, 0, 1);
BUG_ON(ret);
atomic_inc(&root->fs_info->throttle_gen);
wake_up(&root->fs_info->transaction_throttle);
cond_resched();
}
out:
kfree(sorted);
/*
* update the path to show we've processed the entire level 1
* node. This will get saved into the root's drop_snapshot_progress
* field so these drops are not repeated again if this transaction
* commits.
*/
path->slots[1] = nritems;
return 0;
}
/*
* helper function for drop_snapshot, this walks down the tree dropping ref
* counts as it goes.
*/
static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int *level)
{
u64 root_owner;
u64 root_gen;
u64 bytenr;
u64 ptr_gen;
struct extent_buffer *next;
struct extent_buffer *cur;
struct extent_buffer *parent;
u32 blocksize;
int ret;
u32 refs;
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start,
path->nodes[*level]->len, &refs);
BUG_ON(ret);
if (refs > 1)
goto out;
/*
* walk down to the last node level and free all the leaves
*/
while (*level >= 0) {
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
cur = path->nodes[*level];
if (btrfs_header_level(cur) != *level)
WARN_ON(1);
if (path->slots[*level] >=
btrfs_header_nritems(cur))
break;
/* the new code goes down to level 1 and does all the
* leaves pointed to that node in bulk. So, this check
* for level 0 will always be false.
*
* But, the disk format allows the drop_snapshot_progress
* field in the root to leave things in a state where
* a leaf will need cleaning up here. If someone crashes
* with the old code and then boots with the new code,
* we might find a leaf here.
*/
if (*level == 0) {
ret = btrfs_drop_leaf_ref(trans, root, cur);
BUG_ON(ret);
break;
}
/*
* once we get to level one, process the whole node
* at once, including everything below it.
*/
if (*level == 1) {
ret = drop_level_one_refs(trans, root, path);
BUG_ON(ret);
break;
}
bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
blocksize = btrfs_level_size(root, *level - 1);
ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
BUG_ON(ret);
/*
* if there is more than one reference, we don't need
* to read that node to drop any references it has. We
* just drop the ref we hold on that node and move on to the
* next slot in this level.
*/
if (refs != 1) {
parent = path->nodes[*level];
root_owner = btrfs_header_owner(parent);
root_gen = btrfs_header_generation(parent);
path->slots[*level]++;
ret = __btrfs_free_extent(trans, root, bytenr,
blocksize, parent->start,
root_owner, root_gen,
*level - 1, 1);
BUG_ON(ret);
atomic_inc(&root->fs_info->throttle_gen);
wake_up(&root->fs_info->transaction_throttle);
cond_resched();
continue;
}
/*
* we need to keep freeing things in the next level down.
* read the block and loop around to process it
*/
next = read_tree_block(root, bytenr, blocksize, ptr_gen);
WARN_ON(*level <= 0);
if (path->nodes[*level-1])
free_extent_buffer(path->nodes[*level-1]);
path->nodes[*level-1] = next;
*level = btrfs_header_level(next);
path->slots[*level] = 0;
cond_resched();
}
out:
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
if (path->nodes[*level] == root->node) {
parent = path->nodes[*level];
bytenr = path->nodes[*level]->start;
} else {
parent = path->nodes[*level + 1];
bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
}
blocksize = btrfs_level_size(root, *level);
root_owner = btrfs_header_owner(parent);
root_gen = btrfs_header_generation(parent);
/*
* cleanup and free the reference on the last node
* we processed
*/
ret = __btrfs_free_extent(trans, root, bytenr, blocksize,
parent->start, root_owner, root_gen,
*level, 1);
free_extent_buffer(path->nodes[*level]);
path->nodes[*level] = NULL;
*level += 1;
BUG_ON(ret);
cond_resched();
return 0;
}
/*
* helper function for drop_subtree, this function is similar to
* walk_down_tree. The main difference is that it checks reference
* counts while tree blocks are locked.
