linux-hardened/fs/btrfs/delayed-ref.c
Jan Schmidt fc36ed7e0b Btrfs: separate sequence numbers for delayed ref tracking and tree mod log
Sequence numbers for delayed refs have been introduced in the first version
of the qgroup patch set. To solve the problem of find_all_roots on a busy
file system, the tree mod log was introduced. The sequence numbers for that
were simply shared between those two users.

However, at one point in qgroup's quota accounting, there's a statement
accessing the previous sequence number, that's still just doing (seq - 1)
just as it would have to in the very first version.

To satisfy that requirement, this patch makes the sequence number counter 64
bit and splits it into a major part (used for qgroup sequence number
counting) and a minor part (incremented for each tree modification in the
log). This enables us to go exactly one major step backwards, as required
for qgroups, while still incrementing the sequence counter for tree mod log
insertions to keep track of their order. Keeping them in a single variable
means there's no need to change all the code dealing with comparisons of two
sequence numbers.

The sequence number is reset to 0 on commit (not new in this patch), which
ensures we won't overflow the two 32 bit counters.

Without this fix, the qgroup tracking can occasionally go wrong and WARN_ONs
from the tree mod log code may happen.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-06 15:55:17 -04:00

928 lines
25 KiB
C

/*
* Copyright (C) 2009 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/sort.h>
#include "ctree.h"
#include "delayed-ref.h"
#include "transaction.h"
struct kmem_cache *btrfs_delayed_ref_head_cachep;
struct kmem_cache *btrfs_delayed_tree_ref_cachep;
struct kmem_cache *btrfs_delayed_data_ref_cachep;
struct kmem_cache *btrfs_delayed_extent_op_cachep;
/*
* delayed back reference update tracking. For subvolume trees
* we queue up extent allocations and backref maintenance for
* delayed processing. This avoids deep call chains where we
* add extents in the middle of btrfs_search_slot, and it allows
* us to buffer up frequently modified backrefs in an rb tree instead
* of hammering updates on the extent allocation tree.
*/
/*
* compare two delayed tree backrefs with same bytenr and type
*/
static int comp_tree_refs(struct btrfs_delayed_tree_ref *ref2,
struct btrfs_delayed_tree_ref *ref1, int type)
{
if (type == BTRFS_TREE_BLOCK_REF_KEY) {
if (ref1->root < ref2->root)
return -1;
if (ref1->root > ref2->root)
return 1;
} else {
if (ref1->parent < ref2->parent)
return -1;
if (ref1->parent > ref2->parent)
return 1;
}
return 0;
}
/*
* compare two delayed data backrefs with same bytenr and type
*/
static int comp_data_refs(struct btrfs_delayed_data_ref *ref2,
struct btrfs_delayed_data_ref *ref1)
{
if (ref1->node.type == BTRFS_EXTENT_DATA_REF_KEY) {
if (ref1->root < ref2->root)
return -1;
if (ref1->root > ref2->root)
return 1;
if (ref1->objectid < ref2->objectid)
return -1;
if (ref1->objectid > ref2->objectid)
return 1;
if (ref1->offset < ref2->offset)
return -1;
if (ref1->offset > ref2->offset)
return 1;
} else {
if (ref1->parent < ref2->parent)
return -1;
if (ref1->parent > ref2->parent)
return 1;
}
return 0;
}
/*
* entries in the rb tree are ordered by the byte number of the extent,
* type of the delayed backrefs and content of delayed backrefs.
