linux-kernel - Re: The bug of iput() removal from flusher thread?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <873906vumh.fsf@devron.myhome.or.jp>
Date:	Mon, 19 Nov 2012 17:56:22 +0900
From:	OGAWA Hirofumi <hirofumi@...l.parknet.co.jp>
To:	Al Viro <viro@...iv.linux.org.uk>
Cc:	Jan Kara <jack@...e.cz>, linux-fsdevel@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: The bug of iput() removal from flusher thread?

OGAWA Hirofumi <hirofumi@...l.parknet.co.jp> writes:

> Hi,
>
> In 169ebd90131b2ffca74bb2dbe7eeacd39fb83714 commit, writeback doesn't
> __iget()/iput() anymore.
>
> This means nobody moves the inode to lru list. I.e.
>
> 	new_inode()
> 	dirty_inode()
> 	iput_final()
> 		/* keep inode without adding lru */
> 	flush indoes
>         /* clean inode is not on lru */
>
> I noticed this situation in my FS though, I think the same bug is on all
> FSes of linus tree too, after this commit.
>
> Am I missing the something?

This seems to be reproducible by the following,

#!/bin/sh

for i in $(seq -w 1000); do
	for j in $(seq -w 1000); do
        	for k in $(seq -w 1000); do
                	mkdir -p $i/$j
                        echo $i/$j/$k > $i/$j/$k
                        echo 2 > /proc/sys/vm/drop_caches
                done
        done
done

Some inodes never be reclaimed, and ls -l frees those inodes (stat(2)
does iget/iput).
-- 
OGAWA Hirofumi <hirofumi@...l.parknet.co.jp>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/