1
linux/fs/btrfs/ref-verify.c
Filipe Manana 9da45c88e1 btrfs: fix uninitialized return value in the ref-verify tool
In the ref-verify tool, when processing the inline references of an extent
item, we may end up returning with uninitialized return value, because:

1) The 'ret' variable is not initialized if there are no inline extent
   references ('ptr' == 'end' before the while loop starts);

2) If we find an extent owner inline reference we don't initialize 'ret'.

So fix these cases by initializing 'ret' to 0 when declaring the variable
and set it to -EINVAL if we find an extent owner inline references and
simple quotas are not enabled (as well as print an error message).

Reported-by: Mirsad Todorovac <mtodorovac69@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/59b40ebe-c824-457d-8b24-0bbca69d472b@gmail.com/
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-07-02 19:14:57 +02:00

1037 lines
25 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2014 Facebook. All rights reserved.
*/
#include <linux/sched.h>
#include <linux/stacktrace.h>
#include "messages.h"
#include "ctree.h"
#include "disk-io.h"
#include "locking.h"
#include "delayed-ref.h"
#include "ref-verify.h"
#include "fs.h"
#include "accessors.h"
/*
* Used to keep track the roots and number of refs each root has for a given
* bytenr. This just tracks the number of direct references, no shared
* references.
*/
struct root_entry {
u64 root_objectid;
u64 num_refs;
struct rb_node node;
};
/*
* These are meant to represent what should exist in the extent tree, these can
* be used to verify the extent tree is consistent as these should all match
* what the extent tree says.
*/
struct ref_entry {
u64 root_objectid;
u64 parent;
u64 owner;
u64 offset;
u64 num_refs;
struct rb_node node;
};
#define MAX_TRACE 16
/*
* Whenever we add/remove a reference we record the action. The action maps
* back to the delayed ref action. We hold the ref we are changing in the
* action so we can account for the history properly, and we record the root we
* were called with since it could be different from ref_root. We also store
* stack traces because that's how I roll.
*/
struct ref_action {
int action;
u64 root;
struct ref_entry ref;
struct list_head list;
unsigned long trace[MAX_TRACE];
unsigned int trace_len;
};
/*
* One of these for every block we reference, it holds the roots and references
* to it as well as all of the ref actions that have occurred to it. We never
* free it until we unmount the file system in order to make sure re-allocations
* are happening properly.
*/
struct block_entry {
u64 bytenr;
u64 len;
u64 num_refs;
int metadata;
int from_disk;
struct rb_root roots;
struct rb_root refs;
struct rb_node node;
struct list_head actions;
};
static struct block_entry *insert_block_entry(struct rb_root *root,
struct block_entry *be)
{
struct rb_node **p = &root->rb_node;
struct rb_node *parent_node = NULL;
struct block_entry *entry;
while (*p) {
parent_node = *p;
entry = rb_entry(parent_node, struct block_entry, node);
if (entry->bytenr > be->bytenr)
p = &(*p)->rb_left;
else if (entry->bytenr < be->bytenr)
p = &(*p)->rb_right;
else
return entry;
}
rb_link_node(&be->node, parent_node, p);
rb_insert_color(&be->node, root);
return NULL;
}
static struct block_entry *lookup_block_entry(struct rb_root *root, u64 bytenr)
{
struct rb_node *n;
struct block_entry *entry = NULL;
n = root->rb_node;
while (n) {
entry = rb_entry(n, struct block_entry, node);
if (entry->bytenr < bytenr)
n = n->rb_right;
else if (entry->bytenr > bytenr)
n = n->rb_left;
else
return entry;
}
return NULL;
}
static struct root_entry *insert_root_entry(struct rb_root *root,
struct root_entry *re)
{
struct rb_node **p = &root->rb_node;
struct rb_node *parent_node = NULL;
struct root_entry *entry;
while (*p) {
parent_node = *p;