*/
static int comp_entry(struct btrfs_delayed_ref_node *ref2,
struct btrfs_delayed_ref_node *ref1,
bool compare_seq)
{
if (ref1->bytenr < ref2->bytenr)
return -1;
if (ref1->bytenr > ref2->bytenr)
return 1;
if (ref1->is_head && ref2->is_head)
return 0;
if (ref2->is_head)
return -1;
if (ref1->is_head)
return 1;
if (ref1->type < ref2->type)
return -1;
if (ref1->type > ref2->type)
return 1;
/* merging of sequenced refs is not allowed */
if (compare_seq) {
if (ref1->seq < ref2->seq)
return -1;
if (ref1->seq > ref2->seq)
return 1;
}
if (ref1->type == BTRFS_TREE_BLOCK_REF_KEY ||
ref1->type == BTRFS_SHARED_BLOCK_REF_KEY) {
return comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref2),
btrfs_delayed_node_to_tree_ref(ref1),
ref1->type);
} else if (ref1->type == BTRFS_EXTENT_DATA_REF_KEY ||
ref1->type == BTRFS_SHARED_DATA_REF_KEY) {
return comp_data_refs(btrfs_delayed_node_to_data_ref(ref2),
btrfs_delayed_node_to_data_ref(ref1));
}
BUG();
return 0;
}
/*
* insert a new ref into the rbtree. This returns any existing refs
* for the same (bytenr,parent) tuple, or NULL if the new node was properly
* inserted.
*/
static struct btrfs_delayed_ref_node *tree_insert(struct rb_root *root,
struct rb_node *node)
{
struct rb_node **p = &root->rb_node;
struct rb_node *parent_node = NULL;
struct btrfs_delayed_ref_node *entry;
struct btrfs_delayed_ref_node *ins;
int cmp;
ins = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
while (*p) {
parent_node = *p;
entry = rb_entry(parent_node, struct btrfs_delayed_ref_node,
rb_node);
cmp = comp_entry(entry, ins, 1);
if (cmp < 0)
p = &(*p)->rb_left;
else if (cmp > 0)
p = &(*p)->rb_right;
else
return entry;
}
rb_link_node(node, parent_node, p);
rb_insert_color(node, root);
return NULL;
}
/*
* find an head entry based on bytenr. This returns the delayed ref
* head if it was able to find one, or NULL if nothing was in that spot.
* If return_bigger is given, the next bigger entry is returned if no exact
* match is found.
*/
static struct btrfs_delayed_ref_node *find_ref_head(struct rb_root *root,
u64 bytenr,
struct btrfs_delayed_ref_node **last,
int return_bigger)
{
struct rb_node *n;
struct btrfs_delayed_ref_node *entry;
int cmp = 0;
again:
n = root->rb_node;
entry = NULL;
while (n) {
entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
WARN_ON(!entry->in_tree);
if (last)
*last = entry;
if (bytenr < entry->bytenr)
cmp = -1;
else if (bytenr > entry->bytenr)
cmp = 1;
else if (!btrfs_delayed_ref_is_head(entry))
cmp = 1;
else
cmp = 0;
if (cmp < 0)
n = n->rb_left;
else if (cmp > 0)
n = n->rb_right;
else
return entry;
}
if (entry && return_bigger) {
if (cmp > 0) {
n = rb_next(&entry->rb_node);
if (!n)
n = rb_first(root);
entry = rb_entry(n, struct btrfs_delayed_ref_node,
rb_node);
bytenr = entry->bytenr;
return_bigger = 0;
goto again;
}
return entry;
}
return NULL;
}
int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
struct btrfs_delayed_ref_head *head)
{
struct btrfs_delayed_ref_root *delayed_refs;
delayed_refs = &trans->transaction->delayed_refs;
assert_spin_locked(&delayed_refs->lock);
if (mutex_trylock(&head->mutex))
return 0;
atomic_inc(&head->node.refs);
spin_unlock(&delayed_refs->lock);
mutex_lock(&head->mutex);
spin_lock(&delayed_refs->lock);
if (!head->node.in_tree) {
mutex_unlock(&head->mutex);
btrfs_put_delayed_ref(&head->node);
return -EAGAIN;
}
btrfs_put_delayed_ref(&head->node);
return 0;
}
static void inline drop_delayed_ref(struct btrfs_trans_handle *trans,
struct btrfs_delayed_ref_root *delayed_refs,
struct btrfs_delayed_ref_node *ref)
{
