By forcing creates to always go via lookup we lose some
important caching benefits too.
Instead let's trust creates with positive cached entries.
Then we have 3 possible outcomes:
1. Negative dentry - we go via atomic_open and do the create
by name there.
2. Positive dentry, no contention - we just go straight to
ll_intent_file_open and open by fid.
3. positive dentry, contention - by the time we reach the server,
the inode is gone. We get ENOENT which is unacceptable to return
from create. But since we know it's a create, we substitute it
with ESTALE and VFS retries again with LOOKUP_REVAL set, we catch
that in revalidate and force a lookup (same path as before this
patch).
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-8371
Reviewed-on: http://review.whamcloud.com/21168
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>