All of lore.kernel.org
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: npiggin@suse.de, a.p.zijlstra@chello.nl, linux-kernel@vger.kernel.org
Subject: Re: [locking bug] inotify: inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.
Date: Wed, 18 Feb 2009 14:26:42 -0800	[thread overview]
Message-ID: <20090218142642.2505ed5f.akpm@linux-foundation.org> (raw)
In-Reply-To: <20090216081304.GA18980@elte.hu>

On Mon, 16 Feb 2009 09:13:04 +0100
Ingo Molnar <mingo@elte.hu> wrote:

> --- a/fs/notify/inotify/inotify.c
> +++ b/fs/notify/inotify/inotify.c
> @@ -156,7 +156,7 @@ static int inotify_handle_get_wd(struct inotify_handle *ih,
>  	int ret;
>  
>  	do {
> -		if (unlikely(!idr_pre_get(&ih->idr, GFP_KERNEL)))
> +		if (unlikely(!idr_pre_get(&ih->idr, GFP_NOFS)))

Geeze the IDR interface sucks.

>  			return -ENOSPC;

Well that doesn't make a lot of sense.

>  		ret = idr_get_new_above(&ih->idr, watch, ih->last_wd+1, &watch->wd);
>  	} while (ret == -EAGAIN);

And afacit that can't happen.  We hold the lock, so if idr_pre_get()
succeeded, idr_get_new_above() will not return -EAGAIN (which should
have been -ENOMEM).

I'd better stop looking.


      parent reply	other threads:[~2009-02-18 22:27 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-02-16  8:13 [locking bug] inotify: inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage Ingo Molnar
2009-02-16 10:34 ` Peter Zijlstra
2009-02-16 10:46   ` MinChan Kim
2009-02-16 10:46     ` MinChan Kim
2009-02-18 22:26 ` Andrew Morton [this message]

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=20090218142642.2505ed5f.akpm@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=a.p.zijlstra@chello.nl \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=npiggin@suse.de \
    /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.