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From: Al Viro <viro@zeniv.linux.org.uk>
To: Max Kellermann <max.kellermann@ionos.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	Linux Memory Management List <linux-mm@kvack.org>,
	ceph-devel@vger.kernel.org
Subject: Re: Need advice with iput() deadlock during writeback
Date: Wed, 17 Sep 2025 22:10:09 +0100	[thread overview]
Message-ID: <20250917211009.GE39973@ZenIV> (raw)
In-Reply-To: <CAKPOu+8wLezQY05ZLSd4P2OySe7qqE7CTHzYG6pobpt=xV--Jg@mail.gmail.com>

On Wed, Sep 17, 2025 at 10:36:48PM +0200, Max Kellermann wrote:
> On Wed, Sep 17, 2025 at 10:34 PM Al Viro <viro@zeniv.linux.org.uk> wrote:
> > Suppose two threads do umount() on two different filesystems.  The first
> > one to flush picks *everything* you've delayed and starts handling that.
> > The second sees nothing to do and proceeds to taking the filesystem
> > it's unmounting apart, right under the nose of the first thread doing
> > work on both filesystems...
> 
> Each filesystem (struct ceph_fs_client) has its own inode_wq.

Yes, but
	 if (llist_add(&ci->async_llist, &delayed_ceph_iput_list))                                                               
		 schedule_delayed_work(&delayed_ceph_iput_work, 1);                                                              
won't have anything to do with that.


  reply	other threads:[~2025-09-17 21:10 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-17  8:07 Max Kellermann
2025-09-17  8:23 ` Mateusz Guzik
2025-09-17  8:38   ` Max Kellermann
2025-09-17  8:59     ` Mateusz Guzik
2025-09-17  9:20       ` Max Kellermann
2025-09-17  9:32         ` Mateusz Guzik
2025-09-17 12:48         ` Max Kellermann
2025-09-17 20:14       ` Al Viro
2025-09-17 20:19         ` Max Kellermann
2025-09-17 20:29           ` Al Viro
2025-09-17 20:32             ` Max Kellermann
2025-09-17 20:23         ` Mateusz Guzik
2025-09-17 20:34           ` Al Viro
2025-09-17 20:36             ` Max Kellermann
2025-09-17 21:10               ` Al Viro [this message]
2025-09-17 21:19                 ` Max Kellermann
2025-09-17 21:20                   ` Mateusz Guzik
2025-09-17 20:39             ` Mateusz Guzik
2025-09-17 21:02               ` Al Viro
2025-09-17 21:18                 ` Mateusz Guzik
2025-09-17 21:42                 ` Al Viro
2025-09-17 22:58                   ` Mateusz Guzik

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