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From: NeilBrown <neilb@suse.com>
To: "Yan, Zheng" <zyan@redhat.com>, Sage Weil <sage@redhat.com>,
	Ilya Dryomov <idryomov@gmail.com>
Cc: ceph-devel@vger.kernel.org
Subject: [PATCH 0/2]: CEPHFS: allow for races between direct and buffered writes
Date: Wed, 31 Aug 2016 12:56:23 +1000	[thread overview]
Message-ID: <874m61eje0.fsf@notabene.neil.brown.name> (raw)

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Hi,
 it is quite possible for O_DIRECT and buffered writes to a file to
 race.
 The xfstests test suite has a test - generic/036 - which tests this
 case.

 Unlike most filesystems, cephfs does not hold inode_lock() across
 direct writes.  This means that buffer pages can become dirty while
 direct writes are happening.  This confused ceph a little.

 The following two patches allow ceph to handle this possibility a
 little more cleanly.  The more important patch removes a WARN_ON() for
 a circumstance which can easily be triggered.

Thanks,
NeilBrown

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             reply	other threads:[~2016-08-31  2:56 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-31  2:56 NeilBrown [this message]
2016-08-31  2:58 ` [PATCH 1/2] cephfs: ignore error from invalidate_inode_pages2_range() in direct write NeilBrown
2016-08-31 13:47   ` Jeff Layton
2016-09-01  1:01     ` NeilBrown
2016-08-31  2:59 ` [PATCH 2/2] cephfs: remove warning when ceph_releasepage() is called on dirty page NeilBrown
2016-08-31 13:48   ` Jeff Layton
2016-08-31  9:19 ` [PATCH 0/2]: CEPHFS: allow for races between direct and buffered writes Yan, Zheng
2016-09-01  1:13   ` NeilBrown
2016-09-01 14:30     ` Yan, Zheng

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