From: Al Viro <viro@ZenIV.linux.org.uk>
To: Takashi Iwai <tiwai@suse.de>
Cc: Ian Kent <raven@themaw.net>,
autofs@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: 4.8-rc4 spews "BUG: sleeping function called from invalid context at fs/dcache.c:757"
Date: Mon, 29 Aug 2016 16:18:55 +0100 [thread overview]
Message-ID: <20160829151855.GH2356@ZenIV.linux.org.uk> (raw)
In-Reply-To: <s5ha8fv4p8d.wl-tiwai@suse.de>
On Mon, Aug 29, 2016 at 04:35:46PM +0200, Takashi Iwai wrote:
> [<ffffffff81260b26>] dput+0x46/0x400
... which should not be called in atomic contexts
> [<ffffffff8124ff67>] follow_down_one+0x27/0x60
... and neither should this
> [<ffffffff81344da2>] autofs4_mount_busy+0x32/0x110
... nor that (for fsck sake, there's full-blown path_put() in it!)
> [<ffffffff81345081>] should_expire+0x51/0x3d0
... so that would better not be called in atomic either (incidentally,
it also calls dput() directly)
> [<ffffffff81345790>] autofs4_expire_indirect+0x190/0x2d0
... while here it is called under sbi->fs_lock.
> I don't remember of a similar stack trace in the past, so if any, it
> can be a regression in 4.8 kernel. But I cannot say it in 100%, as
> this looks spontaneous, nor I would be able to reproduce it at the
> next boot...
It's old; the race is narrow, but it's been there for quite a while, by
the look of it.
next prev parent reply other threads:[~2016-08-29 15:19 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-29 14:35 4.8-rc4 spews "BUG: sleeping function called from invalid context at fs/dcache.c:757" Takashi Iwai
2016-08-29 15:18 ` Al Viro [this message]
2016-08-30 1:37 ` Ian Kent
2016-08-30 1:55 ` Ian Kent
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