entry = rb_entry(parent_node, struct root_entry, node);
if (entry->root_objectid > re->root_objectid)
p = &(*p)->rb_left;
else if (entry->root_objectid < re->root_objectid)
p = &(*p)->rb_right;
else
return entry;
}
rb_link_node(&re->node, parent_node, p);
rb_insert_color(&re->node, root);
return NULL;
}
static int comp_refs(struct ref_entry *ref1, struct ref_entry *ref2)
{
if (ref1->root_objectid < ref2->root_objectid)
return -1;
if (ref1->root_objectid > ref2->root_objectid)
return 1;
if (ref1->parent < ref2->parent)
return -1;
if (ref1->parent > ref2->parent)
return 1;
if (ref1->owner < ref2->owner)
return -1;
if (ref1->owner > ref2->owner)
return 1;
if (ref1->offset < ref2->offset)
return -1;
if (ref1->offset > ref2->offset)
return 1;
return 0;
}
static struct ref_entry *insert_ref_entry(struct rb_root *root,
struct ref_entry *ref)
{
struct rb_node **p = &root->rb_node;
struct rb_node *parent_node = NULL;
struct ref_entry *entry;
int cmp;
while (*p) {
parent_node = *p;
entry = rb_entry(parent_node, struct ref_entry, node);
cmp = comp_refs(entry, ref);
if (cmp > 0)
p = &(*p)->rb_left;
else if (cmp < 0)
p = &(*p)->rb_right;
else
return entry;
}
rb_link_node(&ref->node, parent_node, p);
rb_insert_color(&ref->node, root);
return NULL;
}
static struct root_entry *lookup_root_entry(struct rb_root *root, u64 objectid)
{
struct rb_node *n;
struct root_entry *entry = NULL;
n = root->rb_node;
while (n) {
entry = rb_entry(n, struct root_entry, node);
if (entry->root_objectid < objectid)
n = n->rb_right;
else if (entry->root_objectid > objectid)
n = n->rb_left;
else
return entry;
}
return NULL;
}
#ifdef CONFIG_STACKTRACE
static void __save_stack_trace(struct ref_action *ra)
{
ra->trace_len = stack_trace_save(ra->trace, MAX_TRACE, 2);
}
static void __print_stack_trace(struct btrfs_fs_info *fs_info,
struct ref_action *ra)
{
if (ra->trace_len == 0) {
btrfs_err(fs_info, " ref-verify: no stacktrace");
return;
}
stack_trace_print(ra->trace, ra->trace_len, 2);
}
#else
static inline void __save_stack_trace(struct ref_action *ra)
{
}
static inline void __print_stack_trace(struct btrfs_fs_info *fs_info,
struct ref_action *ra)
{
btrfs_err(fs_info, " ref-verify: no stacktrace support");
}
#endif
static void free_block_entry(struct block_entry *be)
{
struct root_entry *re;
struct ref_entry *ref;
struct ref_action *ra;
struct rb_node *n;
while ((n = rb_first(&be->roots))) {
re = rb_entry(n, struct root_entry, node);
rb_erase(&re->node, &be->roots);
kfree(re);
}
while((n = rb_first(&be->refs))) {
ref = rb_entry(n, struct ref_entry, node);
rb_erase(&ref->node, &be->refs);
kfree(ref);
}
while (!list_empty(&be->actions)) {
ra = list_first_entry(&be->actions, struct ref_action,
list);
list_del(&ra->list);
kfree(ra);
}
kfree(be);
}
static struct block_entry *add_block_entry(struct btrfs_fs_info *fs_info,
u64 bytenr, u64 len,
u64 root_objectid)
{
struct block_entry *be = NULL, *exist;
struct root_entry *re = NULL;
re = kzalloc(sizeof(struct root_entry), GFP_NOFS);
be = kzalloc(sizeof(struct block_entry), GFP_NOFS);
if (!be || !re) {
kfree(re);
kfree(be);
return ERR_PTR(-ENOMEM);
}
be->bytenr = bytenr;
be->len = len;
re->root_objectid = root_objectid;
re->num_refs = 0;
spin_lock(&fs_info->ref_verify_lock);
exist = insert_block_entry(&fs_info->block_tree, be);
if (exist) {
if (root_objectid) {
struct root_entry *exist_re;
exist_re = insert_root_entry(&exist->roots, re);
if (exist_re)
kfree(re);
} else {
kfree(re);
}
kfree(be);
return exist;
}
be->num_refs = 0;
be->metadata = 0;
be->from_disk = 0;
be->roots = RB_ROOT;
be->refs = RB_ROOT;
INIT_LIST_HEAD(&be->actions);
if (root_objectid)
insert_root_entry(&be->roots, re);
else
kfree(re);
return be;
}
static int add_tree_block(struct btrfs_fs_info *fs_info, u64 ref_root,
u64 parent, u64 bytenr, int level)
{
struct block_entry *be;
struct root_entry *re;
struct ref_entry *ref = NULL, *exist;
ref = kmalloc(sizeof(struct ref_entry), GFP_NOFS);
if (!ref)
return -ENOMEM;
if (parent)
ref->root_objectid = 0;
else
ref->root_objectid = ref_root;
ref->parent = parent;
ref->owner = level;
ref->offset = 0;
ref->num_refs = 1;
be = add_block_entry(fs_info, bytenr, fs_info->nodesize, ref_root);
if (IS_ERR(be)) {
kfree(ref);
return PTR_ERR(be);
}
be->num_refs++;
be->from_disk = 1;
be->metadata = 1;
if (!parent) {
ASSERT(ref_root);
re = lookup_root_entry(&be->roots, ref_root);
ASSERT(re);
re->num_refs++;
}
exist = insert_ref_entry(&be->refs, ref);
if (exist) {
exist->num_refs++;
kfree(ref);
}
spin_unlock(&fs_info->ref_verify_lock);
return 0;
}
static int add_shared_data_ref(struct btrfs_fs_info *fs_info,
u64 parent, u32 num_refs, u64 bytenr,
u64 num_bytes)
{
struct block_entry *be;
struct ref_entry *ref;
ref = kzalloc(sizeof(struct ref_entry), GFP_NOFS);
if (!ref)
return -ENOMEM;
be = add_block_entry(fs_info, bytenr, num_bytes, 0);
if (IS_ERR(be)) {
kfree(ref);
return PTR_ERR(be);
}
be->num_refs += num_refs;
ref->parent = parent;
ref->num_refs = num_refs;
if (insert_ref_entry(&be->refs, ref)) {
spin_unlock(&fs_info->ref_verify_lock);
btrfs_err(fs_info, "existing shared ref when reading from disk?");
kfree(ref);
return -EINVAL;
}
spin_unlock(&fs_info->ref_verify_lock);
return 0;
}
static int add_extent_data_ref(struct btrfs_fs_info *fs_info,
struct extent_buffer *leaf,
struct btrfs_extent_data_ref *dref,
u64 bytenr, u64 num_bytes)
{
struct block_entry *be;
struct ref_entry *ref;
struct root_entry *re;
u64 ref_root = btrfs_extent_data_ref_root(leaf, dref);
u64 owner = btrfs_extent_data_ref_objectid(leaf, dref);
u64 offset = btrfs_extent_data_ref_offset(leaf, dref);
u32 num_refs = btrfs_extent_data_ref_count(leaf, dref);
ref = kzalloc(sizeof(struct ref_entry), GFP_NOFS);
if (!ref)
return -ENOMEM;
be = add_block_entry(fs_info, bytenr, num_bytes, ref_root);
if (IS_ERR(be)) {
kfree(ref);
return PTR_ERR(be);
}
be->num_refs += num_refs;
ref->parent = 0;
ref->owner = owner;
ref->root_objectid = ref_root;
ref->offset = offset;
ref->num_refs = num_refs;
if (insert_ref_entry(&be->refs, ref)) {
spin_unlock(&fs_info->ref_verify_lock);
btrfs_err(fs_info, "existing ref when reading from disk?");
kfree(ref);
return -EINVAL;
}
re = lookup_root_entry(&be->roots, ref_root);
if (!re) {
spin_unlock(&fs_info->ref_verify_lock);
btrfs_err(fs_info, "missing root in new block entry?");
return -EINVAL;
}
re->num_refs += num_refs;
spin_unlock(&fs_info->ref_verify_lock);
return 0;
}
static int process_extent_item(struct btrfs_fs_info *fs_info,
struct btrfs_path *path, struct btrfs_key *key,
int slot, int *tree_block_level)
{
struct btrfs_extent_item *ei;
struct btrfs_extent_inline_ref *iref;
struct btrfs_extent_data_ref *dref;
struct btrfs_shared_data_ref *sref;
struct extent_buffer *leaf = path->nodes[0];
u32 item_size = btrfs_item_size(leaf, slot);
unsigned long end, ptr;
u64 offset, flags, count;
int type;
int ret = 0;
ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
flags = btrfs_extent_flags(leaf, ei);
if ((key->type == BTRFS_EXTENT_ITEM_KEY) &&
flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
struct btrfs_tree_block_info *info;
info = (struct btrfs_tree_block_info *)(ei + 1);
*tree_block_level = btrfs_tree_block_level(leaf, info);
iref = (struct btrfs_extent_inline_ref *)(info + 1);
} else {
if (key->type == BTRFS_METADATA_ITEM_KEY)
*tree_block_level = key->offset;
iref = (struct btrfs_extent_inline_ref *)(ei + 1);
}
ptr = (unsigned long)iref;
end = (unsigned long)ei + item_size;
while (ptr < end) {
iref = (struct btrfs_extent_inline_ref *)ptr;
type = btrfs_extent_inline_ref_type(leaf, iref);
offset = btrfs_extent_inline_ref_offset(leaf, iref);
switch (type) {
case BTRFS_TREE_BLOCK_REF_KEY:
ret = add_tree_block(fs_info, offset, 0, key->objectid,
*tree_block_level);
break;
case BTRFS_SHARED_BLOCK_REF_KEY:
ret = add_tree_block(fs_info, 0, offset, key->objectid,
*tree_block_level);
break;
case BTRFS_EXTENT_DATA_REF_KEY:
dref = (struct btrfs_extent_data_ref *)(&iref->offset);
ret = add_extent_data_ref(fs_info, leaf, dref,
key->objectid, key->offset);
break;
case BTRFS_SHARED_DATA_REF_KEY:
sref = (struct btrfs_shared_data_ref *)(iref + 1);
count = btrfs_shared_data_ref_count(leaf, sref);
ret = add_shared_data_ref(fs_info, offset, count,
key->objectid, key->offset);
break;
case BTRFS_EXTENT_OWNER_REF_KEY:
if (!btrfs_fs_incompat(fs_info, SIMPLE_QUOTA)) {
btrfs_err(fs_info,
"found extent owner ref without simple quotas enabled");
ret = -EINVAL;
}
break;
default:
btrfs_err(fs_info, "invalid key type in iref");
ret = -EINVAL;
break;
}
if (ret)
break;
ptr += btrfs_extent_inline_ref_size(type);
}
return ret;
}
static int process_leaf(struct btrfs_root *root,
struct btrfs_path *path, u64 *bytenr, u64 *num_bytes,
int *tree_block_level)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_buffer *leaf = path->nodes[0];
struct btrfs_extent_data_ref *dref;
struct btrfs_shared_data_ref *sref;
u32 count;
int i = 0, ret = 0;
struct btrfs_key key;
int nritems = btrfs_header_nritems(leaf);
for (i = 0; i < nritems; i++) {
btrfs_item_key_to_cpu(leaf, &key, i);
switch (key.type) {
case BTRFS_EXTENT_ITEM_KEY:
*num_bytes = key.offset;
fallthrough;
case BTRFS_METADATA_ITEM_KEY:
*bytenr = key.objectid;
ret = process_extent_item(fs_info, path, &key, i,
tree_block_level);
break;
case BTRFS_TREE_BLOCK_REF_KEY:
ret = add_tree_block(fs_info, key.offset, 0,
key.objectid, *tree_block_level);
break;
case BTRFS_SHARED_BLOCK_REF_KEY:
ret = add_tree_block(fs_info, 0, key.offset,
key.objectid, *tree_block_level);
break;
case BTRFS_EXTENT_DATA_REF_KEY:
dref = btrfs_item_ptr(leaf, i,
struct btrfs_extent_data_ref);
ret = add_extent_data_ref(fs_info, leaf, dref, *bytenr,
*num_bytes);
break;
case BTRFS_SHARED_DATA_REF_KEY:
sref = btrfs_item_ptr(leaf, i,
struct btrfs_shared_data_ref);
count = btrfs_shared_data_ref_count(leaf, sref);
ret = add_shared_data_ref(fs_info, key.offset, count,
*bytenr, *num_bytes);
break;
default:
break;
}
if (ret)
break;
}
return ret;
}
/* Walk down to the leaf from the given level */
static int walk_down_tree(struct btrfs_root *root, struct btrfs_path *path,
int level, u64 *bytenr, u64 *num_bytes,
int *tree_block_level)
{
struct extent_buffer *eb;
int ret = 0;
while (level >= 0) {
if (level) {
eb = btrfs_read_node_slot(path->nodes[level],
path->slots[level]);
if (IS_ERR(eb))
return PTR_ERR(eb);
btrfs_tree_read_lock(eb);
path->nodes[level-1] = eb;
path->slots[level-1] = 0;
path->locks[level-1] = BTRFS_READ_LOCK;
} else {
ret = process_leaf(root, path, bytenr, num_bytes,
tree_block_level);
if (ret)
break;
}
level--;
}
return ret;
}
/* Walk up to the next node that needs to be processed */
static int walk_up_tree(struct btrfs_path *path, int *level)
{
int l;
for (l = 0; l < BTRFS_MAX_LEVEL; l++) {
if (!path->nodes[l])
continue;
if (l) {
path->slots[l]++;
if (path->slots[l] <
btrfs_header_nritems(path->nodes[l])) {
*level = l;
return 0;
}
}
btrfs_tree_unlock_rw(path->nodes[l], path->locks[l]);
free_extent_buffer(path->nodes[l]);
path->nodes[l] = NULL;
path->slots[l] = 0;
path->locks[l] = 0;
}
return 1;
}
static void dump_ref_action(struct btrfs_fs_info *fs_info,
struct ref_action *ra)
{
btrfs_err(fs_info,
" Ref action %d, root %llu, ref_root %llu, parent %llu, owner %llu, offset %llu, num_refs %llu",
ra->action, ra->root, ra->ref.root_objectid, ra->ref.parent,
ra->ref.owner, ra->ref.offset, ra->ref.num_refs);
__print_stack_trace(fs_info, ra);
}
/*
* Dumps all the information from the block entry to printk, it's going to be
* awesome.