*/
static noinline int walk_down_subtree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int *level)
{
struct extent_buffer *next;
struct extent_buffer *cur;
struct extent_buffer *parent;
u64 bytenr;
u64 ptr_gen;
u32 blocksize;
u32 refs;
int ret;
cur = path->nodes[*level];
ret = btrfs_lookup_extent_ref(trans, root, cur->start, cur->len,
&refs);
BUG_ON(ret);
if (refs > 1)
goto out;
while (*level >= 0) {
cur = path->nodes[*level];
if (*level == 0) {
ret = btrfs_drop_leaf_ref(trans, root, cur);
BUG_ON(ret);
clean_tree_block(trans, root, cur);
break;
}
if (path->slots[*level] >= btrfs_header_nritems(cur)) {
clean_tree_block(trans, root, cur);
break;
}
bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
blocksize = btrfs_level_size(root, *level - 1);
ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
next = read_tree_block(root, bytenr, blocksize, ptr_gen);
btrfs_tree_lock(next);
btrfs_set_lock_blocking(next);
ret = btrfs_lookup_extent_ref(trans, root, bytenr, blocksize,
&refs);
BUG_ON(ret);
if (refs > 1) {
parent = path->nodes[*level];
ret = btrfs_free_extent(trans, root, bytenr,
blocksize, parent->start,
btrfs_header_owner(parent),
btrfs_header_generation(parent),
*level - 1, 1);
BUG_ON(ret);
path->slots[*level]++;
btrfs_tree_unlock(next);
free_extent_buffer(next);
continue;
}
*level = btrfs_header_level(next);
path->nodes[*level] = next;
path->slots[*level] = 0;
path->locks[*level] = 1;
cond_resched();
}
out:
parent = path->nodes[*level + 1];
bytenr = path->nodes[*level]->start;
blocksize = path->nodes[*level]->len;
ret = btrfs_free_extent(trans, root, bytenr, blocksize,
parent->start, btrfs_header_owner(parent),
btrfs_header_generation(parent), *level, 1);
BUG_ON(ret);
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 += 1;
cond_resched();
return 0;
}
/*
* helper for dropping snapshots. This walks back up the tree in the path
* to find the first node higher up where we haven't yet gone through
* all the slots
*/
static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
int *level, int max_level)
{
u64 root_owner;
u64 root_gen;
struct btrfs_root_item *root_item = &root->root_item;
int i;
int slot;
int ret;
for (i = *level; i < max_level && path->nodes[i]; i++) {
slot = path->slots[i];
if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
struct extent_buffer *node;
struct btrfs_disk_key disk_key;
/*
* there is more work to do in this level.
* Update the drop_progress marker to reflect
* the work we've done so far, and then bump
* the slot number
*/
node = path->nodes[i];
path->slots[i]++;
*level = i;
WARN_ON(*level == 0);
btrfs_node_key(node, &disk_key, path->slots[i]);
memcpy(&root_item->drop_progress,
&disk_key, sizeof(disk_key));
root_item->drop_level = i;
return 0;
} else {
struct extent_buffer *parent;
/*
* this whole node is done, free our reference
* on it and go up one level
*/
if (path->nodes[*level] == root->node)
parent = path->nodes[*level];
else
parent = path->nodes[*level + 1];
root_owner = btrfs_header_owner(parent);
root_gen = btrfs_header_generation(parent);
clean_tree_block(trans, root, path->nodes[*level]);
ret = btrfs_free_extent(trans, root,
path->nodes[*level]->start,
path->nodes[*level]->len,
parent->start, root_owner,
root_gen, *level, 1);
BUG_ON(ret);
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 = i + 1;
}
}
return 1;
}
/*
* drop the reference count on the tree rooted at 'snap'. This traverses
* the tree freeing any blocks that have a ref count of zero after being
* decremented.
