Re: [PATCH] use proper mnt_want_write calls for handle ioctls

[Christoph Hellwig <hch@lst.de>]

ping^2?

On Fri, Sep 12, 2008 at 10:44:31AM +0200, Christoph Hellwig wrote:
> ping?  Without this patch the CVS tree won't properly work with
> read-only bind mounts.
> 
> On Thu, Aug 14, 2008 at 10:39:52PM +0200, Christoph Hellwig wrote:
> > Since 2.6.26 all writes to filesystems need to be enclosed by a
> > mnt_want_write / mnt_drop_write pair instead of checking for IS_RDONLY.
> > 
> > XFs was updated for this in mainline but the changes to xfs_ioctl.c
> > were never megred back into the CVS tree.
> > 
> > The original commit introducing this was:
> > 
> > commit 42a74f206b914db13ee1f5ae932dcd91a77c8579
> > Author: Dave Hansen <haveblue@us.ibm.com>
> > Date:   Fri Feb 15 14:37:46 2008 -0800
> > 
> >     [PATCH] r/o bind mounts: elevate write count for ioctls()
> > 
> > Index: linux-2.6-xfs/fs/xfs/linux-2.6/xfs_ioctl.c
> > ===================================================================
> > --- linux-2.6-xfs.orig/fs/xfs/linux-2.6/xfs_ioctl.c	2008-08-14 14:54:53.000000000 -0300
> > +++ linux-2.6-xfs/fs/xfs/linux-2.6/xfs_ioctl.c	2008-08-14 15:15:49.000000000 -0300
> > @@ -543,8 +543,6 @@ xfs_attrmulti_attr_set(
> >  	char			*kbuf;
> >  	int			error = EFAULT;
> >  
> > -	if (IS_RDONLY(inode))
> > -		return -EROFS;
> >  	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
> >  		return EPERM;
> >  	if (len > XATTR_SIZE_MAX)
> > @@ -570,8 +568,6 @@ xfs_attrmulti_attr_remove(
> >  	char			*name,
> >  	__uint32_t		flags)
> >  {
> > -	if (IS_RDONLY(inode))
> > -		return -EROFS;
> >  	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
> >  		return EPERM;
> >  	return xfs_attr_remove(XFS_I(inode), name, flags);
> > @@ -581,6 +577,7 @@ STATIC int
> >  xfs_attrmulti_by_handle(
> >  	xfs_mount_t		*mp,
> >  	void			__user *arg,
> > +	struct file		*parfilp,
> >  	struct inode		*parinode)
> >  {
> >  	int			error;
> > @@ -634,13 +631,21 @@ xfs_attrmulti_by_handle(
> >  					&ops[i].am_length, ops[i].am_flags);
> >  			break;
> >  		case ATTR_OP_SET:
> > +			ops[i].am_error = mnt_want_write(parfilp->f_path.mnt);
> > +			if (ops[i].am_error)
> > +				break;
> >  			ops[i].am_error = xfs_attrmulti_attr_set(inode,
> >  					attr_name, ops[i].am_attrvalue,
> >  					ops[i].am_length, ops[i].am_flags);
> > +			mnt_drop_write(parfilp->f_path.mnt);
> >  			break;
> >  		case ATTR_OP_REMOVE:
> > +			ops[i].am_error = mnt_want_write(parfilp->f_path.mnt);
> > +			if (ops[i].am_error)
> > +				break;
> >  			ops[i].am_error = xfs_attrmulti_attr_remove(inode,
> >  					attr_name, ops[i].am_flags);
> > +			mnt_drop_write(parfilp->f_path.mnt);
> >  			break;
> >  		default:
> >  			ops[i].am_error = EINVAL;
> > @@ -1431,7 +1436,7 @@ xfs_ioctl(
> >  		return xfs_attrlist_by_handle(mp, arg, inode);
> >  
> >  	case XFS_IOC_ATTRMULTI_BY_HANDLE:
> > -		return xfs_attrmulti_by_handle(mp, arg, inode);
> > +		return xfs_attrmulti_by_handle(mp, arg, filp, inode);
> >  
> >  	case XFS_IOC_SWAPEXT: {
> >  		error = xfs_swapext((struct xfs_swapext __user *)arg);
> ---end quoted text---
---end quoted text---