*/
static void dump_block_entry(struct btrfs_fs_info *fs_info,
struct block_entry *be)
{
struct ref_entry *ref;
struct root_entry *re;
struct ref_action *ra;
struct rb_node *n;
btrfs_err(fs_info,
"dumping block entry [%llu %llu], num_refs %llu, metadata %d, from disk %d",
be->bytenr, be->len, be->num_refs, be->metadata,
be->from_disk);
for (n = rb_first(&be->refs); n; n = rb_next(n)) {
ref = rb_entry(n, struct ref_entry, node);
btrfs_err(fs_info,
" ref root %llu, parent %llu, owner %llu, offset %llu, num_refs %llu",
ref->root_objectid, ref->parent, ref->owner,
ref->offset, ref->num_refs);
}
for (n = rb_first(&be->roots); n; n = rb_next(n)) {
re = rb_entry(n, struct root_entry, node);
btrfs_err(fs_info, " root entry %llu, num_refs %llu",
re->root_objectid, re->num_refs);
}
list_for_each_entry(ra, &be->actions, list)
dump_ref_action(fs_info, ra);
}
/*
* Called when we modify a ref for a bytenr.
*
* This will add an action item to the given bytenr and do sanity checks to make
* sure we haven't messed something up. If we are making a new allocation and
* this block entry has history we will delete all previous actions as long as
* our sanity checks pass as they are no longer needed.
*/
int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
struct btrfs_ref *generic_ref)
{
struct ref_entry *ref = NULL, *exist;
struct ref_action *ra = NULL;
struct block_entry *be = NULL;
struct root_entry *re = NULL;
int action = generic_ref->action;
int ret = 0;
bool metadata;
u64 bytenr = generic_ref->bytenr;
u64 num_bytes = generic_ref->num_bytes;
u64 parent = generic_ref->parent;
u64 ref_root = 0;
u64 owner = 0;
u64 offset = 0;
if (!btrfs_test_opt(fs_info, REF_VERIFY))
return 0;
if (generic_ref->type == BTRFS_REF_METADATA) {
if (!parent)
ref_root = generic_ref->ref_root;
owner = generic_ref->tree_ref.level;
} else if (!parent) {
ref_root = generic_ref->ref_root;
owner = generic_ref->data_ref.objectid;
offset = generic_ref->data_ref.offset;
}
metadata = owner < BTRFS_FIRST_FREE_OBJECTID;
ref = kzalloc(sizeof(struct ref_entry), GFP_NOFS);
ra = kmalloc(sizeof(struct ref_action), GFP_NOFS);
if (!ra || !ref) {
kfree(ref);
kfree(ra);
ret = -ENOMEM;
goto out;
}
ref->parent = parent;
ref->owner = owner;
ref->root_objectid = ref_root;
ref->offset = offset;
ref->num_refs = (action == BTRFS_DROP_DELAYED_REF) ? -1 : 1;
memcpy(&ra->ref, ref, sizeof(struct ref_entry));
/*
* Save the extra info from the delayed ref in the ref action to make it
* easier to figure out what is happening. The real ref's we add to the
* ref tree need to reflect what we save on disk so it matches any
* on-disk refs we pre-loaded.
