From: Artem Bityutskiy <dedekind@infradead.org>
To: Cal Page <pagcal@runbox.com>
Cc: ubifs <linux-mtd@lists.infradead.org>
Subject: Re: ubifs: another scheduling while atomic back trace
Date: Thu, 18 Dec 2008 15:53:38 +0200 [thread overview]
Message-ID: <1229608418.30575.4.camel@sauron> (raw)
In-Reply-To: <494A517E.2000405@runbox.com>
On Thu, 2008-12-18 at 08:34 -0500, Cal Page wrote:
> I tracked it down to fs/ubifs/journal.c in make_reservation()?
How did you track? And what pointed you to this function?
> the code is:
> again:
> down_read()
> err = reserve_space()
> if ( !err) return 0
> up_read()
That code really looks hacky, because it takes the lock and assumes the
caller unlocks it. We tried to come up with a better solution, and
debated on this, but concluded that this is the best way.
IOW, this is fine, because the caller unlocks the lock using
'finish_reservation()' call.
Moreover, rw semaphore should not make the code to be atomic.
> Also, I notice fs/fs-writeback.c in writeback_inodes does a
> down_read_trylock. Won't this interfear with the down_read above?
Sorry, I do not see how and what should interfere there.
--
Best regards,
Artem Bityutskiy (Битюцкий Артём)
next prev parent reply other threads:[~2008-12-18 13:52 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-18 13:34 ubifs: another scheduling while atomic back trace Cal Page
2008-12-18 13:53 ` Artem Bityutskiy [this message]
-- strict thread matches above, loose matches on Subject: below --
2008-12-17 17:10 Cal Page
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=1229608418.30575.4.camel@sauron \
--to=dedekind@infradead.org \
--cc=linux-mtd@lists.infradead.org \
--cc=pagcal@runbox.com \
/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.