From: Cyril Hrubis <chrubis@suse.cz>
To: Li Wang <liwang@redhat.com>
Cc: rafael.tinoco@linaro.org, ltp@lists.linux.it
Subject: Re: [LTP] [PATCH] tst_umount: Retry open() after umount to handle delayed device release
Date: Wed, 6 Aug 2025 11:27:23 +0200 [thread overview]
Message-ID: <aJMf-6DEu-9NzLAJ@yuki.lan> (raw)
In-Reply-To: <20250806074405.14890-1-liwang@redhat.com>
Hi!
> Currently, tst_umount() in lib/tst_device.c tries to repeatedly umount()
> a mount point, with a retry loop if it gets EBUSY. However, after umount()
> reports success, devices (especially loop devices) can still be held open
> by another process or kernel, delaying their actual release. This can lead
> to race conditions when the next operation tries to reuse the device like
> mkfs.ext3 error:
This looks like working around a kernel bug to me. The umount() without
MNT_DETACH should make the device reusable once the syscall returns back
to the userspace. At least I wouldn't add this code to LTP unless kernel
devs tells us that this broken behavior is to be expected.
--
Cyril Hrubis
chrubis@suse.cz
--
Mailing list info: https://lists.linux.it/listinfo/ltp
next prev parent reply other threads:[~2025-08-06 9:27 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-19 16:33 [LTP] lib: tst_device.c - /dev/loop0 in use Rafael David Tinoco
2019-01-02 13:19 ` Cyril Hrubis
2025-08-06 7:44 ` [LTP] [PATCH] tst_umount: Retry open() after umount to handle delayed device release Li Wang via ltp
2025-08-06 9:27 ` Cyril Hrubis [this message]
2025-08-11 12:42 ` Li Wang via ltp
2025-08-11 14:20 ` Cyril Hrubis
2025-08-12 3:43 ` Li Wang via ltp
2025-08-12 11:17 ` Cyril Hrubis
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