From: David Howells <dhowells@redhat.com>
To: Max Kellermann <max.kellermann@ionos.com>
Cc: dhowells@redhat.com, netfs@lists.linux.dev,
linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org
Subject: Re: [PATCH] fs/netfs/read_collect: add to next->prev_donated
Date: Fri, 14 Feb 2025 12:47:46 +0000 [thread overview]
Message-ID: <3978045.1739537266@warthog.procyon.org.uk> (raw)
In-Reply-To: <20250210191118.3444416-1-max.kellermann@ionos.com>
Max Kellermann <max.kellermann@ionos.com> wrote:
> David, this seems to fix the bug for me. Please also check if we need
> a "donation_changed" check.
Shouldn't do since at that point we've been holding rreq->lock since the last
check.
> If multiple subrequests donate data to the same "next" request
> (depending on the subrequest completion order), each of them would
> overwrite the `prev_donated` field, causing data corruption and a
> BUG() crash ("Can't donate prior to front").
>
> Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading")
> Closes: https://lore.kernel.org/netfs/CAKPOu+_4mUwYgQtRTbXCmi+-k3PGvLysnPadkmHOyB7Gz0iSMA@mail.gmail.com/
> Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Signed-off-by: David Howells <dhowells@redhat.com>
next prev parent reply other threads:[~2025-02-14 12:47 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-07 18:40 "netfs: Can't donate prior to front" Max Kellermann
2025-02-10 14:07 ` David Howells
2025-02-10 17:41 ` Max Kellermann
2025-02-10 17:45 ` Max Kellermann
2025-02-10 19:11 ` [PATCH] fs/netfs/read_collect: add to next->prev_donated Max Kellermann
2025-02-14 12:47 ` David Howells [this message]
2025-02-20 13:09 ` Max Kellermann
2025-02-20 14:17 ` Greg Kroah-Hartman
2025-02-20 15:00 ` Max Kellermann
2025-02-20 15:10 ` Greg Kroah-Hartman
2025-03-01 14:17 ` Salvatore Bonaccorso
2025-03-01 16:51 ` Max Kellermann
-- strict thread matches above, loose matches on Subject: below --
2025-03-07 16:09 Norbert Lange
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