From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eos.fwall.u-szeged.hu ([160.114.120.248]) by canuck.infradead.org with esmtp (Exim 4.42 #1 (Red Hat Linux)) id 1CJsiS-0002qa-SQ for linux-mtd@lists.infradead.org; Tue, 19 Oct 2004 08:03:50 -0400 Message-ID: <4175035B.80101@inf.u-szeged.hu> Date: Tue, 19 Oct 2004 14:06:51 +0200 From: Ferenc Havasi MIME-Version: 1.0 To: "Artem B. Bityuckiy" References: <417156E1.9000009@yandex.ru> <4173AFAE.6060303@inf.u-szeged.hu> <4173B404.6040100@yandex.ru> <4174C8EF.50604@inf.u-szeged.hu> <4174D508.8050508@yandex.ru> <4174E7D3.9050706@inf.u-szeged.hu> <4174F0F3.7030604@yandex.ru> In-Reply-To: <4174F0F3.7030604@yandex.ru> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-mtd@lists.infradead.org Subject: Re: JFFS2 compression List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Artem B. Bityuckiy wrote: > It isn't needed to store the default compression mode *on flash*. If you > just move the variable jffs2_compression mode to the jffs2_sb_info > structure, you will have per-filesystems compression mode. This means, > for example, that if user changes (dynamically) the compression mode for > one file-system, the compression mode for another file system isn't > changed. I undersand you, but unfortunatelly now there is no way to change compression mode dimamically. There was (using procfs) but when David tried to commit it to the kernel, someone (I don't remember who but one of the kernel developers) declared it bad. David asked me to reimplement it is sysfs, but that is not an easy thing. Not technically. There is no fs subdirectory in sysfs. I read in the mailling list archive of linux-fsdevel@vger.kernel.org. Someone tried to submit a patch to make this fs subdirectory, because he need it for NFS. The answer declared it as very bad, too... (sysfs has a different philosopy...) I had some private discussion with the patch submitter (what happened exactly, what was really the problem,... what is his plan). He wrote that he try it again later. He think the guy who declared his patch bad really hates sysfs (and procfs too). So I decided to wait, too. :( But this new "compressoin configuration" concept may cause that we don't need sysfs/procfs. Bye, Ferenc