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From: Ira Weiny <ira.weiny@intel.com>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: linux-kernel@vger.kernel.org,
	Dan Williams <dan.j.williams@intel.com>,
	Dave Chinner <david@fromorbit.com>,
	Christoph Hellwig <hch@lst.de>,
	"Theodore Y. Ts'o" <tytso@mit.edu>, Jan Kara <jack@suse.cz>,
	Jeff Moyer <jmoyer@redhat.com>,
	linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org,
	linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH V6 7/8] fs/xfs: Change xfs_ioctl_setattr_dax_invalidate() to xfs_ioctl_dax_check()
Date: Wed, 8 Apr 2020 11:13:07 -0700	[thread overview]
Message-ID: <20200408181307.GD569068@iweiny-DESK2.sc.intel.com> (raw)
In-Reply-To: <20200408153717.GH6742@magnolia>

On Wed, Apr 08, 2020 at 08:37:17AM -0700, Darrick J. Wong wrote:
> On Tue, Apr 07, 2020 at 11:29:57AM -0700, ira.weiny@intel.com wrote:
> > From: Ira Weiny <ira.weiny@intel.com>
> > 
> > We only support changing FS_XFLAG_DAX on directories.  Files get their
> > flag from the parent directory on creation only.  So no data
> > invalidation needs to happen.
> > 
> > Alter the xfs_ioctl_setattr_dax_invalidate() to be
> > xfs_ioctl_dax_check().
> > 
> > This also allows use to remove the join_flags logic.
> > 
> > Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> > 
> > ---
> > Changes from v5:
> > 	New patch
> > ---
> >  fs/xfs/xfs_ioctl.c | 91 +++++-----------------------------------------
> >  1 file changed, 10 insertions(+), 81 deletions(-)
> > 
> > diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
> > index c6cd92ef4a05..5472faab7c4f 100644
> > --- a/fs/xfs/xfs_ioctl.c
> > +++ b/fs/xfs/xfs_ioctl.c
> > @@ -1145,63 +1145,18 @@ xfs_ioctl_setattr_xflags(
> >  }
> >  
> >  /*
> > - * If we are changing DAX flags, we have to ensure the file is clean and any
> > - * cached objects in the address space are invalidated and removed. This
> > - * requires us to lock out other IO and page faults similar to a truncate
> > - * operation. The locks need to be held until the transaction has been committed
> > - * so that the cache invalidation is atomic with respect to the DAX flag
> > - * manipulation.
> > + * Only directories are allowed to change dax flags
> >   */
> >  static int
> >  xfs_ioctl_setattr_dax_invalidate(
> > -	struct xfs_inode	*ip,
> > -	struct fsxattr		*fa,
> > -	int			*join_flags)
> > +	struct xfs_inode	*ip)
> >  {
> >  	struct inode		*inode = VFS_I(ip);
> > -	struct super_block	*sb = inode->i_sb;
> > -	int			error;
> > -
> > -	*join_flags = 0;
> > -
> > -	/*
> > -	 * It is only valid to set the DAX flag on regular files and
> > -	 * directories on filesystems where the block size is equal to the page
> > -	 * size. On directories it serves as an inherited hint so we don't
> > -	 * have to check the device for dax support or flush pagecache.
> > -	 */
> > -	if (fa->fsx_xflags & FS_XFLAG_DAX) {
> > -		struct xfs_buftarg	*target = xfs_inode_buftarg(ip);
> > -
> > -		if (!bdev_dax_supported(target->bt_bdev, sb->s_blocksize))
> > -			return -EINVAL;
> > -	}
> > -
> > -	/* If the DAX state is not changing, we have nothing to do here. */
> > -	if ((fa->fsx_xflags & FS_XFLAG_DAX) && IS_DAX(inode))
> > -		return 0;
> > -	if (!(fa->fsx_xflags & FS_XFLAG_DAX) && !IS_DAX(inode))
> > -		return 0;
> 
> Does the !S_ISDIR check below apply unconditionally even if we weren't
> trying to change the DAX flag?

:-/

shoot...  I really screwed this up...

> 
> > -	if (S_ISDIR(inode->i_mode))
> > -		return 0;
> >  
> > -	/* lock, flush and invalidate mapping in preparation for flag change */
> > -	xfs_ilock(ip, XFS_MMAPLOCK_EXCL | XFS_IOLOCK_EXCL);
> > -	error = filemap_write_and_wait(inode->i_mapping);
> > -	if (error)
> > -		goto out_unlock;
> > -	error = invalidate_inode_pages2(inode->i_mapping);
> > -	if (error)
> > -		goto out_unlock;
> > +	if (!S_ISDIR(inode->i_mode))
> > +		return -EINVAL;
> 
> If this entire function collapses to an S_ISDIR check then you might
> as well just hoist this one piece to the caller.

