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ocfs2: handle file attributes issue for reflink.

Browse source 
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: Tao Ma <tao.ma@oracle.com>
This commit is contained in:
Tao Ma 2009-08-18 11:40:59 +08:00 committed by Joel Becker
parent 110a045aca
commit a9063ab9a3
1 changed files with 120 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

122
fs/ocfs2/refcounttree.c
View file

@ -3350,10 +3350,44 @@ out:
return ret;
}
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;
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: