[2/3] ext4: Do not delete unlinked inode from orphan list on failed truncate

It is possible that unlinked inode enters ext4_setattr() (e.g. if
somebody calls ftruncate(2) on unlinked but still open file). In such
case we should not delete the inode from the orphan list if truncate
fails. Note that this is mostly a theoretical concern as filesystem is
corrupted if we reach this path anyway but let's be consistent in our
orphan handling.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/inode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

On Tue, May 21, 2019 at 09:43:57AM +0200, Jan Kara wrote:
> It is possible that unlinked inode enters ext4_setattr() (e.g. if
> somebody calls ftruncate(2) on unlinked but still open file). In such
> case we should not delete the inode from the orphan list if truncate
> fails. Note that this is mostly a theoretical concern as filesystem is
> corrupted if we reach this path anyway but let's be consistent in our
> orphan handling.
> 
> Signed-off-by: Jan Kara <jack@suse.cz>
> ---
>  fs/ext4/inode.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 9bcb7f2b86dd..c7f77c643008 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -5625,7 +5625,7 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
>  			up_write(&EXT4_I(inode)->i_data_sem);
>  			ext4_journal_stop(handle);
>  			if (error) {
> -				if (orphan)
> +				if (orphan && inode->i_nlink)
>  					ext4_orphan_del(NULL, inode);


NIT: While ext4_orphan_del() can be called even if the inode was not on the
orphan list it kind of tripped me up to see this called even if
ext4_orphan_add() fails...

But considering how ext4_orphan_del() works:

Reviewed-by: Ira Weiny <ira.weiny@intel.com>

>  				goto err_out;
>  			}
> -- 
> 2.16.4
>

On Tue 21-05-19 11:13:49, Ira Weiny wrote:
> On Tue, May 21, 2019 at 09:43:57AM +0200, Jan Kara wrote:
> > It is possible that unlinked inode enters ext4_setattr() (e.g. if
> > somebody calls ftruncate(2) on unlinked but still open file). In such
> > case we should not delete the inode from the orphan list if truncate
> > fails. Note that this is mostly a theoretical concern as filesystem is
> > corrupted if we reach this path anyway but let's be consistent in our
> > orphan handling.
> > 
> > Signed-off-by: Jan Kara <jack@suse.cz>
> > ---
> >  fs/ext4/inode.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> > index 9bcb7f2b86dd..c7f77c643008 100644
> > --- a/fs/ext4/inode.c
> > +++ b/fs/ext4/inode.c
> > @@ -5625,7 +5625,7 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
> >  			up_write(&EXT4_I(inode)->i_data_sem);
> >  			ext4_journal_stop(handle);
> >  			if (error) {
> > -				if (orphan)
> > +				if (orphan && inode->i_nlink)
> >  					ext4_orphan_del(NULL, inode);
> 
> 
> NIT: While ext4_orphan_del() can be called even if the inode was not on the
> orphan list it kind of tripped me up to see this called even if
> ext4_orphan_add() fails...
> 
> But considering how ext4_orphan_del() works:
> 
> Reviewed-by: Ira Weiny <ira.weiny@intel.com>

Yes, calling ext4_orphan_del() twice is harmless. You're right we just
shouldn't set 'orphan = 1' if ext4_orphan_add() fails but that's
independent cleanup we could do. Thanks for your review!

								Honza