linux/fs/btrfs/root-tree.c
Deepa Dinamani 95582b0083 vfs: change inode times to use struct timespec64
struct timespec is not y2038 safe. Transition vfs to use
y2038 safe struct timespec64 instead.

The change was made with the help of the following cocinelle
script. This catches about 80% of the changes.
All the header file and logic changes are included in the
first 5 rules. The rest are trivial substitutions.
I avoid changing any of the function signatures or any other
filesystem specific data structures to keep the patch simple
for review.

The script can be a little shorter by combining different cases.
But, this version was sufficient for my usecase.

virtual patch

@ depends on patch @
identifier now;
@@
- struct timespec
+ struct timespec64
  current_time ( ... )
  {
- struct timespec now = current_kernel_time();
+ struct timespec64 now = current_kernel_time64();
  ...
- return timespec_trunc(
+ return timespec64_trunc(
  ... );
  }

@ depends on patch @
identifier xtime;
@@
 struct \( iattr \| inode \| kstat \) {
 ...
-       struct timespec xtime;
+       struct timespec64 xtime;
 ...
 }

@ depends on patch @
identifier t;
@@
 struct inode_operations {
 ...
int (*update_time) (...,
-       struct timespec t,
+       struct timespec64 t,
...);
 ...
 }

@ depends on patch @
identifier t;
identifier fn_update_time =~ "update_time$";
@@
 fn_update_time (...,
- struct timespec *t,
+ struct timespec64 *t,
 ...) { ... }

@ depends on patch @
identifier t;
@@
lease_get_mtime( ... ,
- struct timespec *t
+ struct timespec64 *t
  ) { ... }

@te depends on patch forall@
identifier ts;
local idexpression struct inode *inode_node;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
identifier fn_update_time =~ "update_time$";
identifier fn;
expression e, E3;
local idexpression struct inode *node1;
local idexpression struct inode *node2;
local idexpression struct iattr *attr1;
local idexpression struct iattr *attr2;
local idexpression struct iattr attr;
identifier i_xtime1 =~ "^i_[acm]time$";
identifier i_xtime2 =~ "^i_[acm]time$";
identifier ia_xtime1 =~ "^ia_[acm]time$";
identifier ia_xtime2 =~ "^ia_[acm]time$";
@@
(
(
- struct timespec ts;
+ struct timespec64 ts;
|
- struct timespec ts = current_time(inode_node);
+ struct timespec64 ts = current_time(inode_node);
)

<+... when != ts
(
- timespec_equal(&inode_node->i_xtime, &ts)
+ timespec64_equal(&inode_node->i_xtime, &ts)
|
- timespec_equal(&ts, &inode_node->i_xtime)
+ timespec64_equal(&ts, &inode_node->i_xtime)
|
- timespec_compare(&inode_node->i_xtime, &ts)
+ timespec64_compare(&inode_node->i_xtime, &ts)
|
- timespec_compare(&ts, &inode_node->i_xtime)
+ timespec64_compare(&ts, &inode_node->i_xtime)
|
ts = current_time(e)
|
fn_update_time(..., &ts,...)
|
inode_node->i_xtime = ts
|
node1->i_xtime = ts
|
ts = inode_node->i_xtime
|
<+... attr1->ia_xtime ...+> = ts
|
ts = attr1->ia_xtime
|
ts.tv_sec
|
ts.tv_nsec
|
btrfs_set_stack_timespec_sec(..., ts.tv_sec)
|
btrfs_set_stack_timespec_nsec(..., ts.tv_nsec)
|
- ts = timespec64_to_timespec(
+ ts =
...
-)
|
- ts = ktime_to_timespec(
+ ts = ktime_to_timespec64(
...)
|
- ts = E3
+ ts = timespec_to_timespec64(E3)
|
- ktime_get_real_ts(&ts)
+ ktime_get_real_ts64(&ts)
|
fn(...,
- ts
+ timespec64_to_timespec(ts)
,...)
)
...+>
(
<... when != ts
- return ts;
+ return timespec64_to_timespec(ts);
...>
)
|
- timespec_equal(&node1->i_xtime1, &node2->i_xtime2)
+ timespec64_equal(&node1->i_xtime2, &node2->i_xtime2)
|
- timespec_equal(&node1->i_xtime1, &attr2->ia_xtime2)
+ timespec64_equal(&node1->i_xtime2, &attr2->ia_xtime2)
|
- timespec_compare(&node1->i_xtime1, &node2->i_xtime2)
+ timespec64_compare(&node1->i_xtime1, &node2->i_xtime2)
|
node1->i_xtime1 =
- timespec_trunc(attr1->ia_xtime1,
+ timespec64_trunc(attr1->ia_xtime1,
...)
|
- attr1->ia_xtime1 = timespec_trunc(attr2->ia_xtime2,
+ attr1->ia_xtime1 =  timespec64_trunc(attr2->ia_xtime2,
...)
|
- ktime_get_real_ts(&attr1->ia_xtime1)
+ ktime_get_real_ts64(&attr1->ia_xtime1)
|
- ktime_get_real_ts(&attr.ia_xtime1)
+ ktime_get_real_ts64(&attr.ia_xtime1)
)

@ depends on patch @
struct inode *node;
struct iattr *attr;
identifier fn;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
expression e;
@@
(
- fn(node->i_xtime);
+ fn(timespec64_to_timespec(node->i_xtime));
|
 fn(...,
- node->i_xtime);
+ timespec64_to_timespec(node->i_xtime));
|
- e = fn(attr->ia_xtime);
+ e = fn(timespec64_to_timespec(attr->ia_xtime));
)

@ depends on patch forall @
struct inode *node;
struct iattr *attr;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
identifier fn;
@@
{
+ struct timespec ts;
<+...
(
+ ts = timespec64_to_timespec(node->i_xtime);
fn (...,
- &node->i_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
fn (...,
- &attr->ia_xtime,
+ &ts,
...);
)
...+>
}

@ depends on patch forall @
struct inode *node;
struct iattr *attr;
struct kstat *stat;
identifier ia_xtime =~ "^ia_[acm]time$";
identifier i_xtime =~ "^i_[acm]time$";
identifier xtime =~ "^[acm]time$";
identifier fn, ret;
@@
{
+ struct timespec ts;
<+...
(
+ ts = timespec64_to_timespec(node->i_xtime);
ret = fn (...,
- &node->i_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(node->i_xtime);
ret = fn (...,
- &node->i_xtime);
+ &ts);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
ret = fn (...,
- &attr->ia_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
ret = fn (...,
- &attr->ia_xtime);
+ &ts);
|
+ ts = timespec64_to_timespec(stat->xtime);
ret = fn (...,
- &stat->xtime);
+ &ts);
)
...+>
}

@ depends on patch @
struct inode *node;
struct inode *node2;
identifier i_xtime1 =~ "^i_[acm]time$";
identifier i_xtime2 =~ "^i_[acm]time$";
identifier i_xtime3 =~ "^i_[acm]time$";
struct iattr *attrp;
struct iattr *attrp2;
struct iattr attr ;
identifier ia_xtime1 =~ "^ia_[acm]time$";
identifier ia_xtime2 =~ "^ia_[acm]time$";
struct kstat *stat;
struct kstat stat1;
struct timespec64 ts;
identifier xtime =~ "^[acmb]time$";
expression e;
@@
(
( node->i_xtime2 \| attrp->ia_xtime2 \| attr.ia_xtime2 \) = node->i_xtime1  ;
|
 node->i_xtime2 = \( node2->i_xtime1 \| timespec64_trunc(...) \);
|
 node->i_xtime2 = node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \);
|
 node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \);
|
 stat->xtime = node2->i_xtime1;
|
 stat1.xtime = node2->i_xtime1;
|
( node->i_xtime2 \| attrp->ia_xtime2 \) = attrp->ia_xtime1  ;
|
( attrp->ia_xtime1 \| attr.ia_xtime1 \) = attrp2->ia_xtime2;
|
- e = node->i_xtime1;
+ e = timespec64_to_timespec( node->i_xtime1 );
|
- e = attrp->ia_xtime1;
+ e = timespec64_to_timespec( attrp->ia_xtime1 );
|
node->i_xtime1 = current_time(...);
|
 node->i_xtime2 = node->i_xtime1 = node->i_xtime3 =
- e;
+ timespec_to_timespec64(e);
|
 node->i_xtime1 = node->i_xtime3 =
- e;
+ timespec_to_timespec64(e);
|
- node->i_xtime1 = e;
+ node->i_xtime1 = timespec_to_timespec64(e);
)

