storage/posix: removing deleting entries in case of creation failures

The code is not atomic enough to not to delete a dentry created by a
prallel dentry creation operation.

Change-Id: I9bd6d2aa9e7a1c0688c0a937b02a4b4f56d7aa3d
BUG: 1139988
Signed-off-by: Raghavendra G <rgowdapp@redhat.com>
Reviewed-on: http://review.gluster.org/8327
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>
Reviewed-on: http://review.gluster.org/8675
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
dht: fix rename race

Additional check to check if we created the linkto
file before deleting it in the rename cleanup function

Change-Id: I919cd7cb24f948ba4917eb9cf50d5169bb730a67
BUG: 1139988
Signed-off-by: Nithya Balachandran <nbalacha@redhat.com>
Reviewed-on: http://review.gluster.org/8338
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>
Reviewed-on: http://review.gluster.org/8676
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>