*/
ra->ref.owner = owner;
ra->ref.offset = offset;
ra->ref.root_objectid = ref_root;
__save_stack_trace(ra);
INIT_LIST_HEAD(&ra->list);
ra->action = action;
ra->root = generic_ref->real_root;
/*
* This is an allocation, preallocate the block_entry in case we haven't
* used it before.
*/
ret = -EINVAL;
if (action == BTRFS_ADD_DELAYED_EXTENT) {
/*
* For subvol_create we'll just pass in whatever the parent root
* is and the new root objectid, so let's not treat the passed
* in root as if it really has a ref for this bytenr.
*/
be = add_block_entry(fs_info, bytenr, num_bytes, ref_root);
if (IS_ERR(be)) {
kfree(ref);
kfree(ra);
ret = PTR_ERR(be);
goto out;
}
be->num_refs++;
if (metadata)
be->metadata = 1;
if (be->num_refs != 1) {
btrfs_err(fs_info,
"re-allocated a block that still has references to it!");
dump_block_entry(fs_info, be);
dump_ref_action(fs_info, ra);
kfree(ref);
kfree(ra);
goto out_unlock;
}
while (!list_empty(&be->actions)) {
struct ref_action *tmp;
tmp = list_first_entry(&be->actions, struct ref_action,
list);
list_del(&tmp->list);
kfree(tmp);
}
} else {
struct root_entry *tmp;
if (!parent) {
re = kmalloc(sizeof(struct root_entry), GFP_NOFS);
if (!re) {
kfree(ref);
kfree(ra);
ret = -ENOMEM;
goto out;
}
/*
* This is the root that is modifying us, so it's the
* one we want to lookup below when we modify the
* re->num_refs.
*/
ref_root = generic_ref->real_root;
re->root_objectid = generic_ref->real_root;
re->num_refs = 0;
}
spin_lock(&fs_info->ref_verify_lock);
be = lookup_block_entry(&fs_info->block_tree, bytenr);
if (!be) {
btrfs_err(fs_info,
"trying to do action %d to bytenr %llu num_bytes %llu but there is no existing entry!",
action, bytenr, num_bytes);
dump_ref_action(fs_info, ra);
kfree(ref);
kfree(ra);
kfree(re);
goto out_unlock;
} else if (be->num_refs == 0) {
btrfs_err(fs_info,
"trying to do action %d for a bytenr that has 0 total references",
action);
dump_block_entry(fs_info, be);
dump_ref_action(fs_info, ra);
kfree(ref);
kfree(ra);
kfree(re);
goto out_unlock;
}
if (!parent) {
tmp = insert_root_entry(&be->roots, re);
if (tmp) {
kfree(re);
re = tmp;
}
}
}
exist = insert_ref_entry(&be->refs, ref);
if (exist) {
if (action == BTRFS_DROP_DELAYED_REF) {
if (exist->num_refs == 0) {
btrfs_err(fs_info,
"dropping a ref for a existing root that doesn't have a ref on the block");
dump_block_entry(fs_info, be);
dump_ref_action(fs_info, ra);
kfree(ref);
kfree(ra);
goto out_unlock;
}
exist->num_refs--;
if (exist->num_refs == 0) {
rb_erase(&exist->node, &be->refs);
kfree(exist);
}
} else if (!be->metadata) {
exist->num_refs++;
} else {
btrfs_err(fs_info,
"attempting to add another ref for an existing ref on a tree block");
dump_block_entry(fs_info, be);
dump_ref_action(fs_info, ra);
kfree(ref);
kfree(ra);
goto out_unlock;
}
kfree(ref);
} else {
if (action == BTRFS_DROP_DELAYED_REF) {
btrfs_err(fs_info,
"dropping a ref for a root that doesn't have a ref on the block");
dump_block_entry(fs_info, be);
dump_ref_action(fs_info, ra);
kfree(ref);
kfree(ra);
goto out_unlock;
}
}
if (!parent && !re) {
re = lookup_root_entry(&be->roots, ref_root);
if (!re) {
/*
* This shouldn't happen because we will add our re
* above when we lookup the be with !parent, but just in
* case catch this case so we don't panic because I
* didn't think of some other corner case.
