From: Chris Mason <chris.mason@fusionio.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Chris Mason <clmason@fusionio.com>,
Mikulas Patocka <mpatocka@redhat.com>,
Al Viro <viro@zeniv.linux.org.uk>, Jens Axboe <axboe@kernel.dk>,
Jeff Chua <jeff.chua.linux@gmail.com>,
Lai Jiangshan <laijs@cn.fujitsu.com>, Jan Kara <jack@suse.cz>,
lkml <linux-kernel@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH v2] Do a proper locking for mmap and block size change
Date: Thu, 29 Nov 2012 14:48:40 -0500 [thread overview]
Message-ID: <20121129194840.GC3490@shiny> (raw)
In-Reply-To: <CA+55aFxaHuxaEezkpmGRi4kFGaQFTv9S89N-hJhxBjVa6ZwnbQ@mail.gmail.com>
On Thu, Nov 29, 2012 at 12:26:06PM -0700, Linus Torvalds wrote:
> On Thu, Nov 29, 2012 at 11:15 AM, Chris Mason <chris.mason@fusionio.com> wrote:
> >
> > The fs/buffer.c part makes sense during a quick read. But
> > fs/direct-io.c plays with i_blkbits too. The semaphore was fixing real
> > bugs there.
>
> Ugh. I _hate_ direct-IO. What a mess. And yeah, it seems to be
> incestuously playing games that should be in fs/buffer.c. I thought it
> was doing the sane thing with the page cache.
>
> (I now realize that Mikulas was talking about this mess, while I
> thought he was talking about the AIO code which is largely sane).
It was all a trick to get you to say the AIO code was sane.
It looks like we could use the private copy of i_blkbits that DIO is
already recording.
blkdev_get_blocks (called during DIO) is also checking i_blkbits, but I
really don't get why that isn't byte based instead. DIO is already
doing the shift & mask game.
I think only clean_blockdev_aliases is intentionally using the inode's
i_blkbits, but again that shouldn't be changing for filesystems so it
seems safe to use the DIO copy.
-chris
next prev parent reply other threads:[~2012-11-29 19:48 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAAJw_ZtbhE5Jtd4PsWx8a23QdFTW7aMrKBmRf-bo5Wrean9Xhg@mail.gmail.com>
2012-11-20 18:09 ` Recent kernel "mount" slow Jan Kara
2012-11-21 15:46 ` Jeff Chua
2012-11-22 14:30 ` Jeff Chua
2012-11-22 19:21 ` Linus Torvalds
2012-11-23 13:24 ` Jens Axboe
2012-11-23 22:21 ` Jeff Chua
2012-11-23 23:31 ` Jeff Chua
2012-11-23 23:48 ` Jeff Chua
2012-11-24 21:09 ` Mikulas Patocka
2012-11-24 23:23 ` Jeff Chua
2012-11-27 5:57 ` Jeff Chua
2012-11-27 7:38 ` Jens Axboe
2012-11-27 7:44 ` Jens Axboe
2012-11-27 8:45 ` Jeff Chua
2012-11-27 10:06 ` Jeff Chua
2012-11-27 12:33 ` Jens Axboe
2012-11-28 3:57 ` Mikulas Patocka
2012-11-28 8:33 ` Jens Axboe
2012-11-28 13:05 ` Jeff Chua
2012-11-28 17:25 ` [PATCH] Introduce a method to catch mmap_region (was: Recent kernel "mount" slow) Mikulas Patocka
2012-11-28 19:15 ` Linus Torvalds
2012-11-28 19:43 ` Al Viro
2012-11-28 19:53 ` Linus Torvalds
2012-11-28 22:01 ` [PATCH v2] Do a proper locking for mmap and block size change Mikulas Patocka
2012-11-29 17:19 ` Linus Torvalds
2012-11-29 18:23 ` Mikulas Patocka
2012-11-29 18:46 ` Linus Torvalds
2012-11-29 19:02 ` Linus Torvalds
2012-11-29 19:15 ` Chris Mason
2012-11-29 19:26 ` Linus Torvalds
2012-11-29 19:48 ` Chris Mason [this message]
2012-11-29 19:55 ` Linus Torvalds
2012-11-29 20:10 ` Linus Torvalds
2012-11-29 20:52 ` Linus Torvalds
2012-11-29 21:29 ` Chris Mason
2012-11-29 22:16 ` Linus Torvalds
2012-11-29 22:36 ` Linus Torvalds
2012-11-30 1:16 ` Chris Mason
2012-11-30 2:13 ` Linus Torvalds
2012-11-30 2:27 ` Chris Mason
2012-11-30 2:49 ` Dave Chinner
2012-11-30 14:31 ` Chris Mason
2012-11-30 16:42 ` Linus Torvalds
2012-11-30 16:36 ` Christoph Hellwig
2012-11-30 22:40 ` Dave Chinner
2012-11-30 23:09 ` Christoph Hellwig
2012-11-29 19:50 ` Linus Torvalds
2012-11-28 19:50 ` [PATCH] Introduce a method to catch mmap_region (was: Recent kernel "mount" slow) Mikulas Patocka
2012-11-28 20:03 ` Linus Torvalds
2012-11-28 20:13 ` Linus Torvalds
2012-11-28 20:32 ` Linus Torvalds
2012-11-28 20:47 ` Linus Torvalds
2012-11-28 22:10 ` Mikulas Patocka
2012-11-28 21:29 ` Mikulas Patocka
2012-11-28 22:52 ` Linus Torvalds
2012-11-28 23:13 ` Linus Torvalds
2012-11-29 1:20 ` Mikulas Patocka
2012-11-29 0:38 ` Mikulas Patocka
2012-11-29 2:04 ` Linus Torvalds
2012-11-29 2:58 ` Linus Torvalds
2012-11-29 6:16 ` Linus Torvalds
2012-11-29 6:25 ` Al Viro
2012-11-29 6:30 ` Al Viro
2012-11-29 6:37 ` Linus Torvalds
2012-11-29 6:45 ` Al Viro
2012-11-29 10:57 ` Jeff Chua
2012-11-29 6:33 ` Linus Torvalds
2012-11-29 14:12 ` Chris Mason
2012-11-29 17:26 ` Chris Mason
2012-11-29 17:26 ` Linus Torvalds
2012-11-29 17:51 ` Chris Mason
2012-11-29 18:12 ` Linus Torvalds
2012-11-28 3:59 ` [PATCH 1/2] percpu-rwsem: use synchronize_sched_expedited Mikulas Patocka
2012-11-28 4:01 ` [PATCH 2/2] block_dev: don't take the write lock if block size doesn't change Mikulas Patocka
2012-11-28 14:24 ` Jeff Chua
2012-11-28 22:03 ` Mikulas Patocka
2012-11-28 14:19 ` [PATCH 1/2] percpu-rwsem: use synchronize_sched_expedited Jeff Chua
2012-11-30 0:06 ` Andrew Morton
2012-11-30 3:00 ` Mikulas Patocka
2012-11-30 13:42 ` Paul E. McKenney
2012-11-30 18:57 ` Oleg Nesterov
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