rb_erase(&ref->rb_node, &delayed_refs->root);
ref->in_tree = 0;
btrfs_put_delayed_ref(ref);
delayed_refs->num_entries--;
if (trans->delayed_ref_updates)
trans->delayed_ref_updates--;
}
static int merge_ref(struct btrfs_trans_handle *trans,
struct btrfs_delayed_ref_root *delayed_refs,
struct btrfs_delayed_ref_node *ref, u64 seq)
{
struct rb_node *node;
int merged = 0;
int mod = 0;
int done = 0;
node = rb_prev(&ref->rb_node);
while (node) {
struct btrfs_delayed_ref_node *next;
next = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
node = rb_prev(node);
if (next->bytenr != ref->bytenr)
break;
if (seq && next->seq >= seq)
break;
if (comp_entry(ref, next, 0))
continue;
if (ref->action == next->action) {
mod = next->ref_mod;
} else {
if (ref->ref_mod < next->ref_mod) {
struct btrfs_delayed_ref_node *tmp;
tmp = ref;
ref = next;
next = tmp;
done = 1;
}
mod = -next->ref_mod;
}
merged++;
drop_delayed_ref(trans, delayed_refs, next);
ref->ref_mod += mod;
if (ref->ref_mod == 0) {
drop_delayed_ref(trans, delayed_refs, ref);
break;
} else {
/*
* You can't have multiples of the same ref on a tree
* block.
*/
WARN_ON(ref->type == BTRFS_TREE_BLOCK_REF_KEY ||
ref->type == BTRFS_SHARED_BLOCK_REF_KEY);
}
if (done)
break;
node = rb_prev(&ref->rb_node);
}
return merged;
}
void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info,
struct btrfs_delayed_ref_root *delayed_refs,
struct btrfs_delayed_ref_head *head)
{
struct rb_node *node;
u64 seq = 0;
spin_lock(&fs_info->tree_mod_seq_lock);
if (!list_empty(&fs_info->tree_mod_seq_list)) {
struct seq_list *elem;
elem = list_first_entry(&fs_info->tree_mod_seq_list,
struct seq_list, list);
seq = elem->seq;
}
spin_unlock(&fs_info->tree_mod_seq_lock);
node = rb_prev(&head->node.rb_node);
while (node) {
struct btrfs_delayed_ref_node *ref;
ref = rb_entry(node, struct btrfs_delayed_ref_node,
rb_node);
if (ref->bytenr != head->node.bytenr)
break;
/* We can't merge refs that are outside of our seq count */
if (seq && ref->seq >= seq)
break;
if (merge_ref(trans, delayed_refs, ref, seq))
node = rb_prev(&head->node.rb_node);
else
node = rb_prev(node);
}
}
int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info,
struct btrfs_delayed_ref_root *delayed_refs,
u64 seq)
{
struct seq_list *elem;
int ret = 0;
spin_lock(&fs_info->tree_mod_seq_lock);
if (!list_empty(&fs_info->tree_mod_seq_list)) {
elem = list_first_entry(&fs_info->tree_mod_seq_list,
struct seq_list, list);
if (seq >= elem->seq) {
pr_debug("holding back delayed_ref %#x.%x, lowest is %#x.%x (%p)\n",
(u32)(seq >> 32), (u32)seq,
(u32)(elem->seq >> 32), (u32)elem->seq,
delayed_refs);
ret = 1;
}
}
spin_unlock(&fs_info->tree_mod_seq_lock);
return ret;
}
int btrfs_find_ref_cluster(struct btrfs_trans_handle *trans,
struct list_head *cluster, u64 start)
{
int count = 0;
struct btrfs_delayed_ref_root *delayed_refs;
struct rb_node *node;
struct btrfs_delayed_ref_node *ref;
struct btrfs_delayed_ref_head *head;
delayed_refs = &trans->transaction->delayed_refs;
if (start == 0) {
node = rb_first(&delayed_refs->root);
} else {
ref = NULL;
find_ref_head(&delayed_refs->root, start + 1, &ref, 1);
if (ref) {
node = &ref->rb_node;
} else
node = rb_first(&delayed_refs->root);
}
again:
while (node && count < 32) {
ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
if (btrfs_delayed_ref_is_head(ref)) {
head = btrfs_delayed_node_to_head(ref);
if (list_empty(&head->cluster)) {
list_add_tail(&head->cluster, cluster);
delayed_refs->run_delayed_start =
head->node.bytenr;
count++;
WARN_ON(delayed_refs->num_heads_ready == 0);
delayed_refs->num_heads_ready--;