Oops...  yea this is broken...  All broken.

> Also, where is
> xfs_ioctl_dax_check?

I forgot to change the name.

> 
> <confused>

Much less so than me...  :-/

I'll clean it up.

Thanks, this was really bad on my part...
Ira

> 
> --D
> 
> >  
> > -	*join_flags = XFS_MMAPLOCK_EXCL | XFS_IOLOCK_EXCL;
> >  	return 0;
> > -
> > -out_unlock:
> > -	xfs_iunlock(ip, XFS_MMAPLOCK_EXCL | XFS_IOLOCK_EXCL);
> > -	return error;
> > -
> >  }
> >  
> >  /*
> > @@ -1209,17 +1164,10 @@ xfs_ioctl_setattr_dax_invalidate(
> >   * have permission to do so. On success, return a clean transaction and the
> >   * inode locked exclusively ready for further operation specific checks. On
> >   * failure, return an error without modifying or locking the inode.
> > - *
> > - * The inode might already be IO locked on call. If this is the case, it is
> > - * indicated in @join_flags and we take full responsibility for ensuring they
> > - * are unlocked from now on. Hence if we have an error here, we still have to
> > - * unlock them. Otherwise, once they are joined to the transaction, they will
> > - * be unlocked on commit/cancel.
> >   */
> >  static struct xfs_trans *
> >  xfs_ioctl_setattr_get_trans(
> > -	struct xfs_inode	*ip,
> > -	int			join_flags)
> > +	struct xfs_inode	*ip)
> >  {
> >  	struct xfs_mount	*mp = ip->i_mount;
> >  	struct xfs_trans	*tp;
> > @@ -1236,8 +1184,7 @@ xfs_ioctl_setattr_get_trans(
> >  		goto out_unlock;
> >  
> >  	xfs_ilock(ip, XFS_ILOCK_EXCL);
> > -	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL | join_flags);
> > -	join_flags = 0;
> > +	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
> >  
> >  	/*
> >  	 * CAP_FOWNER overrides the following restrictions:
> > @@ -1258,8 +1205,6 @@ xfs_ioctl_setattr_get_trans(
> >  out_cancel:
> >  	xfs_trans_cancel(tp);
> >  out_unlock:
> > -	if (join_flags)
> > -		xfs_iunlock(ip, join_flags);
> >  	return ERR_PTR(error);
> >  }
> >  
> > @@ -1386,7 +1331,6 @@ xfs_ioctl_setattr(
> >  	struct xfs_dquot	*pdqp = NULL;
> >  	struct xfs_dquot	*olddquot = NULL;
> >  	int			code;
> > -	int			join_flags = 0;
> >  
> >  	trace_xfs_ioctl_setattr(ip);
> >  
> > @@ -1410,18 +1354,11 @@ xfs_ioctl_setattr(
> >  			return code;
> >  	}
> >  
> > -	/*
> > -	 * Changing DAX config may require inode locking for mapping
> > -	 * invalidation. These need to be held all the way to transaction commit
> > -	 * or cancel time, so need to be passed through to
> > -	 * xfs_ioctl_setattr_get_trans() so it can apply them to the join call
> > -	 * appropriately.
> > -	 */
> > -	code = xfs_ioctl_setattr_dax_invalidate(ip, fa, &join_flags);
> > +	code = xfs_ioctl_setattr_dax_invalidate(ip);
> >  	if (code)
> >  		goto error_free_dquots;
> >  
> > -	tp = xfs_ioctl_setattr_get_trans(ip, join_flags);
> > +	tp = xfs_ioctl_setattr_get_trans(ip);
> >  	if (IS_ERR(tp)) {
> >  		code = PTR_ERR(tp);
> >  		goto error_free_dquots;
> > @@ -1552,7 +1489,6 @@ xfs_ioc_setxflags(
> >  	struct fsxattr		fa;
> >  	struct fsxattr		old_fa;
> >  	unsigned int		flags;
> > -	int			join_flags = 0;
> >  	int			error;
> >  
> >  	if (copy_from_user(&flags, arg, sizeof(flags)))
> > @@ -1569,18 +1505,11 @@ xfs_ioc_setxflags(
> >  	if (error)
> >  		return error;
> >  
> > -	/*
> > -	 * Changing DAX config may require inode locking for mapping
> > -	 * invalidation. These need to be held all the way to transaction commit
> > -	 * or cancel time, so need to be passed through to
> > -	 * xfs_ioctl_setattr_get_trans() so it can apply them to the join call
> > -	 * appropriately.
> > -	 */
> > -	error = xfs_ioctl_setattr_dax_invalidate(ip, &fa, &join_flags);
> > +	error = xfs_ioctl_setattr_dax_invalidate(ip);
> >  	if (error)
> >  		goto out_drop_write;
> >  
> > -	tp = xfs_ioctl_setattr_get_trans(ip, join_flags);
> > +	tp = xfs_ioctl_setattr_get_trans(ip);
> >  	if (IS_ERR(tp)) {
> >  		error = PTR_ERR(tp);
> >  		goto out_drop_write;
> > -- 
> > 2.25.1
> > 

