linux-kernel - Re: [PATCH 09/19] pramfs: inode operations for dirs

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Message-ID: <522B51A5.4040003@gmail.com>
Date:	Sat, 07 Sep 2013 18:17:41 +0200
From:	Marco Stornelli <marco.stornelli@...il.com>
To:	Al Viro <viro@...IV.linux.org.uk>
CC:	Linux FS Devel <linux-fsdevel@...r.kernel.org>,
	Vladimir Davydov <vdavydov@...allels.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 09/19] pramfs: inode operations for dirs

Il 07/09/2013 17:08, Al Viro ha scritto:
> On Sat, Sep 07, 2013 at 10:23:42AM +0200, Marco Stornelli wrote:
>
>> +static int pram_rmdir(struct inode *dir, struct dentry *dentry)
>> +{
>> +	struct inode *inode = dentry->d_inode;
>> +	struct pram_inode *pi;
>> +	int err = -ENOTEMPTY;
>> +
>> +	if (!inode)
>> +		return -ENOENT;
>> +
>> +	pi = pram_get_inode(dir->i_sb, inode->i_ino);
>> +
>> +	/* directory to delete is empty? */
>> +	if (pi->i_type.dir.tail == 0) {
>> +		inode->i_ctime = dir->i_ctime;
>> +		inode->i_size = 0;
>> +		clear_nlink(inode);
>> +		pram_write_inode(inode, NULL);
>> +		pram_dec_count(dir);
>> +		err = 0;
>> +	} else {
>> +		pram_dbg("dir not empty\n");
>> +	}
>> +
>> +	return err;
>> +}
>
> ... and here you are paying for delayed removal of entries:
> 	mkdir foo
> 	touch foo/bar
> 	rm -rf foo <foo/bar
> will fail, since opened-and-unlinked file in effect keeps the directory
> where it used to be "not empty" from your rmdir (and rename) POV.
>

Yep. Same problem as before. I think I can move the remove link into 
pram_dec_count and I have to modify the evict path, it should be easy to 
manage.

Thanks for your comments Al!!!!

Marco
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