Re: [PATCH 2/3] ext4: WANR_ON when detect abnormal 'i_reserved_data_blocks'

[yebin (H)]

On 2022/11/21 17:47, Jan Kara wrote:
> On Thu 17-11-22 09:42:45, Ye Bin wrote:
> > From: Ye Bin <yebin10@xxxxxxxxxx>
> >
> > If 'i_reserved_data_blocks' is not cleared which mean something wrong
> > with code, so emit WARN_ON to capture this abnormal closer to the first
> > scene.
> >
> > Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx>
> > ---
> >   fs/ext4/super.c | 13 ++++++++-----
> >   1 file changed, 8 insertions(+), 5 deletions(-)
> >
> > diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> > index 63ef74eb8091..30885a6fe18b 100644
> > --- a/fs/ext4/super.c
> > +++ b/fs/ext4/super.c
> > @@ -1385,11 +1385,14 @@ static void ext4_destroy_inode(struct inode *inode)
> >   		dump_stack();
> >   	}
> >   
> > -	if (EXT4_I(inode)->i_reserved_data_blocks)
> > -		ext4_msg(inode->i_sb, KERN_ERR,
> > -			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
> > -			 inode->i_ino, EXT4_I(inode),
> > -			 EXT4_I(inode)->i_reserved_data_blocks);
> > +	if (EXT4_I(inode)->i_reserved_data_blocks) {
> > +		ext4_warning(inode->i_sb, "Inode %lu (%p): "
> > +			    "i_reserved_data_blocks (%u) not cleared!",
> > +			     inode->i_ino, EXT4_I(inode),
> > +			     EXT4_I(inode)->i_reserved_data_blocks);
> > +
> > +		WARN_ON(1);
> > +	}
> Hum, so I'd think that if this happens, the free space accounting is likely
> wrong so we might as well just force the filesystem to error mode with
> ext4_error() to force fsck?  I also gives a good chance to various test
> systems to detect there is some problem so we don't need the WARN_ON then?
> What do others think?
>
> 								Honza
Thanks for your advice, use ext4_error() maybe is suitable and also 
testable.