tier/dht: unlink fails after lookup in a directory

unlink fails with invalid argument for files that
are being present on cold tier, before attaching.

All of the fops will be hashed to hot_tier after
attach-tier (unless explicitly set the "rule"
option). Lookups sent to directory, will eventually
search the directory using readdirp, and will
populate inode_ctx for the inodes based on the output,
in respective dht_xlators. So the readdirp will
populate inodes_ctx for the files (that is already
present in volume before attaching) in cold-dht
only because it got the entries from the cold-tier.

So when an unlink comes on such an inode, the lookup
associated with the unlink will be send as a
re validate request to cold-tier only, since
already a lookup was performed on the inode,
and the new lookup will succeed. So from the
unlink of dht, it will hash to cold-tier but the
cached_subvol will be cold, since there is a
mismatch in hash and cach , it chose hashed
subvolume and will sent the fop to hot dht,
and the fops fail with EINVAL from the hot-dht
since it does not have inode_ctx stored for
that inode (because, no lookup was performed
from hot-dht).

Back port of>
>Change-Id: Ib7c14a9297a22d615f7a890a060be4809b5a745a
>BUG: 1236032
>Signed-off-by: Mohammed Rafi KC <rkavunga@redhat.com>
>Signed-off-by: Dan Lambright <dlambrig@redhat.com>
>Reviewed-on: http://review.gluster.org/11675
>Tested-by: NetBSD Build System <jenkins@build.gluster.org>
>Tested-by: Gluster Build System <jenkins@build.gluster.com>
>Reviewed-by: Raghavendra G <rgowdapp@redhat.com>

Change-Id: Ie08858867f58df1a3363800aaa87902bdd8256a1
BUG: 1266880
Signed-off-by: Mohammed Rafi KC <rkavunga@redhat.com>
Reviewed-on: http://review.gluster.org/12318
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Dan Lambright <dlambrig@redhat.com>
Tested-by: Dan Lambright <dlambrig@redhat.com>

0 files changed, 0 insertions, 0 deletions