From: Al Viro <viro@ZenIV.linux.org.uk>
To: Dmitry Monakhov <dmonakhov@openvz.org>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 1/2] pipe: fix race with fcntl
Date: Sun, 12 Apr 2015 18:34:58 +0100 [thread overview]
Message-ID: <20150412173458.GO889@ZenIV.linux.org.uk> (raw)
In-Reply-To: <1428858502-5371-2-git-send-email-dmonakhov@openvz.org>
On Sun, Apr 12, 2015 at 09:08:21PM +0400, Dmitry Monakhov wrote:
> Fix other long standing issues caused by fcntl(,F_SETFL,):
> - User can disable O_DIRECT for pipe[1] (paketized IO), but can not enable it again.
> - Currently we do not set O_APPEND on pipe[1] (IMHO it is wrong, but let it be)
> so it is reasonable to completely prohibit change O_APPEND flag on both
> end's of pipe. Add ->check_flags method in order to diallow O_APPEND toggling.
>
> Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
> ---
TBH, all those ->direct_IO != NULL checks seem to be a wrong approach.
If nothing else, it forces several filesystem into inventing a fake
->direct_IO just to fool those tests. How about we
* introduce FMODE_MAY_DIRECT and allow ->open() explicitly set it
* make open_check_o_direct() and fcntl.c check that instead of poking
in ->f_mapping->a_ops, etc.
* provide a variant of generic_file_open() that would set that
bit and use it on the filesystems that handle dio
next prev parent reply other threads:[~2015-04-12 17:34 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-12 17:08 [PATCH 0/2] fs: make pipe/splice fcntl safe Dmitry Monakhov
2015-04-12 17:08 ` [PATCH 1/2] pipe: fix race with fcntl Dmitry Monakhov
2015-04-12 17:34 ` Al Viro [this message]
2015-04-12 17:52 ` Dmitry Monakhov
2015-04-12 17:08 ` [PATCH 2/2] splice: fix race beween splice_write vs fcntl Dmitry Monakhov
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