} else if (count) {
/* the goal of the clustering is to find extents
* that are likely to end up in the same extent
* leaf on disk. So, we don't want them spread
* all over the tree. Stop now if we've hit
* a head that was already in use
*/
break;
}
}
node = rb_next(node);
}
if (count) {
return 0;
} else if (start) {
/*
* we've gone to the end of the rbtree without finding any
* clusters. start from the beginning and try again
*/
start = 0;
node = rb_first(&delayed_refs->root);
goto again;
}
return 1;
}
void btrfs_release_ref_cluster(struct list_head *cluster)
{
struct list_head *pos, *q;
list_for_each_safe(pos, q, cluster)
list_del_init(pos);
}
/*
* helper function to update an extent delayed ref in the
* rbtree. existing and update must both have the same
* bytenr and parent
*
* This may free existing if the update cancels out whatever
* operation it was doing.
*/
static noinline void
update_existing_ref(struct btrfs_trans_handle *trans,
struct btrfs_delayed_ref_root *delayed_refs,
struct btrfs_delayed_ref_node *existing,
struct btrfs_delayed_ref_node *update)
{
if (update->action != existing->action) {
/*
* this is effectively undoing either an add or a
* drop. We decrement the ref_mod, and if it goes
* down to zero we just delete the entry without
* every changing the extent allocation tree.
*/
existing->ref_mod--;
if (existing->ref_mod == 0)
drop_delayed_ref(trans, delayed_refs, existing);
else
WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY ||
existing->type == BTRFS_SHARED_BLOCK_REF_KEY);
} else {
WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY ||
existing->type == BTRFS_SHARED_BLOCK_REF_KEY);
/*
* the action on the existing ref matches
* the action on the ref we're trying to add.
* Bump the ref_mod by one so the backref that
* is eventually added/removed has the correct
* reference count
*/
existing->ref_mod += update->ref_mod;
}
}
/*
* helper function to update the accounting in the head ref
* existing and update must have the same bytenr
*/
static noinline void
update_existing_head_ref(struct btrfs_delayed_ref_node *existing,
struct btrfs_delayed_ref_node *update)
{
struct btrfs_delayed_ref_head *existing_ref;
struct btrfs_delayed_ref_head *ref;
existing_ref = btrfs_delayed_node_to_head(existing);
ref = btrfs_delayed_node_to_head(update);
BUG_ON(existing_ref->is_data != ref->is_data);
if (ref->must_insert_reserved) {
/* if the extent was freed and then
* reallocated before the delayed ref
* entries were processed, we can end up
* with an existing head ref without
* the must_insert_reserved flag set.
* Set it again here
*/
existing_ref->must_insert_reserved = ref->must_insert_reserved;
/*
* update the num_bytes so we make sure the accounting
* is done correctly
*/
existing->num_bytes = update->num_bytes;
}
if (ref->extent_op) {
if (!existing_ref->extent_op) {
existing_ref->extent_op = ref->extent_op;
} else {
if (ref->extent_op->update_key) {
memcpy(&existing_ref->extent_op->key,
&ref->extent_op->key,
sizeof(ref->extent_op->key));
existing_ref->extent_op->update_key = 1;
}
if (ref->extent_op->update_flags) {
existing_ref->extent_op->flags_to_set |=
ref->extent_op->flags_to_set;
existing_ref->extent_op->update_flags = 1;
}
btrfs_free_delayed_extent_op(ref->extent_op);
}
}
/*
* update the reference mod on the head to reflect this new operation
*/
existing->ref_mod += update->ref_mod;
}
/*
* helper function to actually insert a head node into the rbtree.
* this does all the dirty work in terms of maintaining the correct
* overall modification count.
