From: Al Viro <viro@ZenIV.linux.org.uk>
To: Dan Williams <dan.j.williams@intel.com>
Cc: linux-nvdimm@lists.01.org, Jan Kara <jack@suse.cz>,
"Darrick J. Wong" <darrick.wong@oracle.com>,
linux-api@vger.kernel.org, Dave Chinner <david@fromorbit.com>,
Christoph Hellwig <hch@lst.de>,
linux-xfs@vger.kernel.org, linux-mm@kvack.org,
Jeff Moyer <jmoyer@redhat.com>,
linux-fsdevel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Ross Zwisler <ross.zwisler@linux.intel.com>
Subject: Re: [PATCH v9 2/6] fs, mm: pass fd to ->mmap_validate()
Date: Thu, 12 Oct 2017 02:21:32 +0100 [thread overview]
Message-ID: <20171012012131.GD21978@ZenIV.linux.org.uk> (raw)
In-Reply-To: <150776923838.9144.15727770472447035032.stgit@dwillia2-desk3.amr.corp.intel.com>
On Wed, Oct 11, 2017 at 05:47:18PM -0700, Dan Williams wrote:
> The MAP_DIRECT mechanism for mmap intends to use a file lease to prevent
> block map changes while the file is mapped. It requires the fd to setup
> an fasync_struct for signalling lease break events to the lease holder.
*UGH*
That looks like one hell of a bad API. You are not even guaranteed that
descriptor will remain be still open by the time you pass it down to your
helper, nevermind the moment when event actually happens...
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next prev parent reply other threads:[~2017-10-12 1:21 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-12 0:47 [PATCH v9 0/6] MAP_DIRECT for DAX userspace flush Dan Williams
2017-10-12 0:47 ` [PATCH v9 1/6] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags Dan Williams
2017-10-12 13:51 ` Jan Kara
2017-10-12 16:32 ` Linus Torvalds
2017-10-16 7:38 ` Christoph Hellwig
2017-10-16 7:56 ` Jan Kara
2017-10-12 0:47 ` [PATCH v9 2/6] fs, mm: pass fd to ->mmap_validate() Dan Williams
2017-10-12 1:21 ` Al Viro [this message]
2017-10-12 1:28 ` Dan Williams
2017-10-12 2:17 ` Dan Williams
2017-10-12 3:44 ` Dan Williams
2017-10-12 0:47 ` [PATCH v9 3/6] fs: MAP_DIRECT core Dan Williams
2017-10-12 0:47 ` [PATCH v9 4/6] xfs: prepare xfs_break_layouts() for reuse with MAP_DIRECT Dan Williams
2017-10-12 0:47 ` [PATCH v9 5/6] fs, xfs, iomap: introduce break_layout_nowait() Dan Williams
2017-10-12 0:47 ` [PATCH v9 6/6] xfs: wire up MAP_DIRECT Dan Williams
2017-10-12 14:23 ` [PATCH v9 0/6] MAP_DIRECT for DAX userspace flush Christoph Hellwig
2017-10-12 17:41 ` Dan Williams
2017-10-13 6:57 ` Christoph Hellwig
2017-10-13 15:14 ` Dan Williams
2017-10-13 16:38 ` Jason Gunthorpe
2017-10-13 17:01 ` Dan Williams
2017-10-13 17:31 ` Jason Gunthorpe
2017-10-13 18:22 ` Dan Williams
2017-10-14 1:57 ` Jason Gunthorpe
2017-10-16 12:02 ` Sagi Grimberg
2017-10-19 6:02 ` Jason Gunthorpe
2017-10-16 7:30 ` Christoph Hellwig
2017-10-16 7:26 ` Christoph Hellwig
2017-10-16 12:07 ` Sagi Grimberg
2017-10-16 17:43 ` Dan Williams
2017-10-16 19:44 ` Dan Williams
2017-10-17 6:46 ` Christoph Hellwig
2017-10-16 7:22 ` Christoph Hellwig
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