On Fri 16-07-21 11:56:06, Zhang Yi wrote:
> On 2021/7/15 20:08, Jan Kara wrote:
> > On Thu 15-07-21 09:54:51, Zhang Yi wrote:
> >> Now that the inline_data file write end procedure are falled into the
> >> common write end functions, it is not clear. Factor them out and do
> >> some cleanup. This patch also drop ext4_da_write_inline_data_end()
> >> and switch to use ext4_write_inline_data_end() instead because we also
> >> need to do the same error processing if we failed to write data into
> >> inline entry.
> >>
> >> Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
> >
> > Just two small comments below.
> >
> >> diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
> >> index 28b666f25ac2..3d227b32b21c 100644
> >> --- a/fs/ext4/inline.c
> >> +++ b/fs/ext4/inline.c
> > ...
> >> +out:
> >> + /*
> >> + * If we have allocated more blocks and copied less. We will have
> >> + * blocks allocated outside inode->i_size, so truncate them.
> >> + */
> >> + if (pos + len > inode->i_size && ext4_can_truncate(inode))
> >> + ext4_orphan_add(handle, inode);
> >
> > I don't think we need this error handling here. For inline data we never
> > allocate any blocks so shorter writes don't need any cleanup.
> >
> >> - return copied;
> >> + ret2 = ext4_journal_stop(handle);
> >> + if (!ret)
> >> + ret = ret2;
> >> + if (pos + len > inode->i_size) {
> >> + ext4_truncate_failed_write(inode);
> >> + /*
> >> + * If truncate failed early the inode might still be
> >> + * on the orphan list; we need to make sure the inode
> >> + * is removed from the orphan list in that case.
> >> + */
> >> + if (inode->i_nlink)
> >> + ext4_orphan_del(NULL, inode);
> >> + }
> >
> > And this can go away as well...
> >
>
> Yeah, but if we don't call ext4_truncate_failed_write()->..->
> ext4_inline_data_truncate(), it will lead to incorrect larger i_inline_size
> and data entry. Although it seems harmless (i_size can prevent read zero
> data), I think it's better to restore the data entry(the comments need
> change later), or else it will occupy more xattr space. What do you think ?
Good point. I've found this out last time when I was reviewing your patches
and then forgot again. So please leave the code there but fix this
misleading comment:
/*
* If we have allocated more blocks and copied less. We will have
* blocks allocated outside inode->i_size, so truncate them.
*/
Something like:
/*
* If we didn't copy as much data as expected, we need to trim back size of
* xattr containing inline data.
*/
Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
