btrfs: Use ktime_get_real_ts for root ctime

btrfs_root_item maintains the ctime for root updates.  This is not part
of vfs_inode.

Since current_time() uses struct inode* as an argument as Linus
suggested, this cannot be used to update root times unless, we modify
the signature to use inode.

Since btrfs uses nanosecond time granularity, it can also use
ktime_get_real_ts directly to obtain timestamp for the root. It is
necessary to use the timespec time api here because the same
btrfs_set_stack_timespec_*() apis are used for vfs inode times as well.
These can be transitioned to using timespec64 when btrfs internally
changes to use timespec64 as well.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: David Sterba <dsterba@suse.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index a08224eab8b47111b2fc6f7f51ac33e6ca69814e..7d6bc308bf4308f653cc300c1354602ddd0df911 100644 (file)
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -501,8 +501,9 @@ void btrfs_update_root_times(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root)
 {
        struct btrfs_root_item *item = &root->root_item;
-       struct timespec ct = current_fs_time(root->fs_info->sb);
+       struct timespec ct;
 
+       ktime_get_real_ts(&ct);
        spin_lock(&root->root_item_lock);
        btrfs_set_root_ctransid(item, trans->transid);
        btrfs_set_stack_timespec_sec(&item->ctime, ct.tv_sec);