From: Al Viro <viro@ZenIV.linux.org.uk>
To: Dave Chinner <david@fromorbit.com>
Cc: Frank Sorenson <sorenson@redhat.com>,
linux-fsdevel@vger.kernel.org, dwysocha@redhat.com,
lvaz@redhat.com
Subject: Re: [PATCH 0/5] Add trace events for filesystem freeze/thaw events
Date: Wed, 2 Mar 2016 23:22:54 +0000 [thread overview]
Message-ID: <20160302232254.GO17997@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20160302224730.GP29057@dastard>
On Thu, Mar 03, 2016 at 09:47:30AM +1100, Dave Chinner wrote:
> > So let's get it right. Preferably - without need for boot-to-shutdown
> > tracking just to mirror the state. What do we really want?
> >
> > * an ioctl to query the state (frozen/freezing/not frozen) for something in
> > util-linux to use?
> >
> > * /proc/fs/freezing and /proc/fs/frozen, with ->s_id of affected filesystems
> > or, pehaps, one file with (frozen|freezing) + ->s_id?
> >
> > * ability to audit on state changes? That'd need some thought re what to
> > do when some joker freezes the fs syslogd is logging to...
> >
> > * something else entirely?
>
> Such as:
>
> https://lkml.org/lkml/2015/6/16/456
IIRC, there had been a weird use of vfsmounts as proxies for superblocks and
even more strange requirements along the lines "you should just pick one and
use only it in case if there's more than one mountpoint for this fs". It's
been a while, though, so I might've forgotten if that stuff got resolved in
later thread...
Lifetime rules are really odd there; the object is killed as we are about
to gut vfsmount for good, even though the code in there appears to assume
that it would stay connected to mount tree all the way until that point.
Again, that might have been resolved later; I really can't recall right now...
next prev parent reply other threads:[~2016-03-02 23:22 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-02 19:01 [PATCH 0/5] Add trace events for filesystem freeze/thaw events Frank Sorenson
2016-03-02 19:01 ` [PATCH 1/5] fs: simplify freeze_super()/thaw_super() exit handling Frank Sorenson
2016-03-02 20:06 ` Al Viro
2016-03-02 19:01 ` [PATCH 2/5] fs/block_dev.c: simplify freeze_bdev() and thaw_bdev() " Frank Sorenson
2016-03-02 19:01 ` [PATCH 3/5] fs: add trace events for freeze_super() and thaw_super() Frank Sorenson
2016-03-02 20:12 ` Al Viro
2016-03-02 19:01 ` [PATCH 4/5] fs/block_dev.c: add trace events for freeze_bdev() and thaw_bdev() Frank Sorenson
2016-03-02 19:01 ` [PATCH 5/5] fs: enable filesystem freeze/thaw events Frank Sorenson
2016-03-02 20:15 ` Al Viro
2016-03-02 21:47 ` [PATCH 0/5] Add trace events for " Al Viro
2016-03-02 22:47 ` Dave Chinner
2016-03-02 23:22 ` Al Viro [this message]
2016-03-02 23:52 ` Dave Chinner
2016-03-03 11:18 ` Dave Wysochanski
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