On Mon, Jul 24, 2017 at 10:02:30AM -0400, Josef Bacik wrote: > On Mon, Jul 24, 2017 at 02:42:29PM +0200, David Sterba wrote: > > On Fri, Jul 21, 2017 at 01:29:07PM -0400, [email protected] wrote: > > > From: Josef Bacik <[email protected]> > > > > > > We need to use file->private_data for readdir on directories, so just > > > don't allow user space transactions on directories. > > > > > > Signed-off-by: Josef Bacik <[email protected]> > > > --- > > > fs/btrfs/ioctl.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > > > index bedeec6..ddb3811 100644 > > > --- a/fs/btrfs/ioctl.c > > > +++ b/fs/btrfs/ioctl.c > > > @@ -3968,6 +3968,9 @@ static long btrfs_ioctl_trans_start(struct file > > > *file) > > > struct btrfs_trans_handle *trans; > > > int ret; > > > > > > + if (S_ISDIR(inode->i_mode)) > > > + return -EINVAL; > > > > You can't do this, starting a transaction on a directory needs to work. > > The most natural way to run the ioctl is on the mount point. > > > > The file private data would need to be able to hold multipe values, so > > you can add > > > > struct btrfs_inode { > > ... > > struct priv_data { > > void *for_readdir; > > void *for_tranc_ioctl; > > }; > > ... > > }; > > > > then set file->file_private = &btrfs_inode->priv_data; and update all > > uses to check for the embedded pointers. > > Blah I really want to just jetison the user space transaction stuff altogether > so I was hoping this would be a first step. But yeah we can do it your way > too.
I'm fine with removing the trans ioctl, ceph does not use it. We may need one or two release cycles when we mark it deprecated and WARN_ON_ONCE when used. But as it's undocumented and tricky to use I guess nobody will notice. Unfortunatelly this means you still have to add the extra structures for readdir. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
