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From: Kevin Wolf <kwolf@redhat.com>
To: Li Feng <fengli@smartx.com>
Cc: lifeng1519@gmail.com, kyle@smartx.com,
	"open list:All patches CC here" <qemu-devel@nongnu.org>,
	"open list:raw" <qemu-block@nongnu.org>,
	Max Reitz <mreitz@redhat.com>
Subject: Re: [PATCH] file-posix: detect the lock using the real file
Date: Tue, 8 Dec 2020 15:38:22 +0100	[thread overview]
Message-ID: <20201208143822.GA6392@merkur.fritz.box> (raw)
In-Reply-To: <1607432377-87084-1-git-send-email-fengli@smartx.com>

Am 08.12.2020 um 13:59 hat Li Feng geschrieben:
> This patch addresses this issue:
> When accessing a volume on an NFS filesystem without supporting the file lock,
> tools, like qemu-img, will complain "Failed to lock byte 100".
> 
> In the original code, the qemu_has_ofd_lock will test the lock on the
> "/dev/null" pseudo-file. Actually, the file.locking is per-drive property,
> which depends on the underlay filesystem.
> 
> In this patch, make the 'qemu_has_ofd_lock' with a filename be more generic
> and reasonable.
> 
> Signed-off-by: Li Feng <fengli@smartx.com>

Do you know any way how I could configure either the NFS server or the
NFS client such that locking would fail? For any patch related to this,
it would be good if I could even test the scenario.

For this specific patch, I think Daniel has already provided a good
explanation of the fundamental problems it has.

Kevin



  parent reply	other threads:[~2020-12-08 14:40 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-08 12:59 [PATCH] file-posix: detect the lock using the real file Li Feng
2020-12-08 13:45 ` Daniel P. Berrangé
2020-12-09  3:49   ` Li Feng
2020-12-08 14:38 ` Kevin Wolf [this message]
2020-12-09  4:09   ` Li Feng
2020-12-09  9:33   ` Daniel P. Berrangé
2020-12-09 17:43     ` Kevin Wolf
2020-12-10 14:56       ` Li Feng
2020-12-10 15:29         ` Daniel P. Berrangé
2020-12-10 15:53           ` Feng Li
2020-12-10 15:56             ` Daniel P. Berrangé
2020-12-09  4:54 ` [PATCH v2] " Li Feng
2020-12-10 15:59   ` Daniel P. Berrangé
2020-12-10 16:12     ` Feng Li

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