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: <anton@tuxera.com>
Cc: <balbi@kernel.org>
Cc: <bfields@fieldses.org>
Cc: <darrick.wong@oracle.com>
Cc: <dhowells@redhat.com>
Cc: <dsterba@suse.com>
Cc: <dwmw2@infradead.org>
Cc: <hch@lst.de>
Cc: <hirofumi@mail.parknet.co.jp>
Cc: <hubcap@omnibond.com>
Cc: <jack@suse.com>
Cc: <jaegeuk@kernel.org>
Cc: <jaharkes@cs.cmu.edu>
Cc: <jslaby@suse.com>
Cc: <keescook@chromium.org>
Cc: <mark@fasheh.com>
Cc: <miklos@szeredi.hu>
Cc: <nico@linaro.org>
Cc: <reiserfs-devel@vger.kernel.org>
Cc: <richard@nod.at>
Cc: <sage@redhat.com>
Cc: <sfrench@samba.org>
Cc: <swhiteho@redhat.com>
Cc: <tj@kernel.org>
Cc: <trond.myklebust@primarydata.com>
Cc: <tytso@mit.edu>
Cc: <viro@zeniv.linux.org.uk>
2018-06-05 16:57:31 -07:00

497 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*/
#include <linux/err.h>
#include <linux/uuid.h>
#include "ctree.h"
#include "transaction.h"
#include "disk-io.h"
#include "print-tree.h"
/*
* Read a root item from the tree. In case we detect a root item smaller then
* sizeof(root_item), we know it's an old version of the root structure and
* initialize all new fields to zero. The same happens if we detect mismatching
* generation numbers as then we know the root was once mounted with an older
* kernel that was not aware of the root item structure change.
*/
static void btrfs_read_root_item(struct extent_buffer *eb, int slot,
struct btrfs_root_item *item)
{
uuid_le uuid;
int len;
int need_reset = 0;
len = btrfs_item_size_nr(eb, slot);
read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot),
min_t(int, len, (int)sizeof(*item)));
if (len < sizeof(*item))
need_reset = 1;
if (!need_reset && btrfs_root_generation(item)
!= btrfs_root_generation_v2(item)) {
if (btrfs_root_generation_v2(item) != 0) {
btrfs_warn(eb->fs_info,
"mismatching generation and generation_v2 found in root item. This root was probably mounted with an older kernel. Resetting all new fields.");
}
need_reset = 1;
}
if (need_reset) {
memset(&item->generation_v2, 0,
sizeof(*item) - offsetof(struct btrfs_root_item,
generation_v2));
uuid_le_gen(&uuid);
memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE);
}
}
/*
* btrfs_find_root - lookup the root by the key.
* root: the root of the root tree
* search_key: the key to search
* path: the path we search
* root_item: the root item of the tree we look for
* root_key: the root key of the tree we look for
*
* If ->offset of 'search_key' is -1ULL, it means we are not sure the offset
* of the search key, just lookup the root with the highest offset for a
* given objectid.
*
* If we find something return 0, otherwise > 0, < 0 on error.
*/
int btrfs_find_root(struct btrfs_root *root, const struct btrfs_key *search_key,
struct btrfs_path *path, struct btrfs_root_item *root_item,
struct btrfs_key *root_key)
{
struct btrfs_key found_key;
struct extent_buffer *l;
int ret;
int slot;
ret = btrfs_search_slot(NULL, root, search_key, path, 0, 0);
if (ret < 0)
return ret;
if (search_key->offset != -1ULL) { /* the search key is exact */
if (ret > 0)
goto out;
} else {
BUG_ON(ret == 0); /* Logical error */
if (path->slots[0] == 0)
goto out;
path->slots[0]--;
ret = 0;
}
l = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(l, &found_key, slot);
if (found_key.objectid != search_key->objectid ||
found_key.type != BTRFS_ROOT_ITEM_KEY) {
ret = 1;
goto out;
}
if (root_item)
btrfs_read_root_item(l, slot, root_item);
if (root_key)
memcpy(root_key, &found_key, sizeof(found_key));
out:
btrfs_release_path(path);
return ret;
}
void btrfs_set_root_node(struct btrfs_root_item *item,
struct extent_buffer *node)
{
btrfs_set_root_bytenr(item, node->start);
btrfs_set_root_level(item, btrfs_header_level(node));
btrfs_set_root_generation(item, btrfs_header_generation(node));
}
/*
* copy the data in 'item' into the btree
*/
int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_key *key, struct btrfs_root_item
*item)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
struct extent_buffer *l;
int ret;
int slot;
unsigned long ptr;
u32 old_len;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(trans, root, key, path, 0, 1);
