mds: handle fragment notify race #24580
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In the nornal case, mds does not trim dir inode whose child dirfrags are likely being fragmented (see trim_inode()). But when fragmenting subtree roots, following race can happen: - mds.a (auth mds of dirfrag) sends fragment_notify message to mds.c and drops wrlock on dirfragtreelock. - mds.b (auth mds of dir inode) changes dirfragtreelock state to SYNC and send lock message mds.c - mds.c receives the lock message and changes dirfragtreelock state to SYNC - mds.c trim dirfrag and dir inode from its cache - mds.c receives the fragment_notify message The fix is asking replicas to ack fragment_notify message, unlocking dirfragtreelock after mds gets all acks. Fixes: http://tracker.ceph.com/issues/36035 Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
batrick
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Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
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* refs/pull/24580/head: mds: bump mds protocol version mds: handle fragment notify race
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* refs/pull/24580/head: mds: bump mds protocol version mds: handle fragment notify race Reviewed-by: Patrick Donnelly <pdonnell@redhat.com>
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In the nornal case, mds does not trim dir inode whose child dirfrags
are likely being fragmented (see trim_inode()). But when fragmenting
subtree roots, following race can happen:
mds.c and drops wrlock on dirfragtreelock.
SYNC and send lock message mds.c
to SYNC
Fixes: http://tracker.ceph.com/issues/36035
Signed-off-by: "Yan, Zheng" zyan@redhat.com