linux-kernel - Re: [patch 04/14] hpfs: dont call notify

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Message-ID: <Pine.LNX.4.64.0807231412070.1841@artax.karlin.mff.cuni.cz>
Date:	Wed, 23 Jul 2008 14:13:01 +0200 (CEST)
From:	Mikulas Patocka <mikulas@...ax.karlin.mff.cuni.cz>
To:	Miklos Szeredi <miklos@...redi.hu>
cc:	viro@...IV.linux.org.uk, linux-kernel@...r.kernel.org
Subject: Re: [patch 04/14] hpfs: dont call notify_change

What about down_write on i_alloc_sem --- notify change takes that and your 
patch bypasses that.

Mikulas

> From: Miklos Szeredi <mszeredi@...e.cz>
> 
> hpfs_unlink() calls notify_change() to truncate the file before
> deleting.  Replace with explicit call to hpfs_notify_change().
> 
> This is equivalent, except that:
>  - security_inode_setattr() is not called before hpfs_notify_change()
>  - fsnotify_change() is not called after hpfs_notify_change()
> 
> The truncation is just an implementation detail, so both the security
> check and the notification are unnecessary.
> 
> Possibly even the ctime modification is wrong?
> 
> Signed-off-by: Miklos Szeredi <mszeredi@...e.cz>
> CC: Mikulas Patocka <mikulas@...ax.karlin.mff.cuni.cz>
> ---
>  fs/hpfs/namei.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> Index: linux-2.6/fs/hpfs/namei.c
> ===================================================================
> --- linux-2.6.orig/fs/hpfs/namei.c	2008-07-23 00:10:13.000000000 +0200
> +++ linux-2.6/fs/hpfs/namei.c	2008-07-23 00:10:22.000000000 +0200
> @@ -426,7 +426,8 @@ again:
>  			/*printk("HPFS: truncating file before delete.\n");*/
>  			newattrs.ia_size = 0;
>  			newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
> -			err = notify_change(dentry, &newattrs);
> +			newattrs.ia_ctime = current_fs_time(inode->i_sb);
> +			err = hpfs_notify_change(dentry, &newattrs);
>  			put_write_access(inode);
>  			if (!err)
>  				goto again;
> 
> --
> 
--
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