From: Christian Brauner <brauner@kernel.org>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Jan Kara <jack@suse.cz>, "Lai, Yi" <yi1.lai@linux.intel.com>,
Tycho Andersen <tycho@tycho.pizza>,
Andrei Vagin <avagin@google.com>,
Pavel Tikhomirov <snorcht@gmail.com>
Subject: Re: [PATCH 2/4] propagate_umount(): only surviving overmounts should be remounted
Date: Tue, 19 Aug 2025 12:19:30 +0200 [thread overview]
Message-ID: <20250819-aktenordner-sensor-1d90cc27c9ea@brauner> (raw)
In-Reply-To: <20250815233450.GB2117906@ZenIV>
On Sat, Aug 16, 2025 at 12:34:50AM +0100, Al Viro wrote:
> ... as the comments in reparent() clearly say. As it is, we reparent
> *all* overmounts of the mounts being taken out, including those that
> are taken out themselves. It's not only a potentially massive slowdown
> (on a pathological setup we might end up with O(N^2) time for N mounts
> being kicked out), it can end up with incorrect ->overmount in the
> surviving mounts.
>
> Fixes: f0d0ba19985d "Rewrite of propagate_umount()"
> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
> ---
Reviewed-by: Christian Brauner <brauner@kernel.org>
next prev parent reply other threads:[~2025-08-19 10:19 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-15 23:33 [PATCHES][RFC][CFT] mount fixes Al Viro
2025-08-15 23:34 ` [PATCH 1/4] fix the softlockups in attach_recursive_mnt() Al Viro
2025-08-19 10:18 ` Christian Brauner
2025-08-15 23:34 ` [PATCH 2/4] propagate_umount(): only surviving overmounts should be remounted Al Viro
2025-08-19 10:19 ` Christian Brauner [this message]
2025-08-15 23:35 ` [PATCH 3/4] use uniform permission checks for all mount propagation changes Al Viro
2025-08-16 18:28 ` Andrei Vagin
2025-08-19 4:44 ` Pavel Tikhomirov
2025-08-19 10:20 ` Christian Brauner
2025-08-15 23:36 ` [PATCH 4/4] change_mnt_propagation(): calculate propagation source only if we'll need it Al Viro
2025-08-19 10:20 ` Christian Brauner
2025-08-16 15:58 ` [PATCHES][RFC][CFT] mount fixes Al Viro
2025-08-19 16:12 ` [git pull] " Al Viro
2025-08-19 17:31 ` Linus Torvalds
2025-08-19 17:33 ` pr-tracker-bot
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