On Thu 06-05-21 19:47:11, yebin wrote:
>
>
> On 2021/5/6 18:19, Jan Kara wrote:
> > On Thu 06-05-21 16:26:24, yebin wrote:
> > > Thanks for your suggesttion. If you have no objection to following
> > > modification, i will send it as V4.
> > >
> > > diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> > > index 77c84d6f1af6..f9cbd11e1eae 100644
> > > --- a/fs/ext4/extents.c
> > > +++ b/fs/ext4/extents.c
> > > @@ -3206,7 +3206,10 @@ static int ext4_split_extent_at(handle_t *handle,
> > > ext4_ext_mark_unwritten(ex2);
> > >
> > > err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags);
> > > - if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
> > > + if (err != -ENOSPC && err != -EDQUOT)
> > > + goto out;
> > > +
> > > + if (EXT4_EXT_MAY_ZEROOUT & split_flag) {
> > You need:
> >
> > if (err && (EXT4_EXT_MAY_ZEROOUT & split_flag))
> >
> > there, don't you? You don't want to zero-out if there's no error.
>
> If (err != -ENOSPC && err != -EDQUOT) already goto out, so there is needn't
> judge "err" again.
Right, my fault. I was confused.
> > > @@ -3232,22 +3235,23 @@ static int ext4_split_extent_at(handle_t *handle,
> > > ext4_ext_pblock(&orig_ex));
> > > }
> > >
> > > - if (err)
> > > - goto fix_extent_len;
> > > - /* update the extent length and mark as initialized */
> > > - ex->ee_len = cpu_to_le16(ee_len);
> > > - ext4_ext_try_to_merge(handle, inode, path, ex);
> > > - err = ext4_ext_dirty(handle, inode, path + path->p_depth);
> > > - if (err)
> > > - goto fix_extent_len;
> > > -
> > > - /* update extent status tree */
> > > - err = ext4_zeroout_es(inode, &zero_ex);
> > > -
> > > - goto out;
> > > - } else if (err)
> > > - goto fix_extent_len;
> > > -
> > > + if (!err) {
> > > + /* update the extent length and mark as initialized
> > > */
> > > + ex->ee_len = cpu_to_le16(ee_len);
> > > + ext4_ext_try_to_merge(handle, inode, path, ex);
> > > + err = ext4_ext_dirty(handle, inode, path +
> > > path->p_depth);
> > > + if (!err)
> > > + /* update extent status tree */
> > > + err = ext4_zeroout_es(inode, &zero_ex);
> > > + /* At here, ext4_ext_try_to_merge maybe already
> > > merge
> > > + * extent, if fix origin extent length may lead to
> > > + * overwritten.
> > > + */
> > I'd rephrase the comment as:
> >
> > /*
> > * If we failed at this point, we don't know in which state the extent tree
> > * exactly is so don't try to fix length of the original extent as it may do
> > * even more damage.
> > */
> I will replace it with your comment.
> >
> > > + goto out;
> > > + }
> > > + }
> > > + if (err)
> > > + goto fix_extent_len;
> > And you can move this if (err) before if (!err) above to make code easier
> > to read and save one indentation level.
> if (EXT4_EXT_MAY_ZEROOUT & split_flag) do zero-out, if failed, we don't
> need fix extent length.
> But if (!EXT4_EXT_MAY_ZEROOUT & split_flag) we need to fix extent length.
> Maybe i can move
> label "out" behind label "fix_extent_len", then this judement can be
> removed.
> Did i misunderstand what you meant earlier?
Thanks for the update! The diff now looks good to me so feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
for your next posting.
Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