  reply	other threads:[~2020-04-08 18:13 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-07 18:29 [PATCH V6 0/8] Enable per-file/per-directory DAX operations V6 ira.weiny
2020-04-07 18:29 ` [PATCH V6 1/8] fs/xfs: Remove unnecessary initialization of i_rwsem ira.weiny
2020-04-07 23:46   ` Dave Chinner
2020-04-07 18:29 ` [PATCH V6 2/8] fs: Remove unneeded IS_DAX() check ira.weiny
2020-04-09  7:31   ` Christoph Hellwig
2020-04-09 14:57     ` Ira Weiny
2020-04-07 18:29 ` [PATCH V6 3/8] fs/stat: Define DAX statx attribute ira.weiny
2020-04-07 23:47   ` Dave Chinner
2020-04-07 18:29 ` [PATCH V6 4/8] fs/xfs: Make DAX mount option a tri-state ira.weiny
2020-04-07 23:59   ` Dave Chinner
2020-04-08  0:09     ` Ira Weiny
2020-04-08  0:48       ` Dave Chinner
2020-04-09 15:03         ` Ira Weiny
2020-04-07 18:29 ` [PATCH V6 5/8] fs/xfs: Create function xfs_inode_enable_dax() ira.weiny
2020-04-08  0:05   ` Dave Chinner
2020-04-08  0:13     ` Ira Weiny
2020-04-07 18:29 ` [PATCH V6 6/8] fs/xfs: Combine xfs_diflags_to_linux() and xfs_diflags_to_iflags() ira.weiny
2020-04-08  2:08   ` Dave Chinner
2020-04-08 17:09     ` Ira Weiny
2020-04-08 21:02       ` Dave Chinner
2020-04-08 21:28         ` Dan Williams
2020-04-08 22:10           ` Ira Weiny
2020-04-08 23:58           ` Dave Chinner
2020-04-09  0:22             ` Ira Weiny
2020-04-09 12:41               ` Christoph Hellwig
2020-04-09 20:49                 ` Ira Weiny
2020-04-08 22:07         ` Ira Weiny
2020-04-08 23:21           ` Dave Chinner
2020-04-09  0:12             ` Ira Weiny
2020-04-09  0:30               ` Darrick J. Wong
2020-04-09 15:29                 ` Ira Weiny
2020-04-09 16:59                   ` Darrick J. Wong
2020-04-09 17:17                     ` Jan Kara
2020-04-09 20:54                     ` Ira Weiny
2020-04-09  0:49               ` Dave Chinner
2020-04-09 12:40                 ` Christoph Hellwig
2020-04-10  0:27                   ` Dave Chinner
2020-04-07 18:29 ` [PATCH V6 7/8] fs/xfs: Change xfs_ioctl_setattr_dax_invalidate() to xfs_ioctl_dax_check() ira.weiny
2020-04-08  2:23   ` Dave Chinner
2020-04-08  9:58     ` Jan Kara
2020-04-08 21:09       ` Dave Chinner
2020-04-08 22:26         ` Ira Weiny
2020-04-08 23:48           ` Dave Chinner
2020-04-09 12:28             ` Christoph Hellwig
2020-04-08 15:37   ` Darrick J. Wong
2020-04-08 18:13     ` Ira Weiny [this message]
2020-04-16  5:39   ` [fs/xfs] 857c9841f8: xfstests.xfs.046.fail kernel test robot
2020-04-07 18:29 ` [PATCH V6 8/8] Documentation/dax: Update Usage section ira.weiny

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