*/
static noinline void add_delayed_ref_head(struct btrfs_fs_info *fs_info,
struct btrfs_trans_handle *trans,
struct btrfs_delayed_ref_node *ref,
u64 bytenr, u64 num_bytes,
int action, int is_data)
{
struct btrfs_delayed_ref_node *existing;
struct btrfs_delayed_ref_head *head_ref = NULL;
struct btrfs_delayed_ref_root *delayed_refs;
int count_mod = 1;
int must_insert_reserved = 0;
/*
* the head node stores the sum of all the mods, so dropping a ref
* should drop the sum in the head node by one.
*/
if (action == BTRFS_UPDATE_DELAYED_HEAD)
count_mod = 0;
else if (action == BTRFS_DROP_DELAYED_REF)
count_mod = -1;
/*
* BTRFS_ADD_DELAYED_EXTENT means that we need to update
* the reserved accounting when the extent is finally added, or
* if a later modification deletes the delayed ref without ever
* inserting the extent into the extent allocation tree.
* ref->must_insert_reserved is the flag used to record
* that accounting mods are required.
*
* Once we record must_insert_reserved, switch the action to
* BTRFS_ADD_DELAYED_REF because other special casing is not required.
*/
if (action == BTRFS_ADD_DELAYED_EXTENT)
must_insert_reserved = 1;
else
must_insert_reserved = 0;
delayed_refs = &trans->transaction->delayed_refs;
/* first set the basic ref node struct up */
atomic_set(&ref->refs, 1);
ref->bytenr = bytenr;
ref->num_bytes = num_bytes;
ref->ref_mod = count_mod;
ref->type = 0;
ref->action = 0;
ref->is_head = 1;
ref->in_tree = 1;
ref->seq = 0;
head_ref = btrfs_delayed_node_to_head(ref);
head_ref->must_insert_reserved = must_insert_reserved;
head_ref->is_data = is_data;
INIT_LIST_HEAD(&head_ref->cluster);
mutex_init(&head_ref->mutex);
trace_btrfs_delayed_ref_head(ref, head_ref, action);
existing = tree_insert(&delayed_refs->root, &ref->rb_node);
if (existing) {
update_existing_head_ref(existing, ref);
/*
* we've updated the existing ref, free the newly
* allocated ref
*/
kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
} else {
delayed_refs->num_heads++;
delayed_refs->num_heads_ready++;
delayed_refs->num_entries++;
trans->delayed_ref_updates++;
}
}
/*
* helper to insert a delayed tree ref into the rbtree.
*/
static noinline void add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
struct btrfs_trans_handle *trans,
struct btrfs_delayed_ref_node *ref,
u64 bytenr, u64 num_bytes, u64 parent,
u64 ref_root, int level, int action,
int for_cow)
{
struct btrfs_delayed_ref_node *existing;
struct btrfs_delayed_tree_ref *full_ref;
struct btrfs_delayed_ref_root *delayed_refs;
u64 seq = 0;
if (action == BTRFS_ADD_DELAYED_EXTENT)
action = BTRFS_ADD_DELAYED_REF;
delayed_refs = &trans->transaction->delayed_refs;
/* first set the basic ref node struct up */
atomic_set(&ref->refs, 1);
ref->bytenr = bytenr;
ref->num_bytes = num_bytes;
ref->ref_mod = 1;
ref->action = action;
ref->is_head = 0;
ref->in_tree = 1;
if (need_ref_seq(for_cow, ref_root))
seq = btrfs_get_tree_mod_seq(fs_info, &trans->delayed_ref_elem);
ref->seq = seq;
full_ref = btrfs_delayed_node_to_tree_ref(ref);
full_ref->parent = parent;
full_ref->root = ref_root;
if (parent)
ref->type = BTRFS_SHARED_BLOCK_REF_KEY;
else
ref->type = BTRFS_TREE_BLOCK_REF_KEY;
full_ref->level = level;
trace_btrfs_delayed_tree_ref(ref, full_ref, action);
existing = tree_insert(&delayed_refs->root, &ref->rb_node);
if (existing) {
update_existing_ref(trans, delayed_refs, existing, ref);
/*
* we've updated the existing ref, free the newly
* allocated ref
*/
kmem_cache_free(btrfs_delayed_tree_ref_cachep, full_ref);
} else {
delayed_refs->num_entries++;
trans->delayed_ref_updates++;
}
}
/*
* helper to insert a delayed data ref into the rbtree.