if (ret < 0) {
btrfs_abort_transaction(trans, ret);
goto out;
}
if (ret != 0) {
btrfs_print_leaf(path->nodes[0]);
btrfs_crit(fs_info, "unable to update root key %llu %u %llu",
key->objectid, key->type, key->offset);
BUG_ON(1);
}
l = path->nodes[0];
slot = path->slots[0];
ptr = btrfs_item_ptr_offset(l, slot);
old_len = btrfs_item_size_nr(l, slot);
/*
* If this is the first time we update the root item which originated
* from an older kernel, we need to enlarge the item size to make room
* for the added fields.
*/
if (old_len < sizeof(*item)) {
btrfs_release_path(path);
ret = btrfs_search_slot(trans, root, key, path,
-1, 1);
if (ret < 0) {
btrfs_abort_transaction(trans, ret);
goto out;
}
ret = btrfs_del_item(trans, root, path);
if (ret < 0) {
btrfs_abort_transaction(trans, ret);
goto out;
}
btrfs_release_path(path);
ret = btrfs_insert_empty_item(trans, root, path,
key, sizeof(*item));
if (ret < 0) {
btrfs_abort_transaction(trans, ret);
goto out;
}
l = path->nodes[0];
slot = path->slots[0];
ptr = btrfs_item_ptr_offset(l, slot);
}
/*
* Update generation_v2 so at the next mount we know the new root
* fields are valid.
*/
btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
write_extent_buffer(l, item, ptr, sizeof(*item));
btrfs_mark_buffer_dirty(path->nodes[0]);
out:
btrfs_free_path(path);
return ret;
}
int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
const struct btrfs_key *key, struct btrfs_root_item *item)
{
/*
* Make sure generation v1 and v2 match. See update_root for details.
*/
btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
return btrfs_insert_item(trans, root, key, item, sizeof(*item));
}
int btrfs_find_orphan_roots(struct btrfs_fs_info *fs_info)
{
struct btrfs_root *tree_root = fs_info->tree_root;
struct extent_buffer *leaf;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_key root_key;
struct btrfs_root *root;
int err = 0;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = BTRFS_ORPHAN_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = 0;
root_key.type = BTRFS_ROOT_ITEM_KEY;
root_key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
if (ret < 0) {
err = ret;
break;
}
leaf = path->nodes[0];
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(tree_root, path);
if (ret < 0)
err = ret;
if (ret != 0)
break;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
btrfs_release_path(path);
if (key.objectid != BTRFS_ORPHAN_OBJECTID ||
key.type != BTRFS_ORPHAN_ITEM_KEY)
break;
root_key.objectid = key.offset;
key.offset++;
/*
* The root might have been inserted already, as before we look
* for orphan roots, log replay might have happened, which
* triggers a transaction commit and qgroup accounting, which
* in turn reads and inserts fs roots while doing backref
* walking.
*/
root = btrfs_lookup_fs_root(fs_info, root_key.objectid);
if (root) {
WARN_ON(!test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
&root->state));
if (btrfs_root_refs(&root->root_item) == 0)
btrfs_add_dead_root(root);
continue;
}
root = btrfs_read_fs_root(tree_root, &root_key);
err = PTR_ERR_OR_ZERO(root);
if (err && err != -ENOENT) {
break;
} else if (err == -ENOENT) {
struct btrfs_trans_handle *trans;
btrfs_release_path(path);
trans = btrfs_join_transaction(tree_root);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
btrfs_handle_fs_error(fs_info, err,
"Failed to start trans to delete orphan item");
break;
}
err = btrfs_del_orphan_item(trans, tree_root,
root_key.objectid);
btrfs_end_transaction(trans);
if (err) {
btrfs_handle_fs_error(fs_info, err,
"Failed to delete root orphan item");
break;
}
continue;
}
err = btrfs_init_fs_root(root);
if (err) {
btrfs_free_fs_root(root);
break;
}
set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
err = btrfs_insert_fs_root(fs_info, root);
if (err) {
BUG_ON(err == -EEXIST);
btrfs_free_fs_root(root);
break;
}
if (btrfs_root_refs(&root->root_item) == 0)
btrfs_add_dead_root(root);
}
btrfs_free_path(path);
return err;
}
/* drop the root item for 'key' from the tree root */
int btrfs_del_root(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, const struct btrfs_key *key)
{
