From: Christoph Hellwig <hch@infradead.org>
To: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@infradead.org>,
Davidlohr Bueso <dave@stgolabs.net>,
Waiman Long <Waiman.Long@hpe.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org, x86@kernel.org,
linux-alpha@vger.kernel.org, linux-ia64@vger.kernel.org,
linux-s390@vger.kernel.org, linux-arch@vger.kernel.org,
linux-doc@vger.kernel.org, Jason Low <jason.low2@hp.com>,
Jonathan Corbet <corbet@lwn.net>,
Scott J Norton <scott.norton@hpe.com>,
Douglas Hatch <doug.hatch@hpe.com>
Subject: Re: [RFC PATCH-tip v4 02/10] locking/rwsem: Stop active read lock ASAP
Date: Sat, 15 Oct 2016 22:57:31 -0700 [thread overview]
Message-ID: <20161016055731.GA21379@infradead.org> (raw)
In-Reply-To: <20161011210640.GB27872@dastard>
On Wed, Oct 12, 2016 at 08:06:40AM +1100, Dave Chinner wrote:
> Um, I seem to have completely missed that change - when did that
> happen and why?
>
> Oh, it was part of the misguided "enable DAX on block devices"
> changes -
o, that commit just switched it to use ->f_mapping:
- return (filp->f_flags & O_DIRECT) || IS_DAX(file_inode(filp));
+ return (filp->f_flags & O_DIRECT) || IS_DAX(filp->f_mapping->host);
The original version of it goes all the way back to introducing the
current-day DAX code in d475c6346 ("dax,ext2: replace XIP read and write
with DAX I/O");
> Hence I'd suggest that DAX check in io_is_direct() should be removed
> ASAP; the filesystems don't need it as they check the inode DAX
> state directly, and the code it "fixed" is no longer in the tree.
As long as ext4 still uses the overloaded direct_IO we need the
checks for DAX in the filemap.c generic read/write code. It seems
like that's only two spots anyway, but I'd feel much safer once ext4
is switched over to the iomap version of the dax code.
next prev parent reply other threads:[~2016-10-16 5:57 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-18 21:11 [RFC PATCH-tip v4 00/10] locking/rwsem: Enable reader optimistic spinning Waiman Long
2016-08-18 21:11 ` [RFC PATCH-tip v4 01/10] locking/osq: Make lock/unlock proper acquire/release barrier Waiman Long
2016-10-04 19:06 ` Davidlohr Bueso
2016-10-04 21:28 ` Jason Low
2016-10-05 12:19 ` Waiman Long
2016-10-05 15:11 ` Waiman Long
2016-10-06 5:47 ` Davidlohr Bueso
2016-10-06 19:30 ` Waiman Long
2016-10-10 5:39 ` [PATCH] locking/osq: Provide proper lock/unlock and relaxed flavors Davidlohr Bueso
2016-10-06 19:31 ` [RFC PATCH-tip v4 01/10] locking/osq: Make lock/unlock proper acquire/release barrier Jason Low
2016-08-18 21:11 ` [RFC PATCH-tip v4 02/10] locking/rwsem: Stop active read lock ASAP Waiman Long
2016-10-06 18:17 ` Davidlohr Bueso
2016-10-06 21:47 ` Dave Chinner
2016-10-06 22:51 ` Davidlohr Bueso
2016-10-07 21:45 ` Waiman Long
2016-10-09 15:17 ` Christoph Hellwig
2016-10-10 6:07 ` Dave Chinner
2016-10-10 9:34 ` Christoph Hellwig
2016-10-11 21:06 ` Dave Chinner
2016-10-16 5:57 ` Christoph Hellwig [this message]
2016-08-18 21:11 ` [RFC PATCH-tip v4 03/10] locking/rwsem: Make rwsem_spin_on_owner() return a tri-state value Waiman Long
2016-08-18 21:11 ` [RFC PATCH-tip v4 04/10] locking/rwsem: Enable count-based spinning on reader Waiman Long
2016-08-18 21:11 ` [RFC PATCH-tip v4 05/10] locking/rwsem: move down rwsem_down_read_failed function Waiman Long
2016-08-18 21:11 ` [RFC PATCH-tip v4 06/10] locking/rwsem: Move common rwsem macros to asm-generic/rwsem_types.h Waiman Long
2016-08-18 21:11 ` [RFC PATCH-tip v4 07/10] locking/rwsem: Change RWSEM_WAITING_BIAS for better disambiguation Waiman Long
2016-08-19 5:57 ` Wanpeng Li
2016-08-19 16:21 ` Waiman Long
2016-08-22 2:15 ` Wanpeng Li
2016-08-18 21:11 ` [RFC PATCH-tip v4 08/10] locking/rwsem: Enable spinning readers Waiman Long
2016-08-18 21:11 ` [RFC PATCH-tip v4 09/10] locking/rwsem: Enable reactivation of reader spinning Waiman Long
2016-08-18 21:11 ` [RFC PATCH-tip v4 10/10] locking/rwsem: Add a boot parameter to reader spinning threshold Waiman Long
2016-08-24 1:46 ` [lkp] [locking/rwsem] INFO: rcu_preempt detected stalls on CPUs/tasks kernel test robot
2016-08-24 4:00 ` [RFC PATCH-tip v4 10/10] locking/rwsem: Add a boot parameter to reader spinning threshold Davidlohr Bueso
2016-08-24 18:39 ` Waiman Long
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