*/
static noinline void add_delayed_data_ref(struct btrfs_fs_info *fs_info,
struct btrfs_trans_handle *trans,
struct btrfs_delayed_ref_node *ref,
u64 bytenr, u64 num_bytes, u64 parent,
u64 ref_root, u64 owner, u64 offset,
int action, int for_cow)
{
struct btrfs_delayed_ref_node *existing;
struct btrfs_delayed_data_ref *full_ref;
struct btrfs_delayed_ref_root *delayed_refs;
u64 seq = 0;
if (action == BTRFS_ADD_DELAYED_EXTENT)
action = BTRFS_ADD_DELAYED_REF;
delayed_refs = &trans->transaction->delayed_refs;
/* first set the basic ref node struct up */
atomic_set(&ref->refs, 1);
ref->bytenr = bytenr;
ref->num_bytes = num_bytes;
ref->ref_mod = 1;
ref->action = action;
ref->is_head = 0;
ref->in_tree = 1;
if (need_ref_seq(for_cow, ref_root))
seq = btrfs_get_tree_mod_seq(fs_info, &trans->delayed_ref_elem);
ref->seq = seq;
full_ref = btrfs_delayed_node_to_data_ref(ref);
full_ref->parent = parent;
full_ref->root = ref_root;
if (parent)
ref->type = BTRFS_SHARED_DATA_REF_KEY;
else
ref->type = BTRFS_EXTENT_DATA_REF_KEY;
full_ref->objectid = owner;
full_ref->offset = offset;
trace_btrfs_delayed_data_ref(ref, full_ref, action);
existing = tree_insert(&delayed_refs->root, &ref->rb_node);
if (existing) {
update_existing_ref(trans, delayed_refs, existing, ref);
/*
* we've updated the existing ref, free the newly
* allocated ref
*/
kmem_cache_free(btrfs_delayed_data_ref_cachep, full_ref);
} else {
delayed_refs->num_entries++;
trans->delayed_ref_updates++;
}
}
/*
* add a delayed tree ref. This does all of the accounting required
* to make sure the delayed ref is eventually processed before this
* transaction commits.
*/
int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
struct btrfs_trans_handle *trans,
u64 bytenr, u64 num_bytes, u64 parent,
u64 ref_root, int level, int action,
struct btrfs_delayed_extent_op *extent_op,
int for_cow)
{
struct btrfs_delayed_tree_ref *ref;
struct btrfs_delayed_ref_head *head_ref;
struct btrfs_delayed_ref_root *delayed_refs;
BUG_ON(extent_op && extent_op->is_data);
ref = kmem_cache_alloc(btrfs_delayed_tree_ref_cachep, GFP_NOFS);
if (!ref)
return -ENOMEM;
head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
if (!head_ref) {
kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
return -ENOMEM;
}
head_ref->extent_op = extent_op;
delayed_refs = &trans->transaction->delayed_refs;
spin_lock(&delayed_refs->lock);
/*
* insert both the head node and the new ref without dropping
* the spin lock
*/
add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr,
num_bytes, action, 0);
add_delayed_tree_ref(fs_info, trans, &ref->node, bytenr,
num_bytes, parent, ref_root, level, action,
for_cow);
spin_unlock(&delayed_refs->lock);
if (need_ref_seq(for_cow, ref_root))
btrfs_qgroup_record_ref(trans, &ref->node, extent_op);
return 0;
}
/*
* add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref.
