linux-fsdevel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Vivek Goyal <vgoyal@redhat.com>
To: Miklos Szeredi <mszeredi@redhat.com>
Cc: linux-unionfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 16/28] ovl: Do not expose metacopy only dentry from d_real()
Date: Wed, 30 May 2018 17:05:56 -0400	[thread overview]
Message-ID: <20180530210556.GD2717@redhat.com> (raw)
In-Reply-To: <20180529144612.16675-17-mszeredi@redhat.com>

On Tue, May 29, 2018 at 04:46:00PM +0200, Miklos Szeredi wrote:
> From: Vivek Goyal <vgoyal@redhat.com>
> 
> Metacopy dentry/inode is internal to overlay and is never exposed outside
> of it.  Exception is metacopy upper file used for fsync().  Modify d_real()
> to look for dentries/inode which have data, but also allow matching upper
> inode without data for the fsync case.
> 

Hi Miklos,

I am not able to see how in fsync() path d_real() gets called. If we
decide to do fsync() on upper metacopy, then opening upper will not
go through d_real(). And we never issue fsync() on lower.

So I am scratching my head while trying to understand the d_real() and
fsync() connection.

Thanks
Vivek

> Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
> Reviewed-by: Amir Goldstein <amir73il@gmail.com>
> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
> ---
>  fs/overlayfs/super.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
> index e0326a686f45..6687d547ec6b 100644
> --- a/fs/overlayfs/super.c
> +++ b/fs/overlayfs/super.c
> @@ -101,10 +101,13 @@ static struct dentry *ovl_d_real(struct dentry *dentry,
>  	}
>  
>  	real = ovl_dentry_upper(dentry);
> -	if (real && (!inode || inode == d_inode(real)))
> +	if (real && (inode == d_inode(real)))
>  		return real;
>  
> -	real = ovl_dentry_lower(dentry);
> +	if (real && !inode && ovl_has_upperdata(d_inode(dentry)))
> +		return real;
> +
> +	real = ovl_dentry_lowerdata(dentry);
>  	if (!real)
>  		goto bug;
>  
> -- 
> 2.14.3
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

  reply	other threads:[~2018-05-30 21:05 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-29 14:45 [PATCH 00/28] overlayfs: Delayed copy up of data Miklos Szeredi
2018-05-29 14:45 ` [PATCH 01/28] ovl: Initialize ovl_inode->redirect in ovl_get_inode() Miklos Szeredi
2018-05-29 14:45 ` [PATCH 02/28] ovl: Move the copy up helpers to copy_up.c Miklos Szeredi
2018-05-29 14:45 ` [PATCH 03/28] ovl: Provide a mount option metacopy=on/off for metadata copyup Miklos Szeredi
2018-05-29 20:44   ` Randy Dunlap
2018-05-30  8:27     ` Miklos Szeredi
2018-05-29 14:45 ` [PATCH 04/28] ovl: During copy up, first copy up metadata and then data Miklos Szeredi
2018-05-29 14:45 ` [PATCH 05/28] ovl: Copy up only metadata during copy up where it makes sense Miklos Szeredi
2018-05-29 14:45 ` [PATCH 06/28] ovl: Add helper ovl_already_copied_up() Miklos Szeredi
2018-05-29 14:45 ` [PATCH 07/28] ovl: A new xattr OVL_XATTR_METACOPY for file on upper Miklos Szeredi
2018-05-29 14:45 ` [PATCH 08/28] ovl: Use out_err instead of out_nomem Miklos Szeredi
2018-05-29 14:45 ` [PATCH 09/28] ovl: Modify ovl_lookup() and friends to lookup metacopy dentry Miklos Szeredi
2018-05-29 14:45 ` [PATCH 10/28] ovl: Copy up meta inode data from lowest data inode Miklos Szeredi
2018-05-29 14:45 ` [PATCH 11/28] ovl: Add helper ovl_dentry_lowerdata() to get lower data dentry Miklos Szeredi
2018-05-29 14:45 ` [PATCH 12/28] ovl: Fix ovl_getattr() to get number of blocks from lower Miklos Szeredi
2018-05-29 14:45 ` [PATCH 13/28] ovl: Store lower data inode in ovl_inode Miklos Szeredi
2018-05-29 14:45 ` [PATCH 14/28] ovl: Add helper ovl_inode_realdata() Miklos Szeredi
2018-05-29 14:45 ` [PATCH 15/28] ovl: Open file with data except for the case of fsync Miklos Szeredi
2018-05-30 14:30   ` Vivek Goyal
2018-05-30 15:12     ` Miklos Szeredi
2018-05-30 15:48       ` Vivek Goyal
2018-05-29 14:46 ` [PATCH 16/28] ovl: Do not expose metacopy only dentry from d_real() Miklos Szeredi
2018-05-30 21:05   ` Vivek Goyal [this message]
2018-05-31  4:30     ` Amir Goldstein
2018-05-29 14:46 ` [PATCH 17/28] ovl: Move some dir related ovl_lookup_single() code in else block Miklos Szeredi
2018-05-29 14:46 ` [PATCH 18/28] ovl: Check redirects for metacopy files Miklos Szeredi
2018-05-29 14:46 ` [PATCH 19/28] ovl: Treat metacopy dentries as type OVL_PATH_MERGE Miklos Szeredi
2018-05-29 14:46 ` [PATCH 20/28] ovl: Add an inode flag OVL_CONST_INO Miklos Szeredi
2018-05-29 14:46 ` [PATCH 21/28] ovl: Do not set dentry type ORIGIN for broken hardlinks Miklos Szeredi
2018-05-29 14:46 ` [PATCH 22/28] ovl: Set redirect on metacopy files upon rename Miklos Szeredi
2018-05-29 14:46 ` [PATCH 23/28] ovl: Set redirect on upper inode when it is linked Miklos Szeredi
2018-05-29 14:46 ` [PATCH 24/28] ovl: Check redirect on index as well Miklos Szeredi
2018-05-29 14:46 ` [PATCH 25/28] ovl: Disbale metacopy for MAP_SHARED mmap() Miklos Szeredi
2018-05-29 14:46 ` [PATCH 26/28] ovl: Do not do metadata only copy-up for truncate operation Miklos Szeredi
2018-05-29 14:46 ` [PATCH 27/28] ovl: Do not do metacopy only for ioctl modifying file attr Miklos Szeredi
2018-05-29 14:46 ` [PATCH 28/28] ovl: Enable metadata only feature Miklos Szeredi

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180530210556.GD2717@redhat.com \
    --to=vgoyal@redhat.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-unionfs@vger.kernel.org \
    --cc=mszeredi@redhat.com \
    --subject='Re: [PATCH 16/28] ovl: Do not expose metacopy only dentry from d_real()' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).