*/
btrfs_err(fs_info, "failed to find root %llu for %llu",
generic_ref->real_root, be->bytenr);
dump_block_entry(fs_info, be);
dump_ref_action(fs_info, ra);
kfree(ra);
goto out_unlock;
}
}
if (action == BTRFS_DROP_DELAYED_REF) {
if (re)
re->num_refs--;
be->num_refs--;
} else if (action == BTRFS_ADD_DELAYED_REF) {
be->num_refs++;
if (re)
re->num_refs++;
}
list_add_tail(&ra->list, &be->actions);
ret = 0;
out_unlock:
spin_unlock(&fs_info->ref_verify_lock);
out:
if (ret) {
btrfs_free_ref_cache(fs_info);
btrfs_clear_opt(fs_info->mount_opt, REF_VERIFY);
}
return ret;
}
/* Free up the ref cache */
void btrfs_free_ref_cache(struct btrfs_fs_info *fs_info)
{
struct block_entry *be;
struct rb_node *n;
if (!btrfs_test_opt(fs_info, REF_VERIFY))
return;
spin_lock(&fs_info->ref_verify_lock);
while ((n = rb_first(&fs_info->block_tree))) {
be = rb_entry(n, struct block_entry, node);
rb_erase(&be->node, &fs_info->block_tree);
free_block_entry(be);
cond_resched_lock(&fs_info->ref_verify_lock);
}
spin_unlock(&fs_info->ref_verify_lock);
}
void btrfs_free_ref_tree_range(struct btrfs_fs_info *fs_info, u64 start,
u64 len)
{
struct block_entry *be = NULL, *entry;
struct rb_node *n;
if (!btrfs_test_opt(fs_info, REF_VERIFY))
return;
spin_lock(&fs_info->ref_verify_lock);
n = fs_info->block_tree.rb_node;
while (n) {
entry = rb_entry(n, struct block_entry, node);
if (entry->bytenr < start) {
n = n->rb_right;
} else if (entry->bytenr > start) {
n = n->rb_left;
} else {
be = entry;
break;
}
/* We want to get as close to start as possible */
if (be == NULL ||
(entry->bytenr < start && be->bytenr > start) ||
(entry->bytenr < start && entry->bytenr > be->bytenr))
be = entry;
}
/*
* Could have an empty block group, maybe have something to check for
* this case to verify we were actually empty?
*/
if (!be) {
spin_unlock(&fs_info->ref_verify_lock);
return;
}
n = &be->node;
while (n) {
be = rb_entry(n, struct block_entry, node);
n = rb_next(n);
if (be->bytenr < start && be->bytenr + be->len > start) {
btrfs_err(fs_info,
"block entry overlaps a block group [%llu,%llu]!",
start, len);
dump_block_entry(fs_info, be);
continue;
}
if (be->bytenr < start)
continue;
if (be->bytenr >= start + len)
break;
if (be->bytenr + be->len > start + len) {
btrfs_err(fs_info,
"block entry overlaps a block group [%llu,%llu]!",
start, len);
dump_block_entry(fs_info, be);
}
rb_erase(&be->node, &fs_info->block_tree);
free_block_entry(be);
}
spin_unlock(&fs_info->ref_verify_lock);
}
/* Walk down all roots and build the ref tree, meant to be called at mount */
int btrfs_build_ref_tree(struct btrfs_fs_info *fs_info)
{
struct btrfs_root *extent_root;
struct btrfs_path *path;
struct extent_buffer *eb;
int tree_block_level = 0;
u64 bytenr = 0, num_bytes = 0;
int ret, level;
if (!btrfs_test_opt(fs_info, REF_VERIFY))
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
extent_root = btrfs_extent_root(fs_info, 0);
eb = btrfs_read_lock_root_node(extent_root);
level = btrfs_header_level(eb);
path->nodes[level] = eb;
path->slots[level] = 0;
path->locks[level] = BTRFS_READ_LOCK;
while (1) {
/*
* We have to keep track of the bytenr/num_bytes we last hit
* because we could have run out of space for an inline ref, and
* would have had to added a ref key item which may appear on a
* different leaf from the original extent item.
*/
ret = walk_down_tree(extent_root, path, level,
&bytenr, &num_bytes, &tree_block_level);
if (ret)
break;
ret = walk_up_tree(path, &level);
if (ret < 0)
break;
if (ret > 0) {
ret = 0;
break;
}
}
if (ret) {
btrfs_free_ref_cache(fs_info);
btrfs_clear_opt(fs_info->mount_opt, REF_VERIFY);
}
btrfs_free_path(path);
return ret;
}