*/
int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
*root)
{
int ret = 0;
int wret;
int level;
struct btrfs_path *path;
int i;
int orig_level;
struct btrfs_root_item *root_item = &root->root_item;
WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex));
path = btrfs_alloc_path();
BUG_ON(!path);
level = btrfs_header_level(root->node);
orig_level = level;
if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
path->nodes[level] = root->node;
extent_buffer_get(root->node);
path->slots[level] = 0;
} else {
struct btrfs_key key;
struct btrfs_disk_key found_key;
struct extent_buffer *node;
btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
level = root_item->drop_level;
path->lowest_level = level;
wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (wret < 0) {
ret = wret;
goto out;
}
node = path->nodes[level];
btrfs_node_key(node, &found_key, path->slots[level]);
WARN_ON(memcmp(&found_key, &root_item->drop_progress,
sizeof(found_key)));
/*
* unlock our path, this is safe because only this
* function is allowed to delete this snapshot
*/
for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
if (path->nodes[i] && path->locks[i]) {
path->locks[i] = 0;
btrfs_tree_unlock(path->nodes[i]);
}
}
}
while (1) {
wret = walk_down_tree(trans, root, path, &level);
if (wret > 0)
break;
if (wret < 0)
ret = wret;
wret = walk_up_tree(trans, root, path, &level,
BTRFS_MAX_LEVEL);
if (wret > 0)
break;
if (wret < 0)
ret = wret;
if (trans->transaction->in_commit) {
ret = -EAGAIN;
break;
}
atomic_inc(&root->fs_info->throttle_gen);
wake_up(&root->fs_info->transaction_throttle);
}
for (i = 0; i <= orig_level; i++) {
if (path->nodes[i]) {
free_extent_buffer(path->nodes[i]);
path->nodes[i] = NULL;
}
}
out:
btrfs_free_path(path);
return ret;
}
int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *node,
struct extent_buffer *parent)
{
struct btrfs_path *path;
int level;
int parent_level;
int ret = 0;
int wret;
path = btrfs_alloc_path();
BUG_ON(!path);
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);
extent_buffer_get(node);
path->nodes[level] = node;
path->slots[level] = 0;
while (1) {
wret = walk_down_subtree(trans, root, path, &level);
if (wret < 0)
ret = wret;
if (wret != 0)
break;
wret = walk_up_tree(trans, root, path, &level, parent_level);
if (wret < 0)
ret = wret;
if (wret != 0)
break;
}
btrfs_free_path(path);
return ret;
}
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);
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 || IS_ERR(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;
spin_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
spin_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();
BUG_ON(!path);
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);
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;
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(&BTRFS_I(inode)->io_tree, key.offset,
key.offset + num_bytes - 1, GFP_NOFS);
btrfs_drop_extent_cache(inode, key.offset,
key.offset + num_bytes - 1, 1);
unlock_extent(&BTRFS_I(inode)->io_tree, key.offset,
key.offset + num_bytes - 1, 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);
BUG_ON(!new_extent);
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(!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(!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);
btrfs_orphan_cleanup(reloc_root);
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);
BUG_ON(!root_item);
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(!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);
if (root == root->fs_info->extent_root)
btrfs_extent_post_op(trans, root);
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(!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);
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);
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;
}
static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
{
u64 num_devices;
u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
num_devices = root->fs_info->fs_devices->rw_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 __alloc_chunk_for_shrink(struct btrfs_root *root,
struct btrfs_block_group_cache *shrink_block_group,
int force)
{
struct btrfs_trans_handle *trans;
u64 new_alloc_flags;
u64 calc;
spin_lock(&shrink_block_group->lock);
if (btrfs_block_group_used(&shrink_block_group->item) > 0) {
spin_unlock(&shrink_block_group->lock);
trans = btrfs_start_transaction(root, 1);
spin_lock(&shrink_block_group->lock);
new_alloc_flags = update_block_group_flags(root,
shrink_block_group->flags);
if (new_alloc_flags != shrink_block_group->flags) {
calc =
btrfs_block_group_used(&shrink_block_group->item);
} else {
calc = shrink_block_group->key.offset;
}
spin_unlock(&shrink_block_group->lock);
do_chunk_alloc(trans, root->fs_info->extent_root,
calc + 2 * 1024 * 1024, new_alloc_flags, force);