struct btrfs_root *root = fs_info->tree_root;
struct btrfs_path *path;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(trans, root, key, path, -1, 1);
if (ret < 0)
goto out;
BUG_ON(ret != 0);
ret = btrfs_del_item(trans, root, path);
out:
btrfs_free_path(path);
return ret;
}
int btrfs_del_root_ref(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info,
u64 root_id, u64 ref_id, u64 dirid, u64 *sequence,
const char *name, int name_len)
{
struct btrfs_root *tree_root = fs_info->tree_root;
struct btrfs_path *path;
struct btrfs_root_ref *ref;
struct extent_buffer *leaf;
struct btrfs_key key;
unsigned long ptr;
int err = 0;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = root_id;
key.type = BTRFS_ROOT_BACKREF_KEY;
key.offset = ref_id;
again:
ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
BUG_ON(ret < 0);
if (ret == 0) {
leaf = path->nodes[0];
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_root_ref);
WARN_ON(btrfs_root_ref_dirid(leaf, ref) != dirid);
WARN_ON(btrfs_root_ref_name_len(leaf, ref) != name_len);
ptr = (unsigned long)(ref + 1);
WARN_ON(memcmp_extent_buffer(leaf, name, ptr, name_len));
*sequence = btrfs_root_ref_sequence(leaf, ref);
ret = btrfs_del_item(trans, tree_root, path);
if (ret) {
err = ret;
goto out;
}
} else
err = -ENOENT;
if (key.type == BTRFS_ROOT_BACKREF_KEY) {
btrfs_release_path(path);
key.objectid = ref_id;
key.type = BTRFS_ROOT_REF_KEY;
key.offset = root_id;
goto again;
}
out:
btrfs_free_path(path);
return err;
}
/*
* add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY
* or BTRFS_ROOT_BACKREF_KEY.
*
* The dirid, sequence, name and name_len refer to the directory entry
* that is referencing the root.
*
* For a forward ref, the root_id is the id of the tree referencing
* the root and ref_id is the id of the subvol or snapshot.
*
* For a back ref the root_id is the id of the subvol or snapshot and
* ref_id is the id of the tree referencing it.
*
* Will return 0, -ENOMEM, or anything from the CoW path
*/
int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info,
u64 root_id, u64 ref_id, u64 dirid, u64 sequence,
const char *name, int name_len)
{
struct btrfs_root *tree_root = fs_info->tree_root;
struct btrfs_key key;
int ret;
struct btrfs_path *path;
struct btrfs_root_ref *ref;
struct extent_buffer *leaf;
unsigned long ptr;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = root_id;
key.type = BTRFS_ROOT_BACKREF_KEY;
key.offset = ref_id;
again:
ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
sizeof(*ref) + name_len);
if (ret) {
btrfs_abort_transaction(trans, ret);
btrfs_free_path(path);
return ret;
}
leaf = path->nodes[0];
ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
btrfs_set_root_ref_dirid(leaf, ref, dirid);
btrfs_set_root_ref_sequence(leaf, ref, sequence);
btrfs_set_root_ref_name_len(leaf, ref, name_len);
ptr = (unsigned long)(ref + 1);
write_extent_buffer(leaf, name, ptr, name_len);
btrfs_mark_buffer_dirty(leaf);
if (key.type == BTRFS_ROOT_BACKREF_KEY) {
btrfs_release_path(path);
key.objectid = ref_id;
key.type = BTRFS_ROOT_REF_KEY;
key.offset = root_id;
goto again;
}
btrfs_free_path(path);
return 0;
}
/*
* Old btrfs forgets to init root_item->flags and root_item->byte_limit
* for subvolumes. To work around this problem, we steal a bit from
* root_item->inode_item->flags, and use it to indicate if those fields
* have been properly initialized.
*/
void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item)
{
u64 inode_flags = btrfs_stack_inode_flags(&root_item->inode);
if (!(inode_flags & BTRFS_INODE_ROOT_ITEM_INIT)) {
inode_flags |= BTRFS_INODE_ROOT_ITEM_INIT;
btrfs_set_stack_inode_flags(&root_item->inode, inode_flags);
btrfs_set_root_flags(root_item, 0);
btrfs_set_root_limit(root_item, 0);
}
}
void btrfs_update_root_times(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_root_item *item = &root->root_item;
struct timespec64 ct;
ktime_get_real_ts64(&ct);
spin_lock(&root->root_item_lock);
btrfs_set_root_ctransid(item, trans->transid);
btrfs_set_stack_timespec_sec(&item->ctime, ct.tv_sec);
btrfs_set_stack_timespec_nsec(&item->ctime, ct.tv_nsec);
spin_unlock(&root->root_item_lock);
}