All of lore.kernel.org
 help / color / mirror / Atom feed
From: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Richard Weinberger <richard@nod.at>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] fat: Fix d_splice_alias() return code checking
Date: Fri, 24 Oct 2014 00:21:04 +0900	[thread overview]
Message-ID: <87siie95i7.fsf@devron.myhome.or.jp> (raw)
In-Reply-To: <20141020123415.GN7996@ZenIV.linux.org.uk> (Al Viro's message of "Mon, 20 Oct 2014 13:34:15 +0100")

Al Viro <viro@ZenIV.linux.org.uk> writes:

> On Sun, Oct 19, 2014 at 12:39:43PM +0200, Richard Weinberger wrote:
>> d_splice_alias() can return a valid dentry, NULL or an ERR_PTR.
>> Currently the code checks not for ERR_PTR.
>> Fix this by using IS_ERR_OR_NULL().
>
> Why do we need to set ->d_time for non-NULL inode anyway?  AFAICS,
> it's never checked for positive dentries, and the moment when positive
> dentry become negative is when we want to set it anyway.
>
> What am I missing here?  Why not simply do this:

Hm, at least, this changes behavior though (old one drops if parent
changed after target dentry created, then when become negative. New one
drops if changed parent after target became negative.).

However, looks like new behavior is workable. And I think it is worth to try.

Can you add Signed-off-by:?

> diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
> index 6df8d3d..e2dc6bf 100644
> --- a/fs/fat/namei_vfat.c
> +++ b/fs/fat/namei_vfat.c
> @@ -725,15 +725,14 @@ static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
>  			inode = NULL;
>  			goto out;
>  		}
> -		goto error;
> +		inode = ERR_PTR(inode);
> +		goto out;
>  	}
>  
>  	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
>  	brelse(sinfo.bh);
> -	if (IS_ERR(inode)) {
> -		err = PTR_ERR(inode);
> -		goto error;
> -	}
> +	if (IS_ERR(inode))
> +		goto out;
>  
>  	alias = d_find_alias(inode);
>  	if (alias && !vfat_d_anon_disconn(alias)) {
> @@ -754,16 +753,10 @@ static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
>  		dput(alias);
>  
>  out:
> +	if (!inode)
> +		dentry->d_time = dir->i_version;
>  	mutex_unlock(&MSDOS_SB(sb)->s_lock);
> -	dentry->d_time = dentry->d_parent->d_inode->i_version;
> -	dentry = d_splice_alias(inode, dentry);
> -	if (dentry)
> -		dentry->d_time = dentry->d_parent->d_inode->i_version;
> -	return dentry;
> -
> -error:
> -	mutex_unlock(&MSDOS_SB(sb)->s_lock);
> -	return ERR_PTR(err);
> +	return d_splice_alias(inode, dentry);
>  }
>  
>  static int vfat_create(struct inode *dir, struct dentry *dentry, umode_t mode,
> @@ -793,7 +786,6 @@ static int vfat_create(struct inode *dir, struct dentry *dentry, umode_t mode,
>  	inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
>  	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
>  
> -	dentry->d_time = dentry->d_parent->d_inode->i_version;
>  	d_instantiate(dentry, inode);
>  out:
>  	mutex_unlock(&MSDOS_SB(sb)->s_lock);
> @@ -824,6 +816,7 @@ static int vfat_rmdir(struct inode *dir, struct dentry *dentry)
>  	clear_nlink(inode);
>  	inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
>  	fat_detach(inode);
> +	dentry->d_time = dir->i_version;
>  out:
>  	mutex_unlock(&MSDOS_SB(sb)->s_lock);
>  
> @@ -849,6 +842,7 @@ static int vfat_unlink(struct inode *dir, struct dentry *dentry)
>  	clear_nlink(inode);
>  	inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
>  	fat_detach(inode);
> +	dentry->d_time = dir->i_version;
>  out:
>  	mutex_unlock(&MSDOS_SB(sb)->s_lock);
>  
> @@ -889,7 +883,6 @@ static int vfat_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
>  	inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
>  	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
>  
> -	dentry->d_time = dentry->d_parent->d_inode->i_version;
>  	d_instantiate(dentry, inode);
>  
>  	mutex_unlock(&MSDOS_SB(sb)->s_lock);

-- 
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>

      reply	other threads:[~2014-10-23 15:21 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-19 10:39 [PATCH 1/2] fat: Fix d_splice_alias() return code checking Richard Weinberger
2014-10-19 10:39 ` [PATCH 2/2] ocfs2: " Richard Weinberger
2014-10-19 10:39   ` [Ocfs2-devel] " Richard Weinberger
2014-10-20 23:12   ` Andrew Morton
2014-10-20 23:12     ` Andrew Morton
2014-10-22 20:33     ` Richard Weinberger
2014-10-22 20:33       ` Richard Weinberger
2014-10-20 12:34 ` [PATCH 1/2] fat: " Al Viro
2014-10-23 15:21   ` OGAWA Hirofumi [this message]

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=87siie95i7.fsf@devron.myhome.or.jp \
    --to=hirofumi@mail.parknet.co.jp \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=richard@nod.at \
    --cc=viro@ZenIV.linux.org.uk \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.