Commit a9063ab9 authored by Tao Ma's avatar Tao Ma Committed by Joel Becker
Browse files

ocfs2: handle file attributes issue for reflink. 



A reflink creates a snapshot of a file, that means the attributes
must be identical except for three exceptions - nlink, ino, and ctime.

As for time changes, Here is a brief description:

1. Source file:
   1) atime: Ignore. Let the lazy atime code handle that.
   2) mtime: don't touch.
   3) ctime: If we change the tree (adding REFCOUNTED to at least one
             extent), update it.
2. Destination file:
   1) atime: ignore.
   2) mtime: we want it to appear identical to the source.
   3) ctime: update.

The idea here is that an ls -l will show the same time for the
src and target - it shows mtime.  Backup software like rsync and tar
will treat the new file correctly too.

Signed-off-by: default avatarTao Ma <tao.ma@oracle.com>
parent 110a045a

fs/ocfs2/refcounttree.c

+120 −2
Original line number Diff line number Diff line
@@ -3350,10 +3350,44 @@ out: 
	return ret;

}



static int ocfs2_attach_refcount_tree(struct inode *inode,

static int ocfs2_change_ctime(struct inode *inode,

			      struct buffer_head *di_bh)

{

	int ret;

	handle_t *handle;

	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;



	handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),

				   OCFS2_INODE_UPDATE_CREDITS);

	if (IS_ERR(handle)) {

		ret = PTR_ERR(handle);

		mlog_errno(ret);

		goto out;

	}



	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,

				      OCFS2_JOURNAL_ACCESS_WRITE);

	if (ret) {

		mlog_errno(ret);

		goto out_commit;

	}



	inode->i_ctime = CURRENT_TIME;

	di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);

	di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);



	ocfs2_journal_dirty(handle, di_bh);



out_commit:

	ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);

out:

	return ret;

}



static int ocfs2_attach_refcount_tree(struct inode *inode,

				      struct buffer_head *di_bh)

{

	int ret, data_changed = 0;

	struct buffer_head *ref_root_bh = NULL;

	struct ocfs2_inode_info *oi = OCFS2_I(inode);

	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
@@ -3402,12 +3436,21 @@ static int ocfs2_attach_refcount_tree(struct inode *inode, 
						      &dealloc);

			if (ret) {

				mlog_errno(ret);

				break;

				goto unlock;

			}



			data_changed = 1;

		}

		cpos += num_clusters;

	}



	if (data_changed) {

		ret = ocfs2_change_ctime(inode, di_bh);

		if (ret)

			mlog_errno(ret);

	}



unlock:

	ocfs2_unlock_refcount_tree(osb, ref_tree, 1);

	brelse(ref_root_bh);
@@ -3522,6 +3565,74 @@ out: 
	return ret;

}



/*

 * change the new file's attributes to the src.

 *

 * reflink creates a snapshot of a file, that means the attributes

 * must be identical except for three exceptions - nlink, ino, and ctime.

 */

static int ocfs2_complete_reflink(struct inode *s_inode,

				  struct buffer_head *s_bh,

				  struct inode *t_inode,

				  struct buffer_head *t_bh)

{

	int ret;

	handle_t *handle;

	struct ocfs2_dinode *s_di = (struct ocfs2_dinode *)s_bh->b_data;

	struct ocfs2_dinode *di = (struct ocfs2_dinode *)t_bh->b_data;

	loff_t size = i_size_read(s_inode);



	handle = ocfs2_start_trans(OCFS2_SB(t_inode->i_sb),

				   OCFS2_INODE_UPDATE_CREDITS);

	if (IS_ERR(handle)) {

		ret = PTR_ERR(handle);

		mlog_errno(ret);

		return ret;

	}



	ret = ocfs2_journal_access_di(handle, INODE_CACHE(t_inode), t_bh,

				      OCFS2_JOURNAL_ACCESS_WRITE);

	if (ret) {

		mlog_errno(ret);

		goto out_commit;

	}



	spin_lock(&OCFS2_I(t_inode)->ip_lock);

	OCFS2_I(t_inode)->ip_clusters = OCFS2_I(s_inode)->ip_clusters;

	OCFS2_I(t_inode)->ip_attr = OCFS2_I(s_inode)->ip_attr;

	OCFS2_I(t_inode)->ip_dyn_features = OCFS2_I(s_inode)->ip_dyn_features;

	spin_unlock(&OCFS2_I(t_inode)->ip_lock);

	i_size_write(t_inode, size);



	di->i_xattr_inline_size = s_di->i_xattr_inline_size;

	di->i_clusters = s_di->i_clusters;

	di->i_size = s_di->i_size;

	di->i_dyn_features = s_di->i_dyn_features;

	di->i_attr = s_di->i_attr;

	di->i_uid = s_di->i_uid;

	di->i_gid = s_di->i_gid;

	di->i_mode = s_di->i_mode;



	/*

	 * update time.

	 * we want mtime to appear identical to the source and update ctime.

	 */

	t_inode->i_ctime = CURRENT_TIME;



	di->i_ctime = cpu_to_le64(t_inode->i_ctime.tv_sec);

	di->i_ctime_nsec = cpu_to_le32(t_inode->i_ctime.tv_nsec);



	t_inode->i_mtime = s_inode->i_mtime;

	di->i_mtime = s_di->i_mtime;

	di->i_mtime_nsec = s_di->i_mtime_nsec;



	ocfs2_journal_dirty(handle, t_bh);



out_commit:

	ocfs2_commit_trans(OCFS2_SB(t_inode->i_sb), handle);

	return ret;

}



static int ocfs2_create_reflink_node(struct inode *s_inode,

				     struct buffer_head *s_bh,

				     struct inode *t_inode,
@@ -3555,9 +3666,16 @@ static int ocfs2_create_reflink_node(struct inode *s_inode, 
	ret = ocfs2_duplicate_extent_list(s_inode, t_inode, t_bh,

					  &ref_tree->rf_ci, ref_root_bh,

					  &dealloc);

	if (ret) {

		mlog_errno(ret);

		goto out_unlock_refcount;

	}



	ret = ocfs2_complete_reflink(s_inode, s_bh, t_inode, t_bh);

	if (ret)

		mlog_errno(ret);



out_unlock_refcount:

	ocfs2_unlock_refcount_tree(osb, ref_tree, 1);

	brelse(ref_root_bh);

out:

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