btrfs_end_transaction(trans, root);
} else
spin_unlock(&shrink_block_group->lock);
return 0;
}
static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 size)
{
struct btrfs_path *path;
struct btrfs_inode_item *item;
struct extent_buffer *leaf;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_insert_empty_inode(trans, root, path, objectid);
if (ret)
goto out;
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
btrfs_set_inode_generation(leaf, item, 1);
btrfs_set_inode_size(leaf, item, size);
btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(root, path);
out:
btrfs_free_path(path);
return ret;
}
static noinline struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
struct btrfs_block_group_cache *group)
{
struct inode *inode = NULL;
struct btrfs_trans_handle *trans;
struct btrfs_root *root;
struct btrfs_key root_key;
u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
int err = 0;
root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
root_key.type = BTRFS_ROOT_ITEM_KEY;
root_key.offset = (u64)-1;
root = btrfs_read_fs_root_no_name(fs_info, &root_key);
if (IS_ERR(root))
return ERR_CAST(root);
trans = btrfs_start_transaction(root, 1);
BUG_ON(!trans);
err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
if (err)
goto out;
err = __insert_orphan_inode(trans, root, objectid, group->key.offset);
BUG_ON(err);
err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0,
group->key.offset, 0, group->key.offset,
0, 0, 0);
BUG_ON(err);
inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
if (inode->i_state & I_NEW) {
BTRFS_I(inode)->root = root;
BTRFS_I(inode)->location.objectid = 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);
BUG_ON(is_bad_inode(inode));
} else {
BUG_ON(1);
}
BTRFS_I(inode)->index_cnt = group->key.objectid;
err = btrfs_orphan_add(trans, inode);
out:
btrfs_end_transaction(trans, root);
if (err) {
if (inode)
iput(inode);
inode = ERR_PTR(err);
}
return inode;
}
int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
{
struct btrfs_ordered_sum *sums;
struct btrfs_sector_sum *sector_sum;
struct btrfs_ordered_extent *ordered;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct list_head list;
size_t offset;
int ret;
u64 disk_bytenr;
INIT_LIST_HEAD(&list);
ordered = btrfs_lookup_ordered_extent(inode, file_pos);
BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
disk_bytenr + len - 1, &list);
while (!list_empty(&list)) {
sums = list_entry(list.next, struct btrfs_ordered_sum, list);
list_del_init(&sums->list);
sector_sum = sums->sums;
sums->bytenr = ordered->start;
offset = 0;
while (offset < sums->len) {
sector_sum->bytenr += ordered->start - disk_bytenr;
sector_sum++;
offset += root->sectorsize;
}
btrfs_add_ordered_sum(inode, ordered, sums);
}
btrfs_put_ordered_extent(ordered);
return 0;
}
int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start)
{
struct btrfs_trans_handle *trans;
struct btrfs_path *path;
struct btrfs_fs_info *info = root->fs_info;
struct extent_buffer *leaf;
struct inode *reloc_inode;
struct btrfs_block_group_cache *block_group;
struct btrfs_key key;
u64 skipped;
u64 cur_byte;
u64 total_found;
u32 nritems;
int ret;
int progress;
int pass = 0;
root = root->fs_info->extent_root;
block_group = btrfs_lookup_block_group(info, group_start);
BUG_ON(!block_group);
printk(KERN_INFO "btrfs relocating block group %llu flags %llu\n",
(unsigned long long)block_group->key.objectid,
(unsigned long long)block_group->flags);
path = btrfs_alloc_path();
BUG_ON(!path);
reloc_inode = create_reloc_inode(info, block_group);
BUG_ON(IS_ERR(reloc_inode));
__alloc_chunk_for_shrink(root, block_group, 1);
set_block_group_readonly(block_group);
btrfs_start_delalloc_inodes(info->tree_root);
btrfs_wait_ordered_extents(info->tree_root, 0);
again:
skipped = 0;
total_found = 0;
progress = 0;
key.objectid = block_group->key.objectid;
key.offset = 0;
key.type = 0;
cur_byte = key.objectid;
trans = btrfs_start_transaction(info->tree_root, 1);
btrfs_commit_transaction(trans, info->tree_root);
mutex_lock(&root->fs_info->cleaner_mutex);
btrfs_clean_old_snapshots(info->tree_root);
btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1);
mutex_unlock(&root->fs_info->cleaner_mutex);
while (1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
next:
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
if (ret == 1) {
ret = 0;
break;
}
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid >= block_group->key.objectid +
block_group->key.offset)
break;
if (progress && need_resched()) {
btrfs_release_path(root, path);
cond_resched();
progress = 0;
continue;
}
progress = 1;
if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY ||
key.objectid + key.offset <= cur_byte) {
path->slots[0]++;
goto next;
}
total_found++;
cur_byte = key.objectid + key.offset;
btrfs_release_path(root, path);