*/
int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
struct btrfs_trans_handle *trans,
u64 bytenr, u64 num_bytes,
u64 parent, u64 ref_root,
u64 owner, u64 offset, int action,
struct btrfs_delayed_extent_op *extent_op,
int for_cow)
{
struct btrfs_delayed_data_ref *ref;
struct btrfs_delayed_ref_head *head_ref;
struct btrfs_delayed_ref_root *delayed_refs;
BUG_ON(extent_op && !extent_op->is_data);
ref = kmem_cache_alloc(btrfs_delayed_data_ref_cachep, GFP_NOFS);
if (!ref)
return -ENOMEM;
head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
if (!head_ref) {
kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
return -ENOMEM;
}
head_ref->extent_op = extent_op;
delayed_refs = &trans->transaction->delayed_refs;
spin_lock(&delayed_refs->lock);
/*
* insert both the head node and the new ref without dropping
* the spin lock
*/
add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr,
num_bytes, action, 1);
add_delayed_data_ref(fs_info, trans, &ref->node, bytenr,
num_bytes, parent, ref_root, owner, offset,
action, for_cow);
spin_unlock(&delayed_refs->lock);
if (need_ref_seq(for_cow, ref_root))
btrfs_qgroup_record_ref(trans, &ref->node, extent_op);
return 0;
}
int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
struct btrfs_trans_handle *trans,
u64 bytenr, u64 num_bytes,
struct btrfs_delayed_extent_op *extent_op)
{
struct btrfs_delayed_ref_head *head_ref;
struct btrfs_delayed_ref_root *delayed_refs;
head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
if (!head_ref)
return -ENOMEM;
head_ref->extent_op = extent_op;
delayed_refs = &trans->transaction->delayed_refs;
spin_lock(&delayed_refs->lock);
add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr,
num_bytes, BTRFS_UPDATE_DELAYED_HEAD,
extent_op->is_data);
spin_unlock(&delayed_refs->lock);
return 0;
}
/*
* this does a simple search for the head node for a given extent.
* It must be called with the delayed ref spinlock held, and it returns
* the head node if any where found, or NULL if not.
*/
struct btrfs_delayed_ref_head *
btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr)
{
struct btrfs_delayed_ref_node *ref;
struct btrfs_delayed_ref_root *delayed_refs;
delayed_refs = &trans->transaction->delayed_refs;
ref = find_ref_head(&delayed_refs->root, bytenr, NULL, 0);
if (ref)
return btrfs_delayed_node_to_head(ref);
return NULL;
}
void btrfs_delayed_ref_exit(void)
{
if (btrfs_delayed_ref_head_cachep)
kmem_cache_destroy(btrfs_delayed_ref_head_cachep);
if (btrfs_delayed_tree_ref_cachep)
kmem_cache_destroy(btrfs_delayed_tree_ref_cachep);
if (btrfs_delayed_data_ref_cachep)
kmem_cache_destroy(btrfs_delayed_data_ref_cachep);
if (btrfs_delayed_extent_op_cachep)
kmem_cache_destroy(btrfs_delayed_extent_op_cachep);
}
int btrfs_delayed_ref_init(void)
{
btrfs_delayed_ref_head_cachep = kmem_cache_create(
"btrfs_delayed_ref_head",
sizeof(struct btrfs_delayed_ref_head), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
if (!btrfs_delayed_ref_head_cachep)
goto fail;
btrfs_delayed_tree_ref_cachep = kmem_cache_create(
"btrfs_delayed_tree_ref",
sizeof(struct btrfs_delayed_tree_ref), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
if (!btrfs_delayed_tree_ref_cachep)
goto fail;
btrfs_delayed_data_ref_cachep = kmem_cache_create(
"btrfs_delayed_data_ref",
sizeof(struct btrfs_delayed_data_ref), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
if (!btrfs_delayed_data_ref_cachep)
goto fail;
btrfs_delayed_extent_op_cachep = kmem_cache_create(
"btrfs_delayed_extent_op",
sizeof(struct btrfs_delayed_extent_op), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
if (!btrfs_delayed_extent_op_cachep)
goto fail;
return 0;
fail:
btrfs_delayed_ref_exit();
return -ENOMEM;
}