From: Dave Chinner <david@fromorbit.com>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [git pull] vfs.git - including i_mutex wrappers
Date: Sun, 24 Jan 2016 09:34:56 +1100 [thread overview]
Message-ID: <20160123223456.GH6033@dastard> (raw)
In-Reply-To: <20160123145854.GM17997@ZenIV.linux.org.uk>
On Sat, Jan 23, 2016 at 02:58:54PM +0000, Al Viro wrote:
> ->i_mutex wrappers (with small prereq in lustre), fix for too
Please explain, Al?
I haven't heard anything about there being i_mutex changes pending,
and this commit says "over the coming cycle ->i_mutex will become
rwsem". That's a complete surprise to me, and not something that
should be done with no warning.
What's the locking model? How are filesystems supposed to use it?
Are they even allowed to use read-mode locking, and if so, what
operations is it going to be safe to hold the lock in read mode?
Why is this change considered valid now, when previously there's
always been significant push-back to any suggestion that we should
make the i_mutex a rwsem so we can do shared read-only access
locking on inode operations?
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2016-01-23 22:34 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-23 14:58 [git pull] vfs.git - including i_mutex wrappers Al Viro
2016-01-23 22:34 ` Dave Chinner [this message]
2016-01-23 22:44 ` Dave Chinner
2016-01-23 23:09 ` Al Viro
2016-01-23 23:38 ` Al Viro
2016-01-24 0:53 ` Dave Chinner
2016-01-24 1:41 ` Al Viro
2016-01-24 7:04 ` Dave Chinner
2016-01-24 7:48 ` Al Viro
2016-01-23 23:48 ` Linus Torvalds
2016-01-24 0:26 ` Dave Chinner
2016-01-24 1:20 ` Al Viro
2016-01-24 7:17 ` Dave Chinner
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