__alloc_chunk_for_shrink(root, block_group, 0);
ret = relocate_one_extent(root, path, &key, block_group,
reloc_inode, pass);
BUG_ON(ret < 0);
if (ret > 0)
skipped++;
key.objectid = cur_byte;
key.type = 0;
key.offset = 0;
}
btrfs_release_path(root, path);
if (pass == 0) {
btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1);
invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1);
}
if (total_found > 0) {
printk(KERN_INFO "btrfs found %llu extents in pass %d\n",
(unsigned long long)total_found, pass);
pass++;
if (total_found == skipped && pass > 2) {
iput(reloc_inode);
reloc_inode = create_reloc_inode(info, block_group);
pass = 0;
}
goto again;
}
/* delete reloc_inode */
iput(reloc_inode);
/* unpin extents in this range */
trans = btrfs_start_transaction(info->tree_root, 1);
btrfs_commit_transaction(trans, info->tree_root);
spin_lock(&block_group->lock);
WARN_ON(block_group->pinned > 0);
WARN_ON(block_group->reserved > 0);
WARN_ON(btrfs_block_group_used(&block_group->item) > 0);
spin_unlock(&block_group->lock);
put_block_group(block_group);
ret = 0;
out:
btrfs_free_path(path);
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]++;
}
ret = -ENOENT;
out:
return ret;
}
int btrfs_free_block_groups(struct btrfs_fs_info *info)
{
struct btrfs_block_group_cache *block_group;
struct btrfs_space_info *space_info;
struct rb_node *n;
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);
btrfs_remove_free_space_cache(block_group);
down_write(&block_group->space_info->groups_sem);
list_del(&block_group->list);
up_write(&block_group->space_info->groups_sem);
WARN_ON(atomic_read(&block_group->count) != 1);
kfree(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();
while(!list_empty(&info->space_info)) {
space_info = list_entry(info->space_info.next,
struct btrfs_space_info,
list);
list_del(&space_info->list);
kfree(space_info);
}
return 0;
}
int btrfs_read_block_groups(struct btrfs_root *root)
{
struct btrfs_path *path;
int ret;
struct btrfs_block_group_cache *cache;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_space_info *space_info;
struct btrfs_key key;
struct btrfs_key found_key;
struct extent_buffer *leaf;
root = info->extent_root;
key.objectid = 0;
key.offset = 0;
btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
while (1) {
ret = find_first_block_group(root, path, &key);
if (ret > 0) {
ret = 0;
goto error;
}
if (ret != 0)
goto error;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
cache = kzalloc(sizeof(*cache), GFP_NOFS);
if (!cache) {
ret = -ENOMEM;
break;
}
atomic_set(&cache->count, 1);
spin_lock_init(&cache->lock);
mutex_init(&cache->alloc_mutex);
mutex_init(&cache->cache_mutex);
INIT_LIST_HEAD(&cache->list);
read_extent_buffer(leaf, &cache->item,
btrfs_item_ptr_offset(leaf, path->slots[0]),
sizeof(cache->item));
memcpy(&cache->key, &found_key, sizeof(found_key));
key.objectid = found_key.objectid + found_key.offset;
btrfs_release_path(root, path);
cache->flags = btrfs_block_group_flags(&cache->item);
ret = update_space_info(info, cache->flags, found_key.offset,
btrfs_block_group_used(&cache->item),
&space_info);
BUG_ON(ret);
cache->space_info = space_info;
down_write(&space_info->groups_sem);
list_add_tail(&cache->list, &space_info->block_groups);
up_write(&space_info->groups_sem);
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_readonly(cache);
}
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_new_blockgroup = 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;
atomic_set(&cache->count, 1);
spin_lock_init(&cache->lock);
mutex_init(&cache->alloc_mutex);
mutex_init(&cache->cache_mutex);
INIT_LIST_HEAD(&cache->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);
ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
&cache->space_info);
BUG_ON(ret);
down_write(&cache->space_info->groups_sem);
list_add_tail(&cache->list, &cache->space_info->block_groups);
up_write(&cache->space_info->groups_sem);
ret = btrfs_add_block_group_cache(root->fs_info, cache);
BUG_ON(ret);
ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
sizeof(cache->item));
BUG_ON(ret);
finish_current_insert(trans, extent_root, 0);
ret = del_pending_extents(trans, extent_root, 0);
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_key key;
int ret;
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);
memcpy(&key, &block_group->key, sizeof(key));
path = btrfs_alloc_path();
BUG_ON(!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);
btrfs_remove_free_space_cache(block_group);
down_write(&block_group->space_info->groups_sem);
list_del(&block_group->list);
up_write(&block_group->space_info->groups_sem);
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;
spin_unlock(&block_group->space_info->lock);
block_group->space_info->full = 0;
put_block_group(block_group);
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;
}
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