On 2015-12-16 06:10, Duncan wrote:
Qu Wenruo posted on Wed, 16 Dec 2015 09:36:23 +0800 as excerpted:
David Sterba wrote on 2015/12/14 18:32 +0100:
On Thu, Dec 10, 2015 at 10:34:06AM +0800, Qu Wenruo wrote:
Introduce a new mount option "nologreplay" to co-operate with "ro"
mount option to get real readonly mount, like "norecovery" in ext* and
xfs.
Since the new parse_options() need to check new flags at remount time,
so add a new parameter for parse_options().
Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com>
Reviewed-by: Chandan Rajendra <chan...@linux.vnet.ibm.com>
Tested-by: Austin S. Hemmelgarn <ahferro...@gmail.com>
I've read the discussions around the change and from the user's POV I'd
suggest to add another mount option that would be just an alias for any
mount options that would implement the 'hard-ro' semantics.
Say it's called 'nowr'. Now it would imply 'nologreplay', but may cover
more options in the future.
mount -o ro,nowr /dev/sdx /mnt
would work when switching kernels.
That would be nice.
I'd like to forward the idea/discussion to filesystem ml, not only btrfs
maillist.
Such behavior should better be coordinated between all(at least xfs and
ext4 and btrfs) filesystems.
One sad example is, we can't use 'norecovery' mount option to disable
log replay in btrfs, as there is 'recovery' mount option already.
So I hope we can have a unified mount option between mainline
filesystems.
FWIW, I was just reading the mount manpage in connection with a reply for
a different thread, and noticed...
mount (8) (from util-linux 2.27.1) says noload and norecovery are the
same option, for ext3/4 at least. It refers to the xfs (5) manpage, from
xfsprogs, for xfs mount options, and that's not installed here, so I
can't confirm noload for it, but it's there for ext3/4.
Unless it's undocumented, XFS doesn't have it (as much as I hate XFS, I
have to have xfsprogs installed so that I can do recovery for the few
systems at work that actually use it if the need arises).
And noload doesn't have the namespace collision problem norecovery does
on btrfs, so I'd strongly suggest using it, at least as an alias for
whatever other btrfs-specific name we might choose.
I kind of agree with Christoph here. I don't think that noload should
be the what we actually use, although I do think having it as an alias
for whatever name we end up using would be a good thing.
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
