From: Jan Kara <jack@suse.cz>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>,
linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Christoph Hellwig <hch@infradead.org>,
Al Viro <viro@zeniv.linux.org.uk>,
LKML <linux-kernel@vger.kernel.org>,
Edward Shishkin <edward@redhat.com>
Subject: Re: [RFC PATCH 0/3] Stop clearing uptodate flag on write IO error
Date: Mon, 16 Jan 2012 17:01:36 +0100 [thread overview]
Message-ID: <20120116160136.GC16431@quack.suse.cz> (raw)
In-Reply-To: <CA+55aFy0sidnCzPkP6yjnarLZx3a=7QSpgfaf2mUNVy14y3vCw@mail.gmail.com>
On Sat 14-01-12 18:19:02, Linus Torvalds wrote:
> On Thu, Jan 5, 2012 at 6:40 AM, Jan Kara <jack@suse.cz> wrote:
> >
> > for mostly historical reasons we still clear buffer_uptodate flag on write
> > IO errors. This is not only semantically wrong (buffer still has correct data
> > in it)
>
> That statement is so nonsensical that I can't get past it.
>
> When you understand why it is nonsensical, you understand why the bit
> is cleared.
Hum, let me understand this. I understand the meaning of buffer_uptodate
bit as "the buffer has at least as new content as what is on disk". Now
when storage cannot write the block under the buffer, the contents of the
buffer is still "at least as new as what is (was) on disk". Therefore I
made above statement about clearing buffer_uptodate bit being wrong. But
apparently you have a different definition of buffer_uptodate or I was not
clear enough in explaining what I mean... Which is the case?
Honza
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR
next prev parent reply other threads:[~2012-01-16 16:01 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-05 14:40 [RFC PATCH 0/3] Stop clearing uptodate flag on write IO error Jan Kara
2012-01-05 14:40 ` [PATCH 1/3] fs: Convert checks for write IO errors from !buffer_uptodate to buffer_write_io_error Jan Kara
2012-01-05 14:40 ` [PATCH 2/3] fs: Do not clear uptodate flag on write IO error Jan Kara
2012-01-05 14:40 ` [PATCH 3/3] ext2: Replace tests of write IO errors using buffer_uptodate Jan Kara
2012-01-05 22:16 ` [RFC PATCH 0/3] Stop clearing uptodate flag on write IO error Andrew Morton
2012-01-15 2:19 ` Linus Torvalds
2012-01-16 16:01 ` Jan Kara [this message]
2012-01-16 18:55 ` Linus Torvalds
2012-01-16 19:06 ` Linus Torvalds
2012-01-17 0:36 ` Dave Chinner
2012-01-17 0:59 ` Linus Torvalds
2012-01-17 10:46 ` Boaz Harrosh
2012-01-23 3:04 ` Dave Chinner
2012-01-23 21:47 ` Ted Ts'o
2012-01-23 23:49 ` Linus Torvalds
2012-01-24 6:12 ` Dave Chinner
2012-01-24 7:10 ` Linus Torvalds
2012-01-24 12:13 ` Jan Kara
2012-01-24 0:36 ` Dave Chinner
2012-01-26 12:17 ` Ric Wheeler
2012-01-26 20:51 ` Jan Kara
2012-01-26 20:58 ` Ric Wheeler
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