Re: [Drbd-dev] [PATCH] block: read i_size with i_size_read()

From: Lars Ellenberg
Date: Fri Nov 05 2010 - 17:12:19 EST


On Fri, Nov 05, 2010 at 03:27:21PM -0400, Mike Snitzer wrote:
> Convert direct reads of an inode's i_size to using i_size_read().
>
> i_size_{read,write} use a seqcount to protect reads from accessing
> incomple writes. Concurrent i_size_write()s require mutual exclussion
> to protect the seqcount that is used by i_size_{read,write}. But
> i_size_read() callers do not need to use additional locking.
>
> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
> Cc: Jens Axboe <jaxboe@xxxxxxxxxxxx>
> Cc: Neil Brown <neilb@xxxxxxx>
> Cc: drbd-dev@xxxxxxxxxxxxxxxx
> ---
> block/blk-core.c | 4 ++--
> block/compat_ioctl.c | 4 ++--
> block/ioctl.c | 6 +++---
> drivers/block/drbd/drbd_int.h | 2 +-
> drivers/md/md.c | 18 +++++++++---------
> 5 files changed, 17 insertions(+), 17 deletions(-)

DRBD one line fix trivially
Acked-by: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx>


> NOTE: I stopped short of fixing drbd and nbd to use revalidate_disk
> and/or i_size_write.

Ok, we'll pick up the DRBD part of it.

--
: Lars Ellenberg
: LINBIT | Your Way to High Availability
: DRBD/HA support and consulting http://www.linbit.com

DRBD® and LINBIT® are registered trademarks of LINBIT, Austria.
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